检索结果-南通市图书馆

Optical Properties of One-dimensional Three-component Photonic Band Gap Structure

在线全文

学校读者我要写书评

暂无评论

The Journal of china Universities of Posts and Telecommunications 2003年第2期10卷 22-26,33页

作者： CAI Xiang bao (department of Applied mathematics and Physics, Nanjing university of Posts and Telecommunications, Nanjing 210003, P.R.china National Laboratory of Solid State Microstructures, Nanjing university, Nanjing 210093, P.R.china) department of Applied mathematics and Physics Nanjing University of Posts and Telecommunications Nanjing 210003 P. R. China

Theoretical study of the optical properties of one dimensional three component photonic band gap structure, which is composed of three alternating dielectric layers of different refractive indices and thickness in a unit cell, is performed. This one dimensional photonic band gap structure exhibits the transparency band and forbidden band. We find that there are several mini bands of the allowed transmission to be created within the photonic band gap region of the structure if a defect designed specially is introduced inside the structure. This characteristic is very important for some practical applications.

关键词： photonic crystal photonic band gap optical property forbidden band

Isomorphous Substitution of Metallic Elements for Zeolite Y in the Aqueous Solution

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 1990年第4期6卷 332-340页

作者： Tang Yi, Xu Jinsuo and Gao Zi (department of Chemistry, Fudan university, shanghai)

The substitutions of Ti, Fe and Zr into zeolite Y in the aqueous solutions of (NH4)2TiF6, (NH4)3ZrF7 and (NH4)3FeF6 were systematically Investigated. It was found that Ai atoms in the framework can be replaced by some metallic elements and the extent of substitution depends on the M/A1 ratio of the solution. The maximum allowable M/A1 ratio of the aqueous solution Is related with the radius of the M atom and the stability constant of the MFnm- complex. The substituted zeolite samples with crystallinity greater than 80% were characterized by means of XRD, IR, DTA, TPR and NH3-TPD measurements. The incorporation of Ti, Fe and Zr into the zeolite leads to an increase in the unit cell parameter, a lowering of thermal stability and a red shift of the asymmetric stretching frequency. The extent of these changes is apparently related with the ionic radius of the metallic element and the degree of substitution. The results of various characterization methods show that the het-eroatoms are readily Introduced into the zeolite framework by this preparation method. It was also observed that the substitution of heteroatoms may strengthen or weaken the surface acidity of zeolite Y.

关键词： Isomorphous substitution Zeolite Y Crystallinity Unit cell parameter

Number of embeddings of circular and Mbius ladders on surfaces

在线全文

学校读者我要写书评

暂无评论

Science china mathematics 2010年第5期53卷 356-368页

作者： YANG Yan1 & LIU YanPei2 1department of mathematics,Tianjin university,Tianjin 300072,china 2department of mathematics,Beijing Jiaotong university,Beijing 100044,china 1. department of mathematics Tianjin University Tianjin 300072 China2. Department of Mathematics Beijing Jiaotong University Beijing 100044 China

There are many results on the flexibility of(general) embeddings of graphs,but few are known about that of strong *** this paper,we study the flexibility of strong embeddings of circular and Mbius ladders on the projective plane and the Klein bottle by using the joint tree model of *** numbers of(nonequivalent) general embeddings and strong embeddings of circular and Mbius ladders on these two nonorientable surfaces are obtained,*** the structures of those strong embeddings are described.

关键词： embedding strong embedding flexibility circular ladders Mbius ladders

On Some Properties of Infinite-dimensional Bers Fiber Space

在线全文

学校读者我要写书评

暂无评论

Communications in Mathematical Research 1999年第2期 77-82页

作者： Liu Lixin (department of mathematics, Zhongshan university, Guangzhou, 510275) Yang Xiaoming (Hangzhou university Press, Hangzhou university, Hangzhou, 310028)

§１．ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅＴｅｉｃｈｍüｌｅｒｓｐａｃｅｓｄｉｓｃｕｓｓｅｄｉｎｔｈｉｓｐａｐｅｒａｒｅｉｎｆｉｎｉｔｅｄｉｍｅｎｓｉｏｎａｌＴｅｉｃｈｍüｌｅｒｓｐａｃｅｓｗｉｔｈｃｏｍｐｌｅｘｓｔｒｕｃ... 详细信息

§１．ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅＴｅｉｃｈｍüｌｅｒｓｐａｃｅｓｄｉｓｃｕｓｓｅｄｉｎｔｈｉｓｐａｐｅｒａｒｅｉｎｆｉｎｉｔｅｄｉｍｅｎｓｉｏｎａｌＴｅｉｃｈｍüｌｅｒｓｐａｃｅｓｗｉｔｈｃｏｍｐｌｅｘｓｔｒｕｃｔｕｒｅ．Ｔｈｉｓｉｍｐｌｉｅｓｔ...

关键词： Bers Fiber Space Teichmüller Metric Hyperbolic Metric

Partial Synthesis of Macrolide Alkaloid Euonine

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Chemical Letters 1998年第10期9卷 927-928页

作者： Yuan Chao LI Shan Hao JIANG Xiao Yi WANG (shanghai Institute of Materia Medica, Chinese Academy of Sciences, shanghai, 200031 department of Environmental Chemistry and Engineering, Beijing Polytechnic university,Beijing, 100022) Chinese Acad Sci Shanghai Inst Mat Med Shanghai 200031 Peoples R China Beijing Polytech Univ Dept Environm Chem & Engn Beijing 100022 Peoples R China

The macrolide alkaloid euonine 1 with pharmacologic activity was prepared from the alkaloid wilforgine 2. Their structures were confirmed by IR, NMR, MS and optical rotation.

关键词： tripterygium macrolide alkaloid wilforgin euonine

IL-12p40 is not required for islet allograft rejection

在线全文

学校读者我要写书评

暂无评论

Acta Pharmacologica Sinica 2006年第8期27卷 1065-1070页

作者： En-guang BI~(2,5) Wei SHI~(3,5) Jia ZOU~2 Zhen-hua HAO~3 Zhen-hu LI~2 Duan CAI~3 Hua-qun ZHANG~3 Bing SUN~(2,4,6) ~2Laboratory of Molecular Cell Biology shanghai Institutes for Biological Sciences,Chinese Academy of Sciences,Graduate School of the Chinese Academy of Sciences,shanghai 200031,china ~3the Huashan Hospital of Fudan university,shanghai 200040,china ~4E-institutes of shanghai Universities Immunology Division,shanghai 200025.china Laboratory of Molecular Cell Biology Shanghai Institutes for Biological Sciences Chinese Academy of Sciences Graduate School of the Chinese Academy of Sciences Shanghai 200031 China

Aim:To investigate whether IL-12p40 plays a crucial role in regulating islet al-lograft rejection in a streptozotocin(STZ)-induced diabetes mouse ***:C57BL/6 and IL-12p40 gene knockout mice were selected as recipient mice,towhich the diabetes was induced with a treatment of STZ(150-200 mg/kg)by asingle ip ***/c mice were selected as donor mice and islet cells wereisolated from the *** 500 islets were transplanted into recipient mice be-neath the capsule of the left *** the islet transplantation the glu-cose from the mice sera was monitored and the rejection rate of islets was ***:STZ could induce diabetes in the recipient mice within 1 *** of allograft islets,the increased glucose in wild-type(WT)micereturned to normal level and was maintained for 10 ***,the rejectionrate of islet allograft between IL-12p40-deficient mice and WT mice was ***:The results suggested that,although islet allograft rejection is be-lieved to be Th1-cell predominant,the Th1 response inducer,IL-12 and IL-23 arenot essential to induce islet allograft rejection.

关键词： Th1 cells Th2 cells islets of Langerhans transplantation homologous transplantation IL-12p40-deficient mice

Computer Simulation of the Indentation Creep Tests on Particle-Reinforced Composites

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2002年第4期18卷 335-340页

作者： Zhufeng YUE1,2)1)department of Engineering Mechanics, Northwestern Polytechnical university, Xi’an 710072, china2)Institute of Materials, Ruhr university, 44780 Bochum, Germany department of Engineering Mechanics Northwestern Polytechnical University Xi'an 710072 China Institute of Materials Ruhr University 44780 Bochum Germany

A systematical simulation has been carried out on the indentation creep test on particle-reinforced composites. The deformation, failure mechanisms and life are analyzed by three reasonable models. The following five factors have been considered simultaneously: creep property of the particle, creep property of the matrix, the shape of the particle, the volume fraction of the particle and the size (relative size to the particle) of the indentation indenter. For all the cases, the power law respecting to the applied stress can be used to model the steady indentation creep depth rate of the indenter, and the detail expressions have been presented. The computer simulation precision is analyzed by the two-phase model and the three-phase model. Two places of the stress concentration are found in the composites. One is ahead of the indentation indenter, where the high stress state is deduced by the edge of the indenter and will decrease rapidly near to a steady value with the creep time. The other one is at the interface, where the high stress state is deduced by the misfit of material properties between the particles and matrix. It has been found that the creep dissipation energy density other than a stress parameter can be used to be the criterion to model the debonding of the interfaces. With the criterion of the critical creep dissipation energy density, a power law to the applied stress with negative exponent can be used to model the failure life deduced by the debonding of interfaces. The influences of the shape of the particles and the matching of creep properties of particle and matrix can be discussed for the failure. With a crack model, the further growth of interface crack is analyzed, and some important experimental phenomena can be predicted. The failure mechanism which the particle will be punched into matrix has been also discussed. The critical differences between the creep properties of the particles and matrix have been calculated, after a parameter has b

关键词： Indentation creep test Particle-reinforced composites Computer simulation Deformation Failure

PATIENT-SPECIFIC BLOOD DYNAMIC SIMULATIONS IN ASSESSING ENDOVASCULAR OCCLUSION OF INTRACRANIAL ANEURYSMS

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2009年第2期21卷 271-276页

作者： CHEN Jia-liang WANG Sheng-zhang DING Guang-hong YANG Xin-jian LI Hai-yun department of Mechanics and Engineering Science Fudan University Shanghai 200433 China Beijing Institute of Neurosurgery Beijing 100050 China department of Biomedical Engineering Capital Medical University Beijing 100050 China

According to recent studies, there are various potential predictors for surgical outcome for cerebral aneurysms. An accurate surgical outcome assessment would help make better-informed decisions and avoid the risk of rebleeding. It is well known that hemodynamic factors play an important role in the pathogenesis and treatment of intracranial aneurysms. In this article, a computational fluid dynamic analysis is applied to one patient-specific model of the cerebral aneurysm located at the tip of basilar artery, by which the differences of hemodynamic parameters before and after endovascular treatment may be evaluated. Based on the model, we show that the flow behavior near the neck of the aneurysm sees great differences after endovascular treatment as compared with that before treatment, which also affects the wall shear stress and the displacement distribution. In addition, our whole simulation process is based on a series of CFD commercial software packages, which are easily available for doctors to implement such a method in their daily practice. These results would be used to assess the outcome of endovascular treatment for the aneurysm occlusion.

关键词： hemodynamics numerical simulation intracranial aneurysm

Transgenic mice designed to express human α-1,2-fucosyltransferase in combination of human DAF and CD59 to avoid xenograft rejection

在线全文

学校读者我要写书评

暂无评论

Science china(Life Sciences) 2008年第3期51卷 199-204页

作者： LIU BingQian1, CHENG ChuanYu1, WU YuDong1, WEI JinXing1, LI GuangSan2 & MA TengXiang3 1 department of Urology, the First Affiliated Hospital of Zhengzhou university, Zhengzhou 450052, china 2 Institute of Genetics and Development Biology, Chinese Academy of Sciences, Beijing 100101, china 3 Tianjin Institute of Urology, Second Hospital of Tianjin Medical university, Tianjin 300211, china department of Urology the First Affiliated Hospital of Zhengzhou University Zhengzhou 450052 China Institute of Genetics Development Biology Chinese Academy of Sciences Beijing 100101 China Tianjin Institute of Urology Second Hospital of Tianjin Medical University Tianjin 300211 China

The expression of human α-1,2-fucosyltransferase (HT) or complement regulatory proteins has been proved as an strategy to overcome hypercute rejection in discordant xenogeneic organ transplantation. In this study, we examined whether peripheral blood mononuclear cells (PBMCs) from polytransgenic mice expressing the human HT, and complement regulatory proteins (DAF and CD59), can provide more effective protection against xenograft rejection. Transgenic mice were produced by co-injection of gene constructs for human HT, DAF and/or CD59. Flow Cytometry (FCM) was used to screen the positive transgenic mice. PBMCs from transgenic mice were incubated with 15% human serum to evaluate natural antibody binding, complement activation and expression of adhesion molecules. Three transgenes were strongly expressed in PBMCs of transgenic mice, and HT expression signifi- cantly reduced expression of the major xenoepitope galactose-α-1,3-galactose (α-Gal). Functional studies with PBMCs showed that co-expression of HT and DAF or CD59 markedly increased their re- sistance to human serum-mediated cytolysis when compared with single transgenic PBMCs. Moreover, the combined expression of triple transgenes in PBMCs led to the greatest protection against human serum-mediated cytolysis, avoided hyperacute rejection and reduced expression of adhesion mole- cules. Strong co-expression of triple transgenes was completely protected from xenograft hyperacute rejection and partially inhibited acute vascular rejection. The studies suggest that engineering mice to express triple molecules represents an critical step toward prolonging xenograft survival and might be more suitable for xenotransplantation.

关键词： α-1 2-fucosyltransferase complement regulatory proteins galactose-α-1 3-galactose hyperacute rejection acute vascular rejection