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991.
Abstract Picea neoveitchii is an endemic species in China. It had been listed as an endangered species in red data books. It scatters in several locations of south slope of the Qinling Mountain of China. Upon reviewing the related literature, discussing with leading scholars on gymnosperm, ecology and plant conservation, the field survey was carried out in four locations. There are eleven mature individuals and two seedlings surviving in its natural habitats. With the survey of quadrat method in four locations, related community index were calculated such as relative important value (RIV), species richness, similarity index, diversity index and evenness index etc. The community could be sorted and characterized as three groups based on the community parameters. The analysis of vegetation table elucidates that Picea neoveitchii is a dominant species with low grouping rate in most surveyed sites. The RAPD analysis shows target species has intraspecific genetic variability. The estimation of Shannon's phenotypic diversity index (Ho) also explains the difference of genetic variations of different locations. Due to the lack of enough knowledge and professional guide of conservation biological perspective, Picea neoveitchii had been clear-cut for timber production. The extent of occurrence and area of occupancy declined rapidly from 1950s to 1990s. According to the Conservation Category guideline proposed by the World Conservation Union, the conservation status of Picea neoveitchii was reevaluated as Critically Endangered (CR) B2b C2a D. Upon research in areas of ecology, molecular biology, cluster analysis of environmental parameters, a practical conservation strategy is recommended in this research. 相似文献
992.
Valery F. Venda Svyatoslav A. Chachko 《International journal of occupational safety and ergonomics》2013,19(2):93-108
Based on ergodynamics and the hybrid intelligence theory, an analysis of the nuclear power plant operator’s performance is given at the levels of strategies, tactics, and actions. Special attention is paid to the strategies used in the course of severe accidents at nuclear power plants. Data from Ukrainian and Russian power plants and training centres and from accidents around the world were collected and processed. It is shown that in an emergency it is essential for the human operator to be flexible. This flexibility includes two main training and personal factors: a large set of strategies and tactics the operator manages to use, and quick transformations between the strategies (tactics). It was also found that some emergency tasks are too complicated: They require simultaneous use of different strategies, with time strictly limited by nuclear power plant dynamics. Those tasks cannot be successfully solved by any individual operator. Hybrid intelligence systems involving different specialists should be used in those cases in order to avoid failures in emergency problem solving. 相似文献
993.
环境问题是社会各界广泛关注的焦点,而企业是造成环境污染的主体之一,也是环境制度压力的主要调控对象,如何引导和控制企业履行环境责任已成为一个亟须研究的重大议题。根据制度理论,以中国上市公司7459个观测值为基础,采用固定效应模型系统评估了制度压力对企业环境责任的影响,还引入企业环境战略、内部控制作为调节变量进行分析。研究结果表明:制度压力能显著促进企业环境责任的提升;企业环境战略、内部控制等因素正向调节了制度压力与企业环境责任的关系,并且制度压力对企业环境责任的影响在非国有企业、地方国有企业中更强。以上结论在一系列的稳健性检验、反事实检验之后依然成立。这些结论启发了企业管理者运用企业环境战略、内部控制等企业自身因素强化企业环境责任,同时为政府根据企业不同情况有针对性地制定环境政策提供了理论依据。 相似文献
994.
995.
X.B. LiL.J. Dong G.Y. ZhaoM. Huang A.H. LiuL.F. Zeng L. DongG.H. Chen 《Safety Science》2012,50(4):695-704
A case study of Dahu landslide from Linbao Henan in China was discussed in this paper. Based on various kinds of basic data, the 3D numerical model of a geological structure which possesses all kinds of information including the mechanical characteristics and the geometrical parameters of geological discontinuities were known from previous works. Thus, both the whole geological structure and all kinds of geological components involved in a slope can be visualized on computer, the complicated analysis and calculation can be then carried out easily and effectively. Firstly, the combination of 3D numerical model with the limit equilibrium analysis theory in slope stabilization can easily provide the present stability factor. Then according to monitoring data of the total station, the potential sliding trends are analyzed if landslides do not occur. Secondly, there are a number of uncertainties on the factors of multi-forms of disaster, such as, rainfall, earthquake, and mined-out area. The unascertained mathematics theory is applied to the stability comprehensive evaluation. It shows four landslide bodies get to be at unstable state if there are some inducements. Thirdly, sliding distance and movement scope were predicted if landslides occur. On the basis of the analysis above, the treatment of the landslide body called isolated method of culvert was proposed. It has solved the contradiction of landslide and mining radically, and provides important technical assurance for safety and sustainable development of mine. 相似文献
996.
Ghaffar Keshavarz Premkumar ThodiFaisal Khan 《Journal of Loss Prevention in the Process Industries》2012,25(1):159-165
Global demand for natural gas may double by 2030, with Liquefied Natural Gas (LNG) growing perhaps fivefold - driven by continued cost reduction. Propane Pre-cooled Mixed Refrigerant (PPMR) of Air Products and Chemicals Inc. (APCI) currently holds 78% of the liquefaction plants on the market. Since the PPMR process has the largest production capacity, its operational reliability needs to be high as any failure may result in catastrophic consequences. Therefore, operational reliability has a key importance in LNG plants. To achieve an acceptable reliability, usually, a constant interval of a preventive maintenance method is used. The limitation of such a method is that the shutdown strategy is not optimum. This study focuses on determining a risk-based shutdown management strategy for APCI plants with capacity of 4.5 million tons per annum. To achieve the minimum risk for the expected life of an LNG plant, a combination of preventive maintenance, active redundancy and standby redundancy is considered. Results of this study reveal that such a combination can significantly reduce the operational risk. This combination improves the plant reliability and maintains it above a minimum operational reliability. 相似文献
997.
为推动化学品风险评估在我国的开展,对全球产品策略(GPS)进行研究。通过对GPS实施流程的分析,确定实施GPS的核心是开展化学品的风险评估(简称GPS风险评估)。将GPS风险评估与欧盟《化学品注册、评估、授权和限制》(REACH)法规要求的化学品安全评估(简称REACH CSA)和我国新化学物质登记要求的新物质风险评估进行对比,从评估物质的要求、效应评估的范围和方法、暴露评估的范围和方法以及风险表征的方法 4个方面分析其共同点和差异。确定GPS风险评估是简化版的REACH CSA,新物质风险评估相当于REACH CSA中的环境风险评估部分。最后认为,开展化学品全面风险评估是国际化学品管理发展的趋势。针对实际情况,提出宜采取简化评估和优先评估的方法,在我国逐步开展化学品全面风险评估。 相似文献
998.
施卫祖 《中国安全生产科学技术》2012,8(8):88-91
科技兴安战略是安全生产工作的指导思想之一,安全生产以"管理为基础,科技为支撑",不断增强安全生产科技进步与创新,是安全发展的动力。我国安全科技发展存在安全科技人才匮乏、安全科技研发投入少、安全基础理论研究滞后、科技研发成果和技术装备推广应用进展缓慢、安全技术支撑平台不健全等突出矛盾和问题。坚持超前感知安全生产科技发展方向、"大、微、智"安全技术装备发展方向,大力实施科技兴安战略,加快安全生产科技研发、推广应用、技术监督三大体系是当前安全科技工作的迫切任务。 相似文献
999.
从系统整体出发,基于既有建筑节能改造市场发展研究全面规划视角,架构了总括、ESCO驱动力作用机理、政府作用力实施机理、总结四大模块、两大篇共10章的层次体系。结果发现:ESCO驱动力以作用效益为导向,以运行实践与行为规律、作用影响机理、ESCO驱动策略、效益评价与优化策略为核心要素,是内在动力;政府作用力以有效性为基准,以运行特征与政府行为、影响机理与博弈策略、实施影响机理与有效性评价、实施策略为核心要素,是外在动力。在揭示既有建筑节能改造市场动力机制的基础上,提出未来研究发展趋势。 相似文献
1000.