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51.
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When a time harmonic electromagnetic wave impinges on a slaba certain portion of the wave creates heat within the slab throughdipolar and ohmic heating. The electrical and thermal propertiesof the material dictate the dynamical nature of the heatingprocess, as well as the steady-state temperature profile. Thematerial considered here is a slab of fluid. We consider thecase where the fluid is bounded by thin rigid layers of transparentmaterial. The steady-state heating profile governs the typesof convective motions that can occur and also affects the stabilitycharacteristics of temperature, pressure and velocity perturbationsintroduced in the slab. The main objective here is to examinesuch stability characteristics, initially in the linear regime.Both rigid-rigid and rigid-free configurations are considered. 相似文献
53.
A rapid high-performance liquid chromatographic method is described for separating and quantifying four bilirubin species present in serum: bilirubin, bilirubin monoglucuronide, bilirubin diglucuronide, and bilialbumin. Sample preparation consists of dilution with ascorbic acid and dimethylsulfoxide and filtration to remove solid materials. The diluted serum was injected directly onto a wide-pore (300 A) reversed-phase column and the bilirubin species eluted with a water-isopropanol gradient. Excellent agreement was found between the total bilirubin concentration measured by the high-performance liquid chromatographic method and a diazotized sulfanilic acid procedure. 相似文献
54.
Philip L. Bowers 《Geometriae Dedicata》1989,29(2):125-132
It is proved that every convex, complete, two-point homogeneous metric for which small spheres are connected has maximal symmetry. This in turn implies that the standard metrics on the classical spaces of geometry are maximally symmetric. 相似文献
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D. I. Babić K. Streubel R. P. Mirin N. M. Margalit M. G. Peters J. E. Bowers E. L. Hu 《Optical and Quantum Electronics》1996,28(5):475-485
We discuss the fabrication process and characteristics of three consecutive runs of double-fused 1.5-m vertical-cavity lasers. We have measured light-current characteristics of over three hundred lasers with ten different diameters between 6 and 60 m and observe a yield of over 95%. The process and design improvements resulted in a low pulsed threshold current of 3 mA on a number of 6- and 8-m-diameter devices and threshold current density of 2 kA cm–2 on 60-m-diameter devices at room temperature. 相似文献
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Larry D. Bowers 《Trends in analytical chemistry : TRAC》1982,1(8):191-198
Immobilization of enzymes has proved to be useful in stabilizing them, in retrieving and reusing them, and in producing unstable or expensive reagents. Specific technologies have been developed for analytical applications of immobilized enzymes, including probes (e.g., enzyme electrodes) and reactors. The characteristics of these devices and their advantages and disadvantages will be presented. 相似文献
60.
Leeuwenburgh MA Litjens RE Codee JD Overkleeft HS van der Marel GA van Boom JH 《Organic letters》2000,2(9):1275-1277
[formula: see text] Tributyltin radical mediated cyclization of carbohydrate-derived beta-(alkynyloxy)acrylates leading to highly functionalized cis- and trans-fused bicyclic ethers of various ring sizes is described. The efficacy of the radical cyclization is nicely illustrated in the iterative construction of a trans-fused tricyclic tetrahydropyran. 相似文献