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ANovel Non-Isolated Cubic DC-DC Converter with High Voltage Gain for Renewable Energy Power Generation System

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Energy Engineering 2024年第1期121卷 221-241页

作者： qin Yao Yida zeng qingui Jia School of Electrical Engineering Southwest Jiaotong UniversityChengdu610036China

In recent years,switched inductor(SL)technology,switched capacitor(SC)technology,and switched inductor-capacitor(SL-SC)technology have been widely applied to optimize and improve DC-DC boost converters,which can effectively enhance voltage gain and reduce device *** address the issue of low output voltage in current renewable energy power generation systems,this study proposes a novel non-isolated cubic high-gain DC-DC converter based on the traditional quadratic DC-DC boost converter by incorporating a SC and a SL-SC ***,the proposed converter’s details are elaborated,including its topology structure,operating mode,voltage gain,device stress,and power ***,a comparative analysis is conducted on the voltage gain and device stress between the proposed converter and other high-gain ***,a closed-loop simulation system is constructed to obtain simulation waveforms of various devices and explore the dynamic ***,an experimental prototype is built,experimental waveforms are obtained,and the experimental dynamic performance and conversion efficiency are *** theoretical analysis’s correctness is verified through simulation and experimental *** proposed converter has advantages such as high voltage gain,low device stress,high conversion efficiency,simple control,and wide input voltage range,achieving a good balance between voltage gain,device stress,and power *** proposed converter is well-suited for renewable energy systems and holds theoretical significance and practical value in renewable energy *** provides an effective solution to the issue of low output voltage in renewable energy power generation systems.

关键词： Cubic DC-DC converter high voltage gain low device stress high efficiency renewable energy

A new type of lipophilic hydrophobic self-repairing cellulose insulating paper developed with ST-110/FAS/PTFE ternary system as coating substrate

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High Voltage 2024年第2期9卷 474-483页

作者： Zhenglin zeng Jinshan qin Zuhao Wang Weimin Tan Chao Tang College of Engineering and Technology Southwest UniversityChongqingChina International R&D Center for New Technologies of Smart Grid and Equipment ChongqingChina

The moisture generated by the ageing of the oil-paper insulating system can easily lead to the deterioration of the performance of the insulating *** order to alleviate the impact of moisture on the performance of the insulating paper,we developed a kind of lipophilic hydrophobic self-repairing cellulose insulating paper(new insulating paper)based on the ternary system of polytetrafluoroethylene,fluorocarbon surfactant and fluorinated alkyl silane,and accelerated thermal ageing test for 45 days at 130°C was carried *** experimental results show that the new insulating paper with excellent lipophilic property can realise hydrophobic self-repairing through heat treatment after physical *** tensile strength and elongation at break of the new insulating paper increased by 5%–8%and 6.25%–27%respectively compared with the original cellulose insulating *** the end of ageing,the relative dielectric constant and dielectric loss factor of new insulating paper are 10.4%and 9.9%lower than that of the original cel-lulose insulating paper,while the breakdown voltage is 6.8%*** acid and moisture content produced during the ageing process of the insulating oil impregnated with new insulating paper are also less,indicating that the coating can delay the ageing of the insulating paper.

关键词： coating moisture cellulose

Resilience-driven cooperative reconfiguration strategy for unmanned weapon system-of-systems

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Journal of Systems Engineering and Electronics 2024年第4期35卷 932-944页

作者： SUN qin LI Hongxu zeng Yifan ZHANG Yingchao School of Systems Science and Engineering Sun Yat-sen UniversityGuangzhou 510006China

As the unmanned weap system-of systems(UWSoS)becomes complex,the inevitable uncertain interference gradu-ally increases,which leads to a strong emphasis on the resilience of ***,this paper presents a resilience-driven cooperative reconfiguration strategy to enhance the resilience of ***,a unified resilience-driven coopera-tive reconfiguration strategy framework is designed to guide the UWSoS resilience ***,a cooperative reconfiguration strategy algorithm is proposed to identify the optimal cooperative reconfiguration sequence,combining the cooperative pair resilience contribution index(CPRCI)and coop-erative pair importance index(CPII).At last,the effectiveness and superiority of the proposed algorithm are demonstrated through various attack scenario simulations that include differ-ent attack modes and *** analysis results can pro-vide a reference for decision-makers to manage UWSoS.

关键词： resilience strategy unmanned weapon system-of-systems(UWSoS) cooperative reconfiguration unmanned con-frontation

Innovative coaxial high-temperature thin-film sensor with core-shell structure surpassing traditional multilayer films

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Rare Metals 2024年第8期43卷 3854-3867页

作者： Chao Wu Guo-Chun Chen Fu-Xin Zhao Fan Lin Ying-Jun zeng Yan-Zhang Fu Yan-Song Zhang Li-Da Xu qin-Nan Chen Rui Tang dao-Heng Sun Zhen-Yin Hai Pen-Tung Sah Institute of Micro-Nano Science and Technology Xiamen UniversityXiamen 361005China AECC Shenyang Engine Institute Shenyang 110015China School of Aerospace Engineering Xiamen UniversityXiamen 361005China

High-temperature thin-film sensors(TFSs)often suffer from inadequate tolerance to elevated *** this study,an innovative approach is presented to fabricate in situ integrated TFSs with a core-shell structure on alloy components using coaxial multi-ink printing *** method replaces traditional layerby-layer(LbL) deposition and LbL sintering processes and achieves simplified one-step *** coaxial TFS includes a conductive Pt core for conducting and sensing and a dielectric shell for electrical isolation and high-temperature *** coaxial Pt resistance grid demonstrates excellent high-temperature stability,with a resistance drift rate of only 0.08%·h^(-1) at 800 ℃,significantly lower than traditional Pt *** employing this method,a Pt thin-film strain gauge(TFSG) is fabricated that boasts remarkable high-temperature electromechanical *** effectively addresses the problem of sensitivity degradation experienced by traditional LbL Pt TFSGs when subjected to high *** demonstrate the system integration potential of the technique by printing and verifying the functionality of a long-path thinfilm resistance grid on turbine blades,which can withstand butane flame up to ~1300℃.These results showcase the potential of core-shell structure of the coaxial TFS for high-temperature applications,providing a novel approach to develop high-performance TFS beyond traditional multilayer structure.

关键词： Coaxial printing Core-shell structure Thinfilm strain gauge High-temperature stability

Modeling of multiphase flow in low permeability porous media:Effect of wettability and pore structure properties

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第4期16卷 1127-1139页

作者： Xiangjie qin Yuxuan Xia Juncheng Qiao Jiaheng Chen Jianhui zeng Jianchao Cai National Key Laboratory of Petroleum Resources and Engineering China University of PetroleumBeijing102249China Research Institute of Petroleum Exploration and Development Beijing10083China

Multiphase flow in low permeability porous media is involved in numerous energy and environmental ***,a complete description of this process is challenging due to the limited modeling scale and the effects of complex pore structures and *** address this issue,based on the digital rock of low permeability sandstone,a direct numerical simulation is performed considering the interphase drag and boundary slip to clarify the microscopic water-oil displacement *** addition,a dual-porosity pore network model(PNM)is constructed to obtain the water-oil relative permeability of the *** displacement efficiency as a recovery process is assessed under different wetting and pore structure *** show that microscopic displacement mechanisms explain the corresponding macroscopic relative *** injected water breaks through the outlet earlier with a large mass flow,while thick oil films exist in rough hydrophobic surfaces and poorly connected *** variation of water-oil relative permeability is significant,and residual oil saturation is high in the oil-wet *** flooding is extensive,and the residual oil is trapped in complex pore networks for hydrophilic pore surfaces;thus,water relative permeability is lower in the water-wet *** the displacement efficiency is the worst in mixed-wetting systems for poor water *** negatively correlates with invading oil volume fraction due to strong capillary resistance,and a large microporosity corresponds to low residual oil *** work provides insights into the water-oil flow from different modeling perspectives and helps to optimize the development plan for enhanced recovery.

关键词： Low permeability porous media Water-oil flow Wettability Pore structures Dual porosity pore network model(PNM) Free surface model

A Test of U-type for Goodness-of-fit in Regression Models Through Martingale Difference Divergence

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Acta Mathematicae Applicatae Sinica 2024年第4期40卷 979-1000页

作者： Kai XU Yan-qin NIE dao-jiang HE School of Mathematics and Statistics Anhui Normal UniversityWuhu 241002China

Based on the martingale difference divergence,a recently proposed metric for quantifying conditional mean dependence,we introduce a consistent test of U-type for the goodness-of-fit of linear models under conditional mean ***,our test allows heteroscedastic regression models without imposing any condition on the distribution of the error,utilizes effectively important information contained in the distance of the vector of covariates,has a simple form,is easy to implement,and is free of the subjective choice of ***,our mathematical analysis is of own interest since it does not take advantage of the empirical process theory and provides some insights on the asymptotic behavior of U-statistic in the framework of model *** asymptotic null distribution of the proposed test statistic is derived and its asymptotic power behavior against fixed alternatives and local alternatives converging to the null at the parametric rate is also *** particular,we show that its asymptotic null distribution is very different from that obtained for the true error and their differences are interestingly related to the form expression for the estimated parameter vector embodied in regression function and a martingale difference divergence *** the asymptotic null distribution of the test statistic depends on data generating process,we propose a wild bootstrap scheme to approximate its null *** consistency of the bootstrap scheme is *** studies are undertaken to show the good performance of the new test.

关键词： bootstrap goodness-of-fit test linear mean regression martingale difference divergence martingale difference divergence matrix

Systematic review and network meta-analysis of different nonsteroidal anti-inflammatory drugs for juvenile idiopathic arthritis

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World Journal of Clinical Cases 2024年第12期12卷 2056-2064页

作者： Tao zeng Jian-Zhong Ye Hui qin Qian-Qian Xu College of Medicine Jingchu University of Technology JingmenJingmen 448000Hubei ProvinceChina

BACKGROUND Various non-steroidal anti-inflammatory drugs(NSAIDs)have been used for juvenile idiopathic arthritis(JIA).However,the optimal method for JIA has not yet been *** To perform a systematic review and network meta-analysis to determine the optimal *** We searched for randomized controlled trials(RCTs)from PubMed,EMBASE,Google Scholar,CNKI,and Wanfang without restriction for publication date or language at August,*** RCTs that comparing the effectiveness of NSAIDs with each other or placebo for JIA were included in this network *** surface under the cumulative ranking curve(SUCRA)analysis was used to rank the treatments.P value less than 0.05 was identified as statistically *** We included 8 RCTs(1127 patients)comparing 8 different instructions including meloxicam(0.125 qd and 0.250 qd),Celecoxib(3 mg/kg bid and 6 mg/kg bid),piroxicam,Naproxen(5.0 mg/kg/d,7.5 mg/kg/d and 12.5 mg/kg/d),inuprofen(30-40 mg/kg/d),Aspirin(60-80 mg/kg/d,75 mg/kg/d,and 55 mg/kg/d),Tolmetin(15 mg/kg/d),Rofecoxib,and *** were no significant differences between any two NSAIDs regarding ACR Pedi 30 *** SUCRA shows that celecoxib(6 mg/kg bid)ranked first(SUCRA,88.9%),rofecoxib ranked second(SUCRA,68.1%),Celecoxib(3 mg/kg bid)ranked third(SUCRA,51.0%).There were no significant differences between any two NSAIDs regarding adverse *** SUCRA shows that placebo ranked first(SUCRA,88.2%),piroxicam ranked second(SUCRA,60.5%),rofecoxib(0.6 mg/kg qd)ranked third(SUCRA,56.1%),meloxicam(0.125 mg/kg qd)ranked fourth(SUCRA,56.1%),and rofecoxib(0.3 mg/kg qd)ranked fifth(SUCRA,56.1%).CONCLUSION In summary,celecoxib(6 mg/kg bid)was found to be the most effective NSAID for treating ***,piroxicam,and meloxicam may be safer options,but further research is needed to confirm these findings in larger trials with higher quality studies.

关键词： Non-steroidal anti-inflammatory drugs Juvenile idiopathic arthritis Network meta-analysis Systematic review

Microstructure and Mechanical Property of the Large Cross-Sectioned Mg-Gd-Y-Zn-Zr Alloy Produced by Small Extrusion Ratio

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Acta Metallurgica Sinica(English Letters) 2024年第6期37卷 999-1006页

作者： Sen Wang Hucheng Pan Caixia Jiang Zhihao zeng Zhen Pan Weineng Tang Chubin Yang Yuping Ren Gaowu qin Key Laboratory for Anisotropy and Texture of Materials(Ministry of Education) College of Materials Science and EngineeringNortheastern UniversityShenyang110819China Mg and Mg Alloy Institute Technology CenterBaosteel Metal Co.LtdChina Baowu Steel GroupShanghai200940China Jiangxi Provincial Engineering Research Center for Magnesium Alloy Gannan Normal UniversityGanzhou341000China

In this work,the microstructure and mechanical properties of large cross-sectioned Mg-9Gd-3Y-1.2Zn-0.5Zr(VWZ931)samples produced by the small extrusion ratio has been *** as-extruded VWZ931 sample with diameter of~30 mm can exhibit the high yield strength(YS)of 339 MPa,ultimate tensile strength(UTS)of 387 MPa and elongation of 8.2%,*** peak-aged,the YS and UTS of the Mg samples were significantly increased to 435 MPa and 467 *** small extrusion ratio leads to the low fraction of dynamic recrystallized(DRX)grains in VWZ931 sample,and the texture hardening effect can be fully utilized to achieve high *** combined effect of precipitation strengthening due to the long-period stacking ordered phases and theβ′phase,grain boundary strengthening due to the fine DRX grains,heterogeneous deformation-induced strengthening caused by bimodal microstructure,can together contribute to the high strength of present Mg *** findings can shed light on designing other large-sized Mg wrought alloys with high mechanical performance.

关键词： Mg-RE alloy Mechanical property Bimodal grains Texture hardening

Regulating zinc ion transport behavior and solvated structure towards stable aqueous Zn metal batteries

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Journal of Energy Chemistry 2024年第6期93卷 609-626,I0015页

作者： Qiang Ma Aoen Ma Shanguang Lv Bowen qin Yali Xu Xianxiang zeng Wei Ling Yuan Liu Xiongwei Wu College of Materials Engineering Henan International Joint Laboratory of Rare Earth Composite MaterialsHenan University of EngineeringZhengzhou 451191HenanChina Nanozyme Medical Center School of Basic Medical SciencesZhengzhou UniversityZhengzhou 450001HenanChina School of Chemistry and Materials Science Hunan Agricultural UniversityChangsha 410125HunanChina College of Electrical and Information Engineering Hunan UniversityChangsha 410082HunanChina Hunan Province Yin Feng New Energy Co.Ltd. Changsha 410019HunanChina

Aqueous Zn metal batteries(AZMBs)with intrinsic safety,high energy density and low cost have been regarded as promising electrochemical energy storage ***,the parasitic reaction on metallic Zn anode and the incompatibility between electrode and electrolytes lead to the deterioration of electrochemical performance of AZMBs during the *** critical point to achieve the stable cycling of AZMBs is to properly regulate the zinc ion solvated structure and transfer behavior between metallic Zn anode and *** recent years,numerous achievements have been made to resolve the formation of Zn dendrite and interface incompatible issues faced by AZMBs via optimizing the sheath structure and transport capability of zinc ions at electrode-electrolyte *** this review,the challenges for metallic Zn anode and electrode-electrolyte interface in AZMBs including dendrite formation and interface characteristics are *** the influences of different strategies involving designing advanced electrode structu re,artificial solid electrolyte interphase(SEI)on Zn anode and electrolyte engineering to regulate zinc ion solvated sheath structure and transport behavior are summarized and ***,the perspectives for the future development of design strategies for dendrite-free Zn metal anode and long lifespan AZMBs are also given.

关键词： aqueous Zn metal batteries Zn metal anode Transport behavior Solvated structure Dendrite-free