逆向技术溢出、自主技术创新与中国碳排放强度

本文选取2005-2017年中国省级面板数据,对各省逆向技术溢出强度与碳排放强度进行了测度,运用空间杜宾模型,并结合中介效应模型实证检验了中国对外直接投资(OFDI)过程中产生的逆向技术溢出效应对碳排放强度的影响机制。检验结果表明：逆向技术溢出会显著抑制本地碳排放强度,也会通过空间效应抑制周边地区的碳强度,且自主技术创新在其中充当中介变量,本地区母公司能对周边地区的绿色技术发展产生杠杆效应和正向的空间溢出;逆向技术溢出对本地碳排放强度的抑制作用受到东西部区位和经济发展水平的差异性影响;当投资东道国为“一带一路”部分国家时,逆向技术溢出依然能够抑制中国碳排放强度,但自主技术创新不再发挥中介效应;本文为推动中国经济低碳发展,早日实现碳中和任务提供了理论借鉴。     

中国住房价格波动的空间溢出效应研究

研究2003～2010年中国各省区住房价格的空间分布格局与特征,并通过选择适当的空间面板计量模型,实证研究各省区宏观因素对住房价格的影响,以及相邻地区的住房价格变动对本地区住房价格的空间溢出效应。研究结果表明:中国省域间的住房价格在空间分布上存在显著的正相关关系;空间溢出效应是地区住房价格波动不可忽视的重要影响因素。     

数字经济发展对农业碳排放的影响及其时空效应

在中国“双碳”目标背景下,关注数字经济减碳效应在农业领域的影响。利用2010—2020年中国区域面板数据,引入社会化服务角度,通过回归分析模型实证检验区域数字经济发展对农业碳排放的影响机制,并从时间和空间两维度刻画数字经济发展对农业碳排放的动态效应和溢出效应,以期为依靠数字化路径实现农业低碳转型和“双碳”目标、推动农业绿色发展提供量化支撑和理论依据。结果发现：区域数字经济发展对农业碳排放强度有显著抑制作用,且通过提升农业社会化服务水平这一路径会间接影响该抑制作用;区域数字经济发展对农业碳排放强度影响确实存在滞后效应,对将来的农业碳排放强度仍存在较强抑制效果;数字经济发展具有显著空间溢出效应,即本地区数字经济发展对其他省份农业碳排放强度也存在显著抑制作用;数字经济发展降低农业碳排放强度的作用由经济发展落后地区向经济发达地区增强,呈现明显的空间异质性特征。基于此,提出要提升相关农业社会化服务数字化水平、充分利用数字技术和数据要素的时间红利等建议。     

自然资源开发、空间溢出与经济增长——基于空间面板回归偏微分效应分解方法的实证

基于资源诅咒假说,运用空间回归偏微分方法,利用2007～ 2014年中国省际面板数据实证考察了自然资源开发对经济增长的空间溢出效应.主要发现有:中国省域经济增长在不同的空间关联模式下均有显著的空间依赖性和空间异质性;自然资源开发对经济增长的地区内溢出效应、地区间溢出效应和总的空间溢出效应均显著为负,资源诅咒效应明显存在.     

技术进步、结构调整与碳排放强度——基于中国省区层面空间面板数据模型的实证

本文构建了技术进步和结构调整影响碳排放强度的空间溢出效应模型,利用2002—2012年中国30个省区的空间面板数据进行实证分析,揭示出技术进步和结构调整对碳减排的驱动机制,以期为政府相关部门科学制定减排规划提供决策支持和参考.主要结论如下： 技术进步和结构调整的直接效应和总效应之间存在一定的差距,意味着某个省区的碳排放强度不仅受到邻近省区碳排放强度的冲击,还受到各省区之间结构性差异的冲击,这种结构性差异体现在各省区技术进步、产业结构、能源结构以及其他未纳入模型中的空间影响因素之间存在的差异.如果不考虑技术进步和结构调整对碳排放强度的空间溢出效应,对两者碳减排作用的估计会有偏误.     

创新驱动对产业结构升级的溢出效应及其衰减边界

中国经济正处于由高速增长阶段向高质量发展阶段转变的历史时期,创新驱动是推动中国产业结构升级以及做实、做强、做优实体经济的重要动力。利用中国30个省份2005—2015年面板数据,构建地理距离、经济距离空间权重矩阵,并运用空间杜宾模型实证分析了创新驱动对产业结构升级的空间溢出效应及其衰减边界。实证结果表明,创新驱动不仅提升了本地区产业结构升级,还通过空间溢出效应显著地促进了周边地区尤其是地理相近省份产业结构升级;创新驱动对产业结构升级的空间溢出效应还存在显著的空间衰减特征,具体表现为,省份间地理距离在950公里以内为空间溢出效应的显著区域,1050公里为空间溢出的"半衰"距离。     

技术进步对中国家庭部门生活能源消费的动态空间溢出效应

基于2006～2016年中国30个省份的面板数据,首先考察了家庭部门生活能源消费水平的空间相关性,再利用动态空间面板数据模型实证分析了技术进步对生活能源消费长期和短期的动态空间溢出效应。研究结果表明:中国省际生活能源消费存在显著的空间相关性;虽然技术进步和生活能源消费之间不存在环境库兹涅茨曲线关系,但是技术进步存在一定的回弹效应,且技术进步对经济地理相邻省份生活能源消费的空间溢出效应具有长期特性;居民生活能源消费具有显著的跨地区动态消费惯性。     

科技人才集聚、空间溢出与区域技术创新 ——基于空间杜宾模型的偏微分方法

研究旨在探析科技人才集聚能否产生空间溢出效应,进而促进区域技术创新。在对其影响机制进行理论分析的基础上,利用中国2000—2015年的省级面板数据,采用三种空间权重形式,并通过构建多样化的空间计量分析模型进行了实证研究。研究发现:区域技术创新具有显著的空间异质性和空间依赖性;在三种不同的空间权重形式下,科技人才集聚对技术创新均具有显著的空间溢出效应,区域内和区域间的溢出效应均为正。其中,在经济空间权重形式下,区域内与区域间溢出效应最大,在邻接空间权重形式下,区域内与区域间溢出效应最小。     

数字经济对中国城市工业碳生产率的赋能效应

数字经济作为中国工业绿色低碳转型的重要引擎,能否进一步促进城市工业实现经济和环境双重效益亟待研究。本文以2011—2018年中国284个地级市面板数据为样本,利用非期望超效率EBM模型、探索性空间数据分析法和空间计量模型等方法,对城市工业碳生产率进行测算并分析其时空特征,解析数字经济对城市工业碳生产率的赋能效应。研究结果如下：①中国城市工业碳生产率总体呈波动性增长趋势,空间正相关性和集聚现象十分显著,高高集聚与低低集聚现象并存,空间非均衡现象仍然存在。②数字经济可以赋能城市工业碳生产率,且存在明显的空间溢出效应,即数字经济不仅有利于提升本地工业碳生产率,也会通过溢出效应对邻近城市工业碳生产率释放促增红利,该结论经过一系列稳健性检验和内生性检验后依然成立。③数字经济对城市工业碳生产率的赋能效应主要通过产业结构优化来实现,现阶段绿色技术创新尚未发挥机制作用。④数字经济对城市工业碳生产率的赋能效应因城市区位与创新环境差异而存在空间异质性,如东部地区数字经济对周边城市工业碳生产率具有辐射带动效应,而高人才集聚区则表现为负向溢出效应。未来应重视数字经济的空间溢出效应,破除城市“各自为战”的治理方式,利用数字化技术构建城际绿色协同治理体系,突破地理边界以形成区域工业减碳合力。     

知识溢出对中国省域知识生产影响的实证研究

本文通过探索性空间数据分析,发现中国省域知识产出和投入要素具有显著的空间集聚特征。在综合考虑知识产出和投入空间溢出效应的基础上,构建了改进的知识生产空间面板数据模型。通过LM和Wald检验确定空间Durbin模型能够更好地描述中国省域知识生产活动。通过研究发现,知识产出具有显著的正向空间溢出效应;R&D活动人员具有显著的负向空间溢出效应;R&D经费支出和FDI具有正向空间溢出效应,但并不十分显著。根据研究结果,提出了提高省域知识生产效率的政策建议。     

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.     

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.     

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.     

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.