排序方式: 共有19条查询结果,搜索用时 15 毫秒
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Wei Datong Li Chenlu Shao Hanning Tan Zijing Lin Zhixian Dong Xiaoju Yuan Xiaoru 《显形杂志》2021,24(3):597-613
Journal of Visualization - Sensor networks composed of static and mobile sensors are applicable for situation monitoring. In this paper, we propose SensorAware, an interactive system for... 相似文献
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Markovitch O Chen H Izvekov S Paesani F Voth GA Agmon N 《The journal of physical chemistry. B》2008,112(31):9456-9466
Conditional and time-dependent radial distribution functions reveal the details of the water structure surrounding the hydronium during the proton mobility process. Using this methodology for classical multistate empirical valence bond (MS-EVB) and ab initio molecular dynamics trajectories, as well as quantal MS-EVB trajectories, we supply statistical proof that proton hops in liquid water occur by a transition from the H3O+[3H2O] Eigen-complex, via the H5O2+ Zundel-complex, to a H3O+[3H2O] centered on a neighboring water molecule. In the "resting period" before a transition, there is a distorted hydronium with one of its water ligands at a shorter distance and another at a longer distance than average. The identity of this "special partner" interchanges rapidly within the three first-shell water ligands. This is coupled to cleavage of an acceptor-type hydrogen bond. Just before the transition, a partner is selected by an additional translation of the H3O+ moiety in its direction, possibly enabled by loosening of donor-type hydrogen bonds on the opposite side. We monitor the transition in real time, showing how the average structure is converted to a distorted H5O2+ cation constituting the transitional complex for proton hopping between water molecules. 相似文献
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Adsorption of poly(acrylic acid) onto the surface of titanium dioxide and the colloidal stability of aqueous suspension 总被引:5,自引:0,他引:5
The adsorption of poly(acrylic acid) (PAA) in aqueous suspension onto the surface of TiO(2) nanoparticles was investigated. FTIR spectroscopic data provided evidence in support of hydrogen bonding and chemical interaction in the case of the PAA-TiO(2) system. Adsorption isotherms demonstrated that part of the PAA initially added to the suspension was adsorbed onto the TiO(2) surface, after which there was a gradual attainment of an adsorption plateau. The adsorption density of PAA was found to increase with an increase of PAA molecular weight, while it decreased with an increase of pH. The thickness of the PAA adsorption layer was calculated based on measurements of suspension viscosities in the absence and presence of PAA. It was shown that the thickness of the adsorption layer increased with the increase of pH, PAA molecular weight, and its concentration. The surface charge density, the diffuse charge density, and the zeta potential of TiO(2) varied distinctly after PAA adsorption. The shift of pH(iep) toward a lower pH value was observed in the presence of PAA. PAA was found to stabilize the suspension of TiO(2) nanoparticles through electrosteric repulsion. The influence of factors such as PAA molecular weight and its concentration on the colloidal stability of the aqueous suspension was also investigated. 相似文献
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Christian Mans Stephanie Hanning Christoph Simons Anne Wegner Anton Janβen Martin Kreyenschmidt 《Spectrochimica Acta Part B: Atomic Spectroscopy》2007
For the adoption of the EU directive “Restriction on use of certain Hazardous Substances” and “Waste Electrical and Electronic Equipment” using X-ray fluorescence analysis suitable standard materials are required. 相似文献
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Yang Qiu Songliu Yuan Zhaoming Tian Liang Chen Chuanhui Wang Hanning Duan Kai Guo 《Applied Physics A: Materials Science & Processing》2012,107(2):379-383
Single phase Bi1/2Na1/2Cu3Ti4O12 (BNCTO) ceramics with different grain sizes (1.4–4.3 μm) are prepared by a modified Pechini method to investigate their giant
dielectric and nonlinear electrical behaviors. The results show that the giant dielectric and nonlinear electrical behaviors
are strongly dependent on grain size. With the increment of grain size, the dielectric constant increases monotonically from
14110 (for 1.4 μm sample) to 36183 (for 4.3 μm sample) at 1 kHz, in accompaniment with the breakdown voltage reducing from
112.5 to 43.2 V/mm and the nonlinear coefficient reducing from 4.9 to 3.4. On the basis of the internal barrier layer capacitor
(IBLC) model and the IBLC model of Schottky-type potential barrier, an interpretation of the grain size effect on the giant
dielectric and nonlinear electrical behaviors is presented. 相似文献
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Varatharajan Sivasubramaniam Florian Brodkorb Stephanie Hanning Oliver Buttler Hans Peter Loebl Volker van Elsbergen Herbert Boerner Ullrich Scherf Martin Kreyenschmidt 《Solid State Sciences》2009,11(11):1933-1940
Different analytical tools and methodologies are currently employed to determine degradation products of organic blue light emitting devices in order to identify the failure mechanisms which determine the lifetime of these devices. This article provides a deeper understanding of degradation mechanisms of organic light emitting diodes (OLEDs) during device operation. Degradation products of blue emitting devices containing 8% of the phosphorescent emitter iridium(III)bis(4,6-difluorophenyl)-pyridinato-N,C2′ picolinate (FIrpic) in a matrix containing bis(2-methyl-8-quinolinolato)(4-phenylphenolato)aluminium (BAlq) as electron transport layer (ETL), 4,4′,4″-tri(N-carbazolyl)triphenylamine (TCTA) and N,N′-diphenyl-N,N′-bis(1-naphthyl)-1,1′-biphenyl-4,4″-diamine (α-NPD) were investigated using laser desorption ionization (LDI) coupled with a time of flight mass spectrometry (TOF/MS). Especially chemical degradation pathways of the hole transport materials TCTA and α-NPD were investigated. The comparison of experimental data of unstressed and stressed device revealed that new reaction products are formed during the device operation. The linkage of TCTA fragments to the α-NPD core in an interfacial reaction as well as a dimerization of TCTA itself was observed. Ten new reaction products could be characterized via LDI-TOF-MS. Some of these compounds might possess a negative influence on the drop of efficiency and lifetime of blue light emitting devices based on FIrpic. 相似文献
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Hanning Li Yang Yang Prof. Xu Jing Prof. Cheng He Prof. Chunying Duan 《化学:亚洲杂志》2021,16(10):1237-1244
Visible-light-driven hydrogen production coupled with selective organic oxidation has attracted increasing attention, as it not only provides clean and renewable energy, but also utilizes the other half reaction to achieve some value-added organic chemicals. Metal-organic frameworks based on metal clusters and organic ligands self-assembly give a perspective on the formation of multifunctional heterogeneous photocatalyst to significantly boost visible-light photocatalytic activities under mild conditions. By incorporating two types of photoactive units, tricarboxytriphenylamine (H3 TCA ) and tris(4-(pyridinyl)phenyl)amine ( NPy3 ), into a single metal-organic frameworks, a multi-component MOF Co- MIX was obtained. With the redox active metal centers enabling the photoexcitation reduction of protons into hydrogen and the photogenerated holes promoting considerable oxidation of substrates, the resulting Co- MIX exhibits high catalytic activity for the photocatalytic hydrogen production coupled with selective oxidation of benzylamine or 1,2,3,4-tetrahydroisoquinoline. Importantly, the photocatalytic experiments of single-component Co- TCA and Co- NPy3 verified the positive synergistic effects on stability and photocatalytic ability of the two ligands (H3 TCA and NPy3 ) in one single MOF, revealing that the multi-component strategy is very important for the efficient charge separation and excellent photocatalytic activity of the catalyst. 相似文献