Controlling charge polarity in the semiconducting single-walled carbon nanotubes(CNTs) by substitutional doping is a difficult work due to their extremely strong C–C bonding. In this work, an inner doping strategy is...Controlling charge polarity in the semiconducting single-walled carbon nanotubes(CNTs) by substitutional doping is a difficult work due to their extremely strong C–C bonding. In this work, an inner doping strategy is explored by filling CNTs with one-dimensional(1D)-TM_(6)Te_(6) nanowires to form TM_(6)Te_(6)@CNT-(16,0) 1D van der Waals heterostructures(1D-vd WHs). The systematic first-principles studies on the electronic properties of 1D-vd WHs show that N-type doping CNTs can be formed by charge transfer from TM_(6)Te_(6) nanowires to CNTs, without introducing additional carrier scattering.Particularly, contribution from both T M(e.g., Sc and Y) and Te atoms strengthens the charge transfer. The outside CNTs further confine the dispersion of Te-p orbitals in nanowires that deforms the C-π states at the bottom of the conduction band to quasi sp^(3) hybridization. Our study provides an inner doping strategy that can effectively confine the charge polarity of CNTs and further broaden its applications in some novel nano-devices.展开更多
Low-velocity impact tests are carried out to explore the energy absorption characteristics of bio-inspired lattices,mimicking the architecture of the marine sponge organism Euplectella aspergillum.These sea sponge-ins...Low-velocity impact tests are carried out to explore the energy absorption characteristics of bio-inspired lattices,mimicking the architecture of the marine sponge organism Euplectella aspergillum.These sea sponge-inspired lattice structures feature a square-grid 2D lattice with double diagonal bracings and are additively manufactured via digital light processing(DLP).The collapse strength and energy absorption capacity of sea sponge lattice structures are evaluated under various impact conditions and are compared to those of their constituent square-grid and double diagonal lattices.This study demonstrates that sea sponge lattices can achieve an 11-fold increase in energy absorption compared to the square-grid lattice,due to the stabilizing effect of the double diagonal bracings prompting the structure to collapse layer-bylayer under impact.By adjusting the thickness ratio in the sea sponge lattice,up to 76.7%increment in energy absorption is attained.It is also shown that sea-sponge lattices outperform well-established energy-absorbing materials of equal weight,such as hexagonal honeycombs,confirming their significant potential for impact mitigation.Additionally,this research highlights the enhancements in energy absorption achieved by adding a small amount(0.015 phr)of Multi-Walled Carbon Nanotubes(MWCNTs)to the photocurable resin,thus unlocking new possibilities for the design of innovative lightweight structures with multifunctional attributes.展开更多
The fabrication of a new type of one-dimensional Au-Ag porous nanotube（NPT） structure was presented based on a facile combination of nanocrystal growth and surface modification.Ag nanowires with various diameters we...The fabrication of a new type of one-dimensional Au-Ag porous nanotube（NPT） structure was presented based on a facile combination of nanocrystal growth and surface modification.Ag nanowires with various diameters were firstly served as the chemical plating templates via a polyol-process.Then,one-dimensional（1D） Au-Ag porous nanostructures with tailored structural features could be prepared by controlling the individual steps involved in this process,such as nanowire growth,surface modification,thermal diffusion,and dealloying.Structural characterizations reveal these Au-Ag porous nanotubes,non-porous nanotubes and porous nanowires possess novel nano-architectures with multimodal open porosity and excellent structural continuity and integrity,which make them particularly desirable as novel 1D nanocarriers for biomedical,drug delivery and sensing applications.展开更多
Tilted metasurface nanostructures,with excellent physical properties and enormous application potential,pose an urgent need for manufacturing methods.Here,electric-field-driven generative-nanoimprinting technique is p...Tilted metasurface nanostructures,with excellent physical properties and enormous application potential,pose an urgent need for manufacturing methods.Here,electric-field-driven generative-nanoimprinting technique is proposed.The electric field applied between the template and the substrate drives the contact,tilting,filling,and holding processes.By accurately controlling the introduced included angle between the flexible template and the substrate,tilted nanostructures with a controllable angle are imprinted onto the substrate,although they are vertical on the template.By flexibly adjusting the electric field intensity and the included angle,large-area uniform-tilted,gradient-tilted,and high-angle-tilted nanostructures are fabricated.In contrast to traditional replication,the morphology of the nanoimprinting structure is extended to customized control.This work provides a cost-effective,efficient,and versatile technology for the fabrication of various large-area tilted metasurface structures.As an illustration,a tilted nanograting with a high coupling efficiency is fabricated and integrated into augmented reality displays,demonstrating superior imaging quality.展开更多
One-dimensional(1D)nanomaterials and nanostructures have received much attention due to their potential interest for understanding fundamental physical concepts and for applications in constructing nanoscale electric ...One-dimensional(1D)nanomaterials and nanostructures have received much attention due to their potential interest for understanding fundamental physical concepts and for applications in constructing nanoscale electric and optoelectronic devices.Zinc sulfide(ZnS)is an important semiconductor compound ofⅡ-Ⅵgroup,and the synthesis of 1D ZnS nanomaterials and nanostructures has been of growing interest owing to their promising application in nanoscale optoelectronic devices.This paper reviews the recent progress on 1D ZnS nanomaterials and nanostructures,including nanowires,nanowire arrays,nanorods,nanobelts or nanoribbons,nanocables,and hierarchical nanostructures etc.This article begins with a survey of various methods that have been developed for generating 1D nanomaterials and nanostructures,and then mainly focuses on structures,synthesis,characterization,formation mechanisms and optical property tuning,and luminescence mechanisms of 1D ZnS nanomaterials and nanostructures.Finally,this review concludes with personal views towards future research on 1D ZnS nanomaterials and nanostructures.展开更多
One-dimensional Cd S@TiO_2 core-shell heterostructures were fabricated via the hydrolysis of tetrabutyl titanate(TBT) on preformed Cd S nanowires. The as-prepared products were characterized by X-ray diffraction, tran...One-dimensional Cd S@TiO_2 core-shell heterostructures were fabricated via the hydrolysis of tetrabutyl titanate(TBT) on preformed Cd S nanowires. The as-prepared products were characterized by X-ray diffraction, transmission electron microscopy, selected area electron diffraction and diffuse reflectance spectroscopy techniques. Results demonstrated that the hydrolysis of TBT had a great influence on the morphology of the coated TiO_2 shell, resulting in the formation of TiO_2 nanoparticles and nanolayer-modified Cd S@TiO_2 heterostructures. Degradation of methylene blue using Cd S@TiO_2 core-shell heterostructures as photocatalysts under visible light irradiation was investigated. Comparative photocatalytic tests showed that the TiO_2 nanoparticles-modified heterostructure exhibited a superior activity due to the passivity of photogenerated charge carriers.展开更多
A focus of the current nanotechnology has shifted from routine fabrication of nanostructures to designing functional electronic devices and realizing their immense potentials for applications. Due to infusion of multi...A focus of the current nanotechnology has shifted from routine fabrication of nanostructures to designing functional electronic devices and realizing their immense potentials for applications. Due to infusion of multi-functionality into a single system, the utilization of hetero-, core/shell and hierarchical nanostructures has become the key issue for building such devices. ZnS, due to its direct wide bandgap, high index of refraction, high transparency in the visible range and intrinsic polarity, is one of the most useful semiconductors for a wide range of electronics applications. This article provides a dense review of the state-of-the-art research activities in one-dimensional （1D） ZnS-based hetero-, core/shell and hierarchical nanostructures. The particular emphasis is put on their syntheses and applications.展开更多
The synthesis of one-dimensional （1D） semiconductor nanostructures has been studied intensively for a wide range of materials due to their unique structural and physical properties and promising potential for future...The synthesis of one-dimensional （1D） semiconductor nanostructures has been studied intensively for a wide range of materials due to their unique structural and physical properties and promising potential for future technological applications. Among various strategies for synthesizing 1D semiconductor nanostructures, solution-phase synthetic routes are advantageous in terms of cost, throughput, modulation of composition, and the potential for large-scale and environmentally benign production. This article gives a concise review on the recent developments in the solution-phase synthesis of ID semiconductor nanostructures of different compositions, sizes, shapes, and architectures. We first introduce several typical solution-phase synthetic routes based on controlled precipitation from homogeneous solutions, including hydrothermal/solvothermal process, solution-liquid-solid （SLS） process, high-temperature organic-solution process, and low-temperature aqueous-solution process. Subsequently, we discuss two solution-phase synthetic strategies involving solid tem- plates or substrates, such as the chemical transformation of 1D sacrificial templates and the oriented growth of 1D nanostructure arrays on solid substrates. Finally, prospects of the solution-phase approaches to 1D semiconductor nanostructures will be briefly discussed.展开更多
Aluminum nitride （AIN） nanowires, serrated nanoribbons, and nanoribbons were selectively obtained through a simple chloride assisted chemical vapor deposition process. The morphologies of the products could be contr...Aluminum nitride （AIN） nanowires, serrated nanoribbons, and nanoribbons were selectively obtained through a simple chloride assisted chemical vapor deposition process. The morphologies of the products could be controlled by adjusting the deposition position and the flux of the reactant gas. The morphologies and structures of the AIN products were investigated in detail. The formation mechanism of the as-prepared different morphologies of AIN one-dimensional （ID） nanostructures was discussed on the basis of the experimental results.展开更多
The frequency down-conversion of one-dimensional photonic crystals with the coupled cavity structure is investigated by the nonlinear finite-difference time-domain method. The efficient frequency conversion is obtaine...The frequency down-conversion of one-dimensional photonic crystals with the coupled cavity structure is investigated by the nonlinear finite-difference time-domain method. The efficient frequency conversion is obtained by utilizing the advantages of the broad eigenfrequency band, the strong localization and the Bloch phase matching of the coupled cavity structure. More importantly, the signal frequency could be tuned continuously within the whole band of the coupled cavity structure （with a bandwidth to central frequency ratio of 5.4%）, and the gains are homogeneous in the band.展开更多
A new Zn（Ⅱ）coordination polymer,[Zn（nba）2（mbix）]2n（1,Hnba=4-nitrobenzoic acid,mbix=1,3-bis（imidazol-1-ylmethyl）-benzene）,was synthesized and characterized by elemental analyses,IR spectra,TG,fluorescence sp...A new Zn（Ⅱ）coordination polymer,[Zn（nba）2（mbix）]2n（1,Hnba=4-nitrobenzoic acid,mbix=1,3-bis（imidazol-1-ylmethyl）-benzene）,was synthesized and characterized by elemental analyses,IR spectra,TG,fluorescence spectroscopy,single-crystal and powder X-ray diffractions.It belongs to the triclinic system,■ space group,with a=9.341（2）,b=13.029（3）,c=23.660（6）?,α=99.603（6）°,β=90.461（6）°,γ=90.597（5）°,V=2838.9（12）?3 and Z=2.It shows one-dimensional chains which are further linked by C–H···O hydrogen bonds andπ-πstacking interactions to yield a three-dimensional supramolecular structure.In addition,the Natural Bond Orbital（NBO）was analyzed in using the PBE0/LANL2DZ method built in Gaussian 09 Program.The calculation results indicated obvious covalent interaction between the coordinated atoms and Zn（Ⅱ）ion.展开更多
In this study, we designed and fabricated optical materials consisting of alternating ITO and Ag layers. This approach is considered to be a promising way to obtain a light-weight, ultrathin and transparent shielding ...In this study, we designed and fabricated optical materials consisting of alternating ITO and Ag layers. This approach is considered to be a promising way to obtain a light-weight, ultrathin and transparent shielding medium, which not only transmits visible light but also inhibits the transmission of microwaves, despite the fact that the total thickness of the Ag film is much larger than the skin depth in the visible range and less than that in the microwave region. Theoretical results suggest that a high dielectric/metal thickness ratio can enhance the broadband and improve the transmittance in the optical range. Accordingly, the central wavelength was found to be red-shifted with increasing dielectric/metal thickness ratio. A physical mechanism behind the controlling transmission of visible light is also proposed. Meanwhile, the electromagnetic shielding effectiveness of the prepared structures was found to exceed 40 dB in the range from 0.1 GHz to 18 GHz, even reaching up to 70 dB at 0.1 GHz, which is far higher than that of a single ITO film of the same thickness.展开更多
The wave propagation problem in the nonlinear periodic mass-spring structure chain is analyzed using the symplectic mathematical method. The energy method is used to construct the dynamic equation, and the nonlinear d...The wave propagation problem in the nonlinear periodic mass-spring structure chain is analyzed using the symplectic mathematical method. The energy method is used to construct the dynamic equation, and the nonlinear dynamic equation is linearized using the small parameter perturbation method. Eigen-solutions of the symplectic matrix are used to analyze the wave propagation problem in nonlinear periodic lattices. Nonlinearity in the mass-spring chain, arising from the nonlinear spring stiffness effect, has profound effects on the overall transmission of the chain. The wave propagation characteristics are altered due to nonlinearity, and related to the incident wave intensity, which is a genuine nonlinear effect not present in the corresponding linear model. Numerical results show how the increase of nonlinearity or incident wave amplitude leads to closing of transmitting gaps. Comparison with the normal recursive approach shows effectiveness and superiority of the symplectic method for the wave propagation problem in nonlinear periodic structures.展开更多
Two new Ni（ Ⅱ） coordination polymers, {[Ni（tbip）（bipy）（H2O）]-0.5H2O}n 1 and [Ni（tbip）（phen）（H2O）]n 2 （Hatbip = 5-tert-butyl isophthalic acid, bipy = 2,2＇-bipyridine, phen = 1,10-phenanthroline）, have...Two new Ni（ Ⅱ） coordination polymers, {[Ni（tbip）（bipy）（H2O）]-0.5H2O}n 1 and [Ni（tbip）（phen）（H2O）]n 2 （Hatbip = 5-tert-butyl isophthalic acid, bipy = 2,2＇-bipyridine, phen = 1,10-phenanthroline）, have been synthesized under hydrothermal conditions and characterized by elemental analysis, X-ray diffraction, and IR spectroscopy. In the two polymers, H2tbip acts as a tridentate ligand. Compound 1 has a tbip bridged 1-D linear chain which is extended by hydrogen bonds into a 1-D double chain, while compound 2 exhibits a 1-D zigzag chain.展开更多
In recent years,one-dimensional(1D)nanomaterials have raised researcher's interest because of their unique structur-al characteristic to generate and confine the optical signal and their promising prospects in pho...In recent years,one-dimensional(1D)nanomaterials have raised researcher's interest because of their unique structur-al characteristic to generate and confine the optical signal and their promising prospects in photonic applications.In this re-view,we summarized the recent research advances on the spectroscopy and carrier dynamics of 1D nanostructures.First,the condensation and propagation of exciton-polaritons in nanowires(NWs)are introduced.Second,we discussed the properties of 1D photonic crystal(PC)and applications in photonic-plasmonic structures.Third,the observation of topological edge states in 1D topological structures is introduced.Finally,the perspective on the potential opportunities and remaining chal-lenges of 1D nanomaterials is proposed.展开更多
We systematically explore near equilibrium, flow-driven, and flow-activity coupled dynamics of polar active liquid crystals using a continuum model. Firstly, we re-derive the hydrodynamic model to ensure the thermodyn...We systematically explore near equilibrium, flow-driven, and flow-activity coupled dynamics of polar active liquid crystals using a continuum model. Firstly, we re-derive the hydrodynamic model to ensure the thermodynamic laws are obeyed and elastic stresses and forces are consistently accounted. We then carry out a linear stability analysis about constant steady states to study near equilibrium dynamics around the steady states, revealing long-wave instability inherent in this model system and how active parameters in the model affect the instability. We then study model predictions for one- dimensional （1D） spatial-temporal structures of active liquid crystals in a channel subject to physical boundary conditions. We discuss the model prediction in two selected regimes, one is the viscous stress dominated regime, also known as the flow-driven regime, while the other is the full regime, in which all active mechanisms are included. In the viscous stress dominated regime, the polarity vector is driven by the prescribed flow field. Dynamics depend sensitively on the physical boundary condition and the type of the driven flow field. Bulk-dominated temporal periodic states and spatially homogeneous states are possible under weak anchoring conditions while spatially inhomogeneous states exist under strong anchoring conditions. In the full model, flow-orientation interaction generates a host of planar as well as out-of-plane spatial-temporal structures related to the spontaneous flows due to the molecular self-propelled motion. These results provide contact with the recent literature on active nematic suspensions. In addition, symmetry breaking pattems emerge as the additional active viscous stress due to the polarity vector is included in the force balance. The inertia effect is found to limit the long-time survival of spatial structures to those with small wave numbers, i.e., an asymptotic coarsening to long wave structures. A rich set of mechanisms for generating and limiting the flow structures as well as the spatial-temporal structures predicted by the model are displayed.展开更多
Periodic photonic structures can provide rich modulation in propagation of light due to well-defined band structures.Especially near band edges,light localization and the effect of near-zero refractive index have attr...Periodic photonic structures can provide rich modulation in propagation of light due to well-defined band structures.Especially near band edges,light localization and the effect of near-zero refractive index have attracted wide attention.However,the practically fabricated structures can only have finite size,i.e.,limited numbers of periods,leading to changes of the light propagation modulation compared with infinite structures.Here,we study the size effect on light localization and near-zero refractive-index propagation near band edges in one-dimensional periodic structures.Near edges of the band gap,as the structure's size shrinks,the broadening of the band gap and the weakening of the light localization are discovered.When the size is small,an added layer on the surface will perform large modulation in the group velocity.Near the degenerate point with Dirac-like dispersion,the zero-refractive-index effects like the zero-phase difference and near-unity transmittance retain as the size changes,while absolute group velocity fluctuates when the size shrinks.展开更多
Two one-dimensional cobalt（II） compounds {[Co（Hbpma）（H20）4]2·3SO4·4.5H2O}n 1 and {[Co（Hbpma）（NCS）3（H20）]·2.85H2O}n 2 （bpma = N,N＇-bis（3-pyridylmethyl）amine） have been synthesized and st...Two one-dimensional cobalt（II） compounds {[Co（Hbpma）（H20）4]2·3SO4·4.5H2O}n 1 and {[Co（Hbpma）（NCS）3（H20）]·2.85H2O}n 2 （bpma = N,N＇-bis（3-pyridylmethyl）amine） have been synthesized and structurally characterized by single-crystal X-ray diffraction. Complex 1 crystallizes in triclinic, space group Pi with a = 15.8780（5）, b = 16.2187（5）, c = 16.4858（5） A, α = 91.0420（10）,β = 94.5190（10）, γ = 101.4360（10）°, V = 4145.7（2） A3, C24H53Co2N6024.5083, Mr = 1031.76, Z = 4, Dc = 1.653 g/cm3, p（MoKa） = 1.046 mm-1, F（000） = 2148, S = 1.017, the final R = 0.0269 and wR = 0.0644 for 13032 observed reflections （I 〉 2a（/））. For complex 2, it belongs to triclinic, space group Pi with a = 9.3761（11）, b = 10.5814（13）, c = 11.2972（14）A, α= 85.472（2）,β = 88.058（2）,γ = 76.203（2）°, V= 1085.0（2） A3, C15Hzl.v0CoN603.85S3, Mr= 502.79, Z = 2, Dc = 1.539 g/cm3, p（MoKa） = 1.112 mm-1, F（000） = 519, S = 1.070, the final R = 0.0358 and wR = 0.0899 for 3466 observed reflections （I 〉 2σ（I））. Two complexes 1 and 2 are both found to be one-dimensional coordination polymers bridged by the protonated bpma ligands, which are assembled into three-dimensional supramolecular structures through the hydrogen bonding interactions and π-π packing interactions.展开更多
By using the flexible hinge-like ligand 2,2＇-bis（3-hydroxy-l,4-naphthoquinone） （H2bhnq）, two isomorphous one-dimensional zigzag chain coordination polymers have been obtained. Single-crystal X-ray analyses reveal...By using the flexible hinge-like ligand 2,2＇-bis（3-hydroxy-l,4-naphthoquinone） （H2bhnq）, two isomorphous one-dimensional zigzag chain coordination polymers have been obtained. Single-crystal X-ray analyses revealed that the metal centers in these two complexes are distorted octahedra involving four oxygen atoms of two bhnq2 anions, and two oxygen atoms of two DMF molecules situated in trans positions to one another. Crystal data for [Mn（bhnq）（DMF）2]n 1： C26H22MnN2O8, Mr = 545.40, monoclinic, space group C2/c, a = 14.936（3）, b = 10.362（2）, c = 15.901（3）A., β = 99.86（3）°, V = 2424.7（8）A3, Z = 4, Dc = 1.494 g/cm^3, F（000） = 1124,μ = 0.599 mm^-1, final GOOF = 1.025, R = 0.0654 and wR = 0.1537. Crystal data for [Cd（bhnq）（DMF）2]n 2： C26H22CdN2O8, Mr = 602.86, monoclinic, space group C2/c, a = 14.839（3）, b = 10.493（2）, c = 16.034（3）A, β = 99.40（3）°, V = 2463.1（9）A^3, Z = 4, Dc = 1.626 g/cm^3, F（000） = 1216,μ = 0.941 mm^-1, final GOOF = 1.069, R = 0.0358 and wR = 0.0944.展开更多
A new kind of one-dimensional multilayer phononie heterostructure is constructed to obtain a broad acoustic omnidirectional reflection （ODR） band. The heterostructure is formed by combining finite periodic phononic ...A new kind of one-dimensional multilayer phononie heterostructure is constructed to obtain a broad acoustic omnidirectional reflection （ODR） band. The heterostructure is formed by combining finite periodic phononic crystals （PnCs） and Fibonacci （or Thue-Morse） quasiperiodic PnCs. From the numerical results performed by the transfer matrix method, it is found that the ODR bands can be enlarged obviously by using the combination of periodic and quasi-periodic PnCs. Moreover, an application of particle swarm optimization in designing and optimizing acoustic ODR bands is reported. With regards to different thickness ratios and periodic numbers in the heterostructure, we give some optimization examples and finally achieve phononic heterostructure with a very broad ODR bandwidth. The result provides a new approach to achieve broad acoustic ODR bandwidth, and will be applied in design of omnidirectional acoustic mirrors.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant No. 92477205)。
文摘Controlling charge polarity in the semiconducting single-walled carbon nanotubes(CNTs) by substitutional doping is a difficult work due to their extremely strong C–C bonding. In this work, an inner doping strategy is explored by filling CNTs with one-dimensional(1D)-TM_(6)Te_(6) nanowires to form TM_(6)Te_(6)@CNT-(16,0) 1D van der Waals heterostructures(1D-vd WHs). The systematic first-principles studies on the electronic properties of 1D-vd WHs show that N-type doping CNTs can be formed by charge transfer from TM_(6)Te_(6) nanowires to CNTs, without introducing additional carrier scattering.Particularly, contribution from both T M(e.g., Sc and Y) and Te atoms strengthens the charge transfer. The outside CNTs further confine the dispersion of Te-p orbitals in nanowires that deforms the C-π states at the bottom of the conduction band to quasi sp^(3) hybridization. Our study provides an inner doping strategy that can effectively confine the charge polarity of CNTs and further broaden its applications in some novel nano-devices.
基金supported by the Khalifa University of Science and Technology internal grants(Nos.2021-CIRA-109,2020-CIRA-007,and 2020-CIRA-024).
文摘Low-velocity impact tests are carried out to explore the energy absorption characteristics of bio-inspired lattices,mimicking the architecture of the marine sponge organism Euplectella aspergillum.These sea sponge-inspired lattice structures feature a square-grid 2D lattice with double diagonal bracings and are additively manufactured via digital light processing(DLP).The collapse strength and energy absorption capacity of sea sponge lattice structures are evaluated under various impact conditions and are compared to those of their constituent square-grid and double diagonal lattices.This study demonstrates that sea sponge lattices can achieve an 11-fold increase in energy absorption compared to the square-grid lattice,due to the stabilizing effect of the double diagonal bracings prompting the structure to collapse layer-bylayer under impact.By adjusting the thickness ratio in the sea sponge lattice,up to 76.7%increment in energy absorption is attained.It is also shown that sea-sponge lattices outperform well-established energy-absorbing materials of equal weight,such as hexagonal honeycombs,confirming their significant potential for impact mitigation.Additionally,this research highlights the enhancements in energy absorption achieved by adding a small amount(0.015 phr)of Multi-Walled Carbon Nanotubes(MWCNTs)to the photocurable resin,thus unlocking new possibilities for the design of innovative lightweight structures with multifunctional attributes.
基金Project (2012CB932800) supported by the National Basic Research Program of ChinaProject (2012M521330) supported by China Postdoctoral Science Foundation
文摘The fabrication of a new type of one-dimensional Au-Ag porous nanotube（NPT） structure was presented based on a facile combination of nanocrystal growth and surface modification.Ag nanowires with various diameters were firstly served as the chemical plating templates via a polyol-process.Then,one-dimensional（1D） Au-Ag porous nanostructures with tailored structural features could be prepared by controlling the individual steps involved in this process,such as nanowire growth,surface modification,thermal diffusion,and dealloying.Structural characterizations reveal these Au-Ag porous nanotubes,non-porous nanotubes and porous nanowires possess novel nano-architectures with multimodal open porosity and excellent structural continuity and integrity,which make them particularly desirable as novel 1D nanocarriers for biomedical,drug delivery and sensing applications.
基金supported by National Natural Science Foundation of China(No.52025055 and 52275571)Basic Research Operation Fund of China(No.xzy012024024).
文摘Tilted metasurface nanostructures,with excellent physical properties and enormous application potential,pose an urgent need for manufacturing methods.Here,electric-field-driven generative-nanoimprinting technique is proposed.The electric field applied between the template and the substrate drives the contact,tilting,filling,and holding processes.By accurately controlling the introduced included angle between the flexible template and the substrate,tilted nanostructures with a controllable angle are imprinted onto the substrate,although they are vertical on the template.By flexibly adjusting the electric field intensity and the included angle,large-area uniform-tilted,gradient-tilted,and high-angle-tilted nanostructures are fabricated.In contrast to traditional replication,the morphology of the nanoimprinting structure is extended to customized control.This work provides a cost-effective,efficient,and versatile technology for the fabrication of various large-area tilted metasurface structures.As an illustration,a tilted nanograting with a high coupling efficiency is fabricated and integrated into augmented reality displays,demonstrating superior imaging quality.
基金The authors acknowledge the support from the National Major Project of Fundamental Research:Nanomaterials and Nanostructures(Grant No.2005CB623603)the National Natural Science Foundation of China(Grant Nos.10304018,10574131)Special Fund for President Scholarship,Chinese Academy of Sciences.
文摘One-dimensional(1D)nanomaterials and nanostructures have received much attention due to their potential interest for understanding fundamental physical concepts and for applications in constructing nanoscale electric and optoelectronic devices.Zinc sulfide(ZnS)is an important semiconductor compound ofⅡ-Ⅵgroup,and the synthesis of 1D ZnS nanomaterials and nanostructures has been of growing interest owing to their promising application in nanoscale optoelectronic devices.This paper reviews the recent progress on 1D ZnS nanomaterials and nanostructures,including nanowires,nanowire arrays,nanorods,nanobelts or nanoribbons,nanocables,and hierarchical nanostructures etc.This article begins with a survey of various methods that have been developed for generating 1D nanomaterials and nanostructures,and then mainly focuses on structures,synthesis,characterization,formation mechanisms and optical property tuning,and luminescence mechanisms of 1D ZnS nanomaterials and nanostructures.Finally,this review concludes with personal views towards future research on 1D ZnS nanomaterials and nanostructures.
基金financial support Independent Innovation Foundation of Shandong University(IIFSDU-2009JQ011)
文摘One-dimensional Cd S@TiO_2 core-shell heterostructures were fabricated via the hydrolysis of tetrabutyl titanate(TBT) on preformed Cd S nanowires. The as-prepared products were characterized by X-ray diffraction, transmission electron microscopy, selected area electron diffraction and diffuse reflectance spectroscopy techniques. Results demonstrated that the hydrolysis of TBT had a great influence on the morphology of the coated TiO_2 shell, resulting in the formation of TiO_2 nanoparticles and nanolayer-modified Cd S@TiO_2 heterostructures. Degradation of methylene blue using Cd S@TiO_2 core-shell heterostructures as photocatalysts under visible light irradiation was investigated. Comparative photocatalytic tests showed that the TiO_2 nanoparticles-modified heterostructure exhibited a superior activity due to the passivity of photogenerated charge carriers.
基金World Premier International Research Center Initiative(WPI Initiative)on Materials Nanoarchitronics,MEXT,Japanthe Japan Society for the Promotion of Science (JSPS)for a support in the form of a fellowship tenable at the National Institute for Materials Science,Tsukuba,Japan.
文摘A focus of the current nanotechnology has shifted from routine fabrication of nanostructures to designing functional electronic devices and realizing their immense potentials for applications. Due to infusion of multi-functionality into a single system, the utilization of hetero-, core/shell and hierarchical nanostructures has become the key issue for building such devices. ZnS, due to its direct wide bandgap, high index of refraction, high transparency in the visible range and intrinsic polarity, is one of the most useful semiconductors for a wide range of electronics applications. This article provides a dense review of the state-of-the-art research activities in one-dimensional （1D） ZnS-based hetero-, core/shell and hierarchical nanostructures. The particular emphasis is put on their syntheses and applications.
文摘The synthesis of one-dimensional （1D） semiconductor nanostructures has been studied intensively for a wide range of materials due to their unique structural and physical properties and promising potential for future technological applications. Among various strategies for synthesizing 1D semiconductor nanostructures, solution-phase synthetic routes are advantageous in terms of cost, throughput, modulation of composition, and the potential for large-scale and environmentally benign production. This article gives a concise review on the recent developments in the solution-phase synthesis of ID semiconductor nanostructures of different compositions, sizes, shapes, and architectures. We first introduce several typical solution-phase synthetic routes based on controlled precipitation from homogeneous solutions, including hydrothermal/solvothermal process, solution-liquid-solid （SLS） process, high-temperature organic-solution process, and low-temperature aqueous-solution process. Subsequently, we discuss two solution-phase synthetic strategies involving solid tem- plates or substrates, such as the chemical transformation of 1D sacrificial templates and the oriented growth of 1D nanostructure arrays on solid substrates. Finally, prospects of the solution-phase approaches to 1D semiconductor nanostructures will be briefly discussed.
基金the National Natural Science Foundation of China under grant Nos.10674138 and 20571022.
文摘Aluminum nitride （AIN） nanowires, serrated nanoribbons, and nanoribbons were selectively obtained through a simple chloride assisted chemical vapor deposition process. The morphologies of the products could be controlled by adjusting the deposition position and the flux of the reactant gas. The morphologies and structures of the AIN products were investigated in detail. The formation mechanism of the as-prepared different morphologies of AIN one-dimensional （ID） nanostructures was discussed on the basis of the experimental results.
文摘The frequency down-conversion of one-dimensional photonic crystals with the coupled cavity structure is investigated by the nonlinear finite-difference time-domain method. The efficient frequency conversion is obtained by utilizing the advantages of the broad eigenfrequency band, the strong localization and the Bloch phase matching of the coupled cavity structure. More importantly, the signal frequency could be tuned continuously within the whole band of the coupled cavity structure （with a bandwidth to central frequency ratio of 5.4%）, and the gains are homogeneous in the band.
基金supported by the Science and Technology development plan of Jilin Province(2015052006JH)
文摘A new Zn（Ⅱ）coordination polymer,[Zn（nba）2（mbix）]2n（1,Hnba=4-nitrobenzoic acid,mbix=1,3-bis（imidazol-1-ylmethyl）-benzene）,was synthesized and characterized by elemental analyses,IR spectra,TG,fluorescence spectroscopy,single-crystal and powder X-ray diffractions.It belongs to the triclinic system,■ space group,with a=9.341（2）,b=13.029（3）,c=23.660（6）?,α=99.603（6）°,β=90.461（6）°,γ=90.597（5）°,V=2838.9（12）?3 and Z=2.It shows one-dimensional chains which are further linked by C–H···O hydrogen bonds andπ-πstacking interactions to yield a three-dimensional supramolecular structure.In addition,the Natural Bond Orbital（NBO）was analyzed in using the PBE0/LANL2DZ method built in Gaussian 09 Program.The calculation results indicated obvious covalent interaction between the coordinated atoms and Zn（Ⅱ）ion.
基金Project supported by the International Science&Technology Cooperation Program of China(Grant No.2014DFR10020)the Science Foundation of Shanxi Province,China(Grant Nos.201701D121050 and 201701D121007)
文摘In this study, we designed and fabricated optical materials consisting of alternating ITO and Ag layers. This approach is considered to be a promising way to obtain a light-weight, ultrathin and transparent shielding medium, which not only transmits visible light but also inhibits the transmission of microwaves, despite the fact that the total thickness of the Ag film is much larger than the skin depth in the visible range and less than that in the microwave region. Theoretical results suggest that a high dielectric/metal thickness ratio can enhance the broadband and improve the transmittance in the optical range. Accordingly, the central wavelength was found to be red-shifted with increasing dielectric/metal thickness ratio. A physical mechanism behind the controlling transmission of visible light is also proposed. Meanwhile, the electromagnetic shielding effectiveness of the prepared structures was found to exceed 40 dB in the range from 0.1 GHz to 18 GHz, even reaching up to 70 dB at 0.1 GHz, which is far higher than that of a single ITO film of the same thickness.
基金Project supported by the National Natural Science Foundation of China (Nos. 10972182,10772147,and 10632030)the National Basic Research Program of China (No. 2006CB 601202)+4 种基金the National 111 Project of China (No. B07050)the Open Foundation of State Key Laboratory of Structural Analysis of Industrial Equipment (No. GZ0802)the Doctoral Foundation of Northwestern Polytechnical University (No. CX200908)the China Postdoctoral Science Foundation (No. 20090450170)the Northwestern Polytechnical University Foundation for Fundamental Research (No. JC200938)
文摘The wave propagation problem in the nonlinear periodic mass-spring structure chain is analyzed using the symplectic mathematical method. The energy method is used to construct the dynamic equation, and the nonlinear dynamic equation is linearized using the small parameter perturbation method. Eigen-solutions of the symplectic matrix are used to analyze the wave propagation problem in nonlinear periodic lattices. Nonlinearity in the mass-spring chain, arising from the nonlinear spring stiffness effect, has profound effects on the overall transmission of the chain. The wave propagation characteristics are altered due to nonlinearity, and related to the incident wave intensity, which is a genuine nonlinear effect not present in the corresponding linear model. Numerical results show how the increase of nonlinearity or incident wave amplitude leads to closing of transmitting gaps. Comparison with the normal recursive approach shows effectiveness and superiority of the symplectic method for the wave propagation problem in nonlinear periodic structures.
基金supported by the National Natural Science Foundation of China (Nos.20771026 and 20771054)the Henan Tackle Key Problem of Science and Technology (Nos.072102270030 and 072102270034)the Foundation of Education Committee of Henan Province (2006150017 and 2008A150018)
文摘Two new Ni（ Ⅱ） coordination polymers, {[Ni（tbip）（bipy）（H2O）]-0.5H2O}n 1 and [Ni（tbip）（phen）（H2O）]n 2 （Hatbip = 5-tert-butyl isophthalic acid, bipy = 2,2＇-bipyridine, phen = 1,10-phenanthroline）, have been synthesized under hydrothermal conditions and characterized by elemental analysis, X-ray diffraction, and IR spectroscopy. In the two polymers, H2tbip acts as a tridentate ligand. Compound 1 has a tbip bridged 1-D linear chain which is extended by hydrogen bonds into a 1-D double chain, while compound 2 exhibits a 1-D zigzag chain.
基金supported by the Strategic Priority Research Program of Chinese Academy of Sciences(XDB36000000)National Natural Science Foundation of China(22073022,11874130,12074086,22173025)+3 种基金the Support by the DNL Cooperation Fund,CAS(DNL202016)China Postdoctoral Science Foundation(2022M710925)Beijing Municipal Natural Science Foundation(1222030)the CAS Instrument Development Project(No.Y950291).
文摘In recent years,one-dimensional(1D)nanomaterials have raised researcher's interest because of their unique structur-al characteristic to generate and confine the optical signal and their promising prospects in photonic applications.In this re-view,we summarized the recent research advances on the spectroscopy and carrier dynamics of 1D nanostructures.First,the condensation and propagation of exciton-polaritons in nanowires(NWs)are introduced.Second,we discussed the properties of 1D photonic crystal(PC)and applications in photonic-plasmonic structures.Third,the observation of topological edge states in 1D topological structures is introduced.Finally,the perspective on the potential opportunities and remaining chal-lenges of 1D nanomaterials is proposed.
基金supported by the National Natural Science Foundation of China(Grant Nos.DMS-1200487,DMR-1122483,and NIH 2R01GM078994-05A1)the Air Force Office of Scientific Research(AFOSR)(Grant No.FA9550-12-1-0178)the Army Research Office(Grant Nos.ARO-12-60317-MS and SC EPSCoR GEAR(CI and CRP))
文摘We systematically explore near equilibrium, flow-driven, and flow-activity coupled dynamics of polar active liquid crystals using a continuum model. Firstly, we re-derive the hydrodynamic model to ensure the thermodynamic laws are obeyed and elastic stresses and forces are consistently accounted. We then carry out a linear stability analysis about constant steady states to study near equilibrium dynamics around the steady states, revealing long-wave instability inherent in this model system and how active parameters in the model affect the instability. We then study model predictions for one- dimensional （1D） spatial-temporal structures of active liquid crystals in a channel subject to physical boundary conditions. We discuss the model prediction in two selected regimes, one is the viscous stress dominated regime, also known as the flow-driven regime, while the other is the full regime, in which all active mechanisms are included. In the viscous stress dominated regime, the polarity vector is driven by the prescribed flow field. Dynamics depend sensitively on the physical boundary condition and the type of the driven flow field. Bulk-dominated temporal periodic states and spatially homogeneous states are possible under weak anchoring conditions while spatially inhomogeneous states exist under strong anchoring conditions. In the full model, flow-orientation interaction generates a host of planar as well as out-of-plane spatial-temporal structures related to the spontaneous flows due to the molecular self-propelled motion. These results provide contact with the recent literature on active nematic suspensions. In addition, symmetry breaking pattems emerge as the additional active viscous stress due to the polarity vector is included in the force balance. The inertia effect is found to limit the long-time survival of spatial structures to those with small wave numbers, i.e., an asymptotic coarsening to long wave structures. A rich set of mechanisms for generating and limiting the flow structures as well as the spatial-temporal structures predicted by the model are displayed.
基金the National Key Basic Research Program of China(Grant No.2022YFA1404800)the National Natural Science Foundation of China(Grant Nos.12234007 and 12221004)supported by Science and Technology Commission of Shanghai Municipality,China(Grant Nos.19XD1434600,2019SHZDZX01,19DZ2253000,20501110500,and 21DZ1101500)。
文摘Periodic photonic structures can provide rich modulation in propagation of light due to well-defined band structures.Especially near band edges,light localization and the effect of near-zero refractive index have attracted wide attention.However,the practically fabricated structures can only have finite size,i.e.,limited numbers of periods,leading to changes of the light propagation modulation compared with infinite structures.Here,we study the size effect on light localization and near-zero refractive-index propagation near band edges in one-dimensional periodic structures.Near edges of the band gap,as the structure's size shrinks,the broadening of the band gap and the weakening of the light localization are discovered.When the size is small,an added layer on the surface will perform large modulation in the group velocity.Near the degenerate point with Dirac-like dispersion,the zero-refractive-index effects like the zero-phase difference and near-unity transmittance retain as the size changes,while absolute group velocity fluctuates when the size shrinks.
基金supported by the National Natural Science Foundation of China(No.20901059and20771083)the Technological Development Foundation Project of Tian jin Educational Committee(No.20080503)
文摘Two one-dimensional cobalt（II） compounds {[Co（Hbpma）（H20）4]2·3SO4·4.5H2O}n 1 and {[Co（Hbpma）（NCS）3（H20）]·2.85H2O}n 2 （bpma = N,N＇-bis（3-pyridylmethyl）amine） have been synthesized and structurally characterized by single-crystal X-ray diffraction. Complex 1 crystallizes in triclinic, space group Pi with a = 15.8780（5）, b = 16.2187（5）, c = 16.4858（5） A, α = 91.0420（10）,β = 94.5190（10）, γ = 101.4360（10）°, V = 4145.7（2） A3, C24H53Co2N6024.5083, Mr = 1031.76, Z = 4, Dc = 1.653 g/cm3, p（MoKa） = 1.046 mm-1, F（000） = 2148, S = 1.017, the final R = 0.0269 and wR = 0.0644 for 13032 observed reflections （I 〉 2a（/））. For complex 2, it belongs to triclinic, space group Pi with a = 9.3761（11）, b = 10.5814（13）, c = 11.2972（14）A, α= 85.472（2）,β = 88.058（2）,γ = 76.203（2）°, V= 1085.0（2） A3, C15Hzl.v0CoN603.85S3, Mr= 502.79, Z = 2, Dc = 1.539 g/cm3, p（MoKa） = 1.112 mm-1, F（000） = 519, S = 1.070, the final R = 0.0358 and wR = 0.0899 for 3466 observed reflections （I 〉 2σ（I））. Two complexes 1 and 2 are both found to be one-dimensional coordination polymers bridged by the protonated bpma ligands, which are assembled into three-dimensional supramolecular structures through the hydrogen bonding interactions and π-π packing interactions.
基金Supported by the National Natural Science Foundation of China (20701022)the Ningbo Municipal Natural Science Foundation (2007A610024)+1 种基金the Open Foundation of Municipal Key Laboratory(2007A2203)the K.C. Wong Magna Fund in NBU
文摘By using the flexible hinge-like ligand 2,2＇-bis（3-hydroxy-l,4-naphthoquinone） （H2bhnq）, two isomorphous one-dimensional zigzag chain coordination polymers have been obtained. Single-crystal X-ray analyses revealed that the metal centers in these two complexes are distorted octahedra involving four oxygen atoms of two bhnq2 anions, and two oxygen atoms of two DMF molecules situated in trans positions to one another. Crystal data for [Mn（bhnq）（DMF）2]n 1： C26H22MnN2O8, Mr = 545.40, monoclinic, space group C2/c, a = 14.936（3）, b = 10.362（2）, c = 15.901（3）A., β = 99.86（3）°, V = 2424.7（8）A3, Z = 4, Dc = 1.494 g/cm^3, F（000） = 1124,μ = 0.599 mm^-1, final GOOF = 1.025, R = 0.0654 and wR = 0.1537. Crystal data for [Cd（bhnq）（DMF）2]n 2： C26H22CdN2O8, Mr = 602.86, monoclinic, space group C2/c, a = 14.839（3）, b = 10.493（2）, c = 16.034（3）A, β = 99.40（3）°, V = 2463.1（9）A^3, Z = 4, Dc = 1.626 g/cm^3, F（000） = 1216,μ = 0.941 mm^-1, final GOOF = 1.069, R = 0.0358 and wR = 0.0944.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11304286,11274279 and 11174255the Scientific Research Fund of Zhejiang Provincial Education Department under Grant No Y201226257
文摘A new kind of one-dimensional multilayer phononie heterostructure is constructed to obtain a broad acoustic omnidirectional reflection （ODR） band. The heterostructure is formed by combining finite periodic phononic crystals （PnCs） and Fibonacci （or Thue-Morse） quasiperiodic PnCs. From the numerical results performed by the transfer matrix method, it is found that the ODR bands can be enlarged obviously by using the combination of periodic and quasi-periodic PnCs. Moreover, an application of particle swarm optimization in designing and optimizing acoustic ODR bands is reported. With regards to different thickness ratios and periodic numbers in the heterostructure, we give some optimization examples and finally achieve phononic heterostructure with a very broad ODR bandwidth. The result provides a new approach to achieve broad acoustic ODR bandwidth, and will be applied in design of omnidirectional acoustic mirrors.
