One-dimensional Array Research Articles

Self-powered graphene/4H-SiC nanowire array-based ultraviolet photodetectors with fast response time and low dark current for promising wireless ultraviolet communication

Self-powered ultraviolet photodetectors (UV PDs) capable of detecting UV light signals without using an external power supply have become particularly attractive because of their high sensitivity, consistent optical response, ultra-small size, low energy consumption, and long-term robustness for the future. Here we reported a self-powered UV PDs coupling of two-dimensional (2D) single-layer graphene and one-dimensional (1D) 4H-SiC nanowire arrays. The fabricated PDs can feature an ultra-high on-off ratio of 6301 at 0 V and the 2D-1D architectural exhibits a low dark current of ∼4 pA, an ultra-fast response of 4.89 ms. The high performance was associated with the formed heterojunction between the 2D graphene and 1D 4H-SiC nanowire array and the high carrier mobility of the graphene. Moreover, the 2D-1D PDs with a large switching ratio and ultra-fast response time can be beneficial to achieve efficient, real-time, and accurate information transmission under 275 nm UV light, shedding some light on the development of high-performance wireless optical communication systems.

Modulation of Surface Plasmon due to the Inhomogeneity of a One-Dimensional Linear Array of Gold Nanoparticles Observed by Optical Second-Harmonic Generation Microscopy

Modulation of Surface Plasmon due to the Inhomogeneity of a One-Dimensional Linear Array of Gold Nanoparticles Observed by Optical Second-Harmonic Generation Microscopy

High-Performance Flexible Broadband Photothermoelectric Photodetectors Based on Tellurium Films.

Mid- and far-infrared photodetectors that can operate at room temperature are essential for both civil and military applications. However, the widespread use of mid-to-far-infrared photonic technology faces challenges due to the need for low-temperature cooling of existing commercial semiconductors and the limited optical absorption efficiency of two-dimensional materials. We have utilized the photothermoelectric effect to fabricate a self-powered, broadband, and high-performance photodetector based on a one-dimensional tellurium nanorod array film. The device surpasses energy band gap limitations, functioning even at wavelengths up to approximately 10,600 nm. In particular, the detectivity of the device can reach 4.8 × 109 Jones at 4060 nm under room-temperature conditions, which is an order of magnitude higher than that of commercially available photodetectors. It demonstrates fast response and recovery times of 8.3 and 8.8 ms. Furthermore, the device demonstrates outstanding flexibility withstanding over 300 bending cycles and environmental stability. These results suggest a viable approach for designing and developing high-performance, room-temperature, wearable optoelectronic devices.

Photoacoustic imaging of peripheral vessels in extremities by large-scale synthetic matrix array.

Various peripheral vascular diseases (PVD) in extremities, such as arterial atherosclerosis or venous occlusion in arm or legs, are a serious global health threat. Noninvasive vascular imaging is of great value for both diagnosis and assessment of PVD. By scanning a one-dimensional non-focusing linear array, an equivalent large two-dimensional (2D) matrix array with hundreds of thousands or more ultrasound elements is formed, thereby achieving a wide signal reception angle as well as large imaging area for three-dimensional (3D) imaging of peripheral extremities. To provide a feasible bedside and noninvasive imaging method for vascular imaging in extremities. Our system can achieve high-quality photoacoustic (PA) peripheral vessel imaging. The 3D subcutaneous vascular imaging results of the palms and arms of healthy volunteers demonstrate the superior performance of the system. This work proposes a clinically oriented PA 3D subcutaneous vascular imaging system for human extremities. The system employs a synthetic matrix array via scanning a one-dimensional non-focusing linear probe, providing noninvasive, high-resolution, and high-contrast images of human extremities. It has potential application value in the diagnosis and monitoring of vascular diseases.

W-Band FMCW MIMO System for 3-D Imaging Based on Sparse Array

Multiple-input multiple-output (MIMO) technology is widely used in the field of security imaging. However, existing imaging systems have shortcomings such as numerous array units, high hardware costs, and low imaging resolutions. In this paper, a sparse array-based frequency modulated continuous wave (FMCW) millimeter wave imaging system, operating in the W-band, is presented. In order to reduce the number of transceiver units of the system and lower the hardware cost, a linear sparse array with a periodic structure was designed using the MIMO technique. The system operates at 70~80 GHz, and the high operating frequency band and 10 GHz bandwidth provide good imaging resolution. The system consists of a one-dimensional linear array, a motion control system, and hardware for signal generation and image reconstruction. The channel calibration technique was used to eliminate inherent errors. The system combines mechanical and electrical scanning, and uses FMCW signals to extract distance information. The three-dimensional (3-D) fast imaging algorithm in the wave number domain was utilized to quickly process the detection data. The 3-D imaging of the target in the near-field was obtained, with an imaging resolution of 2 mm. The imaging ability of the system was verified through simulations and experiments.

One-dimensional single atom arrays on ferroelectric nanosheets for enhanced CO2 photoreduction

Single-atom catalysts show excellent catalytic performance because of their coordination environments and electronic configurations. However, controllable regulation of single-atom permutations still faces challenges. Herein, we demonstrate that a polarization electric field regulates single atom permutations and forms periodic one-dimensional Au single-atom arrays on ferroelectric Bi4Ti3O12 nanosheets. The Au single-atom arrays greatly lower the Gibbs free energy for CO2 conversion via Au-O=C=O-Au dual-site adsorption compared to that for Au-O=C=O single-site adsorption on Au isolated single atoms. Additionally, the Au single-atom arrays suppress the depolarization of Bi4Ti3O12, so it maintains a stronger driving force for separation and transfer of photogenerated charges. Thus, Bi4Ti3O12 with Au single-atom arrays exhibit an efficient CO production rate of 34.15 µmol·g−1·h−1, ∼18 times higher than that of pristine Bi4Ti3O12. More importantly, the polarization electric field proves to be a general tactic for the syntheses of one-dimensional Pt, Ag, Fe, Co and Ni single-atom arrays on the Bi4Ti3O12 surface.

Underwater optical signal detection system using diffuser-based lensless imaging.

We propose a diffuser-based lensless underwater optical signal detection system. The system consists of a lensless one-dimensional (1D) camera array equipped with random phase modulators for signal acquisition and one-dimensional integral imaging convolutional neural network (1DInImCNN) for signal classification. During the acquisition process, the encoded signal transmitted by a light-emitting diode passes through a turbid medium as well as partial occlusion. The 1D diffuser-based lensless camera array is used to capture the transmitted information. The captured pseudorandom patterns are then classified through the 1DInImCNN to output the desired signal. We compared our proposed underwater lensless optical signal detection system with an equivalent lens-based underwater optical signal detection system in terms of detection performance and computational cost. The results show that the former outperforms the latter. Moreover, we use dimensionality reduction on the lensless pattern and study their theoretical computational costs and detection performance. The results show that the detection performance of lensless systems does not suffer appreciably. This makes lensless systems a great candidate for low-cost compressive underwater optical imaging and signal detection.

Nonlinear regimes of spin wave propagation in a waveguide with a one-dimensional hole array

Purpose. Investigation of spin-wave signal passage in a system of magnetic microwaves separated from each other by a one-dimensional array of holes. Using numerical and experimental methods to show controlled spatial-frequency selection of the signal in linear and nonlinear modes of operation. Methods. Micromagnetic modeling of the spatial intensity distributions of spin waves. Obtaining S-parameters of spin waves propagating in a tangentially magnetized structure using a vector circuit analyzer. Results. The spatially selective properties of the structure in linear and nonlinear modes are demonstrated using micromagnetic modeling. A mechanism for controlling the frequency range of the Bragg zone is revealed using a vector analyzer. Conclusion. The proposed structure can be used as a functional element in planar topologies of magnon networks and parallel signal processing devices based on them.

3,5-Bis(4-pyridyl)-1,2,4-oxadiazole: An Unsymmetric Bidentate Ligand, Polymeric Silver Complex and Antimicrobial Activity Study

1,2,4-Oxadiazole based unsymmetric bidentate ligand, 3,5-bis-(4-pyridyl)-1,2,4-oxadiazole has been employed for complexation with silver nitrate; this ligand has been used for the first time for preparation of any coordination complex. A polymeric array of one-dimensional silver-ligand complex is formed where each metal ion is coordinated to two 4-pyridyl groups of two different ligands and two O-atoms of a nitrate ion. Single crystal X-ray data shows presence of hydrogen bonding and π-π stacking between each one-dimensional array which leads to formation of channels in its solid state. The hydrogen bonding interactions have also been verified by Hirsfeld surface analysis plots. Antimicrobial property study of ligand 3,5-bis-(4-pyridyl)-1,2,4-oxadiazole has been performed with Lactobacillus plantarum and it inhibits the growth at 12.5 μg mL-1.

Experimental realization of one-dimensional single-atom array based on microscale optical dipole traps

Neutral atom array serves as a crucial experimental platform for studying many-body physics, quantum computing, and quantum simulation. In this work, we describe in detail the experimental process of preparing a one-dimensional homogeneous single atom array containing 40 Cs atoms, including the dipole trap array generation device, atomic array fluorescence imaging, and the uniformity optimization of the dipole trap array. The beam waist of the dipole trap is about 1.8 μm, and the spatial resolution of the imaging system is higher than 1.55 μm. The non-uniformity of dipole trap array is mainly caused by the intermodulation effect of multi-tone signal during amplification. The uniformity of the dipole trap array is optimized to 2% (Fig. (a)) by measuring the fluctuations of the dipole trap intensity and the light shift of trapped atom, and providing feedback to adjust the phase and amplitude applied to the multi-tone RF signal on acousto-optic deflectors. Furthermore, the uniformity of oscillation frequency, loading rate, and lifetime for trapped atom in the dipole trap array are measured. These results show that oscillation frequency has a uniformity within 2% (Fig. (b)); mean loading rate is around 58% with a uniformity within 3%; and mean lifetime of single atom in dark trap is around 6(1) s with a uniformity within 8%.

Propagation properties of one-dimensional array vortex beams in a marine atmosphere

Propagation properties of one-dimensional array vortex beams in a marine atmosphere

Exploration of field-like torque and field-angle tunability in coupled spin-torque nano oscillators for synchronization.

We investigate the influence of field-like torque and the direction of the external magnetic field on a one-dimensional array of serially connected spin-torque nano oscillators (STNOs), having free layers with perpendicular anisotropy, to achieve complete synchronization between them by analyzing the associated Landau-Lifshitz-Gilbert-Slonczewski equation. The obtained results for synchronization are discussed for the cases of 2, 10, and 100 oscillators separately. The roles of the field-like torque and the direction of the external field on the synchronization of the STNOs are explored through the Kuramoto order parameter. While the field-like torque alone is sufficient to bring out global synchronization in the system made up of a small number of STNOs, the direction of the external field is also needed to be slightly tuned to synchronize the one-dimensional array of a large number of STNOs. The formation of complete synchronization through the construction of clusters within the system is identified for the 100 oscillators. The large amplitude synchronized oscillations are obtained for small to large numbers of oscillators. Moreover, the tunability in frequency for a wide range of currents is shown for the synchronized oscillations up to 100 spin-torque oscillators. In addition to achieving synchronization, the field-like torque increases the frequency of the synchronized oscillations. The transverse Lyapunov exponents are deduced to confirm the stable synchronization in coupled STNOs due to the field-like torque and to validate the results obtained in the numerical simulations. The output power of the array is estimated to be enhanced substantially due to complete synchronization by the combined effect of field-like torque and tunability of the field-angle.

너비 우선 탐색 기반 비재귀 트리 탐색 알고리즘의 효율적 구현과 성능 비교

The objective of this study is to present an efficient tree traversal algorithm in terms of execution time and implementation complexity. Trees, defined as acyclic connected graphs, are widely used in various fields of computer science. Unlike traditional recursive methods or depth first search implementations, this research proposes an implementation based on breadth first search. The algorithm improves execution time using a non-recursive approach and reduces implementation complexity by using only one-dimensional arrays and loops. Additionally, the algorithm has been optimized through a preprocessing phase. To evaluate the performance of the proposed algorithm compared to existing ones, trees with random structures were generated and their execution times were measured. The results demonstrated that the proposed algorithm exhibits efficient performance.

Review of: "It has been done in the manufacture of nanowires through regular one-dimensional arrays with the help of different physical and chemical methods"

Review of: "It has been done in the manufacture of nanowires through regular one-dimensional arrays with the help of different physical and chemical methods"

Performance research of C# programming language data serializers using the developed software product for testing

The article deals with the issue of using data serializers for the implementation of projects related to the processing of large volumes of data, as well as the support of high-speed data transmission in distributed systems. It is shown that in this context, the choice of the most effective serialization mechanism is critical for ensuring the performance and scalability of applications. The purpose of this work is to study the effectiveness of data serializers of the C# programming language by developing a software product for testing serializers using objects of different size and type. A review of scientific research on the use of various data serialization formats: XML, JSON, BSON, MessagePack, Smile, Protocol Buffers, Flat Buffers, Apache Thrift was conducted. It was concluded that XML and JSON formats are the most popular today, and their comparative analysis was performed. The expediency of using the JSON serialization format is substantiated, which is due to its safety compared to the binary format, its smaller size compared to the XML format, as well as the support of most software development tools. The .NET framework is chosen, which provides standard tools for JSON serialization of the C# programming language, namely: System.Runtime.Serialize.Json and System.Text.Json, which are supplied by default. The most popular software solutions for serializing C# objects are analyzed, the feasibility of testing such serializers as Jil, Json.NET, Utf8Json, SpanJson and standard serializers is shown in order to identify the advantages and disadvantages of their use for the implementation of specific tasks and projects. The C# BenchmarkDotNet programming language library was chosen to create the tester program. It is noted that this framework of the .NET platform allows you to convert methods into tests and create performance testing thanks to a powerful statistical mechanism. A class diagram and a component diagram of the developed software are given. A study of 5 data serializers was conducted, which included the execution of 7 experiments on serialization of objects with different types of data. The consumption of time and working memory during serialization of small and large objects was analyzed; objects containing one-dimensional, two-dimensional and three-dimensional arrays of natural numbers, an object with a complex chain of class inheritance, as well as an object containing a dictionary. The results of experimental studies showed the dependence of the effectiveness of serializers on the type and volume of data to be serialized. It is concluded that there is no one-size-fits-all serializer that will perform best in all cases. Recommendations for the use of various serializers are provided, taking into account the requirements of a specific project

Fluorescent-Probe Characterization for Pore-Space Mapping with Single-Particle Tracking.

Porous solids often contain complex pore networks with pores of various sizes. Tracking individual fluorescent probes as they diffuse through porous materials can be used to characterize pore networks at tens of nanometers resolution. However, understanding the motion behavior of fluorescent probes in confinement is crucial to reliably derive pore network properties. Here, we introduce well-defined lithography-made model pores developed to study probe behavior in confinement. We investigated the influence of probe-host interactions on diffusion and trapping of confined single-emitter quantum-dot probes. Using the pH-responsiveness of the probes, we were able to largely suppress trapping at the pore walls. This enabled us to define experimental conditions for mapping of the accessible pore space of a one-dimensional pore array as well as a real-life polymerization-catalyst-support particle.

Tailoring the Direct Current Modulation Response of Electrically Pumped Semiconductor Nano-Laser Arrays

Semiconductor nano-lasers have been a topic of interest from the perspective of advancing the capabilities of photonic integration. Nano-lasers are perceived as the means to achieve improved functionality in photonic integrated circuits. The properties and performance of nano-lasers have been examined by means of simulations and laboratory measurements. Nano-lasers lend themselves to integration to form dense arrays in both one and two dimensions. In a recent work, a theoretical treatment was presented for the dynamic behaviour of stand-alone electrically pumped nano-laser arrays. In this work, the response of nano-laser arrays to direct current modulation is examined. As in previous works, attention is given to two prototype array geometries: a linear three-element linear array and an equilateral triangular array. Large one-dimensional arrays can be built by repeating this elementary linear array. Two-dimensional photonic integrated circuits can incorporate the triangular arrays studied here. Such prototypical configurations offer opportunities to tailor the modulation response of the nano-laser arrays. The principal factors which provide that capability are the coupling strengths between lasers in the arrays and the direct modulation parameters. The former are fixed at the design and manufacture stage of the array whilst the latter can be chosen. In addition, the enhancement of the spontaneous emission rate via the so-called Purcell effect in nano-lasers offers a device-specific means for accessing a range of modulation responses. Two-dimensional portraits of the regimes of differing modulation responses offer a convenient means for determining the dynamics that may be accessed by varying the laser drive current. It is shown by these means that a rich variety of modulation responses can be accessed in both linear and triangular arrays.

On parametric amplification in discrete Josephson transmission line

We consider the discrete series-connected lossy Josephson transmission line, constructed from Josephson junctions, capacitors and resistors (one-dimensional array of Josephson junctions). We derive equations describing pump, signal, and idler interaction in the system and calculate the thresholds for the parametric amplification.

Impact of Missing Data on Correlation Coefficient Values: Deletion and Imputation Methods for Data Preparation

The correlation coefficient is one of the essential statistical techniques used to discover relationships among variables. Various techniques can quantify correlation, such as Pearson's, Spearman's, and Kendall's correlation coefficients, depending on the data type. As with any use of data, missing data will impact the availability of data, reducing it and potentially affecting the results. Furthermore, the removal of missing-value data from the study when using complete case analysis or available case analysis may result in selection biases. In this paper, we investigate the impact of missing data on the correlation coefficient value by calculating the difference between the correlation coefficient of the original complete dataset and that of a dataset with missing data. Two deletion strategies (Listwise and Pairwise) and three imputation strategies (Mean, k-Nearest Neighbors (k-NN), and Expectation-Maximization) were used to prepare the data before calculating the correlation coefficient. Unique correlation coefficient values were created by converting unique values to a one-dimensional array, and RMSE metrics were used to evaluate the experiments. Eight UCI and Kaggle datasets with different sizes and numbers of attributes were used in this study. The experiment results demonstrate that the Pairwise strategy and k-NN give good results on the correlation coefficient, respectively, when the missing rate is moderate or less. Pairwise uses all the available values and discards only the missing values of the related attribute, while k-NN fills the missing values with new values that produce correlation coefficient values close to the actual values.

A new mixed-ligand mononuclear Co(II) complex derived from 4,4,4-trifluoro-1-phenylbutane-1,3-dione and 1,10-phenanthroline: Synthesis, structural elucidation and quantum-computational studies

In this study, a novel mixed-ligand mononuclear Co(II) complex, denoted as {[Co(TFPBD)2(PHE)]DMF}, was synthesized and characterized using single crystal X-ray diffraction analysis. The central cobalt atom coordinated with two 4,4,4-trifluoro-1-phenylbutane-1,3-dione ligands (TFPBD1 and TFPBD2) and a 1,10-phenanthrene (PHE) ligand, adopting a slightly distorted octahedral geometry. Notably, the non-planar characteristics of the ligands led to the manifestation of non-covalent interactions within the molecular structure, further enhanced by the involvement of the lattice DMF solvent. The crystal lattice arrangement in the {[Co(TFPBD)2(PHE)]DMF} complex was a result of diverse non-covalent interactions, including hydrogen bonds, C-F…π, and Π…π stacking interactions, influenced the crystal's stability. Additionally, the study delved into the unique lattice arrangement consisted of pairwise R12(5) ring motifs along with one-dimensional molecular arrays formed along the crystallographic axes. Furthermore, intermolecular C-F…π Cg…Cg interactions resulting in two-dimensional linear molecular arrays along the a- and b-axes. Quantum computational studies using density functional theory (DFT) were employed to examine the complex's electronic structure and stability and reactivity, highlighting electron-rich and electron-deficient regions. Hirshfeld surface analysis (HSA) and Non-covalent interaction analysis confirmed the significance of intermolecular interactions where 2D fingerprint plots emphasized the prominence of CH…F interactions within the crystal structure. These findings contribute significantly to our understanding of mixed-ligand metal complexes and their potential applications in various scientific domains.