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971.
José L. Ló pez Nico M. Temme 《Transactions of the American Mathematical Society》2004,356(11):4323-4342
Taylor expansions of analytic functions are considered with respect to several points, allowing confluence of any of them. Cauchy-type formulas are given for coefficients and remainders in the expansions, and the regions of convergence are indicated. It is explained how these expansions can be used in deriving uniform asymptotic expansions of integrals. The method is also used for obtaining Laurent expansions in several points as well as Taylor-Laurent expansions.
972.
Binary Decision Diagrams (BDDs) are the state-of-the-art data structure for representation and manipulation of Boolean functions. In general, exact BDD minimization is NP-complete. For BDD-based technology, a small improvement in the number of nodes often simplifies the follow-up problem tremendously. This paper proposes an elitism-based evolutionary algorithm (EBEA) for BDD minimization. It can efficiently find the optimal orderings of variables for all LGSynth91 benchmark circuits with a known minimum size. Moreover, we develop a distributed model of EBEA, DEBEA, which obtains the best-ever variable orders for almost all benchmarks in the LGSynth91. Experimental results show that DEBEA is able to achieve super-linear performance compared to EBEA for some hard benchmarks. 相似文献
973.
S.H Chen 《Journal of luminescence》2004,109(2):93-102
The ZnS:Cu,Al,Au (P22G) phosphor powder was bombarded by an electron beam in an O2 ambient, Ar ambient and other mixture of gases. These gases consisted of mixtures of O2 and COx, and O2, COx and Ar gas. Auger electron spectroscopy (AES) was used to monitor changes in the surface composition of the P22G phosphor during electron bombardment. When the P22G phosphor powder was exposed to the electron beam in a water-rich O2 ambient, a chemically limited ZnO layer was formed on the surface. The electron beam degradation of the P22G phosphor powder was also performed in a dry O2 ambient and a layer of ZnSO4 was formed on the surface. The ZnSO4 formation decayed exponentially with time and it is postulated that this was due to the diffusion of the charge reactants through the ZnSO4 film to the reaction interfaces. The P22G phosphor exposed to the electron beam in an Ar ambient and to the other gas mixtures degraded at a lower rate than in the case of the O2 ambient. This suggests that Ar and COx may suppress the degradation of the P22G phosphor powder. 相似文献
974.
Molecular dynamics simulation of thermodynamic properties of NaCl at high pressures and temperatures 总被引:1,自引:0,他引:1
Qifeng Chen Lingcang Cai Dongquan Chen 《Journal of Physics and Chemistry of Solids》2004,65(6):1077-1081
The expansivity, constant-pressure heat capacity, and isothermal bulk modulus of sodium chloride (NaCl) have been obtained by using molecular dynamics method. The calculated thermodynamic parameters are found to be in agreement with the available experimental data. At an extended temperature and pressure ranges, these parameters have also been predicted. The thermodynamic properties of NaCl are summarized in the pressure 0-500 kbar ranges and the temperature up to 1000 K. 相似文献
975.
It is suggested that the question of existence of a jamming phase transition in a broad class of single-lane cellular-automaton traffic models may be studied using a correspondence to the asymmetric chipping model. In models where such correspondence is applicable, jamming phase transition does not take place. Rather, the system exhibits a smooth crossover between free-flow and jammed states, as the car density is increased. 相似文献
976.
J. L. Hernández–Pastora O. V. Manko V. S. Manko J. Martín E. Ruiz 《General Relativity and Gravitation》2004,36(4):781-797
The extended quadruple–Kerr metric is used to consider equilibrium states of four collinear Kerr particles. We explain our previous failure to solve numerically the full set of the balance equations, and we derive a self–consistent system of the axis conditions leading to the equilibrium of all four constituents which can be black holes or hyperextreme objects. The equilibrium configurations obtained in this paper exhibit similar features with those occurring in the systems of two Kerr particles, for instance, the balance of four Kerr black holes with positive masses does not seem possible. Equilibrium states of two identical compound Kerr objects are also discussed. 相似文献
977.
A. López-Ortega 《General Relativity and Gravitation》2004,36(6):1299-1319
We show that the Dirac equation is separable in the circularly symmetric metric in three dimensions and when the background spacetime is de Sitter we find exact solutions to the radial equations. Using these results we show that the de Sitter horizon has a cross section equal to zero for the massless Dirac field, as in the case of the scalar field. Also, using the improved brick wall model we calculate the fermionic entropy associated with the de Sitter horizon and we compare it with some results previously published. 相似文献
978.
L. K. Seah U. S. Dinish S. K. Ong Z. X. Chao V. M. Murukeshan 《Optics & Laser Technology》2004,36(5):371-376
Imaging of latent fingerprints using time-resolved (TR) method offers a broader platform to eliminate the unwanted background emission. In this paper, a novel TR imaging technique is demonstrated and implemented, which facilitates the detection of latent fingerprints with nanosecond resolution. Simulated experiments were carried out with two overlapping fingerprints treated with two fluorescent powders having different lifetimes in nanosecond range. The dependence of the fluorescence emission intensity in nanosecond resolution of TR imaging is also revealed. 相似文献
979.
A simple and accurate algorithm (phase scanning method) is proposed for 3D surface contouring and dynamic response determination of a vibrating object. A sinusoidal fringe pattern is projected onto a low-frequency vibrating object by a programmable liquid crystal display projector. The fringe patterns are captured by a high-speed CCD camera with a telecentric gauging lens. Phase values are evaluated point by point using phase scanning method. From the phase values of each point on the object, the contour of the specimen at different instants of vibration can be retrieved. In this paper, a small vibrating coin is used to demonstrate the validity of the method and the experimental results are compared with test results on a stationary coin using four-step phase shifting and fast Fourier transform methods. The technique is especially useful in applications where the vibrating object has a complicated shape. 相似文献
980.
Wei Jun Liao Xianfeng Chen Fucheng Chen Yuping Chen Yuxing Xia Yingli Chen 《Optics & Laser Technology》2004,36(8):603-606
In this paper, we first report that a new proton source, glutaric acid, has been used to fabricate optical waveguides in Z-cut lithium niobate crystals. The relationship was experimentally established between proton-exchanged (PE) waveguide parameters and fabrication conditions. It is shown that this new organic acid can be used to obtain deep PE waveguides in fast diffusion speed (0.275 μm2/h at 221°C) and with low loss (0.2 dB/cm). It provides an alternative approach for fabricating PE waveguides in lithium niobate substrate. 相似文献