低廉的费用、简捷的改造,让你实现一直向往的低温高效中药提取工艺

针对目前中药提取温度偏高,有效活性成分容易遭受破坏,大量无效物质被带入提取液给后续提纯工艺造成困难的情况,“用于中药提取的减压提取装置”的开发成功,解决了中药提取工艺长期存在的     

西藏大蒜干粉中大蒜素的提取与测定

本实验对西藏大蒜晒制干粉提取大蒜素进行了三种常规提取和超临界提取的比较实验,并对未经提取的大蒜干粉、提取物、超临界CO2提取剩余干粉进行了大蒜素的含量检测.结果表明:(1)大蒜晒制干粉中每克干粉含活性成分(含硫化合物)0.0341g,超临界CO2萃取后的大蒜干粉中每克干粉含大蒜素为0.77g,超临界CO2萃取的效率理论值为77.6%,(2)超临界CO2萃取实验中实际得到的大蒜素远低于理论值,只有0.0012g每克大蒜干粉,其原因可能是超临界系统容积大损耗大;(3)通过水煮-有机溶剂萃取法、有机溶剂浸泡提取法以及乙醇浸泡提取法三个实验的比较,表明,无论在大蒜油得率、大蒜素纯度以及大蒜素含量方面,水煮-有机溶剂萃取法均比其他两种方法有优势,乙醇浸泡提取法大蒜粗提物多,杂质含量也很最高.     

正交试验优选"前愈"无糖颗粒黄柏的最佳提取工艺

目的:以小檗碱为定量指标,研究“前愈”无糖颗粒的黄柏提取工艺。方法:采用正交试验法进行优选,高效液相色谱法测定小檗碱含量。结果:乙醇浓度对提取有显著性影响,其它对小檗碱的提取也有影响,优选出最佳提取工艺为A3B3C2。结论:药材1O倍量85％乙醇回流提取,两次提取300min为最佳工艺。     

西藏高原猪流行性“混合症”的危害调查（一）

１９９０年以来，我区养猪业发展迅速，主要是藏猪、混血猪和引进的长白品种猪，但是疫流流行猖獗，危害严重。尤其是１９９２－１９９５年间发展死亡严重，发病率达到２５％左右，死亡数量占病数的９５％以上，有些养猪场全部死亡。经过专家临床观察治疗、病理解剖后初步认为该病是由两种以病毒引起的一种综合症，故称之为猪流行性“混合症”。据我们调查全区年均死亡于本病的猪约１．５万头，直接损失年约２０００万元人民币，给国     

农田里长出来的汽车

日本丰田公司用植物淀粉合成乳酸，再用来加工 塑料。他们已培育出淀粉率高出正常品种３０％的红薯， 第一步准备在印尼的苏门答腊播种１万公顷，在这片 农田的中央建一工厂，把周围收获的红薯加工成塑料。 这种塑料制成的部件废弃后埋在土里可分解成水和二 氧化碳，自行降解。由于这种方式减少了工业垃圾，不 仅可用于汽车制造，在家用电器上也可以广泛应用。 戴姆勒—克莱斯勒公司在农田里生产“奔驰”的计 划也在推进中，在主打产品的Ｃ级车中，采用产于南非 的天然麻纤维做成内装修骨架，小型车的外装修也可 以使用。有关专家认为，来自…     

基于MODIS数据的三江平原土地覆被分类

本文以三江平原为研究区域,以250m空间分辨率MODIS/NDVI时间序列数据集为数据源,通过基于Savizkky-Golay滤波重构高质量的NDVI时间序列曲线,并对滤波后的NDVI数据集做主成分变换,通过分析前6个主成分的各时间点的因子载荷曲线,提取地表不同植被类型物候信息的总体差异,采用“分层非监督分类法”,由简到繁,由主类到亚类,逐级分解,最终得到三江平原土地覆盖类型。分类结果表明：旱地、水田、草地、湿地、落叶阔叶林及水体的分类精度均在88%以上。而由于混合像元问题,针阔混交林与居民用地的分类精度较低。对研究结果定性评价发现,基于MODIS/NDVI数据集的土地覆盖分类结果与三江平原实际土地覆盖的空间分布格局基本一致,与MODIS土地覆盖产品相比,在类型识别和空间位置精度方面有本质性的提高,尤其是林地类别和居民用地的识别。本文的分类结果体现了三江平原土地覆被分布细节信息,说明本研究的数据处理技术和分类方法在三江平原土地覆盖制图中具可行性。     

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.     

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.     

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     

Chinese Scientists Use Earth Observation Technologies to Study and Protect Wild Camels

<正>Chinese scientists plan to apply Earth Observation technologies to protect the critically endangered wild camels(Camelus ferus).With the help of remote sensing,satellite positioning,geographical information system and wireless sensors networks,they will be able to access the distribution and population of the wild camels and protect their habitats.The project will be carried out by the International Research Center for Wild Camel Conservation,which was jointly established earlier this year by the Institute of Remote Sensing and Digital Earth(RADI)of the Chinese     

More than Skin Deep – Understand Skin Biology by Means of Dermatogenomics

<正>The Paul Gerson Unna Research Group on Dermatogenomics was founded in October 2012 at the Partner Institute for Computational Biology.The ultimate goal of the group is to understand the biology of skin and skin appendages.