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71.
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
72.
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
73.
74.
[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
75.
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
76.
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
77.
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
78.
[structure: see text] The feasibility of assembling 3JH,H profiles from NMR data collected on relevant, but not necessarily specific, NMR database compounds representing a given stereocluster was demonstrated. By this approach, the 3JH,H profile was created for the contiguous tetraol peracetate stereocluster. The reliability and applicability of the database thus assembled were demonstrated for known peracetates derived from two heptoses. 相似文献
79.
A new type of mesh generator is developed by using a self-organized pattern in a reaction–diffusion system. The system is the Gray–Scott model, which creates a spot pattern in a specific parameter region. The spots correspond to nodes of a mesh. The mesh generator has several advantages: the algorithm is simple and processes to improve the mesh, such as smoothing, (locally) addition, and removal of nodes, are automatically performed by the system. 相似文献
80.
Jun Hayashi Nozomu Hashimoto Noriaki Nakatsuka Hirofumi Tsuji Hiroaki Watanabe Hisao Makino Fumiteru Akamatsu 《Proceedings of the Combustion Institute》2013,34(2):2435-2443
Soot formation characteristics of a lab-scale pulverized coal flame were investigated by performing carefully controlled laser diagnostics. The spatial distributions of soot volume fraction and the pulverized coal particles were measured simultaneously by laser induced incandescence (LII) and Mie scattering imaging, respectively. In addition, the radial distributions of the soot volume fraction were compared with the OH radical fluorescence, gas temperature and oxygen concentration obtained in our previous studies [1], [2]. The results indicated that the laser pulse fluence used for LII measurement should be carefully controlled to measure the soot volume fraction in pulverized coal flames. To precisely measure the soot volume fraction in pulverized coal flames using LII, it is necessary to adjust the laser pulse fluence so that it is sufficiently high to heat up all the soot particles to the sublimation temperature but also sufficiently low to avoid including a too large of a change in the morphology of the soot particles and the superposition of the LII signal from the pulverized coal particles on that from the soot particles. It was also found that the radial position of the peak LII signal intensity was located between the positions of the peak Mie scattering signal intensity and peak OH radical signal intensity. The region, in which LII signal, OH radical fluorescence and Mie scattering coexisted, expanded with increasing height above the burner port. It was also found that the soot formation in pulverized coal flames was enhanced at locations where the conditions of high temperature, low oxygen concentration and the existence of pulverized coal particles were satisfied simultaneously. 相似文献