全文获取类型
收费全文 | 4381篇 |
免费 | 199篇 |
国内免费 | 1736篇 |
专业分类
安全科学 | 308篇 |
废物处理 | 281篇 |
环保管理 | 338篇 |
综合类 | 2440篇 |
基础理论 | 739篇 |
污染及防治 | 1689篇 |
评价与监测 | 160篇 |
社会与环境 | 152篇 |
灾害及防治 | 209篇 |
出版年
2024年 | 9篇 |
2023年 | 69篇 |
2022年 | 231篇 |
2021年 | 179篇 |
2020年 | 126篇 |
2019年 | 144篇 |
2018年 | 150篇 |
2017年 | 230篇 |
2016年 | 279篇 |
2015年 | 295篇 |
2014年 | 317篇 |
2013年 | 478篇 |
2012年 | 358篇 |
2011年 | 433篇 |
2010年 | 275篇 |
2009年 | 268篇 |
2008年 | 346篇 |
2007年 | 270篇 |
2006年 | 256篇 |
2005年 | 165篇 |
2004年 | 122篇 |
2003年 | 169篇 |
2002年 | 133篇 |
2001年 | 103篇 |
2000年 | 128篇 |
1999年 | 112篇 |
1998年 | 102篇 |
1997年 | 114篇 |
1996年 | 82篇 |
1995年 | 86篇 |
1994年 | 61篇 |
1993年 | 61篇 |
1992年 | 56篇 |
1991年 | 44篇 |
1990年 | 27篇 |
1989年 | 9篇 |
1988年 | 6篇 |
1987年 | 6篇 |
1986年 | 5篇 |
1985年 | 2篇 |
1984年 | 3篇 |
1983年 | 3篇 |
1982年 | 3篇 |
1981年 | 1篇 |
排序方式: 共有6316条查询结果,搜索用时 0 毫秒
651.
Ci Zhang Xiaohui Lu Jinghao Zhai Hong Chen Xin Yang Qi Zhang Qianbiao Zhao Qingyan Fu Fei Sh Jing Jin 《环境科学学报(英文版)》2018,30(10):118-132
To investigate formation mechanisms of secondary organic carbon(SOC) in Eastern China,measurements were conducted in an urban site in Shanghai in the summer of 2015. A period of high O_3 concentrations(daily peak 120 ppb) was observed, during which daily maximum SOC concentrations exceeding 9.0 μg/(C·m~3). Diurnal variations of SOC concentration and SOC/organic carbon(OC) ratio exhibited both daytime and nighttime peaks. The SOC concentrations correlated well with O_x(= O_3+ NO_2) and relative humidity in the daytime and nighttime, respectively, suggesting that secondary organic aerosol formation in Shanghai is driven by both photochemical production and aqueous phase reactions. Single particle mass spectrometry was used to examine the formation pathways of SOC. Along with the daytime increase of SOC, the number fraction of elemental carbon(EC) particles coated with OC quickly increased from 38.1% to 61.9% in the size range of 250–2000 nm, which was likely due to gas-to-particle partitioning of photochemically generated semi-volatile organic compounds onto EC particles. In the nighttime, particles rich in OC components were highly hygroscopic, and number fraction of these particles correlated well with relative humidity and SOC/OC nocturnal peaks. Meanwhile, as an aqueous-phase SOC tracer, particles that contained oxalate-Fe(III) complex also peaked at night. These observations suggested that aqueous-phase processes had an important contribution to the SOC nighttime formation. The influence of aerosol acidity on SOC formation was studied by both bulk and single particle level measurements, suggesting that the aqueous-phase formation of SOC was enhanced by particle acidity. 相似文献
652.
采用直接投加复合微生物菌剂原位修复深圳湾污染水体,去除水体中的有机物、氮和磷等污染物,15天检测分析微生物处理对水体溶解氧(DO)、氨态氮(NH4-N)、悬浮物(SS)、总氮(TN)、总磷(TP)变化的影响。结果表明:采用微生物技术修复深圳湾近海污染水环境具有显著效果,试验期间水体中DO明显提高,最佳复配硝化茵(B2)与枯草芽孢杆菌(B6)对NH4-N降低了53.9%,悬浮物(ss)降低了56.9%,总氮(TN)降低52.1%,总磷(TP)降低57.6%。有害弧菌单一菌落数降低了64.9% 相似文献
653.
An online monitoring system for atmospheric nitrous acid (HONO) based on stripping coil and ion chromatography 总被引:1,自引:0,他引:1
Peng Cheng Yafang Cheng Keding Lu Hang Su Qiang Yang Yikan Zou Yanran Zhao Huabing Dong Limin Zeng Yuanhang Zhang 《环境科学学报(英文版)》2013,25(5):895-907
A new instrument for measuring atmospheric nitrous acid(HONO) was developed,consisting of a double-wall glass stripping coil sampler coupled with ion chromatography(SC-IC).SC-IC is featured by small size(50 × 35 × 25 cm) and modular construction,including three independent parts:the sampling unit,the transfer and supporting unit,and the detection unit.High collection efficiency(> 99%) was achieved with 25 μmol/L Na2CO3 as absorption solution even in the presence of highly acidic compounds.This instrument has a detection limit of 8 pptv at 15 min time resolution,with a measurement uncertainty of 7%.Potential interferences from NOx,NO2+SO2,NO2+VOCs,HONO+O3,HNO3,peroxyacetyl nitrite(PAN) and particle nitrite were quantified in laboratory studies and were found to be insignificant under typical atmospheric conditions.Within the framework of the 3C-STAR project,inter-comparison between the SC-IC and LOPAP(long path liquid absorption photometer) was conducted at a rural site in the Pearl River Delta.Good agreement was achieved between the two instruments over three weeks.Both instruments determined a clear diurnal profile of ambient HONO concentrations from 0.1 to 2.5 ppbv.However,deviations were found for low ambient HONO concentrations(i.e.< 0.3 ppbv),which cannot be explained by previous investigated interference species.To accurately determine the HONO budget under illuminated conditions,more intercomparison of HONO measurement techniques is still needed in future studies,especially at low HONO concentrations. 相似文献
654.
赵胜利 《安全.健康和环境》2013,13(2):5-7
系统分析了中国石化河南油田分公司近年来安全典型问题、险肇事件、事故的分布及产生原因,提出了针对性的应对措施。 相似文献
655.
城市地区突发自然灾害常常会对给水排水设施造成不利影响。飓风“桑迪”于2012年10月29日登陆美国,多个东部城市出现大面积停电,缺水,交通中断以及罕见的城市内涝,造成重大人员伤亡和巨额财产损失,严重地影响了当地人们正常的生产和生活。从飓风“桑迪”对美国城市给水和排水系统造成的巨大破坏出发,并结合当地政府采取的紧急应对措施展开讨论,总结其中的经验教训及启示。 相似文献
656.
针对难降解的偶氮染料废水,在以磺化酞菁钴CoPcS为催化剂的情况下,实验研究了催化剂浓度、光照强度、温度、甲基橙初始浓度对降解效果的影响。结果表明:当催化剂CoPcS浓度0.2 g/L,光照强度250 W,温度40℃,pH=1,甲基橙10 mg/L时,在30 min内,甲基橙的降解率高达98.06%。最佳试验条件:pH值为1,催化剂浓度0.2 g/L,甲基橙初始浓度15 mg/L,温度40℃。影响因素主次为:pH值〉甲基橙初始浓度〉温度〉催化剂浓度,该反应符合零级反应动力学方程。 相似文献
657.
Effect of C/N ratio, aeration rate and moisture content on ammonia and greenhouse gas emission during the composting 总被引:3,自引:0,他引:3
Gaseous emission (N2O, CH4 and NH3) from composting can be an important source of anthropogenic greenhouse gas and air pollution. A laboratory scale orthogonal experiment was conducted to estimate the effects of C/N ratio, aeration rate and initial moisture content on gaseous emission during the composting of pig faeces from Chinese Ganqinfen system. The results showed that about 23.9% to 45.6% of total organic carbon (TOC) was lost in the form of CO2 and 0.8% to 7.5% of TOC emitted as CH4. Most of the nitrogen was lost in the form of NH3, which account for 9.6% to 32.4% of initial nitrogen. N2O was also an important way of nitrogen losses and 1.5% to 7.3% of initial total nitrogen was lost as it. Statistic analysis showed that the aeration rate is the most important factor which could affect the NH3 (p = 0.0189), CH4 (p = 0.0113) and N2O (p = 0.0493) emissions significantly. Higher aeration rates reduce the CH4 emission but increase the NH3 and N2O losses. C/N ratio could affect the NH3 (p = 0.0442) and CH4 (p = 0.0246) emissions significantly, but not the N2O. Lower C/N ratio caused higher NH3 and CH4 emissions. The initial moisture content can not influence the gaseous emission significantly. Most treatments were matured after 37 days, except a trial with high moisture content and a low C/N ratio. 相似文献
658.
Binghui Zheng Xiaolei Liu Rui Guo Qing Fu Xingru Zhao Shanjun Wang Sheng Chang Xing Wang Mengjiao Geng Guang Yang 《环境科学学报(英文版)》2017,29(11):97-109
In this work, a method was developed and optimized for the analysis of polyfluoroalkyl and/or perfluoroalkyl substances(PFASs) content in surface water and sediment samples with high instrumental response and good separation. Surface water and sediment samples were collected from the Yangtze River Delta(YRD) to analyze the distribution characteristics of perfluoroalkyl carboxylic acids(PFCAs), perfluoroalkane sulfonic acids(PFSAs), perfluoroalkyl phosphonic acids(PFPAs), perfluoroalkyl phosphinic acids(PFPiAs), and polyfluoroalkyl phosphoric acid diesters(di PAPs). The results showed that the total concentrations of PFCAs and PFSAs in YRD varied from 31 to 902 ng/L. PFCAs(≥ 11 carbons) and PFSAs(≥ 10 carbons atoms) were not detected in any surface water samples. The mean concentrations of all PFCAs and PFSAs in surface water from the sampling areas decreased in the following order:Yangtze river(191 ng/L) ≈ Taihu lake(189 ng/L) Huangpu river(122 ng/L) ≈ Qiantang river(120 ng/L) Jiaxing urban river(100 ng/L). Strong significant(p 0.05) correlations between the concentrations of many of the compounds were found in the sampling areas, suggesting a common source for these compounds. Only perfluorooctanoic acid(PFOA) was observed in all sediment samples, at concentrations varying from 0.02 to 1.35 ng/g. Finally, detection rates of two di PAPs were only 8% and 10%, respectively and the concentration of di PAPs was two to three times lower compared to PFCAs and PFSAs. 相似文献
659.
针对新建铁路专用线沿线的环境特征,提出了铁路专用线声环境影响评价的程序、内容和方法。在目前缺乏新建铁路噪声预测模式的情况下,提出了应对铁路边界噪声、不同距离处的铁路噪声、敏感点噪声、鸣笛噪声进行预测,并以某铁路专用线声环境影响评价为例,对上述四种噪声进行了预测,通过预测得到铁路两侧的声环境状况,并以此为依据提出了铁路噪声的防治对策,以保证铁路专用线沿线声环境质量。 相似文献
660.
以粉煤灰、石灰为主要原料,经混合料制备、成型、蒸压、低温焙烧、粉磨工艺制备的新型水泥既具有普通水泥的胶凝特性,又同时具有水化热低、后期强度高的特点,对过程工艺参数、物料配比对新型水泥的质量影响进行了研究,该工艺有望为粉煤灰在水泥行业的规模化利用提供技术支持。 相似文献