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961.
Marie-Angele De Looze R. Coronini Monique Legentil P. Jeannin Marie-Hélene Magri 《Scientometrics》1996,36(2):167-183
This paper analyses the determination of visibility of journals in which researchers of INRA (National Institute for Agricultural Research) publish. The corpus is comprised of 671 articles published over a period of four years in 258 journals. The advantage of the method applied for determining the visibility of journals is that it combines two approaches: a) bibliometric indicators (coverage by the ISI-publications and by two specific French databases) and b) experts' opinions (10 economists and sociologists). The main results are: a) There is a convergence between the opinion of the experts and «visibility» in the databases, b) The impact factor confirms the main opinions of the experts. The first journals ranked by the experts and JCR Social Sciences are the same but represent only 40 per cent of the total journals analysed. The other journals were revealed by the experts and French databases.«Whoever seeks to pass a balanced but lucid judgement on the general trends of the activity carried out by the profession to which he belongs, is liable to say either banalities or to hurt his colleagues»The notion which we retain of core is that which is successively and conjointly validated by the experts and by the major databases representative of the field.This study was financed by the Department of Rural Economy and Sociology of INRA. 相似文献
962.
The alignment of six fluorescent materials (p-terphenyl, p-quaterphenyl, p-quinquephenyl, diphenylstilbene, 1,4-bis(2-methylstyryl)benzene, and 1,4-bis-2-(5-phenyloxazolyl)benzene) grown from the vapour phase on to friction-deposited, highly oriented poly(tetrafluoroethylene) (PTFE) films was studied. The dichroic ratio of the fluorescent films produced was determined by polarized spectroscopic fluorescence measurements, and the crystallographic orientation of these materials was determined by transmission electron microscopy. The measured dichroic ratios ranged from 1.7 for diphenylstilbene to 5.0 for the p-quaterphenyl film. Electron diffraction patterns revealed that five of the fluorescent materials grew epitaxially on the single crystal-like PTFE films, the fluorescent crystals adopting particular orientations with respect to the crystallographic planes of PTFE. On the other hand, crystals of 1,4-bis-2-(5-phenyloxazolyl) benzene aligned in a fibre pattern, apparently by a grapho-epitaxial mechanism. 相似文献
963.
Arpaia P. Avallone F. Baccigalupi A. De Capua C. 《IEEE transactions on instrumentation and measurement》1996,45(2):462-466
Two real-time algorithms for active power measurements on Pulse Width Modulation (PWM) electric drives are proposed. The former is an off-line algorithm reducing truncation error through an accurate signal period estimation and a proper window. The second is an on-line algorithm based on a low-pass IIR digital filter with an optimized transient phase. Numerical results of the metrological characterization of such algorithms, aimed to suggest criteria for their use, are presented. The experimental results of tests carried out on an actual drive confirm numerical simulations and are in perfect agreement with those of a well-acclaimed algorithm 相似文献
964.
P.E. Labeau 《Reliability Engineering & System Safety》1996,52(1):65-75
Modelling the effect of the dynamic behaviour of a system on its PSA study leads, in a Markovian framework, to a development at first order of the Chapman-Kolmogorov equation, whose solutions are the probability densities of the problem. Because of its size, there is no hope of solving directly these equations in realistic circumstances. We present in this paper a biased simulation giving the marginals and compare different ways of speeding up the integration of the equations of the dynamics. 相似文献
965.
B. Herreros G. Lifante A. Kling J.C. Soares M.F. da Silva P.D. Townsend P.J. Chandler J. Olivares J.M. Cabrera 《Optical Materials》1996,6(4):281-286
We present a structural study of two Nd3+/MgO codoped LiNbO3 waveguides fabricated by two different methods: ion-implantation and proton-exchange. Rutherford backscattering spectrometry in combination with channelling was used to study the influence of the waveguide fabrication method on the possible modification of the LiNbO3 crystal structure within the waveguiding layer. The results show that the ion-implanted waveguide mainly maintains the same properties as the virgin crystal, apart from a deterioration of a thin surface layer, whilst the proton-exchanged waveguide exhibits a quite different behaviour, although its surface is less damaged. 相似文献
966.
G. P. A. Michanetzis Y. F. Missirlis 《Journal of materials science. Materials in medicine》1996,7(1):29-33
Platelet activation and adhesion are important parameters characterizing blood compatibility of biomaterials. A platelet transport theory based on convection diffusion, which describes the influence of wall shear rate, platelet concentration, axial position, hematocrit and red cell size, was originally proposed by Turitto and Baumgartner and later expanded by Aarts. This theory was applied in an in vitro perfusion system for three different materials with wall shear rates between 100s-1 and 4300 s-1 in order to cover the regions of diffusion controlled, reaction controlled and intermediate platelet adherence. Platelet diffusivity and platelet vessel wall surface reactivity were determined for these cases and the constants m and n were calculated using the relation between platelet diffusivity and shear rate as expressed by the following power law function: D
w=m*y
n
w. 相似文献
967.
In this paper, a unified method is presented: (i) to model delaminated stiffened laminated composite shells; (ii) for synthesising
accurate multiple post-buckling solution paths under compressive loading; and (iii) for predicting delamination growth. A
multi-domain modelling technique is used for modelling the delaminated stiffened shell structures. Error-free geometrically
nonlinear element formulations — a 2-noded curved stiffener element (BEAM2) and a 3-noded shell element (SHELL3) — are used
for the finite element analysis. An accurate and simple automated solution strategy based on Newton type iterations is used
for predicting the general geometrically nonlinear and postbuckling behaviour of structures. A simple method derived from
the 3-dimensionalJ-integral is used for computing the pointwise energy release rate at the delamination front in the plate/shell models. Finally,
the influence of post-buckling structural behaviour and the delamination growth on each other has been demonstrated. 相似文献
968.
D Crenesse B Fossat F Craffa P Chaland J Porthe-Nibelle JC Poiree J Gugenheim 《Canadian Metallurgical Quarterly》1994,31(6):540-548
Isolated hepatocytes from the rat were used to assess the maintenance of liver cell function in relation to the composition of the preservation medium. After separation by collagenase, they were incubated in Krebs-Ringer-Bicarbonate medium (KRB), Euro-Collins (EC), or University of Wisconsin (UW) solutions. Potassium influx, cell volume, and transaminase release were measured in cells freshly separated from control livers or from livers preserved in vitro up to 12 h in these media or having undergone orthotopic liver transplantation (OLT). While ion exchange levels were retained in all media, cells shrank significantly in UW but were able to restore their volume after 3 h of liver preservation. With regard to in vivo conditions, UW appears to be the best medium to prevent edema and to maintain more stable potassium exchange and enzyme production. These results are of value for liver transplantation in humans. 相似文献
969.
Mother–daughter dyads from incestuous vs nonclinical families were compared in terms of (1) family life stress, (2) problem-solving appraisal, (3) direct coping behaviors, (4) mother–daughter communication, and (5) family adaptation and cohesion. 15 mother–daughter pairs from an incestuous family involving an adult male caretaker were matched on several variables to 16 mother–daughter pairs from a nonclinical family. The results revealed that mothers from the incest group (compared with the nonclinical group) reported greater amounts of family life stress, had more negative perceptions of their problem-solving appraisal, and reported more communication difficulties. The daughters from the incest group appeared to be quite similar to the nonclinical group daughters, although they did acknowledge more family stress. Implications of the results for therapeutic interventions as well as future research were discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
970.
R Nani P Novello M Decastello A Cavarzerani M Sarpellon 《Canadian Metallurgical Quarterly》1997,63(6):209-212
A clinical case of a patient in whom a right atrial thrombosis was casually discovered by transthoracic echocardiography is described. The hypothesis that also the central venous catheter (CVC) could be seat of thrombosis was done, and was confirmed by chest X-ray with dye injection in the CVC. A thrombolytic therapy with plasminogen tissular activator and with heparin infusion was started. After 24 hours from the beginning of therapy instrumental control were performed (transesophageal echocardiography ECOTEE, chest X-ray with dye injection in CVC), showing the completely dissolution of the thrombus. It is observed that, when in a patient with CVC high degree of thrombogenic factors (age over 60 years, presence of cardiac arrhythmias with ventricular hypokinesis, polyglobulia due to chronic obstructive pulmonary disease, CVC, low levels of antithrombin III) are present, the usual prophylactic measures (subcutaneous heparin, hydrophylic catheter) couldn't be sufficient to avoid superior caval vein thrombosis. The conclusion is drawn that these patient should be studied with ECOTEE and eco Doppler. Chest tomography and superior caval venography are also useful its early diagnosis of superior caval thrombosis. 相似文献