全文获取类型
收费全文 | 679篇 |
免费 | 57篇 |
国内免费 | 64篇 |
专业分类
安全科学 | 71篇 |
废物处理 | 9篇 |
环保管理 | 228篇 |
综合类 | 236篇 |
基础理论 | 97篇 |
环境理论 | 1篇 |
污染及防治 | 25篇 |
评价与监测 | 13篇 |
社会与环境 | 113篇 |
灾害及防治 | 7篇 |
出版年
2024年 | 1篇 |
2023年 | 12篇 |
2022年 | 28篇 |
2021年 | 23篇 |
2020年 | 27篇 |
2019年 | 26篇 |
2018年 | 25篇 |
2017年 | 40篇 |
2016年 | 36篇 |
2015年 | 31篇 |
2014年 | 25篇 |
2013年 | 41篇 |
2012年 | 42篇 |
2011年 | 53篇 |
2010年 | 18篇 |
2009年 | 29篇 |
2008年 | 21篇 |
2007年 | 32篇 |
2006年 | 30篇 |
2005年 | 24篇 |
2004年 | 28篇 |
2003年 | 19篇 |
2002年 | 29篇 |
2001年 | 17篇 |
2000年 | 15篇 |
1999年 | 18篇 |
1998年 | 16篇 |
1997年 | 15篇 |
1996年 | 19篇 |
1995年 | 14篇 |
1994年 | 9篇 |
1993年 | 5篇 |
1992年 | 8篇 |
1991年 | 3篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 4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 | 1篇 |
1980年 | 1篇 |
1978年 | 2篇 |
1976年 | 1篇 |
1972年 | 1篇 |
排序方式: 共有800条查询结果,搜索用时 218 毫秒
381.
Enrico Di Minin Christoph Fink Anna Hausmann Jens Kremer Ritwik Kulkarni 《Conservation biology》2021,35(2):437-446
Social media data are being increasingly used in conservation science to study human–nature interactions. User-generated content, such as images, video, text, and audio, and the associated metadata can be used to assess such interactions. A number of social media platforms provide free access to user-generated social media content. However, similar to any research involving people, scientific investigations based on social media data require compliance with highest standards of data privacy and data protection, even when data are publicly available. Should social media data be misused, the risks to individual users' privacy and well-being can be substantial. We investigated the legal basis for using social media data while ensuring data subjects’ rights through a case study based on the European Union's General Data Protection Regulation. The risks associated with using social media data in research include accidental and purposeful misidentification that has the potential to cause psychological or physical harm to an identified person. To collect, store, protect, share, and manage social media data in a way that prevents potential risks to users involved, one should minimize data, anonymize data, and follow strict data management procedure. Risk-based approaches, such as a data privacy impact assessment, can be used to identify and minimize privacy risks to social media users, to demonstrate accountability and to comply with data protection legislation. We recommend that conservation scientists carefully consider our recommendations in devising their research objectives so as to facilitate responsible use of social media data in conservation science research, for example, in conservation culturomics and investigations of illegal wildlife trade online. 相似文献
382.
Since the 1960s, the development of the Serre-Chevalier winter and summer resort has led to a rapid extension of the urban fabric on the territory of the village of St-Chaffrey. On July 9, 1981, the new neighborhoods built on the alluvial fan of the Verdarel torrent were partly devastated by a channeled debris flow. This disaster prompted the civil authorities to set up an extensive fluvial regulation system, which rapidly contributed to recreating a climate of confidence and security favorable to continuing urban expansion. The combination of catastrophic floods in July 1995, and a new security-oriented national policy on natural hazards, nevertheless led to a return to precautionary measures. The St-Chaffrey town council has therefore been forced by the State to accept a building-free zone on the land-use plan. This measure is perceived as a real denial of the local efficacy of the flood and landslide risk management policy as carried out by the council of St-Chaffrey during the previous 20 years. 相似文献
383.
当前,我国资源破坏和环境污染问题相当严重,要实现中国跨世纪环保政策目标和可持续发展战略,必须有健全的环境保护法律制度作保障。我国现行《环境保护法》制定于20世纪80年代末,已经不能适应现阶段的经济发展要求。本文从环境保护法的立法目的、基本原则、环境法律制度等方面对《环境保护法》的修改进行了论述。 相似文献
384.
The management of solid waste is changing. The traditional approach based on landfilling of mixed refuses is shifting toward
a system based on the at-source sorting of waste into specific fractions. The biological treatment of the organic fraction
is considered to be an appropriate form of disposal not only for the “traditional≓ feedstock such as food scraps and vegetable
and garden waste, but also for biodegradable packaging, when not recyclable in other ways. Any change from a complex system
to another is difficult since many factors are to be organized and optimized. Industry must develop and manufacture compostable
products, municipalities must build composting plants and organize source-separated collection, and regulatory bodies must
define widely acceptable criteria of compostability. In Europe, the European Union has assigned the last task to the CEN,
to provide common criteria and avoid hindrance to commercial exchanges. In Italy the UNI, the national standardization organization,
has produced a working document to contribute to the discussion on the European level. In this paper the UNI scheme is described.
A condensed version of this paper was presented by one of the authors (F.D.I.) at the 5th annual meeting of the BEDP Society,
held in Nashville, September 22–26, 1996, during a session covering International Standards for Biodegradation Testing. 相似文献
385.
谈企业基层安全管理标准化 总被引:8,自引:1,他引:8
企业基层安全管理标准化是企业发展的需要,是安全管理的有效方法。它能够使人、机、环境达到最佳统一,保证安全生产,促进安全管理标准化、科学化、规范化的进程 相似文献
386.
Ralph K Davis Darryll T Pederson 《Journal of the American Water Resources Association》1996,32(1):107-115
ABSTRACT: Ground-water level decline patterns in parts of Nebraska conform to the circular island concept of Bredehoeft et al. (1982), which indicates how water is derived by wells developed in a circular island. If elongated, the center of the island corresponds to a regional ground-water divide while the shoreline corresponds to a regional river. In both versions, ground-water table elevation is a function of recharge and transmissivity. A dynamic equilibrium exists such that the gradient of the water table will convey all recharge to discharge areas. Withdrawals of ground water result initially in mining, with a new equilibrium attained when pumping equals capture. During early development, capture is an important source of water in discharge areas, while mining is more significant in recharge areas. The pattern observed in many areas shows the greatest ground-water level decline in the vicinity of ground-water divides and the steepest gradient near regional rivers. A similar pattern has been observed adjacent to the Arkansas River in south-central Kansas. Similar decline patterns can be modeled for a hypothetical ground-water basin. This is of major importance to water-resource managers because it dictates that management programs be applied to the entire hydrologic system. 相似文献
387.
ABSTRACT In this paper, an artificial neural network-based control strategy is proposed for low voltage DC microgrid (LVDC microgrid) with a hybrid energy storage system (HESS) to improve power-sharing between battery and supercapacitor (SC) to suit the demand-generation imbalance, maintain state-of-charge (SOC) within boundaries and thereby to regulate the dc bus voltage. The conventional controller cannot track the SCs current rapidly with the high-frequency component that will place dynamic stress on the battery, further resulting in shorter battery life. The significant advantage is that in the proposed control strategy, redirections of unwaged battery currents to SCs for fast compensations enhance battery life span. The proposed control strategy effectiveness was investigated by simulations, including a comparison of overshoot/undershoot and settling time in dc bus voltage with a conventional control strategy. The results have been experimentally verified by hardware-in-loop (HIL) on a field-programmable gate array (FPGA)-based real-time simulator. 相似文献
388.
ABSTRACTWhile bioinvasion was an issue of low political salience in Europe, a new regulation addressing it was adopted in 2014 with strong support. This article analyzes the making of the regulation as an intriguing case of policy expansion amid economic crisis. Based on theoretical literature on drivers of EU policy integration and policy dismantling, alternative plausible explanations are explored. Our main finding is that development of economic policy consensus among member states on trade-environment nexus was crucial for progress towards regulatory action. Policy consensus has been driven by a confluence of three domestic factors: trade liberalization, market disintegration, and changing ideas about the desirability of EU-level law, with the European Commission as policy entrepreneur. Low political salience has also had an important effect. It has increased the influence of transnational conservation alliances, which have played a significant catalytic role in building consensus by shifting consciousness to economic reward of policy action vs inaction, and bringing international models for legislative reform to the EU jurisdiction. 相似文献
389.
介绍了我国石化行业环境保护法规、标准体系和建设项目环境保护工作的要求和开展情况,并对欧美发达国家石化行业的法规标准体系、工程建设全过程环境保护工作、成本效益分析、最佳可行技术和部分发展中国家石化项目的环境保护管理进行了分析论述,比较了国内外石化行业环境保护标准、项目环保工作的差异,并对我国石化行业环境保护工作给出了建议。 相似文献
390.
Marcelo Cerucci Jon M. Conrad 《Journal of the American Water Resources Association》2003,39(5):1167-1180
ABSTRACT: Riparian buffers are considered important management options for protecting water quality. Land costs and buffer performance, which are functions of local environmental characteristics, are likely to be key attributes in the selection process, especially when budgets are limited. In this article we demonstrate how a framework involving hydrologic models and binary optimization can be used to find the optimal buffer subject to a budget constraint. Two hydrologic models, SWAT and REMM, were used to predict the loads from different source areas with and without riparian buffers. These loads provided inputs for a binary optimization model to select the most cost efficient parcels to form a riparian buffer. This methodology was applied in a watershed in Delaware County, New York. The models were parameterized using readily available digital databases and were later compared against observed flow and water quality data available for the site. As a result of the application of this method, the marginal utility of incremental increases in buffer widths along the stream channel and the set of parcels to form the best affordable riparian buffer were obtained. 相似文献