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1.
2.
本文给出了一种分析微带印刷天线辐射与散射的数值方法。此方法将印刷天线按三角网格剖分,在导体表面建立积分方程,用全波离散镜像理论给出微带结构的空域格林函数的闭合表达式,未知电流用三角网格上的矢量电流基函数展开并用矩量法求解。与以往的矩形网格上基函数展开相比,此方法能更有效地逼近任意形状的微带结构,最后给出了几个数值结果  相似文献   
3.
Mapping functions forward is required in image warping and other signal processing applications. The problem is described as follows: specify an integer d 1, a compact domain D R d, lattices L 1,L 2 R d, and a deformation function F : D R d that is continuously differentiable and maps D one-to-one onto F(D). Corresponding to a function J : F(D) R, define the function I = J F. The forward mapping problem consists of estimating values of J on L 2 F(D), from the values of I and F on L 1 D. Forward mapping is difficult, because it involves approximation from scattered data (values of I F -1 on the set F(L 1 $#x22C2; D)), whereas backward mapping (computing I from J) is much easier because it involves approximation from regular data (values ofJ on L 2 D). We develop a fast algorithm that approximates J by an orthonormal expansion, using scaling functions related to Daubechies wavelet bases. Two techniques for approximating the expansion coefficients are described and numerical results for a one dimensional problem are used to illustrate the second technique. In contrast to conventional scattered data interpolation algorithms, the complexity of our algorithm is linear in the number of samples.  相似文献   
4.
Adiabatic potential energy, spectroscopic constants, dipole moments, and vibrational levels of the lowest electronic states of the alkali dimer LiNa molecule dissociating into Na (3s, 3p, 4s, 3d, and 4p) + Li (2s, 2p, 3s, and 3p) in 1,3Σ, 1,3Π, and 1,3Δ symmetries are presented. Adiabatic results are also reported for 2Σ, 2Π, and 2Δ electronic states of the molecular ion LiNa+ dissociating into Li (2s, 2p, 3s, and 3p) + Na+ and Li+  + Na(3s, 3p, 4s, 3d, and 4p). We use an ab initio approach involving a non-empirical pseudopotential for the Li (1s2) and Na (1s22s22p6) cores and core valence correlation correction. A very good agreement is obtained for some lowest states of the LiNa and LiNa+ molecules for spectroscopic constants with the available theoretical works. The existence of numerous avoided crossings between electronic states of 2Σ and 2Π symmetries is related to the charge transfer process between the two ionic systems Li+Na and LiNa+.  相似文献   
5.
S N Jena  M R Behera 《Pramana》1995,44(4):357-374
A relativistic model of independent quarks based on Dirac equation with an equally mixed scalar-vector square root confining potential is used to compute the quark core contributions to the static properties like magnetic moments, charge radii and axial vector coupling constant ratios of the baryon octet. The results obtained with appropriate corrections due to centre-of-mass motion agree fairly well with experimental values. The model is also extended to the study of magnetic moments of the quark core of baryons in the charmed andb-flavoured sectors and the overall predictions so obtained compare well with other model predictions.  相似文献   
6.
Spectral- and cepstral-based acoustic measures are preferable to time-based measures for accurately representing dysphonic voices during continuous speech. Although these measures show promising relationships to perceptual voice quality ratings, less is known regarding their ability to differentiate normal from dysphonic voice during continuous speech and the consistency of these measures across multiple utterances by the same speaker. The purpose of this study was to determine whether spectral moments of the long-term average spectrum (LTAS) (spectral mean, standard deviation, skewness, and kurtosis) and cepstral peak prominence measures were significantly different for speakers with and without voice disorders when assessed during continuous speech. The consistency of these measures within a speaker across utterances was also addressed. Continuous speech samples from 27 subjects without voice disorders and 27 subjects with mixed voice disorders were acoustically analyzed. In addition, voice samples were perceptually rated for overall severity. Acoustic analyses were performed on three continuous speech stimuli from a reading passage: two full sentences and one constituent phrase. Significant between-group differences were found for both cepstral measures and three LTAS measures (P < 0.001): spectral mean, skewness, and kurtosis. These five measures also showed moderate to strong correlations to overall voice severity. Furthermore, high degrees of within-speaker consistency (correlation coefficients ≥0.89) across utterances with varying length and phonemic content were evidenced for both subject groups.  相似文献   
7.
Upper limits on the electric dipole moments (EDM) of elementary particles and atoms are presented, and their physical implications are discussed. The implications following from the neutron and atomic experiments are of comparable interest. The nuclear EDMs can be studied at ion storage rings, with the expected sensitivity much better than . This would represent a serious progress in studies of the CP-violation problem. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   
8.
In response to the rapid advancement of auto-refractor technology, most optometry shops provide refraction services. Despite their speed and convenience, the measurement values provided by auto-refractors include a significant degree of error due to psychological and physical factors. Therefore, there is a need for repetitive testing to obtain a smaller mean error value. However, even repetitive testing itself might not be sufficient to ensure accurate measurements. Therefore, research on a method of measurement that can complement auto-refractor measurements and provide confirmation of refraction results needs to be conducted. The customized optometry model described herein can satisfy the above requirements. From the existing optical technologies, using human eye measurement devices to obtain individual relevant optical feature parameters is no longer difficult. These parameters allow us to construct an optometry model for individual eyeballs. They also allow us to compute spot diagrams produced from the optometry model using the CODE V macro programming language before recognizing the geometrical spot diagram with the back-propagation neural network algorithm to obtain the accurate refractive diopter. Results show that the accuracy achieved was above 98% and that this application could significantly enhance the service quality of refraction.  相似文献   
9.
M R Gunye  Ashok Kumar 《Pramana》1980,14(3):223-232
The high spin yrast states uptoJ=22+ in182,184,186Os are studied in a microscopic variational approach with number-conserved projected states. The energy spectra, quadrupole, moments andB (E2) values are calculated by employing the Hamiltonian with quadrupole plus pairing interactions. The results of the calculations are in fair agreement with the available experimental data.  相似文献   
10.
Ashok Kumar  M R Gunye 《Pramana》1980,15(5):435-447
The high spin yrast states up toJ=20+ in184, 186Pt and190, 192, 194Pt are studied in a microscopic approach of variation with number-conserved projected states. The energy spectra, quadrupole moments andB(E2) values are calculated by employing the Hamiltonian with quadrupole plus pairing interactions. The results of the calculations are in fair agreement with the available experimental data.  相似文献   
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