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Chinese Journal of Polymer Science 2001年第1期19卷 71-78页

作者： Shou-xi Chen Zhong-ming Hu Wen-hui Song Yong-ze Jin Ren-yuan Qian State Key Laboratory of Polymer Physics and Chemistry Center for Molecular ScienceInstitute of ChemistryChinese Academy of SciencesBeijing 100080China

Crystalline morphology in a series of CH_(3)-substituted main chain thermotropic aromatic polyesters with even and odd numbered methylene spacers has been studied by polarizing optical microscopy(POM),scanning electron microscopy(SEM)and transmission electron microscopy(TEM).On crystallization from solution evaporation spherulites of radial structure were observed in the polymers with even numbered spacers,but spherulites with concentric rings form in the polymer with odd numbered *** spherulites have a lamellar structure,which is about 10 nm in *** crystallization from nematic glassy state spherulites can not be grown;lamellar structure was only observed around disclinations in a specimen during *** the case of crystallization from nematic melt two types of spherulites can be observed far the sample with even numbered *** the sample with add numbered spacers spherulites can not be formed,but only irregular crystallites.

关键词： crystalline morphology spherulite even-odd flexible spacers CH_(3)-substituted thermotropic aromatic polyester

Characteristics of phosphorus fractionated from the sediment resuspension in abrupt expansion flow experiments

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Journal of Environmental Sciences 2010年第10期22卷 1519-1526页

作者： Jun Wan ze Wang Hezhong yuan . College of Environmental Science and Engineering Hohai University Nanjing 210098 China College of Water Conservancy and Hydropower Engineering Hohai University Nanjing 210098 China. State Key Laboratory of Lake Sediments Process Nanjing Institute of Geography and Limnology Chinese Academy of Sciences Nanjing 210098 China

Phosphorous （P） fraction characteristics in sediment resuspension were investigated under adequately hydrodynamic conditions. Four forms of P in overlying water, including dissolved inorganic P, dissolved total P, total P, and particulate P, and six fractions of P in suspended particulate matter （SPM）, including loosely sorbed P （NH4Cl-P）, redox-sensitive P （BD-P）, aluminum-bound P （Al- P）, organic P （NaOH-nrP）, calcium-bound P （Ca-P） and residual P （Res-P）, were quantified, respectively. Different hydrodynamic conditions resulted in different P form changes. Four states could be ascribed：（1） P desorption by sediment and SPM, and P adsorption by overlying water; （2） P desorption by SPM, and P adsorption by overlying water; （3） P adsorption by SPM, and P desorption by overlying water; and （4） P equilibrium between SPM and overlying water. The contents of P in overlying water acquired peak values in the middle position of the vertical P distribution due to the combined actions of SPM and sediment. P fractions in SPM were in the following order： BD-P 〉 NaOH-nrp 〉 Ca-P 〉 Al-P 〉 Res-P 〉 NH4Cl-P. BD-P in SPM frequently exchanged with P forms in overlying water. Resuspension was favorable to forming Ca-P in SPM.

关键词： phosphorus fractions hydrodynamic conditions suspended particulate matter abrupt expansion flow

ON SOLUTIONS OF MATRIX EQUATION AXAT ＋ BYBT=C

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Journal of Computational Mathematics 2005年第1期23卷 17-26页

作者： yuan-beiDeng xi-yanHu ICMSEC AcademyofMathematicsandSystemSciencesChineseAcademyofSciencesBeijing100080China CollegeofMathematicsandEconometrics HunanUniversityChangsha310082China

By making use of the quotient singular value decomposition (QSVD) of a matrix pair,this paper establishes the necessary and sufficient conditions for the existence of and the expressions for the general solutions of the linear matrix equation AXA^T+BYB^T=C with the unknown X and Y, which may be both symmetric, skew-symmetric, nonnegativede finite, positive definite or some cross combinations respectively. Also, the solutions of some optimal problems are derived.

关键词： matrix equation matrix norm QSVD constrained condition optimal problem

NiS_(2) nanosheet arrays on stainless steel foil as binder-free anode for high-power sodium-ion batteries

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Rare Metals 2022年第4期41卷 1294-1303页

作者： Mou-Ping Fan You-Chen Chen yuan-Mao Chen ze-xi Huang Wen-Li Wu Pan Wang xi Ke Shu-Hui Sun Zhi-Cong Shi Institute of Batteries School of Materials and EnergyGuangdong University of TechnologyGuangzhou 510006China énergie Matériaux et Télécommunications Center Institut National de la Recherche Scientifique (INRS)Varennes QC J3X 1S2Canada

Owing to the wide range and low cost of sodium resources,sodium-ion batteries(SIBs)have received extensive attention and *** sulfides with high theoretical capacity are used as promising anode materials for *** paper presents the electrochemical performance of the binder-free NiS_(2)nanosheet arrays grown on stainless steel(SS)substrate(NiS_(2)/SS)using an in situ growth and sulfidation strategy as anode for sodium ion *** to the close connection between the NiS_(2)nanosheet arrays and the SS current collector,the NiS_(2)/SS anode demonstrates high rate capability with a reversible capacity of 492.5 mAh·g^(-1)at 5.0C *** rate capability is superior to that of NiS_(2)nanoparticles(NiS_(2)/CMC:41.7 mAh·g^(-1)at 5.0C,NiS_(2)/PVDF:7.3 mAh·g^(-1)at 5.0C)and other Ni sulfides(100–450 mAh·g^(-1)at 5.0C)***,the initial reversible specific capacity and Coulombic efficiency of NiS_(2)/SS are 786.5 mAh·g^(-1)and 81%,respec-tively,demonstrating a better sodium storage ability than those of most NiS_(2)anodes reported for *** addition,the amorphization and conversion mechanism during the sodiation/desodiation process of NiS_(2)are proposed after investigation by in situ X-ray diffraction(XRD)measurements of intermediate products at successive charge/discharge stages.

关键词： Sulfide Sodium ion batteries Nanosheet arrays Binder-free Reaction mechanism

Preparation and properties of T-ZnO_(w) enhanced BCP scaffolds with double-layer structure by digital light processing

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Journal of Advanced Ceramics 2022年第4期11卷 570-581页

作者： Ming-Zhu PAN Shuai-Bin HUA Jia-Min WU xi yuan ze-Lin DENG Jun xiAO Yu-Sheng SHI State Key Laboratory of Materials Processing and Die&Mould Technology School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China Engineering Research Center of Ceramic Materials for Additive Manufacturing Ministry of EducationWuhan 430074China Department of Orthopedic Surgery Tongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430030China

Bone scaffolds require both good bioactivity and mechanical properties to keep shape and promote bone *** this work,T-ZnO_(w) enhanced biphasic calcium phosphate(BCP)scaffolds with triply periodic minimal surface(TPMS)-based double-layer porous structure were fabricated by digital light processing(DLP)with high *** of suspension was first discussed to obtain better printing *** sintering,T-ZnO_(w) reacts with b-tricalcium phosphate(β-TCP)to form Ca_(19)Zn_(2)(PO_(4))14,and inhibits the phase transition toα-*** the content of T-ZnO_(w) increasing from 0 to 2 wt%,the flexural strength increases from 40.9 to 68.5 MPa because the four-needle whiskers can disperse stress,and have the effect of pulling out as well as fracture ***,excessive whiskers will reduce the cure depth,and cause more printing defects,thus reducing the mechanical ***,T-ZnO_(w) accelerates the deposition of apatite,and the sample with 2 wt%T-ZnO_(w) shows the fastest mineralization *** good biocompatibility has been proved by cell proliferation *** confirmed that doping T-ZnO_(w) can improve the mechanical strength of BCP scaffolds,and keep good biological property,which provides a new strategy for better bone repair.

关键词： biphasic calcium phosphate(BCP) T-ZnO_(w) digital light processing(DLP) double-layer structure cure property mechanical strength

Texture,Grain Boundary Characterization and Segregation of Phosphorus in an Annealed Interstitial Free Steel

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Journal of Iron and Steel Research International 2014年第9期21卷 844-848页

作者： xin-li SONG Kun PENG ze-xi yuan Juan JIA Jing LIU Li-xia FAN State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and Technology

The {111} fiND plane texture, grain boundary characterization and grain boundary segregation of phos- phorus are investigated for the phosphorus added high strength interstitial free （IF） steel annealed at 810℃ for 60 s to 180 s. The results show that the maximum volume fraction of {111} fiND plane texture is about 85% and the grain boundary Segregation peak of phosphorus is about 14 at. % for the steel annealed at 810℃ for 120 s. The ∑3 and other low-∑CSL （coincident site lattice） boundaries are lowest for the steel annealed for 120 s. Segregation of phosphorus is also found at low angle grain boundaries.

关键词： high strength IF steel texturel grain boundary characterization segregation

Kloosterman Sums and a Problem of ***

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Chinese Annals of Mathematics,Series B 2020年第3期41卷 361-370页

作者： Ping xi yuan YI School of Mathematics and Statistics Xi’an Jiaotong UniversityXi’an 710049China

A classical problem of D. H. Lehmer suggests the study of distributions of elements of Z/pZ of opposite parity to the multiplicative inverse mod p. Zhang initiated this problem and found an asymptotic evaluation of the number of such elements. In this paper, an asymptotic formula for the fourth moment of the error term of Zhang is proved,from which one may see that Zhang’s error term is optimal up to the logarithm *** method also applies to the case of arbitrary positive integral moments.

关键词： D.H.Lehmer problem Kloosterman sum Moment

Atropoenantioselective synthesis of heterobiaryl N-oxides via dynamic kinetic resolution

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Science China Chemistry 2022年第12期65卷 2512-2516页

作者： xi yuan Jian Wang College of Chemistry and Materials Science Anhui Normal UniversityWuhu241002China School of Pharmaceutical Sciences Tsinghua UniversityBeijing100084China

A highly efficient enantioselective construction of heterobiaryl N-oxides was developed.A series of axially chiral heterobiaryl N-oxides were generated via the cascade reaction of aminobenzamides with heterobiaryl aldehydes in the presence of chiral phosphoric acids.A number of atropisomers were afforded in moderate to good yields with excellent enantioselectivities and *** results demonstrate that the heterobiaryl N-oxides can be utilized as efficient chiral ligands in asymmetric catalysis.

关键词： heterobiaryl N-oxides dynamic kinetic resolution chiral phosphoric acids atroposelectivity organocatalysis

Adaptive beam forming for time-variant channels with a multi-beam antenna

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The Journal of China Universities of Posts and Telecommunications 2008年第3期15卷 37-40页

作者： JIANG ze MEI yuan-yuan RUAN Wei College of Electronic Engineering Chongqing University of Posts and Telecommunications Chongqing 400065 China

A multi-beam adaptive antenna is investigated by considering the adaptive beam forming performance for time-variant channels on the focus of mobile to base station or reverse link. This antenna is constructed by Fresnel zone phase-correcting plane （FZP） focusing element and uniformly spaced feeds array. An estimator for the beamforming weight vector in the presence of angle spreads is derived using a code filtering approach. Owing to the time-varying nature of the channels, a recursive method for computing and tracking the above optimal weight vector solution that is easy to implement is applied. The effects of angle spread, maximum Doppler frequency, and forgetting factor are studied. Simulation results showed that this type of adaptive antenna is capable of performing adaptive beam forming for time-variant channels effectively.

关键词： adaptive antenna adaptive beam forming FZP mismatch loss

Inhibition Mechanism of Cholinesterases by Carbamate: A Theoretical Study

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Chemical Research in Chinese Universities 2008年第6期24卷 778-781页

作者： YAO yuan LI ze-sheng State Key Laboratory of Theoretical and Computational Chemistry institute of Theoretical Chemistry Jilin University Changchun 130021 P R. China

The density functional theory at the B3LYP/6-311G（d, p） level was applied to exploring the inhibition mechanism of cholinesterases by carbamate. The results indicate that the inhibition reactions with or without the catalytic effect of the catalytic triad in eholinesterases underwent a two-step addition-elimination mechanism, which is in good agreement with the proposed mechanism. The solvent has a strong effect on the inhibition reactions and the reaction with the catalytic triad in the solvent phase is close to the real reaction under biological condition.

关键词： Carbamate Cholinesterase Inhibition mechanism Solvent effect