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91.
Peak-height changes and energy shifts associated with small (Δx = 0.1 mm) changes in specimen position in a single-stage cylindrical-mirror analyzer have been investigated. A specimen position for optimum signal strength is found experimentally and is predicted from theoretical calculations. An exact theoretical expression for signal intensity is presented in integral form. The integral has been evaluated numerically for finite aperture dimensions. It is found that the position dependence of signal intensity is a result of the finite size of the exit aperture and is not related to emission at the specimen or geometry of entrance aperture. 相似文献
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W. N. Mei A. Holloway 《International Journal of Mathematical Education in Science & Technology》2013,44(8):843-860
In this work, the authors present a commonly used example in electrostatics that could be solved exactly in a conventional manner, yet expressed in a compact form, and simultaneously work out special cases using the method of images. Then, by plotting the potentials and electric fields obtained from these two methods, the authors demonstrate that these two methods provide identical solutions. Furthermore, a number of sum rules are deduced based on the arguments that these two methods should also give the same induced charge, and force. 相似文献
99.
D. G. Holloway 《Contemporary Physics》2013,54(3):230-235
Large differences exist between the theoretical and experimental values of the mechanical strength of solids. Features of this phenomenon for glass are outlined together with a review of the current, incomplete explanation. 相似文献
100.
A direct enantio- and diastereoselective N-acyliminium cyclization cascade through chiral phosphoric acid catalyzed condensation of tryptamines with γ- and δ-ketoacid derivatives to provide architecturally complex heterocycles has been developed. The reaction is technically simple to perform, atom-efficient, and broad in scope. Employing 10 mol % of (R)-BINOL derived chiral phosphoric acids in refluxing toluene allowed the polycyclic product materials to be generated in good yields (53-99%) and moderate to high enantioselectivities (68-98% ee). 相似文献