全文获取类型
收费全文 | 2332篇 |
免费 | 304篇 |
国内免费 | 949篇 |
专业分类
安全科学 | 258篇 |
废物处理 | 104篇 |
环保管理 | 198篇 |
综合类 | 1804篇 |
基础理论 | 408篇 |
污染及防治 | 455篇 |
评价与监测 | 153篇 |
社会与环境 | 117篇 |
灾害及防治 | 88篇 |
出版年
2024年 | 21篇 |
2023年 | 69篇 |
2022年 | 181篇 |
2021年 | 193篇 |
2020年 | 222篇 |
2019年 | 123篇 |
2018年 | 142篇 |
2017年 | 169篇 |
2016年 | 140篇 |
2015年 | 185篇 |
2014年 | 186篇 |
2013年 | 210篇 |
2012年 | 220篇 |
2011年 | 203篇 |
2010年 | 175篇 |
2009年 | 155篇 |
2008年 | 147篇 |
2007年 | 109篇 |
2006年 | 112篇 |
2005年 | 83篇 |
2004年 | 58篇 |
2003年 | 77篇 |
2002年 | 53篇 |
2001年 | 51篇 |
2000年 | 54篇 |
1999年 | 48篇 |
1998年 | 28篇 |
1997年 | 34篇 |
1996年 | 26篇 |
1995年 | 23篇 |
1994年 | 20篇 |
1993年 | 15篇 |
1992年 | 19篇 |
1991年 | 8篇 |
1990年 | 6篇 |
1989年 | 4篇 |
1988年 | 2篇 |
1987年 | 4篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1984年 | 3篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1981年 | 1篇 |
排序方式: 共有3585条查询结果,搜索用时 31 毫秒
921.
Zhe Liu Yong Geng Pan Zhang Huijuan Dong Zuoxi Liu 《Environmental science and pollution research international》2014,21(17):10243-10253
In China, local governments of many areas prefer to give priority to the development of heavy industrial clusters in pursuit of high value of gross domestic production (GDP) growth to get political achievements, which usually results in higher costs from ecological degradation and environmental pollution. Therefore, effective methods and reasonable evaluation system are urgently needed to evaluate the overall efficiency of industrial clusters. Emergy methods links economic and ecological systems together, which can evaluate the contribution of ecological products and services as well as the load placed on environmental systems. This method has been successfully applied in many case studies of ecosystem but seldom in industrial clusters. This study applied the methodology of emergy analysis to perform the efficiency of industrial clusters through a series of emergy-based indices as well as the proposed indicators. A case study of Shenyang Economic Technological Development Area (SETDA) was investigated to show the emergy method’s practical potential to evaluate industrial clusters to inform environmental policy making. The results of our study showed that the industrial cluster of electric equipment and electronic manufacturing produced the most economic value and had the highest efficiency of energy utilization among the four industrial clusters. However, the sustainability index of the industrial cluster of food and beverage processing was better than the other industrial clusters. 相似文献
922.
Ying Su Xiulin Wang Keqiang Li Shengkang Liang Guodong Qian Hong Jin Aiquan Dai 《Environmental science and pollution research international》2014,21(17):10067-10082
At present, the monitoring network of China cannot provide sufficient data to estimate land-based pollutant loads that enter the sea, and estimation methods are imprecisely used. In this study, the selection of monitoring stations, monitoring frequency, and pollutant load estimation methods was studied in Qingdao City, a typical coastal city in China, taken as an example. Land-based pollutant loads from Qingdao were estimated, and load distribution, density, and composition were analyzed to identify the key pollution source regions (SRs) that need to be monitored and controlled. Results show that the administrative land area of Qingdao can be divided into 25 sea-sink source regions (SSRs). A total of 14 more rivers and 62 industrial enterprises should be monitored to determine the comprehensive pollutant loads of the city. Furthermore, the monitoring frequency of rivers should not be less than three times/year; a monitoring frequency of five or more times is preferable. The findings on pollutant load estimation with the use of different estimation methods substantially vary; estimation results with the use of ratio-based methods were 10 and 22 % higher than those with the use of monitoring-based methods in terms of chemical oxygen demand (COD) and total nitrogen (TN), respectively. None-point sources contributed the majority of the pollutant loads at about 70 % of the total COD and 60 % of the total TN. 相似文献
923.
通过滇池流域1992~2010年城市扩张研究,发现城市建设用地增长主要表现为两种形态:一是边缘增长,表现为城市建成区范围不断扩大;二是道路影响增长,表现为环滇池道路两边新城市单元的产生。基于滇池流域城市扩展变化遥感数据,对SLEUTH城市扩展模型进行校准,模拟30 a间(2010~2040年)3种预案下的昆明城市扩展变化过程,并对模拟结果进行分析。3种模拟预测结果表明:任意管理预案下城市无序扩张,大量农林用地被城市建设用地占用,人口和城市建设用地呈现爆发式增长,滇池沿岸被城市包围,会对滇池水环境产生极大的压力;土地总量控制预案下城市的发展完全按照城市总体规划内容进行,没有考虑城市实际发展过程中的经济、人口等因素影响,没有达到滇池生态环境保护的需要;生态环境保护预案下,能相对有效控制建设用地,减少对农林用地、湿地的侵占,利于滇池环境保护。预测发现,从滇池流域水资源现状来看,即使实施了环境保护模式,人均水资源量仍处于“严重短缺”状态。需要通过调整昆明城镇体系和产业布局,降低城市首位度和人口;采取更为严格的空间管制策略,有效控制城市空间扩展,以减少对滇池流域的环境压力 相似文献
924.
Chlorpyrifos is one of the organophosphate pesticides widely used in agricultural practices throughout world. It has resulted in a series of toxicological and environmental problems, such as impacts on many non-target aquatic species, including fish. In the present study, toxic effects of chlorpyrifos on lysozyme activities, contents of IgM and complement C3, and the expressions of IgM and complement C3 at mRNA level in common carp were evaluated by acute exposure of 15 (1/10 LC50) or 75 μg L−1 (1/2 LC50) of chlorpyrifos for 7 d. The results of acute toxicity tests showed that the 96 h-LC50 of chlorpyrifos for common carp was determined to be 149 μg L−1. We also found that chlorpyrifos promoted lysozyme activities at the earlier stages of exposure but inhibited it at the late stages in the serum, hepatopancreas, and spleen of common carp. Furthermore, it was observed that chlorpyrifos-exposure decreased IgM contents in fish serum and spleen while increased it in kidney. No obvious change was found in the contents of complement C3 in fish spleen, while a slight increase of complement C3 was observed in fish serum and kidney after 1 d of chlorpyrifos-exposure. In addition, the results of quantitative real-time PCR showed that IgM and complement C3 expressions were up-regulated at the earlier stage of exposure but down-regulated at later stage. Our results indicate that chlorpyrifos causes immunotoxicity to common carp. 相似文献
925.
初步研制的汞蒸汽被动式检气管是建立在气体分子扩散和化学吸收原理基础上的,新制备的碘化亚铜沉淀和乙醇、甘油、硝酸混合、研碎,伴入经活化的层析硅胶,填充到检气管中,当汞蒸气进入管内时,发生显色反应,检气管显色长度的平方与汞蒸汽浓度及采样时间的乘积成线性关系,检测下限为0.001ug/mL(1h)。该法集采样与分析于一体,结构简单,不需动力,便于携带,操作方便,实验室模拟运用,其灵敏度和标准偏差令人满意。 相似文献
926.
小海湾沉积物中有机氯农药的浓度水平和分布特征 总被引:1,自引:0,他引:1
用GC/ECD法测定了小海地区上下层沉积物中17种有机氯农药的浓度水平和分布特征.结果表明:小海湾上层OCPs含量明显高于下层,且大致呈现由内湾至人海口先增后减的分布特征,入海口处含量的突增可能与泻湖的特殊地理构造有关;DDTs类有机氯农药在内湾的降解程度明显强于人海口地区,α-HCH/γ-HCH比值均处于0~4之间,认为沉积物中HCHs来源于林丹和工业HCH;DDTs含量水平低于厦门湾海域、澳门河口等经济发达地区,高于泉州湾、莱州湾等半敞口型海湾;HCHs含量远低于厦门湾、泉州湾及莱州湾. 相似文献
927.
Assessment of groundwater vulnerability in the Yinchuan Plain,Northwest China using OREADIC 总被引:13,自引:0,他引:13
Groundwater vulnerability assessments provide a measure of the sensitivity of groundwater quality to an imposed contaminant
load and are globally recognized as an essential element of all aquifer management and protection plans. In this paper, the
vulnerability of groundwaters underlying the Yinchuan Plain of Northwest China is determined using OREADIC, a GIS-based assessment
tool that incorporates the key characteristics of the universally popular DRASTIC approach to vulnerability assessment but
has been modified to consider important additional hydrogeological factors that are specific to the region. The results show
that areas of high vulnerability are distributed mainly around Qingtongxia City, Wuzhong City, Lingwu City, and Yongning County
and are associated with high rates of aquifer recharge, shallow depths to the water table, and highly permeable aquifer materials.
The presence of elevated NO3− in the high vulnerability areas endorses the OREADIC approach. The vulnerability maps developed in this study have become
valuable tools for environmental planning in the region and will be used for predictive management of the groundwater resource. 相似文献
928.
应用荧光定量PCR技术和显微计数法对玄武湖蓝藻水华进行了长期监测,结果表明,荧光定量PCR法可同步监测蓝藻、微囊藻和有毒微囊藻的数量,及时准确反映玄武湖蓝藻水华优势种群微囊藻和有毒微囊藻的动态变化。与显微计数法相比,具有需要的样品量少、时效性强、检出下限较低、自动化程度高等优势,可有效地应用于蓝藻水华的监测。 相似文献
929.
以通榆河南段控制单元为研究区,利用现有的平原感潮河网区水量模型、面源污染负荷统计模型和水环境容量模型,估算研究区2010年污染物最大日负荷总量(TMDL),并进行负荷削减和分配研究。结果表明:研究区COD、氨氮(NH3-N)90%保证率(2004年)下的水环境容量分别为7.76万t,0.37万t;xCN2010年污染物入河量,COD、NH3-N的最大年负荷分别为1.99万t,0.28万t。在研究区涉及的各县市中,海安、姜堰、东台是负荷削减的重点区域;对于不同的污染源,城镇生活点源和农业面源是研究区污染物总量控制的关键。 相似文献
930.
Anthropogenic pollution and variability of manganese in alluvial sediments of the Yellow River,Ningxia, northwest China 总被引:9,自引:0,他引:9
Peiyue Li Hui Qian Ken W. F. Howard Jianhua Wu Xinsheng Lyu 《Environmental monitoring and assessment》2014,186(3):1385-1398
Heavy metal pollution of sediments is a global concern and can be a serious problem in heavily industrialized parts of the world. Pollution by manganese is particularly common due to its ubiquitous natural occurrence, ease of mobilization, and extensive association with industry. In Ningxia, China, manganese pollution of Yellow River alluvial sediments was assessed by comparing manganese concentrations in 35 sediment samples with background values derived from similar sediments obtained at sites considered remote from potential sources of contamination. Natural background values of manganese were found to range from 192 to 323 mg/kg for surface sediments, and from 220 to 325 and 283 to 394 mg/kg for subsurface sediments at depths of 45–50 and 95–100 cm, respectively. In the study area, manganese content ranged from 565 to 1,363 mg/kg, indicating anthropogenic pollution extending to a depth of at least 1 m in the study area. All 35 samples were found to exceed the threshold effect concentration (TEC) of 460 mg/kg, below which adverse effects on sediment-dwelling organisms are not expected to occur, and one sample (T12) was found to exceed the probable effect concentration (PEC) of 1,100 mg/kg. PEC defines the threshold above which adverse effects are likely to be observed. Variogram analysis of the surface sediment manganese data revealed adherence to a Gaussian model, and ordinary kriging was used to generate a manganese distribution map. Analysis of the high nugget effect ratio indicates high, small-scale variations that are consistent with potential emissions from an adjacent electrolytic manganese plant. 相似文献