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Numerical Study of two Opposing Weak Polyelectrolyte Brushes by the Self-consistent Field theory

Chinese Journal of Polymer Science 2024年第11期42卷 1668-1678,I0007页

作者： Bei-Ning Wang Huan-da Ding Zhi-Kuan Chen Chao-Hui tong Department of Physics Ningbo UniversityNingbo315211China Ningbo Institute of Northwestern Polytechnical University Ningbo315103China

the self-consistent field theory(SCFt)was employed to numerically study the interaction and interpenetration between two opposing weak polyelectrolyte(PE)brushes formed by grafting weak PE chains onto the surfaces of two long and parallel columns with rectangularshaped cross-section immersed in a salty aqueous *** dependences of the brush heights and the average degree of ionization on various system parameters were also *** the brush separation is relatively large compared with the unperturbed brush height,the degree of interpenetration between the two opposing PE brushes was found to increase with increasing grafting density and bulk degree of *** degree of interpenetration also increases with the bulk salt concentration in the osmotic brush *** results further revealed that,at a brush separation comparable to the unperturbed brush height,the degree of interpenetration does not increase further with increasing bulk degree of ionization,bulk salt concentration in the osmotic regime and grafting *** saturation of the degree of interpenetration with these system parameters indicates that the grafted PE chains in the gap between the two columns retract and tilt in order to reduce the unfavorable electrostatic and steric repulsions between the two opposing PE *** on salt ion concentrations at the midpoint between the two opposing brushes,a quantitative criterion in terms of the unperturbed brush height and Debye screening length was established to determine the threshold value of the brush separation beyond which they are truly independent from each other.

关键词： Polyelectrolyte Polymer brush Self-consistent field theory

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Lax triad Approach to Symmetries of Scalar Modified Kadomtsev–Petviashvili Hierarchy

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Communications in theoretical Physics 2017年第2期67卷 131-136页

作者： Xiao Deng Kui Chen da-Jun Zhang Department of Mathematics Shanghai University Shanghai 200444 China

By means of Lax triads we reconstruct isospectral and nonisospectral scalar modified Kadomtsev–Petviashvili(mKP) hierarchies. In this approach the argument y is treated as an independent variable which is independent of time parameters {t_1, t_2,...}. Consequently, the isospectral and nonisospectral scalar mKP flows can have clear zero curvature representations, which enables us to handle investigation of symmetries of the scalar isospectral mKP hierarchy as freely as for(1+1)-dimensional systems. As a result, we obtain Lie algebraic structures of the scalar mKP flows and construct symmetries for the scalar isospectral mKP hierarchy.

关键词： scalar modified Kadomtsev–Petviashvili hierarchies Lax triads symmetries Lie algebra

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Effect of ti,Sc and Zr additions on microstructure and mechanical properties of rheo-diecasting Al-6Zn-2Mg-2Cu alloys

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China Foundry 2023年第2期20卷 125-133页

作者： Sai-heng Hou Jian Feng Song Chen Fan Zhang da-quan Li State Key Laboratory of Nonferrous Metals and Processes GRINM Group Co.Ltd.Beijing 100088China GRIMAt Engineering Institute Co. Ltd.Beijing 101407China General Research Institute for Nonferrous Metals Beijing 100088China

the microstructure and mechanical properties of rheo-diecasting Al-6Zn-2Mg-2Cu alloys microalloyed with ti,Sc and Sc+Zr were studied by optical microscopy(OM),scanning electron microscopy(SEM),X-ray diffraction(XRD),hardness testing,and tensile *** swirled equilibrium enthalpy device(SEED)process was introduced to prepare the semisolid *** show that the addition of ti,Sc,and Sc+Zr refines the grain size and improves the uniformity of the semisolid slurry and then suppresses the growth of theα-Al grain during solution heat *** microstructure of the four alloys in as-cast state mainly consists of sphericalα-Al and the Mg(Al,Cu,Zn)_(2)(η)eutectic ***,primary Al_(3)Sc,Al_(3)(Sc,Zr)and Al_(3)Zr are also found in the micro-alloying *** solution and aging heat treatment,most of the Mg(Al,Cu,Zn)_(2) phases dissolve into theα-Al matrix,while part of Mg(Al,Cu,Zn)_(2) phases transform to Al_(2)CuMg(S)***,the coarse primary Al_(3)Sc and Al_(3)(Sc,Zr)still remain in the matrix,and promote crack initiation and *** the tensile strength of 553 MPa,yield strength of 463 MPa and elongation of 13.4%at t6 state,trace ti addition generates more attractive mechanical properties than the other three alloys.

关键词： Al-Zn-Mg-Cu alloys rheo-diecasting microstructure mechanical properties micro-alloying

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基于单向散列链的可更新(t,n)门限秘密共享方案

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通信学报 2010年第7期31卷 128-135页

作者：李大伟杨庚南京邮电大学计算机学院江苏南京210003

为了提高可更新秘密共享方案中影子秘密的更新效率,基于单向散列链的特性,提出了一种新型可更新秘密共享方案。该方案使用单向散列链构造更新多项式,避免了生成随机多项式带来的计算开销。秘密共享实现过程基于IBE公钥体制,具有良好的... 详细信息

为了提高可更新秘密共享方案中影子秘密的更新效率,基于单向散列链的特性,提出了一种新型可更新秘密共享方案。该方案使用单向散列链构造更新多项式,避免了生成随机多项式带来的计算开销。秘密共享实现过程基于IBE公钥体制,具有良好的安全性能。影子秘密验证基于有限域上离散对数难解问题,能有效避免参与者欺骗。理论分析和仿真结果显示该方案能在保证安全性的前提下显著提高影子秘密更新的效率。

关键词：秘密共享单向散列链身份加密算法

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Quantification of perfluorinated compounds in atmospheric particulate shows potential connection with environmental event

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Journal of Environmental Sciences 2024年第2期136卷 237-247页

作者： Hua tang Ying Wang Shengling Si Hongli Li david da Yong Chen National Institute of Metrology 18 BeisanhuandongluChaoyang DistrictBeijing 100029China School of Chemistry and Materials Science Nanjing Normal UniversityNanjing 210023China Si Chuan Zhong Ce Biao Wu technology Co.Ltd. Sichuan 610052China Department of Chemistry University of British ColumbiaVancouver V6T 1Z1BCCanada

A method of quantification of perfluorinated compounds(PFCs)from atmospheric particulate matter(APM)is described.A single step pretreatment method,selective pressurized liquid extraction(SPLE),was developed to reduce the high matrix background and avoid contamination from commonly used multiple sample pretreatment *** effective sorbent was selected to purify the PFCs during SPLE,followed by liquid chromatography-tandem mass spectrometry(LC–MS/MS),for quantification of *** affecting the SPLE efficiency,including temperature,static extraction time,and number of extraction cycles used,were *** optimum conditions were found to be 120℃,10 min,and 3 cycles,***-MS/MS method was developed to obtain the optimal sensitivity specific to *** method detection limits(MDLs)were 0.006 to 0.48 ng/g for the PFCs studied and the linear response range was from 0.1 to 100 ng/*** ensure accurate values were obtained,each step of the experiment was evaluated and controlled to prevent *** optimized method was tested by performing spiking experiments in natural particulate matter matrices and good rates of recovery and reproducibility were obtained for all target ***,the method was successfully used to measure 16 PFCs in the APM samples collected in Beijing over five years from 2015 to *** is observed that some PFCs follow the trend of total PFC changes,and can be attributed to the environment influencing events and policy enforcement,while others don't seem to change as much with time of the year or from year to year.

关键词： Selective pressurized liquid extraction Liquid chromatography-mass spectrometry Perfluorinated compounds Atmospheric particulate matter Pollution control

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Nondestructive acquisition of the micro-mechanical properties of high-speed-dry milled micro-thin walled structures based on surface traits

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Chinese Journal of Aeronautics 2021年第5期34卷 438-451页

作者： da QU Wei ZHENG Bo WANG Bo WU Huajun CAO Hao YI the State Key Laboratory of Mechanical transmissions Chongqing UniversityChongqing 400044China College of Mechanical Engineering Chongqing UniversityChongqing 400044China Aerospace Research Institute of Materials&Processing technology Beijing 100076China Centre for Precision Engineering Harbin Institute of TechnologyHarbin 150001China

Requirements for the service performance of aeronautic microelectronic components are increasingly ***,sever issues,that the acquisition of the service performance such as micro-mechanical properties is destructive,limit the subsequent application of the tested *** this issue,this paper proposes a nondestructive acquisition method of the micro-mechanical properties of the accelerometer micro-components,based on analyzing surface *** select qualified components without damage,we firstly developed a quasi-static microtensile tester and then established a combination prediction model of mechanical properties based on micro-milled surface *** model works due to the thin-walled structure,which makes the machined surface traits have significant influences on the mechanical properties such as Young’s modulus,yield strength,tensile strength,and elongation at *** roughness,surface structure,and surface anisotropy are extracted to comprehensively present surface traits from different *** improving the practicability of the model,the principal component analysis(PCA)is adopted to reduce high-dimensional traits explanatory variable space into two dimensions,and regression analysis models are comparative established in predicting the mechanical *** analysis and error analysis are carried out to show the prediction *** maximum prediction error is about 10.62%,but the significance levels in the t-test of the predicted Young’s modulus and yield strength are not ***,kernel support vector regression(SVR)is imported to improve the prediction ability of the combination prediction *** residuals analysis result shows that SVR is effective in enhancing the prediction ability of this model.

关键词： Dimension reduction High-speed dry micro-milling Mechanical property Nondestructive acquisition SVR

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Ruin Probabilities under a Markovian Risk Model

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Acta Mathematicae Applicatae Sinica 2003年第4期19卷 621-630页

作者： Han-xingWang da-fanFang Mao-ningtang DepartmentofMathematicsandInformationScience ChangshaUniversityChangsha410003China DepartmentofMathematics ShanghaiUniversityShanghai200436China

In this paper, a Markovian risk model is developed, in which the occurrence of the claims is described by a point process {N(t)} t≥0 with N(t) being the number of jumps of a Markov chain during the interval [0, t]. For the model, the explicit form of the ruin probability Ψ(0) and the bound for the convergence rate of the ruin probability Ψ(u) are given by using the generalized renewal technique developed in this paper. Finally, we prove that the ruin probability Ψ(u) is a linear combination of some negative exponential functions in a special case when the claims are exponentially distributed and the Markov chain has an intensity matrix (q ij ) i,j∈E such that q m = q m1 and q i = q i(i+1), 1 ≤ i ≤ m−1.

关键词： Risk processes ruin probabilities Markov chains

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miR-31: a key player in CD8 t-cell exhaustion

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Cellular & Molecular Immunology 2017年第12期14卷 954-956页

作者： Siddheshvar Bhela Barry t Rouse Department of Biomedical and Diagnostic Sciences College of Veterinary MedicineUniversity of TennesseeKnoxvilleKnoxvilleTN 37996USA

Over the past decade,miRNAs have emerged as genetic factors that can influence immune functions.1 they act by post-transcriptionally downregulating gene expression either by degrading target mRNAs or by repressing their translation.2 Linking miRNA expression to disease was first accomplished by comparing outcomes in normal animals with those in miR-155 knockout animals.3 our group also used a viral pathogen to show that knocking out miR-155 resulted in less severe inflammatory lesions caused by herpes simplex virus infection,yet animals without miR-155 became more susceptible to developing viral encephalitis.

关键词： encephalitis infection simplex

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Synthesis, Structure and Slow Magnetization Relaxation of Co(Ⅱ) Complexes from a Flexible Imidazole-based Ligand

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Chinese Journal of Structural Chemistry 2019年第1期38卷 137-146,5页

作者： YONG Juan HUANG Wei WU da-Yu School of Petrochemical Engineering Changzhou University

the employment of a flexible imidazole-based ligand(H_2L), condensed from 1 Himidazole-2-carbaldehyde and 1,2-bis(aminooxy)ethane, and Co^(2+) salt has led to the formation of Co(Ⅱ) complexes [Co(H_2L)_2Cl]Cl·4CH_3OH(1) and [Co(H_2L)(NCS)_2]_2·2C_4H_(10)O(2), in the presence of different anions, i.e, Cl-and SCN-, respectively. Single-crystal X-ray analyses show that complex 1 with a square pyramid(C_(4v)) local environment exhibits a two-dimensional(2D)layered(4,4)-net framework and complex 2 displays a dinuclear molecule box with a t_d local environment. By comparison between complexes 1 and 2, the versatile configuration of ligand including cis-and trans-form isomer has a significant effect on the structures of the resulting complexes. the magnetic properties of 1 and 2 are also investigated. the ac magnetic susceptibility revealed that 2 exhibits the characteristic of slow magnetization relaxation.

关键词： crystal engineering flexible ligand cobalt slow magnetization relaxation

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Vitellaria paradoxa nutshells from seven sub-Saharan countries as potential herbal medicines for treating diabetes based on chemical compositions, HPLC fingerprints and bioactivity evaluation

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Chinese Journal of Natural Medicines 2019年第6期17卷 446-460页

作者： LI da XIAO Jian-Qi LIU Wen-Yuan ZHANG Chao-Feng AKIHISA toshihiro ABE Masahiko MAStERS Eliot-t. ZHAI Wei-Wei FENG Feng ZHANG Jie Jiangsu Food and Pharmaceutical Science College Huai’an 223003China Department of Pharmaceutical Analysis China Pharmaceutical UniversityNanjing 210009China Research Institute for Science and technology Tokyo University of ScienceChiba 278-8510Japan World Agroforestry Centre(ICRAF) Nelson Marlbolough Institute of Technology(NMIT)Nelson 7010New Zealand School of traditional Chinese Pharmacy China Pharmaceutical UniversityNanjing 211198China Key Laboratory of Biomedical Functional Materials China Pharmaceutical UniversityNanjing 211198China

the aim of the study was to determine the feasibility of the Vitellaria paradoxa nutshell as a new medicinal resource for treating diabetes. A total of forty-one compounds were identified by HPLC-daD-Q-tOF-MS and phytochemical methods in V. paradoxa nutshell methanol extract. Based on HPLC fingerprints, four characteristic constituents were quantified and the origin of twenty-eight V. paradoxa nutshells from seven sub-Saharan countries was compared, which were classified into three groups with chemometric method. twenty-eight samples contained high total phenolic content, and exhibited moderate-higher antioxidant activity and strong α-glucosidase inhibitory activity. Furthermore, all fractions and isolated compounds were evaluated for their antioxidant and α-glucosidase inhibitory activities, and α-glucosidase inhibitory action mechanism of four characteristic constituents including protocatechuic acid, 3, 5, 7-trihydroxycoumarin,(2 R, 3 R)-(+)-taxifolin and quercetin was investigated via molecular docking method, which were all stabilized by hydrogen bonds with α-glucosidase. the study provided an effective approach to waste utilization of V. paradoxa nutshell, which would help to resolve waste environmental pollution and provide a basis for developing potential herbal resource for treating diabetes.

关键词： Vitellaria paradoxa HPLC fingerprints Antioxidant activity α-Glucosidase inhibitory activity Molecular docking

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