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991.
生物监测及其在环境监测中的应用(Biological Monitoring and Its Application in Environmental Monitoring) 总被引:7,自引:0,他引:7
生物监测是近几十年来发展起来的应用于环境监测领域的一门新兴技术,是指利用生物个体、种群或群落对环境污染或变化所产生的反应,从生物学角度对环境污染状况进行监测和评价.作为环境监测的重要组成部分,生物监测具有敏感性、长期性、连续性、经济性、非破坏性和综合性等优势,有望在生态系统环境监测、总量控制、环境风险评价、环境污染早期预警、突发事件监测和环境标准制定等领域取得突破.在总结国内外相关研究的基础上,从目前在环境监测中应用的生物监测的原理、分类、特点、方法学和实际应用等方面进行综述.尽管生物监测还有不足之处,但可以肯定,其发展和应用将会对环境监测事业产生极大的推动作用,有着非常广阔的发展前景. 相似文献
992.
The use of the organic As compound, roxarsone, as an antibiotic additive to poultry feed continues to raise concern over potential negative environmental impacts. Total As concentration in poultry litter can reach >40 mg kg−1 and both roxarsone and its mineralization product As(V) have been identified in poultry litters (PL). To investigate the fate of these As species upon land application of PL we conducted two studies. In the first, an Orangeburg soil (Ultisol from the Atlantic Coastal Plain) was spiked with either 20 mg kg−1 As(V) or roxarsone and incubated at 10% moisture content for 4 months. Exchangeable As was determined periodically by extraction with 0.1 M PO4. Both As(V) and roxarsone displayed similar desorption; initially, approximately 70% of added As was ligand exchangeable and this decreased to 35% after 4 months incubation, presumably due to either slow sorption reactions or a change in solid phase speciation of As to less exchangeable forms. In the second study, various manipulations of two PL samples were applied to the Orangeburg soil at realistic field application rates. The treatments were wet to 10% moisture content and water soluble As, Cu and organic carbon (DOC) was measured over 30 days. Arsenic and Cu solubility were highest from the dried litter samples. Ashing of the PLs decreased soluble As and Cu, presumably because of the loss of organic matter from the ashed litter and subsequent decrease in DOC. Application of leachates from either PL resulted in higher concentrations of soluble As and Cu than when the soil was amended with equivalent concentrations of soluble As and Cu dissolved in DI H2O. We hypothesize that the increased levels of DOC from the PL treatments enhance As and Cu solubility through competitive sorption and complexation, respectively. In fact, As and Cu solubility was correlated to DOC levels in the amended soil extracts. Even though land application of PL introduced relatively low concentrations of As and Cu to soil it appeared that other soluble constituents of PL significantly enhanced As and Cu solubility. 相似文献
993.
Derivation of predicted no effect concentrations (PNEC) for 2,4,6-trichlorophenol based on Chinese resident species 总被引:4,自引:0,他引:4
2,4,6-Trichlorophenol (2,4,6-TCP) is a common chemical intermediate and a by-product of water chlorination and combustion processes, and is a priority pollutant of the aquatic environment in many countries. Although information on the toxicity of 2,4,6-TCP is available, there is a lack of information on the predicted no-effect concentration (PNEC) of 2,4,6-TCP, mainly due to the shortage of chronic and site-specific toxicity data. In the present study, acute and sub-chronic toxicity of 2,4,6-TCP on six different resident Chinese aquatic species were determined. PNEC values were calculated and compared by use of two approaches: assessment factor (AF) and species sensitivity distribution (SSD). Values for acute toxicity ranged from 1.1 mg L−1 (Plagiognathops microlepis) to 42 mg L−1 (Corbicula fluminea) and the sub-chronic no observed effect concentrations (NOECs) ranged from 0.05 mg L−1 (Mylopharyngodon piceus) to 2.0 mg L−1 (C. fluminea). PNECs obtained by the assessment factor approach with acute (AF = 1000, 0.001 mg L−1) or chronic (AF = 10, 0.005 mg L−1) toxicity data were one order of magnitude less than those from SSD methods (0.057 mg L−1). PNEC values calculated using SSD methods with a 50% certainty for 2,4,6-TCP was less than those obtained by use of the USEPA recommend final chronic value (FCV) method (0.097 mg L−1) and the one obtained by use of the USEPA recommend acute-to-chronic (ACR) methods (0.073 mg L−1). PNECs derived using AF methods were more protective and conservative than that derived using SSD methods. 相似文献
994.
995.
Metribuzin, a triazinone herbicide, is heavily used within the expansive Nzoia River Drainage Basin in Kenya for the optimization of sugarcane yields. For field experiments, soils were spiked with metribuzin and amended with filter mud compost and Tithonia diversifolia leaves. Soils with history of metribuzin application (48 months) were also spiked with metribuzin but not amended with the organic materials. Degradation of metribuzin for the three variants was followed for a period of 102 days. Repeated exposure of metribuzin to soil and addition of filter mud compost to soil enhances the degradation of metribuzin with half dissipation times of 31 and 25 days. In soil amended with Tithonia diversfolia leaves, the half dissipation time was 32 days while in the control (unamended non history soil), it was 36 days. Laboratory studies showed that soil sterilization slowed the degradation of metribuzin, with a half dissipation time of 154 days. This confirmed that metribuzin was biochemically degraded in soil by an adapted community of microbes. 相似文献
996.
We analyze the stock market reaction to 161 major environmental and non-environmental accidents, reported on the front page of the New York Times for half a century. To determine if the market induces a real deterrence effect, we extend the event windows up to one year. On average, the market reacts negatively and enduringly to the announcement of an accident. However, this average effect is largely driven by the airline industry and by government interventions. The estimated average compounded abnormal return following environmental accidents does not differ from zero after one year. This does not exclude, in severe events affecting large firms, huge losses in equity value, but the significant negative cumulative abnormal returns estimated immediately after an environmental accident in previous studies do not persist. Our results suggest that in a market driven by institutional investors, the deterrence effect is likely to be weak. 相似文献
997.
Andrew J. Higgins 《Journal of the American Water Resources Association》1984,20(3):425-434
The project was designed to demonstrate the potential benefits of utilizing sewage sludge as a soil conditioner and fertilizer on Sassafras sandy loam soil. Aerobically digested, liquid sewage sludge was applied to the soil at rates of 0, 22.4, and 44.8 Mg of dry solids/ha for three consecutive years between 1978 and 1981. Groundwater, soil, and crop contamination levels were monitored to establish the maximum sewage solids loading rate that could be applied without causing environmental deterioration. The results indicate that application of 22.4 Mg of dry solids/ha of sludge is the upper limit to ensure protection of the groundwater quality on the site studied. Application rates at or slightly below 22.4 Mg of dry solids/ha are sufficient for providing plant nutrients for the dent corn and rye cropping system utilized in the study. 相似文献
998.
介绍了采油队安全生产巡视管理系统的组成、系统配置与工作过程,叙述了试验与应用情况,分析了其经济效益和社会效益与推广应用前景。 相似文献
999.
陇中黄土高原半干旱区是一个自然条件较为特殊的区域,由于各种因素的约束,几十年来尽管各级政府进行了大量的投资,但其面貌并未有实质性的改变,社会发展水平不高,经济基础薄弱。究其原因,较为低下的人口素质,迅速增长的人口数量,以及由这二者形成的矛盾对社会经济产生的负面影响,是障碍这一地区发展的首要因素。 相似文献
1000.
N. K. Tyagi 《Journal of the American Water Resources Association》1987,23(3):455-462
ABSTRACT: A procedure to determine optimal irrigation scheduling strategies under rotational water delivery systems is presented. The methodology involves integration of water delivery amount and frequency, irrigation management strategies, evapotranspiration sequences and crop-evapotranspiration-production functions to arrive at an optimal irrigation strategy. Application of the methodology to a farm in the service area of Western Yamuna Canal (India) where a two-stage system of rotation, one among the irrigation channels and the other among the farmers, is in vogue, reveals that maximum production is obtained with water application in a rotational manner (RI) rather than with irrigation in every or alternate supply periods. Increase in mean water supply which can be effected through improvement in on-farm conveyance and application systems, has a greater effect on yield than decrease in variance of the supply. Benefit cost analyses indicates that precision land leveling is more cost effective in increasing water supply as compared to water-course lining. 相似文献