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91.
A density functional theory study on the adsorption of CO and O2 on Cu-terminated Cu2O (111) surface
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The adsorptions of CO and 02 molecules individually on the stoichiometric Cu-terminatcd Cu20 (111) surface are investigated by first-principles calculations on the basis of the density functional theory. The calculated results indicate that the CO molecule preferably coordinates to the Cu2 site through its C atom with an adsorption energy of-1.69 eV, whereas the 02 molecule is most stably adsorbed in a tilt type with one O atom coordinating to the Cu2 site and the other O atom coordinating to the Cul site, and has an adsorption energy of -1.97 eV. From the analysis of density of states, it is observed that Cu 3d transfers electrons to 2π orbital of the CO molecule and the highest occupied 5σ orbital of the CO molecule transfers electrons to the substrate. The sharp band of Cu 4s is delocalized when compared to that before the CO molecule adsorption, and overlaps substantially with bands of the adsorbed CO molecule. There is a broadening of the 2π orbital of the 02 molecule because of its overlapping with the Cu 3d orbital, indicating that strong 3d-2π interactions are involved in the chemisorption of the 02 molecule on the surface. 相似文献
92.
Hong Li Xiao-Fang Jia Qing Zhao Ju-Ping Ma Dr. Jian-Dang Liu Prof. Dr. Bang-Jiao Ye Prof. Dr. Yoshihiro Kuroiwa Prof. Dr. Chikako Moriyoshi Zhi-Yong Li Qi Liu Prof. Dr. Jun-Ying Zhang Prof. Dr. Hong-Tao Sun 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(55):12842-12848
Aurivillius phases have been routinely known as excellent ferroelectrics and have rarely been deemed as materials that luminesce in the near-infrared (NIR) region. Herein, it is shown that the Aurivillius phases can demonstrate broadband NIR luminescence that covers telecommunication and biological optical windows. Experimental characterization of the model system Bi2.14Sr0.75Ta2O9−x, combined with theoretical calculations, help to establish that the NIR luminescence originates from defective [Bi2O2]2+ layers. Importantly, the generality of this finding is validated based on observations of a rich bank of NIR luminescence characteristics in other Aurivillius phases. This work highlights that incorporating defects into infinitely repeating [Bi2O2]2+ layers can be used as a powerful tool to space-selectively impart unusual luminescence emitters to Aurivillius-phase ferroelectrics, which not only offers an optical probe for the examination of defect states in ferroelectrics, but also provides possibilities for coupling of the ferroelectric property with NIR luminescence. 相似文献
93.
利用大直径双水电极介质阻挡放电装置,在氩气和空气的混合气体中观察到了相同实验条件下不同边界的放电区域出现不同放电模式的实验现象.其中正方形封闭边界内可形成规则的斑图,而半开放放电区域只能看到随机游走的放电丝.通过采集发射光谱发现封闭边界内激发能较高的几条谱线如696.5,727.3,750.4和772.4nm的相对强度... 相似文献
94.
在氩气、空气混合气体介质阻挡放电中,首次利用光谱方法,测量了圆圈点放电丝中圆圈放电和中心点放电的振动温度,并研究了它们随空气含量的变化.振动温度的计算利用的是氮分子第二正带系(C3Ⅱu→B 3Ⅱg)的发射谱线.结果表明:圆圈放电的振动温度高于中心点放电的振动温度;二者均随空气含量的增加而增加,但圆圈放电振动温度的增加速... 相似文献
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97.
Wei-Li Dong Jun-Ying Xu Li-Xia Xiong Zheng-Ming Li 《Journal of the Iranian Chemical Society》2013,10(3):429-437
A novel series of amides containing N-pyridylpyrazole were designed and synthesized. All of the compounds were characterized and confirmed by IR, 1H NMR, 13C NMR, MS and elemental analysis. The single crystal structure of 9d was determined by X-ray diffraction. The bioassay tests showed that the title compounds exhibited good insecticidal activities against Mythimna separata Walker, diamondback moth and Laphygma exigua Hübner. 相似文献
98.
We designed and synthesized a new pH fluorescent probe, RCE, based on structural changes of rhodamine dye at different pH values. The probe exhibits high selectivity, high sensitivity and quick response to acidic pH, as well as low cytotoxicity, excellent photostability, reversibility and cell membrane permeability. Fluorescence intensity at 584 nm was increased more than 150-fold within pH range 7.51–3.53. This probe has pKa value 4.71, which is valuable for studying acidic organelles. Because of its long absorption and emission wavelengths, RCE can avoid associated cell damage. The probe can selectively stain lysosomes and monitor lysosomal pH changes in living cells. 相似文献
99.
Yong-Sheng Xie Deepak Kumar V.D. Vijaykumar Bodduri P. Srivastava Tarani Bao-Xiang Zhao Jun-Ying Miao Kiwan Jang Dong-Soo Shin 《Tetrahedron letters》2014
A series of benzofuran-2-carboxamides of biological and medicinal significance were synthesized by a microwave-assisted one-pot parallel approach via O-alkylation/Knoevenagel condensation. All the compounds were characterized and assayed for their in vivo anti-inflammatory, analgesic and antipyretic activities. The activity data of all compounds were listed and discussed in detail, among which some derivatives exhibited potent activities of particular interest. 相似文献
100.
Wang RY Liu XY Narayanan J Xiong JY Li JL 《The journal of physical chemistry. B》2006,110(51):25797-25802
A new approach of engineering of molecular gels was established on the basis of a nucleation-initiated network formation mechanism. A variety of gel network structures can be obtained by regulating the starting temperature of the sol-gel transition. This enables us to tune the network from the spherulitic domains pattern to the extensively interconnected fibrillar network. As the consequence of fibrous network structure turning, desirable rheological and other in-use properties of the materials can be obtained accordingly. This approach of micro-/nanostructural fabrication may open up a new route for micro-/nanofunctional materials engineering in general. 相似文献