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81.
82.
Theoretical K-shell photoionization and K X-ray fluorescence (K XRF) cross sections have been fitted empirically in polynomials of photon energy E and atomic number Z. This has been used to develop a computer code KCSPIF to generate K-shell photo-ionization and K XRF cross-sections for any element in the range 5≤Z≤95 and for photon energies, above K-edge–1500 keV, when only the atomic number and photon energy are supplied as the input. 相似文献
83.
The problem of the effect of dust particles on the thermal convection in micropolar ferromagnetic fluid saturating a porous medium subject to a transverse uniform magnetic field has been investigated theoretically. Linear stability analysis and normal mode analysis methods are used to find an exact solution for a flat micropolar ferromagnetic fluid layer contained between two free boundaries. In case of stationary convection, the effect of various parameters like medium permeability, dust particles, non-buoyancy magnetization, coupling parameter, spin-diffusion parameter and micropolar heat conduction parameter are analyzed. For sufficiently large values of magnetic parameter M1, the critical magnetic thermal Rayleigh number for the onset of instability is determined numerically and results are depicted graphically. It is also observed that the critical magnetic thermal Rayleigh number is reduced solely because the heat capacity of clean fluid is supplemented by that of the dust particles. The principle of exchange of stabilities is found to hold true for the micropolar ferromagnetic fluid saturating a porous medium heated from below in the absence of micropolar viscous effect, microinertia and dust particles. 相似文献
84.
85.
Bauer JJ Mittal J Larson CR Hain TC 《The Journal of the Acoustical Society of America》2006,119(4):2363-2371
The present study tested whether subjects respond to unanticipated short perturbations in voice loudness feedback with compensatory responses in voice amplitude. The role of stimulus magnitude (+/- 1,3 vs 6 dB SPL), stimulus direction (up vs down), and the ongoing voice amplitude level (normal vs soft) were compared across compensations. Subjects responded to perturbations in voice loudness feedback with a compensatory change in voice amplitude 76% of the time. Mean latency of amplitude compensation was 157 ms. Mean response magnitudes were smallest for 1-dB stimulus perturbations (0.75 dB) and greatest for 6-dB conditions (0.98 dB). However, expressed as gain, responses for 1-dB perturbations were largest and almost approached 1.0. Response magnitudes were larger for the soft voice amplitude condition compared to the normal voice amplitude condition. A mathematical model of the audio-vocal system captured the main features of the compensations. Previous research has demonstrated that subjects can respond to an unanticipated perturbation in voice pitch feedback with an automatic compensatory response in voice fundamental frequency. Data from the present study suggest that voice loudness feedback can be used in a similar manner to monitor and stabilize voice amplitude around a desired loudness level. 相似文献
86.
Madan Lal Mittal 《Journal of Mathematical Analysis and Applications》2006,314(1):75-84
In this note, a sufficient condition for summability of Fourier series has been obtained which in conjunction with the author's Tauberian theorem [M.L. Mittal, A Tauberian theorem on strong Nörlund summability, J. Indian Math. Soc. 44 (1980) 369-377] on strong Nörlund summability gives a sufficient condition for summability [C,1,2] of a Fourier series. This generalizes results due to Prasad [G. Prasad, On strong Nörlund summability of Fourier series, Univ. Roorkee Res. J. 9 (1966-1967) 1-10] and Varshney [O.P. Varshney, Note on H2 summability of Fourier series, Boll. Un. Mat. Ital. 16 (1961) 383-385]. 相似文献
87.
H. P. S. Bhandari G. Lal N. P. S. Sidhu V. K. Mittal H. S. Sahota 《Journal of Radioanalytical and Nuclear Chemistry》1987,119(5):379-385
Unlike previously reported Zn and Se levels were found to be the same in the hair of mentally retarded children and controls. Non-essential toxic Ag concentration was low whereas that of Hg, Au and Sc rather high in mentally retarded children. 相似文献
88.
Yashaswini Mittal 《Stochastic Processes and their Applications》1979,9(1):67-84
Let {Xi, i?0} be a sequence of independent identically distributed random variables with finite absolute third moment. Then Darling and Erdös have shown that for -∞<t<∞ where and . The result is extended to dependent sequences but assuming that {Xi} is a standard stationary Gaussian sequence with covariance function {ri}. When {Xi} is moderately dependent (e.g. when we get where Ha is a constant. In the strongly dependent case (e.g. when we get for-∞<t<∞. 相似文献
89.
R. S. Saxena Shiva Prasad M. L. Mittal 《Monatshefte für Chemie / Chemical Monthly》1968,99(2):538-544
Zusammenfassung Mit Hilfe der pH- und konduktometrischen Titrationen wurde die Stöchiometrie der Verbindungen untersucht, die bei der Reaktion von Uranylnitrat mit Alkali-Ortho-, Pyro- und Metaarseniten entstehen. Der Verlauf der Titrationskurven zeigt klar die Bildung der Verbindungen 3 UO2O · As2O3, 2 UO2O · As2O3 und UO2O · As2O3 in den pH-Bereichen 7,0–9,9 bzw. 6,0–7,5 bzw. 5,0–6,8. Der Anteil von Uranyl in den Alkaliarseniten wächst mit wachsender Konzentration von Na2O. Die Bildung der Uranylarsenite ist also eine Funktion der H+-Ionenkonzentration. Wir fanden, daß die Ausfällung dieser Verbindungen fast quantitativ ist.
Mit 4 Abbildungen 相似文献
The stoichiometry of the compounds formed by the interaction of uranyl nitrate and different alkali arsenites (ortho-, pyro-, and meta-) have been investigated by means of pH and conductometric titrations. The breaks and inflections in titration curves provide cogent evidence for the formation of 3 UO2O · As2O3, 2 UO2O · As2O3 and UO2O · As2O3 in pH ranges 7.0–9.9, 6.0–7.5 and 5.0–6.8 respectively. The proportion of uranyl increases with the increase in the concentration of Na2O molecules in alkali arsenites. The formation of uranyl arsenites is thus a function of H+ ion concentration. The precipitation of these compounds has been found to be almost quantitative.
Mit 4 Abbildungen 相似文献
90.
P. Manoj H. Mohan V. M. Manoj J. P. Mittal C. T. Aravindakumar 《Research on Chemical Intermediates》2006,32(9):817-826
Pulse radiolysis has been used to investigate the reaction of hydroxyl radical (·OH) and oxide radical anion (O·−) with 2-aminopurine (2AP), a fluorescent analogue of adenine, in aqueous medium. The second-order rate constant for the reaction
of ·OH with 2AP was determined to be 3 × 109 dm3 mol−1s−1 and for the reaction of O·− it was 7.1 × 108 dm3 mol−1s−1. The transient absorption spectrum obtained in the reaction of ·OH at pH 7 has absorption maxima at 370 and 470 nm. The spectrum undergoes a time-dependent transformation at higher time-scale.
The intermediate species was found to react with N,N,N′,N′-tetramethyl-p-phenylenediamine (TMPD). The yield of TMPD·+ was calculated in terms of G(TMPD·+) to be 3.3 × 10−7 mol J−1 at pH 7. The ·OH reactions were also carried out at pH 10 and the transient absorption spectra have λ
max at 400 and 480 nm. The transient spectra obtained in the reaction of O·− at pH ≈14 have maxima at 400 and 480 nm. The transient intermediate species at pH 7 are assigned to the formation of 2AP-4-OH· (54%), 2AP-5-OH· (7%) and 2AP-8-OH· (39%) based on the spectral evidence and TMPD·+ build-up. Both 2AP-4-OH· and 2AP-5-OH· undergo OH− elimination to form a radical cation. At higher pH (pH 10), the dehydration reaction of these OH-adducts leads to a N-centered
radical (2AP-N(9)·, 71%). Formation of 2AP-8-OH· (29%) is also proposed at this pH. In the reaction of O·− with 2AP, it is proposed that a similar nitrogen centered 2AP-N(9)· radical is formed by an electron-transfer reaction at N(9). 相似文献