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1.
2.
Alexander Krasnosel'skii Dmitrii Rachinskii 《NoDEA : Nonlinear Differential Equations and Applications》2002,9(1):93-115
We consider autonomous systems with a nonlinear part depending on a parameter and study Hopf bifurcations at infinity. The
nonlinear part consists of the nonlinear functional term and the Prandtl--Ishlinskii hysteresis term. The linear part of the
system has a special form such that the close-loop system can be considered as a hysteresis perturbation of a quasilinear
Hamiltonian system. The Hamiltonian system has a continuum of arbitrarily large cycles for each value of the parameter. We
present sufficient conditions for the existence of bifurcation points for the non-Hamiltonian system with hysteresis. These
bifurcation points are determined by simple characteristics of the hysteresis nonlinearity. 相似文献
3.
We consider the following Type of problems. Calls arrive at a queue of capacity K (which is called the primary queue), and attempt to get served by a single server. If upon arrival, the queue is full and
the server is busy, the new arriving call moves into an infinite capacity orbit, from which it makes new attempts to reach
the primary queue, until it finds it non-full (or it finds the server idle). If the queue is not full upon arrival, then the
call (customer) waits in line, and will be served according to the FIFO order. If λ is the arrival rate (average number per
time unit) of calls and μ is one over the expected service time in the facility, it is well known that μ > λ is not always
sufficient for stability. The aim of this paper is to provide general conditions under which it is a sufficient condition.
In particular, (i) we derive conditions for Harris ergodicity and obtain bounds for the rate of convergence to the steady
state and large deviations results, in the case that the inter-arrival times, retrial times and service times are independent
i.i.d. sequences and the retrial times are exponentially distributed; (ii) we establish conditions for strong coupling convergence
to a stationary regime when either service times are general stationary ergodic (no independence assumption), and inter-arrival
and retrial times are i.i.d. exponentially distributed; or when inter-arrival times are general stationary ergodic, and service
and retrial times are i.i.d. exponentially distributed; (iii) we obtain conditions for the existence of uniform exponential
bounds of the queue length process under some rather broad conditions on the retrial process. We finally present conditions
for boundedness in distribution for the case of nonpatient (or non persistent) customers.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
4.
Dmitrii S. Silvestrov 《Acta Appl Math》1994,34(1-2):109-124
Coupling procedures for Markov renewal processes are described. Applications to ergodic theorems for processes with semi-Markov switchings are considered.This paper was partly prepared with the support of NFR Grant F-UP 10257-300. 相似文献
5.
Huseyin Bekir Yildiz Jaime Castillo Dmitrii A. Guschin Levent Toppare Wolfgang Schuhmann 《Mikrochimica acta》2007,159(1-2):27-34
An amperometric biosensor for the detection of phenolic compounds was developed based on the immobilization of tyrosinase
within an Os-complex functionalized electrodeposition polymer. Integration of tyrosinase within the redox polymer assures
efficient catechol recycling between the enzyme and the polymer bound redox sites. The non-manual immobilization procedure
improves the reproducibility of fabrication process, greatly reduces the desorption of the enzyme from the immobilization
layer, and, most importantly prevents fast inactivation of the enzyme by its substrate due to fast redox cycling.
A two-layer sensor architecture was developed involving ascorbic acid oxidase entrapped within an electrodeposition polymer
in a second layer on top of the redox polymer/tyrosinase layer. Using this sensor architecture it was possible to eliminate
the current interference arising from direct ascorbate oxidation up to a concentration of 630 μM ascorbic acid. The effects
of the polymer thickness, the enzyme/polymer ratio, and the applied potential were evaluated with respect to optimal sensor
properties. The sensitivity of the optimized sensors for catechol was 6.1 nA μM−1 with a detection limit of 10 nM, and for phenol 0.15 nA μM−1 with a detection limit of 100 nM. 相似文献
6.
A. V. Borovkov Yu. N. Brusil'tsev A. O. Doroshenko 《Theoretical and Experimental Chemistry》1993,28(4):269-273
An investigation was carried out of the spectral-luminescent and acid-base properties at the stage of formation of the hydrogen bond and during the protonation of compounds with annelated aromatic and heterocyclic rings, obtained by introduction of bridging groups -CH=CH- (I), -CH=N- (II) and -CO-N(CH3)-(III) in the 4- and 2-positions of the molecules of 4-substituted derivatives of 2,5-diphenyloxazole. The nature of the reaction center was estabished, and an analysis was carried out of its sensitivity to the electronic influence of the substituents, and the reasons for the observed differences in the properties of compounds of various reaction series are discussed. A comparative analysis of the fluorescent properties of the neutral and protonated forms of the oxazole derivatives studied was made and the conclusion that the generation is possible of laser emission by the protonated forms of compounds of the reaction series (I) was confirmed.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 28, No. 4, pp. 343–349, July–August, 1992. 相似文献
7.
8.
9.
Victor V. Borovkov Michael Anikin Kiyotaka Wasa Yoshiteru Sakata 《Photochemistry and photobiology》1996,63(4):477-482
Abstract— Structurally controlled aggregation course for five porphyrins (etioporphyrin [EP], 5-mono- and 5,15-di-[ p -tol-yl]etioporphyrin [TP and DTP], 5,10,15,20-tetrakis[ p -tol-y1]porphin [TTP], and 5,10,15,20-tetrakis[3,5-di- tert -bu-tylphenyl]porphin [TBP]) in dipalmitoyl-phosphatidyl-choline liposomes has been monitored by fluorescence and absorption spectroscopy. While TBP shows no tendency to aggregate in liposomes, EP, TP, DTP and TTP form a porphyrin-enriched domain in membrane interior with time. The further aggregation steps within porphyrin clusters resulting in formation of stacked porphyrin aggregates have been observed for EP, TP and DTP. 相似文献
10.
L. A. Valkova L. S. Shabyshev N. Yu. Borovkov L. A. Feigin F. Rustichelli 《Journal of inclusion phenomena and macrocyclic chemistry》1999,35(1-2):243-249
The effect is studied of the layer formation conditions on the molecular arrangement of copper tetra- tert-butyl phthalocyanine (CuPctBu4) and copper tetra- tert-butyl tetrabenzotriazaporphin (CuThptBu4) at the air–water interface. The decrease in initial surface concentration of these compounds is shown to affect the molecular orientation, as indicated by the increase in the area per molecule. The data are interpreted in terms of formation of CuPctBu4 and CuThptBu4 monolayers with a face-on molecular arrangement when the initial surface concentration is sufficiently small (N less than 1.6 × 10–7 mole/m2 for CuPctBu4 and N less than 4 × 10–7 mole/m2 for CuThptBu4) and changes in the molecular orientation to edge-on when the N values are higher. It is emphasized that the edge-on orientation on the water surface is not only a molecular but a collective property of the azaporphyrine supramolecular assembly. 相似文献