Decelerating field on a bunch moving in a periodic symmetric structure

2002 ◽  
Vol 293 (1-2) ◽  
pp. 17-22 ◽  
Author(s):  
L. Schächter ◽  
D. Schieber
Keyword(s):  
Symmetric Structure ◽  
Periodic Symmetric Structure

scholarly journals Lightweight design and static analysis of lattice compressor impeller

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Yuan Zhang ◽  
Fanchun Li ◽  
Dejun Jia
Keyword(s):  
Lightweight Design ◽  
Beam Diameter ◽  
Limit Condition ◽  
Symmetric Structure ◽  
Lattice Cell ◽  
Compressor Impeller ◽  
Research Goal ◽  
Design Requirements ◽  
Periodic Symmetric Structure ◽  
Different Diameters

Abstract Taking the compressor impeller as the research object and the lightweight design as the research goal, a lattice filled lattice cell suitable for the application of rotating periodic symmetric structure is designed. Its purpose is to make the rigidity and strength of impeller adjustable and reduce the mass of impeller on the premise of meeting the design requirements. The analysis and comparison of unfilled impeller, solid impeller and lattice filled impeller with different diameters were carried out under the limit condition of 80,000 r/min. The results showed that the average circumferential deformation of lattice impeller tip with beam diameter of 0.2 mm, 0.4 mm and 1 mm was 4.84%, 3.49% and 3.71% lower than that of solid impeller. For the impeller with a lattice beam diameter of 0.4 mm, its weight can be reduced by 22.68% compared with the solid impeller. The average circumferential deformation of the tip of the lattice impeller lies between the unfilled impeller and the solid impeller. The results show that the impeller with lattice filling hub can not only reduce the weight effectively, but also improve the efficiency of the compressor.

scholarly journals Polynomial ring representations of endomorphisms of exterior powers

2021 ◽  
Author(s):  
Ommolbanin Behzad ◽  
André Contiero ◽  
Letterio Gatto ◽  
Renato Vidal Martins
Keyword(s):  
Lie Algebra ◽  
Polynomial Ring ◽  
Vertex Operators ◽  
Exterior Power ◽  
Infinite Dimensional ◽  
Symmetric Structure ◽  
Rational Polynomials ◽  
Exterior Powers ◽  
Vertex Representation ◽  
Countably Infinite

AbstractAn explicit description of the ring of the rational polynomials in r indeterminates as a representation of the Lie algebra of the endomorphisms of the k-th exterior power of a countably infinite-dimensional vector space is given. Our description is based on results by Laksov and Throup concerning the symmetric structure of the exterior power of a polynomial ring. Our results are based on approximate versions of the vertex operators occurring in the celebrated bosonic vertex representation, due to Date, Jimbo, Kashiwara and Miwa, of the Lie algebra of all matrices of infinite size, whose entries are all zero but finitely many.

scholarly journals The Classical Structure of TaCp2(H)(SiMe2H)2

1999 ◽  
Vol 23 (1) ◽  
pp. 14-15
Author(s):  
Ichiro Tanaka ◽  
Takashi Ohhara ◽  
Nobuo Niimura ◽  
Yuji Ohashi ◽  
Qian Jiang ◽  
...  
Keyword(s):  
Neutron Diffraction ◽  
Diffraction Analysis ◽  
Neutron Diffraction Analysis ◽  
Classical Structure ◽  
R Factor ◽  
Symmetric Structure ◽  
Hydride Ligand

Neutron diffraction analysis of TaCp2(H)(SiMe2H)2 (1) has revealed a symmetric structure with a classical, rather than agostic, hydride ligand: the Ta–H distance is 1.785(15) Å, the non-bonding H···Si distances are 2.189(18) and 2.190(17) Å, and the H–Ta–Si angles are 55.2(5) and 55.5(5)°; final R factor = 8.9% for 1295 reflections.

scholarly journals Weyl symmetric structure of QCD vacuum

2012 ◽  
Vol 86 (4) ◽  
Author(s):  
Y. M. Cho ◽  
D. G. Pak ◽  
P. M. Zhang ◽  
L. P. Zou
Keyword(s):  
Qcd Vacuum ◽  
Symmetric Structure

Design and analysis of a novel seven-bar mechanical servo press with dual motors inputs

2016 ◽  
Vol 231 (20) ◽  
pp. 3855-3865
Author(s):  
Chen Liu ◽  
Sheng-Dun Zhao ◽  
Jing-Xiang Li
Keyword(s):  
Metal Forming ◽  
Theoretical Study ◽  
High Capacity ◽  
High Ratio ◽  
Measured Data ◽  
Servo Motor ◽  
Symmetric Structure ◽  
Servo Press ◽  
The Press ◽  
Dynamic Analyses

This paper proposes a novel high capacity servo press system with two servo motor inputs and high ratio force amplifier mechanism for metal forming. First, the press structure was expressed. The force amplifier was made of seven-bar mechanism which possesses quick-return character and high ratio force amplifier. The symmetric structure balanced the force in horizontal direction, and dispersed the forces on two transmission routes. In theoretical study of the new structure, kinematic and dynamic analyses were obtained by examining the geometry of the structure. The performance of press was discussed by example demonstration. Finally, the kinematic experiments and metal forming experiments were carried out on the prototype machine by using grating scale system. The measured data match the theoretical calculation well, which validates the feasibility of this new press mechanism.

The Parallel Mechanism and Variable Acceleration Control Method

2013 ◽  
Vol 579-580 ◽  
pp. 659-664
Author(s):  
Xiang Bo Ouyang ◽  
Ke Tian Li ◽  
Hong Jian Xia ◽  
Su Juan Wang ◽  
Huan Wei Zhou ◽  
...  
Keyword(s):  
Parallel Mechanism ◽  
Control Method ◽  
The Other ◽  
Connecting Rod ◽  
Motion Platform ◽  
The Third ◽  
Symmetric Structure ◽  
Slide Block ◽  
Operation Process ◽  
Moving Platform

t presents the parallel mechanism and variable acceleration control method, which is composed of slider, connecting rod, moving platform and linear guide etc. The motion platform is supported by three connecting rods through hinging, the other end of the connecting rods are respectively hinged with two sliders. Among them two pairs of connecting rod, two sliders and the moving platform formed a symmetric structure that is the so called Parallel Mechanism. The third connecting rod is parallel to one of two connecting rods, so that the two parallel connecting rods, slide block and the moving platform formed a parallelogram structure, it makes that the moving platform is always parallel to liner guiderail in the process of movement. By controlling the two sliders moving in the way of variable acceleration, it can make the trajectory curve, speed curve and acceleration curve of the moving platform are continuous, smooth, so impact and vibration of the moving platform is limited in the operation process.

scholarly journals Contrasting Impacts of Three Extreme El Niños on Double ITCZs over the Eastern Pacific Ocean

Atmosphere ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 424
Author(s):  
Yinlan Chen ◽  
Li Yan ◽  
Gen Li ◽  
Jianjun Xu ◽  
Jingchao Long ◽  
...  
Keyword(s):  
Pacific Ocean ◽  
El Niño ◽  
El Nino ◽  
Intertropical Convergence Zone ◽  
Sea Surface ◽  
Eastern Pacific ◽  
Eastern Pacific Ocean ◽  
Symmetric Structure ◽  
Double Itcz ◽  
Sst Warming

In the recent four decades, there were three record-breaking El Niño events: 1982/1983, 1997/1998, and 2015/2016 events. A double intertropical convergence zone (ITCZ) pattern distinctively emerges over the eastern Pacific Ocean during boreal spring. Based on reanalysis (ERA-Interim) during 1979–2018, this study examines how these three extreme El Niños modulate such double ITCZs. The 1982/1983 and 1997/1998 El Niños moved both northern and southern ITCZs equatorward to form an individual and broad equatorial ITCZ. In contrast, the regulation of 2015/2016 El Niño was unique with a strengthened southern ITCZ to form a symmetric double-ITCZ. The above differences can be attributed to the different meridional structures of sea surface temperatures (SSTs). For the 1982/1983 and 1997/1998 El Niños, there was a meridionally symmetric structure of SST warming with a maximum at the equator. While for 2015/2016 El Niño, there was a meridionally symmetric structure of SST warming with a minimum at the equator.

Interaction Between Coriolis Forces and Mistuning on a Cyclic Symmetric Structure With Geometrical Nonlinearity

2020 ◽  
Author(s):  
Anthony Tacher ◽  
Fabrice Thouverez ◽  
Jason Armand
Keyword(s):  
Standing Wave ◽  
Geometrical Nonlinearity ◽  
Numerical Approach ◽  
Travelling Wave ◽  
Lumped Parameter Model ◽  
Coriolis Forces ◽  
High Speeds ◽  
Symmetric Structure ◽  
Lumped Parameter ◽  
Cyclic Symmetric

Abstract An investigation of the interaction between Coriolis forces and mistuning on a cyclic symmetric structure is presented in this paper. The sensitivity of the eigenvalues and eigenvectors to mistuning is first studied with the perturbation method. A lumped parameter model is used to perform a modal analysis using a numerical approach after which geometrical nonlinearity is added to compare behavior with the linear case. Two different modes are thoroughly investigated for different rotational speeds, the first with an eigenvalue isolated from the others and the second presenting a frequency veering zone. The evolution from a standing wave domination at low speeds to a travelling wave domination at high speeds is observed for the isolated mode, whereas a standing wave domination remains around the veering zone for the second mode studied. It is also shown that the geometrical nonlinearity reinforces the mistuning effect versus the Coriolis forces.

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