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991.
Measurement of research activity still remains a controversial question. The use of the impact factor from the Institute for
Scientific Information (ISI) is quite widespread nowadays to carry out evaluations of all kinds; however, the calculation
formula employed by ISI in order to construct its impact factors biases the results in favour of knowledge fields which are
better represented in the sample, cite more in average and whose citations are concentrated in the early years of the articles.
In the present work, we put forward a theoretical proposal regarding how aggregated normalization should be carried out with
these biases, which allows comparing scientific production between fields, institutions and/or authors in a neutral manner.
The technical complexity of such work, together with data limitations, lead us to propose some adjustments on the impact factor
proposed by ISI which — although they do not completely solve the problem — reduce it and allow glimpsing the path towards
more neutral evaluations. The proposal is empirically applied to three analysis levels: single journals, knowledge fields
and the set of journals from the Journal Citation Report. 相似文献
992.
On a new formal proof model for RFID location privacy 总被引:2,自引:0,他引:2
We discuss a recently proposed formal proof model for RFID location privacy. We show that protocols which intuitively and in several other models are considered not to be location private, are provably location private in this model. Conversely, we also show that protocols which obviously are location private, are not considered location private in this model.Specifically, we prove a protocol in which every tag transmits the same constant message to not be location private in the proposed model. Then we prove a protocol in which a tag's identity is transmitted in clear text to be weakly location private in the model. 相似文献
993.
Jose Manuel Cortés Ana Vázquez Guillermo Santa-María Gracia Patricia Blanch Jesús Villén 《Food chemistry》2009
In the present work supercritical fluid extraction (SFE) is used to obtain carotenoids from tomatoes which were previously treated with pesticides. A procedure to determine pesticides in the extracts by RPLC–GC using the TOTAD interface is proposed. Tomatoes growing in an experimental plot were treated with different pesticides, and after picking, pesticide residues in the tomatoes were analysed and the tomatoes were used to obtain carotenoids by SFE. The carotenoid extracts were analysed using the above mentioned method. The data obtained indicated that trace amounts of the pesticides were extracted together with the carotenoids by SFE. The concentration of pesticide obtained in the second separation vessel was higher than that obtained in the first separation vessel. We conclude that only pesticide-free tomatoes should be used to extract carotenoids for applications as a nutritional supplement or in the cosmetic and pharmaceutical industries. 相似文献
994.
995.
The effect of the main gangliosides (GM1, GM3, GD3) and free sialic acid (Neu5Ac) upon the adhesion of pathogenic bacteria implicated in infant diarrhoea is assessed in vitro using the Caco-2 cell line. Concentrations of the bioactive compounds found in the bioaccessible (soluble) fraction of infant formula and human milk are employed. Bacterial adhesion behaviour included enterotoxigenic Escherichia coli (ETEC), enteropathogenic E.coli (EPEC), Listeria monocytogenes, Salmonella entericaserovartyphi, Shigella sonnei, Campylobacter jejuni and Helicobacter pylori. Three different approaches were assayed: pre-incubation of bacteria and compounds before addition to cells (competition); pre-incubation of the cells with compounds (exclusion); and pre-incubation of cells with bacteria (displacement). Furthermore, the spatial localization of the most abundant gangliosides, GM3 and GD3, in Caco-2 cells has been determined using confocal microscopy. Results show that GM3, GD3, GM1 and Neu5Ac at the assayed concentrations are able to interfere with the adhesion of several pathogenic bacteria involved in neonatal diseases-the greatest effect corresponding to Neu5Ac, followed by GD3, GM1 and GM3. Gangliosides GM3 and GD3 are located in the apical and basolateral membranes of the Caco-2 cells. 相似文献
996.
Miguel Manzano Antonio J. Salinas Francisco J. Gil María Vallet-Regí 《Journal of materials science. Materials in medicine》2009,20(9):1795-1801
In this paper, different organic–inorganic hybrid materials based in the CaO–SiO2–poly(dimethyl siloxane) PDMS system have been characterised by means of nanoindentation and their static mechanical properties
(Young’s modulus, and hardness) have been investigated. These mechanical properties have been discussed in relation to the
chemical composition and structure of the different hybrid materials. Besides, the mechanical behaviour of hybrid materials
is visco-elastic and it therefore presents phenomena of creep that will be influenced by the temperature of the mechanical
test; undoubtedly, a temperature of 37°C accelerates the processes of creep. 相似文献
997.
<正>Corian Lounge展示厅位于时尚之都米兰,虽然处于众多让人眼花缭乱的建筑之中,但第一眼看到Corian Lounge展示厅仍能马上感受到它的卓尔不凡。 相似文献
998.
Nelly Abigail Rodríguez Efrain Almanza María de Jesús Pérez Carlos Rodrigo Mu?iz Scott Packer Russell Steel 《Frontiers of Materials Science in China》2010,4(4):415-419
This study evaluates the degree of sensitization (DOS) of 304 stainless steel joined by friction stir welding (FSW). Single-loop
electrochemical potentiokinetic reactivation tests were performed using a 0.5 mol/L H2SO4 + 0.01 mol/L KSCN solution. Sensitization was promoted by exposition of the stainless steel at temperatures between 400°C
and 850°C. The microstructure was characterized using optical microscopy to identify the weld zone and the base metal. The
samples treated at 550°C showed the most severe intergranular corrosion. The DOS was lower in the weld zone than in the base
metal after heat treatments. This reduction in the DOS for the weld zone indicates that FSW is a beneficial process in joining
stainless steel. 相似文献
999.
Maria do Socorro M. Rufino Jara Pérez‐Jiménez María Tabernero Ricardo E. Alves Edy S. De Brito Fulgencio Saura‐Calixto 《International Journal of Food Science & Technology》2010,45(11):2227-2233
Several tropical fruits have been described as natural sources of dietary fibre (DF) and phenolic compounds, associated with different health effects. The aim of this work was to ascertain the DF, phenolic compounds content (including non‐extractable polyphenols, mostly associated with DF) and antioxidant capacity in acerola fruits and cashew apples from selected clones. ‘BRS 236’ acerola fruits presented a high antioxidant capacity because of the combination of both extractable polyphenols and l ‐ascorbic acid (providing together a Folin value of 170 kg?1 g d.m.). ‘CCP 76’ cashew apples contained 28 g kg?1 d.m. of extractable polyphenols and 13 g kg?1 d.m. of ascorbic acid as well as a high amount of non‐extractable condensed tannins (52 g kg?1 d.m.). DF content was of 260 g kg?1 d.m. in acerola fruit and of 209 g kg?1 d.m. in cashew apple. Acerola fruits and cashew apple should therefore be considered as new natural sources of DF and phenolic compounds. 相似文献
1000.
G. Fernández-Anaya J. C. Martínez-García V. Kučera 《International journal of control》2013,86(7):728-740
The preservation of both robust stability and weighted robust performance properties of controlled linear time-invariant single input single output (SISO) systems is studied, when performing substitutions (of the complex Laplace variable s ) by a particular class of rational strictly positive real functions ( SPR functions), the so-called strictly positive real functions of zero relative degree ( SPR0 functions). Concerning weighted robust performance and model-matching, we provide some results on preservation of controller optimality. 相似文献