Monte Carlo simulation was applied to Assembly Success Bate (ASK) analyses. ASR of two peg-in-hole robot assemblies was used as an example by taking component parts' sizes, manufacturing tolerances and robot repea...Monte Carlo simulation was applied to Assembly Success Bate (ASK) analyses. ASR of two peg-in-hole robot assemblies was used as an example by taking component parts' sizes, manufacturing tolerances and robot repeatability into account. A statistic arithmetic expression was proposed and deduced in this paper, which offers an alternative method of estimating the accuracy of ASR, without having to repeat the simulations. This statistic method also helps to choose a suitable sample size, if error reduction is desired. Monte Carlo simulation results demonstrated the feasibility of the method.展开更多
This study presents a structural analysis algorithm called the finite particle method （FPM） for kinematically indeterminate bar assemblies. Different from the traditional analysis method, FPM is based on the combina...This study presents a structural analysis algorithm called the finite particle method （FPM） for kinematically indeterminate bar assemblies. Different from the traditional analysis method, FPM is based on the combination of the vector mechanics and numerical calculations. It models the analyzed domain composed of finite particles. Newton＇s second law is adopted to describe the motions of all particles. A convected material flame and explicit time integration for the solution procedure is also adopted in this method. By using the FPM, there is no need to solve any nonlinear equations, to calculate the stiffness matrix or equilibrium matrix, which is very helpful in the analysis of kinematically indeterminate structures. The basic formulations for the space bar are derived, following its solution procedures for bar assemblies. Three numerical examples are analyzed using the FPM. Results obtained from both the straight pretension cable and the suspension cable assembly show that the FPM can produce a more accurate analysis result. The motion simulation of the four-bar space assembly demonstrates the capability of this method in the analysis ofkinematically indeterminate structures.展开更多
The microvibrations produced by momentum wheel assemblies（MWA） can degrade the performance of instruments with high pointing precision and stability on spacecraft.This paper concentrates on analyzing and testing the...The microvibrations produced by momentum wheel assemblies（MWA） can degrade the performance of instruments with high pointing precision and stability on spacecraft.This paper concentrates on analyzing and testing the microvibrations produced by MWA.We analyze the disturbance sources produced by mass imbalance,structural mode,bearing irregularity and nonlinear stiffness,and random noise;then,test a well-balanced MWA by a highly sensitive measurement system consisting of a Kistler table and an optical tabletop.The results show that the test system has a resolution of less than 0.003 N in the frequency range of 3-300 Hz.The dynamic imbalance of the MWA cannot excite the radial rocking mode,but there are dynamic amplifications when the poly-harmonic disturbances intersect with the structural modes.Especially at high rotational speed（〉3 000 rev/min）,the main disturbance sources of the MWA come from the bearing irregularity interacting with radial translation mode in the high frequency range.Thus,bearing noise deserves more attention for the well-balanced MWA,and alternative of high quality bearings are proposed to reduce the microvibrations.展开更多
Peptide molecules have design flexibility,self-assembly ability,high biocompatibility,good biodegradability,and easy functionalization,which promote their applications as versatile biomaterials for tissue engineering ...Peptide molecules have design flexibility,self-assembly ability,high biocompatibility,good biodegradability,and easy functionalization,which promote their applications as versatile biomaterials for tissue engineering and biomedicine.In addition,the functionalization of self-assembled peptide nanomaterials with other additive components enhances their stimuli-responsive functions,promoting function-specific applications that induced by both internal and external stimulations.In this review,we demonstrate recent advance in the peptide molecular design,self-assembly,functional tailoring,and biomedical applications of peptide-based nanomaterials.The strategies on the design and synthesis of single,dual,and multiple stimuli-responsive peptide-based nanomaterials with various dimensions are analyzed,and the functional regulation of peptide nanomaterials with active components such as metal/metal oxide,DNA/RNA,polysaccharides,photosensitizers,2D materials,and others are discussed.In addition,the designed peptide-based nanomaterials with temperature-,pH-,ion-,light-,enzyme-,and ROS-responsive abilities for drug delivery,bioimaging,cancer therapy,gene therapy,antibacterial,as well as wound healing and dressing applications are presented and discussed.This comprehensive review provides detailed methodologies and advanced techniques on the synthesis of peptide nanomaterials from molecular biology,materials science,and nanotechnology,which will guide and inspire the molecular level design of peptides with specific and multiple functions for function-specific applications.展开更多
Rice is one of the most important staple food for over half of the world＇s population,and a substantial increase in productivity and quality of rice grain will be required to feed a growing human population.Grain siz...Rice is one of the most important staple food for over half of the world＇s population,and a substantial increase in productivity and quality of rice grain will be required to feed a growing human population.Grain size and shape are the two important components contributing to grain yield and quality,because they impact both yield potential and end-use quality.展开更多
The development of high-voltage direct current gas-insulated switchgear assemblies(DC GIS)of rated voltages up to±550 kV has been completed.DC GIS provide a compact technical solution with a high functional densi...The development of high-voltage direct current gas-insulated switchgear assemblies(DC GIS)of rated voltages up to±550 kV has been completed.DC GIS provide a compact technical solution with a high functional density,optimized for projects with limited space as in offshore HVDC converter platforms,onshore HVDC converter stations and transition stations between different transmission media.Up to now,no standards for testing of gas-insulated DC systems are available,although pre-standardization work is in progress within CIGRE.Some tests can be performed as required in AC GIS standards.Special aspects of DC voltage stress,like the electric field distribution of insulators influenced by the accumulation of electrical charge carriers and the operation-related inhomogeneous temperature distribution,must be considered by additional electric and thermoelectric tests.For DC GIS,the experience of long-term performance is limited today.Although ageing is expected to be of lower importance,tests are recommended.This contribution summarizes the physical and technical background to design and develop compact DC switchgear assemblies using gas-insulated technology.It explains the developed modules of the substation and gives an overview of the performed tests.Furthermore,it provides an insight in the on-going standardization activities and describes applications in converter and transition stations,showing its space-saving characteristics.展开更多
The rapid and precise fabrication of multiscale supramolecular assemblies using micro/nanofluidic techniques has emerged as a dynamic area of research in supramolecular chemistry, materials chemistry, and organic chem...The rapid and precise fabrication of multiscale supramolecular assemblies using micro/nanofluidic techniques has emerged as a dynamic area of research in supramolecular chemistry, materials chemistry, and organic chemistry. This review summarizes the application of micro/nanofluidic techniques in constructing supramolecular assemblies, including nanoscale supramolecular assemblies such as macrocycles and cages, microscale supramolecular assemblies such as metal organic frameworks (MOFs) and covalent organic frameworks (COFs), and macroscale supramolecular assemblies such as supramolecular hydrogels. Compared to conventional synthesis methods, micro/nanofluidic techniques for the production of supramolecular assemblies have significant advantages, including enhanced safety, high reaction rates, improved selectivity/yield, and scalability. Additionally, micro/nanofluidic systems facilitate the creation of precisely controllable micro/nanoconfined environments, allowing for a unique flow behavior that improves our understanding of the supramolecular self-assembly process. Such systems may also lead to the development of novel supramolecular assemblies that differ from those generated via traditional methods.展开更多
Comprehensive Summary Poly-NHC-based organometallic assemblies 3-PF6,3-SbF6 and 3-OTf were obtained and verified by NMR spectroscopy,ESI mass spectrometry and single-crystal X-ray diffraction analyses.Controllable str...Comprehensive Summary Poly-NHC-based organometallic assemblies 3-PF6,3-SbF6 and 3-OTf were obtained and verified by NMR spectroscopy,ESI mass spectrometry and single-crystal X-ray diffraction analyses.Controllable structural interconversion was observed between the poly-NHC-based organometallic assemblies and their self-aggregated dimers in solution affected by concentration,solvent and metal ion.1H NMR spectra of assembly 3-PF6 in CD3CN at different concentrations demonstrated controllable structural interconversion,and 19F NMR spectrum of assembly 3-PF6 at high concentration further evidenced the presence of the free hexafluorophosphate anion and encapsulated hexafluorophosphate anion for its two sets of signals.In addition,single-crystal X-ray diffraction analysis provided clear evidence that in the solid state,two assemblies 3-PF6 were vertically stuck,forming a self-aggregated dimer with an encapsulated hexafluorophosphate anion.Investigating the reversible structural interconversion is beneficial for revealing the intrinsic nature on the atom level and paving the way to design the stimuli-responsive functional system.展开更多
In recent years,multicolor cascade supramolecular assemblies with controllable topological morphology have become a research hotspot due to their wide application in light-emitting materials,cell imaging and other fie...In recent years,multicolor cascade supramolecular assemblies with controllable topological morphology have become a research hotspot due to their wide application in light-emitting materials,cell imaging and other fields.Herein,several kinds of macrocycles including cucurbiturils,calixarene and cyclodextrins are used as building blocks to construct fluorescent assemblies with anthryl-conjugated phenylpyridine(G),wherein cucurbit[8]uril(CB[8])and G can form nanowires at a stoichiometric ratio of n:n through host-guest encapsulation to form a non-covalent heterodimer.Significantly,the macrocycle confinement effect drastically enhances the fluorescence emission of G and emission peak generated bathochromic shift from 500 nm to 600 nm.When the supramolecular polymer is further assembled with amphiphilic calix[4]arene(SC_(4)A8),the fluorescence emission of G?CB[8]further increases to 1.4 times,accompanied by the morphological transformation from linear structure to nanorod structure.Subsequently,a very small amount of dye Cy5 is added to the assembly solution as an energy receptor,and the negatively charged G?CB[8]@SC_(4)A8 system is regarded as an energy donor.The efficient energy transfer process enables near-infrared(NIR)emission at 675 nm with 71%energy transfer efficiency(ΦET)at a donor/receptor ratio of 100:1.Finally,the cascade supramolecular assembly has been successfully applied to targeted imaging in the nucleus of HeLa and A549 cancer cells.展开更多
Self-assembly has been extensively studied in chemistry,physics,biology,and materials engineering and has become an important“bottom-up”approach in creating intriguing structures for different applications.Using dis...Self-assembly has been extensively studied in chemistry,physics,biology,and materials engineering and has become an important“bottom-up”approach in creating intriguing structures for different applications.Using dissipative self-assembly to construct fuel-dependent,energy-consuming,and dynamic nonequilibrium systems is important for developing intelligent life-like materials.Furthermore,dissipative self-assembly has become a research hotspot in materials chemistry,biomedical science,environmental chemistry,and physical chemistry.An in-depth understanding of the process and mechanism provides useful insights to the researchers for devel-oping materials using dissipative self-assembly and also helps guide future innovation in material fabrication.This critical review comprehensively analyzes various chemical fuel input and energy consumption mechanisms,supported by numerous illustrative examples.Versatile transient assemblies,including gels,vesicles,micelles,and nanoparticle aggregates,have been systematically studied in our and other laboratories.The relationship between the molecular structure of precursors and temporal assemblies in dissipative self-assemblies is discussed from the perspective of physical chemistry.Using dissipative self-assembly methods to construct functional assemblies provides important implications for constructing high-energy,nonequilibrium,and intelligent functional materials.展开更多
Displays using direct light emission from microscale inorganic light-emitting diodes(μILEDs)have the potential to be very bright and also very power efficient.High-throughput technologies that accurately and cost-eff...Displays using direct light emission from microscale inorganic light-emitting diodes(μILEDs)have the potential to be very bright and also very power efficient.High-throughput technologies that accurately and cost-effectively assemble microscale devices on display substrates with high yield are key enablers forμILED displays.Elastomer stamp transfer printing is such a candidate assembly technology.A variety ofμILED displays have been designed and fabricated by transfer printing,including passive-matrix and active-matrix displays on glass and plastic substrates.展开更多
文摘Monte Carlo simulation was applied to Assembly Success Bate (ASK) analyses. ASR of two peg-in-hole robot assemblies was used as an example by taking component parts' sizes, manufacturing tolerances and robot repeatability into account. A statistic arithmetic expression was proposed and deduced in this paper, which offers an alternative method of estimating the accuracy of ASR, without having to repeat the simulations. This statistic method also helps to choose a suitable sample size, if error reduction is desired. Monte Carlo simulation results demonstrated the feasibility of the method.
基金supported by the National Natural Science Foundation of China (No. 50638050)the National High-Tech R&D (863) Program (No. 2007AA04Z441), China
文摘This study presents a structural analysis algorithm called the finite particle method （FPM） for kinematically indeterminate bar assemblies. Different from the traditional analysis method, FPM is based on the combination of the vector mechanics and numerical calculations. It models the analyzed domain composed of finite particles. Newton＇s second law is adopted to describe the motions of all particles. A convected material flame and explicit time integration for the solution procedure is also adopted in this method. By using the FPM, there is no need to solve any nonlinear equations, to calculate the stiffness matrix or equilibrium matrix, which is very helpful in the analysis of kinematically indeterminate structures. The basic formulations for the space bar are derived, following its solution procedures for bar assemblies. Three numerical examples are analyzed using the FPM. Results obtained from both the straight pretension cable and the suspension cable assembly show that the FPM can produce a more accurate analysis result. The motion simulation of the four-bar space assembly demonstrates the capability of this method in the analysis ofkinematically indeterminate structures.
文摘The microvibrations produced by momentum wheel assemblies（MWA） can degrade the performance of instruments with high pointing precision and stability on spacecraft.This paper concentrates on analyzing and testing the microvibrations produced by MWA.We analyze the disturbance sources produced by mass imbalance,structural mode,bearing irregularity and nonlinear stiffness,and random noise;then,test a well-balanced MWA by a highly sensitive measurement system consisting of a Kistler table and an optical tabletop.The results show that the test system has a resolution of less than 0.003 N in the frequency range of 3-300 Hz.The dynamic imbalance of the MWA cannot excite the radial rocking mode,but there are dynamic amplifications when the poly-harmonic disturbances intersect with the structural modes.Especially at high rotational speed（〉3 000 rev/min）,the main disturbance sources of the MWA come from the bearing irregularity interacting with radial translation mode in the high frequency range.Thus,bearing noise deserves more attention for the well-balanced MWA,and alternative of high quality bearings are proposed to reduce the microvibrations.
基金support from the National Natural Science Foundation of China(No.51873225)the Taishan Scholars Program of Shandong Province(No.tsqn201909104)+1 种基金the High-Grade Talents Plan of Qingdao University.Dr.Kumbar acknowledges the funding support by the National Institutes of Health(#R01NS134604,#R01EB034202,#R01AR078908,#R01EB030060 and,#R56NS122753)the U.S.Army Medical Research Acquisition Activity(USAMRAA),through the CDMRP Peer-Reviewed Medical Research Program(Award No.W81XWH2010321 and PR230581).
文摘Peptide molecules have design flexibility,self-assembly ability,high biocompatibility,good biodegradability,and easy functionalization,which promote their applications as versatile biomaterials for tissue engineering and biomedicine.In addition,the functionalization of self-assembled peptide nanomaterials with other additive components enhances their stimuli-responsive functions,promoting function-specific applications that induced by both internal and external stimulations.In this review,we demonstrate recent advance in the peptide molecular design,self-assembly,functional tailoring,and biomedical applications of peptide-based nanomaterials.The strategies on the design and synthesis of single,dual,and multiple stimuli-responsive peptide-based nanomaterials with various dimensions are analyzed,and the functional regulation of peptide nanomaterials with active components such as metal/metal oxide,DNA/RNA,polysaccharides,photosensitizers,2D materials,and others are discussed.In addition,the designed peptide-based nanomaterials with temperature-,pH-,ion-,light-,enzyme-,and ROS-responsive abilities for drug delivery,bioimaging,cancer therapy,gene therapy,antibacterial,as well as wound healing and dressing applications are presented and discussed.This comprehensive review provides detailed methodologies and advanced techniques on the synthesis of peptide nanomaterials from molecular biology,materials science,and nanotechnology,which will guide and inspire the molecular level design of peptides with specific and multiple functions for function-specific applications.
基金supported by grants from the National Natural Science Foundation of China (No.91635302)the National Key Research and Development Program of China (2016YFD0100401)+1 种基金the Chinese Academy of Sciences (XDA08010101)the State Key Laboratory of Plant Cell and Chromosome Engineering (PCCEKF-2017-04)
文摘Rice is one of the most important staple food for over half of the world＇s population,and a substantial increase in productivity and quality of rice grain will be required to feed a growing human population.Grain size and shape are the two important components contributing to grain yield and quality,because they impact both yield potential and end-use quality.
基金supported by the Federal Ministry for Economic Affairs and Energy, Germany (FKZ:03ET7511C)the Bavarian Ministry of Economic Affairs, Regional Development and Energy (FKZ:IET-1208-0018)
文摘The development of high-voltage direct current gas-insulated switchgear assemblies(DC GIS)of rated voltages up to±550 kV has been completed.DC GIS provide a compact technical solution with a high functional density,optimized for projects with limited space as in offshore HVDC converter platforms,onshore HVDC converter stations and transition stations between different transmission media.Up to now,no standards for testing of gas-insulated DC systems are available,although pre-standardization work is in progress within CIGRE.Some tests can be performed as required in AC GIS standards.Special aspects of DC voltage stress,like the electric field distribution of insulators influenced by the accumulation of electrical charge carriers and the operation-related inhomogeneous temperature distribution,must be considered by additional electric and thermoelectric tests.For DC GIS,the experience of long-term performance is limited today.Although ageing is expected to be of lower importance,tests are recommended.This contribution summarizes the physical and technical background to design and develop compact DC switchgear assemblies using gas-insulated technology.It explains the developed modules of the substation and gives an overview of the performed tests.Furthermore,it provides an insight in the on-going standardization activities and describes applications in converter and transition stations,showing its space-saving characteristics.
基金the National Nature Science Foundation of China (Nos. 22107028 and 22103062)Program of Shanghai Outstanding Academic Leaders (No. 21XD1421200)Science and Technology Commission of Shanghai Municipality (No. 22JC1403900).
文摘The rapid and precise fabrication of multiscale supramolecular assemblies using micro/nanofluidic techniques has emerged as a dynamic area of research in supramolecular chemistry, materials chemistry, and organic chemistry. This review summarizes the application of micro/nanofluidic techniques in constructing supramolecular assemblies, including nanoscale supramolecular assemblies such as macrocycles and cages, microscale supramolecular assemblies such as metal organic frameworks (MOFs) and covalent organic frameworks (COFs), and macroscale supramolecular assemblies such as supramolecular hydrogels. Compared to conventional synthesis methods, micro/nanofluidic techniques for the production of supramolecular assemblies have significant advantages, including enhanced safety, high reaction rates, improved selectivity/yield, and scalability. Additionally, micro/nanofluidic systems facilitate the creation of precisely controllable micro/nanoconfined environments, allowing for a unique flow behavior that improves our understanding of the supramolecular self-assembly process. Such systems may also lead to the development of novel supramolecular assemblies that differ from those generated via traditional methods.
基金supported by the National Natural Science Fund for Distinguished Young Scholars of China(No.22025107)Shaanxi Fundamental Science Research Project for Chemistry&Biology(No.22JHZ003)。
文摘Comprehensive Summary Poly-NHC-based organometallic assemblies 3-PF6,3-SbF6 and 3-OTf were obtained and verified by NMR spectroscopy,ESI mass spectrometry and single-crystal X-ray diffraction analyses.Controllable structural interconversion was observed between the poly-NHC-based organometallic assemblies and their self-aggregated dimers in solution affected by concentration,solvent and metal ion.1H NMR spectra of assembly 3-PF6 in CD3CN at different concentrations demonstrated controllable structural interconversion,and 19F NMR spectrum of assembly 3-PF6 at high concentration further evidenced the presence of the free hexafluorophosphate anion and encapsulated hexafluorophosphate anion for its two sets of signals.In addition,single-crystal X-ray diffraction analysis provided clear evidence that in the solid state,two assemblies 3-PF6 were vertically stuck,forming a self-aggregated dimer with an encapsulated hexafluorophosphate anion.Investigating the reversible structural interconversion is beneficial for revealing the intrinsic nature on the atom level and paving the way to design the stimuli-responsive functional system.
基金National Natural Science Foundation of China(Nos.22131008 and 21971127)the Fundamental Research Funds for the Central Universitiesthe Haihe Laboratory of Sustainable Chemical Transformations for financial support。
文摘In recent years,multicolor cascade supramolecular assemblies with controllable topological morphology have become a research hotspot due to their wide application in light-emitting materials,cell imaging and other fields.Herein,several kinds of macrocycles including cucurbiturils,calixarene and cyclodextrins are used as building blocks to construct fluorescent assemblies with anthryl-conjugated phenylpyridine(G),wherein cucurbit[8]uril(CB[8])and G can form nanowires at a stoichiometric ratio of n:n through host-guest encapsulation to form a non-covalent heterodimer.Significantly,the macrocycle confinement effect drastically enhances the fluorescence emission of G and emission peak generated bathochromic shift from 500 nm to 600 nm.When the supramolecular polymer is further assembled with amphiphilic calix[4]arene(SC_(4)A8),the fluorescence emission of G?CB[8]further increases to 1.4 times,accompanied by the morphological transformation from linear structure to nanorod structure.Subsequently,a very small amount of dye Cy5 is added to the assembly solution as an energy receptor,and the negatively charged G?CB[8]@SC_(4)A8 system is regarded as an energy donor.The efficient energy transfer process enables near-infrared(NIR)emission at 675 nm with 71%energy transfer efficiency(ΦET)at a donor/receptor ratio of 100:1.Finally,the cascade supramolecular assembly has been successfully applied to targeted imaging in the nucleus of HeLa and A549 cancer cells.
基金the National Natural Science Foundation of China(Grant Nos.22032003 and 22072073).
文摘Self-assembly has been extensively studied in chemistry,physics,biology,and materials engineering and has become an important“bottom-up”approach in creating intriguing structures for different applications.Using dissipative self-assembly to construct fuel-dependent,energy-consuming,and dynamic nonequilibrium systems is important for developing intelligent life-like materials.Furthermore,dissipative self-assembly has become a research hotspot in materials chemistry,biomedical science,environmental chemistry,and physical chemistry.An in-depth understanding of the process and mechanism provides useful insights to the researchers for devel-oping materials using dissipative self-assembly and also helps guide future innovation in material fabrication.This critical review comprehensively analyzes various chemical fuel input and energy consumption mechanisms,supported by numerous illustrative examples.Versatile transient assemblies,including gels,vesicles,micelles,and nanoparticle aggregates,have been systematically studied in our and other laboratories.The relationship between the molecular structure of precursors and temporal assemblies in dissipative self-assemblies is discussed from the perspective of physical chemistry.Using dissipative self-assembly methods to construct functional assemblies provides important implications for constructing high-energy,nonequilibrium,and intelligent functional materials.
文摘Displays using direct light emission from microscale inorganic light-emitting diodes(μILEDs)have the potential to be very bright and also very power efficient.High-throughput technologies that accurately and cost-effectively assemble microscale devices on display substrates with high yield are key enablers forμILED displays.Elastomer stamp transfer printing is such a candidate assembly technology.A variety ofμILED displays have been designed and fabricated by transfer printing,including passive-matrix and active-matrix displays on glass and plastic substrates.
