二茂铁甲酸酯类衍生物的合成及表征

目的:由于二茂铁甲酸具有特殊的物理化学性质,其衍生物具有多种生物活性,以二茂铁甲酸为中间体,利用其性质对一些有机化合物进行修饰改造,生成一系列的二茂铁甲酸酯类衍生物。方法:以二茂铁甲酸、阿魏酸、丹皮酚、1,3-二溴丙烷为原料,采用成酯反应得目标化合物。结果:设计合成了一系列的二茂铁甲酸的衍生物。结论:设计合成的二茂铁甲酸的衍生物,其结构经IR、1H-NMR、ESIMS确认。     

1,4-N,N-取代哌嗪类药物中间体的合成

本研究以二乙醇胺为原料和SOCl2反应,得二-(2-氯乙基)胺。二-(2-氯乙基)胺与3-氯苯胺发生取代反应生成1-(3-氯苯基)哌嗪,再与1-溴-3-氯丙烷发生取代反应生成1-(3-氯苯基)-4-(3-氯丙基)哌嗪。1-(3-氯苯基)-4-(3-氯丙基)哌嗪是进一步合成1,4-N,N-取代哌嗪类药物的重要中间体。     

提高大棚蔬菜效益的几条措施

园土消毒。可在每平方米床土注入3到5克多菌灵(托布津)或300克溴化甲醇消毒灭菌。 喷洒稀土液。在茄果类蔬菜苗期和始花期喷洒浓度为0.2到0.5％硝酸稀土液,能显著提高蔬菜产量,改善品质。     

人体心脏解剖3模型、图片和动画可在3DScience.com获取

世界级3D生物医学模型、影像和动画的领先供应商Zygote Media Group，Inc．宣布公开推出迄今为止最完善的3D心脏模型Zygote Human Heart 3.Zygote心脏是在全球授权使用的唯一知名动画3D心脏模型。     

OLED中间体5-溴-11,11-二甲基-11H-苯并[b]芴的合成及工艺优化

文章以1-溴-2碘萘与2-(甲氧羰基)-苯硼酸为起始原料合成5-溴-11,11-二甲基-11H-苯并[b]芴,考察了催化剂、反应温度、反应溶剂及相关物料配比对反应的影响,优化得出每一步反应的最佳反应条件。优化后目标产品总收率可以达到49.1%,产品纯度99.2%。     

香榧树叶精油成分与化学分类

作者曾经证明香榧叶中具有特征成分榧黄素(kayaflavone)。最近，又从香榧叶中分得一 个新的二萜特征成分香榧酯(torreyagrandate)，为了获得更多的特征成分，我们自榧树叶中共鉴  定出26个精油成分。从组成比看，其特点是苧烯占优势(44．24％)，其次为 α-蒎烯(20．75％)，再次为δ-3-蒈烯(4％)。叶中所含的榧烯醇(torreyol)为特征成分。     

灯盏细辛酚及其制备方法和在制药中的应用（专利申请号：03117754）

本发明涉及一种灯盏细辛有效部位灯盏细辛酚，其制备方法及在制药中的应用，该提取物是从灯盏细辛中提取的新有效部位，主要由活性成分灯盏乙素（黄芩素苷、野黄芩苷）、3，5-二咖啡酰基奎宁酸、1，5-二咖啡酰基奎宁酸、飞蓬酯乙和4，5-二咖啡酰基奎宁酸组成。在有效部位灯盏细辛酚中，灯盏乙素含量1f1％-40％，四个咖啡酸酯含量之和在40％-60％。本发明同时提供有效部位灯盏细辛酚的制备方法、有效成分含量测定方法。该提取物可单独或与其它药用许可的辅料配合后制成口服和注射剂型，适用于各种心脑血管疾病的预防和治疗。     

氨氮测定方法改进

在环境水测试中，氨氮的测定多用纳氏试剂法，该法由纳氏试剂代入的本底较高，因而空白值较高，影响曲线线性；试剂干扰多，影响被测成分多吸光值。本将多次经验加以综合，在保证最低检测浓度不变的前提下，降低标准使用液的浓度(2．00g／ml)，找出了纳氏试剂的最佳加入量(1．5ml)，减少了试剂空白；指出了酒石酸钾钠的最长保存时     

喜树碱-20-O-(3,3'-二硫代二丙酰)单酯合成方法初探

喜树碱具有较强的抗肿瘤活性,喜树碱E环的修饰主要目的是抑制内酯的水解,从而提高E环的稳定性。在喜树碱的E环引入二硫键即可保护α-羟基内酯环又可增强其靶向性。本文以喜树碱(CPT)为原料,与3,3'-二硫代二丙酸在缩合剂的作用下,发生部分O-酰化反应,合成了喜树碱-20-O-(3,3'-二硫代二丙酰)单酯,通过考察缩合剂、反应时间和反应温度对O-酰化反应的影响,选定EDCI为缩合剂剂,以DMAP为缩合活化剂,室温下搅拌反应12小时,经柱层析纯化,产品收率可达62%。     

软土及沼泽地区的路基施工

1、软土及沼泽物理、力学性质 (1)天然含水量高，孔隙比大由于软土、沼泽中的粘粒及有机质含量大，吸水能力强，加之地处常年积水的洼地，土层厚度大，多呈软塑或半流塑状态，天然含水量达30％-70％，有时甚至达200％；孔隙比一般大于1，大多在1．0-2．0之间，在某些地区可达6．0；饱和度一般大于95％，液限在35％-60％之间塑性指数为10%-30％，天然密度约为1．5-1．9kg／m^3。     

Students' Reactions to the Introduction of Videoconferencing for Classroom Instruction

This study examined how students who had no prior experience with videoconferencing would react to the use of videoconferencing as an instructional medium. Students enrolled in seven different courses completed a questionnaire at the beginning of the semester and again at the end of the semester. Students at the origination and remote sites did not differ in their reactions toward videoconferencing but there was a significant difference for gender. Women reacted less favorably to videoconferencing. Compared to the beginning of the semester, students reported significantly less positive attitudes toward taking a course through videoconferencing at the end of the semester. There were no significant differences in students' attitudes toward videoconferencing across courses at the beginning of the semester but there were significant differences across the courses at the end of the semester. The results suggest the need for better preparation for both students and instructors.     

Cooler temperatures inductive to locust outbreaks

Ajoint study by Prof. ZHANG Zhibin from the CAS Institute of Zoology and his co-workers from Norway, US and Swiss have indicated that historical outbreaks of migratory locusts in China were associated with cold spells, suggesting that China＇s projected climate warming could decrease the pest＇s numbers. The study was published in Proceedings of theNational Academy of Sciences on 17 September, 2007.     

Exploring Multiplexity: Social Network Structures in a Computer-Supported Distance Learning Class

A computer-mediated group is a complex entity whose members exchange many types of information via multiple means of communication in pursuit of goals specific to their environment. Over time, they coordinate technical features of media with locally enacted use to achieve a viable working arrangement. To explore this complex interaction, a case study is presented of the social networks of interactions and media use among members of a class of computer-supported distance learners. Results show how group structures associated with project teams dominated who communicated with whom, about what, and via which media over the term, and how media came to occupy their own communication niches: Webboard for diffuse class-wide communication; Internet Relay Chat more to named others but still for general communication across the class; and e-mail primarily for intrateam communication. Face-to-face interaction, occurring only during a short on-campus session, appears to have had a catalytic effect on social and emotional exchanges. Results suggest the need to structure exchanges to balance class-wide sharing of ideas with subgroup interactions that facilitate project completion, and to provide media that support these two modes of interaction.     

Low doses of a red wine ingredient figh diabetes in mice

Aresearch group led by Prof. ZHAI Qiwei from the Institute for Nutritional Sciences under the CAS Shanghai Institutes for Biological Sciences has discovered that even relatively low doses of resveratrol--a chemical found in the skins of red grapes and in red wine--can improve the sensitivity of mice to the hormone insulin, according to a report in the October,2007 issue of Cell Metabolism. As insulin resistance is often characterized as the most critical factor contributing to the development of Type 2 diabetes, the findings“provide a potential new therapeutic approach for preventing or treating” both conditions, the researchers said.     

The Role of Intermediating Institutions in the Diffusion of Electronic Data Interchange (EDI): How Industry Associations Intervened in Denmark, Finland, and Hong Kong

Electronic data interchange (EDI) provides means for interorganizational communication, creates network externalities, requires an advanced information technology (IT) infrastructure, and relies on standards. In the diffusion of such innovations, institutional involvement is imperative. Such institutions contain governmental agencies, national and global standardization organizations, local government, and nonprofit private organizations like industry associations. The last type of organizations we call intermediating institutions. They intermediate or coordinate ("inscribe") the activities of a group of would-be adopters. Unfortunately, little is known of how these organizations shape the EDI diffusion trajectory. In this article we examine one specific type of intermediating organizations?industry associations?and how they advanced the EDI diffusion process in the grocery sectors of Hong Kong, Denmark and Finland. We identify six institutional measures, placed into a matrix formed by the mode of involvement (influence vs. regulation) and the type of diffusion force (supply push vs. demand pull), that can be mobilized to further the EDI diffusion. Industry associations were found to be active users of all these measures to varying degrees. Their role was critical especially in knowledge building, knowledge deployment, and standard setting. Furthermore, institutional involvement varied due to policy and cultural contingencies and power dependencies.     

How Electronic Publishers are Protecting Against Piracy: Doubts About Technical Systems of Protection

The increasing prospects of digital piracy has prompted the perceived need by electronic publishers to adopt technical systems of protection, and governments to reform their copyright laws. This article is a preliminary study of the management of intellectual property by electronic publishers, defined as those involved in the production of online databases, and CD-ROMs. It focuses on three main issues: (1) how electronic publishers view the increasing threat of piracy; (2) the methods of protection employed to protect intellectual property in digital format; and (3) the importance of technological protection of intellectual property in electronic publications. The analysis is based on a sample of 23 UK electronic publishers. The interviews revealed an interesting assortment of protection methods and did not show that technological protection was a preferred way. Instead, the means of protection, in addition to copyright law, comprised niche markets, pricing, trust, bad publicity, and nontechnical and technical means.     

Rough Justice: A Statistical Assessment of ICANN's Uniform Dispute Resolution Policy

Long-standing conflict between domain name registrants and trademark holders prompted the Internet Corporation for Assigned Names and Numbers (ICANN) to create a global, mandatory arbitration procedure known as the Uniform Dispute Resolution Policy (UDRP). The UDRP has been used in 2166 cases involving 3938 domain names as of 1 November 2000. The policy gives the initiator of a complaint, generally a trademark holder, the right to choose which ICANN-accredited dispute resolution service provider (RSP) will handle the case. During the preparation of the UDRP,some feared that complainant selection would lead to "forum shopping" that might bias the results. This article performs a statistical assessment of the forum-shopping thesis and finds support for it. There are statistically significant differences in the various RSPs' propensity to take away names from defendants; there are also major differences in the number of cases brought to each RSP. RSPs who take away names have the larger share of cases. The study examines other variables that might explain differences in market share, such as price, the plaintiff's nationality, or the time taken to decide a case. It finds that nationality and time also are correlated with market share. The study concludes that shopping for a favorable outcome is an important factor in the UDRP.     

Prevalence of soft neurological signs in Chinese people

Prof. Raymond C.K. Chen, a neuropsychologist with the CAS Institute of Psychology, has made novel progress in his studies of schizophrenia. His work has been reported by a recent issue of Behavioural Neurology.     

Molecular motor assembly of a biomimetic system

Active biological molecules and functional structures can be fabricated into a bio-mimetic system by using molecular assembly method. Such materials can be used for the drug delivery, disease diagnosis and therapy, and new nanodevice construction.     

Monoculture Rubber Plantations Have Negative Ef ects on Controlling Splash Erosion

<正>In Xishuangbanna,one of China’s most biodiverse regions,landscape has changed dramatically during the past three decades due to the conversion of tropical rainforest to rubber plantations.In steep areas,terraces are often constructed before planting rubber trees,which causes two important changes in the soil:the destabilization of soil in the bench terraces and the increased vulnerability of unvegetated riser faces to erosion.Few studies have documented the nature and intensity of erosion on bench terraces.Prof.LIU Wenjie and his colleagues from the Xishuangbanna Tropical Botanical Garden(XTBG)conducted a study in Menglun County(21°5′39″N,101°15′55″E),Xishuangbanna to evaluate the influence