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Stress analysis of anisotropic thick laminates in cylindrical bending using a semi-analytical approach

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第11期8卷 1740-1745页

作者： LU chao-feng LIM C.W. XU feng Department of Civil Engineering Zhejiang University Hangzhou 310027 China） Department of Building and Construction City University of Hong Kong Kowloon Hong Kong China Zhejiang Tiandi Environmental Protection Engineering Co. Ltd. Hangzhou 310012 China

Semi-analytical elasticity solutions for bending of angle-ply laminates in cylindrical bending are presented using the state-space-based differential quadrature method (SSDQM). Partial differential state equation is derived from the basic equations of elasticity based on the state space concept. Then, the differential quadrature (DQ) technique is introduced to discretize the longitu- dinal domain of the plate so that a series of ordinary differential state equations are obtained at the discrete points. Meanwhile, the edge constrained conditions are handled directly using the stress and displacement components without the Saint-Venant principle. The thickness domain is solved analytically based on the state space formalism along with the continuity conditions at interfaces. The present method is validated by comparing the results to the exact solutions of Pagano’s problem. Numerical results for fully clamped thick laminates are presented, and the influences of ply angle on stress distributions are discussed.

关键词： Semi-analytical elasticity solution State-space-based differential quadrature method (SSDQM) Angle-ply laminates Cylindrical bending

Hydrodynamic and morphological processes in Yangtze Estuary:State-of-the-art research and its applications by Hohai University

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Water Science and Engineering 2012年第4期5卷 383-398页

作者： Jin-hai ZHENG Yi-xin YAN chao-feng TONG zhi-yi LEI Chi ZHANG State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Hohai University College of Harbor Coastal and Offshore EngineeringHohai University

This paper presents a review of the state-of-the-art research and its applications developed at Hohai University relating to the hydrodynamic and morphological processes in the Yangtze Estuary. Longitudinal, lateral, and horizontal flow circulations have been revealed based on the measurements with acoustic Doppler current profilers （ADCP）. The hydrodynamic mechanism at diversion points as well as the changing patterns of flow and sediment flux in the Yangtze Estuary has been investigated through long-term data analysis. A field survey has been carried out to detect the saltwater intrusion from the North Branch to South Branch. Different numerical models of flow motion, sediment transport, and saltwater intrusion have been developed to simulate the complicated processes and to evaluate the effects of engineering projects. The morphological processes of wetlands over a time scale of decades have been analyzed with an established database. Ideas for further research on the bio-geomorphological model system and long-term evolution mechanisms are put forward.

关键词： Yangtze Estuary hydrodynamic process morphological process saltwater intrusion,Hohai University

Simplified design method and seismic performance of space trusses with consideration of the influence of the stiffness of their lower supporting columns

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Earthquake Engineering and Engineering Vibration 2016年第2期15卷 401-409页

作者： Fan feng Sun Menghan zhi Xudong Key Lab of Structures Dynamic Behavior and Control of the Ministry of Education Harbin Institute of Technology School of Civil Engineering Harbin Institute of Technology

Static and dynamic force performance of two types of space truss structures i.e. square pyramid space truss（SPST） and diagonal on square pyramid space truss（DSPST）, are studied to determine the effect of stiffness of their lower supporting members. A simplified model for the supporting columns and the equivalent spring mass system are presented. Furthermore, the feasibility of the simplified model is demonstrated through theoretical analysis and examples of comparative analysis of the simplified model with the entire model. Meanwhile, from the elastic analysis under frequently occurring earthquakes and elasto-plastic analysis under seldom occurring earthquakes subjected to TAFT and EL-Centro seismic oscillation it is shown that the simplified method can be encompassed in the results from the normal model. It also showed good agreement between the two methods, as well as greatly improved the computational efficiency. This study verified that the dynamic effect of the supporting structures was under considered in space truss design in the past. The method proposed in the paper has important significance for other space truss structures.

关键词： simplified supporting pyramid stiffness truss verified diagonal elasto columns seldom

NUMERICAL INVESTIGATION OF CAVITATION PERFORMANCE OF SHIP PROPELLERS

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Journal of Hydrodynamics 2012年第3期24卷 347-353页

作者： ZHU zhi-feng FANG Shi-liang Key Laboratory of Underwater Acoustic Signal Processing Ministry of Education Southeast University Nanjing 210096 China School of Electrical Engineering and Information Anhui University of Technology Maanshan 243002 China Key Laboratory of Underwater Acoustic Signal Processing Ministry of Education Southeast University Nanjing 210096 China

The cavitation performance of propellers is studied based on viscous multiphase flow theories. With a hybrid grid based on Navier-Stokes （N-S） and bubble dynamics equations, some recent validation results are presented in this paper in the predictions of the thrust, the torque and the vapor volume fraction on the back side of propeller blade for a uniform inflow. The numerical predictions of the hydrodynamic performance and the sheet cavitation under several operating conditions for two propellers agree with the corresponding measured data in general. The thrust and the torque are plotted with respect to the advance rate and the cavitation number. The cavitation performance breakdown is closely related to the strong sheet cavitation around propellers. The models with parameters modified are shown to predict the propeller cavitation well.

关键词： cavitation Reynolds-Averaged Navier-Stokes (RANS) propeller sliding mesh multiphase flow

In situ synthesis of palladium nanoparticles on multi-walled carbon nanotubes and their electroactivity for ethanol oxidation

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Rare Metals 2013年第6期32卷 586-591页

作者： Qing-feng Yi Li-zhi Sun School of Chemistry and Chemical Engineering Hunan University of Science and Technology

Pd nanoparticles(Pd-NPs)were prepared and directly anchored on the surface of multi-walled carbon nanotubes(MWCNTs)in the absence of chemical reduction agent,where MWCNTs were used as both the chemical reduction agent and the support substrate of *** of various surfactants on the in situ deposition of PdNPs on MWCNTs was *** MWCNTs were modified with a cationic surfactant(hexadecyl trimethyl ammonium bromide,CTAB),the amount of the Pd-NPs(Pd-NP/CTAB-MWCNT)generated by such an in situ deposition method gets a notable increase,and the size of the as-synthesized Pd-NPs becomes smaller,compared with those in the absence of any surfactant(Pd-NP/MWCNT)or in the presence of an anionic surfactant SDS(Pd-NP/SDS-MWCNT)and a neutral surfactant OP(PdNP/OP-MWCNT).Results show that the MWCNTs modified with CTAB are propitious to the in situ reduction of Pd2?.Among the prepared catalysts,Pd-NP/CTABMWCNT displays the highest electroactivity for ethanol oxidation in alkaline media.

关键词： Pd nanoparticle Multi-walled carbon nanotube Ethanol oxidation Surfactant

Study of the correlations between main shocks and aftershocks and aftershock synthesis method

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Earthquake Engineering and Engineering Vibration 2019年第4期18卷 759-775页

作者： Zhang Yingnan zhi Xudong Fan feng Key Laboratory of Structural Engineering Disaster Control of Education Ministry (Harbin Institute of Technology) Harbin 150090 China Key Laboratory of Civil Engineering Intelligent Disaster Prevention and Mitigation Control of Ministry of Industry and Information (Harbin Institute of Technology) Harbin 150090 China School of Civil Engineering Harbin Institute of Technology Harbin 150090 China

To consider the infl uence of aftershocks in engineering design, the correlations between main shocks and aftershocks should be examined, and an aftershock simulation method with main shock ground motions needs to be developed. In this study, the data on the sequences of main shock–aftershock ground motions and other related parameters were collected. Using these data, correlations between the magnitude, frequency, duration and energy of the main shock–aftershock ground motions were investigated. The results showed that the magnitude of the aftershock can be larger than that of the main shock. The shapes of the Fourier amplitude spectra of main shocks and aftershocks were similar;however, the predominant frequency and high-frequency components of the aftershock tended to be larger. Considering the magnitude diff erence between the main shock and the aftershock, the correlation of durations was explored. Additionally, a new concept, the duration ratio, was defi ned to describe the concentration of seismic energy release, and main shock energy was strongly positively correlated with the energy attenuated during the main shock–aftershock sequence. Finally, based on these results regarding correlation, an aftershock synthesis using recorded main shock ground motions was constructed with the trigonometric series method for seismic design, and some examples are given to analyze the rationality of this synthetic method.

关键词： main shock-aftershock sequence correlation aftershock synthesis seismic design

Hypoxia-preconditioned bone marrow-derived mesenchymal stem cells protect neurons from cardiac arrest-induced pyroptosis

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Neural Regeneration Research 2025年第4期20卷 1103-1123页

作者： Xiahong Tang Nan Zheng Qingming Lin Yan You Zheng Gong Yangping Zhuang Jiali Wu Yu Wang Hanlin Huang Jun Ke feng Chen Shengli Clinical Medical College of Fujian Medical University Fujian Medical UniversityFuzhouFujian ProvinceChina Department of Emergency Fujian Provincial HospitalFuzhouFujian ProvinceChina Fujian Provincial Key Laboratory of Emergency Medicine FuzhouFujian ProvinceChina The Second Department of Intensive Care Unit Fujian Provincial Hospital South BranchFuzhouFujian ProvinceChina

Cardiac arrest can lead to severe neurological impairment as a result of inflammation,mitochondrial dysfunction,and post-cardiopulmonary resuscitation neurological *** preconditioning has been shown to improve migration and survival of bone marrow–derived mesenchymal stem cells and reduce pyroptosis after cardiac arrest,but the specific mechanisms by which hypoxia-preconditioned bone marrow–derived mesenchymal stem cells protect against brain injury after cardiac arrest are *** this end,we established an in vitro co-culture model of bone marrow–derived mesenchymal stem cells and oxygen–glucose deprived primary neurons and found that hypoxic preconditioning enhanced the protective effect of bone marrow stromal stem cells against neuronal pyroptosis,possibly through inhibition of the MAPK and nuclear factor κB ***,we transplanted hypoxia-preconditioned bone marrow–derived mesenchymal stem cells into the lateral ventricle after the return of spontaneous circulation in an 8-minute cardiac arrest rat model induced by *** results showed that hypoxia-preconditioned bone marrow–derived mesenchymal stem cells significantly reduced cardiac arrest–induced neuronal pyroptosis,oxidative stress,and mitochondrial damage,whereas knockdown of the liver isoform of phosphofructokinase in bone marrow–derived mesenchymal stem cells inhibited these *** conclude,hypoxia-preconditioned bone marrow–derived mesenchymal stem cells offer a promising therapeutic approach for neuronal injury following cardiac arrest,and their beneficial effects are potentially associated with increased expression of the liver isoform of phosphofructokinase following hypoxic preconditioning.

关键词： bone marrow–derived mesenchymal stem cells cardiac arrest cardiac resuscitation hypoxic preconditioning liver isoform of phosphofructokinase mitochondria neuroinflammation oxidative stress pyroptosis reactive oxygen species

CMP体系下基于历史文脉传承的淮安城市遗产价值评估

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华中建筑 2025年第1期43卷 12-17页

作者：单超杨芮冯靖茹苏州大学建筑学院历史建筑保护工程所苏州大学建筑学院东南大学建筑学院

淮安,中国大运河线上最重要的水利枢纽城市之一。自元明清三朝定都北京,大运河重新疏浚、改线、贯通后,北方巨量的物资需求促使漕运兴盛,时值淮安城扼漕运、盐运、河工、榷关、邮驿之机杼,风光一时无两。现下,运河城市遗产的保护传承利... 详细信息

淮安,中国大运河线上最重要的水利枢纽城市之一。自元明清三朝定都北京,大运河重新疏浚、改线、贯通后,北方巨量的物资需求促使漕运兴盛,时值淮安城扼漕运、盐运、河工、榷关、邮驿之机杼,风光一时无两。现下,运河城市遗产的保护传承利用逐渐成为城市发展中的重要部分,淮安城市遗产反映着其城市文化特征,也是城市职能的直接体现。该文利用CMP(保护规划管理)从场所意义出发,对淮安城市遗产进行价值评估,并试图以此构建基于历史文脉保护利用传承导则,助推大运河文化带建设。

关键词：历史文脉淮安 CMP 城市遗产价值评估

维普期刊数据库博看期刊

A Machine Learning Framework with Feature Selection for Floorplan Acceleration in IC Physical Design

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Journal of Computer Science & Technology 2020年第2期35卷 468-474页

作者： Shu-Zheng Zhang Zhen-Yu Zhao chao-chao feng Lei Wang College of Computer Science and Technology National University of Defense TechnologyChangsha 410003China

Floorplan is an important process whose quality determines the timing closure in integrated circuit(IC)physical *** generating a floorplan with satisfying timing result is time-consuming because much time is spent on the generation-evaluation *** machine learning to the floorplan stage is a potential method to accelerate the floorplan ***,there exist two challenges which are selecting proper features and achieving a satisfying model *** this paper,we propose a machine learning framework for floorplan acceleration with feature selection and model stacking to cope with the challenges,targeting to reduce time and effort in integrated circuit physical ***,the proposed framework supports predicting post-route slack of static random-access memory(SRAM)in the early floorplan ***,we introduce a feature selection method to rank and select important *** both feature importance and model accuracy,we reduce the number of features from 27 to 15(44%reduction),which can simplify the dataset and help educate novice ***,we build a stacking model by combining different kinds of models to improve *** 28 nm technology,we achieve the mean absolute error of slacks less than 23.03 ps and effectively accelerate the floorplan process by reducing evaluation time from 8 hours to less than 60 *** on our proposed framework,we can do design space exploration for thousands of locations of SRAM instances in few seconds,much more quickly than the traditional *** practical application,we improve the slacks of SRAMs more than 75.5 ps(177%improvement)on average than the initial design.

关键词： physical design machine learning feature selection design space exploration