模板技术制备介观结构材料（英文）

模板技术是制备介观尺度下具有多重结构材料的简单有效方法。本工作围绕纳米微球及其组装结构，一维纳米纤维及其组装结构而开展。其中重点关于核-壳结构凝胶微球的制备，并以此为模板制备包覆复合微球和中空微球，实现复合微球的形貌和特征尺寸的控制。通过化学改性对单分散聚苯乙烯胶体微粒进行处理，制备了具有核-壳结构的单分散凝胶粒子。以核-壳结构凝胶粒子为模板，制备了二氧化钛包覆聚苯乙烯核壳结构的复合粒子及其中空的二氧化钛粒子。发现在无机前体的溶胶凝胶过程中，电场能诱导复合粒子表面形成贯穿的多孔结构。同样思路，制备了二氧化硅、导电聚苯胺及其复合的核-壳结构和相应的中空微球。对聚苯乙烯胶体晶进行化学改性，制备了核-壳结构的胶体晶凝胶。以此为模板，与第二种具有响应特性凝胶进行复合，得到了敏感特性的胶体晶凝胶。并研究了此复合凝胶的形态及外场响应特性。以多孔氧化铝膜为模板，制备一维结构及其阵列体系。通过调节孔的润湿性，调节一维结构的形态（纤维或中空结构）并可调节双组分核-壳结构纤维的内外相相反转。     

氧化锆增韧氧化铝陶瓷材料的研究进展

综述了氧化锆增韧氧化铝陶瓷材料的增韧机理、ZTA陶瓷材料的制备工艺及应用等方面的研究进展。     

ZTA复相陶瓷增韧的研究进展

氧化锆增韧氧化铝复相陶瓷(即ZTA复相陶瓷)是一种以氧化铝(Al_2O_3)作为主晶相,部分稳定的氧化锆(ZrO_2)作为增韧补强相的陶瓷基复合材料。体系中的Al_2O_3和ZrO_2能产生协同耦合作用,使ZTA复相陶瓷的强度和韧性都得到显著改善,并且价格低于氧化锆陶瓷。但是,随着工业的发展和技术的进步,ZTA复相陶瓷的韧性越来越难以满足需求,国内外的科研工作者们提出了多种途径以提高该陶瓷的韧性。基于此,本文综述了国内外关于ZTA复相陶瓷增韧的研究进展,以期为ZTA陶瓷的应用提供参考。     

不同掺杂浓度对Mn掺杂TiO2粉末样品结构及磁性的影响

利用溶胶-凝胶法制备了不同掺杂浓度的Ti1-xMnxO2胶体,在空气中500℃退火处理,利用XRD、XPS和VSM分别测量了样品的结构、价态和磁特性。研究显示掺杂浓度为2%时,样品的磁滞回线达到饱和,其饱和磁化强度为0.024emu/g。研究表明Mn4+替代Ti4+产生铁磁性,Mn3+替代Ti4+产生顺磁性,样品的磁性不是来自于第二相,而是样品的本征磁性。     

超细氧化铝粉影响青瓷瓷胎强度的作用机理

以无机铝盐为先驱体,六次甲基四胺为催化剂,采用溶胶—凝胶法制备了纳米氧化铝粉体,将纳米氧化铝粉体应用于薄胎厚釉青瓷瓷胎中,研究了粉体对青瓷瓷胎的增强作用。研究结果表明,干凝胶在980℃基本上转变成-αAl2O3,1250℃可与瓷土中SiO2形成增量莫来石,使薄胎在烧成冷却过程中抗厚釉拉裂性能得到提高,胎釉热膨胀系数的失配使釉面形成开片,修饰美化青瓷。     

改变芯液组成控制氧化铝中空纤维膜微结构

采用相分离成型/烧结技术制备了多种结构的氧化铝(Al2O3)中空纤维膜(HFA)。考察了内凝固剂(芯液)的组成与氧化铝中空纤维膜结构之间的规律性。利用SEM观察HFA的微观结构。结果表明:改变内凝固剂的组成能够控制氧化铝中空纤维膜的微观结构。内凝固剂中水含量由100%降低到10%,HFA的指状孔分布位置和长度都发生了变化。当内凝固剂为纯水时,指状孔只分布在HFA的内侧;内凝固剂中水含量低至30%时,指状孔延长形成贯通整个横截面的通孔。     

复合电极对NO_2气敏特性的研究

为提高混合电势型NO_2传感器的气敏特性,在传感器敏感电极ZnFe_2O_4中加入一定量的钇稳定的氧化锆(YSZ)作为复合电极,研究了复合电极对NO_2的气敏特性。实验结果显示:复合电极对NO_2具有更优异的特性,提高了NO_2传感器的响应值和灵敏度。从传感器敏感机理分析,敏感电极中掺入YSZ使得三相反应界面增多是复合电极对NO_2具有优异特性的主要原因。     

高盐油藏复合交联剂弱凝胶体系成胶动态研究与应用

采用多羟甲基化合物与有机锆复配研制了新型复合有机交联剂DQ-1弱凝胶体系,综合运用图像分析系统、激光粒度仪、原子力显微镜、环境扫描电镜等方法研究了聚合物与DQ-1交联过程中颗粒粒径变化特征与微观结构形态。结果表明,成胶突变前(第一阶段),体系粘度和模量与相应的聚合物溶液无明显差别,但体系中的凝胶颗粒尺寸及颗粒数量随交联反应时间的延长而增大变粗。选取八面河油田面4块M4井开展了单井调驱试验,现场跟踪分析表明交联聚合物注入后,压力由注聚前的负压吸水上升至9.5MPa,转水驱后压力稳定在6-6.5MPa,吸水剖面变得相对均衡。对应油井单井日增油最高达4.9t/d,含水下降最大幅度达到10.2%,显示出较好的增油降水效果。     

2-氧-2,4,5,6,7,7a-六氢噻吩并[3,2-c]吡啶盐酸盐的制备

探索制备普拉格雷合成重要中间体2-氧-2,4,5,6,7,7a-六氢噻吩并[3,2-c]吡啶盐酸盐的较优工艺条件,确定5-三苯甲基-4,5,6,7-四氢噻吩并[3,2-c]吡啶的制备过程中,最佳反应配比为正丁基锂:硼酸三丁酯:30%双氧水=1.00∶1.30∶1.30(物质的量比),2-氧-2,,4,,5,6,7,7a-六氢噻吩并[3,2-c]吡啶盐酸盐制备过程中,用浓盐酸调溶液pH值至2～3,同温搅拌反应3h时,可直接得到产品。     

柠檬酸溶胶凝胶法制备铈锆固溶体的物性和氧化还原特性研究

以柠檬酸作为胶凝剂，采用溶胶凝胶法制备了一系列CeXZr1-XO2复合氧化物，分别经600℃和900℃焙烧，应用XRD检测，发现均已形成铈锆固溶体。并应用BET、XRD和TPR对其表相、晶相结构和氧化还原性质进行了分析，发现随着固溶体中铈比例的增加，固溶体稳定性降低；其储氧量测定显示铈锆固溶体用作三效催化剂助剂的最佳比例为1：1。经900℃高温焙烧以后，固溶体晶粒增大不明显，表明本方法适合制备高比表面积和高储氧量的铈锆固溶体；TPR还原峰温度降低，推测可能在于柠檬酸络合物完全分解所致。     

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