全文获取类型
收费全文 | 3179篇 |
免费 | 185篇 |
国内免费 | 453篇 |
专业分类
安全科学 | 675篇 |
废物处理 | 66篇 |
环保管理 | 372篇 |
综合类 | 1590篇 |
基础理论 | 365篇 |
污染及防治 | 319篇 |
评价与监测 | 128篇 |
社会与环境 | 104篇 |
灾害及防治 | 198篇 |
出版年
2024年 | 25篇 |
2023年 | 64篇 |
2022年 | 101篇 |
2021年 | 101篇 |
2020年 | 83篇 |
2019年 | 94篇 |
2018年 | 118篇 |
2017年 | 73篇 |
2016年 | 69篇 |
2015年 | 100篇 |
2014年 | 203篇 |
2013年 | 133篇 |
2012年 | 143篇 |
2011年 | 152篇 |
2010年 | 125篇 |
2009年 | 146篇 |
2008年 | 150篇 |
2007年 | 149篇 |
2006年 | 156篇 |
2005年 | 136篇 |
2004年 | 119篇 |
2003年 | 147篇 |
2002年 | 90篇 |
2001年 | 89篇 |
2000年 | 92篇 |
1999年 | 119篇 |
1998年 | 65篇 |
1997年 | 98篇 |
1996年 | 93篇 |
1995年 | 80篇 |
1994年 | 73篇 |
1993年 | 62篇 |
1992年 | 65篇 |
1991年 | 62篇 |
1990年 | 60篇 |
1989年 | 36篇 |
1988年 | 24篇 |
1987年 | 15篇 |
1986年 | 20篇 |
1985年 | 17篇 |
1984年 | 11篇 |
1983年 | 20篇 |
1982年 | 13篇 |
1981年 | 15篇 |
1980年 | 7篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1976年 | 1篇 |
排序方式: 共有3817条查询结果,搜索用时 62 毫秒
461.
Globalization and multi-spatial trends in the coverage of protected-area conservation (1980-2000) 总被引:2,自引:0,他引:2
This study is focused on the global expansion of protected-area coverage that occurred during the 1980--2000 period. We examine the multi-scale patterning of four of the basic facets of this expansion: i) estimated increases at the world-regional and country-level scales of total protected-area coverage; ii) transboundary protected areas; iii) conservation corridor projects; and iv) type of conservation management. Geospatial patterning of protected-area designations is a reflection of the priorities of global conservation organizations and the globalization of post-Cold War political and economic arrangements. Local and national-level factors (political leadership and infrastructure) as well as international relations such as multilateral and bilateral aid combine with these globalization processes to impact the extent, type, and location of protected-area designations. We conclude that the interaction of these factors led to the creation and reinforcement of marked spatial differences (rather than tendencies toward worldwide evenness or homogenization) in the course of protected-area expansion during the 1980--2000 period. 相似文献
462.
用于四氯乙烯降解的厌氧污泥的培养与驯化研究 总被引:1,自引:0,他引:1
由于四氯乙烯(PCE)的大量使用和不合理的处置使其成为常见的污染物之一。PCE在好氧条件下不发生生物降解,只在厌氧条件下通过还原脱氯发生生物降解。本研究主要是对从不同处理厂获得的厌氧污泥进行培养,选出合适的厌氧污泥,进行降解PCE的厌氧污泥的驯化,为以后进行降解PCE的动力学研究和优势菌种的筛选做准备。同时,在实验中检测到了三氯乙烯(TCE),表明PCE是通过还原脱氯发生生物降解的。 相似文献
463.
采用酒精糟处理液回用技术,去除酒精糟液中对酒精生产有害的物质,得到能回用于糖蜜兑释的处理液,使酒精糟液不再向外排放,以达到治理目的,并对生产能力,产品质量和糖分出率不产生影响。每吨酒精糟液治理费用为0.53元。 相似文献
464.
465.
Effect of pH control at the anode for the electrokinetic removal of phenanthrene from kaolin soil 总被引:14,自引:0,他引:14
Polycyclic aromatic hydrocarbon (PAH)-contaminated soils exist at numerous sites, and these sites may threaten public health and the environment because many PAH compounds are toxic, mutagenic, and/or carcinogenic. PAHs are also hydrophobic and persistent, so conventional remediation methods are often costly or inefficient, especially when the contaminants are present in low permeability and/or organic soils. An innovative technique, electrokinetically enhanced in situ flushing, has the potential to increase soil-solution-contaminant interaction and PAH removal efficiency for low permeability soils; however, the electrolysis reaction at the anode may adversely affect the remediation of low acid buffering capacity soils, such as kaolin. Therefore, the objective of this study was to improve the remediation of low acid buffering soils by controlling the pH at the anode to counteract the electrolysis reaction. Six bench-scale electrokinetic experiments were conducted, where each test employed one of three different flushing solutions, deionized water, a surfactant, or a cosolvent. For each of these solutions, tests were performed with and without a 0.01 M NaOH solution at the anode to control the pH. The test using deionized water with pH control generated a higher electroosmotic flow than the equivalent test performed without pH control, but the electroosmotic flow difference between the surfactant and cosolvent tests with and without pH control was minor compared to that observed with the deionized water tests. Controlling the pH was beneficial for increasing contaminant solubilization and migration from the soil region adjacent to the anode, but the high contaminant concentrations that resulted in the middle or cathode soil regions indicates that subsequent changes in the soil and/or solution chemistry caused contaminant deposition and low overall contaminant removal efficiency. 相似文献
466.
动力学分光光度法测定痕量锑—Sb(Ⅲ)二甲基黄—过氧化氢体系 总被引:1,自引:0,他引:1
本文研究了在NaAc-HCl中痕量Sb(Ⅲ)加速H_2O_2氧化二甲基黄退色的指示反应及动力学条件,建立了动力学光度法测痕量Sb(Ⅲ)的新方法,检出限为6.5×10~(-10)g/ml。 相似文献
467.
Sequential anaerobic-aerobic treatment of an aquifer contaminated by halogenated organics: field results 总被引:1,自引:0,他引:1
In situ, sequential, anaerobic to aerobic treatment of groundwater removed perchloroethene (PCE, 1.1 microM) and benzene (0.8 microM) from a contaminated aquifer. Neither aerobic nor anaerobic treatment alone successfully degraded both the chlorinated and non-chlorinated organic contaminants in the aquifer. After the sequential treatment, PCE, trichloroethene (TCE), vinyl chloride (VC), chloroethane (CA), and benzene were not detectable in groundwater. Desorption of residual aquifer contaminants was tested by halting the groundwater recirculation and analyzing the groundwater after 3 and 7 weeks. No desorption of the chlorinated contaminants or daughter products was observed in the treated portion of the aquifer. Sequential anaerobic to aerobic treatment was successful in remediating the groundwater at this test site and may have broad applications at other contaminated sites. Over the 4-year course of the project, the predominant microbial environment of the test site varied from aerobic to sulfate-reducing, to methanogenic, and back to aerobic conditions. Metabolically active microbial populations developed under all conditions, demonstrating the diversity and robustness of natural microbial flora in the aquifer. 相似文献
468.
Polyacrylamide preparations for protection of water quality threatened by agricultural runoff contaminants 总被引:11,自引:0,他引:11
Entry JA Sojka RE Watwood M Ross C 《Environmental pollution (Barking, Essex : 1987)》2002,120(2):191-200
Waste streams associated with a variety of agricultural runoff sources are major contributors of nutrients, pesticides and enteric microorganisms to surface and ground waters. Water soluble anionic polyacrylamide (PAM) was found to be a highly effective erosion-preventing and infiltration-enhancing polymer, when applied at rates of 1-10 g m(-3) in furrow irrigation water. Water flowing from PAM treated irrigation furrows show large reductions in sediment, nutrients and pesticides. Recently PAM and PAM + CaO and PAM + Al(SO4)3 mixtures have been shown to filter bacteria, fungi and nutrients from animal wastewater. Low concentrations of PAM [175-350 g PAM ha(-1) as PAM or as PAM + CaO and PAM + Al(SO4) mixture] applied to the soil surface, resulted in dramatic decreases (10 fold) of total, coliform and fecal streptococci bacteria in cattle, fish and swine wastewater leachate and surface runoff. PAM treatment also filtered significant amounts of NH4, PO4 and total P in cattle and swine wastewater. This points to the potential of developing PAM as a water quality protection measure in combination with large-scale animal feeding operations. Potential benefits of PAM treatment of animal facility waste streams include: (1) low cost, (2) easy and quick application. (3) suitability for use with other pollution reduction techniques. Research on the efficacy of PAM for removal of protozoan parasites and viruses and more thorough assessment of PAM degradation in different soils is still needed to completely evaluate PAM treatment as an effective waste water treatment. We will present analysis and feasibility of using PAM, PAM + Al(SO4)3, and PAM + CaO application for specific applications. Our results demonstrate their potential efficacy in reducing sediment, nutrients and microorganisms from animal production facility effluents. 相似文献
469.
Hammervold RE Overcamp TJ Grady CP Smets BF 《Journal of the Air & Waste Management Association (1995)》2000,50(6):954-960
A sorptive slurry bioscrubber adds powdered activated carbon (PAC) to a conventional suspended-growth bioscrubber. The activated carbon increases pollutant removal from the gas phase due to adsorption on carbon. The carbon is bioregenerated in the oxidation reactor and recycled to the scrubbing column. A three-stage, conventional bioscrubber was tested with and without carbon. The experiments showed that the PAC improved the removal efficiency of the system and that bioregeneration occurred. At an inlet gas-phase acetone concentration of 50 ppmv, the steady-state removal increased from 88 to 95% when activated carbon was added to the biological slurry. 相似文献
470.
提出总量目标控制是企业环境管理的核心,为企业在发展生产的同时控制和削减污染物的总量,指出可行的实施意见。 相似文献