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991.
沿江开发是当今世界各国经济发展和国土整治关注的焦点,江苏省沿江开发过程中高密度和高强度的产业集聚将对长江江苏段水环境带来压力。根据江苏省沿江各地市社会经济和调查的环境监测资料,分析了沿江大开发背景下长江江苏段的水环境污染负荷及治理现状并预测了未来演变趋势,结果显示:2002年长江江苏段污染负荷的废水总量为210 997.80×10\+4 t,COD\-\{Cr\}总量为380 817.20 t,NH\-3 N总量为28 391.36 t;预测2010年将分别达到395 977.10×10\+4 t、598 197.80 t和42 381.56 t,较2002年分别增长87.7 %、57.1 %和49.3 %。污染源治理方面工业污水90%以上已达到了国家排放标准,而生活污水处理无论在污水处理厂数量还是处理深度都难以满足实际需要。为使长江水域生态环境不受破坏和饮用水源地的供水安全得到保障,提出了优化产业结构、削减污染负荷、加强生活污水处理厂建设和提高沿江主要支流的治理力度等多项调控措施。 相似文献
992.
Małgorzata Baćmaga Jan Kucharski 《Journal of environmental science and health. Part. B》2019,54(4):252-262
Excess fungicides can pose a serious threat to the soil environment. Fungicides can lower the microbiological and biochemical activity of soil and lead to yield declines. Soils contaminated with fungicides have to be remediated to maintain the optimal function of soil ecosystems. This study evaluates the effect of neutralizing substances on soil enzymatic activity and the yield of Triticum aestivum L. in soil contaminated with fungicides. Sandy loam (Eutric Cambisols) with pHKCl 7.0 was contaminated with an aqueous solution of Amistar 250 SC and Falcon 460 EC in the following doses: 0 (soil without fungicide – treated as a control), RD (dose recommended by the manufacturer) and 300?×?RD (dose 300-fold higher than the recommended dose). Soil was supplemented with bentonite and basalt meal at a dose of 10?g kg?1 DM of soil (dry mass of soil). The fungicide dose recommended by the manufacturer did not induce changes in soil enzymatic activity or the yield of T. aestivum L. Our findings indicate that the tested fungicides can be safely applied to protect crops against fungal pathogens. However, when applied at the dose of 300?×?RD, the tested fungicides strongly inhibited soil enzymatic activity and disrupted the growth and development of spring wheat. Soil supplementation with bentonite and basalt meal improved the yield of T. aestivum L., and bentonite was more effective in reducing fungicide stress. The analyzed substances were not highly effective in restoring biochemical homeostasis in soil. 相似文献
993.
上海港船舶大气污染物排放对城市空气质量的影响不容小觑。基于船舶AIS数据,高精度船舶大气污染物排放清单得以建立并应用。2018年11月5—10日召开的第一届中国国际进口博览会期间,在气象条件不利的情况下,通过提前实施船舶排放控制区政策等措施,使船舶单日SOx排放量下降28.5%,一次PM2.5排放量下降25.5%,全市空气质量达到了保障要求。 相似文献
994.
利用上海市虹口监测点2002年O3的连续自动监测数据,分析了该点代表的区域范围内O3的污染水平、变化情况,以及O3与NO、NOx和CO的关系。指出该点O3的污染水平是冬季最低,秋季最高,5月至10月的质量浓度明显高于11月至4月,低质量浓度时段在早晨,高质量浓度时段在中午至午后;O3质量浓度的变化范围和上升速率是5月至10月比11月至4月大;O3的产生主要取决于NOx中NO转换成NO2的程度,而CO也同NO一样,当O3质量浓度在中午至午后较高时,CO质量浓度也不高。 相似文献
995.
On the Role of Spatial,Temporal, and Climatic Forces on Stream Sediment Loading from Rural and Urban Ecosystems 下载免费PDF全文
Audrey L. Squires Jan Boll Erin S. Brooks 《Journal of the American Water Resources Association》2017,53(5):1195-1211
In this study, we characterize the greatest sediment loading events by their sediment delivery behavior; dominant climate, watershed, and antecedent conditions; and their seasonal distribution for rural and urban land uses. The study area is Paradise Creek Watershed, a mixed land use watershed in northern Idaho dominated by saturation excess processes in the upstream rural area and infiltration excess in the downstream urban area. We analyzed 12 years of continuous streamflow, precipitation, and watershed data at two monitoring stations. We identified 137 sediment loading events in the upstream rural section of the watershed and 191 events in the downstream urban section. During the majority of these events conditions were transport limited and the sediment flush occurred early in the event, generally in the first 20% of elapsed event time. Statistical analysis including two dozen explanatory variables showed peak discharge, event duration, and antecedent baseflow explained most of the variation in event sediment load at both stations and for the watershed as a whole (R2 = 0.73‐0.78). In the rural area, saturated soils combined with spring snowmelt in March led to the greatest loading events. The urban area load contribution peaked in January, which could be a re‐suspension of streambed sediments from the previous water year. Throughout the study period, one event contributed, on average, 33% of the annual sediment load but only accounted for 2% of the time in a year. 相似文献
996.
Yun Ma Zhiwei Li Mei Yuan Linhua Chen Shanshan Zhou 《Journal of environmental science and health. Part. B》2017,52(11):796-801
In this study, a bacterial strain, CH-1, capable of degrading 3-bromocarbazole (3-BCZ) was isolated from a polluted soil. Based on its physio-biochemical characteristics and 16S rRNA genes, strain CH-1 was identified as a Stenotrophomonas sp. Strain CH-1 was able to degrade 70% of 50 mg/L 3-BCZ within 8 d at pH 7.0 and 30°C in mineral salt medium (MSM). During the process, the main intermediate metabolite was identified as (2E, 4Z)-6-(2-amino-5-bromophenyl)-2-hydroxy-6-oxhexa-2, 4-dienoic by gas (2E, 4Z)-6-(2-amino-5-bromophenyl)-2-hydroxy-6-oxhexa-2,4-dienoic via gas chromatograph-mass spectrometry (GC-MS) analysis. The metabolite disappeared after 14 d, suggesting that the metabolite can also be degraded by strain CH-1. 3-BCZ is a new persistent organic pollutant. This is the first report of the biodegradation of 3-BCZ. The results indicated that strain CH-1 may be a promising bacterial candidate for the bioremediation of environments polluted with polyhalogenated carbazoles (PHCs). 相似文献
997.
998.
The effects of the warm water discharged by a nuclear power plant (NPP) into a small reservoir are studied. A case study is presented (José Cabrera NPP-Zorita Hidráulica Reservoir) with experimental data of the reservoir stratification and predicted data of the dispersion of radioactive pollutants from operative or accidental releases. The vertical and longitudinal temperature profiles, electrical conductivity and transparency of the reservoir water were measured for an annual cycle. The results indicate that the continuous warm water discharge from the NPP causes permanent and artificial reservoir stratification. The stratification is significant within 1500 m upstream and 1000 m downstream from the warm water outfall. The pollutant dispersion has been predicted by using a flow model based on N(T) perfect-mixing compartments in series with feedback. The model parameter, N(T), is calculated from the longitudinal diffusion coefficient. The prediction of pollutant dispersion by means of this model shows that the stratification slows down the vertical mixing in the whole water body, and reduces the reservoir volume that is effective for the dilution and dispersion of pollutants. This means that, in the case of a radioactive pollutant release, the reservoir radioactivity level could increase significantly. 相似文献
999.
1000.