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排序方式: 共有606条查询结果,搜索用时 31 毫秒
1.
Enzo Benedetti Aldo D'Alessio Mauro Aglietto Giacomo Ruggeri Piergiorgio Vergamini Francesco Ciardelli 《Polymer Engineering and Science》1986,26(1):9-14
Polyolefins functionalized with diethylmaleate were mixed with poly(vinylchloride) (PVC) in different compositions. Intermolecular interactions involving the carbonyl groups of the side chains of the functionalized polyolefins and methine hydrogens of PVC were investigated by means of infrared spectroscopy. The major flexibility of the ester groups attached to the backbone chains, with respect to polyesters, seems to increase the capability of such groups to interact with groups of more polar polymers, thus allowing prediction of easier miscibility, which however also depends on the starting polyolefin structure and function-alization degree. 相似文献
2.
3.
A. T. Adorno C. R. S. Beatrice A. V. Benedetti P. L. Cabot 《Journal of Materials Science》1993,28(2):411-414
Electrical resistivity measurements and scanning electron microscopy was used to study the dissolution of silver on Cu-Ag and Cu-Al-Ag alloys. The results seem to indicate that the dissolution temperature is affected by the addition of aluminium. 相似文献
4.
Zeng Yanwei Xue Wanrong A. Benedetti G. Fagherazzi 《Journal of Materials Science》1994,29(4):1045-1050
By using the X-ray diffraction profile-fitting technique, the microstructures of Sm, Mn-modified PbTiO3 piezoelectric ceramic discs, including ferroelectric domain sizes, microstrains, and their variations with the poling strength have been quantitatively investigated. The results manifest that the modified PbTiO3 ceramics contain a high density of domain walls due to the presence of finely-divided coherent domain structures (tens of nanometres in dimension). The poling treament can evidently influence the domain-size distribution, with a more homogeneous microstructure being developed; however, it simultaneously causes high anisotropic microstrains within the structure which, together with the high density of domain walls, is expected to be responsible for the unusual high electromechanical coupling properties possessed by this material. 相似文献
5.
In this paper an extension of the method of the Fourier series expansion to the fire analysis of composite beams is presented. In particular the extension concerns the introduction of the temperature dependent interaction of all the components: steel beams, concrete slab and steel connectors. These last are considered of finite stiffness, and a proper account is given to the combined effect of thermal degradation of the properties, and stress amplification caused by the differential thermal expansion across the interface.The proposed method compares very well with some experimental fire tests of simply supported and framed composite beams. Due to its relative simplicity and speed, it can be used for design purposes in evaluating the critical temperature in terms of critical deflection. Finally we recall that the method is capable of dealing with every type of fastening distribution, such as discontinuous or variable length. 相似文献
6.
P.M De CamposA.V Benedetti L.A De FariaV Cardoso J.F.C Boodts 《Electrochimica acta》2002,47(8):1283-1295
Electrodes of RhxTi(1−x)Oy nominal composition were prepared by thermal decomposition of the chloride or nitrate precursor salts dissolved in strongly acidic medium and applied by brush to both sides of a Ti° support. A systematic study of the influence of calcination temperature and time as well as oxygen flux was conducted. The coatings were characterised by SEM, EDAX, XRD, open circuit potential measurements and cyclic voltammetry (CV). Visible-ultraviolet spectrophotometry was employed to identify the chemical form of the precursor in solution while thermogravimetric analysis (TGA) was used to assess the decomposition temperature ranges. Optimisation of the coating preparation parameters showed coatings obtained from [Rh(H2O)6](NO3)3 precursor dissolved in HNO3 1:2 (v/v) and fired at 430 °C for 2 h in a 5 l min−1 oxygen stream-furnished stable electrodes having the highest electrochemically active surface area. 相似文献
7.
G. Soraru G. Fagherazzi M. Bottarelli A. Benedetti 《Journal of Materials Science》1985,20(6):2110-2118
The thermal evolution of glass fibres of the SiO2-Li2O-TiO2-Al2O3 system has been investigated by X-ray diffraction, DTA and SEM. Within the range of the compositions investigated (2 to 10 mol % TiO2) SEM and SAXS measurements on bulk materials have shown that a small addition of Al2O3 (3 mol %) does not modify the limits of the immiscibility region present in the ternary system SiO2-LiO2-TiO2. Within this region TiO2-rich droplets are more than likely to be formed. As to tensile strength, the asquenched fibres of the composition placed within the immiscibility dome give higher values than that obtained outside the liquid-liquid region and these values are higher than those measured on E-glass fibres. A slight crystallization in all the fibres leads to a continuous decrease of the initial tensile strength. With regards to the crystal phases presented by the crystallized fibres, the first exothermic peak is due to the simultaneous crystallization of-quartz (ss) and lithium disilicate whereas the second peak is due, most probably, to a-quartz (ss) -spodumene (ss) phase transformation as well as to the formation of Li2TiSiO5. The path of crystallization of the other detected Ti-compounds is similar to that proposed by Furukawa and White. 相似文献
8.
Francesca Truzzi Camilla Tibaldi Anne Whittaker Silvia Dilloo Enzo Spisni Giovanni Dinelli 《International journal of molecular sciences》2021,22(1)
There is a need to assess the relationship between improved rheological properties and the immunogenic potential of wheat proteins. The present study aimed to investigate the in vitro effects of total protein extracts from three modern and two landrace Triticum aestivum commercial flour mixes, with significant differences in gluten strength (GS), on cell lines. Cytotoxicity and innate immune responses induced by wheat proteins were investigated using Caco-2 monocultures, two dimensional (2D) Caco-2/U937 co-cultures, and three dimensional (3D) co-cultures simulating the intestinal mucosa with Caco-2 epithelial cells situated above an extra-cellular matrix containing U937 monocytes and L929 fibroblasts. Modern wheat proteins, with increased GS, significantly reduced Caco-2 cell proliferation and vitality in monoculture and 2D co-cultures than landrace proteins. Modern wheat proteins also augmented Caco-2 monolayer disruption and tight junction protein, occludin, redistribution in 3D co-cultures. Release of interleukin-8 into the cell medium and increased U937 monocyte migration in both 2D and 3D co-cultures were similarly apparent. Immuno-activation of migrating U937 cells was evidenced from cluster of differentiation 14 (CD14) staining and CD11b-related differentiation into macrophages. The modern wheat proteins, with gluten polymorphism relatedness and increased GS, were shown to be more cytotoxic and immunogenic than the landrace wheat proteins. 相似文献
9.
A new short-path distillation system applied to the reduction of cholesterol in butter and lard 总被引:5,自引:0,他引:5
Armando Lanzani Paolo Bondioli Carlo Mariani Liliana Folegatti Stefania Venturini Enzo Fedeli Pierre Barreteau 《Journal of the American Oil Chemists' Society》1994,71(6):609-614
A molecular distillation plant, built particularly to increase the separation efficiency and to obtain safer working conditions,
was tested to remove cholesterol from anhydrous butter and lard. A preliminary experiment was carried out with butter to evaluate
the fractionation obtained at temperatures between 190 and 250°C and residual pressures between 10−3 and 10−4 torr. A second experiment was carried out at 185°C and at the maximum operational vacuum, evaluating the fractionation achieved
within a time scale between 30 and 180 min. Cholesterol was almost completely removed during the second hour with minimal
loss of low-molecular weight triglycerides. An experiment was carried out with lard at 250°C and maximum achievable operational
vacuum (10−4 Torr), lasting approximately 6 h, and cholesterol was removed almost completely during the second hour without significant
modifications in the triglyceride composition. This situation remained constant throughout the duration of the test. 相似文献
10.
In the present study, different types of 75% Cr3C2-25% NiCr coatings were applied on a steel substrate by means of high velocity oxygen fuel spraying (HVOF), and studied using ac and dc electrochemical measurements in an aerated and unstirred 0.5 M H2SO4 solution. Structural characterization was determined before and after electrochemical tests. Differences between all sprayed systems are related to the gun transverse speed and number of deposited layers, which strongly affected the electrochemical characteristics of the coated steels. The coating obtained with a higher torch speed showed better resistance against corrosion. The electrochemical impedance results were analyzed using an equivalent circuit where porosity of the coatings and substrate oxidation were considered. 相似文献