Copper-coated carbon fiber-graphite-copper matrix composite,carbon nanotube-graphite-copper matrix composite and graphite-copper matrix composite were prepared by powder metallurgy.The properties of the composites,such as density,resistivity,Vickers hardness and bend strength,were tested,the microstructure is observed and then the comprehensive performance was compared with each other.The results show that carbon fiber-graphite-copper matrix composite is of the most excellent performance in the three composites.

Three kinds of benzimidazole ramification including 2-（o/i/p）-nitrobenzimidazole were synthesized by one step with o-phenylenediamine and nitrobenzaldehyde as the materials.And they were applied in cemented carbide anticorrosion.The results show that the optimal synthesis technical parameters are as follows：the ratio of o-phenylenediamine to nitrobenzaldehyde is 1.2,reaction temperature 60 ℃,heating duration 20 min.The melting point analysis results show that the synthetic product is the target product.The corrosion inhibition rate of the new corrosion inhibitor is up to 95.6%,better than that of the similar domestic products.

The effects of yttrium on the microstructure of Mg-5.5Al alloy were investigated.The results show that adding yttrium can dramatically refine the crystalline grains of Mg-5.5Al alloy,where punctate Al2Y appears in the matrix.When the dosage of yttrium is 1.2%（mass fraction）,the average grain size is refined to 171 μm from 333 μm.However,once the dosage is over 1.2%,Al2Y phase gradually segregates and grow up,and therefore the effect of grain refinement is reduced.

Platinum carbon（PtCx） nanostructure was prepared by ion beam deposition,and its electron transport property was studied.The microstructure and composition of PtCx nanostructure were analyzed by SEM and EDX,the nanostructure size analyzed by AFM,and its atomic structure analyzed by HRTEM.The AC measurement was performed using a resistance bridge and the electron transport property measured in a cryostat.The results from EDX indicate that PtCx nanostructure has non-metallic behaviour due to the low metal content.The results from HRTEM confirm that the prepared sample is amorphous PtCx nanostructure,which is consistent with the observed electron transport property.

Spinel LiMn2O4 was synthesized by reaction milling with KMnO4,MnSO4·H2O and LiOH·H2O as the raw material.The samples were characterized by XRD and SEM from structure and surface morphology.The results show that the sample after reaction milling is composed of LiMn2O4,Li2SO4·H2O and KLiSO4.After washing,the product is spinel LiMn2O4,but the crystallization degree is incomplete.After heating at 800 ℃ for 30 min,the synthesized LiMn2O4 is complete crystal,and its grains are fine and uniform with an average diameter of about 500 nm.And its initial discharge capacities are 115.8,107,105.5,98.2 mA·h/g at these discharge rates of 0.2,0.5,1 and 3 C,respectively,based on electrochemical tests.It is also of an excellent cycle performance with only 3.2% capacity fading degree after 10 cycles.

Al-Ca alloy was produced by molten salt electrolysis in the CaCl2-CaF2 system and with CaO as the starting material,and the Ca content of the product is up to 14%.The influences of electrolysis temperature and time,and current density on back EMF and current efficiency were investigated.The results from XRD show that the main mineralogical phases of the produced Al-Ca alloy is Al and Al4Ca.According to SEM analysis,the Al-Ca alloy is of homogeneous concentration distribution based on the Al4Ca distribution.

The effects of bismuth addition on the microstructure and mechanical properties of AZ81 magnesium alloy are studied through the alloy preparation,microstructure analysis and tensile tests.The results show that with proper Bi addition to AZ81,the as-cast microstructure of AZ81 is refined,and the Mg3Bi2 grain phase with high thermal stability is observed in the matrix.Proper Bi addition to AZ81 can enhance the mechanical properties at room temperature and high temperature and improve the heat resistance of AZ81 alloy.

The distributing rules of adsorbed ions in exchange column and the influencing factors during dynamic ion exchange are acquired through theoretical analysis.On the above basis,a novel idea of variable-parameter ion exchange and its principles are presented.The application of the variable-parameter ion exchange process in tungsten metallurgy proves its advantages.