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141.
Straightness Measurement Using Laser Diode and CCD Camera 总被引:4,自引:0,他引:4
HAO Qun ZHAO Yang LI Dacheng CAO Mang 《Chinese Journal of Lasers》1999,8(3):215-220
1IntroductionInmanufactureandasembleofmodernmachinesandinstruments,anindispensablerequirementisthecontrolofformandpositionero... 相似文献
142.
G. Teters 《Mechanics of Composite Materials》2005,41(5):461-466
Multicriteria optimization of the structure and geometry of a laminated anisotropic composite plate subjected to the thermal
and biaxial action is considered. From known properties of the monolayer and the given values of variable structural parameters,
the thermoelastic properties of the layered composite are determined. The criteria to be optimized—the transverse critical
load and the longitudinal thermal stresses—depend on two variable design parameters of composite properties and temperature.
In the space of the optimization criteria, the domain of allowable solutions and the Pareto-optimal subdomain are found.
__________
Translated from Mekhanika Kompozitnykh Materialov, Vol. 41, No. 5, pp. 683–690, September–October, 2005. 相似文献
143.
Compromise optimization of a rectangular composite plate subjected to biaxial thermal loading and buckling under the action of shear 总被引:1,自引:1,他引:0
G. Teters 《Mechanics of Composite Materials》2008,44(4):325-330
The compromise optimization of the structure and geometry of a laminated anisotropic composite plate subjected to biaxial
thermal shear loading is considered. From the known properties of the monolayer and given values of a variable structural
parameter, the thermoelastic properties of the layered composite are determined. The optimization criteria — the critical
shear load and the longitudinal and transverse thermal stresses — depend on two variable design parameters of composite properties
and temperature. In the space of optimization criteria, the domain of allowable solutions and the Pareto-optimal subregion
are found.
__________
Translated from Mekhanika Kompozitnykh Materialov, Vol. 44, No. 4, pp. 471–478, July–August, 2008. 相似文献
144.
Hiroshi Tsukahara Tsuneya Ando 《Physica E: Low-dimensional Systems and Nanostructures》2005,29(3-4):614
The density of states and the conductivity are calculated in lateral superlattices with disorder in the period within a self-consistent Born approximation. Although the potential loses its periodicity on average due to disorder, it leads to an opening up of a pseudo-band-gap and modifies the conductivity perpendicular to the superlattice even qualitatively, when the energy reaches the zone boundary. 相似文献
145.
146.
A fourth-order variational inequality of the second kind arising in a plate frictional bending problem is considered. By using regularization method, the original problem can be formulated as a differentiable variational equation, and the corresponding discrete FEM variational equation is presented afterwards. Abstract error estimates and error estimates of the approximation are derived in terms of energy norm and L^2-norm. 相似文献
147.
Yongyang JIN 《数学年刊B辑(英文版)》2008,29(5):567-574
The author obtains some weighted Hardy-type inequalities on H-type groups and anisotropic Heisenberg groups. These inequalities generalize some recent results due to N. Garofalo, E. Lanconelli, I. Kombe and P. Niu et al. 相似文献
148.
Anisotropic energy distribution of sputtered atoms induced by low energy heavy ion bombardment 总被引:1,自引:0,他引:1
Lai Zhang 《辐射效应与固体损伤》2013,168(8):337-347
The theory of anisotropic sputtering published in Phys. Rev. B 71(2), 026101 (2005) and Radiat. Effects Defects Solids 159(5), 301 (2004) has been modified and used to calculate the sputtering yield energy distributions for copper, tungsten, and aluminum targets bombarded by low-energy argon ion. As usual, the electronic stopping is ignored in the analysis. The present theory (modified Sigmund’s theory) has been shown to fit the corresponding experimental results of sputtering yield energy distributions well, except for the cases where the larger ion incident angle and larger sputtering emission angles were considered. The larger discrepancy between the present theory and the experimental result in the latter cases is probably due to the influence of direct recoil atoms on the energy spectrum. Compared with Falcone’s analytical theory, the present theory can reproduce much better experimental results of sputtering phenomena. The fact clearly demonstrates the intrinsic relation between the ion–energy dependence of the total sputtering yield and the sputtering yield energy distribution and suggests the great importance of momentum deposited on the target surface in the physical sputtering 相似文献
149.
CHEN Wanji 《中国科学G辑(英文版)》2006,49(2):213-227
Theoretically, the constant stress patch test is not rigorous. Also, either the patch test of non-zero constant shear for
Mindlin plate problem or non-zero strain gradient curvature of the microstructures cannot be performed. To improve the theory
of the patch test, in this paper, based on the variational principle with relaxed continuity requirement of nonconforming
element for homogeneous differential equations, the author proposed the individual element condition for passing the patch
test and the convergence condition of the element: besides passing the patch test, the element function should include the
rigid body modes and constant strain modes and satisfy the weak continuity condition, and no extra zero energy modes occur.
Moreover, the author further established a variational principle with relaxed continuity requirement of nonconforming element
for inhomogeneous differential equations, the enhanced patch test condition and the individual element condition. To assure
the convergence of the element that should pass the enhanced patch test, the element function should include the rigid body
modes and non-zero strain modes which satisfied the equilibrium equations, and no spurious zero energy modes occur and should
satisfy new weak continuity condition. The theory of the enhanced patch test proposed in this paper can be applied to both
homogeneous and inhomogeneous differential equations. Based on this theory, the patch test of the non-zero constant shear
stress for Mindlin plate and the C0–1 patch test of the non-zero constant curvature for the couple stress/strain gradient theory were established. 相似文献
150.
Lamb wave sensors array for nonviscous liquid sensing 总被引:1,自引:1,他引:0
The interdigital transducer (IDT) can excite Lamb wave in a piezoelectric plate loading with a liquid layer, and the phase
velocity of Lamb wave is associated with the properties of the liquid layer. In this paper, the concept of effective permittivity
is introduced to study the Lamb wave’s potential application in liquid sensing. Considering the measuring of ideal nonviscous
liquid, the sensors array is designed to sense the density and the dielectric constant of the liquid layer simultaneously.
Using LiNbO3 as piezoelectric material, in order to improve the sensors array sensitivity and the electro-mechanical coupling coefficient,
the optimized results including plate thicknesses and cut orientations are presented by numerical simulation. These studies
show that the Lamb wave sensors array can be potential in liquid sensing. 相似文献