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Research on Equivalent Modeling Method of AC-DC Power Networks Integrating with Renewable Energy Generation

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Energy Engineering 2023年第11期120卷 2469-2487页

作者： weigang jin Lei Chen Yifei Li Shencong Zheng Yuqi Jiang Hongkun Chen Central China Branch of State Grid Corporation of China Wuhan430077China School of Electrical Engineering and Automation Wuhan UniversityWuhan430072China

Along with the increasing integration of renewable energy generation in AC-DC power networks,investigating the dynamic behaviors of this complex system with a proper equivalent model is *** paper presents an equivalent modeling method for the AC-DC power networks with doubly-fed induction generator(DFIG)based wind farms to decrease the simulation scale and computational *** the AC-DC power networks,the equivalent modeling strategy in accordance with the physical structure simplification is *** the DFIG-based wind farms,the equivalent modeling based on the sequential identification of multi-machine parameters using the improved chaotic cuckoo search algorithm(ICCSA)is *** light of the MATLAB simulation platform,a two-zone four-DC interconnected power grid with wind farms is built to check the efficacy of the proposed *** simulation analyses and comparative validation in different algorithms and cases,the proposed method can precisely reflect the steady and dynamic performance of the demonstrated system under N-1 and N-2 fault scenarios,and it can efficiently achieve the parameter identification of the wind farms and fulfill the equivalent ***,the proposed approach’s effectiveness and suitability are confirmed.

关键词： Equivalent modeling AC-DC power networks renewable energy generation wind farm improved chaotic cuckoo search algorithm

复合酶在白羽肉鸡低蛋白日粮中的应用效果研究

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饲料工业 2024年第11期45卷 37-43页

作者：岳稳高龙李忠荣刘景方桂友林勤靳伟刚陈鑫珠福建省农业科学院畜牧兽医研究所福建省畜禽遗传育种重点实验室福建福州350013 福建福大百特科技发展有限公司酶高效表达国家工程实验室福建福州350007 福建农林大学动物科学学院(蜂学学院) 福建福州350001 福建福大百特科技发展有限公司博士后科研工作站福建福州350007

试验旨在研究低蛋白日粮中添加复合酶对白羽肉鸡生长性能、血清生化和抗氧化指标、免疫功能和消化器官的影响。将288只1日龄白羽肉鸡随机分为6组,试验期42 d,试验配方设计1~21日龄和22~42日龄两阶段。对照组(CK组)饲喂常规蛋白日粮(两... 详细信息

试验旨在研究低蛋白日粮中添加复合酶对白羽肉鸡生长性能、血清生化和抗氧化指标、免疫功能和消化器官的影响。将288只1日龄白羽肉鸡随机分为6组,试验期42 d,试验配方设计1~21日龄和22~42日龄两阶段。对照组(CK组)饲喂常规蛋白日粮(两阶段粗蛋白水平分别为21.28%和19.04%);试验组均饲喂低蛋白日粮(两阶段粗蛋白水平较CK组分别降低0.97%和0.94%),试验1、2、3组全程分别添加200 mg/kg复合酶A(T1组)、200 mg/kg复合酶B(T2组)、300 mg/kg复合酶B(T3组),试验4组两阶段分别添加复合酶B 100、300 mg/kg;另设低蛋白日粮组(T0组)。试验结束时进行生长性能、血清生化和抗氧化指标、免疫功能和消化器官发育情况的测定分析。结果表明:T2、T3组21日龄活体重、42日龄活体重和欧洲生产效率指数均较高,T3组1~42日龄料重比低于其他组;CK组和T3组血清中尿素(UREA)含量显著低于T4组(P<0.05),T2组血清谷草转氨酶(AST)活性显著高于T1组外的其他组(P<0.05),T0、T1和T2组血清超氧化物歧化酶(SOD)含量显著低于T4组(P<0.05);T4组IgA、IgG和IgE显著高于T0组(P<0.05)。综上所述,在低蛋白日粮中添加复合酶能够提高白羽肉鸡指标和抗氧化能力,促进免疫器官和消化器官发育,提高免疫力。

关键词：复合酶白羽肉鸡生长性能生化和抗氧化指标免疫功能消化器官发育

Optimal structural design for a certain near-space composite propeller of airship using adaptive region division blending model

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Chinese Journal of Aeronautics 2024年第5期37卷 301-316页

作者： weigang AN Tianyu LIN Shigen WANG School of Aeronautics Northwestern Polytechnical UniversityXi’an 710072China

Near-space airship is a frontier and hotspot in current military research and development,and the near-space composite propeller is the key technology for its *** order to obtain higher aerodynamic efficiency at an altitude of 22 km,a certain near-space composite propeller is designed as a long and slender aerodynamic shape with a 10 m diameter,which brings many challenges to the composite structure *** initial design is obtained by the composite structure variable stiffness design method using based on fixed region division blending ***,it weighs 23.142 kg,exceeding the required 20 *** order to meet the structural design requirements of the propeller,a variable stiffness design method using the adaptive region division blending model is proposed in this *** with the methods using the fixed region division blending model,this method optimizes region division,stacking thickness and stacking sequence in a single level,considering the coupling effect among *** a more refined region division,this method can provide a more optimal design for composite tapered ***,to improve the efficiency of optimization subjected to manufacturing constraints,a hierarchical penalty function is proposed to quickly filter out the solutions that do not meet manufacturing *** above methods combined with a Genetic Algorithm(GA)using specific encoding are adopted to optimize the near-space composite *** optimal design of the structure weighs 18.831 kg,with all manufacturing constraints and all structural response constraints being *** with the initial design,the optimal design has a more refined region division,and achieves a weight reduction of 18.6%.This demonstrates that a refined region division can significantly improve the mechanical performance of the composite tapered structure.

关键词： Structural optimization Composite tapered structure Genetic algorithm Adaptive region division Manufacturing constraint Near-space composite propeller

Few-shot incremental radar target recognition framework based on scattering-topology properties

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Chinese Journal of Aeronautics 2024年第8期37卷 246-260页

作者： Chenxuan LI weigang ZHU Bakun ZHU Yonggang LI Graduate School Space Engineering UniversityBeijing 101400China Department of Electronic and Optical Engineering Space Engineering UniversityBeijing 101400China

The continuous emergence of new targets in open scenarios leads to a substantial decrease in the performance of Inverse Synthetic Aperture Radar(ISAR)recognition ***,data scarcity further exacerbates the challenge of identifying new classes of ISAR *** this paper,a few-shot incremental target recognition framework based on Scattering-Topology Properties(STPIL)is ***,STPIL extracts scattering-topology properties of ISAR targets as recognition ***,the pseudo-incremental training strategy effectively alleviates the algorithm’s forgetting of old knowledge,and improves compatibility with new ***,a feature embedding network,with few parameters,is designed based on the graph neural *** embedding network is highly adaptable to changes in data ***,STPIL fully considers the joint distribution and marginal distribution in scattering features,and uses the Brownian distance metric module to make the scattering-topology features more *** results on both the simulation dataset and the public measured data indicate that STPIL can effectively balance new classes with old classes,and has superior performance to other advanced methods in the incremental recognition of targets.

关键词： Brownian distance metric Graph neural networks Incremental learning Inverse Synthetic Aperture Radar(ISAR) Scattering

Aircraft parameter estimation using a stacked long short-term memory network and Levenberg-Marquardt method

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Chinese Journal of Aeronautics 2024年第2期37卷 123-136页

作者： Zhe HUI Yinan KONG weigang YAO Gang CHEN School of Aerospace Science and Technology Xidian UniversityXi’an 710071China Computation Aerodynamics Institution China Aerodynamics Research and Development CenterMianyang 621000China Faculty of Computing Engineering and MediaDe Montfort UniversityLeicester LE19BHUnited Kingdom School of Aerospace Engineering Xi’an Jiaotong UniversityXi’an 710049China

To effectively estimate the unknown aerodynamic parameters from the aircraft’s flight data,this paper proposes a novel aerodynamic parameter estimation method incorporating a stacked Long Short-Term Memory(LSTM)network model and the Levenberg-Marquardt(LM)*** stacked LSTM network model was designed to realize the aircraft dynamics modeling by utilizing a frame of nonlinear functional mapping based entirely on the measured input-output data of the aircraft system without requiring explicit postulation of the *** LM method combines the already-trained LSTM network model to optimize the unknown aerodynamic *** proposed method is applied by using the real flight data,generated by ATTAS aircraft and a bio-inspired morphing Unmanned Aerial Vehicle(UAV).The investigation reveals that for the two different flight data,the designed stacked LSTM network structure can maintain the efficacy of the network prediction capability only by appropriately adjusting the dropout rates of its hidden layers without changing other network parameters(i.e.,the initial weights,initial biases,number of hidden cells,time-steps,learning rate,and number of training iterations).Besides,the proposed method’s effectiveness and potential are demonstrated by comparing the estimated results of the ATTAS aircraft or the bio-inspired morphing UAV with the corresponding reference values or wind-tunnel results.

关键词： Parameter estimation LSTM network model LM method Aerodynamic parameters Flight data Aircraft dynamics modeling Network prediction capability Network parameters

Polymer: Non-fullerene acceptor heterojunction-based phototransistor for short-wave infrared photodetection

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Nano Research 2024年第4期17卷 3087-3095页

作者： jing Li weigang Zhu Yang Han Yanhou Geng Wenping Hu Key Laboratory of Organic Integrated Circuits of Ministry of Education&Key Laboratory of Molecular Optoelectronic Sciences School of Science&Collaborative Innovation Center of Chemical Science and Engineering(Tianjin)Tianjin UniversityTianjin 300072China Key Laboratory of Organic Integrated Circuits of Ministry of Education&Key Laboratory of Molecular Optoelectronic Sciences School of Materials Science and EngineeringTianjin UniversityTianjin 300072China

It remains full of challenge for extending short-wave infrared(SWIR)spectral response and weak-light detection in the context of broad spectral responses for *** this work,a novel poly(2,5-bis(4-hexyldodecyl)-2,5-dihydro-3,6-di-2-thienyl-pyrrolo[3,4-c]pyrrole-1,4-dione-alt-thiophene)(PDPPT3-HDO):COTIC-4F organic bulk-heterojunction is prepared as active layer for bulk heterojunction ***3-HDO serves as a hole transport material,while COTIC-4F enhances the absorption of SWIR light to 1020 *** a result,smooth and connected PDPPT3-HDO film is fabricated by blade coating method and exhibits high hole mobility up to 2.34 cm^(2)·V^(-1)·s^(-1) with a current on/off ratio of 4.72×10^(5) in organic thin film ***3-HDO:COTIC-4F heterojunction phototransistors exhibit high responsivity of 2680 A·W^(-1) to 900 nm and 815 A·W^(-1) to 1020 nm,with fast response time(rise time~20 ms and fall time~100 ms).The photosensitivity of the heterojunction phototransistor improves as the mass ratio of non-fullerene acceptors increases,resulting in an approximately two orders of magnitude enhancement compared to the bare polymer ***,the phototransistor exhibits decent responsivity even under ultra-weak light power of 43μW·cm^(-2) to 1020 *** work represents a highly effective and general strategy for fabricating efficient and sensitive SWIR light photodetectors.

关键词： photodetection phototransistor organic semiconductor heterojunction non-fullerene acceptor

Six-Writings multimodal processing with pictophonetic coding to enhance Chinese language models

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Frontiers of Information Technology & Electronic Engineering 2024年第1期25卷 84-105页

作者： Li weigang Mayara Chew MARINHO Denise Leyi LI Vitor Vasconcelos DE OLIVEIRA Department of Computer Science University of BrasiliaBrasilia 70910-900Brazil Faculty of Economics AdministrationAccounting and ActuariesUniversity of Sao PauloSao Paulo 05508-010Brazil

While large language models(LLMs)have made significant strides in natural language processing(NLP),they continue to face challenges in adequately addressing the intricacies of the Chinese language in certain *** propose a framework called Six-Writings multimodal processing(SWMP)to enable direct integration of Chinese NLP(CNLP)with morphological and semantic *** first part of SWMP,known as Six-Writings pictophonetic coding(SWPC),is introduced with a suitable level of granularity for radicals and components,enabling effective representation of Chinese characters and *** conduct several experimental scenarios,including the following:(1)We establish an experimental database consisting of images and SWPC for Chinese characters,enabling dual-mode processing and matrix generation for CNLP.(2)We characterize various generative modes of Chinese words,such as thousands of Chinese idioms,used as question-and-answer(Q&A)prompt functions,facilitating analogies by *** experiments achieve 100%accuracy in answering all questions in the Chinese morphological data set(CA8-Mor-10177).(3)A fine-tuning mechanism is proposed to refine word embedding results using SWPC,resulting in an average relative error of≤25%for 39.37%of the questions in the Chinese wOrd Similarity data set(COS960).The results demonstrate that SWMP/SWPC methods effectively capture the distinctive features of Chinese and offer a promising mechanism to enhance CNLP with better efficiency.

关键词： Chinese language model Chinese natural language processing(CNLP) Generative language model Multimodal processing Six-Writings

A flexible multiscale algorithm based on an improved smoothed particle hydrodynamics method for complex viscoelastic flows

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Applied Mathematics and Mechanics(English Edition) 2024年第8期45卷 1387-1402页

作者： jinlian REN Peirong LU Tao JIANG Jianfeng LIU weigang LU College of Mathematical Science Yangzhou UniversityYangzhou 225002Jiangsu ProvinceChina College of Hydraulic Science and Engineering Yangzhou UniversityYangzhou 225002Jiangsu ProvinceChina

Viscoelastic flows play an important role in numerous engineering fields,and the multiscale algorithms for simulating viscoelastic flows have received significant attention in order to deepen our understanding of the nonlinear dynamic behaviors of viscoelastic ***,traditional grid-based multiscale methods are confined to simple viscoelastic flows with short relaxation time,and there is a lack of uniform multiscale scheme available for coupling different solvers in the simulations of viscoelastic *** this paper,a universal multiscale method coupling an improved smoothed particle hydrodynamics(SPH)and multiscale universal interface(MUI)library is presented for viscoelastic *** proposed multiscale method builds on an improved SPH method and leverages the MUI library to facilitate the exchange of information among different solvers in the overlapping *** test the capability and flexibility of the presented multiscale method to deal with complex viscoelastic flows by solving different multiscale problems of viscoelastic *** the first example,the simulation of a viscoelastic Poiseuille flow is carried out by two coupled improved SPH methods with different spatial *** effects of exchanging different physical quantities on the numerical results in both the upper and lower domains are also investigated as well as the absolute errors in the overlapping *** the second example,the complex Wannier flow with different Weissenberg numbers is further simulated by two improved SPH methods and coupling the improved SPH method and the dissipative particle dynamics(DPD)*** numerical results show that the physical quantities for viscoelastic flows obtained by the presented multiscale method are in consistence with those obtained by a single solver in the overlapping ***,transferring different physical quantities has an important effect on the numerical results.

关键词： multiscale method improved smoothed particle hydrodynamics(SPH) dissipative particle dynamics(DPD) multiscale universal interface(MUI) complex viscoelastic flow

Tribological properties of low-temperature time-dependent pretreated graphite for mechanical seal pairs in high-speed turbopump

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Friction 2024年第2期12卷 305-318页

作者： Yangyang ZHAO Guoyuan ZHANG Junqian WANG He WANG weigang ZHAO Qunfeng ZENG School of Mechano-Electronic Engineering Xidian UniversityXi’an 710071China Xi’an Aerospace Propulsion Institute Xi’an 710071China Key Laboratory of Education Ministry for Modern Design and Rotor-Bearing System Xi’an Jiaotong UniversityXi’an 710049China

The friction coefficient and wear rate of pretreated graphite with liquid nitrogen were obtained by using a ball-on-disk tester,and the wear of GCr15–graphite seal pairs with the low-temperature time-dependent pretreatment was discussed by comparing the wear *** results show that liquid nitrogen pretreatment can affect the hardness and interlayer spacing of *** range of the friction coefficients of pretreated graphite changes from 0.17 to *** the increase of liquid nitrogen pretreatment time,the wear mechanism of graphite would change from dominated three-body wear to adhesion *** experimental results of the mechanical seal with liquid nitrogen pretreatment show that the wear rate of stator is less than 0.00165 mm^(3)·N^(−1)·m^(−1),and the graphite shows a good low-temperature compatibility.

关键词： graphite low-temperature pretreatment mechanical seal friction and wear