全文获取类型
收费全文 | 163篇 |
免费 | 2篇 |
国内免费 | 2篇 |
专业分类
安全科学 | 1篇 |
废物处理 | 5篇 |
环保管理 | 20篇 |
综合类 | 4篇 |
基础理论 | 35篇 |
环境理论 | 3篇 |
污染及防治 | 58篇 |
评价与监测 | 33篇 |
社会与环境 | 7篇 |
灾害及防治 | 1篇 |
出版年
2023年 | 2篇 |
2022年 | 3篇 |
2021年 | 12篇 |
2020年 | 4篇 |
2019年 | 4篇 |
2018年 | 7篇 |
2017年 | 9篇 |
2016年 | 5篇 |
2015年 | 4篇 |
2014年 | 10篇 |
2013年 | 26篇 |
2012年 | 7篇 |
2011年 | 8篇 |
2010年 | 12篇 |
2009年 | 6篇 |
2008年 | 7篇 |
2007年 | 13篇 |
2006年 | 3篇 |
2005年 | 2篇 |
2004年 | 1篇 |
2003年 | 2篇 |
2002年 | 4篇 |
2001年 | 1篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1996年 | 1篇 |
1994年 | 5篇 |
1991年 | 1篇 |
1988年 | 1篇 |
1982年 | 1篇 |
1978年 | 1篇 |
1976年 | 1篇 |
1966年 | 1篇 |
1959年 | 1篇 |
排序方式: 共有167条查询结果,搜索用时 31 毫秒
41.
Prasad Pai Robert J. Farber Prakash Karamchandani Ivar Tombach 《Journal of the Air & Waste Management Association (1995)》2013,63(5):818-825
ABSTRACT The Nested Grid Model (NGM) is a primitive-equation meteorological model that is routinely exercised over North America for forecasting purposes by the National Meteorological Center. While prognostic meteorological models are being increasingly used to drive air quality models, their use in conducting annual simulations requires significant resources. NGM estimates of wind fields and other meteorological variables provide an attractive alternative since they are typically archived and readily available for an entire year. Preliminary evaluation of NGM winds during the summer of 1992 for application to the region surrounding the Grand Canyon National Park showed serious shortcomings. The NGM winds along the borders between California, Arizona and Mexico tend to be northwesterly with a speed of about 6 m/sec, while the observed flow is predominantly southerly at about 2-5 m/sec. The mesoscale effect of a thermal low pressure area over the highly heated Southern California and western Arizona deserts does not appear to be represented by the NGM because of its coarse resolution and the use of sparse observations in that region. Tracer simulations and statistical evaluation against special high resolution observations of winds in the southwest United States clearly demonstrate the northwest bias in NGM winds and its adverse effect on predictions of an air quality model. The “enhanced” NGM winds, in which selected wind observations are incorporated in the NGM winds using a diagnostic meteorological model provide additional confirmation on the primary cause of the northwest bias. This study has demonstrated that in situations where limited resources prevent the use of prognostic meteorological models, previously archived coarse resolution wind fields in which additional observations are incorporated to correct known biases provide an attractive option. 相似文献
42.
Sandeep Kar Jyoti Prakash Maity Alok Chandra Samal Subhas Chandra Santra 《Environmental monitoring and assessment》2010,168(1-4):561-574
This study proposes a practical method to estimate elemental composition and distribution in order to attribute source and quantify impacts of aerosol particles at an urban region in Kolkata, India. Twelve-hour total particulates were collected in winter (2005–2006) and analyzed by energy-dispersive X-ray fluorescence technique to determine multi-elemental composition, especially trace metals. The aerosols consist of various elements including K, Ca, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Se, and Pb which exhibit significant concentration at various sites (p?<?0.05). The concentration of different metallic elements were found in the order of Zn ?> ?Pb ?> ?Ni ?> ?Cu ?> ?Cr ?>? Co. Statistical multivariate analysis and correlation matrix analyses were performed for factor identification and consequent source apportionment. Contour profiles demonstrate spatial variation of elemental compositions indicating possible source contribution along with meteorological influences. Spatial differences were clearly most significant for Zn, Ni, Pb, and Cu reflecting the importance of anthropogenic inputs, primarily from automobile sources. 相似文献
43.
The main emissions from coal combustion at thermal power plants are carbon dioxide (CO2), nitrogen oxides, sulfur oxides, chlorofluorocarbons (CFCs), and airborne inorganic particles such as fly ash and soot; CO2, methane, and CFCs are greenhouse gases. These emissions are considered to be partially responsible for harmful global climate change. This review summarizes the status of thermal power plants in India and their various types of emissions that directly or indirectly produce harmful effects on the environment and human health. Moreover, it focuses on various types of preventive measures used to avoid/minimize emissions. 相似文献
44.
Incineration of acrylic waste solution in a lab scale quartz tube vertical incinerator showed the presence of 12–15 polycyclic
aromatic hydrocarbons (PAHs) from a list of 16 priority pollutants at 700–1100˚C after an interval of 50˚C. The amount of total 16 PAHs at 900 and 1100˚C was about 8.5 and 1.25 times higher than those at 700˚C (739.48 μg g−1) respectively. The amount of total probable (2A) and possible (2B) human carcinogenic PAHs was minimum at 700˚C. 相似文献
45.
A multivariate time series approach vector autoregression (VAR) along with impulse response function and variance decomposition
technique has been employed to look into the interrelationship among O3, NO, NO2, and volatile organic compounds (VOCs, namely, benzene, ethylbenzene, toluene, and xylene in the present study) using 3 months
long continuous time series data of 1 h average concentration of these pollutants at one of the traffic sites in Delhi, India.
It is found that the VAR of order 2 (i.e., past two lagged values of 1 h interval) is sufficient to represent the observed
time series at the station studied. The impulse response function and variance decomposition analysis indicate that O3 concentration shows an immediate rise and persists for a longer duration (typically 8–10 h) once the impulse of NO2, benzene, ethylbenzene, or xylene is given in the ambient environment. However, in case of toluene, the reverse effect has
been observed. Since O3 forms in the troposphere due to photolysis of NO2, it is not surprising that its impulse triggers O3 formation in the ambient environment. However, in case of VOCs, this has been attributed to their tendency to show higher
inclination toward intermediary reactions leading to the formation of O3 rather than their (VOCs) reaction with O3. Among VOCs, only toluene has been observed to show higher inclination toward its reaction with O3. Apart from this, variance decomposition technique also reveals that the relation of NO with NO2 is more important than the relation of NO with O3 creating a conducive atmosphere for O3 formation in the present scenario. Thus, the multivariate time series approach provides significant insight about the role
played by the dominant individual VOCs and NO
x
in influencing the O3 concentration in ambient urban atmosphere whereas a photochemical modeling approach gives an overall view of NO
x
and VOCs behavior with respect to O3 by using the O3 isopleth technique. 相似文献
46.
Deepak Singh Amit Prakash A. K. Srivastava Krishan Kumar V. K. Jain 《Environmental monitoring and assessment》2013,185(2):1873-1882
The acoustic environment in urban areas has gained prominence in recent times due to rapid industrial and commercial development in metropolitan cities. Various attempts have been made to predict and model the trends in urban ambient noise levels using different statistical and dynamic models. The present study makes an attempt to examine the role of meteorological parameters affecting the ambient noise levels in Delhi. The results show significant improvement in overall noise scenario of Delhi since the introduction of compressed natural gas vehicles in public transport of Delhi. The noise level is significantly reduced by high vegetation cover as well as by low relative humidity over Delhi. The regression models developed for the present study clearly show the significant contribution of meteorological parameters in governing the ambient noise levels in Delhi. 相似文献
47.
Chow JC Watson JG Lowenthal DH Park K Doraiswamy P Bowers K Bode R 《Environmental monitoring and assessment》2008,144(1-3):179-189
PM(2.5) nitrate [Formula: see text] and sulfate ([Formula: see text]) were measured continuously with R&P8400N and R&P8400S instruments, respectively, and compared with filter-based measurements at the Fresno Supersite from October, 2000 through December, 2005. [Formula: see text] concentrations were higher in winter than summer with a long-term decreasing trend. Correlations between 24-h average continuous and filter-based [Formula: see text] were greater than 0.96 in 4 out of 5 years. Continuous [Formula: see text] was generally lower than filter-based [Formula: see text] although the difference decreased over time, from -52% in 2001 to +13% in 2005. These differences were similar in winter (-23%) and summer (-19%) while the corresponding differences between ambient and instrument temperature were -12 and 0.7 degrees C, respectively. Neither seasonal nor long-term trends in [Formula: see text] can be explained by variations in ambient temperature, the difference between ambient and instrument temperature, or changes in aerosol chemical composition. There were no seasonal or long-term trends in [Formula: see text] concentrations, partially due to low concentrations observed in Fresno. Long-term variability in the performance of R&P8400 [Formula: see text] and [Formula: see text] instruments suggest that collocation with filter measurements is needed for long-term measurements. 相似文献
48.
49.
Prakash Karamchandani Christian Seigneur 《Journal of the Air & Waste Management Association (1995)》2013,63(9):175-181
ABSTRACT The rate of formation of secondary particulate matter (PM) in power plant plumes varies as the plume material mixes with the background air. Consequently, the rate of oxidation of sulfur dioxide (SO2) and nitrogen dioxide (NO2) to sulfate and nitric acid, respectively, can be very different in plumes and in the background air (i.e., air outside the plume). In addition, the formation of sulfate and nitric acid in a power plant plume is a strong function of the chemical composition of the background air and the prevailing meteorological conditions. We describe the use of a reactive plume model, the Reactive and Optics Model of Emissions, to simulate sulfate and nitrate formation in a power plant plume for a variety of background conditions. We show that SO2 and NO2 oxidation rates are maximum in the background air for volatile organic compound (VOC)-limited airsheds but are maximum at some downwind distance in the plume when the background air is nitrogen oxide (NOx)-limited. Our analysis also shows that it is essential to obtain measurements of background concentrations of ozone, aldehydes, peroxyacetyl nitrate, and other VOCs to properly describe plume chemistry. 相似文献
50.
Akula Venkatram Prakash Karamchandani Prasad Pai Christine Sloane Pradeep Saxena Robert Goldstein 《Journal of the Air & Waste Management Association (1995)》2013,63(3):286-301
This paper describes the development and application of the Visibility and Haze in the Western Atmosphere (VISHWA) model to understand the source-receptor relationships that govern chemical species relevant to visibility degradation in the western United States. The model was developed as part of a project referred to as Visibility Assessment for Regional Emission Distributions (VARED), the objective of which is to estimate the contributions of various geographical regions, compounds, and emission sources to light scattering and absorption by particles on the Colorado Plateau. The VISHWA model is a modified version of a comprehensive Eulerian model, known as the Acid Deposition and Oxidant Model.1 The modifications were designed to obtain the computational efficiency required to simulate a one-year period at about 1/25th of real time, and at the same time incorporate mechanistic features relevant to realistic modeling of the fate and transport of visibility degrading species. The modifications included use of a condensed chemical mechanism; incorporation of reactions to simulate the formation of secondary organic particles; and use of a semi-Lagrangian advection scheme to preserve concentration peaks during advection. The model was evaluated with 1992 air quality data from Project MOHAVE (Measurements of Haze and Visual Effects) intensive experiments. An important conclusion of this evaluation is that aqueous-phase oxidation of SO2 to sulfate in nonprecipitating clouds makes a significant contribution to observed sulfate levels during winter as well as summer. Model estimates of ambient sulfate for the winter intensive were within a factor of 2 of the observations for 75% of the values. The corresponding statistic for the summer intensive was 90%. Model estimates of carbon were within a factor of 2 of the limited set of observations. 相似文献