The precise characterization of hypersonic glide vehicle(HGV) maneuver laws in complex flight scenarios still faces challenges. Non-stationary changes in flight state due to abrupt changes in maneuver modes place high...The precise characterization of hypersonic glide vehicle(HGV) maneuver laws in complex flight scenarios still faces challenges. Non-stationary changes in flight state due to abrupt changes in maneuver modes place high demands on the accuracy of modeling methods. To address this issue, a novel maneuver laws modeling and analysis method based on higher order multi-resolution dynamic mode decomposition(HMDMD) is proposed in this work. A joint time-space-frequency decomposition of the vehicle's state sequence in the complex flight scenario is achieved with the higher order Koopman assumption and standard multi-resolution dynamic mode decomposition, and an approximate dynamic model is established. The maneuver laws can be reconstructed and analyzed with extracted multi-scale spatiotemporal modes with clear physical meaning. Based on the dynamic model of HGV, two flight scenarios are established with constant angle of attack and complex maneuver laws, respectively. Simulation results demonstrate that the maneuver laws obtained using the HMDMD method are highly consistent with those derived from the real dynamic model, the modeling accuracy is better than other common modeling methods, and the method has strong interpretability.展开更多
The laws of conservation of energy, linear momentum. and angular momentum of a system form a closed unit according to Noether's theorem. A generalization of these laws (including spin) for elementary par- ticles ...The laws of conservation of energy, linear momentum. and angular momentum of a system form a closed unit according to Noether's theorem. A generalization of these laws (including spin) for elementary par- ticles taking into account the states of negative energies of the Dirac vacuum is given. A new interpretation of the β-decay of nuclei without neutrinos. using interactions with Dirac's anti-world is discussed, which ex- plains all characteristics of the β-continuum. A quantum-electrodynamic theory of β-decay is presented in which Fermi's constant g of weak interactions is determined from first principles (without neutrinos). The lat- ter is an expression of e, h, c, m, M, and R, i.e., g is not an independent constant of physics nor is it necessa- ry to measure it.展开更多
This paper,using pseudo-conservation laws in cyclic-service systems, derives some expressions for the weighted sum of the mean waiting time token ring networks with exhaustive limitedservice policies on condition that...This paper,using pseudo-conservation laws in cyclic-service systems, derives some expressions for the weighted sum of the mean waiting time token ring networks with exhaustive limitedservice policies on condition that messages arrived with batch Poisson, and discusses boundary conditions. At the same time, the results of the token ring network with exhaustive and non-exhaustiveservice strategy are obtained. Finally the exact expression of mean waiting time in symmetric ringnetwork with same service strategy is given.展开更多
This paper presents a combination of experimental and numerical investigations on the dynamic response of scaling cabin structures under internal blast loading.The purpose of this study is to modify the similar relati...This paper presents a combination of experimental and numerical investigations on the dynamic response of scaling cabin structures under internal blast loading.The purpose of this study is to modify the similar relationship between the scaled-down model and the prototype of the cabin structures under internal blast loading.According to the Hopkinson’s scaling law,three sets of cabin structure models with different scaling factors combined with different explosive masses were designed for the experimental study.The dynamic deformation process of the models was recorded by a three-dimensional digital imaging correlation(DIC)method and a 3D scanning technology was used to reconstruct the deformation modes of the specimen.In addition,a finite element model was developed for the modification of the scaling law.The experimental results showed that the final deflection-to-thickness ratio was increased with the increase of the model size despite of the similar trend of their deformation processes.The reason for this inconsistency was discussed based on the traditional scaling law and a modified formula considering of the effects of size and strain-rate was provided.展开更多
Function one direction S-rough sets have dynamic characteristics and law characteristics. By using the function one direction S-rough sets, this article presents the concepts of the f-hiding law, F-hiding law, f-hidin...Function one direction S-rough sets have dynamic characteristics and law characteristics. By using the function one direction S-rough sets, this article presents the concepts of the f-hiding law, F-hiding law, f-hiding law dependence and F-hiding law dependence. Based on the concepts above, this article proposes the hidingdependence theorem of f-hiding laws, the hiding-dependence theorem of F-hiding laws, the hiding-dependence separation theorem, the hiding dependence-discovery principle of unknown laws. Finally, the application of the hiding dependence of hiding laws in the discovery of system laws is given.展开更多
For centuries, groups of people desiring to supply themselves with goods, to market their products, or to obtain services of various kinds on a co-operative basis, have made increasing use of co-operative associations...For centuries, groups of people desiring to supply themselves with goods, to market their products, or to obtain services of various kinds on a co-operative basis, have made increasing use of co-operative associations to achieve these purposes. Duringthe period, legislation designed especially for the incorporation and conduct of such associations has been enacted by different counties. Since a co-operative is established and carried on by and for the use of its members, this essay makes a comparison between Canadian and Chinese co-operative laws in terms of membership in the aspects of qualifications, rights and obligations and withdrawal of membership, so as to probe the function of co-operative legislation and find some enlightment from it.展开更多
Recently,foamed polymers have been widely used in the repair of underground engineering disasters by grouting(trenchless technology)due to controllable gelation time and self-expansion.However,the grouting process bec...Recently,foamed polymers have been widely used in the repair of underground engineering disasters by grouting(trenchless technology)due to controllable gelation time and self-expansion.However,the grouting process becomes more complicated due to the complex geological conditions and the self-expansion of slurry.Therefore,this paper adopts a self-made visual experimental device with peripheral pressure and water plugging rate(WPR)monitoring functions to study the influence of main influencing parameters(particle size distribution,grouting amount and dynamic water pump pressure(DWPP))on the spatiotemporal distribution of slurry WPR and diffusion dynamic response(peripheral pressure).The results show that:When grouting amount is 563 g and DWPP is 0.013 MPa,the expansion force of the slurry in the diffusion process is dominant and can significantly change the local sand and gravel skeleton structure.When grouting amount is 563 g,DWPP is 0.013 MPa,and particle size distribution type isⅢ,the flow time of the polymer is shortened,the pores of the gravel are rapidly blocked.Then,the peripheral pressure decreases rapidly with the increase of the distance,and the time to reach the inflection point WPR is shortened.The instantaneous blockage of the pores leads to the delayed transmission of flow field blockage information.展开更多
基金supported by the National Natural Science Foundation of China (Grant No. 12302056)the Postdoctoral Fellowship Program of CPSF:GZC20233445。
文摘The precise characterization of hypersonic glide vehicle(HGV) maneuver laws in complex flight scenarios still faces challenges. Non-stationary changes in flight state due to abrupt changes in maneuver modes place high demands on the accuracy of modeling methods. To address this issue, a novel maneuver laws modeling and analysis method based on higher order multi-resolution dynamic mode decomposition(HMDMD) is proposed in this work. A joint time-space-frequency decomposition of the vehicle's state sequence in the complex flight scenario is achieved with the higher order Koopman assumption and standard multi-resolution dynamic mode decomposition, and an approximate dynamic model is established. The maneuver laws can be reconstructed and analyzed with extracted multi-scale spatiotemporal modes with clear physical meaning. Based on the dynamic model of HGV, two flight scenarios are established with constant angle of attack and complex maneuver laws, respectively. Simulation results demonstrate that the maneuver laws obtained using the HMDMD method are highly consistent with those derived from the real dynamic model, the modeling accuracy is better than other common modeling methods, and the method has strong interpretability.
文摘The laws of conservation of energy, linear momentum. and angular momentum of a system form a closed unit according to Noether's theorem. A generalization of these laws (including spin) for elementary par- ticles taking into account the states of negative energies of the Dirac vacuum is given. A new interpretation of the β-decay of nuclei without neutrinos. using interactions with Dirac's anti-world is discussed, which ex- plains all characteristics of the β-continuum. A quantum-electrodynamic theory of β-decay is presented in which Fermi's constant g of weak interactions is determined from first principles (without neutrinos). The lat- ter is an expression of e, h, c, m, M, and R, i.e., g is not an independent constant of physics nor is it necessa- ry to measure it.
文摘This paper,using pseudo-conservation laws in cyclic-service systems, derives some expressions for the weighted sum of the mean waiting time token ring networks with exhaustive limitedservice policies on condition that messages arrived with batch Poisson, and discusses boundary conditions. At the same time, the results of the token ring network with exhaustive and non-exhaustiveservice strategy are obtained. Finally the exact expression of mean waiting time in symmetric ringnetwork with same service strategy is given.
基金the support from the National Natural Science Foundation of China under Grant No. 11902031,No. 11802030 , No. 11802031Beijing Municipal Science and Technology Project Management Approach under No. Z181100004118002
文摘This paper presents a combination of experimental and numerical investigations on the dynamic response of scaling cabin structures under internal blast loading.The purpose of this study is to modify the similar relationship between the scaled-down model and the prototype of the cabin structures under internal blast loading.According to the Hopkinson’s scaling law,three sets of cabin structure models with different scaling factors combined with different explosive masses were designed for the experimental study.The dynamic deformation process of the models was recorded by a three-dimensional digital imaging correlation(DIC)method and a 3D scanning technology was used to reconstruct the deformation modes of the specimen.In addition,a finite element model was developed for the modification of the scaling law.The experimental results showed that the final deflection-to-thickness ratio was increased with the increase of the model size despite of the similar trend of their deformation processes.The reason for this inconsistency was discussed based on the traditional scaling law and a modified formula considering of the effects of size and strain-rate was provided.
基金supported partly by the Natural Science Foundation of Shandong Province(Y2004A04)Elementaryand Advanced Technology Foundation of Henan Province(082300410040)
文摘Function one direction S-rough sets have dynamic characteristics and law characteristics. By using the function one direction S-rough sets, this article presents the concepts of the f-hiding law, F-hiding law, f-hiding law dependence and F-hiding law dependence. Based on the concepts above, this article proposes the hidingdependence theorem of f-hiding laws, the hiding-dependence theorem of F-hiding laws, the hiding-dependence separation theorem, the hiding dependence-discovery principle of unknown laws. Finally, the application of the hiding dependence of hiding laws in the discovery of system laws is given.
文摘For centuries, groups of people desiring to supply themselves with goods, to market their products, or to obtain services of various kinds on a co-operative basis, have made increasing use of co-operative associations to achieve these purposes. Duringthe period, legislation designed especially for the incorporation and conduct of such associations has been enacted by different counties. Since a co-operative is established and carried on by and for the use of its members, this essay makes a comparison between Canadian and Chinese co-operative laws in terms of membership in the aspects of qualifications, rights and obligations and withdrawal of membership, so as to probe the function of co-operative legislation and find some enlightment from it.
基金Project(2022YFC3801000)supported by the National Key Research and Development Program of ChinaProject(232300421064)supported by the Natural Science Foundation of Henan Province,China+1 种基金Project(241111322700)supported by the Key Research and Development Projects in Henan Province,ChinaProject(52008379)supported by the National Natural Science Foundation of China。
文摘Recently,foamed polymers have been widely used in the repair of underground engineering disasters by grouting(trenchless technology)due to controllable gelation time and self-expansion.However,the grouting process becomes more complicated due to the complex geological conditions and the self-expansion of slurry.Therefore,this paper adopts a self-made visual experimental device with peripheral pressure and water plugging rate(WPR)monitoring functions to study the influence of main influencing parameters(particle size distribution,grouting amount and dynamic water pump pressure(DWPP))on the spatiotemporal distribution of slurry WPR and diffusion dynamic response(peripheral pressure).The results show that:When grouting amount is 563 g and DWPP is 0.013 MPa,the expansion force of the slurry in the diffusion process is dominant and can significantly change the local sand and gravel skeleton structure.When grouting amount is 563 g,DWPP is 0.013 MPa,and particle size distribution type isⅢ,the flow time of the polymer is shortened,the pores of the gravel are rapidly blocked.Then,the peripheral pressure decreases rapidly with the increase of the distance,and the time to reach the inflection point WPR is shortened.The instantaneous blockage of the pores leads to the delayed transmission of flow field blockage information.
