全文获取类型
收费全文 | 4817篇 |
免费 | 490篇 |
国内免费 | 2115篇 |
专业分类
安全科学 | 459篇 |
废物处理 | 201篇 |
环保管理 | 393篇 |
综合类 | 3493篇 |
基础理论 | 890篇 |
污染及防治 | 1199篇 |
评价与监测 | 295篇 |
社会与环境 | 306篇 |
灾害及防治 | 186篇 |
出版年
2024年 | 19篇 |
2023年 | 114篇 |
2022年 | 265篇 |
2021年 | 280篇 |
2020年 | 289篇 |
2019年 | 213篇 |
2018年 | 220篇 |
2017年 | 283篇 |
2016年 | 232篇 |
2015年 | 335篇 |
2014年 | 343篇 |
2013年 | 490篇 |
2012年 | 458篇 |
2011年 | 486篇 |
2010年 | 396篇 |
2009年 | 383篇 |
2008年 | 390篇 |
2007年 | 388篇 |
2006年 | 345篇 |
2005年 | 208篇 |
2004年 | 196篇 |
2003年 | 169篇 |
2002年 | 157篇 |
2001年 | 127篇 |
2000年 | 123篇 |
1999年 | 85篇 |
1998年 | 83篇 |
1997年 | 68篇 |
1996年 | 59篇 |
1995年 | 54篇 |
1994年 | 41篇 |
1993年 | 33篇 |
1992年 | 26篇 |
1991年 | 22篇 |
1990年 | 10篇 |
1989年 | 10篇 |
1988年 | 7篇 |
1987年 | 7篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1981年 | 1篇 |
排序方式: 共有7422条查询结果,搜索用时 453 毫秒
231.
232.
233.
文章初步研究了水华蓝藻生物质对重金属离子Cu2+的吸附特性,包括生物吸附动力学和吸附等温线。生物吸附动力学结果表明,Cu2+的生物吸附可分为两个阶段,第一个阶段能较快地达到平衡,而之后的阶段进行缓慢。透析袋处理的蓝藻生物质在不同pH(3,4,5,6)的铜离子溶液条件下,吸附效率依次为62.4%,78.1%,71.2%,60.35%,吸附最大值为7.81 mg/g。水华蓝藻生物质对Cu2+的生物吸附平衡等温线可以用Freundlich模型精确拟合。水华蓝藻生物质在处理低浓度的含Cu2+废水方面有潜力。湖泊富营养化的优势在于产生低成本的、大量的、可收集的水华,这说明自然环境中的藻类资源如蓝藻水华生物质,可能作为商业中使用的生物吸附剂。 相似文献
234.
235.
针对目前廊坊市环保产业发展现状及存在的问题,以及今后一段时间内环保产品市场的需求进行了分析,并提出了一些建议。 相似文献
236.
通过分析鄂尔多斯市2007—2010年东胜区道路交通噪声污染现状,指出存在的主要问题,提出了相应的污染控制及防治措施,为有效改善城市道路交通噪声污染提供科学依据。 相似文献
237.
Aquatic fungi are common in various aqueous environments and play potentially crucial roles in nutrient and carbon cycling as well as interacting with other organisms. Species of Aspergillus are the most common fungi that occur in water. The present study was undertaken to elucidate the efficacy of two coagulants, aluminum sulfate and ferric chloride, used at different concentrations to treat drinking water, in removing Aspergillusflavus, as well as testing three different filtration media: sand, activated carbon, and ceramic granules, for their removal of fungi from water. The results revealed that both coagulants were effective in removing fungi and decreasing the turbidity of drinking water, and turbidity decreased with increasing coagulant concentration. Also, at the highest concentration of the coagulants, A. flavus was decreased by 99.6% in the treated water. Among ceramic granules, activated carbon, and sand used as media for water filtration, the sand and activated carbon filters were more effective in removing A.flavus than ceramic granules while simultaneously decreasing the turbidity levels in the test water samples. Post-treatment total organic carbon (TOC) and total nitrogen (TN) concentrations in the experimental water did not decrease; on the contrary, TN concentrations increased with the increasing dosage of coagulants. The filtration process had no effect in reducing TOC and TN in tested water. 相似文献
238.
Carbonyl emissions from heavy-duty diesel vehicle exhaust in China and the contribution to ozone formation potential 总被引:6,自引:0,他引:6
Fifteen heavy-duty diesel vehicles were tested on chassis dynamometer by using typical heavy duty driving cycle and fuel economy cycle. The air from the exhaust was sampled by 2,4- dinitrophenyhydrazine cartridge and 23 carbonyl compounds were analyzed by high performance liquid chromatography. The average emission factor of carbonyls was 97.2 mg/km, higher than that of light-duty diesel vehicles and gasoline-powered vehicles. Formaldehyde, acetaldehyde, acetone and propionaidehyde were the species with the highest emission factors. Main influencing factors for carbonyl emissions were vehicle type, average speed and regulated emission standard, and the impact of vehicle loading was not evident in this study. National emission of carbonyls from diesel vehicles exhaust was calculated for China, 2011, based on both vehicle miles traveled and fuel consumption. Carbonyl emission of diesel vehicle was estimated to be 45.8 Gg, and was comparable to gasolinepowered vehicles (58.4 Gg). The emissions of formaldehyde, acetaldehyde and acetone were 12.6, 6.9, 3.8 Gg, respectively. The ozone formation potential of carbonyls from diesel vehicles exhaust was 537 mg O3/km, higher than 497 mg O3/km of none-methane hydrocarbons emitted from diesel vehicles. 相似文献
239.
Taste and odor (T/O) in drinking water often cause consumer complaints and are thus regulated in many countries. However, people in different regions may exhibit different sensitivities toward WO. This study proposed a method to determine the regional drinking water odorant regulation goals (ORGs) based on the odor sensitivity distribution of the local population. The distribution of odor sensitivity to 2-methylisobomeol (2-MIB) by the local population in Beijing, China was revealed by using a normal distribution function/model to describe the odor complaint response to a 2-MIB episode in 2005, and a 2-MIB concentration of 12.9 ng/L and FPA (flavor profile analysis) intensity of 2.5 was found to be the critical point to cause odor complaints. Thus the Beijing ORG for 2-MIB was determined to be 12.9 ng/L. Based on the assumption that the local FPA panel can represent the local population in terms of sensitivity to odor, and that the critical FPA intensity causing odor complaints was 2.5, this study tried to determine the ORGs for seven other cities of China by performing FPA tests using an FPA panel from the corresponding city. ORG values between 12.9 and 31.6 ng/L were determined, showing that a unified ORG may not be suitable for drinking water odor regulations. This study presents a novel approach for setting drinking water odor regulations. 相似文献
240.
Characteristics of atmospheric particles and heavy metals in winter in Chang-Zhu-Tan city clusters, China 总被引:1,自引:0,他引:1
Kai Zhang Fahe Chai Zilong Zheng Qing Yang Juansheng Li Jing Wang Yujie Zhang 《环境科学学报(英文版)》2014,26(1):147-153
To understand the pollution characteristics of atmospheric particles and heavy metals in winter in Chang-Zhu-Tan city clusters, China, total suspended particulate(TSP) and PM10samples were collected in cities of Changsha, Zhuzhou and Xiangtan from December 2011 to January 2012, and heavy metals of Cd, Pb, Cr, and As were analyzed. It shows that the average TSP concentration in Changsha, Zhuzhou and Xiangtan were(183 ± 73),(201 ± 84) and(190 ± 66) μg/m3respectively, and the average PM10 were(171 ± 82),(178 ± 65) and(179 ± 55) μg/m3respectively. The lowest TSP and PM10concentrations occurred at the background Shaping site of Changsha. The average ratio of ρ(PM10)/ρ(TSP) was 91.9%, ranging from 81.3% to 98.9%. Concerning heavy metals, in TSP samples, the concentration of Cr, As, Cd and Pb were 28.8–56.5, 18.1–76.3, 3.9–26.1 and 148.0–460.9 ng/m3, respectively, while in PM10samples, were 16.4–42.1, 15.5–67.9, 3.3–22.2 and 127.9–389.3 ng/m3, respectively. The enrichment factor of Cd was the highest, followed by Pb and As, while that of Cr was the lowest. 相似文献