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Effect of slow monomer addition on molecular parameters of hyperbranched polymers synthesized in the presence of multifunctional core molecules

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Science china Chemistry 2010年第4期53卷 891-897页

作者： ZHOU ZhiPing1. Jia ZhengWei1.& YAN DeYue2.1.1. of Materials Science and engineering, Jiangsu University, Zhenjiang 2.2.1., {2. 2.tate Key Laboratory of Metal Matrix Composites, shanghai Jiao Tong University, shanghai 2.02.0, {2. 1. school of Materials Science and {1. Jiangsu University Zhenjiang 212013 China2. State Key Laboratory of Metal Matrix Composites Shanghai Jiao Tong University Shanghai 200240 China

This study develops the kinetics for the slow monomer addition technique in the synthesis of hyperbranched polymers. Taking the conversion of monomer (x) as a variable, we derived the analytic expressions of molecular size distribution function, average degree of polymerization, polydispersity index and degree of branching. These expressions are not only amenable to the polymerization with high monomer conversion, but also appropriate to describe the whole polymerization process. Comparison with the one-pot polymerization indicates that the slow monomer addition technique improves the molecular weight distribution and increases the degree of branching for the products obtained.

关键词： hyperbranched polymer kinetics molecular weight distribution polydispersity degree of branching

Martensite Transformation and Its Control in DP,TRIP and TWIP Steels

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Journal of Iron and Steel Research International 2011年第S1期18卷 200-207页

作者： LI Lin 1.GAO Yi 2.SHI Wen 1.LIU Ren-dong 2.HE Yan-lin 1.FU Ren-yu 1.ZHANG Mei 1.WANG Hua 1.(1.school of Materials Science and engineering,{2. University,{2. 2.0072.china 2.Ansteel Company,Anshan 1.4001.china Corresponding Author:school of Materials Science and engineering,{2. University,P.O.Box 1.,1.9 Yanchang Road,{2. 2.0072.china) shanghai Univ Sch Mat Sci & Engn Shanghai 200072 Peoples R China Ansteel Co Anshan 114001 Peoples R China

Designing of alloy concept and process for DP,TRIP and TWIP steels stressing at martensite transformation are *** DP steel,austenite volume percent and its carbon content at different intercritical temperatures are calculated as well as the tensile strength of the steel,which meet well with the experimental *** condition for dissolution of carbide is discussed by experiments and predicted by kinetic *** sample TRIP steels are prepared and their concentration profiles are calculated showing different diffusion characteristics of *** also shows carbon enrichment is successful in this stage through the quick diffusion of carbon from ferrite to *** order to maintain the austenite stability or to prevent precipitation of cementite,minimum cooling rate from the intercritical zone to over aging stage is obtained through kinetic *** transformation is estimated,which indicates the carbon rerichment from ferrite of bainite structure to austenite in this stage is also *** HCP martensite transformation and the strain induced martensite transformation in TWIP steel is *** between transformation and mechanical properties in the steel is also mentioned.

关键词： martensite transformation DP TRIP and TWIP steels thermal HCP martensite transformation

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轴向约束钢框架柱火灾升温下屈曲后性能研究

同济大学学报（自然科学版） 2008年第4期36卷 438-443页

作者：王培军李国强同济大学土木工程学院上海200092

提出了一种改进的Jezék方法,用于火灾升温下轴向约束钢框架柱屈曲后性能分析,高温条件下钢材的应力-应变关系考虑了钢柱屈曲后凸侧可能出现的卸载现象.对轴向约束钢柱的参数分析表明,随着约束刚度的增大,钢柱附加轴力增大,屈曲温度降低... 详细信息

提出了一种改进的Jezék方法,用于火灾升温下轴向约束钢框架柱屈曲后性能分析,高温条件下钢材的应力-应变关系考虑了钢柱屈曲后凸侧可能出现的卸载现象.对轴向约束钢柱的参数分析表明,随着约束刚度的增大,钢柱附加轴力增大,屈曲温度降低,但轴向约束对屈曲后性能影响很小;荷载比大的构件抗火性能差,屈曲温度低,屈曲后轴力下降迅速;长细比小的构件,屈曲后轴力下降缓慢,屈曲后抗火性能显著提高;初弯曲大的构件,屈曲温度低,附加轴力小.在局部火灾下,利用约束钢柱的屈曲后性能,可显著提高其抗火性能.

关键词：钢框架柱火灾临界温度屈曲后性能轴向约束

A novel model-free approach for reconstruction of time-delayed gene regulatory networks

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中国科学：生命科学英文版 2006年第2期49卷 190-200页

作者： JIANG Wei1,2. LI Xia1,2.3,4, GUO Zheng1,2.3, LI Chuanxing1, WANG Lihong1 & RAO Shaoqi1,5 1. Department of Bioinformatics, Harbin Medical University, Harbin 150086, china 2. Department of Computer Science, Harbin Institute of Technology, Harbin 150080, china 3. {2. of Life Science and Technology, tongji University, shanghai 200092, china 4. Biomedical engineering Institute, Capital University of Medical Sciences, Beijing 100054, china 5. Departments of Cardiovascular Medicine and Molecular Cardiology, Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA Department of Bioinformatics Harbin Medical University Harbin 150086 China Department of Computer Science Harbin Institute of Technology Harbin 150080 China school of Life Science Technology Tongji University Shanghai 200092 China Biomedical engineering Institute Capital University of Medical Sciences Beijing 100054 China Departments of Cardiovascular Medicine Molecular Cardiology Cleveland Clinic Foundation Cleveland Ohio 44195 USA

Reconstruction of genetic networks is one of the key scientific challenges in functional genomics. This paper describes a novel approach for addressing the regulatory dependencies be-tween genes whose activities can be delayed by multiple units of time. The aim of the proposed ap-proach termed TdGRN (time-delayed gene regulatory networking) is to reversely engineer the dy-namic mechanisms of gene regulations, which is realized by identifying the time-delayed gene regu-lations through supervised decision-tree analysis of the newly designed time-delayed gene expres-sion matrix, derived from the original time-series microarray data. A permutation technique is used to determine the statistical classification threshold of a tree, from which a gene regulatory rule(s) is ex-tracted. The proposed TdGRN is a model-free approach that attempts to learn the underlying regula-tory rules without relying on any model assumptions. Compared with model-based approaches, it has several significant advantages: it requires neither any arbitrary threshold for discretization of gene transcriptional values nor the definition of the number of regulators (k). We have applied this novel method to the publicly available data for budding yeast cell cycling. The numerical results demonstrate that most of the identified time-delayed gene regulations have current biological knowledge supports.

关键词： gene regulatory networks, time delayed, decision tree.

Preparation and Magnetic Properties of Mn-Zn Ferrites by the Co-precipitation Method

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Journal of Wuhan University of Technology(Materials Science) 2009年第6期24卷 875-878页

作者：李雪张俊喜 school of Environmental and Chemical {1. Shanghai University Electrochemical Research Group Shanghai University of Electric PowerKey Laboratory of State Power Corporation of China

Mn-Zn ferrites （Mn1.xZnxFe2.4） with different compositions were prepared by the coprecipitation method, and the influences of such synthesis conditions as pH value, composition and volume ratio （R） of the mixed solution and NH4HCO3 solution on their microstructures and magnetic properties were discussed. The samples were characterized by X-ray diffraction （XRD） and magnetization measurement instrument. Lattice parameters and average crystalline size of the synthesized materials were calculated from the corresponding XRD patterns with the related software Jade.5. For samples of different pH values, only one phase was found when pH values were 7.0, 8.0 and 9.0. The sample with pH value of 7.0 exhibited the highest saturation magnetic induction, the lowest coercive force, and crystallized best. For samples of different R values with pH value of 7.0, only one phase was observed in all samples, and the sample with R value of 2.3 exhibited the highest saturation magnetic induction and the lowest coercive force. The composition has mainly afected the magnetic properties, and the saturation magnetic induction increases with the increase of the content of Zn （x）, but decreases when x is beyond 0.6. The trend of coercive force is on the contrary. However, no magnetism is exhibited when the x value is up to 0.8.

关键词： co-precipitation method microstructure magnetic property Mn-Zn ferrite

A whisker-like carbon composite for the immobilization of laccase and its bioelectrochemistry

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Science china Chemistry 2010年第6期53卷 1332-1336页

作者： MA GuoXian1.2.ZHONG QingDong2.& LU TianHong3 1.epartment of Chemical engineering,shanghai Institute of Technology,shanghai 2.02.3,china 2.4} of Materials Science and engineering,shanghai University,shanghai 2.0072.china 3Department of Chemistry,Nanjing Normal University,Nanjing 2.0097,china 1. Department of Chemical engineering Shanghai Institute of Technology Shanghai 200233 China2. School of Materials Science and Engineering Shanghai University Shanghai 200072 China3. Department of Chemistry Nanjing Normal University Nanjing 210097 China

A novel mesoporous carbon/whisker-like carbon (MCWC) composite was used for the immobilization of laccase (Lac) and its bioelectrochemical behaviors were *** was confirmed by XPS that Lac was strongly adsorbed on the surface of the MCWC *** cyclic voltammetric results showed that the immobilized Lac underwent a direct quasi-reversible electrochemical *** value of the electron transfer rate constant ks was estimated to be 0.770 s-1.indicating a reasonably fast electron transfer between the immobilized Lac and the underlying *** surface concentration (I-) of Lac was estimated to be 2.730 × 1.-1.0}mol/*** experimental results showed that the immobilized Lac displayed an appreciable electrocatalytic activity to the electrochemical reduction of *** properties could be attributed to the particular structure of loosely packed nanometer-scale carbon whiskers and the existence of a large amount of oxygen-containing *** immo- bilization method and the novel carrier (MCWC) may find new applications in fabricating the biocatalysts for biofuel cells.

关键词： laccase whisker-like carbon composite direct electrochemical reaction oxygen bioelectrochemistry

Effect of Solute Drag and Precipitate Pinning on Austenite Grain Growth in Ti-Nb Microalloyed Steels

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Journal of Iron and Steel Research International 2011年第S1期18卷 383-387页

作者： FU Li-ming 1.WANG Huan-rong 2.WANG Wei 2.SHAN Ai-dang 1.(1.school of Materials Science and engineering,{2. Jiaotong University,{2. 2.02.0,china 2.Department of Structural Steels,Baosteel Research Institute,{2. 2.1.00,china) shanghai Jiao Tong Univ Sch Mat Sci & Engn Shanghai 200240 Peoples R China Baosteel Res Inst Dept Struct Steels Shanghai 201900 Peoples R China

A metallurgical model concerning the co-effect of the Nb solute drag and the complex carbonitride precipitates pinning is proposed to predict the recrystallization austenite grain growth of low carbon Nb-containing microalloyed *** analysis,both predicted and experimental,reveals the precipitate pinning plays a dominate role in suppressing the austenite grain growth with less Nb solute drag effect in high temperature region whereas the Nb solute drag predominates in relatively low temperature region.A factor p is suggested to assess the effectiveness of drag and *** pinning and the drag are more effective in restraining grain growth as p>0 and p<0,respectively.A low carbon Nb microalloyed steel and a kind of Ti-modified low carbon Nb steel by Ti substituting for part of Nb are employed to validate the modeling *** theoretical calculations show a good agreement with experimental results.

关键词： grain growth precipitates pinning solute drag Ti-Nb microalloyed steels

Denitrification in tidal flat sediment, Yangtze estuary

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Science china Chemistry 2007年第6期50卷 812-820页

作者： WANG DongQi1.2. CHEN ZhenLou1. XU ShiYuan1. DA LiangJun1. BI ChunJuan1.& WANG Jun1.1.{1. of Resources and Environment Science, East china Normal University, {2. 2.0062. china 2.{1. of Life Science, East china Normal University, {2. 2.0062. china 1. school of Resources and Environment Science East China Normal University Shanghai 200062 China 2. {1. of Life Science East China Normal University Shanghai 200062 China

Sediment denitrification rates at six Yangtze River estuary tidal flat locations(mudflats and salt marshes)were measured from July 2.03 to October *** winter and summer,spatial distribution of denitrification rates was not great in the Yangtze estuary,while in spring and autumn,denitrification rates had a great spatial distribution because of the human activity *** temporal change of denitrification rates was *** ranged from 0.2.to 36.4 umolN·m^(-2.·h^(-1.,and were higher in the *** annual average of sediment denitrification rate was 1..2.1.0}3 mu molN · m^(-2.· h^(-1.in the middle tidal flat and 1..1.±9.45 mu molN·m^(-2.·h^(-1.in the low tidal flat in the Yangtze *** analysis indicated that the temperature was the primary factor controlling the process of denitrification(significant positive correlation,P1.;at the same time,the content of sediment total nitrogen(TN)and the molar ratio of sediment carbon and nitrogen(C/N)had significant positive correlation(P<0.05)and negative correlation(P<0.05)with denitrification rates,*** the Yangtze estuary,increasing of water salinity had no significant inhibition of denitrification because of the wide change range of water salinity.

关键词： Yangtze estuary, tidal flat sediment, denitrification, effect factors

A new scheme of digital communication using chaotic signals in MIMO channels

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Science china(Information Sciences) 2012年第10期55卷 2183-2193页

作者： MA HuanFei 1.& KAN HaiBin 2.1.{1. of Mathematical Sciences,Soochow University,Suzhou 2.5006,china 2.{1. of Computer Science,Fudan University,shanghai 2.0433,china 1. school of Mathematical Sciences Soochow University Suzhou 215006 China 2. {1. of Computer Science Fudan University Shanghai 200433 China

This paper proposes a new digital communication scheme,which uses chaotic signals based on the adaptive synchronization and parameter identification technique of chaotic systems reported *** to the multi signal character,this scheme combines the chaotic signal transmission with the MIMO channel technique in a wireless environment,which is different from the traditional chaotic communication *** a practical perspective,an outline of modulation,channel model,demodulation and non-coherent detection is ***,system performance is evaluated by simulations,and improvements on this scheme are also discussed.

关键词： chaotic modulation chaotic digital communication mapping parameters MIMO channel