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991.
Inelastic X‐ray scattering (IXS) measurements have been performed on an MgO single crystal in order to evaluate IXS as a methodology for accurate and precise determination of elastic constants and sound velocities. By performing the IXS experiment using a 12‐analyzer array, the complete set of single‐crystal elastic constants of MgO were determined to a precision better than 0.8% (sound velocities to better than 0.2%). The results are consistent with values in the literature. The precision and accuracy of this work, which is significantly better than other published work to date, demonstrates the potential of IXS in determining elastic properties.  相似文献   
992.
Photolysis of pyrrole-β-diazonium tetrafluoroborates gave β-fluoropyrroles. These were further converted to 1,3,5,7-tetrafluoroporphyrins, the first example of ring-fluorinated porphyrin derivatives.  相似文献   
993.
A new macrolide named patulolide A was isolated from the culture broth of Penicillium urticae mutants. The structure and absolute configuration of it was determined.  相似文献   
994.
We investigate effective lagrangians in supersymmetric models broken spontaneously at an intermediate energy (~ μ ? MGUT). It is shown to all orders in perturbation theory that the low-energy interactions of light particles are described by an effective lagrangian with explicit but soft supersymmetry breaking of order μ2 / MGUT.  相似文献   
995.
996.
The biologically active site of neocarzinostatin-chromophore   总被引:1,自引:0,他引:1  
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997.
The electron density of the polyoxymethylene molecule was calculated in cylindrical coordinates by a newly derived Fourier method. The density due to hydrogen could be obtained in addition to that from carbon and oxygen. This method is generally applicable to a helical polymer whose unit cell contains only one molecule composed of a number of chemical repeat units in the fiber identity period.  相似文献   
998.
A prototype real-time Chinese character recognition processor, which utilizes the Vander Lugt type complex spatial filter is presented. A real-time correlation operation is performed with a photoconductor-liquid crystal device as an incoherent-to-coherent image converter. Bandpass Fourier transform images passing through a bandpass spatial filter are sequentially recorded on a rotating hologram recording plate as stored reference patterns. It makes possible holding the stable discrimination for noisy unknown input patterns and storing a huge number of reference patterns. The typewritten Chinese characters in practice are experimentally discriminated from very similar ones in the real-time optical correlator. This indicates the possibility of more than 2000 printed Chinese character recognition with the optical correlation.  相似文献   
999.
Heat capacity measurements of a charge-ordered organic conductor (DI-DCNQI)2Ag have been performed in a temperature range between 0.3 and 14 K. We found no thermal anomaly at the Néel temperature ( T(N) = 5.5 K) but instead a T-linear term suggestive of the spin excitations of one-dimensional character in the charge-ordered insulating state. The analysis of the T-linear term and the excess entropy indicates that the charge fluctuations in the charge-ordered state influence the growth of spin excitations at elevated temperatures, which seems to be a peculiar aspect of a 1D charge-ordered system.  相似文献   
1000.
Ueda M  Hayama T  Takamura Y  Horiike Y  Baba Y 《Electrophoresis》2002,23(16):2635-2641
We investigate the possibility of geometrical electrophoresis, which is based on nanofabrication techniques. (GEE) utilizes geometrical effects during electrophoresis, which are generated by physical interactions between walls and a macromolecule confined in spaces smaller than the Flory radius. When a polymer is injected into a small space, confinement energy is usually required. However, the confinement energy form depends on the geometry of the space. In the case of electrophoresis, the electric field itself changes depending on the geometry. Using a nanofabricated quartz chip with a curved channel, we investigated electrophoretic behavior of high molecular weight DNA based on the curvature effect.  相似文献   
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