全文获取类型
收费全文 | 2923篇 |
免费 | 69篇 |
国内免费 | 135篇 |
专业分类
安全科学 | 91篇 |
废物处理 | 75篇 |
环保管理 | 217篇 |
综合类 | 692篇 |
基础理论 | 886篇 |
环境理论 | 5篇 |
污染及防治 | 644篇 |
评价与监测 | 157篇 |
社会与环境 | 305篇 |
灾害及防治 | 55篇 |
出版年
2023年 | 22篇 |
2022年 | 67篇 |
2021年 | 60篇 |
2020年 | 28篇 |
2019年 | 41篇 |
2018年 | 126篇 |
2017年 | 101篇 |
2016年 | 161篇 |
2015年 | 79篇 |
2014年 | 136篇 |
2013年 | 177篇 |
2012年 | 128篇 |
2011年 | 274篇 |
2010年 | 156篇 |
2009年 | 121篇 |
2008年 | 112篇 |
2007年 | 120篇 |
2006年 | 87篇 |
2005年 | 73篇 |
2004年 | 243篇 |
2003年 | 189篇 |
2002年 | 86篇 |
2001年 | 44篇 |
2000年 | 38篇 |
1999年 | 53篇 |
1998年 | 53篇 |
1997年 | 89篇 |
1996年 | 38篇 |
1995年 | 23篇 |
1994年 | 34篇 |
1993年 | 61篇 |
1992年 | 23篇 |
1991年 | 22篇 |
1990年 | 6篇 |
1989年 | 6篇 |
1988年 | 6篇 |
1985年 | 3篇 |
1984年 | 3篇 |
1981年 | 2篇 |
1980年 | 4篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1966年 | 3篇 |
1965年 | 2篇 |
1964年 | 4篇 |
1961年 | 2篇 |
1960年 | 2篇 |
1959年 | 2篇 |
1955年 | 1篇 |
1954年 | 2篇 |
排序方式: 共有3127条查询结果,搜索用时 21 毫秒
1.
进入“十一五”规划期,中国的大城市正面临着“建构资源节约型、环境友好型和谐社会”的重大战略转型。城市地下空间资源的综合开发利用是实现这一伟大战略目标的重要保障之一。作者在研究总结国外大城市地下空间资源综合开发利用成功经验与教训的基础上,分析未来中国城市发展趋势,论述城市地下空间资源综合开发利用的发展方向与战略目标,创造性的提出了实现这一伟大战略目标应该创建的中国式综合管理的体制、机制与法制。本文可供政府决策参考。 相似文献
2.
环境污染事故风险预测评估模式研究 总被引:4,自引:0,他引:4
曾维华 《防灾减灾工程学报》2004,24(3):329-334
从环境风险到环境污染事故演变的一般规律入手,提出了环境污染事故风险预测评估模式,为环境污染事故风险评估、预防与应急响应提供科学手段。环境污染事故风险预测评估模式的提出,一方面丰富和发展了环境安全与应急响应理论;另一方面,对公共安全、企业安全管理与应急响应等工作具有一定指导意义。 相似文献
3.
4.
5.
In multiphase systems capillary pressures play a significant role on fluid movement and retention. The facility to predict
the effect of different thermal remediation strategies requires the knowledge of the effect of temperature on capillary pressure-saturation
relationships in the soils.
The objective of recent study was (a) to develop a technique for routinely measuring the pressure-saturation curves of soil
samples saturated with a nonpolar liquid at different regulated temperatures (b) to build a database using the measured pressure-saturation
curves and the physical, chemical properties of the model soils (c) to establish the dependence of nonaqueous phase liquid
retention on the soil properties and the temperature.
The retention curves (extraction isotherms) with nonaqueous phase liquid were determined using a modified
pressure plate extractor. The wetting phase was a non-aromatic hydrocarbon distillation product. Pressure plates were designed and constructed in
the laboratory of our department. The temperature was held constant at 20, 40 and 60 ∘C.
Statistical analysis was performed involving selected soil parameters and the measured nonaqueous phase liquid retention data.
The results show that knowing some easily measurable soil parameters (bulk density, particle size distribution, humus and
lime content) we can estimate the nonaqueous phase liquid retention of the soils. The measured “extraction isotherms” provide
essential information about the temperature-dependency of pressure-saturation curves. 相似文献
6.
Montserrat Bacardit Lluís Camarero 《Atmospheric environment (Oxford, England : 1994)》2010,44(4):582-595
The chemistry of high mountain snowpacks is a result of the long-range atmospheric transport and deposition of elements. Pyrenean snowpacks contain information about the fluxes of elements over SW Europe in winter. Here we analysed Al, Ti, Mn, Fe, Ni, Cu, Zn, As, Se, Cd and Pb in the 2004–05 winter snowpack in the Central Pyrenees, at an altitude range of 1820–3200 m a.s.l. Ni, As, Se and Cd were not detected in most cases. The concentrations of the remaining elements were comparable to those found in other high mountain areas in Europe and North America considered representative of regional background of atmospheric deposition in populated areas. In contrast, our measurements were higher than those of polar areas, which represent the global background. Single measurements of concentrations and snow accumulation were subject to considerable spatial variability, which may be attributable to strong wind drift and other post-depositional processes. The major ions chemistry of the snow indicated three possible origins for the solutes: terrigenous dust, sea salt spray and polluting S and N aerosols. We found no association between Cu, Zn and Pb and any of these possible sources. This observation therefore indicates that these elements were not preferentially bound to any particular kind of aerosol. Snow collected at altitudes of up to 2050 m a.s.l. presented higher concentrations of several elements than snow above this altitude, thereby indicating a local influence. Snow collected above 2300 m a.s.l. was therefore more representative of broad regional inputs. At these higher altitudes, snow was not enriched in Al, Ti, Mn, Fe or As compared with the composition of the upper continental crust and the local lithology, and these elements (except Mn) appeared almost exclusively in the particulate fraction. This observation indicates that Al, Ti, Mn, Fe and As were present mainly as part of dust particles of terrigenous origin. In contrast, Cu, Zn, and Pb presented medium to high enrichment factors and showed a higher proportion of soluble forms, thereby indicating their polluting character. 相似文献
7.
Lajos Izsó Miklós Antaiovits 《International journal of occupational safety and ergonomics》2013,19(3-4):173-189
An activity analysis method was developed for studying the structure and dynamics of control room operators’ activity during normal operation based on directly observable elements of the operators’ behavior. The method assesses current activity along three dimensions in each 5-min period of the shift. Intensity characterizes arousal level, direction shows whether the activity is directed predominantly at the process control task, at something else, or miscellaneous. Motivation reflects if the activity is driven by intrinsic or extrinsic motivation. A case study is presented, in which 3 morning, 3 afternoon, and 3 night shifts of a Nuclear Power Plant operator crew are involved. The obtained results gave a deeper understanding of the operators’ activity and also revealed an “arousal compensation” tendency. 相似文献
8.
Arne Aarås 《International journal of occupational safety and ergonomics》2013,19(4):409-420
Three periods of work environmental activity in the company will be presented: (a) A period without a work environmental organization and an environmental budget, covered approximately 1 year; (b) A period when an environmental organization with a separate work environmental budget was established. This period covered 15 years; (c) A period when the company was divided in 3 companies without a separate work environmental budget, but still an environmental organization, covering the last 12 years. 相似文献
9.
采用不同形态的PHAs薄膜(聚β-羟基丁酸(PHB)及β-羟基丁酸与β-羟基戊酸的共聚物(PHBV)膜),在各种环境(如土壤和水体)的不同条件下,对膜的生物降解性进行了研究,并对其降解机制作了初步探讨。结果表明:PHAs膜具有生物降解性,在无菌条件下不能被降解;在不同的环境中,如不同土壤和水体,PHAs膜的降解情况不同;不同的条件,如pH、温度,对环境中PHAs膜的降解率有着不同的影响;PHB膜的生物降解速度比PHBV膜快;PHAs膜的厚度对其降解能力有很大影响。 相似文献
10.