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181.
中国经济发展方式的转变动力及其作用途径 总被引：1，自引：0，他引：1
以全要素生产率增长动力作为经济发展方式的转变动力,本文采用1989-2013年4组省际面板数据经由可行广义最小二乘法实证估计了10个动力因素对全要素生产率增长率的贡献水平与作用途径。研究发现:技术创新水平、市场化水平、人力资本存量水平、异质性企业集聚水平和对外开放度的综合指数对中国全要素生产率增长率的回归估计系数分别为0.575 7,0.212 5,0.136 8,0.064 4和0.018,表明技术创新、市场化改革、人力资本积累、异质性企业集聚和对外开放是促进中国经济发展方式转变的直接动力因素。进一步的研究结果显示:技术创新和异质性企业集聚通过提高前沿技术进步率和生产效率变化率以及规模报酬收益率途径,市场化改革通过提高前沿技术进步率途径,人力资本积累与对外开放通过提高前沿技术进步率和规模报酬收益率途径,促进了中国全要素生产率增长。虽然产业结构变迁、城市化、基础设施建设、区域经济政策实施和金融发展对中国全要素生产率的增长表现为负向或拖累作用,但是,产业结构变迁与城市化能够提高前沿技术进步率,基础设施建设和区域经济政策能够提高规模报酬收益率,金融发展能够提高生产效率增长率和规模报酬收益率,这5项动力因素对促进中国全要素生产率增长的正向贡献有待提高。依据上述研究结论,本文提出尽快攻克制约生产率增长的核心技术,统筹考虑产业结构升级、城市化、基础设施建设和区域经济政策实施以及加快金融领域改革等政策建议,以期加快我国经济发展方式转变进程。 相似文献
182.
针对页岩气特殊的开发方式及环评难度比常规气大的特点,运用"压力-状态-响应"框架模型,建立了页岩气开发对生态环境影响的评价指标体系。引入曲线投影的方式,并将投影寻踪方法和动态聚类方法相结合,提出了曲线投影寻踪动态聚类的定量评价方法;基于样本各指标的曲线投影和动态聚类方法寻找最佳投影方向,并建立相应的生态环境影响评价优化模型。结合全局最优经验指导和信息素交流,采用改进的蚁群算法对优化模型进行求解。该算法维持蚁群的多样性,且收敛性较好,同时也避免出现局部最优。对四川省威远页岩气区块进行了实例分析,结果表明:2010年、2011年和2014年的环评属于差类(4级),2012年和2013年的环评属于中类(3级),其中植被覆盖率、空气质量优良率、地表水质达标率、废水排放量、公众对环境的满意度、二氧化硫排放量和废水排放量达标率等指标对生态环境评价的影响较大。在页岩气开发初期,由于开发技术落后,再加上环保投资不高,环保意识不强,造成生态环境问题较为严重。随着学习借鉴美国的经验,及页岩气的开发技术进一步提高,加上国家对生态环境保护的重视,威远页岩气区块生态环境恶化得到有效的遏制。但开发时间越长,开采难度越大,将会产生更多更大的生态环境问题。分析结果与威远页岩气开发区域的实际情况相符,为页岩气气田生态环境影响评价奠定了科学基础。投影寻踪动态聚类方法具有无需设定参数、操作简单、客观等优点,是页岩气开发对生态环境影响评价的一种新方法。 相似文献
183.
当前中国资源环境约束日益凸显,依靠全要素生产率成为解决这些问题的共识。然而仅仅依靠全要素生产率不能转变生产方式,关键在于区分绿色与非绿色偏向。研究使用中国省际面板数据,运用面板与动态空间面板模型方法,对比分析绿色全要素生产率、绿色"软技术"、绿色"硬技术"的影响机制。研究发现:1依靠全要素生产率驱动发展需要区别绿色与非绿色偏向;2必须注重绿色全要素生产率对绿色发展的作用及其运行机制;3不同偏向的绿色全要素生产率的省际空间学习效应不同;4绿色"软技术"对绿色发展贡献不充分。这就意味着,在当前中国资源环境约束日趋收紧的背景下,要区别绿色与非绿色全要素生产率的不同作用,否则将不能促进生产方式转变,实现绿色可持续发展。推动绿色可持续发展,一方面需要重视提升绿色全要素生产率的作用,另一方面需要重视绿色管理技术等绿色"软技术"对绿色发展的贡献。提升绿色全要素生产率,既要重视研发投入、人力资本投入,又要考虑技术市场、劳动智力结构、劳动者年龄结构的影响。提升绿色"软技术"的贡献率,改善绿色技术效率变动的吸纳能力。通过绿色全要素生产率的省际空间学习效应,实现中国省际区域间绿色可持续协同发展。此外,在引进吸收国外先进绿色技术时,既要重视对绿色"硬技术"的吸收,又要重视对绿色"软技术"的再学习。总之,"打铁还需自身硬",中国要继续鼓励支持绿色"硬技术"自主研发,巩固提升绿色"硬技术"对绿色发展的贡献。 相似文献
184.
Nobuhisa Kashiwagi 《Environmetrics》2004,15(8):777-796
A chemical mass balance method is proposed for the case where the existence of an unknown source is suspected. In general, when the existence of an unknown source is assumed in statistical receptor modeling, unknown quantities such as the composition of an unknown source and the contributions of assumed sources become unidentifiable. To estimate these unknown quantities avoiding the identification problem, a Bayes model for chemical mass balance is constructed in the form of composition without using prior knowledge on the unknown quantities except for natural constraints. The covariance of ambient observations given in the form of composition is defined in several ways. Markov chain Monte Carlo is used for evaluating the posterior means and variances of the unknown quantities as well as the likelihood for the proposed model. The likelihood is used for selecting the best fit covariance model. A simulation study is carried out to check the performance of the proposed method. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
185.
Rapid advances in graphics computing and micro-engineering have offered new techniques for prenatal cardiac imaging. Some of them can be non-invasively applied to both clinical and laboratory settings, including dynamic three-dimensional echocardiography, myocardial Doppler imaging, harmonic ultrasound imaging, and B-flow sonography. With clinical constraints, a few others have been mainly used in laboratories, such as endoscopic ultrasound, magnetic resonance imaging and biomicroscopy. Appropriate use and co-use of these new tools will not only provide unique information for better clinical assessment of fetal cardiac disease but also offer new ways to improved understanding of cardiovascular development and pathogenesis. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
186.
Fluctuation of the groundwater level in karstic areas results from different cumulative effects, such as water infiltration from precipitation, human interference on the water resources of a certain area, the Moon's tide effect, air pressure fluctuation, etc. It is practically impossible to measure these effects directly, generating the need for estimations by indirect methods, applied to the registered water level in monitoring wells. The conventional tool to determine latent or background effects governing variability or fluctuations is factor analysis. Since ordinary factor analysis has been elaborated for independent observations and the observed karstwater levels at a certain location represent realizations of time series, dynamic factor analysis has to be used instead. The obtained dynamic factors can then be identified as the above mentioned effects. Once the intensity of an effect has been determined at every observation site, its spatial structure and prediction is aimed to be given. To achieve this goal, universal kriging is used and analyzed for the spatial process of estimated loadings of dynamic factors. The present paper concentrates on the effect of infiltration. The obtained map of the loadings of the dynamic factor corresponding to infiltration provides valuable information on the intensity of this effect. Its importance from the environmental protection point of view is immense, because it helps to determine those potentially dangerous areas where infiltrating contaminated water can quickly, and in vast quantity, reach underground water resources. Copyright © 1999 John Wiley & Sons, Ltd. 相似文献
187.
When CO2 is injected into aquifers in a hydrocarbon basin, either for CO2 geological storage or enhanced oil recovery (EOR), these aquifers are most likely saturated with CH4. Dissolving CO2 into the aqueous phase will cause CH4 to come out of the aqueous phase and partitioning into the CO2‐rich non‐aqueous phase under static conditions. It is not well understood how this process develops under flow conditions, which is the subject of this paper. Although CH4 solubility in brine is low under the subsurface conditions, the effects of CH4 dissolved in saline aquifers cannot be ignored for CO2 sequestration projects. This is due to the changes of the phase behavior, capillary pressure, and relative permeability which has already been recognized by previous studies. This work couples a recently developed thermodynamic model of CO2‐CH4‐brine system with an industrial reservoir simulator and applies it in the simulation of CO2 injection into a CH4 saturated aquifer. Simulation results are compared to field observations from U‐tube sampling and used to provide reasonable explanations. From the simulations, the compositions in U‐tube samples are influenced by U‐tube inlet position, perforation and the reservoir (geological) properties. With the explanations, the U‐tube observations of gas samples can be well matched by numerical simulation results.© 2014 Society of Chemical Industry and John Wiley & Sons, Ltd 相似文献
188.
Marie Chavent Herv Gugan Vanessa Kuentz Brigitte Patouille Jrme Saracco 《Environmetrics》2009,20(8):928-942
Air pollution is a wide concern for human health and requires the development of air quality control strategies. In order to achieve this goal pollution sources have to be accurately identified and quantified. The case study presented in this paper is part of a scientific project initiated by the French Ministry of Ecology and Sustainable Development. For the following study measurements of chemical composition data for particles have been conducted on a French urban site. The first step of the study consists in the identification of the sources profiles which is achieved through principal component analysis (PCA) completed by a rotation technique. Then the apportionment of the sources is evaluated with a receptor modeling using positive matrix factorization (PMF) as estimation method. Finally the joint use of these two statistical methods enables to characterize and apportion five different sources of fine particulate emission. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
189.
The role of rainfall raingauge observations in calibration of radar derived rainfall estimates is investigated. The final goal is the reconstruction of the rainfall fields over the observed area using both information during a rainfall enhancement experiment. Furthermore, we propose a simple protocol to assess the experiment efficacy. A space‐time approach and the use of kriging with external drift are applied and compared. Results are again compared with those one obtained through an ordinary kriging (OK). Data come from a dense raingauge network and a weather radar installed in 1992 for the evaluation of a rain enhancement experiment carried out in Southern Italy. In this paper we report detailed results from one seeding operation carried out on 11 April 1992. The procedure to assess the efficacy of rain enhancement experiment is illustrated for 11 seeding operations. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
190.
D. G. Chen 《Environmetrics》2009,20(1):101-109
The isobologram model is a commonly used and powerful graphical and statistical tool for analyzing the joint action for simple chemical mixtures. Substantial research has been done for the quantitative response and the amount of research in the qualitative framework is minuscule. In this paper, isobologram model is proposed to analyze the joint action of chemical mixtures for quantal dose‐response relationship based on the generalized linear model technique to estimate the associated parameters by the maximum likelihood estimation and then to be used to construct the isobologram so that the joint action from the chemicals can be identified both by the isobologram and the statistical inference for interaction parameter. A real dataset is used to illustrate the application of the developed approach. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献