文中聚焦温敏聚合物的响应机理,通过单电子转移活性自由基聚合法(SET-LRP),以溴化亚铜/三-(2-二甲氨基乙基)胺(CuBr/Me_(6)TREN)原位歧化得到的初生零价铜(Cu^(0))及二价铜与混合配体的络合物(Cu^(Ⅱ)Br_(2)/Me_(6)TREN/PMDETA)为催化体...文中聚焦温敏聚合物的响应机理,通过单电子转移活性自由基聚合法(SET-LRP),以溴化亚铜/三-(2-二甲氨基乙基)胺(CuBr/Me_(6)TREN)原位歧化得到的初生零价铜(Cu^(0))及二价铜与混合配体的络合物(Cu^(Ⅱ)Br_(2)/Me_(6)TREN/PMDETA)为催化体系,实现了温敏单体N-异丙基丙烯酰胺(NIPAM)和甜菜碱两性离子功能单体[2-(甲基丙烯酰基氧基)乙基]二甲基-(3-磺酸丙基)氢氧化铵(DMMPPS)的原位链延伸,制备得到了系列不同嵌段比的温敏聚合物P(NIPAM-b-DMMPPS)。采用核磁共振氢谱和红外光谱对聚合物结构进行了表征。以NIPAM加料比例为40%合成的P(NIPAM-b-DMMPPS)具有最低临界溶解温度(LCST)和最高临界溶解温度(UCST),分别为41℃和25℃。考察了NaCl浓度对P(NIPAMb-DMMPPS)LCST的影响,随着NaCl浓度的增大,LCST略降低。表面张力测试结果表明,表面活性聚合物溶液浓度为1×10^(-2)g/L时,表面张力降低至45 m N/m。P(NIPAM-b-DMMPPS)在石蜡/水体系中表现出温度诱导的乳化-破乳行为,P(NIPAM-b-DMMPPS)吸附在油水界面形成乳液,提高P(NIPAM-b-DMMPPS)中PNIPAM嵌段的比例能够实现从“低温乳化、高温破乳”向“高温乳化、低温破乳”的转变,其在油水乳化破乳领域有良好的应用前景。展开更多
This paper is devoted to experimentally investigating the influence of magnetic field intensity and gas temperature on the plasma jet deflection controlled by magneto hydrodynamics. The catalytic ionization seed CS_2C...This paper is devoted to experimentally investigating the influence of magnetic field intensity and gas temperature on the plasma jet deflection controlled by magneto hydrodynamics. The catalytic ionization seed CS_2CO_3 is injected into combustion gas by artificial forced ionization to obtain plasma fluid on a high-temperature magnetic fluid experimental platform. The plasma jet was deflected under the effect of an external magnetic field, forming a thrust-vector effect.Magnesium oxide was selected as a tracer particle, and a two-dimensional image of the jet flow field was collected using the particle image velocimetry(PIV) measurement method. Through image processing and velocity vector analysis of the flow field, the value of the jet deflection angle was obtained quantitatively to evaluate the thrust-vector effect. The variation of the jet deflection angle with the magnetic field intensity and gas temperature was studied under different experimental conditions. Experimental results show that the jet deflection angle increased gradually with a rise in gas temperature and then increased substantially when the gas temperature exceeded 2300 K. The jet deflection angle also increased with an increase in magnetic induction intensity. Experiments demonstrate it is feasible to use PIV test technology to study the thrust vector under magnetic control conditions.展开更多
An immersion and invariance(l&l)manifold based adaptive control algorithm is presented for a class of continuous stirred tank reactors(CSTR)to realize performance-oriented control in this paper.The nonlinear contr...An immersion and invariance(l&l)manifold based adaptive control algorithm is presented for a class of continuous stirred tank reactors(CSTR)to realize performance-oriented control in this paper.The nonlinear contraction method is combined into the control law design to render the closed-loop CSTR system globally asymptotically stable,firstly.Then,the l&l method is used to form the adaptation law such that the off-the-manifold coordinate(the parameter estimation error)converges to zero using P-monotone property enforced by selecting tuning function in manifold.As a result,the state of the closed-loop CSTR converges to its desired value asymptotically.The simulation is given to illustrate the effectiveness of the presented algorithm.展开更多
In this paper,nonlinear observers are incorporated into the adaptive control to synthesize controllers for a class of uncertain nonlinear systems with unknown sinusoidal disturbances which are presented in matched and...In this paper,nonlinear observers are incorporated into the adaptive control to synthesize controllers for a class of uncertain nonlinear systems with unknown sinusoidal disturbances which are presented in matched and unmatched forms.In addition to magnitudes and phases,frequencies of the sinusoidal disturbances need not be known as well,so long as the overall order is known.Nonlinear observers are constructed to eliminate the effect of unknown sinusoidal disturbances to improve the steady-state output tracking performance-asymptotic output tracking is achieved.The adaptation law is used to obtain the estimate of all unknown parameters.The presented disturbance decoupling algorithms can deal with matched and unmatched unknown sinusoidal disturbances.展开更多
This paper provides a novel fault-tolerant control scheme for a class of nonaffine systems with nonlinearly parameterised(NLP)faults.The nonaffine system is firstly transformed into an augmented one via dynamic feedba...This paper provides a novel fault-tolerant control scheme for a class of nonaffine systems with nonlinearly parameterised(NLP)faults.The nonaffine system is firstly transformed into an augmented one via dynamic feedback control.A fault-tolerant controller with Immersion and Invariance(I&I)adaptation law is designed for the transformed system through dynamic surface control.The controller avoids complexity due to the explosion of terms in backstepping design.The I&I adaptation law is developed to recover the unknown parameters of NLP faults in the system.The proposed scheme can shape the transient performance of the parameter estimation error and tracking error.In the tracking problem,all the signals and tracking error converge exponentially to a small neighbourhood of the origin.In the regulation problem,the system output converges exponentially to zero.A numerical simulation is carried out to verify the effectiveness of the proposed scheme.展开更多
Node classification has a wide range of application scenarios such as citation analysis and social network analysis.In many real-world attributed networks,a large portion of classes only contain limited labeled nodes....Node classification has a wide range of application scenarios such as citation analysis and social network analysis.In many real-world attributed networks,a large portion of classes only contain limited labeled nodes.Most of the existing node classification methods cannot be used for few-shot node classification.To train the model effectively and improve the robustness and reliability of the model with scarce labeled samples,in this paper,we propose a local adaptive discriminant structure learning(LADSL)method for few-shot node classification.LADSL aims to properly represent the nodes in the attributed graphs and learn a metric space with a strong discriminating power by reducing the intra-class variations and enlargingginter-classdifferences.Extensiveexperiments conducted on various attributed networks datasets demonstrate that LADSL is superior to the other methods on few-shot node classification task.展开更多
This paper proposes a robust Immersion and Invariance(I&I)adaptive coordinated controller for a class of uncertain linear-motor-driven biaxial gantry system subject to external disturbances for high-accuracy conto...This paper proposes a robust Immersion and Invariance(I&I)adaptive coordinated controller for a class of uncertain linear-motor-driven biaxial gantry system subject to external disturbances for high-accuracy contour tracking.Firstly,the dynamic model of the gantry system is transformed into task coordinate frame,through which the contour tracking can be regarded as a regulation problem.Based on the transformed system dynamics,an I&I-based adaptation law with smooth projection is proposed to estimate the unknown parameters.Different from traditional adaptive control,the proposed robust I&I adaptive control introduces a new term called tuning function in adaptation law to shape the dynamic behaviour of the estimation vector.Then the stability of the closed-loop system is proved by Lyapunov theory.Finally,comparative experiments are executed on an industrial biaxial gantry system with two different cases to verify the effectiveness of the proposed control law.展开更多
A quantised backstepping robust guidance law of three-dimension(3-D)space for compound control of reaction control jets and aerodynamic surfaces is proposed to attenuate the unknown target manoeuvre in this paper.The ...A quantised backstepping robust guidance law of three-dimension(3-D)space for compound control of reaction control jets and aerodynamic surfaces is proposed to attenuate the unknown target manoeuvre in this paper.The presented guidance law guarantees that the rates of line of sight converge to a residual circle centred at the origin whose radius is depended on the target manoeuvres,quantised length and guidance law gains.The simulations are given to illustrate the effectiveness of the proposed guidance law.展开更多
文摘文中聚焦温敏聚合物的响应机理,通过单电子转移活性自由基聚合法(SET-LRP),以溴化亚铜/三-(2-二甲氨基乙基)胺(CuBr/Me_(6)TREN)原位歧化得到的初生零价铜(Cu^(0))及二价铜与混合配体的络合物(Cu^(Ⅱ)Br_(2)/Me_(6)TREN/PMDETA)为催化体系,实现了温敏单体N-异丙基丙烯酰胺(NIPAM)和甜菜碱两性离子功能单体[2-(甲基丙烯酰基氧基)乙基]二甲基-(3-磺酸丙基)氢氧化铵(DMMPPS)的原位链延伸,制备得到了系列不同嵌段比的温敏聚合物P(NIPAM-b-DMMPPS)。采用核磁共振氢谱和红外光谱对聚合物结构进行了表征。以NIPAM加料比例为40%合成的P(NIPAM-b-DMMPPS)具有最低临界溶解温度(LCST)和最高临界溶解温度(UCST),分别为41℃和25℃。考察了NaCl浓度对P(NIPAMb-DMMPPS)LCST的影响,随着NaCl浓度的增大,LCST略降低。表面张力测试结果表明,表面活性聚合物溶液浓度为1×10^(-2)g/L时,表面张力降低至45 m N/m。P(NIPAM-b-DMMPPS)在石蜡/水体系中表现出温度诱导的乳化-破乳行为,P(NIPAM-b-DMMPPS)吸附在油水界面形成乳液,提高P(NIPAM-b-DMMPPS)中PNIPAM嵌段的比例能够实现从“低温乳化、高温破乳”向“高温乳化、低温破乳”的转变,其在油水乳化破乳领域有良好的应用前景。
基金supported by National Natural Science Foundation of China (No. 90716025)
文摘This paper is devoted to experimentally investigating the influence of magnetic field intensity and gas temperature on the plasma jet deflection controlled by magneto hydrodynamics. The catalytic ionization seed CS_2CO_3 is injected into combustion gas by artificial forced ionization to obtain plasma fluid on a high-temperature magnetic fluid experimental platform. The plasma jet was deflected under the effect of an external magnetic field, forming a thrust-vector effect.Magnesium oxide was selected as a tracer particle, and a two-dimensional image of the jet flow field was collected using the particle image velocimetry(PIV) measurement method. Through image processing and velocity vector analysis of the flow field, the value of the jet deflection angle was obtained quantitatively to evaluate the thrust-vector effect. The variation of the jet deflection angle with the magnetic field intensity and gas temperature was studied under different experimental conditions. Experimental results show that the jet deflection angle increased gradually with a rise in gas temperature and then increased substantially when the gas temperature exceeded 2300 K. The jet deflection angle also increased with an increase in magnetic induction intensity. Experiments demonstrate it is feasible to use PIV test technology to study the thrust vector under magnetic control conditions.
基金supported by National Science Foundation of China(No.61320106009)Open Research Project of the State Key Laboratory of Industrial Control Technology,Zhejiang University,China(No.ICT1433)
文摘An immersion and invariance(l&l)manifold based adaptive control algorithm is presented for a class of continuous stirred tank reactors(CSTR)to realize performance-oriented control in this paper.The nonlinear contraction method is combined into the control law design to render the closed-loop CSTR system globally asymptotically stable,firstly.Then,the l&l method is used to form the adaptation law such that the off-the-manifold coordinate(the parameter estimation error)converges to zero using P-monotone property enforced by selecting tuning function in manifold.As a result,the state of the closed-loop CSTR converges to its desired value asymptotically.The simulation is given to illustrate the effectiveness of the presented algorithm.
基金supported by the National Natural Science Foundation of China(No.60874041,60834001)the Youth Foundation of Henan University of Science and Technology(No.13440018)
文摘In this paper,nonlinear observers are incorporated into the adaptive control to synthesize controllers for a class of uncertain nonlinear systems with unknown sinusoidal disturbances which are presented in matched and unmatched forms.In addition to magnitudes and phases,frequencies of the sinusoidal disturbances need not be known as well,so long as the overall order is known.Nonlinear observers are constructed to eliminate the effect of unknown sinusoidal disturbances to improve the steady-state output tracking performance-asymptotic output tracking is achieved.The adaptation law is used to obtain the estimate of all unknown parameters.The presented disturbance decoupling algorithms can deal with matched and unmatched unknown sinusoidal disturbances.
基金supported by the Fundamental Research Funds for the Central Universities[grant number 2022YJS021][grant number 2022JBZY001]the National Natural Science Foundation of China[grant number 62371032].
文摘This paper provides a novel fault-tolerant control scheme for a class of nonaffine systems with nonlinearly parameterised(NLP)faults.The nonaffine system is firstly transformed into an augmented one via dynamic feedback control.A fault-tolerant controller with Immersion and Invariance(I&I)adaptation law is designed for the transformed system through dynamic surface control.The controller avoids complexity due to the explosion of terms in backstepping design.The I&I adaptation law is developed to recover the unknown parameters of NLP faults in the system.The proposed scheme can shape the transient performance of the parameter estimation error and tracking error.In the tracking problem,all the signals and tracking error converge exponentially to a small neighbourhood of the origin.In the regulation problem,the system output converges exponentially to zero.A numerical simulation is carried out to verify the effectiveness of the proposed scheme.
基金supported by the National Key R&D Program of China(2018YFB1402600)the National Natural Science Foundation of China(Grant Nos.61802028,62192784,61877006,and 62002027)。
文摘Node classification has a wide range of application scenarios such as citation analysis and social network analysis.In many real-world attributed networks,a large portion of classes only contain limited labeled nodes.Most of the existing node classification methods cannot be used for few-shot node classification.To train the model effectively and improve the robustness and reliability of the model with scarce labeled samples,in this paper,we propose a local adaptive discriminant structure learning(LADSL)method for few-shot node classification.LADSL aims to properly represent the nodes in the attributed graphs and learn a metric space with a strong discriminating power by reducing the intra-class variations and enlargingginter-classdifferences.Extensiveexperiments conducted on various attributed networks datasets demonstrate that LADSL is superior to the other methods on few-shot node classification task.
基金the National Natural Science Foundation of China[Grant Number 61673050].
文摘This paper proposes a robust Immersion and Invariance(I&I)adaptive coordinated controller for a class of uncertain linear-motor-driven biaxial gantry system subject to external disturbances for high-accuracy contour tracking.Firstly,the dynamic model of the gantry system is transformed into task coordinate frame,through which the contour tracking can be regarded as a regulation problem.Based on the transformed system dynamics,an I&I-based adaptation law with smooth projection is proposed to estimate the unknown parameters.Different from traditional adaptive control,the proposed robust I&I adaptive control introduces a new term called tuning function in adaptation law to shape the dynamic behaviour of the estimation vector.Then the stability of the closed-loop system is proved by Lyapunov theory.Finally,comparative experiments are executed on an industrial biaxial gantry system with two different cases to verify the effectiveness of the proposed control law.
基金National Science Foundation of China[grant number 61673050]Aeronautical Science Foundation of China[grant number 201401M5001]Open Research Project of the State Key Laboratory of Industrial Control Technology,Zhejiang University,China[grant number ICT1600229].
文摘A quantised backstepping robust guidance law of three-dimension(3-D)space for compound control of reaction control jets and aerodynamic surfaces is proposed to attenuate the unknown target manoeuvre in this paper.The presented guidance law guarantees that the rates of line of sight converge to a residual circle centred at the origin whose radius is depended on the target manoeuvres,quantised length and guidance law gains.The simulations are given to illustrate the effectiveness of the proposed guidance law.
