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排序方式: 共有1831条查询结果,搜索用时 687 毫秒
191.
192.
Antonio Albano Dott. Ing. Giorgio Ghelli Ph.D. Renzo Orsini Dott. 《The VLDB Journal The International Journal on Very Large Data Bases》1995,4(3):403-444
Fibonacci is an object-oriented database programming language characterized by static and strong typing, and by new mechanisms for modeling data-bases in terms of objects with roles, classes, and associations. A brief introduction to the language is provided to present those features, which are particularly suited to modeling complex databases. Examples of the use of Fibonacci are given with reference to the prototype implementation of the language. 相似文献
193.
AR Vaccaro SC Ludwig GR Klein M McQuire D Green NE Green 《Canadian Metallurgical Quarterly》1998,27(11):746-748
We report on two patients who developed bilateral peroneal nerve palsy after using a knee board behind a water ski boat. This device causes the rider's knees to be in a hyperflexed position secured with a strap across the thighs. Treatment for this compressive neuropathy is conservative. Recreational users may wish to limit the duration and frequency of participation in this sport, thus decreasing the predisposition to prolonged nerve compression. In addition, manufacturers may consider making fundamental design changes such as padding the nylon straps or outrigger devices that contact the proximal lateral tibia. 相似文献
194.
Chong-Cook Kim Changhai Wang Yung-Chin Yang YeuKuang Hwu Seung-Kwon Seol Yong-Bum Kwon Chih-Hsiung Chen Huey-Wen Liou Hong-Ming Lin Giorgio Margaritondo Jung-Ho Je 《Materials Chemistry and Physics》2006,100(2-3):292-295
We developed a novel approach to prepare Ni–Au composite nanoparticles using synchrotron radiation X-rays. Ni–Au particles dispersed in aqueous solutions were synthesized with two different irradiation strategies. The first is by exposing to X-rays a mixed electroless solution of Ni and Au at two different temperatures, trying to nucleate Ni nanoparticles homogeneously at room temperature and to deposit Au subsequently on them at the high temperature of 70 °C. The second strategy is to change the pH value of the mixed solution, directly leading to the formation of Ni–Au nanoparticles. In both cases, the Ni–Au composite nanoparticles were successfully formed, as confirmed by the observed ferromagnetic behavior and by the evolution of the Au surface plasmon resonance band. 相似文献
195.
Simone Orcioni Giorgio Biagetti Massimo Conti 《Analog Integrated Circuits and Signal Processing》2004,38(2-3):215-231
A mixed analog-digital fuzzy logic inference processor chip, designed in a 0.35-μm CMOS technology, is presented. The analog fuzzy engine is based on a novel current-mode CMOS circuit used for the implementation of fuzzy partition membership functions. The architecture consists of a 3 inputs—1 output analog fuzzy engine, internal digital registers to store the parameters of the fuzzy controller, and a digital subsystem that allows the programmability of the fuzzy controller via an I 2 C interface. The architecture, circuits, and some Cadence Spectre simulations are presented. 相似文献
196.
Maurizio Penco Luciana Sartore Fabio Bignotti Stefania Della Sciucca Vittorio Ferrari Paolo Crescini Salvatore D'Antone 《应用聚合物科学杂志》2004,91(3):1816-1821
The aim of this work was the development of materials to be used in the field of gas sensing for the detection of organic vapors. Conductive sensors were prepared with carbon black filled blends of poly(vinyl chloride) and diol‐terminated poly(?‐caprolactone), an oligomeric plasticizer. For comparison, blends with di(2‐ethylhexyl)phthalate, a traditional low‐molecular‐weight plasticizer, were also prepared. All sensors were tested upon exposure to different organic vapors. In general, the plasticizer content affected the response rates of the sensors, and a linear variation of the relative resistance with the analyte concentration was observed. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1816–1821, 2004 相似文献
197.
Rate Monotonic vs. EDF: Judgment Day 总被引:13,自引:2,他引:11
Since the first results published in 1973 by Liu and Layland on the Rate Monotonic (RM) and Earliest Deadline First (EDF) algorithms, a lot of progress has been made in the schedulability analysis of periodic task sets. Unfortunately, many misconceptions still exist about the properties of these two scheduling methods, which usually tend to favor RM more than EDF. Typical wrong statements often heard in technical conferences and even in research papers claim that RM is easier to analyze than EDF, it introduces less runtime overhead, it is more predictable in overload conditions, and causes less jitter in task execution.Since the above statements are either wrong, or not precise, it is time to clarify these issues in a systematic fashion, because the use of EDF allows a better exploitation of the available resources and significantly improves system's performance.This paper compares RM against EDF under several aspects, using existing theoretical results, specific simulation experiments, or simple counterexamples to show that many common beliefs are either false or only restricted to specific situations. 相似文献
198.
199.
FM de Benedictis G Tuteri A Bertotto L Bruni R Vaccaro 《Canadian Metallurgical Quarterly》1994,94(4):684-688
Seventeen children with asthma were studied in a double-blind, crossover, placebo-controlled study designed to compare the efficacy of cromolyn sodium with that of nedocromil sodium in preventing exercise-induced asthma. All drugs were delivered through a metered-dose inhaler (cromolyn sodium, 10 mg; nedocromil sodium, 4 mg; placebo, two puffs). Nedocromil sodium and cromolyn sodium provided significant, comparable protection from exercise-induced asthma, and both drugs were better than placebo. We conclude that nedocromil sodium and cromolyn sodium administered by a pressurized aerosol provide equal protection against exercise-induced asthma in children. 相似文献
200.
Lymphotoxin (LT)alpha knockout mice, as well as double LTalpha/tumor necrosis factor (TNF) knockout mice, show a severe splenic disorganization with nonsegregating T/B cell zones and complete absence of primary B cell follicles, follicular dendritic cell (FDC) networks, and germinal centers. In contrast, as shown previously and confirmed in this study, LTbeta-deficient mice show much more conserved T/B cell areas and a reduced but preserved capacity to form germinal centers and FDC networks. We show here that similar to the splenic phenotype of LTbeta-deficient mice, complementation of LTalpha knockout mice with TNF-expressing transgenes leads to a p55 TNF receptor-dependent restoration of B/T cell zone segregation and a partial preservation of primary B cell follicles, FDC networks, and germinal centers. Notably, upon lipopolysaccharide challenge, LTalpha knockout mice fail to produce physiological levels of TNF both in peritoneal macrophage supernatants and in their serum, indicating a coinciding deficiency in TNF expression. These findings suggest that defective TNF expression contributes to the complex phenotype of the LTalpha knockout mice, and uncover a predominant role for TNF and its p55 TNF receptor in supporting, even in the absence of LTalpha, the development and maintenance of splenic B cell follicles, FDC networks, and germinal centers. 相似文献