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《机械工程前沿(英文)》 2022年 第17卷 第2期 doi: 10.1007/s11465-022-0674-6
关键词: harmonic drive meshing flexibility matrix meshing force loading backlash flexspline contact analysis
Gear fault diagnosis using gear meshing stiffness identified by gearbox housing vibration signals
《机械工程前沿(英文)》 2022年 第17卷 第4期 doi: 10.1007/s11465-022-0713-3
关键词: gearbox fault diagnosis meshing stiffness identification transfer path signal processing
Hao XIE,Ruo-feng TONG
《信息与电子工程前沿(英文)》 2016年 第17卷 第1期 页码 32-40 doi: 10.1631/FITEE.1500171
矢量图形作为光栅图像的一种几何表示形式,具有许多优点,例如,定义独立性和编辑功能。将栅格图像转换为矢量图形的一种流行方法是图像网格划分,其目的是找到一个网格以尽可能忠实地表示图像。对于传统的网格划分算法,问题的症结主要在于目标的高非线性度和非平滑度,这使得很难找到理想的最优解。为了改善这种情况,我们提出了一种层次优化算法,解决了从较粗级别到较细级别的问题,并为每个级别提供了其较粗的提升的初始化功能。为了进一步简化问题,将原始的非凸问题转换为线性最小二乘,从而变成凸的,这使问题更容易解决。字典学习框架用于将几何和拓扑完美地结合在一起。然后采用交替方案来求解两个部分。实验表明,对于大多数图像,该算法运行速度快,效果优于现有图像。
关键词: 图像网格化;层次优化;凸化
赵振宇,殷音
《中国工程科学》 2008年 第10卷 第9期 页码 84-87
讨论了工程承包联营体环境动荡性评价指标和工程承包联营体柔性评价指标以及相应的评价方法。通过柔性分析,可以判断出工程承包联营体各方面的柔性程度能否与其相应的环境和内外部因素相适应,并为制订调整联营体柔性度的措施提供帮助,进而提高联营体的管理水平和竞争力。
Effects of Boundary Condition and Helix Angle on Meshing Performance of TI Worm Gearing
SUN Yue-hai, DUAN Lu-qian, WANG Shu-ren, ZHANG Ce
《机械工程前沿(英文)》 2006年 第1卷 第1期 页码 90-95 doi: 10.1007/s11465-005-0006-7
To exactly describe the contact state and contact area of tooth surface of toroidal involute (TI) worm gearing, the authors introduced boundary condition into contact line analysis.With helix angle chosen as parameter, the criterion for the existence of meshing boundary line on the surface of TI worm gearing is derived. Results show that there can be four situations for meshing boundary line on the tooth surface of gear, namely, inexistence of meshing boundary line, a unique line, two lines, and two coincident lines. If the helix angle is equal to or slightly smaller than the bigger angle, which makes two meshing boundary lines superpose, a preferable meshing performance is obtained. Computer simulation proves the validity of the above conclusion.
关键词: preferable inexistence Results validity boundary condition
B. R. JAYALEKSHMI,S.V. JISHA,R. SHIVASHANKAR
《结构与土木工程前沿(英文)》 2015年 第9卷 第3期 页码 307-322 doi: 10.1007/s11709-015-0288-8
关键词: finite element method piled raft tall chimney soil-structure interaction along-wind load
Decellularized extracellular matrix mediates tissue construction and regeneration
《医学前沿(英文)》 2022年 第16卷 第1期 页码 56-82 doi: 10.1007/s11684-021-0900-3
关键词: decellularized extracellular matrix 3D culture organoids tissue repair
Perspective of mixed matrix membranes for carbon capture
Shinji Kanehashi, Colin A. Scholes
《化学科学与工程前沿(英文)》 2020年 第14卷 第3期 页码 460-469 doi: 10.1007/s11705-019-1881-5
Yang YU, Jiafu TANG
《工程管理前沿(英文)》 2019年 第6卷 第2期 页码 183-192 doi: 10.1007/s42524-019-0028-1
关键词: seru production production mode flexibility literature review
《机械工程前沿(英文)》 2023年 第18卷 第2期 doi: 10.1007/s11465-022-0740-0
关键词: design synthesis parallel mechanism hybrid leg mechanism screw theory quadruped robot
《结构与土木工程前沿(英文)》 页码 1100-1116 doi: 10.1007/s11709-023-0967-9
关键词: fiber-reinforced cementitious matrix flexural strengthening shear strengthening carbon fiber-reinforced polymer shear span
A dynamic model of mobile concrete pump boom based on discrete time transfer matrix method
Wu REN, Yunxin WU, Zhaowei ZHANG
《机械工程前沿(英文)》 2013年 第8卷 第4期 页码 360-366 doi: 10.1007/s11465-013-0280-8
Mobile concrete pump boom is typical multi-body large-scale motion manipulator. Due to posture constantly change in working process, kinematic rule and dynamic characteristic are difficult to solve. A dynamics model of a mobile concrete pump boom is established based on discrete time transfer matrix method (DTTMM). The boom system is divided into sub-structure A and sub-structure B. Sub-structure A is composed by the 1st boom and hydraulic actuator as well as the support. And sub-structure B is consists of the other three booms and corresponding hydraulic actuators. In the model, the booms and links are regarded as rigid elements and the hydraulic cylinders are equivalent to spring-damper. The booms are driven by the controllable hydraulic actuators. The overall dynamic equation and transfer matrix of the model can be assembled by sub-structures A and B. To get a precise result, step size and integration parameters are studied then. Next the tip displacement is calculated and compared with the result of ADAMS software. The displacement and rotation angle curves of the proposed method fit well with the ADAMS model. Besides it is convenient in modeling and saves time. So it is suitable for mobile concrete pump boom real-time monitoring and dynamic analysis. All of these provide reference to boom optimize and engineering application of such mechanisms.
关键词: multi-body mobile concrete pump boom discrete time transfer matrix method (DTTMM) kinematic dynamic tip displacement
住宅建筑需求侧柔性——定义、柔性负荷及量化方法 Review
罗正意, 彭晋卿, 曹静宇, 殷荣欣, 邹斌, 谭羽桐, 严晋跃
《工程(英文)》 2022年 第16卷 第9期 页码 123-140 doi: 10.1016/j.eng.2022.01.010
本文综述了近年来关于住宅建筑需求侧柔性的定义、柔性负荷及柔性量化方法方面的研究。首先,针对建筑需求侧柔性、运行柔性和能源柔性等不同的术语,进行了系统的比较和区分;其次,对住宅建筑主要柔性负荷的运行特性和柔性能力进行了总结和比较;再次,对柔性负荷的建模方法和柔性量化指标也进行了详细的综述和总结。最后,提出了当前建筑需求侧柔性领域存在的一些亟待解决的问题。研究结果表明当前针对住宅建筑需求侧柔性的研究主要以中央空调、储水式电热水器、湿电器、冰箱和照明为主,分别占现有研究的36.7%、25.7%、14.7%、9.2%和8.3%。这些柔性负荷在运行特性、使用频率和柔性能力
方面存在较大的差异,而对于它们实际的响应特性有待进一步研究。此外,本文给出了用于柔性负荷建模的白箱、灰箱和黑箱模型在不同应用场合下适用性的建议;对于柔性量化指标,现有研究主要从功率、时间、能量、效率、经济性和环保性等维度提出了大量的指标,但是缺少统一的柔性量化体系。本文能够帮助读者更好地理解建筑需求侧柔性、区分与柔性相关的不同的术语、了解住宅建筑不同柔性负荷的运行特性和柔性能力,同时也能为柔性负荷的建模和柔性量化的相关研究提供指导。
Hui Xue, Dike Tao, Yuteng Weng, Qiqi Fan, Shuang Zhou, Ruilin Zhang, Han Zhang, Rui Yue, Xiaogang Wang, Zuolin Wang, Yao Sun
《医学前沿(英文)》 2019年 第13卷 第5期 页码 575-589 doi: 10.1007/s11684-019-0693-9
关键词: fracture extracellular matrix dentin matrix protein 1 proteoglycan cartilage
Role of salivary matrix metalloproteinase-8 (MMP-8) in chronic periodontitis diagnosis
null
《医学前沿(英文)》 2015年 第9卷 第1期 页码 72-76 doi: 10.1007/s11684-014-0347-x
Periodontitis is an inflammatory disease of the periodontium. Any imbalance between the matrix metalloproteinases (MMPs) secreted by neutrophils and tissue inhibitors initiates the destruction of collagen in gum tissue, leading to chronic periodontitis. This study aimed to correlate salivary levels of MMP-8 and periodontal parameters of chronic periodontitis to establish MMP-8 as a noninvasive marker for the early diagnosis of chronic periodontitis. The study involved 40 subjects visiting the periodontic OPD of Dr. Ziauddin Ahmad Dental College and Hospital, located in Aligarh, U.P., India, from 2011 to 2012. The subjects were divided into two groups: group I consisted of 20 periodontally healthy subjects (controls) while group II consisted of 20 patients with chronic periodontitis. Chronic periodontitis was assessed on the basis of several periodontal parameters, including pocket probing depth (PPD), clinical attachment level (CAL), gingival index (GI), and plaque index (PI). Around 3 ml of unstimulated and whole expectorated saliva was collected for MMP-8 estimation by ELISA using Quantikine human total MMP-8 immunoassay kits. Data were analyzed using STATISTICA (Windows version 6) software. Salivary MMP-8 levels of groups I and II were 190.91±143.89 ng/ml and 348.26±202.1 ng/ml, respectively. The MMP-8 levels and periodontal status (PPD, CAL, GI, and PI) of groups I and II showed positive and significant correlations (for PPD, r = 0.63, P<0.001; for CAL, r = 0.54, P<0.001; for GI, r = 0.49, P<0.001; and for PI, r = 0.63, P<0.001). The results of this study demonstrate elevated concentrations of MMP-8 in individuals with chronic periodontitis.
关键词: matrix metalloproteinase-8 chronic periodontitis pocket probing depth clinical attachment level gingival index plaque index
标题 作者 时间 类型 操作
Meshing stiffness property and meshing status simulation of harmonic drive under transmission loading
期刊论文
Gear fault diagnosis using gear meshing stiffness identified by gearbox housing vibration signals
期刊论文
Effects of Boundary Condition and Helix Angle on Meshing Performance of TI Worm Gearing
SUN Yue-hai, DUAN Lu-qian, WANG Shu-ren, ZHANG Ce
期刊论文
Response in piled raft foundation of tall chimneys under along-wind load incorporating flexibility of
B. R. JAYALEKSHMI,S.V. JISHA,R. SHIVASHANKAR
期刊论文
Design of a novel side-mounted leg mechanism with high flexibility for a multi-mission quadruped earth
期刊论文
Strengthening of reinforced concrete beams using fiber-reinforced cementitious matrix systems fabricated
期刊论文
A dynamic model of mobile concrete pump boom based on discrete time transfer matrix method
Wu REN, Yunxin WU, Zhaowei ZHANG
期刊论文
Glycosylation of dentin matrix protein 1 is critical for fracture healing via promoting chondrogenesis
Hui Xue, Dike Tao, Yuteng Weng, Qiqi Fan, Shuang Zhou, Ruilin Zhang, Han Zhang, Rui Yue, Xiaogang Wang, Zuolin Wang, Yao Sun
期刊论文