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401.
不同地区中小企业发生的工伤事故有其自身的特点和规律。通过对江苏省某市2001—2004年发生在中小企业的工伤死亡事故进行实证分析发现:该市工伤死亡事故集中发生在非煤矿山、建筑等6行业的中小企业中,事故类别以高处坠落、物体打击等6种为主;工龄较短的中青年职工在罹难者人数中所占比例较高;工伤死亡事故的发生频率夏季高于其他3个季节;事故发生的主要原因是违反操作规程。笔者认为:应促进企业增加安全投入,尤其要重视“软”投入;监管部门要明确安全监管重点,分类分级管理企业,以控制和预防工伤事故的发生。 相似文献
402.
After satisfying their quantitative and qualitative needs as regards nutrition, consumers in developed countries are becoming
more involved in the ethical aspects of food production, especially when it relates to animal products. Social demands for
respecting animal welfare in housing systems are increasing rapidly, as is social awareness of human responsibility towards
farm animals. Many studies have been conducted on animal welfare measurement in different production systems, but the available
information for small ruminants remains insufficient. In this study, a 75 criteria-evaluation tool has been set up on the
basis of the five freedoms concept. Animal welfare considerations have been analyzed in 25 documents, including labeling schemes,
regulations, and recommendations from different European countries. The results show many differences between regular and
organic small ruminant farming standards. Emergency measures are generally lacking. A weak representation of psychological
aspects of animal welfare, especially by the current European legislation, is highlighted. 相似文献
403.
The Pacific Northwest encompasses a range of hydrologic regimes that can be broadly characterized as either coastal (where rain and rain on snow are dominant) or interior (where snowmelt is dominant). Forest harvesting generally increases the fraction of precipitation that is available to become streamflow, increases rates of snowmelt, and modifies the runoff pathways by which water flows to the stream channel. Harvesting may potentially decrease the magnitude of hyporheic exchange flow through increases in fine sediment and clogging of bed materials and through changes in channel morphology, although the ecological consequences of these changes are unclear. In small headwater catchments, forest harvesting generally increases annual runoff and peak flows and reduces the severity of low flows, but exceptions have been observed for each effect. Low flows appear to be more sensitive to transpiration from vegetation in the riparian zone than in the rest of the catchment. Although it appears that harvesting increased only the more frequent, geomorphically benign peak flows in several studies, in others the treatment effect increased with return period. Recovery to pre‐harvest conditions appeared to occur within about 10 to 20 years in some coastal catchments but may take many decades in mountainous, snow dominated catchments. 相似文献
404.
Takashi Gomi R. Dan Moore Marwan A. Hassan 《Journal of the American Water Resources Association》2005,41(4):877-898
This paper reviews suspended sediment sources and transport in small forest streams in the Pacific Northwest region of North America, particularly in relation to riparian management. Mass movements, reading and yarding practices, and burning can increase the supply of suspended sediment. Sediment yields recovered to pre‐harvest levels within one to six years in several paired catchment studies. However, delayed mass movements related to roads and harvesting may produce elevated suspended sediment yield one or more decades after logging. There is mixed evidence for the role of streamside tree throw in riparian buffers in supplying sediment to streams. Harvesting within the riparian zone may not increase suspended sediment yield if near stream soils are not disturbed. Key knowledge gaps relate to the relative roles of increased transport capacity versus sediment supply, the dynamics of fine sediment penetration into bed sediments, and the effects of forest harvesting on suspended sediment at different scales. Future research should involve nested catchments to examine suspended sediment response to forest practices at multiple spatial scales, in combination with process‐based field studies. 相似文献
405.
406.
中小城市(城镇)垃圾转运系统优化设计研究 总被引:4,自引:0,他引:4
我国城镇垃圾处理与处置技术的发展,不仅为垃圾转运技术的研究提供了机遇,而且提出了更高的要求。合理有效的资源配置在很大程度上决定了垃圾转运的效率,本文结合典型城镇垃圾转运系统的需求及特点,将系统工程的理论与方法具体化,运用模块化设计理念与方法进行了城镇垃圾转运系统及转运站的优化设计研究。 相似文献
407.
中小企业融资现状及对策探讨 总被引:2,自引:0,他引:2
融资困难始终是困扰中小企业发展的难题.从中小企业融资途径入手,系统地分析了中小企业融的问题,进而从企业方面、金融机构方面和政府三个角度提出相关的措施. 相似文献
408.
409.
发展循环经济是农村城镇化环境保护的必然抉择 总被引:1,自引:0,他引:1
农村城镇化在给农村经济带来繁荣和发展的同时,也带来了外部不经济问题。伴随着农村城镇化进程的加快,农村及城镇环境污染越来越严重。要协调好城镇发展与环境保护问题就必须发展循环经济,在城镇建立起企业内部清洁生产、企业间生态工业园区、工农业的多级生态链接、社会循环利用四个层次的循环模式,实现经济效益、生态效益和社会效益的统一。 相似文献
410.
Judy L. Meyer David L. Strayer J. Bruce Wallace Sue L. Eggert Gene S. Helfman Norman E. Leonard 《Journal of the American Water Resources Association》2007,43(1):86-103
Abstract: The diversity of life in headwater streams (intermittent, first and second order) contributes to the biodiversity of a river system and its riparian network. Small streams differ widely in physical, chemical, and biotic attributes, thus providing habitats for a range of unique species. Headwater species include permanent residents as well as migrants that travel to headwaters at particular seasons or life stages. Movement by migrants links headwaters with downstream and terrestrial ecosystems, as do exports such as emerging and drifting insects. We review the diversity of taxa dependent on headwaters. Exemplifying this diversity are three unmapped headwaters that support over 290 taxa. Even intermittent streams may support rich and distinctive biological communities, in part because of the predictability of dry periods. The influence of headwaters on downstream systems emerges from their attributes that meet unique habitat requirements of residents and migrants by: offering a refuge from temperature and flow extremes, competitors, predators, and introduced species; serving as a source of colonists; providing spawning sites and rearing areas; being a rich source of food; and creating migration corridors throughout the landscape. Degradation and loss of headwaters and their connectivity to ecosystems downstream threaten the biological integrity of entire river networks. 相似文献