Model and empirical study on some collaboration networks

In this paper we present an empirical study of a few practical systems described by cooperation networks, and propose a model to understand the results obtained. We study four non-social systems, which are the Bus Route Networks of Beijing and Yangzhou, the Travel Route Network of China, Huai-Yang recipes of Chinese cooked food, and a social system, which is the Collaboration Network of Hollywood Actors. In order to explain the results related to the degree distribution, act-degree distribution and act-size distribution (especially about the degree distribution, which may be better fitted using a stretched exponential distribution (SED)), we suggest a simple model to show a possible evolutionary mechanism for the emergence of such networks. The analytic and numerical results obtained from the model are in good agreement with the empirical results.     

Chemoselective Catalytic Hydrogenation of α,β-Unsaturated Ketones and α,β-Unsaturated Carboxylic Esters

ＣｈｅｍｏｓｅｌｅｃｔｉｖｅＣａｔａｌｙｔｉｃＨｙｄｒｏｇｅｎａｔｉｏｎｏｆα，β┐ＵｎｓａｔｕｒａｔｅｄＫｅｔｏｎｅｓａｎｄα，β┐ＵｎｓａｔｕｒａｔｅｄＣａｒｂｏｘｙｌｉｃＥｓｔｅｒｓＺＨＡＮＧＪｉｎｇ－ｗｅｎ＊，ＺＨＡＯＪｉａｎ－ｚｈａｎｇ，Ｚ...     

聚合物微腔的研制及其特性分析

采用ＢＭＰＰＶ：ＰＶＫ的混合物作国源介质，将其按一定比例溶于氯仿中，并旋涂在具有９９．５％的反射率的ＤＢＲ上，其上蒸发３００ｎｍ的银膜，形成了面发射型微腔结构，其中ＤＢＲ在入射腔面，银膜为反射腔面，在激发波长３３７．１ｎｍ，频率２０Ｈｚ脉宽１０ｎｓ的氮分子激光器泵浦下，光谱明显等窄化，出现４６０ｎｍ和５３０ｎｍ两个比较强的发光峰，主峰国４６０ｎｍ半宽度为７ｎｍ。     

分布耦合系数对线性啁啾光栅色散的影响

本文从光栅反向耦合波方程出发,经相位共轭变换用Runge-Kuta-Gil方法对其数值求解。针对线性啁啾光栅耦合系数变化服从不同的分布,分析了各种分布对光栅反射谱特性和色散特性的影响。     

锁相电子散斑系统

电子散斑干涉计量在变形量检测¹、无损探伤、振动分析^(2,3)等领域具有广泛的应用前景,目前它之所以未能实用化,最重要的原因就是该系统对环境的要求过高,特别是物体的振动和空气的扰动对测量结果影响很大,甚至会导致测量失败,因而国内外学者在不断寻找解决此问题的锁相技术。本文提出了一种简易的切实可行的锁相方法-光学锁相法,消除了物体的振动和空气扰动对电子散斑测量的影响。     

THE RING OPENING REACTION OF AN EPOXY COMPOUND ON THE TOP OF CHEMISORBED CYSTAMINE STUDIED BY THE SERS TECHNIQUE

Metal foils for Raman scattering were prepared by HNO_3 etching method. These foils werefound to exhibit a strong SERS effect and excellent thermal stability. SERS spectra of cystaminehave been taken to illustrate the usefulness of this sample preparation method in the studies ofchemisorption. The ring opening reactions of an epoxy compound have been observed on the topof chemisorbed cystamine on silver foils.     

软珊瑚Sinularia sp.中次生代谢产物的结构鉴定

细胞毒性;软珊瑚Sinularia sp.中次生代谢产物的结构鉴定     

Study on fluorescence property of dopamine and determination of dopamine by fluorimetry

In this study, a rapid and sensitive high performance liquid chromatography-inductively coupled plasma-mass spectrometry (HPLC-ICP-MS) determination of primary As species in fish tissues and urine is reported. The separation was achieved on an Altima C18 column with a mobile phase containing citric acid and hexanesulfonic acid (pH 4.5). As(V), monomethylarsonic acid (MMA), As(III), dimethylarsinic acid (DMA) and arsenobetaine (AsB) were separated in less than 4 min with retention times of 83, 99, 130, 166 and 208 s, respectively. This separation of five species in less than 4 min should be attractive to those interested in As speciation. The quantification limits were 44, 56, 94, 64, 66 ng l(-1) and the relative standard deviations (R.S.D.) for day-to-day injections of As at 2 mug l(-1) were 2.0, 3.1, 2.4, 3.8 and 4.0%. The procedure was tested using two reference materials (DORM-2 dogfish muscle tissue, NIST SRM 2670 Freeze-dried Urine, normal level) and then applied to real-world samples. The results obtained demonstrate the suitability of the procedure for screening and quantification at physiological levels of primary As species in biological samples.     

中药川白芷化学成分的研究

中药川白芷为伞形科当归属杭白芷 (Ａｎｇｅｌｉｃａｄａｈｕｒｉｃａ (Ｆｉｓｃｈ .ｅｘＨｏｆｆｍ .)Ｂｅｎｔｈ .ｅｔＨｏｏｋ .ｃｖｈａｎｇ ｂａｉｚｈｉＨｏｒｔ)的干燥根。川白芷为我国传统中药 ,主治头疼、鼻炎、癣症等疾病。现代药理实验表明白芷中所含的呋南香豆素具有平喘、降压、抗菌、解痉、光敏、活化交感系激素等多种药理作用[1] 。已有文献对白芷的化学成分进行了研究 ,发现白芷中主要含香豆素成分[2～ 4] 。四川遂宁产川白芷为道地白芷 ,其药性好 ,为进一步研究其活性成分 ,本文对遂宁产川白芷进行化学成分研究。共分离、…     

无纺布上的偕胺肟基团鳌合物的氧化还原反应的研究

 采用各种分析方法系统研究了含偕胺肟基因维尼无纺布与Ａｎ³⁺进行氧化还原反应时的化学结构变化、氧化还原与鳌合吸附的关系以及还原产物的结晶结构和形态．结果表明，含偕胺肟基无纺布与Ａｕ³⁺反应时，开始主要是偕胺肟基被氧化成为酰胺基．此外，有部分偕胺基因被氧化成为羧基．Ａｎ³⁺被还原的同时生成约相等当量的氢离子．反应后期或反应温度高时，氢离子生成量增大．实验结果还表明，在反应起始阶段，Ａｕ³⁺与偕胺肟基因会发生鳌合作用．还原生咸的单质Ａｎ形成“玫瑰花”状的小晶粒粘附于无纺布纤维表面．