全文获取类型
收费全文 | 1872篇 |
免费 | 118篇 |
国内免费 | 265篇 |
专业分类
安全科学 | 114篇 |
废物处理 | 152篇 |
环保管理 | 415篇 |
综合类 | 643篇 |
基础理论 | 150篇 |
污染及防治 | 138篇 |
评价与监测 | 35篇 |
社会与环境 | 124篇 |
灾害及防治 | 484篇 |
出版年
2023年 | 13篇 |
2022年 | 42篇 |
2021年 | 50篇 |
2020年 | 44篇 |
2019年 | 36篇 |
2018年 | 58篇 |
2017年 | 54篇 |
2016年 | 63篇 |
2015年 | 70篇 |
2014年 | 116篇 |
2013年 | 134篇 |
2012年 | 110篇 |
2011年 | 146篇 |
2010年 | 86篇 |
2009年 | 88篇 |
2008年 | 60篇 |
2007年 | 110篇 |
2006年 | 114篇 |
2005年 | 96篇 |
2004年 | 74篇 |
2003年 | 73篇 |
2002年 | 93篇 |
2001年 | 65篇 |
2000年 | 77篇 |
1999年 | 58篇 |
1998年 | 29篇 |
1997年 | 26篇 |
1996年 | 32篇 |
1995年 | 31篇 |
1994年 | 26篇 |
1993年 | 13篇 |
1992年 | 13篇 |
1991年 | 16篇 |
1990年 | 8篇 |
1989年 | 9篇 |
1988年 | 4篇 |
1987年 | 9篇 |
1986年 | 6篇 |
1985年 | 6篇 |
1984年 | 9篇 |
1983年 | 5篇 |
1982年 | 10篇 |
1981年 | 12篇 |
1980年 | 13篇 |
1979年 | 13篇 |
1978年 | 7篇 |
1977年 | 5篇 |
1975年 | 4篇 |
1974年 | 3篇 |
1972年 | 6篇 |
排序方式: 共有2255条查询结果,搜索用时 15 毫秒
991.
Assessing the impact of the Indian Ocean tsunami on households: a modified domestic assets index approach 总被引:1,自引:0,他引:1
Sudha Arlikatti Walter Gillis Peacock Carla S. Prater Himanshu Grover Arul S. Gnana Sekar 《Disasters》2010,34(3):705-731
This paper offers a potential measurement solution for assessing disaster impacts and subsequent recovery at the household level by using a modified domestic assets index (MDAI) approach. Assessment of the utility of the domestic assets index first proposed by Bates, Killian and Peacock (1984) has been confined to earthquake areas in the Americas and southern Europe. This paper modifies and extends the approach to the Indian sub‐continent and to coastal surge hazards utilizing data collected from 1,000 households impacted by the Indian Ocean tsunami (2004) in the Nagapattinam district of south‐eastern India. The analyses suggest that the MDAI scale is a reliable and valid measure of household living conditions and is useful in assessing disaster impacts and tracking recovery efforts over time. It can facilitate longitudinal studies, encourage cross‐cultural, cross‐national comparisons of disaster impacts and inform national and international donors of the itemized monetary losses from disasters at the household level. 相似文献
992.
C. JOSH DONLAN DANA K. WINGFIELD LARRY B. CROWDER CHRIS WILCOX 《Conservation biology》2010,24(6):1586-1595
Abstract: Little is known about how specific anthropogenic hazards affect the biology of organisms. Quantifying the effect of regional hazards is particularly challenging for species such as sea turtles because they are migratory, difficult to study, long lived, and face multiple anthropogenic threats. Expert elicitation, a technique used to synthesize opinions of experts while assessing uncertainty around those views, has been in use for several decades in the social science and risk assessment sectors. We conducted an internet‐based survey to quantify expert opinion on the relative magnitude of anthropogenic hazards to sea turtle populations at the regional level. Fisheries bycatch and coastal development were most often ranked as the top hazards to sea turtle species in a geographic region. Nest predation and direct take followed as the second and third greatest threats, respectively. Survey results suggest most experts believe sea turtles are threatened by multiple factors, including substantial at‐sea threats such as fisheries bycatch. Resources invested by the sea turtle community, however, appear biased toward terrestrial‐based impacts. Results from the survey are useful for conservation planning because they provide estimates of relative impacts of hazards on sea turtles and a measure of consensus on the magnitude of those impacts among researchers and practitioners. Our survey results also revealed patterns of expert bias, which we controlled for in our analysis. Respondents with no experience with respect to a sea turtle species tended to rank hazards affecting that sea turtle species higher than respondents with experience. A more‐striking pattern was with hazard‐based expertise: the more experience a respondent had with a specific hazard, the higher the respondent scored the impact of that hazard on sea turtle populations. Bias‐controlled expert opinion surveys focused on threatened species and their hazards can help guide and expedite species recovery plans. 相似文献
993.
Sylwia Oleszek Mariusz Grabda Etsuro Shibata Takashi Nakamura 《Waste management (New York, N.Y.)》2013,33(9):1835-1842
The growing consumption of electric and electronic equipment results in creating an increasing amount of electronic waste. The most economically and environmentally advantageous methods for the treatment and recycling of waste electric and electronic equipment (WEEE) are the thermal techniques such as direct combustion, co-combustion with plastic wastes, pyrolysis and gasification. Nowadays, this kind of waste is mainly thermally treated in incinerators (e.g. rotary kilns) to decompose the plastics present, and to concentrate metals in bottom ash. The concentrated metals (e.g. copper, precious metals) can be supplied as a secondary raw material to metal smelters, while the pyrolysis of plastics allows the recovery of fuel gases, volatilising agents and, eventually, energy. Indeed, WEEE, such as a printed circuit boards (PCBs) usually contains brominated flame retardants (BFRs). From these materials, hydrobromic acid (HBr) is formed as a product of their thermal decomposition.In the present work, the bromination was studied of copper, silver and gold by HBr, originating from BFRs, such as Tetrabromobisphenol A (TBBPA) and Tetrabromobisphenol A-Tetrabromobisophenol A diglycidyl ether (TTDE) polymer; possible volatilization of the bromides formed was monitored using a thermo-gravimetric analyzer (TGA) and a laboratory-scale furnace for treating samples of metals and BFRs under an inert atmosphere and at a wide range of temperatures. The results obtained indicate that up to about 50% of copper and silver can evolve from sample residues in the form of volatile CuBr and AgBr above 600 and 1000 °C, respectively. The reactions occur in the molten resin phase simultaneously with the decomposition of the brominated resin. Gold is resistant to HBr and remains unchanged in the residue. 相似文献
994.
Elizabeth Robson Gordon Nathalie Butt Hanna Rosner-Katz Allison D. Binley Joseph R. Bennett 《Conservation biology》2020,34(1):276-281
Bias toward legally protecting and prioritizing charismatic taxonomic groups, such as mammals and birds, and against others, such as insects and plants, is well documented. However, the relative costs of conserving various taxonomic groups and the potential of these costs to interact with existing biases have been much less explored. We analyzed conservation programs across more than 2,000 species in 3 countries to investigate the costs of conserving species within taxonomic groups and how these costs might affect conservation planning. For each data set, we tested for differences in mean annual cost among taxonomic groups. For the data set from the United States, recovery plans differed in duration, so we also tested for differences in total costs among taxonomic groups. Although the costs for individual species varied widely, there were strong international consistencies. For example, mammals cost 8–26 times more on average to conserve than plants and 13–19 times more to conserve than aquatic invertebrates. On average, bird species cost 5–30 times more to conserve than plants and 6–14 times more to conserve than aquatic invertebrates. These cost differences could exacerbate unequal resource allocation among taxonomic groups such that more charismatic groups both receive more attention and require more resources, leading to neglect of other taxonomic groups. 相似文献
995.
从银铅锌废渣中回收硝酸银的研究 总被引:1,自引:0,他引:1
介绍了用灼烧、浸取、沉淀、溶转和离子交换等方法,从银铅锌废渣中直接回收硝酸银,收率可达80.12%,AgNO3纯度为99.9%。考察了试料粒度、FeCl3质量浓度、溶液酸度、固液比,反应温度及浸取时间对银浸出率的影响。 相似文献
996.
997.
赖氨酸废水的处理和氨回收 总被引:2,自引:0,他引:2
对赖氨酸浓废水调 p H沉淀处理后的澄清水进行预处理 :先加入石灰乳 ,搅拌、沉淀 ,SO42 -从 2 0 0 0 0 m g/ L 左右降至 130 0 mg/ L 左右 ,去除率为 94%左右 ,然后进行空气吹脱 ,NH3- N从 5 0 0 0 mg/ L左右降至 80 m g/ L左右 ,去除率 >98%。吹脱出水经厌氧生化处理后 ,再进行空气吹脱 ,NH3- N从 70 0 mg/ L 左右降至 85 mg/ L 左右 ,去除率 >86 %。再吹脱出水与稀废水混合后进行好氧生化和 A/ O、O系统处理 ,出水的 COD<10 0 m g/ L,BOD5<2 0 mg/ L,SS<70 mg/ L,NH3- N<2 5 m g/ L。对浓废水与石灰乳混合后搅拌过程中及两次空气吹脱过程中挥发的 NH3进行回收 ,将其与 H2 SO4反应 ,生成的 (NH4) 2 SO4回用于生产 相似文献
998.
谢赛珍 《中国环境管理干部学院学报》2001,(2)
本文综述了我国城市生活垃圾的常规处理方法,根据垃圾处理的无害化、减量化、资源化原则,分析了在垃圾处理过程中存在的主要问题,并论述了垃圾处理的发展趋势。 相似文献
999.
Benedito Braga Paulo S. F. Barbosa 《Journal of the American Water Resources Association》2001,37(4):837-852
ABSTRACT: A network flow algorithm has been developed for the optimization of real‐time operation of a multiple reservoir system. Two purposes have been considered in the operation: flood control and hydropower generation. A special network structure was developed which allows the consideration of river routing. A multiobjective formulation is utilized thus allowing generation of a non‐dominated curve. The effect of imperfect forecast on the performance of the real‐time operation model is also evaluated. An application is made to a subsystem of the Brazilian hydroelectric system, located in the Paranapanema river basin. In this case study, the model showed good performance under the largest flood of the historical records. 相似文献
1000.
Steven D. Shultz Pat M. Fridgen 《Journal of the American Water Resources Association》2001,37(3):595-603
ABSTRACT: The hedonic valuation method was used to quantify the impact of floodplain location on housing values in Fargo‐Moor‐head. Being located in the 100‐year floodplain lowered the home values by $8,990, and such homes were worth $10,241 less than similar homes located outside the floodplain before the major flood event of 1997. Required flood insurance premiums for these homes were determined to account for approximately 81 percent of this price depreciation. In contrast, homes in the 500‐year floodplain were worth $3,100 more than similar homes not in the floodplain. It was concluded that more disclosure is needed regarding the location of the 500‐year floodplain, and that the hedonic valuation method can be used to calculate the economic gains and losses associated with flood mitigation projects or floodplain remapping efforts that result in the reclassification of the legal floodplain status of individual homes. 相似文献