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排序方式: 共有10000条查询结果,搜索用时 31 毫秒
981.
Univ.-Prof. DI Dr. Helmut Habersack DI Marlene Haimann Ass. Prof. Dr. Sándor Baranya Prof. Dr. János Józsa Mag. Angelika Riegler Dr Christine Sindelar DI Marcel Liedermann Johanna Ficsor Gabriella Mohácsiné Simon HR DI Dr. Michael Hengl 《?sterreichische Wasser- und Abfallwirtschaft》2014,66(9-10):340-347
The multiple uses of the Danube River for navigation, hydropower production and as a drinking water supply influence its ecological quality. Flow restrictions due to regulation as well as impacts on the sediment regime such as retention in the catchment area and interruption of the sediment continuum result in changes of the hydromorphological structures and can produce major problems in the context of sediment management. In light of these facts, cross-border investigations of sediment transport at the Danube River are called for. As there are no uniform research approaches shared by Austria and Hungary, the EU-funded project SEDDON (Sediment Research and Management at the Danube River) aims to compare different monitoring and modeling techniques used to determine sediment transport, and to develop mutual solutions. Further, the laboratory equipment currently used for hydraulic model experiments is evaluated and a research channel with a free flowing discharge of up to 10 m3/s without pumping will be constructed, allowing large-scale joint laboratory tests concerning sediment to be performed. 相似文献
982.
983.
Juan Morote Anna Celma Jacques Planas José Placer Inés de Torres Mireia Olivan Juan Carles Jaume Reventós Andreas Doll 《International journal of molecular sciences》2014,15(8):13615-13623
The aim of this study was to analyze the relationship between statin use along with serum cholesterol levels and prostate cancer (PCa) detection and aggressiveness. Statin users of three years or more and serum cholesterol levels (SC) were assessed in 2408 men scheduled for prostate biopsy. SC was classified as normal (NSC: <200 mg/dL) or high (HSC: >200 mg/dL). High-grade PCa (HGPCa) was considered if the Gleason score was greater than 7. Statin users comprised 30.9% of those studied. The PCa detection rate was 31.2% of men on statins and 37% of non-statin users (p < 0.006). The PCa detection rate was 26.3% in men with NSC and 40.6% in those with HSC (p < 0.001). In the subset of NSC men, the PCa rate was 26.5% for statin users and 26.2% for non-users (p = 0.939), while in men with HSC, the PCa rate was 36.4% for statin users and 42.0% for non-statin users (p = 0.063). The HGPCa rate was 41.8% for statin users and 32.5% for non-users (p = 0.012). NSC men had a 53.8% rate of HGPCa, while the rate was only 27.6% in HSC men (p < 0.001). NSC men on statins had an HGPCa rate of 70.2%, while non-statin users had a rate of 41.2% (p < 0.001). The HGPCa rate for HSC men on statins was 18.8%, while the rate was 30.0% (p = 0.011) for non-users. Logistic regression analysis suggested that serum cholesterol levels could serve as an independent predictor of PCa risk, OR 1.87 (95% CI 1.56–2.24) and HGPCa risk, OR 0.31 (95% CI 0.23–0.44), while statin usage could not. Statin treatment may prevent PCa detection through serum cholesterol-mediated mechanisms. A disturbing increase in the HGPCa rate was observed in statin users who normalized their serum cholesterol. 相似文献
984.
Daniel Torres-Salinas Emilio Delgado Lopez-Cózar Evaristo Jiménez-Contreras 《Scientometrics》2009,80(3):761-774
In this work, we compare the difference in the number of citations compiled with Scopus as opposed to the Web of Science (WoS)
with the aim of analysing the agreement among the citation rankings generated by these databases. For this, we analysed the
area of Health Sciences of the University of Navarra (Spain), composed of a total of 50 departments and 864 researchers. The
total number of published works reflected in the WoS during the period 1999–2005 was 2299. For each work, the number of citations
in both databases was recorded. The results indicate that the works received 14.7% more citations in Scopus than in WoS. In
the departments, the difference was greater in the clinical ones than in the basic ones. In the case of the rankings of citations,
it was found that both databases generate similar results. The Spearman and Kendall-Tau coefficients were higher than 0.9.
It was concluded that the difference in the number of citations found did not correspond to the difference of coverage of
WoS and Scopus. 相似文献
985.
C. Magaña-Zavala M. E. Angeles-San Martin F. J. Rodríguez-Gómez D. R. Acosta R. Avila-Godoy A. López-Suárez 《Surface Engineering and Applied Electrochemistry》2010,46(2):115-119
Nickel thin films with regular configuration and similar thickness were deposited on steel AISI 1018 (UNSG 10180) by two different
techniques: magnetron sputtering and electrolytic process. The main aim of this work is to compare the surfaces deposited
films made by the two techniques using the scanning electronic microscopy and to identify their morphological differences
and imperfections. We evaluate the protective coatings properties when the films are in contact with an acid medium. We also
study the thin films coatings by the spectroscopy impedance technique. We obtain that the sputtering deposits present a homogeneous
thin film coating that is better than the one obtained by the electrolytic technique. It is expected that the thin film coatings
made in this work can protect the steel against corrosion when it is in contact with an acid environment. 相似文献
986.
A. Domingo-Cabo C. Lázaro F. López-Gayarre M.A. Serrano-López P. Serna J.O. Castaño-Tabares 《Construction and Building Materials》2009,23(7):2545-2553
This paper presents the results of experimental research into concrete produced by replacing the natural aggregates with recycled aggregates coming from construction waste and concrete work demolitions. The main aim of this work was to determine creep and shrinkage variations experienced in recycled concrete, made by replacing the main fraction of the natural aggregate with a recycled aggregate coming from waste concrete and comparing it to a control concrete. The substitution percentages were 20%, 50% and 100%. Fine natural aggregate was used in all cases and the amount of cement and water–cement ratio remained constant in the mixture. It was possible to state that the evolution of deformation by shrinkage and creep was similar to a conventional concrete, although the results after a period of 180 days showed the influence of the substitution percentage in the recycled aggregates present in the mixture. In the case when 100% coarse natural aggregate was replaced by recycled aggregate there was an increase in the deformations by creep of 51% and by shrinkage of 70% as compared to those experienced by the control concrete. 相似文献
987.
Aguiar Javier M. Baladrón Carlos De La Cuesta Borja Ordás Arnal Isabel Mignot Patrice Carrozzo Gino Comi Paolo 《IEEE network》2009,23(6):43-49
This article presents a new end-to-end architecture model that will enable the deployment of a plethora of different multimedia services from diverse suppliers competitively coexisting over a common access and home networking environment. The model is focused on personal multimedia communication services and terminals. The proposed model is a segmentation of the end-to-end multimedia chain into several business segments. The interfaces among segments and functional entities inside each segment are identified and defined in the work. In order to study the impact level of the results achieved, a comparison with the approximation to NGN provided by current standardization bodies in the field (3GPP and TISPAN) is also included in the article. This comparison highlights the advantages of using this model as a solution to offer PMC services. 相似文献
988.
In this paper a realistic directional channel model that is an extension of the COST 273 channel model is presented. The model
uses a cluster of scatterers and visibility region generation based strategy with increased realism, due to the introduction
of terrain and clutter information. New approaches for path-loss prediction and line of sight modeling are considered, affecting
the cluster path gain model implementation. The new model was implemented using terrain, clutter, street and user mobility
information for the city of Lisbon, Portugal. Some of the model’s outputs are presented, mainly path loss and small/large-scale
fading statistics. 相似文献
989.
J.A. Canteli J.L. Cantero N.C. Marín B. Gómez E. Gordo M.H. Miguélez 《Journal of Materials Processing Technology》2010,210(1):122-128
This work is focused on the cutting performance of a new cermet based on high-speed steel (HSS) matrix with hard phase TiCN. The processing route to manufacture the cermet M2 + 50 vol.% TiCN is described. Orthogonal cutting tests, carried out in a lathe showed the ability of the new cermet to achieve turning operations, showing reasonably wear resistance performing dry cutting operations. Tool life was significantly increased, when the cermet was compared with the reference material M2 without reinforcement and with commercial HSS M2. Evolution of flank wear and chipping wear, being the dominant wear patterns, were analysed. 相似文献
990.
Magdalena Rzepka Fatih Özogul Krzysztof Surówka Magdalena Michalczyk 《International Journal of Food Science & Technology》2013,48(6):1318-1326
Quality and safety parameters of Atlantic bonito gravad during 42 days of storage at 7 ± 1 °C were analysed using monitoring sensory quality, microbial contamination, nucleotide degradation products, biogenic amines (BA), trimethylamine (TMA) and thiobarbituric acid reactive substances (TBARS). The shelf‐life of vacuum packed Atlantic bonito gravad was found to be 28 days. Total viable count (TVC) did not exceed 6 log CFU g?1. Malonodialdehyde (MDA) content did not surpass 10 mg kg?1. Nine biogenic amines were detected. Histamine level at the end of the storage was 355.3 mg kg?1. TMA increased from 53.9 to 619.1 mg kg?1. Among indicators based on the products of nucleotide degradation, the H value is best correlated with the sensory assessment. It can be concluded that the storage temperature of bonito gravad must be below 7 °C to prevent the threat to safety and quality posed by biogenic amines, especially histamine. 相似文献