One-dimensional Structure Research Articles

Antimony Bromide Organic-Inorganic Hybrid Compound with a Long-Chain Diamine Showing Switchable Phase Transition and Second-Harmonic Generation Properties.

Organic-inorganic hybrid metal halides have attracted significant attention in recent years due to their excellent optoelectronic properties and potential applications in solar cells. Herein, the organic-inorganic hybrid molecule [N,N-dimethyl-1,3-propanediamine]SbBr5 (1) was synthesized by reacting a long-chain organic diamine N,N-dimethyl-1,3-propanediamine with SbBr3 as a metal halide precursor in HBr aqueous solution. Compound 1 possesses a one-dimensional chainlike structure with the second-harmonic generation switch and two continuous phase transitions above room temperature. The band gap of compound 1 is about 2.62 eV, exhibiting a semiconductive property, which may have important implications for the development of new optoelectronic devices.

Graphene encapsulated MnO2 nanorods boosts interfacial polarization for microwave absorption

The lightweight and efficient electromagnetic wave (EMW) absorption materials have been a popular research topic. In this work, MnO2 @graphene (MnGr) nanofibers with core-shell structure were synthesized by a one-step hydrothermal method. This one-dimensional linear structure was further self-assembled into a three-dimensional hierarchical MnGr aerogel network structure due to the interlayer forces of graphene sheets. The addition of graphene greatly enhances the interfacial polarization. The significant differences in electronic structure and work function between the outer graphene layer and the inner MnO2 layer greatly enhance the interfacial polarization. The formation of 3D hierarchical MnGr aerogel network structure constructs more fast electron transport channels. With the addition of graphene oxide at 7.5 wt% of the theoretical yield of MnO2, MnGr-7.5 exhibits excellent wave absorption properties. The effective absorption bandwidth (EAB) can reach 6.40 GHz at 2.2 mm. And the minimum reflection loss (RLmin) is − 41.3 dB at 1.8 mm and 17.36 GHz. Finite element physical simulation is used to simulate the response of 3D conductive network to electromagnetic wave. Through calculation, it is found that the inter-lap network structure is beneficial to enhance the loss. The low-cost MnO2 compounded with a small amount of graphene has excellent wave absorption performance and a great application prospect.

Confined pyrolysis-driven one-dimensional carbon structure evolution from polyacrylonitrile fiber and its microwave absorption performance

The evolution of one-dimensional carbon structures from polyacrylonitrile (PAN) fiber precursors is investigated based on confined pyrolysis strategy, which is employed to convert electrospun PAN fibers into carbon in a closed system. Carbon tube with ultra-large diameter derived from silica-coated organic PAN precursor fiber is observed and its low-performance of microwave absorption is revealed. To enhance microwave absorption, cobalt acetylacetonate is introduced as a magnetic resource into PAN, facilitating one-dimensional carbon structure evolution and yielding magnetic/carbon nanofibers. The mechanism resulting in such one-dimensional carbon structure evolution is discussed. The microwave absorption performances of the prepared magnetic carbon nanofibers are analyzed based on their complex permittivity and permeability. Remarkably, the magnetic carbon nanofibers exhibit strong microwave absorption intensity of −42 dB at only 20 wt% filler content. Further simulations are conducted based on radar-absorbing structure with prepared magnetic carbon nanofibers-coated laminate and wing models by using CST software. The laminated composite structure appears the maximum RCS reduction value of 18.70 dBsm at 6 GHz with 3.0 mm thickness in the frequency range of 2–18 GHz. In the corresponding wing structure, highly efficient electromagnetic wave absorption is observed and the RCS reduction can achieve −14.12 dBsm at 10 GHz with 3.5 mm thickness.

Review of: "One-dimensional structures such as nanotubes, oligophenylene vanillin nanowires"

Review of: "One-dimensional structures such as nanotubes, oligophenylene vanillin nanowires"

On line construction of carbon nanotube/polytriazole composite films with high tensile and heat resistant properties

Carbon nanotubes (CNTs) have low densities and excellent mechanical properties due to their unique one-dimensional tubular structures, and are thus considered as an ideal reinforcement for lightweight and high-strength resin-based composites. However, it is still difficult to prepare high-performance composites with a high content of well-aligned CNTs. Besides, limited by the poor heat resistance of epoxy resin, it is still challenging to prepare composites with both high strength and heat resistance. In the present study, a simple on-line process is proposed to prepare CNT/polytriazole composite films. That is, a CNT assembly just having formed in a high temperature reactor is pulled through solution containers for shrinking and resin infiltration and subsequently winded on a drum to form a composite film. By optimizing the resin content and CNT alignment for better densification and inter-binding, the tensile strength of the composite film can reach a high level of 2.52 GPa with a decent elongation of 4.3 %. Associated with the use of the polytriazole resin, the composite could be cured at a low temperature of 80 °C but have a high glass transition temperature of 298 °C. Thus, the present technique is useful for preparing high-strength composite materials which are required to be able to be cured at low temperature but applied at high temperature.

Angular dependence of photonic band gap and omni-directional reflection in one-dimensional photonic crystal applied to a thermophotovoltaic device

In this work, we present a theoretical study and a numerical simulation on omnidirectional reflection in one-dimensional photonic crystal structures for a thermophotovoltaic device. The optical properties are determined using the transfer matrix method. The results show that the angular dependence of photonic bandgaps depends on refractive index contrast and, polarization. However, for both TE and TM polarization, a reflectivity peak with 100% reflectivity is observed. The Te/SiO2 structure is the one with the largest bandwidth of omnidirectional photonic band gap compared with the TiO2/SiO2 and Si/SiO2 structures. The results also show that by designing a giant birefringent optical the Brewster’s angle allows angle the control at any angle for both TE and TM mode.

The Effect of Nanowire Gap for Silicon Nanowire Transistor to the Current-Voltage (I-Vds)

One-dimensional structures are attracting a lot of attention for optimizing applications as one of the most sensitive devices. Among the fabricated devices, silicon nanowires (SiNW) and silicon nanowire transistors (SiNWT) are of particular importance for promising applications fabricated using bottom-up or top-down approaches to nanoscale devices. In this paper, the sensitivity of the current-voltage characteristic to the nanowire gap of a silicon nanowire transistor (SiNWT) was analyzed. SiNWTs with different nanowire gaps were fabricated using scanning probe microscopy by local anodic oxidation (LOA). Varies gaps can be occurring during the fabrication processes and its can be controlled by RASTER programming in LAO. These gaps can give different results of the sensitivity to the volt-ampere response. However, these gaps can be neglected depending on the subject of the studies and important to the other study, especially in nano particle sensors. In this experiment, the nanowires gaps were developed in the range of 100.5-435.6 nm and had been plotted the measurement data with the volt-ampere response. The data was analyzed using a semiconductor analyzer connected to a HP 4156C SPA series software analysis model from Desert Cryogenics. From the results had been measured the Current-Voltage (IV) increases proportionally with the nanowire gap distance in the SINWT device and this results will give significant effects to the application in nanoparticle sensors

Semisupervised hyperspectral image classification based on generative adversarial networks and spectral angle distance

Collecting ground truth labels for hyperspectral image classification is difficult and time-consuming. Without an adequate number of training samples, hyperspectral image (HSI) classification is a challenging problem. Using generative adversarial networks (GANs) is a promising technique for solving this problem because GANs can learn features from both labeled and unlabeled samples. The cost functions widely used in current GAN methods are suitable for 2D nature images. Compared with natural images, HSIs have a simpler one-dimensional structure that facilitates image generation. Motivated by the one-dimensional spectral features of HSIs, we propose a novel semisupervised algorithm for HSI classification by introducing spectral angle distance (SAD) as a loss function and employing multilayer feature fusion. Since the differences between spectra can be quickly calculated using the spectral angle distance, the convergence speed of the GAN can be improved, and the samples generated by the generator model in the GAN are closer to the real spectrum. Once the entire GAN model has been trained, the discriminator can extract multiscale features of labeled and unlabeled samples. The classifier is then trained for HSI classification using the multilayer features extracted from a few labeled samples by the discriminator. The proposed method was validated on four hyperspectral datasets: Pavia University, Indiana Pines, Salinas, and Tianshan. The experimental results show that the proposed model provides very promising results compared with other related state-of-the-art methods.

Computation of Neighborhood M-Polynomial of Cycloparaphenylene and Its Variants.

In the domains of materials and chemical and physical sciences, a significant aspiration is to design and synthesize extensively conjugated macrocycles possessing precisely defined structures. This objective bears substantial promise across a wide range of scientific and technological fields. These molecules offer a unique blend of structural complexity and electronic properties that make them particularly intriguing for both theoretical and practical reasons. Cycloparaphenylene (CPP) radial π-conjugated macrocycles is a specific example of a conjugated macrocycle that has garnered significant attention in the field of chemistry and materials science. It consists of a series of benzene rings linked together in a cyclic arrangement, forming a one-dimensional structure. CPP systems have been on the rise due to their novel and captivating characteristics, encompassing properties, such as electronic properties, heightened electrical conductivity, optoelectronic traits, and mechanical properties. Given the potential applications of CPP, it becomes essential to analyze this structure from a theoretical standpoint. Molecular descriptors play a crucial role in the theoretical analysis of such structures. Research on molecular descriptors has unequivocally demonstrated their significant correlation with the diverse properties of chemical compounds. This article illustrates the neighborhood sum M-polynomial-based descriptors' calculation using edge-partition techniques for CPP and its sidewalls consisting of pyrene and hexabenzocoronene units. The examination of these neighborhood sum M-polynomial-based descriptors for these structures has the potential to establish a foundational framework for delving deeper into CPP and its associated properties.

Psychometric Properties of the Patient Health Questionnaire-9 in Peruvian University Students

Changes that occurred in people’s lives due to the COVID-19 pandemic negatively affected the mental health of the universities, where an increase in symptoms of depression was reported since the beginning of the pandemic, so its evaluation is essential in this context. Therefore, the objective of this study was to analyze the psychometric properties of the Patient Health Questionnaire-9 (PHQ-9) in Peruvian university students. A total of 409 university students between 16 and 45 years of age participated (female = 72.9%; Mage = 22.15; SDage = 3.75). The PHQ-9 and the Emotional Exhaustion Scale (EES) were used. A series of confirmatory factor analyses were conducted to evaluate structures suggested by previous studies, namely a one factor model, a two correlated factor model and a bi-factor model. We found evidence of a one-dimensional structure, both from factor analysis and item response theory, and a positive association with academic emotional exhaustion. Moreover, construct reliability and score reliability reached high magnitudes. Therefore, the PHQ-9 is an instrument with adequate psychometric properties to be used as a measure of depression in university students in the context of the COVID-19 pandemic.

Three functional Cd(II) coordination polymers constructed by the thiazolothiazole extended viologen ligand

Expanding the π-conjugated structure of traditional viologens by incorporating thiazole units to the bipyridine skeleton has attracted more and more attention. In this work, a rigid thiazolothiazole extended viologen ligand (TTVP, 2,5-bis (pyridinium-4-yl) thiazolo [5,4-d] thiazole propionate) has been used to constitute three new functional Cd(II) coordination polymers (CPs), {[Cd(TTVP)0.5(HBTC)(H2O)2]·2H2O}n (1), {[Cd(TTVP)0.5(p-BDC)0.5(p-HBDC)(H2O)]·3H2O}n (2), {[Cd(TTVP)0.5(m-BDC)]}n (3) by introducing different benzenecarboxylic acids as auxiliary ligands (H3BTC = 1,3,5-benzenetricarboxylic acid; p-H2BDC = 1,4-benzenedicarboxylic acid; m-H2BDC = 1,3-benzenedicarboxylic acid). The crystal structures and photochromic capabilities of 1−3 are studied. Both compounds 1 and 2 own one-dimensional (1D) chain-like structure, while compound 3 owns two-dimensional (2D) layered structure. As expected, compounds 1−3 show reversible photochromism due to electron-transfer (ET). In addition, the photo-controlled luminescent properties and the potential application as inkless and erasable printing media are also explored.

Selective detection of Fe3+ and Congo red adsorption properties studies of Ln-complexes based on imidazopyridine carboxylic acid ligand

Five new Ln-complexes [Ln(L)2(OH)(H2O)3]n (1 and 2) and {[Ln2(L)2(HL)2(H2O)8]Cl4·7H2O}n (3–5) [Ln = Nd (1), Sm (2), Eu (3), Ho (4), Er (5), HL = 4-(1H-imidazo[4,5-c]pyridin-2-yl)benzoic acid] were synthesized under solvothermal conditions. The single crystal X‑ray diffraction showed that Ln-complexes 1–5 were one-dimensional (1D) structures. Interestingly, the sensing experimental showed that 1–5 could be considered as promising specificity fluorescent sensor for Fe3+ ions with good reusability and high sensitivity, and the detection limits were 7.14 × 10−6, 3.21 × 10−6, 7.28 × 10−6, 6.74 × 10−6 and 7.42 × 10−6 M, respectively. Ln-complexes 1–5 exhibited excellent adsorption performance to dye Congo red (CR), and the adsorption capacities were 2792 mg·g−1, 2551 mg·g−1, 2858 mg·g−1, 2752 mg·g−1 and 2654 mg·g−1, respectively. Adsorption kinetics and adsorption isotherms showed that the adsorption of 1–5 belongs to the chemical adsorption process, the hydrogen bonding and π-π interactions between the 1–5 host and CR guest molecules resulted in high adsorption capacity.

Vectorial characterization of surface wave via one-dimensional photonic-atomic structure

Quantitative assessment of polarization properties of waves opens up the way for effective exploitation of them in many amazing applications. Tamm surface waves (TSW) that propagate on the interface of periodic dielectric media are proposed for many applications in numerous reports. The polarization state of TSW is not simply intuitive and would not be extracted from reflection spectra. Here considering orientation sensitive nature of the interaction between polarized electromagnetic wave and atom, we try to quantitatively characterize the polarization state of TSWs, excited on the surface of the 1D photonic crystal. To do this we performed direct contact between TSW and rubidium atomic gas by fabrication of a one-dimensional photonic crystal-atomic vapor cell and applied a moderate external magnetic field to create geometrical meaning and a sense of directionality to dark lines in reflection intensity. Our experimental results indicate that transition lines in the reflection spectrum of our hybrid system modify dependent on the orientation of the applied magnetic field and the transverse spin of TSW. We have used these changes to redefine the geometry of Voigt and Faraday for evanescent waves, especially Tamm surface waves. In the end, we performed simple mathematical operations on absorption spectra and extract the ratio of longitudinal and transverse electric field components of the polarization vector of TSW equal to 25\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\frac{2}{5}$$\\end{document}.

From a Dy2 single-molecule magnet (SMM) to a 1D triangle-based Dy(III) chain SMM utilizing formate ions as bridging units

The reaction of Dy(NO3)2·6H2O with a Schiff base ligand N1,N3-bis(5-chlorosalicyladehyde)diethylenetriamine (H2bcsdt) afforded a dinuclear DyIII complex [Dy2(bcsdt)2(NO3)2] (1). The addition of HCOOH to the reaction system from which 1 was prepared generated a coordination polymer with the formula {[Dy3(bcsdt)3(HCOOH)(HCOO)(CO3)]·EtOH}n (2). Single-crystal X-ray diffraction analysis revealed that complex 2 possesses a one-dimensional chain structure based on a {[Dy3(bcsdt)3(HCOOH)(HCOO)(CO3)]·EtOH} repeating unit. In this unit, the three DyIII ions are connected by three oxygen atoms of one CO32– ion and display a nearly perfect triangle topology. The magnetic properties of 1 and 2 were investigated. They both exhibited slow relaxation of magnetization, indicative of single molecule magnet (SMM) behavior.

A temperature sensor based on Si/PS/SiO2 photonic crystals

The present research deals with the extremely sensitive temperature-sensing capabilities of defective one-dimensional photonic crystal structures (Si/PS/SiO2). The proposed structure is realized by putting a defective layer of material silicon Dioxide (SiO2) in the middle of a structure consisting of alternating layers of silicon (Si) and porous silica (PS). The transfer matrix method has been employed to examine the transmission characteristics of the proposed defective one-dimensional photonic crystal in addition to MATLAB software. The transmission spectra of the proposed structure in the visible light domain are computed throughout a temperature range of 25–900 °C, and we study the thermal properties related to the defective mode. Additionally, the impacts of changing the defect layer's thickness are examined. Due to the effects of thermal expansion and the thermo-optical coefficient, the defect mode varies significantly as the temperature increases. Our investigation shows that the proposed structure considerably impacts the transmission intensity of the defective mode. The theoretically obtained numeric values of the quality factor and sensitivity are 2216.6 and 0.085 nm/°C, respectively. The challenges presented by conventional temperature sensors could be overcome by the suggested defective photonic crystal sensor. These results are enough to support our claim that the present design can be used as an ultra-sensitive temperature sensor.

Preparation of antimony selenide thin films by electrochemical deposition and application in optoelectronic devices

Antimony selenide (Sb2Se3) has become a potential semiconductor material for a wide range of optoelectronic applications because of its unique one-dimensional crystal structure and corresponding excellent anisotropic optical and electronic properties. Herein, uniform and flat Sb2Se3 thin films with [hk1]-optimized growth orientation are prepared by adjusting the deposition potentials and selenization temperatures using a facile electrochemical deposition method. Then these films are applied in heterojunction-type photodetectors with the structure of Mo/Sb2Se3/CdS/ZnO/ITO/Ag. The best performances are obtained for devices with a deposition potential of −0.55 V and a selenization temperature of 300 °C. At 0 bias, the detector yielded a responsivity of 25.4 mA/W and a detectivity of 1.06 × 1011 Jones at 635 nm visible light with a light intensity of 5 mW. The results show that high-quality Sb2Se3 thin films can be prepared by electrochemical deposition under proper preparation conditions, which lays the foundation for the application of the electrochemical deposition method in the field of optoelectronic devices.

General deep learning framework for emissivity engineering

Wavelength-selective thermal emitters (WS-TEs) have been frequently designed to achieve desired target emissivity spectra, as a typical emissivity engineering, for broad applications such as thermal camouflage, radiative cooling, and gas sensing, etc. However, previous designs require prior knowledge of materials or structures for different applications and the designed WS-TEs usually vary from applications to applications in terms of materials and structures, thus lacking of a general design framework for emissivity engineering across different applications. Moreover, previous designs fail to tackle the simultaneous design of both materials and structures, as they either fix materials to design structures or fix structures to select suitable materials. Herein, we employ the deep Q-learning network algorithm, a reinforcement learning method based on deep learning framework, to design multilayer WS-TEs. To demonstrate the general validity, three WS-TEs are designed for various applications, including thermal camouflage, radiative cooling and gas sensing, which are then fabricated and measured. The merits of the deep Q-learning algorithm include that it can (1) offer a general design framework for WS-TEs beyond one-dimensional multilayer structures; (2) autonomously select suitable materials from a self-built material library and (3) autonomously optimize structural parameters for the target emissivity spectra. The present framework is demonstrated to be feasible and efficient in designing WS-TEs across different applications, and the design parameters are highly scalable in materials, structures, dimensions, and the target functions, offering a general framework for emissivity engineering and paving the way for efficient design of nonlinear optimization problems beyond thermal metamaterials.

Nanoscale one-dimensional close packing of interfacial alkali ions driven by water-mediated attraction.

The permeability and selectivity of biological and artificial ion channels correlate with the specific hydration structure of single ions. However, fundamental understanding of the effect of ion-ion interaction remains elusive. Here, via non-contact atomic force microscopy measurements, we demonstrate that hydrated alkali metal cations (Na+ and K+) at charged surfaces could come into close contact with each other through partial dehydration and water rearrangement processes, forming one-dimensional chain structures. We prove that the interplay at the nanoscale between the water-ion and water-water interaction can lead to an effective ion-ion attraction overcoming the ionic Coulomb repulsion. The tendency for different ions to become closely packed follows the sequence K+ > Na+ > Li+, which is attributed to their different dehydration energies and charge densities. This work highlights the key role of water molecules in prompting close packing and concerted movement of ions at charged surfaces, which may provide new insights into the mechanism of ion transport under atomic confinement.

Microfiber-Patterned Versatile Perfusable Vascular Networks.

Rapid construction of versatile perfusable vascular networks in vitro with cylindrical channels still remains challenging. Here, a microfiber-patterned method is developed to precisely fabricate versatile well-controlled perfusable vascular networks with cylindrical channels. This method uses tensile microfibers as an easy-removable template to rapidly generate cylindrical-channel chips with one-dimensional, two-dimensional, three-dimensional and multilayered structures, enabling the independent and precise control over the vascular geometry. These perfusable and cytocompatible chips have great potential to mimic vascular networks. The inner surfaces of a three-dimensional vascular network are lined with the human umbilical vein endothelial cells (HUVECs) to imitate the endothelialization of a human blood vessel. The results show that HUVECs attach well on the inner surface of channels and form endothelial tubular lumens with great cell viability. The simple, rapid and low-cost technique for versatile perfusable vascular networks offers plenty of promising opportunities for microfluidics, tissue engineering, clinical medicine and drug development.

Transmission properties of time-dependent one-dimensional metamaterials

We solve the wave equation with periodically time-modulated material parameters in a one-dimensional high-contrast resonator structure in the subwavelength regime exactly, for which we compute the subwavelength quasifrequencies numerically using Muller’s method. We prove a formula in the form of an ODE using a capacitance matrix approximation. Comparison of the exact results with the approximations reveals that the method of capacitance matrix approximation is accurate and significantly more efficient. We prove various transmission properties in the aforementioned structure and illustrate them with numerical simulations. In particular, we investigate the effect of time-modulated material parameters on the formation of degenerate points, band gaps and k-gaps.