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101.
阐述了我国及其他国家环境监测市场管理的经验,以及我国在推进环境监测市场化管理方面的探索;指出了目前环境监测市场化管理中存在的问题,提出,应加快建立适合国情的监测总体格局;建立完善环境监测社会化监管制度体系;充分发挥行业协会在监管中的作用;强化对社会监测机构监管力度;提高社会环境监测机构能力。  相似文献   
102.
Loss of temperature control is one of the major reasons that can lead to runaway reaction. This occurrence is commonly named thermal runway. The aim of this paper is the application of thermal runaway criteria in order to predict the onset of runaway phenomena and define the range of stability related to operating conditions in the reactor, with specific reference to the esterification of acetic anhydride and methanol catalysed by sulphuric acid tested in isoperibolic conditions. The isoperibolic calorimeter has also been used to obtain thermodynamic, kinetic and physical chemistry data necessary to develop a model for the reaction. Some runaway criteria applied in this work require a model for the process, so a model for the analyzed system been developed.Because of the modest reaction enthalpy and low activation energy this reacting system provide a severe test to the runaway criteria.In this work, various runaway criteria have been applied to the experimental and simulated data and the results obtained have been compared.  相似文献   
103.
文章以国内典型压力容器用材245R为例,采用GB/T19624~断裂力学评价方法对于《压力容器定期检验规程》表5、表6中的超标非圆形缺陷可接受准则的安全裕度进行评价,评价结果表明其中可接受准则的部分规定不够保守,就此作者给出相关的修改建议。  相似文献   
104.
A four-stage method of providing conditions for improving the stability of a landscape sector is presented. In the first stage, structure and function of the landscape system is examined, predominantly based on the results of monitoring. In the second stage, a method is suggested for applying monitoring data to a dynamic structure with complex functions of the territory under examination. In the third stage, the territory is optimized as to the function of particular components within it. The optimization consists in controlling the dynamics of the flows of material, energy, and population within the sector. In the fourth stage, the holistic function of the landscape strip should be monitored with respect to representative key factors. The entire concept is based on assuming the existence of destabilizing processes leading to ecocritical situations and determining mitigating factors using heuristic methods of optimization.  相似文献   
105.
关于现代中国安全生产管理体系研究:管理、法规、文化   总被引:1,自引:0,他引:1  
对我国安全生产管理的宏观及微观形势分析,论证了安全生产与国民经济的关系。特别指出从根本上遏制新的事故高峰,关键应强化“大安全观”的安全生产管理体系建设与实践。研究向市场经济转换过程中的中国安全减灾业的发展及管理思路,重点探索了体系化管理、安全文化及安全生产法的主题。  相似文献   
106.
Corn starch and zein mixtures (4 : 1 dry weight) were extruded and injection-molded in the presence of plasticizers (glycerol and water). Tensile strength and percentage elongation of the molded plastics were measured before and after 1 week of storage under a dry or humid condition (11 or 93% RH). With 10–12% glycerol and 6–8% water, injection-molded plastics had relatively good tensile properties (20- to 25-MPa tensile strength and 3.5–4.7% elongation). But while exposed to dry conditions (11% RH), the molded plastics lost weight (0.5–1.5% in 7 days) and became very brittle, with significant decreases in tensile strength and elongation. Partial replacement (5–10%) of starch with a maltodextrin (average DE 5) reduced the glass transition and melting temperatures of the starch-zein mixture as well as the dry storage stability. Using potato starch instead of corn starch significantly improved the dry storage stability of the injection-molded starch-zein plastics (18- vs 11-MPa tensile strength). Anionic corn starches with a maleate or succinate group (DS<0.01) produced injection-molded plastics with improved tensile properties and storage stability. Plastics prepared from the starch maleate and zein mixture retained the strength during 1 week of dry storage without a significant change (26-MPa tensile strength and 3.7% elongation after 1 week of storage).Paper presented at the Bio/Environmentally Degradable Polymer Society—Second National Meeting, August 19–21, 1993, Chicago, Illinois.Journal paper No. J-15561 of the Iowa Agriculture and Home Economics Experiment Station, Ames, Iowa, Project No. 2863.  相似文献   
107.
Channel changes from 1919 to 1989 were documented in two study reaches of the Merced River in Yosemite National Park through a review of historical photographs and documents and a comparison of survey data. Bank erosion was prevalent and channel width increased an average of 27% in the upstream reach, where human use was concentrated. Here, trampling of the banks and riparian vegetation was common, and banks eroded on straight stretches as frequently as on meander bends. Six bridges in the upper reach constrict the channel by an average of 38% of the original width, causing severe erosion. In the downstream control reach, where human use was minimal, channel widths both decreased and increased, with a mean increase of only 4% since 1919. Bank erosion in the control reach occurred primarily on meander bends. The control reach also had denser stands of riparian vegetation and a higher frequency of large woody debris in channels. There is only one bridge in the lower reach, located at the downstream end. Since 1919, bank erosion in the impacted upstream reach contributed a significant amount of sediment (74,800 tonnes, equivalent to 2.0 t/km2/yr) to the river. An analysis of 75 years of precipitation and hydrologic records showed no trends responsible for bank erosion in the upper reach. Sediment input to the upper reach has not changed significantly during the study period. Floodplain soils are sandy, with low cohesion and are easily detached by lateral erosion. The degree of channel widening was positively correlated with the percentage of bare ground on the streambanks and low bank stability ratings. Low bank stability ratings were, in turn, strongly associated with high human use areas. Channel widening and bank erosion in the upper reach were due primarily to destruction of riparian vegetation by human trampling and the effect of bridge constrictions on high flow, and secondarily to poorly installed channel revetments. Several specific recommendations for river restoration were provided to park management.  相似文献   
108.
The thermal oxidative stability of various formulations based on emulsion-grade ABS was studied by the chemiluminescence technique. Emulsion products were found to be essentially less stable than ionic mass polymerization resins. Among the antioxidants studied, Santonox R is clearly more efficient than Irganox 1076 and Irganox 3114, and its superiority is reflected primarily in improved induction period values. The introduction of Tinuvin 770 and Tinuvin 328 UV stabilizers into emulsion resins does not change the durability of the products. In mixtures where both Irganox 1076 and UV stabilizers are present, a certain antagonistic effect was noted at high UV stabilizer concentrations.  相似文献   
109.
Within the context of political democratization, this article explores environmental protection in Hong Kong since the government lauched a ten-year program to “save the environment” in 1989. Examining environmental management by law from a social-choice perspective, it argues that the government has yet to reach an integrative policy orocess. Hence the preconditions for an integrative set of environmental legislation are absent. Institutionally, without a comprehensive green policy, the current arrangements lack a vision as an integrative force to promote effective coordination among various sectoral environmental coordination among various sectoral environmental programs. The dominant approach of policy and law enforcement through consultation has rendered impossible strict enforcement of environmental rules and regulations as local economic growth enjoys a priority over environmental protection. At a time of environmental awakening, the people of Hong Kong are not yet prepared awakening, the people of Hong Kong are not yet prepared to participate in environmental management in a strict legal manner. The overall observation is that Hong Kong has yet to see more mature political, legal, administrative, and social conditions for managing its environment within a legal framework.  相似文献   
110.
分形块体理论及其在三峡高边坡稳定分析中的应用   总被引:4,自引:0,他引:4  
把分形几何与块体理论相结合,提出了分形块体理论,建立了分形块体理论赤平解析法,并将其应用于三峡永久船闸高边坡稳定性分析中。结果表明:分形块体理论符合工程实际,是分析裂隙岩体工程稳定性行之有效的可靠方法。  相似文献   
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