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51.
Wang W Shan D Yang Y Wang C Hu Y Lu X 《Chemical communications (Cambridge, England)》2011,47(24):6975-6977
A new scanning electrochemical microscopy (SECM) model provided a two-dimensional quantitative analysis on a heterogeneous electron transport (ET) process of a functionalized porpyrin by photoinduced ET at the ITO/liquid interface. The basic features of oxidized porphyrin under light source were recorded by feedback approach curves within the framework of the bimolecular ET mechanisms. 相似文献
52.
Ee GC Mah SH Teh SS Rahmani M Go R Taufiq-Yap YH 《Molecules (Basel, Switzerland)》2011,16(11):9721-9727
The extracts of the stem bark of Calophyllum soulattri gave a new pyranocoumarin, soulamarin (1), together with five other xanthones caloxanthone B (2), caloxanthone C (3), macluraxanthone (4), trapezifolixanthone (5) and brasixanthone B (6) one common triterpene, friedelin (7), and the steroidal triterpene stigmasterol (8). The structures of these compounds were established based on spectral evidence (1D and 2D NMR). 相似文献
53.
Dr. Hai‐Feng Xiang Dr. Stephen Sin‐Yin Chui Prof. V. A. L. Roy Prof. Chi‐Ming Che 《化学:亚洲杂志》2011,6(12):3223-3229
Organic photovoltaic (OPV) cells using metal(II) (Pt, Pd, Cu, and Ni) chelates of 8‐hydroxyquinoline (Hq) or 5,7‐dimethyl‐8‐hydroxy‐quinoline (HMe2q) as an electron donor were fabricated by vacuum deposition. The bis(5,7‐dimethyl‐8‐hydroxyquinolinato)platinum(II) [Pt(Me2q)2]‐based OPVs showed the best performance with an open voltage (VOC) of 0.42 V, a short circuit current density (JSC) of 14.8 mA cm?2, and a maximum power conversion efficiency (ηP) of 2.4 %. The X‐ray single‐crystal structures together with the grazing incidence X‐ray diffraction (GIXRD) data of thin film samples reveal that the peripheral methyl substituent(s) and platinum(II) ion are essential for the high degree of film crystallinity resulting in improved performance of the as‐fabricated field‐effect transistors (FETs) and OPV cells. 相似文献
54.
Dr. Jia Wang Dr. Yong Chen Dr. Yuen‐Chi Law Meiyi Li Dr. Ming‐Xin Zhu Dr. Wei Lu Dr. Stephen Sin‐Yin Chui Dr. Nianyong Zhu Prof. Dr. Chi‐Ming Che 《化学:亚洲杂志》2011,6(11):3011-3019
A series of phosphorescent terpyridyl platinum(II) complexes with ancillary biphenylacetylide ligands, namely, [(R3tpy)PtC≡C(biphenyl)]X (R=tBu, H, or Et2N; tpy=2,2′;6′,2′′‐terpyridyl; X is an anion) were synthesized and structurally characterized by various spectroscopic techniques and X‐ray diffraction methods. Despite a lack of long alkyl chain(s) or hydrogen‐bonding motif(s), complexes [(tpy)PtC≡C(biphenyl)]Cl and [(tBu3tpy)PtC≡C(biphenyl)]X (X=Cl, ClO4, PF6, or BF4) were found to gelate water and organic solvents, respectively. The self‐aggregation of these complexes in solutions and the resulting gels were investigated with variable‐temperature (VT) 1H NMR spectroscopy, polarized optical microscopy, and absorption/emission spectroscopy. SEM micrographs on dry gels revealed entangled nanofibers with diameters of 20–40 nm and lengths of tens of micrometers. Powder X‐ray diffraction (PXRD) study revealed various degrees of crystallinity of these fibrillar nanostructures. The substituents on both the terpyridyl and acetylide ligands and counterion of these complexes play a profound but concerted role in tuning the intermolecular metal???metal and/or π–π interactions, and hence the gelation properties. 相似文献
55.
Designing delivery districts for the vehicle routing problem with stochastic demands 总被引:4,自引:0,他引:4
Dag Haugland Sin C. Ho Gilbert Laporte 《European Journal of Operational Research》2007,180(3):997-1010
This paper considers the problem of designing districts for vehicle routing problems with stochastic demands. In particular, demands are assumed to be uncertain at the time when the districts are made, and these are revealed only after the districting decisions are determined. Tabu search and multistart heuristics for this stochastic districting problem are developed and compared. Computational results show that tabu search is superior over multistart. 相似文献
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57.
DingXiaoquan 《高校应用数学学报(英文版)》2005,20(2):151-158
A delayed semi-ratio-dependent predator-prey system in a periodic environment is investigated in this paper. By using a continuation theorem based on Gaines and Mawhin‘s coincidence degree,the global existence of positive periodic solution is studied. A set of easily verifiable sufficient conditions are obtained. 相似文献
58.
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The group of extensions between any two irreducible 2-modularrepresentations of the groups Sp4 (2n) and Suz (2m) is determined. 相似文献