共查询到19条相似文献,搜索用时 78 毫秒
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O2在U和U—Nb合金表面吸附的XPS研究 总被引:2,自引:0,他引:2
采用X射线光电子能谱(XPS)分析研究了298K时O2在金属U和U-Nb合金清洁表面的原位吸附过程,作为对照还研究了经纯Nb表面的吸附,吸附各阶段XPS图谱的变化揭示了O2在U,Nb和N-Nb合金表面的吸附将导至UO2,NbO和Nb2O5等多种产物形成,定量分析表明,O2在U和U-Nb合金表面的饱和吸附量大约分别为45L和40L(1L=1.33x10^-4Pa.s),而O2在金属Nb上的饱和吸附量仅约为10L。 相似文献
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玻璃表面改性的XPS研究 总被引:1,自引:0,他引:1
用硅烷对B-1E型玻璃封接的电子器件座表面进行了处理改性,大大提高了玻璃表面的电气绝缘性能。本文用X射线光电子能谱分析研究了玻璃面Si2P和O1s电子结构作用前后的变化,指出这一相互作用是一种化学过程,作者还提出了硅烷与玻璃表面化学富的理想模型。 相似文献
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等离子体喷涂Sn和ZrO2涂层/U-Nb合金摩擦副的摩擦性能 总被引:1,自引:0,他引:1
探讨了用等离子体喷涂方法制备改善与U-Nb合金之间摩擦性能的减摩层的可行性。比较了U-Nb合金在涂层表面滑动时Sn软涂层,Sn/ZrO2双涂层,ZrO2硬涂层和ZrO2中加入Sn的混合涂层的摩擦特性。结果表明,表层为Sn的单涂层和Sn/ZrO2双涂层的摩擦性能相近,Sn单涂层的摩擦系数最低。ZrO2硬涂层一直保持着较高的摩擦系数,在ZrO2中加入Sn后,涂层的摩擦系数没有得到有效改善。用等离子体喷涂方法制备的ZrO2硬涂层不适合作U-Nb合金的减摩层。切削是Sn、Sn/ZrO2、Sn ZrO2、ZrO2的涂层与U-Nb合金之间主要的摩擦机理。 相似文献
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用XPS研究了金属Ni在不同温度下在空气和水中的氧化行为及生成的表面氧化物的热稳定性。结果表明氧化物除NiO以外还存在Ni_2O_3。在室温下长期暴露空气后Ni表面生成Ni_2O_3更明显。金属Ni在纯水中氧化比空气中慢得多。研究结果还表明:Ni表面氧化物的热稳定性与其生成时的温度密切有关。金属Ni在室温暴露空气生成的NiO在10~(-6)Pa真空中在300℃加热10min即可使其还原成金属Ni。该还原作用是NiO与表面碳氢化合物污染物之间的反应。然而,在200℃以上在空气中加热生成的NiO在相同条件下作真空热处理时不能使其还原成金属。最后本文对不同温度下生成的NiO有不同的热稳定性的原因进行了讨论。 相似文献
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用X射线光电子能谱(XPS)研究了用化学还原法制备的FeNiB超细非晶粉.表征了粉末颗粒表面层各元素状态和分布的特性. 相似文献
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以U-Nb合金为对象,研究了激光焊接过程中U-Nb合金焊接接头的微观组织和力学性能。结果表明,U-Nb合金母材的微观组织为片层状结构,主要物相为α-U+γ-U双相混合珠光体。U-Nb合金焊缝区的组织为致密的α-马氏体,相比于母材中的两相珠光体,屈服强度由820 MPa升高到1 200 MPa,塑性从25%下降到4%左右。 相似文献
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应用EET理论和改进的TFD理论对Al-Mg-Si合金时效过程中析出的U1与U2相的原子成键和结合能进行计算。结果表明:两相晶胞中最强键和次强键都是Al—Si键,其键络比基体Al晶胞中的最强键络都强得多;两析出相晶胞中都以较强的Al—Si键构成主要键络骨架结构,起到增强基体键络强度、强化合金的作用。由于析出相U1比析出相U2具有更强的Al—Si键络结构,且结合能较大,因此,相对U2相来说,U1相更稳定。计算结果还表明:(001)Al//(110)U1相界面处电荷保持连续且连续性较好,界面应变能较低,界面较稳定;界面(001)Al//(010)U2处的面电荷密度偏离连续条件,因此在此界面处,应力较大,界面原子键匹配较差,界面储能(应变能)较高,容易成为新相形核、长大和裂纹萌生的地方。 相似文献
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空气中的Ag熔化时会溶解大量的O2,O2在Ag上的吸附特性对研究其相互作用至关重要。基于分子动力学和蒙特卡洛模拟方法,先根据吸附曲线得到了不同温度、压强下O2在Ag(111)表面上的吸附量,然后建立Ag-O2体系的吸附模型,研究了Ag(111)表面对O2的吸附行为。结果表明,O2会大量吸附在Ag表面,距Ag原子0.325 nm处O2最容易被吸附,但随着温度升高,O2在Ag(111)面上的自由能增加、扩散系数增大且吸附能降低。随着压强增大,O2的吸附量逐渐上升,直至达到饱和吸附。 相似文献
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QI Yunxin TANG Wentai XIA Jianguo Nei Mongol Institute of Metallic Materials Baotou ChinaLI Wang ZHAN Zhenzong Institute of Physical Chemical Engineering Research Tianjin China 《金属学报(英文版)》1991,4(9):219-224
The surface segregation of substrate elements through the Au layer in the Au-Ni-Kovar sys- tem specimens heated at 250—350℃ for 0.5—1.5 h has been studied by SAM and XPS. Visual evidence of the mechanism for Ni and Co surface segregation of the complicated sys- tem has been given,i.e.Ni and Co penetrated the gold layer mainly by grain boundary diffu- sion and then covered the Au layer by surface diffusion.The strdy results of the chemical states of surface segregation elements not only indicate that oxygen adsorption and oxidation reaction are the driving force for the surface segregation of Ni and Co,but also show that the above segregation can result in water absorption on surfaces. 相似文献
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衣藻对铅离子的耐受性研究 总被引:8,自引:0,他引:8
研究结果表明,衣藻对环境中的Pb2+具有较强的耐受性和吸附作用,Pb2+的浓度(每100m1中的添加量)在20 μg以下对衣藻的生长具有促进作用,40μg以上对衣藻的生长逐渐有一定的抑制作用,400μg以上衣藻开始停止生长繁殖.同时,衣藻对Pb2+的吸附量随着初始浓度的增大而增大. 相似文献
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Sun Shuiyu Wang Dianzuo Li Bodan Central-South University of Technoloyy Changsha China 《中国有色金属学会会刊》1993,(3)
The adsorption mechanisms of HS~- ions existing in air-saturated alkaline solutions on sulphide minerals (including pyrite, arsenopyrite, chalcopyrite and galena) were investigated. The measurement of adsorption density, solvent extraction-chemical analysis of neutral sulphur at the surfaces, measurements of pulp potential and voltammogram, and flotation tests were done. Both the electrochemical and non-electrochemi cal adsorption models of HS~- ions were established. The former was observed and resulted in the formation of neutral sulphur (S°)when the pyrite and arsenopyrite were chosen, and hence renders the surfaces hy drophobic and induced the two minerals flotation. It is called Na_2S-induced flotation. On the other hand, the latter took place and did not produce S° when the chalcopyrite and galena were selected, and hence de presses the collectorless flotation of the two minerals. The adsorptions of HS~- ions were mainly influenced by potentials, pH and the electron structures of the mineral surfaces. 相似文献
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FAN Yongnian TANG Baozhen QIAO Guiwen Institute of Metal Research Academia Sinica Shenyang China Associate Professor Institute of Metal Research Academia Sinica Shenyang China 《金属学报(英文版)》1993,6(7):21-24
Interfaces and surfaces of YBa_2Cu_3O_(7-x)(YBCO)-Ag have been studied by SEM-EDXand AES.No effect of Ag on 123 structure in X-ray diffraction pattern was observedfor 0.4 mol Ag doped YBCO.AES analysis indicated that Ag segregated on surfaceof YBCO and resulted in decrease of YBCO-metal lead resistance.In addition,solutionand segregation of Ag as elemental state were often appeared on interfaces and surfacesof high temperature annealed YBCO,whether elemental Ag or compound Ag_2O andAgNO_3 adopted as doping material. 相似文献
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STUDY ON THE PROPERTIES OF DIFFERENT ACTIVATED CARBON FIBERS AND THEIR ADSORPTION CHARACTERISTICS FOR FORMALDEHYDE 总被引:1,自引:0,他引:1
1. IntroductionOne of the undesirable features of the modern day world is the widespread coatami-nation associated with the release of a large number of chemicals into the environment.At presellt, people paid more and more attention to indoor air pollution than ever be-cause people almost spend their 8ty90% time in rooms everyday. FOrmaldehyde and otheraldehydes are main pollutans in indoor air. Formaldel1yde is a kind of poison. Highconceatrated formaldehyde can cause a 8eries of symptoms su… 相似文献
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XPS研究黄铜表面防变色膜 总被引:1,自引:1,他引:0
以聚乙烯醇缩丁醛和茉并三氯唑为主要成分研制的防变色处理剂,在黄铜表面形成的保护膜经X射线光电子能谱(XPS)分析,表明该膜有多层结构,苯并三氮唑在其中起交联偶合作用,保护膜厚为3~5μm。 相似文献
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贮氢合金La(NiSnCo)5.12微包覆镍研究 总被引:8,自引:4,他引:4
研究了化学镀镍法对贮氢合金粉末表面镀镍的工艺。该法无需经过PdCl2活化,在含有0.20moL/LNiSO4,0.40moL/LNaH2PO2,0.06moL/LNa3C6H5O7,0.56moL/LNH4Cl的溶液中,控制pH9.0~9.5,温度50℃,镀镍时间25~30min,可以得到镀镍量为9%~20%(质量分数)的镍镀层。SEM形貌分析表明,获得的镀层厚度和成分均匀,镀层中含有5%(质量分数)的P元素。X射线衍射分析结果显示出镀层为一种非晶态结构。 相似文献