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101.
Lancaster M Goodall DM Bergström ET McCrossen S Myers P 《Journal of chromatography. A》2005,1090(1-2):165-171
This paper presents the first study of imaging of spots on thin-layer chromatographic plates whilst still wet with solvent. Imaging and quantification of Sudan II after development with dichloromethane was carried out in both reflectance and transmission modes, using a charge coupled device (CCD) camera. The relationship between peak area and sample loading was established at low sample loading, and found to be linear over an order of magnitude for both wet and dry modes with r2-values > 0.99. All data processing was carried out using the Beer-Lambert equation. Curvature at high loadings in the plots of integrated absorbance as a function of sample loading was accounted for using an empirical expression designed for use with the Kubelka-Munk treatment and apparent absorbance of the stationary phase due to scattering. Results are consistent with an effective pathlength significantly longer than the thickness of the sorbent layer. The limit of detection on a dry plate (0.5 ng) was found to be lower than on a wetted plate (2 ng). Precision was found to be 1-4% RSD intra-plate and 8-14% RSD inter-plate. Results are compared with quantification of the same analyte on dried plates. 相似文献
102.
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104.
D.A. Hamlin B.F. Myers 《Journal of Quantitative Spectroscopy & Radiative Transfer》1973,13(3):293-295
Hushfar et al. measured the chemiluminescent first-overtone radiation at 2.7 μm from the reaction N+O2 → NO+O, which is followed by the fast quenching reaction N+O → N2+O. From the rate of overtone photons per O2 molecule and the spectrum approximated by a Boltzmann distribution, they computed ?2, the number of overtone photons per NO-forming reaction in the low-density limit when no quenching occurs. We show ?2 is essentially independent of the spectrum, infer the limits on the fundamental-band photon efficiency, ?1, and obtain the initial population distribution of NO(2 ? χ ? 6). 相似文献
105.
S.A. Myers 《Spectrochimica Acta Part B: Atomic Spectroscopy》1979,34(5):213-219
A version of the boosted-output, hollow-cathode lamp has been studied as a possible light source for atomic absorption. Our version of this lamp utilizes a secondary electrical discharge to enhance the emission. passing axially through the center of an open cylindrical cathode. Eventually the increase in intensity is accompanied by a decrease in the absorbance of test solutions due to line-broadening in the lamp. Using the criterion of equivalent absorbance, lamps of this design provided ten to twenty times the intensity of commercial hollow-cathode lamps for the elements studied: aluminum, molybdenum, titanium vanadium and copper. 相似文献
106.
The Casimir energy of the gravitational field in Kaluza-Klein theories is investigated. The mathematical techniques needed to compute the contribution of a single graviton loop to the quantum effective potential on a background manifold of (Minkowski space) ? (N-sphere) are developed. In these computations the cosmological constant plays a dynamical role, acting like a mass for the graviton. The numerical work for the case N = 1 is done explicitly, and a solution to the one-loop corrected equations of motion is found, although it is not stable. The possibility of an imaginary part to the effective potential for N > 1 is noted, and its existence is attributed to tachyonic terms in the mode sum. 相似文献
107.
Second quadrant crazing and shear yielding studies were performed on glassy poly(methyl methacrylate) by means of combined torsion-tension loading. The results are in quantitative agreement with the shear and normal stress yielding criteria proposed by Sternstein and Ongchin. It is shown that four distinct regions of material response exist in the second quadrant and, depending on the stress state, 1) no crazing and no shear yielding, 2) crazing alone, 3) shear yielding alone, or 4) crazing and shear yielding can occur. An analysis of stress field induced brittle-ductile transitions is presented which is in agreement with other studies of high-pressure yielding. 相似文献
108.
G. Feldman M. Andersson J. R. M. Annand R. Codling K. Fissum K. Hansen S. Henshaw L. Isaksson M. A. Kovash M. Lundin D. E. Mittelberger L. Myers A. M. Nathan B. Schröder S. Stave H. R. Weller 《Few-Body Systems》2008,44(1-4):325-328
A new program of Compton scattering on deuterium is under way at the tagged-photon facility at MAX-Lab in Lund, Sweden. We will measure differential cross sections between 60° and 150° over the photon energy range 60–115?MeV in 5?MeV steps, with the ultimate goal of obtaining new precision information on the electric and magnetic polarizabilities of the neutron. 相似文献
109.
110.
Myers 《Fresenius' Journal of Analytical Chemistry》1871,10(1):507-508
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