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Ernst L.J. Hinman W.L. Quam D.H. Thorp J.S. 《Power Delivery, IEEE Transactions on》1992,7(4):1834-1852
The authors describe the relaying concepts of charge comparison. Charge comparison is a new transmission line protection system. It is a form of current differential relaying. Charge comparison largely resolves the traditional problems of current differential relaying of transmission lines, which are that protection is lost if a channel fails, a large channel capacity is required, and precise channel delay compensation is required. This technique is suitable for the protection of two- or three-terminal AC transmission lines, of all lengths and voltage levels, with or without series of shunt compensation, with three-hole or single-pole tripping 相似文献
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E Ernst 《Canadian Metallurgical Quarterly》1995,7(4):259-263
Complementary therapies are frequently used by cancer patients, yet the area is a minefield of hazards and hopes. A distinction between cure and care seems helpful. There are no effective complementary cures and most options that are promoted carry a distinct and, in certain cases, fatal risk. Complementary cancer care is more acceptable and there are options that can be shown to ease suffering. Vis a vis the popularity of complementary cancer treatments, the lack of scientific evidence for most therapies seems unacceptable. The call for more rigorous research is loud and clear. 相似文献
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Ernst Pöppel 《Informatik-Spektrum》2002,73(6):427-437
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E. Gehri 《Holz als Roh- und Werkstoff》1985,43(3):83-88
Zusammenfassung Generell stellen die Verbindungsbereiche Schwachstellen dar. Zwar k?nnen in gewissen F?llen derartige Schwachstellen umgangen
werden. im Vordergrund steht jedoch eine gesicherte Erh?hung der Leistung bekannter Verbindungsarten. Voraussetzung hierfür
sind auf die jeweilige Verbindung (und Holzart) ausgerichtete konstruktive L?sungen. H?ufig lassen sich derartige Entwicklungen
nicht oder nur unvollst?ndig durch bereits normierte Regeln der Baukunde abdecken.
In general jointed areas are considered weak links. Although in certain cases these weak areas may be circumvented, it is
important to make efforts towards improving the performance of established joints. Constructive solutions adapted to specific
joints (and wood species) are one of the preconditions towards this am. Frequently this kind of development is merely insufficiently
or not at all covered by existing standardized regulations in construction technology.
Nach einem Vortrag des Verfassers auf der Dreil?nder-Holztagung 1984 in Augsburg 相似文献
High performance jointing techniques—State of art and development
Nach einem Vortrag des Verfassers auf der Dreil?nder-Holztagung 1984 in Augsburg 相似文献
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Fluorescence microscopy techniques have become important tools in mitosis research. The well-known disadvantages of fluorescence microscopy, rapid bleaching, phototoxicity and out-of-focus contributions blurring the in-focus image are obstacles which still need to be overcome. Confocal fluorescence microscopy has the potential to improve our capabilities of analyzing cells, because of its excellent depth-discrimination and image processing power. We have been using a confocal fluorescence microscope for the study of the mechanism of poleward chromosome movement, and report here (1) a cell preparation technique, which allows labeling of fixation sensitive spindle antigens with acceptable microtubule preservation; (2) the use of image processing methods to represent the spatial distribution of various labeled elements in pseudocolour; (3) a novel immunoelectron microscopic labeling method for microtubules, which allows the visualization of their distribution in semithin sections at low magnification; and (4) a first attempt to study microtubule dynamics with a confocal fluorescence microscope in living cells, microinjected with rhodamine labeled tubulin. Our experience indicates that confocal fluorescence microscopy provides real advantages for the study of spatial colocalization of antigens in the mitotic spindle. It does not, however, overcome the basic limits of resolution of the light microscope. Therefore, it has been necessary to use an electron microscopic method. Our preliminary results with living cells show that it is possible to visualize the entire microtubule network in stereo, but that the sensitivity of the instrument is still too low to perform dynamic time studies. It will be worthwhile to further develop this new type of optical instrumentation and explore its usefulness on both fixed and living cells. 相似文献