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期刊论文 7

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2019 1

2011 1

2009 1

2008 2

2007 1

2001 1

关键词

Griewank；双尺度结构；多尺度量子谐振子算法；量子隧道效应 1

低频振荡 1

分歧理论 1

奇异 1

弹性应变能密度 1

断裂判据 1

潜在危险区（带） 1

煤与瓦斯突出 1

矿井中的动力现象 1

稳定性系数 1

非线性 1

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电力系统低频振荡中的非线性奇异现象

马景兰,王伟,万京生,张永丽

《中国工程科学》 2009年 第11卷 第8期   页码 93-96

摘要：

低频振荡是影响电力系统稳定运行的一个重要方面。阐述了低频振荡产生的机理和分析方法，利用Hopf分歧理论，针对一个四阶模型的单机无穷大系统，分析了在临界点附近时可能出现的非线性奇异现象。研究表明：由于分歧的存在，导致系统稳定性在临界点附近出现奇异，从而影响了电力系统的稳定域。

关键词： 低频振荡     分歧理论     非线性     奇异    

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Vibration analysis of medium and small span bridges subjected to mixed marshalling freight trains

LI Qi, WU Dingjun, HUANG Xiaobin

《结构与土木工程前沿（英文）》 2008年 第2卷 第2期   页码 133-138 doi: 10.1007/s11709-008-0019-5

摘要： It has been reported several times that train derailment occurs when mixed marshalling freight trains traverse bridges at high speeds in China. This study aims to explain this phenomenon numerically based on the train-bridge coupling vibration theory and its associated computer program. The train-bridge vibration characteristic is analyzed by a computer program when mixed marshalling freight trains traverse 32-meter-span prestressed concrete simple beam bridges. The mechanism that dynamic responses of the bridges are prominent and that empty trains are inclined to derail are derived from the dynamic responses analysis. The analysis indicates that the significant differences of axle loads between heavy vehicles and empty vehicles produce periodic forced loadings of large amplitudes. These periodic loadings cause severe vibration of bridges. In turn, severe vibration of the bridges produces intensive counteraction to empty vehicles.

关键词： train-bridge vibration     vibration characteristic     associated computer     train-bridge     phenomenon    

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Experimental study of structural damage identification based on modal parameters and decay ratio of acceleration signals

Zhigen WU, Guohua LIU, Zihua ZHANG

《结构与土木工程前沿（英文）》 2011年 第5卷 第1期   页码 112-120 doi: 10.1007/s11709-010-0069-3

摘要： A novel damage assessment method based on the decay ratio of acceleration signals (DRAS) was proposed. Two experimental tests were used to show the efficiency. Three beams were gradually damaged, and then the changes of dynamic parameters were monitored from initial to failure state. In addition, a new method was compared with the linear modal-based damage assessment using wavelet transform (WT). The results clearly show that DRAS increases in linear elasticity state and microcrack propagation state, while DRAS decreases in macrocrack propagation state. Preliminary analysis was developed considering the beat phenomenon in the nonlinear state to explain the turn point of DRAS. With better sensibility of damage than modal parameters, probably DRAS is a promising damage indicator in damage assessment.

关键词： damage assessment     decay ratio of acceleration signals (DRAS)     wavelet transform (WT)     modal analysis     reinforced concrete beam     beat phenomenon    

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Piezoelectric diffuser/nozzle micropump with double pump chambers

WANG Wei, ZHANG Ying, TIAN Li, CHEN Xiaojie, LIU Xiaowei

《机械工程前沿（英文）》 2008年 第3卷 第4期   页码 449-453 doi: 10.1007/s11465-008-0076-4

摘要： To eliminate check valve fatigue and valve clogging, diffuser/nozzle elements are used for flow rectification in a valveless diffuser/nozzle micropump instead of valves. However, the application of this type of micropump is restricted because of its pulsating or periodic flow and low pump flux. In this paper, a diffuser/nozzle Si/Glass micropump with two pump chambers by IC and MEMS technology is designed. The fabrication process requires only one mask and one etch step, so that the fabrication has the advantages of low cost, short processing period, and facilitation of miniaturization. The pump is equipped with a glass cover board so as to conveniently observe the flow status. Pump-chambers and diffuser elements are fabricated by the anisotropic KOH-etch technique on the silicone substrate, and the convex corner is designed to compensate for an anisotropic etch. The driving force of the micropump is produced by the PZT piezoelectric actuator. The pump performance with both actuators actuated in anti- or same-phase mode is also researched. The result indicates that the micropump achieves great performance with the actuators working at anti-phase. This may be because the liquid flows steadily, pulse phenomenon is very weak, and the optimal working frequency, pump back pressure, and flow rate are both double that of the pump driven in same-phase.

关键词： diffuser/nozzle Si/Glass     phenomenon     rectification     diffuser/nozzle micropump     frequency    

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煤与瓦斯突出潜在危险区（带）预测

鲜学福,许江,王宏图

《中国工程科学》 2001年 第3卷 第2期   页码 39-46

摘要：

煤矿的生产和实践证明，发生在矿井中的动力现象具有分区和成带的特点。文章探讨了把煤、岩和瓦斯作为一个体系，采用力学方法的划分问题。根据对煤岩复合样及含瓦斯煤样在复杂应力状态下力学性质的分析，基于对Drucker-prager理论的修正和完善，建立了它们的断裂判据，并给出了计算稳定性系数和潜在弹性应变能密度的公式，提出了按这两个指标划分煤与瓦斯突出潜在危险区（带）的基本方法。

关键词： 矿井中的动力现象     煤与瓦斯突出     潜在危险区（带）     断裂判据     稳定性系数     弹性应变能密度    

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Pluripotent stem cells exhibiting similar characteristics can be isolated from human fetal bone marrow, heart, liver, muscle, lung, derma, kidney, and fat

FANG Baijun, SONG Yongping, LIN Quande, ZHAO Chunhua, SHI Mingxia

《医学前沿（英文）》 2007年 第1卷 第2期   页码 185-191 doi: 10.1007/s11684-007-0035-1

摘要： Previously, we reported that a cell population derived from human fetal bone marrow (BM), termed here Flk1CD34 postembryonic pluripotent stem cells (PPSCs) that have the characteristics of mesenchymal stem cells (MSCs), could differentiate into ectodermal, endodermal and mesodermal cell types at the single cell level , and that these cells could also differentiate into the epithelium of liver, lung, gut, as well as the hematopoietic and endothelial lineages after transplantion into irradiated non-obese diabetic/severe combined immunodeficient (NOD/SCID) mice. In this study, we further isolated pluripotent stem cells from human fetal heart, liver, muscle, lung, derma, kidney, and fat and then analyzed the characteristics and function of these stem cells. It was found that the phenotype of the culture-expanded pluripotent stem cells from different fetal tissues was similar to BM-derived Flk1CD34 PPSCs, i.e. Flk1 and CD44 positive, GlyA, CD34, CD45, class I-HLA and HLA-DR negative. Morphologically, these cells were fibroblast-like and the doubling time was about 30 h. More importantly, culture-expanded pluripotent stem cells from all these fetal tissues were able to differentiate into cells with morphologic and phenotypic characteristics of adipocytes, osteocytes, neurons, glial cells and hepatocytes. These pluripotent stem cells with characteristics similar to fetal BM-derived Flk1CD34 PPSCs can be selected and cultured from tissues other than the BM. This phenomenon may help explain the stem cell plasticity found in multiple human tissues. In addition, as fetal BM-derived Flk1CD34 PPSCs, these pluripotent stem cells from different fetal tissues had the capacity for self-renewal and multi-lineage differentiation even after being expanded for more than 40 population doublings . Thus, they may be an ideal source of stem cells for treatment of inherited or degenerative diseases.

关键词： endothelial     phenomenon     ectodermal     Flk1CD34 postembryonic     irradiated non-obese    

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Griewank函数优化过程中的独特现象研究 Research Article

Yan Huang, Jian-ping Li, Peng Wang,hep128@qq.com,jpli2222@uestc.edu.cn,qhoalab@163.com

《信息与电子工程前沿（英文）》 2019年 第20卷 第10期   页码 1344-1360 doi: 10.1631/FITEE.1900155

摘要： Griewank函数是一类由二次凸函数和振荡非凸函数构成的典型多模测试函数。这两个组成部分在不同维数下显示出不同的相对重要性。不同于其他多数测试函数，随着函数维数增加，Griewank函数在优化过程出现优化难度先变难、后变易的现象。本文首先通过结构分析、数学分析和量子分析，从方法论角度解释该现象。然后，通过频率变换和幅度变换对Griewank函数作一般化处理。运用具有量子隧道效应的多尺度量子谐振子算法验证Griewank函数特性。实验结果表明Griewank函数的双尺度结构是该现象的主要原因。本文所提量子隧道效应可用于多种群体优化算法中分析解的生成和变化。

关键词： Griewank；双尺度结构；多尺度量子谐振子算法；量子隧道效应    

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标题 作者 时间 类型 操作

电力系统低频振荡中的非线性奇异现象

马景兰,王伟,万京生,张永丽

期刊论文

Vibration analysis of medium and small span bridges subjected to mixed marshalling freight trains

LI Qi, WU Dingjun, HUANG Xiaobin

期刊论文

Experimental study of structural damage identification based on modal parameters and decay ratio of acceleration signals

Zhigen WU, Guohua LIU, Zihua ZHANG

期刊论文

Piezoelectric diffuser/nozzle micropump with double pump chambers

WANG Wei, ZHANG Ying, TIAN Li, CHEN Xiaojie, LIU Xiaowei

期刊论文

煤与瓦斯突出潜在危险区（带）预测

鲜学福,许江,王宏图

期刊论文

Pluripotent stem cells exhibiting similar characteristics can be isolated from human fetal bone marrow, heart, liver, muscle, lung, derma, kidney, and fat

FANG Baijun, SONG Yongping, LIN Quande, ZHAO Chunhua, SHI Mingxia

期刊论文

Griewank函数优化过程中的独特现象研究

Yan Huang, Jian-ping Li, Peng Wang,hep128@qq.com,jpli2222@uestc.edu.cn,qhoalab@163.com

期刊论文