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Stability analysis of slopes with planar failure using variational calculus and numerical methods
Norly BELANDRIA, Roberto ÚCAR, Francisco M. LEÓN, Ferri HASSANI
《结构与土木工程前沿(英文)》 2020年 第14卷 第5期 页码 1262-1273 doi: 10.1007/s11709-020-0657-9
关键词: slopes stability planar failure variational calculus numerical methods
Genetic evidence in planar cell polarity signaling pathway in human neural tube defects
null
《医学前沿(英文)》 2014年 第8卷 第1期 页码 68-78 doi: 10.1007/s11684-014-0308-4
Neural tube defects (NTDs) are a group of birth anomalies having a profound physical, emotional, and financial effects on families and communities. Their etiology is complex, involving environmental and genetic factors that interact to modulate the incidence and severity of the developing phenotype. The planar cell polarity (PCP) pathway controls the process of convergent extension (CE) during gastrulation and neural tube closure and has been implicated in the pathogenesis of NTDs in animal models and human cohorts. This review summarizes the cumulative results of recent studies on PCP signaling pathway and human NTDs. These results demonstrate that PCP gene alterations contribute to the etiology of human NTDs.
关键词: planar cell polarity neural tube defects rare mutations
Static balancing of planar articulated robots
Giuseppe QUAGLIA,Zhe YIN
《机械工程前沿(英文)》 2015年 第10卷 第4期 页码 326-343 doi: 10.1007/s11465-015-0355-9
Static balancing for a manipulator’s weight is necessary in terms of energy saving and performance improvement. This paper proposes a method to design balancing devices for articulated robots in industry, based on robotic dynamics. Full design details for the balancing system using springs are presented from two aspects: One is the optimization for the position of the balancing system; the other is the design of the spring parameters. As examples, two feasible balancing devices are proposed, based on different robotic structures: The first solution consists of linkages and springs; the other consists of pulleys, cross mechanisms and (hydro-) pneumatic springs. Then the two solutions are compared. Pneumatic, hydro-pneumatic and mechanical springs are discussed and their parameters are decided according to the requirements of torque compensation. Numerical results show that with the proper design using the methodology presented in this paper, an articulated robot can be statically balanced perfectly in all configurations. This paper therefore provides a design method of the balancing system for other similar structures.
关键词: robotics static balancing pneumatic spring mechanical spring torque compensation
Cusp points and assembly changing motions in the PRR-PR-PRR planar parallel manipulator
《机械工程前沿(英文)》 2023年 第18卷 第2期 doi: 10.1007/s11465-022-0743-x
关键词: planar parallel manipulator assembly changing motions cusp points quartic polynomial discriminant of repeated roots
Yuzhang WANG, Shilie WENG, Yiwu WENG
《能源前沿(英文)》 2011年 第5卷 第2期 页码 195-206 doi: 10.1007/s11708-011-0148-8
关键词: planar solid oxide fuel cell (SOFC) direct internal reforming chemical reaction methane electrochemical
Static behavior of planar intersecting CFST connection in diagrid structure
Ling LI, Xianzhong ZHAO, Ke KE
《结构与土木工程前沿(英文)》 2011年 第5卷 第3期 页码 355-365 doi: 10.1007/s11709-011-0125-7
关键词: diagrid structure concrete-filled steel tube planar intersecting connection experimental research mechanism analysis
Polyhedral linkages obtained as assemblies of planar link groups
GÖkhan KİPER, Eres SÖYLEMEZ
《机械工程前沿(英文)》 2013年 第8卷 第1期 页码 3-9 doi: 10.1007/s11465-013-0363-6
The study aims to devise means of obtaining polyhedral linkages for homothetic deployment of polyhedral shapes by embedding planar link groups in faces of the polyhedral shape of interest. The questions of which polyhedral shapes may be suitable for such a purpose and what are the compatibility conditions for spatially assembling planar link groups are addressed. Homohedral and tangential polyhedral shapes are found to be suitable for the task and some examples of linkages are worked out.
关键词: polyhedral linkages homothety homohedra tangential polyhedra
Dynamic modeling of flexible-links planar parallel robots
DU Zhaocai, YU Yueqing, ZHANG Xuping, DU Zhaocai
《机械工程前沿(英文)》 2008年 第3卷 第2期 页码 232-237 doi: 10.1007/s11465-008-0032-3
Integrated management of cardiac failure: the cardiac failure clinic
null
《医学前沿(英文)》 2011年 第5卷 第1期 页码 20-25 doi: 10.1007/s11684-011-0106-1
The prevalence of the risk factors and the risk of cardiac failure are both increasing in China. This might be the consequence of the changes of the life conditions (emigration to the urban areas, changes in the diet and life style, lack of physical exercise, etc.). The wide range of clinical presentations of cardiac failure (acute or chronic) and of therapeutic approaches (medical or surgical) makes necessary the integration within the same structure of the various experts involved in the diagnosis and the treatment of cardiac diseases. Technologic and human resources required to offer all the options represent a multifaceted commitment which should be focused optimally in dedicated centers. In these centers, collaboration should replace competition between the medical and the surgical cardiac specialists. Development of team work should permit to optimize the cost efficacy of the treatments. Most of all, such a structure will facilitate the translation of innovative therapies between the research centers and clinical facilities.
关键词: cardiac failure cardiac transplantation mechanical circulatory support
Loss of liver kinase B1 causes planar polarity defects in cochlear hair cells in mice
null
《医学前沿(英文)》 2016年 第10卷 第4期 页码 481-489 doi: 10.1007/s11684-016-0494-3
The tumor suppressor gene liver kinase B1 (LKB1), also called STK11, encodes a serine/threonine kinase. LKB1 plays crucial roles in cell differentiation, proliferation, and polarity. In this study, LKB1 conditional knockout mice (LKB1Pax2 CKO mice) were generated using Pax2-Cre mice to investigate the function of LKB1 in inner ear hair cells during early embryonic period. LKB1Pax2 CKO mice died perinatally. Immunofluorescence and scanning electron microscopy revealed that stereociliary bundles in LKB1Pax2 CKO mice were clustered and misoriented, respectively. Moreover, ectopic distribution of kinocilium bundles resulting from abnormal migration of kinocilium was observed in the mutant mice. The orientation of stereociliary bundles and the migration of kinocilia are critical indicators of planar cell polarity (PCP) of hair cells. LKB1 deficiency in LKB1Pax2 CKO mice thus disrupted hair cell planar polarity during embryonic development. Our results suggest that LKB1 is required in PCP formation in cochlear hair cells in mice.
关键词: LKB1 stereociliary bundles kinocilium planar cell polarity hearing mice
Analysis of the dynamic stress of planar flexible-links parallel robots
DU Zhaocai, YU Yueqing, YANG Jianxin
《机械工程前沿(英文)》 2007年 第2卷 第2期 页码 152-158 doi: 10.1007/s11465-007-0025-7
关键词: numerical simulation Due coupling software SAMCEF flexibility
Progressive failure analysis of notched composite plate by utilizing macro mechanics approach
《结构与土木工程前沿(英文)》 2021年 第15卷 第3期 页码 623-642 doi: 10.1007/s11709-021-0726-8
关键词: progressive failure notched composite plate Hashin failure criterion macro mechanics approach finite element method
Huaqiang CHU, Qiang CHENG, Huaichun ZHOU, Fengshan LIU
《能源前沿(英文)》 2011年 第5卷 第2期 页码 149-158 doi: 10.1007/s11708-010-0124-8
Guangbo HAO,Haiyang LI,Suzen KEMALCAN,Guimin CHEN,Jingjun YU
《机械工程前沿(英文)》 2016年 第11卷 第2期 页码 129-134 doi: 10.1007/s11465-016-0392-z
In order to accurately model compliant mechanism utilizing plate flexures, qualitative planar stress (Young’s modulus) and planar strain (plate modulus) assumptions are not feasible. This paper investigates a quantitative equivalent modulus using nonlinear finite element analysis (FEA) to reflect coupled factors in affecting the modelling accuracy of two typical distributed-compliance mechanisms. It has been shown that all parameters have influences on the equivalent modulus with different degrees; that the presence of large load-stiffening effect makes the equivalent modulus significantly deviate from the planar assumptions in two ideal scenarios; and that a plate modulus assumption is more reasonable for a very large out-of-plane thickness if the beam length is large.
关键词: coupling factors modelling accuracy compliant mechanisms equivalent modulus
张美麟,张晔,杨治义
《中国工程科学》 2002年 第4卷 第6期 页码 5-8
提出了一种关于自由度平面闭链机构的构型方法,即“平面图形构造方法”。利用这种方法进行机构结构综合的主要过程是:先根据机械功能确定运动链的组成成分;再按这些成分构造平面图;最后在平面图上进行机构的构型和变异,并将其中结构最优者转换为机构简图。
标题 作者 时间 类型 操作
Stability analysis of slopes with planar failure using variational calculus and numerical methods
Norly BELANDRIA, Roberto ÚCAR, Francisco M. LEÓN, Ferri HASSANI
期刊论文
Numerical investigation of the chemical and electrochemical characteristics of planar solid oxide fuel
Yuzhang WANG, Shilie WENG, Yiwu WENG
期刊论文
Static behavior of planar intersecting CFST connection in diagrid structure
Ling LI, Xianzhong ZHAO, Ke KE
期刊论文
Dynamic modeling of flexible-links planar parallel robots
DU Zhaocai, YU Yueqing, ZHANG Xuping, DU Zhaocai
期刊论文
Analysis of the dynamic stress of planar flexible-links parallel robots
DU Zhaocai, YU Yueqing, YANG Jianxin
期刊论文
Nongray radiation from gas and soot mixtures in planar plates based on statistical narrow-band spectral
Huaqiang CHU, Qiang CHENG, Huaichun ZHOU, Fengshan LIU
期刊论文
Understanding coupled factors that affect the modelling accuracy of typical planar compliant mechanisms
Guangbo HAO,Haiyang LI,Suzen KEMALCAN,Guimin CHEN,Jingjun YU
期刊论文