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991.
David K. Mueller 《Journal of the American Water Resources Association》1982,18(3):377-382
ABSTRACT: Mass balance models have been common tools in lake quality management for some years. However, verification for use on reservoirs, especially in the Western United States, has been seriously lacking, In this study, such a verification is attempted using data from the U.S EPA National Eutrophication Survey. Several models from the literature are compared for accuracy in application to the western reservoir data. Model standard error and correlation between estimated and observed reservoir phosphorus concentrations are the Criteria used for comparison. Standard errors am further used to calculate uncertainty of trophic state classification based on estimated phosphorus concentration. The model proposed by Dillon and Rigler (1974) proved most accurate, with a correlation coefficient of 0.86 and standard error of 0.2, based on logarithmic transformed values. Deficiencies in the other models appear to & from coefficients fit to lake data and from inappropriate model formulation. 相似文献
992.
G. Dennis Cooke Robert T. Heath Robert H. Kennedy Murray R. McComos 《Journal of the American Water Resources Association》1982,18(4):699-705
ABSTRACT: Recovery of eutrophic lakes after nutrient diversion may be delayed if the lake experiences significant internal phosphorus (p) loading to the water column. A maximum dose of aluminum sulfate, defined herein, was applied to the anaerobic sediments of the hypolimnia of two dimictic Ohio lakes following septic tank diversion, with the objective of attaining long term control of the release of phosphorus to the water column from these sediments. The results were compared to a similar, downstream, untreated lake. Total phosphorus concentration declined sharply after treatment and has remained so through 1980 for both lakes, a period of 5 and 6 years of control, respectively. Internal P loading from anaerobic, hypolimnetic sediments was partially controlled by the treatment but there are other important sources, perhaps in the littoral zone, in these lakes. Algal biomass is Smaller and water transparency has increased. Both lakes became mesotrophic after treatment, as described by the Carlson (1977) trophic state index, and remain in that improved condition to date. No deleterious side effects were observed, although one lake experienced a significant decrease in diversity of planktonic microcrustacea and a lakeward extension of the macrophyte community. This method appears to be an effective and lasting means of accelerating the recovery of a eutrophic lake following nutrient diversion. 相似文献
993.
T. C. Daniel R. C. Wendt P. E. McGuire D. Stoffel 《Journal of the American Water Resources Association》1982,18(1):117-120
ABSTRACT: Loading rates derived from monitoring natural runoff from selected land uses are compared. Land uses selected for evaluation are construction sites, barnyards, and agriculture (dairying). Runoff volumes, sediment, and nutrient fractions were monitored and expressed as areal loadings for comparison purposes. Sediment yield and total phosphorus (total P) loss was directly proportional to runoff (m3/ha). In decreasing order, the loadings for sediment and total P were as follows: construction site > barnyard > general dairying. Runoff from the barnyard area was approximately 10 times higher in soluble phosphorus and ammonium nitrogen than the other land uses under investigation. Areal loss for nitrate nitrogen was highest from the construction site and was attributed to the higher volume of runoff per unit area. Results show that barnyards in a dairying watershed are potentially a major source of sediment and nutrients, especially those dissolved fractions which have the potential for immediate water quality impacts. Relative to general agricultural land, urban construction sites also appear to be a major source of sediment and nutrients. As with barnyard sites, however, the effect of such sites on water quality likely depends on proximity to surface water bodies and other watershed characteristics affecting delivery ratios of contaminants. 相似文献
994.
J. R. Williams 《Journal of the American Water Resources Association》1980,16(5):843-848
ABSTRACT: A model called SPNM from the words “sediment-phosphorus-nitrogen model” was developed for simulating agricultural contributions to water pollution. SPNM is designed to predict sediment, P, and N yields for individual storms on small basins and to route these yields through streams and valleys of large basins. Users need no computer programming experience because the model is a problem-oriented computer language. SPNM is useful in planning water resources projects and in research. Tests of the model on a watershed provided realistic results. 相似文献
995.
Lawrence O. Fine William P. Jensen 《Journal of the American Water Resources Association》1981,17(5):895-897
Fly ashes fiom lignite coal fixed steam electric plants contain appreciable amounts of materials that can, in principle, decrease the phosphorus concentration in surface waters. Typical samples of un-weathered fly ash were used to test efficacies of removal of phosphorus from standard phosphate solutions and actual lake water samples. The effects of changing parameters such as contact time, pH, fly ash/water ratios, and solution temperature are presented. Water soluble and insoluble factors in the ash both appear to be reactive constituents. Trials with municipal waste waters showed near quantitative removal of ortho-phosphate. 相似文献
996.
997.
998.
污水化学除磷技术的现状和进展 总被引:8,自引:0,他引:8
综述了化学除磷的各种方法,原理,特点及其在使用过程中的不足之处。在此基础上,提出了一种新的化学除磷技术—固定化活性氧化镧的化学—吸附除磷技术。通过将其和一般的化学除磷技术进行对比,介绍了该技术所具备的开发潜质。 相似文献
999.
LIU Yong GUO Huai-cheng WANG Li-jing DAI Yong-li ZHANG Xiu-min LI Zi-hai HE Bin 《环境科学学报(英文版)》2006,18(3):596-603
Lake eutrophication caused by excess phosphorus (P) loading from point sources (PS) and nonpoint sources (NPS) is a persistent and serious ecological problem in China. A phosphorus budget, based on material flow analysis(MFA) and system dynamic (SD), is proposed and applied for the agriculture-dominated Qionghai Lake watershed located in southwestern China. The MFA-SD approach will not only cover the transporting process of P in the lake-watershed ecosystems, but also can deal with the changes of P budget due to the dynamics of watershed. P inflows include the fertilizer for agricultural croplands, soil losses, domestic sewage discharges, and the atmospheric disposition such as precipitation and dust sinking. Outflows are consisted of hydrologic export, water resources development, fishery and aquatic plants harvesting. The internal P recycling processes are also considered in this paper. From 1988 to 2015, the total P inflows for Lake Qionghai are in a rapid increase from 35.65 to 78.73 t/a, which results in the rising of P concentration in the lake. Among the total P load 2015, agricultural loss and domestic sewage account for 70.60% and 17.27% respectively, directly related to the rapid social-economic development and the swift urbanization. Future management programs designed to reduce P inputs must be put into practices in the coming years to ensure the ecosystem health in the watershed. 相似文献
1000.
Wang Yayi Wang Shuying Peng Yongzhen Zhu Guibing Ling Yunfang 《Frontiers of Environmental Science & Engineering in China》2007,1(2):226-232
To supply the valuable operating parameters for the popular usage of the new denitrifying phosphors removal process, it is
essential to study the dominant biochemical reactions and the characteristics of denitrifying phosphorus removing bacteria
(DPB). Thus, parallel batch experiments using DPB sludge were carried out to assess the effect of substrates (sewage, HAc,
and endogenous carbon source) on denitrifying dephosphorus removal efficiency in this study. The results showed that the initial
specific phosphorus release rate increased with the high concentration of the short-chain volatile fatty acids ratio in the
influent, and sufficient phosphorus was released by DPB. This improved the subsequent denitrification and phosphorus uptake
efficiency. The specific endogenous denitrification mainly relies on the internal carbon source (PHB) stored by poly-P bacteria.
Denitrifying phosphorus removing bacteria were very hungry when the internal PHB was consumed. Consequently, the specific
endogenous denitrification rate was low and the phosphorus uptake did not happen. On the other hand, in the experiment, the
denitrifying phosphorus removal performance under two temperature conditions (8–10°C and 25–26°C) was also investigated and
analyzed. It was found that the lower temperature decreased the specific phosphorus release and uptake rate, but did not inhibit
the denitrifying phosphorus removal completely. Therefore, the negative influence of the low temperature on the overall phosphorus
removal was not significant.
Translated from Acta Scientiae Circumstantiae, 2006, 26 (2): 186–192 [译自: 环境科学学报] 相似文献