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排序方式: 共有467条查询结果,搜索用时 187 毫秒
41.
The realisation of E-Government Services in Switzerland makes only little progresS. Reasons are — on the one hand — the federal constitution of the Swiss Confederation. On the other hand, public administrations are concerned about the high initial effort and the corresponding financial investmentS. As a partner in the EU–funded project OntoGov the Swiss Federal Chancellery now takes over an active role in the configuration of E–Government services. With the OntoGov system reference process models are provided at various abstraction layerS. Public administrations can adapt these reference models to their specific needs and make them available for the citizenS. Decisions for designing and adapting reference processes are explicitly modelled using ontologies, making the decision process traceable. Thus, subsequent changes in the reference models can be transferred to all the depending models. 相似文献
42.
One-dimensional semiconductor nanowires are a promising candidate for future electronic devices. The epitaxial growth of nanowires
is often mediated by metal seed particles, usually gold particles. In this paper the setup of a simple and robust technique
to generate nanometer-sized aerosol gold particles by spark discharge is described. Furthermore we demonstrate for the first
time that particles generated by spark discharge can be used to design advanced nanoelectronic structures, namely nanowires.
In order to obtain compact, spherical particles suitable for nanowire growth, the sparkgenerated agglomerate particles were
reshaped in a special compaction furnace. The reshaped particles were used to seed the growth of epitaxial GaP and InP nanowires,
by metal organic vapor phase epitaxy, which was shown to be a reliable and reproducible method. This work indicates the possibility
of using spark-discharge generated gold particles for the creation of new electronic devices even at large scale processing. 相似文献
43.
Dipl.-Ing. Norbert Jost Prof. Dr. Ing. Knut Escher Dr.-Ing. Klaus Halter Dipl.-Ing. Erhard Hornbogen 《Forschung im Ingenieurwesen》1992,58(3):46-49
Zusammenfassung Im Fahmen diese Beitrags wird des Modell eines Roboters vorgestellt, der seine Bewegung ohne jegliche elektromotorische oder
pneumatische Antriebe aufsührt. Entsprechende Bauelemente sind übedflüszig, da der Werkstoff, aus dem der Raboter gefertigt
ist, die Greiffunktion selbst durchführt. Dies geschieht über das Signal einer Temperatur?nderung, so da? die Bauteile lediglich
erw?rmt oder abgekühll werden müssen, um die Greifbewegung zu realisieren. Diese Eigenschaft von Werkstoffen nennt man ?Formged?chtnis?:
Der Werkstoff erinnert sich bei Temperatur?nderungen an seine vorherige Form und nimmt diese selbst?ndig an. Es handelt sich
dabei, um eine v?llig neue Werkstoffeigenschaft, nicht um eine lediglich verbesserte. Der Formged?chtniseffekt ist hinsichtlich
seiner Ursachen sehr komplex und neu, so da? zum besseren Verst?ndnis die Grundlagen des Effektes vertieft in diesem Bericht
beschrieben werden. 相似文献
44.
挪威,一个人口只有450万的国家,位于欧洲的北部边缘.因此,它的涂料市场相对较小,但竞争依然是激烈的.由于挪威人对油饰有着执着的兴趣,许许多多的本土和外国的公司部争相代理涂料商店.挪威人普遍都喜爱涂料,挪威也成为世界上每人涂料消耗量最多的国家之一.同时,挪威也拥有国际上发达稳固的船舶运输业和沿海工业--这对船舶专用涂料和防腐蚀保护涂料来说,是一个重要的市场. 相似文献
45.
Zydrunas Vagnorius Knut S?rby 《The International Journal of Advanced Manufacturing Technology》2011,54(1-4):83-92
High-pressure cooling has proven to be very effective when machining with carbide inserts. Longer tool life and improved chip breaking are among the most commonly mentioned advantages. Nevertheless, this cooling method has been reported to reduce the life of ceramic tools in machining of heat-resistant alloys. The main reason for that is said to be the accelerated notch wear. Therefore, in this study, SiAlON ceramic inserts with improved resistance to notching were tested in machining of Inconel?718 under high-pressure cooling. The results were compared to conventional cooling. It turned out that, while notch wear was still slightly increased when high-pressure cooling was applied, it was no longer critical for the tool life. Flank wear, on the other hand, was reduced, which led to significantly longer tool life. The variation of the tool life appeared to be slightly less and chip breaking was considerably improved. This shows that, when used properly, high-pressure cooling can help to increase the productivity in machining of heat-resistant alloys with ceramic tools. 相似文献
46.
Klánová J Diamond M Jones K Lammel G Lohmann R Pirrone N Scheringer M Balducci C Bidleman T Bláha K Bláha L Booij K Bouwman H Breivik K Eckhardt S Fiedler H Garrigues P Harner T Holoubek I Hung H MacLeod M Magulova K Mosca S Pistocchi A Simonich S Smedes F Stephanou E Sweetman A Sebková K Venier M Vighi M Vrana B Wania F Weber R Weiss P 《Environmental science & technology》2011,45(18):7617-7619
47.
The determination of the fluorescence quantum yields (QY, Φ(f)) of a series of fluorescent dyes that span the absorption/excitation and emission ranges of 520-900 and 600-1000 nm is reported. The dyes encompass commercially available rhodamine 101 (Rh-101, Φ(f) = 0.913), cresyl violet (0.578), oxazine 170 (0.579), oxazine 1 (0.141), cryptocyanine (0.012), HITCI (0.283), IR-125 (0.132), IR-140 (0.167), and four noncommercial cyanine dyes with specific spectroscopic features, all of them in dilute ethanol solution. The QYs have been measured relative to the National Institute of Standards and Technology's standard reference material (SRM) 936a (quinine sulfate, QS) on a traceably characterized fluorometer, employing a chain of transfer standard dyes that include coumarin 102 (Φ(f) = 0.764), coumarin 153 (0.544), and DCM (0.435) as links between QS and Rh-101. The QY of Rh-101 has also been verified in direct measurements against QS using two approaches that rely only on instrument correction. In addition, the effects of temperature and the presence of oxygen on the fluorescence quantum yield of Rh-101 have been assessed. 相似文献
48.
49.
Development and application of new nucleic acid-based technologies for microbial community analyses in foods 总被引:8,自引:0,他引:8
Rudi K Nogva HK Moen B Nissen H Bredholt S Møretrø T Naterstad K Holck A 《International journal of food microbiology》2002,78(1-2):171-180
Several challenges still persist in the analysis of microorganisms in foods, particularly in studies of complex communities. Nucleic acid-based methods are promising tools in addressing new questions concerning microbial communities. We have developed several new methods in the field of nucleic acid-based microbial community analyses. These methods cover both sample preparation and detection approaches. The sample preparation method involves simplified DNA purification using paramagnetic beads. As an extension of this method, the same paramagnetic beads are used for both cell separation and DNA purification. This enables full automation. The separate detection of viable and dead bacteria is a major issue in nucleic acid-based diagnostics. We have applied a living/dead dye that binds covalently to DNA and inhibits the PCR from dead cells. In addition, a DNA array-based detection assay has been developed. The assay combines the specificity obtained by enzymatic labeling of DNA probes with the possibility of detecting several targets simultaneously by DNA array hybridization. In combination with 16S rDNA amplification, this is a promising tool for community analyses. Also, we have developed a novel approach for multiplex quantitative PCR. The multiplex PCR has been combined with our DNA array-based detection method. Finally, we are now in the process of adapting a system for monitoring microbial growth and death in real-time through the tagging of bacteria with green fluorescent protein (GFP) combined with fluorescence detection using a high-resolution confocal laser scanner. 相似文献
50.
Knut Hinkelmann Helge Hintze 《Annals of Mathematics and Artificial Intelligence》1997,20(1-4):335-356
Redundant computations in bottom‐up evaluation of logic programs and rule‐based systems can be avoided by caching intermediate
joins – i.e., partial rule instantiations – for later use. Joins can be cached either at representation level by program transformation
techniques introducing supplementary predicates or at implementation level by specialized implementation techniques using
internal memory cells. The efficiency of these state‐saving techniques depends on the selection of premises for storing the
joins. In this paper we first present a general program transformation technique for saving joins which heuristically reorders
subgoals and performs predicate splitting optimization, an extension of unfolding. This state‐saving transformation can be
applied for any goal‐directed and model‐generation evaluation. It does not require any information about the query. We show
that the program transformation approach is equivalent to the specialized state‐saving implementations known from production
systems and model‐generation theorem provers. To use the efficient and complete bottom‐up evaluation also for query answering,
we improve the supplementary extensions of Generalized Magic Sets and Magic Templates rewriting strategies by the presented
state‐saving transformation.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献