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51.
通过浸渍法制备CuO/SBA-15和CuO-CeO2/SBA-15两种介孔材料催化剂,采用BET、XRD、TPR和XPS等对催化剂进行表征,重点考察催化剂对萘氧化反应的催化活性及对产物CO2的选择性。BET、XRD和XPS等实验结果表明CuO高度分散于介孔分子筛SBA-15中,CeO2可促进CuO在载体上的分散,同时能降低催化剂的TPR还原温度。活性测试结果表明CuO/SBA-15对萘氧化反应的催化活性较高,但是催化氧化的CO2选择性较低,温度在380℃时CO2的生成率仅为60%左右;CeO2的添加不仅提高了CO2的生成率,15%CuO-15%CeO2/SBA-15在325℃使CO2生成率达到99%,而且CeO2增强了催化剂的稳定性。 相似文献
52.
实验对比考察了常规混凝和加载磁混凝工艺对微污染河水中COD、浊度和TP等污染物的去除效果,系统研究了混凝剂用量、磁种加载量、搅拌条件和药剂投加顺序等因素对加载磁混凝效果的影响。实验结果表明,加载磁种后沉淀颗粒的体积平均粒径为从常规混凝工艺的50.1μm显著增加到68.6μm;污染物去除效果明显优于常规混凝工艺,尤其对浊度和总磷的去除效果得到了显著的提升;在实验最优条件下COD、浊度和TP的去除率分别达到54.17%、99.28%和75.82%;并且加载磁种后可减少50%以上的混凝剂投加量,同时大大缩短沉淀时间。 相似文献
53.
Laura B. Brentner Sachiyo T. Mukherji Jerald L. Schnoor 《Environmental pollution (Barking, Essex : 1987)》2010,158(2):470-475
Phosphor imager autoradiography is a technique for rapid, sensitive analysis of the localization of xenobiotics in plant tissues. Use of this technique is relatively new to research in the field of plant science, and the potential for enhancing visualization and understanding of plant uptake and transport of xenobiotics remains largely untapped. Phosphor imager autoradiography is used to investigate the uptake and translocation of the explosives 1,3,5-trinitro-1,3,5-triazine (RDX) and 2,4,6-trinitrotoluene within Populus deltoides × nigra DN34 (poplar) and Panicum vigratum Alamo (switchgrass). In both plant types, TNT and/or TNT-metabolites remain predominantly in root tissues while RDX and/or RDX-metabolites are readily translocated to leaf tissues. Phosphor imager autoradiography is further investigated for use in semi-quantitative analysis of uptake of TNT by switchgrass. 相似文献
54.
分析了沥青混凝土搅拌设备的构成以及生产沥青混凝土的工艺及烟尘特点;通过应用工程实例,指出袋式除尘器是沥青混凝土搅拌设备最理想的除尘系统之一。 相似文献
55.
工业废水中多金属离子的吸附净化 总被引:3,自引:1,他引:2
以含有Si、Al、Ca、C元素的矿物材料作为基质,经特定条件处理后造粒成型加工成轻质多孔Si-Al-Ca-C结构的吸附材料。研究了该吸附材料对工业废水中多种金属离子的吸附性能,探讨了影响吸附性能的因素。研究结果表明,在一定条件下,Si-Al-Ca-C吸附材料对工业废水中Al3+、Ca2+、Mn2+、Cu2+、Fe3+、Mg2+、As3+和Zn2+的净化率分别高达99.34%、99.82%、98.26%、98.16%、97.76%、97.01%、100%和89.09%。金属离子残留浓度分别为0.152、0.07、0.012、0.02、0.119、0.311、0和0.259 mg/L,均低于国家污水综合排放标准(GB8978-1996)一级标准。 相似文献
56.
Daniel Paska 《Natural resources forum》2010,34(3):200-210
The amount of electrical and electronic products is increasing rapidly, and this inevitably leads to the generation of large quantities of waste from these goods. Some of the generated e‐waste ends up in regions with sub‐standard recycling systems and may be processed under poor conditions. During uncontrolled incineration, halogenated dioxins and furans can be generated from brominated and chlorinated compounds in the products. In order to reduce the health and environmental risks involved in the recycling stage of the life cycle of electronics, an effective design‐for‐environment process must be established during the product development phase. Knowledge of the chemical substances in the product is crucial to being able to make informed decisions. Through full knowledge of the material content of procured components, phase‐outs of unwanted substances, such as halogenated substances, can be performed in an effective manner. Therefore, information is the key to success in phasing‐out substances; facilitating compliance of legal provisions for manufacturers of electrical and electronic devices; and improving the environmental footprint of products as they reach the end of the life cycle. After an introduction to the challenges of electronics waste management, this paper describes supply chain information systems and how they are used to facilitate substance phase‐outs in the electronics industry. Sony Ericsson has been working with phase‐outs of unwanted substances since it was founded in 2001. Through the introduction of a material declaration system that keeps track of all substances in the components used in the company's products, Sony Ericsson has been able to replace unwanted substances to improve environmental impacts at the recycling stage of a product. 相似文献
57.
Epidemiological studies suggesting the possibility of harmful effects on human (specifically children’s leukaemia) due to
long-term exposure to magnetic fields of extremely low frequency (e.g. 50/60 Hz) and relatively low values (i.e. over the
microtesla range) have stirred high activity in the topic of magnetic field mitigation. To reduce these fields, it is common
to use passive metal screens (e.g. plates made of aluminium or steel). To design them, effective and fast numerical computations
are highly desirable. In this article, a method is presented, which computes various parameters of screens in a given shielding
problem and yields magnetic field distribution and shielding factors. The method takes into consideration the 3D field distribution
and is able to solve systems with large aspect ratios (thin thickness in comparison with its other dimensions); this is a
common problem where other methods such as finite elements often experience difficulties. The presented method computes separately
the field inside and outside the screens. Afterwards, the solutions are “stitched” together along the border of the subregions.
Two practical examples are given of the developed numerical method. 相似文献
58.
突发事件现场警戒区域的研究 总被引:3,自引:2,他引:1
杨春生 《中国安全生产科学技术》2009,5(6):167-170
阐述了事故危险区域、现场警戒区域的基本概念、设置目的和原则,提出将突发事故现场警戒区域分为三层,分别对应现场封锁线、警戒封锁线和交通封锁线,并就吸入毒性危害物质泄漏、燃气泄漏、建筑物火灾等事故,制定了具体的设置方法。现场警戒区域的设定,可在较小成本投入的前提下,通过采取积极的防范和应对措施,有效减少人员伤亡和财产损失,提高救援效率和效果。 相似文献
59.
60.
LCD面板主要由附着偏光片及液晶等有机材料的玻璃面板构成。有机材料的去除及资源化利用是废LCD面板处理的第一步。在水热条件下对废LCD面板进行了降解产酸研究。研究考察了反应温度、反应时间、氧化剂用量、水用量及pH值等对水热产乙酸产率及选择性的影响。通过正交实验确定了水热产乙酸的最佳操作条件:反应温度325℃,反应时间5min,氧化剂(30%H2O2)0.6mL,用水量2mL,近中性环境(pH6-6.5去离子水)。此条件下,乙酸产率及选择性分别为68.83%及70.56%。结果表明,以废LCD面板有机材料为原料,采用水热技术进行产乙酸反应,可实现其资源化再利用。 相似文献