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111.
The structures of Y2Fe17-xCrx are simulated by the ab initio potentials. The site preference of Cr atom in Y2Fe17 is evaluated and the order is determined as 4f, 12j, which is close to the experimental result. Based on the site preference behavior, the calculated parameters and the atom sites of Y-Fe-Cr system are studied. The result corresponds well to observed data. Further, the DOS of the relaxed structures are calculated and the variation in Curie temperature is explained qualitatively by the spin-fluctuation theory. 相似文献
112.
用J─LD2转动惯量测试仪的波纹法测试转动惯量的实验方法,测量精度差,操作不方便.利用实验室现有的仪器改进成光电法测试转动惯量的方法,简单易行,测量精度高,操作方使,实践效果良好. 相似文献
113.
Liu Yongping 《数学年刊B辑(英文版)》1995,16(3):351-360
AVERAGE σ-K WIDTH OF CLASS OF L_p(R~n)IN L_q(R~n)AVERAGEσ-KWIDTHOFCLASSOFL_p(R~n)INL_q(R~n)¥LIUYONGPINGAbstract:Theaverageσ-Kwidt... 相似文献
114.
In this paper we present an application of the grid method to the assessment of crack initiation and growth in brittle materials.
It is shown that a grid deposited on the surface of a structure can be utilized to characterize the crack location and opening.
Furthermore, one single picture only is required to carry out a control over a predefined area.
First, the principle of the method is introduced, showing that a periodical pattern encoding a cracked surface can be analyzed
by signal processing. The phase modulation of the grid can be calculated very accurately for any small deformation of the
structure. Discontinuities due to cracks are easily detected on the phase field and the crack width is proportional to the
amplitude of the discontinuity. Secondly, the performances of the method are presented, mainly depending on the spatial frequency
of both the pattern and the sampling. It is shown that good results can generally be obtained with few setting difficulties
and equipment investment. Finally, we sum up some basic recommendations for the practical use of the technique. 相似文献
115.
Marcela Cecilia González-Araya Luís Alberto Duncan Rangel Marcos Pereira Estellita Lins Luiz Flávio Autran Monteiro Gomes 《Annals of Operations Research》2002,116(1-4):271-288
This paper presents an application of the UTA method for building utility functions for the evaluation criteria defined by the Staff Evaluation Commission (CAD) of the Rio de Janeiro Federal University (UFRJ). Every year, the CAD-UFRJ gives the staff evaluation results for each Postgraduate Engineering Programme. However, the method used to generate the staff evaluation is assumed unknown. Trying to find the CAD-UFRJ preference structure, the evaluation results supplied by CAD-UFRJ are used to apply the UTA method. Some additional information obtained from the CAD-UFRJ data is incorporated in the optimal solutions analysis. 相似文献
116.
在铷蒸气密度为1×10~(10)~3.4×10~(11)cm~(-3)的范围内,测量了光抽运讯号。随着密度的增加,讯号先是增大然后减小,并在密度为5.3×10~(10)cm~(-3)时达到最大值。当密度增加到26.7×10~(10)cm~(-3)时,讯号出现负值。 相似文献
117.
Li Chunming Liu Chengshi 《物理与工程》1998,(4)
本文提出了用光纤传输激光进行F-P标准具实验的方法,测量了激光的波长和谱线宽度. 相似文献
118.
Eve Bofinger 《Annals of the Institute of Statistical Mathematics》1986,38(1):445-450
Summary The selection oft out ofk populations with parameters θ
i
(i=1, ...,k) is said to result in an ψ-correct decision provided ψ (minimum selected θ)>maximum non-selected θ where ψ(θ) (>θ) is an
increasing function. For the cases of location or scale parameters the minimum probability of ψ-correct decision over the
entire parameter space is shown to be no less than the minimum probability of correct selection over a preference zone determined
by ψ(θ). For other types of parameters this result is shown to be true under certain conditions linking the distribution function
and the ψ function. 相似文献
119.
The soft mode dynamics and related properties of perovskite, ABO3-type crystals have been studied using the operator form of the model Hamiltonian proposed by Pytte. The correlations have
been evaluated using the double time thermal Green’s function technique and Dyson’s equation. Without any decoupling, the
higher order correlations, appearing in the dynamical equation, have been evaluated using the renormalized Hamiltonian. The
dielectric properties are directly related to the optical soft mode. The phonon width and shift have been calculated for different
structural phases. The analysis of the temperature dependence of microwave loss tangent and dielectric constant explains the
experimental results. 相似文献
120.
Modeling of terrain impact caused by tracked vehicles 总被引:1,自引:0,他引:1
Analytical models that can predict the terrain impact caused by tracked vehicles on a horizontal plane were developed and tested. The models included a disturbed width model and an impact severity model. Inputs of the terrain impact models included vehicle static properties, vehicle dynamic properties, and terrain properties. The tested vehicles included an M1A1 tank, an M577 Armored Personal Carrier (APC), and an M548 cargo carrier. The models were verified with field tests conducted in Yakima Training Center in Yakima, WA, Fort Riley, KS, and Camp Atterbury, Indiana. The average percentage errors of the disturbed width model for the M1A1, M577, and the M548 were 10.0%, 27.3%, and 8.5%, respectively. The average percentage errors of the impact severity model of the M1A1 and M577 were 25.0% and 21.4%, respectively. 相似文献