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Asymptotic Behavior of the Lipschitz-1／2 Modulus of the PL-process for Truncated and Censored Data

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Acta Mathematica Sinica,English Series 2003年第4期19卷 729-738页

作者： yongzhou GuoFuWU XueLeiJIANG InstituteofAppliedMathematics AcademyofMathematicsandSystemSciencesChineseAcademyofSciencesBeijing100080P.R.China

In this paper, we give a detailed description of the local behavior of theLipschitz-1/2 modulus for cumulative hazard process and PL-process when the data are subject to lefttruncation and right censored observations. We establish laws of the iterated logarithm of theLipschitz-1/2 modulus of PL-process and cumulative hazard process. These results for the PL-processare sharper than other results found in the literature, which can be used to establish theasymptotic properties of many statistics.

关键词： truncated and censored data oscillation modulus Lipschitz-1/2 modulus PL-process cumulative hazard process law of the iterated logarithm

Sequential Confidence Bands for Quantile Densities Under Truncated and Censored Data

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Acta Mathematicae Applicatae Sinica 2005年第2期21卷 311-322页

作者： yongzhou Liu-quanSun AcademyofMathematicsandSystemSciences ChineseAcademyofSciencesBeijing100080China

In this paper an asymptotic distribution is obtained for the maximaldeviation between the kernel quantile density estimator and the quantile density when the data aresubject to random left truncation and right censorship. Based on this result we propose a fullysequential procedure for constructing a fixed-width confidence band for the quantile density on afinite interval and show that the procedure has the desired coverage probability asymptotically asthe width of the band approaches zero.

关键词： Truncated and censored data quantile density estimation maximal deviation asymptotic distribution sequential confidence band

Magnetic field stability of PrFeB magnets developed by GBD for cryogenic permanent magnet undulators

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Journal of Rare Earths 2018年第4期36卷 385-389页

作者： yongzhou He Xiaoqing Bao Qiaogen Zhou Shanghai Institute of Applied Physics(SINAP) Shanghai 201204China University of Science and Technology Beijing(USTB) Beijing 100083China

The magnetic field stability of the PrFeB magnets is one of the key points which affect its application in such devices as cryogenic permanent magnet undulators. In this study, the magnetic properties and micro structure of PrFeB magnets, which were developed by the grain boundary diffusion, were examined. The demagnetizing field distribution of the cryogenic permanent magnet undulator made using the PrFeB magnets was simulated by Radia, and the change mechanism of the irreversible demagnetization following treatments at high temperatures was experimentally studied, The results show that the intrinsic coercivity of the PrFeB magnets can be increased by diffusion of Tb. Meanwhile, the remanence of the magnets displays almost no loss, and the increasing range is closely related to the orientation thickness of the PrFeB magnet, Therefore, the PrFeB magnets developed using grain boundary diffusion are found to have extremely high comprehensive magnetic properties, The irreversible demagnetization of the PrFeB magnets developed by grain boundary diffusion for the CPMU is determined to be significantly improved following high-temperature treatments.

关键词： PrFeB Grain boundary diffusion Undulator Irreversible demagnetization Rare earths

The numerical study of wave-induced pore water pressure response in highly permeable seabed

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Acta Oceanologica Sinica 2012年第6期31卷 46-55页

作者： JIANG Changbo CHENG yongzhou CHANG Liuhong XIA Bo School of Hydraulic Engineering Changsha University of Science and TechnologyChangsha 410004China Key Laboratory of Water Sediment Sciences and Water Disater prevention of Hunan Province Changsha 410004 China

The coupling numerical model of wave interaction with porous medium is used to study wave- induced pore water pressure in high permeability seabed. In the model, the wave field solver is based on the two dimensional Reynolds-averaged Navier-Stokes （RANS） equations with a k-s closure, and Forchheimer equations are adopted for flow within the porous media. By introducing a Velocity-Pressure Correction equation for the wave flow and porous flow, a highly efficient coupling between the two flows is implemented. The numerical tests are conducted to study the effects of seabed thickness, porosity, particle size and intrinsic permeability coefficient on regular wave and solitary wave-induced pore water pressure response. The results indicate that, as compared with regular wave-induced, solitary wave-induced pore water pressure has larger values and stronger action on seabed with different parameters. The results also clearly show the flow characteristics of pore water flow within seabed and water wave flow on seabed. The maximum pore water flow velocities within seabed under solitary wave action are higher than those under regular wave action.

关键词： solitary wave regular wave highly permeable seabed pore water pressure numericalstudy

A bidirectional threshold switching selector with a symmetric multilayer structure

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Science China(Information Sciences) 2021年第4期64卷 208-213页

作者： Qingjiang LI Kun LI yongzhou WANG Sen LIU Bing SONG College of Electronic Science and Technology National University of Defense Technology

Selectors have been proposed as a highly effective tool for suppressing substantial leakage currents without sacrificing the high density of resistive random-access memory（RRAM） crossbar arrays. Among various selector types, the programmable metallization cell（PMC） selector is promising due to its simple structure and high selectivity. In this work, we demonstrate a new PMC selector that exhibits bidirectional threshold switching behavior by implementing symmetric multilayer dielectrics. The proposed Ag/SiTe/HfO2/SiTe/Ag selector device has a low off current( 10～5）, and low threshold voltage variation（< 0.05）. Upon connection to a bipolar RRAM cell via a wire, the proposed selector successfully suppresses the leakage current of an unselected device below the threshold voltage.

关键词： threshold switching selector resistive random access memory leakage current programmable metallization cell

Prediction of longitudinal surface settlement in composite formation using large-diameter shield machine based on machine learning techniques

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Frontiers of Structural and Civil Engineering 2024年第12期18卷 1922-1936页

作者： Jian ZHANG Chen ZHANG Hao QIAN Tugen FENG yongzhou JIAN Ronghua WU Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering Hohai UniversityNanjing 210098China School of Civil Engineering and Surveying&Mapping Engineering Jiangxi University of Science and TechnologyGanzhou 341000China CCCC-SHB Fourth Engineering Co. Ltd.Luoyang 471013China CCCC Tunnel Engineering Co. Ltd.Beijing 100102China

The employment of large-diameter shield machines has increased the likelihood of encountering composite formations,posing engineering challenges associated with excessive surface *** tackle this issue,this study introduces a hybrid model which integrates the extreme learning machine(ELM)with the sparrow search algorithm(SSA)to predict longitudinal surface *** on on-site *** study analyzed longitudinal surface settlement patterns across both homogeneous and composite *** parameters,geological parameters,and geometrical parameters were considered as input ***,this study conducted a comparative analysis of the predictive performance among SSA-ELM,ELM,and SSA-back propagation(BP),with respect to coefficient of determination(R^(2)),mean absolute error(MAE),root mean square error(RMSE),and training ***,in anticipation of potential risks,a feasible optimization approach is ***-ELM outperforms both ELM and SSA-BP in terms of R^(2),MAE,and RMSE,with values of 0.8822,0.3357,and 0.4072,*** training time,SSA-ELM requires 0.2346 s,prior to SSA-BP with a value of *** it is not as fast as ELM,the discrepancy between SSA-ELM and ELM is only 0.1187 ***,SSA-ELM demonstrates higher performance and serves as an effective tool to guide the construction process.

关键词： large-diameter shield machine composite formation extreme learning machine sparrow search algorithm longitudinal surface settlement

Ammonia borane at high pressures

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Chinese Science Bulletin 2014年第36期59卷 5227-5234页

作者： Jiuhua Chen Vadym Drozd yongzhou Sun Shah Najiba Center for High Pressure Science and Technology Advanced Research Jilin University Center for the Study of Matter at Extreme Conditions Department of Mechanical and Materials Engineering Florida International University Miami FL 33199 USA

Ammonia borane has received tremendous research attention in the past decade because of its potential for chemical hydrogen storage. This paper reviews recent studies about the behavior of ammonia borane at high pressures. While much work is still needed to comprehensively understand the pressure influence on this molecular crystal, a phase diagram based on the available experimental and theoretical data is constructed. Raman spectroscopy studies indicate five transitions upon compression up to 65 GPa at ambient temperature. Diffraction experiments and theoretical studies demonstrate that three of these transitions are first-order phase transformations in the sequence of I4mm-Cmc21-P21-(different) P21, and two are iso-structural. A low-temperature phase(Pmn21) and a high-temperature high-pressure phase(Pmna) are also recognized.

关键词：高温高压硼烷氨衍射实验分子晶体理论数据拉曼光谱环境温度

An experimental investigation of the velocity field under cnoidal waves over the asymmetric rippled bed

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Acta Oceanologica Sinica 2007年第1期26卷 130-139页

作者： CHENG yongzhou WANG Yongxue JIANG Changbo CHEN Chun State Key Laboratory of Coastal and Offshore Engineering Dalian University of Technology Dalian 116024 China Department of River and Ocean Engineering Changsha University of Science and Technology Changsha 410076 China

The evolution of an initially flat sandy bed is studied in a laboratory wave flume under enoidal waves and acoustic Doppler velocimeter （ADV） was utilized in the detailed velocity measurements at different positions. The ripple formation and evolution have been analyzed by CCD images and the asymmetric rippled bed is induced by the nonlinear wave flow. The flow structure and a complete process of vortex formation, evolvement and disappearance were observed on the asymmetric rippled bed under cnoidal waves. With the increasing nonlinearity of waves, which is an important factor in the sand ripple formation, the vortex intensity becomes stronger and shows different characteristics on both sides of the ripple crest. The vorticity and wave velocity reach their maximum values at different phase angles. The vortex value reaches the maximum value at a small phase angle with the increasing Ursell number. The near bed flow patterns are mainly determined by the ripple forms and the averaged longitudinal velocity over a wave period above the ripple trough and crest are positive, which indicates the possibility of significant onshore sediment transport and a corresponding ripple drift. The phase averaged vertical velocity has noticeable positive values near the bottom of the ripple crest and trough. Sediments may be lifted from the ripple surface, picked up in suspension by the local velocity, and deposited over the crest and on the lee of the ripples.

关键词： ripple cnoidal wave velocity vortex

A hydrogel system containing molybdenum-based nanomaterials for wound healing

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Nano Research 2023年第4期16卷 5368-5375页

作者： yongzhou Lu Chuanlong Jia Chengchen Gong Han Wang Qin Xiao Jinxiao Guo Dalong Ni Nan Xu Department of Dermatology Shanghai East HospitalSchool of MedicineTongji UniversityShanghai 200092China Department of Orthopaedics Shanghai Key Laboratory for Prevention and Treatment of Bone and Joint DiseasesShanghai Institute of Traumatology and OrthopaedicsRuijin HospitalShanghai Jiao Tong University School of MedicineShanghai 200025China Department of Orthopaedics Shanghai Jiao Tong University Affiliated Sixth People’s HospitalShanghai Jiao Tong UniversityShanghai 200233China

Wound delayed healing or non-healing has seriously affected patients’quality of life and has been a significant economic burden for public health systems *** reactive oxygen species(ROS)play important roles for impeding the process of wound ***,we report a hydrogel system containing low-valence-state molybdenum nanomaterials(Mo hydrogel)for wound healing by scavenging the detrimental *** in vitro and in vivo results demonstrate that the synthesized Mo hydrogel can accelerate wound healing,promote angiogenesis,and stimulate the expression of growth *** the molybdenum is an essential element for the survival of all organisms,such novel Mo-hydrogel has the great potential to be clinically translated for wound healing.

关键词： antioxidants wound healing hydrogel reactive oxygen species molybdenum