The main goal of this paper is to establish the boundedness of bilinear strongly singular operator T^(-)and its commutator Tb_(1),b_(2)on generalized Morrey spaces M_(p)^(u)(μ)over non-homogeneous metric measure spac...The main goal of this paper is to establish the boundedness of bilinear strongly singular operator T^(-)and its commutator Tb_(1),b_(2)on generalized Morrey spaces M_(p)^(u)(μ)over non-homogeneous metric measure spaces.Under assumption that the Lebesgue measurable functions u,u1 and u2 belong to W_(τ)forτ∈(0,2),and u1u2=u.The authors prove that T_(-)is bounded from product spaces M_(p1)^(u1)(μ)×M_(p2)^(u2)(μ)into spaces M_(p)^(u)(μ),where 1/p=1/p_(1)+1/p_(2)with 1<p1,p2<∞;and also bounded from product spaces M_(p1)^(u1)(μ)×M_(p2)^(u2)(μ)into generalized weak Morrey spaces WM_(p)^(u)(μ).Furthermore,the author also show that commutator Tb1,b2 generated by b_(1),b_(2)∈RBMO(μ)and T is bounded from product spaces M_(p1)^(u1)(μ)×M_(p2)^(u2)(μ)into spaces M_(p)^(u)(μ).展开更多
Let(X,d,μ)be a non-homogeneous metric measure space satisfying the geometrically doubling condition and the upper doubling condition.In this setting,the authors prove that the commutator M_(b)^(α)formed by b∈RBMO(...Let(X,d,μ)be a non-homogeneous metric measure space satisfying the geometrically doubling condition and the upper doubling condition.In this setting,the authors prove that the commutator M_(b)^(α)formed by b∈RBMO(μ)and the fractional maximal function M^((α))is bounded from Lebesgue spaces L^(p)(μ)into spaces L^(q)(μ),where 1/q=1/p-αforα∈(0,1)and p∈(1,1/α).Furthermore,the boundedness of the M_(b)^(α)on Orlicz spaces L^Φ(μ)is established.展开更多
The aim of this paper is to establish the necessary and sufficient conditions for the compactness of fractional integral commutator[b,I_(γ)]which is generated by fractional integral I_(γ)and function b∈Lip_(β)(μ)...The aim of this paper is to establish the necessary and sufficient conditions for the compactness of fractional integral commutator[b,I_(γ)]which is generated by fractional integral I_(γ)and function b∈Lip_(β)(μ)on Morrey space over non-homogeneous metric measure space,which satisfies the geometrically doubling and upper doubling conditions in the sense of Hytonen.Under assumption that the dominating functionλsatisfies weak reverse doubling condition,the author proves that the commutator[b,I_(γ)]is compact from Morrey space M_(q)^(p)(μ)into Morrey space M_(t)^(s)(μ)if and only if b∈Lip_(β)(μ).展开更多
Let {(Xi, Si, μi) : i ℃ N} be a sequence of probability measure spaces and (*Xi, L(*Si), L(*μi)) be the Loeb measure space with respect to (Xi, Si, μi) for i ℃ N. Let X =× Xi, S = ×Si,μ = ×μi. We...Let {(Xi, Si, μi) : i ℃ N} be a sequence of probability measure spaces and (*Xi, L(*Si), L(*μi)) be the Loeb measure space with respect to (Xi, Si, μi) for i ℃ N. Let X =× Xi, S = ×Si,μ = ×μi. We prove that × L(*Si) CL(*S) and in embedding meaning.展开更多
In this paper,we solve the obstacle problems on metric measure spaces with generalized Ricci lower bounds.We show the existence and Lipschitz continuity of the solutions,and then we establish some regularities of the ...In this paper,we solve the obstacle problems on metric measure spaces with generalized Ricci lower bounds.We show the existence and Lipschitz continuity of the solutions,and then we establish some regularities of the free boundaries.展开更多
In this paper, the boundedness in Lebesgue spaces of commutators and multilinear commutators generated by θ-type Calderon-Zygmund operators with RBMO（μ） functions on non-homogeneous metric measure spaces is obtained.
In this paper,we define new measures called respectively graph measure of noncompactness and graph measure of weak noncompactness.Moreover,we apply the obtained results to discuss the incidence of some perturbation re...In this paper,we define new measures called respectively graph measure of noncompactness and graph measure of weak noncompactness.Moreover,we apply the obtained results to discuss the incidence of some perturbation results realized in [2] on the behavior of essential spectra of such closed densely defined linear operators on Banach spaces.These results are exploited to investigate the essential spectra of a multidimensional neutron transport operator on L1 spaces.展开更多
The problem of embedding the Tsallis, Rényi and generalized Rényi entropies in the framework of category theory and their axiomatic foundation is studied. To this end, we construct a special category MES rel...The problem of embedding the Tsallis, Rényi and generalized Rényi entropies in the framework of category theory and their axiomatic foundation is studied. To this end, we construct a special category MES related to measured spaces. We prove that both of the Rényi and Tsallis entropies can be imbedded in the formalism of category theory by proving that the same basic partition functional that appears in their definitions, as well as in the associated Lebesgue space norms, has good algebraic compatibility properties. We prove that this functional is both additive and multiplicative with respect to the direct product and the disjoint sum (the coproduct) in the category MES, so it is a natural candidate for the measure of information or uncertainty. We prove that the category MES can be extended to monoidal category, both with respect to the direct product as well as to the coproduct. The basic axioms of the original Rényi entropy theory are generalized and reformulated in the framework of category MES and we prove that these axioms foresee the existence of an universal exponent having the same values for all the objects of the category MES. In addition, this universal exponent is the parameter, which appears in the definition of the Tsallis and Rényi entropies. It is proved that in a similar manner, the partition functional that appears in the definition of the Generalized Rényi entropy is a multiplicative functional with respect to direct product and additive with respect to the disjoint sum, but its symmetry group is reduced compared to the case of classical Rényi entropy.展开更多
There exists an increasing need for Milli-Arc-Seconds(MAS)accuracy pointing measurement for current and future space systems.To meet the 0.1″space pointing measurement accuracy requirements of spacecraft in future,th...There exists an increasing need for Milli-Arc-Seconds(MAS)accuracy pointing measurement for current and future space systems.To meet the 0.1″space pointing measurement accuracy requirements of spacecraft in future,the influence of spacecraft micro-vibration on a 0.1″Space Pointing Measuring Instrument(SPMI)is studied.A Quasi-Zero Stiffness Device(QZSD)with adaptive adjustment and variable stroke was proposed.Then,a series of micro-vibration experiments of the SPMI were carried out.The influence of the micro-vibration generated by Guidance Navigation Control(GNC)attitude control components under different attitudes on the SPMI was analyzed.Point spread function of image motion in micro-vibration was also derived.Further,the changes of image motion under the micro-vibration environment were evaluated by extracting the gray centroid of the images,and the experiment processes and results are deeply discussed.The results show that the firstorder frequency of the QZSD system is 0.114 Hz,and it is induced by a double pendulum system;the image motion of single flywheel spinning reached 0.015 pixels;whilst the image motion reached 0.03 pixels when three flywheels are combined spinning.These latest findings provide a beneficial theoretical and technical support for the development of spacecraft with 0·1″pointing accuracy.展开更多
It is proved that if μ and v be finite measures on a measurable space (X, S) and v is absolutely continuous with respect to v, then it is holds that L(* S, * μ) L(* S, *v), while L(*S, *μ) and L(*S, V) are the Loeb...It is proved that if μ and v be finite measures on a measurable space (X, S) and v is absolutely continuous with respect to v, then it is holds that L(* S, * μ) L(* S, *v), while L(*S, *μ) and L(*S, V) are the Loeb algebras with respect to measure spaces (X, S,μ) and (X,S,v).展开更多
In this paper, we firstly give a general inequality for the lower order eigenvalues of elliptic operators in weighted divergence form on compact smooth metric measure spaces with boundary（possibly empty）. Then using...In this paper, we firstly give a general inequality for the lower order eigenvalues of elliptic operators in weighted divergence form on compact smooth metric measure spaces with boundary（possibly empty）. Then using this general inequality, we get some universal inequalities for the lower order eigenvalues of elliptic operators in weighted divergence form on a connected bounded domain in the smooth metric measure spaces.展开更多
In deep space exploration,many engineering and scientific requirements require the accuracy of the measured Doppler frequency to be as high as possible.In our paper,we analyze the possible frequency measurement points...In deep space exploration,many engineering and scientific requirements require the accuracy of the measured Doppler frequency to be as high as possible.In our paper,we analyze the possible frequency measurement points of the third-order phase-locked loop(PLL)and find a new Doppler measurement strategy.Based on this finding,a Doppler frequency measurement algorithm with significantly higher measurement accuracy is obtained.In the actual data processing,compared with the existing engineering software,the accuracy of frequency of 1 second integration is about 5.5 times higher when using the new algorithm.The improved algorithm is simple and easy to implement.This improvement can be easily combined with other improvement methods of PLL,so that the performance of PLL can be further improved.展开更多
Surface potential decay of polymers for electrical insulation can help to determine the dark conductivity for spacecraft charging analysis. Due to the existence of radiation-induced conductivity, it decays fast in the...Surface potential decay of polymers for electrical insulation can help to determine the dark conductivity for spacecraft charging analysis. Due to the existence of radiation-induced conductivity, it decays fast in the first few hours after irradiation and exponentially slowly for the remaining time. The measurement of dark conductivity with this method usually takes the slow part and needs a couple of days. Integrating the Fowler formula into the deep dielectric charging equations, we obtain a new expression for the fast decay part. The experimental data of different materials, dose rates and temperatures are fitted by the new expression. Both the dark conductivity and the radiation-induced conductivity are derived and compared with other methods. The result shows a good estimation of dark conductivity and radiation-induced conductivity in high-resistivity polymers, which enables a fast measurement of dielectric conductivity within about 600 rain after irradiation.展开更多
This paper presents a coordinated target localization method for clustered space robot.According to the different measuring capabilities of cluster members,the master-slave coordinated relative navigation strategy for...This paper presents a coordinated target localization method for clustered space robot.According to the different measuring capabilities of cluster members,the master-slave coordinated relative navigation strategy for target localization with respect to slavery space robots is proposed;then the basic mathematical models,including coordinated relative measurement model and cluster centralized dynamics,are established respectively.By employing the linear Kalman flter theorem,the centralized estimator based on truth measurements is developed and analyzed frstly,and with an intention to inhabit the initial uncertainties related to target localization,the globally stabilized estimator is designed through introduction of pseudo measurements.Furthermore,the observability and controllability of stochastic system are also analyzed to qualitatively evaluate the convergence performance of pseudo measurement estimator.Finally,on-orbit target approaching scenario is simulated by using semi-physical simulation system,which is used to verify the convergence performance of proposed estimator.During the simulation,both the known and unknown maneuvering acceleration cases are considered to demonstrate the robustness of coordinated localization strategy.展开更多
The discrete frame and the continuous frame in a Hilbert space are discussed. By the tool excess of a sequence, a sufficient and necessary condition is presented under which a discrete frame is equivalent to a continu...The discrete frame and the continuous frame in a Hilbert space are discussed. By the tool excess of a sequence, a sufficient and necessary condition is presented under which a discrete frame is equivalent to a continuous frame with respect to the whole natural numbers with a positive Borel measure. And some examples are given to illuminate the condition.展开更多
Light pen coordinate measuring system(LPCMS)is a kind of portable coordinate measuring technique based on vision metrology.In classical LPCMS,the measuring range is limited to the camera’s field of view.To overcome t...Light pen coordinate measuring system(LPCMS)is a kind of portable coordinate measuring technique based on vision metrology.In classical LPCMS,the measuring range is limited to the camera’s field of view.To overcome this defect,a new LPCMS is designed in this paper to fulfil whole space coordinate measurement.The camera is installed on a turntable instead of a tripod,so that the camera can rotate to track the movement of the light pen.The new system can be applied to large scale onsite measurement,and therefore it notably extends the application of LPCMS.To guarantee the accuracy of the new system,a method to calibrate the parameters of the tracking turntable is also proposed.Fixing the light pen at a stationary position,and changing the azimuth angles of the turntable’s two shafts,so that the camera can capture the images of the light pen from different view angles.According to the invariant spatial relationship between the camera and the pedestal of the tracking turntable,a system of nonlinear equations can be established to solve the parameters of the turntable.Experimental results show that the whole space coordinate measuring accuracy of the new system can reach 0.25 mm within 10 m.It can be concluded that the newly designed system can significantly expand the measuring range of LPCMS without losing too much accuracy.展开更多
This paper give some sufficient condition on the nonlinear cross section to insure thewell-posedness and asymptotic behavior of a class of time-dependent neutron transport equations inspaces of measures.
In this paper we discuss about c-frames, namely continuous frames. Since, cframes are generalizations of discrete frames, we generalize some results of discrete frames to continuous version. We explain some results ab...In this paper we discuss about c-frames, namely continuous frames. Since, cframes are generalizations of discrete frames, we generalize some results of discrete frames to continuous version. We explain some results about relations of projections in Hilbert spaces and c-frames to characterize these frames. Also, we will specify（precisely） the synthesis and frame operators of Bochner integrable c-frames. Finally, we classify Hilbert-Schmidt operators by c-frames and express some new identities for Parseval c-frames.展开更多
Einstein’s energy mass formula is shown to consist of two basically quantum components E(O) = mc2/22 and E(D) = mc2(21/22). We give various arguments and derivations to expose the quantum entanglement physics residin...Einstein’s energy mass formula is shown to consist of two basically quantum components E(O) = mc2/22 and E(D) = mc2(21/22). We give various arguments and derivations to expose the quantum entanglement physics residing inside a deceptively simple expression E = mc2. The true surprising aspect of the present work is however the realization that all the involved “physics” in deriving the new quantum dissection of Einstein’s famous formula of special relativity is actually a pure mathematical necessity anchored in the phenomena of volume concentration of convex manifold in high dimensional quasi Banach spaces. Only an endophysical experiment encompassing the entire universe such as COBE, WMAP, Planck and supernova analysis could have discovered dark energy and our present dissection of Einstein’s marvelous formula.展开更多
The space charge accumulation in the heterogeneous insulation composed of cross-linked polyethylene(XLPE)cable and silicone rubber(SiR)accessory poses a serious threat to the safe operation of the high voltage direct ...The space charge accumulation in the heterogeneous insulation composed of cross-linked polyethylene(XLPE)cable and silicone rubber(SiR)accessory poses a serious threat to the safe operation of the high voltage direct current(HVDC)cable.When the cable is in heavy load,the charge transport behaviour in XLPE/SiR becomes more complicated due to the high temperature.In order to investigate the charge transport characteristics of XLPE/SiR under heavy load condition,the simultaneous measurement of space charge and relaxation current is performed on XLPE/SiR at both 70℃ and 30℃ with different polarities.The results show that the polarity of the interface charges in XLPE/SiR is always consistent with that of the SiR side electrode,and the influence of high temper-ature(70℃)caused by heavy load on the interface charge accumulation of XLPE/SiR is reversed at different polarities.The interface trap depth of XLPE/SiR is consistently greater than the bulk trap depths in both XLPE and SiR.When at high temperature of 70℃,the depth and density of interface traps increase,and the bulk traps in XLPE and SiR also exhibit increased depth.The component of polarisation relaxation current associated with space charge activity increases and exhibits longer decay time at 70℃,indicating more active and complex charge trapping-detrapping activities under heavy load condition.In this paper,an advanced simultaneous measurement is used to correlate the internal charge distribution with the external current for analysis,and the charge transport characteristics of XLPE/SiR under heavy load condition is revealed.The results can provide reference for the operation and maintenance of HVDC cable,and can also provide a basis for the space charge regulation of heterogeneous insulation at HVDC cable accessories.展开更多
基金Supported by the National Natural Science Foundation of China(Grant No.12201500)the Science Foundation for Youths of Gansu Province(Grant No.22JR5RA173)the Young Teachers’Scientific Research Ability Promotion Project of Northwest Normal University(Grant No.NWNU-LKQN2020-07)。
文摘The main goal of this paper is to establish the boundedness of bilinear strongly singular operator T^(-)and its commutator Tb_(1),b_(2)on generalized Morrey spaces M_(p)^(u)(μ)over non-homogeneous metric measure spaces.Under assumption that the Lebesgue measurable functions u,u1 and u2 belong to W_(τ)forτ∈(0,2),and u1u2=u.The authors prove that T_(-)is bounded from product spaces M_(p1)^(u1)(μ)×M_(p2)^(u2)(μ)into spaces M_(p)^(u)(μ),where 1/p=1/p_(1)+1/p_(2)with 1<p1,p2<∞;and also bounded from product spaces M_(p1)^(u1)(μ)×M_(p2)^(u2)(μ)into generalized weak Morrey spaces WM_(p)^(u)(μ).Furthermore,the author also show that commutator Tb1,b2 generated by b_(1),b_(2)∈RBMO(μ)and T is bounded from product spaces M_(p1)^(u1)(μ)×M_(p2)^(u2)(μ)into spaces M_(p)^(u)(μ).
基金the Science Foundation for Youths of Gansu Province(Grant No.22JR5RA173)Master Foundation of Northwest Normal University(Grant No.2022KYZZ-S121).
文摘Let(X,d,μ)be a non-homogeneous metric measure space satisfying the geometrically doubling condition and the upper doubling condition.In this setting,the authors prove that the commutator M_(b)^(α)formed by b∈RBMO(μ)and the fractional maximal function M^((α))is bounded from Lebesgue spaces L^(p)(μ)into spaces L^(q)(μ),where 1/q=1/p-αforα∈(0,1)and p∈(1,1/α).Furthermore,the boundedness of the M_(b)^(α)on Orlicz spaces L^Φ(μ)is established.
基金Supported by the Scientific Startup Foundation for Doctors of Northwest Normal University(Grant No.0002020203)the Innovation Fund Project for Higher Education of Gansu Province(Grant No.2020A-010)。
文摘The aim of this paper is to establish the necessary and sufficient conditions for the compactness of fractional integral commutator[b,I_(γ)]which is generated by fractional integral I_(γ)and function b∈Lip_(β)(μ)on Morrey space over non-homogeneous metric measure space,which satisfies the geometrically doubling and upper doubling conditions in the sense of Hytonen.Under assumption that the dominating functionλsatisfies weak reverse doubling condition,the author proves that the commutator[b,I_(γ)]is compact from Morrey space M_(q)^(p)(μ)into Morrey space M_(t)^(s)(μ)if and only if b∈Lip_(β)(μ).
基金The Special Science Foundation (00jk207) of the Educational Committee of Shaanxi Province.
文摘Let {(Xi, Si, μi) : i ℃ N} be a sequence of probability measure spaces and (*Xi, L(*Si), L(*μi)) be the Loeb measure space with respect to (Xi, Si, μi) for i ℃ N. Let X =× Xi, S = ×Si,μ = ×μi. We prove that × L(*Si) CL(*S) and in embedding meaning.
基金supported by the National Key R&Dprogram of China(2021YFA1003001)。
文摘In this paper,we solve the obstacle problems on metric measure spaces with generalized Ricci lower bounds.We show the existence and Lipschitz continuity of the solutions,and then we establish some regularities of the free boundaries.
基金supported by NSF of Anhui Province(No.1608085QA12)NSF of Education Committee of Anhui Province(Nos.KJ2016A506 and KJ2017A454)+2 种基金Excellent Young Talents Foundation of Anhui Province(No.GXYQ2017070)Doctoral Scientific Research Foundation of Chaohu University(No.KYQD-201605)Scientific Research Project of Chaohu University(No.XLY-201501)
文摘In this paper, the boundedness in Lebesgue spaces of commutators and multilinear commutators generated by θ-type Calderon-Zygmund operators with RBMO（μ） functions on non-homogeneous metric measure spaces is obtained.
文摘In this paper,we define new measures called respectively graph measure of noncompactness and graph measure of weak noncompactness.Moreover,we apply the obtained results to discuss the incidence of some perturbation results realized in [2] on the behavior of essential spectra of such closed densely defined linear operators on Banach spaces.These results are exploited to investigate the essential spectra of a multidimensional neutron transport operator on L1 spaces.
文摘The problem of embedding the Tsallis, Rényi and generalized Rényi entropies in the framework of category theory and their axiomatic foundation is studied. To this end, we construct a special category MES related to measured spaces. We prove that both of the Rényi and Tsallis entropies can be imbedded in the formalism of category theory by proving that the same basic partition functional that appears in their definitions, as well as in the associated Lebesgue space norms, has good algebraic compatibility properties. We prove that this functional is both additive and multiplicative with respect to the direct product and the disjoint sum (the coproduct) in the category MES, so it is a natural candidate for the measure of information or uncertainty. We prove that the category MES can be extended to monoidal category, both with respect to the direct product as well as to the coproduct. The basic axioms of the original Rényi entropy theory are generalized and reformulated in the framework of category MES and we prove that these axioms foresee the existence of an universal exponent having the same values for all the objects of the category MES. In addition, this universal exponent is the parameter, which appears in the definition of the Tsallis and Rényi entropies. It is proved that in a similar manner, the partition functional that appears in the definition of the Generalized Rényi entropy is a multiplicative functional with respect to direct product and additive with respect to the disjoint sum, but its symmetry group is reduced compared to the case of classical Rényi entropy.
基金the support from the National Natural Science Foundation of China(No.51905034,52275083)。
文摘There exists an increasing need for Milli-Arc-Seconds(MAS)accuracy pointing measurement for current and future space systems.To meet the 0.1″space pointing measurement accuracy requirements of spacecraft in future,the influence of spacecraft micro-vibration on a 0.1″Space Pointing Measuring Instrument(SPMI)is studied.A Quasi-Zero Stiffness Device(QZSD)with adaptive adjustment and variable stroke was proposed.Then,a series of micro-vibration experiments of the SPMI were carried out.The influence of the micro-vibration generated by Guidance Navigation Control(GNC)attitude control components under different attitudes on the SPMI was analyzed.Point spread function of image motion in micro-vibration was also derived.Further,the changes of image motion under the micro-vibration environment were evaluated by extracting the gray centroid of the images,and the experiment processes and results are deeply discussed.The results show that the firstorder frequency of the QZSD system is 0.114 Hz,and it is induced by a double pendulum system;the image motion of single flywheel spinning reached 0.015 pixels;whilst the image motion reached 0.03 pixels when three flywheels are combined spinning.These latest findings provide a beneficial theoretical and technical support for the development of spacecraft with 0·1″pointing accuracy.
基金Supported by the Special Science Foundation of the Education Committee of Shaanxi Province(03jk066)
文摘It is proved that if μ and v be finite measures on a measurable space (X, S) and v is absolutely continuous with respect to v, then it is holds that L(* S, * μ) L(* S, *v), while L(*S, *μ) and L(*S, V) are the Loeb algebras with respect to measure spaces (X, S,μ) and (X,S,v).
基金Supported by the National Natural Science Foundation of China(Grant No.11401131)the Natural Science Foundation of Hubei Provincial Department of Education(Grant No.Q20154301)
文摘In this paper, we firstly give a general inequality for the lower order eigenvalues of elliptic operators in weighted divergence form on compact smooth metric measure spaces with boundary（possibly empty）. Then using this general inequality, we get some universal inequalities for the lower order eigenvalues of elliptic operators in weighted divergence form on a connected bounded domain in the smooth metric measure spaces.
基金supported by the National Natural Science Foundation of China(Grant Nos.11773060,11973074,U1831137 and 11703070)National Key Basic Research and Development Program(2018YFA0404702)+1 种基金Shanghai Key Laboratory of Space Navigation and Positioning(3912DZ227330001)the Key Laboratory for Radio Astronomy of CAS。
文摘In deep space exploration,many engineering and scientific requirements require the accuracy of the measured Doppler frequency to be as high as possible.In our paper,we analyze the possible frequency measurement points of the third-order phase-locked loop(PLL)and find a new Doppler measurement strategy.Based on this finding,a Doppler frequency measurement algorithm with significantly higher measurement accuracy is obtained.In the actual data processing,compared with the existing engineering software,the accuracy of frequency of 1 second integration is about 5.5 times higher when using the new algorithm.The improved algorithm is simple and easy to implement.This improvement can be easily combined with other improvement methods of PLL,so that the performance of PLL can be further improved.
基金Supported by the Fundamental Research Funds for the Central Universities in Nanjing University of Aeronautics and Astronautics under Grant No NS2014089
文摘Surface potential decay of polymers for electrical insulation can help to determine the dark conductivity for spacecraft charging analysis. Due to the existence of radiation-induced conductivity, it decays fast in the first few hours after irradiation and exponentially slowly for the remaining time. The measurement of dark conductivity with this method usually takes the slow part and needs a couple of days. Integrating the Fowler formula into the deep dielectric charging equations, we obtain a new expression for the fast decay part. The experimental data of different materials, dose rates and temperatures are fitted by the new expression. Both the dark conductivity and the radiation-induced conductivity are derived and compared with other methods. The result shows a good estimation of dark conductivity and radiation-induced conductivity in high-resistivity polymers, which enables a fast measurement of dielectric conductivity within about 600 rain after irradiation.
基金supported by the National Natural Science Foundation of China (No.11102018)
文摘This paper presents a coordinated target localization method for clustered space robot.According to the different measuring capabilities of cluster members,the master-slave coordinated relative navigation strategy for target localization with respect to slavery space robots is proposed;then the basic mathematical models,including coordinated relative measurement model and cluster centralized dynamics,are established respectively.By employing the linear Kalman flter theorem,the centralized estimator based on truth measurements is developed and analyzed frstly,and with an intention to inhabit the initial uncertainties related to target localization,the globally stabilized estimator is designed through introduction of pseudo measurements.Furthermore,the observability and controllability of stochastic system are also analyzed to qualitatively evaluate the convergence performance of pseudo measurement estimator.Finally,on-orbit target approaching scenario is simulated by using semi-physical simulation system,which is used to verify the convergence performance of proposed estimator.During the simulation,both the known and unknown maneuvering acceleration cases are considered to demonstrate the robustness of coordinated localization strategy.
基金Supported by the Department of Education Scientic Research Plan Project of Hubei Province(B2013221)
文摘The discrete frame and the continuous frame in a Hilbert space are discussed. By the tool excess of a sequence, a sufficient and necessary condition is presented under which a discrete frame is equivalent to a continuous frame with respect to the whole natural numbers with a positive Borel measure. And some examples are given to illuminate the condition.
基金State Administration of Science,Technology and Industry for the National Defense(No.JSJL2014206B001)。
文摘Light pen coordinate measuring system(LPCMS)is a kind of portable coordinate measuring technique based on vision metrology.In classical LPCMS,the measuring range is limited to the camera’s field of view.To overcome this defect,a new LPCMS is designed in this paper to fulfil whole space coordinate measurement.The camera is installed on a turntable instead of a tripod,so that the camera can rotate to track the movement of the light pen.The new system can be applied to large scale onsite measurement,and therefore it notably extends the application of LPCMS.To guarantee the accuracy of the new system,a method to calibrate the parameters of the tracking turntable is also proposed.Fixing the light pen at a stationary position,and changing the azimuth angles of the turntable’s two shafts,so that the camera can capture the images of the light pen from different view angles.According to the invariant spatial relationship between the camera and the pedestal of the tracking turntable,a system of nonlinear equations can be established to solve the parameters of the turntable.Experimental results show that the whole space coordinate measuring accuracy of the new system can reach 0.25 mm within 10 m.It can be concluded that the newly designed system can significantly expand the measuring range of LPCMS without losing too much accuracy.
基金Supported by the Natural Science Foundation of Henan Provience(9902).
文摘This paper give some sufficient condition on the nonlinear cross section to insure thewell-posedness and asymptotic behavior of a class of time-dependent neutron transport equations inspaces of measures.
文摘In this paper we discuss about c-frames, namely continuous frames. Since, cframes are generalizations of discrete frames, we generalize some results of discrete frames to continuous version. We explain some results about relations of projections in Hilbert spaces and c-frames to characterize these frames. Also, we will specify（precisely） the synthesis and frame operators of Bochner integrable c-frames. Finally, we classify Hilbert-Schmidt operators by c-frames and express some new identities for Parseval c-frames.
文摘Einstein’s energy mass formula is shown to consist of two basically quantum components E(O) = mc2/22 and E(D) = mc2(21/22). We give various arguments and derivations to expose the quantum entanglement physics residing inside a deceptively simple expression E = mc2. The true surprising aspect of the present work is however the realization that all the involved “physics” in deriving the new quantum dissection of Einstein’s famous formula of special relativity is actually a pure mathematical necessity anchored in the phenomena of volume concentration of convex manifold in high dimensional quasi Banach spaces. Only an endophysical experiment encompassing the entire universe such as COBE, WMAP, Planck and supernova analysis could have discovered dark energy and our present dissection of Einstein’s marvelous formula.
基金National Natural Science Foundation of China,Grant/Award Number:52207025Science and Technology Commission of Shanghai Municipality,Grant/Award Number:20YF1414700“Chen Guang”project supported by Shanghai Municipal Education Commission and Shanghai Education Development Foundation,Grant/Award Number:21CGA63。
文摘The space charge accumulation in the heterogeneous insulation composed of cross-linked polyethylene(XLPE)cable and silicone rubber(SiR)accessory poses a serious threat to the safe operation of the high voltage direct current(HVDC)cable.When the cable is in heavy load,the charge transport behaviour in XLPE/SiR becomes more complicated due to the high temperature.In order to investigate the charge transport characteristics of XLPE/SiR under heavy load condition,the simultaneous measurement of space charge and relaxation current is performed on XLPE/SiR at both 70℃ and 30℃ with different polarities.The results show that the polarity of the interface charges in XLPE/SiR is always consistent with that of the SiR side electrode,and the influence of high temper-ature(70℃)caused by heavy load on the interface charge accumulation of XLPE/SiR is reversed at different polarities.The interface trap depth of XLPE/SiR is consistently greater than the bulk trap depths in both XLPE and SiR.When at high temperature of 70℃,the depth and density of interface traps increase,and the bulk traps in XLPE and SiR also exhibit increased depth.The component of polarisation relaxation current associated with space charge activity increases and exhibits longer decay time at 70℃,indicating more active and complex charge trapping-detrapping activities under heavy load condition.In this paper,an advanced simultaneous measurement is used to correlate the internal charge distribution with the external current for analysis,and the charge transport characteristics of XLPE/SiR under heavy load condition is revealed.The results can provide reference for the operation and maintenance of HVDC cable,and can also provide a basis for the space charge regulation of heterogeneous insulation at HVDC cable accessories.
