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131.
132.
K. Fröhlich 《e & i Elektrotechnik und Informationstechnik》2002,119(1):15-21
It is discussed to what extent tools, provided by modern information technology, reasonably improve the performance of high voltage circuit breakers in transmission systems of electric power. Controlled switching, properly applied, has a high potential to increase life expectancy of the breaker itself and of the adjacent equipment. Power quality can also be improved. The technical advantage of controlled switching is beyond doubt, although the economic benefits are not easily quantified. In terms of breaker intelligence, another very important aspect is condition diagnosis. In particular a model based diagnosis seems to point to the future. Condition diagnosis giving maintainance requirements and pre-warning of impending failures should facilitate the tasks of the operating personnel. As a conclusion it can be stated that more intelligence of circuit breakers would be useful. 相似文献
133.
Surveyed 38 rehabilitation counselors to investigate the relationship of experienced burnout to self-concept and job setting. Ss completed the Maslach Burnout Inventory and a questionnaire about their work. The emotional exhaustion component of burnout emerged as the key factor in the results. Emotional exhaustion was related to work overload and a perceived lack of control. It was also linked to dissatisfaction with certain aspects of the job. Findings are consistent with previous theorizing and research on burnout by J. Gaines and J. M. Jermier (see record 1984-10923-001) and C. Maslach and S. E. Jackson (see record 1985-24012-001) and underscore the relevance of this phenomenon for the rehabilitation profession. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
134.
Droplet formation on Si surfaces bombarded by 10 keV beams from a liquid metal indium ion source has been observed. It has been verified that excess indium is transported in the ion beam, probably in the form of charged droplets. SIMS, SEM and RBS techniques have been used to study the distribution of droplets at the surface. At the specified ion source operating conditions, equilibrium droplet coverage is of the order of 25%. Individual droplets have an average diameter of 0.35 ωm and an average height of 2.2 nm. At a bombardment current density of 0.1 mA cm?2, equilibrium coverage is reached in about 1 s. 相似文献
135.
C. Schönbauer Dipl.-Ing. 《e & i Elektrotechnik und Informationstechnik》2003,120(10):304-306
The new law for the support of electricity produced by renewable sources in Austria (Ökostromgesetz) which came into force with the beginning of 2003, shows its impacts already after the first months. Investments into wind power have increased considerably. These will be accompanied by activities for electricity production by biomass and biogas. The 4%-target quota will probably be reached earlier than the 2008 target period of the law. 相似文献
136.
Time dependent behavior of elements combining ultra-high performance fiber reinforced concretes (UHPFRC) and reinforced concrete 总被引:1,自引:1,他引:0
Structural elements combining Ultra-High Performance Fiber Reinforced Concretes (UHPFRC) and concrete offer a high potential
in view of rehabilitation and modification of existing structures. The investigation of the time-dependent behavior of composite
“UHPFRC-concrete” elements is a fundamental step in the determination of durability and serviceability. For this, an experimental
program was conducted on large composite “UHPFRC-concrete” beams and a numerical model was validated with the test results.
The experimental results and a parametric study performed with the numerical model showed that UHPFRC and normal strength
reinforced concrete are compatible in the long-term and that the critical period of composite “UHPFRC-concrete” elements are the first 90 days after the casting of the UHPFRC layer. Thus, the high potential
of such composite elements can be exploited also in the long term. 相似文献
137.
Holden Ronald R.; Woermke Christina; Fekken G. Cynthia 《Canadian Metallurgical Quarterly》1993,25(1):1
Evaluated the effects of increasing scale reliability and of priming dimensional activation on the construct validity of personality test item differential response latencies. 93 undergraduates were computer-administered items from the 3 lengthened scales of the Personality Research Form. Findings show that differential response latencies can demonstrate remarkably strong evidence for their construct validity. In addition, the priming of personality traits may enhance the construct validity of their corresponding differential response latencies. Results support a model of test item responding where differential item response latencies reflect the interaction of an individual's schema with test item content. (French abstract) (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
138.
Zusammenfassung Aufgrund von Eingangs- und Ausgangsst?rungen des Me?systems sowie einer endlichen Frequenzaufl?sung treten stets systematische
(Bias-) und zuf?llige Fehler bei gemessenen Frequenzg?ngen und deren Varianzen auf. Auf solchen Frequenzg?ngen und Varianzen
beruhende Sch?tzungen der modalen Parameter sind damit ebenfalls systematisch verzerrt. Um die Genauigkeit und Sicherheit
der modalen Parameter zu erh?hen, wird ein Sch?tzverfahren vorgestellt, in dem der Einflu? der Biasfehler auf die Sch?tzung
n?herungsweise in einer diagonalen Wichtungsmatrix berücksichtigt wird. Es wird gezeigt, da? die systematischen Fehler Einflu?
auf die Absch?tzung der statistischen Sicherheit der modalen Parameter haben. Anhand zweier Beispiele wird die Wirksamkeit
des Sch?tzverfahrens demonstriert.
Prof. Dr.-Ing. Dr.-Ing. E.h.H.K. T?nshoff: Dipl.-Ing.Z. Liu, Institut für Fertigungstechnik und Spanende Werkzeugmaschinen (IFW), Universit?t Hannover. 相似文献
139.
140.
Y. Romanyshyn S. Guimond H. Kuhlenbeck S. Kaya R. P. Blum H. Niehus S. Shaikhutdinov V. Simic-Milosevic N. Nilius H.-J. Freund M. V. Ganduglia-Pirovano R. Fortrie J. Döbler J. Sauer 《Topics in Catalysis》2008,50(1-4):106-115
Oxidation catalysts are modeled by oxide single crystals, thin oxide films, as well as supported oxide nanoparticles. We characterize the surface of those materials using a variety of surface sensitive techniques including scanning tunneling microscopy and spectroscopy, photoelectron spectroscopy, infrared spectroscopy, and thermal desorption spectroscopy. We find temperature dependent structural transformations from V2O5(001) to V2O3(0001) via V6O13(001). V2O3(0001) is found to be vanadyl terminated in an oxygen ambient and it loses the vanadyl termination after electron bombardment. It is shown that the concentration of vanadyl groups controls the selectivity of the methanol oxy-dehydrogenation towards formaldehyde. A proposal for the mechanism is made. The results on single crystalline thin films are compared with similar measurements on deposited vanadia nanoparticles. The experimental results are correlated with theoretical calculations and models. 相似文献