全文获取类型
收费全文 | 993篇 |
免费 | 76篇 |
国内免费 | 328篇 |
专业分类
安全科学 | 80篇 |
废物处理 | 25篇 |
环保管理 | 259篇 |
综合类 | 548篇 |
基础理论 | 236篇 |
污染及防治 | 116篇 |
评价与监测 | 90篇 |
社会与环境 | 41篇 |
灾害及防治 | 2篇 |
出版年
2023年 | 11篇 |
2022年 | 21篇 |
2021年 | 29篇 |
2020年 | 29篇 |
2019年 | 22篇 |
2018年 | 29篇 |
2017年 | 30篇 |
2016年 | 40篇 |
2015年 | 62篇 |
2014年 | 50篇 |
2013年 | 74篇 |
2012年 | 55篇 |
2011年 | 71篇 |
2010年 | 55篇 |
2009年 | 55篇 |
2008年 | 47篇 |
2007年 | 86篇 |
2006年 | 76篇 |
2005年 | 62篇 |
2004年 | 48篇 |
2003年 | 60篇 |
2002年 | 52篇 |
2001年 | 39篇 |
2000年 | 40篇 |
1999年 | 36篇 |
1998年 | 41篇 |
1997年 | 29篇 |
1996年 | 21篇 |
1995年 | 22篇 |
1994年 | 15篇 |
1993年 | 13篇 |
1992年 | 9篇 |
1991年 | 2篇 |
1990年 | 7篇 |
1989年 | 4篇 |
1988年 | 3篇 |
1987年 | 8篇 |
1986年 | 6篇 |
1985年 | 3篇 |
1984年 | 3篇 |
1983年 | 5篇 |
1981年 | 2篇 |
1980年 | 4篇 |
1979年 | 5篇 |
1978年 | 3篇 |
1977年 | 3篇 |
1975年 | 3篇 |
1973年 | 1篇 |
1972年 | 2篇 |
1970年 | 1篇 |
排序方式: 共有1397条查询结果,搜索用时 93 毫秒
991.
Suiliang HUANG Yafei JIA Sam S. Y. WANG 《Frontiers of Environmental Science & Engineering》2009,3(2):178-185
The effects of chemical spills on aquatic nontarget organisms were evaluated in this study. Based on a review of three types of current eco-toxicological models of chemicals, i.e., ACQUATOX model of the US-EPA, Hudson River Model of PCBs, and critical body residual (CBR) model and dynamic energy budget (DEBtox) model, this paper presents an uncoupled numerical ecotoxicological model. The transport and transformation of spilled chemicals were simulated by a chemical transport model (including flow and sediment transport), and the mortalities of an organism caused by the chemicals were simulated by the extended threshold damage model, separately. Due to extreme scarcity of data, this model was applied to two hypothetical cases of chemical spills happening upstream of a lake. Theoretical analysis and simulated results indicated that this model is capable of reasonably predicting the acute effects of chemical spills on aquatic ecosystems or organism killings. 相似文献
992.
2012年10月对太湖流域93个样点大型底栖动物进行调查,分析西部丘陵水生态功能区和东部平原水生态功能区底栖动物群落结构及其与环境因子的关系.共采集到底栖动物104种,隶属4门8纲19目46科85属.各样点的底栖动物总密度差别很大,介于1.33~39080ind./m2.西部丘陵区的物种丰富度、物种多样性均高于东部平原区.东部平原区的优势种主要为铜锈环棱螺和霍甫水丝蚓等耐污种,而西部丘陵区的优势种中包括清洁种(毛翅目和蜉蝣目幼虫).相似性分析结果表明2个生态区底栖动物群落具有显著差异,铜锈环棱螺、霍甫水丝蚓、锯齿新米虾、大沼螺、苏氏尾鳃蚓等是造成2生态区之间群落结构差异的主要原因.典范对应分析结果表明影响底栖动物群落结构的主要因素为栖境多样性、营养状态及底质异质性.Goodnight-Whitley指数和BPI指数评价结果表明西部丘陵区整体处于轻污染状态,而东部平原区大部分采样点处于轻污染状态和中污染状态,部分采样点处于重污染状态. 相似文献
993.
Yongshan CHEN Xiuping XI Gang YU Qiming CAO Bin WANG Fran ois VINCE Youwei HONG 《Frontiers of Environmental Science & Engineering》2015,9(3):394
An environmental risk assessment was performed for pharmaceutical compounds present in the aquatic environment of China. Predicted environmental concentration (PEC) of the compounds were calculated according to European Medicines Evaluation Agency (EMEA) guidelines. Available ecotoxicological data compromised by applying a very conservative assessment factor (AF) were employed to calculate the predicted no-effect concentration (PNEC). The screening principle and the risk assessment were based on risk quotient (RQ), which derived from the PEC and related PNEC values. PEC results indicated that all the compounds except sulfadimethoxine and levocarnitine, should carry out phase II risk assessment in EMEA guideline. RQ values suggested that more than 36 pharmaceuticals may be imposed health threats to the aquatic environment; especially the antibiotic therapeutic class including amoxicillin, sulfasalazine, trimethoprim, oxytetracycline and erythromycin showed high RQ values. These substances with high RQ value (RQ≥1) were regarded as top-priority pharmaceuticals for control in the aquatic environment of China. However, the antibiotic substances which had low risk quotient (RQ <1), should be reassessed by its potentially induced resistance under low concentration in future. 相似文献
994.
995.
Estuaries and coastal lagoons are characterized by a strong spatial and temporal variability of physicochemical characteristics and productivity patterns. In these environments, the magnitude and direction of the ecological responses to inorganic nutrient increase (i.e. eutrophication) are difficult to predict. In the framework of the project, New Indicators of Trophic state and environmental quality of marine coastal ecosystems and transitional environments (NITIDA), we analysed benthic indicators of trophic state, ecosystem efficiency, and environmental quality in four different transitional environments. The trophic state of the sediments was assessed in terms of quantity and bioavailability of sediment organic C pools; ecosystem efficiency was determined in terms of the prokaryote efficiency in exploiting enzymatycally degraded organic C; environmental quality was determined in terms of meiofaunal diversity. Here, we provide a synopsis of the results obtained and a meta-analysis of the scores assessments obtained using the different ecological indicators of environmental quality and demonstrate that trophic state, ecosystem efficiency, and biodiversity in transitional ecosystems are closely linked. We conclude that the assessment of the environmental quality of transitional ecosystems should be based upon a battery of trophic state indicators and ‘sensors’ of ecosystem functioning, efficiency, and quality. 相似文献
996.
Aquatic plant tissue (nitrogen) N and phosphorus (P) concentrations, together with the N:P ratio in general, respond poorly to ambient nutrient supply. The variability in plant tissue nutrient concentrations appears to be highly conditioned by taxonomic (mostly species) effects. The significant role that other attributes of the surrounding environment may have in modifying the degree of taxonomic dependence on plant nutrient concentration is yet to be tested with a broader characterisation of plant life forms (bryophytes, helophytes, hydrophytes), so as to investigate implications for ecosystem processes. Plant samples (378) were collected across 65 sites spanning a wide range of aquatic habitats (lotic and lentic) and biophysical zones (floodplain, glacial terraces, mountains) located in NE Scotland. Significant differences in plant tissues N, P and the N:P were found after grouping sampling sites by either habitat or biophysical zones; the latter even after removing the largest taxonomic effect. The range in plant tissue N and P was relatively wide within habitats and zones, reflecting the high species diversity of the studied area. As a group, bryophytes had smaller N and P concentrations, and consequently wider biomass C:N and C:P ratios, a situation which may impose constraints on the flow of energy through food-webs of the mountain and bog areas where they dominate. 相似文献
997.
Harieth Hellar-Kihampa Sanja Potgieter-Vermaak Katleen Van Meel Giuliana Gatto Rotondo Michael Kishimba Réne Van Grieken 《毒物与环境化学》2013,95(3):525-544
River-bed sediments from the Pangani basin, Tanzania, were characterized for elemental compositions, following contamination risks from rapid expansions of human activities in the area. Samples were collected during two individual seasons and analyzed by high-polarizing beam energy dispersive X-ray fluorescence (EDXRF) for eight major and 14 trace elements. Evaluation of enrichment factors (EFs) was used to investigate the elemental flux and assess the contributions of natural and anthropogenic influences. The abundances of the major elements followed the order Si?>?Al?>?Fe?>?Ca?>?K?>?Ti?>?Mn?>?P, similar to that of the upper earth's crust, and were generally from the weathering of the bed-rock. The high concentrations of typical anthropogenic trace-elements (Cr?160?mg?kg?1, V?85?mg?kg?1, Ni?60?mg?kg?1, Cu?87?mg?kg?1, La?90?mg?kg?1) coupled with high EFs (>2) in some locations indicated contamination associated with agricultural and industrial activities. Factor analysis extracted five principal components that contributed to 96.0% of the total observed variance. The results indicated that river-bed sediments of the Pangani basin were influenced to a larger extent by lithogenic sources than anthropogenic impacts. 相似文献
998.
999.
1000.
以猛炸药TNT为最终目标降解物,采用响应曲面分析方法(RSM ),探讨紫外光光照时间、电解电流、溶液 pH 三者交互作用对 TNT 废液降解处理效果的影响,并对工艺参数进行优化。结果表明:试验因子与评价指标之间的关系符合二次方程模型;UV/TiO2协同交变脉冲电流对 TNT 废液处理最优工艺条件是:紫外光光照时间2.5 h(波长366~380 nm ,催化剂为 TiO2)、电解电流75 A(脉冲峰值电流)、溶液 pH 3.7,在此工艺条件下,TNT 废液的 COD 去除率可达81.34%。 相似文献