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881.
In this paper the distribution of the maximum number of customers in a retrial orbit for a single server queue with Markovian
arrival process and phase type services is studied. Efficient algorithm for computing the probability distribution and some
interesting numerical examples are presented. 相似文献
882.
We have carried out some photon interaction measurements using 59.54 keV γ-rays from a 241Am source. These include γ attenuation studies as well as photoelectric absorption studies in various samples. The attenuation
studies have been made using leaf and wood samples, samples like sand, sugar etc., which contain particles of varying sizes
as well as pellets and aqueous solutions of rare earth compounds. In the case of the leaf and wood samples, we have used the
γ-ray attenuation technique for the determination of the water content in fresh and dried samples. The variation of the attenuation
coefficient with particle size has been investigated for sand and sugar samples. The attenuation studies as well as the photoelectric
studies in the case of rare earth elements have been carried out on samples containing such elements whose K-absorption edge
energies lie below and close to the γ-energy used. Suitable compounds of the rare earth elements have been chosen as mixture
absorbers in these investigations. A narrow beam good geometry set-up was used for the attenuation measurements. A well-shielded
scattering geometry was used for the photoelectric measurements. The mixture rule was invoked to extract the values of the
mass attenuation coefficients for the elements from those of the corresponding compounds. The results are consistent with
theoretical values derived from the XCOM package. 相似文献
883.
B. Rustem 《Journal of Optimization Theory and Applications》1993,76(3):429-453
In this paper, we consider two algorithms for nonlinear equality and inequality constrained optimization. Both algorithms utilize stepsize strategies based on differentiable penalty functions and quadratic programming subproblems. The essential difference between the algorithms is in the stepsize strategies used. The objective function in the quadratic subproblem includes a linear term that is dependent on the penalty functions. The quadratic objective function utilizes an approximate Hessian of the Lagrangian augmented by the penalty functions. In this approximation, it is possible to ignore the second-derivative terms arising from the constraints in the penalty functions.The penalty parameter is determined using a strategy, slightly different for each algorithm, that ensures boundedness as well as a descent property. In particular, the boundedness follows as the strategy is always satisfied for finite values of the parameter.These properties are utilized to establish global convergence and the condition under which unit stepsizes are achieved. There is also a compatibility between the quadratic objective function and the stepsize strategy to ensure the consistency of the properties for unit steps and subsequent convergence rates.This research was funded by SERC and ESRC research contracts. The author is grateful to Professors Laurence Dixon and David Mayne for their comments. The numerical results in the paper were obtained using a program written by Mr. Robin Becker. 相似文献
884.
激光对生物分子的共振激发作用 总被引:7,自引:0,他引:7
在生物分子的“谐”和“非谐”振子势模型的基础上,用量子力学讨论了激光对生物分子的共振激作用;并用之对激光的生物激活、诱变机理的“共振吸收”定性理论作一解析分析。 相似文献
885.
三维立体成像及其应用 总被引:3,自引:0,他引:3
本文首先介绍了三种传统的主要三维立体成像方法,即透镜板三维成像方法,投影式三维显示和全息照相术,其次,重点对于采用计算机产生的三维立体景象的方法进行了综述,其中包括人们近年来研究较多的自动立体成像技术等,最后给出了三维立体成像技术在航空航天,工业,教育,医学,军事等领域的应用实例,并预测了三维立体成像技术今后的主要发展方向。 相似文献
886.
R. B. King 《Russian Chemical Bulletin》1993,42(11):1772-1781
Reactions of disodium tetracarbonylferrate, Na2Fe(CO)4, with sterically hindered dialkylaminodichlorophosphines, R2NPCl2 (R2N=diisopropylamino, dicyclohexylamino, and 2,2, 6, 6-tetramethylpiperidino) in diethyl ether lead to the air-stable phosphorus-bridging carbonyl derivatives (R2NP)2COFe2(CO)6 as the major products. The phosphorus-bridging carbonyl group in (i-Pr2NP)2COFe2(CO)6 has been found to undergo the following types of reactions: 1)Reduction, 2)Acylation, 3)Extrusion of the carbonyl group. The mechanisms of the reactions have been considered.This work was presented at the Workshop «The Modern Problems of Heteroorganic Chemistry» held on the ship «Nikolai Bauman» during the period May 8–13, 1993.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 1858–1867, November, 1993. 相似文献
887.
T. S. Lee S. B. Lee J. M. Kim J. S. Kim S. H. Suh J. H. Song I. H. Park S. U. Kim M. J. Park 《Journal of Electronic Materials》1995,24(9):1057-1059
In order to improve the Zn homogeneity along the axial direction of CdZnTe boule, we have employed a modified Bridgman technique
using a (Cd, Zn) alloy source in communication with the melt, whose temperature has been gradually changed from 800 to 840°C
during growth. Electron probe microanalysis (EPMA) measurements of Zn composition in the boule shows an excellent homogeneity
of Zn along the axis of the CdZnTe boule compared with results in a boule grown by using a fixed source temperature. We have
performed a numerical simulation to obtain the approximate temperatures of additional heating and cooling needed to improve
the radial Zn homogeneity. CdZnTe boule has been grown by seeded vertical Bridgman furnace with two zones of heater and cooler.
Ultraviolet/visible spectroscopic measurements of Zn composition over the length of the boule indicate that the radial distribution
of Zn composition is very homogeneous in the body region of the boule, where the radial variation of Zn composition is ±0.0005. 相似文献
888.
Santanu Bhattacharya Basudeb Saha Amitava Dutta Pradyot Banerjee 《Coordination chemistry reviews》1998,170(1):47-74
This review narrates the electron transfer reactions of various nickel(III) and nickel(IV) complexes reported during the period 1981 until today. The reactions have been categorized mainly with respect to the type of nickel complexes. The reactivity of nickel(III) complexes of macrocycles, 2,2′-bipyridyl and 1,10-phenanthroline, peptides and oxime–imine, and of nickel(IV) complexes derived from oxime–imine, oxime and miscellaneous ligands with various organic and inorganic electron donors have been included. Kinetic and mechanistic features associated with such interactions have been duly analyzed. The relevance of Marcus cross-relation equations in the delineation of the electron transfer paths has also been critically discussed. 相似文献
889.
A. M. Chebotarev 《Mathematical Notes》1996,60(5):544-561
We prove that the Hudson-Parthasarathy equation corresponds, up to unitary equivalence, to the strong resolvent limit of Schrödinger Hamiltonians in Fock space and that the symmetric form of this equation corresponds to the weak limit of the Schrödinger Hamiltonians.Translated fromMatematicheskie Zametki, Vol. 60, No. 5, pp. 726–750, November, 1996. 相似文献
890.
Wang Binglin Ma Shiming Chian Jian Zong Huiqi Tang Quanyong 《Radiation Physics and Chemistry》1998,52(1-6):439-442
The radiation facility was made by Sulzer Company in Switzerland. The designed capacity is 3.7 × 1016Bq( 1MCi) and 12.21 × 1015Bq(330kCi)of Cobalt -60 source was loaded at the first phase. Current cobalt -60 source-loading is 2.4 × 1016Bq(650kCi). The equipment assembling and installation regulating and testing were completed at the end of 1988. The facility was put into commissioning in 1989. It operates 7000–8000 hours per year. The facility has been utilized to carry out many research work and irradiate many kinds of items. Lots of economical benefits have been gained since then. Now it is becoming a radiation processing model base in China. This paper summarized the strong and weak points of the design of the facility through in eight years' practice and analysed the economical benefits. 相似文献