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151.
Prof. Dr. Mohamed Alaasar Dr. Yu Cao Yan Liu Prof. Dr. Feng Liu Prof. Dr. Carsten Tschierske 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(67):e202201857
Spontaneous generation of chirality from achiral molecules is a contemporary research topic with numerous implications for technological applications and for the understanding of the development of homogeneous chirality in biosystems. Herein, a series of azobenzene based rod-like molecules with an 3,4,5-trialkylated end and a single n-alkyl chain involving 5 to 20 aliphatic carbons at the opposite end is reported. Depending on the chain length and temperature these achiral molecules self-assemble into a series of liquid and liquid crystalline (LC) helical network phases. A chiral isotropic liquid (Iso1[*]) and a cubic triple network phase with chiral I23 lattice were found for the short chain compounds, whereas non-cubic and achiral cubic phases dominate for the long chain compounds. Among them a mesoscale conglomerate with I23 lattice, a tetragonal phase (Tetbi) containing one chirality synchronized and one non-synchronized achiral network, an achiral double network meso-structure with Ia d space group and an achiral percolated isotropic liquid mesophase (Iso1) were found. This sequence is attributed to an increasing strength of chirality synchronization between the networks, combined with a change of the preferred mode of chirophilic self-assembly between the networks, switching from enantiophilic to enantiophobic with decreasing chain length and lowering temperature. These nanostructured and mirror symmetry broken LC phases exist over wide temperature ranges which is of interest for potential applications in chiral and photosensitive functional materials derived from achiral compounds. 相似文献
152.
Enzo Marinari Giorgio Parisi Federico Ricci-Tersenghi Juan J. Ruiz-Lorenzo Francesco Zuliani 《Journal of statistical physics》2000,98(5-6):973-1074
We discuss replica symmetry breaking (RSB) in spin glasses. We update work in this area, from both the analytical and numerical points of view. We give particular attention to the difficulties stressed by Newman and Stein concerning the problem of constructing pure states in spin glass systems. We mainly discuss what happens in finite-dimensional, realistic spin glasses. Together with a detailed review of some of the most important features, facts, data, and phenomena, we present some new theoretical ideas and numerical results. We discuss among others the basic idea of the RSB theory, correlation functions, interfaces, overlaps, pure states, random field, and the dynamical approach. We present new numerical results for the behaviors of coupled replicas and about the numerical verification of sum rules, and we review some of the available numerical results that we consider of larger importance (for example, the determination of the phase transition point, the correlation functions, the window overlaps, and the dynamical behavior of the system). 相似文献
153.
154.
The numerical method used in this study is the moving particle semi-implicit (MPS) method, which is based on particles and their interactions. The particle number density is implicitly required to be constant to satisfy incompressibility. A semi-implicit algorithm is used for two-dimensional incompressible non-viscous flow analysis. The particles whose particle number densities are below a set point are considered as on the free surface. Grids are not necessary in any calculation steps. It is estimated that most of computation time is used in generation of the list of neighboring particles in a large problem. An algorithm to enhance the computation speed is proposed. The MPS method is applied to numerical simulation of breaking waves on slopes. Two types of breaking waves, plunging and spilling breakers, are observed in the calculation results. The breaker types are classified by using the minimum angular momentum at the wave front. The surf similarity parameter which separates the types agrees well with references. Breaking waves are also calculated with a passively moving float which is modelled by particles. Artificial friction due to the disturbed motion of particles causes errors in the flow velocity distribution which is shown in comparison with the theoretical solution of a cnoidal wave. © 1998 John Wiley & Sons, Ltd. 相似文献
155.
J. T. Graham R. G. Alamo L. Mandelkern 《Journal of Polymer Science.Polymer Physics》1997,35(2):213-223
Nominal stress-strain curves of a series of random ethylene-hexene copolymers having narrow composition and most probable molecular weight distributions were investigated. A series of such molecular weight copolymers with a constant concentration of branches were crystallized under a variety of conditions. In each molecular weight series the level of crystallinity was approximately constant. Particular attention was focused on the yield region and the nature of the yielding process. It was found, quite surprisingly, that the yield stress was not solely dependent on the crystallinity level. Moreover, the shape of the force-elongation curve in the yield region was very dependent on the molecular weight and the crystallization mode. These changes in yielding correlated quite well with the overall crystallite structure that was characterized by thin section transmission electron microscopy. The orthorhombic unit cell of polyethylene was maintained in all the samples despite the changes that occurred in the overall crystallite structure. © 1997 John Wiley & Sons, Inc. 相似文献
156.
ZHENG Zhi-Gang 《理论物理通讯》2005,43(1):107-112
Recent developments in studies of
directed transport processes in interacting particle systems are retrospected.
Due to the interactions among elements, the
directed transport process exhibits complicated and novel cooperative dynamics.
We considered various possibilities in achieving ratchet motion by breaking
different symmetries of many-body systems. It is shown that
the directional transport can even be induced by breaking the coupling
symmetry and the spatiotemporal symmetries. 相似文献
157.
PENG Yan-Ze 《理论物理通讯》2005,43(2):205-207
New exact solutions in terms of the Jacobi
elliptic functions are obtained to the (2+1)-dimensional breaking
soliton equation by means of the modified mapping method. Limit
cases are studied, and new solitary wave solutions and triangular
periodic wave solutions are obtained. 相似文献
158.
The (2+1)-dimensional breaking soliton equation describes the interaction of a Riemann wave propagating along the y-axis with a long wave along the
x-axis. In this paper, with the aid of symbolic computation, six
kinds of new special exact soltion-like solutions of
(2+1)-dimensional breaking soliton equation are obtained by using
some general transformations and the further generalized
projective Riccati equation method. 相似文献
159.
PENG Yan-Ze E.V. Krishnan 《理论物理通讯》2005,44(11)
The singular manifold method is used to obtain two general solutions to a (2 1)-dimensional breaking soliton equation, each of which contains two arbitrary functions. Then the new periodic wave solutions in terms of the Jacobi elliptic functions are generated from the general solutions. The long wave limit yields the new types of dromion and solitary structures. 相似文献
160.
We explore the possibility to generate new parity symmetry in the quantum Rabi model after a bias is introduced. In contrast to a mathematical treatment in a previous publication [J. Phys. A 46(2013) 265302], we consider a physically realistic method by involving an additional spin into the quantum Rabi model to couple with the original spin by an Ising interaction, and then the parity symmetry is broken as well as the scaling behavior of the ground state by introducing a bias. The rule can be found that the parity symmetry is broken by introducing a bias and then restored by adding new degrees of freedom. Experimental feasibility of realizing the models under discussion is investigated. 相似文献