全文获取类型
收费全文 | 130篇 |
免费 | 10篇 |
国内免费 | 36篇 |
专业分类
安全科学 | 19篇 |
废物处理 | 21篇 |
环保管理 | 20篇 |
综合类 | 71篇 |
基础理论 | 1篇 |
污染及防治 | 37篇 |
评价与监测 | 7篇 |
出版年
2022年 | 2篇 |
2021年 | 4篇 |
2020年 | 2篇 |
2019年 | 5篇 |
2018年 | 4篇 |
2017年 | 6篇 |
2016年 | 8篇 |
2015年 | 6篇 |
2014年 | 6篇 |
2013年 | 12篇 |
2012年 | 8篇 |
2011年 | 11篇 |
2010年 | 10篇 |
2009年 | 9篇 |
2008年 | 7篇 |
2007年 | 3篇 |
2006年 | 14篇 |
2005年 | 7篇 |
2004年 | 8篇 |
2003年 | 7篇 |
2002年 | 9篇 |
2001年 | 5篇 |
2000年 | 6篇 |
1999年 | 2篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1996年 | 4篇 |
1995年 | 3篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1979年 | 1篇 |
1971年 | 2篇 |
排序方式: 共有176条查询结果,搜索用时 31 毫秒
151.
对中国石化股份公司济南分公司常减压装置从初常顶瓦斯回收轻烃压缩机系统的运行情况进行了分析和总结,取得了满意的使用效果和显著的综合效益。 相似文献
152.
膜蒸馏-结晶工艺是一种新的回收纯物质方法,尤其从废水中分离出晶体。对于膜蒸馏-结晶技术进行了综述,介绍了膜蒸馏-结晶技术的优点,以及工艺控制的关键技术。概述了膜蒸馏-结晶的起源和国内外研究现状,指出了膜蒸馏-结晶在高浓度无机盐废水中应用的优势,预测其在该方向上很好的发展前景。 相似文献
153.
154.
废锌锰电池真空蒸馏法去除汞的研究 总被引:2,自引:0,他引:2
废锌锰电池回收利用中的一个关键问题是实现汞的无害化。介绍了使用真空蒸馏装置,通过单因素实验和正交实验,研究蒸馏温度、系统压强和蒸馏时间对去除汞的综合影响;寻找去除汞的最优工艺条件。根据实验结果,使用真空蒸馏的方法处理锌锰电池优化的工艺参数为:蒸馏温度500~600℃,蒸馏时间60~80min,系统压强3000~7000Pa。 相似文献
155.
甲醛生产在化学工业生产中属于能耗较多的产品之一,回收甲醛生产过程中的化学反应热量不但节省大量能源,对于降低甲醛生产成本,改善生产环境都具有现实意义。 相似文献
156.
采用萃取精馏法从醋酸水溶液中分离回收醋酸是一新的研究方向,而适宜溶剂的筛选是研究关键.本实验以高沸点含氮类有机化合物作为醋酸-水萃取精馏的候选溶剂,采用平衡组分分析法对溶剂进行了实验筛选.结果表明,溶剂的引入使体系的相对挥发度有较大程度的提高,其中N-甲基乙酰胺(NMA)使水对醋酸的相对挥发度提高最多,为4.75.因此实验确定NMA为最优溶剂,并进行了醋酸-水萃取精馏的工艺实验.与普通精馏结果对比表明,以NMA为溶剂的萃取精馏法分离醋酸-水的效果非常显著,研究结果对开发环保型的醋酸-水分离新工艺具有重要意义. 相似文献
157.
A method of direct contact membrane distillation (DCMD) with a self-made hollow polyvinylidene fluoride membrane was applied to prepare high concentration polyaluminum chloride (PACl) with high Alb content based on chemical synthesis. The permeate flux and Al species distribution were investigated. The experimental results showed that the permeate flux decreased from 14 to 6 kg/(m2·hr) at the end of the DCMD process, which can be mainly attributed to the formation of NaCl deposits on the membrane surface. The Alb content decreased slightly, only from 86.3% to 84.4%, when the DCMD experiment finished, correspondingly the Alc content increased slightly from 7.2% to 8.5%, and the Ala content remained at 7% during the whole DCMD process. A PACl with Alb content of 84% at total aluminum concentration 2.2 mol/L was successfully prepared by the chemical synthesis-DCMD method. 相似文献
158.
The process of producing synthetic gas from waste plastics by steam reforming was investigated. To evaluate this process,
the steam reforming of the oils derived from low-density polyethylene and polystyrene were carried out using a laboratory-scale
fluidized bed of Ni-Al2O3 catalysts. The performance of gasification in terms of carbon conversion, gas yield, and gas compositions was examined. Although
oils derived from plastics contain many kinds of heavy hydrocarbons and aromatics, they were well gasified at temperatures
above 1023 K with a steam/carbon ratio of 3.5 and a weight hourly space velocity of 1 h−1. The hydrogen content of the product gas was very high at approximately 72 vol% for polyethylene-derived oil and 68 vol%
for polystyrene-derived oil. These compositions agreed well with the values calculated from chemical equilibrium. 相似文献
159.
160.
The lead removal from the metallic mixture of waste printed circuit boards by vacuum distillation was optimized using experimental design, and a mathematical model was established to elucidate the removal mechanism. The variables studied in lead evaporation consisted of the chamber pressure, heating temperature, heating time, particle size and initial mass. The low-level chamber pressure was fixed at 0.1 Pa as the operation pressure. The application of two-level factorial design generated a first-order polynomial that agreed well with the data for evaporation efficiency of lead. The heating temperature and heating time exhibited significant effects on the efficiency, which was validated by means of the copper–lead mixture experiments. The optimized operating conditions within the region studied were the chamber pressure of 0.1 Pa, heating temperature of 1023 K and heating time of 120 min. After the conditions were employed to remove lead from the metallic mixture of waste printed circuit boards, the efficiency was 99.97%. The mechanism of the effects was elucidated by mathematical modeling that deals with evaporation, mass transfer and condensation, and can be applied to a wider range of metal removal by vacuum distillation. 相似文献