作者机构：
[Liu, Luxuan; Tang, Dongbao; Jia, Zhaoyuan; Tan, Yuyu] Univ South China, Sch Elect Engn, Ultrafast Micronano Technol & Adv Laser Mfg Key La, Hengyang 421001, Peoples R China.;[Duan, Ziwei] Sun Yat Sen Univ, Sch Biomed Engn, Shenzhen Campus, Shenzhen 518107, Peoples R China.;[Lang, Lijun] Chinese Univ Hong Kong, Dept Comp Sci & Engn, Ho Sin Hang Engn Bldg, Hong Kong 999077, Peoples R China.
摘要：
Traditional centrifuges, extensively employed in biology, chemistry, medicine, and other domains for tasks such as blood separation and pathogen extraction, have certain limitations. Their high cost, substantial size, and reliance on electricity restrict their range of application. Contemporary centrifuges, inspired by everyday items like paper trays and egg beaters, boast characteristics such as ease of operation, independence from electricity, and portability. These features offer unique advantages in specific situations, such as electricity shortages, inadequate infrastructure, and challenging medical conditions. Consequently, we designed a hand-powered portable centrifuge driven by pulling a rope. Our experiments revealed significant performance factors, including load capacity, rope length, and frequency of rope pulling. The results demonstrated that the revolutions per minute (RPM) of a hand-powered portable centrifuge were directly proportional to the length of the rope and the frequency of pulling, up to a certain limit, while inversely proportional to the load. When used for separating and washing polystyrene microspheres, the portable centrifuge's performance equaled that of traditional centrifuges. According to relevant calculations, this centrifuge could be capable of meeting the application of blood separation. Therefore, we believe this portable centrifuge will find meaningful applications in similar areas, particularly in resource-poor settings.
作者机构：
[Chen, Zenghui; Luo, Yonggang] Univ South China, Sch Elect Engn, Hunan Prov Key Lab Ultrafast Micro Nano Technol &, Hengyang 421001, Peoples R China.;[Deng, Li] Univ South China, Sch Mech Engn, Hengyang 421001, Peoples R China.;[Chen, Zenghui] Univ South China, Sch Elect Engn, Hengyang 421001, Peoples R China.
通讯机构：
[Chen, ZH ] U;Univ South China, Sch Elect Engn, Hengyang 421001, Peoples R China.
关键词：
Optical frequency comb;I;Q demodulation;Optical vector network analysis
摘要：
An ultrafast optical vector network analysis (OVNA) based on dual optical frequency comb (OFC) and I/Q demodulation technology is proposed and demonstrated. The responses of the DUT with broadband are characterized by propagating the signal OFC through the DUT, and then detecting interference signals using digital signal processor with retrieval algorithm. Without the need of the acousto-optic modulator or optical filter in the scheme, the frequency aliasing can be eliminated by using the I/Q demodulation module, so that the spectral utilization efficiency of the OFC is improved significantly. Meanwhile, the wideband measurement with high acquisition rates can also be achieved. In simulation process, the single spectrum of HCN molecule with linewidth of 1 GHz and bandwidth of 10 GHz can be rapidly measured, and the measurement time is only 1 mu s in theory. Our proposed OVNA opens the door to realize a real-time detection in the field of trace molecular sensing.
摘要：
It is crucial to correctly predict the S-matrix with plasma and set the optimal impedance matching device in the ion cyclotron resonance heating (ICRH) antenna system design. In this paper, a hybrid circuit/3DLHDAP code to verify the S-matrix measurements in the presence of plasma and optimize the load-resilient conjugate-T circuit for Large Helical Device (LHD) ICRH antennas has been developed and benchmarked. The variation of S-matrices for handshake form (HAS) and field-aligned-impedance-transforming (FAIT) antenna systems with density, magnetic field and coupling distance during heating obtained by the code's simulations agrees with that of with the LHD ICRH experiments. The mutual coupling of toroidally aligned HAS antennas is larger than that of poloidally aligned FAIT antennas over a wide range of densities. When the density and coupling distance increase, under a magnetic field on the magnetic axis of 2.75 T and 1.0 T, within a certain density change range, at the minimum voltage position with vacuum injection, the change rule of the antennas' S-a_minV_ 11 and S-a_minV_ 22 with density is opposite to that with coupling distance, which means that under certain conditions, adjusting the coupling distance may make up for the S-parameters changes caused by plasma density variation, keeping the minimum voltage position fixed, and may make impedance matching easier to achieve during long-pulse operation. Based on obtaining the S parameters, conjugate-T circuits for the HAS and FAIT antennas are designed with the hybrid circuit/3DLHDAP code, which can keep the reflection coefficients low without controlling impedance matching device over a wide range of plasma parameters region. The related results in this paper may provide some guidance for the high-power long-pulse operation of the ICRH antenna system on the fusion device.
摘要：
With the wide application of pulsed power technology in tumor ablation, sewage treatment, and other related fields, researchers have found that bipolar electrical pulses are more effective than unipolar electrical pulses. In this article, a new bipolar pulse generator is proposed, which combines the features of boost circuit and Marx circuit to significantly improve the boost ratio of output pulse and the tunability of pulse peak. In order to improve the load regulation rate and peak stability of bipolar pulse power supply, a bipolar pulse power supply based on peak closed-loop control method is designed in this article. The high-voltage pulse is attenuated, and its peak is sampled by the pulse peak sampling circuit, and the pulse peak voltage is fed back to the DSP controller for comparison with the set peak value, and the proportional integral differential (PID) adjustment is performed according to the voltage deviation, and the boost ratio of the pulse generator is changed to realize the constant peak output of the bipolar pulse. In order to verify the feasibility of the proposed bipolar pulse generator with peak closed-loop control scheme, simulation and experimental studies of the bipolar pulse power supply with five-stage peak closed-loop control were conducted. The results show that the output repetition frequency of 5 kHz, pulsewidth of 5– $10~\mu \text{s}$ , and peak pulse value within ±2.0 kV can be stabilized when the input voltage is 100 V.
通讯机构：
[Wang, Y ] U;Univ South China, Sch Elect Engn, Hunan Prov Key Lab Ultrafast Micro Nano Technol &, Hengyang 421001, Peoples R China.
摘要：
Wireless rechargeable sensor network (WRSN) uses mobile chargers (MCs) to charge sensor nodes wirelessly to solve the energy problems faced by traditional wireless sensor network. In WRSN, mobile charging schemes with multiple MCs supplementing energy are quite common. How to properly plan the MC's moving path to reduce the charge energy loss and deploy nodes to improve network coverage rate has become a huge research challenge. In this paper, a collaborative energy optimization algorithm (CEOA) is proposed for multiple chargers based on k-mean++ and node collaborative scheduling. The CEOA combines internal energy optimization and external device power supply, effectively prolongs network lifetime, and improves network coverage rate. It uses the k-mean++ to cluster nodes in the network; then, the nodes in the network are scheduled to sleep based on the confident information coverage (CIC) model. Finally, the CEOA uses a main mobile charger to carry multiple auxiliary mobile chargers to charge all the nodes in the cluster. Simulation results show that the proposed algorithm increases the network lifetime by more than 8 times and the coverage rate by about 20%.
摘要：
In practical wireless sensor networks (WSNs), cascading failures are closely related to network load distribution, which in turn strongly relies on the locations of multiple sink nodes. For such a network, understanding how the multisink placement affects its cascading robustness is essential but still largely missing in the field of complex networks. To this end, this paper puts forward an actual cascading model for WSNs based on the multisink-oriented load distribution characteristics, in which two load redistribution mechanisms (i.e., global routing and local routing) are designed to imitate the most commonly used routing schemes. On this basis, a number of topological parameters are considered to quantify the sinks' locations, and then, the relationship between these quantities with network robustness is investigated on two typical WSN topologies. Moreover, by employing the simulated annealing approach, we find the optimal multisink placement for maximizing network robustness and compare the topological quantities before and after the optimization to validate our findings. The results indicate that for the sake of enhancing the cascading robustness of a WSN, it is better to place its sinks as hubs and decentralize these sinks, which is independent of network structure and routing scheme.
摘要：
At present, system-level fault detection and diagnosis (FDD) research often uses correlation-based machine learning methods combined with multiple heterogeneous diagnosis methods to improve the fault detection rate (FDR), that is, decision-level fusion. Since it does not take into account the causal direction of the decision relationship, it will affect the realization of the fusion objectives, and lead to the reduction of the fusion range and the decrease of the global decision on FDR. In this regard, the structural causal model (SCM), a commonly used causal model in causal science, can use the causal graph to ensure causal direction of fusion, and the structural equation can be used to achieve fusion objectives to increase FDR, which can improve this problem. In this paper, we propose seven fusion objectives according to the diagnostic advantage interval of each preliminary method, and use SCM to construct causal graph and structural equation to achieve decision-level fusion according to the proposed seven fusion objectives, thereby improving FDR. The proposed method is validated through the simulation platform Tennessee Eastman process. We choose to combine the prediction results of Linear Discriminant Analysis method and Gaussian Naive Bayes method to achieve decision-level fusion. The results show that compared with the single method and the Bayesian network decision-level fusion method, the proposed method can achieve the best results in the FDR of each single system state and average FDR, and the above indicators are significantly improved.
作者机构：
[Lu, Zhendong; Luo, Xiao-Qing; Liu, Qin-Ke; Luo, XQ; Zhou, Yaojie; Wang, Xin-Lin] Univ South China, Sch Elect Engn, Hengyang 421001, Peoples R China.;[Li, Yan] Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Peoples R China.;[Liu, W. M.] Chinese Acad Sci, Inst Phys, Beijing Natl Lab Condensed Matter Phys, Beijing 100190, Peoples R China.;[Wang, Xin-Lin] Univ South China, Sch Mech Engn, Hunan Prov Key Lab Ultrafast Micro Nano Technol &, Hengyang 421001, Peoples R China.
通讯机构：
[Luo, XQ ] U;Univ South China, Sch Elect Engn, Hengyang 421001, Peoples R China.
摘要：
Chiral metasurfaces, with appealing properties for studying light-matter interactions at the nanoscale, have emerged as a promising platform for the realization of chiral optical responses, thereby showing advantages in chirality-related applications. The conventional approaches primarily concentrate on circular dichroism and the high Q factor of the chiral resonances, while little attention has been paid to the aspects of flexibility and controllability in the modulation of optical chirality, further inhibiting the implementation of tunable and multifunctional chiral metadevices. Here, we employ a planar chiral silicon metasurface governed by bound states in the continuum (BICs) to unravel steerable chiral optical responses. In particular, the BIC-based intrinsic and extrinsic planar chiralities can be precisely steered by breaking the in-plane symmetry and the illumination symmetry, respectively. Moreover, a hybrid Si−VO2 metasurface, manifested by the chiral coupled-mode theory, showcases the feasibility of actively tuning the dissipative loss while maintaining chiral quasi-BICs, then yielding desired loss-steered optical chirality. Our results provide alternative insights into tunable optical chirality and pave the way for advancements in chiroptical applications.
摘要：
Two-dimensional (2D) GeSe has been proven promising in fast and broadband optoelectronic applications for its complicated band structure, inert surface property, and excellent stability. The major challenge is the deficiency of the effective technique for controllably prepared large-scale few-to-monolayer GeSe films. For this purpose, a layer-by-layer thinning method by thermal sublimation for manufacturing large-scale mixed few-layer GeSe with direct bandgaps is proposed, and an optimized sublimation temperature of 300 °C in vacuum is evaluated by atomic force microscopy. Scanning electron microscopy, transmission electron microscopy, energy-dispersive spectra, and fluorescence mapping measurements are performed on the thinned GeSe layers, and results are well-indexed to the orthorhombic lattice structure with direct bandgaps with an atomic ratio of Ge/Se ≈ 5:4. Raman and fluorescence spectra show an α-type crystalline structure of the thinned GeSe films, indicating the pure physical process of the sublimation thinning. Both the bulk and few-layer GeSe films demonstrate broadband absorption. Conductivity of the few-layer GeSe device indicates the overall crystalline integrity of the film after thermal thinning. Given the convenience and efficiency, we provide an effective approach for fabrication of large-scale 2D materials that are difficult to be prepared by traditional methods.
期刊：
IET Communications,2023年17(2):207-214 ISSN：1751-8628
通讯作者：
Shujing Xie
作者机构：
[Xie, Shujing] Univ South China, Sch Elect Engn, Hengyang 421001, Hunan, Peoples R China.
通讯机构：
[Shujing Xie] S;School of Electrical Engineering, University of South China, Hengyang, Hunan, People's Republic of China
关键词：
asynchronous cooperative spectrum sensing;cooperative spectrum sensing;fuzzy hypothesis testing;noise power uncertainty;number of samples;sample size;sequential probability ratio detection;synchronous cooperative spectrum sensing
摘要：
Spectrum sensing is a critical part in Cognitive radio networks to detect the available frequency resources, and its timeliness and accuracy are extremely important. The conventional detectors usually fail to be robust in the presence of noise uncertainty, hence an asynchronous cooperative spectrum sensing approach based on sequential probability ratio detection in fuzzy hypothesis testing is proposed. In the approach, sequential detection in fuzzy hypothesis testing is done by each cognitive radio to form local decisions, then fusion centre sequentially accumulates the local decisions of cooperative cognitive radios to make a global decision. Simulation results show that the proposed approach can reduce the average number of samples and overcome noise uncertainty when compared with conventional or selective asynchronous cooperative sensing and non-cooperative sensing.
摘要：
Vulnerability assessment is one of the effective ways to prevent cascading failures of a distribution network (DN). Considering topological structure and operation status, a comprehensive assessment method based on the technique for order preference by similarity to ideal solution (TOPSIS) is proposed to accurately identify the vulnerable parts of the DN. In the method, the improved structural vulnerability indices based on complex network theory are defined, such as degree and network efficiency. And the electrical betweenness and power flow transfer entropy are established to evaluate the state vulnerability of a DN. Combining the analytic hierarchy process (AHP) and the entropy weight method, a comprehensive weight matrix of each vulnerability index is obtained. Based on the weighted vulnerability indices, the TOPSIS method is proposed to calculate the comprehensive vulnerability of each node and line in the DN. Moreover, the obtained comprehensive vulnerability results are corrected by the grey correlation degree to accurately identify vulnerable parts in the DN. In addition, the system transmission efficiency index is established to describe the degree of system performance degradation of the DN under different attack strategies. The simulation results of IEEE 33-bus test case show that the proposed method can effectively identify vulnerable nodes and lines in the DN.
通讯机构：
[Yuehua Li] S;School of Electrical Engineering, University of South China, Hengyang 421001, China<&wdkj&>Author to whom correspondence should be addressed.
关键词：
pixel circuit;voltage programming;threshold voltage variation;mobility variation;OLED degradation
摘要：
In recent years, the active-matrix organic light-emitting diode (AMOLED) displays have been greatly required. A voltage compensation pixel circuit based on an amorphous indium gallium zinc oxide thin-film transistor is presented for AMOLED displays. The circuit is composed of five transistors-two capacitors (5T2C) in combination with an OLED. In the circuit, the threshold voltages of both the transistor and the OLED are extracted simultaneously in the threshold voltage extraction stage, and the mobility-related discharge voltage is generated in the data input stage. The circuit not only can compensate the electrical characteristics variation, i.e., the threshold voltage variation and mobility variation, but also can compensate the OLED degradation. Furthermore, the circuit can prevent the OLED flicker, and can achieve the wide data voltage range. The circuit simulation results show that the OLED current error rates (CERs) are lower than 3.89% when the transistor's threshold voltage variation is +/- 0.5V, lower than 3.49% when the mobility variation is +/- 30%.
作者机构：
[Huang, Zuyan; Zhang, Xiaozhi; Yin, Ruyi; Yang, Bin] Univ South China, Coll Elect Engn, Hengyang 421001, Peoples R China.
通讯机构：
[Yang, B ] U;Univ South China, Coll Elect Engn, Hengyang 421001, Peoples R China.
关键词：
infrared and visible image fusion;transformer;deep learning;residual dense block
摘要：
Infrared and visible image fusion technologies are used to characterize the same scene using diverse modalities. However, most existing deep learning-based fusion methods are designed as symmetric networks, which ignore the differences between modal images and lead to source image information loss during feature extraction. In this paper, we propose a new fusion framework for the different characteristics of infrared and visible images. Specifically, we design a dual-stream asymmetric network with two different feature extraction networks to extract infrared and visible feature maps, respectively. The transformer architecture is introduced in the infrared feature extraction branch, which can force the network to focus on the local features of infrared images while still obtaining their contextual information. The visible feature extraction branch uses residual dense blocks to fully extract the rich background and texture detail information of visible images. In this way, it can provide better infrared targets and visible details for the fused image. Experimental results on multiple datasets indicate that DSA-Net outperforms state-of-the-art methods in both qualitative and quantitative evaluations. In addition, we also apply the fusion results to the target detection task, which indirectly demonstrates the fusion performances of our method.
摘要：
To study the effect of three different types of nozzles (straight conical, Venturi, and streamline) on the decontamination effect of radioactively contaminated metals abrasive jet, the gas-solid two-phase flow in the abrasive jetting process is numerically simulated by the method of CFD-DEM coupling simulation. The coverage and distribution uniformity of abrasive particles, the impact velocity, and the wear of the nozzle itself are focused on, and the rationality and reliability of the simulation experiment method and the evaluation method of the experimental results are proved by the verification experiments. The results show that the Venturi nozzle is more suitable for the decontamination of radioactively contaminated metals because it has the advantages of uniform abrasive distribution, high abrasive impact velocity, and good nozzle wear. The nozzle is mainly subjected to low-angle micro-cutting erosion wear, so when selecting nozzle materials, more emphasis should be placed on high-hardness materials to resist micro-cutting wear. The impact distance has a very obvious impact on the decontamination effect of the abrasive. In the decontamination process, the impact distance should be set reasonably, and the uniformity of the abrasive particle distribution should be fully considered to ensure the decontamination effect.
通讯机构：
[Aixiang Wei] S;School of Integrated Circuits, Guangdong University of Technology, Guangzhou 510006, Guangdong, China<&wdkj&>School of Information Science, Guangzhou Xinhua University, Dongguan 523133, Guangdong, China
摘要：
Transition metal doping is an effective method to induce a structural phase transition and improve the electrocatalytic performance of transition metal chalcogenides (TMDs). In this study, MoxRe1-xS2 nanosheets with Mo fraction x from 0 to 1 were grown on a carbon nanotube/carbon cloth (CNT@CC) substrate using a hydrothermal method by changing the molar ratio of Na2MoO4$2H(2)O to NH4ReO4 in the precursor solution. The effect of the Mo fraction x on the phase structure and electrocatalytic performance for the hydrogen evo-lution reaction (HER) of MoxRe1-xS2 nanosheets was studied. The results indicated that MoxRe1-xS2 consists of the 1T' phase (Re, Mo)S-2 and the 2H phase (Mo, Re)S-2, and the proportion of the 1T' phase is in the range of 40-50%. Mo0.5Re0.5S2/CNT@CC shows the best HER catalytic activity with an overpotential of 85 mV at a current density of 10 mAcm(-2), a Tafel slope of 38 mV dec(-1) and a charge transfer resistance of 1.04 U. This excellent HER catalytic activity is attributed to the phase transition, defects and S vacancies on the basal planes, as well as the synergistic effect between the MoxRe1-xS2 nanosheets and CNT. (c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
期刊：
IEEE Transactions On Electron Devices,2023年71(1):11-17 ISSN：0018-9383
作者机构：
[He, Hongyu] Yangtze Univ, Sch Elect & Informat, Jingzhou 434023, Peoples R China.;[Yin, Junli] Univ South China, Sch Elect Engn, Hengyang 421001, Peoples R China.;[Lin, Xinnan] Anhui Polytech Univ, Sch Integrated Circuits, Wuhu 241000, Peoples R China.;[He, Hongyu; Zhang, Shengdong] Peking Univ, Shenzhen Grad Sch, Sch Elect & Comp Engn, Shenzhen 518005, Peoples R China.
关键词：
Ambipolar organic thin-film transistor (OTFT);Computational modeling;drain current model;Electron traps;Integrated circuit modeling;Mathematical models;Organic semiconductors;Organic thin film transistors;Semiconductor device modeling;surface potential;temperature characteristics;trap states
摘要：
A surface-potential-based drain current model is presented for ambipolar organic thin-film transistors (OTFTs). First, following the multiple trapping and release (MTR) conduction mechanism, a drain current model is presented for unipolar OTFTs considering exponentially distributed trap state density in the energy gap of an organic semiconductor. Next, from the model for unipolar OTFTs, analyzing electrons or (and) holes in different regimes, the model for ambipolar OTFTs is presented. The presented model can describe the drain current by compact expressions and can estimate the trap states density. The model is verified by available experimental data considering temperature characteristics.
