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Two types of nanocrystalline porous TiO2 electrodes were prepared by the hydrothermal and painting methods. The incident photon-to-current efficiency and photoelectrical
conversion efficiency were both improved by chemical treatments of titanium tetrachloride and titanium isopropoxide. The surface
roughness, quantities of adsorbed dye, photocurrent-voltage curves, IR spectra and UV-visible absorption spectra were measured,
and the mechanism of chemical treatments was discussed. 相似文献
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吴遵义 《北京工商大学学报(自然科学版)》2006,24(4):5-8
以钛酸丁酯、无水异丙醇、钒酸铵和氯铂酸为原料,采用so l-gel法合成了复合催化剂V-T iO2、P t-T iO2和V-P t-T iO2.XRD、SEM和UV-V is研究结果表明:V、P t对T iO2的晶型影响不大,但对其形貌和紫外可见吸收有影响.考察了复合催化剂对三氯乙酸的光催化降解活性,结果表明:V、P t均能提高其催化活性,而且V和P t之间能协同大幅度提高其催化活性,并对产生该结果的原因进行了探讨. 相似文献
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考察了不同载 Ti量的 TiCl_4/MgCl_2-n-BuOH-SiCl_4 与烷基铝相互作用产生的EPR 谱、不同作用时间形成的 EPR 谱的特征变化,以及它们与催化剂催化烯烃聚合活性的关联。结果表明,不同载Ti 量催化剂的 EPR主要是暴露于催化剂表面的孤立 Ti~(3+)离子贡献。表征催化剂中处于不同畸变配体场Ti~(3+)物类的g=1.95与g=1.97信号强度比值随载 Ti量增加而减小;g=1.99 信号的形成和增长与催化剂聚合活性有一定对应关系。 相似文献
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钛白石膏的物相组成及其脱水性能的研究 总被引:1,自引:0,他引:1
为进一步开发利用钛白石膏,利用XRD和DTG考察了钛白石膏的物相组成及其脱水性能。结果表明,钛白石膏的主要成份是二水石膏,杂质主要是铁、铝、镁、钛、硅,其中含量最高的铁主要以Fe2O3存在。钛白石膏的脱水反应发生在115℃~152℃,脱水机理与化学石膏的脱水机理相似,只是脱水峰温较化学石膏的略高。 相似文献
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针对铝热还原法制备的高钛铁中氧含量高、夹杂多等缺点,提出了以铝热法高钛铁为原料进行真空还原精炼制备低氧高钛铁的新思路.研究了精炼温度、精炼渣等因素对精炼效果的影响,采用XRD,SEM及化学元素分析等手段对高钛铁合金进行了表征.结果表明:还原精炼后合金的微观结构均匀致密,夹杂物得到有效去除,氧含量急剧降低;2 000℃时以CaO-Al2O3为精炼渣制备的高钛铁合金中各元素的质量分数分别为钛74.5%,铁18.2%,铝2.17%,硅0.81%,氧3.20%,完全符合优质高钛铁的技术指标. 相似文献
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本文设计了一种制备 Ti-48A1-2Cr-2Nb(at%)合金的粉末冶金方法。首先采用非自耗电弧熔炼炉炼制出较脆的富铝 Ti-54 A1-2.25 Cr-2.25 Nb(at%)合金,然后机械破碎成—200目的粉末。在合金粉末中按比例加入—200目Ti粉,调到所需成分。混合粉末首先经CIP成形,然后经HIP固结成致密体。后续热处理使成分均匀和获得理想的微观组织。本文还重点研究了后续热处理工艺对合金的微观组织与力学性能影响。 相似文献
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提出了钛白表面苯乙烯固相接枝改性新工艺,并对工艺的各主要影响因素进行了较为详细的研究,得出了最佳的工艺条件.在此基础上,分析研究了力化学法钛白表面苯乙烯固相接枝改性机理,认为钛白苯乙烯改性的作用机理是负离子聚合反应和自由基聚合反应; 钛白和改性剂的性能是该工艺能够实施的内因和热力学因素,搅拌磨中的机械力化学作用、引发剂的化学作用、外加热和自生热以及由此产生的体系温度变化是该工艺能够实施的外因和重要动力学因素,由外因和内因的共同作用使这一工艺得以顺利高效进行. 相似文献
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Erdem Karakulak 《矿物冶金与材料学报》2017,24(1):83-90
Powder metallurgical Cu-Ti alloys with different titanium additions produced by hot pressing were characterized by optical microscopy, scanning electron microscopy, X-ray diffraction analysis, and hardness, wear and bending tests. The addition of titanium to copper caused the formation of different intermetallic layers around titanium particles. The titanium content of the intermetallics decreased from the center of the particle to the copper matrix. The hardness, wear resistance, and bending strength of the materials increased with increasing Ti content, whereas strain in the bending test decreased. Worn surface analyses showed that different wear mechanisms were active during the wear test of specimens with different chemical compositions. Changes in the properties of the materials with titanium addition were explained by the high hardness of different Cu-Ti intermetallic phases. 相似文献
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利用热丝化学气相沉积技术,在多孔钛膜上生长重掺硼金刚石薄膜,研究了碳源浓度对复合膜表面形貌及薄膜质量的影响.结果表明钛膜表面沉积的掺硼金刚石薄膜因碳源浓度的不同而不同,掺硼金刚石薄膜的质量随碳源浓度的减小而提高.金刚石/钛复合膜因碳源浓度的不同会产生复杂的变化,在重掺杂高碳源浓度下金刚石生长抑制碳化钛的形成. 相似文献
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激光加工技术可在材料表面形成多种纹理结构,为了研究激光加工所得不同纹理结构对材料润湿性的影响,通过纳秒激光加工技术在金属钛表面分别加工直线、网格和点阵的表面纹理结构。采用扫描电子显微镜、接触角测量仪、粗糙度分析仪和X射线光电子能谱分别对激光加工后的钛表面进行表面形貌、接触角、粗糙度与化学成分的表征与分析。结果表明:初经激光纹理加工后试样表面的粗糙度较激光加工前均显著提高,但此时3种纹理结构试样表面接触角均小于90°;随着时间的推移,被加工材料表面化学成分的改变带来了材料表面自由能的变化,进而使被加工表面接触角总体呈现上升趋势;待试样表面化学成分稳定后接触角也基本保持不变,并且对于每种纹理结构而言,其接触角随粗糙度的增加而升高。直线、网格和点阵纹理结构试样表面接触角最终可达157.2°,153.1°和134.6°,从而实现了钛表面润湿性由亲水性向疏水性的转变。 相似文献
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掺铜TiO2的制备及其光催化降解铝试剂1的研究 总被引:5,自引:1,他引:4
采用sol-gel法和高温灼烧制备了掺杂不同量的Cu^2 的TiO2/glass膜及纳米TiO2颗粒.研究了其对铝试剂的光催化降解过程,并由紫外吸收光谱对降解的中间产物进行了初步探讨.结果表明掺杂量为0.07%的Cu^2 时,光催化活性最佳.结合压电传感技术在线检测了不同气体氛围对TiO2光催化剂催化效果的影响,定量说明O2有利于光催化,而N2对其有抑制作用. 相似文献
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YANG Zhihu DU Shubin SU Hong ZHANG Yanping REN Shouting & ZENG Xiantang . Institute of Modern Physics Chinese Academy of Sciences Lanzhou China . China Institute of Atomic Energy Beijing China Correspondence should be addressed to Yang Zhihu 《科学通报(英文版)》2004,49(23):2443-2446
Spectra of highly charged ions have found wideapplications in X-ray laser, inertial confinement fusion,magnetic confinement fusion, astrophysics and plasmaphysics, serving as a key tool for diagnosing plasma state.Therefore it is very important to measure and provide pre-cise data of highly charged state spectra. In principle, any spectrum of any element can be ob-tained by the interaction of ions with appropriate energyand solid targets. Uranium spectra of H-like, He-like andLi-like i… 相似文献
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Surface modification is often performed using grit or shot blasting treatment for improving the performances of biomedical implants. The effects of blasting treatments using steel slag balls and spherical shots on the surface and subsurface of titanium were studied in this paper. The treatments were conducted for 60–300 s using 2–5 mm steel slag balls and 3.18 mm spherical shots. The surface morphology, roughness, and elemental composition of titanium specimens were examined prior to and after the treatments. Irregular and rough titanium surfaces were formed after the treatment with the steel slag balls instead of the spherical shots. The former treatment also introduced some bioactive elements on the titanium surface, but the latter one yielded a harder surface layer. In conclusion, both steel slag ball and shot blasting treatment have their own specialization in modifying the surface of metallic biomaterials. Steel slag ball blasting is potential for improving the osseointegration quality of implants; but the shot blasting is more appropriate for improving the mechanical properties of temporary and load bearing implants, such as osteosynthesis plates. 相似文献
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电子束熔化成型技术(electron beam melting,EBM)是3D打印的代表性技术之一,特别适合传统工艺不易加工的Ti-6Al-4V合金(TC4钛合金)的快速成型,目前在航空航天、化工、生物医疗等领域展示出巨大的应用前景。从EBM的原理出发,综述了EBM制备TC4钛合金的显微组织、缺陷以及力学性能。分析了受成型工艺参数和成型件位置等因素影响的冷却速度的变化所导致的TC4钛合金的显微组织发生变化;并指出了导致TC4钛合金出现缺陷的主要原因。EBM成型TC4钛合金的拉伸性能已与锻造TC4钛合金相当,其较低的疲劳强度可以通过热等静压处理提高。 相似文献
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Nanostructured Fe-doped titanium dioxide was synthesized from titanium containing electric furnace molten slag (TCEFMS) by using an alkali fusion, followed by a hydrolyzation-acidolysis-calcination route. The effects of alkali/slag mass ratio, calcinating temperature, calcinating time, and water/slag mass ratio on the extraction efficiency and purity of products were systematically studied in this paper. It is indicated that the best extraction efficiency of nanostructured Fedoped titanium dioxide is 99.35%, when the molten slag is calcinated at 700°C for 1 h with the mass ratio of alkali/molten slag of 1.5:1. The influence of alkali/slag mass ratio on the photocatalytic activity of final products was evaluated by the photodegradation of methyl blue under visible light irradiation. A maximum photodegradation efficiency of 88.12% over 30 min was achieved under the optimum conditions. 相似文献
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在低价钛试剂促进下,以2-(2-硝基苯基)苯并咪唑和碳酸二三氯甲酯为原料,经过串联还原偶联反应,一步合成了一系列苯并咪唑并[1,2-c]喹唑啉-6(5 H)-酮衍生物.产物结构通过红外光谱、核磁共振氢谱和元素分析确证. 相似文献