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891.
892.
Craig A. Stow Kenneth H. Reckhow Song S. Qian Estel Conrad Lamon George B. Arhonditsis Mark E. Borsuk Dongil Seo 《Journal of the American Water Resources Association》2007,43(6):1499-1507
Abstract: The National Research Council recommended Adaptive Total Maximum Daily Load implementation with the recognition that the predictive uncertainty of water quality models can be high. Quantifying predictive uncertainty provides important information for model selection and decision‐making. We review five methods that have been used with water quality models to evaluate model parameter and predictive uncertainty. These methods (1) Regionalized Sensitivity Analysis, (2) Generalized Likelihood Uncertainty Estimation, (3) Bayesian Monte Carlo, (4) Importance Sampling, and (5) Markov Chain Monte Carlo (MCMC) are based on similar concepts; their development over time was facilitated by the increasing availability of fast, cheap computers. Using a Streeter‐Phelps model as an example we show that, applied consistently, these methods give compatible results. Thus, all of these methods can, in principle, provide useful sets of parameter values that can be used to evaluate model predictive uncertainty, though, in practice, some are quickly limited by the “curse of dimensionality” or may have difficulty evaluating irregularly shaped parameter spaces. Adaptive implementation invites model updating, as new data become available reflecting water‐body responses to pollutant load reductions, and a Bayesian approach using MCMC is particularly handy for that task. 相似文献
893.
Marat Khabibullov 《Environmental management》1991,15(6):749-763
The prevailing system of environmental management strongly depends on the economic and political structures of a country and
is influenced by the current condition of them. Environmental degradation in the Soviet Union has been caused mainly by the
political and economic misconceptions listed in this article. With the transformation of its state order to the model of Western
democracies, the Soviet Union is experiencing a deep economic crisis of restructuring, reflected in a parallel crisis in its
system of environmental management, which is manifest in the form of rapid transformation. This is characterized by the contradiction
of the state’s old administrative institutions, which still exist, with the efforts to use market mechanisms of environmental
control. Such methods include various fees and payments for the use of natural resources or for pollution and creation of
specialized regional funds and banks to finance environmental programs. All these occur in the context of the strengthening
of regional sovereignty, the introduction of self-accounting for economic units, the adoption of comprehensive legal enactments,
and the setting up of an efficient administrative system of their enforcement. Public activism, as one of the principal actors
in this structure, also has undergone quick maturation. Nevertheless the future development of the new Soviet system of environmental
control remains uncertain because of the present unpredictability of the overall situation in the short run. 相似文献
894.
我国农村耕地利用及保护对策 总被引:2,自引:0,他引:2
论述了当前我国土地资源利用中存在的耕地数量减少、耕地质量下降、土地利用结构和布局不合理、土地资源未能得到有效配置等问题,分析了这些问题产生的原因,并在此基础上提出了相应的耕地保护对策。 相似文献
895.
On 1 March 1997, powerful tornadoes touched down in Arkansas (USA) on a Saturday afternoon. Twenty-six fatalities and 400 non-fatal injuries were reported. We performed a population-based cross-sectional study to determine factors associated with appropriate responses to tornado warnings. Of 146 survey participants, 140 (96 per cent) knew the difference between 'tornado watch' and 'tornado warning' and were aware of when the warning was announced. Of those 140 participants, 64 (45.7 per cent) responded to the warning by seeking shelter, and 58 (90.6 per cent) of those 64 acted within five minutes of hearing the warning. Four factors were positively associated with those seeking shelter: having graduated from high school (OR = 4.2, 95 per cent CI = 1.1-15.5); having a basement in one's house (OR = 3.8, 95 per cent exact CI = 1.1-17.1); hearing a siren (OR = 4.4, 95 per cent CI = 1.3-18.9); and having prepared a household plan of response when tornadoes occur (OR = 2.6, 95 per cent CI = 1.1-6.3). On the basis of these findings, we recommend: first, that people who live in tornadoprone areas have a personal plan of action to help them respond immediately to warnings; second, public-health education officials in areas with frequent tornadic activity should do more to educate the public about what they can do to protect themselves from a tornado; and third, that emergency-management officials planning protection measures for vulnerable communities should consider that most people have limited time (our study documented five minutes) in which to respond to a tornado warning. Thus, shelters in tornado-prone areas should be quickly accessible by residents. 相似文献
896.
如何提高COD比色法测试的精密度和准确度 总被引:3,自引:0,他引:3
针对COD比色法测试的技术特点,通过总结日常分析、验收考核中存在的经验和问题,给出了如何提高COD测试仪测量精密度、准确度的方法和仪器质量的核查方法。 相似文献
897.
随着我国机动车数量与日俱增以及越来越多的企业依托便利的交通条件建设在高速公路沿线,严重影响了高速公路周围的大气环境。围绕辽宁省环境保护局近期制定并发布的《沈大沈丹无烟路工程实施方案》的内容,探讨了高速公路环境保护工作中的问题和解决方法,为今后高速公路的环境保护工作提供参考。 相似文献
898.
Katja Malmborg Elin Enfors-Kautsky Cibele Queiroz Albert Norstrm Lisen Schultz 《Ambio》2021,50(2):314
The ecosystem service concept is recognized as a useful tool to support sustainability in decision-making. In this study, we collaborated with actors in the Helge å catchment, southern Sweden, in an iterative participatory ecosystem service assessment. Through workshops and interviews, we jointly decided which ecosystem services to assess and indicators to use in order to achieve a sense of ownership and a higher legitimacy of the assessment. Subsequently, we explored the landscape-level interactions between the 15 assessed services, and found that the area can be described using three distinct ecosystem service bundles. The iterative, participatory process strengthened our analysis and created a shared understanding and overview of the multifunctional landscape around Helge å among participants. Importantly, this allowed for the generated knowledge to impact local strategic sustainability planning. With this study, we illustrate how similar processes can support local decision-making for a more sustainable future.Electronic supplementary materialThe online version of this article (10.1007/s13280-020-01378-w) contains supplementary material, which is available to authorized users. 相似文献
899.
重金属对水体的污染已经成为危害最大的污染之一。综述了水体重金属污染的处理方法,主要有化学法、物理化学法和生物法,并对水体重金属污染处理技术的发展方向进行了展望。 相似文献
900.
The impact of the extreme heat wave that affected Melbourne, Australia, in two distinct phases in January and February 2009 was severe, with 374 (heat) and 173 (bushfire) excess deaths. Whilst the human health issues have been covered in detail in policy and academic arenas, much less attention has been paid to the adverse impacts on urban infrastructure. Analysis of this event, underpinned by participatory actor-based research, has shown that the impacts were experienced disproportionately across different infrastructure types. For water, telecommunications and airports, the impacts were relatively minor and the impact on rail transport and roads (and to a lesser extent, seaports) was of moderate significance, whereas research findings indicate that the electricity sector was found to be the most vulnerable. This paper focuses on the sectors that were worst impacted: electricity, rail and road transport. Commentary identifies the direct and indirect impacts of the heat event, including associated cascading effects, as well as considering actual and potential adaptation responses both before and after the event. Concluding, the authors reflect on the implications of the heat wave for urban resilience, emphasising the crucial importance of understanding the urban environment as a complex and interconnected system. 相似文献