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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

Shield Excavation Analysis: Ground Settlement & Mechanical Responses in Complex Strata

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Structural Durability & Health Monitoring 2024年第3期18卷 341-360页

作者： Baojun qin Guangwei Zhang Wei Zhang CCCC Rail Transit Branch Beijing101300China School of Civil Engineering Fujian University of TechnologyFuzhou350118China

This study delves into the effects of shield tunneling in complex coastal strata, focusing on how this constructionmethod impacts surface settlement, the mechanical properties of adjacent rock, and the deformation of tunnelsegments. It investigates the impact of shield construction on surface settlement, mechanical characteristics ofnearby rock, and segment deformation in complex coastal strata susceptible to construction disturbances. Utilizingthe Fuzhou Binhai express line as a case study, we developed a comprehensive numerical model using theABAQUS finite element software. The model incorporates factors such as face force, grouting pressure, jack force,and cutterhead torque. Its accuracy is validated against field monitoring data from engineering projects. Simulationswere conducted to analyze ground settlement and mechanical changes in adjacent rock and segments acrossfive soil layers. The results indicate that disturbances are most significant near the excavation zone of the shieldmachine, with a prominent settlement trough forming and stabilizing around 2.0–3.0 D from the excavation. Theexcavation face compresses the soil, inducing lateral expansion. As grouting pressure decreases, the segmentexperiences upward buoyancy. In mixed strata, softer layers witness increased cutting, intensifying disturbancesbut reducing segment floatation. These findings offer valuable insights for predicting settlements, ensuring segmentand rock safety, and optimizing tunneling parameters.

关键词： Shield construction complex strata finite element method mechanical properties of surrounding rock segment deformation settlement prediction

Research on the MPPT of Photovoltaic Power Generation Based on Improved WOA and P&O under Partial Shading Conditions

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Energy Engineering 2024年第4期121卷 951-971页

作者： Jian Zhong Lei Zhang Ling qin School of Electrical Engineering Nantong UniversityNantong226019China

Partial shading conditions(PSCs)caused by uneven illumination become one of the most common problems in photovoltaic(PV)systems,which can make the PV power-voltage(P-V)characteristics curve show *** maximum power point tracking(MPPT)methods have shortcomings in tracking to the global maximum power point(GMPP),resulting in a dramatic decrease in output *** order to solve the above problems,intelligent algorithms are used in ***,the existing intelligent algorithms have some disadvantages,such as slow convergence speed and large search ***,an improved whale algorithm(IWOA)combined with the P&O(IWOA-P&O)is proposed for the MPPT of PV power generation in this ***,IWOA is used to track the range interval of the GMPP,and then P&O is used to accurately find the MPP in that *** with other algorithms,simulation results show that this method has an average tracking efficiency of 99.79%and an average tracking time of 0.16 s when tracking ***,experimental verification is conducted,and the results show that the proposed algorithm has better MPPT performance compared to popular particle swarm optimization(PSO)and PSO-P&O algorithms.

关键词： Photovoltaic power generation maximum power point tracking whale algorithm perturbation and observation

Evolution and Determinants of Population Agglomeration in Less Developed Metropolitan Areas:A Case Study of the Taiyuan Metropolitan Area,China

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Chinese Geographical Science 2024年第4期34卷 739-751页

作者： qin Zhiqin LIANG Ye AN Shuwei DOU Yongjing School of Economics and Management Shanxi UniversityTaiyuan 030031China School of Urban Economics and Public Affairs Capital University of Economics and BusinessBeijing 100070China School of Geography Science Taiyuan Normal UniversityJinzhong 030619China

It is of importance to enhance the urban areas'capacity for population aggregation in underdeveloped regions,aiming to rectify the imbalanced and insufficient pattern of economic development in *** the Taiyuan Metropolitan Area(TMA)in central China as a case study,this paper examines the evolutionary process and characteristics of population agglomeration from 2000 to 2020,and identifies factors associated with agglomeration and their spatial *** findings indicated that:1)against the background of sustained population shrinkage in the provincial area,the TMA showed a demographic trend of steady increase,albeit with a decelerated growth *** the metropolitan area,urban population size continued to grow rapidly,whereas the rural areas endured sustained *** in city size continued to widen,and the polarization of concentrated population in the core cities kept increasing.2)Agglomerations in both secondary and service industries had significant positive effects on local population agglomeration,with the former effect being *** economic development,government fiscal expenditure,and financial advancement all contributed to facilitating local population *** a spatial spillover perspective,service agglomeration and financial development promoted population agglomeration in surrounding ***,fiscal expenditure inhibited such *** for industrial agglomeration and regional economic development,their spatial spillover effects were *** results obtained reveal several policy implications aimed at enhancing the population agglomeration capacity of the metropolitan area in underdeveloped regions during the new era.

关键词： population agglomeration population shrinkage spatial spillover effects Taiyuan Metropolitan Area(TMA) China

In-situ UV-Vis Spectroscopy of Trisulfur Radicals in Lithium-Sulfur Batteries

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Chemical Research in Chinese Universities 2024年第2期40卷 279-286页

作者： DOU Renju WANG qin REN Xiaoyan LU Lehui School of Applied Chemistry and Engineering University of Science and Technology of ChinaHefei230026P.R.China State Key Laboratory of Electroanalytical Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun130022P.R.China

Here we employ in-situ UV-Vis spectroscopy to monitor the sulfur redox reaction with oxygen-containing molecules as an additive,for example,biphenyl-4,4′-dicarboxylic acid(BDC).Furthermore,Raman spectrum,electron paramagnetic resonance(EPR),and electrospray ionization-mass spectrometry(ESI-MS)measurements reveal that the formation of BDC-S_(3)•^(‒)complexes can establish the long-term stability of polysulfide radicals,change the kinetics of sulfur redox reaction,and then generate decent capacity retention and rate *** to the density functional theory(DFT)analysis,S_(3)•^(‒)radicals are the underlying product of S_(6)^(2‒)cleavage,owing to the decreased chemical energy and the increased stability of S_(3)•^(‒)radicals through Lewis acid-base *** assembled Li-S batteries with BDC additive deliver a high reversible capacity of 420 mA·h·g^(−1)over 200 cycles with over 98%Coulombic efficiency,under the current density of 0.2 C.

关键词： Radical Polysulfide In-situ UV-Vis Spectroscopy Electrolyte additive Lithium-sulfur battery

Distributed Dynamic Load in Structural Dynamics by the Impulse-Based Force Estimation Algorithm

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Computer Modeling in Engineering & Sciences 2024年第6期139卷 2865-2891页

作者： Yuantian qin Yucheng Zhang Vadim V.Silberschmidt College of Astronautics Nanjing University of Aeronautics and AstronauticsNanjing210016China Wolfson School of Mechanical Electrical and Manufacturing EngineeringLoughborough UniversityLoughboroughLE113TUUK

This paper proposes a novel approach for identifying distributed dynamic loads in the time *** polynomial andmodal analysis,the load is transformed intomodal space for coefficient *** allows the distributed dynamic load with a two-dimensional form in terms of time and space to be simultaneously identified in the form of modal force,thereby achieving dimensionality *** Impulse-based Force Estimation Algorithm is proposed to identify dynamic loads in the time ***,the algorithm establishes a recursion scheme based on convolution integral,enabling it to identify loads with a long history and rapidly changing forms over ***,the algorithm introduces moving mean and polynomial fitting to detrend,enhancing its applicability in load *** aforementioned methodology successfully accomplishes the reconstruction of distributed,instead of centralized,dynamic loads on the continuum in the time domain by utilizing acceleration *** validate the effectiveness of the method,computational and experimental verification were conducted.

关键词： Distributed force estimation time domain deconvolution recursion

Unveiling the Contribution of Lactic Acid to the Passivation Behavior of Ti-6Al-4V Fabricated by Laser Powder Bed Fusion in Hank’s Solution

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Acta Metallurgica Sinica(English Letters) 2024年第1期37卷 102-118页

作者： Yu-Hang Chu Liang-Yu Chen Bo-Yuan qin Wenbin Gao Fanmin Shang Hong-Yu Yang Lina Zhang Peng qin Lai-Chang Zhang School of Materials Science and Engineering Jiangsu University of Science and TechnologyZhenjiang212100China Foshan(Southern China)Institute for New Materials Foshan528200China Key Laboratory of Automobile Materials Ministry of Education and Department of Materials Science and EngineeringJilin UniversityChangchun130025China Centre for Advanced Materials and Manufacturing School of EngineeringEdith Cowan University270 Joondalup DriveJoondalupPerthWA6027Australia

In actual physiological environments,bacteria can activate the immune system and release lactic ***,the detailed contribution of lactic acid to the passivation behavior of titanium(Ti)alloys is still *** current work investigated the in vitro passivation behavior of Ti-6Al-4V(TC4)alloys fabricated by laser powder bed fusion in Hank's solution with and without adding lactic *** methods,inductively coupled plasma atomic emission spectrometer,and X-ray photoelectron spectroscopy were jointly *** lactic acid decreases the corrosion resistance of samples by degrading the formed passive *** film formed in the(lactic acid)-containing solution exhibits a higher level of oxygen vacancies and a lower thickness,attributed to the suppressed formation of Ti^(4+)transformed from Ti^(3+)and Ti^(2+).Moreover,the presence of lactic acid would increase the open circuit potential,relieve the ions release,and hinder the deposition of calcium phosphates within 24 h immersion.

关键词： Titanium alloy Corrosion behavior Passive film Lactic acid Laser powder bed fusion

Cluster analysis reveals a homogeneous subgroup of PCOS women with metabolic disturbance associated with adverse reproductive outcomes

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Chinese Medical Journal 2024年第5期137卷 604-612页

作者： Hanxiao Chen Rujun Zeng Xun Zeng Lang qin The Reproductive Medical Center Department of Obstetrics and GynecologyWest China Second University HospitalSichuan UniversityChengduSichuan 610041China Key Laboratory of Birth Defects and Related of Women and Children of Ministry of Education West China Second University HospitalSichuan UniversityChengduSichuan 610041China

Background:Polycystic ovarian syndrome(PCOS)is a heterogeneous and complex reproductive endocrinological disease that could lead to *** were many attempts to classify PCOS but it remains unclear whether there is a specific subgroup of PCOS that is associated with the best or worst reproductive outcomes of assisted reproductive techniques(ART).Methods:Infertile PCOS patients who underwent their first cycle of in vitro fertilization(IVF)in West China Second University Hospital,Sichuan University from January 2019 to December 2021 were *** clinical and laboratory information of each individual were *** cluster analysis was *** ovarian stimulation parameters and reproductive outcomes were collected and compared between the different clusters of ***:Our analysis clustered women with PCOS into"reproductive","metabolic",and"balanced"clusters based on nine *** group was characterized by high levels of testosterone(T),sex hormone-binding globulin(SHBG),follicular stimulation hormone(FSH),luteinizing hormone(LH),and anti-Müllerian hormone(AMH).Metabolic group was characterized by high levels of body mass index(BMI),fasting insulin,and fasting *** group was characterized by low levels of the aforementioned reproductive and metabolic parameters,except for *** with PCOS patients in reproductive and balanced clusters,those in metabolic cluster had lower rates of good quality day 3 embryo and blastocyst ***,PCOS patients in the reproductive cluster had greater fresh embryo transfer(ET)cancelation rate and clinical pregnancy rate after fresh ET than metabolic cluster(odds ratio[OR]=3.37,95%confidence interval[CI]:1.77-6.44,and OR=6.19,95%CI:1.58-24.24,respectively).And compared with PCOS of metabolic cluster,PCOS of balanced cluster also had higher chance for fresh ET cancelation(OR=2.83,95%CI:1.26-6.35).Conclusion:Our study suggested that PCOS patients in met

关键词： Polycystic ovarian syndrome Assisted reproductive techniques Clustering analysis Metabolic disturbance Clinical pregnancy

Socioeconomic inequalities in cancer incidence and mortality:An analysis of GLOBOCAN 2022

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Chinese Medical Journal 2024年第12期137卷 1407-1413页

作者： Wei Cao Kang qin Feng Li Wanqing Chen Office of Cancer Screening National Cancer Center/National Clinical Research Center for Cancer/Cancer HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100021China Hangzhou Center for Disease Control and Prevention HangzhouZhejiang 310021China The Third People’s Hospital of Xiaoshan HangzhouZhejiang 311251China

Background:Given the recent updates in cancer burden estimates by GLOBOCAN 2022,this study was undertaken to provide pertinent perspectives within the context of the Human Development Index(HDI)and major world ***:Datasets sourced from GLOBOCAN encompassed cancer cases and deaths across all cancer types in 2022,alongside projections up to *** incidences and deaths of the top 10 cancers within China and four distinct HDI-classified regions were compared using descriptive ***-standardized incidence rates(ASIRs)and mortality rates(ASMRs)worldwide for the most prevalent cancers in 2022 across ten largest economies and four-tier HDIs were *** top five cancer types concerning both incidence and mortality in China were delineated by sex and age ***:In males,prostate cancer predominated in countries with low,high(except China),and very high *** and liver cancers were prominent causes of death in countries with low *** females,breast and cervical cancers predominated in countries with low-to-medium *** and colorectal cancer incidence and deaths increased with high HDI for both *** and ASMRs for breast,prostate,lung,and colorectal cancers in the top 10 economies were higher than the global ***,liver,stomach,and cervical cancers in most Western countries exhibited lower *** China,hematologic malignancies(43%)were prevalent among children aged 0-14 years,whereas thyroid cancer led among adolescents and young adults aged 15-39 *** incidence and mortality,lung cancer predominated for individuals over 40 years,except for females aged 40-59 years,in whom breast cancer *** trends indicated substantial increases in new cancer cases(76.6%)and deaths(89.7%)over the next three ***:Infection-and poverty-related cancer burdens are offset by increased prostate,breast,colorectal,and lung cancer incidence associated with rapid societal and economic transi

关键词： Incidence Mortality Tumor burden China Human Development Index Hematologic neoplasms Lung neoplasms Breast neoplasms Colorectal neoplasms Thyroid neoplasms Liver neoplasms Prostatic neoplasms Early detection of cancer