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Preparation of amphiphilic graft copolymer with polyisoprene backbone by combination of anionic polymerization and "click" reaction

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Chinese Chemical Letters 2012年第3期23卷 347-350页

作者： Fei shao Xu Feng Ni zhi Quan Shen MOE Key Laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science and EngineeringZhejiang UniversityHangzhou 310027China

A novel graft copolymer consisting of polyisoprene backbone and hydrophilic side chain with carbamic acid ester functional group was prepared via thiol-ene＂click＂reaction and alcohol-isocyanate *** was synthesized by anionic polymerization using n-butyl lithium as initiator,and the pendant hydroxyl groups were introduced by the thiol-ene reaction of mercaptoethanol with the double bond of 1,2-addition units of PI backbone in the presence of radical initiator azobisisobutyronitrile. Isocyanate end group capped poly（ethylene glycol）（mPEG-NCO） was grafted onto the PI backbone through alcoholisocyanate reaction between the pendant hydroxyl groups and isocyanate group of *** structure of the graft copolymer were characterized and confirmed by means of size-exclusion chromatography,~1H NMR and FTIR spectroscopy.

关键词： Graft-copolymer Thiol-ene addition Isocyanate Click reaction

A Note on Normal Forms of Quantum States and Separability

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Communications in Theoretical Physics 2008年第12期50卷 1307-1311页

作者： LI Ming FEI shao-Ming Wang zhi-Xi Department of Mathematics Capital Normal University Beijing 100037 China Institut fiir angewandte Mathematik Universitat Bonn D-53115 Germany

We study the normal form of multipartite density *** is shown that the correlation matrix(CM)separability criterion can be improved from the normal form we obtained under filtering *** on CMcriterion the entanglement ... 详细信息

关键词： separable state entanglement witness

Permeation of dimethyl sulfoxide into articular cartilage at subzero temperatures

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2012年第3期13卷 213-220页

作者： shao-zhi ZHang Xiao-yi YU Guang-ming CHEN Institute of Refrigeration and Cryogenics Zhejiang University Hangzhou 310027 China

Osteochondral allografting has been proved to be a useful method to treat diseased or damaged areas of joint surfaces. Operational long-term stocks of grafts which supply a buffer between procurement and utilization would contribute to the commercialization or industrialization of this technology. Vitrification has been thought to be a promising method for successful preservation of articular cartilage （AC）, but high concentration cryoprotectants （CPAs） are used which may cause high cellular toxicity. An effective way to reduce CPA toxioity is to increase CPA concen- tration gradually while the temperature is lowered. Understanding the mechanism of （31~A permeation at subzero temperatures is important for designing the cryopreservation protocol. In this research, the permeation of dimethyl sulfoxide （MezSO） in ovine AC at subzero temperatures was studied experimentally. Pretreated AC discs were ex- posed in Me2SO solutions for different time （0, 5, 15, 30, 50, 80, and 120 min） at three temperature levels （-10, -20, and -30℃）. The Me2SO concentration within the tissue was determined by ultraviolet （UV） spectrophotometry. The diffusion coefficients were estimated to be 0.85×10-6, 0.48×10-8, and 0.27×10-6 cm2/s at -10, -20, and -,30℃, respectively, and the corresponding activation energy was 29.23 kJ/mol. Numerical simulation was performed to com- pare two Me2SO addition protocols, and the results demonstrated that the total loading duration could be effectively reduced with the knowledge of permeation kinetics.

关键词： Articular cartilage Vitrification Dimethyl sulfoxide Permeation Diffusion coefficient Subzero temperature

Comparative Studies on Properties of Polymers with Bulky Side Groups Synthesized by Cyclopolymerization of α,ω-Dienes and α,ω-Diynes

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Chinese Journal of Polymer Science 2019年第2期37卷 149-156页

作者： shao-Fei Song Xiao-Yu Liu Hao Zhang zhi-Sheng Fu Jun-Ting Xu zhi-Qiang Fan Ministry of Education Key Laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science and Engineering Zhejiang University

Four polymers containing five-membered rings in the main chain, with or without conjugation structure along the backbone and with or without conjugated pendent groups, were designed and synthesized by metathesis cyclopolymerization of functionalized α,ω-diynes, and cyclopolymerization of functionalized α,ω-dienes catalyzed by the α-diimine palladium-based catalyst, respectively. High to moderate monomer conversions were achieved. Chain structure, molecular weight, and molecular weight distribution(MWD) of the cyclopolymerization products were characterized by ~1 H-, ^(13) C-NMR, FTIR, and GPC. The polymers showed regular main chain structures,moderately high molecular weight, and narrow MWD. Thermal properties and chain stacking behaviors of the polymers were investigated by differential scanning calorimetry(DSC) and X-ray diffraction(XRD) as well as atomic force microscopy(AFM). The polymer with conjugation system in both the backbone and the pendent groups exhibited UV-Vis absorption at a much longer wavelength than those with the conjugation only in the backbone or only in the side groups. The polymers with conjugated backbone need more space for chain stacking, and the conjugated backbone causes enhanced size of polymer particles assembled from solution. The results showed that primary microstructures of the polymer exerted significant influences on the physical properties.

关键词： Cyclopolymerization α,ω-Diene α,ω-Diyne Conjugation system Properties

Purification and studies on characteristics of cholinesterases from Daphnia magna

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2013年第4期14卷 325-335页

作者： Yan-xia Yang Li-zhi NIU shao-nan LI Institute of Pesticide and Environmental Toxicology College of Agriculture and BiotechnologyZhejiang University

Due to their significant value in both economy and ecology,Daphnia had long been employed to investigate in vivo response of cholinesterase(ChE) in anticholinesterase exposures,whereas the type constitution and property of the enzyme remained unclear.A type of ChE was purified from Daphnia magna using a three-step procedure,i.e.,Triton X-100 extraction,ammonium sulfate precipitation,and diethylaminoethyl(DEAE)-Sepharose Fast-Flow *** to sodium dodecyl sulfate polyacrylamide gel electrophoresis(SDS-PAGE),molecular mass of the purified ChE was estimated to be 84 *** on substrate studies,the purified enzyme preferred butyrylthiocholine iodide(BTCh) [with maximum velocity(Vmax)/Michaelis constant(Km)=8.428 L/(min·mg protein)] to acetylthiocholine iodide(ATCh) [with V max /Km =5.346 L/(min·mg protein)] as its *** of the purified enzyme was suppressed by high concentrations of either ATCh or *** studies showed that the purified enzyme was more sensitive towards inhibition by tetraisopropylpyrophosphoramide(iso-OMPA) than by 1,5-bis(4-allyldimethylammoniumphenyl) pentan-3-one dibromide(BW284C51).Result of the study suggested that the purified ChE was more like a type of pseudocholinesterase,and it also suggested that Daphnia magna contained multiple types of ChE in their bodies.

关键词： Crustacea Pseudocholinesterase Cholinesterase Substrate preference Selective inhibitors

Tumor microenvironment: driving forces and potential therapeutic targets for breast cancer metastasis

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Chinese Journal of Cancer 2017年第3期36卷 121-130页

作者： Hong-Yan Xie zhi-Min shao Da-Qiang Li Shanghai Cancer Center and Institutes of Biomedical Sciences Shanghai Medical CollegeFudan UniversityShanghai 200032P.R.China Cancer Institute Shanghai Medical CollegeFudan UniversityShanghai 200032P.R.China Department of Oncology Shanghai Medical CollegeFudan UniversityShanghai 200032P.R.China Key Laboratory of Breast Cancer in Shanghai Shanghai Medical CollegeFudan UniversityShanghai 200032P.R.China Department of Breast Surgery Shanghai Medical CollegeFudan UniversityShanghai 200032P.R.China

Distant metastasis to specific target organs is responsible for over 90%of breast cancer?related deaths,but the underlying molecular mechanism is *** evidence suggests that the interplay between breast cancer cells and the target organ microenvironment is the key determinant of organ?specific metastasis of this lethal ***,we highlight new findings and concepts concerning the emerging role of the tumor microenvironment in breast cancer metastasis;we also discuss potential therapeutic intervention strategies aimed at targeting compo?nents of the tumor microenvironment.

关键词： Breast cancer Invasion and metastasis Tumor microenvironment

Ground State Mass Spectrum for Scalar Diquarks with Bethe-Salpeter Equation

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Communications in Theoretical Physics 2007年第2期47卷 287-292页

作者： Wang zhi-Gang WAN shao-Long Yang Wei-Min Department of Physics North China Electric Power University Baoding 071003 China Department of Modern Physics University of Science and Technology of China Hefei 230026 China

In this article, we study the structures of the pseudoscalar mesons π, K and the scalar diquarks U^a, D^a, Sa in the framework of the coupled rainbow Schwinger-Dyson equation and ladder Bethe-Salpeter equation with the confining effective potential. The u, d, s quarks have small current masses, and the renormalization is very large, the mass poles in the timelike region are absent which implements confinement naturally. The Bethe-Salpeter wavefunctions of the pseudoscalar mesons π, K, and the scalar diquarks U^a, D^a, S^a have the same type （Gaussian type） momentum dependence, center around zero momentum and extend to the energy scale about q^2 = 1 GeV^2, which happens to be the energy scale for the chiral symmetry breaking, the strong interactions in the infrargd region result in bound （or quasl-bound） states. The numerical results for the masses and decay constants of the π and K mesons can reproduce the experimental values, and the ground state masses of the scalar diquarks U^a, D^a, S^a are consistent with the existing theoretical calculations. We suggest a new Lagrangian which may explain the uncertainty of the masses of the scalar diauarks.

关键词： Schwinger-Dyson equation Bethe-Salpeter equation diquark confinement

A continuous-discontinuous cellular automaton method for cracks growth and coalescence in brittle material

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Acta Mechanica Sinica 2014年第1期30卷 73-83页

作者： Fei Yan Xia-Ting Feng Peng-zhi Pan shao-Jun Li State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of Science

A method of continuous-discontinuous cellular automaton for modeling the growth and coalescence of multiple cracks in brittle material is presented. The method uses the level set to track arbitrary discontinuities, and calculation grids are independent of the discontinuities and no remeshing are required with the crack growing. Based on Grif- fith fracture theory and Mohr-Coulumb criterion, a mixed fracture criterion for multiple cracks growth in brittle mate- rial is proposed. The method treats the junction and coales- cence of multiple cracks, and junction criterion and coales- cence criterion for brittle material are given, too. Besides, in order to overcome the tracking error in the level set ap- proximation for crack junction and coalescence, a dichotomy searching algorithm is proposed. Introduced the above the- ories into continuous-discontinuous cellular automaton, the present method can be applied to solving multiple crack growth in brittle material, and only cell stiffness is needed and no assembled global stiffness is needed. Some numerical examples are given to shown that the present method is efficient and accurate for crack junction, coalescence and percolation problems.

关键词： Continuous-discontinuous cellular automatonmethod Multiple crack growth Discontinuous cellular au-tomaton Junction criterion - Coalescence criterion

A review on passenger emergency evacuation from multimodal transportation hubs

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Journal of Traffic and Transportation Engineering(English Edition) 2022年第4期9卷 591-607页

作者： zhiman Xu Qiang Bai Yuqi shao Aihui Hu zhi Dong College of Transportation Engineering Chang'an UniversityXi'an 710064China

Multimodal transportation hubs serve as transfer points with the function of collecting,transferring,and distributing passengers and play a significant role in the entire multimodal transportation *** an emergency,the development of an effective and efficient emergency evacuation strategy to evacuate passengers from multimodal transportation hubs is very *** paper aims to conduct a comprehensive review on passenger emergency evacuations from multimodal transportation hubs,summarize the achievements,identify gaps in existing literature,thus to lay a solid foundation for future *** paper first reviewed studies on evacuee behavior characteristics in emergency evacuations,including pedestrian characteristics,pedestrian behavior characteristics,and pedestrian flow *** evacuation models,including pedestrian evacuation models and multimodal transportation evacuation models,were *** addition,a retrospective analysis was carried out for evacuation *** is found that while many studies have been conducted on passenger emergency evacuations from multimodal transportation hubs,most of them focus more on evacuating pedestrians from inside to outside of hub buildings;the studies on evacuation at multimodal transfer points are *** is also found that most existing studies tried to establish a general model to handle all types of emergency evacuations;in fact,a model would be more efficient if it is just established for a specific emergency and for a specific type of ***,existing data collection methods may collect biased data;new data collection methods need to be explored to increase the accuracy of data *** study directions include the evacuation at multimodal transfer points,interactive effects between individual pedestrian behavior and pedestrian group behavior,more specific types of emergency evacuations,more accurate data collection methods,and tradeoffs between cost and benefit in eme

关键词： Multimodal transportation hubs Emergency evacuation Passengers Pedestrian behavior Evacuation simulation