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81.
Khor Soo Wei Lee Yean Kee Abas Mhd Radzi Bin Tay Kheng Soo 《Journal of Sol-Gel Science and Technology》2017,82(3):834-845
Journal of Sol-Gel Science and Technology - This study demonstrated the application of chalcone-based dithiocarbamate derivative as metal capturing ligand for the removal of mercury ion (Hg2+) in... 相似文献
82.
Reductive Coupling of Diynes at Rhodium Gives Fluorescent Rhodacyclopentadienes or Phosphorescent Rhodium 2,2’‐Biphenyl Complexes
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Carolin Sieck Dr. Meng Guan Tay Dr. Marie‐Hélène Thibault Dr. Robert M. Edkins Dr. Karine Costuas Prof. Dr. Jean‐François Halet Dr. Andrei S. Batsanov Dr. Martin Haehnel Dr. Katharina Edkins Dr. Andreas Lorbach Dr. Andreas Steffen Prof. Dr. Todd B. Marder 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(30):10523-10532
Reactions of [Rh(κ2‐O,O‐acac)(PMe3)2] (acac=acetylacetonato) and α,ω‐bis(arylbutadiynyl)alkanes afford two isomeric types of MC4 metallacycles with very different photophysical properties. As a result of a [2+2] reductive coupling at Rh, 2,5‐bis(arylethynyl)rhodacyclopentadienes ( A ) are formed, which display intense fluorescence (Φ=0.07–0.54, τ=0.2–2.5 ns) despite the presence of the heavy metal atom. Rhodium biphenyl complexes ( B ), which show exceptionally long‐lived (hundreds of μs) phosphorescence (Φ=0.01–0.33) at room temperature in solution, have been isolated as a second isomer originating from an unusual [4+2] cycloaddition reaction and a subsequent β‐H‐shift. We attribute the different photophysical properties of isomers A and B to a higher excited state density and a less stabilized T1 state in the biphenyl complexes B , allowing for more efficient intersystem crossing S1→Tn and T1→S0. Control of the isomer distribution is achieved by modification of the bis‐ (diyne) linker length, providing a fundamentally new route to access photoactive metal biphenyl compounds. 相似文献
83.
A.A. Kamel CM. Ma M.S. El-Aasser F.J. Micale J.W. Vanderhoff 《Journal of Dispersion Science and Technology》2013,34(2-3):315-330
The electrophoretic mobility behavior of well-characterized polystyrene latex particles, carrying one type of surface functional endgroups, has been studied as a function of pH. At low pH, the interaction of protons with the functional endgroups increased in the order: Hydroxyl > carboxyl > sulfate; at high pH the order of interaction was reversed; and at intermediate pH no interactions were observed. The particles of the polystyrene latexes in their different forms at the intermediate pH range, dispersed in deionized water, all exhibited the same mobility irrespective of the functional endgroup. The origin of charge in these systems is explained as being the result of either the preferential adsorption of hydroxyl ions or an electron - injection mechanism due to the overlap of local intrinsic molecular - ion states in polystyrene and water. At low concentrations of functional endgroups, the surface properties of the polystyrene latexes are largely dependent upon the hydrophobic nature of the surface. 相似文献
84.
Phase retrieval in two-wavelength DSSI (digital speckle shearing interferometry) using a combined filtering method is proposed for small deformation derivative measurement. A simultaneous two-wavelength illumination and 3-CCD camera are employed in the experimental setup. The proposed method, which uses a two-wavelength technique does not require the conventional spatial phase unwrapping and has the advantage of good noise suppression for phase retrieval. Experimental results obtained show that using the proposed combined filtering method sensitivity similar to the single wavelength technique can be achieved. 相似文献
85.
Dr. Junkuo Gao Qiuling Tay Dr. Pei‐Zhou Li Dr. Wei‐Wei Xiong Prof. Dr. Yanli Zhao Prof. Dr. Zhong Chen Prof. Dr. Qichun Zhang 《化学:亚洲杂志》2014,9(1):131-134
A new two‐dimensional (2D) oxosulfide, (N2H4)2Mn3Sb4S8(μ3‐OH)2 ( 1 ), has been successfully synthesized under surfactant–thermal conditions with hexadecyltributylphosphonium bromide as the surfactant. Compound 1 has a layered structure and contains a novel [Mn3(μ3‐OH)2]n chain along the b‐axis. The photocatalytic activity for compound 1 has been demonstrated under visible‐light irradiation and continuous H2 evolution was observed. Our results indicate that surfactant–thermal synthesis could be a promising method for growing novel crystalline oxochalcogenides with interesting structures and properties. 相似文献
86.
Linking (n − 2)-dimensional panels inn-space II: (n − 2, 2)-frameworks and body and hinge structures
Tiong-Seng Tay 《Graphs and Combinatorics》1989,5(1):245-273
An (n – 1, 2)-framework inn-space is a structure consisting of a finite set of (n – 2)-dimensional panels and a set of rigid bars each joining a pair of panels using ball joints. A body and hinge (or (n + 1,n – 1)-) framework inn-space consists of a finite set ofn-dimensional bodies articulated by a set of (n – 2)-dimensional hinges, i.e., joints in 2-space, line hinges in 3-space, plane-hinges in 4-space, etc. In this paper we characterize the graphs of all rigid (n – 1, 2)- and (n + 1,n – 1)-frameworks inn-space. Rigidity here is statical rigidity or equivalently infinitesimal rigidity. 相似文献
87.
Almost Minimum Diameter Orientations of Semicomplete Multipartite and Extended Digraphs 总被引:1,自引:0,他引:1
An orientation of a digraph D is a spanning subdigraph of D obtained from D by deleting exactly one arc between x and y for every pair x≠y of vertices such that both x
y and y
x are in D. Almost minimum diameter orientations of certain semicomplete multipartite and extended digraphs are considered, several
generalizations of results on orientations of undirected graphs are obtained, some conjectures are posed.
Received: August 31, 2000 Final version received: October 30, 2001
Acknowledgments. Part of this work was done when the first author was visiting the Department of Mathematics, National University of Singapore.
The departmental hospitality and financial support are very much appreciated. 相似文献
88.
Tiong-Seng Tay 《Discrete and Computational Geometry》1994,11(1):97-109
The calotte condition is the projective condition that a cycle of lines radiating from the vertices of a planen-gon be the correct projection of a ring of faces surrounding ann-gonal piece of plane in space, the spatial figure being not entirely coplanar. This condition can be expressed as a homogeneous
bracket polynomial. In general, this polynomial is not Cayley factorable. Henry Crapo conjectured that it becomes so when
multiplied by a product ofn−4 brackets. It is the purpose of this article to prove this conjecture. 相似文献
89.
Photooxygenatlon of oximc derivatives in methanolic sodium hydroxide solution at ice temperature enabled the recovery of the parent ketones in high yield. This method is useful to deprotect a ketoxime. 相似文献
90.
Zirconium oxide (ZrO2) thin films deposited at room temperature by the filtered cathodic vacuum arc (FCVA) technique are detailed in terms of the film structure, composition, morphology, and optical and mechanical properties, which are tailored by the oxygen (O2) flow rate during deposition. The relationships between the film structure, composition, morphology, and properties are emphasized. With an increasing O2 flow rate, the film evolves in structure from amorphous, through a pure monoclinic phase with varying preferential orientation, to amorphous again, accompanied by an increase in the O/Zr atomic ratio and a conversion of Zr ions from low oxidation states into Zr4+. Such a structural trend arises from the change in composition, and influences the film morphology and mechanical properties so that the amorphous films exhibit small clusters on the surface and smoother morphology as well as lower hardness compared with the polycrystalline films. The film composition rather than the density dominates the optical properties, where the transmittance and the optical band gap increase with increasing O/Zr values, while the refractive index and extinction coefficients behave conversely with the lowest refractive index (2.16 at 550 nm) approaching the bulk value (2.2) . PACS 68.55.Jk; 78.66.Nk; 68.37.Ps 相似文献