全文获取类型
收费全文 | 381篇 |
免费 | 2篇 |
国内免费 | 11篇 |
专业分类
安全科学 | 3篇 |
废物处理 | 16篇 |
环保管理 | 50篇 |
综合类 | 45篇 |
基础理论 | 80篇 |
环境理论 | 2篇 |
污染及防治 | 111篇 |
评价与监测 | 64篇 |
社会与环境 | 22篇 |
灾害及防治 | 1篇 |
出版年
2023年 | 3篇 |
2022年 | 23篇 |
2021年 | 21篇 |
2020年 | 8篇 |
2019年 | 8篇 |
2018年 | 10篇 |
2017年 | 20篇 |
2016年 | 10篇 |
2015年 | 9篇 |
2014年 | 20篇 |
2013年 | 46篇 |
2012年 | 14篇 |
2011年 | 22篇 |
2010年 | 20篇 |
2009年 | 20篇 |
2008年 | 17篇 |
2007年 | 22篇 |
2006年 | 14篇 |
2005年 | 11篇 |
2004年 | 8篇 |
2003年 | 5篇 |
2002年 | 7篇 |
2001年 | 2篇 |
1999年 | 1篇 |
1997年 | 1篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1994年 | 6篇 |
1992年 | 1篇 |
1991年 | 2篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1982年 | 1篇 |
1980年 | 2篇 |
1979年 | 4篇 |
1978年 | 2篇 |
1976年 | 6篇 |
1975年 | 1篇 |
1974年 | 4篇 |
1973年 | 3篇 |
1972年 | 2篇 |
1971年 | 2篇 |
1967年 | 1篇 |
1966年 | 1篇 |
1965年 | 1篇 |
1964年 | 1篇 |
1962年 | 1篇 |
1961年 | 1篇 |
1959年 | 1篇 |
1955年 | 1篇 |
排序方式: 共有394条查询结果,搜索用时 343 毫秒
141.
Pramod Chandra 《Natural resources forum》2020,44(3):274-285
The medicinal and aromatic plants resources of Uttarakhand, India offer significant opportunities of employment and livelihood for rural communities and contribute a large share in the medicinal and aromatic plants trade of India. With the growing trade of medicinal and aromatic plants resources in the global market, the medicinal and aromatic plants business of Uttarakhand is also continuously growing in terms of trade volume, value and market reach. But, considering the ecological importance as well as unregulated exploitations of these resources, the growing business activities in this sector appear incompatible to the sustainability agenda. Through a mini review, this study assesses the medicinal and aromatic plants sector of Uttarakhand and identifies key challenges that seem incompatible for resource and business sustainability and offers some prospective research directions essential for identifying pragmatic solutions to support sustainability in the sector. This review identifies nine key challenges to sustainability in Uttarakhandʼs medicinal and aromatic plants sector. It is therefore pertinent that future research focus on the prevailing challenges of the medicinal and aromatic plants sector of Uttarakhand to develop strategies for sustainable business prospects. 相似文献
142.
P. V. Suresh Kavitha G. Menon K. S. Prakash S. Prudhvi A. Anudeep 《Environmental science and pollution research international》2016,23(20):20111-20119
Chemical looping combustion (CLC) is an inherent CO2 capture technology. It is gaining much interest in recent years mainly because of its potential in addressing climate change problems associated with CO2 emissions from power plants. A typical chemical looping combustion unit consists of two reactors—fuel reactor, where oxidation of fuel occurs with the help of oxygen available in the form of metal oxides and, air reactor, where the reduced metal oxides are regenerated by the inflow of air. These oxides are then sent back to the fuel reactor and the cycle continues. The product gas from the fuel reactor contains a concentrated stream of CO2 which can be readily stored in various forms or used for any other applications. This unique feature of inherent CO2 capture makes the technology more promising to combat the global climate changes. Various types of CLC units have been discussed in literature depending on the type of fuel burnt. For solid fuel combustion three main varieties of CLC units exist namely: syngas CLC, in situ gasification-CLC (iG-CLC) and chemical looping with oxygen uncoupling (CLOU). In this paper, theoretical studies on the iG-CLC unit burning Indian coal are presented. Gibbs free energy minimization technique is employed to determine the composition of flue gas and oxygen carrier of an iG-CLC unit using Fe2O3, CuO, and mixed carrier—Fe2O3 and CuO as oxygen carriers. The effect of temperature, suitability of oxygen carriers, and oxygen carrier circulation rate on the performance of a CLC unit for Indian coal are studied and presented. These results are analyzed in order to foresee the operating conditions at which economic and smooth operation of the unit is expected. 相似文献
143.
Shanmugam Packialakshmi N. K Ambujam Prakash Nelliyat 《Environment, Development and Sustainability》2011,13(2):423-438
This paper describes the informal groundwater market existing in the urban–peri-urban interface of Chennai. The private water
tanker suppliers and packaged water industries utilize the land and water resources of the peri-urban villages. Thus, the
groundwater sources in peri-urban areas play a significant role in meeting the growing urban demand. The villages that are
experiencing the groundwater market are highly influenced by the urbanization and its related activities, due to their proximity
to the city. The transfer of groundwater from the peri-urban villages not only deprives the peri-urban areas of their water
rights but also leads to environmental damage. Agriculture declined in the water marketed villages in the range of 20–95 per
cent during 1990–2007. The pre-monsoon and post-monsoon groundwater level fluctuation varied from 2–6 m to 0–5 m, respectively,
during 1971–2007. The declining trend of the groundwater table and agriculture is highly significant in the water marketing
villages. Moreover, the present groundwater quality is also in a susceptible state due to over extraction. Hence, strengthening
the legal and institutional framework to ensure an equitable access to water for both urban and peri-urban areas is urgently
required. This paper also describes the characteristics of the groundwater transfer, quantification of the marketed water,
the role of the existing regulatory framework, and the institutional mechanisms. Many stakeholder’s meeting and focus group
discussions have been conducted in the villages under study for understanding the socio-economic implications of the water
market. The study ultimately emphasized a sustainable groundwater extraction/market which will safeguard the interests of
the peri-urban and urban communities. 相似文献
144.
In relation to fluoride in ground water, dental fluorosis is studied in seven villages, viz., Nasipur, Vabanandapur, and Deshnabagram
under Nalhati I block and Kamdebpur, Chalk Atla, Nowapara, and Junitpur under Rampurhat II block, of Birbhum district, West
Bengal, India. Water samples (N = 70) were collected from the tube wells of the mentioned villages in the months of December 2010 to February 2011 and analyzed
for fluoride and other water parameters. The study result revealed that the fluoride levels of almost all the water samples
(95.7%) were higher than 1.5 mg/L, with mean values of 3.15 and 3.83 mg/L in Nalhati I block and Rampurhat II block, respectively.
Dental fluorosis of 490 respondents was visually determined by a competent dentist using Dean’s index (DI) and the tooth surface
index of fluorosis (TSIF). According to the DI, the percentage of severely affected respondents was lowest in Chalk Atla (0%)
and highest in Deshnabagram (50%). The percentage of severely affected respondents was lowest in Kamdebpur and Chalk Atla
(0%) and highest in Nowapara (20%) according to the TSIF score. The age group 10–20 years showed the highest percentage of
severe DI (40.8%) and the age group 21–30 years showed the highest percentage of severe TSIF (22.51%) compared to the other
age groups in the study. The positive relationship between the fluoride level in water and the severity of dental fluorosis
has been proved statistically. The high mean score of dental fluorosis indicates that dental fluorosis is endemic throughout
the study area. 相似文献
145.
Prakash N Sudha PN Renganathan NG 《Environmental science and pollution research international》2011,19(7):2930-2941
Purpose
Chitosan with nylon 6 membranes was evaluated as adsorbents to remove copper and cadmium ions from synthetic industrial wastewater.Methods
Chitosan and nylon 6 with glutaraldehyde blend ratio with (1:1+Glu, 1:2+Glu, and 2:1+Glu) have been prepared and these were used as membranes to remove copper and cadmium ions from synthetic industrial wastewater. Characterization of the synthesized membrane has been done with FTIR, XRD, TGA/DTA, DSC, and SEM. Chemical parameters for quantities of adsorption of heavy metal contamination have been done and the kinetics of adsorption has also been carried out.Results
The optimal pH for the removal of Cd(II) and Cu(II) using chitosan with nylon 6. Maximum removal of the metals was observed at pH 5 for both the metals. The effect of adsorbent dose also has a pronounced effect on the percentage of removal of the metals. Maximum removal of both the metals was observed at 5 g/100 ml of the adsorbent.Conclusion
Copper and cadmium recovery is parallel at all time. The percentage of removal of copper increased with increase in the pH from 3 to 5. In the case of cadmium containing wastewater, the maximum removal of metal occurred at pH 5. The uptake amount of Cu2+ ions on chitosan increased rapidly with increasing contact time from 0 to 360 min and then reaches equilibrium after 360 min; the equilibrium constant for copper and cadmium ions is more or less the same for the adsorption reaction. 相似文献146.
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
147.
Shruti Pavagadhi Raghu Betha Shriram Venkatesan Rajasekhar Balasubramanian Manoor Prakash Hande 《Environmental science and pollution research international》2013,20(4):2569-2578
Air particulate matter (PM) samples were collected in Singapore from 21 to 29 October 2010. During this time period, a severe regional smoke haze episode lasted for a few days (21–23 October). Physicochemical and toxicological characteristics of both haze and non-haze aerosols were evaluated. The average mass concentration of PM2.5 (PM with aerodynamic diameter of ≤2.5 μm) increased by a factor of 4 during the smoke haze period (107.2 μg/m3) as compared to that during the non-smoke haze period (27.0 μg/m3). The PM2.5 samples were analyzed for 16 priority polycyclic aromatic hydrocarbons (PAHs) listed by the United States Environmental Protection Agency and 10 transition metals. Out of the seven PAHs known as potential or suspected carcinogens, five were found in significantly higher levels in smoke haze aerosols as compared to those in the background air. Metal concentrations were also found to be higher in haze aerosols. Additionally, the toxicological profile of the PM2.5 samples was evaluated using a human epithelial lung cell line (A549). Cell viability and death counts were measured after a direct exposure of PM2.5 samples to A459 cells for a period of 48 h. The percentage of metabolically active cells decreased significantly following a direct exposure to PM samples collected during the haze period. To provide further insights into the toxicological characteristics of the aerosol particles, glutathione levels, as an indirect measure of oxidative stress and caspase-3/7 levels as a measure of apoptotic death, were also evaluated. 相似文献
148.
Sumit Sharma Navin Chandra Kothiyal 《Environmental science and pollution research international》2013,20(12):8986-8995
In this study, a natural adsorbent (activated dry flowers (ADF)) was prepared from plant-derived waste biomass by chemical activation and employed for chromium (VI) removal from aqueous medium using experimental batch technique. Experiments were carried out as function of adsorbent dosage, pH, and contact time. The maximum chromium (Vl) removal was observed at initial pH 3 (~94 % removal). The equilibrium data was fitted well to Langmuir isotherm. The adsorption capacity of ADF was found to be 4.40 (mg chromium (Vl)/g) which was comparable to the adsorption capacity of some other adsorbents documented. Among various kinetic models applied, pseudo second-order model was found to explain the kinetics of chromium (VI) adsorption most effectively (R 2 >0.99). Thermodynamic parameters such as ΔG, ΔS, and ΔH shows that adsorption process was spontaneous and endothermic at all the concentration ranges studied. Desorption of chromium (Vl) with 2 N NaOH was effective (~71 %) and, hence, there exists the possibility of recycling the ADF. The major advantages of using ADF as an adsorbent are due to its effectiveness in reducing the concentration of chromium (Vl) to very low levels. It requires little processing and is reversible as well as eco-friendly in contrast to traditional methods. 相似文献
149.
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
150.
Stephen O'Neill Lava Prakash Yadav 《Journal of Environmental Planning and Management》2016,59(2):342-359
Mandatory taxes and/or voluntary contributions are commonly adopted as the payment vehicle when eliciting willingness to pay (WTP) in environmental valuation studies. While mandatory taxes may arouse negative feelings, voluntary contributions may lead to strategic behaviour (over bidding) or free riding (under bidding). In this paper, we explore an alternative payment vehicle which avoids the draconian undertones associated with taxes and may be more incentive compatible than a voluntary contribution – a tax that incorporates a refund option. The template for such a payment vehicle is the value added tax charged to tourists in Ireland, but which can be reclaimed on exiting the country. In the context of raising public funds to support the conservation of rural countryside landscape, a comparison is made between the elicited WTP via a mandatory tax and that elicited via the alternative payment method incorporating a refund option. While we observe similar participation rates between the two payment methods, the refund option reveals a higher stated WTP. 相似文献