We consider the inverse problem of finding guiding pattern shapes that result in desired self-assembly morphologies of block copolymer melts.Specifically,we model polymer selfassembly using the self-consistent field t...We consider the inverse problem of finding guiding pattern shapes that result in desired self-assembly morphologies of block copolymer melts.Specifically,we model polymer selfassembly using the self-consistent field theory and derive,in a non-parametric setting,the sensitivity of the dissimilarity between the desired and the actual morphologies to arbitrary perturbations in the guiding pattern shape.The sensitivity is then used for the optimization of the confining pattern shapes such that the dissimilarity between the desired and the actual morphologies is minimized.The efficiency and robustness of the proposed gradient-based algorithm are demonstrated in a number of examples related to templating vertical interconnect accesses(VIA).展开更多
Directed self-assembly has been used to create micro-nano scale patterns,including chiral periodic structures of organic molecules,for potential applications in optics,photonics,metamaterials,and medical and sensing t...Directed self-assembly has been used to create micro-nano scale patterns,including chiral periodic structures of organic molecules,for potential applications in optics,photonics,metamaterials,and medical and sensing technologies.This study presents a straightforward approach for fabricating large-scale chiral grating porphyrin assemblies through template-assisted techniques.The solution of tetrakis(4-sulfonatophenyl)porphyrin(TPPS)was induced by chiral amino acids(L/D-arginine and L/D-serine)to selfassemble into highly ordered chiral grating structures with the assistance of sodium dodecyl sulfate(SDS).The structures show precise line widths(5.5μm)and gaps(18μm).Using in situ optical microscopy and second harmonic generation(SHG)microscopy,the chiral characteristics and dynamic evolution of the template-assisted self-assembly are investigated.It is found that the chirality of amino acids induced TPPS self-assembled into chiral structures and the liquid contraction interface significantly enhanced the chirality of the assemblies.This study is significant for understanding the mechanism of chiral evolution and designing novel micro-nano materials with predetermined chiral properties.展开更多
Directed self-assembly(DSA)emerges as one of the most promising new patterning techniques for single digit miniaturization and next generation lithography.DSA achieves high-resolution patterning by molecular assembly ...Directed self-assembly(DSA)emerges as one of the most promising new patterning techniques for single digit miniaturization and next generation lithography.DSA achieves high-resolution patterning by molecular assembly that circumvents the diffraction limit of conventional photolithography.Recently,the International Roadmap for Devices and Systems listed DSA as one of the advanced lithography techniques for the fabrication of 3-5 nm technology node devices.DSA can be combined with other lithography techniques,such as extreme ultra violet(EUV)and 193 nm immersion(193i),to further enhance the patterning resolution and the device density.So far,DSA has demonstrated its superior ability for the fabrication of nanoscale devices,such as fin field effect transistor and bit pattern media,offering a variety of configurations for high-density integration and low-cost manufacturing.Over 1 T in-2 device density can be achieved either by direct templating or coupled with nanoimprinting to improve the throughput.The development of high x block copolymer further enhances the patterning resolution of DSA.In addition to its superiority in high-resolution patterning,the implementation ofDSA on a 300 mm pivot line fully demonstrates its potential for large-scale,high-throughput,and cost-effective manufacturing in industrial environment.展开更多
Wettability transition is a significant responsive mechanism which is widely applied to construct smart materials and systems.The broad-spectrum responsiveness of the wettability transition makes it a promising way to...Wettability transition is a significant responsive mechanism which is widely applied to construct smart materials and systems.The broad-spectrum responsiveness of the wettability transition makes it a promising way to expand innovative applications.Here,we develop a track-guided self-transportation system mediated by sequential wettability transition accompanied with capillary transportation.Alkaline fuel is loaded into polydimethylsiloxane(PDMS)cuboid to trigger the wettability transition of distributed superhydrophobic tracks laid in shallow water.After the wettability transition,the induced capillary force can propel the repetitive track-to-track transportation of PDMS.Importantly,the spacing between adjacent tracks is rationally designed based on multiple factors including threshold of wettability transition,diffusion kinetics and capillary interaction.Furthermore,the track-guided transportation system is applied to realize directed self-assembly of multiple PDMS building blocks for designated configuration,which increases the complexity and intelligence of self-assembly systems.展开更多
Layer-by-layer polyelectrolyte self-assembly, a common method for preparing high-quality ultra-thin films, was employed to direct the self-assembly behavior of polystyrene-block-poly(methyl methacrylate)(PS-b-PMMA) bl...Layer-by-layer polyelectrolyte self-assembly, a common method for preparing high-quality ultra-thin films, was employed to direct the self-assembly behavior of polystyrene-block-poly(methyl methacrylate)(PS-b-PMMA) block copolymer for the first time. Differing from the previous neutral polymer brushes anchored to silicon substrates via chemical modification, polyelectrolyte multilayers(PEMs) were anchored by electrostatic interaction and provided a stable, smooth, and neutral interface. In the present study, PS-b-PMMA was deposited on poly(acrylamide hydrochloride)/poly(acrylic acid)(PAH/PAA) PEMs prepared by layer-by-layer self-assembly to successfully yield vertical nanodomains after thermal annealing. Seven layered PEMs revealed an excellent, smooth surface, with a low roughness of 0.6 nm. The periodic structure with interlamellar spacing of 47 nm was determined by grazing-incidence small-angle X-ray scattering(GISAXS). The morphology of the PS-b-PMMA nanodomains depended on the polyanion-to-polycation concentration ratio, which is related to the interaction between the block copolymer and the substrate. Our results demonstrate that layer-by-layer self-assembly is a helpful method for the phase separation of block polymers and the fabrication of vertical, ordered nanodomains.展开更多
Hierarchical plasmonic biomaterials constructed from small nanoparticles(NPs)that combine into larger micron-sized structures exhibit unique properties that can be harnessed for various applications.Using diffusion-li...Hierarchical plasmonic biomaterials constructed from small nanoparticles(NPs)that combine into larger micron-sized structures exhibit unique properties that can be harnessed for various applications.Using diffusion-limited aggregation(DLA)and defined peptide sequences,we developed fractal silver biomaterials with a Brownian tree structure.This method avoids complex redox chemistry and allows precise control of interparticle distance and material morphology through peptide design and concentration.Our systematic investigation revealed how peptide charge,length,and sequence impact biomaterial morphology,confirming that peptides act as bridging motifs between particles and induce coalescence.Characterization through spectroscopy and microscopy demonstrated that arginine-based peptides are optimal for fractal assembly based on both quantitative and qualitative measurements.Additionally,our study of diffusion behavior confirmed the effect of particle size,temperature,and medium viscosity on nanoparticle mobility.This work also provides insights into the facet distribution in silver NPs and their assembly mechanisms,offering potential advancements in the design of materials for medical,environmental,and electronic applications.展开更多
While enol-keto tautomerism has attracted great interest in Schiff bases and related compounds in solution and crystal states,the self-assembly of energy-unfavored keto form were scarcely investigated.Here,we report a...While enol-keto tautomerism has attracted great interest in Schiff bases and related compounds in solution and crystal states,the self-assembly of energy-unfavored keto form were scarcely investigated.Here,we report a keto-form directed self-assembly of a naphthalene-attached enantiomeric N-salicylideneanil analog L/DGG-Nap accompanied with a significantly amplified circularly polarized luminescence(CPL).It was found that LGG-Nap exists as a mixture of enol and keto form in monomer at a diluted toluene solution.The increment of the concentrations leads to the formation of predominated keto form,which subsequently triggers the self-assembly.Cryo-transmission electron microscopy(Cryo-TEM)revealed that a hierarchical assembly process happened upon increasing the concentration of LGG-Nap in toluene.Individual nanofibers formed at 1×10-4 mol/L and transferred into helical nanofiber bundles in 5×10-3 mol/L.Interestingly,while these is nearly no circular dichroism(CD)or CPL in the monomeric solution,the assembly showed strong CD and CPL.Remarkably,the dissymmetry factor(glum)was significantly amplified from zero in solution through the 0.005 in individual nanofiber to 0.1 in nanofiber bundles.This work demonstrates that the enol-keto tautomerism can be broken and trigger the self-assembly upon increasing the concentration,which can subsequently direct the chiral self-assembly and significantly amplify the dissymmetry factor of assembled CPL materials.展开更多
Recently,hollow carbon nanospheres(HCSs)have garnered significant attention as potential Li metal hosts owing to their unique large voids and ease of fabrication.However,similar to other nanoscale hosts,their practica...Recently,hollow carbon nanospheres(HCSs)have garnered significant attention as potential Li metal hosts owing to their unique large voids and ease of fabrication.However,similar to other nanoscale hosts,their practical performance is limited by inhomogeneous agglomeration,increased binder requirements,and high tortuosity within the electrode.To overcome these problems and high tortuosity within the electrode,this study introduces a pomegranate-like carbon microcluster composed of primary HCSs(P-CMs)as a novel Li metal host.This unique nanostructure can be easily prepared using the spray-drying technique,enabling its mass production.Comprehensive analyses with various tools demonstrate that compared with HCS hosts,the P-CM host requires a smaller amount of binder to fabricate a sufficiently robust and even surface electrode.Furthermore,owing to reduced tortuosity,the well-designed P-CM electrode can provide continuous and shortened pathways for electron/ion transport,accelerating the Li-ion transfer kinetics and prohibiting preferential Li plating at the upper region of the electrode.Due to these characteristics,Li metal can be effectively encapsulated in the large inner voids of the primary HCSs constituting the P-CM,thereby enhancing the electrochemical performance of P-CM hosts in Li metal batteries.Specifically,the Coulombic efficiency of the P-CM host can be maintained at 97%over 100 cycles,with a high Li deposition areal capacity of 3 mAh·cm^(-2)and long cycle life(1000 h,1 mA·cm^(-2),and 1.0 mAh·cm^(-2)).Furthermore,a full cell incorporating a LiFePO4 cathode exhibits excellent cycle life.展开更多
The layer-by-layer deposition strategy of additive manufacturing makes it ideal to fabricate dissimilar alloy components with varying functionality,which has promising application potential in a large number of indust...The layer-by-layer deposition strategy of additive manufacturing makes it ideal to fabricate dissimilar alloy components with varying functionality,which has promising application potential in a large number of industrial areas.In this study,two components composed of ERCuAl-A2 aluminum bronze(CuAl9)and Inconel 718 nickel-based superalloy were fabricated with different deposition orders by wire-arc directed energy deposition.Subject to changes in heat input and thermophysical properties of the substrate,the transition region of the deposited Cu-Ni component with the bottom half of CuAl9 and the top half of Inconel 718 is narrow and serrated.This region features a laminated intermetallic compound layer due to the convection and rapid cooling in the molten pool.In contrast,the Ni-Cu component deposited in the opposite order exhibits a 2 mm gradient transition zone.Within this region,a large number of diverse precipitates were found as well as regional variations in grain size due to the multi-layer partial remelting.Both two components show strong bonds and their tensile specimens tested along the vertical direction always fracture at the softer CuAl9 side.Excellent tensile properties along the horizontal direction were obtained for Cu-Ni(Ultimate tensile strength:573 MPa,yield stress:302 MPa,elongation:22%),while those of Ni-Cu are much lower due to the existence of the solidification cracks in the transition zone.The results from this study provide a reference for the additive manufacturing of Cu/Ni dissimilar alloy components,as well as their microstructure and mechanical properties control.展开更多
Four glycoluril-based amphiphilic molecular clips(AMCs)M1~M4 have been prepared for intracellular delivery of short DNA.M1~M4 have two methyl groups on its convex surface and four cations on its aromatic side arm,whic...Four glycoluril-based amphiphilic molecular clips(AMCs)M1~M4 have been prepared for intracellular delivery of short DNA.M1~M4 have two methyl groups on its convex surface and four cations on its aromatic side arm,which can be used to construct self-assembled nanoparticles in aqueous solution driven by hydrophobic interaction.Dynamic light scattering experiments show that M1 and M2 can be driven hydrophobically to aggregate into extremely stable nanoparticles in water at the micromolar concentrations.Fluorescence titration and zeta potential experiments support that the nanoparticles formed by M1 and M2 are able to efficiently encapsulate short DNA(sDNA).Fluorescence imaging and flow cytometry studies reveal that their nano sizes enable intracellular delivery of the encapsulated sDNA into both normal and cancer cells,with delivery percentage reaching up to 94%,while in vitro experiments indicate that the two compounds have excellent biocompatibility and low cytotoxicity.展开更多
Solution and aging treatment were conducted on the laser directed energy deposition(LDED)-prepared carbon nanotubes(CNTs)-reinforced WE43(CNTs/WE43)layers to optimize their microstructure and surface properties in thi...Solution and aging treatment were conducted on the laser directed energy deposition(LDED)-prepared carbon nanotubes(CNTs)-reinforced WE43(CNTs/WE43)layers to optimize their microstructure and surface properties in this study.The microstructure of the WE43 and CNTs/WE43 layers was systematically compared.The dissolution of divorced eutectics at the grain boundaries was retarded by CNTs during solution treatment.The spot segregation composed of Mg_(24)Y_(5),CNTs,and Zr cores in the solution treated CNTs/WE43 layer presented a slight decreasing in Y content.The grain growth of both types of layers underwent three stages:slow,rapid,and steady-state.The significant inhibitory effect of CNTs on the grain growth of the LDED WE43 matrix was more pronounced than the promoting effect of temperature,resulting in a 47%increase at 510℃ and a 35%increase at 540℃ in the grain growth exponent compared to the WE43 layers at 510℃.During the subsequent aging treatment at 225℃,the precipitation sequences from plate-shaped β″to plate-shaped and globular β′ were observed in both types of layers.CNTs can facilitate an increase in the nucleation rate of precipitates,but without accelerating precipitation hardening rate.The long and short diameters of the precipitates in peak-aged state were decreased by 48.5%and 43.1%by addition of CNTs,respectively.The wear resistance of both the WE43 and CNTs/WE43 layers can be significantly enhanced through solution and aging treatment.The enhancement in wear resistance for the CNTs/WE43 layers is considerably greater than that of the WE43 layers.展开更多
Nowadays,high-stable and ultrasensitive heavy metal detection is of utmost importance in water quality monitoring.Nanoparticle-enhanced laser-induced breakdown spectroscopy(NELIBS)shows high potential in hazardous met...Nowadays,high-stable and ultrasensitive heavy metal detection is of utmost importance in water quality monitoring.Nanoparticle-enhanced laser-induced breakdown spectroscopy(NELIBS)shows high potential in hazardous metal detection,however,encounters unstable and weak signals due to nonuniform distribution of analytes.Herein,we developed an interface self-assembly(ISA)method to create a uniformly distributed gold nanolayer at a liquid-liquid interface for positive heavy metal ions capture and NELIBS analysis.The electrostatically selfassembled Au nanoparticles(NPs)-analytes membrane was prepared at the oil-water interface by injecting ethanol into the mixture of cyclohexane and Au NPs-analytes water solution.Then,the interface self-assembled Au NPs-analytes membrane was transformed onto a laser-processed superhydrophilic Si slide for detection.Three heavy metals(cadmium(Cd),barium(Ba),and chromium(Cr))were analyzed to evaluate the stability and sensitivity of the ISA method for NELIBS.The results(Cd:RSD=3.6%,LoD=0.654 mg/L;Ba:RSD=3.4%,LoD=0.236 mg/L;Cr:RSD=7.7%,LoD=1.367 mg/L)demonstrated signal enhancement and high-stable and ultrasensitive detection.The actual sample detection(Cd:RE=7.71%,Ba:RE=6.78%)illustrated great reliability.The ISA method,creating a uniform distribution of NP-analytes at the interface,has promising prospects in NELIBS.展开更多
Diphenylalanine and its analogs cause many concerns owing to their perfect self-assembly properties in the fields of biology,medicine,and nanotechnology.Experimental research has shown that diphenylalanine-based analo...Diphenylalanine and its analogs cause many concerns owing to their perfect self-assembly properties in the fields of biology,medicine,and nanotechnology.Experimental research has shown that diphenylalanine-based analogs with ethylenediamine linkers(PA,P=phenylalanine,and A=analog)can self-assemble into spherical assemblies,which can serve as novel anticancer drug carriers.In this work,to understand the assembly pathways,drug loading behavior,and formation mechanism of PA aggregates at the molecular level,we carried out dissipative particle dynamics(DPD)simulations of PA molecule systems.Our simulation results demonstrate that PA molecules spontaneously assemble into nanospheres and can self-assemble into drug-loaded nanospheres upon addition of the cancer chemotherapeutic agent doxorubicin(DOX).We also found that the hydrophobic side chain beads of PA molecules exhibited a unique onion-like distribution inside the nanospheres,which was not observed in the experiment.The onion-like nanospheres were verified by calculating the radial distribution function(RDF)of the DPD beads.Furthermore,based on the analysis of the percentages of different interaction components in the total nonbonded energies,main chain-side chain interactions between PA molecules may be important in the formation of onion-like nanospheres,and the synergistic effects of main chain-side chain,main chain-drug,side chain-drug,and main chain-solvent interactions are significant in the formation of drug-loaded nanospheres.These findings provide new insights into the structure and self-assembly pathway of PA assemblies,which may be helpful for the design of efficient and effective drug delivery systems.展开更多
The potential of metal nanoclusters in biomedical applications is limited due to aggregation-caused quenching(ACQ).In this study,an in situ self-assembled pitaya structure was proposed to obtain stable fluorescence em...The potential of metal nanoclusters in biomedical applications is limited due to aggregation-caused quenching(ACQ).In this study,an in situ self-assembled pitaya structure was proposed to obtain stable fluorescence emission through protein coronas-controlled distance between gold nanoclusters(Au NCs).Interestingly,the gold ion complexes coated with proteins of low isoelectric point(pI)nucleate at the secondary structure of proteins with high p I through ionic exchange within cells,generating fluorescent Au NCs.It is worth noting that due to the steric hindrance formed by the protein coronas on the surface of Au NCs,the distance between Au NCs can be controlled,avoiding electron transfer caused by close proximity of Au NCs and inhibiting fluorescence ACQ.This strategy can achieve fluorescence imaging of clinical tissue samples without observable side effects.Therefore,this study proposes a distance-controllable self-assembled pitaya structure to provide a new approach for Au NCs with stable fluorescence.展开更多
The development of new and efficient extractants plays a key role in the separation and recovery of rare earth elements.In this pape r,the extractant(N,N-methyl py ridineethyl-N',N'-dicyclohexyl-3-oxadiglycola...The development of new and efficient extractants plays a key role in the separation and recovery of rare earth elements.In this pape r,the extractant(N,N-methyl py ridineethyl-N',N'-dicyclohexyl-3-oxadiglycolamide,MPyEDChDGA) with a new structure was synthesized,and the pyridine group was successfully grafted onto the 3-oxadiglycolamide structure.Using MPyEDChDGA for efficient enrichment of rare earth ions,the self-assembled solids were recovered by simple filtration without further backextraction and final precipitation,achieving a one-step strategy for the recovery of rare earth ions.Several important parameters affecting the self-assembly extraction,including pH,diluent,temperature,and extractant concentration,were systematically evaluated using La(NO_(3))_(3),Tb(NO_(3))_(3),and Lu(NO_(3))_(3) as representatives.The self-assembled solids were investigated in detail by X-ray diffraction(XRD),scanning electron microscopy(SEM),1H nuclear magnetic resonance(1H NMR),Fourier transform infrared spectroscopy(FT-IR),Raman,and X-ray photoelectron spectroscopy(XPS) analyses.The stoichiometry of the extraction species was characterized using the Job's method and electrospray ionization mass spectrometry(ESI-MS).In addition,MPyEDChDGA was applied to the recovery of Sm in SmCoCu simulated liquid,and the results show that MPyEDChDGA has good selectivity of Sm from transition metals(Co,Cu).The separation factor of Sm/Co can reach 6281±117,which provides a new approach to recovering Sm from SmCoCu scrap magnets.This study presents an efficient and convenient new strategy for the recovery and separation of rare earth elements.展开更多
Amphiphilic asymmetric brush copolymers(AABCs)possess unique self-assembly behaviors owing to their asymmetric brush architecture and multiple functionalities of multicomponent side chains.However,the synthesis of AAB...Amphiphilic asymmetric brush copolymers(AABCs)possess unique self-assembly behaviors owing to their asymmetric brush architecture and multiple functionalities of multicomponent side chains.However,the synthesis of AABCs presents challenges,which greatly limits the exploration of their self-assembly behaviors.In this work,we employed dissipative particle dynamics(DPD)simulations to investigate the self-assembly behaviors of AABCs in selective solution.By varying the copolymer concentration and structure,we conducted the self-assembly phase diagrams of AABCs,revealing complex morphologies such as channelized micelles with one or more solvophilic channels.Moreover,the number,surface area,and one-dimensional density distribution of the channelized micelles were calculated to demonstrate the internal structure and morphological transformation during the self-assembly process.Our findings indicate that the morphology of the internal solvophilic channels is greatly influenced by the copolymer structure,concentration,and interaction parameters between the different side chains.The simulation results are consistent with available experimental observations,which can offer theoretical insights into the self-assembly of AABCs.展开更多
The precise control over the hierarchical self-assembly of sophisticated structures with comparable complexities and functions relying on the modulation of basic building blocks is elusive and highly desirable.Here,we...The precise control over the hierarchical self-assembly of sophisticated structures with comparable complexities and functions relying on the modulation of basic building blocks is elusive and highly desirable.Here,we report a fluorinated N-heterocyclic carbene(NHC)–based pillarplex with a tunable quaternary structure,employed as an efficient building block for constructing hierarchical superstructures.Initially,multiple noncovalent interactions in the NHC-based pillarplex,particularly those between the fluorinated pillarplex and PF_(6)-anions,induce the formation of a supramolecular gel at high concentrations.Additionally,this hierarchical self-assembled structure can be regulated by adjusting anion types,facilitating the controlled transformation from a supramolecular gel into a supramolecular channel upon the introduction of four monocarboxylic acids as anions.The study provides insight into the construction and controlled regulation of superstructures based on NHC-based pillarplexes.展开更多
Polymerization-induced self-assembly(PISA)has become one of the most versatile approaches for scalable preparation of linear block copolymer nanoparticles with various morphologies.However,the controlled introduction ...Polymerization-induced self-assembly(PISA)has become one of the most versatile approaches for scalable preparation of linear block copolymer nanoparticles with various morphologies.However,the controlled introduction of branching into the core-forming block and the effect on the morphologies of block copolymer nanoparticles under PISA conditions have rarely been explored.Herein,a series of multifunctional macromolecular chain transfer agents(macro-CTAs)were first synthesized by a two-step green light-activated photoiniferter polymerization using two types of chain transfer monomers(CTMs).These macro-CTAs were then used to mediate reversible addition-fragmentation chain transfer(RAFT)dispersion polymerization of styrene(St)to prepare block copolymers with different core-forming block structures and the assemblies.The effect of the core-forming block structure on the morphology of block copolymer nanoparticles was investigated in detail.Transmission electron microscopy(TEM)analysis indicated that the brush-like core-forming block structure facilitated the formation of higher-order morphologies,while the branched core-forming block structure favored the formation of lower-order morphologies.Moreover,it was found that using macroCTAs with a shorter length also promoted the formation of higher-order morphologies.Finally,structures of block copolymers and the assemblies were further controlled by changing the structure of macro-CTA or using a binary mixture of two different macro-CTAs.We expect that this work not only sheds light on the synthesis of block copolymer nanoparticles but also provide important mechanistic insights into PISA of nonlinear block copolymers.展开更多
Antiferromagnetic(AFM)spintronics have sparked extensive research interest in the field of information storage due to the considerable advantages offered by antiferromagnets,including non-volatile data storage,higher ...Antiferromagnetic(AFM)spintronics have sparked extensive research interest in the field of information storage due to the considerable advantages offered by antiferromagnets,including non-volatile data storage,higher storage density,and accelerating data processing.However,the manipulation and detection of internal AFM order in antiferromagnets hinders their applications in spintronic devices.Here,we proposed a design idea for an AFM material that is self-assembled from one-dimensional(1D)ferromagnetic(FM)chains.To validate this idea,we screened a two-dimensional(2D)selfassembled CrBr_(2)antiferromagnet of an AFM semiconductor from a large amount of data.This 2D CrBr_(2)antiferromagnet is composed of 1D FM CrBr_(2)chains that are arranged in a staggered and parallel configuration.In this type of antiferromagnet,the write-data operation of information is achieved in 1D FM chains,followed by a self-assembly process driving the assembly of 1D FM chains into an antiferromagnet.These constituent 1D FM chains become decoupled by external perturbations,such as heat,pressure,strain,etc.,thereby realizing the read-data operation of information.We anticipate that this antiferromagnet,composed of 1D FM chains,can be realized not only in the 1D to 2D system,but also is expected to expand to 2D to three-dimensional(3D)system,and even 1D to 3D system.展开更多
The development of the Internet of Things(IoT)has brought convenience to people’s lives,but it also introduces significant security risks.Due to the limitations of IoT devices themselves and the challenges of re-host...The development of the Internet of Things(IoT)has brought convenience to people’s lives,but it also introduces significant security risks.Due to the limitations of IoT devices themselves and the challenges of re-hosting technology,existing fuzzing for IoT devices is mainly conducted through black-box methods,which lack effective execution feedback and are blind.Meanwhile,the existing static methods mainly rely on taint analysis,which has high overhead and high false alarm rates.We propose a new directed fuzz testing method for detecting bugs in web service programs of IoT devices,which can test IoT devices more quickly and efficiently.Specifically,we identify external input entry points using multiple features.Then we quickly find sensitive targets and paths affected by external input sources based on sensitive data flow analysis of decompiled code,treating them as testing objects.Finally,we performa directed fuzzing test.We use debugging interfaces to collect execution feedback and guide the programto reach sensitive targets based on programpruning techniques.We have implemented a prototype system,AntDFuzz,and evaluated it on firmware fromten devices across five well-known manufacturers.We discovered twelve potential vulnerabilities,seven of which were confirmed and assigned bug id by China National Vulnerability Database(CNVD).The results show that our approach has the ability to find unknown bugs in real devices and is more efficient compared to existing tools.展开更多
文摘We consider the inverse problem of finding guiding pattern shapes that result in desired self-assembly morphologies of block copolymer melts.Specifically,we model polymer selfassembly using the self-consistent field theory and derive,in a non-parametric setting,the sensitivity of the dissimilarity between the desired and the actual morphologies to arbitrary perturbations in the guiding pattern shape.The sensitivity is then used for the optimization of the confining pattern shapes such that the dissimilarity between the desired and the actual morphologies is minimized.The efficiency and robustness of the proposed gradient-based algorithm are demonstrated in a number of examples related to templating vertical interconnect accesses(VIA).
基金funding from the National Natural Science Foundation of China(NSFC,Nos.22173112 and 91856121)Chinese Academy of Sciences for support(No.YJKYYQ20180014)。
文摘Directed self-assembly has been used to create micro-nano scale patterns,including chiral periodic structures of organic molecules,for potential applications in optics,photonics,metamaterials,and medical and sensing technologies.This study presents a straightforward approach for fabricating large-scale chiral grating porphyrin assemblies through template-assisted techniques.The solution of tetrakis(4-sulfonatophenyl)porphyrin(TPPS)was induced by chiral amino acids(L/D-arginine and L/D-serine)to selfassemble into highly ordered chiral grating structures with the assistance of sodium dodecyl sulfate(SDS).The structures show precise line widths(5.5μm)and gaps(18μm).Using in situ optical microscopy and second harmonic generation(SHG)microscopy,the chiral characteristics and dynamic evolution of the template-assisted self-assembly are investigated.It is found that the chirality of amino acids induced TPPS self-assembled into chiral structures and the liquid contraction interface significantly enhanced the chirality of the assemblies.This study is significant for understanding the mechanism of chiral evolution and designing novel micro-nano materials with predetermined chiral properties.
文摘Directed self-assembly(DSA)emerges as one of the most promising new patterning techniques for single digit miniaturization and next generation lithography.DSA achieves high-resolution patterning by molecular assembly that circumvents the diffraction limit of conventional photolithography.Recently,the International Roadmap for Devices and Systems listed DSA as one of the advanced lithography techniques for the fabrication of 3-5 nm technology node devices.DSA can be combined with other lithography techniques,such as extreme ultra violet(EUV)and 193 nm immersion(193i),to further enhance the patterning resolution and the device density.So far,DSA has demonstrated its superior ability for the fabrication of nanoscale devices,such as fin field effect transistor and bit pattern media,offering a variety of configurations for high-density integration and low-cost manufacturing.Over 1 T in-2 device density can be achieved either by direct templating or coupled with nanoimprinting to improve the throughput.The development of high x block copolymer further enhances the patterning resolution of DSA.In addition to its superiority in high-resolution patterning,the implementation ofDSA on a 300 mm pivot line fully demonstrates its potential for large-scale,high-throughput,and cost-effective manufacturing in industrial environment.
基金supported by the National Natural Science Foundation of China(Nos.52122315,21972008)Beijing Nova Program(No.Z201100006820021).
文摘Wettability transition is a significant responsive mechanism which is widely applied to construct smart materials and systems.The broad-spectrum responsiveness of the wettability transition makes it a promising way to expand innovative applications.Here,we develop a track-guided self-transportation system mediated by sequential wettability transition accompanied with capillary transportation.Alkaline fuel is loaded into polydimethylsiloxane(PDMS)cuboid to trigger the wettability transition of distributed superhydrophobic tracks laid in shallow water.After the wettability transition,the induced capillary force can propel the repetitive track-to-track transportation of PDMS.Importantly,the spacing between adjacent tracks is rationally designed based on multiple factors including threshold of wettability transition,diffusion kinetics and capillary interaction.Furthermore,the track-guided transportation system is applied to realize directed self-assembly of multiple PDMS building blocks for designated configuration,which increases the complexity and intelligence of self-assembly systems.
基金financially supported by the National Natural Science Foundation of China (Nos. 11605149, 11405259, U1932118, and U1732123)the Natural Science Foundation of Hunan Province (No. 2017JJ3309)+3 种基金the China Postdoctoral Science Foundation (No. 2017 M622595)the Zhejiang Public Service Technology Research Program/Analytical Test (No. LGC19F040001)the National Key R&D Program of China (No. 2017YFA0403000)the Science and Technology Commission of Shanghai Municipality (No. 17JC1400802)
文摘Layer-by-layer polyelectrolyte self-assembly, a common method for preparing high-quality ultra-thin films, was employed to direct the self-assembly behavior of polystyrene-block-poly(methyl methacrylate)(PS-b-PMMA) block copolymer for the first time. Differing from the previous neutral polymer brushes anchored to silicon substrates via chemical modification, polyelectrolyte multilayers(PEMs) were anchored by electrostatic interaction and provided a stable, smooth, and neutral interface. In the present study, PS-b-PMMA was deposited on poly(acrylamide hydrochloride)/poly(acrylic acid)(PAH/PAA) PEMs prepared by layer-by-layer self-assembly to successfully yield vertical nanodomains after thermal annealing. Seven layered PEMs revealed an excellent, smooth surface, with a low roughness of 0.6 nm. The periodic structure with interlamellar spacing of 47 nm was determined by grazing-incidence small-angle X-ray scattering(GISAXS). The morphology of the PS-b-PMMA nanodomains depended on the polyanion-to-polycation concentration ratio, which is related to the interaction between the block copolymer and the substrate. Our results demonstrate that layer-by-layer self-assembly is a helpful method for the phase separation of block polymers and the fabrication of vertical, ordered nanodomains.
基金University of California,San Diego-Cellular and Molecular Medicine Electron Microscopy Core,Grant/Award Number:SCR_022039National Institutes of Health,Grant/Award Numbers:S10 OD023527,R21 DE029917,R01 DE031307,S10OD023555-A1National Science Foundation,Grant/Award Numbers:DMR-2242375,DMR-2011924,ECCS-2025752。
文摘Hierarchical plasmonic biomaterials constructed from small nanoparticles(NPs)that combine into larger micron-sized structures exhibit unique properties that can be harnessed for various applications.Using diffusion-limited aggregation(DLA)and defined peptide sequences,we developed fractal silver biomaterials with a Brownian tree structure.This method avoids complex redox chemistry and allows precise control of interparticle distance and material morphology through peptide design and concentration.Our systematic investigation revealed how peptide charge,length,and sequence impact biomaterial morphology,confirming that peptides act as bridging motifs between particles and induce coalescence.Characterization through spectroscopy and microscopy demonstrated that arginine-based peptides are optimal for fractal assembly based on both quantitative and qualitative measurements.Additionally,our study of diffusion behavior confirmed the effect of particle size,temperature,and medium viscosity on nanoparticle mobility.This work also provides insights into the facet distribution in silver NPs and their assembly mechanisms,offering potential advancements in the design of materials for medical,environmental,and electronic applications.
基金National Natural Science foundation of China(Nos.21861132002,21773043,21973020 and 21890734).
文摘While enol-keto tautomerism has attracted great interest in Schiff bases and related compounds in solution and crystal states,the self-assembly of energy-unfavored keto form were scarcely investigated.Here,we report a keto-form directed self-assembly of a naphthalene-attached enantiomeric N-salicylideneanil analog L/DGG-Nap accompanied with a significantly amplified circularly polarized luminescence(CPL).It was found that LGG-Nap exists as a mixture of enol and keto form in monomer at a diluted toluene solution.The increment of the concentrations leads to the formation of predominated keto form,which subsequently triggers the self-assembly.Cryo-transmission electron microscopy(Cryo-TEM)revealed that a hierarchical assembly process happened upon increasing the concentration of LGG-Nap in toluene.Individual nanofibers formed at 1×10-4 mol/L and transferred into helical nanofiber bundles in 5×10-3 mol/L.Interestingly,while these is nearly no circular dichroism(CD)or CPL in the monomeric solution,the assembly showed strong CD and CPL.Remarkably,the dissymmetry factor(glum)was significantly amplified from zero in solution through the 0.005 in individual nanofiber to 0.1 in nanofiber bundles.This work demonstrates that the enol-keto tautomerism can be broken and trigger the self-assembly upon increasing the concentration,which can subsequently direct the chiral self-assembly and significantly amplify the dissymmetry factor of assembled CPL materials.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIT)(No.2020R1C1C1003375)。
文摘Recently,hollow carbon nanospheres(HCSs)have garnered significant attention as potential Li metal hosts owing to their unique large voids and ease of fabrication.However,similar to other nanoscale hosts,their practical performance is limited by inhomogeneous agglomeration,increased binder requirements,and high tortuosity within the electrode.To overcome these problems and high tortuosity within the electrode,this study introduces a pomegranate-like carbon microcluster composed of primary HCSs(P-CMs)as a novel Li metal host.This unique nanostructure can be easily prepared using the spray-drying technique,enabling its mass production.Comprehensive analyses with various tools demonstrate that compared with HCS hosts,the P-CM host requires a smaller amount of binder to fabricate a sufficiently robust and even surface electrode.Furthermore,owing to reduced tortuosity,the well-designed P-CM electrode can provide continuous and shortened pathways for electron/ion transport,accelerating the Li-ion transfer kinetics and prohibiting preferential Li plating at the upper region of the electrode.Due to these characteristics,Li metal can be effectively encapsulated in the large inner voids of the primary HCSs constituting the P-CM,thereby enhancing the electrochemical performance of P-CM hosts in Li metal batteries.Specifically,the Coulombic efficiency of the P-CM host can be maintained at 97%over 100 cycles,with a high Li deposition areal capacity of 3 mAh·cm^(-2)and long cycle life(1000 h,1 mA·cm^(-2),and 1.0 mAh·cm^(-2)).Furthermore,a full cell incorporating a LiFePO4 cathode exhibits excellent cycle life.
基金supported by the Key Research and Development Program of Shaanxi Province(2023-YBGY361)the National Natural Science Foundation of China(52275374 and 52205414)+1 种基金the Postdoctoral Fellowship Program of CPSF(GZC20232098)as well as the Xiaomi Foundation through Xiaomi Young Scholar Program。
文摘The layer-by-layer deposition strategy of additive manufacturing makes it ideal to fabricate dissimilar alloy components with varying functionality,which has promising application potential in a large number of industrial areas.In this study,two components composed of ERCuAl-A2 aluminum bronze(CuAl9)and Inconel 718 nickel-based superalloy were fabricated with different deposition orders by wire-arc directed energy deposition.Subject to changes in heat input and thermophysical properties of the substrate,the transition region of the deposited Cu-Ni component with the bottom half of CuAl9 and the top half of Inconel 718 is narrow and serrated.This region features a laminated intermetallic compound layer due to the convection and rapid cooling in the molten pool.In contrast,the Ni-Cu component deposited in the opposite order exhibits a 2 mm gradient transition zone.Within this region,a large number of diverse precipitates were found as well as regional variations in grain size due to the multi-layer partial remelting.Both two components show strong bonds and their tensile specimens tested along the vertical direction always fracture at the softer CuAl9 side.Excellent tensile properties along the horizontal direction were obtained for Cu-Ni(Ultimate tensile strength:573 MPa,yield stress:302 MPa,elongation:22%),while those of Ni-Cu are much lower due to the existence of the solidification cracks in the transition zone.The results from this study provide a reference for the additive manufacturing of Cu/Ni dissimilar alloy components,as well as their microstructure and mechanical properties control.
文摘Four glycoluril-based amphiphilic molecular clips(AMCs)M1~M4 have been prepared for intracellular delivery of short DNA.M1~M4 have two methyl groups on its convex surface and four cations on its aromatic side arm,which can be used to construct self-assembled nanoparticles in aqueous solution driven by hydrophobic interaction.Dynamic light scattering experiments show that M1 and M2 can be driven hydrophobically to aggregate into extremely stable nanoparticles in water at the micromolar concentrations.Fluorescence titration and zeta potential experiments support that the nanoparticles formed by M1 and M2 are able to efficiently encapsulate short DNA(sDNA).Fluorescence imaging and flow cytometry studies reveal that their nano sizes enable intracellular delivery of the encapsulated sDNA into both normal and cancer cells,with delivery percentage reaching up to 94%,while in vitro experiments indicate that the two compounds have excellent biocompatibility and low cytotoxicity.
基金supported by the National Natural Science Foundation of China(52005264).
文摘Solution and aging treatment were conducted on the laser directed energy deposition(LDED)-prepared carbon nanotubes(CNTs)-reinforced WE43(CNTs/WE43)layers to optimize their microstructure and surface properties in this study.The microstructure of the WE43 and CNTs/WE43 layers was systematically compared.The dissolution of divorced eutectics at the grain boundaries was retarded by CNTs during solution treatment.The spot segregation composed of Mg_(24)Y_(5),CNTs,and Zr cores in the solution treated CNTs/WE43 layer presented a slight decreasing in Y content.The grain growth of both types of layers underwent three stages:slow,rapid,and steady-state.The significant inhibitory effect of CNTs on the grain growth of the LDED WE43 matrix was more pronounced than the promoting effect of temperature,resulting in a 47%increase at 510℃ and a 35%increase at 540℃ in the grain growth exponent compared to the WE43 layers at 510℃.During the subsequent aging treatment at 225℃,the precipitation sequences from plate-shaped β″to plate-shaped and globular β′ were observed in both types of layers.CNTs can facilitate an increase in the nucleation rate of precipitates,but without accelerating precipitation hardening rate.The long and short diameters of the precipitates in peak-aged state were decreased by 48.5%and 43.1%by addition of CNTs,respectively.The wear resistance of both the WE43 and CNTs/WE43 layers can be significantly enhanced through solution and aging treatment.The enhancement in wear resistance for the CNTs/WE43 layers is considerably greater than that of the WE43 layers.
基金supported by the National Natural Science Foundation of China(No.62075069 and 52303092)the Water Conservancy Technology project of Hunan Province,China(XSKJ2021000-32)+1 种基金the City University of Hong Kong(#7005507)the Open Project of Yunnan Precious Metals Laboratory Co.,Ltd(grant number YPML-2023050278).
文摘Nowadays,high-stable and ultrasensitive heavy metal detection is of utmost importance in water quality monitoring.Nanoparticle-enhanced laser-induced breakdown spectroscopy(NELIBS)shows high potential in hazardous metal detection,however,encounters unstable and weak signals due to nonuniform distribution of analytes.Herein,we developed an interface self-assembly(ISA)method to create a uniformly distributed gold nanolayer at a liquid-liquid interface for positive heavy metal ions capture and NELIBS analysis.The electrostatically selfassembled Au nanoparticles(NPs)-analytes membrane was prepared at the oil-water interface by injecting ethanol into the mixture of cyclohexane and Au NPs-analytes water solution.Then,the interface self-assembled Au NPs-analytes membrane was transformed onto a laser-processed superhydrophilic Si slide for detection.Three heavy metals(cadmium(Cd),barium(Ba),and chromium(Cr))were analyzed to evaluate the stability and sensitivity of the ISA method for NELIBS.The results(Cd:RSD=3.6%,LoD=0.654 mg/L;Ba:RSD=3.4%,LoD=0.236 mg/L;Cr:RSD=7.7%,LoD=1.367 mg/L)demonstrated signal enhancement and high-stable and ultrasensitive detection.The actual sample detection(Cd:RE=7.71%,Ba:RE=6.78%)illustrated great reliability.The ISA method,creating a uniform distribution of NP-analytes at the interface,has promising prospects in NELIBS.
基金financially supported by the National Natural Science Foundation of China(Nos.20904047 and 12074151)the Natural Science Foundation of Zhejiang Province(Nos.LY17A040001 and LY19F03004)。
文摘Diphenylalanine and its analogs cause many concerns owing to their perfect self-assembly properties in the fields of biology,medicine,and nanotechnology.Experimental research has shown that diphenylalanine-based analogs with ethylenediamine linkers(PA,P=phenylalanine,and A=analog)can self-assemble into spherical assemblies,which can serve as novel anticancer drug carriers.In this work,to understand the assembly pathways,drug loading behavior,and formation mechanism of PA aggregates at the molecular level,we carried out dissipative particle dynamics(DPD)simulations of PA molecule systems.Our simulation results demonstrate that PA molecules spontaneously assemble into nanospheres and can self-assemble into drug-loaded nanospheres upon addition of the cancer chemotherapeutic agent doxorubicin(DOX).We also found that the hydrophobic side chain beads of PA molecules exhibited a unique onion-like distribution inside the nanospheres,which was not observed in the experiment.The onion-like nanospheres were verified by calculating the radial distribution function(RDF)of the DPD beads.Furthermore,based on the analysis of the percentages of different interaction components in the total nonbonded energies,main chain-side chain interactions between PA molecules may be important in the formation of onion-like nanospheres,and the synergistic effects of main chain-side chain,main chain-drug,side chain-drug,and main chain-solvent interactions are significant in the formation of drug-loaded nanospheres.These findings provide new insights into the structure and self-assembly pathway of PA assemblies,which may be helpful for the design of efficient and effective drug delivery systems.
基金supported by the National Natural Science Foundation of China(Nos.82061148012,82027806,21974019)SEU Innovation Capability Enhancement Plan for Doctoral Students(No.CXJH_SEU 24138)Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.KYCX24_0469)。
文摘The potential of metal nanoclusters in biomedical applications is limited due to aggregation-caused quenching(ACQ).In this study,an in situ self-assembled pitaya structure was proposed to obtain stable fluorescence emission through protein coronas-controlled distance between gold nanoclusters(Au NCs).Interestingly,the gold ion complexes coated with proteins of low isoelectric point(pI)nucleate at the secondary structure of proteins with high p I through ionic exchange within cells,generating fluorescent Au NCs.It is worth noting that due to the steric hindrance formed by the protein coronas on the surface of Au NCs,the distance between Au NCs can be controlled,avoiding electron transfer caused by close proximity of Au NCs and inhibiting fluorescence ACQ.This strategy can achieve fluorescence imaging of clinical tissue samples without observable side effects.Therefore,this study proposes a distance-controllable self-assembled pitaya structure to provide a new approach for Au NCs with stable fluorescence.
基金Project supported by the Natural Science Foundation of Shandong Province (ZR2022QB067)。
文摘The development of new and efficient extractants plays a key role in the separation and recovery of rare earth elements.In this pape r,the extractant(N,N-methyl py ridineethyl-N',N'-dicyclohexyl-3-oxadiglycolamide,MPyEDChDGA) with a new structure was synthesized,and the pyridine group was successfully grafted onto the 3-oxadiglycolamide structure.Using MPyEDChDGA for efficient enrichment of rare earth ions,the self-assembled solids were recovered by simple filtration without further backextraction and final precipitation,achieving a one-step strategy for the recovery of rare earth ions.Several important parameters affecting the self-assembly extraction,including pH,diluent,temperature,and extractant concentration,were systematically evaluated using La(NO_(3))_(3),Tb(NO_(3))_(3),and Lu(NO_(3))_(3) as representatives.The self-assembled solids were investigated in detail by X-ray diffraction(XRD),scanning electron microscopy(SEM),1H nuclear magnetic resonance(1H NMR),Fourier transform infrared spectroscopy(FT-IR),Raman,and X-ray photoelectron spectroscopy(XPS) analyses.The stoichiometry of the extraction species was characterized using the Job's method and electrospray ionization mass spectrometry(ESI-MS).In addition,MPyEDChDGA was applied to the recovery of Sm in SmCoCu simulated liquid,and the results show that MPyEDChDGA has good selectivity of Sm from transition metals(Co,Cu).The separation factor of Sm/Co can reach 6281±117,which provides a new approach to recovering Sm from SmCoCu scrap magnets.This study presents an efficient and convenient new strategy for the recovery and separation of rare earth elements.
基金supported by the National Science Foundation for Distinguished Young Scholars(No.52325308)the National Natural Science Foundation of China(Nos.52273008 and 52073092)+1 种基金Shanghai Scientific and Technological Innovation Projects(No.22ZR1479300)Shanghai Rising-Star Program(No.23QA1402500).
文摘Amphiphilic asymmetric brush copolymers(AABCs)possess unique self-assembly behaviors owing to their asymmetric brush architecture and multiple functionalities of multicomponent side chains.However,the synthesis of AABCs presents challenges,which greatly limits the exploration of their self-assembly behaviors.In this work,we employed dissipative particle dynamics(DPD)simulations to investigate the self-assembly behaviors of AABCs in selective solution.By varying the copolymer concentration and structure,we conducted the self-assembly phase diagrams of AABCs,revealing complex morphologies such as channelized micelles with one or more solvophilic channels.Moreover,the number,surface area,and one-dimensional density distribution of the channelized micelles were calculated to demonstrate the internal structure and morphological transformation during the self-assembly process.Our findings indicate that the morphology of the internal solvophilic channels is greatly influenced by the copolymer structure,concentration,and interaction parameters between the different side chains.The simulation results are consistent with available experimental observations,which can offer theoretical insights into the self-assembly of AABCs.
基金financial support from the National Natural Science Fund for Distinguished Young Scholars of China(No.22025107)Shaanxi Fundamental Science Research Project for Chemistry&Biology(No.22JHZ003)+2 种基金the Key International Scientific and Technological Cooperation and Exchange Project of Shaanxi Province(No.2023-GHZD-15)the National Youth Top-notch Talent Support Program of Chinathe FM&EM International Joint Laboratory of Northwest University。
文摘The precise control over the hierarchical self-assembly of sophisticated structures with comparable complexities and functions relying on the modulation of basic building blocks is elusive and highly desirable.Here,we report a fluorinated N-heterocyclic carbene(NHC)–based pillarplex with a tunable quaternary structure,employed as an efficient building block for constructing hierarchical superstructures.Initially,multiple noncovalent interactions in the NHC-based pillarplex,particularly those between the fluorinated pillarplex and PF_(6)-anions,induce the formation of a supramolecular gel at high concentrations.Additionally,this hierarchical self-assembled structure can be regulated by adjusting anion types,facilitating the controlled transformation from a supramolecular gel into a supramolecular channel upon the introduction of four monocarboxylic acids as anions.The study provides insight into the construction and controlled regulation of superstructures based on NHC-based pillarplexes.
基金financially supported by the National Natural Science Foundation of China(Nos.22171055 and 52222301)the Guangdong Natural Science Foundation for Distinguished Young Scholar(No.2022B1515020078)the Science and Technology Program of Guangzhou(No.2024A04J2821)。
文摘Polymerization-induced self-assembly(PISA)has become one of the most versatile approaches for scalable preparation of linear block copolymer nanoparticles with various morphologies.However,the controlled introduction of branching into the core-forming block and the effect on the morphologies of block copolymer nanoparticles under PISA conditions have rarely been explored.Herein,a series of multifunctional macromolecular chain transfer agents(macro-CTAs)were first synthesized by a two-step green light-activated photoiniferter polymerization using two types of chain transfer monomers(CTMs).These macro-CTAs were then used to mediate reversible addition-fragmentation chain transfer(RAFT)dispersion polymerization of styrene(St)to prepare block copolymers with different core-forming block structures and the assemblies.The effect of the core-forming block structure on the morphology of block copolymer nanoparticles was investigated in detail.Transmission electron microscopy(TEM)analysis indicated that the brush-like core-forming block structure facilitated the formation of higher-order morphologies,while the branched core-forming block structure favored the formation of lower-order morphologies.Moreover,it was found that using macroCTAs with a shorter length also promoted the formation of higher-order morphologies.Finally,structures of block copolymers and the assemblies were further controlled by changing the structure of macro-CTA or using a binary mixture of two different macro-CTAs.We expect that this work not only sheds light on the synthesis of block copolymer nanoparticles but also provide important mechanistic insights into PISA of nonlinear block copolymers.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12435001,12304006,and 12404265)the Natural Science Foundation of Shanghai,China(Grant No.23JC1401400)+1 种基金the Fundamental Research Funds for the Central Universities of East China University,the Natural Science Foundation of WIUCAS(Grant No.WIUCASQD2023004)the Natural Science Foundation of Wenzhou(Grant No.L2023005)。
文摘Antiferromagnetic(AFM)spintronics have sparked extensive research interest in the field of information storage due to the considerable advantages offered by antiferromagnets,including non-volatile data storage,higher storage density,and accelerating data processing.However,the manipulation and detection of internal AFM order in antiferromagnets hinders their applications in spintronic devices.Here,we proposed a design idea for an AFM material that is self-assembled from one-dimensional(1D)ferromagnetic(FM)chains.To validate this idea,we screened a two-dimensional(2D)selfassembled CrBr_(2)antiferromagnet of an AFM semiconductor from a large amount of data.This 2D CrBr_(2)antiferromagnet is composed of 1D FM CrBr_(2)chains that are arranged in a staggered and parallel configuration.In this type of antiferromagnet,the write-data operation of information is achieved in 1D FM chains,followed by a self-assembly process driving the assembly of 1D FM chains into an antiferromagnet.These constituent 1D FM chains become decoupled by external perturbations,such as heat,pressure,strain,etc.,thereby realizing the read-data operation of information.We anticipate that this antiferromagnet,composed of 1D FM chains,can be realized not only in the 1D to 2D system,but also is expected to expand to 2D to three-dimensional(3D)system,and even 1D to 3D system.
文摘The development of the Internet of Things(IoT)has brought convenience to people’s lives,but it also introduces significant security risks.Due to the limitations of IoT devices themselves and the challenges of re-hosting technology,existing fuzzing for IoT devices is mainly conducted through black-box methods,which lack effective execution feedback and are blind.Meanwhile,the existing static methods mainly rely on taint analysis,which has high overhead and high false alarm rates.We propose a new directed fuzz testing method for detecting bugs in web service programs of IoT devices,which can test IoT devices more quickly and efficiently.Specifically,we identify external input entry points using multiple features.Then we quickly find sensitive targets and paths affected by external input sources based on sensitive data flow analysis of decompiled code,treating them as testing objects.Finally,we performa directed fuzzing test.We use debugging interfaces to collect execution feedback and guide the programto reach sensitive targets based on programpruning techniques.We have implemented a prototype system,AntDFuzz,and evaluated it on firmware fromten devices across five well-known manufacturers.We discovered twelve potential vulnerabilities,seven of which were confirmed and assigned bug id by China National Vulnerability Database(CNVD).The results show that our approach has the ability to find unknown bugs in real devices and is more efficient compared to existing tools.
