scholarly journals Concept System and Application of Point Group Symmetry in Mechanical Structure Design

Symmetry ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1507
Author(s):  
Xiuming Chen ◽  
Qingying Qiu ◽  
Chao Yang ◽  
Peien Feng
Keyword(s):  
Point Group ◽  
Radial Force ◽  
Structure Design ◽  
Group Symmetry ◽  
Gear Pump ◽  
Point Group Symmetry ◽  
Concept System ◽  
Selection Principles ◽  
New Type ◽  
Almost All

Symmetry has been widely and deeply researched in basic science, and many mature results have been obtained so far. However, the widespread existence of symmetry in applied science is not in direct proportion to the attention it has received. Through a large number of examples studies, almost all mechanical structures are found to have symmetry, and most of them have the characteristics of point group symmetry. Therefore, the concept of point group symmetry in crystallography was extended to the field of machinery and adjusted according to the mechanical structures. First of all, the classification of mechanical point group symmetry is proposed, and how point group symmetry is applied in machinery is illustrated with examples. Then, the requirements of symmetry are analyzed and compared. Furthermore, the data mining software RapidMiner is used to mine the association rules between requirements and symmetry. Based on the mining results, the four selection principles of point group symmetry are summarized to provide ideas for structure design. Finally, a new type of gear pump with radial force balancing is invented by comprehensively using the mining results and selection principles.

Gas Phase Spin Relaxation of ZX3Y Molecules in the Dipolar Approximation

1975 ◽  
Vol 53 (7) ◽  
pp. 723-738 ◽  
Author(s):  
B. C. Sanctuary ◽  
R. F. Snider
Keyword(s):  
Kinetic Theory ◽  
Gas Phase ◽  
Magnetic Relaxation ◽  
Dipolar Coupling ◽  
Point Group ◽  
Group Symmetry ◽  
Subsequent Paper ◽  
Point Group Symmetry ◽  
Proper Treatment ◽  
Gas Kinetic Theory

The gas kinetic theory of nuclear magnetic relaxation of a polyatomic gas, as formulated in the previous paper, is evaluated for ZX3Y molecules relaxing via a dipolar coupling Hamiltonian. Stress is given to a proper treatment of point group symmetry, here C3v, and the possibility of molecular inversion is included. The detailed formula for the spin traces is however restricted to X nuclei with spin 1/2. A subsequent paper uses these results to elucidate the structure of the high density dependence of T1 forCF3H.

scholarly journals Spin-reversal energy barriers of 305 K for Fe2+ d6 ions with linear ligand coordination

Nanoscale ◽  
2017 ◽  
Vol 9 (30) ◽  
pp. 10596-10600 ◽  
Author(s):  
Lei Xu ◽  
Ziba Zangeneh ◽  
Ravi Yadav ◽  
Stanislav Avdoshenko ◽  
Jeroen van den Brink ◽  
...  
Keyword(s):  
Solid State ◽  
Magnetic Anisotropy ◽  
Point Group ◽  
Group Symmetry ◽  
Point Group Symmetry ◽  
State Matrix ◽  
Magnetic Anisotropy Energy ◽  
Spin Reversal ◽  
Ligand Coordination ◽  
Li Ion

A remarkably large magnetic anisotropy energy of 305 K is computed by quantum chemistry methods for divalent Fe2+ d6 substitutes at Li-ion sites with D6h point-group symmetry within the solid-state matrix of Li3N.

Tunable double Weyl phonons driven by chiral point group symmetry

2021 ◽  
Vol 103 (10) ◽  
Author(s):  
Y. J. Jin ◽  
Z. J. Chen ◽  
X. L. Xiao ◽  
H. Xu
Keyword(s):  
Point Group ◽  
Group Symmetry ◽  
Point Group Symmetry

scholarly journals Dodecaallylhexasilacyclohexane

IUCrData ◽  
2017 ◽  
Vol 2 (6) ◽  
Author(s):  
Yoshiyuki Mizuhata ◽  
Yamato Omatsu ◽  
Norihiro Tokitoh
Keyword(s):  
Title Compound ◽  
Point Group ◽  
Chair Conformation ◽  
Group Symmetry ◽  
Point Group Symmetry ◽  
Compound C

The molecule of the title compound, C36H60Si6, exhibits point group symmetryCi, with the centre of inversion located at the centre of the Si6ring. The Si6ring has a chair conformation. In the crystal, molecules are linkedviaC—H...π(allyl) interactions.

scholarly journals Synthesis, structure determination and characterization by UV–Vis and IR spectroscopy of bis(diisopropylammonium) cis-dichloridobis(oxalato-κ2 O 1,O 2)stannate(IV)

2019 ◽  
Vol 75 (6) ◽  
pp. 742-745
Author(s):  
Bougar Sarr ◽  
Abdou Mbaye ◽  
Cheikh Abdoul Khadir Diop ◽  
Mamadou Sidibe ◽  
Yoann Rousselin
Keyword(s):  
Crystal Structure ◽  
Metal Ion ◽  
Point Group ◽  
Chain Structure ◽  
Chloride Ions ◽  
Group Symmetry ◽  
Point Group Symmetry ◽  
Chloride Dihydrate ◽  
Distorted Octahedral Coordination ◽  
Distorted Octahedral

The organic–inorganic title salt, (C6H16N)2[Sn(C2O4)2Cl2] or ( i Pr2NH2)2[Sn(C2O4)2Cl2], was obtained by reacting bis(diisopropylammonium) oxalate with tin(IV) chloride dihydrate in methanol. The SnIV atom is coordinated by two chelating oxalate ligands and two chloride ions in cis positions, giving rise to an [Sn(C2O4)2Cl2]2− anion (point group symmetry 2), with the SnIV atom in a slightly distorted octahedral coordination. The cohesion of the crystal structure is ensured by the formation of N—H...O hydrogen bonding between (iPr2NH2)+ cations and [SnCl2(C2O4)2]2− anions. This gives rise to an infinite chain structure extending parallel to [101]. The main inter-chain interactions are van der Waals forces. The electronic spectrum of the title compound displays only one high intensity band in the UV region assignable to ligand–metal ion charge-transfer (LMCT) transitions. An IR spectrum was also recorded and is discussed.

Pseudo-symmetry in multiple twinned crystals having M3M point group symmetry

1971 ◽  
Vol 2 (12) ◽  
pp. 3485-3486 ◽  
Author(s):  
Santiago Harriague ◽  
Harry A. Leibovich
Keyword(s):  
Point Group ◽  
Group Symmetry ◽  
Point Group Symmetry

WHICH WILL WIN IN THE GEAR PUMP TECHNOLOGY

2013 ◽  
Vol 37 (1) ◽  
pp. 129-134 ◽  
Author(s):  
Hai-Lin Zhu ◽  
Jun Pan ◽  
Min Zou ◽  
Hong-Nen Wu ◽  
Xingpei Qin
Keyword(s):  
Working Life ◽  
Radial Pressure ◽  
Radial Force ◽  
Gear Pump ◽  
Ring Gear ◽  
Flow Pulsation ◽  
Gear Pumps ◽  
New Type ◽  
Flexible Ring ◽  
Short Working

There exist three major problems in current gear pumps. They are unbalanced radial force, big excessive flow pulsation and short working life. In order to solve the problems above, a new type of gear pump with flexible ring gear is introduced. Pumping action is achieved through meshing between a flexible ring gear and a rigid external gear. Thus radial pressure forces are hydraulically balanced and the volumetric displacement is doubled for the new pump.

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