食物综合生产能力地区间差异的定量评估——以河北省为例

我国历来较多关注食物中的粮食,而忽视畜产品、水产品等其它食物类型,使得在分析地区食物生产能力时出现较大的偏差。区域间的土地利用统筹问题得到前所未有的重视,加强对地区间食物生产能力差异研究很有必要。本文从各类食物的折算入手,以县为研究单元,从土地生产食物的现实能力、持续能力和潜力3个角度构建了一套完整的计算方法,旨在对各县的食物综合生产能力进行定量计算,其中现实生产能力、持续生产能力、产出潜力分别考虑的要素有单位食物生产用地的生产能力和食物生产用地变化指数,生产基础稳定性、生产能力稳定性和投入-产出能力,单位食物用地的食物生产潜力和食物用地的增长潜力。在此基础上,首先统一折算各类型食物为等谷量单位来计算各指标的具体值,并利用标准化方法将各指标值转换为可进行统一运算的标准值,然后对各指标赋予权重并计算而求得食物综合生产能力的评价值,最后根据其大小而划分为极高、高、中、低和极低等5个级别,以便于对结果进行分析。本文以河北省为例,对该方法进行了实证分析,结果显示,研究结论能得到较合理的解释,说明该方法具有推广和应用的可行性。     

国家复杂产品生产能力——一个基于IPO范式的思考

从经济学"投入-生产-产出"(IPO)范式的过程视角,探讨以创新为核心思想的复杂产品生产能力(包括技术能力和管理能力),并构建从资源投入、组织范式到复杂产品生产,再到生产绩效产出的全过程能力分析框架。分析表明,国家复杂产品生产能力是一个系统,需要用系统思维方式构建更为宏大的理论;以及,更要体现政策研究的规范性、描述性和工具性的统一。     

耕地占补平衡等级折算方法的比较研究——以陕西省周至县为例

耕地占补平衡等级折算系数的计算与占补平衡的内涵有关,耕地占补平衡的根本目的是保证一定时间内区域耕地生产能力和粮食产量不降低,也就是说,耕地占补平衡应以现实产量为平衡标准.土地利用等指数更接近现实产量,标准粮产量和利用质量等指数两者同样反映了不同利用方式下的土地粮食生产能力,因此通过标准粮产量和利用质量等指数建立函数关系,可以很好地反映不同质量等别耕地粮食生产能力的差异.本文使用陕西省周至县农用地分等成果,分别利用等别自然质量等指数、等别利用等指数以及利用等指数-标准粮产量确定农用地占补平衡中被占用耕地和补充耕地的数量关系,通过理论分析以及对3种结果的综合分析,认为被占用耕地和补充耕地的数量关系可利用等指数-标准粮产量来确定.     

基于集约利用的农村居民点用地标准探讨——以湖北省孝感市孝南区为例

农村居民点用地集约利用是当前新农村建设中的热点问题.本文假定农村居民点用地像一个工厂或是农场,农村居民点用地是均质分布的.在这里,农村居民点用地是与劳动力、资本和技术进步相互独立的生产要素,都被转化成产出.以C-D生产函数为基础建立C-D生产函数修正模型,运用该模型探讨近郊区和远郊区(农村腹地)农村居民点用地集约利用的最佳人均投入量估算,并以湖北孝感市孝南区为例进行实证,估算了在现有经济与技术条件下,其近郊区代表--新铺镇的最佳人均农村居民点用地量,为86m2,这个标准远远低于现状水平,由此可见.新铺镇农村居民点用地仍有较大潜力可挖.从调查获取信息得知.基于农户意愿的人均居民点用地的可接受的最低标准为50m2,从充分尊重农民意愿的角度上看,新铺镇的农村居民点用地集约利用的潜力释放工作也有较大的可行性.     

复杂产品生产能力研究：一个基于IPO范式的思考

复杂产品是“中国制造2025”的重要组成部分之一,已日益成为现代经济的“技术资产骨架”和国家经济实力的象征。鉴于目前尚无成果专门针对复杂产品生产能力展开研究,本文从经济学“投入-生产-产出”（IPO）范式的过程视角,探讨了以创新为核心思想的复杂产品生产能力（包括技术能力和管理能力）,并构建了从资源投入、组织范式到复杂产品生产,再到生产绩效产出的全过程能力分析框架。分析表明,相关分阶段研究理论基础已经比较清晰,但国家复杂产品生产能力是一个系统,需要用系统思维方式构建更为宏大的理论,本文迈出了起始的一步;以及,今后对国家复杂产品生产能力的研究,更要体现政策研究的规范性、描述性和工具性的统一。     

近10年重庆土地利用平衡及未来情景分析

土地利用平衡问题的产生大多由经济发展的驱动所引起,而用地间的相互消、长形成最终的土地利用格局。本文采用历史统计、资料文献及未来经济发展设想等数据,运用数理统计方法,分析了近10年重庆土地利用的平衡格局及未来情景,结果表明：①重庆直辖10年间,主要土地利用格局体现为建设用地的快速增加和耕地资源的持续减少,且建设用地扩张带来的二、三产业产值和拉动固定资产的投资率较低。期间,土地利用平衡着重考虑盘活存量,少占耕地的集约＂增效＂途经,以及整理开源增加耕地或其它农用地的＂减压＂举措;②对比重庆未来土地需求与供给情景,2007年-2020年间,满足经济跨越式发展的适应性建设用地需求为16.87万hm2,而总共后备资源的适应性现实潜力,折算前也才仅有12.61万hm2,供需前缺口高达4.25万hm2,为此,必须探索＂节流＂与＂开源＂的新路子;③借助新的经济发展环境和政策导向,做好耕地流转集约＂开源＂置换建设占用耕地,跨县域甚至跨区域的农村宅基地置换城镇住房,耕作层熟土剥离转换建设占用的支撑视角,可平衡重庆未来的土地利用情景,开辟增加耕地新渠道,统一城乡建设用地配置,确保建设占用和农业生产的用地需求     

耕地占补平衡等级折算方法的比较研究

耕地占补平衡等级折算系数的计算与占补平衡的内涵有关,耕地占补平衡的根本目的是保证一定时间内区域耕地生产能力和粮食产量不降低,也就是说,耕地占补平衡应以现实产量为平衡标准。土地利用等指数更接近现实产量,标准粮产量和利用质量等指数两者同样反映了不同利用方式下的土地粮食生产能力,因此通过标准粮产量和利用质量等指数建立函数关系,可以很好地反映不同质量等别耕地粮食生产能力的差异。本文使用陕西省周至县农用地分等成果,分别利用等别自然质量等指数、等别利用等指数以及利用等指数-标准粮产量确定农用地占补平衡中被占用耕地和补充耕地的数量关系,通过理论分析以及对3种结果的综合分析,认为被占用耕地和补充耕地的数量关系可利用等指数-标准粮产量来确定。     

我国农业科技综合能力的系统分析

农业科技综合能力是农业综合生产能力大系统中的子系统之一，而农业综合生产能力又是综合国力的有机组成部分，是社会生产力在农业部门的具体体现。农业科技综合能力是由多要素综合投入形成的，并通过多种产出所体现的“科技产品”的综合生产能力。在分析其投入产出关系的基础上，筛选出适合我国国情的三列指标系，构建成评价指标体系，并应用综合指数法对数据进行了无量纲化处理，以增强其可比性。通过对投入系、中间产出系和最终产出系之间比例的分析，对全国划分为四种类型，以便按华北、华东、中南、西南等各区农业科技发展的特点进行分类指导。最后还剖析农业科技综合能力与农业综合生产能力之间的关系，雄辩地证明了科学技术在增强农业综合生产能力上起着重大的促进作用。     

基于集约利用的农村居民点用地标准探讨

农村居民点用地集约利用是当前新农村建设中的热点问题。本文假定农村居民点用地像一个工厂或是农场,农村居民点用地是均质分布的。在这里,农村居民点用地是与劳动力、资本和技术进步相互独立的生产要素,都被转化成产出。以C—D生产函数为基础建立C—D生产函数修正模型,运用该模型探讨近郊区和远郊区（农村腹地）农村居民点用地集约利用的最佳人均投入量估算,并以湖北孝感市孝南区为例进行实证,估算了在现有经济与技术条件下,其近郊区代表——新铺镇的最佳人均农村居民点用地量,为86m^2,这个标准远远低于现状水平,由此可见,新铺镇农村居民点用地仍有较大潜力可挖。从调查获取信息得知,基于农户意愿的人均居民点用地的可接受的最低标准为50m^2,从充分尊重农民意愿的角度上看,新铺镇的农村居民点用地集约利用的潜力释放工作也有较大的可行性。     

建设用地集约利用潜力研究——以广西宾州镇为例

采用分析与综合等方法,总结建设用地利用潜力的内涵,创建基于社会投资能力的农村居民点整理潜力模型,结合人均指标法和提高容积率法,提出测算建设用地集约利用潜力的系统方法,并以广西宾阳县宾州镇为例进行实证研究。     

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.     

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.     

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