首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   221篇
  免费   19篇
  国内免费   3篇
安全科学   52篇
废物处理   2篇
环保管理   55篇
综合类   63篇
基础理论   22篇
污染及防治   5篇
评价与监测   10篇
社会与环境   16篇
灾害及防治   18篇
  2023年   2篇
  2022年   6篇
  2021年   4篇
  2020年   6篇
  2019年   8篇
  2018年   6篇
  2017年   13篇
  2016年   11篇
  2015年   6篇
  2014年   12篇
  2013年   10篇
  2012年   12篇
  2011年   16篇
  2010年   14篇
  2009年   12篇
  2008年   4篇
  2007年   21篇
  2006年   15篇
  2005年   17篇
  2004年   12篇
  2003年   6篇
  2002年   2篇
  2001年   4篇
  2000年   5篇
  1999年   4篇
  1998年   1篇
  1997年   3篇
  1996年   4篇
  1995年   1篇
  1994年   2篇
  1993年   2篇
  1989年   1篇
  1985年   1篇
排序方式: 共有243条查询结果,搜索用时 46 毫秒
151.
Agri-environment schemes (AESs) have been implemented across EU member states in an attempt to reconcile agricultural production methods with protection of the environment and maintenance of the countryside. To determine the extent to which such policy objectives are being fulfilled, participating countries are obliged to monitor and evaluate the environmental, agricultural and socio-economic impacts of their AESs. However, few evaluations measure precise environmental outcomes and critically, there are no agreed methodologies to evaluate the benefits of particular agri-environmental measures, or to track the environmental consequences of changing agricultural practices. In response to these issues, the Agri-Environmental Footprint project developed a common methodology for assessing the environmental impact of European AES. The Agri-Environmental Footprint Index (AFI) is a farm-level, adaptable methodology that aggregates measurements of agri-environmental indicators based on Multi-Criteria Analysis (MCA) techniques. The method was developed specifically to allow assessment of differences in the environmental performance of farms according to participation in agri-environment schemes. The AFI methodology is constructed so that high values represent good environmental performance. This paper explores the use of the AFI methodology in combination with Farm Business Survey data collected in England for the Farm Accountancy Data Network (FADN), to test whether its use could be extended for the routine surveillance of environmental performance of farming systems using established data sources. Overall, the aim was to measure the environmental impact of three different types of agriculture (arable, lowland livestock and upland livestock) in England and to identify differences in AFI due to participation in agri-environment schemes. However, because farm size, farmer age, level of education and region are also likely to influence the environmental performance of a holding, these factors were also considered. Application of the methodology revealed that only arable holdings participating in agri-environment schemes had a greater environmental performance, although responses differed between regions. Of the other explanatory variables explored, the key factors determining the environmental performance for lowland livestock holdings were farm size, farmer age and level of education. In contrast, the AFI value of upland livestock holdings differed only between regions. The paper demonstrates that the AFI methodology can be used readily with English FADN data and therefore has the potential to be applied more widely to similar data sources routinely collected across the EU-27 in a standardised manner.  相似文献   
152.
Ezgi Orhan 《Disasters》2016,40(1):45-64
The lack of attention paid to businesses in disaster management systems from the standpoint of state policies hampers efforts to build community resilience. This paper examines, therefore, the extent of business preparedness for disasters. Empirical research was conducted in Adapazarı, Turkey, 13 years after the İzmit earthquake, which struck the northwest of the country on 17 August 1999, claiming the lives of some 17,000 people. For the study, 232 firms were selected to inquire about their preparedness before and after the event. It is hypothesised that business preparedness is influenced by the following set of variables: business size; business sector; business age; financial condition prior to the disaster; occupancy tenure; market range; education level; and previous disaster experience. In line with the findings of the research, a policy framework is constructed to rationalise the allocation of resources for building resilience at the aggregate level by facilitating business preparedness.  相似文献   
153.
为了满足石油化工生产中对高要求操作模式下采用异型设备的安全联锁回路进行SIL定级的需求,避免因误用同型PFH公式导致SIL等级评估误差。考虑各通道差异性及其失效顺序的遍历性,以MonteCarlo仿真值为多元线性回归模型观察样本,以改进共因失效部分多样性修正因子确定方法,提出异型KooN冗余结构每小时危险失效平均频率(PFH)的计算公式;比较该模型独立失效部分与异型1oo2结构Markov模型PFH结果,并分别将该模型和传统同型PFH公式应用于海上采油平台高完整性压力保护系统(HIPPS)异型关断阀子系统的比较分析。研究结果表明:在不同检测周期内,所提出的PFH计算模型与Markov模型PFH计算结果相对误差均保持在10-3数量级;但当检测周期大于3 a时,使用同型PFH公式会出现对HIPPS子系统SIL等级的误判,造成井口压力联锁保护功能过保护或欠保护。研究结果有助于生产单位准确评估联锁保护风险和设备维护投入。  相似文献   
154.
本文为我国的排污权交易设计了一套管理信息系统。该系统设计采用C/S和B/S混合架构体系,充分发挥了两者的长处。该系统一方面可以同时为环境管理部门、排污企业和社会公众三类主体提供信息化服务,大大方便了排污权的交易过程,并保证了排污权交易的公平与透明;另一方面可以使环境管理人员方便地查询和检索相关企业,简化了环境管理工作。  相似文献   
155.
郑晓笛 《环境工程》2015,33(4):156-160
中国目前面临着前所未有的大规模城镇化进程与产业升级,大量传统工业企业搬迁或改制,工业类棕地大面积暴露。在空间特征上,工业类棕地的场地地形基本平坦,最显著的空间元素为大型的工业建筑遗产。在污染特征上,此类棕地的污染以土壤污染与地下水污染为主,隐蔽性强、潜伏期长,项目周期长且具有不确定性。著名的美国西雅图市煤气厂公园经历了长达半个多世纪、几轮的环境勘测与污染治理过程,至今场地中仍然可能残存有污染物质,充分体现了工业类棕地的上述特征。  相似文献   
156.
随着因特网的发展,越来越多的人在网上使用邮件与朋友,家人聊天,甚至利用它在网上做生意.现在没有一种通讯方式能与之相比.使用E-mail邮件效率高,费用低,省时间.论述了如何正确地写好商务英语E-mail邮件.掌握这些技巧是商务活动成功的关键之一.参4.  相似文献   
157.
Metal price fluctuations have recently been of interest not only because of their cyclical volatility but also of their interaction with business cycles. A related issue is whether metal prices move together sufficiently to collectively reflect macroeconomic influences. Correlation or the tendency for prices to move together has been termed “comovement”, where the commonality in prices reflects the tendency of commodity markets to respond to common business cycle and trend factors. Metal prices are known to respond to macroeconomic influences and the latter might well explain the common factor which causes them to move together. Our goal is to provide an estimate of the common factor in metal prices and to relate this factor to important macroeconomic influences. The prices we study are for aluminum, copper, tin, lead and zinc; the macroeconomic variables include industrial production, consumer prices, interest rates, stock prices, and exchange rates. Our results confirm that the common factor in metal prices can be related to such macroeconomic influences.  相似文献   
158.
充分利用校园绿化进行园林教学的尝试   总被引:2,自引:0,他引:2  
园林专业是实践性很强的学科,教学内容跨度大、涉及面广。针对我院园林专业实践性强的特点,利用校园植物进行园林专业在树种识别、标本制作等方面的实践教学改革,有效地提高了教学质量。  相似文献   
159.
- Sustainable chemistry - Section editors: Klaus Günter Steinhäuser, Steffi Richter, Petra Greiner, Jutta Penning, Michael AngrickBackground, Aim and Scope Chemicals play a vital role in the day-to-day life of industrialised societies. Their use is not restricted to the chemical enterprises per se, but is a crucial part of production processes in a lot of industrial sectors. Traditional instruments of environmental policy (such as bans, restrictions) can only deal with the most hazardous substances. The Johannesburg Implementation Plan of 2002 calls for more sustainable patterns of production and consumption, and sets the year of 2020 as a goal to use chemicals in a way that human health and the environment are not endangered. Political instruments should not only gather more knowledge about the properties of chemicals, but should also stimulate the environmentally sound use of chemicals. Existing business models should therefore be reviewed in relation to this strategic approach to encourage marketing options with respect to the environmental focus.Main Features Business models were examined for their effects on the consumption of chemicals and amount of waste emissions in relation to their economic potential. Different possibilities for cooperation of supplier, user and disposal companies were elaborated and examined with a view to the specific situation in Austria.Results and Discussion A range of cooperative models – summarised under the term ‘chemical leasing’ - was identified, which can contribute to a more efficient use of resources. 12 main possible application areas (cleaning, lubrication, paint stripping and others) have been identified in Austria. If chemical leasing models were applied in these areas, the amounts of chemicals currently used could be reduced by one third (53,000 tonnes per year). Cost reductions of up to 15 % can be expected.Conclusion The application of chemical leasing models can contribute considerably to achieving more sustainable and resource-efficient patterns of production. The Austrian Ministry for Environment has therefore decided to subsidise the further practical implementation of these new service-oriented business models. Pilot projects in 4 enterprises, which are supervised by consulting companies, are currently being carried out. Recommendation and Outlook The experiences of the pilot projects will serve as valuable building blocks for the wider use of chemical leasing models. Furthermore, the UNIDO Cleaner Production Centres have expressed their clear interest and will examine the possibility to use chemical leasing as a part of their Cleaner Production Programmes.  相似文献   
160.
针对大型商场营业厅设计疏散人数指标体系的研究现状与存在问题,提出了设计疏散人数指标体系的安全保证率理念,论证了大型商场营业厅设计疏散人数取双休日(而不取黄金周)人数指标的合理性.进一步优化了大型商场营业厅疏散人数指标体系,进一步减少了以此为根据设计的楼梯间宽度,为修编<建筑设计防火规范>提供参考依据.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号