The energy band structure,density of electronic states and optical properties of Ni3V2O8 were calculated by using first-principle plane-wave ultra-soft pseudo-potential method based on density functional theory with generalized gradient approximation.The results show that Ni3V2O8 has indirect band gap with a width of 1.0eV,and its electrons near Fermi energy level have weak mobility.The energy bands near Fermi level are formed with Ni d、Vdand Oporbits,and there is a strong hybridization interaction among the three orbits.When the incident photons have 2.16 eV energy,the electrons transit from Ni dorbit within the top valance bands to Oporbit within the bottom conduction bands.When the incident photons have 3.14 eV energy,the electrons transit from Vdorbit within the middle valance bands to Oporbit within the middle conduction bands.The strongest absorption peak appears at 7.26 eV in the absorption spectrum of Ni3V2O8 with an optical band gap of 3.47 eV.

The contributions of strengthening action for yield strength of aged Mg-5Y-3Sm-0.8Ca-0.5Sb alloy were investigated by microstructure analysis,tensile tests and theoretic calculation.The results show that on the basis of grain-refinement strengthening,the alloy exhibits significant precipitation strengthening at the expense of losing part of solid solution strengthening,resulting in greatly increased yield strength.The contribution of solid solution strengthening for alloy yield strength is slightly less than that of grain-refinement strengthening,and the contribution of precipitation strengthening is more than 50% total yield strength.

（Pr-Nd）（28.8-x）D（y2）HoxFebalNb（0.2）B（1.05） sintered NdFeB permanent magnet was prepared on the massproduction line,and the effects were studied of Ho replacement for part of Pr-Nd metal on the magnetic properties,microstructure and corrosion resistance of the permanent magnet.The results show that the growth of Nd2Fe（14） B columnar crystal in the alloy can be promoted after partial Pr-Nd is substituted by Ho,and Nd-rich phase in the form of sheets more uniformly distributes in the crystal grains of Nd2Fe（14） B matrix phase,resulting in dense microstructure,increased intrinsic coercivity but decreased remanence,improved corrosion resistance and reduced weight loss of the permanent magnet.The best comprehensive properties are as follows：remanence（Br）of 1.237 T,intrinsic coercivity（H（cj））of 1.76MA/m,the square degree of J-H demagnetization curve（Hk/H（cj））of 0.99,achieved under the conditions of 3% Ho addition.

H2 or CO pretreated In/γ-Al2O3 catalyst has significantly improved activity.Activity test results show pretreatment can enhance catalyst activity due to its effect on indium species from catalyst surface.The improvement of H2 is stronger than CO.XRD results show thatγ-Al2O3 carrier remains original crystal type.IR analysis results show that pretreatment can increase the content of indium low-valence oxides to improve denitrification activity of the catalyst.Because the surface has well dispersed indium particle cluster and chemically adsorbed oxygen,In/γ-Al2O3-H catalyst shows relatively high catalytic activity.Formation of monodentate nitrate and bidentate nitrate on catalyst surface is an important factor to reduce the catalytic activity of the catalyst.The pretreated catalyst has improved activity due to the formation of—NO2 and—ONO.

The recent development is reviewed of preparation of special alloys and intermetallic compounds with electro-deoxidation method.The reduction mechanism is summarized in the preparation process of intermetallic compounds.Advantages and present problems are also pointed out of electro-deoxidation process during alloy production.

Based on cointegration theory,the long-term equilibrium relationship was investigated between molybdenum price and gross national product or steel production.And a long-term equilibrium cointegration model and an error correction model were established to predict molybdenum price.The results show that the three variables have cointegration relationship.Error correction model has higher prediction precision than long-term equilibrium cointegration model.The predicted results with the above models for molybdenum price in 2016 indicate that molybdenum price will continue to decline to 615 yuan per mtu within the next year.

The phase composition of the molybdenum ammonia leaching residue was analyzed by XRD.The results indicate that there are calcium molybdate and a small amount of low-valence molybdenum compounds in the residue.Thermodynamic research of calcium molybdate leaching with sodium carbonate shows that the leaching reaction spontaneously occurs at the temperature higher than 86℃.The higher the temperature,the easier the leaching reaction.The optimum process parameters of residue leaching with sodium carbonate at high temperature are established as follows：sodium carbonate concentration 70g/L,reaction temperature 190℃,pretreating time 1.5h,liquid-solid ratio 3∶1.Under the optimal leaching conditions,the molybdenum leaching ratio can reach 91.44%,the molybdenum content in the residue decreases to 1.91%,and calcium molybdate is completely leached.Kinetic study of the leaching process shows that the apparent activation energy is 10.38kJ/mol in the leaching reaction of molybdenum ammonia leaching residue with sodium carbonate,and the leaching process is mainly controlled by solid-membrane diffusion.

The Δ_fGθ of CoPO_4,Co_3（PO_4）_2 and MeCoPO_4（Me=Li,Na,K,Mg_（0.5））was estimated by congeneric linearity rule.Theφ-pH diagram of the Me-Co-P-H_2O system at 298.15 K was drawn according to the thermodynamic calculation.Thermodynamic analysis was made of lithium extraction using lithium ion battery electrode material LiCoPO_4,and the differences were discussed of adsorption behaviors between Na＋,K＋ or Mg2＋ and Li＋ in salt lake by CoPO_4.The results show that CoPO_4/LiCoPO_4 electrode is stable in aqueous solution（pH=4~11）.Controlling the redox potential of the system at 0.066~0.201V（vs SHE）,CoPO_4 material can absorb Li＋ selectively from the natural brine containing a large number of Na＋,K＋ and Mg2＋,and then Li＋can be desorbed reversibly from lithium-inserted CoPO_4 ion sieve material by controlling the redox potential over 0.201V（vs SHE）.

The process was investigated of capping reduction-high temperature carbonization to prepare ultra-coarse grained WC powder.WO_3 is put into a special boat for hydrogen reduction at 930～980 ℃ at first and then carbonization at 2 300℃.Compared with the two processes of traditional medium temperature reduction-high temperature carbonization and doping reduction-high temperature carbonization,the process of capping reduction-high temperature carbonization can produce ultra-coarse grained WC powder with fuller particles,coarser grain size,more uniform particle size distribution and more complete crystal.WC powder prepared by this process has abrasive grain size of 7.4μm,reaching the requirement of ultra-coarse grained WC for grain size.

High-temperature oxidation-resistant protective coating was prepared by slurry fusion sintering on the surface of Nb-W alloy Nb521-1 used in aerospace engine.The bottom layer and surface layer were successively prepared by twice slurry fusion sintering processes to obtain silicide composite coating.Morphology and element content of the coating were analyzed by SEM and EDS.High temperature oxidation resistance at 1 700 ℃ and thermal cycling performance from room temperature to 1 600 ℃ of the coating were tested.And the failure mechanism of the coating was preliminarily discussed.The results show that there is a diffusion layer between the composite coating and the substrate attributed to their mutual diffusion,and the interface is of metallurgical bond.The coating can be continuously used at 1 700 ℃ for 22 h,and its limit frequency of thermal cycling tests from room temperature to 1 600℃ is 1 124 times.The composite coating can effectively prevent the external oxygen from further diffusion to the substrate,and therefore the substrate is well protected in high temperature environment.