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Chinese Physics B 2013年第5期22卷 355-362页

作者： Rajib Basu g. C. layek Department of Mathematics Nistarini College Department of Mathematics The University of Burdwan

Double-diffusive stationary and oscillatory instabilities at the marginal state in a saturated porous horizontal fluid layer heated and salted from above are investigated theoretically under the Darcy＇s framework for a porous medium. The contributions of Soret and Dufour coefficients are taken into account in the analysis. linear stability analysis shows that the critical value of the Darcy-Rayleigh number depends on cross-diffusive parameters at marginally stationary convec- tion, while the marginal state characterized by oscillatory convection does not depend on the cross-diffusion terms even if the condition and frequency of oscillatory convection depends on the cross-diffusive parameters. The critical value of the Darcy-Rayleigh number increases with increasing value of the solutal Darcy-Rayleigh number in the absence of cross- diffusive parameters. The critical Darcy-Rayleigh number decreases with increasing Soret number, resulting in destabiliza- tion of the system, while its value increases with increasing Dufour number, resulting in stabilization of the system at the marginal state characterized by stationary convection. The analysis reveals that the Dufour and Soret parameters as well as the porosity parameter play an important role in deciding the type of instability at the onset. This analysis also indicates that the stationary convection is followed by the oscillatory convection for certain fluid mixtures. It is interesting to note that the roles of cross-diffusive parameters on the double-diffusive system heated and salted from above are reciprocal to the double-diffusive system heated and salted from below.

关键词： double-diffusive convection porous media Soret and Dufour effects linear stability analysis

Effect of Calcining Temperature on the Structure of li_4Ti_5O_(12)

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复旦学报（自然科学版） 2007年第5期46卷 844-845页

作者： g.J.Wang N.H.Zhao l.J.Fu B.Wang Y.P.Wu Deparment of Chemistry & Shanghai Key laboratory of Molecular Catalysis and Innovative Materials Fudan University

1 Introduction Recently there had considerable interest in li4Ti5O12 as a potential anode for use in li-ion batteries. Usually, it was used as an anode combined with a high voltage cathode[1-5]. It has many advantages compared to the currently used graphite. For example, it presents virtually unlimited cycle life due to zero strain or volume change when lithium intercalates into and de-intercalates from[6]. generally, li4Ti5O12 was prepared by a solid-state reaction from stoichiometric amounts of li2CO3...

关键词： lithium-ion battery li4Ti5O12 anode materials electrochemical property

Structural and molecular features of intestinal strictures in rats with Crohn's-like disease

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World Journal of gastroenterology 2016年第22期22卷 5154-5164页

作者： Petra Talapka Anikó Berkó lajos István Nagy lalitha Chandrakumar Mária Bagyánszki lászló géza Puskás éva Fekete Nikolett Bódi Department of Physiology Anatomy and Neuroscience Faculty of Sciences and Informatics University of Szeged H-6726 Szeged Hungary Avidin ltd. H-6726 Szeged Hungary

AIM: To develop a new rat model we wanted to gain a better understanding of stricture formation in Crohn’s disease (CD).METHODS: Chronic colitis was induced locally by the administration of 2,4,6-trinitrobenzenesulfonic acid (TNBS). The relapsing inflammation characteristic to CD was mimicked by repeated TNBS treatments. Animals were randomly divided into control, once, twice and three times TNBS-treated groups. Control animals received an enema of saline. Tissue samples were taken from the strictured colonic segments and also adjacent proximally and distally to its 60, 90 or 120 d after the last TNBS or saline administrations. The frequency and macroscopic extent of the strictures were measured on digital photographs. The structural features of strictured gut wall were studied by light- and electron microscopy. Inflammation related alterations in TgF-beta 2 and 3, matrix metalloproteinases 9 (MMP9) and TIMP1 mRNA and protein expression were determined by quantitative real-time PCR and western blot analysis. The quantitative distribution of caspase 9 was determined by post-embedding ***: Intestinal strictures first appeared 60 d after TNBS treatments and the frequency of them increased up to day 120. From day 90 an intact lamina epithelialis, reversible thickening of lamina muscularis mucosae and irreversible thickening of the muscularis externa were demonstrated in the strictured colonic segments. Nevertheless the morphological signs of apoptosis were frequently seen and excess extracellular matrix deposition was recorded between smooth muscle cells (SMCs). Enhanced caspase 9 expression on day 90 in the SMCs and on day 120 also in myenteric neurons indicated the induction of apoptosis. The mRNA expression profile of TgF-betas after repeated TNBS doses was characteristic to CD, TgF-beta 2, but not TgF-beta 3 was up-regulated. Overexpression of MMP9 and down-regulation of TIMP1 were demonstrated. The progressive increase in the amount

关键词： Crohn’ s disease Rat model TgF-beta Intestinal strictures MMP9 TIMP1

MHD graphene-polydimethylsiloxane Maxwell nanofluid flow in a squeezing channel with thermal radiation effects

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Applied Mathematics and Mechanics(English Edition) 2019年第9期40卷 1269-1284页

作者： g.C.SHIT S.MUKHERJEE Department of Mathematics Jadavpur University

The magnetohydrodynamic (MHD) graphene-polydimethylsiloxane (PDMS) nanofluid flow between two squeezing parallel plates in the presence of thermal radiation effects is investigated. The energy efficiency of the system via the Bejan number is studied extensively. The governing partial differential equations are converted by using the similarity transformations into a set of coupled ordinary differential equations. The set of these converted equations is solved by using the differential transform method (DTM). The entropy generation in terms of the Bejan number, the coefficient of skin-friction, and the heat transfer rate is furthermore investigated under the effects of various physical parameters of interest. The present study shows that the Bejan number, the velocity and thermal profiles, and the rate of heat transfer decrease with a rise in the Deborah number De while the skin-friction coefficient increases. It is also observed that the entropy generation due to frictional forces is higher than that due to thermal effects. Thus, the study bears the potential application in powder technology as well as in biomedical engineering.

关键词： graphene-polydimethylsiloxane (PDMS) Maxwell fluid differential transform method (DTM) thermal radiation Bejan number

gamma Irradiation Effects in InBi_(0.8) Te_(0.2) Crystals grown by Horizontal Directional Freezing

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Acta Metallurgica Sinica(English letters) 2015年第10期28卷 1205-1213页

作者： C.J.Ajayakumar A.g.Kunjomana Department of Physics Crystal Research CentreChrist University

The high-energy gamma-ray irradiation treatment using Co-60 isotope offers the possibility of engineering mechanical and optoelectronic properties of In Bi0.8Te0.2crystals. Tellurium-doped indium bismuthide（In Bi） crystals were prepared by horizontal directional freezing technique. Dose-dependent modifications in structure, composition and surface topographical features have been analyzed by X-ray powder diffraction, X-ray energy-dispersive analysis, transmission electron and atomic force microscopy, respectively. Dielectric constant and dielectric loss were found to increase with the cumulative dose of radiation, and a shift in the ferroelectric transition temperature（Tc） from 405 to 410 K was observed for25 k gy. Upon irradiation, there is an enhancement in microhardness（HV）, yield stress（ry） and stiffness constant（C11）.The optical transmittance was decreased by 12.45%, resulting in a reduction in the optical band gap from 0.210 e V to0.198 e V. These results indicate the suitability of In Bi0.8Sb0.2crystals for low-wavelength infrared applications.

关键词： Crystal growth Dielectric properties Optical properties Hardness Irradiation

ANTIBACTERIAl POlY(D,l-lACTIDE)(PDllA)FIBROUS MEMBRANES MODIFIED WITH QUATERNARY AMMONIUM MOIETIES

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Chinese Journal of Polymer Science 2010年第4期28卷 581-588页

作者：李新松 K.g.Neoh School of Chemistry and Chemical Engineering Southeast University Department of Chemical and Biomolecular Engineering National University of Singapore

Antibacterial poly（D,l-lactide）（PDllA） fibrous membranes were developed via electrospinning, followed by surface modification which involved plasma pretreatment, UV-induced graft copolymerization of 4-vinylpyridine （4VP） and quaternization of the grafted pyridine groups with hexylbromide. The success of modification with quaternized pyridinium groups on the PDllA fibrous membranes was ascertained by X-ray photoelectron spectroscopy （XPS）. The antibacterial activities of these membranes were assessed against gram-positive Staphylococcus aureus （S. aureus） and gram-negative Escherichia coli （E. coli）. The PDllA fibrous membranes modified with quatemized pyridinium groups showed antibacterial efficiency against both bacteria as high as 99.999%. The results demonstrated that the antibacterial activity was based on the interaction of the positive charge of pyridinium group and negatively charged cell membrane of bacteria, resulting in loss of membrane permeability and cell leakage.

关键词： Poly(D,l-lactide) Antibacterial Electrospinning Surface modification

Novel insight into mechanisms of cholestatic liver injury

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World Journal of gastroenterology 2012年第36期18卷 4985-4993页

作者： Benjamin l Woolbright Hartmut Jaeschke Department of Pharmacology Toxicology and TherapeuticsUniversity of Kansas Medical CenterKansas CityKS 66160United States

Cholestasis results in a buildup of bile acids in serum and in *** studies into the mechanisms of cholestatic liver injury strongly implicated bile acidinduced apoptosis as the major cause of hepatocellular *** work has focused both on the role of bile acids in cell signaling as well as the role of sterile inflammation in the *** in modern analytical methodology have allowed for more accurate measuring of bile acid concentrations in serum,liver,and bile to very low levels of ***,toxic bile acid levels are seemingly far lower than previously *** initial hypothesis has been based largely upon the exposure of μmol/l concentrations of toxic bile acids and bile salts to primary hepatocytes in cell culture,the possibility that in vivo bile acid concentrations may be far lower than the observed in vitro toxicity has far reaching implications in the mechanism of *** review will focus on both how different bile acids and different bile acid concentrations can affect hepatocytes during cholestasis,and additionally provide insight into how these data support recent hypotheses that cholestatic liver injury may not occur through direct bile acid-induced apoptosis,but may involve largely inflammatory cell-mediated liver cell necrosis.

关键词： Bile acids Cholestasis Apoptosis Necro-sis Neutrophils Innate immunity Bile duct ligation

Artificial boundary conditions for Euler–Bernoulli beam equation

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Acta Mechanica Sinica 2014年第5期30卷 687-692页

作者： Shao-Qiang Tang Eduard g.Karpov HEDPS CAPT and LTCS College of EngineeringPeking University Department of Civil and Materials Engineering University of Illinois at ChicagoChicago IL60607 USA

In a semi-discretized Euler-Bernoulli beam equa- tion, the non-nearest neighboring interaction and large span of temporal scales for wave propagations pose challenges to the effectiveness and stability for artificial boundary treat- ments. With the discrete equation regarded as an atomic lattice with a three-atom potential, two accurate artificial boundary conditions are first derived here. Reflection co- efficient and numerical tests illustrate the capability of the proposed methods. In particular, the time history treatment gives an exact boundary condition, yet with sensitivity to nu- merical implementations. The AlEX （almost EXact） bound- ary condition is numerically more effective.

关键词： Euler-Bernoulli beam. Artificial boundary con- dition - Wave propagation

中国海外战略支点空间选择的逻辑框架与模型建构

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自然资源学报 2023年第11期38卷 2687-2703页

作者：马学广蒋策南开大学周恩来政府管理学院天津300350

全球化深入发展和区域化嬗变重构推动着全球政治经济格局的持续重塑,而海外战略支点以其突出的地缘影响对国家的海外战略部署起到显著支撑作用。基于地缘政治理论、新国家空间理论和区位理论,构建中国海外战略支点空间选择的逻辑框架与... 详细信息

全球化深入发展和区域化嬗变重构推动着全球政治经济格局的持续重塑,而海外战略支点以其突出的地缘影响对国家的海外战略部署起到显著支撑作用。基于地缘政治理论、新国家空间理论和区位理论,构建中国海外战略支点空间选择的逻辑框架与模型,并明晰具体行动路径。研究发现:(1)地缘政治、国家选择和区位资源分别主导高、中、低尺度海外战略支点空间选择逻辑;(2)各尺度海外战略支点的空间选择逻辑各有侧重但又相互嵌套,从而塑造了空间选择的逻辑框架;(3)根据海外战略支点空间选择模型,在具体实践中应参考“政府主导、多元联动”的行动路径。研究成果可以丰富战略支点研究框架,为提升中国地缘政治影响力提供理论借鉴和政策启示。

关键词：海外战略支点空间选择逻辑框架模型建构地缘政治理论新国家空间理论区位理论