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771.
772.
处理生活污水的植物品种的筛选 总被引:16,自引:0,他引:16
以小型碎石床人工湿地生态系统和无土栽培2种方法,模拟研究了广东园林绿化中常用的27种植物对生活污水中氮、磷、COD的降解能力,表明野芋头、花叶万年青、象草、姜花、绿公主、富贵竹、再力花、大花叶万年青、芦苇、花芦苇、美人蕉、文殊兰、水芋头、风车草、红草、蜘蛛兰、千手观音、水葱和花蝴蝶等18种植物,可以作为人工湿地生态系统选种植物,从而扩大了可选植物品种范围,配合适当,可达到美化环境和净化污水2种功能,可适用于面源性水污染的治理。象草的研究表明,它是一种既有强污水降解能力又能作饲料的品种,适用于畜牧场的水污染治理。 相似文献
773.
通过在垂直流模拟人工土柱上种植不同的花卉植物,研究了垂直流花卉人工湿地对污水COD、BOD5、TN和TP的净化效果的影响。结果表明,所选用的5种陆生花卉,甚至鲜切花卉对化粪池污水有比较好的净化效果,它们对BOD5的去除率可达到92.04%以上,对TP的去除率甚至可达到97.77%以上。而且种植花卉植物的人工湿地出水水质要好于不种植物的对照湿地系统。 相似文献
774.
Occurrence and fate of heavy metals in the wastewater treatment process 总被引:19,自引:0,他引:19
The occurrence and the fate of heavy metals (Cd, Pb, Mn, Cu, Zn, Fe and Ni) during the wastewater treatment process were investigated in the wastewater treatment plant (WTP) of the city of Thessaloniki, northern Greece, operating in the activated sludge mode. For this purpose, wastewater and sludge samples were collected from six different points of the plant, namely, the influent (raw wastewater, RW), the effluent of the primary sedimentation tank (primary sedimentation effluent, PSE), the effluent of the secondary sedimentation tank (secondary sedimentation effluent, SSE), sludge from the primary sedimentation tank (primary sludge, PS), activated sludge from the recirculation stream (activated sludge, AS), and the digested/dewatered sludge (final sludge, FS).
The distribution of metals between the aqueous and the solid phase of wastewater was investigated. Good exponential correlation was found between the metal partition coefficient, logKp, and the suspended solids concentration. The mass balance of heavy metals in the primary, secondary and the whole treatment process showed good closures for all metal species. The relative distribution of individual heavy metals in the treated effluent and the sludge streams indicated that Mn and Cu are primarily (>70%) accumulated in the sludge, while 47–63% of Cd, Cr, Pb, Fe, Ni and Zn remain in the treated effluent. 相似文献
775.
The aim of this study was to characterize the biological treatment of heavy metal-contaminated water employing Myriophyllum species, namely M. spicatum L. and M. triphyllum. Both species were found to be capable of removing cadmium (Cd) from water; the latter significantly outperformed. Myriophyllum species were treated with 0, 2, 4, 6, 8, 16 mg l−1 cadmium solutions for 24, 48, 72, 96 h, respectively. Cd uptake of both species was the lowest at 2 mg l−1 and the highest at 16 mg l−1. Concentration related cadmium stress on both species exhibit significant difference on pigment levels (8–16 mg l−1). These findings contribute to the fact that submerged aquatic plants can be used for the removal of heavy metals. 相似文献
776.
We investigated quantitatively the sensitivity of plant species response curves to sampling characteristics (number of plots, occurrence and frequency of species), along a simulated pH gradient. We defined 54 theoretical unimodal response curves, issued from combinations of six values for optimum (opt = 3, 4, …, 8), three values for tolerance (tol = 0.5, 1.0, and 1.5, sensu ter Braak and Looman [ter Braak, C.J.F., Looman, C.W.N., 1986. Weighted averaging, logistic regression and the Gaussian response model. Vegetatio 65, 3–11]), and three values for maximum probability of presence (pmax = 0.05, 0.20, and 0.50). For each of these 54 theoretical response curves, we built artificial binary data sets (presence/absence) to test the influence of species occurrence, frequency, or number of available plots. With real data extracted from EcoPlant, a phytoecological database for French forests [Gégout, J.-C., Coudun, Ch., Bailly, G., Jabiol, B., 2005. EcoPlant: a forest sites database linking floristic data with soil characteristics and climatic conditions. J. Veg. Sci. 16, 257–260], we compared the ecological response of 50 plant species to soil pH, based first on a small data set (100 randomly sampled plots), and then based on the whole data set available (3810 plots). 相似文献
777.
Shiro Tsuyuzaki 《Environmental management》1995,19(5):773-777
To determine the status of the vegetation of ski slopes in northeastern-central Honshu, Japan, 94 plots (2×2 m) were set up
on five ski areas (101–520 m elevation) which were established between 1945 and 1985 by forest clear-cutting, land modification,
and seeding. Six vegetation types were recognized: five grasslands dominated byDigitaria adscendens, Miscanthus sinensis, Zoysia japonica, Festuca rubra, andPteridium aquilinum var.latiusculum, respectively, and bare areas of very low to no vegetation cover. Of the dominant species,F. rubra is the only introduced species; it does not, however, appear to persist. After the introduced grassland declinesM. sinensis or annual grasslands develop. Native plants, especially woody species, can establish inM. sinensis grassland but do not establish in the other grasslands. It is concluded that the introduction of exotic species is inappropriate
to maintain ski slope vegetation, and the development ofM. sinensis grassland is desirable to promote natural revegetation. 相似文献
778.
The approach developed by Environment Canada to assess risk to aquatic and terrestrial plants in nontarget habitats potentially
exposed to pesticides evaluated for registration is described. An anonymous sample of pesticide submissions is used to illustrate
the approach and to examine its merits and limitations in relation to test species, response variability, testing protocols,
ecological relevance, and comparability with other regulatory agencies. Future directions are identified, particularly in
relation to impending nontarget-plant testing guidelines for pesticide registration in Canada. This approach incorporates
some of the latest research and developments in the field of risk assessment for plants. The novelty of this approach also
lies in the use of the plant screening data routinely generated by chemical pesticide companies, which is intended to provide
a maximum amount of information to evaluators at minimal increment cost to registrants. The proposed approach can serve as
a basis for guideline development and modernization for other jurisdictions. 相似文献
779.
Channel incision is a widespread phenomenon that results in stream and riparian habitat degradation. Fishes and physical habitat
variables were sampled at base flow from three incised stream channels and one reference stream in northwest Mississippi,
USA, to quantify incision effects on fish habitat and provide a basis for habitat rehabilitation planning and design. Incised
channels were sampled in spring and autumn; the reference channel was sampled only in the autumn. Incised channel habitat
quality was inferior to the reference channel despite the presence of structures designed to restore channel stability. Incised
channels had physical habitat diversity levels similar to a nonincised reference channel, but contained fewer types of habitat.
At base flow, incised channels were dominated by shallow, sandy habitats, moderate to high mean local Froude numbers, and
had relatively little organic debris in their beds. In contrast, the reference stream had greater mean water depth, contained
more woody debris, and provided more deep pool habitat. Fish assemblages in incised channels were composed of smaller fishes
representing fewer species relative to the reference site. Fish species richness was directly proportional to the mean local
Froude number, an indicator of the availability of pool habitat. 相似文献
780.
Runyao Huang Jin Xu Li Xie Hongtao Wang Xiaohang Ni 《Frontiers of Environmental Science & Engineering》2022,16(9):117