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   119篇
  免费   1篇
  国内免费   7篇
安全科学   3篇
废物处理   2篇
环保管理   32篇
综合类   30篇
基础理论   28篇
污染及防治   21篇
评价与监测   8篇
社会与环境   3篇
  2023年   1篇
  2022年   1篇
  2020年   2篇
  2018年   2篇
  2017年   1篇
  2015年   1篇
  2014年   5篇
  2013年   11篇
  2012年   4篇
  2011年   10篇
  2010年   3篇
  2009年   14篇
  2008年   9篇
  2007年   8篇
  2006年   9篇
  2005年   5篇
  2004年   3篇
  2003年   4篇
  2002年   5篇
  2001年   5篇
  2000年   7篇
  1999年   1篇
  1998年   2篇
  1997年   4篇
  1996年   2篇
  1994年   3篇
  1992年   1篇
  1991年   1篇
  1990年   2篇
  1988年   1篇
排序方式: 共有127条查询结果,搜索用时 609 毫秒
31.
Proximity and connections to surface waters may play significant roles in determining impacts of manure spills. As occurred in many U.S. states, Minnesota adopted in 2000 more stringent regulations on Concentrated Animal Feeding Operations (CAFOs) including restrictions on siting new facilities near surface waters. The objectives of this study were to determine whether CAFO proximity to surface waters decreased following the siting restrictions and to evaluate implications of siting restrictions. Permit dates, locations, and distances to nearest surface water bodies for 111 west central Minnesota CAFOs were determined based on satellite imagery, historical records, and correspondence with regulatory officials. Average distance between surface waters and facilities permitted after 2000 was greater than for facilities permitted before 2000. The increase in average distance between CAFOs and public surface waters was significant for open water (1790 m, p = 0.03), but not for streams (280 m, p = 0.47). Decreased CAFO proximity to surface waters should benefit water quality, but after 2000 facilities continued to be permitted close to hydraulic connections not covered by the siting restriction. Comprehensive manure spill tracking and long term targeted water quality monitoring are needed to evaluate effectiveness of siting restrictions and other strategies for protecting surface waters from manure spills.  相似文献   
32.
ABSTRACT

Sustainable agriculture implies trade-offs with farm animal welfare. Proposals to increase agricultural productivity and ecological sustainability alike, are often linked to intensification, which may restrict animal welfare. Despite the growing importance of farm animal welfare for the alignment of agricultural and environmental policy, determinants of decision-making at the EU level remain unexplored. This article contributes to closing this research gap, broadening our understanding of why policymakers vote for the enactment of animal welfare policies. Applying the Social Identities in the Policy Process (SIPP) perspective we highlight the role of group membership for individual decision-making. By means of a quantitative analysis of voting behaviour in the European Parliament on two animal welfare policies, we show that different identities are salient. The strongest predictor is political group membership. In case of defections from the group line, the salience of national, sectoral and also demographic identities adds to the understanding of decision-making.  相似文献   
33.
两类混凝剂处理公厕水冲物的初步研究   总被引:1,自引:0,他引:1  
本文采用无机凝聚剂、有机絮凝剂和有机-无机混凝剂对公共厕所水冲物进行了固液分离研究.条件实验表明,供试的无机凝聚剂中,铁盐对水冲物的混凝速度最快,絮凝体相对于铝盐紧实,而铝盐的絮凝体大于铁盐;有机絮凝剂对供试水冲物的混凝效果随着PAM分子量的增加,效果增强.从处理后的水质看,铝盐普遍优于铁盐.与无机凝聚剂混合使用,能显著加快铝盐的分离,使处理后的絮凝体沉淀体积变小,湿渣的含水量降低2~3倍.气浮处理后的清液,其各项主要水质指标均达到国家污水综合排放二级标准(GB 8978-1996).  相似文献   
34.
西子生态农场的综合开发利用研究   总被引:8,自引:0,他引:8  
介绍了西子生态农场建设的情况。农场采用德国引进的固液分离技术处理畜禽粪便,制取沼气,沼气发电用于整个农场。沼液,沼渣得到综合利用、整个农场实现污水循环使用,取得了良好的经济效益。,社会效益和生态效益,具有推广价值。  相似文献   
35.
Objective: The objective of this study was to investigate whether the 5-point harness or the impact shield child restraint system (CRS) or both have the potential to cause chest injuries to children. This is determined by examining whether the loading to the chest reaches the internal organ injury threshold for children.

Method: The chest injury risk to a child occupant in a CRS was investigated using Q3 dummy tests, finite element (FE) simulations (Q3 dummy and human models), and animal tests. The investigation was done for 2 types of CRSs (i.e., the impact shield CRS and 5-point harness CRS) based on the UN R44 dynamic test specifications.

Results: The tests using a Q3 dummy indicated that although the chest deflection of the dummy in the impact shield CRS was large, it was less than the injury threshold (40 mm). Computational biomechanics simulations (using finite element FE analysis) showed that the Q3 dummy's chest is loaded by the shield and deforms substantially under this load. To clarify whether chest injuries due to chest compression can occur with an impact shield or with the 5-point harness CRS, 7 experiments were performed using Tibetan miniature pigs with weights ranging from 9.7 to 13 kg. Severe chest and abdominal injuries (lung contusion, coronary artery laceration, liver laceration) were found in the tests using the impact shield CRS. No chest injuries were present when using the 5-point harness CRS.

Conclusion: When using the impact shield CRS, the chest deformed substantially in dummy tests and FE simulations, and chest and abdominal injuries were observed in pig tests. It is possible that these chest injuries could also occur to child occupants sitting in the impact shield CRS.  相似文献   

36.
Ecologists are increasingly actively involved in conservation. We identify five key topics from a broad sweep of ecology that merit research attention to meet conservation needs. We examine questions from landscape ecology, behavioral ecology, ecosystem dynamics, community ecology, and nutrient cycling related to key topics. Based on literature review and publication trend assessment, consultation with colleagues, and roundtable discussions at the 24th International Congress for Conservation Biology, focused research on the following topics could benefit conservation while advancing ecological understanding: 1. Carbon sequestration, requiring increased linkages to biodiversity conservation; 2. Ecological invasiveness, challenging our ability to find solutions to ecological aliens; 3. Individual variation, having applications in the conservation of rare species; 4. Movement of organisms, integrating ecological processes across landscapes and scales and addressing habitat fragmentation; and 5. Trophic-level interactions, driving ecological dynamics at the ecosystem-level. Addressing these will require cross-disciplinary research under the overarching framework of conservation ecology.  相似文献   
37.
Public debate on acceptable farm animal husbandry suffers from a confusion of tongues. To clarify positions of various stakeholder groups in their joint search for acceptable solutions, the concept of animal welfare was split up into three notions: no suffering, respect for intrinsic value, and non-appalling appearance of animals. This strategy was based on the hypothesis that multi-stakeholder solutions should be based on shared values rather than on compromises. The usefulness of such an artificial value distinction strategy was tested in a small series of experiments. The results demonstrate that the chosen concept to distinguish between values is effective in a stakeholder context. Farmers’ views on doing good to animals appeared to be largely based on their value to prevent suffering and predominantly focused on the provision of regular care. Their priority for this value is clearly shared with other stakeholders, providing a basis for joint solutions. The concept of intrinsic value does not play a discernable role in farmers’ considerations. Based on the varying views on welfare, it can be inferred that there is a gradual rather than a principal difference between government legislation and farmers’ values, whereas public perception and acceptance of farm practices remains complicated. Distinction between value groups and focusing on a selected notion (such as no suffering) proved to be effective in bringing representatives of stakeholder groups together, but is unlikely to bridge the emotional gap between commercial farm practices and public ideals.  相似文献   
38.
Livestock production today faces thedifficult task of effectively meeting emergingconsumer concerns while remaining competitive on majortarget markets. Meeting consumer concerns aboutproduct safety and animal welfare are identified askey attention points for future livestock production.The relevance of these issues pertains to productionefficiency and economic benefits and tore-establishing meat sector image and consumer trust.The current paper analyses consumer concerns about theethical issues of meat safety and animal welfare fromcurrent livestock production. The research methodologyis based on literature review, secondary data sources,and primary research through focus group discussionsand a survey of 320 meat consumers in Belgium.Objectives were to assess importance attached byconsumers to product safety and animal welfare asethical issues in commercial livestock production, andto evaluate consumer perception of these issues forbeef, pork, and poultry. Significant differences inissue importance and perception are identified amongconsumer groups based on socio-demographic andbehavioral characteristics. From the analysis, meatsafety emerges as an absolute but minimum requirementfor future success of livestock and meat production.Additionally, animal welfare can be expected to becomea critical theme especially for pork and poultryacceptance.  相似文献   
39.
日本畜禽产业排泄物处理与循环利用的现状与技术   总被引:1,自引:0,他引:1  
20世纪40年代后,日本畜禽产业结构向大型集约化方向发展,年畜禽粪便排放总量7600万t左右。同时,由于畜禽产业等中小规模企业排出含有高氮磷等污染物的废水,致使湖泊、海域的富营养化问题日益严重。日本《水质污浊防止法》规定:饲养规模在50m2以上的养猪场和200m2以上的养牛场的排泄物排放标准为:总氮<120mg/L,总磷<16mg/L。牲畜粪便处理技术的研究和开发,一方面着重于高效脱氮除磷技术,另一方面,从资源的有效利用角度考虑,建立各种排水与废弃物处置的自立型循环共生系统。本文介绍了当前日本畜产业排泄物的处理与循环利用的现状与技术,特别是复合回收型处理系统及远程自动控制等技术的应用,推进了生物量循环的循环型社会的形成,同时,实现环境改善与资源的再利用。  相似文献   
40.
研究了用超声波萃取城市污水处理厂污泥中动植物油和矿物油的方法,并与索氏提取法进行比较.结果表明,超声波萃取法对污泥中矿物油和动植物油测定操作简单快速,标样回收率高,精密度好.  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