全文获取类型
收费全文 | 448篇 |
免费 | 4篇 |
国内免费 | 24篇 |
专业分类
安全科学 | 148篇 |
废物处理 | 13篇 |
环保管理 | 41篇 |
综合类 | 175篇 |
基础理论 | 14篇 |
污染及防治 | 45篇 |
评价与监测 | 28篇 |
社会与环境 | 5篇 |
灾害及防治 | 7篇 |
出版年
2024年 | 1篇 |
2023年 | 8篇 |
2022年 | 2篇 |
2021年 | 12篇 |
2020年 | 12篇 |
2019年 | 1篇 |
2018年 | 3篇 |
2017年 | 6篇 |
2016年 | 12篇 |
2015年 | 14篇 |
2014年 | 26篇 |
2013年 | 29篇 |
2012年 | 39篇 |
2011年 | 20篇 |
2010年 | 8篇 |
2009年 | 21篇 |
2008年 | 22篇 |
2007年 | 13篇 |
2006年 | 18篇 |
2005年 | 12篇 |
2004年 | 21篇 |
2003年 | 25篇 |
2002年 | 11篇 |
2001年 | 18篇 |
2000年 | 15篇 |
1999年 | 31篇 |
1998年 | 22篇 |
1997年 | 17篇 |
1996年 | 7篇 |
1995年 | 5篇 |
1994年 | 9篇 |
1993年 | 8篇 |
1992年 | 2篇 |
1991年 | 3篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1982年 | 1篇 |
排序方式: 共有476条查询结果,搜索用时 15 毫秒
371.
Han YJ Holsen TM Evers DC Driscoll CT 《Environmental pollution (Barking, Essex : 1987)》2008,156(3):1348-1356
Changes in deposition of gaseous divalent mercury (Hg(II)) and particulate mercury (Hg(p)) in New Hampshire due to changes in local sources from 1996 to 2002 were assessed using the Industrial Source Complex Short Term (ISCST3) model (regional and global sources and Hg atmospheric reactions were not considered). Mercury (Hg) emissions in New Hampshire and adjacent areas decreased significantly (from 1540 to 880 kg yr−1) during this period, and the average annual modeled deposition of total Hg also declined from 17 to 7.0 μg m−2 yr−1 for the same period. In 2002, the maximum amount of Hg deposition was modeled to be in southern New Hampshire, while for 1996 the maximum deposition occurred farther north and east. The ISCST3 was also used to evaluate two future scenarios. The average percent difference in deposition across all cells was 5% for the 50% reduction scenario and 9% for the 90% reduction scenario. 相似文献
372.
Y. C. Sharma P. Aggarwal T. N. Singh 《Environment, Development and Sustainability》2009,11(3):589-599
India is the first country to introduce environmental legislation in the constitution but because of lengthy legal procedures,
it is very difficult to control environmental deterioration. There are many factors responsible for this deterioration. Coal
mining is one such activity where deterioration is very severe and the present communication aims this aspect. Coal is the
one of the most essential mineral having large reserves in India. It’s mining and beneficiation produce a variety of pollutants.
The main pollutants emitted during the processing of coal are green house gases, coal dust and acid mine drainage. Many reports
on different aspects of coal mining are available including reports on emission of different pollutants but the present work
is probably only of it’s kind in which the authors have tried to determine environment liability directly in terms of economy.
It was found that greenhouse liabilities, coal dust liability and sulphur liability are accounted for 12.07, 5.0 and 101.97
US$, making an overall 2.4% of the total economic gains due to coal mining. During the calculations approximate number of
total workers and other parameters have been taken into consideration. Who pays for this irreversible damage is a question.
Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue. 相似文献
373.
In this study, three river floodplain soils with different compositions of carbonaceous materials and a reference coal sample were extracted with water using the accelerated solvent extraction (ASE) method. The desorption enthalpy values for 2-ring PAHs were highest in the coal sample, with values in the soil samples decreasing with decrease in coal content. The values for the higher condensed PAHs showed that the highest desorption enthalpies were from the samples with the largest amount of coal-derived particles. Elevated desorption enthalpies indicated a strong bonding between PAHs and geosorbents. Moreover, with the application of ASE this study was able to conclude that the PAHs in the samples were preferentially adsorbed to carbonaceous materials with high surface areas. 相似文献
374.
Invasive species and coal bed methane development in the Powder River Basin, Wyoming 总被引:1,自引:0,他引:1
Bergquist E Evangelista P Stohlgren TJ Alley N 《Environmental monitoring and assessment》2007,128(1-3):381-394
One of the fastest growing areas of natural gas production is coal bed methane (CBM) due to the large monetary returns and
increased demand for energy from consumers. The Powder River Basin, Wyoming is one of the most rapidly expanding areas of
CBM development with projections of the establishment of up to 50,000 wells. CBM disturbances may make the native ecosystem
more susceptible to invasion by non-native species, but there are few studies that have been conducted on the environmental
impacts of this type of resource extraction. To evaluate the potential effects of CBM development on native plant species
distribution and patterns of non-native plant invasion, 36 modified Forest Inventory and Analysis plots (each comprised of
four 168-m2 subplots) were established in the Powder River Basin, Wyoming. There were 73 168-m2 subplots on control sites; 42 subplots on secondary disturbances; 14 on major surface disturbances; eight on well pads; and
seven on sites downslope of CBM wells water discharge points. Native plant species cover ranged from 39.5 ± 2.7% (mean ± 1
SE) in the secondary disturbance subplots to 17.7 ± 7.5% in the pad subplots. Non-native plant species cover ranged from 31.0
± 8.4% in the discharge areas to 14.7 ± 8.9% in the pad subplots. The control subplots had significantly less non-native species
richness than the combined disturbance types. The combined disturbance subplots had significantly greater soil salinity than
the control sites. These results suggest that CBM development and associated disturbances may facilitate the establishment
of non-native plants. Future research and management decisions should consider the accumulative landscape-scale effects of
CBM development on preserving native plant diversity. 相似文献
375.
选煤厂输煤系统转载点粉尘产出控制技术 总被引:3,自引:0,他引:3
针对选煤厂输煤系统转载点多、产尘量大、粉尘污染严重的问题,对输煤系统转载点处的产尘原因进行了分析,提出了加装特殊设计的导料槽、安装复膜扁布袋除尘器及增加湿式降尘系统等控制措施,并对改造前后转载点处的粉尘浓度进行了对比.结果表明,改造后转载点处的作业环境达到了治理目标的要求. 相似文献
376.
In order to study the influences of coal dust components on the explosibility of hybrid mixture of methane and coal dust, four kinds of coal dust with different components were selected in this study. Using the standard 20 L sphere, the maximum explosion pressure, explosion index and lower explosion limits of methane/coal dust mixtures were measured. The results show that the addition of methane to different kinds of coal dust can all clearly increase their maximum explosion pressure and explosion index and decrease their minimum explosion concentration. However, the increase in the maximum explosion pressure and explosion index is more significant for coal dust with lower volatile content, while the decrease in the minimum explosion concentration is more significant for coal dust with higher volatile content. It is concluded that the influence of methane on the explosion severity is more pronounced for coal dust with lower volatile content, but on ignition sensitivity it is more pronounced for coal dust with higher volatile content. Bartknecht model for predicting the lower explosion limits of methane/coal dust mixture has better applicability than Le Chatelier model and Jiang model. Especially, it is more suitable for hybrid mixtures of methane and high volatile coal dust. 相似文献
377.
In underground coal mining, methane explosions often can cause tremendous disasters. In the meantime, carbon monoxide (CO), generated during the process of coal oxidation, may appear in the air. Therefore, the explosion characteristics of the mixture of CH4 and CO must be investigated to prevent gas explosion accidents in coal mines. We conducted experiments by using a 20-L nearly spherical gas explosion testing device. The software FLACS was used to simulate the explosion of the mixture of CH4 and CO at various mixing concentrations, and the simulation results corresponded to experimental results. With the increase of CO concentration, both upper and lower explosive limits of CH4 decreased. On the whole, the explosion characteristic parameters of CH4 and the mixture are similar. When CH4 concentration was below the stoichiometric concentration, the addition of CO could promote the intensity of gas explosion; oppositely, excessive CO would inhibit the gas explosion reaction. The inhibitory effects become more significant as the concentration of CH4 increases. 相似文献
378.
379.
ABSTRACTAn efficient coal de-capacity quota allocation scheme is key for accelerating China’s coal supply-side structure reform. This paper allocates the coal de-capacity quota from the perspective of efficiency to seek the optimal capacity allocation in each Chinese province. First, we estimate the coal capacity of 24 coal-producing provinces based on boundary production function model. According to the actual coal overcapacity in each province, we initially allocate the coal de-capacity quota of reducing 0.8 billion tons among them. Then, we optimize the initial allocation plan by using the zero-sum gains data envelopment model (ZSG-DEA) considering backward coal capacity, coal economic output, and coal resource endowment of each province. The results indicate that: First, there is coal overcapacity all over China, and there are obvious differences among the provinces. Second, the optimal allocation results show that the large coal producing provinces, including Shanxi, Inter Mongolia, Shaanxi, etc., need to undertake most of the coal de-capacity tasks, while the old coal producing provinces in northeast and west China should undertake a heavier burden of coal de-capacity. Third, the “one-size fits-all” approach burdens the small coal producing provinces with reducing coal capacity, leading to a general low enthusiasm for coal de-capacity in these regions. 相似文献
380.
空气和煤气吹脱法处理高氨氮废水的对比研究 总被引:1,自引:0,他引:1
研究了在实验室使用空气吹脱法去除高浓度氨氮废水的条件,通过正交实验得出其影响因素大小顺序为:废水pH>气液比r>废水温度tw>表面活性剂浓度c,最佳吹脱条件为pH=11.0,r=550,c=10mg/L,tw=75℃,最高氨氮去除效率达到71.4%。在某焦化厂以终冷塔后焦炉煤气为解吸介质,现场试验影响因素大小顺序为:o废水pH>废水温度tw>气液比r>煤气温度tg>表面活性剂浓度c,最佳吹脱条件为pH=11.5,tw=90℃,r=650,tg=55℃,c=20mg/L。为煤气吹脱解吸回收氨工艺的应用提出了建议。 相似文献