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481.
D. Newnham J. Ballard M. Page 《Journal of Quantitative Spectroscopy & Radiative Transfer》1993,50(6):571-577
Laboratory measurements of the ν12 absorption band of gaseous N2O5 have been made using Fourier transform infrared (FTIR) spectroscopy at seven different temperatures between 233 and 293 K. Integrated band strengths and absorbance cross-sections per molecule show no significant temperature dependence. Their average values are Sint = (4.09±0.17) × 10-17 cm molecule -1 and σpeak = (1.90±0.08) × 10-18 cm2 molecule-1. 相似文献
482.
483.
C. B. Chapman S. C. Ward Dale F. Cooper M. J. Page 《The Journal of the Operational Research Society》1984,35(12):1055-1065
Credit policies are shown to be important in the basic economic order quantity inventory model. An economic order quantity model is derived which explicitly considers possible credit periods allowed by suppliers. This model is shown to be very sensitive to the length of the credit period, and to the relationship between the credit period and inventory level. It is also shown to be more sensitive to estimates of demand for inventory items and less sensitive to order costs than the basic economic order quantity model. A practical example illustrates this sensitivity, shows how inventory costs may be considerably reduced by taking the existence of a credit period into account, and demonstrates the implications for inventory and credit policies. 相似文献
484.
Abstract— An attempt was made to determine whether entrainment of the circadian rhythms of locomotor activity and ERG amplitude of the crayfish involved extraretinal photoreception. The results of a variety of experiments involving surgical lesions and localized illumination provided evidence that both rhythms can be entrained via an extraretinal pathway. The data also demonstrate that the caudal photoreceptor is unnecessary for entrainment. Our evidence to date suggests that the extraretinal photoreceptor is located in the supraesophageal ganglion; however, the possibility of photoreceptive input from other regions of the CNS, particularly the optic lobe, has not been eliminated. It is also tentatively concluded that the circadian oscillators for both the locomotor and the ERG amplitude rhythms are located within the supraesophageal ganglion, but more data are needed to confirm this conclusion. 相似文献
485.
Ainscow TA Aldalur I Beezer AE Connor JA Garbett NC Mitchell JC Page AL Tindale N Turner KA Willson RJ 《Journal of colloid and interface science》1999,213(1):87-91
Measurement of the kinetics of extraction of copper(II) by 19 different 5-alkyl-2-hydroxybenzaldoximes (alkyl is C7H15 and C9H19) from acidic (hydrogen sulfate buffer) aqueous solution in the range pH 3.4-2.0, into 20% v/v toluene in n-hexane is reported. The lowering of the interfacial tension has been measured in some cases. The solubility of the extractants in water has been measured spectrophotometrically. A modified Taylor-Aris dispersion technique has been used to measure the diffusion coefficients in n-hexane and Orfom SX7 of some of the extractants and of the copper(II) complexes which they form. At low initial bulk concentrations (<10 mol m-3) of the extractants, the rate of extraction is controlled by the rate of diffusion of the extractant from the bulk to the organic-aqueous interface. The diffusion coefficient is related to the steric bulk of the alkyl substituent. At higher initial bulk concentrations (200 mol m-3) of the extractants, when the interface is saturated, the rate of extraction is inversely related to the apparent steric bulk of the alkyl substituent. Copyright 1999 Academic Press. 相似文献
486.
D. W. Page 《Journal of Analytical and Applied Pyrolysis》2003,70(2):169-183
Analytical pyrolysis was performed to characterise the organic matter present in sediments from Corin Reservoir, a major water supply for Canberra, Australia. Pyrolysis of the whole sediment yielded furans, methoxyphenols, aliphatic products and nitrogenous compounds that are indicative of carbohydrates, lignin, lipids and proteins respectively. There was a decrease in the observed relative peak area of polysaccharide and lignin-derived marker compounds with increasing depth of sediment and an increase in nitrogenous marker compounds. In addition, eucalyptol, a molecular marker compound characteristic of eucalyptus—the dominant vegetation of the surrounding catchment—was detected. 相似文献
487.
488.
A general formalism is given for treating vibrational mode mixing, frequency shifts, and atomic equilibrium position shifts under electronic excitation in resonance Raman scattering. The theory is exact for first-order scattering at T = 0 K for all linear and quadratic electron-phonon coupling strengths. Numerical results illustrating mode mixing are presented. 相似文献
489.
M. Heimlich P. A. Beeley J. A. Page 《Journal of Radioanalytical and Nuclear Chemistry》1989,132(2):281-291
The gamma-ray spectrum analysis program, GAMANAL, has been modifed to operate on a microcomputer. The program uses an algorithm involving a Gaussian and a tailing term for fitting and resolving peaks obtained from spectrometers using germanium semiconductor detectors. Gamma-ray energies, intensities and absolute photon emission rates can be determined. A graphical output showing the original and fitted data can also be obtained. The results generated by the program are stored on disk as ASCII files for futher analysis. This allows the use of other computer programs and languages in tasks such as decay curve analysis, radionuclide activity measurements and neutron activation analysis. 相似文献
490.
The concentrations of cadmium, nickel, and zinc in standard solutions were determined by energy-dispersive X-ray fluorescence analysis of deposits prepared by flow electrolysis on graphite cloth electrodes. Reduction of the metal species in solution was complete only if cadmium or zinc was the major constituent (80 or 90 mole%, respectively). Deposits of cadmium and zinc, and cadmium-rich Cd---Ni, Cd---Zn, and Cd---Ni---Zn deposits were analysed. For pure metals the detected X-ray intensity displayed a power-law relationship, Rnp, for up to 10−4 moles. The enhancement effect of the cadmium on the nickel and zinc signals, and the absorption and enhancement effects between nickel and zinc, were corrected empirically. The absorption of cadmium X-rays by nickel and zinc was insignificant. Deposits of pure copper on heavier electrodes displayed similar fluorescent intensities. 相似文献