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121.
Co3O4纳米棒的制备及其对气相甲苯的催化氧化   总被引:2,自引:2,他引:0  
闫清云  李新勇  肇启东  曲振平 《环境科学》2011,32(12):3689-3693
采用低温水热法制备棒状纳米结构的Co3O4,通过加入少量的表面活性剂(聚乙烯吡咯烷酮简称PVP),在95℃下低温反应,并调控制备过程的老化时间、溶液的pH这2个因素合成了棒状Co3O4纳米结构.X射线衍射(XRD)、透射电镜(TEM)表明制得的是呈立方晶体的Co3O4纳米棒,氢气程序升温还原(H2-TPR)、N2吸附脱附等表征手段表明老化时间和pH会影响Co3 O4纳米棒的尺寸、孔隙结构,进而影响其比表面积大小.采用气相甲苯作为目标物,运用气相色谱(GC)对Co3 O4的催化性能进行研究.结果表明在该实验中,调控老化时间和pH制得的Co3O4纳米棒只影响其低温降解效果,在温度低于260℃,活性最好的是pH=9,老化时间为12 h的催化剂;当温度高于260℃后,其降解曲线基本一致.  相似文献   
122.
废水中总氮测定的预处理一般采用经典的压力蒸汽灭菌器消解,其缺点是消解时间较长、操作较为繁锁。经多次试验并查阅了相关资料,可以用COD消解仪、电热恒温干燥箱和微波炉代替压力蒸汽灭菌器进行消解。在保证测量准确性和精度的前提下,可以节约时间、简化操作步骤,提高工作效率。  相似文献   
123.
一株低温高效植物油降解菌的驯化筛选及固定化研究   总被引:1,自引:1,他引:0  
为了解决因低温而导致的废水中油脂难以处理的问题,从冬季重庆大学餐厅排污管道的底泥中分离出1株可低温降解植物油的菌株DJ-1。将此菌株多次驯化培养后,在5℃条件下利用其对含20g/L菜籽油复筛培养基的模拟含油废水进行处理。经过3 d处理,可去除废水中70.63%的植物油。经16S rDNA测序分析,该菌株为假单胞菌的一个未定种属(相似度为99%)。使用泥炭和木屑作为固定化载体,按照m(泥炭)∶m(木屑)∶m(菌液)=1∶4∶20的比例将扩培后的DJ-1菌剂制作成细菌固定化菌粉。在5℃条件下利用菌粉对含20 g/L菜籽油复筛培养基的模拟含油废水进行处理,菌粉投加量为0.15 g/L。经过3 d处理,废水中植物油的降解率达到77.34%,5 d后达到85.22%。  相似文献   
124.
应用显色剂与氨在一定条件下反应生成一种蓝绿色化合物的原理,研制出一种简单、快速测定氨气含量的试剂盒.对不同实验条件进行比较,筛选出了最佳实验条件.采样体积0.1 L,检测管外径3.2~3.3 mm,内径1.8 mm,吸附载体为80~100目活化SiO2/SnO2复合材料与吸附剂、催化剂、显色剂的混合物,采气速度为0.01 L/min,采样时间10 min,显色时间5 min.实验结果表明,检测试剂盒显色强度与氨气浓度呈线性关系,最低检测浓度为0.1 mg/m3,重现性较好.与国标对照实验中,6次测定结果的平均相对误差为6.23%,小于15%; 一次测定最大相对误差7.4%,小于25%; 重复测定的相对标准偏差为5%~8%; 样品中加入2 μg的氨,其回收率为95%~110%,符合GB 7530-87要求.一定量的有机胺、甲醛、H2S会产生干扰.试剂盒使用寿命在8个月以上.  相似文献   
125.
箱式水幕系统中箱体内部结构对喷嘴出流的影响   总被引:1,自引:0,他引:1  
地下建筑由于其地理位置的特殊性,极高的火灾发生率以及较大的火灾损失使得地下建筑中的消防系统举足轻重,在传统的消防分区及设施都不适合的情况下,箱式水幕系统是较适用于地下建筑中消防系统之一.为了得到均匀的水幕,本文利用数值计算,分析了箱体的外形及内部结构设计对水幕出水质量的影响,认为通过一定的结构措施可以得到出水效果较好的水幕.  相似文献   
126.
一次性餐盒材料中全氟辛酸和全氟辛烷磺酸沥出性研究   总被引:1,自引:0,他引:1  
利用高效液相色谱-串联质谱检测方法对一次性餐盒材料中可沥出性全氟辛酸(PFOA)和全氟辛烷磺酸(PFPS)进行了研究.分别选取水、3%乙酸(W/W)、15%乙醇(V/V)和正己烷4种浸取液模拟餐盒材料在使用过程中可能接触到的水性、酸性、酒精类和油脂类条件.材料经4种溶液浸提后,浸取液用固相萃取净化和浓缩,目标分析物PFOA和PFOS采用内标法进行定量.研究表明,一次性餐盒材料在模拟条件下中有以PFOA为主的伞氟类化合物从材料中沥出,其中酸性环境对PFOA的浸取率最高(2296 ng·m~(-2)), 为其它3种方法的82.8倍;4种浸提条件下PFPS的沥出率都比较低,浓度仪为0.7 ng·m~(-2)-5.4 ng·m~(-2).  相似文献   
127.
Dedicated, skilled and relatively cheap manpower coupled with efficient manufacturing techniques has elevated China’s status as the world’s factory. China is now capable of producing virtually any product, from cheap toys to some of the most sophisticated goods and equipment. The resultant economic benefits and associated enormous consumption due to rise in per capita income are accompanied by an equally unprecedented negative environmental impact arising from the huge increase of end-of-life (EoL) products. This study aims to understand and prioritise EoL product reverse logistics (RL) factors from Chinese manufacturing sector perspective. Multiple case studies in five different industries within the manufacturing sector have been carried out and analytic hierarchy process (AHP) has been employed to prioritise the governing factors for the successful RL implementation in the Chinese manufacturing sector. Results indicate that Chinese firms are unlikely to embark on RL operations without external factors such as strict government legislation.  相似文献   
128.
This paper proposes an empirically grounded framework for examining the preparedness and recovery phases of disaster management activities and processes pertaining to predictable disasters within a developed country. The two‐stage framework provides a single model composed of important preparedness and recovery initiatives, as well as activities and processes derived from empirical data collected for case studies from Australia: the ‘Black Saturday’ bushfires in the state of Victoria in February 2009; and Cyclone Larry in March 2006. The framework enables a variety of analyses, including the generation of insights into disaster management preparedness and recovery in the context of events in wealthy developed countries. The paper combines two empirical examples, a series of bushfires and a severe tropical cyclone, to enhance understanding of, and to contribute to better, disaster preparedness and recovery in the future. The paper contributes to the growing literature on disasters, preparedness, recovery and associated logistics, and other issues.  相似文献   
129.
A plethora of untapped resources exist within disaster‐affected communities that can be used to address relief and development concerns. A systematic review of the literature relating to community participation in humanitarian logistics activities revealed that communities are able to form ad hoc networks that have the ability to meet a wide range of disaster management needs. These structures, characterised as Collaborative Aid Networks (CANs), have demonstrated efficient logistical capabilities exclusive of humanitarian organisations. This study proposes that CANs, as a result of their unique characteristics, present alternatives to established humanitarian approaches to logistics, while also mitigating the challenges commonly faced by traditional humanitarian organisations. Furthermore, CANs offer a more holistic, long‐term approach to disaster management, owing to their impact on development through their involvement in humanitarian logistics. This research provides the foundation for further theoretical analysis of effective and efficient disaster management, and details opportunities for policy and practice.  相似文献   
130.
We used a closed-ended viewer box in the measurement of Secchi depth and compared the results with simultaneous naked-eye measurements. We have shown that use of such a viewer box increases Secchi depth measurement by removing the interfering effects of water surface glare and glitter. A viewer box also increases between-observer precision. Measurements made both with and without the viewer box are slightly greater on the shady side of the boat than on the sunny side; the latter is the preferred side if Secchi data are to be related to other optical properties. As expected, the difference between viewer box and naked eye measurements increases with increasing wave height but not with increasing illuminance. Because of the lack of uniformity in the way Secchi depth is estimated, and the inherent optical problems with current Secchi depth procedures, an appeal is made for production of a standardized protocol for Secchi observations, including the use of a closed-ended viewer box on the sunny side of the boat.  相似文献   
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