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Vibration Characteristics and Power Transmission of Coupled Rectangular Plates with Elastic Coupling Edge and Boundary Restraints

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Chinese Journal of Mechanical Engineering 2012年第2期25卷 262-276页

作者： CHEN Yuehua jin Guoyong du jingtao LIU Zhigang College of Power and Energy Engineering Harbin Engineering UniversityHarbin 150001China

Coupled-plate structures are widely used in the practical engineering such as aeronautical,civil and naval engineering *** works can be found on the vibration of the coupled-plate structure due to the increased mathematical complexity compared with the single plate *** order to study analytically the vibration characteristics and power transmission of the coupled-plate structure,an analytical model consisting of three coupled plates elastically restrained along boundary edges and elastically coupled with arbitrary angle is considered,in which four groups of springs are distributed consistently along each edge of the model to simulate the transverse shearing forces,bending moments,in-plane longitudinal forces and in-plane shearing forces *** elastic coupling condition and general boundary condition of both flexural and in-plane vibrations taken into account by setting the stiffness of corresponding springs,the double Fourier series solution to the dynamic response of the structure was obtained by employing the Rayleigh-Ritz *** order to validate the model,the natural frequency and velocity response of the model are firstly checked against results published in literatures and the ANSYS data,and good agreement was ***,numerical simulation of the effects of several relevant parameters on the vibration characteristics and power transmission of the coupled structure were performed,including boundary conditions,coupling conditions,coupling angle,and location of the external *** and energy transmission behaviors were analyzed *** results show that the power transmission can be significantly influenced by the boundary restraints and the location of *** the excitation is located at the central symmetry point of the model,the energy flow shows a symmetrical *** the location deviates from the central symmetry point,the power circumfluence occurs and the vortex energy field is formed

关键词： vibration power transmission coupled-plate structure elastic restraints

The Harmonic Decomposition Reconstruction for the Exponential Radon Transform

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Wuhan University Journal of Natural Sciences 2002年第1期7卷 1-5页

作者： Wang jin-ping du jin-yuan School of Mathematics and Statistics Wuhan University Wuhan 430072 Hubei China

The exponential Radon transform, a generalization of the Radon transform, is defined and studied as a mapping of function spaces. It is represented in terms of Fourier transform of its domain and range, and this leads... 详细信息

关键词： exponential radon transform Fourier transform harmonic decomposition inversion

Special Issue: Functional Polymer Materials

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Chinese Journal of Polymer Science 2024年第7期42卷 895-896,I0004页

作者： Gu, Jun-Wei Wang, du-jin Shaanxi Key Laboratory of Macromolecular Science and Technology School of Chemistry and Chemical Engineering Northwestern Polytechnical University Xi’an China Beijing National Laboratory for Molecular Sciences CAS Key Laboratory of Engineering Plastics Institute of Chemistry Chinese Academy of Sciences Beijing China

The rapid development of science has led to a significant role for polymer materials in multitude fields,including industry,medicine,energy,and the environment,*** a leading academic journal in the field of polymer,Chinese Journal of Polymer Science has been dedicated to fostering the advancement and utilization of polymer science.

关键词： polymer Polymer Functional

Oxidation damage zone formed in creep fatigue crack growth of GH4169 alloy at 650℃

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Journal of Iron and Steel Research International 2023年第12期30卷 2582-2592页

作者： Lan-zhou Liu Yi-fei Gao jin-hui du Teng An Central Iron and Steel Research Institute Beijing100081China NCS Testing Technology Co. Ltd.Beijing100081China Beijing Cisri-Gaona Materials and Technology Co. Ltd.Beijing100081China

In the creep fatigue crack growth of GH4169 alloy,oxidation is a prominent damage source,which is mainly manifested as the oxidation damage zone in front of crack *** order to investigate the property of the oxidation damage zone formed in the creep fatigue crack growth,crack growth tests of directly aged GH4169 alloy were conducted at 650℃ in air under various load *** tests were performed to observe the damage characteristics at crack *** tests were systematically executed to quantify the dependency of oxidation damage zone size on load and holding *** crack propagation of the GH4169 alloy has a close relationship with grain boundary oxidation at 650℃.An oxidation damage zone in front of crack tip includes intergranular microcracks and oxidised but uncracked grain *** size has been calculated from transient crack growth rate and described as a function of maximum stress intensity factor and holding *** on oxidation damage zone size,a novel model has been developed to predict the creep fatigue crack growth rate of the GH4169 alloy at 650℃.

关键词： Performance evaluation Creep fatigue crack growth-Directly aged GH4169 alloy Intergranular crack propagation Oxidation damage zone

Simple recursive algorithm for linear-in-the-parameters nonlinear model identification

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Science in China(Series F) 2009年第10期52卷 1739-1745页

作者： LI PingKang jin TaoTao du XiuXia School of Mechanical Electrical and Control Engineering Beijing Jiaotong University Beijing 100044 China

This paper introduces a simple recursive algorithm for nonlinear dynamic system identification using linear-in-the-parameters models for NARX or RBF network where both the structure and parameters can be obtained simultaneously and recursively. The main objective is to improve the numerical stability when the model terms are highly correlated. This is based on the ＂innovation＂ idea and net contribution criteria. Using the recursive formulae for the computation of the Moore-Penrose inverse of matrices and the net contribution of model terms, it is possible to combine the structure term determination and parameters estimation within one framework by adding and deleting an item in the selected candidate model. The formulae for enhancing and reducing a matrix are given. Simulation results show the proposed method is numerically more stable than existing approaches.

关键词： nonlinear dynamic system linear-in-the-parameters models NARX RBF Moore-Penrose inverse

Prognostic Evaluation for Oral Squamous Cell Carcinoma:A Novel Method Based on m6A Methylation Regulators

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Current Medical Science 2022年第4期42卷 841-846页

作者： Li XU Cheng YU Xi-jin du Department of Stomatology Tongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430030China

Objective:This study aimed to examine a novel method for prognostic evaluation of patients with oral squamous cell carcinoma(OSCC)based on the expression of heterogeneous nuclear ribonucleoprotein C(HNRNPC),YTH domain-binding protein 2(YTHDF2),and methyltransferase 14(METTL14).Methods:We obtained the RNA sequence and clinical information of OSCC patients from The Cancer Genome Atlas *** optical method was established by the least absolute shrinkage and selection operator Cox regression algorithm,which was used to calculate the risk score of every *** addition,all samples(n=239)were classified into high-risk(n=119)and low-risk(n=120)groups,and the overall survival(OS)time and clinical characteristics were compared between ***,bioinformatics analysis was carried *** set enrichment analysis was performed to investigate the signaling pathways of HNRNPC,YTHDF2,and ***:The two groups showed significantly different OS time,tumor grades,tumor stages,and pathologic T stages(P<0.05).The receiver operating characteristic analysis identified that our method was effective and it was more accurate than use of age,gender,tumor grade,tumor stage,pathologic T stage,and pathologic N stage in OSCC prognostic *** set enrichment analysis revealed that HNRNPC,YTHDF2,and METTL14 were mainly associated with ubiquitin-mediated proteolysis,cell cycle,RNA degradation,and spliceosome signaling ***:The method based on the expression of HNRNPC,YTHDF2,and METTL14 can predict the prognosis of patients with OSCC independently,and its prognostic value is better than that of clinicopathological characteristic indicators.

关键词： oral squamous cell carcinoma m6A methylation regulators RNA modification prognostic prediction The Cancer Genome Atlas

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动车组齿轮箱油中硫含量的红外光谱分析

光谱学与光谱分析 2025年第1期45卷 239-245页

作者：杜瑾瑶贺石中杨智宏张琳颖张静茹广州机械科学研究院有限公司设备润滑与检测研究所广东广州510530 工业摩擦润滑技术国家地方联合工程研究中心广东广州510530

针对高铁动车组牵引系统中齿轮箱润滑油中硫元素损失较快的问题,需要对在用齿轮油硫含量进行监测,以确定最佳的换油时机。分析了红外光谱图中齿轮油含硫添加剂特征吸收峰的衰减机制;选择与硫含量相关性最高的1164 cm-1特征峰的峰高作为... 详细信息

针对高铁动车组牵引系统中齿轮箱润滑油中硫元素损失较快的问题,需要对在用齿轮油硫含量进行监测,以确定最佳的换油时机。分析了红外光谱图中齿轮油含硫添加剂特征吸收峰的衰减机制;选择与硫含量相关性最高的1164 cm-1特征峰的峰高作为输入变量构建了一元线性回归模型(LR),采用5折交叉验证下的测试集R^(2)确定最佳主成分个数构建了偏最小二乘回归模型(PLSR),最后根据偏最小二乘回归系数优选了6个特征吸收峰用于构建特征峰优化后的PLSR模型(RF-PLSR)。采用所建的模型分别对预测集39个油样进行预测,结果表明一元线性回归模型和偏最小二乘回归模型均具有很好的预测能力。一元线性回归模型的预测R^(2)为0.961,RMSE为973.1,RPD为5.084。PLSR模型和特征峰优化后的RF-PLSR模型的预测R^(2)分别为0.997和0.994,RMSE分别为250.1和376.3,RPD分别为19.780和13.149。说明经过特征峰优化后建立的RF-PLSR模型在降低模型复杂度的同时,仍可以保持较高的精度和预测能力,由于消除了不相关变量的信息,使模型的可解释性更好。红外光谱技术为齿轮油中硫含量的检测提供了一种可靠而精确的方法,为齿轮油的状态监测提供一种可行的解决方案。

关键词：齿轮箱油硫含量红外光谱在用油监测

Appendiceal bleeding caused by vascular malformation: A case report

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World Journal of Clinical Cases 2024年第14期12卷 2457-2462页

作者： Qin Ma jin-Jie du Department of General Surgery Fuling Hospital Affiliated to Chongqing UniversityChongqing 408000China Department of Geriatrics Fuling Hospital Affiliated to Chongqing UniversityChongqing 408000China

BACKGROUND Acute lower gastrointestinal bleeding(LGIB)is a common occurrence in clinical ***,appendiceal bleeding is an extremely rare condition that can easily be overlooked and *** preoperative detection of appen-diceal bleeding often poses challenges due to the lack of related guidelines and consensus,resulting in controversial treatment *** SUMMARY We presented a case of a 33-year-old female who complained of hematochezia that had lasted for 1 *** revealed continuous bleeding in the appen-diceal orifice.A laparoscopic appendectomy was performed immediately,and a pulsating blood vessel was observed in the mesangium of the appendix,accor-dingly,active bleeding into the appendicular lumen was *** examination revealed numerous hyperplastic vessels in the appendiceal mucosa and dilated capillary *** The preoperative detection of appendiceal bleeding is often challenging,colo-noscopy is extremely important,bowel preparation is not routinely recommend-ed for patients with acute LGIB or only low-dose bowel preparation is *** appendectomy is the most appropriate treatment for appendiceal bleeding.

关键词： Lower gastrointestinal bleeding Appendiceal bleeding Colonoscopy Vas-cular malformation Laparoscopic appendectomy Case report

Non-normal Hasemann Boundary Value Problem

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Wuhan University Journal of Natural Sciences 2001年第3期6卷 649-651页

作者： Cai Hao-tao du jin-yuan Coll. of Mathematics and Statistics Wuhan University Wuhan 430072 China

We will discuss the non-normal Hasemann boundary value problem: we may find these results are coincided with those of normal Hasemann boundary value problem and non-normal Riemann boundary value problem.

关键词： non-normal positive transformation canonical function