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41.
Tohru Sakakibara Kiyotaka SuzukiAkiko Sakai Miwa ShindoChihiro Nagano Shinya NarumiYasuhiro Kajihara Katsura Mochizuki 《Tetrahedron letters》2003,44(30):5711-5714
Methyl 4,6-O-benzylidene-2,3-dideoxy-3-C-p-tolylsulfonyl-2-C-p-tolylthio-β-d-glucopyranoside and its 5a-carba-dl-analog exit mainly in a non-chair conformation in solutions, but the latter occupies a chair conformation in a solid state. 相似文献
42.
P. MORLIÉRE M. BAZIN L. DUBERTRET R. SANTUS T. SA E. MELO G. HÜPPE J. HAIGLE P. FORLOT A. BERNARD 《Photochemistry and photobiology》1991,53(1):13-19
5-Geranoxypsoralen, commonly called bergamottin, a major furocoumarin contained in bergamot oil, is reported in vitro as a highly photoreactive psoralen. In ethanol, it exhibits quite a high triplet state quantum yield (approximately 0.37). The triplet state is involved in subsequent photochemistry which depends on the initial concentration and on the presence of oxygen. In contrast to most psoralens, absorption and fluorescence data suggest that 5-geranoxypsoralen does not interact with DNA in the dark. No UVA-induced interstrand cross-links in DNA were shown. 相似文献
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An interstitial hydroxyl radical (HO*) has been generated in bulk amorphous SiO2 (a-SiO2) loaded with interstitial H2O molecules and exposed to F2 laser light (hnu = 7.9 eV, lambda = 157 nm) at 77 K. F2 laser light dissociates an O-H bond of interstitial H2O into a pair of hydrogen atom (H0) and HO*. The resultant H0 disappears below 150 K, whereas HO* is detectable after thermal annealing at 200 K. The electron paramagnetic resonance (EPR) signal of the interstitial HO* recorded at 77 K is similar to that formed in amorphous ice, indicating that HO* is confined in an orthorhombic field by hydrogen bonding, probably with adjacent H2O molecules, silanol (SiOH) groups, and bridging oxygen atoms in the a-SiO2 network. 相似文献
47.
Kajihara M Sugie T Maeda H Sano A Fujioka K Urabe Y Tanihara M Imanishi Y 《Chemical & pharmaceutical bulletin》2003,51(1):15-19
Drug release mechanism from silicone carrier differs depending on physicochemical properties of the drug. So far, there have been few reports on controlled release of insoluble drug and on simultaneous release of two kinds of water-soluble drugs. The purposes of this study are to establish methods for (1). continuous release of insoluble drug, and (2). release of two kinds of water-soluble drugs from silicone carrier. Polystyrene beads (PSTB) and proteins such as interferon (IFN) and human serum albumin (HSA) were used as model drugs. PSTB was released from silicone only when citric acid (CA) and sodium bicarbonate (SB) existed as additives. The release patterns of IFN and HSA were almost same in the case of matrix and covered-rod formulations, but double-layered formulation released them in different patterns. As far as we are aware, this is the first report on the release of insoluble drug from silicone and the controlled release of two kinds of water-soluble drugs. 相似文献
48.
The TDDFT method is first applied in a series of tetra-nuclear transition metal clusters studies for nonlinear optical properties. The results indicate that the charge transfer inside the metal core [MCu3X4] (M=W, Mo; X=S, O, Cl, Se, Br) makes contribution to the optical nonlinearity. It is possible to enhance the hyperpolarizability by substituting the ligands of the clusters. 相似文献
49.
Yu-Ming ZHENG Hong-Min LIU Ben-Hao SA Zhong-Dao LU Zhong-Qi WANG Xiao-Ze ZHANG 《理论物理通讯》1993,19(1):71-74
A simple Monte Carlo simulation and even a partition method can be used to reproduce quite well the power law behavior between the factorial moment and the charge interval of fragment charge distributions from the multifragmentation of 197Au nucleus bombarding emulsion at~1 GeV/nucleon. This indicates that the above power law seems not to be a unique precursor of the intermittent behavior in nuclear multifragmentations. 相似文献
50.
The charge dispersion of fragments in high energy p+Cu,Kr and Xe reactions are calculated by statistical model and Monte Carlo technique.The corresponding data are reproduced quite well.It is shown that the charge dispersions are all nearly gaussian.The mass dependence of the most probable fragment charge reflects the rest target memory effect. 相似文献