bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of high-operation-temperature (up to 150 K) mid-wave infrared photodetectors based on p–n junctions in PbTe single crystals
Authors: Auslender M. , Dzundza B. , Towe E. , Shneck R. , Dashevsky Z.
Published: August 2024

One of the characteristic features of PbTe is an uncommon growth of bandgap with increasing temperature, which is quite opposite to the bandgap behavior of the semiconductors commonly used in electronics, for example, Si, Ge, GaAs, and InSb. This specificity allows one to increase the operating temperature of photodiodes fabricated using PbTe up to about 150 K. At the first stage of development, we prepared infrared (IR) photodiodes on the base of bulk single crystalline PbTe. To this end, the ingots with a diameter of about 40 mm were grown by the Czochralski technique. Then, the PbTe p–n junctions were fabricated by using indium donor diffusion to diffuse indium into the PbTe samples. Current–voltage and capacitance–voltage characteristics and spectral detectivity were measured over a wide temperature range and analyzed. The dark saturation current density at T = 100 K was of the order of 10−7 A/cm2. Finally, the unique solid-state multi-stage thermoelectric cooler operated at temperatures up to 150 K was developed. The present study would pave the way to creating a module for efficient photodetection in the mid-wave IR range combining two solid-state devices, namely, the p–n photodiode and thermoelectric cooler, while the latter supports the former.
Effect of dissolved KOH and NaCl on the solubility of water in hydrogen: A Monte Carlo simulation study
Authors: Habibi Parsa , Dey Poulumi , Vlugt Thijs J. H. , Moultos Othonas A.
Published: August 2024

Vapor–Liquid Equilibria (VLE) of hydrogen (H2) and aqueous electrolyte (KOH and NaCl) solutions are central to numerous industrial applications such as alkaline electrolysis and underground hydrogen storage. Continuous fractional component Monte Carlo simulations are performed to compute the VLE of H2 and aqueous electrolyte solutions at 298–423 K, 10–400 bar, 0–8 mol KOH/kg water, and 0–6 mol NaCl/kg water. The densities and activities of water in aqueous KOH and NaCl solutions are accurately modeled (within 2% deviation from experiments) using the non-polarizable Madrid-2019 Na+/Cl− ion force fields for NaCl and the Madrid-Transport K+ and Delft Force Field of OH− for KOH, combined with the TIP4P/2005 water force field. A free energy correction (independent of pressure, salt type, and salt molality) is applied to the computed infinite dilution excess chemical potentials of H2 and water, resulting in accurate predictions (within 5% of experiments) for the solubilities of H2 in water and the saturated vapor pressures of water for a temperature range of 298–363 K. The compositions of water and H2 are computed using an iterative scheme from the liquid phase excess chemical potentials and densities, in which the gas phase fugacities are computed using the GERG-2008 equation of state. For the first time, the VLE of H2 and aqueous KOH/NaCl systems are accurately captured with respect to experiments (i.e., for both the liquid and gas phase compositions) without compromising the liquid phase properties or performing any refitting of force fields.
High-performance broadband photodetector with imaging application based on tantalum nickel selenium at room temperature
Authors: Gao Lin , Huang Yuhang , Wu Han
Published: August 2024

Infrared photodetectors (PDs) are widely used in fields such as military, medical, and aerospace. Traditional semiconductor materials including Si, InGaAs, and HgCdTe show high performance in a wide spectral range with the imaging function. Nevertheless, they also have limitations such as low-temperature operation, high cost, and toxicity. Fortunately, two-dimensional (2D) materials with narrow bandgaps featuring adjustable gaps, mechanical flexibility, and superior optoelectronic properties have the potential to bridge the gap between traditional materials in optoelectronic devices. However, 2D materials’ performance with respect to responsivity (Rλ) and external quantum efficiency (EQE) needs improvement. Tantalum nickel selenium (Ta2NiSe5) with a direct bandgap and high carrier mobility has prospects for broadband PD research. This study combines mechanical exfoliation and micro-nano-processing technology to prepare Ta2NiSe5 nanosheets and design a Ta2NiSe5-based PD, which has a broadband light response from 520 to 1550 nm with an Rλ value of up to 1.07 A/W. The highest EQE of the PD is 2.55, with the lowest noise equivalent power of 2.39 × 10−12 W/Hz1/2 and the highest specific detectivity (D*) of 9.3 × 108 cm Hz1/2/W. The response speed is stable with low power consumption, and the PD can perform high-resolution imaging through different liquids. Hence, Ta2NiSe5-based PDs have photoelectric properties including broadband detection, high responsiveness, and low-light detection, with a broad range of application in new optoelectronics.
Enhancing wafer defect detection via ensemble learning
Authors: Pan A. Su , Nie B. Xingyang , Zhai C. Xiaoyu
Published: August 2024

Wafer inspection is crucial for semiconductor manufacturing, as it identifies defects in wafers before manufacturing. Wafer defect detection avoids wasting time and production capacity, boosts productivity, and assures production quality. In this paper, we propose an ensemble learning-based method for wafer defect detection that fuses the classification results of four models, namely, ResNet, ResNeSt, ResNeSt + CBAM, and ResNeSt + Self-attention. During the integration phase, we employ a hybrid strategy that combines weighted averaging and voting to determine weight coefficients. Our analysis shows that the model’s performance surpasses that of the arithmetic mean model within an interval of 0.8–1, according to our mathematical derivations. Furthermore, results demonstrate and substantiate that optimal performance is attained by setting the weighting value to 1. We experimentally validated the effectiveness of the proposed method on the WM-811k industrial dataset. In the experiments, the ensemble learning based method achieves an accuracy of 99.70%, which outperforms the individual model. Our approach outperforms the traditional arithmetic mean model by combining the strengths of all prediction models to improve prediction accuracy. Experimental results demonstrate that the proposed method has the potential to be an ideal option for wafer defect detection.
Effects of yaw angle on hydrodynamic performance for an oblique planing hull
Authors: Li Jianming
Published: August 2024

High-speed small crafts are extensively used in various environments. However, these planing vessels are prone to motion instabilities, particularly during turning and course-changing maneuvers. Understanding their behavior under a fixed yaw angle is crucial in the early design stages. This paper presents a numerical study to evaluate the influence of yaw angle on the hydrodynamic performance of high-speed planing hulls. The results indicate that the yaw angle has a significant influence on the hull’s running attitudes, as well as hydrodynamic forces and moments. At large yaw angles, air is drawn into the roll-down side, resulting in a small dynamic wetted surface area in high-speed cases. A negative pressure region is observed under high-speed conditions, with asymmetric conditions accentuating (mitigating) this negative pressure region on the roll-down (roll-up) sides. The peaks of sectional lift and resistance are typically observed near the stagnation line in most cases. The sectional sway force is more pronounced behind the center of gravity when the planing speed is slightly above the critical velocity of the trim angle, resulting in a positive yaw moment and suggesting a trend toward a reduction in the yaw angle. It is evident that the aerodynamic resistance on the transom surface is considerable in high-speed cases. The understanding of these phenomena is crucial for the effectiveness of high-speed small craft designs.
Designing polysaccharide materials for tissue repair and regeneration
Authors: Jin Anqi , Shao Yunyuan , Wang Fangyan , Feng Jiayin , Lei Lanjie , Dai Minghai
Published: August 2024

Tissue repair and regeneration are critical processes for maintaining the integrity and function of various organs and tissues. Recently, polysaccharide materials and protein materials have garnered interest for use in tissue repair strategies. However, polysaccharides are more stable and unaffected by temperature and pH changes compared to proteins, and some polysaccharides can provide stronger mechanical support, which is particularly important for constructing tissue-engineered scaffolds and wound dressings. This Review provides an in-depth overview of the origins of polysaccharides, the advantages of polysaccharide materials, and processing and design strategies. In addition, the potential of polysaccharide materials for the restoration of tissues such as skin, heart, and nerves is highlighted. Finally, we discuss in depth the challenges that polysaccharide materials still face in tissue repair, such as the stability of the material, regulating mechanical characteristics and deterioration rates under different conditions. To achieve more effective tissue repair and regeneration, future research must focus on further improving the characteristics and functionalities of polysaccharide materials.
An IL-23-STAT4 pathway is required for the proinflammatory function of classical dendritic cells during CNS inflammation
Authors: Alakhras Nada S. , Zhang Wenwu , Barros Nicolas , Sharma Anchal , Ropa James , Priya Raj , Yang X. Frank , Kaplan Mark H.
Published: August 2024

Although many cytokine pathways are important for dendritic cell (DC) development, it is less clear what cytokine signals promote the function of mature dendritic cells. The signal transducer and activator of transcription 4 (STAT4) promotes protective immunity and autoimmunity downstream of proinflammatory cytokines including IL-12 and IL-23. In experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS),
Stat4
−/−
mice are resistant to the development of inflammation and paralysis. To define whether STAT4 is required for intrinsic signaling in mature DC function, we used conditional mutant mice in the EAE model. Deficiency of STAT4 in CD11c-expressing cells resulted in decreased T cell priming and inflammation in the central nervous system. EAE susceptibility was recovered following adoptive transfer of wild-type bone marrow–derived DCs to mice with STAT4-deficient DCs, but not adoptive transfer of STAT4- or IL-23R-deficient DCs. Single-cell RNA-sequencing (RNA-seq) identified STAT4-dependent genes in DC subsets that paralleled a signature in MS patient DCs. Together, these data define an IL-23-STAT4 pathway in DCs that is key to DC function during inflammatory disease.
An optimal Bayesian strategy for comparing Wiener–Hunt deconvolution models in the absence of ground truth
Authors: Harroué B , Giovannelli J-F , Pereyra M
Published: August 2024

This paper considers the quantitative comparison of several alternative models to perform deconvolution in situations where there is no ground truth data available. With applications to very large data sets in mind, we focus on linear deconvolution models based on a Wiener filter. Although comparatively simple, such models are widely prevalent in large scale setting such as high-resolution image restoration because they provide an excellent trade-off between accuracy and computational effort. However, in order to deliver accurate solutions, the models need to be properly calibrated in order to capture the covariance structure of the unknown quantity of interest and of the measurement error. This calibration often requires onerous controlled experiments and extensive expert supervision, as well as regular recalibration procedures. This paper adopts an unsupervised Bayesian statistical approach to model assessment that allows comparing alternative models by using only the observed data, without the need for ground truth data or controlled experiments. Accordingly, the models are quantitatively compared based on their posterior probabilities given the data, which are derived from the marginal likelihoods or evidences of the models. The computation of these evidences is highly non-trivial and this paper consider three different strategies to address this difficulty—a Chib approach, Laplace approximations, and a truncated harmonic expectation—all of which efficiently implemented by using a Gibbs sampling algorithm specialised for this class of models. In addition to enabling unsupervised model selection, the output of the Gibbs sampler can also be used to automatically estimate unknown model parameters such as the variance of the measurement error and the power of the unknown quantity of interest. The proposed strategies are demonstrated on a range of image deconvolution problems, where they are used to compare different modelling choices for the instrument’s point spread function and covariance matrices for the unknown image and for the measurement error.
Passivated indium oxide thin-film transistors with high field-effect mobility (128.3 cm2 V−1 s−1) and low thermal budget (200 °C)
Authors: Xiao Na , Khandelwal Vishal , Yuvaraja Saravanan , Chettri Dhanu , Mainali Genesh , Liu Zhiyuan , Hassine Mohamed Ben , Tang Xiao , Li Xiaohang
Published: August 2024

Here, we demonstrate a high-mobility indium oxide (In2O3) thin-film transistor (TFT) with a sputtered alumina (Al2O3) passivation layer (PVL) with a low thermal budget (200 °C). The sputtering process of the Al2O3 PVL plays a positive role in improving the field-effect mobility (µ
FE) and current on/off ratio (I
ON/I
OFF) performance of the In2O3 TFTs. However, these enhancements are limited due to the high density of intrinsic trap defects in the In2O3 channels, as reflected in their large hysteresis and poor bias stability. Treating the In2O3 channel with oxygen (O2) plasma prior to sputtering the Al2O3 PVL results in notable improvements. Specifically, a high µ
FE of 128.3 cm2V−1 s−1, a high I
ON/I
OFF over 106 at V
DS of 0.1 V, a small hysteresis of 0.03 V, and a negligible threshold voltage shift under negative bias stress are achieved in the passivated In2O3 TFT (with O2 plasma pretreatment), representing a significant improvement compared to the passivated In2O3 TFT (without O2 plasma pretreatment) and the unpassivated In2O3 TFT. The remarkable reduction of intrinsic trap defects in the passivated In2O3 TFT compensated by O2 plasma is the primary mechanism underlying the improvement in µ
FE and bias stability, as validated by x-ray photoelectron spectra, hysteresis analysis, and temperature-stress electrical characterizations. Plasma treatment effectively compensates for intrinsic trap defects in oxide semiconductor (OS) channels, when combined with sputter passivation, resulting in a significant enhancement of the overall performance of OS TFTs under low thermal budgets. This approach offers valuable insights into advancing OS TFTs with satisfactory driving capability and wide applicability.
N = 2 a = 1 supersymmetric KdV equation and its Darboux–Bäcklund transformations
Authors: Yang XiaoXia , Xue Lingling , Liu Q P
Published: August 2024

In this paper, we study the N = 2 a = 1 supersymmetric KdV equation. We construct its Darboux transformation and the associated Bäcklund transformation. Furthermore, we derive a nonlinear superposition formula, and as applications we calculate some solutions for this supersymmetric KdV equation and recover the related results for the Kersten–Krasil’shchik coupled KdV-mKdV system.
Recension of boron nitride phase diagram based on high-pressure and high-temperature experiments
Authors: Zhang 张 Ruike 瑞柯 , Guo 郭 Ruiang 睿昂 , Li 李 Qian 倩 , Li 李 Shuaiqi 帅琦 , Long 龙 Haidong 海东 , He 贺 Duanwei 端威
Published: August 2024

Cubic boron nitride and hexagonal boron nitride are the two predominant crystalline structures of boron nitride. They can interconvert under varying pressure and temperature conditions. However, this transformation requires overcoming significant potential barriers in dynamics, which poses great difficulty in determining the c-BN/h-BN phase boundary. This study used high-pressure in situ differential thermal measurements to ascertain the temperature of h-BN/c-BN conversion within the commonly used pressure range (3–6 GPa) for the industrial synthesis of c-BN to constrain the P–T phase boundary of h-BN/c-BN in the pressure–temperature range as much as possible. Based on the analysis of the experimental data, it is determined that the relationship between pressure and temperature conforms to the following equation:

P
=
a
+

1
b

T

. Here, P denotes the pressure (GPa) and T is the temperature (K). The coefficients are a = −3.8±0.8 GPa and b = 229.8±17.1 GPa/K. These findings call into question existing high-pressure and high-temperature phase diagrams of boron nitride, which seem to overstate the phase boundary temperature between c-BN and h-BN. The BN phase diagram obtained from this study can provide critical temperature and pressure condition guidance for the industrial synthesis of c-BN, thus optimizing synthesis efficiency and product performance.
Single pair of charge-2 Dirac and charge-2Weyl phonons in GeO2
Authors: He 何 Dong-Chang 东昌 , Liu 刘 Jia-Xi 嘉希 , Liu 刘 Pei-Tao 培涛 , Li 李 Jiang-Xu 江旭 , Chen 陈 Xing-Qiu 星秋
Published: August 2024

The presence of a pair of Weyl and Dirac points (WP–DP) in topological semimetal states is intriguing and sought after due to the effects associated with chiral topological charges. However, identifying these states in real materials poses a significant challenge. In this study, by means of first-principles calculations we predict the coexistence of charge-2 Dirac and charge-2 Weyl phonons at high-symmetry points within a noncentrosymmetric P41212 space group. Furthermore, we propose GeO2 as an ideal candidate for realizing these states. Notably, we observe two distinct surface arcs that connect the Dirac and Weyl points across the entire Brillouin zone, which could facilitate their detection in future experimental investigations. This study not only presents a tangible material for experimentalists to explore the topological properties of WP–DP states but also opens up new avenues in the quest for ideal platforms to study chiral particles.
Intercontinental frequency ratio measurement of

171

Yb and

88

Sr optical lattice clocks
Authors: Morzyński Piotr , Bilicki Sławomir , Bober Marcin , Kovačić Domagoj , Ciuryło Roman , Zawada Michał , Nawrocki Jerzy , Dunst Piotr , Kobayashi Takumi , Hosaka Kazumoto , Akamatsu Daisuke
Published: August 2024

We report a remote, intercontinental frequency comparison between 171Yb (NMIJ) and 88Sr (UMK) optical lattice clocks. The frequencies were compared via the Global Positioning System Precise Point Positioning technique over the period from 10 March 2020, 00:00 UTC until 15 March 2020, 00:00 UTC. The comparison of the optical clocks yields results with a relative frequency uncertainty of

6.3
×

10

−
15

.
Research on the charging strategy of battery swapping stations under the optimization of peak-valley electricity price of electrical technology
Authors: Cai Xin , Chen Liangliang , Han Huachun
Published: August 2024

With the deepening reform of the intelligent power grid, electric technology has become an important part of the high-tech industry. Against the background of peak-valley electricity prices, this paper studies the charging strategy of battery swapping stations considering scene reduction technology. First, the electric passenger vehicle replacement demand scenario set is simulated. Then, the scenario reduction technology based on Kantorovich distance is adopted to effectively reduce the scenario set of power change demand by week. Finally, the proposed charging strategy considering the peak-valley electricity price of the electrical technology mechanism is analyzed and verified. The results show that the strategy can effectively reduce the battery charging cost and realize the economic operation of the battery swapping station.
Sequence impedance modeling of grid-following LC-type voltage source converter
Authors: Chen Yu , Sun Chenghao , Qi Fujun , Zhang Haijuan , Chu Xiaodong , Ye Hua
Published: August 2024

This paper establishes the impedance model of a grid-following converter without grabbing control delay and frequency coupling effects into attention, and uses the sinusoidal linearization to operate method to create both sides of the sequence impedance model in order to study the oscillation problem of power systems that contain renewable energy. The grid-connected system’s stability will be evaluated in light of this. MATLAB/Simulink simulations were completed to inspect the veracity of the created resistance model and the reliability analysis results.
Dual virtual vector duty cycle model predicts power control of dual three-phase permanent magnet generator
Authors: Zhang Bo , Liu Weiting
Published: August 2024

The large vector model for predicting power control (MPPC) of a traditional two-three-phase permanent magnet synchronous generator is used to solve the problems of high current harmonics, sharp power pulsation, and unstable phase current. A dual virtual vector duty cycle model is proposed to predict power control. This method obtains 12 virtual voltage vectors by selecting the two vectors of the outermost and secondary outer layers of the rectifier, and then directly introduces the 12 virtual voltage vectors into the power value function for iterating, and then obtains an optimal virtual vector that minimizes the value function. The two vectors adjacent to the optimal vector are brought into the value function, and the suboptimal vector that makes the value function smaller is selected. Finally, the duty cycle modulation is carried out together with the zero vector, and the function of each vector is calculated by using the idea of no beat. The experimental results show that the double virtual vector duty cycle MPPC can effectively reduce current harmonics, reduce current and power pulsation, and improve current stability.
Fault line selection algorithm for single-phase grounding faults in distribution networks based on multi-feature fusion of multi-level wavelet decomposition coefficients
Authors: Li Jinyao , Wu Shouyuan , Gao Lixue
Published: August 2024

This paper introduces a novel method for determining fault lines, addressing the time-consuming nature of traditional steady-state quantity methods and the susceptibility to errors in transient quantity methods. A multi-feature fusion technique, involving multi-level wavelet decomposition coefficients, is employed. This involves the extraction of zero-sequence current wavelet transform coefficients with the Discrete Wavelet Transform (DWT), and the formation of a similarity function through the S-transform. Subsequently, an energy measure function is derived by integrating these coefficients. A function representing faultiness, aligned with various fault lines, is then developed and used as the primary criterion for identifying the faulted line. Simulation data from a single-phase grounding fault model in a distribution network confirms the efficacy of the method in choosing fault lines.
Physical neural network using skyrmion-based spin torque nano-oscillators
Authors: Xiong Shan , Liang Xue , Xing Xiangjun , Zhou Yan
Published: August 2024

Due to physical limitations on the miniaturization of traditional electronic devices, architectures based on emerging principles have become the focus of current research to meet the needs of rapidly developing information technologies in the post-Moore era. Neuromorphic devices hold huge potential for use in future artificial intelligence (AI) chips beyond conventional architectures. Benefiting from a wealth of nonlinear dynamic characteristics of spin torque nano-oscillators (STNOs), studies of neuromorphic computations and their applications based on STNOs are attracting growing attention. In this article, at first, we construct a magnetic skyrmion-based STNO and analyze its characteristics; on this basis, we propose a physical echo state network (ESN) including eight skyrmion-based STNOs, which is utilized to implement an image recognition task. Micromagnetic simulations of the nonlinear response of skyrmion-based STNOs to current pulses imply that such a physical neural network has remarked performance in handwritten digit recognition. The high precision, low energy consumption, and fast processing speed of STNO-based neuromorphic devices are desirable in multitudinous practical applications, possibly leveraging the use of STNO-based physical neural networks in the field of artificial intelligence.
Automatic detection system of secondary equipment in smart substation based on decision tree and support vector machine
Authors: Fu Zhong , Song Pengfei
Published: August 2024

Because the current method is not effective in detecting secondary equipment in smart substations, the actual loss value is unstable and the recall rate is low, and the expected detection effect cannot be achieved, an automatic detection system for secondary equipment in smart substation based on decision tree and support vector machine is designed. Firstly, the connection structure of the front-end detection circuit is designed, and the detection sensor is designed by combining the current sensor, voltage sensor, and power factor sensor. A decision tree is used to sample the detection data, and kernel function is introduced to convert nonlinear data into linear data under support vector machine, to realize the transformation of secondary equipment data in smart substation from low dimension to high dimension and complete the design of automatic detection system. The experimental results show that the detection effect of the designed system is closer to the actual loss value under some actual losses, which can improve the automatic detection effect. The designed system has the best performance in the recall rate, with little fluctuation and the most stable performance.
Modification and characterisation of nickel-based alloy materials for ultra-supercritical power generation
Authors: Zhang Xiaolong
Published: August 2024

Ultra-supercritical power generation technology has consistently pioneered energy-efficient utilization techniques, with the development and application of tubing serving as the cornerstone for ultra-supercritical power plant units. Among numerous candidate materials, nickel-based alloys have garnered widespread attention due to their exceptional high-temperature strength and corrosion resistance. This study primarily delineates the modification techniques employed for nickel-based alloy materials utilized in 700°C ultra-supercritical units, encompassing solid-solution strengthening, high-entropy alloys, additive manufacturing, and surface-coating. Additionally, this paper consolidates characterization methodologies for nickel-based alloys, focusing on morphological and crystallinity characterization and mechanical performance evaluations, thereby offering valuable insights and guidance for researchers in this field.
Ti3AlC2-modified NiCrAlY as a metallic bond coat for thermal barrier coatings: a study on high-temperature oxidation resistance
Authors: He Wenbin , Li Junliang , Liu Kun
Published: August 2024

Thermal barrier coatings (TBCs) are employed in high-temperature gas turbines to reduce the surface temperature of metallic components such as turbine blades. In order to enhance the operational performance of conventional TBCs under high-temperature and high-pressure conditions, this study designs and prepares a novel TBC with YSZ as the ceramic layer and NiCrAlY as the bond coat. Different amounts of Ti3AlC2 particles (5wt%, 10wt%, and 15wt%) are added to the bond coat. The microstructure and organization of the coatings are characterized by using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). The resistance to high-temperature oxidation of the coatings is evaluated through atmospheric muffle furnace testing. When the Ti3AlC2 content is 5wt%, the coating exhibits less weight gain than traditional TBCs after oxidation at 950°C for 80 hours. Compared to coatings with Ti3AlC2 content of 10wt% and 15wt%, the coating with 5wt% Ti3AlC2 achieves the optimal resistance to high-temperature oxidation.
Mode I interlaminar fracture toughness of glare laminates by single cantilever beam
Authors: Hua Xiaoge , Tian Zheng
Published: August 2024

GLARE laminates, also known as Glass Fiber Reinforced Aluminum Laminates, have emerged as critical materials for fuselage and wing skin applications due to their outstanding fatigue resistance and good damage tolerance. Among the various modes of failure in GLARE laminates, interfacial delamination plays a significant role in determining their overall performance. However, GLARE laminates suffer complicated failure mechanisms and have a complex multi-interface system. Clearly, it is crucial to accurately determine the feasibility and accuracy of the SCB (Single Cantilever Beam) method for GLARE laminates by combining finite element simulation with experiments. Meanwhile, a detailed investigation was conducted on the influence of fiber laying and the loading rate of GLARE laminates. The findings revealed that the SCB tests resulted in pure Mode I interlaminar fracture failure. Furthermore, it was observed that loading rates range of 1~5 mm/min achieves reasonable and effective Mode I interlaminar fracture toughness. Additionally, finite element simulation results demonstrated the absence of in-plane shear failure within the fiber layer, leading to the production of pure Mode I interlaminar fracture.
Mass-controlled contact variable stiffness elastic metamaterials for bandgap tuning
Authors: Lyu Ronghao , Zhang Kai
Published: August 2024

The tunability of elastic metamaterials has emerged as a focal point in recent years within the realm of metamaterial research. However, achieving extensive bandgap tuning at low frequencies and identifying appropriate control mechanisms remain challenging tasks in existing studies. In this research, we propose a novel approach based on mass-controlled contact-variable stiffness locally resonant elastic metamaterials. By altering the mass and orientation of oscillators, the contact state of the variable stiffness structure can be modified within the unit cell, resulting in significant variations in effective stiffness and enabling broad bandgap tuning at low frequencies. Furthermore, the gravitational field control method employed in this study offers simplicity, rapidity, and ease of manipulation. The materials utilized in this research are readily accessible, and the structure’s simplicity facilitates ease of fabrication, thus holding promise for practical applications in scenarios such as vibration and noise reduction in ships, vehicles, buildings, and other related fields.
Research on the effect of mg doping on the properties of ZnO nanorods
Authors: Tian Xue , Yang Yingying , Sun Yuanping
Published: August 2024

Semiconductor materials, as the core of the new generation of information technology, and nano ZnO as the third-generation semiconductor, have high absorption and transparency in the visible light range, as well as a wide bandgap, making it widely applicable in the field of optoelectronic components. This article prepared Mg-doped ZnO nanorods using a low-temperature water bath method and studied the effect of Mg doping on the structure and luminescent properties of the samples using scanning electron microscopy (SEM), X-ray diffraction (XRD), and photoluminescence (PL) analysis. The SEM results indicate that the obtained sample has a double-columnar ZnO nanorod structure. As the Mg doping concentration increases, the size of ZnO nanorods first increases and then decreases. When the Mg doping concentration reaches 2%, the size of ZnO nanorods reaches its maximum, about 7.94 μm. The XRD results indicate that the obtained ZnO sample has a hexagonal wurtzite structure, and there is no additional Mg impurity phase in the sample, indicating that Mg2+ has successfully replaced Zn2+ into the lattice. The PL spectrum indicates that the obtained sample has a maximum UV emission value of around 395 nm and exhibits green (520 nm, 566 nm) and orange (600 nm) luminescence characteristics. With the increase of Mg doping concentration, the UV emission peak strengthens and shifts red, and the visible emission peak weakens, which improves the photocatalytic performance of ZnO nanorods.
Effect of salt concentration on the antibubble lifetime
Authors: Liu Shuheng , An Ji , Liu Ziqi , Zhao Guilin , Gao Rui
Published: August 2024

Antibubble lifetime has attracted increasing attention since it limits the practical applications of antibubbles. This paper presents an experimental study on the effect of salt concentration on the antibubble lifetime. With a uniform salt solution by fully stirring, the antibubble lifetime is observed to increase first but then decrease with the salt concentration. The lifetime extension is not significant. However, in a nonuniform salt solution without stirring, the generated heavy antibubbles suspended near the container’s bottom have a much longer lifetime, about an order of magnitude higher. Along with the free dissolution of salt, a blurred liquid layer emerges near the container’s bottom due to the formation of worm-like micelles. These micelles endow the liquid viscoelastic properties and slow down the air drainage in the film, leading to a significantly longer lifetime. This study provides a feasible method to investigate the air drainage in the film because of the slow drainage speed. Moreover, the long lifetime makes the following experimental processes of antibubbles more convenient.
Analysis of circumferential CO2 arc welding welded shield machine hob to investigate the welding residual stress fields
Authors: Xue Xiaojie , Chen Jianfu , Huang Shuhua , Zhang Liang , Tian Zhaoping
Published: August 2024

This paper investigates the distribution and formation rules of welding residual stress during the process of shield machine hob welding using CO2 arc welding. A corresponding three-dimensional digital model is created using the FEA software to research the distribution of welding residual stress during the single pass wire filling welding. The numerical model of a shield machine hob is verified by the welding experiments. This study utilizes numerical computational methods to describe the causes and changes of welding residual stress and strain during the welding process. According to the calculations, the results indicate that compressive axial residual stress is observed on the outer surface of the hob body near the weld line. Conversely, tensile axial residual stress is evident on the inner surface in contrast. Additionally, both the outer and inner surfaces of the hob body exhibit tensile hoop residual stress. Near the weld line, the upper surface of the hob ring shows tensile transversal and longitudinal residual stresses. The main reason for this phenomenon is that different plastic strains are generated because of the thermal contracting deformation at the various surfaces and internal stress self-balance. Moreover, the internal residual stress distribution of fillet weld is investigated, which is obviously different from the external of fillet weld.
Preparation of butyl bonded poly (styrene-divinylbenzene) microspheres by Grignard reaction
Authors: Jiang Meijuan , Jin Fuqiang , Zhang Hao , Yi Xiaolu , Zhao Xin
Published: August 2024

The alkylated poly(styrene-divinylbenzene) (PSD) microspheres are attractive chromatographic column packings for high-performance liquid chromatography. In this paper, the butyl bonded PSD microspheres were prepared by the reaction of brominated PSD microspheres with n-butylmagnesium bromide. Fourier transform infrared (FTIR) spectroscopy and solid-state 13C nuclear magnetic resonance (NMR) spectroscopy were used to analyze the polymers. FTIR spectra analysis could establish the occurrence of bromination of PSD microspheres and the reaction of brominated PSD microspheres with n-butylmagnesium bromide. And 13C NMR results illustrated that the Grignard reaction had the largest conversion at the 1-bromobutane adding amount of 0.05 mol according to the analysis of the peak height ratios. The prepared microspheres are expected to serve as chromatographic packing.
Preparation and autocatalytic properties of CNTs/Co3O4/AP Core-shell composite energetic materials
Authors: Li Linpeng , Ba Shuhong
Published: August 2024

To change the thermal decomposition property of AP, band structure/state density of nickel oxide, tricobalt tetraoxide carbon nanotubes, and graphite were emulated by using Materials Studio. The results indicate that the catalytic performance of the indirect gap semiconductor Co3O4 and the indirect gap semiconductor CNTs was excellent, and the band gaps were 0.076 eV and 0.168 eV, respectively. CNTs/Co3O4/AP were made by using the solvent-nonsolvent method. The construction of CNTs/Co3O4/AP composites was analyzed by using XRD and TG-DSC according to the tests. The samples were tested for thermal decomposition performance by using DSC, and the results indicated that the high-temperature temperature of AP significantly decreased by 155.58°C. The above results make clear that the CNTs/Co3O4/AP has good autocatalytic performance.
Strain-rate dependent dynamic constitutive model of tempered glass
Authors: Li Lei , Liu Bangxian , An Erfeng
Published: August 2024

Tempered glass is essentially different from float glass in dynamic mechanical properties, although it is toughened float glass made by physics and they have the same chemical composition. The dynamic mechanical properties of tempered glass are investigated in this paper by using the modified techniques of the Split Hopkinson Pressure Bar (SHPB), and the curves of stress-strain are obtained in various strain rates. Experimental results show that tempered glass is sensitive to strain rates and its dynamic curves of stress-strain are nonlinear. Further study reveals the phenomenon of “pseudo-plastic yield” is completely different from that of ductile materials, and dynamic Young’s modulus and dynamic compressive strength of tempered glass increase with the increasing strain rates. Based on the damage mechanics theory, a kind of constitutive model with damage of tempered glass is given. A strain rate-dependent constitutive model with damage of tempered glass is created by the use of polynomial fitting, according to SHPB experimental results.
Static and dynamic mechanical behavior and constitutive parameters determination of high nitrogen austenitic stainless steel
Authors: Hong Xiaowen , Shi Anshun , Ge Yuanyuan , Fan Xuefei , Qin Chao , Yu Guoji , Wang Lujie
Published: August 2024

In order to obtain the material model parameters for numerical simulation of the ballistic performance of high nitrogen austenitic stainless steel (HNASS) perforated armour, the static and dynamic mechanical properties and material fracture experiments of HNASS have been carried out. Parameters for the Johnson-Cook constitutive and failure model were then adjusted based on the experimental findings. The penetration process of perforated armour against 12.7 mm armour-piercing incendiary shells (API) was simulated by AUTODYN software and the simulation results were compared with the ballistic test results. The findings indicate that using model parameters acquired from mechanical experiments for penetration simulation results in matching failure modes of the perforated armor and penetration depths of body armor with test outcomes, confirming the reliability of the model parameters.
Research on improving parallel sequence sampling method in ship type optimization
Authors: Li Dongqin , Lu Lingfeng
Published: August 2024

To solve the problem of complex and time-consuming simulation calculations in ship type optimization, the application of approximate model technology based on spatial segmentation sequence sampling is becoming increasingly widespread. Based on the Kriging approximation model and the cross-leaving one error method, a new sampling strategy is proposed during the iterative sampling process. The importance of adding sample subspaces and surrounding subspaces is considered in the design space, and parallel thinking is added to develop an efficient parallel sequence sampling method to improve sample aggregation. The proposed method was applied to optimize ship types, and its effectiveness was verified.
Mechanical properties and mechanism analysis of modified red layer filler with slag powder
Authors: Gao Yuan , Niu Haoying , Zhang Bingbing
Published: August 2024

In order to study the mechanical properties of slag micropowder cured red layer filler and its microscopic action mechanism, the mechanical properties of red layer filler with different dosages of slag micropowder were investigated by using test methods such as no lateral limit and straight shear, and the microscopic properties and improvement mechanism of slag micropowder cured red layer filler were analysed by using test methods such as X-ray diffraction, infrared spectroscopy, laser particle size, nuclear magnetic resonance, thermogravimetric analysis, and scanning electron microscopy. The experimental results show that the addition of slag powder can significantly improve the mechanical strength and water stability of the red-layer filler. The microscopic experiments such as X-ray diffraction and infrared spectroscopy proved that the action mechanism of slag micropowder-modified red layer filler is ion exchange and hydration. More importantly, using scanning electron microscopy (SEM), it can be visually observed that the improved red layer filler causes the soil particles to flocculate into sheets or clumps with the increase of hydration gel materials, forming lamellar accumulation or flocculation structures, and the structural integrity is significantly improved.
Significant carbonate burial in The Bahamas seagrass ecosystem
Authors: Fu Chuancheng , Frappi Sofia , Havlik Michelle Nicole , Howe Wells , Harris S David , Laiolo Elisa , Gallagher Austin J , Masqué Pere , Duarte Carlos M
Published: August 2024

Seagrass meadows store significant amounts of carbonate (CaCO3) in sediment, contributing to coastal protection but potentially offsetting their effectiveness as carbon sinks. Understanding the accumulation of CaCO3 and its balance with organic carbon (Corg) in seagrass ecosystems is crucial for developing seagrass-based blue carbon strategies for climate change mitigation. However, CaCO3 accumulation in seagrass meadows varies significantly across geographic regions, with notable data gaps in the Caribbean and Central America. Here, we sampled 10 seagrass meadows across an extensive island chain in The Bahamas, part of the largest seagrass ecosystem and one of the largest CaCO3 banks globally, to evaluate CaCO3 stock, accumulation rate, and its balance with Corg sequestration. Seagrass meadows in The Bahamas store 6405–8847 Tg of inorganic carbon (Cinorg) in the upper meter sediment, with an annual accumulation rate of 38.3–52.9 Tg of Cinorg, highlighting these meadows as hotspots for CaCO3 burial. CaCO3 contributes 67 ± 8% (mean ± standard error) of the sediment accumulation, indicating its important role in seabed elevation. Sediment Cinorg showed no significant relationship with Corg, with an average Corg : Cinorg ratio of 0.069 ± 0.002, ∼ 10 times lower than the threshold (Corg : Cinorg ratio of about 0.63) at which seagrass ecosystem transition from CO2 sources to sinks. However, the available air–sea gas flux measurement was only 1/5 of the calculated CO2 emission expected from calcification, suggesting that part of the accumulated CaCO3 is supported by allochthonous inputs. Furthermore, no perceivable relationship between seagrass density and either CaCO3 stock or accumulation rate was observed, indicating that seagrass may play a limited role in supporting CaCO3 production. Further studies on water chemistry, calcification rate, air–sea CO2 flux, and comparison between seagrass and unvegetated habitats are required to elucidate the carbon budget of this globally significant ecosystem.
Exploring the Guideline Criteria for Malaysian Garden Design Concept
Authors: Zakaria A Z , Mohd Hussain N H , Mat Nayan N
Published: August 2024

The Malaysian Garden concept (MGC) is guided by principles and criteria reflecting traditional Malay design elements and contemporary approaches. Previously, the criteria of the guidelines provided by the National Landscape Department (NLD) for Malaysian Garden design can be used as a reference to evaluate the implementation and design enforcement of public parks in Malaysia. However, the effectiveness of these guidelines in achieving the desired aesthetic and functional goals of Malaysian Gardens needs to be clarified. As Malaysia undergoes rapid social, cultural, and environmental changes, the existing guidelines must be more relevant and applicable. Thus, there is a need to critically examine and compare traditional and contemporary approaches to Malaysian Garden design and evaluate the effectiveness of current guideline criteria in achieving desired outcomes. The study’s objective is to determine how effective these criteria are in achieving the desired aesthetic and functional goals of Malaysian Gardens and the limitations of these criteria. The study adopted a comparative analysis approach to analyze traditional and contemporary Malaysian Garden designs and evaluate their adherence to current guidelines. The comparative analysis between traditional and contemporary approaches is interesting and valuable. It allows the researchers to evaluate the effectiveness of existing criteria considering current needs and evolving cultural contexts. The study also involves interviewing Malaysian Garden experts and other relevant stakeholders to gain insights into their perspectives on current guideline criteria and potential modifications to reflect current needs better. This study can catalyze development guidelines or recommendations for implementing Malaysian Garden design principles in public parks. Analysis of existing public parks in Malaysia to assess the extent to which they adhere to Malaysian Garden design guidelines and identify areas for improvement. The study’s findings will contribute to developing more effective guideline criteria for Malaysian Garden design that reflect the country’s cultural heritage and current needs.
Walkability Identification of Tourism Area at Ngarsopuro and Gatot Subroto Corridor
Authors: Sari Pratiwi Anjar , Suminar Lintang
Published: August 2024

Ngarsopuro and Gatot Subroto corridor is one of the main corridors in downtown Surakarta due to its strategic location in CBD (Central Business District) area and the two sultanate areas of Surakarta (Mangkunegaran and Kasunanan). The site’s function influences pedestrian activity in this corridor as a cultural arts tourism center. Pedestrian comfort is a priority in the arrangement of an urban area. Pedestrian comfort is one aspect of the concept of walkability. This study aims to identify the quality and pedestrian facilities in tourist areas using the concept of walkability. The method used in this research is a descriptive qualitative method through field observation to observe and identify the condition of pedestrian facilities in the Ngarsopuro and Gatot Subroto corridors. The discussion compared the corridor’s existing situation with the walkability principle. The results showed that the quality of pedestrian paths on the Ngarsopuro and Gatot Subroto corridors needs to be improved. Some of the problems found are the lack of greenery, the lack of facilities for disabled people, and the condition of the facilities that are not maintained. This issue affects the comfort of pedestrians, who are actors in the concept of walkability. The study’s results are expected to be an evaluation and input in improving the quality of pedestrian ways in tourist areas.