For the appearance of the additive perturbation of controller gain when the controller parameter has minute adjustment at the initial running stage of system,to avoid the adverse effects,this paper investigates the mi...For the appearance of the additive perturbation of controller gain when the controller parameter has minute adjustment at the initial running stage of system,to avoid the adverse effects,this paper investigates the mixed H_2/H_∞ state feedback attitude control problem of microsatellite based on extended LMI method.Firstly,the microsatellite attitude control system is established and transformed into corresponding state space form.Then,without the equivalence restriction of the two Lyapunov variables of H_2 and H∞performance,this paper introduces additional variables to design the mixed H_2/H_∞ control method based on LMI which can also reduce the conservatives.Finally,numerical simulations are analyzed to show that the proposed method can make the satellite stable within 20 s whether there is additive perturbation of the controller gain or not.The comparative analysis of the simulation results between extended LMI method and traditional LMI method also demonstrates the effectiveness and feasibility of the proposed method in this paper.展开更多
This paper investigates the pose and motion estimation problem using single camera measurement for spacecraft. The leader spacecraft of three-dimensional shape is observed by a calibrated camera fixed on the follower ...This paper investigates the pose and motion estimation problem using single camera measurement for spacecraft. The leader spacecraft of three-dimensional shape is observed by a calibrated camera fixed on the follower spacecraft. Based on dual numbers,an integrated observation model is proposed based on a combination of multiple geometric features including points,lines and circles,which can improve the robustness and accuracy of the estimation algorithm. A six-degree-of-freedom relative motion model is proposed by using the dual quaternion representation,in which the rotation-translation coupling effect due to the points deviating from the center of the mass is described. Employing the proposed observation model and dynamics model,an Extended Kalman Filter is presented to estimate the relative state between the two spacecraft. Numerical simulations are performed to evaluate the proposed approaches,showing the convergence of relative estimation errors and superior estimation performance.展开更多
Li metal has become a strong candidate for anode due to its high theoretical specific capacity and lowest electrochemical potential.However,the poor reversibility caused by continuous chemical and electrochemical degr...Li metal has become a strong candidate for anode due to its high theoretical specific capacity and lowest electrochemical potential.However,the poor reversibility caused by continuous chemical and electrochemical degradation hinders the practical application of Li metal.Solid-solution-based metal alloy phases have been proposed as hosts for regulating the non-dendrite electrodeposition,but the fundamental understanding remains unclear due to the drastically different deposition behaviors of Li on them.Here we found the difference in the diffusion coefficient of Li atoms on solid-solution-based metal alloy phases(Li-Mg and Li-Ag alloys)was a major contributor to the different deposition behaviors.The low Li atom diffusion coefficient of Li-Mg alloy showed a preferential Li accumulation on the upper surface rather than the inward-growth plating of Li atoms into alloy foil in Li-Ag alloy.By the process of secondary recrystallization,we improved the diffusion coefficient of Li atoms in Li-Mg alloy that facilitates the inward transfer rather than surface plating of Li atoms.In this case,the recrystallized Li-Mg alloy underwent a solidsolution phase change in the delithiation-lithiation cycles which yielded a high Coulombic efficiency of 99.3%with a reversible gravimetric capacity of 2,874 mAh·g−1 and superior cycling stability over 5,000 h without dendrite growth.展开更多
Sodium metal batteries(SMBs)are rising as viable alternatives to lithium-ion systems due to their superior energy density and sodium's relative abundance.However,SMBs face significant impediments,particularly the ...Sodium metal batteries(SMBs)are rising as viable alternatives to lithium-ion systems due to their superior energy density and sodium's relative abundance.However,SMBs face significant impediments,particularly the exceedingly high negative-to-positive capacity ratios(N/P ratios)which severely encumber energy density and hinder their practical application.Herein,a novel nucleophilic Na_(3)P interphase on aluminum foil has been designed to significantly lower the nucleation energy barrier for sodium atom deposition,resulting in a remarkable reduction of nucleation overpotential and efficient mitigation of dendritic growth at high sodium deposition of 5 mA h cm^(−2).The interphase promotes stable cycling in anode-less SMB configurations with a low N/P ratio of 1.4 and high cathode mass loading of 11.5 mg cm^(−2),and demonstrates a substantial increase in high capacity retention of 92.4%after 500 cycles even under 1 C rate condition.This innovation signifies a promising leap forward in the development of high-energy-density,anode-less SMBs,offering a potential solution to the longstanding issues of cycle stability and energy efficiency.展开更多
This paper studies the proximate satellite interception guidance strategies where both the interceptor and target can perform orbital maneuvers with magnitude limited thrusts. This problem is regarded as a pursuit-eva...This paper studies the proximate satellite interception guidance strategies where both the interceptor and target can perform orbital maneuvers with magnitude limited thrusts. This problem is regarded as a pursuit-evasion game since satellites in both sides will try their best to capture or escape. In this game, the distance of these two players is small enough so that the highly nonlinear earth-centered gravitational dynamics can be reduced to the linear Clohessy-Wiltshire(CW) equations. The system is then simplified by introducing the zero effort miss variables. Saddle solution is formulated for the pursuit-evasion game and time-to-go is estimated similarly as that for the exoatmospheric interception. Then a vector guidance is derived to ensure that the interception can be achieved in the optimal time. The proposed guidance law is validated by numerical simulations.展开更多
Because of its high theoretical specific capacity and low reduction potential,Li metal is considered to be key to reaching high energy density in rechargeable batteries.In this context,most of the research has focused...Because of its high theoretical specific capacity and low reduction potential,Li metal is considered to be key to reaching high energy density in rechargeable batteries.In this context,most of the research has focused on suppressing dendrite formation during Li deposition to improve the cycling reversibility and safety of the batteries.Here,covalent organic framework(COF)film coating on a commercial polypropylene separator is applied as an ion redistributor to eliminate Li dendrites.The COF crystallites consist of ordered nanochannels that hinder the movement of anions while allowing Li-ions to transport across,leading to a high Li-ion transference number of 0.77±0.01.The transport of Li-ions across the COF film can be considered to be analogous to beads passing through a Galton Board,a model that demonstrates a statistical concept of a normal distribution.Thus,an even distribution of Li-ions is obtained at the COF/Li metal interface.The controlled Li-ion flux yields a smooth Li metal surface after 1,000 h(500 times)of cycling,leading to a significantly improved cycling stability and reversibility,as demonstrated by Cu||Li half cells,Li||Li symmetric cells,and Li Fe PO4||Li full cells.These results suggest that,following the principle of a Galton Board,nanopore insulators such as COF-based materials are effective ion distributors for the different energy storage or conversion systems.展开更多
Cancer imposes a severe threat to people’s health and lives,thus pressing a huge medical and economic burden on individuals and communities.Therefore,early diagnosis of cancer is indispensable in the timely preventio...Cancer imposes a severe threat to people’s health and lives,thus pressing a huge medical and economic burden on individuals and communities.Therefore,early diagnosis of cancer is indispensable in the timely prevention and effective treatment for patients.Exosome has recently become an attractive cancer biomarker in noninvasive early diagnosis because of the unique physiology and pathology functions,which reflects remarkable information regarding the cancer microenvironment,and plays an important role in the occurrence and evolution of cancer.Meanwhile,biosensors have gained great attention for the detection of exosomes due to their superior properties,such as convenient operation,real-time readout,high sensitivity,and remarkable specificity,suggesting promising biomedical applications in the early diagnosis of cancer.In this review,the latest advances of biosensors regarding the assay of exosomes were summarized,and the superiorities of exosomes as markers for the early diagnosis of cancer were evaluated.Moreover,the recent challenges and further opportunities of developing effective biosensors for the early diagnosis of cancer were discussed.展开更多
During operation of a lithium metal battery,uneven lithium deposition often results in the growth of lithium dendrites and causes a rapid decay in battery performance and even leads to safety issues.This is still the ...During operation of a lithium metal battery,uneven lithium deposition often results in the growth of lithium dendrites and causes a rapid decay in battery performance and even leads to safety issues.This is still the main hurdle hindering the practical application of lithium metal anodes.We report a new type of Janus separator fabricated by introducing a molecular sieve coating on the surface of the polypropylene separator that serves as a redistribution layer for lithium ions.Our results show that using this layer,the growth of lithium dendrites can be largely inhibited and the battery performance greatly improved.In a typical Li||Cu half-cell with the Janus separator,the Coulombic efficiency of the lithium metal anode can be maintained at>98.5%for over 500 cycles.The cycling life span is also extended by a factor of 8 in the Li||Li symmetric cell.Furthermore,the high-strength coating improves the mechanical properties of the separator,thus enhancing safety.The effectiveness of our strategy is demonstrated by both the inhibited growth of lithium dendrites and the improved battery performance.Our methodology could eventually be generalized for electrode protection in other battery systems.展开更多
文摘For the appearance of the additive perturbation of controller gain when the controller parameter has minute adjustment at the initial running stage of system,to avoid the adverse effects,this paper investigates the mixed H_2/H_∞ state feedback attitude control problem of microsatellite based on extended LMI method.Firstly,the microsatellite attitude control system is established and transformed into corresponding state space form.Then,without the equivalence restriction of the two Lyapunov variables of H_2 and H∞performance,this paper introduces additional variables to design the mixed H_2/H_∞ control method based on LMI which can also reduce the conservatives.Finally,numerical simulations are analyzed to show that the proposed method can make the satellite stable within 20 s whether there is additive perturbation of the controller gain or not.The comparative analysis of the simulation results between extended LMI method and traditional LMI method also demonstrates the effectiveness and feasibility of the proposed method in this paper.
文摘This paper investigates the pose and motion estimation problem using single camera measurement for spacecraft. The leader spacecraft of three-dimensional shape is observed by a calibrated camera fixed on the follower spacecraft. Based on dual numbers,an integrated observation model is proposed based on a combination of multiple geometric features including points,lines and circles,which can improve the robustness and accuracy of the estimation algorithm. A six-degree-of-freedom relative motion model is proposed by using the dual quaternion representation,in which the rotation-translation coupling effect due to the points deviating from the center of the mass is described. Employing the proposed observation model and dynamics model,an Extended Kalman Filter is presented to estimate the relative state between the two spacecraft. Numerical simulations are performed to evaluate the proposed approaches,showing the convergence of relative estimation errors and superior estimation performance.
基金funding support from the National Natural Science Foundation of China(Nos.22125902,U2032202,and 21975243)the National Program for Support of Topnotch Young Professionals,the Fundamental Research Funds for the Central Universities(No.WK2030020032)+1 种基金the DNL cooperation Fund,CAS(No.DNL202020)the Anhui Science Fund for Distinguished Young Scholars(No.2208085J15).
文摘Li metal has become a strong candidate for anode due to its high theoretical specific capacity and lowest electrochemical potential.However,the poor reversibility caused by continuous chemical and electrochemical degradation hinders the practical application of Li metal.Solid-solution-based metal alloy phases have been proposed as hosts for regulating the non-dendrite electrodeposition,but the fundamental understanding remains unclear due to the drastically different deposition behaviors of Li on them.Here we found the difference in the diffusion coefficient of Li atoms on solid-solution-based metal alloy phases(Li-Mg and Li-Ag alloys)was a major contributor to the different deposition behaviors.The low Li atom diffusion coefficient of Li-Mg alloy showed a preferential Li accumulation on the upper surface rather than the inward-growth plating of Li atoms into alloy foil in Li-Ag alloy.By the process of secondary recrystallization,we improved the diffusion coefficient of Li atoms in Li-Mg alloy that facilitates the inward transfer rather than surface plating of Li atoms.In this case,the recrystallized Li-Mg alloy underwent a solidsolution phase change in the delithiation-lithiation cycles which yielded a high Coulombic efficiency of 99.3%with a reversible gravimetric capacity of 2,874 mAh·g−1 and superior cycling stability over 5,000 h without dendrite growth.
基金support from the National Natural Science Foundation of China(22125902,22109150,22279126,U2032202,and 21975243)the DNL cooperation Fund,CAS(DNL202020)+1 种基金the National Key R&D Program of China(no.2022YFA1504101)as well as,the Anhui Provincial Natural Science Foundation(2108085QB65).
文摘Sodium metal batteries(SMBs)are rising as viable alternatives to lithium-ion systems due to their superior energy density and sodium's relative abundance.However,SMBs face significant impediments,particularly the exceedingly high negative-to-positive capacity ratios(N/P ratios)which severely encumber energy density and hinder their practical application.Herein,a novel nucleophilic Na_(3)P interphase on aluminum foil has been designed to significantly lower the nucleation energy barrier for sodium atom deposition,resulting in a remarkable reduction of nucleation overpotential and efficient mitigation of dendritic growth at high sodium deposition of 5 mA h cm^(−2).The interphase promotes stable cycling in anode-less SMB configurations with a low N/P ratio of 1.4 and high cathode mass loading of 11.5 mg cm^(−2),and demonstrates a substantial increase in high capacity retention of 92.4%after 500 cycles even under 1 C rate condition.This innovation signifies a promising leap forward in the development of high-energy-density,anode-less SMBs,offering a potential solution to the longstanding issues of cycle stability and energy efficiency.
基金co-supported by the National Natural Science Foundation of China (Nos.61603115,91438202 and91638301)China Postdoctoral Science Foundation (No.2015M81455)+1 种基金the Open Fund of National Defense Key Discipline Laboratory of Micro-Spacecraft Technology of China (No.HIT.KLOF.MST.201601)the Heilongjiang Postdoctoral Fund of China (No.LBH-Z15085)
文摘This paper studies the proximate satellite interception guidance strategies where both the interceptor and target can perform orbital maneuvers with magnitude limited thrusts. This problem is regarded as a pursuit-evasion game since satellites in both sides will try their best to capture or escape. In this game, the distance of these two players is small enough so that the highly nonlinear earth-centered gravitational dynamics can be reduced to the linear Clohessy-Wiltshire(CW) equations. The system is then simplified by introducing the zero effort miss variables. Saddle solution is formulated for the pursuit-evasion game and time-to-go is estimated similarly as that for the exoatmospheric interception. Then a vector guidance is derived to ensure that the interception can be achieved in the optimal time. The proposed guidance law is validated by numerical simulations.
基金the Natural Science Foundation of China(5176114504621975243)+2 种基金the 100 Talents Program of the Chinese Academy of SciencesNational Program for Support of Topnotch Young Professionaland i Ch EM。
文摘Because of its high theoretical specific capacity and low reduction potential,Li metal is considered to be key to reaching high energy density in rechargeable batteries.In this context,most of the research has focused on suppressing dendrite formation during Li deposition to improve the cycling reversibility and safety of the batteries.Here,covalent organic framework(COF)film coating on a commercial polypropylene separator is applied as an ion redistributor to eliminate Li dendrites.The COF crystallites consist of ordered nanochannels that hinder the movement of anions while allowing Li-ions to transport across,leading to a high Li-ion transference number of 0.77±0.01.The transport of Li-ions across the COF film can be considered to be analogous to beads passing through a Galton Board,a model that demonstrates a statistical concept of a normal distribution.Thus,an even distribution of Li-ions is obtained at the COF/Li metal interface.The controlled Li-ion flux yields a smooth Li metal surface after 1,000 h(500 times)of cycling,leading to a significantly improved cycling stability and reversibility,as demonstrated by Cu||Li half cells,Li||Li symmetric cells,and Li Fe PO4||Li full cells.These results suggest that,following the principle of a Galton Board,nanopore insulators such as COF-based materials are effective ion distributors for the different energy storage or conversion systems.
基金This work was supported by the National Natural Science Foundation of China(No.81772593).
文摘Cancer imposes a severe threat to people’s health and lives,thus pressing a huge medical and economic burden on individuals and communities.Therefore,early diagnosis of cancer is indispensable in the timely prevention and effective treatment for patients.Exosome has recently become an attractive cancer biomarker in noninvasive early diagnosis because of the unique physiology and pathology functions,which reflects remarkable information regarding the cancer microenvironment,and plays an important role in the occurrence and evolution of cancer.Meanwhile,biosensors have gained great attention for the detection of exosomes due to their superior properties,such as convenient operation,real-time readout,high sensitivity,and remarkable specificity,suggesting promising biomedical applications in the early diagnosis of cancer.In this review,the latest advances of biosensors regarding the assay of exosomes were summarized,and the superiorities of exosomes as markers for the early diagnosis of cancer were evaluated.Moreover,the recent challenges and further opportunities of developing effective biosensors for the early diagnosis of cancer were discussed.
基金the National Natural Science Foundation of China(Nos.U2032202,21975243 and 51672262)the National Program for Support of Topnotch Young Professional and the Fundamental Research Funds for the Central Universities(No.WK2060000026).
文摘During operation of a lithium metal battery,uneven lithium deposition often results in the growth of lithium dendrites and causes a rapid decay in battery performance and even leads to safety issues.This is still the main hurdle hindering the practical application of lithium metal anodes.We report a new type of Janus separator fabricated by introducing a molecular sieve coating on the surface of the polypropylene separator that serves as a redistribution layer for lithium ions.Our results show that using this layer,the growth of lithium dendrites can be largely inhibited and the battery performance greatly improved.In a typical Li||Cu half-cell with the Janus separator,the Coulombic efficiency of the lithium metal anode can be maintained at>98.5%for over 500 cycles.The cycling life span is also extended by a factor of 8 in the Li||Li symmetric cell.Furthermore,the high-strength coating improves the mechanical properties of the separator,thus enhancing safety.The effectiveness of our strategy is demonstrated by both the inhibited growth of lithium dendrites and the improved battery performance.Our methodology could eventually be generalized for electrode protection in other battery systems.