全文获取类型
收费全文 | 8828篇 |
免费 | 393篇 |
国内免费 | 3199篇 |
专业分类
安全科学 | 581篇 |
废物处理 | 538篇 |
环保管理 | 656篇 |
综合类 | 4606篇 |
基础理论 | 1493篇 |
污染及防治 | 3463篇 |
评价与监测 | 366篇 |
社会与环境 | 364篇 |
灾害及防治 | 353篇 |
出版年
2024年 | 17篇 |
2023年 | 163篇 |
2022年 | 454篇 |
2021年 | 379篇 |
2020年 | 290篇 |
2019年 | 297篇 |
2018年 | 306篇 |
2017年 | 392篇 |
2016年 | 474篇 |
2015年 | 512篇 |
2014年 | 648篇 |
2013年 | 881篇 |
2012年 | 727篇 |
2011年 | 752篇 |
2010年 | 582篇 |
2009年 | 516篇 |
2008年 | 631篇 |
2007年 | 492篇 |
2006年 | 487篇 |
2005年 | 348篇 |
2004年 | 271篇 |
2003年 | 322篇 |
2002年 | 303篇 |
2001年 | 231篇 |
2000年 | 273篇 |
1999年 | 286篇 |
1998年 | 229篇 |
1997年 | 221篇 |
1996年 | 191篇 |
1995年 | 153篇 |
1994年 | 117篇 |
1993年 | 117篇 |
1992年 | 106篇 |
1991年 | 81篇 |
1990年 | 34篇 |
1989年 | 34篇 |
1988年 | 25篇 |
1987年 | 16篇 |
1986年 | 14篇 |
1985年 | 10篇 |
1984年 | 6篇 |
1983年 | 4篇 |
1982年 | 9篇 |
1981年 | 6篇 |
1979年 | 2篇 |
1976年 | 1篇 |
1974年 | 2篇 |
1973年 | 3篇 |
1972年 | 2篇 |
1970年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
951.
Chromium(VI)-containing sorbents in the form of sludge or solid residue from treatment processes are often landfilled or used as fill materials, therefore the long-term stability of metal binding is important. The reduction of Cr(VI)–Cr(III) through heat treatment may be a useful detoxification method. After heating at 500, 900, 1000, and 1100 °C for 4 h, the transformation of chemical states of chromium on 105 °C-dried, 7.9% Cr(VI)-doped TiO2 powders was studied on the basis of surface area measurements, scanning electron microscopy (SEM) images, X-ray diffraction (XRD), and extended X-ray absorption fine structure (EXAFS) spectra. It was shown that Cr(VI) was reduced to Cr(III) in the Cr(VI)-doped samples after heating within 500–900 °C. The present results also suggested that the chromium octahedral was bridged to the titanium tetrahedral and was incorporated in TiO2 minerals formed after 1000 °C treatment. 相似文献
952.
风险投资-"节能减排"新视角 总被引:1,自引:0,他引:1
近30年来,我国的改革开放取得了举世瞩目的成就,国民经济始终保持高速增长,目前已成为世界第四大经济体。然而我国经济的发展是以牺牲环境和资源为代价的,高能耗、高污染成为经济增长的副产品,而环境和资源制约极有可能成为我国持续高速发展的瓶颈。“十一五规划”提出,2006—2010期间单位GDP能耗降低20%左右、主要污染物排放总量减少10%的约束性指标。当前“节能减排”的形势十分严峻。本文分析了我国“节能减排”效果不甚理想的原因,认为发展风险投资是促进“节能减排”的方法之一,并给出相应的政策建议。 相似文献
953.
954.
The growth properties and biodegradation mechanism of a Gram-negative bacterium, Pseudomonas nitroreducens TX1 that was able to grow on branched octylphenol polyethoxylates (OPEO(n), average n=9.5) as the sole carbon source over a wide concentration range (1-100,000 mgl(-1)) were studied. Analysis of growth factors indicated the highest specific growth rate (micro) of 0.53 h(-1) was obtained at an initial concentration of 5,000 mgl(-1) OPEO(n). An optimal C/N ratio of 12 was obtained for (NH(4))(2)SO(4) as the nitrogen source in a cultivated medium at pH 7. The kinetic analysis demonstrated that bacterial growth and OPEO(n) degradation followed the Monod equation and were based on a substrate concentration inhibition model and pseudo-first-order reaction, respectively. The substrate inhibition coefficient was over 18,000 mgl(-1) and this indicates that the strain has an ability to sustain growth at high concentrations of OPEO(n) and use it as the sole carbon source under such a stress condition. Furthermore, LC-MS analysis showed that the biodegradation mechanism of dodecyl octaethoxylate (AEO8) by P. nitroreducens TX1 was the sequential cleavage of the ethoxylate chain. 相似文献
955.
Yanying Bai Weiping Chen Andrew C. Chang Albert L. Page 《Journal of environmental science and health. Part. B》2013,48(6):531-539
Potentially hazardous trace elements such as Cd, Cu, Cr, Ni and Zn are expected to accumulate in biosolids–amended soil and remain in the soil for a long period of time. In this research, uptake of metals by food plants including cabbage, carrot, lettuce and tomato grown on soils 10 years after biosolids application was studied. All the five metals were significantly accumulated in the biosolids-amended soils. The accumulation of metal in soil did not result in significant increase in concentrations of Cu, Cr and Ni in the edible plant tissues. However, the Cd and Zn concentrations of the edible tissues of plants harvested from the biosolids receiving soils were significantly enhanced in comparison with those of the unaffected soils. The plant uptake under Greenfield sandy loam soil was generally higher than those under the Domino clayey loam soil. The metal concentration of edible plant tissue exhibited increasing trends with respect to the concentrations of the ambulated metals. The extents of the increases were plant species dependent. The indigenous soil metals were absorbed by the plants in much higher rates than those of the biosolids–receiving soils. It appeared that the plant uptake of the indigenous soil-borne metal and the added biosolids-borne metals are independent of one another and mathematically are additive. 相似文献
956.
Chien-jung Tien Colin S. Chen 《Journal of environmental science and health. Part. B》2013,48(9):901-912
This study aimed to determine the toxicity of three organophosphorous pesticides, chlorpyrifos, terbufos and methamidophos, to three indigenous algal species isolated from local rivers and algal mixtures. The diatom Nitzschia sp. (0.30–1.68 mg L?1 of EC50 -the estimated concentration related to a 50% growth reduction) and the cyanobacteria Oscillatoria sp. (EC50 of 0.33–7.99 mg L?1) were sensitive to single pesticide treatment and the chlorophyta Chlorella sp. was the most tolerant (EC50 of 1.29–41.16 mg L?1). In treatment with the mixture of three pesticides, Chlorella sp. became the most sensitive alga. The antagonistic joint toxic effects on three indigenous algae and algal mixtures were found for most of the two pesticide mixtures. The results suggested that mixture of pesticides might induce the detoxification mechanisms more easily than the single pesticide. The synergistic interactions between terbufos and methamidophos to algal mixtures and between methamidophos and chlorpyrifos to Nitzschia sp. indicated methamidophos might act as a potential synergist. Differential sensitivity of three families of algae to these pesticides might result in changes in the algal community structures after river water has been contaminated with different pesticides, posing great ecological risk on the structure and functioning of the aquatic ecosystem. 相似文献
957.
新风量作为评价室内环境质量的重要指标,越来越受到相关行业主管部门的重视。关于新风量的卫生要求和测试方法较多,本文针对目前使用较广泛的示踪气体法和风管法,分析其适用范围和评价方法,并提出建议。 相似文献
958.
While the innovativeness and market potential of a new product is normally emphasized, its environmental impact is often neglected. Despite their ability to help designers reduce the environmental impact of products throughout their life cycle, many eco-design methods focus on the redesign of existing products, necessitating a more innovative design capacity. This work describes a novel model to accelerate the preliminary eco-innovation product design by integrating the advantages of case-based reasoning and the TRIZ method. Previous cases from a database support a novel design to satisfy functional performances under the CBR framework. The innovative principles and evolution patterns of the TRIZ method can enhance the design level of new products to achieve eco-innovation. Four eco-innovation concepts for a PC mouse demonstrate the effectiveness of the proposed model. 相似文献
959.
Ching-Ho Lin Chin-Hsing Lai Yee-Lin Wu Ming-Jen Chen 《Atmospheric environment (Oxford, England : 1994)》2010,44(35):4364-4371
Determining the destructions of both ozone and odd oxygen, Ox, in the nocturnal boundary layer (NBL) is important to evaluate the regional ozone budget and overnight ozone accumulation. This work develops a simple method to determine the dry deposition velocity of ozone and its destruction at a polluted nocturnal boundary layer. The destruction of Ox can also be determined simultaneously. The method is based on O3 and NO2 profiles and their surface measurements. Linkages between the dry deposition velocities of O3 and NO2 and between the dry deposition loss of Ox and its chemical loss are constructed and used. Field measurements are made at an agricultural site to demonstrate the application of the model. The model estimated nocturnal O3 dry deposition velocities from 0.13 to 0.19 cm s?1, very close to those previously obtained for similar land types. Additionally, dry deposition and chemical reactions account for 60 and 40% of the overall nocturnal ozone loss, respectively; ozone dry deposition accounts for 50% of the overall nocturnal loss of Ox, dry deposition of NO2 accounts for another 20%, and chemical reactions account for the remaining 30%. The proposed method enables the use of measurements made in typical ozone field studies to evaluate various nocturnal destructions of O3 and Ox in a polluted environment. 相似文献
960.
本文通过对水价与需求关系的探讨,推导出水价与需求的理想公式,并就该公式进行了分析,提出了解决城市水资源供需矛盾的经济对策。 相似文献