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161.
The power system in India accounts for nearly one-third of CO2 emissions of the country as a whole. A comparison of some of the technical options to reduce CO2 emissions is presented in this paper. A linear programming framework is used to simulate the integrated optimal operation of the three regional grids, and it is shown that such operations lead to lower fuel costs and to lower CO2 emissions. The same framework is used to see how a rise in thermal efficiency translates into a CO2 emissions reduction. Reduced fuel requirements also lead to reductions in other pollutants ie SO2, NOx and fly ash. The reductions in CO2 emissions and other pollutants are at far lower cost in the case of integrated optimal operations as compared to reductions due to gas fuelled generation or thermal efficiency improvements. However, thermal efficiency improvements under optimal integrated operations result in much higher reductions in operating costs, coal consumption and total emissions of all pollutants.  相似文献   
162.
Arsenic contaminating groundwater in Bangladesh is one of the largest environmental health hazards in the world. Because of the potential risk to human health through consumption of agricultural produce grown in fields irrigated with arsenic contaminated water, we have determined the level of contamination in 100 samples of crop, vegetables and fresh water fish collected from three different regions in Bangladesh. Arsenic concentrations were determined by hydride generation atomic absorption spectrophotometry. All 11 samples of water and 18 samples of soil exceeded the expected limits of arsenic. No samples of rice grain (Oryza sativa L.) had arsenic concentrations more than the recommended limit of 1.0 mg/kg. However, rice plants, especially the roots had a significantly higher concentration of arsenic (2.4 mg/kg) compared to stem (0.73 mg/kg) and rice grains (0.14 mg/kg). Arsenic contents of vegetables varied; those exceeding the food safety limits included Kachu sak (Colocasia antiquorum) (0.09-3.99 mg/kg, n=9), potatoes (Solanum tuberisum) (0.07-1.36 mg/kg, n=5), and Kalmi sak (Ipomoea reptoms) (0.1-1.53 mg/kg, n=6). Lata fish (Ophicephalus punctatus) did not contain unacceptable levels of arsenic. These results indicate that arsenic contaminates some food items in Bangladesh. Further studies with larger samples are needed to demonstrate the extent of arsenic contamination of food in Bangladesh.  相似文献   
163.
A systematic effort was made to assess the emission of methane from paddy fields using closed chamber technique. Methane emission measurements were performed over a year during the Kharif (wet season), Rabi (dry season), and fallow periods. Various soil parameters like redox potential, organic carbon and ferrous ion were determined to evaluate their control on methane emissions. Diurnal measurement of the flux showed a minimum (0.44?mg?m?2?h?1) in the morning (8?a.m.), which increased gradually to a value of 1.16?mg?m?2?h?1 till the evening due to the rise in soil temperature. The seasonally integrated flux (E SIF) for CH4 was calculated. The E SIF for methane during Kharif and Rabi crops were found to be 5.97?g?m?2 and 2.59?g?m?2, respectively. It was observed that the methane flux was maximum during flowering and fertilizer application stages for both paddy cropping seasons. The redox potential was low and the ferrous ion was higher during flowering and tiller stages. The methane emission was higher at E AIF) was calculated for methane to make a budget estimate of methane emission from rice cultivated under rain fed drought prone water regime.  相似文献   
164.
An accident leading to bursting of a compressed natural gas (CNG) cylinder fitted to a passenger bus in India resulted one person died and four persons injured. This paper presents the incident, the human factor involved, safety issues and lesson learned.  相似文献   
165.
Widespread loss of primary habitat in the tropics has led to increased interest in production landscapes for biodiversity conservation. In the Western Ghats biodiversity hotspot in India, shade coffee plantations are located in close proximity to sites of high conservation value: protected and unprotected forests. Coffee is grown here under a tree canopy that may be dominated by native tree species or by nonnative species, particularly silver oak (Grevillea robusta). We investigated the influence of properties at the local scale and the landscape scale in determining bird communities in coffee plantations, with particular emphasis on species of conservation priority. We used systematic point counts in 11 coffee plantation sites and analyzed data in a randomized linear modeling framework that addressed spatial autocorrelation. Greater proportion of silver oak at the local scale and distance to contiguous forests at the landscape scale were implicated as factors most strongly driving declines in bird species richness and abundance, while increased basal area of native tree species, a local-scale variable, was frequently related to increased bird species richness and abundance. The influence of local-scale variables increased at greater distances from the forest. Distance to forests emerged as the strongest predictor of declines in restricted-range species, with 92% reduction in the abundance of two commonly encountered restricted-range species (Pompadour Green Pigeon and Yellow-browed Bulbul) and a 43% reduction in richness of bird species restricted to Indian hill forests within 8 km of forests. Increase in proportion of silver oak from 33% to 55% was associated with 91% reduction in the abundance of one commonly encountered restricted-range species (Crimson-fronted Barbet). One conservation strategy is providing incentives to grow coffee in a biodiversity-friendly manner. One implication of our study is that plantations located at varying distances to the forest cannot be compared fairly for biodiversity friendliness by existing certification methodology. Another is that conservation of existing forests at the landscape scale is essential for maintaining higher biodiversity in coffee plantations. Incentive schemes that promote conservation of remnant forests at the landscape scale and biodiversity-friendly practices locally and that relate to coffee communities as a whole rather than individual planters are likely to be more effective.  相似文献   
166.
Environmental Science and Pollution Research - The discharge of emerging pollutants, such as beta-blockers (BB), has been recognized as one of the major threats to the environment due to the...  相似文献   
167.

Biofuels extracted from plant biomass can be used as fuel in CI engines to lower a hazardous atmospheric pollutant and mitigate climate risks. Furthermore, its implementation is hampered by inevitable obstacles such as feedstocks and the crop area required for their cultivation, leading to a lack of agricultural land for the expansion of food yields. Despite this, microalgae have been discovered to be the most competent and unwavering source of biodiesel due to their distinguishing characteristics of being non-eatable and requiring no cropland for cultivation. The objectives of this paper was to look into the potential of a novel, formerly underappreciated biodiesel from microalgae species which could be used as a fuel substitute. Transesterification is being used to extract the biodiesel. Microalgae are blended with petroleum diesel in percentage to create microalgae blends (MAB) as needed for experimentation. The impact of biodiesel on performance as well as exhaust emission attributes of a 1-cylinder diesel engine was experimentally studied. Compared to petroleum diesel, different blend of microalgae biodiesel showed a decline in torque and hence brake power, resulting in an average fall of 7.14 % in brake thermal efficiency and 11.54 % increase in brake-specific fuel consumption. There were wide differences in exhaust emission characteristics, including carbon monoxide and hydrocarbon, as the blend ratio in diesel increased. Moreover, nitrogen oxides and carbon dioxides increase in all algae biodiesel blends, but they are still within the acceptable range of petroleum diesel.

  相似文献   
168.
Environmental Science and Pollution Research - The objective of this paper is to examine, for a panel of seven countries from the European Union, spanning the period 1986–2015, whether the...  相似文献   
169.
Environmental Economics and Policy Studies - This study estimates health cost of salinity contamination in drinking water in the severe salinity affected three south-western districts of...  相似文献   
170.
Das  Saudamini  DSouza  Nisha Maria 《Ambio》2020,49(4):950-961
Ambio - The vulnerabilities of coastal communities have increased in recent years, as more people have to live in hazard-prone areas due to population growth. The east coast of India is one such...  相似文献   
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