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science china Chemistry 2004年第5期47卷 414-419页

作者： WU Yukai1, OU Yuxiang1, LIU Zhiguo1,2 , LIU Jinquan1, MENG zheng1 & CHEN Boren1 1. school of materials {3. and Engineering, beijing Institute of technology, beijing 100081, china 2. school of Chemistry and Chemical Engineering, Henan university, Kaifeng 475001, china 1. school of materials science and Engineering Beijing Institute of Technology 100081 Beijing China 2. school of Chemistry and Chemical Engineering Henan University 475001 Kaifeng China

Tetranitrodiazidoacetylhexaazaisowurtzitane (TNDAIW) is a novel polyazapolycyclic caged polyazidonitramine explosive first synthesized in our laboratory. All of the possible con- formers of TNDAIW are optimized using both the AM1 and PM3.methods. TNDAIW is predicted to have more polymorphs than hexanitrohexaazoisowurtzitane (CL-20). The HF/6-3.G(d) level of theory is used to investigate the lowest energy structures of D-TNDAIW for both AM1 and PM3. The possible conformers of TNDAIW are predicted to be more stable than epsilon-CL-20 based on the N-NO2 bond lengths. The impact and shock sensitivities of both the possible DA- and DP-TNDAIW are lower than the corresponding ones of epsilon-CL-20. TNDAIW with the possible conformers is estimated to be a promising novel high energy density explosive.

关键词： tetranitrodiazidoacetylhexaazaisowurtzitane, molecular modeling, impact and shock sensitivities.

Oxidation-induced strengthening behavior of reaction formed Al_4SiC_4 ceramics

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Rare Metals 2007年第S1期26卷 94-98页

作者： HUANG Xiaoxiao1,2),WEN Guangwu1,3.,LIU Ruitang2),and zheng Xin1)1) school of materials {3. and technology,Harbin Institute of technology,Harbin 150001,china 2) school of Material {3. and Chemical Engineering,Harbin Engineering university,Harbin 150001,china 3. school of materials {3. and technology,Harbin Institute of technology at Weihai,Weihai 264209,china Harbin Inst Technol Sch Mat Sci & Technol Harbin 150001 Peoples R China Harbin Inst Technol Sch Mat Sci & Chem Engn Harbin 150001 Peoples R China Harbin Inst Technol Sch Mat Sci & Technol Weihai 264209 Peoples R China

The bending strengths of Al4SiC4 ceramics were investigated from room temperature to 13.0 ℃ in air and in vacuum,*** is a novel property that the bending strength increases with increasing test temperatures up to 13.0 ℃ in *** strength value of Al4SiC4 ceramics is 449.7 MPa at 13.0 ℃ in air,which is about 1.5 times of that at room temperature(3.0 MPa).The self-healing behavior of the flaws on the specimen surface due to the oxidation of the surface layer of the Al4SiC4 ceramics is considered as the main enhancement mechanism at high temperatures.

关键词： calcination and hot pressing surface strength Al_4SiC_4

Interface Stability of the SiC Particles/Fe Matrix Composite System

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Journal of Wuhan university of technology(materials {3.) 2006年第3期21卷 49-53页

作者：汤文明 school of materials science and Engineering Hefei University of TechnologyHefei 230009China

The interface reaction between the SiC particles （ SiCp ） and Fe was stndicd during sintering the SiCp reinforced Fe matrix composites at 1423.K for 1 h. In the composite having 3.t% （weight ratio） SiCp （the 3.iCp/ Fe composite）, the interface reaction products of Fe3.Si, the carbon precipitates, and Fe3.C or pearlite were generated. Fe3.Si coustructs the bright matrix of the reaction zone in the original situation of the SiCp. The carbon precipitates are randondy embedded in the reaction zone. Fe3.C or pearlite exists at the grain boundaries of the Fe matrix. As increasing the SiCp concentration in the SiCp/ Fe composite, the inteusity of the interface reaction between SiCp and Fe iacreases. After the 10SiCp/ Fe composite （ having 10wt .% SiCp ） sintered at 1423.K for 1 h, all of SiCp are decomposed, and replaced by the reaction zone composed of Fe3.Si and the carbon precipitates. No Fe3.C or pearlite was genertaed during the reaction. The effects of the techniques of oxidizing of SiCp , coating SiCp by interaction with the Cr powder, and alloying the Fe matrix by ad{3. the Cr element on the interface stability of the SiCp/ Fe composite system were also investigated, respectitely. The oxide membrane and the coating layer on SiCp can inhibit the interface reaction between SiCp and Fe by isolating SiCp from the Fe matrix during sintering. The interface reaction does not occur in the 3.SiCp/ Fe- 10 Cr composite but in the 3.SiCp/ Fe-5 Cr composite. In the SiCp/ Fe-Cr alloy composites, the interface reaction between SiCp and the Fe- Cr alloys is weaker than that between SiCp and Fe . The Cr element behaves as a diluent, it causes a redaction in the interface reaction, which is proportional to the amount of the element added.

关键词： interface reaction interface stability oxidation of SiC coating alloying

Superplasticity and Superplastic Bulging Behavior of ZrO_2/Ni Nanocomposite

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Journal of Wuhan university of technology(materials {3.) 2011年第1期26卷 56-60页

作者：丁水 Aerospace Research Institute of materials and Processing technology

ZrO2/Ni nanocomposite was produced by pulse electrodeposition and its superplastic properties were investigated by the tensile and bulging tests. The as-deposited nickel matrix has a narrow grain size distribution with a mean grain size of 45 nm. A maximum elongation of 605% was observed at 723.K and a strain rate of 1.67×10-3.-1 by tensile test. Superplastic bulging tests were subsequently performed using dies with diameters of 1 mm and 5 mm respectively based on the optimal superplastic forming temperature. The effects of forming temperature and gas pressure on bulging process were experimentally investigated. The results indicated that ZrO2/Ni nanocomposite samples can be readily bulged at 723.K with H/d value （defined as dome apex height over the die diameter） larger than 0.5, indicating that the nanocomposite has good bulging ability. SEM and TEM were used to examine the microstructure of the as-deposited and bulged samples. The observations showed that significant grain coarsening occurs during superplastic bulging, and the microstructure is found to depend on the forming temperature.

关键词： superplasticity bulging microstructure ZrO2/Ni nanocomposite

Electrical Breakdown Characteristic of Nanostructured W-Cu Contacts materials

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Journal of Wuhan university of technology(materials {3.) 2006年第4期21卷 32-35页

作者：王俊勃 school of Mechanical and Electrical Engineering Xi'an Polytechnic UniversityXi'an 710048 ChinaSchool of Science Xi'an Jiaotong University Xi'an 710049China

Nanostructured （ NS ）W-Cu composite powder was prepared by mechanical alloying （ MA ）, and nanostructared bulk of W-Cu contact material was fabricated by hot press sintering in an electrical vacuum furnace. The rnicrostructure, electric conductivity, hardness and break down voltage of NS W- Cu alloys were measured and compared to those of conventional W-Cu alloys prepared by powder metallurg＇y. The experimental results show that microstructural refinement and uniformity can improve the breakdown behavior and the electric arc stability of nanostructared W- Cu contacts materials. Also, the wanostructured W- Cu contact material shows the characteristic of spreading electric arcs, which is of benefit to electric arc erosion.

关键词： nanostructured materials W-Cu alloy electrical breakdown

Partial Inverse Grain Size Dependence of Strength in High Mn Steels Microalloyed With Nb

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Journal of Iron and Steel Research International 2012年第9期19卷 68-72页

作者： ding Hua 1 , 2 , LI Hua-ying 1 , ding hao 1 , QIU Chun-lin 2 , TANG {3.-you 1 ( 1.school of materials and Metallurgy , Northeastern university , Shenyang 110819 , Liaoning , china 2.State Key Lab of Rolling and Automation , Northeastern university , Shenyang 110819 , Liaoning , china ) [a] school of materials and Metallurgy Northeastern University Shenyang 110819 Liaoning China [b] State Key Lab of Rolling and Automation Northeastern University Shenyang 110819 Liaoning China

Two steels without and with Nb addition were chosen to investigate the effects of Nb on the microstructures and the mechanical properties of Fe-Mn-Al-Si *** results revealed that Nb refined the grains markedly and both TRIP and TWIP effects occurred during deformation *** Nb containing steel possesses higher yield strength and much lower tensile strength , the latter being explained by the suppression of TRIP effect due to the increase of stacking fault *** indicates grain refining is secondary for strengthening of steels when TRIP or TWIP effect exists during the deformation of low carbon and high Mn steels.

关键词： grain size strength high Mn steel Nb

In-situ growth and photoluminescence of β-Ga_2O_3.cone-like nanowires on the surface of Ga substrates

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science china(Technological sciences) 2009年第6期52卷 1712-1721页

作者： LIU RuiNi1,YANG HeQing1,ZHANG RuiGang1,DONG HongXing1,CHEN XiaoBo1,LI Li1,ZHANG LiHui1,MA JunHu1 & zheng HaiRong2 1 Key Laboratory of Macromolecular science of Shaanxi Province,school of Chemistry and {3. science,Shaanxi Normal university,Xi’an 710062,china 2 school of Physics & Information technology,Shaanxi Normal university,Xi’an 710062,china 1. Key Laboratory of Macromolecular science of Shaanxi Province School of Chemistry and Materials Science Shaanxi Normal University Xi’an 710062 China 2. school of Physics & Information technology Shaanxi Normal University Xi’an 710062 China

β-Ga2O3.cone-like nanowires have been in-situ grown on the surface of gallium grains and films by heating gallium substrates at 750-1000℃ for 2h in *** controllable synthesis of β-Ga2O3.nano-wires with different diameters and lengths was achieved by adjusting the heating temperature and *** as-synthesized products were characterized by means of X-ray diffraction,scanning electron mi-croscopy and transmission electron *** results showed that the β-Ga2O3.nanowires are single crystalline with a monoclinic structure and have a controllable diameter and length in the range of 3.-100nm and 0.5-1.5μm,respectively.A possible mechanism was also proposed to account for the formation of β-Ga2O3.cone-like *** spectra of the β-Ga2O3.nanowires obtained at different temperatures were measured at room temperature,and a strong blue photolumi-nescence with peaks at 43. and 460nm and a weak red photoluminescence with peak at 713.m were *** blue light emission intensity decreases with increasing the reaction temperature,how-ever,the red light emission intensity hardly *** blue and red light emissions originate from the recombination of an electron on an oxygen vacancy with a hole on a gallium-oxygen vacancy pair and the nitrogen dopants,etc.,respectively.

关键词： β-Ga2O3 cone-like nanowires photoluminescence in-situ growth

Microstructure and Mechanical Properties of Nb-Microalloyed X100 High Deformability Pipeline Steel

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Journal of Iron and Steel Research International 2011年第S1期18卷 707-711页

作者： MENG De-liang 1,KANG Yong-lin 1,AN Shou-yong 2,XIA Dian-xiu 2,SUN hao 2,zheng Xiao-fei 1 (1.school of {3. science and Engineering,university of science and technology beijing,beijing 100083.china 2.technology Center of Jinan Iron and Steel Co.,Ltd.,Jinan 250101,Shangdong,china) Univ Sci & Technol beijing Sch Mat Sci & Engn Beijing 100083 Peoples R China Jinan Iron & Steel Co Ltd Ctr Technol Jinan 250101 Shangdong Peoples R China

A low carbon Nb-microalloyed high deformability pipeline steel with X100 grade has been processed by TMCP and followed two-stage cooling *** microstructure is characterized by ferrite/bainite *** effective grain size is 1.85μm in *** volume of ferrite is about 10-15% and the grains sizes are mostly less than 5μ*** bainite consists of granular-bainite and lath-bainite,with M/A islands finely *** longitudinal tensile yield strength,uniform elongation,yield ratio are 647MPa,7.6% and 0.78,***/bainite multiphase have large strain hardenability that resulting high strength and high deformability *** of Nb also improves the strength and uniform deformability by precipitation strengthening and grain refinement.

关键词： pipeline steel high deformability high strength microalloyed steel strain based design

pH-Dependent Stability of EGX, A Multi-functional Cellulase from Mollusca, Ampullaria crossean

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Acta Biochimica et Biophysica Sinica 2004年第9期36卷 603-608页

作者： Wen-Ying LI2, Ji WANG1, Yan-Hong LI1, Ming ding1, Gen-Jun XU1,3. Lan-Ying LIU2, and Fu-Kun Zhao1,3. 1Key Laboratory of Proteomics, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological sciences, the Chinese Academy of sciences,Graduate school of the Chinese Academy of sciences, Shanghai 20003., china 2College of Life science, Jilin university, Changchun 13.023. china College of Life science, Zhejiang university of science and technology, Hangzhou 3.0018, china Key Laboratory ofProteomics Institute of Biochemistry and Cell BiologyShanghai Institutes for Biological Sciencesthe Chinese Academy of SciencesGraduate School of the Chinese Academy of SciencesShanghai 200031China

The cellulase activity and stability of EGX, a multi-functional cellulase previously purified from the mollusca Ampullaria crossean, was systematically studied under different pH. The pH induced con- formation and stability change of EGX have been investigated by using the intrinsic fluorescence, ANS fluorescence and CD spectrum. It has been found that the conformation and activity of this cellulase were strongly dependent on the pH. EGX was stable for both the enzyme activity and the conformation from pH 5.6 to pH 7.4. As shown by intrinsic and ANS fluorescence, no red shift of emission maximum occurred and a negligible intensity change was observed at pH 5.6–7.4. The activity of EGX remained about 80% in pH 5.6–7.4 and obviously decreased out of side the pH range. Urea-induced changes in EGX at pH 5.4 and pH 8.0 were measured by intrinsic fluorescence and CD spectrum. At pH 5.4, a significantly red shift of emission maximum occurred when the concentration of urea was 5 M compared to the concentration was 3.M at pH 8.0. The α-helix at pH 5.4 was 40.51% in the absence of urea and 3..04% in the presence of 4 M urea. At pH 8.0 the α-helix was 7.23. in the presence of 4 M urea. The data indicated that EGX was much susceptible to urea-induced unfol{3. at pH 8.0 and much stable at pH 5.4. The greater pH dependent stability of EGX may allow the enzyme to adequately catalyze the hydrolysis of cellulosic materials under natural or industrial extreme conditions.

关键词： multi-functional cellulase stability Ampullaria crossean fluorescence spectroscopy pH-dependent structural change CD spectrum

Whisker Orientation Function and Elastic Modulus of the as-cast 20% SiC_W/Mg Composite

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Rare Metals 2001年第4期20卷 270-274页

作者： Chuanhai Jiang1, Jiansheng Wu1, Mingyi zheng2, Dezun Wan 2 1) Key Laboratory for High Temperature materials and Tests of the Ministry of Education, Shanghai Jiaotong {3.. Shanghai 20003., china 2) school of materials science and Engineering, Harb Harbin Inst Technol Sch Mat Sci & Engn Harbin 150001 Peoples R China

The relationship between the plane-orientation function and the space-orientation function of whiskers in whisker-reinforced metal matrix composites was analyzed theoretically. The actual orientation of whiskers in the as-cast 20%SiCw/Mg composite (SiCw content in volume fraction) were investigated, and the elastic modulus of the composite was measured with an ultrasonic velocity analyzer. Results show that there is an evident difference between the plane-orientation function and the space-orientation function of whiskers and the space-orientation function can represent the actual condition of the composite. Only by using the space-orientation function of whiskers, the difference of elastic modulus of the as-cast composite in different directions can be explained reasonably.

关键词： SiC whisker Mg composite whisker orientation elastic modulus