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161.
Michael White Marilyn Gambone Haw Yen Prasad Daggupati Katrin Bieger Debjani Deb Jeff Arnold 《Journal of the American Water Resources Association》2016,52(1):269-274
The Soil and Water Assessment Tool (SWAT) is widely used in the United States (U.S.) to simulate hydrology and water quality simulation. Process‐based models like SWAT require a great deal of data to accurately represent the natural world, including topography, land use, soils, weather, and management. With the exception of management, all these data are available nationally from multiple sources. To date, credible SWAT studies in the U.S. have assembled suitable management data (operation scheduling, fertilization application rates, and plant growth parameterization). In this research, we develop a national management database for SWAT using existing U.S. Department of Agriculture data sources. These data are compatible with existing SWAT interfaces and are relatively easy to use. Although management data from local sources is preferred, these data are not always available. This work is intended to fill this void with more reasonable management data than the existing defaults. This national database covers all major cultivated crops and should facilitate improved SWAT applications in the U.S. These data were tested in two case studies and found to produce satisfactory SWAT predictions. The database developed in this research is freely available on the web. 相似文献
162.
Dani Jagadeesh B. Prem Kumar P. Sudhakara C. Venkata Prasad A. Varada Rajulu J. I. Song 《Journal of Polymers and the Environment》2013,21(4):930-936
Novel bio-based green films were prepared using wheat protein isolate (WPI) by solution casting method using Propylene Glycol as a plasticizer for packaging applications. The effect of the plasticizer content (10, 15, 20 and 25 wt%) on mechanical properties (tensile strength, young’s modulus and % of elongation) was investigated. A thermal degradation and phase transition of the prepared WPI was assessed by means of TGA and DSC analysis. The results showed that the tensile strength and young’s modulus decreased and % of elongation increased with increasing PG content. The ATR-FTIR and SEM were used for structural characterization and morphology of the films, respectively. FTIR studies reveals that the intensity of the bands corresponding to the amide groups increases with increasing PG content tending to increase protein–PG interactions. Further, the glass transition temperature was decreased and the thermal stability of the WPI was found to be increased by plasticization. The overall thermal stability of the films was improved and is attributed to the increase in mobility of the polymer chains. 相似文献
163.
Dinesh Bhatt Shreedhar Maskey Mukand S. Babel Stefan Uhlenbrook Krishna C. Prasad 《Regional Environmental Change》2014,14(4):1291-1301
Understanding crop responses to climate is essential to cope with anticipated changes in temperature and precipitation. We investigated the climate–crop yield relationship and the impact of historical climate on yields of rice, maize and wheat in the Koshi basin of Nepal. The results show significant impact of growing season temperature and precipitation on crop production in the region. Rice, maize and wheat cultivated at altitudes below 1,100, 1,350 and 1,700 m amsl (above mean sea level), respectively, suffer from stress due to higher temperatures particularly during flowering and yield formation stages. Responses of crop yields to a unitary increment in growing season mean temperature vary from ?6 to 16 %, ?4 to 11 % and ?12 to 3 % for rice, maize and wheat, respectively, depending on the location and elevation in the basin. In most parts of the basin, we observe warming trends in growing season mean temperatures of rice, maize and wheat over the last few decades with clear evidence of negative impacts on yields. However, at some high-elevation areas, positive impacts of warming are also observed on rice and maize yields. If the observed trends in temperature continue in future, the impact is likely to be mostly negative on crop production in the basin. However, crop production may gain from the warming at relatively higher altitudes provided other conditions, e.g., water availability, soil fertility, are favorable. 相似文献
164.
Biomass fuels are used by the majority of resource poor households in low-income countries. Though biomass fuels, such as
dung-briquette and firewood are apparently cheaper than the modern fuels indoor pollution from burning biomass fuels incurs
high health costs. But, the health costs of these conventional fuels, mostly being indirect, are poorly understood. To address
this gap, this study develops probit regression models using survey data generated through interviews from households using
either dung-briquette or biogas as the primary source of fuel for cooking. The study investigates factors affecting the use
of dung-briquette, assesses its impact on human health, and estimates the associated household health costs. Analysis suggests
significant effects of dung-briquette on asthma and eye diseases. Despite of the perception of it being a cheap fuel, the
annual health cost per household due to burning dung-briquette (US16.94) is 61.3 (US 16.94) is 61.3% higher than the annual cost of biogas
(US 10.38), an alternative cleaner fuel for rural households. For reducing the use of dung-briquette and its indirect health
costs, the study recommends three interventions: (1) educate women and aboriginal people, in particular, and make them aware
of the benefits of switching to biogas; (2) facilitate tree planting in communal as well as private lands; and (3) create
rural employment and income generation opportunities. 相似文献
165.
Woli KP Hayakawa A Kuramochi K Hatano R 《Environmental monitoring and assessment》2008,137(1-3):251-260
River water quality was evaluated with respect to eutrophication and land use during spring snowmelt and summer base flow
periods in Abashiri (mixed cropland-livestock farming) and Okoppe (grassland-based dairy cattle farming), eastern Hokkaido,
Japan. Water from rivers and tributaries was sampled during snowmelt and summer base flow periods in 2005, and river flow
was measured. Total N (TN), NO3–N, and Si concentrations were determined using standard methods. Total catchment and upland areas for each sampling site
were determined with ArcGIS hydrology modeling software and 1:25,000-scale digital topographic maps. Specific discharge was
significantly higher during snowmelt than during base flow. In both areas, TN concentrations increased, whereas Si concentrations
decreased, with increased specific discharge, and were significantly higher during snowmelt. The Si:TN mole ratio decreased
to below or close to the threshold value for eutrophication (2.7) in one-third of sites during snowmelt. River NO3–N concentrations during base flow were significantly and positively correlated with the proportion of upland fields in the
catchment in both the Abashiri (r = 0.88, P < 0.001) and Okoppe (r = 0.43, P < 0.01) areas. However, the regression slope, defined as the impact factor (IF) of water quality, was much higher in Abashiri
(0.025) than in Okoppe (0.0094). The correlations were also significantly positive during snowmelt in both areas, but IF was
four to eight times higher during snowmelt than during base flow. Higher discharge of N from upland fields and grasslands
during snowmelt and the resulting eutrophication in estuaries suggest that nutrient discharge during snowmelt should be taken
into account when assessing and monitoring the annual loss of nutrients from agricultural fields. 相似文献
166.
P. Rama Chandra Prasad Nidhi Nagabhatla C. S. Reddy Stutee Gupta K. S. Rajan S. H. Raza C. B. S. Dutt 《Environmental monitoring and assessment》2010,160(1-4):541-553
The present study outlines an approach to classify forest density and to estimate canopy closure of the forest of the Andaman and Nicobar archipelago. The vector layers generated for the study area using satellite data was validated with the field knowledge of the surveyed ground control points. The methodology adopted in this present analysis is three-tiered. First, the density stratification into five zones using visual interpretation for the complete archipelago. In the second step, we identified two island groups from the Andaman to investigate and compare the forest strata density. The third and final step involved more of a localised phytosociological module that focused on the North Andaman Islands. The results based on the analysis of the high-resolution satellite data show that more than 75% of the mangroves are under high- to very high-density canopy class. The framework developed would serve as a significant measure to forest health and evaluate management concerns whilst addressing issues such as gap identification, conservation prioritisation and disaster management—principally to the post-tsunami assessment and analysis. 相似文献
167.
Kamala Kanta Borah Bhabajit Bhuyan Hari Prasad Sarma 《Environmental monitoring and assessment》2010,169(1-4):347-352
Drinking water quality with respect to lead, iron, fluoride, and arsenic has been carried out in and around tea gardens of Darrang district of Assam, India. The district lies between 26°25′ and 26°55′ northern latitude and 91°45′ and 91°20′ east longitude and covers an area of 3,465.30 km2. Twenty-five different sampling stations were selected for the study. Iron, lead, and arsenic were analyzed by using an atomic absorption spectrometer, Perkin Elmer AA 200, while fluoride was measured by the SPADNS method using a UV–VIS spectrometer, Shimadzu 1240 model. The study revealed that the water sources in the area are heavily polluted with lead. Statistical analysis of the data is presented to determine the distribution pattern, localization of data, and other related information. Statistical observations imply non-uniform distribution of the studied parameters with a long asymmetric tail either on the right or left side of the median. 相似文献
168.
The oxides of nitrogen—NO
x
(NO and NO2)—are an important constituent of the troposphere. The availability of relatively higher spatial (0.25° grid) and temporal
(daily) resolution data from ozone monitoring instrument (OMI) onboard Aura helps us to better differentiate between the point
sources such as thermal power plants from large cities and rural areas compared to previous sensors. The annual and seasonal
(summer and winter) distributions shows very high mean tropospheric NO2 in specific pockets over India especially over the Indo-Gangetic plains (up to 14.2 × 1015 molecules/cm2). These pockets correspond with the known locations of major thermal power plants. The tropospheric NO2 over India show a large seasonal variability that is also observed in the ground NO2 data. The multiple regression analysis show that the influence of a unit of power plant (in gigawatts) over tropospheric
NO2 (×1015 molecules/cm2) is around ten times compared to a unit of population (in millions) over India. The OMI data show that the NO2 increases by 0.794 ± 0.12 (×1015 molecules/cm2; annual) per GW compared to a previous estimate of 0.014 (×1015 molecules/cm2) over India. The increase of tropospheric NO2 per gigawatt is found to be 1.088 ± 0.18, 0.898 ± 0.14, and 0.395 ± 0.13 (×1015 molecules/cm2) during winter, summer, and monsoon seasons, respectively. The strong seasonal variation is attributed to the enhancement
or suppression of NO2 due to various controlling factors which is discussed here. The recent increasing trend (2005–2007) over rural thermal power
plants pockets like Agori and Korba is due to recent large capacity additions in these regions. 相似文献
169.
Poonam Prasad Meenal Chaurasia R. A. Sohony Indrani Gupta R. Kumar 《Environmental monitoring and assessment》2013,185(7):5987-5992
The chemical, physical and biological characteristics of water with respect to its suitability describe its quality. Concentration of pesticides or fertilisers degrades the water quality and affects marine life. A comprehensive environmental data information system helps to perform and complete common tasks in less time with less effort for data verification, data calculations, graph generation, and proper monitoring, which helps in the further mitigation step. In this paper, focus is given to a web-based system developed to express the quality of water in the imprecise environment of monitoring data. Water samples were analyzed for eight different surface water parameters, in which four parameters such as pH, dissolved oxygen, biochemical oxygen demand, and fecal coliform were used for the water quality index calculation following MPCB Water Quality Standards of class A-II for best designated use. The analysis showed that river points in a particular year were in very bad category with certainty level of 0–38 % which is unsuitable for drinking purposes; samples in bad category had certainty level that ranged from 38 to 50 %; samples in medium to good category had certainty levels from 50 to 100 %, and the remaining samples were in good to excellent category, suitable for drinking purposes, with certainty levels from 63 to 100 %. 相似文献
170.
Thakur Ravindra Singh Kumar Aditya Lugun Onila Ansari Nasreen Ghazi Prasad Satgur Das Triparna Gupta Neha Patel Devendra Kumar 《Environmental science and pollution research international》2023,30(10):25181-25192
Environmental Science and Pollution Research - In recent years, special attention has been given to emission research that led to the deposition of toxicants from road traffic. Thus, it is... 相似文献