共查询到20条相似文献,搜索用时 93 毫秒
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采用水热法合成了一系列不同Ag2CO3含量的新型Ag2CO/ZnO异质结复合光催化剂,运用X射线粉末衍射(XRD)、扫描电镜(SEM)、X射线光电子能谱(XPS)、傅里叶变换红外光谱(FT-IR)、紫外-可见漫反射吸收光谱(UV-visDRS)等系列手段对所制备的光催化剂进行了表征,并以紫外光(254nm)为光源,评价了催化剂光催化降解甲基橙的活性,考察了不同Ag2CO3复合量、不同水热温度对ZnO复合光催化剂反应活性的影响.结果表明.当Ag2CO3含量为2%、水热温度为140℃,复合光催化剂具有最大的光催化活性,降解率达到86.31%.Ag2CO3/ZnO异质结复合光催化剂具有更高的光催化活性主要原因是复合光催化剂对紫外光有很强的吸收能力,适量A龅C03能提高光生电子一空穴对的分离效率,并改善催化剂的物理性能. 相似文献
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微量Ag对Al-Cu-Mg合金显微组织与力学性能的影响 总被引:1,自引:2,他引:1
研究了Ag元素对Al-8Cu-0.5Mg合金显微组织、室温及高温力学性能的影响。结果表明:均匀分布在铝基体{001}面和{111}面上共存的θ′和Ω(成分为Al2Cu)沉淀相能对含Ag合金起强化作用;而不含Ag的合金只有θ′一种沉淀相。含Ag合金中小尺寸以及近间距的θ′和Ω沉淀相提高了室温及高温下合金的屈服强度和拉伸强度。然而,与不含Ag的合金相比,由于这种小尺寸及近间距的θ′和Ω沉淀相在变形过程中具有与基体的内在不相容性,含银合金的伸长率降低。 相似文献
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影响特高品位矿石中Au、Ag准确测定的因素主要有AgCl、PbCl2沉淀和Au、Ag矿物的硅酸盐包裹体,W、Mo、Sb和Pb等竞争吸附,容量分析的滴定终点干扰,以及待测溶液的介质及浓度等。研究确定了HCl-HNO3-KClO3(-NH4 HF2)和( NH2)2 CS封闭溶样,泡沫塑料分段富集(或活性炭富集),AAS法硫脲介质测定矿石中的Au、Ag。该方法可有效避免各影响因素干扰,且操作简便、不污染环境,分析结果的精密度( RSD )为0.66%~0.93%,国家标准样品加标回收率为98%~102%。 相似文献
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光谱选择性透过涂层在节能窗上能有效反射红外光,通过减少室内外的热传递而降低能耗。本文分别测量SiN膜和Ag膜的透射光谱和光学常数,利用TFCale软件对SiN/Ag/SiN选择性透过涂层的各层厚度进行优化设计并利用磁控溅射进行制备。使用紫外-可见-近红外分光光度计(UV/VIS/NIR)、扫描电子显微镜(SEM)和俄歇电子能谱(AES)测试与表征涂层的选择透过特性、微观形貌与成分分布。结果表明,实际制备的涂层厚度及光学性能与理论设计值具有良好的一致性。当SiN/Ag/SiN涂层的各层厚度分别为30/15/35 nm时,其可见光和近红外波段的透射率分别为73.1%和17.2%,体现出明显的选择透过性。观察Ag膜的生长模式,发现15 nm的Ag膜仍处于岛状粒子生长阶段,上层的SiN层粒子会在沉积过程中进入Ag岛之间的缝隙。探究不同类型涂层的光学性能,发现金属Ag薄膜对选择透过涂层的红外透过率有显著影响,且外层的SiN薄膜是保证涂层可见光透过率的关键因素。 相似文献
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An inorganic nanomaterials combination of Sm, Ag, and TiO2 was synthesized using supercritical fluid drying (SCFD) combined with solgel techniques. The structure, photocatalysis and bacteriostatic activity of the materials were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XRPS), photocatalytic performance, and antibacterial activity experiments. The XRD results showed that the average particle diameter of Sm/Ag/TiO2 was 14.62 nm and Ag and Sm ions were dispersed on the surface of TiO2 in a highly dispersed, amorphous form. The TEM image showed that the size of the particle was 12 nm using the scherer formula. The XPS result showed that the element Sm was doped and Ag was loaded inorganic nanomaterials successfully. Sm/Ag/TiO2 exhibited optimal photocatalytic properties at 600 oC, the photocatalytic optimal proportion of Sm/Ag/TiO2 was 2:2:100. When the molar ratio was 2:2:100, the bacteriostatic circle diameter was 16 mm for Staphylococcus aureus, the minimum bacteriostatic concentration was 200μg/mL for white beads coccus, and the minimum bactericidal concentration was 2×10^4μg/mL for white beads coccus. The SEM results showed that the antibacterial material attached to the candida albicans cell surface, cells appeared fold deformation. Therefore the inorganic nanomaterials Sm/Ag/TiO2 had high temperature resistance, good photocatalytic and antibacterial characteristics in visible light. 相似文献
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在304L不锈钢的成分基础上,添加不同质量分数(0.072%~0.132%)的Ag,并对其热轧板进行固溶处理和冷轧,发现材料的显微组织均为均匀的奥氏体组织,且随着Ag含量的增加,屈服强度及伸长率变化均不明显。利用OM、SEM和TEM观察不同变形条件下材料中Ag颗粒变化,发现Ag颗粒主要为材料冶炼时未熔入到基体内的Ag,其在基体中弥散分布,呈椭球形或球形;Ag颗粒有2种存在形式,即几纳米到几十纳米的富Ag相、由多个纳米级Ag相团簇聚集在一起形成的几百纳米到几微米的Ag颗粒聚集物。另外,热轧后,富Ag颗粒聚集物沿轧制方向变成带状、棒状,部分分裂为椭球状或球状;进一步冷轧变形后,富Ag颗粒的尺寸减小,且变形量越大,Ag颗粒尺寸越小。 相似文献
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André Zimmer lvaro Niedersberg Correia Lima Rafael Mello Trommer Saulo Roca Bragana Carlos Pérez Bergmann 《钢铁研究学报(英文版)》2008,15(3):11-0
The heat transfer in a steelmaking ladle was studied. The evaluation of heat transfer of the steel was performed by measuring steel temperature in points including all refining steel process. In the ladle, the temperatures in the refractories and the shell were also measured. To evaluate the thermal profile between the hot and cold faces of the ladle in the slag line position, an experiment which shows the importance of thermal contact resistance was carried out. Higher heat losses in the tapping and the vacuum were verified. The temperature measurements of the ladle indicate distinct thermal profiles in each stage of steel refining. Moreover, as each stage of the process depends on the previous one, the complexity of the ladle thermal control is incremental. So a complete model of heat losses in the ladle is complex. 相似文献
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Gary Phetteplace 《Canadian Metallurgical Quarterly》2007,133(1):32-38
Geothermal heat pumps can be considered a sustainable technology, as they reclaim and recycle thermal energy from the earth. In climates with a near balance in the annual heating and cooling loads, they function essentially as a seasonal energy storage scheme. This paper presents an overview of the technology. The various types of geothermal heat pumps are explained along with their relative merits. Detailed discussion is included on the most common method of ground coupling for commercial scale applications, the vertical borehole heat exchanger. Issues with sizing the heat exchanger and grouting it are discussed, as well as the motivation for in situ thermal properties testing. In-building equipment, including the heat pumps themselves, is briefly described. Experience with geothermal heat pumps to date is presented for both residential and commercial scale applications. Regional market penetration and competitiveness are also discussed for both residential and commercial scale applications. The paper concludes that the overall outlook for expanded application of geothermal heat pumps is very favorable. 相似文献
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蓄热式热交换器的可用能分析 总被引:5,自引:0,他引:5
本文把可用能分析的方法引入到蓄热式热交换器热工特性的研究中,提出的可用能效率综合了传热和流动两方面的因素。研究表明可用能效率比温度效率和热效率能更真实反映蓄热式热交换器的热工行为,并可用于指导蓄热式热交换器的优化设计。 相似文献
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The temperature propagation in a layered structure is of great importance in determining the thermal induced strain in the structure, and in particular the thermal induced stress along the interfaces of the structure due to the different thermal expansion coefficients of the layer media. In this paper, an exact analytical solution is obtained based on the Fourier-Biot heat conduction equation for a two-layer structure with or without a base boundary. Characteristic frequencies or the temperature fluctuation response of two-layer structures are identified. Once the temperature distribution is known, one can compute the stress distribution in the structure. The application of the model to understanding measured temperature data for two-layer structures such as concrete pavements is addressed. 相似文献
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针对热连轧厂关注较少的轧钢加热炉炉体散热损失问题作了讨论,借用其他单位的经验进行论述,对常用隔热材料优缺点进行分析,阐述了减少散热损失的方法和热连轧厂可采取的措施。 相似文献