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721.
多环芳烃 [Polycyclicaromatichydrocarbons (PAHs) ]是海洋常见的污染物 ,由于具有致癌性和致突变性而成为必须检测的污染物 .有关多环芳烃对鱼类的血液学指标的影响 ,国外已有一些报道[1 ,2 ] ,国内的报道还很少 .有人认为白细胞数、白细胞的吞噬能力等免疫毒理学指标能较好地反映水体污染状况 .而血红蛋白能否作为污染监测的生物标志物 ,多环芳烃对鱼类血红蛋白是否存在毒性影响 ,这些尚无定论 .80年代以来 ,各国水生毒理学家越来越重视毒物的联合作用 ,已研究的毒物种类较广泛 ,包括金属间的联合作用… 相似文献
722.
采用人工污染土壤、尾矿砂、污泥等不同载体的污染源来模拟土壤污染 ,研究其对水稻生长、吸收养分和吸收重金属的影响。结果表明 ,不同污染载体对水稻生长的影响不同 ,其影响的大小顺序为人工污染土壤 >尾矿砂 >污泥 >尾矿砂 +污泥。不同污染载体对水稻吸收重金属的影响亦不同 ,以纯化学试剂的形式添加到土壤中的重金属最易被提取出来 ,植物从中吸收的Cu、Zn、Pb、Cd最多 ,而从以污泥为污染载体的土壤中吸收的Zn、Pb、Cd最少。研究表明 ,用添加纯化学试剂的方法来模拟污染土壤对生态与环境的影响是可行的 ,确定土壤负载容量是安全的 ,因为在实验条件下它对供试植物的影响最明显 相似文献
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725.
Abdel-Wahab MM Wang C Vanegas-Useche LV Parker GA 《Waste management (New York, N.Y.)》2011,31(6):1109-1120
The removal ability of gutter brushes for road sweeping for various debris types and different sweeping parameters is studied through experimental tests. The brushing test rig used comprises two commercial gutter brushes, a concrete test bed, and an asphalt test road with a gutter of 0.25 cm width and 10° slope. The brush-surface contact area is determined by sweeping sand on the concrete test bed. Sweeping problems are identified and discussed, and sweeping criteria for the different debris types are suggested. Also, optimum sweeping parameters are proposed for each debris type. In addition, debris removal mechanisms are discussed and analysed. The results indicate that for large heavy debris such as stones and gravel, it is not difficult to achieve large removal forces, because the steel bristles are relatively stiff. Conversely, high removal forces are not needed for particles of millimetre or micron sizes, but bristle curvature has to be appropriate to remove particles from road concavities. Finally, it is found that mud, especially dry mud on a rough surface, is the hardest debris to sweep, requiring a brush with a large tilt angle and a very large penetration to produce large removal forces. 相似文献
726.
Mosses and lichens are useful biological indicators of environmental contamination for a variety of metals and radionuclides of both natural and artificial origin. These plants lack a well-developed root system and rely largely on atmospheric deposition for nourishment. Therefore in the study, different lichens (Cladonia convoluta, Cladonia foliacea) and mosses (Homalothecium sericeum, Hypnum lacunosum, Hypnum cupressiforme, Tortella tortuosa, Didymodon acutus, Syntrichia ruralis, Syntrichia intermedia, Pterogonium graciale, Isothecium alopecuroides, Pleurochatae squarrosa) were collected around the Yata?an (Mu?la), Soma (Manisa), Seyitömer - Tunçbilek (Kütahya) coal-fired power plants and investigated for potential use as biomonitors for 210Po and 210Pb deposition. While the activity concentrations of 210Po and 210Pb in lichens are in the ranges of 151 ± 7-593 ± 21 and 97 ± 5-364 ± 13 Bq kg−1, for mosses the ranges for 210Po and 210Pb are 124 ± 5-1125 ± 38 and 113 ± 4-490 ± 17 Bq kg−1, respectively. In the study, the moss samples were observed to accumulate more 210Po and 210Pb compared to lichens. While the most suitable biomonitor was a moss species (H. lacunosum) for Yata?an (Mu?la), it was another moss species (S. intermedia) for Soma (Manisa) and Seyitömer - Tunçbilek (Kütahya) sites. 210Po concentrations were found higher than 210Pb concentrations at the all sampling stations. 相似文献
727.
Ahmed MK Habibullah-Al-Mamun M Hossain MA Arif M Parvin E Akter MS Khan MS Islam MM 《Chemosphere》2011,84(1):143-149
This experiment was conducted to study the genotoxic potentials of sodium arsenite (NaAsO2) in freshwater fish Oreochromis mossambicus by using alkaline comet assay and micronucleus (MN) test. Fish were exposed to three different concentrations (3 ppm, 28 ppm and 56 ppm) of arsenic and gill, liver and blood tissue samples were collected after 48 h, 96 h and 192 h of exposure. Arsenic exposure induced DNA damage in all tissues examined in a concentration dependent manner. A significant (p < 0.05) increase in the comet tail DNA (%) of the exposed fish liver, gill, and blood was observed after 48 h and 96 h of exposure, but a decline in DNA damage was recorded in all the tissues at all the three concentrations studied after 192 h of exposure. Liver tissue exhibited significantly (p < 0.05) higher DNA damage at all the concentrations examined, followed by gill and blood. Higher liver tail DNA (51.38 ± 0.21%) refers that it is more prone to injury to arsenic toxicity than the gill and blood. In blood samples arsenic induced micronucleus formation in a concentration dependent manner and highest (5.8 ± 0.46%) value was recorded in 56 ppm after 96 h of exposure, whereas, it was decreased after 192 h of exposure at all the three concentrations of NaAsO2 examined which refers to the DNA repairing ability of fish to arsenic toxicity. The results of this study depict the genotoxic potentials of arsenic to fish which in turns provide insight on advanced study in aquatic toxicology. 相似文献
728.
Whereas biochemical and molecular parameters have been well recognised as important “signposts” of individual disturbance to endocrine disrupting chemical’s (EDCs) exposure, behavioural endpoints are yet greatly overlooked as a routine tool in environmental risk assessment of EDCs. However, life histories are intimately associated with numerous inter- and intra-specific interactions, which invariably depend on the performance of effective behaviours. Within fish species, one of the most important factors influencing energy turnover earlier in the development is locomotor activity. This essential trait reflects the organism’s ability to generate and coordinate the metabolic energy required for both reproductive and non-reproductive behaviours. Inappropriate movement responses due to toxic effects of contaminants may ultimately impact important ecological variables.Therefore, in the present study, the swimming bursts of zebrafish juveniles exposed for 40 d to the synthetic estrogen ethinylestradiol (EE2), tested at environmentally relevant concentrations (nominal concentrations of 0.5, 1 and 2 ng L−1), were investigated in order to address the potential of rapid-behaviour patterns as an effective response indicator of estrogenic endocrine disrupting chemical’s exposure. This synthetic estrogen was selected due to its high prevalence in aquatic ecosystems, ability to mimic natural estrogens and proven record of causing negative effects in fish reproduction. The behavioural responses were compared with established endpoints used in the screening of EE2 effects at adulthood. Results indicate that zebrafish juveniles’ swimming activity was significantly decreased upon EE2 exposure. Since reduced locomotion of zebrafish may impact foraging, predator avoidance, drift and transport, and even interfere with social and reproductive behaviours, a fitness decline of wild fish populations can ultimately be hypothesized. Furthermore, behavioural endpoints were found to display higher sensitivity to EE2 than either vitellogenin gene induction or reproductive parameters determined at adulthood.Overall, the findings of this work not only demonstrate the power of high-throughput behavioural responses, able to act as sensitive early warning signals of EDC exposure, but also highlight the potential of behavioural endpoints in providing a more comprehensive and non-invasive measure of EDC’s exposure. 相似文献
729.
为了解海洋生物修复的发展趋势与研究前沿,本研究以Web of Science核心数据库近17年(1996-2022)的文献为研究对象,运用CiteSpace软件进行文献计量分析与可视化知识图谱分析。研究发现,近年来我国海洋生物修复领域快速发展,发文量位列第一;该领域主要研究内容为海洋污染物、海洋污染治理技术和海洋环境,研究热点集中在“生物降解”和“原油污染生物修复”;国际间的学术合作呈现出“大分散、小集中”的特征,研究机构之间交流较少,跨地区合作亟待加强;当前研究聚焦于海洋生物修复技术的开发与优化,国内外学者应该加强学术交流与合作,突破技术难关,加快恢复海洋生态环境。 相似文献
730.
次级河流回水区叶绿素a与影响因子的多元分析——以临江河为例 总被引:4,自引:0,他引:4
为了对次级河流回水区富营养化进行深入研究,把长江次级河流之一的临江河回水区为研究对象,根据2007年10月至2008年9月临江河回水区中游叶绿素a含量及其水质理化指标的监测数据,分析了临其叶绿素a浓度的时间分布,对叶绿素a浓度及影响因子进行相关分析,找出与叶绿素a显著相关的环境因子并建立多元逐步回归模型。结果表明:临江河回水区叶绿素a浓度峰值主要集中在5月上旬至9月下旬,变化范围为227~661 mg/m3。临江河回水区叶绿素a浓度变化受多个环境因子共同影响,与水温、流速、透明度、COD、总磷之间显著相关,而与总氮相关性不显著。经过叶绿素a及其影响因子的相关分析,建立了以水温、流速和总磷为自变量,叶绿素a浓度为应变量的逐步线性回归模型,模型初步验证结果表明:多元逐步回归模型可以用来描述临江河回水区叶绿素a浓度的变化。通过对临江河回水区叶绿素a及其影响因子的分析,控制临江河回水区水体中磷含量应是其富营养化防治工作的重点,防治工作应主要在春末和整个夏季,尤其是在5、6月份。 相似文献