The solid solution aging heat treatment of Pb-Sb-Sn alloy was carried out to study the effects of different quenching methods on the microstructure，mechanical properties and corrosion resistance of Pb-Sb-Sn alloy in natural aging. The results showed that，after the Pb-Sb-Sn alloy was held at 230 ℃ for 1 h，the gas-quenched and water-quenched （60 ℃） organization of some α-Pb grains were transformed from coarse dendritic crystals to columnar crystals and equiaxial crystals，and the lamellar eutectic organization composed of a mixture of α' phase （secondary Pb） and β-phase （SbSn compounds） was more dense，and the area fraction of β-phase was reduced，with a decrease in the gas-quenched organization from 19.28% to 17.65%，the water-quenched （60 ℃） organization decreased to 15.11%，indicating that after solid solution quenching，Sb and Sn atoms were solidly dissolved into Pb matrix to form a supersaturated solid solution，and electron back scatter diffraction （EBSD） characterization showed that the grains of the as-cast organization were mainly oriented along the <101>，and after solid solution aging treatment，the grains of the gas-quenched organization were mainly oriented between the <001> <101>，while the grains of the water-quenched （60 ℃） organization were mainly oriented between <001> <111>，so the grain orientation of Pb-Sb-Sn alloy after heat treatment was different with the quenching method. In addition，the orientation difference angle of the as-cast organization was mainly distributed in the range of 0°~15° and 35°~50°，and the orientation difference angle of the gas-quenched and water-quenched （60 ℃） organizations was distributed in the range of 0°~15° and 45°~60° With the increase of quenching rate，the density of small-angle grain boundaries and large-angle grain boundaries gradually increased，and mainly around the eutectic organization. At the same time，the faster the quenching rate，the higher the average local orientation difference of the grains，and the higher the dislocation density，the average local orientation difference of the as-cast specimens was 0.135°，0.183° after aging for 15 d in the gas-quenched specimens，and 0.404° in the water-quenched （60 ℃） specimens. The analysis of microstructure and morphology revealed that the area fraction of β-phase gradually increased during natural aging after quenching，indicating that SbSn phase precipitated during natural aging，and micron-sized rod-like β' phase and nanometer-sized granular β″ phase precipitates diffusely inside α-Pb. The larger β' phase led to the matrix fracture and reduced the mechanical properties of the matrix，whereas the finer β″ phase strengthens the matrix，and the faster the quench rate，the greater the number of fine β″ phase precipitates and the less the number of coarse β' phase precipitates during aging. In terms of mechanical properties，the hardness and tensile strength of as-cast Pb-Sb-Sn alloy were maintained at about HBS 15 and 44 MPa，respectively；the initial value of hardness of natural aging specimen after gas quenching was HBS 15，and reached a peak value of HBS 18.13 after 12 d of aging and remained stable，and the tensile strength was fluctuating slightly from 49 to 52 MPa；and the initial value of hardness of natural aging specimen after water quenching （60 ℃） was HBS 16.43，and reached a peak value of HBS 19 after 4 d of aging，and then remained stable，and the tensile strength was kept at 57 MPa. Analyzing the fracture morphology，it was found that the fracture mode of the three specimens after aging for 15 d was quasi-dissolution fracture，and all the three fractures had dissolution surfaces and tearing ribs，and some of the dissolution surfaces were in the form of a "river-like" pattern. Electrochemical corrosion in 3.5% NaCl solution，the experimental results show that in the case of corrosion potential was basically the same，the as-cast specimen corrosion current was the largest，and then the gas quenching specimen，and finally the water quenching （60 ℃） specimen，and electrochemical corrosion of the specimen after the characterization of the morphology of the specimen was found，the as-cast specimen compared to the heat treatment specimen corrosion was more serious，the surface had more corrosion spots and corrosion of the center of the crater ，and the surface had more corrosion spots and corrosion center pits，and there were more corrosion shedding strip corrosion products on the surface of the specimen，which had poorer corrosion resistance；while the gas quenching specimen and the water quenching （60 ℃） specimen had only corrosion spots and the center of the corrosion pits on the surface，which had a more intact surface，in addition to which it could be seen that the larger the quenching rate was，the better the integrity of the corrosion on the surface was. Due to Pb-Sb-Sn alloy corrosion occurred first in Pb-rich phase，and SbSn compounds were biased in α-Pb dendrites，α-Pb played a role in enclosing the role of protection in the corrosion，and the smaller the dendritic arm spacing，the more dense the eutectic organization，the more conducive to resisting the corrosion of α-Pb，so the solid solution quenching could improve the corrosion resistance of Pb-Sb-Sn alloy and with the increase of the quenching rate，the surface corrosion integrity of Pb-Sb-Sn alloy was better. Therefore，solid solution quenching could improve the corrosion resistance of Pb-Sb-Sn alloy，and with the increase of quenching rate，the corrosion resistance was also improved accordingly.

Industrial production wastewater has high chemical oxygen demand （COD） value and complex composition，which precludes effective treatment via a single unit operation. Direct discharge into the natural environment without treatment will cause environmental pollution，damage the ecosystem and threaten human health. Therefore，it is particularly important to seek an advanced and efficient process for the treatment of industrial wastewater.Heterogeneous catalytic ozonation，as a kind of advanced oxidation processes （AOPs），has attracted more and more attention from researchers due to its strong oxidizability and the ability to decompose ozone into reactive oxygen species to attack pollutants. However，the development of environmentally friendly and efficient cheap catalysts to promote ozone decomposition still faces enormous challenges. In this paper，actual high-COD flame retardant manufacturing wastewater collected from Xurui Industrial Wastewater Treatment Plant was used as the treatment target to investigate the COD removal performance of ozone catalytic oxidation over Fe-based amorphous alloy catalysts and its underlying reaction mechanism. Firstly，the master alloy rod was prepared by vacuum magnetron tungsten arc melting furnace，and then the master alloy rod was heated and spun into amorphous ribbon by high vacuum single roller-spinning and spray casting system to obtain the catalyst. X-ray diffraction （XRD），ultraviolet spectrophotometer，scanning electron microscopy （SEM） and electron spin resonance （ESR） were used to systematically analyze the structure，catalytic performance，surface morphology change，and the type and contribution of free radicals of the catalyst. In addition，the effects of ozone concentration and pH value on the efficiency of ozone catalytic oxidation were also discussed. The results showed that compared with the ozone oxidation method without obvious COD removal effect，the combination of amorphous alloy catalyst and ozone could effectively improve COD removal rate. Among Fe₇₈Si₉B₁₃，（CoFe）₈₀B₂₀，（CoFeNi）₈₀B₂₀，（CoFeMn）₈₀B₂₀ and zero-valent iron （ZVI） samples，Fe₇₈Si₉B₁₃ showed the best catalytic efficiency，and COD of wastewater could be removed by 15.28% within 2 h. （CoFe）₈₀B₂₀，（CoFeNi）₈₀B₂₀，（CoFeMn）₈₀B₂₀ and ZVI couldonly remove COD of wastewater by 11.61%，7.9%，4.19% and 3.23%，respectively. In particular，it was observed during the experiment that ZVI powder was easily adhered to the inner wall of the reactor，resulting in a poor catalytic effect.As the reaction progresses，a large number of holes and corrosion pits appeared on the surface of Fe₇₈Si₉B₁₃，constantly exposing new substrates，and gradually evolving into a three-dimensional nanoflower-like structure，increasing active sites，promoting ozone decomposition to produce free radicals to attack pollutants. Secondly，the optimal ozone concentration was explored. The experimental results showed that COD removal ratios at ozone concentrations of 4，24，34，39，42 and 44 mg·L^-1 were 17.95%，22.09%，30.95%，31.58%，32.09% and 32.19%，respectively. Among them，when O₂ flow rate was 1.5 L·min^-1，that was，the ozone concentration was 34.0 mg·L^-1，COD removal effect hadreached 30.95%.When the ozone concentration continued to increase，COD removal rate did not increase much. In view of the cost and environmental friendliness，34.0 mg·L^-1 was selected as the optimal ozone concentration. Similarly，the reaction time was investigated，revealing a COD removal efficiency of 30.9% at 2 h. Prolonging the reaction time only marginally improved the removal efficiency. Therefore，2 h was selected as the optimal reaction time to balance efficiency and cost-effectiveness.The lower pH，the better COD removal effect of ozone catalytic oxidation.When pH was 3，5，7，and 9，COD of wastewater could be removed by 35.67%，31.02%，30.58% and 15.51%，respectively. This might be due to the acidic environment to promote the consumption of the catalyst，thereby promoting the production of more free radicals and degrading pollutants. However，no acid-base adjustment treatment of neutral wastewater could avoid additional cost increase，and the removal efficiency at pH 7 was only about 5% different from that at pH3，which still had a good COD removal ratio.The removal effect of wastewater with different COD values was also studied. The production wastewater with COD values of 5600，7500，16000，36000，40000 and 44000 mg·L^-1 were selected as the degradation target. The experiment was carried out under the conditions of ozone concentration of 34.0 mg·L^-1，catalyst dosage of 1 g·L^-1，pH 7 and room temperature. COD removal ratios after 2 h were 45.21%，31.04%，16.86%，10.47%，17.63% and 9.09%，respectively. With the increase of COD value，the removal ratio of COD decreased as a whole，but the removal rate of wastewater with COD of 40000 mg·L^-1 increased instead，which might be due to the fact that the organic pollutants in this kind of wastewater were more easily degraded. In addition，although the removal ratiowas reduced，COD degradation amount increased with the increase of COD value of the raw water，indicating that the ozone catalytic oxidation had a good degradation effect on COD of the raw water，and could better adapt to different concentrations of production wastewater.Throughout nine consecutive cycling tests，Fe₇₈Si₉B₁₃ catalyst consistently maintained a removal efficiency exceeding 26%，demonstrating its excellent cycling stability. Electron paramagnetic resonance tests showed that a large amount of hydroxyl radical （·OH） radicals could be produced in the ozone catalytic oxidation system，but this result was not observed in the ozone oxidation system，which further emphasized the role of the catalyst. In addition，the active site Fe in Fe₇₈Si₉B₁₃ had a variety of valence states，which could further promote the electron transfer of O₃ molecules and promote the reaction.

Aiming at the limitations in magnetic regulation of high-entropy oxides （HEOs），this study systematically investigated the influence mechanisms of crystal structures （perovskite and spinel） and elemental doping （Cr，Cu，Sb） on HEOs' magnetic properties. Perovskite-structured samples—HEO-Cr （La（Cr_0.2Mn_0.2Fe_0.2Co_0.2Ni_0.2）O₃），HEO-Cu （La（Mn_0.2Fe_0.2Co_0.2Ni_0.2Cu_0.2）O₃），and HEO-CrSb （La（Cr_0.18Mn_0.18Fe_0.18Co_0.18Ni_0.18Sb_0.1）O₃）—were prepared via a template method，while spinel-structured samples—S-HEO-Cr （（Cr_0.5Mn_0.5Fe_0.5Co_0.5Ni_0.5）O₃） and S-HEO-Cu （（Mn_0.5Fe_0.5Co_0.5Ni_0.5Cu_0.5）O₃）—were synthesized by the sol-gel method. Systematic characterizations and analyses of the samples' morphology，structure，composition，valence states，and magnetic properties （including susceptibility-temperature curves （χ-T），hysteresis loops （M-H），and Arrott plots （M²-H/M）） were conducted using scanning electron microscopy （SEM），X-ray diffraction （XRD），X-ray photoelectron spectroscopy （XPS），and physical property measurement system （PPMS）. SEM results showed that elemental doping and structural differences significantly affected the morphology：perovskite samples exhibited nanocubic structures （HEO-Cr was regular，while HEO-Cu showed irregular agglomeration），and spinel samples displayed complex morphologies （S-HEO-Cr formed blocky/polyhedral networks，and S-HEO-Cu presented agglomerated spherical particles）. XRD confirmed that all samples were high-purity single phases：perovskites matched the standard pattern of LaCo_0.4Fe_0.6O₃，and spinels corresponded to NiCr₂O₄ （S-HEO-Cr） and CuFe₂O₄ （S-HEO-Cu），indicating good crystallinity. XPS verified the successful incorporation of all designed elements and revealed mixed valence states of Cr （Cr³⁺/Cr²⁺） and Cu （Cu/Cu²⁺）. Magnetic studies demonstrated that Cr and Cu played decisive roles in magnetic types：Cr doping significantly enhanced ferromagnetic （FM） interactions，leading to a high Curie temperature （T_C） of 263 K in perovskite HEO-Cr. Its hysteresis loops showed remanence （M_r） and coercivity （H_c） at low temperatures，but the unsaturated behavior at high temperatures indicated competition between FM and antiferromagnetic （AFM） interactions. In contrast，Cu doping strengthened AFM interactions and suppressed long-range magnetic order，reducing T_C of HEO-Cu to 86 K，with weak M_r and H_c at low temperatures primarily due to the Jahn-Teller effect of Cu²⁺（d⁹）. Introducing Sb into HEO-Cr to form HEO-CrSb drastically decreased T_C to 14 K，suggesting that the 5s²5p³ electronic configuration of Sb^3+/5+ weakened Cr-related FM coupling by altering the electronic structure of B-site ions and enhancing lattice distortion. Crystal structure differences leaded to distinct magnetic behaviors：perovskites exhibited complex magnetic competition （FM/AFM coexistence） due to intricate double-exchange/superexchange interactions among multiple transition metal ions at B-sites，showing obvious phase transitions （FM-paramagnetic，PM） with tunable temperatures （14~263 K）. Spinel samples，however，showed no obvious phase transitions within the tested range and exhibited simpler magnetic behaviors （S-HEO-Cr was ferrimagnetic，and S-HEO-Cu showed unsaturated high-field behavior due to Cu²⁺），as their geometrically frustrated structures restricted long-range magnetic order. Arrott plot analysis indicated that perovskite samples primarily underwent second-order phase transitions （with possible first-order transitions at low temperatures），while spinel samples showed purely second-order transitions. In summary，this work revealed the internal mechanisms of HEOs' magnetic regulation via Cr/Cu/Sb doping and structural differences. Precisely selecting doping elements and crystal structures can effectively alter magnetic competition and finely tune phase transition temperatures over a wide range （14~263 K），providing critical theoretical and experimental foundations for designing HEOs with specific magnetocaloric properties.

A high-sulfur lead-zinc ore from Yunnan，containing valuable associated germanium，presented significant challenges in conventional beneficiation due to its complex mineralogy. Process mineralogy studies revealed that the ore contained 7.08%Pb，20.26%Zn，27.46%S，50.38 g·t^-1 Ag and 26.00 g·t^-1 Ge，with lead and zinc mainly occurring as galena and sphalerite. Pyrite accounted for about 32% of the mineral composition，and both galena and sphalerite exhibited fine-grained，uneven dissemination：galena was mostly in the range of –2.56+0.04 mm and sphalerite in –10.24+0.16 mm，making liberation and selective flotation difficult. The traditional high-alkali process （using large amounts of lime） commonly applied to such ores suffered from severe mutual contamination between lead and zinc concentrates，high reagent costs，expensive wastewater treatment due to alkaline discharge，and poor recovery of germanium，which was mainly hosted in sphalerite and tended to be lost in tailings under high pH conditions. To overcome these problems，a novel low-alkali preferential flotation process was developed based on the surface property differences of galena，sphalerite and pyrite，without any lime addition. After determining the optimal grinding fineness of 75% passing 0.074 mm，lead flotation was carried out using zinc sulfate as the depressant for sphalerite and a newly developed phosphonate ester collector P1. P1 collector exhibited strong selective affinity for lead atoms on galena surfaces via coordination bonding，while showing negligible interaction with zinc and iron atoms，thus effectively collecting galena without floating sphalerite or pyrite. A closed-circuit lead flotation flowsheet consisting of one rougher，three cleaners and three scavengers yielded a lead concentrate assaying 66.86% Pb with a Pb recovery of 88.88%. The lead concentrate also contained 350.25 g·t^-1 Ag，corresponding to an Ag recovery of 65.59%. The zinc content in the lead concentrate was only 5.00%，significantly lower than that obtained with the conventional high-lime process，demonstrating excellent selectivity. The tailings from the lead circuit were then subjected to zinc flotation. Copper sulfate was added as an activator to replace surface Zn²⁺ with Cu²⁺ on sphalerite，forming a copper sulfide film that enhances collector adsorption. A mixed thionocarbamate collector P2 was introduced as the zinc collector. Under low-alkaline conditions （natural pH~8.5），the zinc flotation circuit comprising one rougher，one cleaner and two scavengers produced a zinc concentrate grading 54.44% Zn with a Zn recovery of 95.11%. The zinc concentrates also contained 28.85 g·t^-1 Ag and 58.08 g·t^-1 Ge，corresponding to Ag recovery of 20.26% and Ge recovery as high as 77.12%. Germanium，which was largely enriched in the zinc concentrate due to its solid-solution occurrence in sphalerite，could thus be further recovered by subsequent hydrometallurgical processes，providing an additional economic benefit. A subsequent sulfur flotation stage using ethyl xanthate recovered a sulfur concentrate with 51.54% S，achieving a S recovery of 38.58% from the lead-zinc tailings. Compared with the original plant process （a typical high-lime flowsheet），the new low-alkali process achieved a 2.88 percentage point increase in Pb recovery （from 86.00% to 88.88%） and a 1.78 percentage point increase in Zn recovery （from 93.33% to 95.11%）. More importantly，the recovery of associated silver in the lead concentrate increased from 51.03% to 65.59%，and the recovery of germanium in the zinc concentrate rose from 65.83% to 77.12%，indicating that the low-alkali environment prevents surface passivation of germanium-bearing minerals and allows efficient activation and collection. The elimination of lime also reduced reagent costs by approximately 10.36 RMB per ton of raw ore，and the tailings wastewater had a near-neutral pH （7.5~8.5），requiring no acid neutralization and substantially lowering wastewater treatment expenses. The mutual contamination between lead and zinc concentrates was markedly reduced，which improved the market value of both products and reduces smelter penalties. The successful development and validation of this low-alkali preferential flotation process，using the novel collectors P1 and P2，demonstrated that high-sulfur lead-zinc ores containing precious and rare metals like germanium could be efficiently separated without lime. The process not only achieved superior metallurgical performance but also offered significant environmental and economic advantages. It provided a practical and sustainable alternative to conventional high-alkaline technologies and served as a valuable reference for the low-alkali beneficiation of similar complex lead-zinc ores.

Carbon fiber reinforced plastics （CFRP），characterized by high specific strength，fatigue resistance，and a low coefficient of thermal expansion，have found widespread applications in fields such as aerospace. However，with a resistivity ranging from approximately 1.3×10^-5 to 1.9×10^-5 Ω·m，CFRP exhibits poor conductivity when used as antenna reflectors and waveguides. Furthermore，due to its anisotropic properties，surface metallization is required to enhance microwave transmission efficiency. To achieve metallization of CFRP surface，Cu film with Ti interlayer was deposited on CFRP surface using direct current pulsed magnetron sputtering technology in this paper. The thickness of Ti interlayer was approximately 50 nm，and the thickness of Cu film was approximately 1.2 μm. During the preparation of this thin film，sputtering power and deposition pressure were varied to optimize the relationship between resistivity and deposition parameters. To investigate the microstructural changes in Cu film，various analytical techniques such as scanning electron microscopy （SEM），dual beam focused ion beam （FIB） microscope，X-ray diffraction （XRD），four-point probe resistivity tester，stylus profilometer，and transmission electron microscopy （TEM） were employed to analyze the film microstructures. Additionally，given the temperature resistance characteristics of CFRP，close attention was paid to the changes in deposition temperature during the film deposition process. The results showed that as the sputtering power was increased from 300 to 700 W，the enhanced sputtering yield increased the bombardment effect of particles on the film surface，which in turn boosted the mobility of atoms on the film surface. This promoted the preferential growth of the film along the （111） crystal plane. Consequently，the average grain diameter in the film increased from approximately 35 to 47 nm，and the texture coefficient value of the （111） plane rose from 1.99 to 2.63. Additionally，a twinned structure gradually formed，and the resistivity decreased from 4.36×10^-8 to 3.77×10^-8 Ω·m. However，when the sputtering power continued to be increased，the grain size in the film began to decrease，resulting in a subsequent increase in resistivity to approximately 3.98×10^-8 Ω·m. When the sputtering power was set at 700 W，cross-sectional images revealed the abundant presence of layered columnar crystals，which were entirely perpendicular to the surface. The cross-sections of these columnar crystals measured between tens of nanometers and one or two hundred nanometers. Other grains，observable with distinct background colors，exhibited relatively irregular shapes and extended obliquely towards the surface. TEM analysis of the layered columnar crystals showed that they possessed a twinned crystal structure，with the growth direction of the twinned grains perpendicular to the film surface. This occurred because during the film deposition process，when particles incident on the film surface carried appropriate energy，sufficient compressive stress formed in the sub-surface layer. This compressive stress promoted the transformation of grains into twins and contributed to the formation of a dense film structure，thereby reducing the resistivity of the Cu film. The shift in the diffraction angle of Cu film's （111） plane during XRD testing further confirmed the presence of compressive stress within the film. Surface morphology tests indicated that，when the sputtering power was 700 W，grain growth in the sub-surface layer was particularly pronounced. When the sputtering power was maintained at 700 W and the deposition pressure was increased from 0.20 to 0.60 Pa，collisions between ions became more frequent. Consequently，the number of charged ions began to decrease，and the energy transferred by charged particles to the film surface started to diminish. This led to a reduction in the compressive stress within the film. The average grain diameter decreased slightly，from 47 to 41 nm. Simultaneously，the twinned crystal structure ceased to appear. As a result，the resistivity of the film increased from 3.77×10^-8 to 5.17×10^-8 Ω·m. When the deposition pressure exceeded 0.40 Pa，as observed in XRD patterns，there was no shift in the diffraction angle position of Cu film's （111） plane，indicating that the stress state within the film remained unchanged during the deposition process. At a deposition pressure of 0.80 Pa，due to a further weakening of ion collisions with the film，the deposited atoms exhibited island-like growth on the film surface，resulting in a zigzag pattern. The gaps between these islands provided space for grain growth，leading to a slight increase in grain diameter. Simultaneously，the resistivity of the film decreased slightly to 4.84×10^-8 Ω·m. During the magnetron sputtering deposition of Cu films，increasing the bias voltage could enhance ion beam bombardment，generating compressive stress that densifies the film and might even lead to the formation of twin crystal structures. However，excessively high bias voltage resulted in a gradual rise in the deposition temperature. Continuously applying a high negative bias voltage during film deposition on CFRP surfaces could elevate the temperature，causing components such as resin in CFRP to 'vaporize' and escape，thereby contaminating the metallic film. This study provided technical support for the low-temperature deposition of dense Cu films.

As the lightest metallic structural material （density of 1.35~1.65 g·cm^-3），ultra-light magnesium-lithium alloy has shown significant application potential in aerospace，new energy vehicles，and electronic devices due to its excellent specific strength，damping performance，and electromagnetic shielding properties. For instance，in the aerospace field，magnesium-lithium alloys are widely used in the manufacturing of satellite shells and aircraft structural components because of their low density and high specific strength. In the automotive industry，the use of magnesium-lithium alloys also helps to achieve lightweighting of vehicle bodies and reduce energy consumption. In the field of electronic communications，magnesium-lithium alloys，with their superior heat dissipation performance and electromagnetic shielding capabilities，have become ideal materials for manufacturing the shells of mobile phones，laptops，and other electronic devices，effectively enhancing the stability and service life of these devices. Despite the significant application potential of magnesium-lithium alloys in many fields，their relatively low absolute strength （with tensile strength generally below 200 MPa at room temperature） is a bottleneck restricting their engineering applications. In recent years，significant progress has been made in research on strengthening mechanisms of magnesium-lithium alloys，mainly in four directions：Secondary-phase strengthening achieves performance improvement by regulating precipitated phases and dispersed phases. Precipitation strengthening is based on Orowan bypass mechanism （such as Al₃Li （Mg） phase and Mg₂Si phase in Mg-4Li-3 （Al-Si） alloy，which increases the tensile strength to 295 MPa） and the dislocation bypass mechanism （such as AlCuMg phase in Mg-5Li-3Al-2Zn alloy with Cu，which enhances the overall hardness of the alloy）. Dispersed strengthening introduces dispersed phases into the matrix material to form small and uniformly distributed second-phase particles，thereby hindering dislocation movement and increasing the strength and hardness of the alloy. For example，the addition of ceramic particles （such as TiB₂，which increases the tensile strength of LA103 by 33.8%） or intermetallic compounds （such as the introduction of Al-Si eutectic，which increases the strength of Mg-12Li-7 （Al-Si） alloy by 80%） can significantly enhance the overall mechanical properties of the material. Solid solution strengthening relies on solute atoms （such as Zn，Y，La） to induce lattice distortion and hinder dislocation movement，making the alloy more difficult to undergo plastic deformation and thereby enhancing the overall strength of the alloy. For instance，the addition of yttrium promotes the precipitation of MgLi₂Al phase and inhibits the brittle AlLi phase，but excessive lanthanum can lead to performance degradation due to brittle intergranular phases. Fine grain strengthening mainly optimizes the mechanical properties of materials through the Hall-Petch effect by refining grains. For example，rapid cooling processes can refine the grains of Mg-14Li-3Al-3Ce alloy，resulting in a yield strength of 105.5 MPa；the addition of grain refiners such as rare earth element Y can form Al₂Y nanophases to control the α/β phase ratio；while elements such as Mn and Ca can enhance the overall strength of the alloy by suppressing grain boundary migration through segregation，but the addition amount must be strictly controlled to avoid eutectic embrittlement. Due to the limited effect of grain boundary strengthening，conventional plastic deformation （rolling，extrusion，etc.） has limited effects on enhancing the strength of magnesium-lithium alloys. However，the emergence of severe plastic deformation techniques （ECAP：equal channel angular pressing；HPT：high pressure torsion；ARB：accumulative roll bonding；MDF：multi-directional forging） can achieve ultrafine grain preparation to further enhance the strength of magnesium-lithium alloys. For example，the ECAP process refines the α-Mg phase of Mg-9Li alloy to 500~700 nm，resulting in a tensile strength of 206 MPa；HPT treatment reduces the grain size of LZ91 alloy from 30 μm to 230 nm and exhibits 400% superplasticity；the ultrafine-grained high-strength Mg-5Li-1Al sheet prepared by ARB has an average grain size of 100 nm and a tensile strength of up to 318 MPa while maintaining ideal plasticity. Despite a series of breakthroughs，current research and technological development still face challenges such as coarsening of precipitated phases，formation of brittle phases，high process costs，and difficulty in coordinating process parameters. On the basis of understanding the advantages and disadvantages of existing processes，integrating different strengthening mechanisms to compensate for the deficiencies of single strengthening methods and achieving the synergistic effect of different mechanisms is of great research value. In the future，efforts should be focused on multi-mechanism synergy （such as the "fine grain+precipitation+dispersion" composite system），the design of new high-entropy alloys，the integration of additive manufacturing and SPD technology，and cross-scale simulation and prediction，in order to break through the strength-plasticity inversion relationship，develop a new generation of magnesium-lithium alloy systems with low density，high strength and toughness，and corrosion resistance，and promote their large-scale application in extreme environments. This article focused on the current research status of strengthening mechanisms of magnesium-lithium alloys at home and abroad and introduced some processes. It discussed the existing problems and predicted the future development direction of magnesium-lithium alloys，with the aim of providing references and guidance for further research and practical application in this field.

Beryllium and its alloys，as a rare metal material with superior physical and mechanical properties，have irreplaceable applications in strategic engineering fields such as aviation，aerospace，and nuclear. Because of this，the study of mechanical behavior （properties） related to its service reliability and safety has been an important topic of concern in beryllium science. For a long time，research on the mechanics of beryllium has mainly focused on the macroscopic mechanical behavior （properties） directly related to engineering applications，but little progress has been made in the study of its micromechanical behavior （properties） due to the limitations of research tools. The exploration of cross-scale correlations between the macroscopic and microscopic mechanical properties of beryllium has also been carried out even less. In this paper，the elastic modulus，plastic work ratio （ratio of plastic work to total work），hardness （yield strength） and other mechanical parameters with cross-scale characteristics were token as the objects of investigation，and the nanoindentation test method in the micro-scale and the loading\unloading tensile test method in the macro-scale were adopt to obtain the macroscopic and microscopic information of the above parameters，respectively. The microscopic mechanical property parameter values were obtained from the nanoindentation load-displacement curve （P-h curve） based on Oliver-Pharr model，and the macroscopic mechanical property parameter values were obtained from the continuous loading\unloading curve （stress-strain curve） based on the analysis of stress-strain hysteresis loop characteristics. The results showed that：1） The modulus of elasticity exhibited similar trends on macro and micro scales，decreasing monotonically with deformation and at close numerical levels. The consistency of the evolution curves of the modulus of elasticity at the macro scale for different elongation rates was more significant than the micro scale values. 2） On the microscopic scale，the plastic work W_p of specimens with different macroscopic elongations satisfied the same proportionality relationship between the plastic work W_p and the total work W，W_p=0.8461W，and its residual deformation permanent plastic deformation h_f had a more significant proportionality relationship with the maximum deformation h_max，h_f=0.85h_max；and the relationship between the maximum load P_max and the maximum deformation h_max was not sensitive to the macroscopic elongation either. On the macroscopic scale，the consistency of the mathematical characteristics of the relationship between the plastic work W_p and the total work W of the specimens with different elongations was less than that of the microscopic scale，with W_p/W of about 0.25，which was much smaller than the microscopic value. 3） The grain microhardness H was insensitive to the macroscopic elongation，with a value of about 4.5 GPa，which corresponded to a yield stress value of about 1.5 GPa according to the theory of indentation mechanics，which was much larger than the macroscopic yield stress value of 0.4~0.5 GPa. In addition，the size effect of grain microhardness was also weak，and there was no significant change in H value for different deformations h_max for each specimen. Therefore，for beryllium metal，it could be assumed that grain properties played a major role in determining properties like elastic modulus，while the influence of the plastic properties of the grains themselves was not obvious in the determination of macroscopic plastic mechanical properties such as strength and elongation. In other words，the variability in the mechanical properties of the beryllium grains themselves，as the microscopic units that made up the macroscopic metallic material，was not significant. It had been shown that the cracking and slipping behavior of beryllium grains had the characteristic of being confined within the grains. It could thus be speculated that the factors determining the variability of the macroscopic plastic properties were likely to come more from the grain boundary behavior.

With the rapid development of the nuclear industry，the safety of nuclear reactors has become a global concern. During normal operation or accident scenarios，control rods may undergo chemical interactions with their cladding materials upon contact，thereby affecting their service life. As new control rod materials are developed，investigating the chemical compatibility between control rods and their cladding materials is crucial. Eu₂O₃，with its high thermal neutron absorption cross-section and high melting point，is a suitable neutron-absorbing material for control rods in nuclear reactors，particularly under high-temperature operating conditions. However，Eu₂O₃ exhibits relatively poor chemical stability in water or humid air. Given its high thermal neutron absorption cross-section and melting point，and the fact that the addition of ZrO₂ can enhance its chemical stability，Eu₂O₃-ZrO₂ ceramics are considered a promising candidate material for new accident-tolerant control rods. Meanwhile，316L stainless steel，known for its excellent corrosion resistance and mechanical properties，is widely used for structural components in nuclear reactors. Therefore，the chemical compatibility of Eu₂O₃-ZrO₂ ceramics with 316L stainless steel cladding under accident conditions has attracted significant attention. To study the chemical compatibility between Eu₂O₃-ZrO₂ ceramics and 316L stainless steel，this paper investigated the compatibility by forming a diffusion couple through close contact between Eu₂O₃-ZrO₂ ceramics and 316L stainless steel. The study focused on the chemical compatibility under simulated accident temperatures （1000~1200 ℃） after heat treatment for 20~60 h. Eu₂O₃-ZrO₂ ceramics with a molar ratio of Eu₂O₃∶ZrO₂=2∶1 was used in the experiment. The microstructure of the diffusion couple interface was analyzed using scanning electron microscopy （SEM） and energy-dispersive spectroscopy （EDS） to reveal the chemical compatibility and interdiffusion behavior between Eu₂O₃-ZrO₂ ceramics and 316L stainless steel cladding under simulated accident conditions. The experimental results showed that the surface of Eu₂O₃-ZrO₂ ceramics changed from brown to yellow. Measurements of the sample dimensions revealed no significant changes before and after the experiment，indicating the preservation of the ceramics' apparent mass and structural integrity. Macroscopic observations of 316L stainless steel revealed the formation of a thin film on its surface. X-ray diffraction （XRD） analysis of the film on the surface of 316L stainless steel showed the presence of a small amount of SiO₂ phase，with no other phases detected. EDS results indicated that the main components of the film were Eu，O，Cr，and Si，with Eu content ranging from 24.37% to 33.49%，Cr content from 9.15% to 11.57%，O content from 43.24% to 54.70%，and Si content from 0.75% to 7.68%. Interface reactions occurred between Eu₂O₃-ZrO₂ ceramics and 316L stainless steel at the interface，accompanied by mutual diffusion of elements. Fe，Cr，Ni，and Si from 316L stainless steel，as well as Eu and O from the ceramics，diffused toward the interface. Eu and O diffused into the stainless-steel matrix，while Si accumulated in the diffusion zone within 316L stainless steel matrix. For the cross-section of 316L stainless steel，after heat treatment at 1000 ℃ for 20~60 h，the diffusion distances of the elements were 7.51，10.71，and 15.45 μm，respectively. After heat treatment at 1100 ℃ for 20~60 h，the diffusion distances were 13.53，18.15，and 22.80 μm，respectively. After heat treatment at 1200 ℃ for 20~60 h，the diffusion distances were 20.19，32.89，and 36.40 μm，respectively. In the chemical compatibility experiment at 1200 ℃ for 60 h，interface reactions between Eu₂O₃-ZrO₂ ceramicsand 316L stainless steel occurred，resulting in a decrease in Fe content in stainless steel from an initial 70.52% （non-diffusion zone） to 7.75% （diffusion zone），a decrease in Cr content from 16.73% to 2.58%，a decrease in Ni content from 9.44% to 0.95%，and an increase in Si content from 0.75% to 14.35%. Meanwhile，Eu and O contents in 316L stainless steel increased from the initial 0 to 30.28% and 44.09%，respectively，indicating the diffusion of Eu and O from the ceramics into the stainless steel matrix. The diffusion depth as a function of temperature and time was plotted as Δx² against time t，and linear fitting was performed to obtain the diffusion coefficients of Eu at different temperatures. Under heat treatment conditions of 1000~1200 ℃ for 20~60 h，the diffusion coefficients of Eu in stainless steel were （9.93±1.05）×10^-16，（2.38±0.05）×10^-15，and （6.49±0.46）×10^-15 m²·s^-1，respectively. The data indicated that the diffusion coefficient of Eu increased with temperature. Therefore，the reaction rate of Eu₂O₃-ZrO₂ ceramics with 316L stainless steel could be predicted within the temperature range of 1000~1200 ℃ using diffusion kinetics. This helpedto estimate its service life and mitigate the impact and damage of accidents. The diffusion reaction kinetics at the interface were further analyzed，and Arrhenius relationship between the diffusion coefficient （k） of Eu in 316L stainless steel and temperature （T） was established as：lnk=–（20.80±1.06）–（1.46±0.12）×10⁵/RT，where R is the gas constant and T is the temperature in Kelvin. The diffusion activation energy of Eu was calculated to be （146±12） kJ·mol^-1 using Arrhenius equation. Temperature was the primary factor affecting the chemical compatibility between Eu₂O₃-ZrO₂ ceramics and 316L stainless steel. Studying their chemical compatibility under accident conditions helped to ensure that no harmful chemical reactions occur between the control rod materials and the reactor structural materials under high-temperature conditions，thereby enhancing the safety and reliability of nuclear reactors.

The laser arc hybrid welding technology was used to weld the cladding structure of the radioisotope heat source，and the effects of different pulse frequencies on the microstructure and mechanical properties of the welded joint of L605 cobalt-based alloy cladding structure were studied in this paper. During the welding process，a high-speed camera was used to observe the changes in the arc morphology in laser arc hybrid welding when the pulse frequency was 250 Hz. Under the combined action of laser and arc，the laser heat source provides efficient local heating and had a significant attraction to the arc，causing the front end of the arc to tend to the laser irradiation area，thereby effectively suppressing the sputtering phenomenon and improving the stability of the molten pool. The edges of the macroscopic morphology of the weld of the cladding workpiece were more flush，and the surface was well-formed. On the cross-section of the cladding structure，the end plug cover and the outer cladding tube wall were well fused，without obvious welding defects such as pores or unfused areas，and the molten pool presented a "bell jar" shape. The upper part of the molten pool was greatly affected by the arc and had a wider area，while the lower part was deeply affected by the laser and had a deeper melting zone. The overall molten pool cross-section showed the typical characteristics of laser and arc hybrid heat sources. The pulse frequency had a significant effect on the microstructure of the welded joint. With the change of the pulse frequency，the microstructure morphology and grain size of the welded joint changed significantly. When no pulse current was applied，the upper part of the welded joint showed an equiaxed crystal structure，while the lower part of the welded joint was a long columnar crystal. This was because a temperature gradient was formed from top to bottom during the cooling of the molten pool：the cooling rate of the upper part was higher，and the grains grew in an equiaxed morphology；the lower part was close to the substrate，the cooling rate was lower，and the grains grew perpendicular to the heat flow direction to form columnar crystals. After the pulse frequency was introduced，the grains of the welded joint were further refined as the pulse frequency increases，and the fusion zone was almost completely composed of equiaxed crystals. At the same time，in order to further study the diffusion behavior of alloy elements at the interface of the weld zone and the fusion zone under different pulse frequencies，the diffusion of alloy elements at the interface of the fusion zone and the weld zone after welding was analyzed by scanning electron microscopy （SEM），energy spectrum analysis （EDS） and X-ray diffraction （XRD） and other test methods. The results showed that CrFeNi and FeNi phases existed in the weld zone at different frequencies，and W element was also found in the weld zone. With the change of pulse frequency，the physical phase in the weld zone did not change significantly，and W-rich particles were precipitated in the base metal zone. Compared with direct current，pulse current significantly increased the content of Cr element and reduced the content of Co element. The effect of pulse current on the hardness of the weld joint was small when no pulse current was applied，and when pulse current was applied，the hardness value in the depth direction of the weld showed a downward trend. The average hardness of the weld surface area was about HV 450，and the hardness of the heat-affected zone was HV 320，which was close to the hardness of the base metal （about HV 300）. Microstructure analysis showed that the increase in pulse frequency promoted grain refinement and the transformation of columnar crystals into equiaxed crystals，thereby improving the mechanical properties. After direct current welding，the fracture extended along the crystal cleavage plane，and there was no obvious dimple structure on the tensile fracture，showing cleavage fracture；after the introduction of pulse current，a large number of dimples gradually appeared on the tensile fracture，showing ductile fracture. With the increase of pulse frequency，the number of dimples on the fracture gradually increased，and was mainly concentrated at the fracture interface.

Organic dye wastewater poses a significant threat to aquatic environments，and traditional treatment methods are often inefficient and costly. Photocatalysis，as one of the advanced oxidation processes （AOPs），has garnered considerable attention for its ability to effectively degrade organic pollutants using semiconductor photocatalysts under sunlight，converting them into non-toxic，harmless small molecules （H₂O，CO₂，etc.）. It is recognized for its high efficiency，rapid action，cost-effectiveness，and environmental friendliness. BiPO₄ is a low-cost，non-toxic photocatalyst widely used in water treatment，but its 3.85 eV band gap limits solar energy utilization，hindering dye wastewater degradation. To enhance its visible light absorption，strategies like doping and heterojunction formation are often used. Graphitic carbon nitride （g-C₃N₄），with a 2.9 eV band gap，absorbs visible light up to 460 nm but suffers from poor electron-hole pair separation. Combining g-C₃N₄ with BiPO₄ forms a heterojunction that broadens light absorption and improves photocatalytic efficiency，making it a key research area. Therefore，in this study，BiPO₄/g-C₃N₄ composite photocatalyst was successfully designed and synthesized using a hydrothermal method. Its crystal structure，microstructure and photoelectric properties were systematically analyzed through characterization techniques，including X-ray diffraction （XRD），scanning electron microscopy （SEM），ultraviolet-visible diffuse reflectance spectroscopy （UV-Vis DRS） and transient photocurrent measurements. XRD analysis revealed g-C₃N₄'s pure phase with a strong （002） diffraction peak at 27.4°，while BiPO₄ displayed a highly crystalline monoclinic phase. In BiPO₄/g-C₃N₄ composite photocatalyst，g-C₃N₄ peaks were weak due to its low content and uniform dispersion. SEM images showed g-C₃N₄'s lamellar structure and BiPO₄'s rod-like morphology. The composite's layered g-C₃N₄ structure improved BiPO₄ dispersion，reducing aggregation and enhancing catalytic activity. Energy dispersive X-ray spectroscopy （EDX） confirmed uniform distribution of C，N，Bi，P，and O，verifying successful composite synthesis. UV-Vis DRS spectroscopy revealed that BiPO₄ absorbed only in UV region （~330 nm），while BiPO₄/g-C₃N₄ composite photocatalyst extended absorption to ~430 nm，shifting into the visible light range. This enhanced absorption was attributed to the formation of a heterojunction structure in BiPO₄/g-C₃N₄ composite photocatalyst，which facilitated charge transfer at the interface，leading to a red shift of the absorption edge. This shift effectively broadened the light absorption range of the catalyst，significantly improving its photocatalytic activity. Kubelka-Munk function analysis revealed that the band gaps of BiPO₄ and g-C₃N₄ were 3.80 and 2.70 eV，respectively，consistent with literature values. BiPO₄/g-C₃N₄ composite photocatalyst exhibited a band gap of 2.90 eV，indicating successful synthesis and excellent visible light responsiveness. The variation in band gap directly influenced the light absorption range，where a smaller band gap corresponded to a wider absorption range，and vice versa. Photocurrent measurements further validated the superior performance of BiPO₄/g-C₃N₄ composite photocatalyst. Under visible light irradiation，the photocurrent intensity of the composite was significantly higher than that of pure BiPO₄ and g-C₃N₄，indicating superior electron-hole separation efficiency and charge transfer ability. This enhanced photocurrent response was attributed to the in situ composite formation of BiPO₄ on g-C₃N₄，which improved the carrier migration efficiency and，consequently，enhanced the photocatalytic performance. A series of catalytic degradation experiments were conducted using methylene blue as the model water pollutant. The results showed that as the illumination time increased，the degradation efficiency of BiPO₄，g-C₃N₄ and BiPO₄/g-C₃N₄ gradually increased. After 120 min of illumination，the degradation rates of BiPO₄，g-C₃N₄ and BiPO₄/g-C₃N₄ were 70%，84%，and 97%，respectively. BiPO₄/g-C₃N₄ composite photocatalyst exhibited the highest catalytic activity among all samples. The combination of g-C₃N₄ and BiPO₄ expanded light absorption，generated more electrons and holes and allowed effective separation of electrons and holes，thereby enhancing the catalytic degradation ability of BiPO₄/g-C₃N₄ composite photocatalyst. Catalytic degradation experiments with different dyes showed significant variations in the degradation activity of BiPO₄，g-C₃N₄ and BiPO₄/g-C₃N₄，indicating that the catalysts exhibited some selectivity during dye degradation. The degradation rates of different dyes，from high to low，were as follows：Rhodamine B，methyl violet，malachite green，methylene blue and methyl orange. Under the same conditions，BiPO₄/g-C₃N₄ composite photocatalyst exhibited better photocatalytic degradation performance compared to g-C₃N₄ and BiPO₄. Cyclic testing results showed that after five cycles，the catalyst still maintained a degradation rate of 86% for methylene blue，demonstrating that BiPO₄/g-C₃N₄ composite photocatalyst had good stability and reusability，with high potential for commercial applications. Radical quenching experiments were conducted using disodium ethylenediaminetetraacetate （EDTA-2Na），isopropyl alcohol （IPA），and benzoquinone （BQ） to detect holes （h⁺），hydroxyl radicals （·OH） and superoxide radicals （·O₂^-）. The results showed that the three scavengers inhibited the methylene blue degradation to different extents. The addition of BQ significantly reduced the catalytic degradation efficiency，indicating that ·O₂^- played a dominant role in the degradation process. The addition of IPA also inhibited degradation，suggesting that h⁺ and ·O₂^- were the main active species in BiPO₄/g-C₃N₄ composite photocatalyst，with ·OH also involved in the degradation of organic pollutants. In summary，this study proposed a novel BiPO₄/g-C₃N₄composite photocatalyst to eliminate secondary pollution and provided a new approach for the rapid and deep treatment of dye wastewater，with broad application prospects.