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A study of boundary vorticity dynamics and identification of large-scale structures in flow field based on two-dimensional flow around a bluff body

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Journal of Hydrodynamics 2019年第2期31卷 231-248页

作者： Da-peng Zhang Yu-zhu Chen Xi-lin xie Department of Aeronautics and Astronautics Fudan UniversityShanghai 200433China

A method based on decomposition of acceleration field and Lie derivative is introduced to identify shearing and rotational *** method is validated on two typical kinds of model *** dynamics of flow around bluff body is studied,illustrated by numerical examples of flow around an elliptic cylinder,a slanted elliptic cylinder and an elliptic cylinder with a pair of bumps on the front *** explain the generation of vortical structures and how they evolve into inner flow field,boundary vorticity dynamics analysis is *** vorticity flux as well as the enstrophy diffusion flux creates vorticity sources and vorticity sinks,which generate or consume boundary vorticity,then shearing layers are generated and interact with each other finally create *** results provide potential in accurate flow control by boundary deformation,and show that relevant theoretical conclusions can be effectively applied in revealing the flow mechanisms.

关键词： Boundary vorticity dynamics large-scale structures Lie derivative

Geant4 simulation of 238U(n,f) reaction induced by D-T neutron source

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Nuclear Science and Techniques 2017年第1期28卷 49-56页

作者： Chang-lin Lan Meng Peng Yi Zhang Zheng Wei Ze-En Yao Bao-lin xie School of Nuclear Science and Technology Lanzhou University Lanzhou 730000 China Key Laboratory of Special Function Materials and Structure Design Ministry of Education Lanzhou 730000 China

Knowledge of actinides(n,f) fission process induced by neutron is of importance in the field of nuclear power and nuclear engineering,especially for reactor *** this work,fission characteristics of^(238)U(n,f) reaction induced by D-T neutron source were simulated with Geant4 code from multiple perspectives,including the fission production yields,total nubar,kinetic energy distribution,fission neutron spectrum and cumulative γ-ray spectrum of the fission *** simulation results agree well with the experimental nuclear reaction data(EXFOR) and evaluated nuclear data(ENDF).Mainly,this work was to examine the rationality of the parametric nuclear fission model in Geant4 and to direct our future experimental measurements for the cumulative fission yields of ^(238)U(n,f) reaction.

关键词： Fission characteristics Geant4 code 238U(n,f) reaction D-T neutron source Decayed c-ray spectrum

STABILITY OF DENSITY STRATIFIED FLOW IN THE BOUNDARY LAYER

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Journal of Hydrodynamics 2006年第5期18卷 505-511页

作者： xie Ming-liang lin Jian-zhong State Key Laboratory of Fluid Power Transmission and Control Zhejiang University Hangzhou 310027 China China Jiliang University Hangzhou 310018 China

The stability of the laminar flat plate boundary layer is investigated numerically by solving the linear Orr-Sommerfeld equations for the disturbulence amplitude function. These equations include the terms of viscosity, density stratification, and diffusion. Neutral stability curve and the critical Re numbers are computed for various Richardson （Ri） numbers and Schmidt （Sc） numbers. The results show that the larger the Ri, the larger the critical Re for Sc 〈 10. The flow is stable for Ri 〈 0, when Sc is very small or the mass diffusion coefficient is very large. But for Ri 〉 0, the effects of diffusion are reversed for Sc 〈 10. For Sc 〉 10, the critical Re rapidly decreases to zero as the Sc increases for a given Ri number. The critical Re rapidly decreases as the Ri increases.

关键词： stability stratified flow boundary layer blasius flow

PARTIAL CARBAMOYLATION OF CELLULOSE MICROSPHERES: A NEW METHOD TO PREPARE ADSORBENTS FOR LIQUID CHROMATOGRAPHY

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Chinese Journal of Polymer Science 2013年第12期31卷 1725-1732页

作者： Wei Chen Qin Bin 柏正武周兴平 Xiao-lin xie Key Lab for Large-Format Battery Materials and Systems Ministry of EducationSchool of Chemistry and Chemical EngineeringHuazhong University of Science and Technology Key Lab of Green Chemical Process Ministry of EducationHubei Key Laboratory of Novel Chemical Reactor and Green Chemical TechnologyWuhan Institute of Technology

Micron-sized cellulose microspheres were prepared through sol-gel method using NaOH/urea solution to dissolve cellulose, then cross-linked by 1,6-hexanylene diisocyanate （HDI）, toluene 2,4-diisocyanate （TDI） and 1,4-phenylene diisocyanate （PDI）, respectively. The reaction conditions for partial modification of the microspheres were studied. The degree of substitution （DS） in cellulose was controlled by adjusting the reaction conditions. HDI-crosslinked microspheres were partially modified with phenyl isocyanate to obtain chiral stationary phases （CSPs）. The CSPs of a lower degree of crosslinking （DC） showed better chiral recognition ability than those of a higher DC. Meanwhile the CSPs prepared by pre- modification exhibited better chiral recognition ability than those prepared by pre-crosslinking.

关键词： Cellulose Microspheres Functionalization Chiral stationary phase Chiral recognition.

Vorticity vector-potential method based on time-dependent curvilinear coordinates for two-dimensional rotating flows in closed configurations

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Journal of Hydrodynamics 2018年第2期30卷 218-234页

作者： Yuan Fu Da-peng Zhang Xi-lin xie Department of Aeronautics and Astronautics Fudan University Shanghai 200433 China

In this study, a vorticity vector-potential method for two-dimensional viscous incompressible rotating driven flows is developed in the time-dependent curvilinear coordinates. The method is applicable in both inertial and non-inertial frames of reference with the advantage of a fixed and regular calculation domain. The numerical method is applied to triangle and curved triangle configurations in constant and varying rotational angular velocity cases respectively. The evolutions of flow field are studied. The geostrophic effect, unsteady effect and curvature effect on the evolutions are discussed.

关键词： Rotating driven flow time-dependent curvilinear coordinate geostrophic effect unsteady effect curvature effect

Vascular resection in pancreatic adenocarcinoma with portal or superior mesenteric vein invasion

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World Journal of Gastroenterology 2013年第46期19卷 8740-8744页

作者： Gang Pan Kun-lin xie Hong Wu Department of Hepatobiliary Pancreatic Surgery West China Hospital Sichuan University

AIM:To evaluate long-term survival after the Whipple operation with superior mesenteric vein/portal vein resection(SMV/PVR)in relation to resection ***:We evaluated 118 patients who underwent the Whipple operation for pancreatic adenocarcinoma at our Department of Hepatobiliary Pancreatic Surgery between 2005 and ***-eight of these patients were diagnosed with microscopic PV/SMV invasion by frozen-section examination and underwent SMV/*** 28 patients,the length of SMV/PVR was≤3 *** the other 30 patients,the length of SMV/PVR was>*** and survival data were ***:SMV/PVR was performed successfully in *** was a significant difference between the two groups(SMV/PVR≤3 cm and SMV/PVR>3 cm)in terms of the mean survival time(18 mo vs 11 mo)and the overall 1-and 3-year survival rates(67.9%and14.3%vs 41.3%and 5.7%,P3 cm resection.

关键词： Pancreatic adenocarcinoma Whipple op-eration Vascular resection

Petatrichol B: A Pentacyclic Triterpenoid with Unusual Skeleton from Petasites tricholobus

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Chinese Chemical Letters 2005年第10期16卷 1351-1353页

作者： Wei Dong xie Ping lin LI Zhong Jian JIA College of Chemistry and Chemical Engineering National Laboratory of Applied Organic Chemistry Lanzhou University Lanzhou 730000

A novel pentacyclic triterpenoid, petatrichol B, was isolated from the rhizome of Petasites tricholobus. Its structure was established by means of spectroscopic analysis （EIMS, HRSIMS, IR, 1D NMR and 2D NMR）.

关键词： Petasites tricholobus Compositae triterpenoid petatrichol B.

Quantification of Trace Amounts of Impurities in High Purity Cobalt by High Resolution Inductively Coupled Plasma Mass Spectrometry

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Chinese Chemical Letters 2006年第8期17卷 1077-1080页

作者： Hua lin xie Xi Du NIE You Gen TANG Department of Chemistry Hunan Institute of Technology Hengyang 421008 School of Chemistry and Chemical Engineering Central south university Changsha 410083

An analytical method using high resolution inductively coupled plasma mass spectrometry （HR-ICP-MS） for rapid simultaneous determination of Be, Mg, Al, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, Ge, As, Se, Mo, Ag, Cd, Sn, Sb, Ba, Pt, Au and Pb in high purity cobalt was described. Sample digestions were performed in closed microwave vessels using HNO3 and HCl. The matrix effects due to the presence of excess HCl and Co were evaluated. The usefulness of high mass resolution for overcoming some spectral interference was demonstrated. The optimum conditions for the determination was tested and discussed. Correction for matrix effects, Sc, Rh and Bi were used as internal standards. The detection limits is 0.003-0.57 μg/g, the recovery ratio is 92.2%-111.2%, and the RSD is less than 3.6%. The method is accurate, quick and convenient. It has been applied to the determination of trace impurities in high purity cobalt with satisfactory results.

关键词： High resolution inductively coupled plasma mass spectrometry high purity cobalt,trace impurities matrix effect spectral interference internal standards.

Facile access to C-N bonds via unexpected side reactions of Knoevenagel condensation and their application in high-efficiency organic solar cells

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Science China Chemistry 2024年第1期67卷 323-329页

作者： Daobin Yang Shuncheng Yang Hongqian Wang lin xie Pengyu Yan Ziyi Ge Zhejiang Engineering Research Center for Energy Optoelectronic Materials and Devices Ningbo Institute of Materials Technology and EngineeringChinese Academy of SciencesNingbo 315201China School of Materials Science and Chemical Engineering Ningbo UniversityNingbo 315211China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China

The construction of C-N bonds is of great importance in the fields of biology,medicine,chemistry and materials ***,the replacement of organic base from pyridine to piperidine in the Knoevenagel condensation process unexpectedly yields a series of novel organic molecules containing C-N ***,the synthesis method does not require any external transition-metals catalysis,and photo-/***,when the new compound 1b is added as a third component to a well-known binary system of PM6:Y6,the efficiency of the organic solar cell is significantly improved,resulting in an outstanding efficiency of 18.0%,which is one of the highest values reported to date for PM6:Y6-based ternary organic solar cells.

关键词： C-N bonds Knoevenagel condensation cross-coupling reaction third component organic solar cells