The influences were investigated of smelting speed and tungsten element segregation on service performance of tantalum strip as superconducting wire barrier.The results show that the tantalum ingot can be purified and its microstructure also can be improved by slowing down the first smelting speed and raising up the second smelting speed,and therefore the product of tantalum strip has fine and homogeneous microstructure.By strictly controlling the tungsten content in the raw materials（≤0.002%）and reducing welding points or applying other welding equipment without tungsten welding pins,tungsten impurity into the ingot can be avoided and tungsten segregation in the ingot can be reduced to prevent fracture of tantalum strip during the service.

The effect was studied of quenching at different temperature on microstructure and hydrogen storage properties of 40Ti-40V-10Cr-10 Mn alloy.The results show that the unquenched sample is V-based solid solution with body centered structure having two close characteristic diffraction peaks of BCC-1phase and BCC-2phase.The sample quenched at 1 473 Khas a single BCC-1phase.Both the samples quenched at1 573 Kand 1 673 Kconsist of BCC-1phase,BCC-2phase and C14-Laves phase with hexagonal closepacked structure.The results of kinetic mechanism study show that the hydrogen absorption kinetic process of all the samples can be described by chemical reaction mechanism,while their equations of kinetic mechanism are significantly different and thus their hydrogen absorption rates are different.With the increase of quenching temperature of the samples,their hydrogen absorption capacity at 298 K decreases firstly and then increases（getting the minimum at 1 573 Kand the sample quenched at 1 673 Kclose to the unquenched sample）,their hydrogen desorption capacity and hysteresis at 298 Kare gradually improved,and their hydrogen desorption capacity at 373 Kalso decreases at first and then increases（getting the minimum at 1 573 Kand the sample quenched at 1 673 Khigher obviously than the unquenched sample）.

Ti35alloy bar was annealed at 700 ℃for 8h,and then investigated by full immersion corrosion tests and polarization curves and electrochemical impedance spectroscopy in 8mol/L nitric acid.The experimental results show that through a long time of annealing,the grain size of Ti35 alloy bar obviously increases,its corrosion current density decreases,impedance arc radius significantly increases,phase angle platform broadens and modulus value increases,resulting in its corrosion resistance greatly improved in concentrated nitric acid.

Co2＋doped YPO4：Eu3＋phosphors were successfully synthesized with hydrothermal method.The crystal structure,element valence state and luminescent properties of the as-synthesized samples were investigated by XRD,XPS,FT-IR and FL.The results show that all the samples from hydrothermal synthesis are single-phase Co2＋doped YPO4：Eu3＋crystals with tetragonal xenotime structure,they can effectively emit characteristic orange-red luminescence of Eu3＋with UV light excitation,and the fluorescence lifetime is approximately 4.6ms.A small amount of Co2＋and Eu3＋codoping has less influence on phase composition and crystal structure of product matrix,but has a significant impact on its luminescent properties.The intensity of emission peak located at 595 nm of YPO4：2%Eu3＋,0.10 %Co2＋sample is about 21.1%higher than that of YPO4：2%Eu3＋sample.

The effects of aluminum on the microstructure and mechanical properties of as-cast Mg-5Gd-3Y alloy were studied by using X-ray diffraction,scanning electron microscopy,metallurgical microscopy and tensile performance test.The results show that as-cast Mg-5Gd-3Yalloy consists ofα-Mg matrix and eutectic phases of Mg5 Gd and Mg24Y5.After adding Al element to Mg-5Gd-3Yalloy,there are new Al2 Gd and Al2 Y phases separating out to effectively refine alloy grains and improve its mechanical properties.

The resistance was measured of Na3AlF6-AlF3-LiF-MgF2-Al2O3-Nd2O3-CuO molten salt system with TH2810 DLCR digital bridge tester,and then its electrical conductivity was tested by CVCC technique.Meanwhile,the regression equation including temperature,composition and electrical conductivity of the molten salt was developed by data fitting with the least square method.The results show that the molten salt conductivity increases with the increase of temperature or CuO content,but decreases with Nd2O3 and Al2O3content increasing.Simultaneously adding Nd2O3 and CuO of the same mass ratio at a certain temperature,the electrical conductivity of molten salt system increases with the increase of Nd2O3 and CuO content.

Bismuth telluride nanopowder was synthesized with solvothermal method to prepare thermoelectric material by hot pressing sintering.Phase composition and grain size of the nanopowder and thermoelectric properties of the sintered material were determined and analyzed.The results show that the nanopowder synthesized using TeO2 as tellurium source has higher phase purity,better crystallization properties and smaller grain size than using Te as tellurium source.When solvothermal reaction temperature is 130 ℃ or140 ℃,there are small amount of bismuth and tellurium metallic phases and BiTe phase in the synthesized powder.When the temperature is 150 ℃ or 160 ℃,the synthesized powder consists of pure Bi2Te3 phase,and the synthesized powder at 150 ℃ has smaller grain size and better crystallization properties.Compared with bismuth telluride thermoelectric material prepared by traditional zone melting-hot pressing sintering,the material prepared by solvothermal synthesis-hot pressing sintering has lower thermal conductivity and better comprehensive thermoelectric properties.

CuS crystal was synthesized via solvothermal route employing CuCl2 as copper source,（NH2）2CS as sulfur source and C2H6O2-NH3·H2O mixed solution as solvent.The crystal structure and optical properties of the as-synthesized samples were investigated by XRD,FL,FT-IR and UV-Vis.The influences were also discussed of some synthesis conditions on the optical properties of the as-prepared samples.The results show that the prepared sample by solvothermal synthesis is CuS crystal of pure hexagonal covellite structure.There are three strong PL emission peaks of blue and green light at 470.8nm,498.4nm and577.6nm in the photoluminescence spectrum of CuS crystal.The ultraviolet-visible spectra exhibit that synthesis conditions have significant influences on the optical properties of the samples.When reactant concentration in the reaction system is 0.30 mol/L,copper to sulfur molar ratio is 3∶2,glycol to ammonia volume ratio is 4∶1,and the solvothermal reaction temperature and time are 140 ℃ and 2h,the as-prepared sample displays excellent near-infrared absorption performance.

Experiments were carried out of equal channel angular pressing and torsion（ECAPT）of SiCP/Al composites with different process parameters.The effects were studied of deformation temperature,deformation passes and SiC mass fraction on composite compactness during deformation.The microstructure of the sample was observed by optical microscope.The results show that such defects as micropore and aggregation in the sample decreases by ECAPT treatment,SiC particles disperse in aluminum matrix and sample density significantly increases.The ratio of SiC particles affects material micropore amount as an important parameter of ECAPT process to affect material compactness.

Tungsten and vanadium were recovered from spent SCR denitration catalyst by high pressure leaching with Na2CO3.The effects were investigated of roasting pretreatment temperature,type and dosage of the leaching additive,Na_2CO_3 dosage,liquid-solid ratio,leaching time and temperature for tungsten and vanadium leaching.The phases of spent SCR denitration catalyst were analyzed by XRD characterization before and after leaching.The results show that spent SCR denitration catalyst can be leached without roasting pretreatment,and the optimized experimental conditions are as follows:Na_2CO_3addition of 20%,NaOH addition of 8%,liquid-solid ratio of 2∶1,leaching time of 2hand leaching temperature of 230 ℃.Under the above conditions,the leaching rates of tungsten and vanadium reach 75.06% and 89.35%,respectively.In addition,the XRD analysis results show that titanium exists mainly in the form of anatase TiO_2 in spent SCR denitration catalyst,and high-temperature roasting can promote TiO_2 transition from anatase to rutile,inhibiting tungsten and vanadium leaching.Part of tungsten may exist in TiO_2 in the form of solid solution,and therefore the microstructure of TiO_2 should be destroyed by strengthening leaching conditions to further improve the leaching rate of tungsten.