Controlled synthesis of one-dimensional Au-Ag porous nanostructures

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.

One-Dimensional Magnetic FeCoNi Alloy Toward Low-Frequency Electromagnetic Wave Absorption

Rational designing of one-dimensional(1D)magnetic alloy to facilitate electromagnetic(EM)wave attenuation capability in low-frequency(2-6 GHz)microwave absorption field is highly desired but remains a significant challenge.In this study,a composite EM wave absorber made of a FeCoNi medium-entropy alloy embedded in a 1D carbon matrix framework is rationally designed through an improved electrospinning method.The 1D-shaped FeCoNi alloy embedded composite demonstrates the high-density and continuous magnetic network using off-axis electronic holography technique,indicating the excellent magnetic loss ability under an external EM field.Then,the in-depth analysis shows that many factors,including 1D anisotropy and intrinsic physical features of the magnetic medium-entropy alloy,primarily contribute to the enhanced EM wave absorption performance.Therefore,the fabricated EM wave absorber shows an increasing effective absorption band of 1.3 GHz in the low-frequency electromagnetic field at an ultrathin thickness of 2 mm.Thus,this study opens up a new method for the design and preparation of high-performance 1D magnetic EM absorbers.

One-dimensional Chain Topology in [Ag(C_6H_6NCl)_2](ClO_4), Generated through Weak Interaction between Molecules

The mononuclear complex [Ag(C6H6NCl)2](ClO() has been prepared and structurally analyzed by single-crystal X-ray diffraction. The complex crystallizes in the monoclinic system, space group C2/c with unit cell parameters: a=15.5314(2), b=8.0247(8), c=15.3701(2)?.β=118.832(2)°, V=1678.2(3)?3, Z=4, Mr=462.46, Dc=1.830Mg/m3, F(000)=912, μ(MoKα) = 1.694cm-1. The final R and wR are 0.0472 and 0.1272 for 1484 observed reflections with I≥3σ(I). The Ag atom is coordinated by two nitrogen atoms of 4-chloromethyl-pyridine in a linear coordination geometry. Each molecule is further linked by the weak interaction between the Cl and Ag atoms to form a one-dimensional chain structure with Ag－Cl distance of 3.240?.

Synthesis, Characterization and Crystal Structure Determination of a Thiocyanato Bridged One-dimensional Polymeric Complex of Cadmium(Ⅱ)

A new one-dimensional polymeric complex [Cd（SCN）2（H2O）]L （L = N,N′-bis（furan- 2-ylmethylene）hydrazine） has been synthesized and characterized by IR, UV spectra, TG-DTA technique and single-crystal X-ray diffraction analysis. It crystallizes in triclinic, pace group P1^- with a = 5.9268（8）, b = 10.8678（15）, c = 13.3671（19） A, α = 109.295（2）, β = 95.092（2）, γ = 97.8580（10）°, V = 796.70（19）A^3, Z = 2, C12H10CdN4O3S2, Mr = 434.76, μ = 1.648 mm^-1, Dc = 1.812 g/cm^3, F（000） = 428, R = 0.0308 and wR = 0.0769. The crystal structure reveals that the structure of [Cd（SCN）2（H2O）]n features di-μ-1,3-thiocyante bridges and 1D chains. The octahedrally coordinated Cd atom is surrounded by one oxygen atom from water molecule, three S atoms and two N atoms from five di-μ-1,3 thiocyanato bridges. The Cd atoms are connected by two di-μ-1,3 thiocyanato bridges with the Cd（1）…Cd（1A） separation of 4.239（1） A and Cd（1）...Cd（1B） of 5.852（1）/~. In addition, the one-dimensional straight chain structure is further connected by multiform intermolecular N-H…O hydrogen bonds and π-π interactions to form a three-dimensional supramolecular structure.

Three-dimensional/one-dimensional perovskite heterostructures for stable tri-state synaptic memristors

Memristors have great potential in neural network computation.Perovskite memristors exhibit excellent resistive-switching(RS)properties between high resistance state(HRS)and low resistance state(LRS)state under applied voltage due to the extraordinary ion migration and superior charge transfer.However,the stability issue of traditional three-dimensional(3D)perovskites is still challenging.Here,one-dimensional(1D)(CH_(3))_(3)SPbI_(3)perovskite passivation layer was in-situ formed on 3D perovskite film,which was further applied in stable synaptic memristor.The memristor was provided with three resistance states due to the heterojunction electric field coupled with ion migration.The on/off ratio of memristors was obviously improved from 10 to over 60.The RS characteristics of 3D/1D perovskite memristor remained unchanged after 10^(3)s read and 300 switching cycles.The 3D/1D perovskite memristor effectively exhibited versatile synaptic plasticity behaviors including long-term potentiation,long-term depression and paired-pulse facilitation by controlling the input voltages.Notably,the novel device provides a new candidate for next-generation neuromorphic computing.

Compensation for the Influence of Radar-Target Relative Speed on Step Frequency MMW Target Identification

Aim To study the influence of radar-target relative speed on frequency MMW high-resolution ore-dimension distance profile and the compensation for it. Methods Based on the distance travelled by the electromagnetic wave, analyses were made for the compensation algorithm and the expression of the inverse FFT base distance was given.The relative importance of different compensation terms was studied in great detail. The concept of searching compensation was put forward. Results and Condclusion Dcm-△Dvimis the be distance of inverse FFT transformation, the effect caused by the distance △Dim on one-dimension profile is negligible, and the effect caused by the distance Dvim should not be neglected and must be compensated.

Nanofiber/nanowires-based flexible and stretchable sensors

Nanofibers/nanowires with one-dimension(1D)nanostructure or well-patterned microstructure have shown distinctly advantages in flexible and stretchable sensor fields,owing to their remarkable tolerance against mechanical bending or stretching,outstanding electronic/optoelectronic properties,good transparency,and excellent geometry.Herein,latest summaries in the unique structure and properties of nanofiber/nanowire function materials and their applications for flexible and stretchable sensor are highlighted.Several types of high-performance nanofiber/nanowire-based flexible pressure and stretchable sensors are also reviewed.Finally,a conclusion and prospect for 1D nanofiber/nanowires-based flexible and stretchable sensors are also intensively discussed.This summary offers new insights for the development of flexible and stretchable sensor based 1D nanostructure in next-generation flexible electronics.

Data Acquisition System for Electron Energy Loss Coincident Spectrometers

A Data Acquisition System （DAQ） for electron energy loss coincident spectrometers （EELCS） has been developed. The system is composed of a Multiplex Time-Digital Converter （TDC） that measures the flying time of positive and negative ions and a one-dimension positionsensitive detector that records the energy loss of scattering electrons. The experimental data are buffered in a first-in-first-out（FIFO） memory module, then transferred from the FIFO memory to PC by the USB interface. The DAQ system can record the flying time of several ions in one collision, and allows of different data collection modes. The system has been demonstrated at the Electron Energy Loss Coincident Spectrometers at the Laboratory of Atomic and Molecular Physics, USTC. A detail description of the whole system is given and experimental results shown.

Solvability of Non-homogeneous Mixed Type Multi-point BVPs for Second Order Differential Equations with p-Laplacian

A class of multi-point boundary value problems are studied.Easily verified suffcient conditions to guarantee the existence of at least one solutions of above mentioned BVPs are established.The examples are presented to illustrate the main results.

Geometric stability and electronic structure of infinite and finite phosphorus atomic chains

One-dimensional mono- or few-atomic chains were successfully fabricated in a variety of two-dimensional materials, like graphene, BN, and transition metal dichalcogenides, which exhibit striking transport and mechanical properties. How- ever, atomic chains of black phosphorus （BP）, an emerging electronic and optoelectronic material, is yet to be investigated. Here, we comprehensively considered the geometry stability of six categories of infinite BP atomic chains, transitions among them, and their electronic structures. These categories include mono- and dual-atomic linear, armchair, and zigzag chains. Each zigzag chain was found to be the most stable in each category with the same chain width. The mono-atomic zigzag chain was predicted as a Dirac semi-metal. In addition, we proposed prototype structures of suspended and sup- ported finite atomic chains. It was found that the zigzag chain is, again, the most stable form and could be transferred from mono-atomic armchair chains. An orientation dependence was revealed for supported armchair chains that they prefer an angle of roughly 35°-37° perpendicular to the BP edge, corresponding to the [110] direction of the substrate BP sheet. These results may promote successive research on mono- or few-atomic chains of BP and other two-dimensional materials for unveiling their unexplored physical properties.

CHEBYSHEV PSEUDOSPECTRAL DOMAIN DECOMPOSITION METHOD OF ONE－DIMENSIONAL ELLIPTIC PROBLEMS

This paper is devoted to the Chebyshev pseudospectral domain decomposition method of one-dimensional elliptic problems,it is easily applied to complex geometry.The approximate accuracy can be increased by increasing the order of approximation in fixed number of subdomains,rather than by resorting to a further partitioning.The stability and the convergence of this method are proved.

The Meaning of an Infinitely Great Velocity

An instantaneous velocity where a moment of the clock only corresponds to an arbitrary distance or position in space cannot be implied in Axiom 1, but it indicates that there is only one dimensional existence, space or time, where a certain moment only corresponds to itself specifically, not to any other time or any given length of space. Further, a definition of velocity that consists of two dimensions representing the relationship between space and time is not valid and there is only one-dimensional space or time that is independent of each other in Axiom 1. As a result, the principle of relativity and the principle of the constant velocity of light are replaced by the principle of an inertial system and the principle of universal invariant velocity in Axiom 1. Unlike two dimensions whose magnitude is determined by the ratio, the magnitude of a single dimension is determined by the unit values of one dimension, which indicates that an infinitely great velocity is meaningless. Further, if the two inertial systems are infinite versus finite in Axiom 3, then this extension of the infinitely great velocity can be defined as inextensible.

Photoelectrocatalytic activity of an ordered and vertically aligned TiO2 nanorod array/BDD heterojunction electrode

Rutile TiO_2 nanorod(TiNR) arrays were fabricated on a boron-doped diamond(BDD) substrate by a simple hydrothermal synthesis method. A fluorine-doped tin oxide(FTO) electrode grown with TiNR arrays was also prepared using the same technology for comparison. Field-emission scanning electron microscopy results show that oriented TiNR arrays can grow vertically on the surface of BDD and FTO electrodes. TiNR arrays grown on both electrodes had the same length(3 μm). In comparison with the TiNR/FTO electrode, the TiNR/BDD electrode demonstrated a higher photoelectrocatalytic activity for the degradation of water and organic compounds, which is mostly attributed to the formation of a p-n heterojunction between the TiNR arrays and BDD at high potential, apart from the density of TiNR. A linear relationship between the photoelectrocatalytic current and the organic concentration can be observed on both electrodes. However, the linear range between net photoelectrocatalytic current values and organic compound concentrations for the TiNR/BDD electrode are much greater than those for the TiNR/FTO electrode, which makes the TiNR/BDD electrode a versatile material for the photocatalytic degradation and sensing of organic compounds.

Fast satellite prediction for four-axis telescopes

The features of the method are as follows: Adopting an optimum average small arc to four-axis prediction,the azimuth and altitude of the tracking axis need not be adjusted during the same observation procedure.The prediction has been used for three different types of telescopes for many years and all demands of users have been satisfied.In this method,the prediction contents were more than others.Separating the unknowns,the actual equations for operation were concise,and the needed machine time was much less,even for the prediction of multistation.