This paper studies conformal invariance and conserved quantity of third-order Lagrange equations for non- conserved mechanical systems. Third-order Lagrange equations, the definition and a determining equation of conf...This paper studies conformal invariance and conserved quantity of third-order Lagrange equations for non- conserved mechanical systems. Third-order Lagrange equations, the definition and a determining equation of conformal invariance of the system are presented. The conformal factor expression is deduced from conformal invariance and Lie symmetry. The necessary and sufficient condition that conformal invaxiance of the system would have Lie symmetry under single-parameter infinitesimal transformations is obtained. The corresponding conserved quantity of conformal invariance is derived with the aid of a structure equation. Lastly, an example is given to illustrate the application of the results.展开更多
Recently, reconsidering the Rastall idea T_(μ;νν)^(v)=α_(,μ) through relativistic thermodynamics gives a new form for the scalar field α which led us to construct modern modified theory of gravity debugged ‘non...Recently, reconsidering the Rastall idea T_(μ;νν)^(v)=α_(,μ) through relativistic thermodynamics gives a new form for the scalar field α which led us to construct modern modified theory of gravity debugged ‘non-conserved gravity theory’ Fazlollahi 2023 Euro. Phys. J. C 83 923. This theory unlike other modified theories of gravity cannot directly explain the current acceleration expansion in the absence of the cosmological constant and or existence of other forms of dark energy. Hence, in this study we have reinvestigated holographic dark energy Ρ_(X)~H^(2) in the non-conserved theory of gravity. In this context, the density and pressure of dark energy depend on the non-conserved term and density of the dust matter field. As shown, due to non-conservation effects on large-scale structures, unlike the original holographic model, our model onsets an acceleration epoch for the current Universe satisfies observations. Moreover, the interaction and viscous scenarios are studied for this model.展开更多
This paper focuses on the Noether symmetries and the conserved quantities for both holonomic and nonholonomic systems based on a new non-conservative dynamical model introduced by E1-Nabulsi. First, the E1-Nabulsi dyn...This paper focuses on the Noether symmetries and the conserved quantities for both holonomic and nonholonomic systems based on a new non-conservative dynamical model introduced by E1-Nabulsi. First, the E1-Nabulsi dynamical model which is based on a fractional integral extended by periodic laws is introduced, and E1-Nabulsi-Hamilton's canoni- cal equations for non-conservative Hamilton system with holonomic or nonholonomic constraints are established. Second, the definitions and criteria of E1-Nabulsi-Noether symmetrical transformations and quasi-symmetrical transformations are presented in terms of the invariance of E1-Nabulsi-Hamilton action under the infinitesimal transformations of the group. Fi- nally, Noether's theorems for the non-conservative Hamilton system under the E1-Nabulsi dynamical system are established, which reveal the relationship between the Noether symmetry and the conserved quantity of the system.展开更多
This paper studies the conformal invariance by infinitesimal point transformations of non-conservative Lagrange systems. It gives the necessary and sufficient conditions of conformal invariance by the action of infini...This paper studies the conformal invariance by infinitesimal point transformations of non-conservative Lagrange systems. It gives the necessary and sufficient conditions of conformal invariance by the action of infinitesimal point transformations being Lie symmetric simultaneously. Then the Noether conserved quantities of conformal invariance are obtained. Finally an illustrative example is given to verify the results.展开更多
According to the Herglotz variational principle and differential variational principle of Herglotz type, we study the adiabatic invariants for a non-conservative nonholonomic system. Firstly, the differential equation...According to the Herglotz variational principle and differential variational principle of Herglotz type, we study the adiabatic invariants for a non-conservative nonholonomic system. Firstly, the differential equations of motion of the non-conservative nonholonomic system based upon the generalized variational principle of Herglotz type are given, and the exact invariant for the non-conservative nonholonomic system is introduced. Secondly, a new type of adiabatic invariant for the system under the action of a small perturbation is obtained. Thirdly, the inverse theorem of the adiabatic invariant is given. Finally, an example is given.展开更多
In order to reasonably explain the phenomenon of cell bioelectricity,we proposed the conservation law of cell membrane area,established the ion inequality equation,and therefore paid attention to the mystery of“θ-τ...In order to reasonably explain the phenomenon of cell bioelectricity,we proposed the conservation law of cell membrane area,established the ion inequality equation,and therefore paid attention to the mystery of“θ-τ”.We researched and analyzed the“θ-τ”mystery,discussed the parity non-conservation in weak interactions,suggested possible experiments to test the parity non-conservation in weak interactions,and gave our research and analysis conclusions:The parity non-conservation in weak interactions,is still a“conjecture”;The experimental scheme suggested in the papers by C.N.Yang et al.cannot determine whether the weak interaction can separate left and right,and it is impossible to directly answer whetherθandτin the“θ-τ”mystery are the same particle;The Co60βdecay experiment such as C.S.Wu is a pseudo-mirror experiment,whether the experimental result violates parity conservation is only based on the assumption of C.N.Yang et al.In fact,experiments such as polarized Co60 did not overturn the so-called“law of parity conservation”.The mirror image principle does not have any physical meaning,does not correspond to any physical conservation quantity,and cannot be destroyed by any physical experiment.In the process of turning“mirror symmetry”and“mirror asymmetry”into so-called physical“common sense”and scientific“facts”respectively,the methods of transformation are“stealing concepts”and“circular argumentation”.The“θ-τ”mystery is a“man-made”mystery.θandτare two different particles,which may be the result of the same precursor particle being divided into two.The work of C.N.Yang,T.D.Lee,C.S.Wu et al.has brought quantum physicists from the“small black room”to the“bigger black room”or“smaller black room”.The right and wise choice is to go back through the door that came in.With the development of science today,it is time for some contents to reform from the bottom.展开更多
This paper deals with the problem of the postbuckling response of a thin cantilever beam ofnon-linear material, subjected to subtangential follower forces. Based on the well-knownBernoulli-Euler bending moment-curvatu...This paper deals with the problem of the postbuckling response of a thin cantilever beam ofnon-linear material, subjected to subtangential follower forces. Based on the well-knownBernoulli-Euler bending moment-curvature relation, the proposed problem is reduced to a specialeigenvalue problem of non-linear differential equation. An approximate solution is achieved byusing a simple and very effective technique, which leads to reliable results even in the case of verylarge deflections. The initial postbuckling path depending on the subtangential follower forces inequilibrium is then obtained. Moreover, the individual and coupling effect of the subtangential fol-lower force, the material non-linearity and the beam slenderness ratio on the initial postbucklingpath are also discussed in detail.展开更多
In this work,thermodynamic models for the energetics and kinetics of inhomogeneous gradient materials with microstructure are formulated in the context of continuum thermodynamics and material theory.For simplicity,at...In this work,thermodynamic models for the energetics and kinetics of inhomogeneous gradient materials with microstructure are formulated in the context of continuum thermodynamics and material theory.For simplicity,attention is restricted to isothermal conditions.The materials of interest here are characterized by(1) first- and secondorder gradients of the deformation field and(2) a kinematic microstructure field and its gradient(e.g.,in the sense of director,micromorphic or Cosserat microstructure).Material inhomogeneity takes the form of multiple phases and chemical constituents,modeled here with the help of corresponding phase fields.Invariance requirements together with the dissipation principle result in the reduced model field and constitutive relations.Special cases of these include the wellknown Cahn-Hilliard and Ginzburg-Landau relations.In the last part of the work,initial boundary value problems for this class of materials are formulated with the help of rate variational methods.展开更多
Bias non-conservation characteristics of radio-frequency noise mechanism of 40-nm n-MOSFET are observed by modeling and measuring its drain current noise. A compact model for the drain current noise of 40-nm MOSFET is...Bias non-conservation characteristics of radio-frequency noise mechanism of 40-nm n-MOSFET are observed by modeling and measuring its drain current noise. A compact model for the drain current noise of 40-nm MOSFET is proposed through the noise analysis. This model fully describes three kinds of main physical sources that determine the noise mechanism of 40-nm MOSFET, i.e., intrinsic drain current noise, thermal noise induced by the gate parasitic resistance, and coupling thermal noise induced by substrate parasitic effect. The accuracy of the proposed model is verified by noise measurements, and the intrinsic drain current noise is proved to be the suppressed shot noise, and with the decrease of the gate voltage, the suppressed degree gradually decreases until it vanishes. The most important findings of the bias non-conservative nature of noise mechanism of 40-nm n-MOSFET are as follows.(i) In the strong inversion region, the suppressed shot noise is weakly affected by the thermal noise of gate parasitic resistance. Therefore, one can empirically model the channel excess noise as being like the suppressed shot noise.(ii) In the middle inversion region, it is almost full of shot noise.(iii) In the weak inversion region, the thermal noise is strongly frequency-dependent, which is almost controlled by the capacitive coupling of substrate parasitic resistance. Measurement results over a wide temperature range demonstrate that the thermal noise of 40-nm n-MOSFET exists in a region from the weak to strong inversion, contrary to the predictions of suppressed shot noise model only suitable for the strong inversion and middle inversion region. These new findings of the noise mechanism of 40-nm n-MOSFET are very beneficial for its applications in ultra low-voltage and low-power RF, such as novel device electronic structure optimization, integrated circuit design and process technology evaluation.展开更多
Weak- and hyperfine-interaction-induced 1 s2s 1S0→ 1S2 1 S0 E 1 transition rates for the isoelectronic sequence of Helike ions have been calculated using the multi-configuration Dirac-Hartree-Fock (MCDHF) and rela...Weak- and hyperfine-interaction-induced 1 s2s 1S0→ 1S2 1 S0 E 1 transition rates for the isoelectronic sequence of Helike ions have been calculated using the multi-configuration Dirac-Hartree-Fock (MCDHF) and relativistic configuration interaction methods. The results should be helpful for the future experimental investigations of parity non-conservation effects.展开更多
A kinetic flux-vector splitting (KFVS) scheme is applied for solving a reduced six-equation two-phase flow model of Saurel et al. [1]. The model incorporates single velocity, two pressures and relaxation terms. An add...A kinetic flux-vector splitting (KFVS) scheme is applied for solving a reduced six-equation two-phase flow model of Saurel et al. [1]. The model incorporates single velocity, two pressures and relaxation terms. An additional seventh equation, describing the total mixture energy, is added to the model to guarantee the correct treatment of shocks in the single phase limit. Some salient features of the model are that it is hyperbolic with only three wave propagation speeds and the volume fraction remains positive. The proposed numerical scheme is based on the direct splitting of macroscopic flux functions of the system of equations. The second order accuracy of the scheme is achieved by using MUSCL-type initial reconstruction and Runge-Kutta time stepping method. Moreover, a pressure relaxation procedure is used to fulfill the interface conditions. For validation, the results of suggested scheme are compared with those from the high resolution central upwind and HLLC schemes. The central upwind scheme is also applied for the first time to this model. The accuracy, efficiency and simplicity of the KFVS scheme demonstrate its potential for modeling two-phase flows.展开更多
Diffuse interfaces appear with any Eulerian discontinuity capturing compressible flow solver. When dealing with multifluid and multimaterial computations, interfaces smearing results in serious difficulties to fulfil ...Diffuse interfaces appear with any Eulerian discontinuity capturing compressible flow solver. When dealing with multifluid and multimaterial computations, interfaces smearing results in serious difficulties to fulfil contact conditions, as spurious oscillations appear. To circumvent these difficulties, several approaches have been proposed. One of them relies on multiphase flow modelling of the numerically diffused zone and is based on extended hyperbolic systems with stiff mechanical relaxation (Saurel and Abgrall, 1999 [4], Saurel et al., 2009 [6]). This approach is very robust, accurate and flexible in the sense that many physical effects can be included: surface tension, phase transition, elastic-plastic materials, detonations, granular effects etc. It is also able to deal with dynamic appearance of interfaces. However it suffers from an important drawback when long time evolution is under interest as the interface becomes more and more diffused. The present paper addresses this issue and provides an efficient way to sharpen interfaces. A sharpening flow model is used to correct the solution after each time step. The sharpening process is based on a hyperbolic equation that produces a steady shock in finite time at the interface location. This equation is embedded in a “sharpening multiphase model” redistributing volume fractions, masses, momentum and energy in a consistent way. The method is conservative with respect to the masses, mixture momentum and mixture energy. It results in diffused interfaces sharpened in one or two mesh points. The method is validated on test problems having exact solutions.展开更多
We present a method for determining the motion of an electron in a hydrogen atom, which starts from a field Lagrangean foundation for non-conservative systems that can exhibit chaotic behavior. As a consequence, the p...We present a method for determining the motion of an electron in a hydrogen atom, which starts from a field Lagrangean foundation for non-conservative systems that can exhibit chaotic behavior. As a consequence, the problem of the formation of the atom becomes the problem of finding the possible stable orbital attractors and the associated transition paths through which the electron mechanical energy varies continuously until a stable energy state is reached.展开更多
From 1990 to 2005 NASA did six flybys of Earth in order to boost the energy of each spacecraft, enabling them to go deeper into the solar system. These six flybys showed an unexpected violation in the conservation of ...From 1990 to 2005 NASA did six flybys of Earth in order to boost the energy of each spacecraft, enabling them to go deeper into the solar system. These six flybys showed an unexpected violation in the conservation of energy of up to 100 sigmas, matching a simple physical formula related to the input and output spacecraft velocities relative to the Earth rotational plane. Mysteriously, occasionally the effect was not present. After several years of reviewing the data and evaluating all sources of perturbation known to NASA, no solution was identified. NASA sent the final report to the author above for further review. Independently, the author’s firm Optical Physics Company had published research into the vacuum field, finding that it was not constant but varied across the Earth’s orbit and was also separately detected being radiated by the Sun. The physics we had learned was applied to the NASA passes, allowing all the anomalies they had encountered to be explained and adding considerably to our understanding of the vacuum field. We hypothesized a radially emitted vacuum field (which controls the rate of time) would couple the radial direction r with time t to add a gtr term in the metric tensor. We then combined the previously published experimental data of the vacuum field radiated by the Sun with the NASA data to develop a formula for the emission of the vacuum field from warm rotating bodies, accurate to about 1%. 25 candidate formulas were evaluated, based on powers of radial acceleration and temperature, and one was definitively selected. This research offers a linkage between the vacuum field whose spectrum is proportional to h and an effect on the metric tensor of gravity. Since both gravity and h control time rates, it seemed credible they could both affect the metric tensor.展开更多
According to the corresponding relations between general forces and general displacements, the balancing and geometrical equations of elasticity are multiplied by the corresponding virtual quantities, integrated with ...According to the corresponding relations between general forces and general displacements, the balancing and geometrical equations of elasticity are multiplied by the corresponding virtual quantities, integrated with volume and area, and then added algebraically. Proceeding to the next step, by substituting constitutive relation and considering that body force and surface force are both fellow forces, the generalized quasi-variational principles with the two kinds of variables of the first type are established in non-conservative systems. Through substituting another constitutive relation, using similar methods as above, the generalized quasi-variational principles with the two kinds of variables of the second type are established in non-conservative systems. By using the generalized quasi-complementary energy principles with the two kinds of variables of the first type, a method for solving two kinds of variables (internal force and deformation) is given for non-conservative systems of the typical fellow forces.展开更多
In this paper,the symplectic perturbation series methodology of the non-conservative linear Hamiltonian system is presented for the structural dynamic response with damping.Firstly,the linear Hamiltonian system is bri...In this paper,the symplectic perturbation series methodology of the non-conservative linear Hamiltonian system is presented for the structural dynamic response with damping.Firstly,the linear Hamiltonian system is briefly introduced and its conservation law is proved based on the properties of the exterior products.Then the symplectic perturbation series methodology is proposed to deal with the non-conservative linear Hamiltonian system and its conservation law is further proved.The structural dynamic response problem with eternal load and damping is transformed as the non-conservative linear Hamiltonian system and the symplectic difference schemes for the non-conservative linear Hamiltonian system are established.The applicability and validity of the proposed method are demonstrated by three engineering examples.The results demonstrate that the presented methodology is better than the traditional Runge–Kutta algorithm in the prediction of long-time structural dynamic response under the same time step.展开更多
The direct and indirect power flows among three non-conservatively series-coupled oscillators subjected to random forces have been investigated by the numerical method. The relationship between the power flows and the...The direct and indirect power flows among three non-conservatively series-coupled oscillators subjected to random forces have been investigated by the numerical method. The relationship between the power flows and the parameters of the oscillators and couplings have been studied. It is shown that the indirect power flow is caused by the resonant transmission between the indirectly coupled oscillators. Once the parameters of the oscillator elements have been settled, the indirect power flow is mainly determined by the coupling stiffness k3 and k4, and is less infiuenced by coupling dampings c3 and c4. The indirect power flow cannot be ignored in strong coupling conditions. Because of the resonant transmission between the indirectly coupled oscillators, the indirect power flow still cannot be neglected even if the coupling stiffness is relatively small and the coupling damping is relatively great展开更多
In this paper we present a 2D/3D high order accurate finite volume scheme in the context of direct Arbitrary-Lagrangian-Eulerian algorithms for general hyperbolic systems of partial differential equations with non-con...In this paper we present a 2D/3D high order accurate finite volume scheme in the context of direct Arbitrary-Lagrangian-Eulerian algorithms for general hyperbolic systems of partial differential equations with non-conservative products and stiff source terms.This scheme is constructed with a single stencil polynomial reconstruction operator,a one-step space-time ADER integration which is suitably designed for dealing even with stiff sources,a nodal solver with relaxation to determine the mesh motion,a path-conservative integration technique for the treatment of non-conservative products and an a posteriori stabilization procedure derived from the so-called Multidimensional Optimal Order Detection(MOOD)paradigm.In this work we consider the seven equation Baer-Nunziato model of compressible multi-phase flows as a representative model involving non-conservative products as well as relaxation source terms which are allowed to become stiff.The new scheme is validated against a set of test cases on 2D/3D unstructured moving meshes on parallel machines and the high order of accuracy achieved by the method is demonstrated by performing a numerical convergence study.Classical Riemann problems and explosion problems with exact solutions are simulated in 2D and 3D.The overall numerical code is also profiled to provide an estimate of the computational cost required by each component of the whole algorithm.展开更多
The method to calculate the coupling loss factors for non-conservatively coupled structures by using the mobilities of substructures is studied. By using the form of the energy balance equations of conservatively coup...The method to calculate the coupling loss factors for non-conservatively coupled structures by using the mobilities of substructures is studied. By using the form of the energy balance equations of conservatively coupled systems, the relationship between the coupling loss factors and the energy ratios in non-conservatively coupled systems is derived. The method to calculate the energy ratios by using the mobilities of substructures is introduced, and experiment verification is carried out. The test data agree well with the predicted results.展开更多
Traditional Statistical Energy Analysis (SEA) theory can not deal with dynamic problems concerned with non-conservatively coupled systems. In this paper, based on the theory of power flow between them and energy distr...Traditional Statistical Energy Analysis (SEA) theory can not deal with dynamic problems concerned with non-conservatively coupled systems. In this paper, based on the theory of power flow between them and energy distribution in non-conservatively coupled osillators, equations of power balance and those for calculation of each concerned power flow and other power items are derived to develop SEA theory for non-conscrvativcly coupled systems. Results show that conservative coupling is only a special case of non-conservative coupling situations, effect of coupling damping on power flow and energy distribution in non-conservatively coupled systems arc not negligible unless coupling damping is much smaller compared with internal one. As an application of the theory, energy problems of non-conservatively coupled plates are studied theoretically and experimentally.展开更多
基金Project supported by the Graduate Students Innovative Foundation of China University of Petroleum (East China) (Grant NoS2009-19)
文摘This paper studies conformal invariance and conserved quantity of third-order Lagrange equations for non- conserved mechanical systems. Third-order Lagrange equations, the definition and a determining equation of conformal invariance of the system are presented. The conformal factor expression is deduced from conformal invariance and Lie symmetry. The necessary and sufficient condition that conformal invaxiance of the system would have Lie symmetry under single-parameter infinitesimal transformations is obtained. The corresponding conserved quantity of conformal invariance is derived with the aid of a structure equation. Lastly, an example is given to illustrate the application of the results.
文摘Recently, reconsidering the Rastall idea T_(μ;νν)^(v)=α_(,μ) through relativistic thermodynamics gives a new form for the scalar field α which led us to construct modern modified theory of gravity debugged ‘non-conserved gravity theory’ Fazlollahi 2023 Euro. Phys. J. C 83 923. This theory unlike other modified theories of gravity cannot directly explain the current acceleration expansion in the absence of the cosmological constant and or existence of other forms of dark energy. Hence, in this study we have reinvestigated holographic dark energy Ρ_(X)~H^(2) in the non-conserved theory of gravity. In this context, the density and pressure of dark energy depend on the non-conserved term and density of the dust matter field. As shown, due to non-conservation effects on large-scale structures, unlike the original holographic model, our model onsets an acceleration epoch for the current Universe satisfies observations. Moreover, the interaction and viscous scenarios are studied for this model.
基金supported by the National Natural Science Foundation of China(Grant Nos.10972151 and 11272227)the Innovation Program for Postgraduate in Higher Education Institutions of Jiangsu Province,China(Grant No.CXLX11_0961)
文摘This paper focuses on the Noether symmetries and the conserved quantities for both holonomic and nonholonomic systems based on a new non-conservative dynamical model introduced by E1-Nabulsi. First, the E1-Nabulsi dynamical model which is based on a fractional integral extended by periodic laws is introduced, and E1-Nabulsi-Hamilton's canoni- cal equations for non-conservative Hamilton system with holonomic or nonholonomic constraints are established. Second, the definitions and criteria of E1-Nabulsi-Noether symmetrical transformations and quasi-symmetrical transformations are presented in terms of the invariance of E1-Nabulsi-Hamilton action under the infinitesimal transformations of the group. Fi- nally, Noether's theorems for the non-conservative Hamilton system under the E1-Nabulsi dynamical system are established, which reveal the relationship between the Noether symmetry and the conserved quantity of the system.
基金Project supported by the National Natural Science Foundation of China (Grant Nos 10472040, 10572021 and 10772025)the Outstanding Young Talents Training Found of Liaoning Province of China (Grant No 3040005)
文摘This paper studies the conformal invariance by infinitesimal point transformations of non-conservative Lagrange systems. It gives the necessary and sufficient conditions of conformal invariance by the action of infinitesimal point transformations being Lie symmetric simultaneously. Then the Noether conserved quantities of conformal invariance are obtained. Finally an illustrative example is given to verify the results.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11572212,11272227,and 10972151)the Innovation Program for Postgraduade in Higher Education Institutions of Jiangsu Province,China(Grant No.KYCX18_2548)
文摘According to the Herglotz variational principle and differential variational principle of Herglotz type, we study the adiabatic invariants for a non-conservative nonholonomic system. Firstly, the differential equations of motion of the non-conservative nonholonomic system based upon the generalized variational principle of Herglotz type are given, and the exact invariant for the non-conservative nonholonomic system is introduced. Secondly, a new type of adiabatic invariant for the system under the action of a small perturbation is obtained. Thirdly, the inverse theorem of the adiabatic invariant is given. Finally, an example is given.
文摘In order to reasonably explain the phenomenon of cell bioelectricity,we proposed the conservation law of cell membrane area,established the ion inequality equation,and therefore paid attention to the mystery of“θ-τ”.We researched and analyzed the“θ-τ”mystery,discussed the parity non-conservation in weak interactions,suggested possible experiments to test the parity non-conservation in weak interactions,and gave our research and analysis conclusions:The parity non-conservation in weak interactions,is still a“conjecture”;The experimental scheme suggested in the papers by C.N.Yang et al.cannot determine whether the weak interaction can separate left and right,and it is impossible to directly answer whetherθandτin the“θ-τ”mystery are the same particle;The Co60βdecay experiment such as C.S.Wu is a pseudo-mirror experiment,whether the experimental result violates parity conservation is only based on the assumption of C.N.Yang et al.In fact,experiments such as polarized Co60 did not overturn the so-called“law of parity conservation”.The mirror image principle does not have any physical meaning,does not correspond to any physical conservation quantity,and cannot be destroyed by any physical experiment.In the process of turning“mirror symmetry”and“mirror asymmetry”into so-called physical“common sense”and scientific“facts”respectively,the methods of transformation are“stealing concepts”and“circular argumentation”.The“θ-τ”mystery is a“man-made”mystery.θandτare two different particles,which may be the result of the same precursor particle being divided into two.The work of C.N.Yang,T.D.Lee,C.S.Wu et al.has brought quantum physicists from the“small black room”to the“bigger black room”or“smaller black room”.The right and wise choice is to go back through the door that came in.With the development of science today,it is time for some contents to reform from the bottom.
文摘This paper deals with the problem of the postbuckling response of a thin cantilever beam ofnon-linear material, subjected to subtangential follower forces. Based on the well-knownBernoulli-Euler bending moment-curvature relation, the proposed problem is reduced to a specialeigenvalue problem of non-linear differential equation. An approximate solution is achieved byusing a simple and very effective technique, which leads to reliable results even in the case of verylarge deflections. The initial postbuckling path depending on the subtangential follower forces inequilibrium is then obtained. Moreover, the individual and coupling effect of the subtangential fol-lower force, the material non-linearity and the beam slenderness ratio on the initial postbucklingpath are also discussed in detail.
基金Financial support of Subproject M03 in the Transregional Collaborative Research Center SFB/TRR 136 by the German Science Foundation(DFG)
文摘In this work,thermodynamic models for the energetics and kinetics of inhomogeneous gradient materials with microstructure are formulated in the context of continuum thermodynamics and material theory.For simplicity,attention is restricted to isothermal conditions.The materials of interest here are characterized by(1) first- and secondorder gradients of the deformation field and(2) a kinematic microstructure field and its gradient(e.g.,in the sense of director,micromorphic or Cosserat microstructure).Material inhomogeneity takes the form of multiple phases and chemical constituents,modeled here with the help of corresponding phase fields.Invariance requirements together with the dissipation principle result in the reduced model field and constitutive relations.Special cases of these include the wellknown Cahn-Hilliard and Ginzburg-Landau relations.In the last part of the work,initial boundary value problems for this class of materials are formulated with the help of rate variational methods.
基金Project supported by the National Natural Science Foundation of China(Grant No.69901003)the Scientific Research Fund of Sichuan Provincial Education Department
文摘Bias non-conservation characteristics of radio-frequency noise mechanism of 40-nm n-MOSFET are observed by modeling and measuring its drain current noise. A compact model for the drain current noise of 40-nm MOSFET is proposed through the noise analysis. This model fully describes three kinds of main physical sources that determine the noise mechanism of 40-nm MOSFET, i.e., intrinsic drain current noise, thermal noise induced by the gate parasitic resistance, and coupling thermal noise induced by substrate parasitic effect. The accuracy of the proposed model is verified by noise measurements, and the intrinsic drain current noise is proved to be the suppressed shot noise, and with the decrease of the gate voltage, the suppressed degree gradually decreases until it vanishes. The most important findings of the bias non-conservative nature of noise mechanism of 40-nm n-MOSFET are as follows.(i) In the strong inversion region, the suppressed shot noise is weakly affected by the thermal noise of gate parasitic resistance. Therefore, one can empirically model the channel excess noise as being like the suppressed shot noise.(ii) In the middle inversion region, it is almost full of shot noise.(iii) In the weak inversion region, the thermal noise is strongly frequency-dependent, which is almost controlled by the capacitive coupling of substrate parasitic resistance. Measurement results over a wide temperature range demonstrate that the thermal noise of 40-nm n-MOSFET exists in a region from the weak to strong inversion, contrary to the predictions of suppressed shot noise model only suitable for the strong inversion and middle inversion region. These new findings of the noise mechanism of 40-nm n-MOSFET are very beneficial for its applications in ultra low-voltage and low-power RF, such as novel device electronic structure optimization, integrated circuit design and process technology evaluation.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11274254,11147108,10979007,U1331122,and U1332206)in part by the National Basic Research Program of China(Grant No.2013CB922200)
文摘Weak- and hyperfine-interaction-induced 1 s2s 1S0→ 1S2 1 S0 E 1 transition rates for the isoelectronic sequence of Helike ions have been calculated using the multi-configuration Dirac-Hartree-Fock (MCDHF) and relativistic configuration interaction methods. The results should be helpful for the future experimental investigations of parity non-conservation effects.
文摘A kinetic flux-vector splitting (KFVS) scheme is applied for solving a reduced six-equation two-phase flow model of Saurel et al. [1]. The model incorporates single velocity, two pressures and relaxation terms. An additional seventh equation, describing the total mixture energy, is added to the model to guarantee the correct treatment of shocks in the single phase limit. Some salient features of the model are that it is hyperbolic with only three wave propagation speeds and the volume fraction remains positive. The proposed numerical scheme is based on the direct splitting of macroscopic flux functions of the system of equations. The second order accuracy of the scheme is achieved by using MUSCL-type initial reconstruction and Runge-Kutta time stepping method. Moreover, a pressure relaxation procedure is used to fulfill the interface conditions. For validation, the results of suggested scheme are compared with those from the high resolution central upwind and HLLC schemes. The central upwind scheme is also applied for the first time to this model. The accuracy, efficiency and simplicity of the KFVS scheme demonstrate its potential for modeling two-phase flows.
文摘Diffuse interfaces appear with any Eulerian discontinuity capturing compressible flow solver. When dealing with multifluid and multimaterial computations, interfaces smearing results in serious difficulties to fulfil contact conditions, as spurious oscillations appear. To circumvent these difficulties, several approaches have been proposed. One of them relies on multiphase flow modelling of the numerically diffused zone and is based on extended hyperbolic systems with stiff mechanical relaxation (Saurel and Abgrall, 1999 [4], Saurel et al., 2009 [6]). This approach is very robust, accurate and flexible in the sense that many physical effects can be included: surface tension, phase transition, elastic-plastic materials, detonations, granular effects etc. It is also able to deal with dynamic appearance of interfaces. However it suffers from an important drawback when long time evolution is under interest as the interface becomes more and more diffused. The present paper addresses this issue and provides an efficient way to sharpen interfaces. A sharpening flow model is used to correct the solution after each time step. The sharpening process is based on a hyperbolic equation that produces a steady shock in finite time at the interface location. This equation is embedded in a “sharpening multiphase model” redistributing volume fractions, masses, momentum and energy in a consistent way. The method is conservative with respect to the masses, mixture momentum and mixture energy. It results in diffused interfaces sharpened in one or two mesh points. The method is validated on test problems having exact solutions.
文摘We present a method for determining the motion of an electron in a hydrogen atom, which starts from a field Lagrangean foundation for non-conservative systems that can exhibit chaotic behavior. As a consequence, the problem of the formation of the atom becomes the problem of finding the possible stable orbital attractors and the associated transition paths through which the electron mechanical energy varies continuously until a stable energy state is reached.
文摘From 1990 to 2005 NASA did six flybys of Earth in order to boost the energy of each spacecraft, enabling them to go deeper into the solar system. These six flybys showed an unexpected violation in the conservation of energy of up to 100 sigmas, matching a simple physical formula related to the input and output spacecraft velocities relative to the Earth rotational plane. Mysteriously, occasionally the effect was not present. After several years of reviewing the data and evaluating all sources of perturbation known to NASA, no solution was identified. NASA sent the final report to the author above for further review. Independently, the author’s firm Optical Physics Company had published research into the vacuum field, finding that it was not constant but varied across the Earth’s orbit and was also separately detected being radiated by the Sun. The physics we had learned was applied to the NASA passes, allowing all the anomalies they had encountered to be explained and adding considerably to our understanding of the vacuum field. We hypothesized a radially emitted vacuum field (which controls the rate of time) would couple the radial direction r with time t to add a gtr term in the metric tensor. We then combined the previously published experimental data of the vacuum field radiated by the Sun with the NASA data to develop a formula for the emission of the vacuum field from warm rotating bodies, accurate to about 1%. 25 candidate formulas were evaluated, based on powers of radial acceleration and temperature, and one was definitively selected. This research offers a linkage between the vacuum field whose spectrum is proportional to h and an effect on the metric tensor of gravity. Since both gravity and h control time rates, it seemed credible they could both affect the metric tensor.
基金partly financially supported by the National Natural Science Foundation of China(Grant No.10272034)the Natural Science Foundation of Harbin(Grant No.HEUF04003).
文摘According to the corresponding relations between general forces and general displacements, the balancing and geometrical equations of elasticity are multiplied by the corresponding virtual quantities, integrated with volume and area, and then added algebraically. Proceeding to the next step, by substituting constitutive relation and considering that body force and surface force are both fellow forces, the generalized quasi-variational principles with the two kinds of variables of the first type are established in non-conservative systems. Through substituting another constitutive relation, using similar methods as above, the generalized quasi-variational principles with the two kinds of variables of the second type are established in non-conservative systems. By using the generalized quasi-complementary energy principles with the two kinds of variables of the first type, a method for solving two kinds of variables (internal force and deformation) is given for non-conservative systems of the typical fellow forces.
基金This work was supported by the National Nature Science Foundation of China(Grant 11772026)Defense Industrial Technology Development Program(Grants JCKY2017208B001 and JCKY2018601B001)Beijing Municipal Science and Technology Commission via project(Grant Z191100004619006),and Beijing Advanced Discipline Center for Unmanned Aircraft System.
文摘In this paper,the symplectic perturbation series methodology of the non-conservative linear Hamiltonian system is presented for the structural dynamic response with damping.Firstly,the linear Hamiltonian system is briefly introduced and its conservation law is proved based on the properties of the exterior products.Then the symplectic perturbation series methodology is proposed to deal with the non-conservative linear Hamiltonian system and its conservation law is further proved.The structural dynamic response problem with eternal load and damping is transformed as the non-conservative linear Hamiltonian system and the symplectic difference schemes for the non-conservative linear Hamiltonian system are established.The applicability and validity of the proposed method are demonstrated by three engineering examples.The results demonstrate that the presented methodology is better than the traditional Runge–Kutta algorithm in the prediction of long-time structural dynamic response under the same time step.
文摘The direct and indirect power flows among three non-conservatively series-coupled oscillators subjected to random forces have been investigated by the numerical method. The relationship between the power flows and the parameters of the oscillators and couplings have been studied. It is shown that the indirect power flow is caused by the resonant transmission between the indirectly coupled oscillators. Once the parameters of the oscillator elements have been settled, the indirect power flow is mainly determined by the coupling stiffness k3 and k4, and is less infiuenced by coupling dampings c3 and c4. The indirect power flow cannot be ignored in strong coupling conditions. Because of the resonant transmission between the indirectly coupled oscillators, the indirect power flow still cannot be neglected even if the coupling stiffness is relatively small and the coupling damping is relatively great
基金W.B.has been financed by the European Research Council(ERC)under the European Union’s Seventh Framework Programme(FP7/2007-2013)with the research project STiMulUs,ERC Grant agreement no.278267R.L.has been partially funded by the ANR under the JCJC project“ALE INC(ubator)3D”JS01-012-01the“International Centre for Mathematics and Computer Science in Toulouse”(CIMI)partially supported by ANR-11-LABX-0040-CIMI within the program ANR-11-IDEX-0002-02.The authors would like to acknowledge PRACE for awarding access to the SuperMUC supercomputer based in Munich,Germany at the Leibniz Rechenzentrum(LRZ).Parts of thematerial contained in this work have been elaborated,gathered and tested while W.B.visited the Mathematical Institute of Toulouse for three months and R.L.visited the Dipartimento di Ingegneria Civile Ambientale e Meccanica in Trento for three months.
文摘In this paper we present a 2D/3D high order accurate finite volume scheme in the context of direct Arbitrary-Lagrangian-Eulerian algorithms for general hyperbolic systems of partial differential equations with non-conservative products and stiff source terms.This scheme is constructed with a single stencil polynomial reconstruction operator,a one-step space-time ADER integration which is suitably designed for dealing even with stiff sources,a nodal solver with relaxation to determine the mesh motion,a path-conservative integration technique for the treatment of non-conservative products and an a posteriori stabilization procedure derived from the so-called Multidimensional Optimal Order Detection(MOOD)paradigm.In this work we consider the seven equation Baer-Nunziato model of compressible multi-phase flows as a representative model involving non-conservative products as well as relaxation source terms which are allowed to become stiff.The new scheme is validated against a set of test cases on 2D/3D unstructured moving meshes on parallel machines and the high order of accuracy achieved by the method is demonstrated by performing a numerical convergence study.Classical Riemann problems and explosion problems with exact solutions are simulated in 2D and 3D.The overall numerical code is also profiled to provide an estimate of the computational cost required by each component of the whole algorithm.
文摘The method to calculate the coupling loss factors for non-conservatively coupled structures by using the mobilities of substructures is studied. By using the form of the energy balance equations of conservatively coupled systems, the relationship between the coupling loss factors and the energy ratios in non-conservatively coupled systems is derived. The method to calculate the energy ratios by using the mobilities of substructures is introduced, and experiment verification is carried out. The test data agree well with the predicted results.
文摘Traditional Statistical Energy Analysis (SEA) theory can not deal with dynamic problems concerned with non-conservatively coupled systems. In this paper, based on the theory of power flow between them and energy distribution in non-conservatively coupled osillators, equations of power balance and those for calculation of each concerned power flow and other power items are derived to develop SEA theory for non-conscrvativcly coupled systems. Results show that conservative coupling is only a special case of non-conservative coupling situations, effect of coupling damping on power flow and energy distribution in non-conservatively coupled systems arc not negligible unless coupling damping is much smaller compared with internal one. As an application of the theory, energy problems of non-conservatively coupled plates are studied theoretically and experimentally.