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Effects of Inhibitory Signal on Criticality in Excitatory-Inhibitory Networks

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Communications in Theoretical Physics 2019年第6期71卷 746-752页

作者： Fan wang sheng-jun wang Physics and Information Technology Shaanxi Normal University

We study the criticality in excitatory-inhibitory networks consisting of excitable elements. We investigate the effects of the inhibitory strength using both numerical simulations and theoretical analysis. We show that the inhibitory strength cannot affect the critical point. The dynamic range is decreased as the inhibitory strength *** simulate of decreasing the efficacy of excitation and inhibition which was studied in experiments, we remove excitatory or inhibitory nodes, delete excitatory or inhibitory links, and weaken excitatory or inhibitory coupling strength in critical excitatory-inhibitory network. Decreasing the excitation, the change of the dynamic range is most dramatic as the same as previous experimental results. However, decreasing inhibition has no effect on the criticality in excitatory-inhibitory network.

关键词： criticality excitable network dynamic range

Power law decay of stored pattern stability in sparse Hopfield neural networks

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Communications in Theoretical Physics 2021年第2期73卷 108-116页

作者： Fei Fang Zhou Yang sheng-jun wang School of Physics and Information Technology Shaanxi Normal UniversityXi'an 710119China

Hopfield neural networks on scale-free networks display the power law relation between the stability of patterns and the number of *** stability is measured by the overlap between the output state and the stored pattern which is presented to a neural *** simulations the overlap declines to a constant by a power law *** we provide the explanation for the power law behavior through the signal-to-noise ratio *** show that on sparse networks storing a plenty of patterns the stability of stored patterns can be approached by a power law function with the *** is a difference between analytic and simulation results that the analytic results of overlap decay to *** difference exists because the signal and noise term of nodes diverge from the mean-field approach in the sparse finite size networks.

关键词： Hopfield neural network attractor neural networks associative memory

Self-Organized Criticality in an Anisotropic Earthquake Model

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Communications in Theoretical Physics 2018年第3期69卷 280-284页

作者： Bin-Quan Li sheng-jun wang School of Physics and Information Technology Shaanxi Normal University Xi＇an 710119 China

We have made an extensive numerical study of a modified model proposed by Olami,Feder,and Christensen to describe earthquake *** situations were considered in this *** situation is that the energy of the unstable site is redistributed to its nearest neighbors randomly not averagely and keeps itself to *** other situation is that the energy of the unstable site is redistributed to its nearest neighbors randomly and keeps some energy for itself instead of reset to *** boundary conditions were considered as *** analyzing the distribution of earthquake sizes,we found that self-organized criticality can be excited only in the conservative case or the approximate conservative case in the above *** evidence indicated that the critical exponent of both above situations and the original OFC model tend to the same result in the conservative *** only difference is that the avalanche size in the original model is *** result may be closer to the real world,after all,every crust plate size is different.

关键词： self-organized criticality earthquake model power-law

Quasi-periodic events on structured earthquake models

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Chinese Physics B 2019年第9期28卷 50-56页

作者： Bin-Quan Li Zhi-Xi Wu sheng-jun wang Institute of Computational Physics and Complex Systems Lanzhou UniversityLanzhou 730000China School of Physics and Information Technology Shaanxi Normal UniversityXi’an 710119China

There has been much interest in studying quasi-periodic events on earthquake *** we investigate quasiperiodic events in the avalanche time series on structured earthquake models by the analysis of the autocorrelation function and the fast Fourier *** random spatial earthquake models, quasi-periodic events are robust and we obtain a simple rule for a period that is proportional to the choice of unit time and the dissipation of the ***, computer simulations validate this rule for two-dimensional lattice models and cycle graphs, but our simulation results also show that small-world models, scale-free models, and random rule graphs do not have periodic *** the periodicity of avalanche does not depend on the criticality of the system or the average degree of the system or the size of the system,there is evidence that it depends on the time series of the average force of the system.

关键词： quasi-periodic event self-organized criticality earthquake model

Effects of cooling rates on microporosity in DC casting Al-Li alloy

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China Foundry 2022年第2期19卷 177-190页

作者： Yu-xuan Zhang jun-sheng wang Dong-xu Chen Bing wang Chi Zhang Zheng-an wang School of Materials Science and Engineering Beijing Institute of TechnologyBeijing 100081China Advanced Research Institute of Multidisciplinary Science Beijing Institute of TechnologyBeijing 100081China Chinalco Southwest Aluminium(Group)Co. Ltd.Chongqing 401326China

During the direct chill(DC)casting process,primary cooling from the mold and bottom block,and secondary cooling from the waterjets produce a concave solid *** depth of this liquid pocket and mushy zone not only depends on the solidification range of the alloy but also the boundary conditions such as cooling ***-Li alloys solidify in a long solidification range increasing the susceptibility of porosity nucleation in the semi-solid *** this study,the effects of cooling rate on the porosity formation were quantified for the large ingot casting using X-ray computed tomography(XCT).By characterizing pore size distributions at four different cooling conditions,the correlation between the mechanical properties at both room and high temperatures and the microstructure features was *** constitutive equations were *** is found that increasing the cooling rate reduces the grain size,increases the number density of micropores,and minimizes the number of large pores,thereby improving the mechanical ***,long mushy zones and deep liquid pockets in Al-Li alloys can be effectively controlled by controlling the boundary conditions of the DC casting solidification process,thereby obtaining castings with excellent mechanical properties.

关键词： Al-Li alloys microporosity cooling rate XCT constitutive equation

First total synthesis of eudistalbin A

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Chinese Chemical Letters 2010年第8期21卷 889-891页

作者： Pu Yong Zhang jun Lei wang sheng Biao Wan Tao Jiang School of Medicine and Pharmacy Key Laboratory of Marine DrugsMinistry of Education Ocean University of ChinaQingdao 266003China

Eudistalbin A was isolated from marine tunicate eudistoma album and possess cytotoxic activity（ED_（50）3.2μg/mL） in vitro against the growth of KB human buccal carinoma *** synthetic eudistalbin A showed potent inhibitory activity against the breast carcinoma cell line MDA-231 with an IC_（50） value of 2.1μmol/L using the metabolic assay *** structures of new compounds were confirmed by ~1H NMR,^（13）C NMR,HRMS and optical rotation.

关键词： β-Carboline Eudistalbin A Pictet-Spengler reaction Henry reaction Total synthesis

Effects of refractory period on dynamical range in excitable networks

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Chinese Physics B 2019年第12期28卷 378-382页

作者： Ya-Qin Dong Fan wang sheng-jun wang Zi-Gang Huang School of Physics and Information Technology Shaanxi Normal UniversityXi'an 710119China School of Life Science and Technology Xi'an Jiaotong UniversityXi'an 710049China

Effects of refractory period on the dynamical range in excitable networks are studied by computer simulations and theoretical analysis. The first effect is that the maximum or peak of the dynamical range appears when the largest eigenvalue of adjacent matrix is larger than one. We present a modification of the theory of the critical point by considering the correlation between excited nodes and their neighbors, which is brought by the refractory period. Our analysis provides the interpretation for the shift of the peak of the dynamical range. The effect is negligible when the average degree of the network is large. The second effect is that the dynamical range increases as the length of refractory period increases, and it is independent of the average degree. We present the mechanism of the second effect. As the refractory period increases,the saturated response decreases. This makes the bottom boundary of the dynamical range smaller and the dynamical range extend.

关键词： criticality branching process random network dynamical range

Phase-field simulation of superconductor vortex clustering in the vicinity of ferromagnetic domain bifurcations

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Chinese Physics B 2020年第12期29卷 99-102页

作者： Hasnain Mehdi Jafri Jing wang Chao Yang jun-sheng wang Hou-Bing Huang School of Materials Science&Engineering Beijing Institute of TechnologyBeijing 100081China Advanced Research Institute of Multidisciplinary Science Beijing Institute of TechnologyBeijing 100081China

Superconductors and ferromagnets are highly non-compatible materials due to the natures of their respective electronic *** when artificially brought together,they develop interesting characteristics,one of which,vortex clustering,is discussed here in this ***-field and micromagnetic simulations are performed to investigate the superconductor and ferromagnet bilayer,*** ferromagnet with uniaxial anisotropy is observed to develop the maze domain,whereas the superconductor subjected to the influence of the ferromagnetic stray field displays a vortex *** vortices in superconductors at certain locations are observed to be precisely located over magnetic domain *** enhanced out-of-plane stray field at bifurcations around the curved domain walls and the convergent Lorentz force due to screening currents in superconductor are attributed to the formation of clusters at bifurcation *** of the inter-vortex spacing between straight and bifurcated domain is clearly *** importantly,inter-vortex spacing is predicted to serve as a precise tool to map local ferromagnet domain shapes.

关键词： superconductor–ferromagnet bilayer vortex pinning vortex clustering bifurcated domains

Phase order in one-dimensional piecewise linear discontinuous map

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Chinese Physics B 2018年第10期27卷 240-244页

作者： Ru-Hai Du sheng-jun wang Tao Jin Shi-Xian Qu Institute of Theoretical ＆ Computational Physics Shaanxi Normal UniversityXi＇an 710119China School of Physics and Information Technology Shaanxi Normal UniversityXi＇an 710119China

The phase order in a one-dimensional（1 D） piecewise linear discontinuous map is investigated. The striking feature is that the phase order may be ordered or disordered in multi-band chaotic regimes, in contrast to the ordered phase in continuous systems. We carried out an analysis to illuminate the underlying mechanism for the emergence of the disordered phase in multi-band chaotic regimes, and proved that the phase order is sensitive to the density distribution of the trajectories of the attractors. The scaling behavior of the net direction phase at a transition point is observed. The analytical proof of this scaling relation is obtained. Both the numerical and analytical results show that the exponent is 1, which is controlled by the feature of the map independent on whether the system is continuous or discontinuous. It extends the universality of the scaling behavior to systems with discontinuity. The result in this work is important to understanding the property of chaotic motion in discontinuous systems.

关键词： chaos piecewise discontinuous map direction phase