全文获取类型
收费全文 | 846篇 |
免费 | 58篇 |
国内免费 | 83篇 |
专业分类
安全科学 | 98篇 |
废物处理 | 11篇 |
环保管理 | 255篇 |
综合类 | 293篇 |
基础理论 | 115篇 |
环境理论 | 1篇 |
污染及防治 | 45篇 |
评价与监测 | 42篇 |
社会与环境 | 116篇 |
灾害及防治 | 11篇 |
出版年
2024年 | 1篇 |
2023年 | 15篇 |
2022年 | 29篇 |
2021年 | 28篇 |
2020年 | 37篇 |
2019年 | 26篇 |
2018年 | 34篇 |
2017年 | 44篇 |
2016年 | 39篇 |
2015年 | 37篇 |
2014年 | 30篇 |
2013年 | 47篇 |
2012年 | 48篇 |
2011年 | 63篇 |
2010年 | 24篇 |
2009年 | 41篇 |
2008年 | 32篇 |
2007年 | 39篇 |
2006年 | 38篇 |
2005年 | 29篇 |
2004年 | 34篇 |
2003年 | 27篇 |
2002年 | 35篇 |
2001年 | 20篇 |
2000年 | 20篇 |
1999年 | 24篇 |
1998年 | 18篇 |
1997年 | 17篇 |
1996年 | 20篇 |
1995年 | 22篇 |
1994年 | 16篇 |
1993年 | 9篇 |
1992年 | 11篇 |
1991年 | 7篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 5篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1976年 | 1篇 |
1972年 | 1篇 |
1968年 | 1篇 |
排序方式: 共有987条查询结果,搜索用时 15 毫秒
111.
浅谈我国冰雹的分布规律及其保险对策 总被引:2,自引:0,他引:2
本文从冰雹灾害的分布规律着手,研究我国雹灾对策形式之一——雹灾保险,在对世界各国雹灾保险借鉴的基础上,选择我国雹灾保险的模式,建立适合我国国情的雹灾保险。 相似文献
112.
113.
114.
115.
Marek Makowski Lszl Somlydy David Watkins 《Journal of the American Water Resources Association》1996,32(5):937-951
ABSTRACT: This paper presents the implementation of one element of a decision support system (DSS) for regional water quality management, applied to the Nitra River Basin in Slovakia. A model-based, aspiration-led methodology for multicriteria decision support has been used for the study. Several reusable, modular software tools have been developed and implemented: a problem-specific generator to produce the core part of the mathematical programming model, tools for the generation and interactive modification of multicriteria problems, and a solver for the resulting mixed-integer optimization problem. Provided in the paper are the following: a complete formulation of the mathematical model (including the imbedded water quality model), a summary of the aspiration-reservation-led multiple criteria optimization approach applied to decision support, and an overview of results that illustrate the applied approach and provide some interesting insights to the case study. 相似文献
116.
Løkke S 《Environmental science and pollution research international》2006,13(5):342-349
Background, Aim and Scope
The paper investigates the development of the institutional basis of the present modes of chemicals regulation and management, with special attention to interrelations with the precautionary principle. Main Features: The paper elucidates on how the precautionary principle has been shaped in relation to chemicals regulation and management since Carson's Silent Spring (years before the principle was confirmed as a policy-principle in German and European legislation. Furthermore, it is examined how the precautionary principle interacted with the development of the present chemicals regulatory regime, in a complex interplay within the OECD and Member Countries. The present modes of precaution in the new EU chemical legislation – REACH – are investigated with respect to the precautionary principle, and tested against two contemporary problems; brominated flame retardants and endocrine disrupting substances. Results: The analysis demonstrates the changing character of the integration of the precautionary principle. The main tendencies are from implicit to more explicit precaution and from a closed expert-orientation towards a more deliberative approach to scientific knowledge and uncertainty. The results demonstrate that the precautionary principle is manifest in both the design of the testing strategy and in policy provisions. In particular, the substitution of hazardous substances with less hazardous is important. Discussion: Despite explicit attention to the precautionary principle, is the present reformulation of the European Chemicals policy in danger of falling into loop-holes that equal problems related to the present regulation of existing chemicals? 'Precaution' has been reduced virtually to an abstract concept that is more or less devoid of practical meaning in the regulatory process. Conclusions: It is concluded that the role of the precautionary principle in chemicals regulation will require continued scrutiny in the future shaping of the REACH strategy. Perspectives: Continued development of robust and precaution-based chemicals regulation will have to involve both new data-generation strategies and new forms of political decision-making, with special attention given to transparency and deliberative policymaking. 相似文献117.
We investigate the stock market response to firm disclosure of positive environmental information and the link from that information to environmental outcomes. We classify environmental media releases by informational content and value relevance, and assess the abnormal stock returns of each type of event. While announcements of future environmental activities lead to the largest favorable stock market reactions, there is no guaranteed link from this type of information to environmental outcomes. Further analysis of the abnormal returns shows that the magnitude of the stock market reaction depends on firm financial characteristics across all event types rather than on firm environmental performance. Our results indicate that the ability for voluntary environmental information disclosure to induce environmental self-regulation is limited to the extent that firms are able to follow through with their announcements of planned environmental activities. 相似文献
118.
Large TNT equivalent explosions usually arise from accidents occurring during the transportation, storage, and manufacturing of chemicals relevant to process industries. The blast wave generated by the explosion will spread and interact with the surrounding factories and storehouses, damaging the building structures within several kilometers and causing significant casualties and property losses. This study aims to develop an efficient numerical simulation method to predict blast loads to estimate the consequences of accidents involving far-field free air bursts or surface burst explosions. Before its interaction with the interested target, a blast wave is generated in the numerical model by specifying the initial and boundary conditions of the disturbed air. Based on empirical data of incident overpressure, an explicit formula to calculate the air particle velocity is derived from the governing equations of a perfect inviscid gas. A simplified path line method is proposed to calculate the air density. The proposed method is applied to the LS-DYNA CESE solver to simulate the blast loads on building structures in the far field. Validations against empirical data and experiments indicate that the proposed method is sufficiently accurate for engineering applications and, through a case study, presents a more efficient performance than the LOAD_BLAST_ENHANCED (LBE) and mapping methods. 相似文献
119.
Over the last three decades, ambient concentrations of sulfur dioxide (SO2) air pollution have declined by approximately 80%. This paper tests whether the 1970 Clean Air Act and its subsequent amendments caused this decline. The centerpiece of this legislation is the annual assignment of all counties to SO2 nonattainment or attainment categories. Polluters face stricter regulations in nonattainment counties. There are two primary findings. First, regulators pay little attention to the statutory selection rule in their assignment of the SO2 nonattainment designations. Second, SO2 nonattainment status is associated with modest reductions in SO2 air pollution, but a null hypothesis of zero effect generally cannot be rejected. This finding holds whether the estimated effect is obtained with linear adjustment or propensity score matching. Overall, the evidence suggests that the nonattainment designation played a minor role in the dramatic reduction of SO2 concentrations over the last 30 years. 相似文献
120.
Ojeda J. Sanchez E. Fernandez-Palacios A. Moreira J. M. 《Journal of Coastal Conservation》1995,1(1):109-118
This paper deals with the application of satellite images to characterize some aspects of the circulation dynamics of the
Tinto-Odiel estuary using turbidity patterns as ‘natural tracers’. 15 images (Landsat TM and Spot HRV) were processed to provide
synoptic, instantaneous views of the circulation patterns under different environmental conditions. In addition, a comparison
was made between results of oceanographic field work, using biplanes and fluorescent tracers, and satellite image turbidity
patterns used as ‘ground truth’ data for specific hydroclimatic situations. This approach allowed (1) the identification and
mapping of dynamic processes of interest during a theoretical tidal cycle, (2) the elaboration of additional information on
the ‘flow schemes’ at the mouth of the estuary with improved spatial and temporal resolution, and (3) the supply of basic
data to improve the knowledge of exchange processes between estuarine and coastal waters. The results of this study are considered
to be useful for the management of the estuarine system. 相似文献