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131.
132.
133.
在汉纳范模型的基础上,增加了3个有关躯干的围度指标。通过代表人体主要特征的形态学参数,利用逐步回归分析法,建立回归方程。用以预测那些不易测准或需专门测量仪器检测的参数,简化了模型的个体化过程。 相似文献
134.
对数学规划模型的结构作了深入分析。从纵向揭示了数学规划模型自然、清晰的层次结构;横向又把复合模型分解成若干基本模型,而基本模型又可由决策用户十分熟悉的二维形式加以描述。在此基础上,给出了建模语言(FQL)的语法和语义。它除了具有建模能力外,消除了代数形式的索引;更重要的是具有数据库查询和模型操作能力。 相似文献
135.
D. Kast A. Jungclaus K.P. Lieb M. Górska G. de Angelis P.G. Bizzeti A. Dewald C. Fahlander H. Grawe R. Peusquens M. De Poli H. Tiesler 《The European Physical Journal A - Hadrons and Nuclei》1998,3(2):115-128
In the neutron deficient isotopes 104,105In lifetimes of high spin states in the range from 0.5 ps to 600 ps have been measured in a coincidence recoil distance Doppler
shift (RDDS) experiment. By combining the Doppler shift attenuation (DSA) and RDDS methods at few μm flight distances, the
problem of delayed feeding has been avoided and very short lifetimes in the range 0.5–0.8 ps have been determined. Shell model
calculations with strong restrictions for the neutron orbitals reveal good agreement with experimental level energies and
still fair agreement for most measured B(M1) and B(E2) values.
Received: 30 June 1998 相似文献
136.
J. M. Pico C. P. Menaut J. Fernández J. L. Legido M. I. Paz Andrade 《Journal of solution chemistry》1991,20(1):115-124
Excess molar enthalpies hE at 25 and 35° C and atmospheric pressure, are reported for the binary mixtures formed by a 2-butanone and 2-pentanone with 1-chlorobutane, 1-chloropentane, 1-chlorohexane, or 1-chlorooctane. The hE values for all the mixtures are positive, increasing as the 1-chloroalkane length increases and as the ketone length decreases. Excess molar enthalpies depend slightly on the temperature. The experimental values together with those from the literature were used to calculate the interaction parameters for the Dang-Tassios version of the UNIFAC model.Communicated at the Festsymposium celebrating Dr. Henry V. Kehiaian's 60th birthday, Clermont-Ferrand, France, 17–18 May 1990. 相似文献
137.
138.
Simple expressions are given for the mean delay, mean waiting time, and mean busy period length in a multiplexer. Data streams with active periods having a general distribution are permitted, and the data rate during the active periods can be random. Data can also arrive in batches. The key restrictions of the model are that the sources are independent, idle periods are exponentially distributed, and a source generates at least enough data during an active period to keep the server busy throughout the period. The exact formulas allow evaluation of the error in approximations such as a heavy traffic diffusion approximation.Both continuous and discrete time models are considered. The discrete-time model includes that studied by Viterbi and subsequently generalized by Neuts. The Pollaczek-Khinchine formula for the mean amount of work in anM/GI/1 queue is retrieved as a limiting case.Preliminary version presented at IEEE INFOCOM, San Francisco, April 1993. 相似文献
139.
A. Gorban' 《Mathematical and Computer Modelling》2002,35(13):7047-1370
An explicitly solvable Riabouchinsky model with a partially penetrable obstacle is introduced. This model applied to the estimation of the efficiency of free flow turbines allows us to take into account the pressure drop past the lamina. 相似文献
140.
Hiroshi Ito Masaki Okazaki Dolores C. Miller 《Journal of polymer science. Part A, Polymer chemistry》2004,42(6):1478-1505
Radical copolymerizations of electron‐deficient 2‐trifluoromethylacrylic (TFMA) monomers, such as 2‐trifluoromethylacrylic acid and t‐butyl 2‐trifluoromethylacrylate (TBTFMA), with electron‐rich norbornene derivatives and vinyl ethers with 2,2′‐azobisisobutyronitrile as the initiator were investigated in detail through the analysis of the kinetics in situ with 1H NMR and through the determination of the monomer reactivity ratios. The norbornene derivatives used in this study included bicyclo[2.2.1]hept‐2‐ene (norbornene) and 5‐(2‐trifluoromethyl‐1,1,1‐trifluoro‐2‐hydroxylpropyl)‐2‐norbornene. The vinyl ether monomers were ethyl vinyl ether, t‐butyl vinyl ether, and 3,4‐dihydro‐2‐H‐pyran. Vinylene carbonate was found to copolymerize with TBTFMA. Although none of the monomers underwent radical homopolymerization under normal conditions, they copolymerized readily, producing a copolymer containing 60–70 mol % TFMA. The copolymerization of the TFMA monomer with norbornenes and vinyl ethers deviated from the terminal model and could be described by the penultimate model. The copolymers of TFMA reported in this article were evaluated as chemical amplification resist polymers for the emerging field of 157‐nm lithography. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 1478–1505, 2004 相似文献