Comprehensive Assessment and Promotion Policy of Producer Services’ Competitiveness in Beijing City:A Comparative Analysis among Beijing,Tianjin,Shanghai,Guangzhou and Shenzhen

The five central cities-Beijing,Tianjin,Shanghai,Guangzhou and Shenzhen-of the three most important strategic regions in China,namely Beijing-Tianjin-Hebei metropolitan region,the Yangtze River Delta and the Pearl River Delta,are taken as a comparative analysis on urban producer services’ competitiveness,especially focusing on the comparative advantages and disadvantages of producer services in Beijing.Firstly,based on an integrated indicator system including one objective hierarchy,four standard hierarchies and 35 indicator hierarchies,the study applies factor analysis model and analytic hierarchy process model reformed by entropy technology to measure the comprehensive competitiveness of producer services in the above five cities.Secondly,Beijing has comparative advantages of capital resource,industrial base,scientific research resource and market scale,since it takes the first place of the five cities in the comprehensive competitiveness of producer services,the competitiveness of industrial development,business environment and living environment,only inferior to Shanghai in the competitiveness of talent capital.Thirdly,Beijing has comparative disadvantages in the level of producer services development,urban innovation capability and living environment.Finally,five proposals are put forth to enhance the competitiveness of producer services in Beijing,namely perfecting the system of laws and statutes,supporting the development of industry association,implementing scientific development planning,introducing preferential fiscal and taxation policies and strengthening human capital reserve.     

CGE Simulation for Levying Carbon Tax in China and International Experience of Levying Carbon Tax

Levying carbon tax is conducive to reducing carbon dioxide emissions and protecting the environment.The author firstly reviewed some relevant empirical studies on carbon tax both home and abroad,and then established the CGE model and simulated levying carbon tax in China.The study found that levying carbon tax would have little impact on China’s economy:in a short-term,China’s GDP might decrease by 0.51%,while in a long-term it might decrease by 0.08%;however,the carbon dioxide emissions would be substantially reduced.Meanwhile,levying carbon tax has some negative impact on the output of each industry in the very economic structure;of this,the mineral extractive industries would be influenced the most.Then the author summarized experience of levying carbon tax in foreign countries.     

The Dual Model for Tourism Resource Productivity Improvement

For natural resource science, resource productivity studying is an important subject. But researches on tourism resource productivity are limited. The most significant influencing factor on tourism resource productivity is the potential market scale of tourist locations, and second most important influencing factor is the resource endowment. Regional urban population is significantly correlated with region tourist numbers, being the decisive factor of region potential tour market scale. In tourism development, the dual model should be adopted: on one hand to enhance tour spot attractiveness, on the other hand to cultivate the potential market by improving urbanization level and other means. In the situation of tourism development fever spreading, the dual model for improving tourism productivity helps to avoid the "Great Leap Forward" which means that too rapid tourism construction divorces from actual market demand.     

液化天然气(LNG)瞬时泄漏扩散的模拟研究

对液化天然气泄漏扩散过程进行了分析,考虑其泄漏后发生闪蒸时的液滴夹带以及混合空气量,将闪蒸完的状态作为箱模型的初始状态,考虑空气的湿度影响建立了重气扩散过程的箱模型,并应用实例进行了验证,得出了泄漏后有火灾爆炸危险性的区域以及距离泄漏源的位置,为应急救援预案的制定提供参考,模拟结果显示了重气扩散过程中的重力沉降,空气夹带等一般特征,同时云团初始闪蒸时的液滴夹带对云团的扩散行为具有一定的影响,不能忽略.最后提出了今后的研究方向.     

一种灾害等级的区间数评估模型

由于灾害损失本身的复杂性及灾情统计方面存在的问题,利用区间数替代单一实数值作为灾害等级评估指标的输入更加符合实际。基于上述思路,提出了一种基于区间数的灾害等级评估新模型。首先,给出区间数距离的新定义,该定义能够充分利用区间数所携带的信息;然后,利用线性加权评价函数计算评估对象与评价标准之间的综合相对距离测度,评估对象隶属于综合距离测度最小值所对应的灾害等级。该模型建模过程思路清晰,物理意义明确,计算过程简捷,评估结论符合实际。最后,用实例说明模型的应用方法。     

二维相关地震动作用下结构的随机反应

假定两水平方向的地震动为平稳随机过程,基于地震动主轴模型的假设,讨论了二维地震动分量的空间相关性,在单分量平稳模型的基础上给出了二维水平地震动随机模型的相关函数矩阵。该相关函数模型可以为二维地震下结构随机反应分析提供地震动输入。利用状态空间方法和随机振动理论建立了线性多自由度体系在二维地震激励下的随机反应分析方法,导出了结构的位移反应相关函数和速度反应相关函数,可在时域内直接计算结构的二维随机地震反应的统计特征。最后,通过一个二层框架结构计算实例,说明了这种方法的运用,讨论了地震动强度以及地震动主轴方位角对结构反应的影响。该方法可以为结构抗震可靠性评估提供基础。     

简易垃圾填埋场的安全分析

以福建省晋江市铜锣山垃圾填埋场为例,采用系统的安全分析方法--事故树分析法对该简易垃圾填埋场进行安全分析,发现铜锣山垃圾填埋场存在发生火灾、爆炸、垃圾堆体崩塌及因发生火灾或爆炸事故对邻近建筑物造成破坏的可能性,确定了影响该垃圾填埋场安全的主要因素,提出了有效的安全防范措施.     

澳门特别行政区土壤自然消减能力与污染背景

澳门是我国人口密度最大的城市.选择澳门特别行政区不同功能区绿地土壤为研究对象,首先,通过野外布点采样,调查分析了表层土壤中9种重金属元素(Cr、Ni、Cu、Cd、Pb、Cr、Zn、As、Hg)和16种优先控制多环芳烃(PAHs)的分布特征;其次,利用累积频率分布曲线法估算了土壤重金属和PAHs的土壤污染背景;最后,基于...     

三峡库区水质和水龄数值模拟研究

三峡水库是我国重要的生态屏障和水资源战略储备库,保护水库的水质安全对于国家经济发展和社会稳定具有重要战略意义.本文基于EFDC模型模拟了2010-2014年三峡库区及主要支流的水动力水质过程,重点研究上游来水和重点支流对库区水质的影响及水龄变化特征,结果表明:①模型可定量研究重点支流输入对库区水质的影响,17条支流中仅...     

Application of Agriculture‐Developed Demographic Analysis for the Conservation of the Hawaiian Alpine Wekiu Bug

Insects that should be considered for conservation attention are often overlooked because of a lack of data. The detailed information necessary to assess population growth, decline, and maximum range is particularly difficult to acquire for rare and cryptic species. Many of these difficulties can be overcome with the use of life table analyses and heat energy accumulation models common in agriculture. The wekiu bug (Nysius wekiuicola), endemic to the summit of one volcanic mountain in Hawaii, is a rare insect living in an environmentally sensitive alpine stone desert, where field‐based population assessments would be inefficient or potentially detrimental to natural and cultural resources. We conducted laboratory experiments with the insects by manipulating rearing temperatures of laboratory colonies and made detailed observations of habitat conditions to develop life tables representing population growth parameters and environmental models for wekiu bug phenology and demographic change. Wekiu bugs developed at temperatures only found in its environment on sunny days and required the thermal buffer found on cinder cones for growth and population increase. Wekiu bugs required approximately 3.5 months to complete one generation. The bug developed optimally from 26 to 30 °C, temperatures that are much higher than the air temperature attains in its elevational range. The developmental temperature range of the species confirmed a physiological reason why the wekiu bug is only found on cinder cones. This physiology information can help guide population monitoring and inform habitat restoration and conservation. The wekiu bug was a candidate for listing under the U.S. Endangered Species Act, and the developmental parameters we quantified were used to determine the species would not be listed as endangered or threatened. The use of developmental threshold experiments, life table analyses, and degree day modeling can directly inform otherwise unobservable habitat needs and demographic characteristics of extremely rare insects. Aplicación de Análisis Demográfico de Desarrollo Agrícola para la Conservación del Insecto Weiku Alpino Hawaiano