Dual mobility(DM)bearings have gained significant attention in the field of total hip arthroplasty(THA)as a valid treatment option in cases of revision for instability after THA whereas its use in primary THA is still...Dual mobility(DM)bearings have gained significant attention in the field of total hip arthroplasty(THA)as a valid treatment option in cases of revision for instability after THA whereas its use in primary THA is still a matter of debate.This manuscript explores the pathology,incidence,diagnosis,treatment options,prognosis,ongoing studies in the literature,and future perspectives related to the use of DM bearings employed in primary THA.DM bearings are primarily designed to address one of the major concerns in THA:Instability of the prosthetic hip.Instability is both for the surgeon and the patient a devastating postoperative complication,leading to significant pain and subsequent apprehension by the patient and may require revision surgeries.The use of DM implants poses the worry of wear-related complications,such as accelerated polyethylene wear and osteolysis,which also pose challenges to long-term implant survival.This technique has seen a steady rise in recent years,with multiple studies reporting favorable outcomes.The incidence of their utilization varies among institutions and surgeons,reflecting differing preferences and patient populations.The diagnosis of instability and wear-related complications in THA often involves clinical assessment,imaging modalities such as X-rays,computed tomography scans,and sometimes advanced imaging techniques like magnetic resonance imaging.DM bearings can be considered as an option when patients present neurologic pathologies such as Parkinson's disease or recurrent dislocations after THA.DM bearings provide an additional articulation point within the implant,facilitating a greater range of motion and inherent stability.This design allows for reduced risk of dislocation and improved functional outcomes.Various implant manufacturers offer different designs and sizes of DM bearings to suit individual patient needs.Current literature suggests that the use of DM bearings in primary THA has demonstrated promising outcomes in terms of enhanced stability,reduced dislocation rates展开更多
This paper focuses on linear-quadratic(LQ)optimal control for a class of systems governed by first-order hyperbolic partial differential equations(PDEs).Different from most of the previous works,an approach of discret...This paper focuses on linear-quadratic(LQ)optimal control for a class of systems governed by first-order hyperbolic partial differential equations(PDEs).Different from most of the previous works,an approach of discretization-then-continuousization is proposed in this paper to cope with the infinite-dimensional nature of PDE systems.The contributions of this paper consist of the following aspects:(1)The differential Riccati equations and the solvability condition of the LQ optimal control problems are obtained via the discretization-then-continuousization method.(2)A numerical calculation way of the differential Riccati equations and a practical design way of the optimal controller are proposed.Meanwhile,the relationship between the optimal costate and the optimal state is established by solving a set of forward and backward partial difference equations(FBPDEs).(3)The correctness of the method used in this paper is verified by a complementary continuous method and the comparative analysis with the existing operator results is presented.It is shown that the proposed results not only contain the classic results of the standard LQ control problem of systems governed by ordinary differential equations as a special case,but also support the existing operator results and give a more convenient form of computation.展开更多
Most fundamental themes in mathematical physics and modern engineering are investigated by the closed form traveling wave solutions of nonlinear evolution equations.In our research,we ascertain abundant new closed for...Most fundamental themes in mathematical physics and modern engineering are investigated by the closed form traveling wave solutions of nonlinear evolution equations.In our research,we ascertain abundant new closed form traveling wave solution of the nonlinear integro-differential equations via Ito equation,integro-differential Sawada-Kotera equation,first integro-differential KP hierarchy equation and second integro-differential KP hierarchy equation by two variable(G/G,1/G)-expansion method with the help of computer package like Mathematica.Some shape of solutions like,bell profile solution,anti-king profile solution,soliton profile solution,periodic profile solution etc.are obtain in this investigation.Trigonometric function solution,hyperbolic function solution and rational function solution are established by using our eminent method and comparing with our results to all of the well-known results which are given in the literature.By means of free parameters,plentiful solitary solutions are derived from the exact traveling wave solutions.The method can be easier and more applicable to investigate such type of nonlinear evolution models.展开更多
In this paper, a Birkhoff-Noether method of solving ordinary differential equations is presented. The differential equations can be expressed in terms of Birkhoff＇s equations. The first integrals for differential equ...In this paper, a Birkhoff-Noether method of solving ordinary differential equations is presented. The differential equations can be expressed in terms of Birkhoff＇s equations. The first integrals for differential equations can be found by using the Noether theory for Birkhoffian systems. Two examples are given to illustrate the application of the method.展开更多
In this paper, we consider the oscillatory and asymptotic behavior of solution of first order nonlinear neutral functional differential equation with piecewise constant dealy. We prove that all solutions of the equati...In this paper, we consider the oscillatory and asymptotic behavior of solution of first order nonlinear neutral functional differential equation with piecewise constant dealy. We prove that all solutions of the equation are nonoscillatory and several criteria for the asymptotic behavior of nonoscillatory solutions of the equation are also obtained.展开更多
An alternative method of solving Lagrange＇s first-order partial differential equation of the form（a1x ＋b1y＋C1z）p＋ （a2x ＋b2y＋c2z）q =a3x ＋b3y＋c3z,where p = Эz/Эx, q = Эz/Эy and ai, bi, ci （i = 1,2,3） a...An alternative method of solving Lagrange＇s first-order partial differential equation of the form（a1x ＋b1y＋C1z）p＋ （a2x ＋b2y＋c2z）q =a3x ＋b3y＋c3z,where p = Эz/Эx, q = Эz/Эy and ai, bi, ci （i = 1,2,3） are all real numbers has been presented here.展开更多
By virtue of the fixed point indices, we discuss the existence of the multiple positive periodic solutions to singular differential equation with state-dependent delay under the conditions concerning the first eigenva...By virtue of the fixed point indices, we discuss the existence of the multiple positive periodic solutions to singular differential equation with state-dependent delay under the conditions concerning the first eigenvalue of the relevant linear operator. The results in this paper are optimal and totally generalize many present results.展开更多
Friction force(f)usually increases with the normal load(N)macroscopically,according to the classic law of Da Vinci–Amontons(f=μN),with a positive and finite friction coefficient(μ).Herein near-zero and negative dif...Friction force(f)usually increases with the normal load(N)macroscopically,according to the classic law of Da Vinci–Amontons(f=μN),with a positive and finite friction coefficient(μ).Herein near-zero and negative differential friction(ZNDF)coefficients are discovered in two-dimensional(2D)van der Waals(vdW)magnetic CrI_(3)commensurate contacts.It is identified that the ferromagnetic–antiferromagnetic phase transition of the interlayer couplings of the bilayer CrI_(3)can significantly reduce the interfacial sliding energy barriers and thus contribute to ZNDF.Moreover,phase transition between the in-plane(p_(x)and p_(y))and out-of-plane(p_(z))wave-functions dominates the sliding barrier evolutions,which is attributed to the delicate interplays among the interlayer vdW,electrostatic interactions,and the intralayer deformation of the CrI_(3)layers under external load.The present findings may motivate a new concept of slide-spintronics and are expected to play an instrumental role in design of novel magnetic solid lubricants applied in various spintronic nano-devices.展开更多
In this study, a collocation technique is presented for approximate solution of the fractional-order logistic population model. Actually, we develop the Bessel collocation method by using the fractional derivative in ...In this study, a collocation technique is presented for approximate solution of the fractional-order logistic population model. Actually, we develop the Bessel collocation method by using the fractional derivative in the Caputo sense to obtain the approximate solutions of this model problem. By means of the fractional derivative in the Caputo sense, the collocation points, the Bessel functions of the first kind, the method transforms the model problem into a system of nonlinear algebraic equations. Numerical applications are given to demonstrate efficiency and accuracy of the method. In applications, the reliability of the scheme is shown by the error function based on the accuracy of the approximate solution.展开更多
We characterize the complex differential equations of the form dy/dx=a_(n)(x)y^)n_+a_(n-1)(x)y^(n-1)+…+a_(1)(x)y+a_(0)(x) where a_(j)(x) are meromorphic functions in the variable x for j = 0,..., n that admit either ...We characterize the complex differential equations of the form dy/dx=a_(n)(x)y^)n_+a_(n-1)(x)y^(n-1)+…+a_(1)(x)y+a_(0)(x) where a_(j)(x) are meromorphic functions in the variable x for j = 0,..., n that admit either a Weierstrass first integral or a Weierstrass inverse integrating factor.展开更多
This paper deals with the existence of Darboux first integrals for the planar polynomial differential systems x=x-y+P n+1(x,y)+xF2n(x,y),y=x+y+Q n+1(x,y)+yF2n(x,y),where P i(x,y),Q i(x,y)and F i(x,y)are homogeneous po...This paper deals with the existence of Darboux first integrals for the planar polynomial differential systems x=x-y+P n+1(x,y)+xF2n(x,y),y=x+y+Q n+1(x,y)+yF2n(x,y),where P i(x,y),Q i(x,y)and F i(x,y)are homogeneous polynomials of degree i.Within this class,we identify some new Darboux integrable systems having either a focus or a center at the origin.For such Darboux integrable systems having degrees 5and 9 we give the explicit expressions of their algebraic limit cycles.For the systems having degrees 3,5,7 and 9and restricted to a certain subclass we present necessary and sufficient conditions for being Darboux integrable.展开更多
文摘Dual mobility(DM)bearings have gained significant attention in the field of total hip arthroplasty(THA)as a valid treatment option in cases of revision for instability after THA whereas its use in primary THA is still a matter of debate.This manuscript explores the pathology,incidence,diagnosis,treatment options,prognosis,ongoing studies in the literature,and future perspectives related to the use of DM bearings employed in primary THA.DM bearings are primarily designed to address one of the major concerns in THA:Instability of the prosthetic hip.Instability is both for the surgeon and the patient a devastating postoperative complication,leading to significant pain and subsequent apprehension by the patient and may require revision surgeries.The use of DM implants poses the worry of wear-related complications,such as accelerated polyethylene wear and osteolysis,which also pose challenges to long-term implant survival.This technique has seen a steady rise in recent years,with multiple studies reporting favorable outcomes.The incidence of their utilization varies among institutions and surgeons,reflecting differing preferences and patient populations.The diagnosis of instability and wear-related complications in THA often involves clinical assessment,imaging modalities such as X-rays,computed tomography scans,and sometimes advanced imaging techniques like magnetic resonance imaging.DM bearings can be considered as an option when patients present neurologic pathologies such as Parkinson's disease or recurrent dislocations after THA.DM bearings provide an additional articulation point within the implant,facilitating a greater range of motion and inherent stability.This design allows for reduced risk of dislocation and improved functional outcomes.Various implant manufacturers offer different designs and sizes of DM bearings to suit individual patient needs.Current literature suggests that the use of DM bearings in primary THA has demonstrated promising outcomes in terms of enhanced stability,reduced dislocation rates
基金supported by the National Natural Science Foundation of China under Grant Nos.61821004 and 62250056the Natural Science Foundation of Shandong Province under Grant Nos.ZR2021ZD14 and ZR2021JQ24+1 种基金Science and Technology Project of Qingdao West Coast New Area under Grant Nos.2019-32,2020-20,2020-1-4,High-level Talent Team Project of Qingdao West Coast New Area under Grant No.RCTDJC-2019-05Key Research and Development Program of Shandong Province under Grant No.2020CXGC01208.
文摘This paper focuses on linear-quadratic(LQ)optimal control for a class of systems governed by first-order hyperbolic partial differential equations(PDEs).Different from most of the previous works,an approach of discretization-then-continuousization is proposed in this paper to cope with the infinite-dimensional nature of PDE systems.The contributions of this paper consist of the following aspects:(1)The differential Riccati equations and the solvability condition of the LQ optimal control problems are obtained via the discretization-then-continuousization method.(2)A numerical calculation way of the differential Riccati equations and a practical design way of the optimal controller are proposed.Meanwhile,the relationship between the optimal costate and the optimal state is established by solving a set of forward and backward partial difference equations(FBPDEs).(3)The correctness of the method used in this paper is verified by a complementary continuous method and the comparative analysis with the existing operator results is presented.It is shown that the proposed results not only contain the classic results of the standard LQ control problem of systems governed by ordinary differential equations as a special case,but also support the existing operator results and give a more convenient form of computation.
文摘Most fundamental themes in mathematical physics and modern engineering are investigated by the closed form traveling wave solutions of nonlinear evolution equations.In our research,we ascertain abundant new closed form traveling wave solution of the nonlinear integro-differential equations via Ito equation,integro-differential Sawada-Kotera equation,first integro-differential KP hierarchy equation and second integro-differential KP hierarchy equation by two variable(G/G,1/G)-expansion method with the help of computer package like Mathematica.Some shape of solutions like,bell profile solution,anti-king profile solution,soliton profile solution,periodic profile solution etc.are obtain in this investigation.Trigonometric function solution,hyperbolic function solution and rational function solution are established by using our eminent method and comparing with our results to all of the well-known results which are given in the literature.By means of free parameters,plentiful solitary solutions are derived from the exact traveling wave solutions.The method can be easier and more applicable to investigate such type of nonlinear evolution models.
基金Project supported by the National Natural Science Foundation of China （Grant Nos 10572021 and 10472040） and Doctoral Programme Foundation of Institution of Higher Education of China （Grant No 20040007022）.
文摘In this paper, a Birkhoff-Noether method of solving ordinary differential equations is presented. The differential equations can be expressed in terms of Birkhoff＇s equations. The first integrals for differential equations can be found by using the Noether theory for Birkhoffian systems. Two examples are given to illustrate the application of the method.
文摘In this paper, we consider the oscillatory and asymptotic behavior of solution of first order nonlinear neutral functional differential equation with piecewise constant dealy. We prove that all solutions of the equation are nonoscillatory and several criteria for the asymptotic behavior of nonoscillatory solutions of the equation are also obtained.
文摘An alternative method of solving Lagrange＇s first-order partial differential equation of the form（a1x ＋b1y＋C1z）p＋ （a2x ＋b2y＋c2z）q =a3x ＋b3y＋c3z,where p = Эz/Эx, q = Эz/Эy and ai, bi, ci （i = 1,2,3） are all real numbers has been presented here.
基金Supported by National Natural Science Foundation of China (No.10626029, No.10701040)Edu-cational Department of Jiangxi Province (No.GJJ08358, No.GJJ08359, No.JXJG07436)Jiangxi University of Finance and Economics (No.04232015, No.JXCDJG0813).
文摘By virtue of the fixed point indices, we discuss the existence of the multiple positive periodic solutions to singular differential equation with state-dependent delay under the conditions concerning the first eigenvalue of the relevant linear operator. The results in this paper are optimal and totally generalize many present results.
基金supported by the National Natural Science Foundation of China(Nos.12074345,12174349,11674289,11804306,11634011 and U2030120)Henan Provincial Key Science and Technology Research Projects(No.212102210130).
文摘Friction force(f)usually increases with the normal load(N)macroscopically,according to the classic law of Da Vinci–Amontons(f=μN),with a positive and finite friction coefficient(μ).Herein near-zero and negative differential friction(ZNDF)coefficients are discovered in two-dimensional(2D)van der Waals(vdW)magnetic CrI_(3)commensurate contacts.It is identified that the ferromagnetic–antiferromagnetic phase transition of the interlayer couplings of the bilayer CrI_(3)can significantly reduce the interfacial sliding energy barriers and thus contribute to ZNDF.Moreover,phase transition between the in-plane(p_(x)and p_(y))and out-of-plane(p_(z))wave-functions dominates the sliding barrier evolutions,which is attributed to the delicate interplays among the interlayer vdW,electrostatic interactions,and the intralayer deformation of the CrI_(3)layers under external load.The present findings may motivate a new concept of slide-spintronics and are expected to play an instrumental role in design of novel magnetic solid lubricants applied in various spintronic nano-devices.
文摘In this study, a collocation technique is presented for approximate solution of the fractional-order logistic population model. Actually, we develop the Bessel collocation method by using the fractional derivative in the Caputo sense to obtain the approximate solutions of this model problem. By means of the fractional derivative in the Caputo sense, the collocation points, the Bessel functions of the first kind, the method transforms the model problem into a system of nonlinear algebraic equations. Numerical applications are given to demonstrate efficiency and accuracy of the method. In applications, the reliability of the scheme is shown by the error function based on the accuracy of the approximate solution.
基金partially supported by the Ministerio de Economia,Industria y Competitividad,Agencia Estatal de Investigacion grant MTM2016-77278-P (FEDER)the Agència de Gestio d’Ajuts Universitaris i de Recerca grant 2017SGR1617+1 种基金the H2020 European Research Council grant MSCA-RISE-2017-777911partially supported by FCT/Portugal through the pro ject UID/MAT/04459/2013。
文摘We characterize the complex differential equations of the form dy/dx=a_(n)(x)y^)n_+a_(n-1)(x)y^(n-1)+…+a_(1)(x)y+a_(0)(x) where a_(j)(x) are meromorphic functions in the variable x for j = 0,..., n that admit either a Weierstrass first integral or a Weierstrass inverse integrating factor.
基金supported by National Natural Science Foundation of China (Grant No. 11271252)Ministerio de Economiay Competitidad of Spain (Grant No. MTM2008-03437)+2 种基金 Agència de Gestió d’Ajuts Universitaris i de Recerca of Catalonia (Grant No. 2009SGR410)ICREA Academia,Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20110073110054)a Marie Curie International Research Staff Exchange Scheme Fellowship within the 7th European Community Framework Programme (Grant Nos. FP7-PEOPLE-2012-IRSES-316338 and 318999)
文摘This paper deals with the existence of Darboux first integrals for the planar polynomial differential systems x=x-y+P n+1(x,y)+xF2n(x,y),y=x+y+Q n+1(x,y)+yF2n(x,y),where P i(x,y),Q i(x,y)and F i(x,y)are homogeneous polynomials of degree i.Within this class,we identify some new Darboux integrable systems having either a focus or a center at the origin.For such Darboux integrable systems having degrees 5and 9 we give the explicit expressions of their algebraic limit cycles.For the systems having degrees 3,5,7 and 9and restricted to a certain subclass we present necessary and sufficient conditions for being Darboux integrable.
