隆昌板鸭制作工艺

隆昌县的板鸭以制工精细,集色、香、味、美一体,闻名全省。它的特点是:鸭体平整光洁,干燥无皱纹,紫里透红,香油四溢,味美可口,是隆昌著名的腌腊制品。入冬后板鸭长期供不应求,大量销往成都、重庆及边沿     

PET/CT机房及周围辐射环境监测与评价

目的:了解PET/CT项目运行时对周围环境产生的辐射影响,评估辐射工作人员的受照剂量水平,为PET/CT项目的辐射防护与安全管理提供科学依据.方法:以某一大型医院的PET/CT项目为例,根据相关标准与技术规范对机房及周围开展辐射环境监测,使用监测仪器测定场所的X-γ辐射剂量率与表面污染水平,并通过监测数据估算工作人员的受照剂量.结果:该PET/CT机房周围部分测点的放射性水平偏高,对PET/CT工作人员产生最大年有效剂量为1.36 mSv.结论:PET/CT辐射工作人员所接受年剂量均低于(GB18871-2002)《电离辐射防护与辐射源安全基本标准》附录B中的限值要求,工作场所的设备和地面的表面污染监测结果低于(GB18871-2002)《电离辐射防护与辐射源安全基本标准》附录B中的控制水平.应继续加强PET/CT工作场所的辐射安全管理,增加工作人员的防护意识,严格按照流程操作,以减少额外的附加照射,避免辐射事故的产生.     

辐射的危害与健康防护

人类自古至今生活在一个充满辐射的自然环境中,辐射与阳光、空气、水都是人类生命的一部分.人体接受辐射的途径以及在正常情况下会接受多少剂量?人体接受多少剂量才会对健康产生影响?我们应该深入了解什么是辐射,能利用它的优点,而避开它的危险性,不再只是莫名的害怕.     

~(60)Coγ射线对菊花组培苗及幼苗生长的影响

通过辐射诱变与组织培养相结合,利用不同剂量的<'60>Coγ射线辐射菊花组培苗,确定菊花组培苗的适宜辐射剂量,并对辐射剂量对组培苗及幼苗生长的影响进行了阐述.     

你知道吗?

榴莲为何闻着臭?德国科学家从泰国榴莲中提取出有气味的物质,用质谱仪和气相色谱仪分析后,确定其中的50种化合物和榴莲独特的气味有关。分析结果表明:榴莲的强烈气味绝不是只来自于一种化合物,而是多种化合物的混合产物。研究团队认真辨识出了这里每种化合物的气味。它们的气味可谓千差万别,有水果味、臭鼬味、金属味、橡胶味、烧焦味、烤洋葱味、大蒜味、奶酪味、洋葱味     

基础科学

Sm填充方钴矿化合物的合成及热电性能The Synthesis and Thermoelectric Properties of Samarium-filled Skutterudite SmyFexCo4-xSb12采用高温熔融法结合固相反应法合成了一系列单相的SmyFexCo4-xSb12化合物,并探索了Sm填充分数对其热电性能的影响规律.结果表明,随着Sm填充分数的增加,载流子浓度及电导率降低;塞贝克系数随温度的升高和Sm填充分数的增加而增大;     

深源地震折合能量的标度性及其与深度的关系

利用1987年1月至2001年12月的哈佛CMT目录和美国NEIC地震辐射能量目录,研究了全球范围内震源深度大于70km的地震的辐射能量与地震矩之比(或称折合能量)随地震矩的变化及其与震源深度之间的关系.结果表明对震源深度为70～400km的地震,折合能量随地震矩的增加而降低;对于深度大于400km的地震,折合能量随地震矩的增加而增加.这一特征与浅源地震似乎很不相同.     

我国学者在仿生催化和有机小分子催化研究领域获重要突破

正在国家自然科学基金项目(项目资助号:21672148、21472125)等资助下,上海师范大学资源化学教育部重点实验室赵宝国课题组受L-苏氨酸醛缩酶(L-threonine aldolase)催化甘氨酸与醛之间的羟醛缩合(aldol reaction)的启发,提出和实现了以羰基化合物(醛或酮)为催化剂,催化伯胺a-位官能团化,实现由简单易得     

几种醛胺二糖的合成及其生化研究

目的合成几种醛胺二糖化合物,通过对其结构和生化性能的研究,明确了不同的醛胺二糖结构对其生物活性的作用机制。方法:采用化学合成的方法,以戊糖缩二胺(即化合物[1])为原料,合成一系列有机化合物[2-8]。结果:利用H.NMR对这些化合物进行表征,确认其结构。通过对革兰氏细菌的抗菌实验进行生物化学方面的研究。结论:实验结果表明这些醛胺二糖化合物均具有较高的抗菌活性,尤其是化合物[2-4]。     

最新科教新闻

研究显示吸烟可在短时间内对基因造成伤害美国明尼苏达大学的研究小组说,已有证据表明香烟中一类有害化合物多环芳烃具有致癌性,而他们的研究重点关注多环芳烃对人体脱氧核糖核酸(DNA)造成伤害的具体途径。多环芳烃是指含有一个苯环以上的芳香化合物,是煤、石油、木材、烟草等有机物不完全燃烧时产生的挥发性产物。志愿者吸入香烟烟雾后,他们血液内的"菲"迅速转化成一种可对DNA造成伤害的有毒物质。这种     

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