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51.
G. L. Chia 《Journal of Graph Theory》1995,19(2):251-261
A graph is chromatically unique if it is uniquely determined by its chromatic polynomial. Let G be a chromatically unique graph and let Km denote the complete graph on m vertices. This paper is mainly concerned with the chromaticity of Km + G where + denotes the join of graphs. Also, it is shown that a large family of connected vertextransitive graphs that are not chromatically unique can be obtained by taking the join of some vertex-transitive graphs. © 1995 John Wiley & Sons, Inc. 相似文献
52.
The effects of power ultrasound on four metal-nonmetal powdered systems: copper-sulphur iron-sulphur, zinc-sulphur and magnesium-sulphur in various solvents, such as hexane and carbon disulphide, are briefly examined here. For each system, a sonication time of 30 min was affected. The sonicated products are analysed by X-ray diffraction, X-ray fluorescence and atomic absorption spectrophotometry to determine their qualitative and quantitative compositions and the percentage yields of the products obtained are then compared and discussed. 相似文献
53.
Flavone ( 1 ) was easily reduced by using the electrochemical method to give two hydrodimers of 2,2′‐biflavanone(racemate) ( 5a ) and 2,2′‐biflavanone(meso) ( 5b ) and one reductive product of flavanone ( 6 ). Their yields were dependent on the nature of electrodes, the kinds of supporting electrolytes and the reaction temperature. They were found to afford higher yields of 2,2′‐biflavanone(racemate) ( 5a ) and 2,2′‐biflavanone (meso) ( 5b ) (32.4% and 24.8%, 35.8% and 13.4%, respectively,) in the reaction conditions of Pb(‐)/C(+)‐H2SO4‐7F/mol and C(‐)/C(+)‐H2SO4‐5F/mol. 相似文献
54.
C.M. Lin C.T. Chia V. I. Mashanov H.H. Cheng 《光散射学报》2005,17(3):283-284
pacc:7830,7850C Wepresentthemicro-Ramanstudyof curvedGexSi1-x/GeySi1-yheterostructure,and foundthestrainofthecurvedthinlayerispropor tionaltothecurvature,i.e.inverselyproportional tothediameter.TheopticalandelectricpropertiesofSi1-x GexalloygrownonSisubst… 相似文献
55.
Silver‐Assisted Chemical Etching on Silicon with Polyvinylpyrrolidone‐Mediated Formation of Silver Dendrites 下载免费PDF全文
Metal‐assisted chemical etching (MaCE) on silicon (Si)—mediated by polyvinylpyrrolidone (PVP)—is systematically investigated herein. It is found that the morphologies and crystallographic natures of the grown silver (Ag) dendrites can be significantly modulated, with the presence of PVP in the MaCE process leading to the formation of faceted Ag dendrites preferentially along the (111) crystallographic phase, rather than along the (200) phase. Further explorations of the PVP‐mediated effect on Si etching are also revealed. In contrast to the aligned Si nanowires formed by MaCE without PVP addition, only distributed nanopores with sizes of 200 to 400 nm appear on the Si surfaces in the presence of PVP. The origin of surface polishing on Si in the PVP‐mediated MaCE process can be attributed to the distinct transport pathway of holes supplied by the Ag+ ions, where the holes are injected directly into the primary Ag seeds, rather than through Ag dendrites, thus leading to the isotropic etching of the Si surface. 相似文献
56.
Prof. Dr. Konstantin V. Kudryavtsev Chia‐Chun Yu Polina M. Ivantcova Prof. Dr. Vladimir I. Polshakov Dr. Andrei V. Churakov Prof. Dr. Stefan Bräse Prof. Dr. Nikolay S. Zefirov Prof. Dr. Jih‐Hwa Guh 《化学:亚洲杂志》2015,10(2):383-389
Functionalized oligomeric organic compounds with well‐defined β‐proline scaffold have been synthesized by a cycloadditive oligomerization approach in racemic and enantiopure forms. The structure of the novel β‐peptides was investigated by NMR spectroscopic and X‐ray methods determining the conformational shapes of the β‐proline oligomers in solution and solid states. The main structural elements subject to conformational switches are β‐peptide bonds between 5‐arylpyrrolidine‐2‐carboxylic acid units existing in Z/E configurations. The whole library of short β‐peptides and intermediate acrylamides has been tested on antiproliferative activity towards the hormone‐refractory prostate cancer cell line PC‐3 revealing several oligomeric compounds with low micromolar and submicromolar activities. Bromine‐substituted dimeric and trimeric acrylamides induced caspase‐dependent apoptosis of PC‐3 cells through cell‐cycle arrest and mitochondrial damage. 相似文献
57.
Chih‐Hsien Wang Chia‐Chi Huang Long‐Liu Lin Wenlung Chen 《Journal of Raman spectroscopy : JRS》2016,47(8):940-947
Disulfide bond is relevant to many protein folding/unfolding functions and conformational diseases. To elucidate the effects of disulfide bonds on protein folding, unfolding, and misfolding, we performed Fourier transform–Raman measurements on serial chemical‐induced denaturations of bovine serum albumin (BSA). By directly monitoring Raman stretching at S–S (~507 cm−1), S–H (~2566 cm−1), amide I (1655 cm−1 for α‐helix; 1667 cm−1 for β‐sheet structure), and amide III (>1300 cm−1 for α‐helix; 1246 cm−1 for β‐sheet structure), the status of disulfide bonds and secondary structure of BSA at different states were elucidated. Both disulfide bonds and secondary structure (mostly in α‐helix) of BSA appeared relatively stable even when the protein was unfolded by urea solution. However, disulfide bonds were completely reduced and protein secondary structure changed from α‐helix to a relatively β‐sheet dominant when the protein was modified by the mixed solution of urea and dithiothreitol (urea/DTT). Adhering to these structural changes, the protein proceeded to different degrees of polymerization. BSA would aggregate into a high molecular mass (over 700 kDa) of protein ensemble when it was exposed to the mixed urea/DTT solution. An irreversible change in S–S/S–H conversion and secondary structure was responsible for protein misfolding. We demonstrate here that Fourier transform–Raman directly probe S–S/S–H conversion and secondary structural change of BSA at different states, and these results clearly indicate that disulfide bonds and secondary structure of BSA serve as concrete frameworks to stabilize protein structure. As the frameworks collapse, the protein undergoes an irreversible structural change and results in protein misfolding. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
58.
Chia‐Chun Chou 《International journal of quantum chemistry》2015,115(7):419-425
A simple and easy‐to‐implement method is presented for the study of time‐dependent reaction dynamics by propagating an ensemble of transmitted quantum trajectories. During the trajectory evolution, reflected trajectories are gradually removed and all the remaining trajectories represent the transmitted subensemble. The removal process of reflected trajectories avoids numerical instabilities arising from node formation in the reactant region, and allows stable long‐time propagation of transmitted trajectories. This method is applied to a two‐dimensional model chemical reaction. Excellent computational results are obtained for the time‐dependent reaction probabilities evaluated by the time integration of the probability flux. © 2014 Wiley Periodicals, Inc. 相似文献
59.
this paper presents a series solution to von Kármán nonlinear equations of a rectilinearly orthotropic rectangular plate under the combined action of lateral load and in-plane tension with the titled edge restraints. In the formulation the edge moments are replaced by an equivalent pressure near the edges. Using generalized double Fourier series for the deflection and stress function, governing equations are reduced to an infinite set of algebraic equations for coefficients in these series. Numerical results for deflections, bending moments and in-plane forces are graphically presented for various values of aspect ratio and material properties and for different edge conditions. 相似文献
60.
Dr. M. K. Prabhakara Dr. C. Y. Chia 《Archive of Applied Mechanics (Ingenieur Archiv)》1976,45(2):131-139
Summary An analysis based on the von Kármán-type large-deflection equations of plates is presented for the postbuckling behavior of homogeneous and symmetrically laminated anisotropic rectangular plates. Boundary conditions for both simply supported and clamped edges are considered. A solution is obtained by expressing the force function and transverse deflection as double series involving the appropriate beam eigen-functions. Numerical results are presented for graphite-epoxy angle-ply laminates and homogeneous anisotropic plates. In the cases of buckling of anisotropic plates and postbuckling of isotropic and orthotropic plates, the present solution is in good agreement with existing solutions.
The results presented in this paper were obtained in the course of research sponsored by the National Research Council of Canada. 相似文献
Übersicht Es wird das Nachbeulverhalten von homogenen, symmetrisch geschichteten, anisotropen Rechteckplatten auf der Grundlage der von Kármán angegebenen Platten-Gleichungen für große Auslenkungen untersucht. Dabei werden sowohl einfach aufliegende, wie auch eingespannte Ränder als Randbedingungen berücksichtigt. Lösungen werden dadurch gewonnen, daß die Belastungsfunktion und die Querauslenkung als doppelte Reihen von geeigneten Balken-Eigenfunktionen angesetzt werden. Für Graphit-Epoxid-Schichtplatten und anisotrope homogene Platten werden numerische Ergebnisse mitgeteilt. Die erhaltenen Lösungen stimmen in den Fällen des Beulens von anisotropen Platten sowie des Nachbeulens von isotropen und orthotropen Platten gut mit bekannten Lösungen überein.
The results presented in this paper were obtained in the course of research sponsored by the National Research Council of Canada. 相似文献