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941.
942.
Marí a J. Gonzá lez 《Proceedings of the American Mathematical Society》1998,126(5):1429-1431
Let be a Fuchsian group. We show that the existence of a set on with no -equivalent points and positive logarithmic capacity does not imply that is of convergence type.
943.
M. Diot C. de Braver P. Germain 《Journal of inclusion phenomena and macrocyclic chemistry》1998,30(2):143-150
Heat capacities of anhydrous -cyclodextrin were measured between 10 K to 300 K using an adiabatic low-temperature calorimeter. Two distinct types of thermal behaviour were observed in the temperature range 50–130 K, depending on the way the sample was cooled. In the absence of hydration water molecules, we assumed that the two types of thermal behaviour could be attributed to freezing in more or less ordered states of the hydroxyl groups engaged in the intramolecular interglucose flip-flop-type interactions. 相似文献
944.
Hideaki Yamashita 《Queueing Systems》1994,18(1-2):167-182
We study a discrete-time, classified multi-server queue with a shared buffer. There arem servers and each server belongs to one ofk classes (mk), so thatk kinds of jobs can be served in the system. We characterize a bursty arrival process using bursts which consist of the same kind of jobs. Once the first job of a burst arrives at the queue, the successive jobs will arrive on every time slot until the last job of the burst arrives. The numbers of jobs of a burst and the inter-arrival times of bursts are assumed to be i.i.d., respectively, and the service time is assumed to be equal to one slot. We propose an efficient numerical method to exactly obtain the job loss probability, the waiting time distribution and the mean queue length. We apply this model to the ATM switch with a shared buffer and obtain the performance measures. Numerical results show the advantage of the ATM switch with a shared buffer compared to the one with output buffers. 相似文献
945.
Queueing network models have been extensively used to represent and analyze resource sharing systems, such as production, communication and information systems. Queueing networks with blocking are used to represent systems with finite capacity resources and with resource constraints. Different blocking mechanisms have been defined and analyzed in the literature to represent distinct behaviors of real systems with limited resources. Exact product form solutions of queueing networks with blocking have been derived, under special constraints, for different blocking mechanisms. In this paper we present a survey of product form solutions of queueing networks with blocking and equivalence properties among different blocking network models. By using such equivalences we can extend product form solutions to queueing network models with different blocking mechanisms. The equivalence properties include relationships between open and closed product form queueing networks with different blocking mechanisms.This work has been partially supported by CNR Project Research Funds Progetto Finalizzato Sistemi Informatici e Calcolo Parallelo and by MURST Project Research Funds Performability hw/sw di sistemi distribuiti e paralleli. 相似文献
946.
The vapor heat capacities of acetic acid, propionic acid, n-butyric acid at various temperatures under atmospheric pressure were measured with a multicomponent vapor flow calorimeter. The results show that the vapor heat capacities of carboxylic acids are much larger than those of the ideal gases at the same temperature and that the vapor heat capacities decrease with increasing temperature. The effect of association in the vapor phase on the vapor heat capacity was studied. 相似文献
947.
E. P. Tishkova L. A. Kudryavtseva R. A. Shagidullina B. E. Ivanov 《Russian Chemical Bulletin》1994,43(9):1488-1492
The effect of dicationic surfactants on the hydrolysis of bis(4-nitrophenyl) ethyl phosphate in a borate buffer is studied. The presence of long-chain surfactants results in a significant (up to 50-fold) increase in the observed rate constant (k
obs) of the process. The catalytic effect of micelles increases with increasing alkyl chain length due to the strengthening of binding of the reagents by micelles. The presence of two cationic centers in the surfactant molecule enhances the catalytic properties of micelles. The dependence ofk
obs of hydrolysis of the substrate on the borate buffer concentration is studied. Alkaline hydrolysis is more sensitive to the added surfactant than the reaction involving borate ions.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1576–1580, September, 1994. 相似文献
948.
H. Shigematsu Y. Akishige T. Matsui T. Tojo H. Kawaji T. Atake 《Journal of Thermal Analysis and Calorimetry》2005,81(3):555-558
Summary The phase diagram of the mixed crystal (K1-xRbx)2SeO4 was determined by means of thermal analysis and neutron scattering experiments. The hexagonal to orthorhombic phase transition line exists for any x. The normal-incommensurate phase transition temperature decreases continuously with increasing Rb content. However, the incommensurate-commensurate phase transition was not observed except for K2SeO4. According to the clear softening of the Σ2- Σ 3 phonon branches and the finite frequency at 0 K for x>0.34, an existence of the hypothetical phase transition was confirmed. 相似文献
949.
Measurements with a plate transducer, up to 1600°C, are investigated in the current paper. The calibration of the transducer, comparative measurements concerning the accuracy of specific heat capacity determination, the modelling for the high-temperature range and results for three steels are presented. The results are used to develop the database dbs for thermal simulation computations. 相似文献
950.
Rabindra N. Roy Julie A. Carlsten Jodi Niederschmidt William S. Good J. Michelle Rook Christina Brewe Amanda J. Kilker Lakshmi N. Roy Kathleen M. Kuhler 《Journal of solution chemistry》1997,26(3):309-317
ThepK
2
values for 3-[(l,l-Dimethyl-2-hydroxymethyl)amino]-2-hydroxypropanesulfonic acid (AMPSO), and 3-[N,N-Bis(-hydroxyethyl)amino]-2-hydroxypropanesulfonic
acid (DIPSO) have been determined at 12 temperatures over the range 5 to 55‡C by measurements of the emf of cells without
liquid junction containing hydrogen and silver-silver chloride electrodes. The values of pK
2 for AMPSO and DIPSO were found to be 9.138 and 7.576, respectively, at 25‡C. The thermodynamic quantities, δG‡, δH‡, δS‡,
and δC
p
‡
were calculated from the change of the equilibrium constants with temperature. These buffer substances are useful as secondary
pH standards in the physiological region of pH 7 to 9.
Camille and Henry Dreyfus Fellow, 1994–1996. 相似文献