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91.
Tamotsu Fujisawa Toshio Sato Tatsuo Kawara Masatoshi Kawashima Hirofumi Shimizu Yasuhiro Ito 《Tetrahedron letters》1980,21(22):2181-2184
Various organocuprates react with β-propiolactones to give β-substituted propionic acids in high yields. 相似文献
92.
Isolation of bufotalin 3-suberoyl-histidine and -3-methylhistidine esters from the skin of Schneider
Two novel bufotoxins, bufotalin 3-suberoyl-histidine and -3-methyl- histidine esters, were isolated from the skin of the Formosan toad, Schneider. 相似文献
93.
94.
Hirofumi Kawazumi Takayuki Oomori Naoki Yamani Teiichiro Ogawa 《Chemical physics letters》1984,106(4):351-353
The 1B2u-1A1g fluorescence emission of benzene excited by controlled electron impact was measured in the 14 – 100 eV region. The optically forbidden 6° levels were preferentially, excited. This indicates that a non-dipole transition takes place under low-energy electron-molecule collisions. 相似文献
95.
Three-dimensional spatial distribution function (SDF) of solvent is a fundamental quantity for analysis of solvation. However, its calculation has been very limited because long computational time is required. We here developed a novel and robust method to construct approximated SDFs of solvent sites from radial distribution functions. In this method, the expansion of SDFs in real solid harmonics around atoms of solute leads to a linear equation, from which SDFs are evaluated with reasonable computational time. This method is applied to the analysis of the solvation structure of liquid water, as an example. The successful results clearly show that this method is very powerful to investigate solvation structure. 相似文献
96.
97.
[Structure: see text] 12-hydroxydaphnetoxins, members of the structurally fascinating daphnane diterpene family, exhibit a wide range of significant biological activities. A general route to the BC-ring system of 12-hydroxy daphnetoxins is reported based on D-ribose. Depending on the choice of protecting groups and solvent, the oxidopyrylium-alkene [5+2] cycloaddition originating from A provides cycloadduct diastereomer B or C with good to excellent selectivity. 相似文献
98.
Tsukamoto K Ohishi H Hiyama Y Maezaki N Tanaka T Ishida T 《Chemical communications (Cambridge, England)》2006,(34):3606-3608
Potassium salts of p-tert-butylcalix[6]arene p-bromophenylalanine derivative formed sizable octameric cages in the solid state that were revealed by X-ray crystallographic analysis. 相似文献
99.
A new method to evaluate the weights of resonance structures from molecular orbital wave function is proposed, which is based on the second quantization of singlet-coupling. The present method is useful to analyze molecules of which the electronic structures are well localizable. The evaluation is carried out through localization of molecular orbitals followed by algebraic calculation of density matrices. This method is applied to H(2)O, H(3)O(+), and BH(3). The calculated weights of covalent and ionic structures are in excellent agreement with those of the previous works and our chemical intuition. 相似文献
100.
Rietveld IB Kobayashi K Yamada H Matsushige K 《The journal of physical chemistry. B》2006,110(46):23351-23364
Poly(vinylidene fluoride) film formation with electrospray deposition has been studied with support of a droplet evaporation model. The input parameters of the model consist basically of the solvent, the solute concentration, the flow rate, and the solution conductivity. The model provides the droplet size, the solute concentration, the droplet velocity, and the shear stress of the droplet at impact as a function of the distance between the nozzle and the substrate. With some additional experimental information such as the size change of the film with spray distance and the viscosity of the solution, the growth rate of the film and the shear rate of the droplet at impact can be determined. Growth rate is shown to define distinct regimes of film formation. In those regimes, only a single factor or a limited number of factors controls the film morphology. The most important factors include the shear rate and the surface energy. It is found that at a specific range of growth rates only the shear rate determines the morphology of the polymer film. Growth rate, as the defining quantity of film morphology, is not limited to polymer solutions. Therefore, the growth rate, in combination with the control factors mentioned above, functions as a general framework through which understanding and control of film formation with electrospray deposition can be improved. 相似文献