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841.
842.
单室燃气火灾后果模拟研究 总被引:1,自引:0,他引:1
燃气泄漏着火是引发火灾的一个重要原因,其发展过程包括多相湍流流动、燃烧、传热多个分过程。本文将理想单室燃气泄漏火灾的传热传质过程采用CFD(Compulational Fluid Dynamics)方法进行了计算机模拟,对其发展规律及危害性进行了深入研究,得出了火场中的流场、泻度场及有害气体浓度场的分布,为定量研究火灾烟气流动过程以及建立不同危险等级的危险区域提出了依据和研究方法。 相似文献
843.
井喷点火过程天然气爆炸后果分析 总被引:2,自引:0,他引:2
尚文启 《中国安全生产科学技术》2006,2(6):7-9
井喷失控事故发生后,尽快点火是减少人员伤亡的最有效措施之一。然而,点火过程中一旦发生天然气爆炸,其可能的爆炸伤害范围、破坏范围以及是否在可接受风险范围,就成为决策能否点火的关键。本文应用蒸汽云爆炸的肿当量模型和冲击波峰值超压模型,提出了天然气井喷失控后,发生天然气爆炸的人员死亡区、重伤区和轻伤区的计算方法;假设井喷的天然气无阻流量,计算了可能的人员伤害范围,并对计算结果进行了分析。分析发现,在井喷失控后,最大限度地减少井喷失控时间,以及最大限度地防止天然气在某一区域的大量积聚,是减轻井喷失控天然气爆炸后果的最佳措施。 相似文献
844.
康东伟 《中国环境管理干部学院学报》2006,16(4):43-45
昌黎黄金海岸自然保护区存在着土地权属、资源保护与开发矛盾、经费不足和管理执法力量薄弱等诸多现实问题.因此,结合保护区概况,提出发展生态旅游,解决土地权属、协调资源保护与开发关系和实施社区共管等方式等可行性对策与措施. 相似文献
845.
自然灾害保险风险分析 总被引:7,自引:1,他引:7
在考虑自然灾害的危险性、灾害的经济与社会易损性和风险区的工程防御能力的基础上,建立了自然灾害保险风险分析的数学模型。选择给人类社会造成重大损失的地震、地质灾害、洪水和台风等4种自然灾害作为灾害危险度评判的灾种,利用所建立的数学模型,对中国由然灾害保险风险进行了评判。并根据评判结果绘制了中国自然灾害保险风险区划图。 相似文献
846.
Bjørn K. Myskja 《Journal of Agricultural and Environmental Ethics》2006,19(3):225-238
Public policy on the development and use of genetically modified organisms (GMOs) has mainly been concerned with defining proper strategies of risk management. However, surveys and focus group interviews show that although lay people are concerned with risks, they also emphasize that genetic modification is ethically questionable in itself. Many people feel that this technology “tampers with nature” in an unacceptable manner. This is often identified as an objection to the crossing of species borders in producing transgenic organisms. Most scientists reject these opinions as based on insufficient knowledge about biotechnology, the concept of species, and nature in general. Some recent projects of genetic modification aim to accommodate the above mentioned concerns by altering the expression of endogenous genes rather than introducing genes from other species. There can be good scientific reasons for this approach, in addition to strategic reasons related to greater public acceptability. But are there also moral reasons for choosing intragenic rather than transgenic modification? I suggest three interrelated moral reasons for giving priority to intragenic modification. First, we should respect the opinions of lay people even when their view is contrary to scientific consensus; they express an alternative world-view, not scientific ignorance. Second, staying within species borders by strengthening endogenous traits reduces the risks and scientific uncertainty. Third, we should show respect for nature as a complex system of laws and interconnections that we cannot fully control. The main moral reason for intragenic modification, in our view, is the need to respect the “otherness” of nature. 相似文献
847.
唐家龙 《中国人口.资源与环境》2006,16(2):19-22
从分析可持续发展的内在要求与经济人假设之间的冲突出发,构建了利他状态下的资源代际分配效用函数。通过对非凸状偏好及利他的心理价格变化下消费均衡解的比较静态分析,作者指出。在后代人缺位情况下可以利用宏观和微观因素对当代人的利他度加以影响。实现利他的资源代际分配模式,从而在理论意义和实践意义上拓展了可持续发展理论。 相似文献
848.
在西部大开发中 ,能源占有举足轻重的作用。我国西部的塔里木、准噶尔、吐 -哈、柴达木、鄂尔多斯、四川等六大含油气盆地含有丰富的天然气资源 ,储量大于 5 0 0× 10 8m3的 9个大气田中 ,西部就占 7个。中国天然气预测资源总量为 38× 10 12 m3,其中西部天然气预测资源量为 2 2 .4× 10 12 m3,占天然气预测资源总量的 5 8.9%。仅就西部的塔里木盆地而言 ,剩余可采储量为 3397× 10 8m3,按年产 12 0× 10 8m3计算 ,储采比为 2 8,塔里木盆地天然气有动态稳产 30年的储量保证 ,这对于“西气东输”工程的实施、西部经济的腾飞和可持续发展具有重要意义 相似文献
849.
Spatial proximity of emissions sources to receptors may affect sensitivity to potential adverse human health effects. This research investigates whether receptor sensitivity to the location of emission sources can be utilized efficiently to minimize health risk in selecting sites for industrial enterprises, thermal electric stations, etc. A sensitivity function that is independent of the location of pre-existing emission sources is derived and applied to Minsk, Belarus. The function estimates exposures based on weather and climatic conditions as well as the distribution of population density at a given locality. Arraying prospective sites based on their sensitivity function magnitude provides a technique for minimizing health risk based on receptor sensitivity to the spatial proximity of atmospheric emissions sources. 相似文献
850.
Sourcing sediment using multiple tracers in the catchment of Lake Argyle,Northwestern Australia 总被引:5,自引:0,他引:5
Control of sedimentation in large reservoirs requires soil conservation at the catchment scale. In large, heterogeneous catchments,
soil conservation planning needs to be based on sound information, and set within the framework of a sediment budget to ensure
that all of the potentially significant sources and sinks are considered.
The major sources of sediment reaching the reservoir, Lake Argyle, in tropical northwestern Australia, have been determined
by combining measured sediment fluxes in rivers with spatial tracer-based estimates of proportional contributions from tributaries
of the main stream entering the lake, the Ord River. The spatial tracers used are mineral particle magnetics, the strontium
isotopic ratio, and the neodymium isotopic ratio. Fallout of 137Cs has been used to estimate the proportion of the sediment in Lake Argyle eroded from surface soils by sheet and rill erosion,
and, by difference, the proportion eroded from subsurface soils by gully and channel erosion. About 96% of the sediment in
the reservoir has come from less than 10% of the catchment, in the area of highly erodible soils formed on Cambrian-age sedimentary
rocks. About 80% of the sediment in the reservoir has come from gully and channel erosion. A major catchment revegetation
program, designed to slow sedimentation in the reservoir, appears to have had little effect because it did not target gullies,
the major source of sediment. Had knowledge of the sediment budget been available before the revegetation program was designed,
an entirely different approach would have been taken. 相似文献