On the symplectic superposition method for free vibration of rectangular thin plates with mixed boundary constraints on an edge

A novel symplectic superposition method has been proposed and developed for plate and shell problems in recent years.The method has yielded many new analytic solutions due to its rigorousness.In this study,the first endeavor is made to further developed the symplectic superposition method for the free vibration of rectangular thin plates with mixed boundary constraints on an edge.The Hamiltonian system-based governing equation is first introduced such that the mathematical techniques in the symplectic space are applied.The solution procedure incorporates separation of variables,symplectic eigen solution and superposition.The analytic solution of an original problem is finally obtained by a set of equations via the equivalence to the superposition of some elaborated subproblems.The natural frequency and mode shape results for representative plates with both clamped and simply supported boundary constraints imposed on the same edge are reported for benchmark use.The present method can be extended to more challenging problems that cannot be solved by conventional analytic methods.

Simulated and experimental studies on the array dielectric barrier discharge of water electrodes

A kind of dielectric barrier discharge（DBD） device composed of water electrodes with 3×3forms can produce large-area low-temperature plasmas at atmospheric pressure.To reflect the discharge characteristics of DBD better,a dynamic simulation model,which is based on the voltage controlled current source（CCS）,is established,then the established model in Matlab/Simulink is used to simulate the DBD in air.The voltage-current waves and Lissajous at a voltage of 10 kV,11 kV and 12 kV peak value with a frequency of 15 kHz are studied.The change of the discharge power of DBD with a different amplitude and frequency of applied voltage is also analyzed.The result shows the voltage-current waves,Lissajous and discharge power of DBD under different conditions from the simulation agree well with those of the experiment.In addition,we propose a method to calculate the dielectric barrier capacitance Cd and the gap capacitance Cg,which is valid through analyzing the variation of capacitance at different voltage amplitudes.

MicroRNAs in the neural system

Precise spatio-temporal control of gene expression at transcriptional and translational levels is required for both of proper developmental programming of the central nervous system and the performing of normal brain functions.Many studies have demonstrated that micro-RNAs(miRNAs),a class of endogenous small RNAs,participate in post-transcriptional regulation of gene expression,and thus execute regulatory functions in various biologic processes.Emerging evidence indicates that miRNAs participate in gene regulatory networks during the developmental,physiologic,and pathological processes of the brain.In this review,we attempt to summarize some of the recent advances in research on the involvement of miRNAs in the regulation of neuronal development,neuroplasticity,and brain diseases,revealing their indispensable roles in neural functions.