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Finite NPDM-groups

Acta Mathematica Sinica,English Series 2021年第2期37卷 306-314页

作者： jian Ji cao Xiu Yun GUO School of Applied Mathematics Shanxi University of Finance and EconomicsTaiyuan 030006P.R.China Department of Mathematics Shanghai UniversityShanghai 200444P.R.China

In this paper the classification is given for finite groups in which the normalizer of every non-normal cyclic subgroup of order divided by the minimal prime of |G| is a maximal subgroup.

关键词： Normalizer cyclic subgroup maximal subgroup

Class conditional distribution alignment for domain adaptation

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Control Theory and Technology 2020年第1期18卷 72-80页

作者： Kai cao Zhipeng TU Yang ming Key Lab of Systems and Control Academy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100190China

In this paper,we study the problem of domain adaptation,which is a crucial ingredient in transfer learning with two domains,that is,the source domain with labeled data and the target domain with none or few *** adaptation aims to extract knowledge from the source domain to improve the performance of the learning task in the target domain.A popular approach to handle this problem is via adversarial training,which is explained by the H△H-distance ***,traditional adversarial network architectures just align the marginal feature distribution in the feature *** alignment of class condition distribution is not ***,we proposed a novel method based on pseudo labels and the cluster assumption to avoid the incorrect class alignment in the feature *** experiments demonstrate that our framework improves the accuracy on typical transfer learning tasks.

关键词： Domain adaptation distribution alignment feature cluster

Dual-negative-objective Coordinated Control of Brushless Doubly Fed Induction Generator under Unbalanced Grid Voltage

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CES Transactions on Electrical Machines and Systems 2024年第3期8卷 347-355页

作者： ming Cheng Zheng cao Xiaoming Yan School of Electrical Engineering Southeast UniversityNanjing 210096China School of Electrical and Automation Engineering Nanjing Normal University Nanjing 210023China

This article proposes a dual-negative-objective coordinated control strategy for brushless doubly fed induction generator(BDFIG)based wind power generation system under unbalanced grid *** alleviate the mechanical stress and impaction on rotating shaft,the negative control objective(NCO)of machine side converter(MSC)is set to suppress the ripple of electromagnetic *** the NCO of grid side converter(GSC)is selected to suppress the oscillation of total output active power or the unbalanced degree of total output current for BDFIG generation *** comparison with traditional single converter control scheme of the MSC or GSC,dual NCOs can be satisfied at the same time due to the enlarged freedom degree in the proposed improved coordinated control system for back-toback *** effectiveness of proposed control strategy is validated by simulation and experimental results on a dual-cagerotor BDFIG(DCR-BDFIG)prototype.

关键词： Brushless doubly fed induction generator Dual-negative-objective Freedom degree Unbalanced grid voltage

Male reproductive function before and after the adjustment of the COVID-19 prevention policy:a multicenter study in China

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Asian Journal of Andrology 2024年第3期26卷 308-314页

作者： jian-Zheng Li Han Wu Li Wang Yun-Shan Wang Feng Kong Long-Qiao cao ming Liang Xiong Wang ming-Zhen Yuan Shandong Provincial Hospital Affiliated to Shandong First Medical University Jinan 250000China Institute of Women Children and Reproductive HealthShandong UniversityJinan 250012China Engineering Laboratory of Urinary Organ and Functional Reconstruction of Shandong Province Jinan 250000China The First People’sHospital of Jining Jining 272000China Department of Reproductive Medicine The Second Affiliated Hospital of Shandong University of Traditional Chinese MedicineJinan 250000China Reproductive Medicine Center Affiliated Yantai Yuhuangding Hospital of Qingdao UniversityYantai 264000China

At the end of 2022,the adjustment of the coronavirus disease 2019(COVID-19)pandemic control policy in China resulted in alarge-scale increase in public *** compare the fertility parameters of male patients before and after the adjustments ofthe COVID-19 pandemic control policy in China,we collected data on patients’medical histories and laboratory examinations ontheir first visits between June 2022 and March 2023 in five different *** were divided into five groups according tothe timeline of the policy *** data we collected from male patients included semen quality and serum reproductivehormone levels,and intergroup comparisons were made using the Mann–Whitney U and Chi-square *** total,16784 casesunderwent regular semen analysis,11180 had sperm morphology assessments,and 7200 had reproductive hormone *** showed declining trends in semen volume,sperm motility,and the progressive sperm motility rate after the policy *** comparison revealed an initial decrease and gradual recovery in progressive motility *** morphology analysisshowed increased neck and tail abnormalities after the policy *** significant change in hormone levels was *** the adjustment of the COVID-19 prevention policy in China,a decline in sperm motility and morphology was *** trend may gradually recover over 2 *** the policy adjustment,reproductive hormone levels were relatively stablethroughout,except for an increase in luteinizing hormone(LH).These changes in semen parameters suggest that the policyadjustment had a short-to medium-term impact on male reproductive function.

关键词： COVID-19 multicenter study reproduction SARS-CoV-2 semen analysis

Resonance response of fluid-conveying pipe with asymmetric elastic supports coupled to lever-type nonlinear energy sink

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Applied Mathematics and Mechanics(English Edition) 2022年第12期43卷 1873-1886页

作者： Runqing cao Zhijian WANG jian ZANG Yewei ZHANG Faculty of Aerospace Engineering Shenyang Aerospace UniversityShenyang 110136China

This paper studies the vibration absorber for a fluid-conveying pipe,where the lever-type nonlinear energy sink(LNES)and spring supports are coupled to the asymmetric ends of the *** pseudo-arc-length method integrated with the harmonic balance method is used to investigate the steady-state responses ***,the numerical solution of the fluid-conveying pipe is calculated with the Runge-Kutta ***,a special response,called the collapsible closed detached response(CCDR),is first observed when the vibration response of mechanical structures is ***,the relationship between the CCDR and the main structure primary response(PR)is *** addition,the closed detached response(CDR)is also observed to research the resonance response of the fluid-conveying *** appearance of either the CCDR or the CDR does affect the resonance ***,the mentioned two phenomena underline that the trend of vibration responses under external excitation goes continuous and ***,the main advantage of the LNES is presented by contrasting the LNES with the nonlinear energy sink(NES)coupled to the same pipe *** is found that the LNES can reduce the resonance response amplitude by 91.33%.

关键词： fluid-conveying pipe vibration attenuation collapsible closed detached response(CCDR) lever-type nonlinear energy sink(LNES) elastic support

Joining SiO_(2)based ceramics:recent progress and perspectives

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Journal of Materials Science & Technology 2022年第13期108卷 110-124页

作者： Haohan Wang Jinghuang Lin Junlei Qi jian cao State Key Laboratory of Advanced Welding and Joining Harbin Institute of TechnologyHarbin 150001China

Nowadays,SiO_(2)based material is one of the widest used materials in optical,microelectromechanical system,aerospace and some other *** practical application,SiO_(2)based materials are required to be joined with themselves or other heterogeneous materials to assemble products with various *** the joining quality directly affects the mechanical performances and functional properties of assembled *** many researchers studied different joining technologies,explored the microstructure of joining interface and tested after-joining properties,a review that summarizes the recent cutting-edge researches and development tendency of joining technologies for SiO_(2)based ceramics is still ***,according to different applications and requirements,this review summarizes the widely used joining technologies and discusses corresponding joining mechanisms,current research progress and suitable *** to the wide applications in specific industry,laser welding,anodic bonding and wafer bonding are discussed in ***,brazing,the widest used method in SiO_(2)joining,has been elaborated deeply in its wetting mechanism,residual stress control,interfacial microstructure and mechanical performance *** the end,this review proposed the future development trends of SiO_(2)ceramics joining,aiming at offering a full-view of potential improvements in SiO_(2)ceramic joining technologies.

关键词： SiO_(2)joining current research progress brazing future development trend

Heat Transfer Characteristics of the Microfluidic Biomimetic Chameleon Skin with Active Thermal Camouflage

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Journal of Bionic Engineering 2023年第2期20卷 722-733页

作者： Lujia Li Huanhuan Li jian cao Songjing Li Department of Fluid Control and Automation Harbin Institute of TechnologyHarbin150001China

Natural organisms have different techniques to avoid enemies,such as chameleon skin with innate camouflage ability to change with the surrounding *** by this,a microfluidic biomimetic chameleon skin based on infrared(IR)information processing is proposed for active thermal camouflage in a dynamic infrared *** circulation in microcavities distributed under the skin is controlled by a thermal camouflage *** structure and working principle of the biomimetic skin are introduced,and the thermal camouflage system is established and tested to explore the heat transfer characteristics between the skin and the *** mechanism of collecting the background infrared information and regulating the skin temperature through the control signal generated by the infrared information processing system is ***,the dynamic thermal response of the skin is tested when transitioning between different temperature backgrounds,modeling the ambient temperature of the sand,woodland and lakes where chameleons *** performance of the skin is evaluated by measuring the camouflage responding time of the skin to an external heat *** results show that the chameleon biomimetic skin is naturally transitioned and matched by infrared information processing and *** limitation that the conventional thermal camouflage technology cannot adapt to the dynamic combat environment is overcome and the weaknesses of a small camouflage band range and a single form of camouflage are resolved in this study,thus effectively improving the target’s survivability in combat.

关键词： Biomimetic skin Thermal camouflage Microfluidics Infrared Chameleon

Force-position collaborative optimization of rope-driven snake manipulator for capturing non-cooperative space targets

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Chinese Journal of Aeronautics 2024年第9期37卷 369-384页

作者： Xiaofeng LI jian TIAN Cheng WEI Xibin cao School of Astronautics Harbin Institute of TechnologyHarbin 150001China Beijing Instiuteof Spacecraft System Engineering China Academy of Space TechnolgyBeijing 100094Chia

With the rapid development of space activities,non-cooperative space targets increase swiftly,such as failed satellites and upper stages,threating normal spacecrafts *** there are some problems in the capture process,such as excessive collision and fast tumbling of targets,manipulator with redundant Degrees of Freedom(DOFs)can be used to improve the compliance and therefore solve these *** Rope-Driven Snake Manipulator(RDSM)is a combina-tion of hyper-redundant DOFs and better compliance,and therefore it is suitable for capturing *** this paper,a snake manipulator mechanism is designed,and the complete kinematic model and system dynamic model considering RDSM,target and contact is ***,to obtain the configuration of joint with hyper-redundant DOFs,an improved motion dexterity index is pro-posed as the joint motion optimization ***,the force-position collaborative optimization index is designed to adjust active stiffness,and the impedance control method based on the modified index is used to capture the space ***,the proposed force-position collaborative opti-mization method is verified by virtual prototype *** results demonstrate that based on the proposed method,the collision force is reduced by about 25%compared to normal impe-dance control,showing higher safety.

关键词： Capturing non-cooperative spacetargets Rope-driven snakemanipu-lator Force-position collaborative optimization Redundant degrees of free-dom Active stiffness adjustment

Effect of K-doping on the Electrochemical Performance of Ca_3Co_4O_9 Anode for Li-ion Batteries

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Journal of Materials Science & Technology 2010年第7期26卷 669-672页

作者： Jina cao Hongquan Liu jian Xie caoshao cao Xinbing Zhao Department of Materials Science and Engineering Zhejiang University Hangzhou 310027 China

Ca3CO4O9 （CCO） and Ca2.95K0.05Co4O9 （CKCO） powders have been prepared by the polyacrylamide gel method. CKCO shows increased capacity and better cycling stability compared with CCO. After cycled for 50 cycles at 0.5 C, CKCO retains a capacity of 223 mAh.g-1, almost twice than CCO. The electrochemical impedance spectroscopy （EIS） tests shows the CKCO sample has a lower initial charge transfer resistance （Rot） and undergoes smaller Rot change during cycling than the CCO sample, indicating improved electrochemical performance by K-doping.

关键词： Lithium-ion battery Anode Ca3Co4O9 K-doping