Two sets of super-synchronization speed control assemblies for two 80 MVA motor-generator units have been developed successfully in order to satisfy the demand of the toroidal field system in the HL-2A tokamak. Based ...Two sets of super-synchronization speed control assemblies for two 80 MVA motor-generator units have been developed successfully in order to satisfy the demand of the toroidal field system in the HL-2A tokamak. Based on the three-phase logical no-circumfluence a.c./a.c. cycloconverter, the speeds of two 2500 kW double fed drive motors have been regulated by means of the vector control technology. The maximum operating speed of each motor- generator unit has been raised from 1488 rpm （revolutions per minute） to 1650 rpm and the released energy of each unit during a pulsed discharge can reach 500 MJ. As a result, the toroidal field system has the capacity to provide 2.8 tesla （T） in HL-2A experiments.展开更多
The controlled self-assembly of discrete metal-organic nanocapsules(MONCs),and metal-organic frameworks(MOFs)based on the MONCs are achieved.Specifically,the solvothermal reaction of nickel nitrate hexahydrate and C-m...The controlled self-assembly of discrete metal-organic nanocapsules(MONCs),and metal-organic frameworks(MOFs)based on the MONCs are achieved.Specifically,the solvothermal reaction of nickel nitrate hexahydrate and C-methylpyrogallol[4]arene in mixed DMF/MeOH solution leads to the unexpected form of discrete nickel-seamed hexameric pyrogallol[4]arene MONCs,and MONC-based three-dimensional(3D)MOF.Notably,the latter MOF is constructed from the aforementioned nickelseamed MONC building blocks and formate linkers in-situ generated from the hydrolysis of DMF solve nt.Interestingly,introducing pyridine and formic acid in the reaction conditions leads to the controlled assemblies of the discrete MONC and MONC-based 3D MOF structures.Moreover,the variabletemperature magnetic susceptibilities of both the abovementioned compounds have been investigated,indicating typical antiferromagnetic interactions between the metal centers.展开更多
To eliminate the load weight limit of carrier rockets and reduce the burden on support structures,in-orbit assembly is a key technology to make design of scattering a large diameter telescope into submirror modules,wh...To eliminate the load weight limit of carrier rockets and reduce the burden on support structures,in-orbit assembly is a key technology to make design of scattering a large diameter telescope into submirror modules,which requires smooth operation of assembly robots,and flexible force control technology is necessary. A ground demonstration system is presented for in-orbit assembly focusing on flexible force control. A six-dimensional force/torque sensor and its data acquisition system are used to compensate for gravity. For translation and rotation,an algorithm for flexible control is proposed. A ground transportation demonstration verifies accuracy and smoothness of flexible force control,and the transportation and assembly task is completed automatically. The proposed system is suitable for the development of in-orbit assembly robots.展开更多
The attitude control system design and its control effect are affected considerably by the mass-property parameters of the spacecraft. In the mission of on-orbit servicing, as fuel is expended, or the payloads are add...The attitude control system design and its control effect are affected considerably by the mass-property parameters of the spacecraft. In the mission of on-orbit servicing, as fuel is expended, or the payloads are added or removed, the center of mass will be changed in certain axe; consequently, some thrusters＇ directions are deviated from the center of mass（CM） in certain plane. The CM of assembled spacecraft estimation and thruster direction control are studied. Firstly, the attitude dynamics of the assembled spacecraft is established based on the Newton-Euler method. Secondly, the estimation can be identified by the least recursive squares algorithm. Then, a scheme to control the thrusters＇ directions is proposed. By using the gimbal installed at the end of the boom, the angle of the thruster is controlled by driving the gimbal; therefore, thrusters can be directed to the CM again. Finally, numerical simulations are used to verify this scheme. Results of the numerical simulations clearly show that this control scheme is rational and feasible.展开更多
An electrochemical biosensing platform was developed based on glucose oxidase(GOx)/Fe3O4-reduced graphene oxide(Fe3O4-RGO) nanosheets loaded on the magnetic glassy carbon electrode(MGCE).With the advantages of the mag...An electrochemical biosensing platform was developed based on glucose oxidase(GOx)/Fe3O4-reduced graphene oxide(Fe3O4-RGO) nanosheets loaded on the magnetic glassy carbon electrode(MGCE).With the advantages of the magnetism, conductivity and biocompatibility of the Fe3O4-RGO nanosheets, the nanocomposites could be facilely adhered to the electrode surface by magnetically controllable assembling and beneficial to achieve the direct redox reactions and electrocatalytic behaviors of GOx immobilized into the nanocomposites. The biosensor exhibited good electrocatalytic activity, high sensitivity and stability. The current response is linear over glucose concentration ranging from 0.05 to 1.5 m M with a low detection limit of0.15 μM. Meanwhile, validation of the applicability of the biosensor was carried out by determining glucose in serum samples. The proposed protocol is simple, inexpensive and convenient, which shows great potential in biosensing application.展开更多
Based on the problems of complex assembly process route, low resource utilization, low assembly efficiency and low quality in the production process of assembly workshop, a knowledge-based intelligent assembly worksho...Based on the problems of complex assembly process route, low resource utilization, low assembly efficiency and low quality in the production process of assembly workshop, a knowledge-based intelligent assembly workshop management and control mode is proposed. By constructing an intelligent assembly workshop with real assembly workshop, knowledge assembly workshop and assembly workshop management and control system working together, On the basis of realizing real-time information collection of resource location information, assembly process information and assembly quality information, Euclidean distance algorithm, Markov method and Manhattan distance algorithm are used to realize resource optimization scheduling, assembly process and quality control.展开更多
Despite extensive research on magnetic skyrmions and antiskyrmions,a significant challenge remains in crafting nontrivial high-order skyrmionic textures with varying,or even tailor-made,topologies.We address this chal...Despite extensive research on magnetic skyrmions and antiskyrmions,a significant challenge remains in crafting nontrivial high-order skyrmionic textures with varying,or even tailor-made,topologies.We address this challenge,by focusing on a construction pathway of skyrmionic metamaterials within a monolayer thin film and suggest several skyrmionic metamaterials that are surprisingly stable,i.e.,long-lived,due to a self-stabilization mechanism.This makes these new textures promising for applications.Central to our approach is the concept of’simulated controlled assembly’,in short,a protocol inspired by’click chemistry’that allows for positioning topological magnetic structures where one likes,and then allowing for energy minimization to elucidate the stability.Utilizing high-throughput atomistic-spin-dynamic simulations alongside state-of-the-art AI-driven tools,we have isolated skyrmions(topological charge Q=1),antiskyrmions(Q=−1),and skyrmionium(Q=0).These entities serve as foundational’skyrmionic building blocks’to form the here-reported intricate textures.In this work,two key contributions are introduced to the field of skyrmionic systems.First,we present a novel combination of atomistic spin dynamics simulations and controlled assembly protocols for the stabilization and investigation of new topological magnets.Second,using the aforementioned methods we report on the discovery of skyrmionic metamaterials.展开更多
Research into controlling the self-assembly of discrete porous organic cages(POCs)with specific geometries and functions is difficult,but important for understanding their structure-property relationship,as well as se...Research into controlling the self-assembly of discrete porous organic cages(POCs)with specific geometries and functions is difficult,but important for understanding their structure-property relationship,as well as self-assembly behavior in supramolecular chemistry.Herein,we report the self-assembly of two POCs based on the same tetraformyl-functionalized calix[4]resorcinarene(C4RACHO)and 2,4-diaminophenol dihydrochloride(DAP)organic building blocks,including a[3+6]triangular prism(CPOC-201-OH)and a[4+8]square prism(CPOC-401-OH),as determined by single X-ray crystallographic analysis.Both POCs exhibit large intrinsic cavities,rich oxygen sites,and high porosity with Brunauer-Emmett-Teller(BET)specific surface areas up to 966 m^(2)·g^(-1).Owing to such virtues,both cages can effectively capture iodine in aqueous media with removal rate>99%within 2 min.展开更多
Thin-film materials with flexibility and stretchability are essential for wearable smart technologies.However,achieving both superior mechanical properties and multi-stimuli responsiveness in ultrathin films remains a...Thin-film materials with flexibility and stretchability are essential for wearable smart technologies.However,achieving both superior mechanical properties and multi-stimuli responsiveness in ultrathin films remains a significant challenge.Herein,we report a novel class of multifunctional thin-film materials fabricated via dynamic covalent self-assembly of two key components:a renowned aggregation-induced emission(AIE)luminogen,tetraphenylethylene with four benzaldehyde groups(TTPE-CHO),serving as the emissive and rigid backbone,and hydrazide-functionalized polyethylene glycol(PEG 400 and PEG 600)chains,imparting flexibility.The resulting films exhibit green fluorescence,high flexibility,stretchability,anisotropic morphological features,and multiple stimuli-responsive properties—capabilities that are severely limited in the absence of PEG chains.Remarkably,even at an ultrathin thickness of only 4μm,the TTPE-DTH-400-G film achieves a record-breaking tensile stress of 47 MPa,demonstrating outstanding mechanical strength and elasticity.Furthermore,it enables reversible vapor-triggered actuation and exhibits exceptional fluorescence sensing performance for detecting the sarin analog diethyl chlorophosphate(DCP),with an ultralow detection limit of 1 ppt and a rapid response time.This study presents an effective strategy for integrating rigid and flexible components to construct functional thin films with superior mechanical properties and intelligent responsiveness,paving the way for advanced applications in wearable electronics and real-time hazardous substance detection.展开更多
Mesoporous carbon nanomaterials have shown a great application potential in energy storage and conversion fields due to their outstanding conductivity,tunable pore structure,and good chemical stability.Nevertheless,ho...Mesoporous carbon nanomaterials have shown a great application potential in energy storage and conversion fields due to their outstanding conductivity,tunable pore structure,and good chemical stability.Nevertheless,how to accurately control the pore structure,especially directly assembling the mesoporous carbon onto different substrates remains a big challenge.Herein,we have successfully assembled two kinds of highly nitrogen-doped mesoporous carbon onto carbon nanotubes(NMC/CNTs)based on a facile cooperative assembly process assisted by triblock PEO_(20)PPO_(70)PEO_(20)(P123)and PEO_(106)PPO_(70)PEO_(106)(F127)copolymers.The experimental results indicate that the P_(123)/F_(127)mass ratio has a profound effect on the pore structure,leading to the formation of NMC/CNTs composites with spherical pore structure(S-NMC/CNTs)and cylindrical pore structure(CNMC/CNTs).In virtue of fast electron/ion transfer kinetics,the as-prepared S-NMC/CNTs anode demonstrates an excellent electrochemical performance for lithium-ion batteries,and it delivers a high reversible capacity of 588.1 mAh∙g^(−1)at the current of 0.1 A∙g^(−1)after 100 cycles,along with a superior cycling stability.Specifically noted,the controlled assembly route developed in our work can also be applied to other support materials with different structures and compositions.展开更多
While self-assembly is relatively well-known and widely used to form hierarchical structures and thin film coatings,controlled assembly is less known and utilized.Our prior work has demonstrated the concept of control...While self-assembly is relatively well-known and widely used to form hierarchical structures and thin film coatings,controlled assembly is less known and utilized.Our prior work has demonstrated the concept of controlled assembly of macromolecules such as star polymers[molecular weight(M_(w))∼383 kDa,hydrodynamic radius R∼13.8 nm]in droplets.This work extends this concept to smaller molecules,in this case,poly(ethylene glycol)bis-tetrazine(PEGbisTz,M_(w) 8.1 kDa,R∼1.5 nm).The key to controlled molecular assembly is to first deliver ultrasmall volumes(sub-fL)of solution containing PEG-bisTz to a substrate.The solvent evaporates rapidly due to the minute volume,thus forcing the assembly of solute,whose overall size and dimension are dictated by the initial liquid geometry and size.Using prepatterned surfaces,this work revealed that the initial liquid shape can be further tuned,and we could control the final assembly of solute such as PEGbisTz molecules.The degree of control was demonstrated by varying the micropatterns and delivery conditions.This work demonstrated the validity of controlled assembly for PEG-bisTz and enables three-dimensional(3D)nanoprinting of functional materials.The technology has promising applications in nanophotonics,nanoelectronics,nanocomposite materials,and tissue engineering.展开更多
We report a novel strategy to control and construct sequential assembly of DNA functionalized gold nanoparticles(AuNPs)from a single solution.We systematically investigated the temperature-dependent kinetics of DNA-li...We report a novel strategy to control and construct sequential assembly of DNA functionalized gold nanoparticles(AuNPs)from a single solution.We systematically investigated the temperature-dependent kinetics of DNA-linked AuNP assembly.A sharp kinetic transition in the assembly process,strongly dependent on temperature,was identified.As the temperature increased,the assembly rate rose continuously until it reached a critical kinetic temperature(T_(crit)).Beyond this point,the assembly rate sharply decreased to near zero within a narrow temperature window of 2–3℃.This sharp kinetic transition is advantageous for designing highly specific detection systems.We leveraged the transition to control the assembly of AuNPs functionalized with DNA strands that differ by single-base mismatches.Using AuNPs of different sizes,we demonstrated the sequential assembly of AuNPs functionalized with perfectly matched DNA strands,followed by assembly of AuNPs with DNA containing a single-base mismatch,and finally assembly of AuNPs with DNA containing two-base mismatches.We also first assembled AuNPs functionalized with DNA containing two-base mismatches at a lower temperature,followed by assembling AuNPs with DNA containing a single-base mismatch at a higher temperature.Both approaches of controlled sequential assembly are useful for bottom-up assembly applications to form desirable nanostructures.展开更多
With unique physicochemical properties and biological effects,magnetic nanomaterials(MNMs)play a crucial role in the biomedical field.In particular,magnetic iron oxide nanoparticles(MIONPs)are approved by the United S...With unique physicochemical properties and biological effects,magnetic nanomaterials(MNMs)play a crucial role in the biomedical field.In particular,magnetic iron oxide nanoparticles(MIONPs)are approved by the United States Food and Drug Administration(FDA)for clinical applications at present due to their low toxicity,biocompatibility,and biodegradability.Despite the unarguable effectiveness,massive space for improving such materials'performance still needs to be filled.Recently,many efforts have been devoted to improving the preparation methods based on the materials'biosafety.Besides,researchers have successfully.regulated the performance of magnetic nanoparticles(MNPs)by changing their sizes,morphologies,compositions;or by.aggregating as-synthesized MNPs in an orderly arrangement to meet various clinical requirements.The rise of cloud computing and artificial intelligence techniques provides novel ways for fast material characterization,automated data analysis,and mechanism demonstration.In this review,we summarized the studies that focused on the preparation routes and performance regulations of high-quality MNPs,and their special properties applied in biomedical detection,diagnosis,and treatment.At the same time,the future.development of MNMs was also discussed.展开更多
This paper deals with the problem of planned lead time calculation in a Material Requirement Planning （MRP） environment under stochastic lead times. The objective is to minimize the sum of holding and backlogging co...This paper deals with the problem of planned lead time calculation in a Material Requirement Planning （MRP） environment under stochastic lead times. The objective is to minimize the sum of holding and backlogging costs. The proposed approach is based on discrete time inventory control where the decision variables are integer. Two types of systems are considered： multi-level serial-production and assembly systems. For the serial production systems （one type of component at each level）, a mathematical model is suggested. Then, it is proven that this model is equivalent to the well known discrete Newsboy Model. This directly provides the optimal values for the planned lead times. For multilevel assembly systems, a dedicated model is proposed and some properties of the decision variables and objective function are proven. These properties are used to calculate lower and upper limits on the decision variables and lower and upper bounds on the objective function. The obtained limits and bounds open the possibility to develop an efficient optimization algorithm using, for example, a Branch and Bound approach. The paper presents the proposed models in detail with corresponding proofs and se＇~eral numerical examples. Some advantages of the suggested models and perspectives of this research are discussed.展开更多
基金the Tenth-Five-Year Nuclear Energy Development of the Commission of Science and TechnologyNational Defense Industry of the China National Nuclear Corporation
文摘Two sets of super-synchronization speed control assemblies for two 80 MVA motor-generator units have been developed successfully in order to satisfy the demand of the toroidal field system in the HL-2A tokamak. Based on the three-phase logical no-circumfluence a.c./a.c. cycloconverter, the speeds of two 2500 kW double fed drive motors have been regulated by means of the vector control technology. The maximum operating speed of each motor- generator unit has been raised from 1488 rpm （revolutions per minute） to 1650 rpm and the released energy of each unit during a pulsed discharge can reach 500 MJ. As a result, the toroidal field system has the capacity to provide 2.8 tesla （T） in HL-2A experiments.
基金the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB20000000)the National Nature Science Foundation of China(No.51603206)the Nature Science Foundation of Fujian Province(No.2016J05056)。
文摘The controlled self-assembly of discrete metal-organic nanocapsules(MONCs),and metal-organic frameworks(MOFs)based on the MONCs are achieved.Specifically,the solvothermal reaction of nickel nitrate hexahydrate and C-methylpyrogallol[4]arene in mixed DMF/MeOH solution leads to the unexpected form of discrete nickel-seamed hexameric pyrogallol[4]arene MONCs,and MONC-based three-dimensional(3D)MOF.Notably,the latter MOF is constructed from the aforementioned nickelseamed MONC building blocks and formate linkers in-situ generated from the hydrolysis of DMF solve nt.Interestingly,introducing pyridine and formic acid in the reaction conditions leads to the controlled assemblies of the discrete MONC and MONC-based 3D MOF structures.Moreover,the variabletemperature magnetic susceptibilities of both the abovementioned compounds have been investigated,indicating typical antiferromagnetic interactions between the metal centers.
基金Supported by the National Natural Science Foundation of China(No.11672290)
文摘To eliminate the load weight limit of carrier rockets and reduce the burden on support structures,in-orbit assembly is a key technology to make design of scattering a large diameter telescope into submirror modules,which requires smooth operation of assembly robots,and flexible force control technology is necessary. A ground demonstration system is presented for in-orbit assembly focusing on flexible force control. A six-dimensional force/torque sensor and its data acquisition system are used to compensate for gravity. For translation and rotation,an algorithm for flexible control is proposed. A ground transportation demonstration verifies accuracy and smoothness of flexible force control,and the transportation and assembly task is completed automatically. The proposed system is suitable for the development of in-orbit assembly robots.
基金supported by the National Natural Science Foundation of China(11302010)
文摘The attitude control system design and its control effect are affected considerably by the mass-property parameters of the spacecraft. In the mission of on-orbit servicing, as fuel is expended, or the payloads are added or removed, the center of mass will be changed in certain axe; consequently, some thrusters＇ directions are deviated from the center of mass（CM） in certain plane. The CM of assembled spacecraft estimation and thruster direction control are studied. Firstly, the attitude dynamics of the assembled spacecraft is established based on the Newton-Euler method. Secondly, the estimation can be identified by the least recursive squares algorithm. Then, a scheme to control the thrusters＇ directions is proposed. By using the gimbal installed at the end of the boom, the angle of the thruster is controlled by driving the gimbal; therefore, thrusters can be directed to the CM again. Finally, numerical simulations are used to verify this scheme. Results of the numerical simulations clearly show that this control scheme is rational and feasible.
基金supported by the National Natural Science Foundation of China (21373138)Shanghai Sci. & Tech. Committee (12JC1407200)Program for Changjiang Scholars and Innovative Research Team in University (IRT1269)
文摘An electrochemical biosensing platform was developed based on glucose oxidase(GOx)/Fe3O4-reduced graphene oxide(Fe3O4-RGO) nanosheets loaded on the magnetic glassy carbon electrode(MGCE).With the advantages of the magnetism, conductivity and biocompatibility of the Fe3O4-RGO nanosheets, the nanocomposites could be facilely adhered to the electrode surface by magnetically controllable assembling and beneficial to achieve the direct redox reactions and electrocatalytic behaviors of GOx immobilized into the nanocomposites. The biosensor exhibited good electrocatalytic activity, high sensitivity and stability. The current response is linear over glucose concentration ranging from 0.05 to 1.5 m M with a low detection limit of0.15 μM. Meanwhile, validation of the applicability of the biosensor was carried out by determining glucose in serum samples. The proposed protocol is simple, inexpensive and convenient, which shows great potential in biosensing application.
文摘Based on the problems of complex assembly process route, low resource utilization, low assembly efficiency and low quality in the production process of assembly workshop, a knowledge-based intelligent assembly workshop management and control mode is proposed. By constructing an intelligent assembly workshop with real assembly workshop, knowledge assembly workshop and assembly workshop management and control system working together, On the basis of realizing real-time information collection of resource location information, assembly process information and assembly quality information, Euclidean distance algorithm, Markov method and Manhattan distance algorithm are used to realize resource optimization scheduling, assembly process and quality control.
基金support from the Swedish Research Council(grant numbers VR 2016-05980,VR 2019-05304,2022-04720,and 2023-04239)the Knut and Alice Wallenberg Foundation(grant numbers 2018.0060,2021.0246,and 2022.0108)is acknowledged.A.D.and O.E.acknowledge support from the Wallenberg Initiative Materials Science for Sustainability(WISE),funded by the Knut and Alice Wallenberg Foundation(KAW).Q.X.acknowledges financial support from the China Scholarship Council(201906920083)+5 种基金I.P.M.acknowledges support from the Crafoord Foundation(Grant No.20231063)A.E.acknowledges financial support fromÅForsk(22-441)the Göran Gustafsson Foundation.A.B.and O.E acknowledges support from eSSENCEThe computations were enabled by resources provided by theNational Academic Infrastructure for Supercomputing in Sweden(NAISS)the Swedish National Infrastructure for Computing(SNIC)at NSC and PDC,partially funded by the Swedish Research Council through grant agreements No.2022-06725 and no.2018-05973GPU resources are provided by KAW(Berzelius-2022-141).
文摘Despite extensive research on magnetic skyrmions and antiskyrmions,a significant challenge remains in crafting nontrivial high-order skyrmionic textures with varying,or even tailor-made,topologies.We address this challenge,by focusing on a construction pathway of skyrmionic metamaterials within a monolayer thin film and suggest several skyrmionic metamaterials that are surprisingly stable,i.e.,long-lived,due to a self-stabilization mechanism.This makes these new textures promising for applications.Central to our approach is the concept of’simulated controlled assembly’,in short,a protocol inspired by’click chemistry’that allows for positioning topological magnetic structures where one likes,and then allowing for energy minimization to elucidate the stability.Utilizing high-throughput atomistic-spin-dynamic simulations alongside state-of-the-art AI-driven tools,we have isolated skyrmions(topological charge Q=1),antiskyrmions(Q=−1),and skyrmionium(Q=0).These entities serve as foundational’skyrmionic building blocks’to form the here-reported intricate textures.In this work,two key contributions are introduced to the field of skyrmionic systems.First,we present a novel combination of atomistic spin dynamics simulations and controlled assembly protocols for the stabilization and investigation of new topological magnets.Second,using the aforementioned methods we report on the discovery of skyrmionic metamaterials.
基金supported by the National Nature Science Foundation of China(22071244,22275191)Youth Innovation Promotion Association CAS(2022305)+1 种基金Natural Science Foundation of Fujian Province of China(2022J01503,2020J05087)Self-deployment Project Research Program of Haixi Institutes,Chinese Academy of Sciences(CXZX-2022-GH01).
文摘Research into controlling the self-assembly of discrete porous organic cages(POCs)with specific geometries and functions is difficult,but important for understanding their structure-property relationship,as well as self-assembly behavior in supramolecular chemistry.Herein,we report the self-assembly of two POCs based on the same tetraformyl-functionalized calix[4]resorcinarene(C4RACHO)and 2,4-diaminophenol dihydrochloride(DAP)organic building blocks,including a[3+6]triangular prism(CPOC-201-OH)and a[4+8]square prism(CPOC-401-OH),as determined by single X-ray crystallographic analysis.Both POCs exhibit large intrinsic cavities,rich oxygen sites,and high porosity with Brunauer-Emmett-Teller(BET)specific surface areas up to 966 m^(2)·g^(-1).Owing to such virtues,both cages can effectively capture iodine in aqueous media with removal rate>99%within 2 min.
基金supported by the National Key Research and Development Program of China(2022YFA12055002)the National Natural Science Foundation of China(22272101,22427802)the Program of Introducing Talents of Discipline to Universities(“111”project,B14041)。
文摘Thin-film materials with flexibility and stretchability are essential for wearable smart technologies.However,achieving both superior mechanical properties and multi-stimuli responsiveness in ultrathin films remains a significant challenge.Herein,we report a novel class of multifunctional thin-film materials fabricated via dynamic covalent self-assembly of two key components:a renowned aggregation-induced emission(AIE)luminogen,tetraphenylethylene with four benzaldehyde groups(TTPE-CHO),serving as the emissive and rigid backbone,and hydrazide-functionalized polyethylene glycol(PEG 400 and PEG 600)chains,imparting flexibility.The resulting films exhibit green fluorescence,high flexibility,stretchability,anisotropic morphological features,and multiple stimuli-responsive properties—capabilities that are severely limited in the absence of PEG chains.Remarkably,even at an ultrathin thickness of only 4μm,the TTPE-DTH-400-G film achieves a record-breaking tensile stress of 47 MPa,demonstrating outstanding mechanical strength and elasticity.Furthermore,it enables reversible vapor-triggered actuation and exhibits exceptional fluorescence sensing performance for detecting the sarin analog diethyl chlorophosphate(DCP),with an ultralow detection limit of 1 ppt and a rapid response time.This study presents an effective strategy for integrating rigid and flexible components to construct functional thin films with superior mechanical properties and intelligent responsiveness,paving the way for advanced applications in wearable electronics and real-time hazardous substance detection.
基金the Shuguang Program supported by Shanghai Education Development Foundation and Shanghai Municipal Education Commission(No.18SG35)the Basic Research Program of Shanghai Municipal Government(No.21JC1406002)the Shanghai Engineering Research Center of Advanced Thermal Functional Materials(Shanghai Polytechnic University).
文摘Mesoporous carbon nanomaterials have shown a great application potential in energy storage and conversion fields due to their outstanding conductivity,tunable pore structure,and good chemical stability.Nevertheless,how to accurately control the pore structure,especially directly assembling the mesoporous carbon onto different substrates remains a big challenge.Herein,we have successfully assembled two kinds of highly nitrogen-doped mesoporous carbon onto carbon nanotubes(NMC/CNTs)based on a facile cooperative assembly process assisted by triblock PEO_(20)PPO_(70)PEO_(20)(P123)and PEO_(106)PPO_(70)PEO_(106)(F127)copolymers.The experimental results indicate that the P_(123)/F_(127)mass ratio has a profound effect on the pore structure,leading to the formation of NMC/CNTs composites with spherical pore structure(S-NMC/CNTs)and cylindrical pore structure(CNMC/CNTs).In virtue of fast electron/ion transfer kinetics,the as-prepared S-NMC/CNTs anode demonstrates an excellent electrochemical performance for lithium-ion batteries,and it delivers a high reversible capacity of 588.1 mAh∙g^(−1)at the current of 0.1 A∙g^(−1)after 100 cycles,along with a superior cycling stability.Specifically noted,the controlled assembly route developed in our work can also be applied to other support materials with different structures and compositions.
基金supported by the National Science Foundation(nos.CHE-1808829 and DMR 1809612)National Institutes of Health(no.R01DC014461)the United States,and the Gordon and Betty Moore Foundation.
文摘While self-assembly is relatively well-known and widely used to form hierarchical structures and thin film coatings,controlled assembly is less known and utilized.Our prior work has demonstrated the concept of controlled assembly of macromolecules such as star polymers[molecular weight(M_(w))∼383 kDa,hydrodynamic radius R∼13.8 nm]in droplets.This work extends this concept to smaller molecules,in this case,poly(ethylene glycol)bis-tetrazine(PEGbisTz,M_(w) 8.1 kDa,R∼1.5 nm).The key to controlled molecular assembly is to first deliver ultrasmall volumes(sub-fL)of solution containing PEG-bisTz to a substrate.The solvent evaporates rapidly due to the minute volume,thus forcing the assembly of solute,whose overall size and dimension are dictated by the initial liquid geometry and size.Using prepatterned surfaces,this work revealed that the initial liquid shape can be further tuned,and we could control the final assembly of solute such as PEGbisTz molecules.The degree of control was demonstrated by varying the micropatterns and delivery conditions.This work demonstrated the validity of controlled assembly for PEG-bisTz and enables three-dimensional(3D)nanoprinting of functional materials.The technology has promising applications in nanophotonics,nanoelectronics,nanocomposite materials,and tissue engineering.
基金supported by the Canadian Institutes for Health Research,the Natural Sciences and Engineering Research Council of Canada,and the Canada Research Chairs program.
文摘We report a novel strategy to control and construct sequential assembly of DNA functionalized gold nanoparticles(AuNPs)from a single solution.We systematically investigated the temperature-dependent kinetics of DNA-linked AuNP assembly.A sharp kinetic transition in the assembly process,strongly dependent on temperature,was identified.As the temperature increased,the assembly rate rose continuously until it reached a critical kinetic temperature(T_(crit)).Beyond this point,the assembly rate sharply decreased to near zero within a narrow temperature window of 2–3℃.This sharp kinetic transition is advantageous for designing highly specific detection systems.We leveraged the transition to control the assembly of AuNPs functionalized with DNA strands that differ by single-base mismatches.Using AuNPs of different sizes,we demonstrated the sequential assembly of AuNPs functionalized with perfectly matched DNA strands,followed by assembly of AuNPs with DNA containing a single-base mismatch,and finally assembly of AuNPs with DNA containing two-base mismatches.We also first assembled AuNPs functionalized with DNA containing two-base mismatches at a lower temperature,followed by assembling AuNPs with DNA containing a single-base mismatch at a higher temperature.Both approaches of controlled sequential assembly are useful for bottom-up assembly applications to form desirable nanostructures.
基金supported by the National Key Research and Development Program of China(No.2017YFA0104302)the National Natural Science Foundation of China(Nos.51832001,61821002,and 31800843)。
文摘With unique physicochemical properties and biological effects,magnetic nanomaterials(MNMs)play a crucial role in the biomedical field.In particular,magnetic iron oxide nanoparticles(MIONPs)are approved by the United States Food and Drug Administration(FDA)for clinical applications at present due to their low toxicity,biocompatibility,and biodegradability.Despite the unarguable effectiveness,massive space for improving such materials'performance still needs to be filled.Recently,many efforts have been devoted to improving the preparation methods based on the materials'biosafety.Besides,researchers have successfully.regulated the performance of magnetic nanoparticles(MNPs)by changing their sizes,morphologies,compositions;or by.aggregating as-synthesized MNPs in an orderly arrangement to meet various clinical requirements.The rise of cloud computing and artificial intelligence techniques provides novel ways for fast material characterization,automated data analysis,and mechanism demonstration.In this review,we summarized the studies that focused on the preparation routes and performance regulations of high-quality MNPs,and their special properties applied in biomedical detection,diagnosis,and treatment.At the same time,the future.development of MNMs was also discussed.
文摘This paper deals with the problem of planned lead time calculation in a Material Requirement Planning （MRP） environment under stochastic lead times. The objective is to minimize the sum of holding and backlogging costs. The proposed approach is based on discrete time inventory control where the decision variables are integer. Two types of systems are considered： multi-level serial-production and assembly systems. For the serial production systems （one type of component at each level）, a mathematical model is suggested. Then, it is proven that this model is equivalent to the well known discrete Newsboy Model. This directly provides the optimal values for the planned lead times. For multilevel assembly systems, a dedicated model is proposed and some properties of the decision variables and objective function are proven. These properties are used to calculate lower and upper limits on the decision variables and lower and upper bounds on the objective function. The obtained limits and bounds open the possibility to develop an efficient optimization algorithm using, for example, a Branch and Bound approach. The paper presents the proposed models in detail with corresponding proofs and se＇~eral numerical examples. Some advantages of the suggested models and perspectives of this research are discussed.
