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701.
702.
实施工业污水排放的有效监管是水环境保护的重要环节。为借鉴国内外相关领域的理论和实践经验,促进我国监管制度的完善。从监管理论、委托-代理框架下激励监管理论以及工业水环境监管三方面的研究进展进行综述。  相似文献   
703.
导游是旅游从业一线人员,代表着旅游业的形象,关系着旅游业的良性发展。在游客追求低廉出游价格时,导游因其弱势群体地位最终成为旅游服务利益方的牺牲品,导游生存、发展与管理已成为困扰旅游业的一大难题。SPC理论即服务利益链理论强调顾客与员工的让渡价值,认为企业盈利能力的增强主要源于顾客和员工的企业忠诚度并最终源于企业对内部员工的服务质量。基于SPC理论,探讨了我国服务型导游管理模式的构建,指出旅游服务各利益方应服务导游,创造导游良好的就业和发展环境,以解决导游管理难题。  相似文献   
704.
突变理论在矿山安全中的应用   总被引:1,自引:0,他引:1  
矿山企业的安全状况,直接关系到我国资源工业的发展,如何提高矿山安全,是矿山重大危险源辨识与评价技术研究的重点。笔者应用突变理论这一工具,对矿井内因火灾、矿山安全投资、煤层注水效果进行研究,其中的结论可服务于生产实际  相似文献   
705.
Crown fire endangers fire fighters and can have severe ecological consequences. Prediction of fire behavior in tree crowns is essential to informed decisions in fire management. Current methods used in fire management do not address variability in crown fuels. New mechanistic physics-based fire models address convective heat transfer with computational fluid dynamics (CFD) and can be used to model fire in heterogeneous crown fuels. However, the potential impacts of variability in crown fuels on fire behavior have not yet been explored. In this study we describe a new model, FUEL3D, which incorporates the pipe model theory (PMT) and a simple 3D recursive branching approach to model the distribution of fuel within individual tree crowns. FUEL3D uses forest inventory data as inputs, and stochastically retains geometric variability observed in field data. We investigate the effects of crown fuel heterogeneity on fire behavior with a CFD fire model by simulating fire under a homogeneous tree crown and a heterogeneous tree crown modeled with FUEL3D, using two different levels of surface fire intensity. Model output is used to estimate the probability of tree mortality, linking fire behavior and fire effects at the scale of an individual tree. We discovered that variability within a tree crown altered the timing, magnitude and dynamics of how fire burned through the crown; effects varied with surface fire intensity. In the lower surface fire intensity case, the heterogeneous tree crown barely ignited and would likely survive, while the homogeneous tree had nearly 80% fuel consumption and an order of magnitude difference in total net radiative heat transfer. In the higher surface fire intensity case, both cases burned readily. Differences for the homogeneous tree between the two surface fire intensity cases were minimal but were dramatic for the heterogeneous tree. These results suggest that heterogeneity within the crown causes more conditional, threshold-like interactions with fire. We conclude with discussion of implications for fire behavior modeling and fire ecology.  相似文献   
706.
As frequent travel across international borders has become common for an ever-increasing number of workers, it is essential to understand what helps these international business travelers (IBTs) thrive and embrace their global work responsibilities. This study's purpose is to examine the role of developmental opportunities (i.e., work role challenges) in helping IBTs see frequent travel as a predominantly beneficial experience. By integrating two theories of motivation—conservation of resources theory and the challenge-hindrance demands framework—I build a moderated mediation model of IBTs' intent to cease their global work responsibilities (i.e., global role turnover intentions). Using latent moderated structural equation modeling, I test the model on a sample of 204 IBTs collected at two time points. Results show that, through the psychological state of thriving at work, travel frequency has a negative indirect association with IBTs' global role turnover intentions when IBTs' work roles are challenging and a positive association when their work lacks challenge. This is primarily the case regarding the challenge of being responsible for others at work. The novelty of IBTs' work tasks is also a salient challenge but to a lesser extent. This study contributes to literatures on global work, work role design, and thriving.  相似文献   
707.
With the development of modern automatic control systems, chemical accidents are of low frequency in most chemical plants, but once an accident happens, it often causes serious consequences. Near-misses are the precursor of accidents. As the process progresses, near misses caused by abnormal fluctuation of process variables may eventually lead to accidents. However, variables that may lead to serious consequences in the production process cannot update the risk in the life cycle of the process by traditional risk assessment methods, which do not pay enough attention to the near misses. Therefore, this paper proposed a new method based on Bayesian theory to dynamically update the probability of key variables associated with process failure risk and obtain the risk change of the near-misses. This article outlines the proposed approach and uses a chemical process of styrene production to demonstrate the application. In this chemical process, the key variables include flow rate, liquid level, pressure and temperature. In order to study the dynamic risk of the chemical process with consideration of near misses, according to the accumulated data of process variables, firstly the abnormal probability of the variables and the failure rate of safety systems associated with the variables were updated with time based on Bayesian theory. On the basis of the dynamic probability of key process variables, an event tree of possible consequences caused by variable anomalies was established. From the logical relationship of the event tree, the probability of different consequences can be obtained. The results show that the proposed risk assessment method based on Bayesian theory can overcome the shortcomings of traditional analysis methods. It shows the dynamic characteristics of the probability of different near misses, and achieves the dynamic risk analysis of chemical process accidents.  相似文献   
708.
Information communication technologies (ICTs; e.g., smartphones) enable employees to work anywhere and anytime, blurring work and family boundaries. Building on this trend, this study draws from work–family border/boundary theory to examine antecedents and consequences of employees' weekly experiences of ICT demands (i.e., being accessible and contacted for work after hours via ICTs). A sample of 546 elementary teachers completed a registration survey and a weekly diary for 5 weeks. Multilevel modeling results suggest that ICT demands as a form of work intrusion in the home can constitute a source of significant weekly strain (i.e., negative rumination, negative affect, and insomnia). As border crossers, teachers' adoption of a technological boundary tactic (i.e., keeping work email alerts turned off on mobile phones) was related to lower weekly ICT demands. As important border keepers at work, school principals' work–family support was related to teachers' lower weekly ICT demands, whereas parents' after-hours boundary expectations were related to teachers' higher weekly ICT demands. Moreover, teachers' boundary control was found as a mediating mechanism by which the two border keepers influenced teachers' ICT demands−negative rumination link. That is, teachers who received fewer boundary expectations and/or more work–family support had greater boundary control, which in turn buffered the ICT demands–negative rumination relationship.  相似文献   
709.
大力发展现代物流业和皖江城市带承接产业转移示范区建设是两大重要国家级战略.首先对轴—辐理论的国内外研究现状进行了总结和归纳,分析了轴—辐网络的结构及其优劣势.其次,设计了物流中心性指数的评价指标体系,运用主成分分析法对皖江城市带的9个地级城市进行物流节点等级划分,根据分析结果的总得分和区位特征确定合肥、芜湖、安庆3个一级物流节点,形成轴三角.分析了各级物流节点间的干线及支线物流通道,构建了皖江城市带轴—辐物流网络空间.  相似文献   
710.
生物法废气净化专用微生物菌种及其作用   总被引:31,自引:4,他引:27       下载免费PDF全文
用气相培育驯化法培养获得废气净化专用菌种,由其挂膜制作的生物膜填料塔对废气中甲苯进行净化,实验结果表明,气相培养法所得菌种对甲苯的净化性能明显优于液相培养法所得菌种.生物膜通过吸附-生物降解作用过程净化气相中的甲苯,使针对挥发性有机废气生物净化过程提出的吸附-生物膜动力学理论的依据得到了验证.  相似文献   
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