全文获取类型
收费全文 | 1643篇 |
免费 | 469篇 |
国内免费 | 157篇 |
专业分类
安全科学 | 111篇 |
废物处理 | 87篇 |
环保管理 | 136篇 |
综合类 | 875篇 |
基础理论 | 301篇 |
污染及防治 | 604篇 |
评价与监测 | 43篇 |
社会与环境 | 44篇 |
灾害及防治 | 68篇 |
出版年
2024年 | 17篇 |
2023年 | 42篇 |
2022年 | 78篇 |
2021年 | 62篇 |
2020年 | 40篇 |
2019年 | 34篇 |
2018年 | 51篇 |
2017年 | 74篇 |
2016年 | 92篇 |
2015年 | 89篇 |
2014年 | 121篇 |
2013年 | 144篇 |
2012年 | 145篇 |
2011年 | 112篇 |
2010年 | 108篇 |
2009年 | 107篇 |
2008年 | 117篇 |
2007年 | 100篇 |
2006年 | 86篇 |
2005年 | 74篇 |
2004年 | 32篇 |
2003年 | 58篇 |
2002年 | 55篇 |
2001年 | 48篇 |
2000年 | 44篇 |
1999年 | 58篇 |
1998年 | 50篇 |
1997年 | 41篇 |
1996年 | 39篇 |
1995年 | 37篇 |
1994年 | 22篇 |
1993年 | 25篇 |
1992年 | 20篇 |
1991年 | 13篇 |
1990年 | 5篇 |
1989年 | 7篇 |
1988年 | 11篇 |
1987年 | 1篇 |
1986年 | 5篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1982年 | 2篇 |
1981年 | 1篇 |
排序方式: 共有2269条查询结果,搜索用时 0 毫秒
321.
322.
Pinpin Lu Xiaojian Zhang Chiqian Zhang Zhangbin Niu Shuguang Xie Chao Chen 《环境科学学报(英文版)》2014,26(2):323-331
This study investigated the bacterial regrowth in drinking water distribution systems receiving finished water from an advanced drinking water treatment plant in one city in southem China. Thirteen nodes in two water supply zones with different aged pipelines were selected to monitor water temperature, dissolved oxygen (DO), chloramine residual, assimilable organic carbon (AOC), and heterotrophic plate counts (HPC). Regression and principal component analyses indicated that HPC had a strong correlation with chloramine residual. Based on Chick-Watson's Law and the Monod equation, biostability curves under different conditions were developed to achieve the goal of HPC 100 CFU/mL. The biostability curves could interpret the scenario under various AOC concentrations and predict the required chloramine residual concentration under the condition of high AOC level. The simulation was also carded out to predict the scenario with a stricter HPC goal (≤50 CFU/mL) and determine the required chloramine residual. The biological regrowth control strategy was assessed using biostability curve analysis. The results indicated that maintaining high chloramine residual concentration was the most practical way to achieve the goal of HPC ≤ 100 CFU/mL. Biostability curves could be a very useful tool for biostability control in distribution systems. This work could provide some new insights towards biostability control in real distribution systems. 相似文献
323.
324.
三界谷来地区主要出露中、新生代火山岩。进行 1/5万区域地质调查时,采用火山活动旋回-火山构造-火山地层-岩相、岩性-体化思路,按照同旋回火山机构或火山喷发区为单元,确定岩石地层单位和填图单元。火山岩划分为九种岩相类型,建立了两个岩相模式和一个三相一体成因模式。根据火山岩浆作用的旋回性及其产物与火山构造形迹时、空、成因一致性原理,将中、新生代火山岩浆作用分为四个火山活动旋回,圈定了相应的火山机构或火山喷发中心,建立了竹田头复活破火山演化模式。新生代玄武岩中发现二辉斜长麻粒岩等深源包体,为研究区域深部地质作用过程提供了证据。侵入岩按岩石谱系单元划分了七个岩石单元一个超单元,将侵入岩-潜火山岩-火山岩作为岩浆作用整体研究,为正确阐明岩浆作用及其演化规律奠定了基础。区域线型构造发育,与环形火山构造组合,形成火山岩区特有的线一环构造格局。中上元古界陈蔡群变质岩划分为上、下两个岩组,探讨了变质岩的原岩性质及其形成的大地构造环境。 相似文献
325.
326.
Fengchun Xie Tingting Cai Yang Ma Haiying Li Chuncheng Li Zhiyuan Huang Gaoqing Yuan 《Journal of Cleaner Production》2009,17(16):1494-1498
The paper presents a novel cleaner process for metal recovery from the Printed Circuit Board (PCB) waste sludge by assistance of ultrasound. The process can effectively recover heavy metals at low cost with high separation and recovery efficiency, produce high quality products and also achieve zero waste discharge with operation at industrial scale. With the PCB waste sludge containing (wet content) 3.14–4.85% copper and 3.71–4.23% iron, copper recovery efficiency of 95.2–97.5% and iron recovery efficiency of 97.1–98.5% were achieved, while the purity of copper sulfate produced by the process was 98.0% and the produced ferric chloride had a satisfied quality for using as a coagulant material for the plant on-site wastewater treatment. The process had been successfully scaled up to the industrial scaled applications in a heavy metal recovery plant in city of Huizhou, China for more than two years. The novel cleaner heavy metal recovery process has a great prospect on the applications of resources recovery and environmental protection practices. 相似文献
327.
Chengdu is a megacity in the southwest of China with high ozone (O3) mixing ratio. Observation of volatile organic compounds (VOCs), NO2 and O3 with high temporal resolution was conducted in Chengdu to investigate the chemical processes and causes of high O3 levels. The hourly mixing ratios of VOCs, NO2, and O3 were monitored by an online system from 28 August to 7 October, 2016. According to meteorological conditions, Chengdu, with relative warm weather and low wind speed, is favorable to O3 formation. Part of the O3 in Chengdu may be transported from the downtown area. In O3 episodes, the average mixing ratios of NO2 and O3 were 20.20?ppbv and 47.95?ppbv, respectively. In non-O3 episodes, the average mixing ratios of NO2 and O3 were 16.38?ppbv and 35.15?ppbv, respectively. The average mixing ratio of total VOCs (TVOCs) was 40.29?ppbv in non-O3 episodes, which was lower than that in O3 episodes (53.19?ppbv). Alkenes comprised 51.7% of the total O3 formation potential (OFP) in Chengdu, followed by aromatics which accounted for 24.2%. Ethylene, trans-pentene, propene, and BTEX (benzene, ethylbenzene, toluene, m/p-xylene, o-xylene) were also major contributors to the OFP in Chengdu. In O3 episodes, intensive secondary formations were observed during the campaign. Oxygenated VOCs (OVOCs), such as acetone, Methylethylketone (MEK), and Methylvinylketone (MVK) were abundant. Isoprene rapidly converted to MVK and Methacrolein (MACR) during O3 episodes. Acetone was mainly the oxidant of C3-C5 hydrocarbons. 相似文献
328.
329.
Yu Yan Xuesong Wang Zhengchao Huang Kun Qu Wenbin Shi Zimu Peng Limin Zeng Shaodong Xie Yuanhang Zhang 《环境科学学报(英文版)》2023,35(5):143-157
The coastal eco-city of Fuzhou in Southeastern China has experienced severe ozone (O3)episodes at times in recent years.In this study,three typical synoptic circulations types (CTs)that influenced more than 80%of O3polluted days in Fuzhou during 2014-2019 were identified using a subjective approach.The characteristics of meteorological conditions linked to photochemical formation and transport of O3under the three CTs were summarized.Comprehensive Air Quality Mod... 相似文献
330.