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Refined Evaluation of Satellite Precipitation Products against Rain Gauge Observations along the Sichuan–Tibet Railway

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Journal of Meteorological Research 2022年第5期36卷 779-797页

作者： Zhiqiang LIN Xiuping YAO Jun DU zhenbo zhou Plateau Atmosphere and Environment Key Laboratory of Sichuan Province School of Atmospheric SciencesChengdu University of Information TechnologyChengdu 610225 China Meteorological Administration Training Centre China Meteorological AdministrationBeijing 100081 Tibet Institute of Plateau Atmosphericand Environmental Science Lhasa 850000

Being constructed in southwestern China, the Sichuan–Tibet Railway(STR) travels across the eastern Tibetan Plateau where there is the most complex terrain and changeable weather in the world. Due to sparse ground-based observations over the Tibetan Plateau, precipitation products retrieved by remote sensing are more widely used;however,satellite-based precipitation products(SPPs) have not yet been strictly and systematically evaluated along the *** study aims to evaluate the performance of six SPPs by a series of metrics with available ground observations along the STR during 1998–2020. The six SPPs include the datasets derived from the Tropical Rainfall Measuring Mission(TRMM), Climate Prediction Center morphing technique(CMORPH), Global Precipitation Measurement(GPM), Global Satellite Mapping of Precipitation(GSMaP), Precipitation Estimation from Remotely Sensed Information Using Artificial Neural Networks(PERSIANN), and Fengyun-2 satellites precipitation estimate(FY2PRE). The results indicate that most of the SPPs can capture the precipitation characteristics on multiple timescales(monthly,daily, hourly, and diurnal cycle) as shown by the evaluated metrics. The probability density functions of the daily and hourly precipitation are also well represented by the SPPs, and 30 mm day^(-1) and 16 mm h^(-1) are identified as the daily and hourly thresholds of extreme precipitation events along the STR. The best SPP varies at different timescales:GPM and GSMaP are suitable for the monthly and daily scale, and FY2PRE and GPM are suited to the hourly *** general, GPM is relatively optimum on multiple timescales, and PERSIANN gives the worst performance. In addition, the SPPs perform worse at higher altitudes and for more intense precipitation. Overall, the results from this study are expected to provide essential reference for using the SPPs in meteorological services and disaster prevention in the STR construction and its future operation.

关键词： eastern Tibetan Plateau Sichuan–Tibet Railway(STR) satellite-based precipitation products evaluation multiple timescales

Research on the Critical Buckling Pressure of Bucket Foundations with Inner Compartments for Offshore Wind Turbines

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Journal of Ocean University of China 2023年第2期22卷 419-428页

作者： SUN Guodong LIU Run LI Qingxin HUANG Guoyu zhou zhenbo ZHANG Cheng State Key Laboratory of Hydraulic Engineering Simulation and Safety Tianjin UniversityTianjin 300072China Southern Offshore Wind Power Joint Development Co. Ltd.Zhuhai 519080China Changjiang Survey Planning Design and Research Co. Ltd.Wuhan 430010China

In the process of suction penetration of bucket foundations with inner compartments for offshore wind turbines,most researches focus on soil seepage failure and soil plugs,while the buckling of foundations is rarely ***,theoretical calculation methods for critical buckling pressures of the skirt and bulkheads of the bucket foundation are first presented according to the stability theory of a cylindrical shell and the small deflection theory of a thin plate,***,two types of models with and without considering the skirt-soil interaction are developed for the calculation of critical buckling pressure of the bucket *** a practical project as an example,theoretical and numerical methods are used to obtain the critical buckling pressures of a bucket *** this work,the theoretical method and the finite element model considering the skirt-soil interaction for calculating the critical buckling pressure of bucket foundations are firstly *** results can help to optimize the design process of offshore wind turbine foundations and improve the safety of offshore wind power systems.

关键词： offshore wind power bucket foundation suction penetration critical buckling pressure

Vibration attenuation performance of wind turbine tower using a prestressed tuned mass damper under seismic excitation

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Earthquake Engineering and Engineering Vibration 2024年第2期23卷 511-524页

作者： Lei zhenbo Liu Gang Wang Hui Hui Yi School of Civil Engineering Chongqing UniversityChongqing 400045China Key Laboratory of New Technology for Construction of Cities in Mountain Area Chongqing UniversityMinistry of EducationChongqing 400045China

With the rapid development of large megawatt wind turbines,the operation environment of wind turbine towers(WTTs)has become increasingly *** particular,seismic excitation can create a resonance response and cause excessive vibration of the *** investigate the vibration attenuation performance of the WTT under seismic excitations,a novel passive vibration control device,called a prestressed tuned mass damper(PS-TMD),is presented in this ***,a mathematical model is established based on structural dynamics under seismic ***,the mathematical analytical expression of the dynamic coefficient is deduced,and the parameter design method is obtained by system tuning ***,based on a theoretical analysis and parameter design,the numerical results showed that the PS-TMD was able to effectively mitigate the resonance under the harmonic basal ***,the time-history analysis method is used to verify the effectiveness of the traditional pendulum tuned mass damper(PTMD)and the novel PS-TMD device,and the results indicate that the vibration attenuation performance of the PS-TMD is better than the *** addition,the PS-TMD avoids the nonlinear effect due to the large oscillation angle,and has the potential to dissipate hysteretic energy under seismic excitation.

关键词： wind turbine tower prestressed tuned mass damper vibration control seismic excitation numerical simulation

Compositionally graded high-voltage P2-type cathode with superior structural stability and redox kinetics for advanced Na-ion batteries

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Nano Research 2024年第4期17卷 2755-2762页

作者： Peiyu Hou Mohan Dong zhenbo Sun Feng Li School of Physics and Technology University of JinanJinan 250022China

Layered P2-type cathodes with high voltage,large capacity,and easy synthesis show great potential for developing sodium(Na)-ion batteries(NIBs).However,the P2–O2 phase transition makes their structural degradation and the Na^(+)/vacancy ordering lowers their redox ***,we rationally propose a compositionally graded P2-type cathode,where nickel(Ni)and manganese(Mn)fractions decrease gradually,and cobalt(Co)content increases contiguously from the inside to the outside of a secondary *** these particles,the Ni/Mn-based compound delivers high capacity and high *** the surface of particles,the Co/Mn-based solid solution offers a stable buffer *** from these synergistic effects,this graded P2-type cathode shows the elimination of P2–O2 transformation even when charged to 4.4 V,which enables good structural stability,maintaining capacity retention reaching~80%within 300 ***,the Na^(+)/vacancy ordering superstructure is further suppressed,and the Na^(+)diffusion kinetics is significantly *** proposed graded structure with optimized chemical composition offers a new perspective for eliminating the unwanted phase transition and thus enhancing the electrochemistry of high-voltage layered cathodes for advanced NIBs.

关键词： Na-ion battery P2-type cathode composition regulation phase transition redox stability

A Time Series Short-Term Prediction Method Based on Multi-Granularity Event Matching and Alignment

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Computers, Materials & Continua 2024年第1期78卷 653-676页

作者： Haibo Li Yongbo Yu zhenbo Zhao Xiaokang Tang College of Computer Science and Technology Huaqiao UniversityXiamen361021China

Accurate forecasting of time series is crucial across various *** prediction tasks rely on effectively segmenting,matching,and time series data *** instance,regardless of time series with the same granularity,segmenting them into different granularity events can effectively mitigate the impact of varying time scales on prediction ***,these events of varying granularity frequently intersect with each other,which may possess unequal *** minor differences can result in significant errors when matching time series with future ***,directly using matched events but unaligned events as state vectors in machine learning-based prediction models can lead to insufficient prediction ***,this paper proposes a short-term forecasting method for time series based on a multi-granularity event,MGE-SP(multi-granularity event-based short-termprediction).First,amethodological framework for MGE-SP established guides the implementation *** framework consists of three key steps,including multi-granularity event matching based on the LTF(latest time first)strategy,multi-granularity event alignment using a piecewise aggregate approximation based on the compression ratio,and a short-term prediction model based on *** data from a nationwide online car-hailing service in China ensures the method’s *** average RMSE(root mean square error)and MAE(mean absolute error)of the proposed method are 3.204 and 2.360,lower than the respective values of 4.056 and 3.101 obtained using theARIMA(autoregressive integratedmoving average)method,as well as the values of 4.278 and 2.994 obtained using k-means-SVR(support vector regression)*** other experiment is conducted on stock data froma public data *** proposed method achieved an average RMSE and MAE of 0.836 and 0.696,lower than the respective values of 1.019 and 0.844 obtained using the ARIMA method,as well as the values of 1.350 and 1.172 obtained usin

关键词： Time series short-term prediction multi-granularity event alignment event matching

On the use of deep learning for phase recovery

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Light(Science & Applications) 2024年第2期13卷 190-235页

作者： Kaiqiang Wang Li Song Chutian Wang zhenbo Ren Guangyuan Zhao Jiazhen Dou Jianglei Di George Barbastathis Renjie zhou Jianlin Zhao Edmund Y.Lam Department of Electrical and Electronic Engineering The University of Hong KongHong Kong SARChina School of Physical Science and Technology Northwestern Polytechnical UniversityXi’anChina Department of Biomedical Engineering The Chinese University of Hong KongHong Kong SARChina School of Information Engineering Guangdong University of TechnologyGuangzhouChina Department of Mechanical Engineering Massachusetts Institute of TechnologyCambridgeMAUSA

Phase recovery(PR)refers to calculating the phase of the light field from its intensity *** exemplified from quantitative phase imaging and coherent diffraction imaging to adaptive optics,PR is essential for reconstructing the refractive index distribution or topography of an object and correcting the aberration of an imaging *** recent years,deep learning(DL),often implemented through deep neural networks,has provided unprecedented support for computational imaging,leading to more efficient solutions for various PR *** this review,we first briefly introduce conventional methods for ***,we review how DL provides support for PR from the following three stages,namely,pre-processing,in-processing,and *** also review how DL is used in phase image ***,we summarize the work in DL for PR and provide an outlook on how to better use DL to improve the reliability and efficiency of ***,we present a live-updating resource(https://***/kqwang/phase-recovery)for readers to learn more about PR.

关键词： networks phase optics

Effects of Nitrogen Doping on Microstructures and Irradiation Resistance of Ti-Zr-Nb-V-Mo Refractory High-Entropy Alloy

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Acta Metallurgica Sinica(English Letters) 2024年第6期37卷 1007-1018页

作者： Huanzhi Zhang Tianxin Li Qianqian Wang zhenbo Zhu Hefei Huang Yiping Lu Engineering Research Center of High Entropy Alloy Materials(Liaoning Province) School of Materials Science and EngineeringDalian University of TechnologyDalian116024China Shanghai Institute of Applied Physics Chinese Academy of Sciences(CAS)Shanghai201800China

Interstitial strengthening with nitrogen(N)is one of the effective ways to improve the mechanical properties of HEAs,but the effects of N on the microstructures and mechanical properties of the irradiated HEAs have not been studied ***,the microstructures and mechanical properties of N-free and N-doped Ti_(2)ZrNbV_(0.5)Mo_(0.2)HEAs before and after He irradiation were *** results showed that the solid solution strengthening caused by interstitial N improved the yield strength at room temperature and 1023 K without significantly reducing plasticity.N doping significantly promoted the growth,aggregation and wider spatial distribution of He bubbles by enhancing the mobility of He atoms/He-vacancy complexes,with the average size of He bubbles increasing from 10.4 nm in N-free HEA to 31.0 nm in N-doped *** addition,N-doped HEA showed a much higher irradiation hardness increment and hardening fraction than N-free *** to conventional materials doped with N,the introduction of N into Ti_(2)ZrNbV_(0.5)Mo_(0.2)HEA had adverse effects on its resistance to He bubble growth and irradiation *** results of this study indicated that N doping may not improve the irradiation resistance of HEAs.

关键词： High-entropy alloys Nitrogen doping Mechanical properties Helium bubbles Irradiation resistance

A Novel Approach for Rapid Evaluating Cavitation Erosion Resistance of Metallic Materials

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Acta Metallurgica Sinica(English Letters) 2024年第7期37卷 1231-1237页

作者： Yu Li zhenbo Qin Xiaoyang Du Da-Hai Xia Zepeng Gao Yiwen Zhang Zhong Wu Wenbin Hu Tianjin Key Laboratory of Composite and Functional Materials School of Materials Science and EngineeringTianjin UniversityTianjin300072China Key Laboratory of Advanced Ceramics and Machining Technology(Ministry of Education) Tianjin UniversityTianjin300072China Joint School of National University of Singapore and Tianjin University International Campus of Tianjin UniversityFuzhou350207China

For the evaluation of cavitation erosion resistance of metallic materials,it has always been a time-consuming technical *** paper innovatively proposed a parameter named cavitation hardening rate to characterize the plastic deformation and work hardening behavior of metallic materials during the cavitation process and then found a positive correlation between cavitation hardening rate and strain hardening ***,the relationship between cavitation volume loss and strain hardening index was obtained,and a simple and rapid evaluation method for cavitation erosion resistance was established.

关键词： Cavitation erosion Evaluation method Cavitation hardening rate Volume loss

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脂润滑弧齿锥齿轮热弹流润滑与效率研究

摩擦学学报（中英文） 2024年第3期44卷 323-334页

作者：王振博郑鹏沈阳工业大学机械工程学院辽宁沈阳110870

基于油动重载四旋翼无人机的特殊应用条件,研究了无人机齿轮箱内脂润滑弧齿锥齿轮的润滑状态及啮合效率.推导了适用于弧齿锥齿轮的脂润滑雷诺方程,采用计算油膜剪切力和微凸体接触摩擦力组成的复合摩擦系数代替摩擦系数经验公式的方法,... 详细信息

基于油动重载四旋翼无人机的特殊应用条件,研究了无人机齿轮箱内脂润滑弧齿锥齿轮的润滑状态及啮合效率.推导了适用于弧齿锥齿轮的脂润滑雷诺方程,采用计算油膜剪切力和微凸体接触摩擦力组成的复合摩擦系数代替摩擦系数经验公式的方法,研究了在无人机各种工况下的齿面润滑情况和啮合效率.结果表明,本研究中提出的考虑粗糙度的脂润滑雷诺方程能够很好预测文献中的试验结果;弧齿锥齿轮的齿面较为复杂,不能用油润滑的中心油膜厚度算法近似估计脂润滑弧齿锥齿轮整个齿面上的润滑状态;1个啮合周期内的齿面摩擦系数在节点处最大;低转速情况下,齿面将进入混合润滑状态;1个啮合周期内啮合效率的变化与啮合位置密切相关,在啮入点处效率最低;在转速不变的前提下,润滑脂黏度越高,效率损失越大.

关键词：啮合效率热弹流润滑状态摩擦系数混合润滑