全文获取类型
收费全文 | 459篇 |
免费 | 21篇 |
国内免费 | 57篇 |
专业分类
安全科学 | 30篇 |
废物处理 | 2篇 |
环保管理 | 34篇 |
综合类 | 190篇 |
基础理论 | 34篇 |
污染及防治 | 118篇 |
评价与监测 | 103篇 |
社会与环境 | 23篇 |
灾害及防治 | 3篇 |
出版年
2023年 | 21篇 |
2022年 | 11篇 |
2021年 | 8篇 |
2020年 | 15篇 |
2019年 | 8篇 |
2018年 | 14篇 |
2017年 | 8篇 |
2016年 | 9篇 |
2015年 | 8篇 |
2014年 | 25篇 |
2013年 | 15篇 |
2012年 | 19篇 |
2011年 | 43篇 |
2010年 | 31篇 |
2009年 | 35篇 |
2008年 | 35篇 |
2007年 | 26篇 |
2006年 | 14篇 |
2005年 | 9篇 |
2004年 | 15篇 |
2003年 | 10篇 |
2002年 | 14篇 |
2001年 | 12篇 |
2000年 | 12篇 |
1999年 | 18篇 |
1998年 | 18篇 |
1997年 | 18篇 |
1996年 | 5篇 |
1995年 | 21篇 |
1994年 | 15篇 |
1993年 | 5篇 |
1992年 | 12篇 |
1991年 | 4篇 |
1990年 | 1篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1981年 | 1篇 |
排序方式: 共有537条查询结果,搜索用时 62 毫秒
211.
GIS技术在城区大气降尘污染分区评价中的应用 总被引:13,自引:0,他引:13
应用地理信息系统(GIS)技术分析了焦作市城区大气降尘污染状况。根据1995年城区降尘实测数据,绘制了降尘量等值线图,分析了城区降尘污染持的空间分布特征,引入降尘污染指数,将降尘污染程度做了六级划分,并利用ARC/INFO软件进行图像处理,生成拓扑关系,从而对焦作城区降尘污染程度进行了分区和评价。 相似文献
212.
Chein-Jung Shiu Shaw Chen Liu Chih-Chung Chang Jen-Ping Chen Charles C.K. Chou Chuan-Yao Lin Chea-Yuan Young 《Atmospheric environment (Oxford, England : 1994)》2007,41(40):9324-9340
An observation-based method (OBM) is developed to evaluate the ozone (O3) production efficiency (O3 molecules produced per NOx molecule consumed) and O3 production rate (P(O3)) during a field campaign in southern Taiwan. The method can also provide an estimate of the concentration of OH. A key step in the method is to use observed concentrations of two aromatic hydrocarbons, namely ethylbenzene and m,p-xylene, to estimate the degree of photochemical processing and amounts of photochemically consumed NOx and NMHCs by OH. In addition, total oxidant (O3+NO2) instead of O3 itself turns out to be very useful for representing ozone production in the OBM approach. The average O3 production efficiency during the field campaign in Fall (2003) is found to be about 10.2±3.9. The relationship of P(O3) with NOx is examined and compared with a one-dimensional (1D) photochemical model. Values of P(O3) derived from the OBM are slightly lower than those calculated in the 1D model. However, OH concentrations estimated by the OBM are about a factor of 2 lower than the 1D model. Fresh emissions, which affect the degree of photochemical processing appear to be a major cause of the underestimate. We have developed a three-dimensional (3D) OBM O3 production diagram that resembles the EKMA ozone isopleth diagram to study the relationship of the total oxidant versus O3 precursors. The 3D OBM O3 production diagram suggests that reducing emissions of NMHCs are more effective in controlling O3 than reducing NOx. However, significant uncertainties remain in the OBM, and considerable more work is required to minimize these uncertainties before a definitive control strategy can be reached. The observation-based approach provides a good alternative to measuring peroxy radicals for evaluating the production of O3 and formulating O3 control strategy in urban and suburban environments. 相似文献
213.
铁岭市各类大气污染源浓度贡献分析 总被引:2,自引:0,他引:2
利用铁岭市2004年的PM10(可吸入颗粒物)和SO2(二氧化硫)大气环境监测资料、污染源排放清单资料和气象资料,以及AERMOD模型(1)进行了铁岭市大气环境质量区域评价。结果表明:铁岭市低架源对地面浓度的贡献较大,高架源对地面浓度的贡献相对较小。 相似文献
214.
Bu Duo Lulu Cui Zhenzhen Wang Rui Li Liwu Zhang Hongbo Fu Jianmin Chen Huifang Zhang A. Qiong 《环境科学学报(英文版)》2018,30(1):28-42
Atmospheric pollutants including SO2, NO2, CO, O3 and inhalable particulate matter (PM2.5 and PM10) were monitored continuously from March 2014 to February 2015 to investigate characteristics of air pollution at Lhasa, Tibetan Plateau. Species exhibited similar seasonal variations except O3, with the peaks in winter but low valleys in summer. The maximum O3 concentration was observed in spring, followed by summer, autumn, and winter. The positive correlation between O3 and PM10 in spring indicated similar sources of them, and was assumed to be turbulent transport. Temperature was the dominant meteorological factor for most species in spring. High temperature accelerates O3 photochemistry, and favors air disturbance which is conductive to dust resuspension in spring. Relative humidity (RH) and atmospheric pressure were the main meteorological factors in summer. RH showed negative correlations with species, while atmospheric pressure posed opposite situation. Wind speed (WS) was the dominant meteorological factor in autumn, the negative correlations between WS and species indicated diffusion by wind. Most species showed non-significant correlations with meteorological factors in winter, indicating the dependence of pollution on source emission rather than restriction by meteorology. Pollution weather character indicated that emissions were from biomass burning and dust suspension, and meteorological factors also played an important role. Air stream injection from the stratosphere was observed during O3 pollution period. Air parcels from Southwest Asia were observed during air pollution period in winter. An enhancement in air pollutants such as O3 would be expected in the future, more attention should be given to countermeasures for prevention of air pollution in the future. 相似文献
215.
Bulk (wet and dry) deposition samples were collected in Saitama Prefecture, Japan throughout a year (February 8, 2012 to February 7, 2013) to estimate the influence of dioxins emitting from waste incinerators on river water quality. The annual deposition flux of dioxins was 3.3 ng-toxic equivalent (TEQ)/m2/year. Source identification using indicative congeners estimated that 82% of dioxin TEQ in the bulk deposition (2.7 ng-TEQ/m2/year) was combustion-originated, indicating that most of the dioxins in the deposition were derived from waste incinerators. In Saitama prefecture the annual flux of combustion-originated dioxins in depositions was apparently consistent with that of dioxin emission into the air from waste incinerators. The TEQ of combustion-originated dioxins in the deposition per rainfall was 2.4 pg-TEQ/L on annual average, exceeding the environmental quality standard (EQS) for water in Japan of 1 pg-TEQ/L. This suggests there is a possibility that dioxins in atmospheric deposition have a significant influence on the water quality of urban rivers which rainwater directly flows into because of many paved areas in the basins. The influence of combustion-originated dioxin in the deposition on the water quality of Ayase River, an urban river heavily polluted with dioxins, was estimated at 0.29 pg-TEQ/L on annual average in 2015. It seems that dioxins in atmospheric deposition from waste incinerators have a significant influence on water quality of some urban rivers via rainwater though the dioxins in the ambient air have achieved the EQS for atmosphere at all monitoring sites in Japan. 相似文献
216.
Rate constants for the reactions of ozone with 1-octen-3-ol, 1-nonen-3-ol and 1-nonen-4-ol have been determined at 298 ± 1 K and atmospheric pressure for the first time. The experiments were performed in a 100-L FEP Teflon film bag using absolute rate method; the rate constants were(1.91 ± 0.19) × 10~(-17),(1.89 ± 0.20) × 10~(-17), and(0.83 ± 0.08) × 10~(-17)cm~3/(molecule·sec) for 1-octen-3-ol, 1-nonen-3-ol, and 1-nonen-4-ol, respectively. The rate constants have been compared with those of unsaturated alcohols structural homologs, and used to estimate the reaction reactivity. The electronegativity of carbon–carbon double bond was calculated by atomic charges analysis. The calculated results show that the electronic effect of the lone pair electrons of hydroxyl oxygen is the main cause of the difference in rate coefficient. According to the obtained rate constants, the atmospheric lifetimes of studied unsaturated alcohols were also estimated, which indicates that the reaction with ozone is an important loss pathway in the atmosphere, especially in polluted areas. 相似文献
217.
Myat Sandar Win Zhengyang Tian Hui Zhao Kai Xiao Jiaxian Peng Yu Shang Minghong Wu Guangli Xiu Senlin Lu Shinich Yonemochi Qingyue Wang 《环境科学学报(英文版)》2018,30(9):13-31
Atmospheric humic-like substances(HULIS) are not only an unresolved mixture of macroorganic compounds but also powerful chelating agents in atmospheric particulate matters(PMs); impacting on both the properties of aerosol particles and health effects by generating reactive oxygen species(ROS). Currently, the interests of HULIS are intensively shifting to the investigations of HULIS-metal synergic effects and kinetics modeling studies, as well as the development of HULIS quantification, findings of possible HULIS sources and generation of ROS from HULIS. In light of HULIS studies, we comprehensively review the current knowledge of isolation and physicochemical characterization of HULIS from atmospheric samples as well as HULIS properties(hygroscopic, surface activity, and colloidal) and possible sources of HULIS.This review mainly highlights the generation of reactive oxygen species(ROS) from PMs, HULIS and transition metals, especially iron. This review also summarized the mechanism of ironorganic complexation and recent findings of OH formation from HULIS-metal complexes. This review will be helpful to carry out the modeling studies that concern with HULIS-transition metals and for further studies in the generation of ROS from HULIS-metal complexes. 相似文献
218.
George Y. Jumper Edmund A. Murphy Frank H. Ruggiero John R. Roadcap Anthony J. Ratkowski Jean Vernin Hervé Trinquet 《Environmental Fluid Mechanics》2007,7(5):351-370
In July 2002, a multi-sensor campaign was conducted in southern France to investigate the hypothesized connection between
gravity waves and optical turbulence. A generalized scidar (GS) was mounted on the 1.93 m diameter telescope at l’Observatoire
de Haute-Provence (OHP). The GS provides continuous profiles of optical turbulence with 300 m vertical resolution from telescope
altitude up to 25 km. Thermosondes, which provide in situ measurement of optical turbulence by measuring temperature variance,
were launched at the OHP site and at a site approximately 20 km west-northwest of OHP. Gravity wave activity was deduced from
temperature and wind velocity measured by radiosondes, which are part of the thermosonde system. In this paper, gravity waves
were analyzed using techniques for simple two-dimensional mountain waves, with only fair results. Mesoscale models were run
at moderately high resolution for the period. The forecasts were analyzed for wave activity, and a post processor model was
used to diagnose the optical turbulence. Mountain waves were evident in the forecast, but quantitative comparison showed the
forecast to be inadequate in predicting wave strength. The forecast optical turbulence was in fair agreement with measurements
with notable exceptions.
This paper is declared a work of the U.S. Government and is not subject to copyright protection in the United States. The
U.S. Government’s right to retain a non-exclusive, royalty-free license in and to any copyright is acknowledged.
Presented at the Turbulence and Waves in Stably Stratified Atmospheric Shear Flows: Measurements, High Resolution Simulations
and Numerical Prediction Challenges Conference, 13–15 September 2004, Lighthill Institute of Mathematical Sciences, University
College London, London, UK. 相似文献
219.
Janusz A. Pudykiewicz Anna S. Koziol 《Atmospheric environment (Oxford, England : 1994)》1998,32(24):5541
The most common technique used for numerical simulations of tracer mixing is that of the numerical solution of the advection–diffusion equation with the unresolved fluxes parameterized using the similarity theory. Despite correct predictions of the overall directions of transport, models based on a numerical solution of the advection–diffusion equation lack sufficient accuracy to correctly reproduce the coupling of mixing with small scale processes which are sensitive to the microstructure of the tracer distribution. The objective of this paper is to revisit the basic formalism employed in numerical models used to investigate atmospheric tracers. The main mathematical method proposed here is the theory of kinematics of mixing which could be applied effectively for simulations of atmospheric transport processes. At the beginning of the paper, we introduce simple mathematical transformations in order to demonstrate how complex topological structures are created by mixing processes. These idealistic flow systems are essential to explain transport properties of much more complex three-dimensional geophysical flows. An example of the application of the kinematics of mixing to the analysis of tracer transport on a planetary scale is presented in the following sections. The complex filamentary structures simulated in the numerical experiment are evaluated using some commonly applied statistical measures in order to compare the results with the data published in the literature. The results of the experiment are also analysed with the help of simple conceptual models of fluid filaments. The microstructure of the tracer distribution introduced in the paper is essential to increase our understanding of atmospheric transport and to develop more realistic parameterizations of small-scale mixing. The presented results could also be used to improve calculations of the coupling between microphysical processes and tracer mixing. 相似文献
220.
Pollution survey of polycyclic aromatic hydrocarbons in surface water of Hangzhou, China 总被引:8,自引:0,他引:8
The concentrations of 10 polycyclic aromatic hydrocarbons (PAHs) were simultaneously measured for five times (July and November 1999–2002) in four water bodies of Hangzhou, China. To investigate possible sources of PAH contamination, sediments, soils, runoff water and atmospheric particles of the region were also analyzed for their PAH contents. The maximum levels of PAHs in the water bodies (34.4–67.7 μg/l) were found in July, while significantly lower PAH concentrations (4.7–15.3 μg/l) were measured in November. The contamination is substantial and it may have resulted in acute toxic effects on aquatic organisms. The measured PAH concentrations in sediments and soils (224–4222 ng/g), runoff water (8.3 μg/l) and air particles (2.3 μg/m3) are discussed in relation to concentrations and patterns found in the surface water bodies. Comparison of PAH levels in sediments and soils led to the conclusion that the erosion of soil material does not contribute significantly to the contamination of sediments. The atmospheric PAH deposition to water bodies in the city area of Hangzhou was estimated to be 530 tons/a, while the contribution of surface runoff water was estimated to be 30.7 tons/a. The ratios of selected PAH were then used to illuminate the possible origin of PAHs in the examined samples (petrogenic, pyrogenic). 相似文献