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881.
沈韩  许华  陈敏  李景德 《物理学报》2004,53(5):1529-1533
关键词:  相似文献   
882.
The behavior of the molten system acetamide-electrolyte, including the peculiarity of the structure and the consequent relevant properties, such as the megavalue of the dielectric constant, was reported earlier. The probable structure is a micellar system composed of salt micelles dispersed in an amorphous solvent. The present paper reports measurements in a related system: fluoroacetamide-sodium trifluoroacetate. The phase diagram, the ultrasonic absorption of both longitudinal and shear waves, and the longitudinal relaxation time of the nuclear magnetic momentum were measured at different temperatures. The most importnat result was thatT 1 (NMR relaxation time) on the19F nucleus shows that the amide and salt participate in different environments. The amide environment is less rigid; this proves that the system must be considered microheterogeneous. Moreover, the present system exhibited: 1) a less extended concentration area where supercooling phenomena occur; 2) a much broader curve of the real part of the mechanical impedance versus frequency; 3) a higher bulk viscosity in comparison with the CH3CONH2?CF3COONa supercapacitive system.  相似文献   
883.
This work establishes an asymptotic bound on the characteristic function of signed linear serial rank statistics. The result is obtained under rather general conditions including the important case of van der Waerden scores. It generalizes the result of Seoh (1983, Ph.D. Thesis, Department of Mathematics, Indiana University) and constitutes an essential step to the elaboration of Berry-Esséen's bounds and the establishment of Edgeworth expansions. These statistics constitute a natural tool for testing the hypothesis of white noise with a symmetrical (unspecified) distribution in comparison to other alternative hypothesis of serial dependence.  相似文献   
884.
对拟在HIRFL-CSRm上建造的纵向Palmer冷却进行了数值优化计算,得出了最佳带宽、最佳增益及最短冷却时间,并运用Fokker-Planck方程进行了模拟,得到了动量散度分布函数在冷却过程中随时间的变化,从而为纵向冷却系统的具体设计和优化提供了重要的理论依据.  相似文献   
885.
A sojourn time analysis is provided for a cyclic-service tandem queue with general decrementing service which operates as follows: starting once a service of queue 1 in the first stage, a single server continues serving messages in queue 1 until either queue 1 becomes empty, or the number of messages decreases to k less than that found upon the server's last arrival at queue 1, whichever occurs first, where 1 ≤ k ≤ ∞. After service completion in queue 1, the server switches over to queue 2 in the second stage and serves all messages in queue 2 until it becomes empty. It is assumed that an arrival stream is Poissonian, message service times at each stage are generally distributed and switch-over times are zero. This paper analyzes joint queue-length distributions and message sojourn time distributions.  相似文献   
886.
A regularly preemptive model D,MAP/D 1,D 2/1 is studied. Priority customers have constant inter-arrival times and constant service times. On the other hand, ordinary customers' arrivals follow a Markovian Arrival Process (MAP) with constant service times. Although this model can be formulated by using the piecewise Markov process, there remain some difficult problems on numerical calculations. In order to solve these problems, a novel approximation model MAP/MR/1 with Markov renewal services is proposed. These two queueing processes become different due to the existence of idle periods. Thus, a MAP/MR/1 queue with a general boundary condition is introduced. It is a model with the exceptional first service in each busy period. In particular, two special models are studied: one is a warm-up queue and the other is a cool-down queue. It can be proved that the waiting time of ordinary customers for the regular preemption model is stochastically smaller than the waiting time of the former model. On the other hand, it is stochastically larger than the waiting time of the latter model.  相似文献   
887.
On the evaluation of strategies for branching bandit processes   总被引:1,自引:0,他引:1  
Glazebrook [1] has given an account of improved procedures for strategy evaluation for resource allocation in a stochastic environment. These methods are extended in the paper in such a way that they can be applied to problems which, for example, have precedence constraints and/or an arrivals process of new jobs. Theoretical results, backed up by numerical studies, show that quasi-myopic heuristics often perform well.  相似文献   
888.
CoherenceTimeMeasurementofPicosecondPulsesUsingReverseSaturableAbsorptioninLeadPhthalocyanineLIFengSONGYinglinYANGKunLUIShuti...  相似文献   
889.
张波  刘慧 《光学学报》1998,18(9):238-1242
对时间积分声光相关器的原理进行了理论分析,通过实验得到了叠加在包络上的相关峰波形,为了对其进行修正,引入了后处理电路,最后得到了比较理想的相关峰波形。  相似文献   
890.
Cyclic cellular automata are two-dimensional cellular automata which generalize lattice versions of the Lorentz gas and certain biochemistry models of artificial life. We show that rotators and time reversibility play a special role in the creation of closed orbits in cyclic cellular automata. We also prove that almost every orbit is closed (periodic) and the absence of diffusion for the flipping rotator model (also known as the ant).  相似文献   
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