The working principle of cement roller press and current development of wear resistance on the cement grinding system status at home and abroad was described. The main improvement of previous research on the wear resi...The working principle of cement roller press and current development of wear resistance on the cement grinding system status at home and abroad was described. The main improvement of previous research on the wear resistance of roller press was proposed from three aspects of wear-resistant material, roller press roller structure, and surface morphology.展开更多
In this paper, a QP-free feasible method with piecewise NCP functions is proposed for nonlinear inequality constrained optimization problems. The new NCP functions are piecewise linear-rational, regular pseudo-smooth...In this paper, a QP-free feasible method with piecewise NCP functions is proposed for nonlinear inequality constrained optimization problems. The new NCP functions are piecewise linear-rational, regular pseudo-smooth and have nice properties. This method is based on the solutions of linear systems of equation reformulation of KKT optimality conditions, by using the piecewise NCP functions. This method is implementable and globally convergent without assuming the strict complementarity condition, the isolatedness of accumulation points. Purr thermore, the gradients of active constraints are not requested to be linearly independent. The submatrix which may be obtained by quasi-Newton methods, is not requested to be uniformly positive definite. Preliminary numerical results indicate that this new QP-free method is quite promising.展开更多
In this paper, we present a new successive approximation damped Newton method for the nonlinear complementarity problem based on its equivalent nonsmooth equations. Under suitable conditions, we obtain the global conv...In this paper, we present a new successive approximation damped Newton method for the nonlinear complementarity problem based on its equivalent nonsmooth equations. Under suitable conditions, we obtain the global convergence result of the proposed algorithms. Some numerical results are also reported.展开更多
In this paper,we propose a novel nonlinear oscillator with strong irrational nonlinearities having smooth and discontinuous characteristics depending on the values of a smoothness parameter.The oscillator is similar t...In this paper,we propose a novel nonlinear oscillator with strong irrational nonlinearities having smooth and discontinuous characteristics depending on the values of a smoothness parameter.The oscillator is similar to the SD oscillator,originally introduced in Phys Rev E 69(2006).The equilibrium stability and the complex bifurcations of the unperturbed system are investigated.The bifurcation sets of the equilibria in parameter space are constructed to demonstrate transitions in the multiple well dynamics for both smooth and discontinuous regimes.The Melnikov method is employed to obtain the analytical criteria of chaotic thresholds for the singular closed orbits of homoclinic,homo-heteroclinic,cuspidal heteroclinic and tangent homoclinic orbits of the perturbed system.展开更多
The use of bionic non-smooth surfaces is a popular approach for saving energy because of their drag reduction property. Conventional non-smooth structures include riblets and dimples. Inspired by sand dunes, a novel v...The use of bionic non-smooth surfaces is a popular approach for saving energy because of their drag reduction property. Conventional non-smooth structures include riblets and dimples. Inspired by sand dunes, a novel variable ovoid non-smooth structure is proposed in this study. The body of the variable ovoid dimple was designed based on three size parameters, the radius, semimajor, and depth, and a 3D model was created based on UG software. The constructed variable dimples were placed in a rectangular array on the bottom of a square tube model. Following ANSYS meshing, the grid model was imported into FLUENT, where the flow characteristics were calculated. Results of skin friction reduction were achieved and the effect of the design parameters on different variable ovoid dimples was obtained by orthogonal testing. Various aspects of the skin friction reduction mechanism were discussed including the distribution of velocity vectors, variation in boundary layer thickness, and pressure distribution.展开更多
In this paper, a class of delay differential equations with nonlinear impulsive control is discussed. Based on the nonsmooth analysis, criteria of stability are obtained for delay differential equations with nonlinear...In this paper, a class of delay differential equations with nonlinear impulsive control is discussed. Based on the nonsmooth analysis, criteria of stability are obtained for delay differential equations with nonlinear impulses control under certain conditions. These criteria can be applied to some neural network models. At the end of the paper, two examples are provided to illustrate the feasibility and effectiveness of the proposed results.展开更多
This paper presents an experimental investigation of effects of a kind of streamwise-grooved blade on the performance of an axial-flow fan. The flow field at 25% chord downstream from the trailing edge at hub was meas...This paper presents an experimental investigation of effects of a kind of streamwise-grooved blade on the performance of an axial-flow fan. The flow field at 25% chord downstream from the trailing edge at hub was measured using a 5-hole pressure probe at different mass-flow conditions. The fan performance of the groove blades was compared with that of the smooth blades. The measurement results indicate that: ( 1 ) the non-smooth blades increase mass flow of the fan at the same throttle conditions except a near stall condition; (2) the non-smooth blades reduce the relative total pressure loss in the rotor passage and increase the fan's total pressure rise at the test mass-flow conditions except the near stall condition; (3) Negative benefits are obtained at a near stall condition when the smooth blades are replaced by the non-smooth ones. The fan mass flow decreases 0.9% while the total-pressure rise decreases 2.4% at the near stall condition.展开更多
The development of a high-performance cemented carbide drill bit is of great significance to the reduction of rock drilling-cost. The non-smooth features of a biological surface provide an insight into how they can ob...The development of a high-performance cemented carbide drill bit is of great significance to the reduction of rock drilling-cost. The non-smooth features of a biological surface provide an insight into how they can obtain low friction and good wear resistance with evolving surface morphology. By analyzing the mechanism of the surface of a dung beetle for reducing soil wear and adherence, we design a cemented carbide drill bit with a bionic surface, which is expected to have superior anti-wearing and anti-sticking properties for drilling the soft coal seam. Inspired from the characteristics of the head and pronotum surface of the dung beetle, optimized non-smooth surface of the drill bit was constructed. The working performance of this innovative drill was experimentally tested. With comparative experiments under the identical drilling conditions, the wear rates, drilling times of conventional drills and bionic drills were measured. Compared with the conventional counterpart, the drill designed exhibits better performance in reducing wear and sticking drilling-breaks, therefore achieving higher levels of efficiency. The diameter of the dome and pit on the bit surface is in the range of 0.8–1.2 mm, and the bionic drill bits could get better performance with preferable drilling speeds and wear rates.展开更多
In this paper, nonsmooth univex, nonsmooth quasiunivex, and nonsmooth pseudounivex functions are introduced. By utilizing these new concepts, sufficient optimality conditions for a weakly efficient solution of the non...In this paper, nonsmooth univex, nonsmooth quasiunivex, and nonsmooth pseudounivex functions are introduced. By utilizing these new concepts, sufficient optimality conditions for a weakly efficient solution of the nonsmooth multiobjective programming problem are established. Weak and strong duality theorems axe also derived for Mond-Weir type multiobjective dual programs.展开更多
The authors establish a general monotonicity formula for the following elliptic system △ui+fi(x,ui,…,um)=0 in Ω,where Ω belong to belong to R^n is a regular domain, (fi(x, u1,... ,um)) = △↓F(x,→↑u), F...The authors establish a general monotonicity formula for the following elliptic system △ui+fi(x,ui,…,um)=0 in Ω,where Ω belong to belong to R^n is a regular domain, (fi(x, u1,... ,um)) = △↓F(x,→↑u), F(x,→↑u ) is a given smooth function of x ∈ R^n and →↑u = (u1,…,um) ∈ R^m. The system comes from understanding the stationary case of Ginzburg-Landau model. A new monotonicity formula is also set up for the following parabolic systemδtui-△ui-fi(x,ui,…,um)=0 in(ti,t2)×R^n,where t1 〈 t2 are two constants, (fi(x,→↑u ) is given as above. The new monotonicity formulae are focused more attention on the monotonicity of nonlinear terms. The new point of the results is that an index β is introduced to measure the monotonicity of the nonlinear terms in the problems. The index β in the study of monotonieity formulae is useful in understanding the behavior of blow-up sequences of solutions. Another new feature is that the previous monotonicity formulae are extended to nonhomogeneous nonlinearities. As applications, the Ginzburg-Landau model and some different generalizations to the free boundary problems are studied.展开更多
H61der and gradient estimates for the correctors in the homogenization are presented based on the translation invariance and Li-Vogelius's gradient estimate. If the coefficients are piecewise smooth and the homogeniz...H61der and gradient estimates for the correctors in the homogenization are presented based on the translation invariance and Li-Vogelius's gradient estimate. If the coefficients are piecewise smooth and the homogenized solution is smooth enough, the interior error of the first-order expansion is O(e) in the HSlder norm; it is O(e) in W1,∞ based on the Avellaneda-Lin's gradient estimate when the coefficients are Lipschitz continuous. These estimates can be partly extended to the nonlinear parabolic equations.展开更多
This paper introduces some new generalizations of the concept of (~, p)-invexity for non- differentiable locally Lipschitz functions using the tools of Clarke subdifferential. These functions are used to derive the ...This paper introduces some new generalizations of the concept of (~, p)-invexity for non- differentiable locally Lipschitz functions using the tools of Clarke subdifferential. These functions are used to derive the necessary and sufficient optimality conditions for a class of nonsmooth semi-infinite minmax programming problems, where set of restrictions are indexed in a compact set. Utilizing the sufficient optimality conditions, the authors formulate three types of dual models and establish weak and strong duality results. The results of the paper extend and unify naturally some earlier results from the literature.展开更多
This paper investigates the nonlinear dynamics of network-based dynamical systems where network communication channels of finite data rates are inserted into the closed loops of the control systems. The authors analyz...This paper investigates the nonlinear dynamics of network-based dynamical systems where network communication channels of finite data rates are inserted into the closed loops of the control systems. The authors analyze the bifurcation and chaotic behavior of the non-smooth dynamical systems. The authors first prove that for almost all system parameters there are no periodic orbits. This result distinguishes this type of non-smooth dynamical systems from many others exhibiting border-collision bifurcations. Next, the authors show analytically that the chaotic sets are separated from the region containing the line segment of all fixed points with a finite distance. Finally, the authors employ a simple model to highlight that both the number of clients sharing a common network channel and fluctuations in the available network bandwidth have significant influence on the performance of such dynamical systems.展开更多
The author proves the local existence of smooth solutions to the finite extensible nonlinear elasticity (FENE) dumbbell model of polymeric flows in some weighted spaces if the non-dimensional parameter b > 2.
基金Supported by the Planning Project of Science and Technology Development of Jilin Province (09ZDGG001)~~
文摘The working principle of cement roller press and current development of wear resistance on the cement grinding system status at home and abroad was described. The main improvement of previous research on the wear resistance of roller press was proposed from three aspects of wear-resistant material, roller press roller structure, and surface morphology.
基金supported by the Natural science Foundation of China(10371089,10571137)
文摘In this paper, a QP-free feasible method with piecewise NCP functions is proposed for nonlinear inequality constrained optimization problems. The new NCP functions are piecewise linear-rational, regular pseudo-smooth and have nice properties. This method is based on the solutions of linear systems of equation reformulation of KKT optimality conditions, by using the piecewise NCP functions. This method is implementable and globally convergent without assuming the strict complementarity condition, the isolatedness of accumulation points. Purr thermore, the gradients of active constraints are not requested to be linearly independent. The submatrix which may be obtained by quasi-Newton methods, is not requested to be uniformly positive definite. Preliminary numerical results indicate that this new QP-free method is quite promising.
文摘In this paper, we present a new successive approximation damped Newton method for the nonlinear complementarity problem based on its equivalent nonsmooth equations. Under suitable conditions, we obtain the global convergence result of the proposed algorithms. Some numerical results are also reported.
基金supported by the National Natural Science Foundation of China (Grant No. 10872136,11072065 and 10932006)
文摘In this paper,we propose a novel nonlinear oscillator with strong irrational nonlinearities having smooth and discontinuous characteristics depending on the values of a smoothness parameter.The oscillator is similar to the SD oscillator,originally introduced in Phys Rev E 69(2006).The equilibrium stability and the complex bifurcations of the unperturbed system are investigated.The bifurcation sets of the equilibria in parameter space are constructed to demonstrate transitions in the multiple well dynamics for both smooth and discontinuous regimes.The Melnikov method is employed to obtain the analytical criteria of chaotic thresholds for the singular closed orbits of homoclinic,homo-heteroclinic,cuspidal heteroclinic and tangent homoclinic orbits of the perturbed system.
基金Project supported by the National Natural Science Foundation of China (No. 51375439)
文摘The use of bionic non-smooth surfaces is a popular approach for saving energy because of their drag reduction property. Conventional non-smooth structures include riblets and dimples. Inspired by sand dunes, a novel variable ovoid non-smooth structure is proposed in this study. The body of the variable ovoid dimple was designed based on three size parameters, the radius, semimajor, and depth, and a 3D model was created based on UG software. The constructed variable dimples were placed in a rectangular array on the bottom of a square tube model. Following ANSYS meshing, the grid model was imported into FLUENT, where the flow characteristics were calculated. Results of skin friction reduction were achieved and the effect of the design parameters on different variable ovoid dimples was obtained by orthogonal testing. Various aspects of the skin friction reduction mechanism were discussed including the distribution of velocity vectors, variation in boundary layer thickness, and pressure distribution.
基金supported by Natural Science Foundation of China under Grant Nos.10972018 and 11072013
文摘In this paper, a class of delay differential equations with nonlinear impulsive control is discussed. Based on the nonsmooth analysis, criteria of stability are obtained for delay differential equations with nonlinear impulses control under certain conditions. These criteria can be applied to some neural network models. At the end of the paper, two examples are provided to illustrate the feasibility and effectiveness of the proposed results.
基金The authors would like to acknowledge National Natural Science Foundation of China for the support projects Grant No.50376002.
文摘This paper presents an experimental investigation of effects of a kind of streamwise-grooved blade on the performance of an axial-flow fan. The flow field at 25% chord downstream from the trailing edge at hub was measured using a 5-hole pressure probe at different mass-flow conditions. The fan performance of the groove blades was compared with that of the smooth blades. The measurement results indicate that: ( 1 ) the non-smooth blades increase mass flow of the fan at the same throttle conditions except a near stall condition; (2) the non-smooth blades reduce the relative total pressure loss in the rotor passage and increase the fan's total pressure rise at the test mass-flow conditions except the near stall condition; (3) Negative benefits are obtained at a near stall condition when the smooth blades are replaced by the non-smooth ones. The fan mass flow decreases 0.9% while the total-pressure rise decreases 2.4% at the near stall condition.
基金supported by the National Natural Science Foundation of China(Grant Nos.51204122&51134018)the Natural Science Foundation of Jiangsu Province(Grant No.BK20140411)+3 种基金State Key Laboratory of Mechanics and Control of Mechanical Structures(Nanjing University of Aeronautics and AstronauticsMCMS-0414Y01)the National Basic Research Program of China(“973”Project)(Grant No.2014CB239203)the 111 Project(Grant No.B14006)
文摘The development of a high-performance cemented carbide drill bit is of great significance to the reduction of rock drilling-cost. The non-smooth features of a biological surface provide an insight into how they can obtain low friction and good wear resistance with evolving surface morphology. By analyzing the mechanism of the surface of a dung beetle for reducing soil wear and adherence, we design a cemented carbide drill bit with a bionic surface, which is expected to have superior anti-wearing and anti-sticking properties for drilling the soft coal seam. Inspired from the characteristics of the head and pronotum surface of the dung beetle, optimized non-smooth surface of the drill bit was constructed. The working performance of this innovative drill was experimentally tested. With comparative experiments under the identical drilling conditions, the wear rates, drilling times of conventional drills and bionic drills were measured. Compared with the conventional counterpart, the drill designed exhibits better performance in reducing wear and sticking drilling-breaks, therefore achieving higher levels of efficiency. The diameter of the dome and pit on the bit surface is in the range of 0.8–1.2 mm, and the bionic drill bits could get better performance with preferable drilling speeds and wear rates.
基金supported by the National Natural Science Foundation of China under Grant No.11001287the Natural Science Foundation Project of Chongqing(CSTC 2010BB9254)the Education Committee Project Research Foundation of Chongqing under Grant No.KJ100711
文摘In this paper, nonsmooth univex, nonsmooth quasiunivex, and nonsmooth pseudounivex functions are introduced. By utilizing these new concepts, sufficient optimality conditions for a weakly efficient solution of the nonsmooth multiobjective programming problem are established. Weak and strong duality theorems axe also derived for Mond-Weir type multiobjective dual programs.
基金Project supported by the National Natural Science Foundation of China (No. 10631020)the Specialized Research Fund for the Doctoral Program of Higher Education (No. 20060003002)
文摘The authors establish a general monotonicity formula for the following elliptic system △ui+fi(x,ui,…,um)=0 in Ω,where Ω belong to belong to R^n is a regular domain, (fi(x, u1,... ,um)) = △↓F(x,→↑u), F(x,→↑u ) is a given smooth function of x ∈ R^n and →↑u = (u1,…,um) ∈ R^m. The system comes from understanding the stationary case of Ginzburg-Landau model. A new monotonicity formula is also set up for the following parabolic systemδtui-△ui-fi(x,ui,…,um)=0 in(ti,t2)×R^n,where t1 〈 t2 are two constants, (fi(x,→↑u ) is given as above. The new monotonicity formulae are focused more attention on the monotonicity of nonlinear terms. The new point of the results is that an index β is introduced to measure the monotonicity of the nonlinear terms in the problems. The index β in the study of monotonieity formulae is useful in understanding the behavior of blow-up sequences of solutions. Another new feature is that the previous monotonicity formulae are extended to nonhomogeneous nonlinearities. As applications, the Ginzburg-Landau model and some different generalizations to the free boundary problems are studied.
基金supported by National Natural Science Foundation of China (Grant No.90916027)Special Funds for National Basic Research Program of China (973 Program) (Grant No. 2010CB832702)the State Key Laboratory of Scientific and Engineering Computing
文摘H61der and gradient estimates for the correctors in the homogenization are presented based on the translation invariance and Li-Vogelius's gradient estimate. If the coefficients are piecewise smooth and the homogenized solution is smooth enough, the interior error of the first-order expansion is O(e) in the HSlder norm; it is O(e) in W1,∞ based on the Avellaneda-Lin's gradient estimate when the coefficients are Lipschitz continuous. These estimates can be partly extended to the nonlinear parabolic equations.
基金supported by the National Board of Higher Mathematics(NBHM)Department of Atomic Energy,India,under Grant No.2/40(12)/2014/R&D-II/10054
文摘This paper introduces some new generalizations of the concept of (~, p)-invexity for non- differentiable locally Lipschitz functions using the tools of Clarke subdifferential. These functions are used to derive the necessary and sufficient optimality conditions for a class of nonsmooth semi-infinite minmax programming problems, where set of restrictions are indexed in a compact set. Utilizing the sufficient optimality conditions, the authors formulate three types of dual models and establish weak and strong duality results. The results of the paper extend and unify naturally some earlier results from the literature.
基金supported by an the National Natural Science Foundation of China under Grant No.60804015,and an NSERC grant to the third author
文摘This paper investigates the nonlinear dynamics of network-based dynamical systems where network communication channels of finite data rates are inserted into the closed loops of the control systems. The authors analyze the bifurcation and chaotic behavior of the non-smooth dynamical systems. The authors first prove that for almost all system parameters there are no periodic orbits. This result distinguishes this type of non-smooth dynamical systems from many others exhibiting border-collision bifurcations. Next, the authors show analytically that the chaotic sets are separated from the region containing the line segment of all fixed points with a finite distance. Finally, the authors employ a simple model to highlight that both the number of clients sharing a common network channel and fluctuations in the available network bandwidth have significant influence on the performance of such dynamical systems.
文摘The author proves the local existence of smooth solutions to the finite extensible nonlinear elasticity (FENE) dumbbell model of polymeric flows in some weighted spaces if the non-dimensional parameter b > 2.