全文获取类型
收费全文 | 162篇 |
免费 | 7篇 |
国内免费 | 25篇 |
专业分类
安全科学 | 11篇 |
废物处理 | 4篇 |
环保管理 | 13篇 |
综合类 | 77篇 |
基础理论 | 25篇 |
污染及防治 | 13篇 |
评价与监测 | 51篇 |
出版年
2022年 | 2篇 |
2021年 | 2篇 |
2019年 | 2篇 |
2018年 | 4篇 |
2017年 | 2篇 |
2016年 | 5篇 |
2015年 | 4篇 |
2014年 | 7篇 |
2013年 | 19篇 |
2012年 | 10篇 |
2011年 | 16篇 |
2010年 | 3篇 |
2009年 | 12篇 |
2008年 | 8篇 |
2007年 | 9篇 |
2006年 | 9篇 |
2005年 | 8篇 |
2004年 | 10篇 |
2003年 | 7篇 |
2002年 | 16篇 |
2001年 | 9篇 |
2000年 | 7篇 |
1999年 | 2篇 |
1998年 | 5篇 |
1997年 | 2篇 |
1996年 | 5篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1991年 | 1篇 |
1988年 | 1篇 |
1987年 | 2篇 |
排序方式: 共有194条查询结果,搜索用时 15 毫秒
161.
162.
163.
164.
165.
利用吹扫捕集测量水和废水中氯乙烯,其检出限低,为0.024μg/L,优于目前所用的《生活饮用水卫生规范》中推荐方法(1.0μ/L),结果准确,操作快捷方便,无溶剂污染,干扰少,更能满足环境样品痕量监测的要求。 相似文献
166.
建立了中心切割顶空气相色谱法测定复杂有机废水中苯系物的方法。该方法采用DB-1701色谱柱对样品进行初级分离,当目标组份出峰流出时切换至HP-INNOWAX柱进一步分离,避免了大量复杂基质对苯系物分析的干扰。该方法具有较好的准确度和精密度,苯系物的检测限可达到0.000 3~0.000 4 mg/L,采用外标法定量时,分析标准曲线的相关系数在0.999 8~0.999 9之间,苯系物回收率为86.8%~89.7%。 相似文献
167.
Volatile organic compounds (VOCs) are regulated aerial pollutants that have environmental and health concerns. Swine operations produce and emit a complex mixture of VOCs with a wide range of molecular weights and a variety of physicochemical properties. Significant progress has been made in this area since the first experiment on VOCs at a swine facility in the early 1960s. A total of 47 research institutions in 15 North American, European, and Asian countries contributed to an increasing number of scientific publications. Nearly half of the research papers were published by U.S. institutions.Investigated major VOC sources included air inside swine barns, in headspaces of manure storages and composts, in open atmosphere above swine wastewater, and surrounding swine farms. They also included liquid swine manure and wastewater, and dusts inside and outside swine barns. Most of the sample analyses have been focusing on identification of VOC compounds and their relationship with odors. More than 500 VOCs have been identified. About 60% and 10% of the studies contributed to the quantification of VOC concentrations and emissions, respectively. The largest numbers of VOC compounds with reported concentrations in a single experimental study were 82 in air, 36 in manure, and 34 in dust samples.The relatively abundant VOC compounds that were quantified in at least two independent studies included acetic acid, butanoic acid (butyric acid), dimethyl disulfide, dimethyl sulfide, iso-valeric, p-cresol, propionic acid, skatole, trimethyl amine, and valeric acid in air. They included acetic acid, p-cresol, iso-butyric acid, butyric acid, indole, phenol, propionic acid, iso-valeric acid, and skatole in manure. In dust samples, they were acetic acid, propionic acid, butyric acid, valeric acid, p-cresol, hexanal, and decanal. Swine facility VOCs were preferentially bound to smaller-size dusts.Identification and quantification of VOCs were restricted by using instruments based on gas Chromatography (GC) and liquid chromatography (LC) with different detectors most of which require time-consuming procedures to obtain results. Various methodologies and technologies in sampling, sample preparation, and sample analysis have been used. Only four publications reported using GC based analyzers and PTR-MS (proton-transfer-reaction mass spectrometry) that allowed continuous VOC measurement. Because of this, the majority of experimental studies were only performed on limited numbers of air, manure, or dust samples. Many aerial VOCs had concentrations that were too low to be identified by the GC peaks.Although VOCs emitted from swine facilities have environmental concerns, only a few studies investigated VOC emission rates, which ranged from 3.0 to 176.5 mg d−1 kg−1 pig at swine finishing barns and from 2.3 to 45.2 g d−1 m−2 at manure storages. Similar to the other pollutants, spatial and temporal variations of aerial VOC concentrations and emissions existed and were significantly affected by manure management systems, barn structural designs, and ventilation rates.Scientific research in this area has been mainly driven by odor nuisance, instead of environment or health concerns. Compared with other aerial pollutants in animal agriculture, the current scientific knowledge about VOCs at swine facilities is still very limited and far from sufficient to develop reliable emission factors. 相似文献
168.
外加水在渗吸过程中可以促进煤体瓦斯解吸,减小煤层瓦斯含量,从而减少瓦斯事故的发生频率。为了研究含瓦斯煤水分分布规律,采用NMR(核磁共振成像)技术,针对不含瓦斯煤进行定量外加水渗吸实验。研究结果表明:型煤中的水分主要受毛细管力和重力作用的影响;在自下向上吸水和自上向下吸水渗吸过程中,毛细管力作用相同,径向方向上水分扩散速度相近,但在轴向方向上的扩散速度具有明显差异,由于重力作用的影响,分别产生抑制和促进作用;水分三向扩散半径与时间符合朗格缪尔函数关系。 相似文献
169.
170.
毛细管电泳法直接测定化工废水中邻苯二甲酸二丁酯 总被引:1,自引:1,他引:0
采用胶束毛细管电泳法,在分离水中5种邻苯二甲酸酯的基础上,对化工废水中邻苯二甲酸二丁酯进行了直接测定.以峰面积定量,标准曲线在4 mg/L~50 mg/L线性关系良好,检出限为0.64 mg/L,加标回收率为104%~106%. 相似文献