全文获取类型
收费全文 | 27314篇 |
免费 | 1769篇 |
国内免费 | 2772篇 |
专业分类
安全科学 | 4046篇 |
废物处理 | 464篇 |
环保管理 | 6326篇 |
综合类 | 12815篇 |
基础理论 | 2440篇 |
环境理论 | 36篇 |
污染及防治 | 1501篇 |
评价与监测 | 1562篇 |
社会与环境 | 1569篇 |
灾害及防治 | 1096篇 |
出版年
2024年 | 64篇 |
2023年 | 339篇 |
2022年 | 573篇 |
2021年 | 791篇 |
2020年 | 970篇 |
2019年 | 681篇 |
2018年 | 594篇 |
2017年 | 841篇 |
2016年 | 1028篇 |
2015年 | 981篇 |
2014年 | 1182篇 |
2013年 | 1540篇 |
2012年 | 1626篇 |
2011年 | 1966篇 |
2010年 | 1321篇 |
2009年 | 1598篇 |
2008年 | 1192篇 |
2007年 | 1711篇 |
2006年 | 1689篇 |
2005年 | 1388篇 |
2004年 | 1305篇 |
2003年 | 1220篇 |
2002年 | 1086篇 |
2001年 | 981篇 |
2000年 | 935篇 |
1999年 | 840篇 |
1998年 | 584篇 |
1997年 | 533篇 |
1996年 | 361篇 |
1995年 | 323篇 |
1994年 | 263篇 |
1993年 | 258篇 |
1992年 | 189篇 |
1991年 | 124篇 |
1990年 | 82篇 |
1989年 | 69篇 |
1988年 | 68篇 |
1987年 | 54篇 |
1986年 | 48篇 |
1985年 | 49篇 |
1984年 | 61篇 |
1983年 | 36篇 |
1982年 | 38篇 |
1981年 | 31篇 |
1980年 | 40篇 |
1979年 | 45篇 |
1978年 | 33篇 |
1977年 | 20篇 |
1973年 | 20篇 |
1971年 | 21篇 |
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
121.
气相和颗粒物中邻苯二甲酸酯的采样与检测技术 总被引:2,自引:0,他引:2
对邻苯二甲酸酯的性质及其在环境空气中的存在状态、样品采集技术与分析方法进行了综述,侧重介绍了样品的采集、净化、采样效率和采样与分析全过程的质量控制。 相似文献
122.
Macroinvertebrate Regionalisation for use in the Management of Aquatic Ecosystems in Victoria, Australia 总被引:5,自引:0,他引:5
The development of a broader, more holistic approach to aquaticecosystem management has been called for in recent years. Physical and chemical objectives alone are no longer consideredsufficient for the protection of aquatic ecosystems and shouldbe supplemented with biological objectives. The ubiquitousand sedentary nature of macroinvertebrates, combined with theirmeasurable response to environmental conditions, favour their use as important indicators in environmental policies. To establish biological objectives, there is a need for a regionalframework to limit the variability between ecosystems. Past studies have demonstrated that an a posteriori regionalisationapproach may be more useful than an a priori approach in explaining single component (e.g. macroinvertebrates) patternsacross ecosystems. This is particularly important as aquaticresource management agencies often focus on one or twocomponents of the ecosystem to assess environmental health. This study uses an a posteriori method to delineate and describebiological regions based on edge and riffle macroinvertebrate data. The regionalisation will provide a framework for settingbiological objectives, based on the range of reference conditionsmeasured within each separate region. The objectives will includeregional checklists for taxa and biotic indices. Predictive modelling in the style of RIVPACS or AUSRIVAS will also be usedwithin each region to develop objectives, incorporating local, regional and systematic features as predictor variables. 相似文献
123.
Finnamore A Alonso A Santisteban J Cordova S Valencia G de la Cruz A Polo R 《Environmental monitoring and assessment》2002,76(1):43-53
By applying principles of adaptive management, and by using the valuable information that arthropods provide from assessment and monitoring programs, managers can identify and reduce possible impacts on biodiversity in development projects. In 1996, the Smithsonian Institution's Monitoring and Assessment of Biodiversity program worked together with Shell Prospecting and Development Peru to establish an adaptive management program to protect biodiversity in a natural gas exploration project in a Peruvian rainforest. In this paper, we outlined the conceptual steps involved in establishing an assessment and monitoring program for arthropods, including setting objectives, evaluating the results and making decisions. We also present the results of the assessment using some of groups of arthropods, and summarize the steps taken to identify appropriate groups for monitoring. 相似文献
124.
We propose a modelling framework for the design of a Pigouvian effluent tax, in an environmental management problem implicating
several economic agents located in a river basin. The proposed charging system allows for the agents' geographical position
relative to the river's sections, at which environmental standards are to be enforced, and takes into account the possible
different market structures within which the agents are operating. In particular, we consider industrial agents competing
on an oligopolistic market, and a set of farmers acting as price takers on a large market. A regional authority's goal is
to induce agents to some sort of cooperation which would result in the satisfaction of the common environmental constraints.
The economic process on one side, and the pollution transport and accumulation on the other, constitute two dynamic processes
in two different time scales. As the economic process is much slower than the other process we can neglect the latter's transients
and concentrate on the time invariant steady state solutions to the transportation equation. The model thus constructed has
some noncooperative game and optimal control problem's features with space being the ‘running’ variable.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
125.
工作场所空气中硫酸雾(SO3)的分析 总被引:1,自引:0,他引:1
王连弟 《环境监测管理与技术》1997,9(3):36-37
采用碘量法测定工作场所空气中的三氧化硫及硫酸雾,三氧化硫及硫酸雾经中性水吸收后与碘化钾和碘酸钾反应,析出的碘与淀粉指示剂作用产生蓝色,进行比色测定。 相似文献
126.
共振光散射技术是一项在普通荧光分光光度计上进行测量的光散射技术,文章简要介绍了光散射现象,共振光散射的基本原理并作了定量基础讨论,对共振光散射技术在环境分析中的应用作了初步研究。 相似文献
127.
128.
Georgios D. Gikas Trisevgeni Yiannakopoulou Vassilios A. Tsihrintzis 《Environmental Modeling and Assessment》2006,11(3):219-233
SWAT ver. 2000 was used to predict hydrographs, and sediment, nitrate and total phosphorus loadings from a 1349 km2 mountainous/agricultural watershed in Northern Greece. The model was calibrated and verified using continuous meteorological
data from eight stations within the drainage area, and runoff, sediment and nutrient concentrations measured at nine stations
located within the main tributaries of the watershed, for the time period from May 1st, 1998 to January 31st, 2000. Model
validation methodology and resulting input parameters appropriate for Mediterranean drainage basins are presented. Predicted
by the model hydrographs, sedimentographs and pollutographs are plotted against observed values and show good agreement. Model
performance is evaluated using the root mean square error computation and scattergrams of predicted versus observed data.
The validated model is also used to test the effectiveness of three alternative cropping scenarios in reducing nutrient loadings
from the agricultural part of the watershed. The study showed that this model, if properly validated, can be used effectively
in testing management scenarios in Mediterranean drainage basins. 相似文献
129.
将有时序多目标决策方法应用于地面水环境质量优势的比较,介绍了决策方法的原理和评价步骤。实例分析表明该方法计算过程简便,分辨率高,排序结果与实际环境质量状况相符合。 相似文献
130.
酸性法测定高锰酸盐指数加热时间的选择 总被引:1,自引:0,他引:1
张美萍 《环境监测管理与技术》1997,9(1):38-38
酸性法测定高锰酸盐指数,会因实验条件的差异产生不同的结果。对不同加热时间,加热方式等因素进行了试验,结果表明加热时间以水浴加热沸腾30min或电炉直接加热8min为宜。 相似文献