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排序方式: 共有8952条查询结果,搜索用时 9 毫秒
961.
Roland Gabriel Jürgen Kunz Lars Schwarze Peter Fettke Christian Scheer Franz Lehner Konrad Walser Thomas Deelmann 《WIRTSCHAFTSINFORMATIK》2006,48(3):218-222
Ohne Zusammenfassung 相似文献
962.
Florie VidbergAuthor Vitae Rabah ZeggariAuthor Vitae Christian PieralliAuthor Vitae Clotilde Amiot Christophe RouxAuthor Vitae Bruno WacogneAuthor Vitae 《Sensors and actuators. B, Chemical》2011,157(1):19-25
We present a simple optical micro-system used to measure the transmission spectra of oocytes in order to qualify their maturation stage. Two applications of the device are possible: (i) the evaluation of the maturation stages of oocytes, and (ii) the development of a fertilization indicator. For the first application, GV, MI and MII oocytes were also analysed. Transmission spectra allow the 3 maturation stages to be identified but cannot be used to estimate the maturity of an unknown oocyte. Oocytes are subject to continuous development. This is why spectral separation of the 3 maturation stages cannot be made although they can be visually identified. However, the visual observation remains biologist-dependent. We therefore investigated the temporal maturation evolution of the oocytes in terms of transmission spectra and probability analysis. Results show that oocytes to be fertilized should not only be chosen in the MII stage, but also at the right time during the MII stage. This particular aspect requires further investigation. However, spectral measurements could be used as a technique for monitoring the maturation evolution of the oocytes. Fertilized oocytes exhibiting fertilization abnormalities were also tested. The device proved to be an efficient fertilization indicator. 相似文献
963.
Sillam-Dussès D Sémon E Lacey MJ Robert A Lenz M Bordereau C 《Journal of chemical ecology》2007,33(10):1960-1977
In the framework of an evolutionary study, trail pheromones have been studied in the most basal extant termite, Mastotermes darwiniensis (Mastotermitidae), and two other basal termites, the Termopsidae Porotermes adamsoni (Porotermitinae) and Stolotermes victoriensis (Stolotermitinae). Although workers of M. darwiniensis do not walk in single file while exploring a new environment under experimental conditions and are unable to follow artificial
trails in ‘open field’ experiments, they do secrete a trail-following pheromone from their sternal glands. This unique behavior
might reflect a primitive function of communication of the sternal gland. The major component of the pheromone appears to
be the same in the three basal species: the norsesquiterpene alcohol (E)-2,6,10-trimethyl-5,9-undecadien-1-ol. This represents a new chemical category of trail-following pheromones for termites.
The quantity of pheromone was estimated as 20 pg/individual in M. darwiniensis, 700 pg/individual in P. adamsoni, and 4 pg/individual in S. victoriensis. The activity threshold was 1 ng/cm in M. darwiniensis and 10 pg/cm in P. adamsoni. In M. darwiniensis, the trail pheromone was secreted by sternal gland 4 and to a lesser degree by sternal gland 3, sternal gland 5 being almost
inactive. This study highlighted phylogenetic relationships between the Mastotermitidae and two subfamilies of the Termopsidae,
the Porotermitinae and the Stolotermitinae. Furthermore, it indicated a heterogeneity within the Termopsidae, with Porotermitinae
and Stolotermitinae on one hand, and Termopsinae on the other. Finally, Mastotermitidae and Termopsidae, with C14 trail pheromones,
are clearly separated from the Kalotermitidae, Rhinotermitidae, and Termitidae that secrete C12 or C20 trail pheromones. 相似文献
964.
Dynamic mechanical analysis and differential scanning calorimetry were used to investigate the relaxations and crystallization of high‐density polyethylene (HDPE) reinforced with calcium carbonate (CaCO3) particles and an elastomer. Five series of blends were designed and manufactured, including one series of binary blends composed of HDPE and amino acid treated CaCO3 and four series of ternary blends composed of HDPE, treated or untreated CaCO3, and a polyolefin elastomer [poly(ethylene‐co‐octene) (POE)] grafted with maleic anhydride. The analysis of the tan δ diagrams indicated that the ternary blends exhibited phase separation. The modulus increased significantly with the CaCO3 content, and the glass‐transition temperature of POE was the leading parameter that controlled the mechanical properties of the ternary blends. The dynamic mechanical properties and crystallization of the blends were controlled by the synergistic effect of CaCO3 and maleic anhydride grafted POE, which was favored by the core–shell structure of the inclusions. The treatment of the CaCO3 filler had little influence on the mechanical properties and morphology. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3907–3914, 2007 相似文献
965.
Thorsten Falk Ralf Heese Christian Kaspar Malgorzata Mochol Daniel Pfeiffer Michael Thygs Robert Tolksdorf 《Informatik-Spektrum》2006,29(3):201-209
Zusammenfassung The importance of the Internet for job procurement is increasing for the reason that three quarters of the people in the employment age are online. On the other hand because ever more companies are publishing their job offers on the Web. However, due to the large number of openings published online it is almost impossible for job seekers and job portals to gain an overview of the entire employment market. Since job offers lack semantically meaningful annotations, the search and integration into databases are made highly difficult. Applying Semantic Web technologies to the e-recruitment process provides advantages for all participants in the market. In this paper we describe a method for analysing the domain-specific language of an application domain. We use this method to describe the e-recruitment process and the necessary ontologies for annotating job offers and job applications. In conclusion, we present the prototypical implementation of the scenario based on Semantic Web, especially semantic matching. 相似文献
966.
Ulrich Glaser Kai Esmark Martin Streibl Christian Russ Krzysztof Domaski Mauro Ciappa Wolfgang Fichtner 《Microelectronics Reliability》2007,47(7):1044-1053
Diodes and diode strings in 90 nm and beyond technologies are investigated by measurement and device simulation. After a thorough calibration, the device simulator is utilised to achieve a better understanding and an enhanced device performance of diode strings under static and transient ESD conditions. Thereto, parasitic transistors and a so far neglected parasitic thyristor (SCR) in the diode string are regarded, exploited and optimised. 相似文献
967.
Carbon dioxide intensities in economic terms (GDP in PPP terms) in industrialized and developing countries have been shown to converge, and it has been argued that technology diffusion, leading to the use of similar technologies in all countries, is an important reason for this convergence. Indicators based on CO2 per output in PPP terms, however, give in comparison to physical indicators limited understanding of the process of technology diffusion. In order to analyze the technology diffusion hypothesis in more detail, we therefore study the trend in carbon dioxide emissions in relation to the production output in four separate sectors: iron and steel; paper, board and pulp; coal fuelled power plants; and natural gas fuelled power plants, in each of 12 countries, between 1980 and 1998. The indicators converge in each sector, indicating that across countries, technologies with more similar carbon dioxide efficiencies are used today than 25 years ago. We also find that at least some developing countries with high energy prices use more efficient technologies than industrialized countries with low energy prices. 相似文献
968.
Summary. A complete communication system is broken down into a number of protocol layers each of which provides services to the layer
above it and uses services provided by its underlying layer. A service specification defines a particular ordering of the
operations that a given layer provides to the layer above it. The active elements in each layer are called entities and they
use a protocol in order to implement their service definition. On the basis of this relation between the service and protocol
concepts we have developed algorithms for deriving protocol entity specifications from a formal service specification. The
derived protocol entities ensure the correct ordering of the service primitives by exchanging synchronization messages through
an underlying communication medium. This paper presents an extended version of our earlier derivation algorithms. This version
of the algorithm can handle all operators and unrestricted process invocation and recursion as defined by basis LOTOS. The
correctness of this derivation algorithm is formally proved.
Received: January 1992 / Accepted: February 1996 相似文献
969.
970.
Um kontaminiertes Grubenwasser langfristig kostengünstig reinigen zu k?nnen, sind Methoden mit geringstm?glichen Investitions-
und Unterhaltungskosten n?tig. Dazu wurden in Gro?britannien und Deutschland in den zurückliegenden Jahren unterschiedliche
passive Reinigungssysteme in Betrieb genommen (z. B. anoxische Karbonatkan?le, konstruierte Feuchtgebiete, reaktive Barrieren,
Gro?oberfl?chenfilter). 相似文献