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1.
[目的/意义]探究个体决策的有限理性对于网络舆情传播的影响,从网民心理的微观层面来构建网络舆情传播模型。[方法/过程]以病毒动力学理论为基础,引入考虑个体心理参照点的前景理论,构建网络舆情传播模型,并求解模型的基本再生数,进行数值仿真对基本再生数的计算结果进行验证分析。[结果/结论]网络舆情传播扩散规模,与微博用户接触到的接触消极微博内容的比例β、相关舆情事件评论或转发中传达负面情绪的评论内容占比p、被感染网民的自愈率q等有密切关系。 相似文献
2.
基于供应链核心企业间权力的差异,通过构建低碳制造商主导（M1S）、传统制造商主导（M2S）、双方均势（MVN）等模式下的博弈模型,研究不同模式下供应链碳减排水平和利润的变化,最后对比分析了不同模式下双向技术溢出和碳转移对供应链碳减排水平的影响。研究发现：（1）碳转移和水平技术溢出效应均降低供应链碳减排水平;垂直技术溢出效应提升供应链碳减排水平,但其提升效果取决于碳转移量的多少。（2）受权力结构变动影响,低碳制造商势力的增强能够提高供应链碳减排水平,但会对碳转移量更加敏感;传统制造商势力的增强会降低垂直技术溢出效应的减排激励作用,同时促使碳转移消极影响提前到来。（3）碳交易价格上涨会加剧碳转移对供应链碳减排水平的消极影响,其强度与权力结构及消费者低碳偏好呈现出五种变动趋势。（4）制造商是否在供应链中占据主导地位与碳减排水平直接挂钩,与其可获得的最高收益之间并无必然联系。 相似文献
3.
透过社会-技术范式视角,低碳转型是一个打破高碳锁定、从高碳的社会-技术范式向低碳的社会-技术范式转型的过程。这一过程是多要素参与、复杂、动态和长周期的。从多层视角来看,转型过程离不开三个层面的相互作用：利基（niche）培育了破坏式低碳创新,使之成为推动范式更迭的内在动量;地景（landscape）对高碳社会-技术范式施加压力,为低碳创新的成长提供了机会之窗;最终原先主导的高碳社会-技术范式瓦解,高碳“锁定”被打破,新的动态稳定的低碳社会-技术范式形成。中国汽车低碳交通转型的案例,说明了社会-技术范式及多层视角对上述复杂和不确定性过程进行认知和分析时的有效性。相关行动者特别是政策制定者在引导低碳转型时,需要改变相对线性的技术替代认识论立场及相应的政策手段,采用范式更替的认识论立场和转型策略。 相似文献
4.
《中国科技论坛》2019,(7)
本文为了探究低碳情境下制造业企业技术采纳的微观决策动力和由此涌现的宏观扩散现象,构建了环境规制下制造业企业低碳技术扩散博弈模型,以小世界网络为载体,设计演化规则,通过数值仿真探索各要素对低碳技术扩散的驱动效应。研究发现,在不考虑环境规制情况下低碳技术扩散的深度取决于企业低碳竞争性收益增量与投入量的差值;在此基础上,上调碳税税率、加大碳补贴力度和提高碳排放权交易价格均对低碳技术在网络中的扩散有正向作用,当规制实施力度达到一定阈值可实现低碳技术全网扩散;小规模企业网络的扩散深度对碳税税率的变化较敏感,扩散速度对规制强度敏感性较弱;大规模企业网络的扩散深度对碳补贴力度和碳排放权交易价格的变化较敏感,扩散速度对规制强度敏感性也相对较强。 相似文献
5.
陈坤 《科学学与科学技术管理》2011,32(4)
将系统动力学引入产业技术路线图制定过程中,实施动态仿真,在界定系统边界的基础上,构建产业技术创新系统动力学模型,并给出主要系统动力学方程,旨在利用系统动力学定量、动态预测的特点对产业技术路线图的制定和更新提供参考和支持. 相似文献
6.
基于创新扩散理论,利用演化博弈方法建立市场机制和政府规制下低碳技术创新扩散的链式过程中创新提供者与潜在采纳者间的演化博弈模型,探讨二者间相互作用对宏观扩散的影响机制。理论研究和数值仿真结果表明,市场机制下将低碳技术创新的转移价格控制在一定范围内系统才能达到低碳技术创新成功扩散的理想状态;政府规制下对创新提供者和潜在采纳者实施补贴和减税政策对低碳技术创新扩散有显著正向作用,但采取惩罚措施易导致低碳技术创新扩散的失败。 相似文献
7.
定性分析产业转移中金融支持的作用.从系统动力学视角提出产业转移中金融支持的基本分析框架,结合金融生态环境的正反馈特征,分析产业和政府资金流、人才流和金融业发展环境的因果关系,建立金融支持系统流图和系统动力学模型,应用Vensim PLE对模型进行仿真模拟,验证模型的有效性.结果表明,模型对金融支持的实际演化过程具有较高的拟合程度,并能够为区域产业经济发展提供有效的决策支持. 相似文献
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9.
技术转移是一个复杂的、非线性的动态系统,现有研究未能将技术转移系统的动态演化纳入到分析框架中。本文借鉴系统动力学方法对中国技术转移系统演化进行动态仿真研究,从纵向视角界定了技术转移系统包括技术研发系统、技术传播系统和技术应用系统及其边界,构建了技术转移系统动力学模型,运用2000年-2009年中国宏观数据,进行仿真实验。实验结果表明,政府的财政科技经费投入强度的增加带来的效果不如企业科技经费投入强度增加带来的效果,且技术传播子系统对于经费投入的敏感度并不高;最后,根据动态仿真实验结果,为促进中国技术转移系统的良性发展提出相应的政策建议。 相似文献
10.
国际贸易中的碳排放转移问题正在日益受到人们关注,中国在全球化经济中的分工角色对于碳转移有着深刻的影响。本文在多区域投入产出模型计算产业完全碳排放强度的研究基础上,采用2007年中国对外进出口贸易数据,分析基于国际分工背景下的中国贸易隐含二氧化碳空间转移路径,结果显示：国际产业分工形成以中国为中转站的两条碳转移路径,一条是中国从哈萨克斯坦、中东国家、澳大利亚、巴西、俄罗斯联邦、印度（Ⅲ类）输入能源和金属类高碳产业产品,制成中、低碳类的工业制成品输出到世界各国,主要是欧美国家（Ⅰ类）;另一条是中国从东盟、韩国、亚洲其他未定义地区及日本（Ⅱ类）输入中、低碳产品的半成品或零部件,组装成中、低碳类的工业制成品后再输出世界各国,主要也是欧美国家。在考虑了国际产业分工背景下用于出口的进口隐含二氧化碳后,2007年各类国家和地区向中国净转移贸易隐含二氧化碳为：Ⅰ类国家181.51MtCO2、Ⅱ类国家13.74MtCO2、Ⅲ类国家5.82MtCO2。在考虑了国际分工后,中国进口的大部分产品不是用于最终消费而是为了生产,而生产产品中有相当大的部分是用于出口,在总体上中国是在替发达国家排放二氧化碳。 相似文献
11.
A research 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 in red wine-can improve the sensitivity of mice to the hormone insulin according to a report in the October issue of Cell Metabolism.…… 《中国科学院院刊(英文版)》2008,22(1):14-15
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. 相似文献
12.
《中国科学院院刊(英文版)》2008,22(1):2-3
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. 相似文献
13.
Marjorie Armstrong-Stassen Margaret Landstrom Ramona Lumpkin 《The Information Society》1998,14(2):153-164
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. 相似文献
14.
《中国科学院院刊(英文版)》2008,22(1)
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." 相似文献
15.
A joint study by Prof. ZHANG Zhibin from the CAS Institute of Zoology his co-workers from Norway US 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 the National Academy of Sciences on September .…… 《中国科学院院刊(英文版)》2008,22(1):6-7
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. 相似文献
16.
Caroline Haythornthwaite 《The Information Society》2001,17(3):211-226
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. 相似文献
17.
Active biological molecules 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 therapy new nanodevice construction.…… 《中国科学院院刊(英文版)》2008,22(1):22-22
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. 相似文献
18.
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. 相似文献
19.
Leah A. Lievrouw 《The Information Society》2000,16(2):155-159
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. 相似文献
20.
Puay Tang 《The Information Society》1998,14(1):19-31
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. 相似文献