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11.
Mustansir Barma 《Pramana》1997,49(1):155-160
When the dynamics of a system partitions the phase space of configurations into very many disjoint sectors, we are faced with an assignment problem: Given a configuration, how can we tell which sector it belongs to? We study this problem in connection with the dynamics of deposition and evaporation ofk particles at a time, from a lattice substrate. Fork ≥ 3, the system shows complex behaviour: (a) The number of disjoint sectors in phase space grows exponentially with the size. (b) The asymptotic time dependence of the autocorrelation function shows slow decays, with power laws which depend on the sector. Both (a) and (b) are explained in terms of a nonlocal construct known as the irreducible string (IS), formed from a particle configuration by applying a deletion algorithm. The IS provides a label for sectors; the multiplicity of possible IS’s accounts for (a), and let us determine sector numbers and sizes. The elements of the IS are conserved; thus their motion is responsible for the slow modes of the system, and accounts for (b) as well. 相似文献
12.
In this paper, a new variational formulation for a reaction-diffusion problem in broken Sobolev space is proposed. And the new formulation in the broken Sobolev space will be proved that it is well-posed and equivalent to the standard Galerkin variational formulation. The method will be helpful to easily solve the original partial differential equation numerically. And the method is novel and interesting, which can be used to deal with some complicated problem, such as the low regularity problem, the differential-integral problem and so on. 相似文献
13.
The nonstationary rectilinear motion of an amphibian air-cushion vehicle (AACV) on a water surface covered with finely broken ice is considered for various modes of velocity variation. The influence of
the water depth, flotation parameters, and mode of motion on the wave resistance of the vehicle is analyzed. Maneuvering methods
for increasing or decreasing the wave resistance of AACVs are proposed.
__________
Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 48, No. 1, pp. 97–102, January–February, 2007. 相似文献
14.
岩石(煤)的碎胀与压实特性研究 总被引:36,自引:1,他引:36
本文通过自行设计的一套岩石(煤)的松散和压实试验方案及相应的实验设备,对兖州矿区岩(煤)样进行了较为系统的碎胀与压实特性研究,测定了岩石(煤)的碎胀系数、碎胀曲线、压实曲线和侧压曲线. 相似文献
15.
R. H. W. Hoppe 《高等学校计算数学学报(英文版)》2021,14(1):31-46
We are concerned with the derivation of Poincaré-Friedrichs type inequalities in the broken Sobolev space $W^{2,1}$($Ω$; $\mathcal{T}_h$) with respect to a geometrically conforming, simplicial triagulation $\mathcal{T}_h$ of a bounded Lipschitz domain $Ω$ in $\mathbb{R}^d$ , $d$ $∈$ $\mathbb{N}$.
Such inequalities are of interest in the numerical analysis of nonconforming finite
element discretizations such as ${\rm C}^0$ Discontinuous Galerkin (${\rm C}^0$${\rm DG}$) approximations
of minimization problems in the Sobolev space $W^{2,1}$($Ω$), or more generally, in the
Banach space $BV^2$($Ω$) of functions of bounded second order total variation. As
an application, we consider a ${\rm C}^0$${\rm DG}$ approximation of a minimization problem in$BV^2$($Ω$) which is useful for texture analysis and management in image restoration. 相似文献
16.
J. L. Musfeldt John R. Reynolds D. B. Tanner Jose P. Ruiz Jiping Wang Martin Pomerantz 《Journal of Polymer Science.Polymer Physics》1994,32(14):2395-2404
Optical absorption and photo-luminescence measurements were performed on a series of semiconducting polymers, based upon phenylene linkages, that have discrete emitter units. In these polymers, broken conjugation has been achieved in two ways: by introducing metalinkages between various numbers of para-connected aromatic groups or by severe steric distortion of a fully conjugated main chain. In either case, electronic states are localized on relatively small units, resulting in a large (π, π*) band gap. The band gap decreases with increasing emitter unit conjugation, as expected. Blue light emission was observed from these materials, with the peak emission wavelength red shifted (by greater than 1 eV on average) from the peak absorption. © 1994 John Wiley & Sons, Inc. 相似文献
17.
有机玻璃中条形药包爆炸破碎区发展过程的高速摄影研究 总被引:1,自引:1,他引:0
采用高速摄影方法,对有机玻璃中条形装药爆炸破碎区的发展过程进行了研究。结果表明,爆炸后形成的破碎区大致可分为柱部和端部两部分,其发展特征是,由条形装药柱中部向两端过渡的破坏区扩展速度逐渐减慢。 相似文献
18.
On Word Equations Originated from Discrete Dynamical Systems Related to Antisymmetric Cubic Maps with Some Applications
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Elias Abboud 《数学学报(英文版)》2018,34(11):1663-1676
In this article, we solve some word equations originated from discrete dynamical systems related to antisymmetric cubic map. These equations emerge when we work with primitive and greatest words. In particular, we characterize all the cases for which <β1β1>=<β2β2> where β1 and β2 are the greatest words in <<β1>> and <<β2>> of M(n). 相似文献
19.
Bo-Hao Chen Jun-Jia Xu Wei-Ren Lai Chung-Kai Chang Jeng-Lung Chen Jyh-Fu Lee Jin-Ming Chen Hwo-Shuenn Sheu Jey-Jau Lee Yoshiki Kubota Ming-Hsi Chiang Yasutaka Kitagawa Yu-Chun Chuang I-Jui Hsu 《中国化学会会志》2023,70(5):1187-1199
Two cobalt(II) halide complexes with 1,2,4-triazole as a ligand were synthesized. Their structures were determined by extended x-ray absorption fine structure (EXAFS) and powder x-ray diffraction (XRD). Both complexes [Co(Htrz)Cl2]n ( 1 ) and {[Co(Htrz)2(trz)]BF4}n ( 2 ) form one-dimensional polymeric chain and the distances of Co⋯Co are 3.3521(2) Å and 3.8629(2) Å, respectively. The Htrz and Cl− are bridging ligands to connect two Co(II) ions in 1 , and the local environment of Co site is in a distorted octahedron with {CoN2Cl4} core. In complex 2 , two Htrz and one trz are bridging ligands to connect two Co(II) ions, and the local geometry of Co is in a pseudo octahedron with {CoN6} core. The analysis of Co LII,III-edge XAS indicates that the Co(II) of both complexes are at high spin state with t2g5eg2 configuration and the crystal field strength (10Dq) is about 1.2 eV. The broken-symmetry DFT calculations indicate that antiferromagnetic coupling state of Co⋯Co is the most stable state in both complexes; and the coupling constants of 1 and 2 are −0.32 cm−1 and −3.70 cm−1, respectively. Based on the distances of Co⋯Co and coupling constants, such antiferromagnetic interaction is achieved through triazole ligands. 相似文献
20.
Distinguishing Protonation States of Histidine Ligands to the Oxidized Rieske Iron–Sulfur Cluster through 15N Vibrational Frequency Shifts
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The Rieske [2Fe–2S] cluster is a vital component of many oxidoreductases, including mitochondrial cytochrome bc1; its chloroplast equivalent, cytochrome b6f; one class of dioxygenases; and arsenite oxidase. The Rieske cluster acts as an electron shuttle and its reduction is believed to couple with protonation of one of the cluster′s His ligands. In cytochromes bc1 and b6f, for example, the Rieske cluster acts as the first electron acceptor in a modified Q cycle. The protonation states of the cluster′s His ligands determine its ability to accept a proton and possibly an electron through a hydrogen bond to the electron carrier, ubiquinol. Experimental determination of the protonation states of a Rieske cluster′s two His ligands by NMR spectroscopy is difficult, due to the close proximity of the two paramagnetic iron atoms of the cluster. Therefore, this work reports density functional calculations and proposes that difference vibrational spectroscopy with 15N isotopic substitution may be used to assign the protonation states of the His ligands of the oxidized Rieske [2Fe–2S] complex. 相似文献