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   13561篇
  免费   1279篇
  国内免费   1239篇
安全科学   1893篇
废物处理   318篇
环保管理   3098篇
综合类   7134篇
基础理论   1111篇
环境理论   49篇
污染及防治   468篇
评价与监测   824篇
社会与环境   1000篇
灾害及防治   184篇
  2024年   34篇
  2023年   159篇
  2022年   220篇
  2021年   354篇
  2020年   410篇
  2019年   354篇
  2018年   314篇
  2017年   581篇
  2016年   603篇
  2015年   665篇
  2014年   642篇
  2013年   916篇
  2012年   965篇
  2011年   995篇
  2010年   793篇
  2009年   728篇
  2008年   534篇
  2007年   849篇
  2006年   857篇
  2005年   764篇
  2004年   669篇
  2003年   617篇
  2002年   478篇
  2001年   486篇
  2000年   489篇
  1999年   332篇
  1998年   238篇
  1997年   216篇
  1996年   163篇
  1995年   175篇
  1994年   100篇
  1993年   117篇
  1992年   62篇
  1991年   38篇
  1990年   31篇
  1989年   18篇
  1988年   10篇
  1987年   8篇
  1986年   10篇
  1984年   6篇
  1982年   7篇
  1981年   7篇
  1980年   6篇
  1979年   9篇
  1978年   6篇
  1977年   9篇
  1976年   5篇
  1975年   6篇
  1973年   5篇
  1972年   5篇
排序方式: 共有10000条查询结果,搜索用时 298 毫秒
11.
This study addresses the use of message carriers to convey corporate social responsibility information to promote eco-purchasing involvement. The work tests various media formats transmitted via social media. The effects of corporate vs. peer communication in a corporate social responsibility campaign in stimulating self-reported eco-purchasing involvement are indicated. The research varies communication dimensions of a fictional corporate social responsibility campaign sent through social media. Multiple media formats; new release; article; and advertisement were tested, as was the inclusion of social media persuasive sentiment. The analysis of source/format combinations and source/format/sentiment combinations found statistically significant differences for consumer-to-consumer communication in stimulating eco-purchasing involvement in certain circumstances. This research suggests an emerging role for the consumer communicator as a content co-creator and validates the effective use of articles and news releases instead of advertising on social media, yielding managerial and scholarly implications.  相似文献   
12.
San Vicente Bay is a coastal shallow embayment in Central Chile with multiple uses, one of which is receiving wastewater from industrial fisheries, steel mill effluents, and domestic sewage. A simulation model was developed and applied to dissolved oxygen consumption by organic residues released into this embayment. Three compartments were established as function of: depth, circulation and outfall location. The model compartments had different volumes, and their oxygen saturation value was used as baseline. The parameters: (a) BOD5 of the industrial and urban effluents, (b) oxygen demand by organic sediments, (c) respiration, (d) photosynthesis and (e) re-aeration were included in the model. Iteration results of the model showed severe alterations in Compartment 1, with a decrease of 65% in the oxygen below saturation. Compartment 2 showed a small decline (10%) and compartment 3 did not show apparent changes in oxygen values. Measures recommended for remediation were to decrease the BOD5 loading by 30% in the affected sector. Iteration of the model for 200 h following recommendations derived from the preceding results produced an increase in saturation of 60% (5 ml O2 L−1), which suggested an improvement of the environmental conditions.  相似文献   
13.
三峡库区水土流失特点及其环境危害防治措施探讨   总被引:15,自引:0,他引:15  
水土流失是三峡库区主要环境问题之一,也是库区产生大量泥沙的根本因素,更是造成库区人民生活贫困的根源。本文就三峡库区水土流失的特点及其环境危害作了分析,提出了相应的防治措施,为水土流失防治工程提供科学依据。  相似文献   
14.
生态文明建设对环境法理论变革的影响   总被引:1,自引:0,他引:1  
随着人类社会由工业文明向生态文明的转变,环境法理论也随之发生着变革。近年来。众多学者对环境法理论的变革问题进行了热烈的讨论。生态文明的法律观。承认自然界及其生物具有内在价值。主张人与自然的和谐发展。为生态文明建设提供了坚实的法学理论支持。  相似文献   
15.
环境保护是科学发展观的题中之意,科学发展观关于环境保护的论述,是党的环境保护理论的精髓。学习实践科学发展观活动,是一个哲学内涵非常丰富的课题,是十分难得的研究环境哲学的大好机遇。试点经验显示了环境保护在学习实践科学发展观活动中的重要作用。他们一方面在科学发展中通过转变发展方式,调整经济结构,解决环境难题;一方面坚持环境保护与经济发展并重,在保护环境中求发展,努力实现环境与经济“双赢”。其共性是,注重治本、注重生态、注重政策。深入学习实践科学发展观,关键在实践,要深入一线,深入调研,融人群众的实践,总结来自一线的新鲜经验。要适应新形势,了解新情况,解决新问题。在学习实践科学发展观活动中,不断提高落实科学发展观,在科学发展中,提高解决环境问题的能力,实现环境与发展、环境与经济的“双赢”。  相似文献   
16.
企业安全管理体系标准模式的比较研究   总被引:7,自引:4,他引:3  
采用对比分析法和实证分析法,对当前国内外流行的企业安全管理体系标准模式及其评价方法进行比较研究,旨在把握诸多标准模式的原则、路径、结构、方法和共性特征及其可以发挥的具体优点,将研究的标准模式的评价方法归纳为两大类即体系认证审核法和综合考评打分法,并对两类评价方法的优缺点进行剖析。体系认证审核法的优点是过程方法、符合性及抽样,考评打分法则提供了安全绩效准则。对吸收融合两类评价方法的优点形成综合性评价方法的途径和方式进行了探讨,为企业建立有效、适用的安全管理体系提供了依据。  相似文献   
17.
我国消防标准体系分析   总被引:6,自引:2,他引:4  
为明确我国消防标准体系发展的方向和重点,分别从消防标准的数量、标龄、类型、属性和采标情况等5个方面对我国消防标准体系进行分析,并与国际标准化组织、欧盟标准化委员会和美国的消防标准体系进行了比较。研究结果表明:我国消防标准体系整体适用性在不断增强;需制定周期性标准复审计划;消防基础试验类和管理类标准应成为下一步消防标准制修订的重点;消防强制性标准所占比例有待进一步下调;需建立国际标准动态跟踪机制,同时应注重将我国先进的消防标准转化为国际标准。  相似文献   
18.
This study investigates the inherent optical properties (IOP) of a Brazilian river during a non-natural, anthropogenically mediated, toxic spill of a wood-pulping factory (the ‘Cataguazes accident’). The results indicated an outstanding transformation in the river water chromophoric dissolved organic matter (CDOM) pools. For instance, increases in CDOM absorption coefficients, a CDOM (λ), which were averaged at specific spectral intervals, , ranged from 58-fold at the UV-B and UV-A ranges to 95-fold at the PAR range. As a result, the water color expressed as CDOM absorption at 440 nm, a CDOM (440), varied from 4.16 to 365.03 m-1. For S-coefficient, the variations ranged from ∼1.1 to 5.6-fold, respectively, at the 300–650 nm and UV-B range. The variability of S as a proxy of dissolved chromophores was thus clearly influenced by the spectral range used. Optical proportions were also investigated through the use of and S ratios at the UV-B, UV-A, and PAR ranges and, in the case of , also at the NIR range. This approach also showed clear variations between the water samples, likely reflecting changes in the composition of optically active substances in the river system. As a whole, the findings obtained here indicated that both the quantity and quality of the chromophoric material dissolved in the river water were greatly altered by the toxic spill. The changes in the optical properties of the river water, although extreme and likely with no parallel in the literature, were quite rapid as indicated by the optical resilience of the system. Overall, this study indicates that IOP might be thought, and possibly used, as a metric tool for monitoring the state of waters and aquatic ecosystems.  相似文献   
19.
阐述了开展工业区群环境影响评价的意义,比较了单个工业园区和工业区群环评的异同,以广州番禺区工业区群环评项目为例,简述了该环评的主要内容和特点,并提出了建议。  相似文献   
20.
The increase in damage due to natural disasters is directly related to the number of people who live and work in hazardous areas and continuously accumulate assets. Therefore, land use planning authorities have to manage effectively the establishment and development of settlements in flood-prone areas in order to avoid the further increase of vulnerable assets. Germany faced major destruction during the flood in August 2002 in the Elbe and Danube catchments, and many changes have been suggested in the existing German water and planning regulations. This article presents some findings of a “Lessons Learned” study that was carried out in the aftermath of the flood and discusses the following topics: 1) the establishment of comprehensive hazard maps and flood protection concepts, 2) the harmonization of regulations of flood protection at the federal level, 3) the communication of the flood hazard and awareness strategies, and 4) how damage potential can be minimized through measures of area precaution such as resettlement and risk-adapted land use. Although attempts towards a coordinated and harmonized creation of flood hazard maps and concepts have been made, there is still no uniform strategy at all planning levels and for all states (Lae nder) of the Federal Republic of Germany. The development and communication of possible mitigation strategies for “unthinkable extreme events” beyond the common safety level of a 100-year flood are needed. In order to establish a sustainable and integrated flood risk management, interdisciplinary and catchment-based approaches are needed.  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