全文获取类型
收费全文 | 2328篇 |
免费 | 261篇 |
国内免费 | 283篇 |
专业分类
安全科学 | 233篇 |
废物处理 | 136篇 |
环保管理 | 447篇 |
综合类 | 559篇 |
基础理论 | 521篇 |
污染及防治 | 704篇 |
评价与监测 | 114篇 |
社会与环境 | 76篇 |
灾害及防治 | 82篇 |
出版年
2024年 | 5篇 |
2023年 | 31篇 |
2022年 | 71篇 |
2021年 | 63篇 |
2020年 | 52篇 |
2019年 | 66篇 |
2018年 | 97篇 |
2017年 | 99篇 |
2016年 | 110篇 |
2015年 | 103篇 |
2014年 | 140篇 |
2013年 | 379篇 |
2012年 | 139篇 |
2011年 | 169篇 |
2010年 | 144篇 |
2009年 | 111篇 |
2008年 | 135篇 |
2007年 | 125篇 |
2006年 | 110篇 |
2005年 | 93篇 |
2004年 | 79篇 |
2003年 | 81篇 |
2002年 | 93篇 |
2001年 | 102篇 |
2000年 | 66篇 |
1999年 | 48篇 |
1998年 | 15篇 |
1997年 | 25篇 |
1996年 | 10篇 |
1995年 | 13篇 |
1994年 | 17篇 |
1993年 | 7篇 |
1992年 | 12篇 |
1991年 | 15篇 |
1990年 | 4篇 |
1989年 | 3篇 |
1988年 | 5篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1984年 | 4篇 |
1983年 | 6篇 |
1982年 | 3篇 |
1981年 | 8篇 |
1979年 | 2篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1973年 | 1篇 |
1966年 | 1篇 |
1960年 | 1篇 |
排序方式: 共有2872条查询结果,搜索用时 913 毫秒
532.
Ding Wei Chen Hong Chang Han Wang Yupeng Zhou Dian Feng Wei 《Environmental science and pollution research international》2022,29(54):81468-81480
Environmental Science and Pollution Research - Multirotor UAVs (unmanned aerial vehicles) have been widely used in urban vertical wind environment testing, whereas less attention has been given to... 相似文献
533.
534.
高职院校专职辅导员队伍建设现状及对策分析 总被引:2,自引:0,他引:2
李常 《湖南环境生物职业技术学院学报》2009,15(3):104-106
高职院校专职辅导员队伍是学生思想政治教育和日常管理工作的主力军,发挥着极其重要的作用.在新形势下,高职院校专职辅导员队伍在选聘配备,使用与管理,教育培训、激励等方面都存在着不足之处.高职院校应坚持选聘标准,优化引进人才;建立科学客观的专职辅导员评估体系;强化各类教育培训,提高专职辅导员专业水平;优化激励制度,创造良好的留人环境;建立合理的专职辅导员流动机制.参4. 相似文献
535.
四种不同的方法去除沉积物有机质,采用振荡平衡法研究了有机农药、非离子表面活性剂在沉积物上的吸附行为及非离子表面活性剂对有机农药吸附的影响.结果表明,经HCl处理后,沉积物有机碳含量增加,而经Na4 P2O7,NaOH和H2O2处理后沉积物有机碳含量均降低;甲基对硫磷、西维因的吸附取决于沉积物有机碳的分配作用,与矿物质无关;沉积物矿物组分的表面作用和微孔性作用使得高极性有机农药克百威在低有机碳含量沉积物七的吸附量增加;Tween-80使甲基对硫磷在未处理和HCl处理的沉积物上的吸附量减少,在NaOH处理和H2O2处理的沉积物上的吸附量增加. 相似文献
536.
Arsenite [As(III)]-oxidizing bacteria play important roles in reducing arsenic [As] toxicity and mobility in As-contaminated
areas. As-resistant bacteria were isolated from the soils of two abandoned mines in the Republic of Korea. The isolated bacteria
showed relatively high resistances to As(III) up to 26 mM. The PCR-based 16S rRNA analysis revealed that the isolated As-resistant
bacteria were close relatives to Serratia marcescensa, Pseudomonas putida, Pantoea agglomerans, and Alcaligenes sp. Among the five As-resistant bacterial isolates, Alcaligenes sp. strain RS-19 showed the highest As(III)-oxidizing activity in batch tests, completely oxidizing 1 mM of As(III) to As(V)
within 40 h during heterotrophic growth. This study suggests that the indigenous bacteria have evolved to retain the ability
to resist toxic As in the As-contaminated environments and moreover to convert the species to a less toxic form [e.g., from
As(III) to As(V)] and also contribute the biogeochemical cycling of As by being involved in speciation of As. 相似文献
537.
R. J. Davies‐Colley D. G. Smith 《Journal of the American Water Resources Association》2001,37(5):1085-1101
ABSTRACT: Suspended sediment causes a range of environmental damage, including benthic smothering, irritation of fish gills, and transport of sorbed contaminants. Much of the impact, while sediment remains suspended, is related to its light attenuation, which reduces visual range in water and light availability for photosynthesis. Thus measurement of the optical attributes of suspended matter in many instances is more relevant than measurement of its mass concentration. Nephelometric turbidity, an index of light scattering by suspended particles, has been widely used as a simple, cheap, instrumental surrogate for suspended sediment, that also relates more directly than mass concentration to optical effects of suspended matter. However, turbidity is only a relative measure of scattering (versus arbitrary standards) that has no intrinsic environmental relevance until calibrated to a ‘proper’ scientific quantity. Visual clarity (measured as Secchi or black disc visibility) is a preferred optical quantity with immediate environmental relevance to aesthetics, contact recreation, and fish habitat. Contrary to common perception, visual clarity measurement is not particularly subjective and is more precise than turbidity measurement. Black disc visibility is inter‐convertible with beam attenuation, a fundamental optical quantity that can be monitored continuously by beam transmissometry. Visual clarity or beam attenuation should supplant nephelometric turbidity in many water quality applications, including environmental standards. 相似文献
538.
Tiao J. Chang Timothy A. Bartrand Richard Germain 《Journal of the American Water Resources Association》2001,37(1):115-123
ABSTRACT: A regional water conservation system for drought management involves many uncertain factors. Water received from precipitation may stay on the ground surface, evaporate back into the atmosphere, or infiltrate into the ground. Reliable estimates of the amount of evapotranspiration and infiltration are not available for a large basin, especially during periods of drought. By applying a geographic information system, this study develops procedures to investigate spatial variations of unavailable water for given levels of drought severity. Levels of drought severity are defined by truncated values of monthly precipitation and daily streamflow to reflect levels of water availability. The greater the truncation level, the lower the precipitation or streamflow. Truncation levels of monthly precipitation are recorded in depth of water while those of daily streamflow are converted into monthly equivalent water depths. Truncation levels of precipitation and streamflow treated as regionalized variables are spatially interpolated by the unbiased minimum variance estimation. The interpolated results are vector values of precipitation and streamflow at a grid of points covering the studied basin. They are then converted into raster‐based values and expressed graphically. The image subtraction operation is used to subtract the image of streamflow from that of precipitation at their corresponding level of drought severity. It is done on a cell‐by‐cell basis resulting in new attribute values to form the spatial image representing a spatial distribution of potential water loss at a given level of drought severity. 相似文献
539.
ABSTRACT: Vermont is one of approximately half a dozen states for which no official drought mitigation plan exists. Given the recurring nature of this natural hazard, current contingency measures should be expanded upon into a coherent mitigation framework. The types of drought and impacts resulting from the 1998 to 1999 event were the focus of a previous article in this volume. The present article builds on the understanding of drought characteristics specific to the Vermont context and introduces the rationale behind a proposed drought planning framework. Pivotal organizations and institutions that should be involved in this process are also presented. 相似文献
540.
Kun‐Yeun Han Sang‐Ho Kim Deg‐Hyo Bae 《Journal of the American Water Resources Association》2001,37(3):695-708
ABSTRACT: This study developed a QUAL2E‐Reliability Analysis (QUAL2E‐RA) model for the stochastic water quality analysis of the downstream reach of the main Han River in Korea. The proposed model is based on the QUAL2E model and incorporates the Advanced First‐Order Second‐Moment (AFOSM) and Mean‐Value First‐Order Second‐Moment (MFOSM) methods. After the hydraulic characteristics from standard step method are identified, the optimal reaction coefficients are then estimated using the Broyden‐Fletcher‐Goldfarb‐Shanno (BFGS) method. Considering variations in river discharges, pollutant loads from tributaries, and reaction coefficients, the violation probabilities of existing water quality standards at several locations in the river were computed from the AFOSM and MFOSM methods, and the results were compared with those from the Monte Carlo method. The statistics of the three uncertainty analysis methods show that the outputs from the AFOSM and MFOSM methods are similar to those from the Monte Carlo method. From a practical model selection perspective, the MFOSM method is more attractive in terms of its computational simplicity and execution time. 相似文献