The principle,research progress,advantages and disadvantages are briefly introduced of several titanium powder preparation technologies such as atomization method,hydrogenation dehydrogenation method,thermal reduction method,and radio frequency plasma spheroidization method.According to the deficiencies of each technology,the future development trend of titanium powder preparation is pointed out.

Perovskite oxide La0.6Ca0.4Co0.9Mn0.1O3 was prepared by sol-gel method under different conditions,and its electrocatalytic properties in bifunctional oxygen electrode was investigated,then the best synthesis conditions were determined.The TG-DSC curves show that the lowest synthesis temperature of La0.6Ca0.4Co0.9Mn0.1O3 is above 600℃.On this basis,the effects of the initial pH value of the solution,the amount of citric acid and the calcination temperature have been studied on the catalytic performance of perovskite oxide bifunctional oxygen electrode.The results of physicochemical characterization and electrochemical performance test of perovskite oxides show that the catalytic activity of perovskite oxides is better when the initial pH of the solution is 5,the molar ratio of metal ions to citric acid is 2∶3,and the calcination temperature is 750℃.

The annealing treatment of ATI425 titanium alloy bars in the range of 650~800℃was carried out at different temperatures.The microstructure,tensile properties at room temperature and Vickers hardness of the annealed ATI425 alloy bars were tested by metallographic microscope,universal testing machine and microhardness tester.The experimental results show that the yield strength and tensile strength of the ATI425 alloy annealed at 650℃decrease by about 30MPa,the elongation increases by 2%,and the Vickers hardness decreases by about 20 HV1 compared with those of the hot-working titanium alloy ATI425.When the heat treatment temperature is raised from 650℃to 800℃,the secondaryαphase in the alloy is equiaxly spheroidized,the primaryαphase grows up and the number of β phase decreases.Also the strength and Vickers hardness and microstructure is well at the annealing temperature controlled between 700℃and 750℃,which provides a reference for further production and application.

Vanadium carbide(VC)nanowhiskers were synthesized by high temperature carbothermal reduction using precursors as raw materials.The effects of synthesis temperature and time on phase composition and microstructure of the reactive products were investigated using XRD,SEM,FESEM and TEM.The results show that VC nanowhiskers with a diameter of about 80nm,good linearity and smooth surface are prepared at 1000℃for 2h.The synthesis temperature and time have important influences on the growth of VC whiskers.Both too low synthesis temperature and too short reaction time are not conducive to the reduction of V2O3 to VC.If the synthesis temperature is too high and the reaction time is too long,VC particles are easily obtained,which is not conducive to the preparation of whiskers.

Nano-MoS2 modified lithium-rich manganese-based cathode material Li1.2Mn0.54Ni0.13Co0.13O2 was prepared by simple liquid-phase grinding method.The constant current charge and discharge test results show that the nano-MoS2 modified material exhibits excellent electrochemical cycle stability.3%MoS2 modified material has a discharge specific capacity of up to 235mA·h/g after 120cycles at 0.5C,and the capacity retention ratio reaches 88.4%,which is significantly higher than 70.1%capacity retention ratio and 153.8mA·h/g discharge specific capacity of the blank.In addition,the voltage decay of 3%MoS2 modified material is only 0.44 Vafter 120 cycles compared with the blank of 0.70 V.It can be seen that the voltage decay of the material during cycle is also significantly improved.

Lithium-rich manganese-based cathode materials Li1.2[Ni0.13Co0.13Mn0.54]O2 with particle size of 200~300nm were successfully synthesized via the coprecipitation-high temperature solid-state method.And MnMoO4 with oxygen vacancy was deposited on the surface of the materials via wet chemical deposition to improve the electrochemical performance.It is found that surface-modified MnMoO4 successfully induces the formation of spinel LiMn2O4 structure on the surface of the materials,and the special surface heterogeneity can reduce the side-reaction between the bulk and the electrolyte,effectively accommodate oxygen loss during the first charge and promote lithium ion diffusion.Compared with the initial material,the initial Coulombic efficiency of the material modified with MnMoO4 increases from 74.41%to 81.48%,and the capacity of the modified material after 100cycles boosts from 175.8mA·h/g to 205.7mA·h/g,exhibiting excellent electrochemical properties.

The 17Ni/(10NiO-NiFe2O4)cermets doped with CoO and Cr2O3 compound additives were prepared by powder metallurgy.The phase and morphology of the cermets were analyzed by XRD and SEM,and their relative density,microhardness,fracture toughness and flexural strength were also tested.The effects of different content and ratio of CoO and Cr2O3 compound additives on the mechanical properties of the cermets were investigated.The results show that CoO and Cr2O3 compound additives are dissolved into the NiFe2O4lattice of the ceramic matrix phase,which promotes sintering densification and also results in the mechanical properties of the cermets improved.When the composite doping amount of CoO and Cr2O3 is 1%(CoO/Cr2O3 mass ratio of 1∶2),the microhardness and fracture toughness of the cermet are 740.65 N/mm^2and 9.61MPa·m^1/2,which are 7.35%and 169.19%higher than those of the undoped cermet,respectively.When the composite doping amount of CoO and Cr2O3 is 2%(CoO/Cr2O3 mass ratio of 2∶1),the flexural strength of the cermet is as high as 175.66MPa,which is 31.97%higher than that of the undoped cermet.

WC-8% Co bi-crystallinity cemented carbide was prepared with different proportion of coarse and fine WC particles.The mechanical properties and microstructure were studied by observing the metallographic microstructure of the alloy and comparing the physical and mechanical properties such as hardness(HRA),coercive force(Hc),bending strength(TRS)and fracture toughness(KIC).The results show that the proportion of coarse and fine WC particles and the size of WC grains are the important factors to improve the mechanical properties and microstructure of the inhomogeneous structure alloy.Based on proportion optimization,the bi-crystallinity cemented carbide with good mechanical properties can be prepared by adding 21%~24%coarse WC particles.With the increase of the ratio of coarse WC particles in the alloy,HRA and Hcslightly decrease,KICincreases from 14MPa·m^1/2 to 19.7MPa·m^1/2,and TRS increases at first and then decreases,with a maximum value of 3498MPa.

A field experimental study was carried out of tobacco wastewater treatment from a cigarette factory by membrane bioreactor(MBR).The process flow,equipment and main operation control parameters were introduced in detail.The main process steps include hydrolysis acidification,aerobic aeration,MBR membrane filtration and secondary settlement tank drainage.The actual operation results show that MBR process has a good effect on the treatment of tobacco wastewater from cigarette factories.The quality of the produced water in the system meets the quality standards for urban landscaping water.And the operational problems of serious membrane fouling in common wastewater treatment systems are solved.

The process of deep chromium removal from Na2WO4 solution by reductive hydrolysis-magnesium salt coprecipitation was studied,and the separation of tungsten from chromium in chromium magnesium slag was realized by once alkali leaching.The results show that after adding 3 times the theoretical amount of Na2S at 70℃,controlling the pH value at 8~9 for 0.5 h,adding 1%MgSO4 solution to continue the reaction for 0.5 h,and then filtrating,the ratio of Cr content to WO3 content in the filtrate is less than 1.6×10^-4.When the final alkalinity of chromium magnesium slag leaching is controlled at 30~40 g/L,WO3 recovery is more than 96%,and the ratio of Cr content to WO3 content in the leaching solution is less than 1.6×10^-4.