Taking a three-cable flexible photovoltaic(PV)support structure as the research subject,a finite element model was established.Utilizing a full-order flutter analysis method,the flutter critical wind speed and flutter...Taking a three-cable flexible photovoltaic(PV)support structure as the research subject,a finite element model was established.Utilizing a full-order flutter analysis method,the flutter critical wind speed and flutter frequency of the flexible PV support structure at a tilt angle of 0°were calculated.The results showed good agreement with wind tunnel test data.Further analysis examined the pretension effects in the load-bearing and stabilizing cables on the natural frequency and flutter critical wind speed of the flexible PV support structure.The research findings indicate increasing the pretension in the load-bearing cables significantly raises the natural frequencies of the first four modes.Specifically,as the pretension in the load-bearing cables increases from 22 to 102 kN,the flutter critical wind speed rises from 17.1 to 21.6 m/s.By contrast,the pretension in the stabilizing cable has a smaller effect on the natural frequency and flutter critical wind speed of the flexible PV support structure.When the pretension in the stabilizing cable increased from 22 to 102 kN,the flutter critical wind speed increased from 17.1 to 17.7 m/s.For wind-resistant design of flexible PV support structures,it is recommended to prioritize increasing the pretension in the load-bearing cables to enhance the structural flutter performance.展开更多
We find that the fractional-order Hindmarsh-Rose model neuron demonstrates various types of firing behavior as a function of the fractional order in this study.There exists a clear difference in the bifurcation diagra...We find that the fractional-order Hindmarsh-Rose model neuron demonstrates various types of firing behavior as a function of the fractional order in this study.There exists a clear difference in the bifurcation diagram between the fractional-order Hindmarsh-Rose model and the corresponding integer-order model even though the neuron undergoes a Hopf bifurcation to oscillation and then starts a period-doubling cascade to chaos with the decrease of the externally applied current.Interestingly,the discharge frequency of the fractional-order Hindmarsh-Rose model neuron is greater than that of the integer-order counterpart irrespective of whether the neuron exhibits periodic or chaotic firing.Then we demonstrate that the firing behavior of the fractional-order Hindmarsh-Rose model neuron has a higher complexity than that of the integer-order counterpart.Also,the synchronization phenomenon is investigated in the network of two electrically coupled fractional-order model neurons.We show that the synchronization rate increases as the fractional order decreases.展开更多
This paper considers the mixed covolume method for the second-order elliptic equations over quadrilaterals.Superconvergence results are established in this paper on quadrilateral grids satisfying the h^2-parallelogram...This paper considers the mixed covolume method for the second-order elliptic equations over quadrilaterals.Superconvergence results are established in this paper on quadrilateral grids satisfying the h^2-parallelogram condition when the lowest-order Raviart-Thomas space is employed in the mixed covolume method.The authors prove O(h^2) accuracy between the approximate velocity or pressure and a suitable projection of the real velocity or pressure in the L^2 norm.Numerical experiments illustrating the theoretical results are provided.展开更多
To reduce computational cost,we study some two-scale finite element approximations on sparse grids for elliptic partial differential equations of second order in a general setting.Over any tensor product domain ?R^d w...To reduce computational cost,we study some two-scale finite element approximations on sparse grids for elliptic partial differential equations of second order in a general setting.Over any tensor product domain ?R^d with d = 2,3,we construct the two-scale finite element approximations for both boundary value and eigenvalue problems by using a Boolean sum of some existing finite element approximations on a coarse grid and some univariate fine grids and hence they are cheaper approximations.As applications,we obtain some new efficient finite element discretizations for the two classes of problem:The new two-scale finite element approximation on a sparse grid not only has the less degrees of freedom but also achieves a good accuracy of approximation.展开更多
基金The National Natural Science Foundation of China(No.52338011,52208481),China Postdoctoral Science Foundation(No.2023M730581).
文摘Taking a three-cable flexible photovoltaic(PV)support structure as the research subject,a finite element model was established.Utilizing a full-order flutter analysis method,the flutter critical wind speed and flutter frequency of the flexible PV support structure at a tilt angle of 0°were calculated.The results showed good agreement with wind tunnel test data.Further analysis examined the pretension effects in the load-bearing and stabilizing cables on the natural frequency and flutter critical wind speed of the flexible PV support structure.The research findings indicate increasing the pretension in the load-bearing cables significantly raises the natural frequencies of the first four modes.Specifically,as the pretension in the load-bearing cables increases from 22 to 102 kN,the flutter critical wind speed rises from 17.1 to 21.6 m/s.By contrast,the pretension in the stabilizing cable has a smaller effect on the natural frequency and flutter critical wind speed of the flexible PV support structure.When the pretension in the stabilizing cable increased from 22 to 102 kN,the flutter critical wind speed increased from 17.1 to 17.7 m/s.For wind-resistant design of flexible PV support structures,it is recommended to prioritize increasing the pretension in the load-bearing cables to enhance the structural flutter performance.
基金supported by the National Natural Science Foundation of China(Grant Nos.11272241and 10972170)
文摘We find that the fractional-order Hindmarsh-Rose model neuron demonstrates various types of firing behavior as a function of the fractional order in this study.There exists a clear difference in the bifurcation diagram between the fractional-order Hindmarsh-Rose model and the corresponding integer-order model even though the neuron undergoes a Hopf bifurcation to oscillation and then starts a period-doubling cascade to chaos with the decrease of the externally applied current.Interestingly,the discharge frequency of the fractional-order Hindmarsh-Rose model neuron is greater than that of the integer-order counterpart irrespective of whether the neuron exhibits periodic or chaotic firing.Then we demonstrate that the firing behavior of the fractional-order Hindmarsh-Rose model neuron has a higher complexity than that of the integer-order counterpart.Also,the synchronization phenomenon is investigated in the network of two electrically coupled fractional-order model neurons.We show that the synchronization rate increases as the fractional order decreases.
基金supported by the '985' program of Jilin Universitythe National Natural Science Foundation of China under Grant No.10971082the NSAF of China under Grant No.11076014
文摘This paper considers the mixed covolume method for the second-order elliptic equations over quadrilaterals.Superconvergence results are established in this paper on quadrilateral grids satisfying the h^2-parallelogram condition when the lowest-order Raviart-Thomas space is employed in the mixed covolume method.The authors prove O(h^2) accuracy between the approximate velocity or pressure and a suitable projection of the real velocity or pressure in the L^2 norm.Numerical experiments illustrating the theoretical results are provided.
基金supported by National Natural Science Foundation of China(Grant Nos.10971059,11071265 and 11171232)the Funds for Creative Research Groups of China(Grant No.11021101)+2 种基金the National Basic Research Program of China(Grant No.2011CB309703)the National Center for Mathematics and Interdisciplinary Sciences,Chinese Academy of Sciencesthe Program for Innovation Research in Central University of Finance and Economics
文摘To reduce computational cost,we study some two-scale finite element approximations on sparse grids for elliptic partial differential equations of second order in a general setting.Over any tensor product domain ?R^d with d = 2,3,we construct the two-scale finite element approximations for both boundary value and eigenvalue problems by using a Boolean sum of some existing finite element approximations on a coarse grid and some univariate fine grids and hence they are cheaper approximations.As applications,we obtain some new efficient finite element discretizations for the two classes of problem:The new two-scale finite element approximation on a sparse grid not only has the less degrees of freedom but also achieves a good accuracy of approximation.
