Fusobacterium nucleatum(F.nucleatum),an oral anaerobe,is prevalent in colorectal cancer and is closely related to increased cancer cell growth,metastasis,and poor treatment outcomes.Bacterial vaccines capable of selec...Fusobacterium nucleatum(F.nucleatum),an oral anaerobe,is prevalent in colorectal cancer and is closely related to increased cancer cell growth,metastasis,and poor treatment outcomes.Bacterial vaccines capable of selectively eliminating bacteria present a promising approach to targeting intratumor F.nucleatum,thereby enhancing cancer treatment.Although adjuvants have been employed to enhance the immune response,the vaccine’s effectiveness is constrained by inadequate T-cell activation necessary for eradicating intracellular pathogens.In this study,we developed a minimalistic,biomimetic nanovaccine by integrating highly immunostimulatory adjuvant cholesterol-modified CpG oligonucleotides into the autologously derived F.nucleatum membranes.Compared to the traditional vaccines consisting of inactivated bacteria and Alum adjuvant,the nanovaccine coupled with bacterial membranes and adjuvants could remarkably improve multiple antigens and adjuvant co-delivery to dendritic cells,maximizing their ability to achieve effective antigen presentation and strong downstream immune progress.Notably,the nanovaccine exhibits outstanding selective prophylactic and therapeutic effects,eliminating F.nucleatum without affecting intratumoral and gut microbiota.It significantly enhances chemotherapy efficacy and reduces cancer metastasis in F.nucleatum-infected colorectal cancer.Overall,this work represents the rational application of bacterial nanovaccine and provides a blueprint for future development in enhancing the antitumor effect against bacterial-infected cancer.展开更多
Inertial characteristics of non-cooperative targets are crucial for space capture and sub-sequent on-orbit servicing.Previous methods for identifying inertial parameters involve proximity operations,which are associat...Inertial characteristics of non-cooperative targets are crucial for space capture and sub-sequent on-orbit servicing.Previous methods for identifying inertial parameters involve proximity operations,which are associated with the risk of collision with non-cooperative targets.This paper introduces a long-range,contactless method for identifying the inertial parameters of a non-cooperative target during the pre-capture phase.Specifically,electrostatic interaction is used as an external excitation to alter the target's motion.A force estimation algorithm that uses measure-ments from visual and potential sensors is proposed to estimate the electrostatic interaction and eliminate the need for force sensors.Furthermore,a recursive estimation-identification framework is presented to concurrently estimate the coupled motion state,weak electrostatic interaction,and inertial parameters of the target.The simulation results show that the proposed method extends the identification distance to 170 times that of the previous method while maintaining high identifica-tion precision forall parameters.展开更多
The participation of photovoltaic(PV)plants in supporting the transient voltage caused by commutation failure in the line-commutated-converter-based high voltage direct current(LCC-HVDC)system is of great significance...The participation of photovoltaic(PV)plants in supporting the transient voltage caused by commutation failure in the line-commutated-converter-based high voltage direct current(LCC-HVDC)system is of great significance,as it can enhance the DC transmission ability.However,it is found that the gridfollowing(GFL)PV converters face the problem of mismatch between reactive power response and transient voltage characteristic when the voltage converts from low voltage to overvoltage,further aggravating the overvoltage amplitude.Thus,this article proposes a transient voltage support strategy based on the gridforming(GFM)medium voltage PV converter.The proposed strategy takes the advantage of the close equivalent electrical distance between the converter and grid,which can autonomously control the converter terminal voltage through GFM control with adaptive voltage droop coefficient.The simulation results show that the proposed strategy can ensure the output reactive power of the PV converter quickly matches the transient voltage characteristic at different stages,indicating that the proposed strategy can effectively support the transient voltage.展开更多
The optimal planning and operation of multi-type flexible resources(FRs)are critical prerequisites for maintaining power and energy balance in regional power grids with a high proportion of clean energy.However,insuff...The optimal planning and operation of multi-type flexible resources(FRs)are critical prerequisites for maintaining power and energy balance in regional power grids with a high proportion of clean energy.However,insufficient consideration of the multi-dimensional and heterogeneous features of FRs,such as the regulation characteristics of diversified battery energy storage systems(BESSs),poses a challenge in economically relieving imbalance power and adequately sharing feature information between power supply and demand.In view of this disadvantage,an optimal planning and operation method based on differentiated feature matching through response capability characterization and difference quantification of FRs is proposed in this paper.In the planning stage,a model for the optimal planning of diversified energy storages(ESs)including Lithium-ion battery(Li-B),supercapacitor energy storage(SCES),compressed air energy storage(CAES),and pumped hydroelectric storage(PHS)is established.Subsequently,in the operating stage,the potential,direction,and cost of FR response behaviors are refined to match with the power and energy balance demand(PEBD)of power grid operation.An optimal operating algorithm is then employed to quantify the feature differences and output response sequences of multi-type FRs.The performance and effectiveness of the proposed method are demonstrated through comparative studies conducted on an actual regional power grid in northwest China.Analysis and simulation results illustrate that the proposed method can effectively highlight the advantages of BESSs compared with other ESs,and economically reduce imbalance power of the regional power grid under practical operating conditions.展开更多
Line-commutated converter based high voltage direct current(LCC-HVDC)has been applied for transferring bulk power from wind farms to load centers through long distances in many countries.When the blocking fault of the...Line-commutated converter based high voltage direct current(LCC-HVDC)has been applied for transferring bulk power from wind farms to load centers through long distances in many countries.When the blocking fault of the LCC-HVDC system occurs,the surplus reactive power accumulated at the sending end will lead to an overvoltage,thus causing the discon・nection of the wind turbines.To maintain the reliable connection of wind turbines and ensure the stability of the power system,this paper introduces a superconducting magnetic energy storage(SMES)unit to connect in parallel with the rotor side of the doubly fed induction generator(DFIG).By controlling the energy side converter and rotor side converter to inject demagnetizing current and reactive current into the rotor,the proposed scheme can effectively stabilize key parameters of the wind turbine and provide desirable reactive power support,showing a favorable high voltage ride through(HVRT)performance.Several cases based on PSCAD/EMTDC&MATLAB/Simuiink co-simulation together with economic analysis are conducted to demonstrate the feasibility and superiority of the proposed scheme on enhancing HVRT capability of DFIG-based wind farms.展开更多
The valuation of premium power based on perceived utility(PU,i.e.,perceived effectiveness or satisfaction degree of customers)and their willingness to pay has been researched for years.One of the remaining challenges ...The valuation of premium power based on perceived utility(PU,i.e.,perceived effectiveness or satisfaction degree of customers)and their willingness to pay has been researched for years.One of the remaining challenges is the accurate evaluation of PU.PU is the foundation of premium power evaluation,and it is essential for the decision-making process of investments on premium power by high-tech manufacturers(HTMs).This paper presents a framework to effectively evaluate PU.In this framework,factors influencing PU were classified to be quantitative and qualitative.An indication system(IS)was then constructed based on those influencing factors.Finally,PU was evaluated by the IS,considering psychological perception and decision-making behavior of HTMs.The effectiveness of the proposed PU-evaluation framework was demonstrated through field case studies.展开更多
Experimental and theoretical studies have confirmed that,relative to a one-shot voltage fault,a doubly-fed induction generator(DFIG)will suffer a greater transient impact during continuous voltage faults.This paper pr...Experimental and theoretical studies have confirmed that,relative to a one-shot voltage fault,a doubly-fed induction generator(DFIG)will suffer a greater transient impact during continuous voltage faults.This paper presents the design and application of an effective scheme for DFIGs when a commutation failure(CF)occurs in a line-commutated converter based high-voltage direct current(LCC-HVDC)transmission system.First,transient demagnetization control without filters is proposed to offset the electromotive force(EMF)induced by the natural flux and other low-frequency flux components.Then,a rotor-side integrated impedance circuit is designed to limit the rotor overcurrent to ensure that the rotor-side converter(RSC)is controllable.Furthermore,coordinated control of the demagnetization and segmented reactive currents is implemented in the RSC.Comparative studies have shown that the proposed scheme can limit rotor fault currents and effectively improve the continuous fault ride-through capability of DFIGs.展开更多
In order to achieve a straight ballistic trajectory of missile and reduce the update frequency of the missile normal acceleration for the interception of maneuvering target,a backstepping-based parallel approaching gu...In order to achieve a straight ballistic trajectory of missile and reduce the update frequency of the missile normal acceleration for the interception of maneuvering target,a backstepping-based parallel approaching guidance method is designed with nonlinear disturbance observer(NDO)technique and event-triggered(ET)mechanism in this paper.In order to suppress the adverse e®ect of target maneuver,the NDO is designed to estimate the target maneuvering acceleration.Then,the NDO-based backstepping method is used to obtain the normal acceleration of missile and realize the parallel approaching guidance.In order to reduce the update frequency of missile normal acceleration,the ET mechanism is employed in the parallel approaching guidance method.If the missile trajectory is relatively straight,the normal acceleration of missile remains unchanged.On the contrary,if the missile trajectory is not straight,the normal acceleration of missile is updated to make the missile trajectory straight.In this way,the ET-based parallel approaching guidance can be obtained.Furthermore,a determined method for the initial missile°ight-path angle is proposed to keep the normal acceleration of missile at zero in the initial stage of interception.Besides,Lyapunov stability analysis method is used to prove that all signals in the closed-loop guidance system are uniformly ultimately bounded.Finally,simulation results show the e®ectiveness of the proposed guidance method.展开更多
During the power modulation process of line com-mutated converter-based high-voltage direct current(LCC-HVDC),the transient power mismatch between the fast-change converter station and the slow-response reactive power...During the power modulation process of line com-mutated converter-based high-voltage direct current(LCC-HVDC),the transient power mismatch between the fast-change converter station and the slow-response reactive power compen-sators(RPCs)can cause transient voltage disturbances at the weak sending end of the AC grid.To mitigate such voltage dis-turbances,this paper proposes a coordinated feedback power control method for the hybrid multi-infeed HVDC(HMI-HVDC)system comprising an LCC-HVDC and voltage source converter-based HVDC(VSC-HVDC)systems.The mechanism of the disturbance caused by transient power mismatch is quan-titatively analyzed,and the numerical relationship between the instantaneous unbalanced power and the AC voltage is derived.Based on the numerical relationship and considering the time-varying relationship of reactive power between converter sta-tions,the unbalanced power is set as the feedback and coordi-nately distributed among the inverter stations of VSC-HVDC,and the rectifier and the inverter stations of LCC-HVDC.Simu-lation results verify that the proposed method can effectively suppress voltage disturbance without relying on remote commu-nication,thus enhancing the operation performance of the HMI-HVDC system.展开更多
基金partially supported by the National Research Programs of China(2022YFA1206500 and 2020YFA0211100)the National Natural Science Foundation of China(52172285 and 52325106)+1 种基金the Suzhou Key Laboratory of Nanotechnology and Biomedicine,the Collaborative Innovation Centre of Suzhou Nano Science and Technologythe 111 Program from the Ministry of Education of China.
文摘Fusobacterium nucleatum(F.nucleatum),an oral anaerobe,is prevalent in colorectal cancer and is closely related to increased cancer cell growth,metastasis,and poor treatment outcomes.Bacterial vaccines capable of selectively eliminating bacteria present a promising approach to targeting intratumor F.nucleatum,thereby enhancing cancer treatment.Although adjuvants have been employed to enhance the immune response,the vaccine’s effectiveness is constrained by inadequate T-cell activation necessary for eradicating intracellular pathogens.In this study,we developed a minimalistic,biomimetic nanovaccine by integrating highly immunostimulatory adjuvant cholesterol-modified CpG oligonucleotides into the autologously derived F.nucleatum membranes.Compared to the traditional vaccines consisting of inactivated bacteria and Alum adjuvant,the nanovaccine coupled with bacterial membranes and adjuvants could remarkably improve multiple antigens and adjuvant co-delivery to dendritic cells,maximizing their ability to achieve effective antigen presentation and strong downstream immune progress.Notably,the nanovaccine exhibits outstanding selective prophylactic and therapeutic effects,eliminating F.nucleatum without affecting intratumoral and gut microbiota.It significantly enhances chemotherapy efficacy and reduces cancer metastasis in F.nucleatum-infected colorectal cancer.Overall,this work represents the rational application of bacterial nanovaccine and provides a blueprint for future development in enhancing the antitumor effect against bacterial-infected cancer.
基金supported by the National Natural Science Foundation of China (No.6200326).
文摘Inertial characteristics of non-cooperative targets are crucial for space capture and sub-sequent on-orbit servicing.Previous methods for identifying inertial parameters involve proximity operations,which are associated with the risk of collision with non-cooperative targets.This paper introduces a long-range,contactless method for identifying the inertial parameters of a non-cooperative target during the pre-capture phase.Specifically,electrostatic interaction is used as an external excitation to alter the target's motion.A force estimation algorithm that uses measure-ments from visual and potential sensors is proposed to estimate the electrostatic interaction and eliminate the need for force sensors.Furthermore,a recursive estimation-identification framework is presented to concurrently estimate the coupled motion state,weak electrostatic interaction,and inertial parameters of the target.The simulation results show that the proposed method extends the identification distance to 170 times that of the previous method while maintaining high identifica-tion precision forall parameters.
基金supported by the Science and Technology Project of State Grid Corporation of China(5500-202258115A-1-1-ZN).
文摘The participation of photovoltaic(PV)plants in supporting the transient voltage caused by commutation failure in the line-commutated-converter-based high voltage direct current(LCC-HVDC)system is of great significance,as it can enhance the DC transmission ability.However,it is found that the gridfollowing(GFL)PV converters face the problem of mismatch between reactive power response and transient voltage characteristic when the voltage converts from low voltage to overvoltage,further aggravating the overvoltage amplitude.Thus,this article proposes a transient voltage support strategy based on the gridforming(GFM)medium voltage PV converter.The proposed strategy takes the advantage of the close equivalent electrical distance between the converter and grid,which can autonomously control the converter terminal voltage through GFM control with adaptive voltage droop coefficient.The simulation results show that the proposed strategy can ensure the output reactive power of the PV converter quickly matches the transient voltage characteristic at different stages,indicating that the proposed strategy can effectively support the transient voltage.
基金This work was supported by the Science and Technology Major Project of Tibetan Autonomous Region of China(No.XZ202201ZD0003G).
文摘The optimal planning and operation of multi-type flexible resources(FRs)are critical prerequisites for maintaining power and energy balance in regional power grids with a high proportion of clean energy.However,insufficient consideration of the multi-dimensional and heterogeneous features of FRs,such as the regulation characteristics of diversified battery energy storage systems(BESSs),poses a challenge in economically relieving imbalance power and adequately sharing feature information between power supply and demand.In view of this disadvantage,an optimal planning and operation method based on differentiated feature matching through response capability characterization and difference quantification of FRs is proposed in this paper.In the planning stage,a model for the optimal planning of diversified energy storages(ESs)including Lithium-ion battery(Li-B),supercapacitor energy storage(SCES),compressed air energy storage(CAES),and pumped hydroelectric storage(PHS)is established.Subsequently,in the operating stage,the potential,direction,and cost of FR response behaviors are refined to match with the power and energy balance demand(PEBD)of power grid operation.An optimal operating algorithm is then employed to quantify the feature differences and output response sequences of multi-type FRs.The performance and effectiveness of the proposed method are demonstrated through comparative studies conducted on an actual regional power grid in northwest China.Analysis and simulation results illustrate that the proposed method can effectively highlight the advantages of BESSs compared with other ESs,and economically reduce imbalance power of the regional power grid under practical operating conditions.
基金supported by the National Natural Science Foundation of China(No.51907134).
文摘Line-commutated converter based high voltage direct current(LCC-HVDC)has been applied for transferring bulk power from wind farms to load centers through long distances in many countries.When the blocking fault of the LCC-HVDC system occurs,the surplus reactive power accumulated at the sending end will lead to an overvoltage,thus causing the discon・nection of the wind turbines.To maintain the reliable connection of wind turbines and ensure the stability of the power system,this paper introduces a superconducting magnetic energy storage(SMES)unit to connect in parallel with the rotor side of the doubly fed induction generator(DFIG).By controlling the energy side converter and rotor side converter to inject demagnetizing current and reactive current into the rotor,the proposed scheme can effectively stabilize key parameters of the wind turbine and provide desirable reactive power support,showing a favorable high voltage ride through(HVRT)performance.Several cases based on PSCAD/EMTDC&MATLAB/Simuiink co-simulation together with economic analysis are conducted to demonstrate the feasibility and superiority of the proposed scheme on enhancing HVRT capability of DFIG-based wind farms.
基金supported by the Research Initiation Fund of Zhejiang Sci-Tech University“Research on the Premium Power Theory Valuation”(No.19022396-Y)。
文摘The valuation of premium power based on perceived utility(PU,i.e.,perceived effectiveness or satisfaction degree of customers)and their willingness to pay has been researched for years.One of the remaining challenges is the accurate evaluation of PU.PU is the foundation of premium power evaluation,and it is essential for the decision-making process of investments on premium power by high-tech manufacturers(HTMs).This paper presents a framework to effectively evaluate PU.In this framework,factors influencing PU were classified to be quantitative and qualitative.An indication system(IS)was then constructed based on those influencing factors.Finally,PU was evaluated by the IS,considering psychological perception and decision-making behavior of HTMs.The effectiveness of the proposed PU-evaluation framework was demonstrated through field case studies.
基金supported by the National Natural Science Foundation of China(No.51907134)。
文摘Experimental and theoretical studies have confirmed that,relative to a one-shot voltage fault,a doubly-fed induction generator(DFIG)will suffer a greater transient impact during continuous voltage faults.This paper presents the design and application of an effective scheme for DFIGs when a commutation failure(CF)occurs in a line-commutated converter based high-voltage direct current(LCC-HVDC)transmission system.First,transient demagnetization control without filters is proposed to offset the electromotive force(EMF)induced by the natural flux and other low-frequency flux components.Then,a rotor-side integrated impedance circuit is designed to limit the rotor overcurrent to ensure that the rotor-side converter(RSC)is controllable.Furthermore,coordinated control of the demagnetization and segmented reactive currents is implemented in the RSC.Comparative studies have shown that the proposed scheme can limit rotor fault currents and effectively improve the continuous fault ride-through capability of DFIGs.
基金supported in part by the National Natural Science Foundation of China under Grants No.62003269Foundation of Science and Technology on Aerospace Flight Dynamics Laboratory(6142210200308).
文摘In order to achieve a straight ballistic trajectory of missile and reduce the update frequency of the missile normal acceleration for the interception of maneuvering target,a backstepping-based parallel approaching guidance method is designed with nonlinear disturbance observer(NDO)technique and event-triggered(ET)mechanism in this paper.In order to suppress the adverse e®ect of target maneuver,the NDO is designed to estimate the target maneuvering acceleration.Then,the NDO-based backstepping method is used to obtain the normal acceleration of missile and realize the parallel approaching guidance.In order to reduce the update frequency of missile normal acceleration,the ET mechanism is employed in the parallel approaching guidance method.If the missile trajectory is relatively straight,the normal acceleration of missile remains unchanged.On the contrary,if the missile trajectory is not straight,the normal acceleration of missile is updated to make the missile trajectory straight.In this way,the ET-based parallel approaching guidance can be obtained.Furthermore,a determined method for the initial missile°ight-path angle is proposed to keep the normal acceleration of missile at zero in the initial stage of interception.Besides,Lyapunov stability analysis method is used to prove that all signals in the closed-loop guidance system are uniformly ultimately bounded.Finally,simulation results show the e®ectiveness of the proposed guidance method.
基金This work was supported in part by the State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources(No.LAPS23020).
文摘During the power modulation process of line com-mutated converter-based high-voltage direct current(LCC-HVDC),the transient power mismatch between the fast-change converter station and the slow-response reactive power compen-sators(RPCs)can cause transient voltage disturbances at the weak sending end of the AC grid.To mitigate such voltage dis-turbances,this paper proposes a coordinated feedback power control method for the hybrid multi-infeed HVDC(HMI-HVDC)system comprising an LCC-HVDC and voltage source converter-based HVDC(VSC-HVDC)systems.The mechanism of the disturbance caused by transient power mismatch is quan-titatively analyzed,and the numerical relationship between the instantaneous unbalanced power and the AC voltage is derived.Based on the numerical relationship and considering the time-varying relationship of reactive power between converter sta-tions,the unbalanced power is set as the feedback and coordi-nately distributed among the inverter stations of VSC-HVDC,and the rectifier and the inverter stations of LCC-HVDC.Simu-lation results verify that the proposed method can effectively suppress voltage disturbance without relying on remote commu-nication,thus enhancing the operation performance of the HMI-HVDC system.
