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IR STUDY ON MONOMOLECULAR PARTICLE AGGLOMERATES OF POLYSTYRENE OBTAINED BY FREEZE-DRYING OF ITS DILUTE SOLUTION

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chinese Journal of Polymer science 2002年第4期20卷 381-383页

作者： Song Wang Qing-hua Wang Rong-shi Cheng Research Center of Materials beijing Institute of technology beijing 100081,{4. Department of Chemistry Nanjing university Nanjing 210093,{4. Research Center of Materials Beijing Institute of Technology 北京 100081 Department of Chemistry Nanjing University Nanjing 210093

The monomolecular particle agglomerates of polystyrenes were obtained by freeze-drying of its very dilute solutions of 1.3 x 10(-5)-2.0 x 10(-5) g/mL in benzene:cylcohexane (100:1) solvents, and they were annealed at room temperature for hundred days before use. According to C-13-NMR measurement the polystyrenes should be practically atactic. The number average molecular weights of the samples are 2.80 x 10(3), 2.00 x 10(4., and 1.55 x 10(6), respectively. The freeze-dried aPS with a molecular weight higher than 10(4. show two new IR absorption bands at 1098 and 1261 cm(-1), which are absent in the normal aPS and freeze-dried styrene oligomer. It was also found that the low molecular weight samples can only form powders, whereas the freeze-dried aPS with higher molecular weight form a mixture of powders and fibrils, of which the longer fibrils show a much stronger 1261 cm(-1) band than the shorter fibrils and the powder. It seems that the 1261 cm(-1) band corresponds to the stacking behavior of monomolecular particles.

关键词： monomolecular particles atactic polystyrene FTIR spectroscopy

NUMERICAL SIMULATION ON DEFORMATION CHARACTERISTICS OF AS WIRE BY CASTEX

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chinese Journal of Mechanical Engineering 2001年第1期14卷 5-8,17页

作者： shi Zhiyuan Wang Wanjun Wang Xinhua Metallurgical Engineering school,beijing university of {4. and technology Wen Jinglin Northeastern university 北京科技大学冶金学院北京东北大学辽宁

Castex(continuous cast and extrusion)is a latest metallurgical technology Making of AS wire(aluminum clad steel wire) by Castex is an advanced bonding technology of bimetal In order to study the deformation character of AS wire the numerical simulation is performed with FE method From the simulation result the following conclusions are obtained:① The simulation is carried out sequentially in three zones:initial extrusion,cavity filling and bonding ② In the first zone the shearing deformation governs the whole zone,while in that of cavity filling, the deformation mainly concentrates on transition arc of the concave mould In addition, in the last zone, the dominant deformation lies at the boundary of concave mould, surface of steel wire and entry of sizing band Due to the movement of steel wire, the direction of shear stress on its surface is opposite to that on the boundary of concave die

关键词： Castex AS wire FE method Elasto plastic Deformation characteristic

Suitability evaluation for land reclamation in mining area:A case study of Gaoqiao bauxite mine

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中国有色金属学会会刊：英文版 2011年第S3期21卷 506-515页

作者： WANG shi-dong1, 2, LIU Chang-hua2, ZHANG He-bing2 1. College of Resources science and technology, beijing Normal {4., beijing 100875, china 2. school of Surveying and Land Information Engineering, Henan Polytechnic {4., Jiaozuo 4.4.00, china College of Resources science and technology Beijing Normal University Beijing 100875 China school of Surveying and Land Information Engineering Henan Polytechnic University Jiaozuo 454000 China

Suitability evaluation plays an important role in land reclamation because the choice of evaluation methods affects the accuracy and objectivity of the suitability evaluation results. Furthermore, it influences the decision-making related to land reclamation. An improved method, which is called limit comprehensive conditions method, was developed after different suitability evaluation methods were studied. Based on this method, the reclaimed land of the Gaoqiao bauxite mining area was evaluated. The Gaoqiao mining area was divided into seven evaluation units that were evaluated respectively by selecting evaluation factors and establishing grade standards. The results show that the proposed method is more applicable and easier to handle. Moreover, its evaluation results are more scientific compared with the traditional evaluation methods. The improved method can be beneficial to the rapid monitoring and the effective management of reclaimed land in the opencast mine area.

关键词： mining area land reclamation suitability evaluation Gaoqiao bauxite mine

Genetic relationship between parasitized and non-parasitized Haloxylon ammodendron in the Alxa Desert

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Journal of Systematics and Evolution 2009年第3期47卷 255-262页

作者： 1,2,3Xu-Mei WANG 1Dong-Ye YANG 4.ong-Zhen TIAN 5Peng-Fei TU 2Qi-shi SUN 1Xiao-Bo LI 1(school of Pharmacy, Shanghai Jiao Tong university, Shanghai 20024., china) 2(College of Traditional {4. Materia Medica, Shenyang Pharmaceutical university, Shenyang 110016, china) 3(school of Medicine, Xi’an Jiaotong university, Xi’an 710061, china) 4.Forest and Desert Control Research Institute of Alxa League, Alxa League 750306, china) 5(Modern Research Center of Traditional {4. Medicine, school of Pharmaceutical sciences, Peking university, beijing 100083, china) (school of Pharmacy Shanghai Jiao Tong University Shanghai 200240 China) (College of Traditional chinese Materia Medica Shenyang Pharmaceutical University Shenyang 110016 China) (school of Medicine Xi’an Jiaotong University Xi’an 710061 China) (Forest and Desert Control Research Institute of Alxa League Alxa League 750306 China) (Modern Research Center of Traditional chinese Medicine School of Pharmaceutical Sciences Peking University Beijing 100083 China)

Haloxylon ammodendron (C. A. Mey.) Bunge is a host for the holoparasitic plant Cistanche deserticola Y. C. Ma, the original source of medicinal material known as Herba Cistanchis. The inter-simple sequence repeat marker was used to assess the genetic variations and relationships among six accessions of H. ammodendron with a total of 120 individuals collected from three localities in the Alxa Desert, Inner Mongolia, china. At each locality, individuals both parasitized (PP) by C. deserticola and non-parasitized (NP) were sampled. The results showed that Nei’s gene diversity and Shannon’s index of PP accessions were higher, but were not significantly different, from those of NP accessions. An unweighted pair-group method arithmetic average dendrogram showed two clusters, one that included all PP accessions, and the other the NP accessions. Genetic differentiation therefore existed between PP and NP accessions, which might be attributed to low gene flow between the NP and PP groups (Nmship between genetic distance and geographic distance within each group, although not statistically significant in this study, might be associated with high gene flow in both the NP and PP groups.

关键词： genetic relationship Haloxylon ammodendron ISSR marker parasitism.

Advanced landfill leachate treatment using a two-stage UASB-SBR system at low temperature

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Journal of Environmental sciences 2010年第4期22卷 481-485页

作者： Hongwei Sun,Qing Yang,Yongzhen Peng,Xiaoning shi,Shuying Wang,Shujun Zhang Key Laboratory of beijing Water Quality science and Water Envirocnnment Recovery Engineering,beijing {4. of technology,beijing 100124.china Key Laboratory of beijing Water Quality science and Water Environment Recovery Engineering Beijing University of Technology Beijing 100124 China

A two-stage upflow anaerobic sludge blanket （UASB） and sequencing batch reactor （SBR） system was introduced to treat landfill leachate for advanced removal of COD and nitrogen at low temperature. In order to improve the total nitrogen （TN） removal efficiency and to reduce the COD requirement for denitrification, the raw leachate with recycled SBR nitrification supematant was pumped into the first-stage UASB （UASB1） to achieve simultaneous denitrification and methanogenesis. The results showed that UASB1 played an important role in COD removal and UASB2 and SBR further enhanced the nutrient removal efficiency. When the organic loading rates of UASB1, UASB2 and SBR were 11.95, 1.63 and 1.29 kg COD/（m^***）, respectively, the total COD removal efficiency of the whole system reached 96.7%. The SBR acted as the real undertaker for NH4.＋-N removal due to aerobic nitrification. The system obtained about 99.7% of NH4.＋-N removal efficiency at relatively low temperature （14.9-10.9℃）. More than 98.3% TN was removed through complete denitrification in UASB 1 and SBR. In addition, temperature had a significant effect on the rates of nitrification and denitrification rather than the removal of TN and NH4.＋-N once the complete nitrification and denitrification were achieved.

关键词： landfill leachate two-stage UASB-SBR advanced nitrogen removal low temperature nitrification denitrification

A TTCN-3-based protocol testing system and its extension

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science in china(Series F) 2008年第11期51卷 1703-1722页

作者： YIN Xia1,3,WANG ZhiLiang2,3,JING ChuanMing1,3 & shi XinGang2,3 1 Department of Computer science and technology,Tsinghua university,{4. 100084.china 2 Network Research Center,Tsinghua university,{4. 100084.china 3 Tsinghua National Laboratory for Information science and technology(TNList) ,{4. 100084.china Department of Computer science and technology Tsinghua University Beijing China Tsinghua National Laboratory for Information science and technology (TNList) Beijing China Network Research Center Tsinghua University Beijing China

The protocol testing technology used in the next generation Internet should satisfy some new challenges and requirements. This paper focuses on the test suite description and test implementation techniques. TTCN-3 is chosen as the test suite description language and extended in both syntax and semantics to satisfy the requirements of protocol robustness testing. PITSv3, a protocol integrated testing system based on TTCN-3, is developed, and the extensions for robustness testing are implemented. Finally, two practical test applications are presented.

关键词： protocol testing TTCN-3 PITSv3 robustness testing

COMPUTER SIMULATION OF EFFECT OF ORIENTATION DIFFERENCE ON MECHANICAL PROPERTIES OF BICRYSTALLINE SPECIMENS

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Acta Metallurgica Sinica(English Letters) 1991年第1期4卷 13-16页

作者： WEI Chao QIAN Rengen LIN shi XIAO Jimei university of science and technology {4.,{4.,china Dept.of Mathematics and Mechanics,university of science and technology {4.,Bijing 100083,china

Based on the experimental results of the work-hardening processes of single crystals,the ac- commodation processes of polycrvstal deformation and the assumption of idealized polycrystal,the stress-strain relation of elasto-plastic deformation crystal was *** effect of orientation difference on the mechanical properties of the bicrvstalline specimens of aluminum was simulated by means of the finite element method(FEM)of elasto-plastic *** results are in good agreement with the experimental results made by Clark and Chalmers in 1954.

关键词： bicrystal orientation difference grain boundary computer simulation finite element method

Research on the Long Time Swelling Properties of Poly (vinyl alcohol)/Hydroxylapatite Composite Hydrogel

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Journal of Bionic Engineering 2009年第1期6卷 22-28页

作者： De-kun Zhang~(1,3), Da-gang Wang~2, Jun-jie Duan~(1,3), shi-rong Ge~(2,3)1. school of Materials science and Engineering, china {4. of Mining and technology, Xuzhou 221116, P. R. china2. school of Mechanical and Electrical Engineering, china {4. of Mining and technology, Xuzhou 221116, P. R. china3. Biotribology Center, National Key Laboratory of Tribology, Tsinghua {4., beijing 100083, P. R. china school of Materials science and Engineering China University of Mining and Technology Xuzhou P. R. China Biotribology Center National Key Laboratory of Tribology Tsinghua University Beijing P. R. China school of Mechanical and Electrical Engineering China University of Mining and Technology Xuzhou P. R. China

Poly(vinyl alcohol)/hydroxylapatite(PVA/HA)composite hydrogel was prepared by repeated freezing and *** water loss properties of the resultant hydrogel were investigated by using optical *** time immersion tests of PVA/HA composite hydrogel were carried out in the diluted calf serum solution to study the change laws of swelling properties with the freezing-thawing cycles and HA *** micro-morphologies of PVA/HA composite hydrogel after long time immersion were observed by means of the high-accuracy 3D *** results show that the swelling process of PVA/HA composite hydrogel is the converse process of its water *** time swelling ratio curves of PVA/HA composite hydrogel in the calf serum solution are manifested as four stages of quick increase,decrease,slow decrease and stable balance,and its equilibrium swelling ratio decreases with the increase of freezing-thawing cycles and HA *** is revealed that the network structure of the composite hydrogel immersed for a long period is significantly improved with the increase of HA content. Perfect network structures of PVA/HA composite hydrogel as well as full and equilibrium tissues after swelling equilibrium are obtained when the HA content is 3% and the number of freezing-thawing cycles is 7.

关键词： poly (vinyl alcohol) hydroxyapatite composite hydrogel swelling property morphology

Nd-doped barium titanate ceramics with various Ti/Ba ratios prepared by sol-gel method

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science china Chemistry 2005年第Z1期48卷 60-64页

作者： shi Qizhen,CUI Bin,WANG Hui,TIAN Jing,CHANG Zhuguo & HOU Yudong Department of Chemistry,Northwest university,Shaanxi Key Laboratory of Physico-lnorganic Chemistry,Xi’an 710069,china Key Laboratory of Advanced Functional Materials of china Education Ministry,{4. university of technology,{4. 100022,china Department of Chemistry Northwest University Shaanxi Key Laboratory of Physico-lnorganic Chemistry Xi’an China Key Laboratory of Advanced Functional Materials of china Education Ministry Beijing University of Technology Beijing China

The Nd-doped BaTiO3 nanocrystalline powders and ceramics with different Ti/Ba ratios were prepared by sol-gel method. Phases and microstructures of the Nd-doped BaTiO3based powders and ceramics were characterized by XRD, SEM and TEM methods. The results revealed that the powders synthesized by sol-gel method were nanometer scale (30-60 nm)and were mainly composed of cubic BaTiO3 with a small amount of BaCO3. After sintering at high temperature, both cubic BaTiO3 and BaCO3 were transformed into tetrahedron BaTiO3 *** dielectric properties of the ceramics were also determined and the influence of Ti/Ba ratio on the dielectric properties was discussed. The Tc did not change with the variation of Ti/Ba ratio,while the εmax increased firstly and then decreased. The excess TiO2 is benefit for the modification of ceramics' microstructure and dielectric properties.

关键词： sol-gel method, dielectric properties, nanometer materials, Nd-doped barium titanate, Ti/Ba mole ratio.