论融资约束下企业最优投资时机选择

利用企业投资的三期静态模型,考察了企业投资额、自有资金与外部融资之间的关系。通过比较企业在不同期间即时投资和延迟投资的投资收益,求解得到企业在融资约束下的投资临界值,进而得出了企业在投资可延迟条件下的最优投资时机和投资规则。     

Bridging the divide in urban sustainability: from human exemptionalism to the new ecological paradigm

This paper reviews the main bodies of contemporary urban sustainability theory. From this analysis, two underpinning paradigms of urban sustainability are identified: (1) The ‘Human Exemptionalism Paradigm’ (HEP), which emphasizes the ability of humans to overcome environmental problems—see Urban Sociology, Urban Ecology, Urban Geography, Urban Psychology and Political Economy; and (2) The ‘New Ecological Paradigm’ (NEP), which emphasizes the criticality of ecological limits to human progress—see Urban Metabolism, Energy/Emergy Analysis and Ecological Footprinting. Each of these approaches is critically reviewed, highlighting their main assumptions, theoretical and practical foci. It is argued in the paper that if the related issues of urban sustainability and development are to be progressed, there needs to be: (1) a greater maturation of the NEP approaches, which are ‘relative newcomers’ to the area of urban theory; and (2) greater integration and dialogue between the HEP and NEP approaches to urban sustainability than has hitherto been the case.

中国融资租赁业的竞争与差异化发展

本文通过对中国融资租赁业三大市场主体对比,分析三大租赁业主体的比较优势。银行系租赁公司具有网点优势,且适合面相资金密集型行业,创新模式多样化;厂商系租赁机构擅于在专业型领域占据龙头,而独立第三方融资租赁主体的竞争优势则是能够提供给客户多元选择和增值服务。在此基础上,通过SWOT分析,确定三类融资租赁主体未来的市场定位和发展方向。     

Tweeting India’s Nirbhaya protest: a study of emotional dynamics in an online social movement

Abstract

Previous research has recognized the role of emotions in protests and social movements in the offline world. Despite the current scenario of ubiquitous social media and ‘Twitter revolutions,’ our knowledge about the connections between emotions and online protests still remains limited. In this study, we examine whether online protest actions follow the same emotional groundwork for supporting and nurturing a social movement as in the offline world, and how these emotions vary across various stages of the social movement. Through a computer-assisted emotion analysis of 65,613 Twitter posts (tweets), posted during the Nirbhaya social movement (movement against the Delhi gang-rape incident) in India, we identified a strong resemblance between online emotional patterns and offline protest emotions as discussed in literature. Formal statistical testing of a range of emotions (negativity, positivity, anger, sadness, anxiety, certainty, individualism, collectivism, and achievement) demonstrates that they significantly differed across stages of the social movement; as such, they influenced the course of the online protest, resonating parallels with offline events. The findings highlight the importance of anger and anxiety in stirring the collective conscience, and identify that positive emotion was pervasive during the protest event. Implications of these findings are discussed.     

The Global Alliance for Public Relations and Communication Management: Origins,influences, issues and prospects

This paper chronicles the formation and development of the Global Alliance for Public Relations and Communication Management (GA) up to 2002. It sets the GA's genesis within the context of other internationalisation initiatives undertaken by the wider public relations practitioner community and draws links between the formation of the GA and the emerging phenomenon of globalisation. The paper's intent is to describe the formation of the GA from a historical perspective, to understand the forces that led to its creation and to appreciate the different drivers and motivation of founding members. These factors provide a springboard to consider some of the issues that currently challenge GA, some of which were inherent in the governance model it chose at its inception.     

Bisphenol A: How the Most Relevant Exposure Sources Contribute to Total Consumer Exposure

Bisphenol A (BPA) is an endocrine disrupting chemical that is found in human urine throughout industrial societies around the globe. Consumer exposure pathways to BPA include packaged food, household dust, air, and dental fillings. To date, information on the relative contribution of the different pathways to total consumer exposure is lacking, but is key for managing substance‐associated risks. We investigated the relative contributions of the pathways known to be most relevant for nine different consumer groups. Our results suggest that the most important pathways for infants and children are the use of polycarbonate (PC) baby bottles and for adults and teenagers the consumption of canned food. Dental surgery can also considerably contribute over a short time directly after the surgery. For infants fed with PC baby bottles with mean dose rates of 0.8 μg/kg_bw/d the highest exposure dose rate was calculated. This dose rate is far below the tolerable daily intake of 50 μg/kg_bw/d. However, it is of the same order of magnitude as recently reported concentrations that caused low‐dose health effects in rodents. We find a pattern of falling exposure levels with rising age that is supported by urinary concentrations of BPA available for selected consumer groups. Similarly, the exposure levels we predict are confirmed by the levels reported in these studies.     

Valuation of road safety effects in cost–benefit analysis

Cost–benefit analysis is a common method for evaluating the social economic impact of transport projects, and in many of these projects the saving of human lives is an issue. This implies, within the framework of cost–benefit analysis, that a monetary value should be attached to saving human lives. This paper discusses the ‘Value of a Statistical Life’ (VoSL), a concept that is often used for monetising safety effects, in the context of road safety. Firstly, the concept of ‘willingness to pay’ for road safety and its relation to the VoSL are explained. The VoSL approach will be compared to other approaches to monetise safety effects, in particular the human capital approach and ‘quality adjusted life years’. Secondly, methods to estimate the VoSL and their applicability to road safety will be discussed. Thirdly, the paper reviews the VoSL estimates that have been found in scientific research and compares them with the values that are used in policy evaluations. Finally, a VoSL study in the Netherlands will be presented as a case study, and its applicability in policy evaluation will be illustrated.     

基于数字照相技术的边坡变形自动化监测技术研究

将数字摄影测量技术应用于边坡位移自动监测。在边坡上布设固定标志点，将非量测数码相机置于边坡正面，运用程序控制相机间隔一定时间对边坡进行拍摄。对拍摄图像预处理后使用圆心亚像素识别算法确定测点亚像素位置。根据标志初始实际距离与初始相片像素距离建立物象比例，对比各次识别结果得到各测点实际的相对位移。运用GPS技术和计算机技术，本系统可实现数据交换、控制指令发送和预警的适时监控。本系统采用非量测数码相机，相对于传统边坡检测方法具有成本低，精度高，需要人工干预少等优点，现场试验50 m距离识别精度达到3 mm，取得较好效果，可以作为大量边坡自动化监测的有效手段。     

爆夯法处理水下抛石基床在曹妃甸的应用

唐山港曹妃甸港区通用码头工程是曹妃甸港区第一个较大规模采用沉箱结构的重力式码头。根据爆夯法处理水下抛石基床在曹妃甸通用码头工程中的应用实例,对爆夯工艺的施工方法和实际效果进行了总结,为该工法在曹妃甸类似工程应用积累了经验。     

稠油油藏注蒸汽储层热伤害规律实验研究

针对稠油油藏注蒸汽过程中储层的热伤害问题，研究了稠油油藏热采过程注入的高温、高pH 热流体对储层 渗透率的影响，研究中利用正反向流动实验方法，研究了高温冷凝液注入疏松砂岩后引起的微粒运移作用及储层渗透 率的变化特征；并利用储层矿物的水热反应实验，分析了疏松砂岩油藏注蒸汽开发过程中的微粒运移机理。实验结果 表明，注蒸汽过程中，稠油油藏储层渗透率随温度及pH 值的升高而降低。高速流动的蒸汽及冷凝液造成储层内固相 微粒的运移及滞留，使储层非均质性进一步加剧；同时，高温、高pH 的蒸汽冷凝液既促使黏土矿物发生膨胀又造成储 层矿物发生溶解与转化，从而进一步加剧了稠油油藏疏松砂岩储层的储层热伤害。