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排序方式: 共有149条查询结果,搜索用时 15 毫秒
1.
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A consistent realization of an operatorial deformed Heisenberg-Weyl (HW) algebra is given. The explicit construction of the
deformation matrix is discussed. The corresponding generalized Fock-like space is analyzed. 相似文献
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Shaul K. Bar-Lev Daoud Bshouty Peter Enis Gérard Letac I-Li Lu Donald Richards 《Journal of Theoretical Probability》1994,7(4):883-929
A natural exponential family (NEF)F in ? n ,n>1, is said to be diagonal if there existn functions,a 1,...,a n , on some intervals of ?, such that the covariance matrixV F (m) ofF has diagonal (a 1(m 1),...,a n (m n )), for allm=(m 1,...,m n ) in the mean domain ofF. The familyF is also said to be irreducible if it is not the product of two independent NEFs in ? k and ? n-k , for somek=1,...,n?1. This paper shows that there are only six types of irreducible diagonal NEFs in ? n , that we call normal, Poisson, multinomial, negative multinomial, gamma, and hybrid. These types, with the exception of the latter two, correspond to distributions well established in the literature. This study is motivated by the following question: IfF is an NEF in ? n , under what conditions is its projectionp(F) in ? k , underp(x 1,...,x n )∶=(x 1,...,x k ),k=1,...,n?1, still an NEF in ? k ? The answer turns out to be rather predictable. It is the case if, and only if, the principalk×k submatrix ofV F (m 1,...,m n ) does not depend on (m k+1,...,m n ). 相似文献
5.
The inhibition performance of five azomethine derivatives such as: 1-(4-Methyloxy phenylimino)-1-(phenylhydrazono)-propan-2-one (SB1), 1-(4-Methylphenylimino)-1-(phenylhydrazono) propan-2-one (SB2), 1-(phenylimino)-1(phenylhydrazono)-propan-2-one (SB3), 1-(4-Bromo phenylimino)-1(phenylhydrazono)-propan-2-one (SB4) and 1-(4-Chlorophenylimino)-1(phenylhydrazono) -propan-2-on (SB5) as corrosion inhibitors for mild steel in sulfuric acid 0.5 ?M were investigated using different methods. All experimental results demonstrate that these compounds are eficients inhibitors. The inhibition efficiencies () increase with inhibitors concentration. At 7.5 10?5 ?M, the was 97.27%, 96.31%, 94.23%, 93.19 and 91.64% for SB1, SB2, SB3, SB4 and SB5, respectively. The potentiodynamic polarization results indicated that all the studied inhibitors act as mixed type. The adsorption process on mild steel surface obeyed Langmuir isotherm. The associated activation parameters and thermodynamic have been calculated and discussed. The adsorbed film formed on the metal surface was characterized by SEM and EDX. 相似文献
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Emad M. Hussien Mohamed Rizk Amira M. Daoud Rasha Th. El-Eryan 《Electroanalysis》2021,33(7):1771-1777
Simple, sensitive, accurate and inexpensive differential pulse (DPV) and square wave (SWV) voltammetric methods utilizing zeolite modified carbon paste electrode (ZMCPE) were developed for the determination of Oxymetazoline hydrochloride (OXM) in nasal drops. Various experimental parameters were optimized using cyclic voltammetry (CV). Calibration curves were linear over the concentration ranges 9.8×10−8–3.6×10−6 M and 9.8×10−6–9×10−5 M for DPV and SWV, respectively. The DPV method showed a limit of detection (LOD) of 1.04×10−7 M. The method was applied for the determination of OXM in pharmaceutical formulation with an average recovery of 101.18 % (%RSD=0.41, n=9). 相似文献
8.
It is shown how to derive fractional supersymmetric quantum mechanics of order k as a superposition of k-1 copies of ordinary supersymmetric quantum mechanics. 相似文献
9.
The X-ray diffraction, vibrational and impedance spectroscopy studies of (Cs)0.26(Rb)0.74H(SO4)0.89(SeO4)0.11 (CsRbHSSe) new solid solution are presented. The title compound undergo a superionic phase transition (SPT) at This transition was confirmed by an abrupt increase of conductivity. The bulk impedance parameters of CsRbHSSe, RbH(SO4)0.81(SeO4)0.19 (RbHSSe) and CsH(SO4)0.76(SeO4)0.24 (CsHSSe) were determined from an analysis of AC conductivity data measured in a wide temperature range. The charge carriers concentration in the samples investigated has been evaluated using the Almond-West formalism and shown to be independent of temperature. 相似文献
10.
Shinwari D Scherer RC DeWitt KJ Afjeh AA 《The Journal of the Acoustical Society of America》2003,113(1):487-497
Modeling the human larynx can provide insights into the nature of the flow and pressures within the glottis. In this study, the intraglottal pressures and glottal jet flow were studied for a divergent glottis that was symmetric for one case and oblique for another. A Plexiglas model of the larynx (7.5 times life size) with interchangeable vocal folds was used. Each vocal fold had at least 11 pressure taps. The minimal glottal diameter was held constant at 0.04 cm. The glottis had an included divergent angle of 10 degrees. In one case the glottis was symmetric. In the other case, the glottis had an obliquity of 15 degrees. For each geometry, transglottal pressure drops of 3, 5, 10, and 15 cm H2O were used. Pressure distribution results, suggesting significantly different cross-channel pressures at glottal entry for the oblique case, replicate the data in another study by Scherer et al. [J. Acoust. Soc. Am. 109, 1616-1630 (2001b)]. Flow visualization using a LASER sheet and seeded airflow indicated separated flow inside the glottis. Separation points did not appear to change with flow for the symmetric glottis, but for the oblique glottis moved upstream on the divergent glottal wall as flow rate increased. The outgoing glottal jet was skewed off-axis for both the symmetric and oblique cases. The laser sheet showed asymmetric circulating regions in the downstream region. The length of the laminar core of the glottal jet was less than approximately 0.6 cm, and decreased in length as flow increased. The results suggest that the glottal obliquity studied here creates significantly different driving forces on the two sides of the glottis (especially at the entrance to the glottis), and that the skewed glottal jet characteristics need to be taken into consideration for modeling and aeroacoustic purposes. 相似文献