作者机构：
CENT CHINA NORMAL UNIV,WUHAN 430070,PEOPLES R CHINA.;WUHAN UNIV,WUHAN 430072,PEOPLES R CHINA.;[江胶宁; YU, XP; HE, S] 华中师范大学;[JIAN, M] 武汉大学
关键词：
DYNAMIC;CAPI;GROW;TURN
摘要：
A stochastic economic growth model may be transformed into a deterministic economic growth model with an infinite dimentional Banach space of state-contingent capital stocks [6]. This paper proves that under the framework, the stochastic analogues of the asymptotic turnpike theorems in the standard deterministic economic growth model [5] will continue to hold if we assume that essentially smooth programs satisfy uniformly essentially dominant diagonal condition.
期刊：
Computational and Theoretical Chemistry,1994年115(3):309-314 ISSN：2210-271X
通讯作者：
ZHAN, CG
作者机构：
KEIO UNIV, FAC SCI & TECHNOL, DEPT CHEM, YOKOHAMA, KANAGAWA 223, JAPAN.;BEIJING UNIV, DEPT CHEM, BEIJING 100871, PEOPLES R CHINA.;[ZHAN, CG] CENT CHINA NORMAL UNIV, DEPT CHEM, WUHAN 430070, PEOPLES R CHINA.
通讯机构：
[ZHAN, CG] C;CENT CHINA NORMAL UNIV, DEPT CHEM, WUHAN 430070, PEOPLES R CHINA.
摘要：
A new quantum chemical definition of oxidation number is proposed, in the present paper, as a direct generalization of the corresponding classical definition. According to the proposed general definition, the oxidation number can be calculated by use of molecular orbital data and a population analysis method or by use of other quantum chemical methods. For the practical calculation, we present a corresponding concrete calculation procedure within the framework of the maximum overlap population principle, which is very simple and very easy to use. The calculated numerical results are, on the whole, in good agreement with chemists' intuitive concepts of chemical bonding.
摘要：
Let X1,...,X(N) (where N > m) be independent N(m)(mu, SIGMA) random vectors, and put [GRAPHICS] where T is upper-triangular with positive diagonal elements. The author considers the problem of estimating SIGMA, and restricts his attention to the class of estimates D = {T' DELTA*T + Nb* XBAR XBAR':DELTA* is any diagonal matrix and b* is any nonnegative constant} because it has the following attractive features: (a) Its elements are all quadratic forms of the sufficient and complete statistics (XBAR, T). (b) It contains all estimates of the form aA + NbXBARXBAR' (a greater-than-or-equal-to 0 and b greater-than-or-equal-to 0), which construct a complete subclass of the class of nonnegative quadratic estimates D* = {X'BX : B greater-than-or-equal-to 0} (where X = (X1,...,X(N)') for any strict convex loss function. (c) It contains all invariant estimates under the transformation group of upper-triangular matrices. The author obtains the characteristics for an estimate of the form T' DELTAT + NbXBARXBAR' (DELTA = diag{delta1,...,delta(m)} greater-than-or-equal-to 0 and b greater-than-or-equal-to 0) of SIGMA to be admissible in D when the loss function is chosen as tr(SIGMA-1 SIGMA - I)2, and shows, by an example, that aA + NbXBARXBAR' (a greater-than-or-equal-to 0 and b greater-than-or-equal-to 0) is admissible in D* can not imply its admissibility in D.
作者机构：
NATL LAB LASER TECHNOL,WUHAN 430074,PEOPLES R CHINA;HUAZHONG NORMAL UNIV,DEPT PHYS,WUHAN 430070,PEOPLES R CHINA;[LI, GX] CCAST,WORLD LAB,POB 8730,BEIJING 100080,PEOPLES R CHINA.
通讯机构：
[LI, GX] C;CCAST,WORLD LAB,POB 8730,BEIJING 100080,PEOPLES R CHINA.
摘要：
We have studied the steady-state behavior of a V configuration three-level atom driven by a single-mode laser field in a broadband squeezed vacuum bath. The influences of the bath and the relative directions of the atomic dipole moments are discussed.
期刊：
Monthly Notices of the Royal Astronomical Society,1994年270(1):131-137 ISSN：0035-8711
通讯作者：
YU, WF
作者机构：
[YANG, LT; WU, XB; YU, WF] HUAZHONG NORMAL UNIV,INST ASTROPHYS,WUHAN 430070,PEOPLES R CHINA.;[YU, WF] INST HIGH ENERGY PHYS,HIGH ENERGY ASTROPHYS LAB,BEIJING 100039,PEOPLES R CHINA.
通讯机构：
[YU, WF] I;INST HIGH ENERGY PHYS,HIGH ENERGY ASTROPHYS LAB,BEIJING 100039,PEOPLES R CHINA.
关键词：
accretion, accretion discs;instabilities;MHD
摘要：
The stability of an isothermal magnetized accretion disc with radial viscous force is examined in this paper. We confirm the former conclusion that viscous stress acting in the radial direction damps the radial oscillations. We also find that consideration of the radial viscosity does not give rise to any new mode of instability. The radial magnetic field is important to disc instability if the vertical component of the magnetic field is zero.
期刊：
SCIENCE IN CHINA SERIES B-CHEMISTRY,1993年36(6):641-648 ISSN：1001-652X
通讯作者：
HUANG, TB
作者机构：
HUAZHONG NORMAL UNIV,DEPT CHEM,WUHAN 430070,PEOPLES R CHINA.;HUAZHONG NORMAL UNIV,CTR ANAL & TESTING,WUHAN 430070,PEOPLES R CHINA.;[HUANG, TB] HUAZHONG NORMAL UNIV,INST ORGAN SYNTH,WUHAN 430070,PEOPLES R CHINA.
通讯机构：
[HUANG, TB] H;HUAZHONG NORMAL UNIV,INST ORGAN SYNTH,WUHAN 430070,PEOPLES R CHINA.
摘要：
Ten years after the first synthesis of neutral two-coordinated phosphorus in 1962, the first phosphenium cations were synthesized by Fleming, Lupton and Jekot in 1972[1]. Up to now, though 30 years have passed, the members of these phosphenium cations are still very few. the research of phosphenium cations is only limited in France, America and other countries. In our laboratory work was done on a new unique cation: the 5-methylthio-3-N-phenyl-2,3-2(H)-1,3,4,2-thiadiazaphosphenium cation which was found and characterized by 261.9 ppm conclusively of P-31 NMR. It also has an electric conductivity in nucleophilic and electrophilic reactions. We are interested in noticing that these phosphenium cations are stabilized by one sulfur atom besides nitrogen atoms.
作者机构：
HUA ZHONG NORMAL UNIV,INST PARTICLE PHYS,WUHAN 430070,PEOPLES R CHINA.;TSING HUA UNIV,INST MODERN PHYS,BEIJING 100084,PEOPLES R CHINA.;[SHEN, K] CCAST,WORLD LAB,POB 8730,BEIJING 100080,PEOPLES R CHINA.
通讯机构：
[SHEN, K] C;CCAST,WORLD LAB,POB 8730,BEIJING 100080,PEOPLES R CHINA.
摘要：
Chiral Ward-Takahashi identities with composite fields are generalized to finite temperature and applied to investigate the chiral phase transition and phase structure in the (2 + 1)-dimensional chiral Gross-Neveu model. In terms of these identities, the mass spectra of fermions and bound states and the Goldberger-Treiman relation at finite temperature are obtained. The vertex correction between the fermion and bound states σ is evaluated beyond the leading order in the 1N expansion at zero and finite temperatures. With the aid of the gap equation derived from Ward-Takahashi identities, the phase structure is discussed at zero and finite temperatures. It turns out that (i) at zero temperature, the vertex correction is very small and its influence on the phase structure can be neglected and (ii) at nonzero temperature, the infrared divergence in the vertex correction will make the results of the chiral phase transition obtained at the leading order invalid in next to the leading order and the phase structure is in agreement with Coleman's theorem.
摘要：
In this paper, we have investigated the influence of the counter-rotating terms on the squeezing of light in the two-photon Jaynes-Cummings model by means of the nonrelativistic QED. We verified that the effect of the virtual-photon field increases the squeezing. The relations between the degree of squeezing and the frequency of field, the mean photon number, and the atom-field coupling constant have also been analyzed.
摘要：
The stability of the sonic point in isothermal disc accretion is examined for the case in which the viscous stress has a diffusive form, rather than the form of the conventional Shakura-Sunyaev-type alpha-model. The results show that the sonic point is always a saddle and always stable against small-amplitude perturbations, in contrast to the case of the alpha-model. The results suggest that the topological type of the sonic point and the stability of the point against small-amplitude perturbations are related for a wide range of problems: a saddle-type sonic point is stable, while a nodal one is unstable.
作者机构：
[XU, C] Institute of Particle Physics, Huazhong Normal University, Wuhan 430070, China
通讯机构：
[XU, C] H;HUAZHONG NORMAL UNIV, INST PARTICLE PHYS, WUHAN 430070, PEOPLES R CHINA.
摘要：
In this paper we will describe a new nuclear emulsion technique, a digital controlled method, for making fast and accurate measurement and three-dimensional reconstruction of charged particle tracks in a special nuclear emulsion chamber, which is used as detector with target foil of silver, gold or lead nuclei by the CERN/EMU01 experiment and has the best resolution in the investigation of very high multiplicity in ultra-relativistic heavy ion collisions.
通讯机构：
[XIAO, CY ] ;HUAZHONG NORMAL UNIV,DEPT PHYS,WUHAN 430070,PEOPLES R CHINA.
关键词：
晶体;掺杂;钛掺杂绿宝石;电特性;局域格点
摘要：
The lasing action of titanium-doped chrysoberyl crystal (Ti:BeAl2O4) is related to the crystal-field levels of Ti3+ ions at the mirror sites, for which two kinds of energy-level diagrams were suggested under different local symmetries. To ascertain which one is reasonable, first-principle calculations are performed on the energy levels of Ti3+ ions with four cluster model . The study supports the energy-level diagram suggested by Sugimoto et al. under C(s) symmetry, but disfavors that proposed by Chiba et al. under D2h symmetry. Moreover, the results indicate that the impurity will introduce some local lattice distortion within C(s) symmetry and a reasonable distorted geometrical configuration of cluster (TiO6)9- is proposed, with which experimental data can be satisfactorily explained and for which various electronic properties are further presented.
作者机构：
[ZHAN, CG; HU, ZM] HUBEI NORMAL UNIV,DEPT CHEM,HUANGSHI 435002,PEOPLES R CHINA.;[ZHAN, CG] CENT CHINA NORMAL UNIV,DEPT CHEM,WUHAN 430070,PEOPLES R CHINA.
通讯机构：
[ZHAN, CG] C;CENT CHINA NORMAL UNIV,DEPT CHEM,WUHAN 430070,PEOPLES R CHINA.
关键词：
Hybrid orbital;Maximum bond order;Maximum bond order hybrid orbital;Maximum bond order principle;Natural hybrid orbital
摘要：
Based on the simplified calculation scheme of the maximum bond order principle and the basic idea of the maximum overlap symmetry orbital method, a simple procedure is suggested for constructing systematically the bonding hybrid orbitals, called ''maximum bond order hybrid orbitals'', for a given molecule from the first-order density matrix obtained from a molecular orbital calculation. As an example, the proposed procedure is performed for some typical small molecules by use of the density matrix obtained from CNDO/2 calculation. It is shown that the bonding hybrid orbitals constructed by using the procedure are extremely close to those by using the natural hybrid orbital procedure and in good agreement with chemical intuition, and that the proposed procedure can be performed more easily than the natural hybrid orbital procedure and can give simultaneously the values of the maximum bond order for all bonds in molecules.
作者机构：
CENT CHINA NORMAL UNIV,DEPT CHEM,WUHAN 430070,PEOPLES R CHINA.;HUBEI NORMAL UNIV,DEPT CHEM,HUANGSHI 435002,PEOPLES R CHINA.;[HU, ZM] Department of Chemistry, Central China Normal University, Wuhan, The People's Republic of China<&wdkj&>Departmjent of Chemistry, Hubei Normal University, Huangshi, The People's Republic of China;[ZHAN, CG] Department of Chemistry, Central China Normal University, Wuhan, The People's Republic of China
关键词：
Hybridization;Maximum bond order;Maximum bond order hybrid orbital;NMR;Nuclear spin coupling constant
摘要：
The excellent correlativity between the maximum bond order hybrid orbitals and the nuclear spin-spin coupling constants of directly bonded C-H and C-C is shown in the present paper. The maximum bond order hybrid orbital procedure is performed by use of the first-order density matrices obtained from CNDO/2 calculation to get the bonding hybrid orbitals and the corresponding maximum bond orders for a number of hydrocarbons and hetero-substituted hydrocarbons. The relations between the obtained calculation results and the experimental coupling constants are examined by using the basic relationships proposed by Muller and Pritchard, by Maksic et al. and by Gil, and summarized in the concrete relationships which are the most suitable for the maximum bond order hybrid orbital calculation. The obtained relationships combined with the maximum bond order hybrid orbital calculation is quite successful in predicting substituent effects on the C-H and C-C coupling constants in molecules which contain no substituents of the −I
− type.
期刊：
Computational and Theoretical Chemistry,1993年279:47-52 ISSN：2210-271X
通讯作者：
Chang-Guo Zhan
作者机构：
CENT CHINA NORMAL UNIV, DEPT CHEM, WUHAN 430070, PEOPLES R CHINA.;HUAZHONG UNIV SCI & TECHNOL, DEPT SOLID STATE ELECTR, WUHAN 430074, PEOPLES R CHINA.;[ZHENG, F] Department of Chemistry, Central China Normal University, Wuhan 430070 People's Republic of China<&wdkj&>Department of Solid State Electronics, Huazhong University of Science and Technology, Wuhan 430074 People's Republic of China;[ZHAN, CG] Department of Chemistry, Central China Normal University, Wuhan 430070 People's Republic of China;[Xing-Tiao Li] Department of Solid State Electronics, Huazhong University of Science and Technology, Wuhan 430074 People's Republic of China
通讯机构：
[Chang-Guo Zhan] D;Department of Chemistry, Central China Normal University, Wuhan 430070 People's Republic of China
摘要：
It is shown that the maximum overlap symmetry molecular orbital (MOSMO) procedure can be employed to construct the crystal orbitals and study the band structures by using the Bloch function basis set. The concrete MOSMO calculations on the extended Hiickel molecular orbital (EHMO) approximation level using Bloch functions for some organic polymers and graphite show that the calculated band gaps are close to those worked out by using the ordinary linear combination of atomic orbitals (LCAO) method if the same parameterization is adopted. Because the MOSMO procedure is more easily performed than the ordinary LCAO procedure, the MOSMO calculation using Bloch functions may be feasible in large systems.
作者机构：
CHINESE CTR ADV SCI & TECHNOL,WORLD LAB,BEIJING 100080,PEOPLES R CHINA.;HUAZHONG NORMAL UNIV,DEPT PHYS,WUHAN 430070,PEOPLES R CHINA.;UNIV SCI & TECHNOL CHINA,DEPT PHYS,HEFEI 230026,PEOPLES R CHINA.;[YANG, JL] UNIV SCI & TECHNOL CHINA,CTR FUNDAMENTAL PHYS,HEFEI 230026,PEOPLES R CHINA.
通讯机构：
[YANG, JL] U;UNIV SCI & TECHNOL CHINA,CTR FUNDAMENTAL PHYS,HEFEI 230026,PEOPLES R CHINA.
摘要：
The stability, electronic and magnetic properties, and reactivity of icosahedral M Co12 clusters are studied using the discrete variational local-spin-density-functional method, where M=Ti, V, Cr, Mn, Fe, Co, and Ni. By means of the binding-energy calculation, we obtained the M-Co bond length of the clusters and compared their relative stability. We calculated the electronic structure of the clusters in their equilibrium configurations. The calculated results show that all the clusters have metallic character, and that the clusters with M being Ti, Mn, or Co have closed electronic shells while the others have open electronic shells and are expected to distort further. The results also indicate that the cluster moment is reduced by the substitution of the central Co atom with an M atom, and that the average moment per atom of all clusters is larger than that of the bulk Co. Based on the results of electronic structures, we further analyzed the reactivity of the clusters toward H2, N2, and CO molecules and found a strong dependence on the central M atom. Our results compare well with the available experimental results.
