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231.
Mohammad Torabi Fereidoun Mobasheri 《Journal of the American Water Resources Association》1973,9(6):1089-1099
ABSTRACT: The main objective of this paper is to present a stockastic dynamic programming model useful in determining the optimal operating policy of a single multipurpose surface reservoir. It is the unreliability of forecasting the amount of future streamflow which makes the problem of a reservoir operation a stochastic process. In this paper the stochastic nature of the streamflow is taken into account by considering the correlation between the streamflows of each pair of consecutive time intervals. This interdependence is used to calculate the probability of transition from a given state and stage to its succeeding ones. A dynamic programming model with a physical equation and a stochastic recursive equation is developed to find the optimum operational policy. For illustrative purposes, the model is applied to a real surface water reservoir system. 相似文献
232.
三峡库区中小城镇城市降雨径流污染特征及现状研究 总被引:1,自引:0,他引:1
本研究采用从微观到宏观,在库区沿岸城镇诸多相关因素相似前提下,选择涪陵市为典型试验区;从水文因素,街道地表物累积冲刷规律研究着手,建立累积、冲刷计算模式,计算出涪陵市年降雨径流污染负荷和库区污染荷载因子,同时选择具有代表性的集水闭合小区进行水质、水量同步观测试验进行验证;确定外推因子,计算三峡库区城市降雨径流年冲刷入长江的总固体,SS,BOD5,COD,T-N,T-P3量分别为53968吨,380 相似文献
233.
The Management of a Large Mediterranean Reservoir: Storage Regimens of the Yesa Reservoir,Upper Aragon River Basin,Central Spanish Pyrenees 总被引:2,自引:0,他引:2
Agriculture in Mediterranean countries is mainly based upon the irrigation of productive areas in the lowlands. For this reason, it is necessary to store large volumes of water in reservoirs located in mountain headwaters. These reservoirs have a relatively simple regimen of storage, increasing the water stored during the wet season (from October until May) and reaching the maximum volume shortly before the beginning of the hot, very dry season, when the water is released. This paper considers the storage regimen (inflow and outflow) of the Yesa Reservoir in the Spanish Pyrenees as an example of management of a large reservoir in a mountain Mediterranean environment, subject to a strong interannual variability. On average, the highest water storage level is achieved by retaining the high flows of the Aragón River in autumn and spring. Nevertheless, the irregularity of rainfalls and the existence of changes in the hydrological regimen lead to changes in the patterns of reservoir filling. Two patterns were identified in the Yesa Reservoir: (1) a quick increase of the stored volume in autumn, a stabilization in winter, and a new increase in spring; and (2) a continuous increase from October until May. These patterns are distributed in time over different periods since the construction of the reservoir in 1959, demonstrating the adjustment of the reservoir management to changes in the hydrological regimen. 相似文献
234.
本文通过实地考察表明,三峡库区有资源植物2068种,其中药用植物1006种、纤维植物140种、油脂植物76种、观赏植物74种、野果植物54种、芳香植物54种、树脂树胶植物68种、淀粉与糖类植物52种、鞣料植物32种、珍稀植物47种以及其它类型植物465种。 相似文献
235.
长江三峡库区滑坡灾害危险性评价 总被引:17,自引:3,他引:14
长江三峡地区滑坡崩塌分布广泛,灾害严重,特别是在三峡水利工程枢纽兴建以后,古滑崩体的复活以及岸坡失稳势必会对未来的三峡水库以及城镇居民建设、公路交通安全造成一定的影响。因此,以长江三峡地区的滑坡编目资料为基础,对该地区的滑坡特征进行了全面的分析,并对其形成机制进行了初步的探讨。同时,综合滑坡灾害诱发因素,运用信息量地滑坡灾害空间预测,并以此为基础结合土地使用情况将该地区划分五个不同等级即极危险区、 相似文献
236.
资源工程体系建设探讨——以三峡库区坡地资源开发保护体系建设为例 总被引:2,自引:1,他引:1
申元村 《长江流域资源与环境》1998,(2)
资源工程是实现社会经济发展的基本途径。资源开发体系和保护体系建设是构成资源工程体系的主要内容。文章阐述了如何设计一个资源开发和保护体系的总体思路(包括原则、目标、内容、行动、效益评估),并以长江三峡库区坡地资源利用保护为例,通过植物篱农林复合技术,使水土流失和环境退化基本得到了控制,经济产出比纯柑桔系统和纯粮食作物系统分别高出1/5和1/4,成为开发与保护融为一体、经济和生态相互促进的技术。这一技术值得在中国东部湿润半湿润区域推广。 相似文献
237.
水射流技术处理软基防渗工程实例 总被引:1,自引:0,他引:1
介绍了在西沙群岛永兴岛的特殊地基条件下,采用高压喷射注浆技术对大型地下集水池进行封底,并获得圆满成功的工程实例,总结了采用高压喷射注浆技术处理珊瑚礁(Coralreef) 地基的成功经验 相似文献
238.
黄河北干流与渭河相遇洪水分析 总被引:2,自引:0,他引:2
黄河北干流与渭河位于黄土高原,暴雨是洪水的重要成因.本文分析了近2000年的历史资料,提出该地区的洪水具有周期性,19世纪洪水达到高峰,20世纪洪水规模有所降低,并分析了黄河北干流与渭河及其支流径、洛河洪水相遇问题:四河相遇的概率很小,多形成特大洪水,两河相遇是较常发生的事件,多形成中等以下洪水。三门峡水库的淤积使该地区洪水灾害加剧.同时还分析了该地区洪水对黄河下游洪水的影响。 相似文献
239.
水库下游洪灾淹没损失的估算 总被引:10,自引:2,他引:10
本文为评价水库的防洪效益,探讨了水库下游保护区内洪水灾害淹没损失的估算方法,并通过实例进行了检验。这对水库的防洪规划及其它防洪效益定量估算问题有很大的意义。 相似文献
240.
A new, higher dam was installed at Kerkini Reservoir in 1982, causing habitat and landscape disruption. A decrease in the
area of grassland and shallow water areas, the rapid disappearance of reedbeds, the appearance of beds ofNymphaea, and the disappearance of half the forest area were all observed between 1982 and 1991. With the new hydrological regime,
a lacustrine system was created, with an extensive, rather deep (4–8 m), pelagic zone favorable for the development of coarse
fish species throughout the year. After 1982, an increase in fishing effort and a change in the relative abundance of fish
species in the catch, including the disappearance of eels and wels, were observed. The impact of the rise in the water level
of breeding aquatic birds led to a general decline in species typical of marshy habitats in favor of species preferring deeper
open water habitats. A decrease was recorded in bird species that feed largely on invertebrates and to a lesser extent fish
(e.g., glossy ibis) and that require extensive shallow feeding areas. There was a decline in geese, whose nests were regularly
flooded, and a major increase in piscivorous birds, particularly diving birds (e.g., cormorants), which prefer deeper open
water and benefitted directly from the large increase in coarse fish biomass. The disappearance of birds breeding in flooded
meadows (e.g., black-winged stilts) and of those restricted to reedbeds (e.g., marsh harrier) occurred from 1983. Over the
same period, the changes in populations of wintering birds at Kerkini were different from those occurring in other wetlands
in northern Greece. The changes recorded in the populations of wintering birds at Kerkini did not therefore result from overall
regional trends but from the major habitat modifications that occurred to this wetland. As for breeding birds, strictly piscivorous
species increased greatly as a result of the increased availability of fish, but also due to the appearance of many suitable
night roosting sites (flooded trees) and to the great increase in the area of open water greater than 2 m deep. Today, Kerkini
has become the most important breeding site in Greece for a majority of colonial waterbirds. In contrast, wintering shorebirds
practically disappeared. The many changes recorded in the status of breeding and wintering birds at Kerkini can mostly be
explained by the changes that occurred in the functioning of the ecosystem and in the habitat structure following the inauguration
of the new hydrological regime. These changes did not all occur at the same time: some were immediate and others required
a delay before they could be detected. 相似文献