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1.
The inconsistency of the energy equation used in the literature is pointed out and a new consistent energy equation is given.
With this new energy equation, calculations are made for the limit-cycle behaviors of thermally unstable accretion disks around
black holes. From the comparison of our numerical results with those obtained using the inconsistent energy equation, it is
found that the inconsistent energy equation undervalues the temperature and overvalues the effective optical depth when the
accreted gas becomes effectively optically thin. Thus, it is dangerous if the inconsistent energy equation is used in the
studies of very hot and optically thin accretion flows such as advection-dominated accretion flows (ADAFs), and our new energy
equation is likely to be a better alternative.
Supported by the National Basic Research Program of China (Grant No. 2009CB824800), the National Natural Science Foundation
of China (Grant Nos. 10673009 and 10833002), and the Natural Science Foundation of Fujian Province of China (Grant No. V0750001) 相似文献
2.
First-principles study of interphase Ni3Sn in Sn--Ni alloy for anode of lithium ion battery 下载免费PDF全文
This paper investigates the mechanism of Li insertion into interphase Ni3Sn in Ni-Sn alloy for the anode of lithium ion battery by means of the first-principles plane-wave pseudopotential. Compared with other phases, it is found that the Ni3Sn has larger relative expansion ratio and lower electrochemical potential, with its specific plateaus voltage around 0.3 eV when lithium atoms are filled in all octahedral interstitial sites, and the relative expansion ratio increasing dramatically when the lithiated phase transits from octahedral interstitial sites to tetrahedral interstitial sites. So this phase is a devastating phase for whole alloy electrode materials. 相似文献
3.
Engineering the near-field imaging of a rectangular-lattice photonic-crystal slab in the second band
Imaging properties of a two-dimensional rectangular-lattice photonic crystal (PC) slab consisting of air holes immersed in
a dielectric are studied in this work. The field patterns of electromagnetic waves radiated from a point source through the
PC slab are calculated with the finite-difference time-domain method. Comparing the field patterns with the corresponding
equifrequency-surface contours simulated by the plane-wave expansion method, we find that an excellent-quality near-field
image may be formed through the PC slab by the mechanisms of the simultaneous action of the self-collimation effect and the
negative-refraction effect. Near-field imaging may be obtained within two different frequency regions in two vertical directions
of the PC slab.
Supported by the Research Foundation of the State Ethnic Affairs Commission of China (Grant No. 07ZY15), the National Key
Basic Research Special Foundation of China (Grant Nos. 2004CB719804 and 2006CB921702), the National Natural Science Foundation
of China (Grant Nos. 10674185 and 10705056), and the Youth Foundation of Central University of Nationalities (Grant No. CUN0207) 相似文献
4.
Structures and electronic properties of SimN8-m(0 〈 m 〈 8) clusters: a density functional theory study 下载免费PDF全文
The geometries, electronic structures and related properties of SimN8-m(0 〈 m 〈 8) clusters are studied using density functional theory (DFT) with hybrid functional B3LYP. The calculated results reveal several trends. For any stoichiometric clusters, the lowest energy isomers with an alteration of N and Si atoms are favourable in energy if the numbers of Si and N atoms are large enough to form ... Si N-Si-N... alternative chains. The bond lengths of single Si-N bonds are very close to the corresponding values of the bulk and other SiN clusters. The geometries for N-rich and Si4N4 clusters are planar structures, but three-dimensional structures are favourable in energy for Si-rich clusters. With the increase of m, the isotropic polarizability and average polarizability increase, the total binding energies generally decrease, the HOMO-LUMO gap and vertical ionization potential oscillate with increasing number of valence electrons, and their values with even valence electrons are larger than those with odd valence electrons. The atomic charges, IR and Raman properties are also reported. 相似文献
5.
MingZhen Ma HaiTao Zong HaiYan Wang YanPeng Qi SunXing Liang AiJun Song WeiGuo Zhang Qiang Wang XinYu Zhang Qin Jing Gong Li RiPing Liu 《中国科学G辑(英文版)》2008,51(4):438-444
The fluidity and filling ability of glass-forming Zr-based alloy melt in copper mould were investigated both theoretically
and experimentally. The major factors which affected the flowing behavior of the metallic melt in the mold were determined,
which provides the foundation for overcoming the contradiction between the filling and formation of amorphous alloy during
the rapid cooling process of the metallic melts. The casting factors to prepare a metallic ring were discussed and selected.
As a result, a Zr-based bulk metallic glass ring was prepared successfully.
Supported by the National Natural Science Foundation of China (Grant No. 50731005), SKPBRC (Grant No. 2006CB605201/2007CB616915),
PCSIRT (Grant No. IRT0650), the Natural Science Foundation of Hebei Province of China (Grant No. E2004000209), the Scientific
Research Foundation of Education Department of Hebei Province of China (Grant No. 2004464), and the Experts and Scholars Fund
of Personnel Department of Hebei Province, China (Grant No. 2003) 相似文献
6.
Previously the perihelion advance in binary system was computed approximately. We will present an exact analytical solution
to nonlinear differential equation of perihelion advance by method of Jacobian elliptic function and the advanced angle between
successive perihelions.
Project supported by the Scientific Research Foundation for the Returned Overseas Chinese Scholars from Ministry of Education,
China (Grant No. [2004]527) and the Natural Science Foundation of Hunan Province, China (Grant No. 06JJ2026) 相似文献
7.
The probability of successful controlled teleportation of an unknown qubit using a general three-particle state is investigated.
The analytic expressions of maximal probabilities via several kinds of tripartite states are given, including a tripartite
Greenberger-Horne-Zeilinger state and a tripartite W-state.
Supported by the National Natural Science Foundation of China (Grant No. 10671054), the Key Project of Science and Technology
Research of Ministry of Education of China (Grant No. 207011), and the Natural Science Foundation of Hebei Province, China
(Grant No. 07M006) 相似文献
8.
Using the finite-difference time-domain (FDTD) method, we simulate the coupling between a gold nanorod and gold nanoparticles
with different plasmonic resonant frequencies/volumes as well as that between the nanorod and a dielectric nanosphere. The
influences of coupling with different nanoparticles on the excitation of a forbidden longitudinal surface plasmon mode of
the nanorod under normal incidence are investigated. It is found that the cause of this excitation is the broken symmetry
of the local electric field experienced by the nanorod resulting from the charge pileup on the other nanoparticle. This result
is valuable for understanding the near-field optical characterization of plasmonic metal nanoparticles.
Supported by the National Natural Science Foundation of China (Grant Nos. 10821062 and 10804004), the National Basic Research
Program of China (Grant No. 2007CB307001), and the Specialized Research Fund for the Doctoral Program of Higher Education
(Grant No. 200800011023)
Contributed by GONG QiHuang 相似文献
9.
Many physical systems can be modeled as quasi-Hamiltonian systems and the stochastic averaging method for quasi-Hamiltonian
systems can be applied to yield reasonable approximate response statistics. In the present paper, the basic idea and procedure
of the stochastic averaging method for quasi Hamiltonian systems are briefly introduced. The applications of the stochastic
averaging method in studying the dynamics of active Brownian particles, the reaction rate theory, the dynamics of breathing
and denaturation of DNA, and the Fermi resonance and its effect on the mean transition time are reviewed.
Supported by the National Natural Science Foundation of China (Grant Nos. 10772159 and 10802074), the Research Fund for the
Doctoral Program of Higher Education of China (Grant No. 20060335125), and the Zhejiang Provincial Natural Science Foundation
of China (Grant No. Y7080070) 相似文献
10.
Elastic scattering of two H(^2Sg) and N(^4Su) atoms at low temperatures and accurate spectroscopic parameters of NH (X^3∑^-) radical 下载免费PDF全文
This paper reports that the interaction potential for the X3Z- state of NH radical is constructed at the CCSD(T)/ cc-PV6Z level of theory. Using this potential, this paper calculates the spectroscopic parameters (De, Re, ωe, ωeχe, αe and Be) and their values are of 3.578eV, 0.10368nm, 3286.833cm^-1, 78.433cm^-1, 0.6469cm^-1 and 16.6735cm^-1 respectively, which are in excellent agreement with the experiments. Then the total of 14 vibrational states has been found when J=0 by solving the radial Schrodinger equation of nuclear motion. For each vibrational state, the vibrational manifolds are reported for the first time. And last, the total cross sections, s-wave, p-wave and d-wave cross sections are computed for the elastic collisions between two ground-state atoms (hydrogen and nitrogen) at low temperatures. It finds that the total elastic cross sections are dominated by s-wave scattering when the collision energy is below 10^-6a.u. The pronounced shape resonance is found at energy of 6.1 × 10^-6a.u. Calculations have shown that the shape resonance comes from the p-wave contributions. 相似文献
11.
The coherent-entangled state |α, x; λ> with real parameters λ is proposed in the two-mode Fock space, which exhibits the properties of both the coherent and entangled states. The completeness relation of |α, x; λ> is proved by virtue of the technique of integral within an ordered product of operators. The corresponding squeezing operator is derived, with its own squeezing properties. Furthermore, generalized P-representation in the coherent-entangled state is constructed. Finally, it is revealed that superp... 相似文献
12.
We have performed magnetization measurements and electron spin resonance (ESR) on polycrystalline manganites of Nd0.5Sr0.5-xBaxMnO3 (x = 0.1). Phase separation and phase transitions are observed from the susceptibility and the ESR spectra data. Between 260 K (~ Tc) and 185 K (~ TN), the system coexists of the paramagnetic phase and the ferromagnetic (FM) phase. Between 185 K and 140 K, the system coexists of the FM phase and the antiferromagnetic (AFM) phase. These results indicate that the system has a very complex magnetic state due to the origin of the instability stemming from manganite Nd0.5Sr0.4Ba0.1MnO3 by partially substituting the larger Ba^2+ ions for the smaller Sr^2+ ions. 相似文献
13.
The electronic structure of stressed CrSi2 was calculated using the first-principle methods based on plane-wave pseudo-potential theory. The calculated results showed
that, under the uniaxial compression, the energy level of CrSi2 shifted toward high energy and its energy gap became wider with the increasing uniaxial stress, while the gap became narrower
under the negative uniaxial stress. When the negative uniaxial stress was up to −18.5 GPa, CrSi2 was converted into a direct-gap semiconductor with the band gap of 0.32 eV.
Supported by the National Natural Science Foundation of China (Grant No. 60566001), the Specialized Research Fund for the
Doctoral Program of Higher Education of China (Grant No. 20050657003), the Scientific Research Foundation for the Returned
Overseas Chinese Scholars, Ministry of Education of China (Grant No. (2005)383), the Program for the Excellent Young Talents
of Guizhou Province (Grant No. 20050528), the Specialized Nomarch Research Fund for the Excellent Science and Technology and
Education Talent’s Projects of Guizhou Province, Scientific and Technological Projects for the Returned Overseas Chinese Scholars,
the Guizhou Province (Grant No. (2004)03), and the Top Talent’s Scientific Research Project of Organization Department of
Guizhou Province 相似文献
14.
Theoretical investigation on near-infrared and visible absorption spectra of nanometallic aluminium
with oxide coating in nanoenergetic materials: size and shape effects 下载免费PDF全文
The effects of metal core dimension, oxide shell thickness and ellipsoid aspect ratio of Al-Al2O3 core-shell nanoparticles on the near-infrared and visible absorption spectra of nanocomposite Al-Al2O3/nitrocellulose(NC) film are investigated by numerical calculations. Both the size-dependent interband transitions and frequency-dependent free electron damping of the nanometallic aluminium are taken into account in the calculations. Oxidation effect of nanoaluminium is also analysed. It is shown that oxidation may enhance but may also reduce the optical absorption, depending on the excited light energy and initial dimension of nanoparticle. Metal core size and excited light energy dominate the absorption characteristic. The absorption ability of ellipsoidal nanoparticles is larger than that of spheroidal nanoparticles and increases by the square index as the aspect ratio increases. These calculations will provide some significant theoretical guidance for the preparation and laser ignition of nanoenergetic materials. 相似文献
15.
A protocol of quantum secret sharing between multiparty and multiparty with four states was presented. It was shown that this
protocol can nullify the Trojan horse attack with a multi-photon signal, the fake-signal attack with Einstein-Podolsky-Rosen
pairs, the attack with single photons, and the attack with invisible photons. In addition, the upper bounds of the average
success probabilities were given for dishonest agent eavesdropping encryption using the fake-signal attack with any two-particle
entangled states.
Supported by the National Natural Science Foundation of China (Grant No. 10671054), the Key Project of Science and Technology
Research of Education Ministry of China (Grant No. 207011) and the Natural Science Foundation of Hebei Province, China (Grant
Nos. A2005000140 and 07M006) 相似文献
16.
According to the method of path integral quantization for the canonical constrained system in Becchi-Rouet-Stora-Tyutin scheme,
the supersymmetric electromagnetic interaction system was quantized. Both the Hamiltonian of the supersymmetric electromagnetic
interaction system in phase space and the quantization procedure were simplified. The BRST generator was constructed, and
the BRST transformations of supersymmetric fields were gotten; the effective action was calculated, and the generating functional
for the Green function was achieved; also, the gauge generator was constructed, and the gauge transformation of the system
was obtained. Finally, the Ward-Takahashi identities based on the canonical Noether theorem were calculated, and two relations
between proper vertices and propagators were obtained.
Supported by Knowledge Innovation Project of the Chinese Academy of Sciences (Grant Nos. KJCX2-SW-N02 and KJCX2-SW-N016),
the National Natural Science Foundation of China (Grant Nos. 10435080 and 10575123), Beijing Natural Science Foundation (Grant
No. 1072005) and the Science and Technology Development Foundation of Beijing Municipal Education Committee (Grant No. Km200310005018) 相似文献
17.
The steady-state optical bistability (OB) and optical multistability (OM) behavior in the quasi-Λ-type atomic system driven
by a probe field and a coherent coupling field inside a unidirectional ring cavity are shown, and the effects of coupling-field
detuning and coupling-field intensity on the OB and OM behavior are investigated. The transition from OB to OM or vice versa is found by varying the detuning of the coherent coupling field or by adjusting the intensity of the coupling field. The
influence of the atomic cooperation parameter on the OM behavior is also discussed.
Supported by the Natural Science Foundation of Jiangxi of China (Grant No. 2007GZW0819), the National Basic Research Program
of China (Grant No. 2005CB724508), and the Foundation of Talent of Jinggang of Jiangxi Province (Grant No. 2008DQ00400) 相似文献
18.
The field of medical photonics is rapidly expanding, and a wide variety of optical technologies and instruments have recently
been developed for diagnostic, therapeutic and basic science applications in medicine. This review presents the recent advances
and application of medical photonics, and the obtained results from our laboratory are highlighted. Finally, the challenges
and future prospects for the transition from technological exploration to clinical studies are discussed.
Supported by the National Natural Science Foundation of China (Grant No. 60678054), the PhD Program Foundation of Ministry
of Education (Grant No. 200803940001), the Key Grants from Ministry of Education (Grant No. 209063), and the Fujian Provincial
Natural Science Foundation (Grant No. 2008J0001) 相似文献
19.
This paper reports that high quality CuGeO3 single crystals were successfully grown by floating-zone technique and the magnetic property was studied. The temperature dependence of magnetic susceptibility below the spin-Peierls (SP) transition temperature (Tsp) under magnetic fields applying along both the a- and c-axis direction can be fitted well by a model of noninteracting dimmers. The spin gap derived from the fitting is consistent with other reports. There is a very weak anisotropy in the fitting parameters for different directions, which should be expected from a SP system. A small upturn in susceptibility at low temperature due to paramagnetic impurities and/or defects can be observed. A suppression of the upturn by magnetic field is first discovered in this system and the possible origins for this suppression are discussed. 相似文献
20.
A new concept and its methodology for studying human meridians are presented based on rigorous and scientific observation
on the objective existence of human meridians in view of biomedical optics. According to this methodology, the infrared radiant
characteristics of acupuncture meridians over human body and the optical transport properties of light propagating along the
meridian are reported. This study, thus, confirms the existence of acupuncture meridians, sheds new light on an approach to
investigation of human meridians and offers a new perspective in understanding the potential meridian functions such as energy
and information transfer and physiological regulation.
Supported by the National Key Basic Research Program of China (Grant No. 2006CB504505), the National Natural Science Foundation
of China (Grant Nos. 60578056 and 30572309), the Science Research Foundation of Ministry of Health & United Fujian Provincial
Health and Education Project for Tackling the Key Research of China (Grant No. WKJ2005-2-004), the Young Scientists and Technicians
Innovation Project of Fujian Province (Grant No. 2007F3026), and the Fund from Fujian Normal University (Grant No. 2008100218) 相似文献