技术进步与能源消费的经济门槛效应研究北大核心CSSCI

为探究技术进步与能源消费的内在关系,本文采用面板门槛回归方法,结合1990—2012年我国省际面板数据构建面板门槛回归模型,以经济发展水平为门槛变量,实证研究了技术进步对能源消费的影响。研究显示:技术进步对能源消费的影响存在显著的"经济门槛效应",当经济发展水平高于门槛值时,虽然技术进步仍会促进能源的消耗,但其推动作用会逐步减弱,且东部地区技术进步对能源消费的促进作用要小于中西部地区。     

FDI和环境规制对技术创新的影响——基于中国省际面板数据分析

采用我国2000—2014年30个省份的面板数据构建面板门槛回归模型,从FDI及其与环境规制相结合的角度实证分析FDI对技术创新的影响。研究结果表明,FDI对技术创新存在显著的门槛效应,当经济发展水平和环境规制强度跨越相应门槛时,其能有效促进技术创新;环境规制会抑制FDI技术溢出效应,对技术创新产生间接影响;FDI技术溢出效应存在明显的地区性差异。政府应结合不同地区的现状,有针对性地提高地区经济发展水平,合理制定地区环境规制强度,以此显著提升地区技术创新能力。     

产业结构变动、地区市场化水平与能源消费

基于中国2000~2013年的省际面板数据,以第三产业与第二产业产值之比度量产业结构变动,在将地区市场化水平纳入分析框架的前提下,采用门槛回归分析方法,对产业结构变动与能源消费之间的关系进行实证考察.结果表明,产业结构变动对能源消费存在显著的基于地区市场化水平的"双门槛效应",即产业结构变动与能源消费之间存在显著的非线性关系,随着地区市场化水平的提高,产业结构变动对降低能源消费的作用越来越大.     

技术进步回弹效应的形成路径分析

基于中国30个省市自治区的面板数据,采用Malmquist指数分解法和两步GMM回归方法,从回弹效应视角分析技术进步影响能源消费的直接和间接效应,并将回弹效应分解为能源价格效应、城市化效应、能源结构效应和产权结构效应。研究发现：广义技术进步对能源消费的影响呈现倒U型关系,狭义技术进步对能源消费的影响呈现正U型关系。技术进步虽然会通过促进能源低碳化减少能源消费,但也会通过加速城市化扩张和加剧市场竞争增加能源需求,产生回弹效应。相比之下,能源价格由于受到政府宏观调控,对回弹效应的影响不显著。     

技术进步回弹效应的形成路径分析——以建筑业为例

基于30个省市自治区的面板数据,采用Malmquist指数分解法和两步GMM回归方法,从回弹效应视角分析技术进步影响能源消费的直接和间接效应,并将回弹效应分解为能源价格效应、城市化效应、能源结构效应和产权结构效应。研究发现,广义技术进步对能源消费的影响呈现倒U型关系,狭义技术进步对能源消费的影响呈现正U型关系。技术进步虽然会通过促进能源低碳化减少能源消费,但也会通过加速城市化扩张和加剧市场竞争增加能源需求,产生回弹效应。相比之下,能源价格由于受到政府宏观调控,对回弹效应的影响不显著。     

金融发展与海归回流的知识溢出效应关系实证

基于中国1995-2013年省级面板数据,本文利用门槛面板模型检验了金融发展水平与海归回流知识溢出效应的关系。结果发现:海归回流知识溢出与技术进步的联系显著依赖于各省市金融发展水平,只有当金融发展水平越过一定门槛值之后,海归回流才会对回流国产生显著的技术进步正效应;当金融发展水平跨越第二个门槛值时,东、中、西部地区的海归回流对技术进步的影响效应均为正,且东部地区的海归回流对东部地区技术进步的影响存在明显的"加速、跃升"正效应,但西部地区海归回流对该区的技术进步效应产生的促进作用较为有限。本文认为受金融发展水平门槛限制,我国金融发展水平相对低下的省份还不能为释放更多的海归知识溢出效应提供必要的金融环境支持。     

贸易自由化对研发技术进步影响的异质门槛效应北大核心CSSCI

基于2004—2012年中国工业行业31个细分行业的面板数据,采用门槛回归技术实证研究了贸易自由化对研发技术进步影响的异质门槛效应。研究表明:(1)贸易自由化与研发技术进步呈倒"N"型的非线性关系,即随着贸易自由化水平由低变高,其对研发技术进步会产生先降低后提高再降低的影响规律;(2)贸易自由化的研发技术进步效应还取决于市场化水平、外商直接投资等影响,在环境规制、外商直接投资及行业利润门槛条件下贸易自由化对研发技术进步的影响总体呈负向效应,而在市场化水平门槛条件下呈倒"U"型特征,在企业规模门槛条件下呈"U"型特征;(3)不同门槛条件下贸易自由化对研发技术进步的门槛效应存在明显的行业异质性特征,其中具有负向影响的行业分布较为集中。     

贸易自由化对研发技术进步影响的异质门槛效应

基于2004—2012年中国工业行业31个细分行业的面板数据,采用门槛回归技术实证研究了贸易自由化对研发技术进步影响的异质门槛效应。研究表明:(1)贸易自由化与研发技术进步呈倒"N"型的非线性关系,即随着贸易自由化水平由低变高,其对研发技术进步会产生先降低后提高再降低的影响规律;(2)贸易自由化的研发技术进步效应还取决于市场化水平、外商直接投资等影响,在环境规制、外商直接投资及行业利润门槛条件下贸易自由化对研发技术进步的影响总体呈负向效应,而在市场化水平门槛条件下呈倒"U"型特征,在企业规模门槛条件下呈"U"型特征;(3)不同门槛条件下贸易自由化对研发技术进步的门槛效应存在明显的行业异质性特征,其中具有负向影响的行业分布较为集中。     

技术获取型FDI溢出与信息化发展水平门槛效应

基于中国2003-2010年省域面板数据,以信息化发展指数(IDI)作为门槛变量,构建面板数据门槛回归模型,实证检验技术获取型FDI溢出对技术进步的作用效果。结果表明:人力资本、研发投入是长期推动我国技术进步的重要因素。区域信息化发展不均衡,东部地区门槛值最高,中部地区门槛值最低且呈现集中趋势,西部地区门槛值跨度最大。随着信息化水平的提升,全国与西部地区的技术获取型FDI溢出对技术进步的促进作用呈现出"两头高、中间低"且明显增强的趋势,东部地区呈现稳步增强的促进趋势且贡献率最高,中部地区的抑制作用正逐渐减弱。     

中国能源消费强度的区域差异及影响因素分析

能源消费强度反映国民经济发展中对能源的利用效率,其变动方向及影响因素受到学术界广泛关注。但研究中大多以我国总体能源消费强度的变化为对象,对地域差异关注不足。本文选取多项指标,构建能源消费规模份额指数、能耗强度指数、增长速度指数、综合消费指数,从不同角度刻画中国能源消费的区域差异。在此基础上,利用回归分析法,定量研究了地区能源消费强度的影响因素。结果表明,我国地区间能源消费强度的差异与地区总体经济发展水平、地区工业化程度、地区经济重型化程度存在直接关系,尤其是地区经济重型化程度的提高将会显著增加地区经济能耗强度。现阶段,控制高耗能重化工业的重复建设与盲目投资。对于减小能源消耗强度具有重要的意义。同时,经济发展水平和经济结构的地域差异性,要求我国能源战略的推进与实施必须制定相应的地区政策才能确保国家宏观战略的顺利实施。     

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.     

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.     

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.     

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.     

To serve and promote science development via innovation

CAS should stick to the principle of rendering service to, and giving impetus for, the development of China＇s science enterprise by making S＆T innovations, said CAS President LU Yongxiang. The CAS president made the remarks in a recent talk to communicate the gist of the winter session of the Party＇s Leading-member Group at CAS, which was held from 7 to 11 January in Beijing.     

Tracing the origin and early radiation of birds——Paleornithologist ZHOU Zhonghe

With great care, Dr. ZHOU Zhonghe takes out a package wrapped by cotton tissue from a drawer and says: "This is the gem of our collections: the fossil of a bird that lived 125 million years ago!" Then, pointing at a tiny mound, he explains: "Look, this is the claw and that is the head. It was in the egg shell and ready to hatch ... The species fell into a family of waterside inhabitants."     

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.     

The Information Environment and Universal Service

This essay focuses on universal service and the Internet as means to support social and political participation. The emphasis on access to telecommunications systems in conventional approaches to universal service is contrasted with access to content. A model of the information environment is described that accounts for the roles of content and conduit, both of which are necessary conditions to achieve true access. A method is outlined for employing information indicators to observe or measure the information environment.     

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.