Abstract An adaptive dynamic surface control （DSC） scheme is proposed for the multiinput and multioutput （MIMO） attitude motion of nearspace vehicles （NSVs） in the presence of external dis turbance, system uncer...Abstract An adaptive dynamic surface control （DSC） scheme is proposed for the multiinput and multioutput （MIMO） attitude motion of nearspace vehicles （NSVs） in the presence of external dis turbance, system uncertainty and input saturation. The external disturbance and the system uncer tainty are efficiently tackled using a Nussbaum disturbance observer （NDO）, and the adaptive controller is constructed by combining the dynamic surface control technique to handle the problem of ＂explosion of complexity＂ inherent in the conventional backstepping methodl For handling the input saturation, an auxiliary system is designed with the same order as that of the studied MIMO attitude system. Using the error between the saturation input and the desired control input as the input of the designed auxiliary system, a series of signals are generated to compensate for the effect of the saturation in the dynamic surface control design. It is proved that the developed control scheme can guarantee that all signals of the closedloop control system are semiglobally uniformly bounded. Finally, simulation results illustrate that the proposed control scheme can achieve satis factory tracking performance under the composite effects of the input saturation and the external disturbance.展开更多
核电机组(nuclear power plant,NPP)具有单机容量大、核安全要求高等特性,失磁故障会影响核电机组安全性。为研究核电机组失磁时的机网协调控制策略,建立了大型压水堆核电机组的发电机模型、汽轮机及其控制系统模型、反应堆堆芯控制系...核电机组(nuclear power plant,NPP)具有单机容量大、核安全要求高等特性,失磁故障会影响核电机组安全性。为研究核电机组失磁时的机网协调控制策略,建立了大型压水堆核电机组的发电机模型、汽轮机及其控制系统模型、反应堆堆芯控制系统模型、励磁系统模型及失磁故障数学模型,研究了核电机组在不同功率水平运行时的失磁动态响应特性及机理。结果表明:满载失磁对反应堆及热力系统冲击大,核电机组应可靠跳闸;低功率运行失磁时,核电机组可以短期内维持并网异步运行;核电机组发生失磁导致厂用电的可靠性和供电质量下降,应该采取相应措施提高厂用电的可靠性。展开更多
In this paper,we consider the Cahn-Hilliard-Hele-Shaw(CHHS)system with the dynamic boundary conditions,in which both the bulk and surface energy parts play important roles.The scalar auxiliary variable approach is int...In this paper,we consider the Cahn-Hilliard-Hele-Shaw(CHHS)system with the dynamic boundary conditions,in which both the bulk and surface energy parts play important roles.The scalar auxiliary variable approach is introduced for the physical system;the mass conservation and energy dissipation is proved for the CHHS system.Subsequently,a fully discrete SAV finite element scheme is proposed,with the mass conservation and energy dissipation laws established at a theoretical level.In addition,the convergence analysis and error estimate is provided for the proposed SAV numerical scheme.展开更多
As a basic functional unit,living cell with sophisticated structures play an indispensable role in life activities.Since the abnormality of important molecules inside cells is closely related to diseases,the dynamic a...As a basic functional unit,living cell with sophisticated structures play an indispensable role in life activities.Since the abnormality of important molecules inside cells is closely related to diseases,the dynamic analysis and spatio-temporal monitoring of specific molecules in living cells can provide precious information for the diagnosis and treatment of diseases.More recently,DNA has not only been recognized as the carrier of genetic information,but has also used as a robust building block for the assembly of multitudinous nanoscale structures due to the intrinsic advantages of high programmability of classic Watson–Crick base-pairing rule.Intensive study promotes the rapid progress of nanotechnology in various fields,such as bioimaging,diagnosis,and therapeutics.Among numerous well-defined DNA nanomaterials,DNA nanomachines have been widely exploited in cell imaging owing to their desirable ability to achieve high-resolution temporal and spatial images in response to endogenous or exogenous stimuli.In brief,elaborate DNA nanomachines can undergo structural changes upon the stimuli of target analytes or environmental factors,resulting in rapid increase or reduction of output signals and thereby indirectly reflecting the expression level of targets.DNA nanomachines with high sensitivity and specificity contribute to the recognition of diseased tissues.In this review,we introduce the basic assembly modules of DNA nanomachines and summarize the recent advances in dynamic DNA nanomachines for diseased-cell imaging.Finally,the current challenges and future directions of DNA nanomachines for bioimaging are discussed.展开更多
基金supported by Jiangsu Natural Science Foundation(No.SBK20130033)Program for New Century Excellent Talents in University of China(No.NCET-11-0830)+2 种基金The Six Talents Peak Project of Jiangsu Province(No.2012-XXRJ-010)Aeronautical Science Foundation of China(No.20145152029)the Specialized Research Fund for the Doctoral Program of Higher Education of China(No.20133218110013)
文摘Abstract An adaptive dynamic surface control （DSC） scheme is proposed for the multiinput and multioutput （MIMO） attitude motion of nearspace vehicles （NSVs） in the presence of external dis turbance, system uncertainty and input saturation. The external disturbance and the system uncer tainty are efficiently tackled using a Nussbaum disturbance observer （NDO）, and the adaptive controller is constructed by combining the dynamic surface control technique to handle the problem of ＂explosion of complexity＂ inherent in the conventional backstepping methodl For handling the input saturation, an auxiliary system is designed with the same order as that of the studied MIMO attitude system. Using the error between the saturation input and the desired control input as the input of the designed auxiliary system, a series of signals are generated to compensate for the effect of the saturation in the dynamic surface control design. It is proved that the developed control scheme can guarantee that all signals of the closedloop control system are semiglobally uniformly bounded. Finally, simulation results illustrate that the proposed control scheme can achieve satis factory tracking performance under the composite effects of the input saturation and the external disturbance.
文摘核电机组(nuclear power plant,NPP)具有单机容量大、核安全要求高等特性,失磁故障会影响核电机组安全性。为研究核电机组失磁时的机网协调控制策略,建立了大型压水堆核电机组的发电机模型、汽轮机及其控制系统模型、反应堆堆芯控制系统模型、励磁系统模型及失磁故障数学模型,研究了核电机组在不同功率水平运行时的失磁动态响应特性及机理。结果表明:满载失磁对反应堆及热力系统冲击大,核电机组应可靠跳闸;低功率运行失磁时,核电机组可以短期内维持并网异步运行;核电机组发生失磁导致厂用电的可靠性和供电质量下降,应该采取相应措施提高厂用电的可靠性。
基金supported by NSFC(Grant No.11871441)supported by NSF(Grant No.DMS-2012669).
文摘In this paper,we consider the Cahn-Hilliard-Hele-Shaw(CHHS)system with the dynamic boundary conditions,in which both the bulk and surface energy parts play important roles.The scalar auxiliary variable approach is introduced for the physical system;the mass conservation and energy dissipation is proved for the CHHS system.Subsequently,a fully discrete SAV finite element scheme is proposed,with the mass conservation and energy dissipation laws established at a theoretical level.In addition,the convergence analysis and error estimate is provided for the proposed SAV numerical scheme.
基金supported by National Natural Science Foundation of China(NSFC)(grant NO:22174020).
文摘As a basic functional unit,living cell with sophisticated structures play an indispensable role in life activities.Since the abnormality of important molecules inside cells is closely related to diseases,the dynamic analysis and spatio-temporal monitoring of specific molecules in living cells can provide precious information for the diagnosis and treatment of diseases.More recently,DNA has not only been recognized as the carrier of genetic information,but has also used as a robust building block for the assembly of multitudinous nanoscale structures due to the intrinsic advantages of high programmability of classic Watson–Crick base-pairing rule.Intensive study promotes the rapid progress of nanotechnology in various fields,such as bioimaging,diagnosis,and therapeutics.Among numerous well-defined DNA nanomaterials,DNA nanomachines have been widely exploited in cell imaging owing to their desirable ability to achieve high-resolution temporal and spatial images in response to endogenous or exogenous stimuli.In brief,elaborate DNA nanomachines can undergo structural changes upon the stimuli of target analytes or environmental factors,resulting in rapid increase or reduction of output signals and thereby indirectly reflecting the expression level of targets.DNA nanomachines with high sensitivity and specificity contribute to the recognition of diseased tissues.In this review,we introduce the basic assembly modules of DNA nanomachines and summarize the recent advances in dynamic DNA nanomachines for diseased-cell imaging.Finally,the current challenges and future directions of DNA nanomachines for bioimaging are discussed.
