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81.
Swee-Ping Chia 《Physics letters. [Part B]》1990,240(3-4):465-470
The flavour-changing radiative decay b→sγ is analysed, and is found to be sensitive to the WWγ coupling. QCD corrections are found to play an important role. A good measurement of the branching ratio for B→K*γ may allow us to test the gauge coupling for WWγ of the standard model. 相似文献
82.
Yu‐Liang Yang Dr. Wen‐Ying Liao Wan‐Yun Liu Chih‐Chuang Liaw Dr. Chia‐Ning Shen Dr. Zih‐You Huang Shih‐Hsiung Wu Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(43):11573-11580
Six photosensitive polyketides, malbranpyrroles A–F, were discovered from the thermophilic fungus Malbranchea sulfurea by using intact‐cell desorption/ionization on silicon mass (ICD‐MS) and LC‐SPE‐NMR. These two strategies facilitate the searching and structural determination of unstable natural products. The ICD‐MS indicated that only brown hyphae of M. sulfurea can produce malbranpyrroles. The biosynthetic pathway of malbranpyrroles was evidenced by 13C isotope precursors and amino acid feeding experiments. The cytotoxicity data revealed that the conformation of the conjugated system in malbranpyrroles does not affect cytotoxic potency against cancer cell lines. In addition, the chlorine atom was shown to be the pharmacophore for cytotoxicity. 相似文献
83.
C-藻蓝蛋白的电致发光 总被引:1,自引:1,他引:0
藻胆蛋白(phycobiliProteins)是藻类光合作用过程中最重要的拍光色素之一,它具有吸收太阳光能并将其高效地(几乎100%)转移到光合反应中心的功能[1].它在可见光区的吸收光谱主要归因于与脱辅基蛋白共价相连的线性四吡咯发色团[2]. 相似文献
84.
Chia‐Fen Lee Chia‐Jen Wen Chia‐Lung Lin Wen‐Yen Chiu 《Journal of polymer science. Part A, Polymer chemistry》2004,42(12):3029-3037
Poly [N‐isopropylacrylamide (NIPAAm)–chitosan] crosslinked copolymer particles were synthesized by soapless emulsion copolymerization of NIPAAm and chitosan. An anionic initiator [ammonium persulfate (APS)] and a cationic initiator [2,2′‐azobis(2‐methylpropionamidine)dihydrochloride (AIBA)] were used to initiate the reaction of copolymerization. The chitosan–NIPAAm copolymer synthesized by using APS as the initiator showed a homogeneous morphology and exhibited the characteristic of a lower critical solution temperature (LCST). The copolymer synthesized by using AIBA as an initiator showed a core–shell morphology, and the characteristic of LCST was insignificant. The LCST of the chitosan–NIPAAm copolymer depended on the morphology of the copolymer particles. In addition, the chitosan–NIPAAm copolymer particles were processed to form copolymer disks. Then, the effect of various variables such as the chitosan/NIPAAm weight ratio, the concentration of crosslinking agent, and the pH values on the swelling ratio of chitosan–NIPAAm copolymer disks were investigated. Furthermore, caffeine was used as the model drug to study the characteristics of drug loading of the chitosan–NIPAAm copolymer disks. Variables such as the chitosan/NIPAAm weight ratio and the concentration of the crosslinking agent significantly influenced the behavior of caffeine loading. Two factors (pore size and swelling ratio) affected the behavior of caffeine release from the chitosan–NIPAAm copolymer disks. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 3029–3037, 2004 相似文献
85.
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
86.
用分光光度法研究了2,3,7-三羟基-9-(3,5-二溴-4-氨基)苯基荧光酮的离解平衡和离解常数;以其为显色剂,进行了钼(VI)的分光光度法研究,在0.2~0.8mol·L-1HCl溶液中,CTMAB存在下,显色剂与Mo(VI)生成灵敏的红色三元配合物,ε530=1.56×105L·mol-1·cm-1,用于测定钢中的钼,结果满意. 相似文献
87.
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
88.
在室温和液氮温度下,用氩离子激光器的5145Å激光激发,测量了蒽单品的喇曼散射谱,其喇曼活性主模振动的实验值和理论值符合的较好。计算了旋转振动的均方振幅,并对低波数振动喇曼谱的温度效应进行了讨论。 相似文献
89.
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
90.
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