首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   316篇
  免费   20篇
  国内免费   36篇
安全科学   58篇
废物处理   22篇
环保管理   23篇
综合类   183篇
基础理论   8篇
污染及防治   43篇
评价与监测   23篇
社会与环境   2篇
灾害及防治   10篇
  2022年   4篇
  2021年   6篇
  2020年   7篇
  2019年   3篇
  2018年   4篇
  2017年   8篇
  2016年   8篇
  2015年   10篇
  2014年   15篇
  2013年   18篇
  2012年   28篇
  2011年   24篇
  2010年   26篇
  2009年   26篇
  2008年   11篇
  2007年   14篇
  2006年   17篇
  2005年   25篇
  2004年   9篇
  2003年   21篇
  2002年   10篇
  2001年   15篇
  2000年   16篇
  1999年   11篇
  1998年   11篇
  1997年   13篇
  1996年   2篇
  1995年   4篇
  1992年   2篇
  1991年   1篇
  1990年   2篇
  1989年   1篇
排序方式: 共有372条查询结果,搜索用时 98 毫秒
101.
DFT calculations in gas and aqueous solution phases have been performed to study the mechanism of carbamate formation by the absorption of CO2 in 2-amino-2-methyl-1-propanol (AMP). The results reveal the importance of considering the effect of water as solvent for the reaction to proceed. Furthermore water molecules play an important role as a basic reactant leading to stable intermediates formation. These results point at a single-step, third order reaction as the most probable mechanism for the formation of carbamate by the absorption process.  相似文献   
102.
以改进后的双循环多级水幕塔对烟气进行除尘脱硫性能的研究,利用双循环不同pH值控制的优点和多级水幕的效果,增加气液接触面积和传质动力,提高SO2吸收效果。在正交实验的最佳运行工况基础上,实验从烟气流量、上下两段pH、L/G和SO2进气浓度等方面进行单因素研究。结果表明,除尘效率维持在98%以上,进气SO2浓度在5 000 mg/m3以下时,脱硫率在93%以上。上段pH值为6、下段pH值为5、L/G在15左右的脱硫效率和运行工况最佳,无结垢现象发生。改进后的吸收塔具有良好的应用前景,实验结果对于现场脱硫设备的调试和运行有很好的参考价值。  相似文献   
103.
A facile and novel method has been developed for the determination of cadmium, chromium, copper, lead, and zinc from various water samples using FAAS. In the present investigation, a syringe was loaded with sorbent (rice bran) for the separation and enrichment of cadmium, chromium, copper, lead, and zinc, prior to their analysis by flame atomic absorption spectrometry which was described to substitute the batch and column techniques. The syringe was loaded with 2.0 g of sorbent in order to retain the analyte elements. Six milliliter of sample solution (pH 8.0 ± 0.2) was drawn into the syringe in 15 s and discharged over a period of 15 s. Then, 2.0 M HCl eluent was drawn into the syringe and ejected back to desorb the analyte elements. At the optimum conditions, the percentage recoveries of Cd, Cr, Cu, Pb, and Zn was in the range of 95.5–99.4% with SD of 0.10%. The elements could be concentrated by drawing and discharging several portions of sample successively. The detailed study of various interferences made the confirmation of the method highly selective. The risk of contamination is less than that with the column technique. The method was successfully applied for the determination of Cd, Cr, Cu, Pb, and Zn in spiked and natural water samples. The results obtained are in good agreement with the reported methods at the 95% confidence level.  相似文献   
104.
改进优化传统双碱法烟气脱硫工艺,对脱硫塔及附属设施设计要点进行分析,在山西某化工厂2×55t/h三废炉烟气脱硫工程中得到较好运用,为同类烟气脱硫工程提供参考。  相似文献   
105.
华北地区某电厂排烟冷却塔烟气抬升高度的光学照相法实测结果显示,选用S/P模式计算出排烟冷却塔烟气括升高度是合理的。在环境风速小、空气潮湿条件下,采用排烟冷却塔排放方式有利于污染物稀释扩散;在环境风速大、空气干燥、逆温等不利气象条件时,采用排烟冷却塔排放方式,烟气抬升高度较低。  相似文献   
106.
n-Hexane is widely used in industrial production as an organic solvent. As an industrial exhaust gas, the contribution of n-hexane to air pollution and damage to human health are attracting increasing attention. In the present study, aqueous solutions of two fluorocarbon surfactants(FSN100 and FSO100) were investigated for their properties of solubilization and dynamic absorption of n-hexane, as well as their capacity for regeneration and n-hexane recovery by thermal distillation. The results show that the two fluorocarbon surfactants enhance dissolution and absorption of n-hexane, and their effectiveness is closely related to their concentrations in solution. For low concentration solutions(0.01%–0.30%), the partition coefficient decreases dramatically and the saturation capacity increases significantly with increasing concentration, but the changes for both are more modest when the concentration is over 0.30%. The FSO100 solution presents a smaller partition coefficient and a greater saturation capacity than the FSN100 solution at the same concentration,indicating a stronger solubilization for n-hexane. Thermal distillation is a feasible method to recover n-hexane from these absorption solutions, and to regenerate them. With 90 sec heating at 80–85°C, the recovery of n-hexane ranges between 81% and 85%, and the regenerated absorption solution maintains its original performance during reuse. This study provides basic information on two fluorocarbon surfactants for application in the treatment of industrial n-hexane waste gases.  相似文献   
107.
目前,反渗透废水中,高浓度的含盐量会对环境带来严重危害。本研究运用热能喷雾处理反渗透浓盐水技术,对反渗透(Reverse Osmosis,RO)出水进行处理。结果表明,该技术在热量值为4.8×106 kcal、空气流量为60 m3/h的条件下,处理效率达到了90%以上。产出的冷凝水的水质符合饮用水的相关标准;在处理量为10 L/h~12 L/h时,可达到废水零排放的效果;在处理量大于12 L/h时,排出的废水总溶解物( Total dissolved sol-ids,TDS)很高。  相似文献   
108.
两种不锈钢在冷却塔冷凝酸液中的耐蚀性能   总被引:4,自引:2,他引:2  
目的分析304不锈钢和316L不锈钢在电厂冷却塔内海水及烟气形成的模拟冷凝酸液环境中的耐蚀性能。方法利用浸泡试验和电化学试验方法测试两种不锈钢在模拟冷凝酸液中的腐蚀形貌、腐蚀率和极化曲线。结果 304不锈钢在模拟冷凝酸液中的耐蚀性能较差,其腐蚀率及钝态稳定性受冷凝酸液pH值的影响较大;316L不锈钢在模拟冷凝酸液中的耐蚀性能较好,其腐蚀率及钝态稳定性受冷凝酸液pH值的影响较小。结论 316L不锈钢在冷却塔冷凝酸液中的耐蚀性能明显优于304不锈钢。  相似文献   
109.
When designing energy efficient buildings it is useful to study existing climate—responsive building typologies. The wind towers or wind-catchers of Yazd city in Iran are typical examples of such a typology. Although many previous studies have investigated the performance of various types of wind catcher systems, studies based on a long-term real-life measurement can be rarely found. In this study a long-term whole year monitoring campaign on an existing full scale four sided wind catcher in Yazd was carried out in 2014–2015. Three prevailing wind directions were identified and the measured on-site wind speeds were used to estimate the wind induced natural ventilation potential of the tower. A shaft/tower airflow performance index was developed. The monitoring results were compared to the ASHRAE Standard 62:2001 ventilation rate requirement. Results show that the total ventilation rate of the wind tower surpasses the ASHRAE Standard requirements. Furthermore it shows that the shafts are exposed to the prevailing wind directions perform better. For more effective natural ventilation a wind tower with adaptable openings/shafts are proposed.  相似文献   
110.
中央广播电视发射塔环境电磁辐射测试研究   总被引:3,自引:0,他引:3  
对发射7套电视节目和5套调频节目,发射总功率240KW的中央广播电视塔电磁辐射场强监测结果表明:(1)由于节目频率不同,发射机功率及发射天线形式、高度、增益不同,电磁波到达地面最大场强值的距离是不同的;在近距离内高层建筑各层所接收到的场强大小也是不同的。(2)电视与调频信号在近距离昼夜电平无明显变化。(3)电视塔周围2000米内环境综合场强最大值为284~328μW/cm2,所有环境测量值均小于公众导出限值40μW/cm2。  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号