排序方式: 共有34条查询结果,搜索用时 421 毫秒
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Celliers PM Collins GW Da Silva LB Gold DM Cauble R Wallace RJ Foord ME Hammel BA 《Physical review letters》2000,84(24):5564-5567
Simultaneous measurements of shock velocity and optical reflectance at 1064, 808, and 404 nm of a high pressure shock front propagating through liquid deuterium show a continuous increase in reflectance from below 10% and saturating at approximately (40-60)% in the range of shock velocities from 12 to 20 &mgr;m/ns (pressure range 17-50 GPa). The high optical reflectance is evidence that the shocked deuterium reaches a conducting state characteristic of a metallic fluid. Above 20 &mgr;m/ns shock velocity (50 GPa pressure) reflectance is constant indicating that the transformation is substantially complete. 相似文献
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Donchev AG Galkin NG Illarionov AA Khoruzhii OV Olevanov MA Ozrin VD Pereyaslavets LB Tarasov VI 《Journal of computational chemistry》2008,29(8):1242-1249
The recently introduced force field (FF) QMPFF3 is thoroughly validated in gas, liquid, and solid phases. For the first time, it is demonstrated that a physically well-grounded general purpose FF fitted exclusively to a comprehensive set of high level vacuum quantum mechanical data applied as it is to simulation of condensed phase provides high transferability for a wide range of chemical compounds. QMPFF3 demonstrates accuracy comparable with that of the FFs explicitly fitted to condensed phase data, but due to high transferability it is expected to be successful in simulating large molecular complexes. 相似文献
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Ganesh Kamath Igor Kurnikov Boris Fain Igor Leontyev Alexey Illarionov Oleg Butin Michael Olevanov Leonid Pereyaslavets 《Journal of computer-aided molecular design》2016,30(11):977-988
We present the performance of blind predictions of water—cyclohexane distribution coefficients for 53 drug-like compounds in the SAMPL5 challenge by three methods currently in use within our group. Two of them utilize QMPFF3 and ARROW, polarizable force-fields of varying complexity, and the third uses the General Amber Force-Field (GAFF). The polarizable FF’s are implemented in an in-house MD package, Arbalest. We find that when we had time to parametrize the functional groups with care (batch 0), the polarizable force-fields outperformed the non-polarizable one. Conversely, on the full set of 53 compounds, GAFF performed better than both QMPFF3 and ARROW. We also describe the torsion-restrain method we used to improve sampling of molecular conformational space and thus the overall accuracy of prediction. The SAMPL5 challenge highlighted several drawbacks of our force-fields, such as our significant systematic over-estimation of hydrophobic interactions, specifically for alkanes and aromatic rings. 相似文献
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I. Ogawa T. Idehara M. Pereyaslavets W. Kasparek 《International Journal of Infrared and Millimeter Waves》1999,20(4):543-558
Gaussian optics can be used to design a quasi-optical system converting the TE06 mode output (f=388 GHz) of a submillimeter wave gyrotron into a well-collimated, linearly-polarized free-space beam with a circular cross-section. A quasi-optical antenna produces a main beam with an elliptical cross-section, which is then converted by two mirrors into a well-collimated beam with a circular cross-section. 相似文献
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M. Pereyaslavets T. Idehara I. Ogawa S. Mitsudo 《International Journal of Infrared and Millimeter Waves》1999,20(6):1195-1205
An inexpensive and quick method for the approximate estimation of the mode content of the output of a submillimeter-wave gyrotron requires a thermographic pattern measurement in one cross section only. 相似文献
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We show that the isomorphism problem is solvable in the class of central extensions of word-hyperbolic groups,and that the isomorphism problem for biautomatic groups reduces to that for biautomatic groups with finite centre.We describe an algorithm that,given an arbitrary finite presentation of an automatic group Γ,will construct explicit finite models for the skeleta of K(Γ,1) and hence compute the integral homology and cohomology of Γ. 相似文献
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Gui-Qiang G.Chen School of Mathematical Sciences Fudan University Shanghai China Mathematical Institute University of Oxford - St Giles Oxford OX LB UK 《数学物理学报(B辑英文版)》2010,30(2):391-427
We are concerned with the derivation and analysis of one-dimensional hyperbolic systems of conservation laws modelling fluid flows such as the blood flow through compliant axisymmetric vessels.Early models derived are nonconservative and/or nonhomogeneous with measure source terms,which are endowed with infinitely many Riemann solutions for some Riemann data.In this paper,we derive a one-dimensional hyperbolic system that is conservative and homogeneous.Moreover,there exists a unique global Riemann solution for the Riemann problem for two vessels with arbitrarily large Riemann data,under a natural stability entropy criterion.The Riemann solutions may consist of four waves for some cases.The system can also be written as a 3×3 system for which strict hyperbolicity fails and the standing waves can be regarded as the contact discontinuities corresponding to the second family with zero eigenvalue. 相似文献