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471.
京沪高速铁路地震预警系统的方案及关键参数研究   总被引:5,自引:0,他引:5  
京沪高速铁路及沿线区域跨越 4个主要的地震带 ,带内地震活动活跃 ,地震是对高速列车行车安全危害最大的自然灾害。在对京沪高速铁路及沿线区域地震危险性调查的基础上 ,对地震预警系统的构成、监测设备的设置方案及报警模式等一些关键问题进行了研究。通过对京沪高速铁路各类典型构筑物的大量的地震响应统计分析 ,给出了机械式地震仪的预警水平 ,并提出了适于P波检测的M -R判别标准 ,为京沪高速铁路安全监控系统中地震预警系统的建设提供理论依据。  相似文献   
472.
473.
A modified transient version of the Streeter-Phelps model along with the energy balance equation is employed to analyze the effects of waste heat discharge from power plants on stream water quality. Analysis is also made to examine the effects of the upstream water quality and stream velocity on the downstream DO concentration level. The resulting coupled nonlinear hyperbolic partial differential equations representing the energy, BOD and DO concentrations are solved by the method of characteristics and simulated on a digital computer. Final numerical results indicate that the allowable quantity of thermal discharge does heavily depend on the upstream quality.  相似文献   
474.
ABSTRACT: The purpose of this work is to study the installation of artificial aerators for water quality control of a stream which receives thermal and organic waste discharges. The location and numer of diffuser type aerators to be installed along the stream are determined so as to maintain the stream DO content above a certain minimum requirement (4 mg/l or 5 mg/l) for normal aquatic life. Effects of the stream velocity, upstream BOD concentration and rates of thermal and organic waste discharges to the stream are examined.  相似文献   
475.
1 深入学习邓小平理论,努力维护林业改革与发展的安全环境和林区社会稳定  深入学习邓小平理论是当前重大而紧迫的任务。当前,林业各项改革正稳步推进,但改革不可能一帆风顺,已经出现了这样那样的问题,也还会出现其它的问题。要解决这些问题,就要求我们深入学习邓小平理论,坚持解放思想、实事求是的思想路线,从改革、发展、稳定的大局出发,做好各项工作。1.1 讲学习,用理论指导实践  “讲学习、讲政治、讲正气”是今年全党、全国的一项重要工作,是进一步深刻领会邓小平理论的重要举措。“讲学习”冠以“三讲”之首,说…  相似文献   
476.
党的十五大提出发展多种形式的公有制经济,在这种新形势下,环境管理如何转轨,本文进行了探讨和研究。  相似文献   
477.
Lee CT  Lin NH  Hsu WC  Chang YL  Chang SY 《Chemosphere》1999,38(2):425-443
The Mei-yu (plum rain) season is a short but important period when the weather changes from spring to summer in Taiwan. In this study, size-segregated aerosols were collected alternately at 5 sampling sites in northwestern Taiwan from June 16 to 24, 1994. For the first time in Taiwan, this study revealed the aerosol mass spectra and water-soluble ions in the Mei-yu season. For all samples, a bi-modal aerosol mass spectra was found with modal diameters at 3.2 and 0.32 microm, respectively. The aerosol samples were able to be divided into different groups to show their mass and ion spectra according to the calculated 5-hr backward air trajectory. The utilization of enrichment factors showed that aerosol Cl-, Na+, and Mg2+ for all sizes, and super-micron SO4(2-) were related to the sea. Both the scheme of "chlorine loss" (Ohta and Okita, 1990) and a multivariate analysis (Thurston and Spengler, 1985) for categorizing water-soluble ions showed that sea-salts were major contributors in the prevalence of a sea breeze. In contrast, the secondary salts were significant for land breeze and a mix of land-sea breeze. In conclusion, the influence of local circulation on the distribution of aerosol mass and ionic species was found to be prominent.  相似文献   
478.
ABSTRACT

The drive range of electric vehicle (EV) is one of the major limitations that impedes its universalism. A great deal of research has been devoted to drive range improvement of EV, an accurate and efficiency energy consumption estimation plays a crucial role in these researches. However, the majority of EV’s energy consumption estimation models are based on single motor EV, these models are not suitable for dual-motor EVs, which are composed of more complex transmission mechanisms and multiple operating modes. Thus, an energy consumption estimation model for dual-motor EV is proposed to estimate battery power. This article focuses on studying the operating modes and system efficiency in each operating mode. The limitation of working area of each mode ensures the vehicle dynamic performance, then PSO algorithm is adopted to optimize the torque (speed) distribution between two motors to improve the system efficiency in the coupled driving mode. Finally, the energy consumption estimation model is established by multiple linear regression (MLR). The result shows that the proposed model has a high precision in energy consumption estimation of dual-motor EV.  相似文献   
479.
480.
Simultaneous removal of hydrogen sulfide (H2S) and ammonia (NH3) gases from gaseous streams was studied in a biofilter packed with granule activated carbon. Extensive studies, including the effects of carbon (C) source on the growth of inoculated microorganisms and gas removal efficiency, product analysis, bioaerosol emission, pressure drop, and cost evaluation, were conducted. The results indicated that molasses was a potential C source for inoculated cell growth that resulted in removal efficiencies of 99.5% for H2S and 99.2% for NH3. Microbial community observation by scanning electron microscopy indicated that granule activated carbon was an excellent support for microorganism attachment for long-term waste gas treatment. No disintegration or breakdown of biofilm was found when the system was operated for 140 days. The low bioaerosol concentration emitted from the biofilter showed that the system effectively avoided the environmental risk of bioaerosol emission. Also, the system is suitable to apply in the field because of its low pressure drop and treatment cost. Because NH3 gas was mainly converted to organic nitrogen, and H2S gas was converted to elemental sulfur, no acidification or alkalinity phenomena were found because of the metabolite products. Thus, the results of this study demonstrate that the biofilter is a feasible bioreactor in the removal of waste gases.  相似文献   
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