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Miniaturized power detection module operating in millimeter wave band

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Journal of Electronic Science and Technology 2024年第2期22卷 69-76页

作者： Xiang zhou zhi-Yong Zhong School of Electronic Science and Engineering University of Electronic Science and Technology of ChinaChengdu611731China

The miniaturized broadband detection module can be embedded into the microwave application system such as the front end of the transmitter to detect the power or other parameters in real *** is highly prospective in military and scientific *** this paper,a broadband power detection module operating at 2..5 GHz-40.0 GHz is designed by using low-barrier Schottky diode as the detector and a comparator for threshold *** module can dynamically detect the power range between-10 dBm and 10 dBm with the detection accuracy of 0.1 ***,the temperature compensation circuit is also applied to improve the measurement *** a result,the resulted error low to±1 dB in the temperature range of -55℃ to +85℃ is *** designed module is encapsulated by a Kovar alloy with a small volume of 9 mm×6 mm×3 *** endows the designed module the advantages of small size,easy integration,and low cost,and even it is applicable to high-reliability environments such as satellites.

关键词： Diode Miniaturization Power detection Temperature compensation

Rts: learning robustly from time series data with noisy label

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Frontiers of Computer Science 2024年第06期18卷 186332-186332页

作者： zhou zhi JIN Yi-Xuan Li Yu-Feng National Key Laboratory for Novel Software Technology Nanjing University

Significant progress has been made in machine learning with large amounts of clean labels and static data. However, in many real-world applications, the data often changes with time and it is difficult to obtain massive clean annotations, that is, noisy labels and time series are faced simultaneously. For example, in product-buyer evaluation, each sample records the daily time behavior of users, but the long transaction period brings difficulties to analysis, and salespeople often erroneously annotate the user’s purchase behavior. Such a novel setting, to our best knowledge, has not been thoroughly studied yet, and there is still a lack of effective machine learning methods. In this paper, we present a systematic approach RTS both theoretically and empirically, consisting of two components, Noise-Tolerant Time Series Representation and Purified Oversampling Learning. Specifically, we propose reducing label noise’s destructive impact to obtain robust feature representations and potential clean samples. Then, a novel learning method based on the purified data and time series oversampling is adopted to train an unbiased model. Theoretical analysis proves that our proposal can improve the quality of the noisy data set. Empirical experiments on diverse tasks, such as the house-buyer evaluation task from real-world applications and various benchmark tasks, clearly demonstrate that our new algorithm robustly outperforms many competitive methods.

关键词： weakly-supervised learning time-series classification class-imbalanced learning

Magnetic emission intensity enhancement for amorphous alloys by constructing a multi-phase structure withα-Fe nanocrystals

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Nano Research 2024年第7期17卷 6630-6637页

作者： Ke Liu zhi Qin Jie Shen zhi Cheng Shiyue You Liang Ma Jing {2. Wen Chen State Key Laboratory of Advanced Technology for Materials Synthesis and Processing School of Materials Science and EngineeringWuhan University of TechnologyWuhan 430070China Sanya Science and Education Innovation Park Wuhan University of TechnologySanya 572024China Hubei Longzhong Laboratory Wuhan University of Technology Xiangyang Demonstration ZoneXiangyang 441000China

The perturbation in the magnetic field generated by the rotation or oscillation of magnetic domains in magnetic materials can emit low-frequency electromagnetic waves,which are expected to be used in low-frequency ***,the magnetic emission intensity,defined by the perturbation ability,of current commercially applied amorphous alloys,such as Metglas,cannot meet the application requirements for low-frequency antennas due to the domain motion energy ***,a multi-phase Metglas amorphous alloy was constructed by incorporatingα-Fe nanocrystals using rapid annealing to manipulate the domain *** was found that 3.89 times higher magnetic emission intensity is obtained compared to the pristine due to the synergism of the deformation and displacement ***,the low-frequency magnetic emission performance verification was carried out by preparing magnetoelectric composites as the antenna vibrator by assembling the alloy and macro piezoelectric fiber composites(MFC).Enhancements of magnetic emission intensity are found at 93.3%and 49.2.at the first and second harmonic frequencies compared with the unmodified alloy ***,the approach leads to the development of high-performance communication with a novel standard for evaluation.

关键词： multi-phase amorphous alloys magnetic emission intensity enhancing mechanism magnetic domain pinning theory Jiles-Atherton model analysis

Liquid-phase epitaxial layer by layer brushing fabrication of metalorganic frameworks films

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Nano Research 2024年第6期17卷 5698-5704页

作者： Li-Mei Chang Rui Zhai zhi-zhou Ma Jian-Dong Huang zhi-Gang Gu Jian Zhang College of Chemistry Fuzhou UniversityFuzhou 350108China State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China University of Chinese Academy of Sciences Beijing 100049China

Development of metal-organic framework(MOF)films is of great importance to expand their ***,we report a facile and universal method of liquid-phase epitaxial(LPE)layer by layer(LBL)brushing approach for fabricating MOF films on various substrates in a high-throughput *** MOF films preparation method offers a great prospective to cost-effectively construct films with short preparation time and little reagent ***,this LBL brushing approach has been implemented successfully to assemble various MOF films,including HKUST-1,zeolitic imidazolate framework-8(ZIF-8),Cu(bdc),and Cu_(2.(L)_(2.P(L=bdc,ndc,and cam;P=dabco and bipy).Afterwards,the classic MOF HKUST-1 and ZIF-8 films were grown on sensor chip electrode and porous fiber support for good volatile organic compounds(VOCs)selective sensing and water purification *** study demonstrates that this LBL brushing preparation method can be employed to synthesize various MOF films with a variety of characteristics to realize their sensing and separation applications.

关键词： metal-organic framework porous materials layer by layer fabrication film

Beamline design for multipurpose muon beams at CSNS EMuS

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Nuclear Science and Techniques 2024年第5期35卷 1-12页

作者： Yang Hong Ying-Peng Song Lu-Ping zhou Jing-Yu Tang zhi-Hao zhou Nikolaos Vassilopoulos Institute of High Energy Physics Chinese Academy of Sciences(CAS)Beijing 100049China Spallation Neutron Source Science Center Dongguan 523803China University of Chinese Academy of Sciences Beijing 100049China Radiotherapy Physics and Technology Center Cancer CenterWest China HospitalSichuan UniversityChengdu 610041China Xi’an Jiaotong University Health Science Center Xi’an 710049China Department of Radiation Oncology First Affiliated Hospital of Xi’an Jiaotong UniversityXi’an 710049China School of Nuclear Science and Technology University of Science and Technology of ChinaHefei 230027China

A new muon beam facility,called the Experimental Muon Source(EMuS),was proposed for construction at the China Spallation Neutron Source(CSNS).The design of the complex muon beamlines for the EMuS baseline scheme,which is based on superconducting solenoids,superferric dipoles and room-temperature magnets,is presented *** muon beams,including surface muons,decay muons and low energy muons,have been developed for multipurpose *** optics design and simulation results of the trunk beamline and branch beamlines are *** a proton beam power of 2. kW at a standalone target station that consists of a conical graphite target and high-field superconducting solenoids,the muon beam intensity in the trunk beamline varies from 10^(7)/s for surface muons to 10^(10)/s for high-momentum decay *** at the endstations,these values vary from 10^(5)/s for surface muons to 10^(8)/s for decay muons.

关键词： Surface muons Decay muons Muon beamline Superconducting solenoids Multi-channel electrostatic separator

Enhanced degradation of tetracycline by gas-liquid discharge plasma coupled with g-C_(3)N_(4)/TiO_(2.

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Plasma Science and Technology 2024年第9期26卷 69-78页

作者： Zhenhai WANG Zikai zhou Sen WANG zhi FANG College of Electrical Engineering and Control Science Nanjing Tech UniversityNanjing 211816People’s Republic of China

Plasma-catalysis is considered as one of the most promising technologies for antibiotic degradation in *** the plasma-catalytic system,one of the factors affecting the degradation effect is the performance of the photocatalyst,which is usually restricted by the rapid recombination of electrons and holes as well as narrow light absorption *** this research,a photocatalyst g-C_(3)N_(4)/TiO_(2. was prepared and coupled with gas-liquid discharge(GLD)to degrade tetracycline(TC).The performance was examined,and the degradation pathways and mechanisms were *** show that a 90%degradation rate is achieved in the GLD with g-C_(3)N_(4)/TiO_(2. over a 10 min *** the pulse voltage is conducive to increasing the degradation rate,whereas the addition of excessive g-C_(3)N_(4)/TiO_(2. tends to precipitate agglomerates,resulting in a poor degradation *** redox properties of the g-C_(3)N_(4)/TiO_(2. surface promote the generation of oxidizing active species(H2.2.O3)in *** quenching experiments showed that·OH,hole(h^(+)),play important roles in the TC degradation by the discharge with g-C_(3)N_(4)/TiO_(2..Two potential degradation pathways were proposed based on the *** toxicity of tetracycline was reduced by treatment in the ***,the g-C_(3)N_(4)/TiO_(2. composites exhibited excellent recoverability and stability.

关键词： gas-liquid discharge plasma-catalysis g-C_(3)N_(4)/TiO_(2. TC degradation

Theoretical insights into efficient oxygen evolution reaction using non-noble metal single-atom catalysts on W2.O2.MXene

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Rare Metals 2024年第10期43卷 5082-5094页

作者： Jing-Yu zhou zhi-Cheng Han Shu Zhao Tao Yang Da-zhou Yan Hai-Jun Yu Institute of Advanced Battery Materials and Devices College of Materials Science and EngineeringBeijing University of Technology Key Laboratory of Advanced Functional Materials Ministry of EducationBeijing University of Technology China ENFI Engineering Corporation National Engineering Research Center of Silicon-Based Materials Manufacturing Technology

The pursuit of highly active oxygen evolution reaction （OER） catalysts,especially those free of noble metals,is a focal point in fuel cell *** extensive density functional theory calculations,this study designed and evaluated the activity and stability of singleatom catalysts （SACs） composed of 3d,4d and 5d transition metals supported on tungsten-based MXene for OER *** highlighted the exceptional OER performance of Ni@W2.O2.Rh@W2.O2.nd Pt@W2.O2.displaying remarkably low overpotentials The catalytic activity of TM@W2.O2.ACs exhibited a robust correlation with surface properties,particularly the d-band center index and surface work *** Ni@W2.O2.Rh@W2.O2.nd Pt@W2.O2.merged as promising candidates for OER and oxygen reduction reaction （ORR） bifunctional catalysis,while Pt@W2.O2.nd Rh@ W2.O2.howed high potential for OER and hydrogen evolution reaction （HER） bifunctional catalysis The effectiveness of tungsten-based MXene as a substrate for non-noble-metal SACs marks a breakthrough in OER catalyst design,driving advancements towards sustainable energy solutions and addressing critical challenges in energy conversion and storage.

关键词： Density functional theory MXene Non-noble metal Oxygen evolution reaction Single-atom catalysts

Molecular Dynamics Simulation Studies on the Micromorphology and Proton Transport of Nafion/Ti_(3)C_(2.T_(x) Composite Membrane

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Chinese Journal of Polymer Science 2024年第3期42卷 373-387,I0009页

作者： zhi-Yue Han Su-Peng Pei Chun-Yang Yu Yong-Feng zhou School of Chemical and Environmental Engineering Shanghai Institute of TechnologyShanghai 201418China School of Chemistry&Chemical Engineering Frontiers Science Center for Transformative MoleculesShanghai Key Laboratory of Electrical Insulation and Thermal AgingShanghai Jiao Tong UniversityShanghai 200240China Key Laboratory of Green and High-end Utilization of Salt Lake Resources Chinese Academy of SciencesXining 810008China

The perfluorosulfonic acid(PFSA) membrane doped with two-dimensional conductive filler Ti_(3)C_(2.T_(x) is a fuel cell proton exchange membrane with high application potential. Experimental studies showed that the proton conductivity of Nafion/Ti_(3)C_(2.T_(x) composite membrane is improved significantly compared with that in pure Nafion. However, the microscopic mechanism of doping on the enhancement of membrane performance is remain unclear now. In this work, molecular dynamics simulation was used to investigate the microscopic morphology and proton transport behaviors of Nafion/Ti_(3)C_(2.T_(x) composite membrane at the molecular level. The results shown that there were significant differences about the diffusion kinetics of water molecules and hydroxium ions in Nafion/Ti_(3)C_(2.T_(x) at low and high hydration levels in the nanoscale *** the increase of water content, Ti_(3)C_(2.T_(x) in membrane was gradually surrounded by ambient water molecules to form a hydration layer, and forming a relatively continuous proton transport channel between Nafion polymer and Ti_(3)C_(2.T_(x) monomer. The continuous proton transport channel could increase the number of binding sites of proton and thus achieving high proton conductivity and high mobility of water molecules at higher hydration level. The current work can provide a theoretical guidance for designing new type of Nafion composite membranes.

关键词： Nafion/Ti_(3)C_(2.T_(x)composite membrane Proton transport Molecular dynamics simulation

Security-constrained Transmission Maintenance Optimization Considering Generation and Operational Risk Costs

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Journal of Modern Power Systems and Clean Energy 2024年第3期12卷 767-781页

作者： Dan Xu zhi Cai Qian Cheng Guodong Huang Jingyang zhou Junjie Tang Beijing Key Laboratory of Research and System Evaluation of Power Dispatching Automation Technology China Electric Power Research InstituteBeijing 100192China State Key Laboratory of Power Transmission Equipment&System Security and New Technology Chongqing UniversityChongqing 400044China

With the large-scale integration of renewable energy,the traditional maintenance arrangement during the load valley period cannot satisfy the transmission demand of renewable energy ***,in a market-oriented operation mode,the power dispatching control center aims to reduce the overall power purchase cost while ensuring the security of the power ***,a security-constrained transmission maintenance optimization model considering generation and operational risk costs is proposed *** model is built on double-layer optimization framework,where the upper-layer model is used for maintenance and generation planning,and the lowerlayer model is primarily used to address the operational security risk arising from the random prediction error and N-1 transmission ***,a generation-maintenance iterative algorithm based on a defined cost feedback is included to increase solution *** cost is determined using long-term security-constrained unit commitment,and the operational risk cost is obtained using a double-layer N-1 risk assessment *** electrical correlation coupling coefficient is proposed for the solution process to avoid maintenance of associated equipment simultaneously,thereby improving model convergence *** IEEE 118-bus system is used as a test case for illustration,and test results suggest that the proposed model and algorithm can reduce the total cost of transmission maintenance and system operation while effectively improving the solution efficiency of the joint optimization model.

关键词： Transmission maintenance security-constrained unit commitment iterative algorithm cost feedback N−1 risk assessment