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Multi-harmonic forced vibration and resonance of simple beams to moving vehicles
《结构与土木工程前沿(英文)》 页码 981-993 doi: 10.1007/s11709-023-0979-5
关键词: forced vibration linear Euler beam moving load harmonic structure frequency modulation end restraints
Evaluation of the harmonic scalpel in open surgery for abdominal aortic aneurysm
null
《医学前沿(英文)》 2012年 第6卷 第1期 页码 85-88 doi: 10.1007/s11684-012-0174-x
The harmonic scalpel is a hemostatic device primarily designed for use in laparoscopic surgery. During the last few years, many surgeons have begun to use the harmonic scalpel in open surgery. Several papers have cited the benefits of the device compared with conventional knot-tying techniques; however, no evidence showing the advantages of using the harmonic scalpel in complicated abdominal aortic aneurysm (AAA) surgery has been presented. The aim of the present study is to determine the value of the harmonic scalpel in open operation for AAA. A total of 153 patients who underwent open surgery for AAA at the Department of Vascular Surgery of Guangdong General Hospital, China between January 2001 and December 2010, were retrospectively analyzed. Open surgery performed with the harmonic scalpel on 105 patients was compared with open operation using conventional knot-tying techniques on 48 patients. The operative time, intraoperative blood loss, total postoperative drainage fluid volumes, hospital stay, and postoperative complications between the two groups were compared. The harmonic scalpel group was associated with a shorter operation time (113.2±23.6 min vs. 232.1±39.2 min, P<0.01) and lower intraoperative blood loss (126.1±96.6 ml vs. 592.1±207.2 ml, P<0.01). Postoperative drainage fluid volumes were greater in the conventional surgery group than in the harmonic scalpel group (702.1±192.8 ml vs. 198.5±97.4 ml, P<0.01). The hospital stay was shorter for the harmonic scalpel group than for the conventional surgery group (10.7±3.3 d vs. 16.5±4.7 d, P<0.05). No differences between the postoperative complications or hospital mortality of the two groups were found. The harmonic scalpel is a safe and minimally invasive tool in open surgery for AAA and is associated with shorter operative time, shorter hospital stay, and lower intraoperative blood loss and postoperative drainage fluid volumes compared with conventional knot-tying techniques.
关键词: abdominal aortic aneurysm harmonic scalpel minimally invasive
An investigation into the vibration of harmonic drive systems
M. Masoumi, H. Alimohammadi
《机械工程前沿(英文)》 2013年 第8卷 第4期 页码 409-419 doi: 10.1007/s11465-013-0275-5
Harmonic drive systems are precise and specific transmission gear systems which are beneficial in terms of the high transmission ratio and almost zero backlash. These inherent and spectacular properties result in using this mechanism in robotic and space sciences where the precision and lightwieght play an important role. This paper presents a vibration analysis of harmonic drive systems using the shell theory. Equations of vibration for the flexspline and the circular spline of the system are derived and used to find the natural frequencies for both parts and, moreover, vibration response of the system under the operating condition is calculated. Also, obtained vibration equations are utilized to study the effects of different involved parameters such as the geometry of the flexspline and its gear tooth, eccentricity, and unbalancing on the vibrational behavior of the system.
关键词: harmonic drive system strain wave gearing mechanism vibration analysis natural frequencies
《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
Mohammad Javad REZVANIL, Mohammad Hossein KARGARNOVIN, Davood YOUNESIAN
《机械工程前沿(英文)》 2011年 第6卷 第4期 页码 409-418 doi: 10.1007/s11465-011-0245-8
The response of an infinite Timoshenko beam subjected to a harmonic moving load based on the third-order shear deformation theory (TSDT) is studied. The beam is made of laminated composite, and located on a Pasternak viscoelastic foundation. By using the principle of total minimum potential energy, the governing partial differential equations of motion are obtained. The solution is directed to compute the deflection and bending moment distribution along the length of the beam. Also, the effects of two types of composite materials, stiffness and shear layer viscosity coefficients of foundation, velocity and frequency of the moving load over the beam response are studied. In order to demonstrate the accuracy of the present method, the results TSDT are compared with the previously obtained results based on first-order shear deformation theory, with which good agreements are observed.
关键词: timoshenko composite beam pasternak viscoelastic foundation third-order shear deformation theory (TSDT) harmonic moving load
Effect of harmonic distortion on electric energy meters of different metrological principles
Illia DIAHOVCHENKO, Vitalii VOLOKHIN, Victoria KUROCHKINA, Michal ŠPES, Michal KOSTEREC
《能源前沿(英文)》 2019年 第13卷 第2期 页码 377-385 doi: 10.1007/s11708-018-0571-1
关键词: current distortion electric energy meter harmonics power quality
Yixian LI; Limin SUN; Wang ZHU; Wei ZHANG
《结构与土木工程前沿(英文)》 2022年 第16卷 第4期 页码 448-460 doi: 10.1007/s11709-022-0805-5
关键词: dynamic stiffness principal component analysis response reconstruction damage localization under-determined equation
Yufei YUE, Qianming XU, Peng GUO, An LUO
《能源前沿(英文)》 2019年 第13卷 第1期 页码 16-26 doi: 10.1007/s11708-018-0572-0
关键词: tundish induction heating power supply (TIHPS) constant temperature control input harmonic current blocking load voltage feedforward
Modeling of dynamic response of poroelastic soil layers under wave loading
Mehmet Bar?? Can üLKER
《结构与土木工程前沿(英文)》 2014年 第8卷 第1期 页码 1-18 doi: 10.1007/s11709-014-0233-2
关键词: dynamic response of soils coupled flow-deformation finite elements analytical solution harmonic waves
Power quality investigation of a solar PV transformer-less grid- connected system fed DVR
Akhil GUPTA,Saurabh CHANANA,Tilak THAKUR
《能源前沿(英文)》 2014年 第8卷 第2期 页码 240-253 doi: 10.1007/s11708-014-0322-x
关键词: data-based maximum power point tracking (MPPT) total harmonic distortion (THD) proportional integral control voltage restorer pulse width modulation
Structural dynamic analysis of the orbiting scroll wrap in the scroll compressor
Yicai LIU, Yubo XIA, Peng YAN, Yinbin LI, Haibo XIE
《能源前沿(英文)》 2013年 第7卷 第1期 页码 19-25 doi: 10.1007/s11708-012-0223-9
关键词: scroll compressor orbiting scroll wrap model analysis harmonic analysis
朱瑞林,朱国林
《中国工程科学》 2012年 第14卷 第10期 页码 90-96
当偏心转子绕定轴旋转时,实际上只有其几何圆心作简谐振动(正/余弦运动),某些情况下由转子驱动的构件(如活塞)并不能作同样的简谐振动,因此在一些过程设备上应用双偏心转子时,会引起一些相关问题,如压力变化问题。为此,在分析一种过程强化装置中所采用的双偏心转子的运动规律的基础上,发现了由于偏心转子所驱动的两活塞的运动不完全对称,可能引起设备内介质压力变化的原因,并提出了相应的解决措施。
H. AFGHOUL,F. KRIM,D. CHIKOUCHE,A. BEDDAR
《能源前沿(英文)》 2016年 第10卷 第2期 页码 203-212 doi: 10.1007/s11708-015-0381-7
关键词: conventional PI controller fractional calculus (FC) total harmonic distortion (THD) Oustaloup continuous approximation (OCA) single phase active power filter (SPAPF)
《环境科学与工程前沿(英文)》 2021年 第15卷 第6期 doi: 10.1007/s11783-021-1419-1
• Pore structure affects biologically activated carbon performance.
关键词: Granular activated carbon Biologically activated carbon filter Bacterial community structure Pore structure
Hierarchical fractal structure of perfect single-layer graphene
T. Zhang, K. Ding
《机械工程前沿(英文)》 2013年 第8卷 第4期 页码 371-382 doi: 10.1007/s11465-013-0279-1
The atomic lattice structure of perfect single-layer graphene that can actually be regarded as a kind of hierarchical fractal structure from the perspective of fractal geometry was studied for the first time. Three novel and special discoveries on hierarchical fractal structure and sets were unveiled upon examination of the regular crystal lattices of the single-layer graphene. The interior fractal-type structure was discovered to be the fifth space-filling curve from physical realm. Two efficient methods for calculating the fractal dimension of this fresh member was also provided. The outer boundary curve had a fractal dimension equal to one, and a multi-fractal structure from a naturally existing material was found for the first time. A series of strict self-similar hexagons comprised a rotating fractal set. These hexagons slewed at a constant counterclockwise angle of 19.1° when observed from one level to the next higher level. From the perspective of fractal geometry, these pioneering discoveries added three new members to the existing regular fractal structures and sets. A fundamental example of a multi-fractal structure was also presented.
关键词: hierarchical fractal structure fractal dimension the fifth space-filling curve multi-fractal structure
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
Dynamic analysis of composite beam subjected to harmonic moving load based on the third-order shear deformation
Mohammad Javad REZVANIL, Mohammad Hossein KARGARNOVIN, Davood YOUNESIAN
期刊论文
Effect of harmonic distortion on electric energy meters of different metrological principles
Illia DIAHOVCHENKO, Vitalii VOLOKHIN, Victoria KUROCHKINA, Michal ŠPES, Michal KOSTEREC
期刊论文
A dynamic stiffness-based framework for harmonic input estimation and response reconstruction considering
Yixian LI; Limin SUN; Wang ZHU; Wei ZHANG
期刊论文
Constant temperature control of tundish induction heating power supply for metallurgical manufacturing
Yufei YUE, Qianming XU, Peng GUO, An LUO
期刊论文
Modeling of dynamic response of poroelastic soil layers under wave loading
Mehmet Bar?? Can üLKER
期刊论文
Power quality investigation of a solar PV transformer-less grid- connected system fed DVR
Akhil GUPTA,Saurabh CHANANA,Tilak THAKUR
期刊论文
Structural dynamic analysis of the orbiting scroll wrap in the scroll compressor
Yicai LIU, Yubo XIA, Peng YAN, Yinbin LI, Haibo XIE
期刊论文
Robust switched fractional controller for performance improvement of single phase active power filter under unbalanced conditions
H. AFGHOUL,F. KRIM,D. CHIKOUCHE,A. BEDDAR
期刊论文
Influence of pore structure on biologically activated carbon performance and biofilm microbial characteristics
期刊论文