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排序方式: 共有382条查询结果,搜索用时 31 毫秒
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Vasile-Dan Hodoroaba Steffi Rades Patrizia Borghetti Erik Ortel Thomas Wirth Sarai García Estíbaliz Gómez Miren Blanco Gabriele Alberto Gianmario Martra 《Surface and interface analysis : SIA》2020,52(12):829-834
The characteristics of TiO2 coatings can greatly influence their final performance in large-scale applications. In the present study, self-assembly of TiO2 nanoparticles (NPs) in multiple layers was selected as a deposition procedure on various substrates. For this, the main prerequisite constitutes the surface modification of both NPs and substrate with, for example, silane coupling agents. A set of functionalized TiO2 NPs has been produced by reaction with either (3-aminopropyl)triethoxysilane (APTES) or (3-aminopropyl)phosphonic acid (APPA) to functionalize the NP surface with free amino-groups. Then, the complementary functionalized NP set can be obtained from an aliquot of the first one, through the conversion of free surface amino groups to aldehydes by reaction with glutaraldehyde (GA). Several types of TiO2 NPs differing in size, shape, and specific surface area have been functionalized. Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), SEM/ energy-dispersive X-ray spectroscopy (EDS), XPS, Auger electron spectroscopy (AES), and Time-of-Flight (ToF)-SIMS analyses have been carried out to evaluate the degree of functionalization, all the analytical methods employed demonstrating successful functionalization of TiO2 NP surface with APTES or APPA and GA. 相似文献
376.
Axel Munk Jean-Pierre Stockis Janis Valeinis G?tz Giese 《Annals of the Institute of Statistical Mathematics》2011,63(5):939-959
We establish a data-driven version of Neyman??s smooth goodness-of-fit test for the marginal distribution of observations generated by an ??-mixing discrete time stochastic process ${(X_t)_{t \in \mathbb {Z}}}$ . This is a simple extension of the test for independent data introduced by Ledwina (J Am Stat Assoc 89:1000?C1005, 1994). Our method only requires additional estimation of the cumulative autocovariance. Consistency of the test will be shown at essentially any alternative. A brief simulation study shows that the test performs reasonable especially for the case of positive dependence. Finally, we illustrate our approach by analyzing the validity of a forecasting method (??historical simulation??) for the implied volatilities of traded options. 相似文献
377.
Steffi Rades Andreas Kornowski Prof. Dr. Horst Weller Prof. Dr. Barbara Albert 《Chemphyschem》2011,12(9):1756-1760
The reaction of lithium tetrahydridoborate and iron bromide in high boiling ether as reaction medium produces an ultrafine, pyrophoric and magnetic precipitate. X‐ray and electron diffraction proved the product to be amorphous. According to X‐ray absorption fine structure spectroscopy (XAFS) the precipitate has FeB structure up to nearly two coordination spheres around an iron absorber atom. Transmission electron microscopy (TEM) confirms the ultrafine powder to be nanoscale. Subsequent annealing at 450 °C causes the atoms to arrange in a more distinct FeB structure, and further thermal treatment to 1050 °C extends the local structure to the α‐modification of FeB. Between 1050 °C and 1500 °C α‐FeB is transformed into β‐FeB. 相似文献
378.
Giese M Albrecht M Bannwarth C Raabe G Valkonen A Rissanen K 《Chemical communications (Cambridge, England)》2011,47(30):8542-8544
Anion-π interactions in crystals of fluorobenzyl ammonium salts depend on the degree of fluorination at the aromatics. 相似文献
379.
ABSTRACT From surface tensions of liquids and Lifshitz-van der Waals (LW) and Lewis acid-base (AB) surface tension components and the AB electron-acceptor γ+ and electron-donor γ˙ parameters determined by contact angle (θ) measurements (using the Young-Dupré equation for polar systems), the interfacial work of salvation (Wst) between various contact angle liquids (L) and a moderately polar solid (S), such as polymethylmethacrylate (PMMA) could be determined. From these WSL -values the maximum values of the equilibrium association constant, Ka, are obtained for the adsorption of molecules of liquids, L, onto a solid substratum, S. From the Ka-values and the vapor pressures of the various liquids, the maximum number of liquid molecules adsorbed from the gaseous phase onto the solid surface can be determined, at 20°C and 76cm Hg ambient atmospheric pressure. This yields the maximum value for the fraction, ?, of the surface area of the solid that will be covered by molecules of the liquid, L, emanating from the liquid drop, via the gaseous state. From these ?-values, using Cassie's approach, the maximum amount, Δθ, can be determined by which the observed contact angle is lower than the ideal contact angle, as a consequence of the coverage of the solid substratum by adsorbed molecules originating from the contact angle liquid. For most of the contact angle liquids used, the maximum deviation, Δθ, is well under 1°; for water on PMMA it is about 1½°. 相似文献
380.
Giese RW 《Journal of chromatography. A》2011,1218(17):2349