A new high accuracy 6D ( Dimension ) wide range measuring technology and the method of coordinate transformations have been developed in a project for automobile body-in- white measurement in Michigan , U S A . The re...A new high accuracy 6D ( Dimension ) wide range measuring technology and the method of coordinate transformations have been developed in a project for automobile body-in- white measurement in Michigan , U S A . The requirements and the special features about the measured objective are mainly stated. The main instruments used in the project are introduced. The 6D measuring system , the method for coordinate transformations and the design of 3D optical target with hollow tetrahedron are described in detail . The 6D system and the technology can be certainly used in many other kinds of geometric mea- suring projects .展开更多
In this paper,a class of time-varying output group formation containment control problem of general linear hetero-geneous multiagent systems(MASs)is investigated under directed topology.The MAS is composed of a number...In this paper,a class of time-varying output group formation containment control problem of general linear hetero-geneous multiagent systems(MASs)is investigated under directed topology.The MAS is composed of a number of tracking leaders,formation leaders and followers,where two different types of leaders are used to provide reference trajectories for movement and to achieve certain formations,respectively.Firstly,compen-sators are designed whose states are estimations of tracking lead-ers,based on which,a controller is developed for each formation leader to accomplish the expected formation.Secondly,two event-triggered compensators are proposed for each follower to evalu-ate the state and formation information of the formation leaders in the same group,respectively.Subsequently,a control protocol is designed for each follower,utilizing the output information,to guide the output towards the convex hull generated by the forma-tion leaders within the group.Next,the triggering sequence in this paper is decomposed into two sequences,and the inter-event intervals of these two triggering conditions are provided to rule out the Zeno behavior.Finally,a numerical simulation is intro-duced to confirm the validity of the proposed results.展开更多
Based on the GC-MS analytical data of aromatic fractions of over forty highly mature coal-bearing source rock samples collected from the Upper Triassic Xujiahe Formation in the northern Sichuan Basin, the thermal evol...Based on the GC-MS analytical data of aromatic fractions of over forty highly mature coal-bearing source rock samples collected from the Upper Triassic Xujiahe Formation in the northern Sichuan Basin, the thermal evolution of aromatic hydrocarbons during late-mature to over-mature stage （R0=1.13%-2.85%） was characterized, and aromatic indicators suitable for recognizing the organic source and sedimentary environment of high maturity source rocks were discussed. The results indicated that the concentrations of low carbon-cycle naphthalene as well phenanthrene series reduce gradually with increasing Ro at the highly mature levels. However, some high-cyclic components such as chrysene, benzofluoranthene, and benzo[e]pyrene are relatively enriched, in companying an enhancement of parent aromatic compounds. The variations are attributed to thermal cracking and polymerization reactions due to continuous dehydrogenation under enhanced burial temperature. As thermal maturity rises, MPI1 （Methylphenanthrene Index） values display a two-modal varying trend, namely, increasing when Ro is below 1.80% and decreasing above 1.8% Ro. The relationships between Ro and MPI1 are Ro=0.98MPI1＋0.37 for R0〈1.80% and R0=-0.90MPI1＋3.02 at R0〉1.8%, being different from the previous research. The amount of dibenzofurans declines sharply at Ro higher than 1.1%, leading to a significant change of relative composition among dibenzothiophenes, dibenzofurans and fluorenes （referred as three-fluorenes series composition）. Thus, this parameter appears to be unsuitable for identifying the sedimentary environment of the highly matured source rocks. 4-/1-MDBT （methyldibenzothiophene） ratio could be served as an effective indicator for organic facies, and can distinguish coals from mudstones at over-maturity in this case. The ratios of 2,6-/2,10-DMP （dimethylphenanthrene） and 1,7-/1,9-DMP and relative abundance of triaromatic steroids in these highly mature rocks could be considered as biological source parameters for relati展开更多
A carrier frequency offset （CFO） estimator was developed based on an interference cancellation scheme for an orthogonal frequency division multiplex access uplink. An initial CFO estimate was first ob- tained based ...A carrier frequency offset （CFO） estimator was developed based on an interference cancellation scheme for an orthogonal frequency division multiplex access uplink. An initial CFO estimate was first ob- tained based on the received training signals at each user＇s prescribed subcarder positions. Then, the re- ceived training signals were compensated by using the initial CFO estimates in the frequency domain and the multi-user interferences were estimated. Finally, the interference-cancelled training signals were used to reliably estimate each user＇s CFO. The CFO estimator performance was evaluated by the bit error rate per- formances of the CFO compensation-based receivers at the base station. Simulations show that with this optima CFO compensation receiver, the performance gain with the esti- mated CFO values is approximately 3 dB better at the 0.1% bit error rate than the initial CFO estimates.展开更多
Planar motion for a rigid body with an elastic beam in a field of central gravitational force wasinvestigated, and both of the orbital motion and attitude motion were under consideration. The equations ofmotion of the...Planar motion for a rigid body with an elastic beam in a field of central gravitational force wasinvestigated, and both of the orbital motion and attitude motion were under consideration. The equations ofmotion of the system were derived by the variational principle, and on view point of generalized Hamiltoniandynamics, the sufficient conditions for the stability of one class of relative equilibria were given by the energy-momentum method.展开更多
In this paper we describe a multi-grid algorithm for mixed problems with penalty by the linear finite element approximation. It is proved that the convergence rate of the algorithm is bound ed away from 1 independentl...In this paper we describe a multi-grid algorithm for mixed problems with penalty by the linear finite element approximation. It is proved that the convergence rate of the algorithm is bound ed away from 1 independently of the meshsize. For convenience, we only discuss Jacobi relaxation as smoothing operator in detail.展开更多
The quantitative result of annual polar motion excitation by the ocean is presented for the first time. The atmospheric excitation amounts to more than double of the oceanic excitation. The sum of atmospheric and ocea...The quantitative result of annual polar motion excitation by the ocean is presented for the first time. The atmospheric excitation amounts to more than double of the oceanic excitation. The sum of atmospheric and oceanic excitations approximates more to the observed annual polar motion excitation, compared with atmospheric excitation only This suggests that the atmosphere and ocean are the main excitation sources of annual polar motion.展开更多
The integration of qubits with long coherence times and functional quantum devices on a single chip,and thus the realization of an allsolidstate quantum computing chip,is an important goal in current experimental rese...The integration of qubits with long coherence times and functional quantum devices on a single chip,and thus the realization of an allsolidstate quantum computing chip,is an important goal in current experimental research on quantum information processing.Among various quantum platforms,a series of significant progresses have been made in photonic quantum chips and superconducting quantum chips,while both the number of qubits and the complexity of quantum circuits have been increasing.Although these two chip platforms have respective unique advantages and potentials,their shortcomings have been gradually revealed and need to be solved.By introducing phonon-integrated devices,it is possible to combine all unsuspended phononic,photonic,and superconducting quantum devices organi-cally on the same chip to achieve coherent coupling among them.Here,we provide a prospect and a short review on the integrated photonic,superconducting,and hybrid quantum chips for quantum information processing.展开更多
This paper discusses consensus problems for high-dimensional networked multi-agent systems with fixed topology. The communication topology of multi-agent systems is represented by a digraph. A new consensus protocol i...This paper discusses consensus problems for high-dimensional networked multi-agent systems with fixed topology. The communication topology of multi-agent systems is represented by a digraph. A new consensus protocol is proposed, and consensus convergence of multigent systems is analyzed based on the Lyapunov stability theory. The consensus problem can be formulated into solving a feasible problem with bilinear matrix inequality （BMI） constrains. Furthermore, the consensus protocol is extended to achieving tracking and formation control. By introducing the formation structure set, each agent can gain its individual desired trajectory. Finally, numerical simulations are provided to show the effectiveness of our strategies. The results show that agents from arbitrary initial states can asymptotically reach a consensus. In addition, agents with high-dimensional can track any target trajectory, and maintain desired formation during movement by selecting appropriate structure set.展开更多
The adsorption of fibrinogen can be used as a quick indicator of surface haemocompatibility because of its prominent role in coagulation and platelet adhesion. In this work the molecular interaction between fibrinogen...The adsorption of fibrinogen can be used as a quick indicator of surface haemocompatibility because of its prominent role in coagulation and platelet adhesion. In this work the molecular interaction between fibrinogen and a modified titanium oxide surface/platelet has been studied by quartz crystal microbalanee with dissipation （QCM-D） in situ. In order to further characterize the conformation of adsorbed fibrinogen, αC and γ-chain antibody were used to check the orientation and denaturation of fibrinogen on solid surface. QCM-D investiga- tions revealed the fibrinogen have the trend to adsorb on hydropllilic surface in a side-on orientation by positively charged αC domains, which would reduce the exposure of platelet bonding site on γ chain and enable less platelet adhesion and be activated. These obser- vations suggest that certain conformations of adsorbed fibrinogen are less platelet adhesive than others, which opens a possibility for creating a non-platelet adhesive substrates.展开更多
文摘A new high accuracy 6D ( Dimension ) wide range measuring technology and the method of coordinate transformations have been developed in a project for automobile body-in- white measurement in Michigan , U S A . The requirements and the special features about the measured objective are mainly stated. The main instruments used in the project are introduced. The 6D measuring system , the method for coordinate transformations and the design of 3D optical target with hollow tetrahedron are described in detail . The 6D system and the technology can be certainly used in many other kinds of geometric mea- suring projects .
基金supported in part by the National Key Research and Development Program of China(2018YFA0702200)the National Natural Science Foundation of China(52377079,62203097,62373196)。
文摘In this paper,a class of time-varying output group formation containment control problem of general linear hetero-geneous multiagent systems(MASs)is investigated under directed topology.The MAS is composed of a number of tracking leaders,formation leaders and followers,where two different types of leaders are used to provide reference trajectories for movement and to achieve certain formations,respectively.Firstly,compen-sators are designed whose states are estimations of tracking lead-ers,based on which,a controller is developed for each formation leader to accomplish the expected formation.Secondly,two event-triggered compensators are proposed for each follower to evalu-ate the state and formation information of the formation leaders in the same group,respectively.Subsequently,a control protocol is designed for each follower,utilizing the output information,to guide the output towards the convex hull generated by the forma-tion leaders within the group.Next,the triggering sequence in this paper is decomposed into two sequences,and the inter-event intervals of these two triggering conditions are provided to rule out the Zeno behavior.Finally,a numerical simulation is intro-duced to confirm the validity of the proposed results.
基金supported by the Key State Science and Technology Project(Grant No.2011ZX05005-03-009HZ)the Specialized Research Fund for the Doctoral Program of Higher Education(Grant No.20130101110051)
文摘Based on the GC-MS analytical data of aromatic fractions of over forty highly mature coal-bearing source rock samples collected from the Upper Triassic Xujiahe Formation in the northern Sichuan Basin, the thermal evolution of aromatic hydrocarbons during late-mature to over-mature stage （R0=1.13%-2.85%） was characterized, and aromatic indicators suitable for recognizing the organic source and sedimentary environment of high maturity source rocks were discussed. The results indicated that the concentrations of low carbon-cycle naphthalene as well phenanthrene series reduce gradually with increasing Ro at the highly mature levels. However, some high-cyclic components such as chrysene, benzofluoranthene, and benzo[e]pyrene are relatively enriched, in companying an enhancement of parent aromatic compounds. The variations are attributed to thermal cracking and polymerization reactions due to continuous dehydrogenation under enhanced burial temperature. As thermal maturity rises, MPI1 （Methylphenanthrene Index） values display a two-modal varying trend, namely, increasing when Ro is below 1.80% and decreasing above 1.8% Ro. The relationships between Ro and MPI1 are Ro=0.98MPI1＋0.37 for R0〈1.80% and R0=-0.90MPI1＋3.02 at R0〉1.8%, being different from the previous research. The amount of dibenzofurans declines sharply at Ro higher than 1.1%, leading to a significant change of relative composition among dibenzothiophenes, dibenzofurans and fluorenes （referred as three-fluorenes series composition）. Thus, this parameter appears to be unsuitable for identifying the sedimentary environment of the highly matured source rocks. 4-/1-MDBT （methyldibenzothiophene） ratio could be served as an effective indicator for organic facies, and can distinguish coals from mudstones at over-maturity in this case. The ratios of 2,6-/2,10-DMP （dimethylphenanthrene） and 1,7-/1,9-DMP and relative abundance of triaromatic steroids in these highly mature rocks could be considered as biological source parameters for relati
基金Supported by the National Key Basic Research and Development (973) Program of China (No. 2007CB310601)
文摘A carrier frequency offset （CFO） estimator was developed based on an interference cancellation scheme for an orthogonal frequency division multiplex access uplink. An initial CFO estimate was first ob- tained based on the received training signals at each user＇s prescribed subcarder positions. Then, the re- ceived training signals were compensated by using the initial CFO estimates in the frequency domain and the multi-user interferences were estimated. Finally, the interference-cancelled training signals were used to reliably estimate each user＇s CFO. The CFO estimator performance was evaluated by the bit error rate per- formances of the CFO compensation-based receivers at the base station. Simulations show that with this optima CFO compensation receiver, the performance gain with the esti- mated CFO values is approximately 3 dB better at the 0.1% bit error rate than the initial CFO estimates.
基金This work was supported by the National Natural Science Foundation of China(Grant No.19402005).
文摘Planar motion for a rigid body with an elastic beam in a field of central gravitational force wasinvestigated, and both of the orbital motion and attitude motion were under consideration. The equations ofmotion of the system were derived by the variational principle, and on view point of generalized Hamiltoniandynamics, the sufficient conditions for the stability of one class of relative equilibria were given by the energy-momentum method.
基金This work was supported by China State Major Key Project for Basic Researches
文摘In this paper we describe a multi-grid algorithm for mixed problems with penalty by the linear finite element approximation. It is proved that the convergence rate of the algorithm is bound ed away from 1 independently of the meshsize. For convenience, we only discuss Jacobi relaxation as smoothing operator in detail.
文摘The quantitative result of annual polar motion excitation by the ocean is presented for the first time. The atmospheric excitation amounts to more than double of the oceanic excitation. The sum of atmospheric and oceanic excitations approximates more to the observed annual polar motion excitation, compared with atmospheric excitation only This suggests that the atmosphere and ocean are the main excitation sources of annual polar motion.
基金supported by the National Key Research and De-velopment Program of China(Grant No.2017YFA0304303)National Nat-ural Science Foundation of China(Grant Nos.11874342,12061131011,92165209,11925404,11922411)+1 种基金Key-Area Research and Development Program of Guangdong Province Grant No.2020B0303030001China Postdoctoral Science Foundation(Grant No.BX2021167).
文摘The integration of qubits with long coherence times and functional quantum devices on a single chip,and thus the realization of an allsolidstate quantum computing chip,is an important goal in current experimental research on quantum information processing.Among various quantum platforms,a series of significant progresses have been made in photonic quantum chips and superconducting quantum chips,while both the number of qubits and the complexity of quantum circuits have been increasing.Although these two chip platforms have respective unique advantages and potentials,their shortcomings have been gradually revealed and need to be solved.By introducing phonon-integrated devices,it is possible to combine all unsuspended phononic,photonic,and superconducting quantum devices organi-cally on the same chip to achieve coherent coupling among them.Here,we provide a prospect and a short review on the integrated photonic,superconducting,and hybrid quantum chips for quantum information processing.
基金Supported by the National Natural Science Foundation of China （No. 61075065,60774045, U1134108） and the Ph. D Programs Foundation of Ministry of Education of China （ No. 20110162110041 ）.
文摘This paper discusses consensus problems for high-dimensional networked multi-agent systems with fixed topology. The communication topology of multi-agent systems is represented by a digraph. A new consensus protocol is proposed, and consensus convergence of multigent systems is analyzed based on the Lyapunov stability theory. The consensus problem can be formulated into solving a feasible problem with bilinear matrix inequality （BMI） constrains. Furthermore, the consensus protocol is extended to achieving tracking and formation control. By introducing the formation structure set, each agent can gain its individual desired trajectory. Finally, numerical simulations are provided to show the effectiveness of our strategies. The results show that agents from arbitrary initial states can asymptotically reach a consensus. In addition, agents with high-dimensional can track any target trajectory, and maintain desired formation during movement by selecting appropriate structure set.
基金ACKNOWLEDGMENTS This work was supported by the National Natural Science Foundation of China （No.9732011CB606200 and No.81330031） and Fundamentat Research Funds for the Central Universities （No.SWJTU11CX054）. The authors gratefully acknowledge assistance of Mr. Hai-bei Liu at Qsense company for consulting.
文摘The adsorption of fibrinogen can be used as a quick indicator of surface haemocompatibility because of its prominent role in coagulation and platelet adhesion. In this work the molecular interaction between fibrinogen and a modified titanium oxide surface/platelet has been studied by quartz crystal microbalanee with dissipation （QCM-D） in situ. In order to further characterize the conformation of adsorbed fibrinogen, αC and γ-chain antibody were used to check the orientation and denaturation of fibrinogen on solid surface. QCM-D investiga- tions revealed the fibrinogen have the trend to adsorb on hydropllilic surface in a side-on orientation by positively charged αC domains, which would reduce the exposure of platelet bonding site on γ chain and enable less platelet adhesion and be activated. These obser- vations suggest that certain conformations of adsorbed fibrinogen are less platelet adhesive than others, which opens a possibility for creating a non-platelet adhesive substrates.
