bluuebunny/crossref_metadata_2025_split huggingface dataset:
Non-contact characterization of material anisotropy of additive manufacturing components by electromagnetic acoustic resonance technique
Authors: Yuan Xinyi , Li Weibin , Deng Mingxi 
Published: October 2023

Abstract
The degree of material anisotropy in additive manufacturing (AM) components is greatly influenced by the AM process parameters and machine setup. It is crucial to develop an effective technique for evaluating the material anisotropy in AM components to optimize AM process parameters and component design. This paper proposed a non-contact ultrasonic characterization method using the electromagnetic acoustic resonance technique to characterize the anisotropy of AM components. Various electromagnetic acoustic transducers (EMATs) were designed and utilized to characterize the material anisotropy and to determine the principal direction of the AM components. The degree of anisotropy in AM components was characterized using radial radiation EMATs. The relationship between the degree of anisotropy and the laser scanning angle was explored and further determined through the acoustic birefringence factor. Experimental results demonstrated that the anisotropy of AM components is intricately associated with the laser scanning angle, and specific angles can render the AM components isotropic. Moreover, understanding the principal directions is of significance for structural design and analyzing stress distribution in anisotropic components. Therefore, the principal directions of AM components were obtained by rotating the linear polarization EMAT. Changes in the resonance spectrum captured by the linear polarization EMAT while evaluating of principal directions were clearly illustrated, despite negligible alterations in linear ultrasonic features. Metallographic diagrams further validated the experimental findings. This investigation presented a highly accurate and reliable alternative for characterizing the anisotropy of AM components.
Sb-saturated high-temperature growth of extended, self-catalyzed GaAsSb nanowires on silicon with high quality
Authors: Schmiedeke P , Döblinger M , Meinhold-Heerlein M A , Doganlar C , Finley J J , Koblmüller G 
Published: October 2023

Abstract
Ternary GaAsSb nanowires (NW) are key materials for integrated high-speed photonic applications on silicon (Si), where homogeneous, high aspect-ratio dimensions and high-quality properties for controlled absorption, mode confinement and waveguiding are much desired. Here, we demonstrate a unique high-temperature (high-T >650 °C) molecular beam epitaxial (MBE) approach to realize self-catalyzed GaAsSb NWs site-selectively on Si with high aspect-ratio and non-tapered morphologies under antimony (Sb)-saturated conditions. While hitherto reported low-moderate temperature growth processes result in early growth termination and inhomogeneous morphologies, the non-tapered nature of NWs under high-T growth is independent of the supply rates of relevant growth species. Analysis of dedicated Ga-flux and growth time series, allows us to pinpoint the microscopic mechanisms responsible for the elimination of tapering, namely concurrent vapor–solid, step-flow growth along NW side-facets enabled by enhanced Ga diffusion under the high-T growth. Performing growth in an Sb-saturated regime, leads to high Sb-content in VLS-GaAsSb NW close to 30% that is independent of Ga-flux. This independence enables multi-step growth via sequentially increased Ga-flux to realize uniform and very long (>7 μm) GaAsSb NWs. The excellent properties of these NWs are confirmed by a completely phase-pure, twin-free zincblende (ZB) crystal structure, a homogeneous Sb-content along the VLS-GaAsSb NW growth axis, along with remarkably narrow, single-peak low-temperature photoluminescence linewidth (<15 meV) at wavelengths of ∼1100–1200 nm.
Numerical study of divertor detachment in TCV H-mode scenarios
Authors: Yang H , Ciraolo G , Février O , Galassi D , Bucalossi J , Bufferand H , Gorno S , Henderson S , Reimerdes H , Theiler C , Bagnato F , Falchetto G , Fedorczak N , Rivals N , Tamain P ,   the TCV Team
Published: October 2023

Abstract
The effect of divertor closure and nitrogen seeding on the detachment process has been studied by performing 2D numerical simulations of tokamak à configuration variable (TCV) H-mode divertor scenarios with the SOLEDGE3X-EIRENE edge plasma transport code. The simulations reveal that, in the cases with only deuterium gas fuelling, detachment occurs at a similar level of divertor neutral pressure (

≈

0.76 Pa), despite the difference in divertor closure achieved by changing the length of the outer baffle. Nitrogen reduces the target temperature with little effect on the upstream density and momentum loss but drops the upstream pressure, leading to a decrease in the target particle flux and divertor neutral pressure. Furthermore, when the radiation front starts to move up from the outer target, the peak parallel heat flux level at the outer target remains approximately the same (

≈

2.3

MW m−2), regardless of whether it is a deuterium fuelling scan, a nitrogen seeding scan at a fixed fuelling rate, or a change in the length of the outer baffle. An empirical partial detachment qualifier calibrated on AUG experimental data was compared with the TCV simulations. The results show good agreement in detachment state prediction, indicating the potential of this detachment qualifier to be applied in devices of different sizes, emphasizing the combined influence of input power entering the divertor, neutral pressure, and the concentration and species of impurity in achieving divertor detachment.
Mechanical, electronic, optical, piezoelectric and ferroic properties of strained graphene and other strained monolayers and multilayers: an update
Authors: Naumis Gerardo G , Herrera Saúl A , Poudel Shiva P , Nakamura Hiro , Barraza-Lopez Salvador 
Published: October 2023

Abstract
This is an update of a previous review (Naumis et al 2017 Rep. Prog. Phys.
80 096501). Experimental and theoretical advances for straining graphene and other metallic, insulating, ferroelectric, ferroelastic, ferromagnetic and multiferroic 2D materials were considered. We surveyed (i) methods to induce valley and sublattice polarisation (P) in graphene, (ii) time-dependent strain and its impact on graphene’s electronic properties, (iii) the role of local and global strain on superconductivity and other highly correlated and/or topological phases of graphene, (iv) inducing polarisation P on hexagonal boron nitride monolayers via strain, (v) modifying the optoelectronic properties of transition metal dichalcogenide monolayers through strain, (vi) ferroic 2D materials with intrinsic elastic (σ), electric (P) and magnetic (M) polarisation under strain, as well as incipient 2D multiferroics and (vii) moiré bilayers exhibiting flat electronic bands and exotic quantum phase diagrams, and other bilayer or few-layer systems exhibiting ferroic orders tunable by rotations and shear strain. The update features the experimental realisations of a tunable two-dimensional Quantum Spin Hall effect in germanene, of elemental 2D ferroelectric bismuth, and 2D multiferroic NiI2. The document was structured for a discussion of effects taking place in monolayers first, followed by discussions concerning bilayers and few-layers, and it represents an up-to-date overview of exciting and newest developments on the fast-paced field of 2D materials.
Persistent MgB2 joints for react and wind magnets
Authors: Guven M , Zagura P , Barker C M , Kutukcu M N , Atamert S , Grovenor C R M , Speller S C 
Published: October 2023

Abstract
Ultra-low resistance joints are a key technology enabling superconducting magnets to operate in persistent mode and to achieve the temporal stability required for nuclear magnetic resonance and magnetic resonance imaging (MRI) applications. High performance superconducting joints are manufactured routinely for Nb–Ti and Nb3Sn magnets, but technologies for joining other technological superconductors are still in the early stages of development. Here we report the use of a simple cold pressing and heat treatment procedure to fabricate persistent MgB2 joints with resistance values <10−12 Ω between MgB2 wires that have already undergone the full wire reaction process. Trapped persistent currents of 172 A and 160 A were achieved under self-field and 1 T background field conditions respectively at a temperature of 20 K. This corresponds to a critical current ratio of 78% under these conditions, outperforming previously reported joints using fully reacted MgB2 wire. These findings are relevant for the development of commercial MRI magnets with MgB2 wires utilizing react and wind methods.
A theoretical analysis of performance enhancement of SPR sensor based on ZnO and BaTiO3 for NH3 detection
Authors: Ghanizadeh Sara , Naghshara Hamid , Meshginqalam Bahar 
Published: October 2023

Abstract
Surface plasmon resonance (SPR) sensors have attracted enormous attention due to their applications in various fields. A novel SPR-based sensor with ZnO and BaTiO3 metal oxide layers is designed for NH3 gas detection. Gold and silver are used as plasmonic materials and corresponding results are compared. The prism and plasmonic materials effects on sensor response are investigated. Moreover, thicknesses of gold and silver and metal oxide layers are optimized to obtain suitable performance parameters. sensor response is analyzed in terms of minimum reflectance, sensitivity, detection accuracy and quality parameter. Applying ZnO and BaTiO3 layers lead to 37.88% and 26.03% enhancement of quality parameter and 37.91% and 26.07% improvement of detection accuracy, and more than 3.4 times improvement of detection resolution in gold and silver-based sensors, respectively. The recommended sensor structure provides appropriate performance parameters for 1 to 200 ppm of NH3 gas that can have potential applications in toxic gas sensing.
Investigating Ag2S quantum dot buffer layer in CZTSSe photovoltaics for enhanced performance
Authors: Yadav Shweta , Chauhan R K , Mishra Rajan , Kumar Saurabh 
Published: October 2023

Abstract
This study focuses on optimizing the performance of CZTSSe (Copper Zinc Tin Sulphide/Selenide) photovoltaic (PV) cells by incorporating an Ag2S quantum dot (QD) buffer layer. CZTSSe, with its significant Direct bandgap (1–1.5 eV) and the absorption coefficient (>104 cm−1), shows promise for efficient visible-range light absorption. Ag2S quantum dots, known in terms of their favourable attributes, such as high absorption, low solubility, and minimal surface recombination, are explored as a buffer layer material. The effects of the Ag2S quantum dot (QD) buffer layer on the optical and electrical characteristics of CZTSSe photovoltaic (PV) cells are comprehensively examined using simulation characterization. Key parameters, including Short-circuit (JSC), fill factor (FF), open-circuit voltage (VOC), and power conversion efficiency (PCE), are analyzed to validate device characteristics. The SCAPS-1d simulator is employed for performance assessment and enhancement through tuning device parameters such as energy bandgap, absorber layer thickness, buffer layer thickness, defect density, and acceptor concentrations of the absorber and hole transport layer (HTL), and donor concentrations of the buffer. Additionally, temperatures, as well as series-shunt resistance’s influence on device effectiveness, are explored. The study aims to maximize light absorption, enhance charge conduction, reduce carrier loss due to recombination, and upgrade CZTSSe PV cells’ overall performance. The CZTSSe solar unit achieves its highest PCE of 27.56% when employing an Ag2S buffer layer and Cu2O hole transport layer. The study provides valuable knowledge about the optimization of CZTSSe solar cells and the potential benefits of utilizing Ag2S QD in the role of buffer layer material. This research contributes to the understanding of enhancing CZTSSe PV cell performance through the incorporation of Ag2S QD buffer layers and presents pragmatic directives that can be employed to facilitate the progression of CZTSSe-based photovoltaic devices.
A 111dB-SNDR 20kHz-BW Delta-Sigma Modulator with Auto-Zeroing and Class-AB Amplifier
Authors: Luan Gaofeng , Xing Xinpeng , Feng Haigang , Gielen Georges 
Published: October 2023

Abstract
This paper describes the design of a high-precision audio Delta-Sigma modulator. To guarantee the modulator linearity and resolution with a limited oversampling rate (OSR), 4th-order 1-bit architecture is chosen. Auto-zeroing technique is used to reduce offset and low-frequency noise. To optimize power consumption, the switched-capacitor loop filter is implemented by feedforward structure with a passive adder and class-AB two-stage amplifiers. A clock generator with optimized non-overlapping pulse widths is designed to improve precision. Simulation results in 180nm CMOS show that with a 10.24MHz sampling rate, the presented modulator achieves 111dB signal-to-noise-and-distortion ratio (SNDR) at 20kHz bandwidth (BW) and consumes 17.9mW power under 3.3V supply, corresponding to an excellent figure-of-merit (FoM) of 171.5dB. Simulation results in process corners and temperatures show that the modulator is robust over variations.
VIHCEMOS-CFAR Detector Based on Improved VI-CFAR
Authors: Qin Tian-Ci , Wang Zhong-Xun , Huang Yong , Wei Hao-Xuan , Liu Yan 
Published: October 2023

Abstract
A variability index heterogeneous clutter estimate modified ordered statistics constant false alarm rate (VIHCEMOS-CFAR) detector based on improved VI-CFAR is proposed. First calculate the VI and MR values and then judge the clutter background: If the background is uniform, cell averaging (CA) target detection strategy is adopted; HCE detection strategy is adopted if it is clutter edge background; If it is a complex background composed of multiple targets or strong clutter, the OS detection strategy is adopted. The method of judging the interfering targets and strong clutter in the reference window by using the phase characteristics is used to calculate the accurate k. The Modified-OS algorithm with corrected k is proposed as the detection strategy in the multi-target environment to improve the target detection performance in practical projects. Through detailed experiments, it is proved that VIHCEMOS has adaptive clutter background capability and better detection performance than all other CFAR detection algorithms in multi-target environment.
Comparison of 1T1R and 1C1R ReRAM Arrays
Authors: Alshaya Abdulaziz , Malik Adil , Mifsud Andrea , Papavassiliou Christos 
Published: October 2023

Abstract
The rise of memristors with potential applications in memory has attracted wide interests. Memristors are typically assembled in crossbar arrays with data bits encoded by the resistance of individual cells. The 1T1R cell structure is the most popular for memristive memory as it eliminates sneak path currents. The transistor not only allows for flexible selection of memory cells but also facilitates the programming for computing-in-memory applications. In this paper, we replace the selector in the 1T1R configuration with a capacitor to form a selectorless and passive combination of ReRAM structure. Moreover, we evaluate the merits of the two structures in SkyWater 130nm CMOS technology by comparing the writing technique, power consumption, switching speed, and memory density. Furthermore, we compared the complexity of the readout method between 1T1R and 1C1R for a memory application. This work shows that the 1C1R configuration is a promising memory structure that consumes less energy, switches faster, has higher density, and has a simpler readout method when compared to 1T1R.
Overview of Magnetic Field Sensor
Authors: Wang Silin , Gao Junji 
Published: October 2023

Abstract
This article summarizes the commonly used in magnetic sensors Hall sensors, Anisotropic magnetoresistive sensor (AMR), Giant magnetoresistance effect sensor (GMR) and Tunneling magnetoresistance sensor (TMR). The structure and working principle of each sensor are introduced. In addition, some error sources of magnetic sensors and the calibration techniques used are introduced, and some typical application examples of each sensor are introduced.
Photodetector based on ZnO/PbS-EDT heterojunction
Authors: Liang Xingchen , Liu Shilin , Ding Yijing , Li Qing 
Published: October 2023

Abstract
This paper presents the fabrication of a photodetector using a ZnO/PbS-EDT heterojunction. The combination of PbS QDs with narrow bandgap and ZnO QDs with excellent electron transport properties results in a high-performance photodetector with broad-spectrum capabilities. The solid-state ligands are used to exchange PbS QDs to form a thick light-absorbing layer. The study also discusses the effect of UV treatment on the morphology of the PbS film and its impact on the device performance. The UV-treated devices exhibit good performance even when operated at 0V. When subjected to 940 nm light irradiation, the maximum responsivity is 37.5 mA/w, the detectivity is 1.16x1012 Jones, and the rise and fall time are 53 μs and 35 μs, respectively. This device demonstrates remarkable performance with its fast response, high responsivity, and low noise.
Classification of Sequential Circuits as Causal Functions
Authors: Nishimura’ Shunji 
Published: October 2023

Abstract
In sequential circuits, the current output can depend on both past and current inputs. However, certain kinds of sequential circuits do not refer to all of the past inputs to generate the current output; but only to a subset of past inputs. This paper investigates which subset of past inputs a sequential circuit refers to, and proposes a new classification of sequential circuits based on this criterion. While the conventional classification of sequential circuits distinguishes between synchronous and asynchronous circuits, the new classification consolidates synchronous circuits and multiple clock domain circuits into the same category. This is consistent with the notion that “multiple clock domain circuits are analogous to synchronous circuits,” and thus, the proposed classification appears valid from this perspective. It is expected that a method underlying our classification will allow a deeper understanding of sequential circuits.
A 540-mA, 0.0487-ps-FOM Digital LDO based on Bi-directional Binary Search with Dual-loop Control
Authors: Chen Meiling , Chen Jianhua , Chen Weijian , Cheng Jie , Zeng Yanhan 
Published: October 2023

Abstract
A dual-loop digital low-dropout regulator based on the bi-directional binary search method is implemented in a 0.18-μm CMOS process in this paper. To improve the transient response, a bi-directional successive approximation register without initialization is proposed in coarse loop. To speed up fine adjustment during heavy loads, a two-dimensional MOSFET array is adopted to improve fine regulation step. Simulation results demonstrate that, during load current steps between 540 mA and 40 mA, the undershoot/overshoot is 364 mV/161 mV, and the digital LDO settles within 210 ns. For a supply voltage of 1.4 V with 200 mV dropout, the current efficiency is as high as 99.99% and the figure of merit is as low as 0.0487 ps.
Digital Background Calibration Techniques for 2GS/s 12bit Time-Interleaved Pipelined ADC
Authors: Qian Lei , Xing Xinpeng , Feng Haigang , Gielen Georges 
Published: October 2023

Abstract
This paper presents digital background(BG) calibration techniques which are utilized to correct both inter-stage gain error (IGE) and inter-channel mismatches in a 12-bit 2GS/s 4-channel time-interleaved pipeline ADC. The inter-stage gain is mitigated by Least Mean Square (LMS) based calibration with a proposed Pseudo Noise (PN) codes injected into 1.5bit MDAC stages, which has neither input amplitude limitation nor comparator requirement. The inter-channel offset and gain mismatches are eliminated by Modified Moving Average (MMA) and LMS –based calibrations respectively. The inter-channel sampling time mismatch is estimated by correlation function and compensated by digital-controlled delay line. Simulation results in 40nm CMOS show that the presented calibration techniques improve the 2GS/s TI ADC SNDR from 46.2138dB to 6761.49dB 35dB and SFDR from 50.8150.09dB to 82.3574.04dB with a Nyquist input, consuming only 23.3mW power in a 184um*183um area.
A calibration-free 10.7 fJ/conv.-step 12-bit 120-MS/s pipelined SAR ADC in 40nm CMOS
Authors: Li Nan , He Xinyuan , Xing Xinpeng 
Published: October 2023

Abstract
A calibration-free 12-bit 120-MS/s 2-stage pipelined successive approximation register (pipelined SAR) analog-to-digital converter (ADC) is presented in this paper. In asynchronous SAR ADCs, capacitive digital-to-analog converters (CDACs) are designed with bottom-plate sampling to improve sampling accuracy and split-capacitor array to save switching energy. Furthermore, both reference scaling technique and a PVT-stabilized closed-loop residue amplifier are implemented in this design to obtain an accurate inter-stage gain, enabling no additional calibration required in the pipelined SAR ADC. The prototype ADC in 40nm CMOS technology achieves a peak signal-to-noise-distortion ratio (SNDR) of 73.4 dB and 88.91dB spurious-free-dynamic-range (SFDR) at 120 MS/s sampling rate, consuming 4.88 mW power from 0.9 V supply voltage, and corresponding to an excellent figure-of-merit (FoM) of 10.7 fJ/conv.-step.
A Reconfigurable Analog Baseband for Multistandard Wireless Receivers in 22-nm CMOS
Authors: Huang Mingjing , He Xiaoyong 
Published: October 2023

Abstract
This paper presents a low noise, and high linearity reconfigurable receiver (RX) analog baseband (ABB) with tunable bandwidth (BW) and gain for multi-standard applications. The designed ABB consists of a programmable gain amplifier (PGA) and a second-order active RC low-pass filter (LPF) with cutoff frequency range from 0.7 MHz–10 MHz, whereas the gain could be tuned between 0 dB and 49 dB. The proposed ABB is implemented in 22 nm CMOS process. The post-simulation results show that the current consumption is 3.36 mA from 1 V supply and the area occupies 571×328 μm
2. The ABB achieves 42.8 dBm in-band third-order harmonic intercept point (IIP3). The spurious-free dynamic range (SFDR) and in-band total harmonic distortion (THD) is 83.2 dBc and is -83.1 dB, respectively. The input referred in-band integrated noise (IRN) is 144.8 μVrms
. A digital DCOC is used to calibrate the output DC level.
Influence of Inverter Voltage Switching on Windings of Asynchronous Motor
Authors: Liu Dong 
Published: October 2023

Abstract
Focus on the stator winding insulation of asynchronous motor, the transition process of the pulse voltage output by the frequency converter was analyzed, the voltage equivalent mathematical models and simulation model of the stator winding, reactor and cable were established. For rolling mill in metallurgical industry, the different voltage slope was verified by using real high-power asynchronous motor and frequency converter for pulse voltage test. Aiming at the voltage oscillation caused by different cables length, the second order system fitting was used to analyze the voltage spectrum characteristics, and the reactor’s suppression effect for voltage oscillation was also verified.