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91.
Zoltan Zyman Matthias Epple Anton Goncharenko Dmytro Rokhmistrov Oleg Prymak Kateryna Loza 《Journal of materials science. Materials in medicine》2017,28(3):52
Thermal evolution of amorphous calcium phosphate (ACP) powder from a fast nitrate synthesis with a Ca/P ratio of 1:1 were studied in the range of 20–980?°C. The powder consisted of amorphous dicalcium phosphate anhydrate (CaHPO4) after heating to 200?°C. CaHPO4 gradually condensed to amorphous calcium pyrophosphate Ca2P2O7 (CPP) between 200 to 620?°C. Amorphous CPP crystallized at 620–740?°C to a metastable polymorph α′-CPP of the high-temperature phase α-CPP and β-CPP. The α′-CPP/ β-CPP phase ratio reached a maximum at 800?°C (60?wt% α′-CPP/40?wt% β-CPP), and α′-CPP gradually transformed to β-CPP at a higher temperature. Some β-TCP occurred at 900?°C, so that a three-phasic mixture was obtained in the powder heated to 980?°C. The occurrence of metastable α′-CPP is attributed to Ostwald’s step rule, and a mechanism for β-TCP formation is proposed. The advantages of prospective biomaterials from these powders are discussed. 相似文献
92.
93.
Anton Batliner Stefan Steidl Björn Schuller Dino Seppi Thurid Vogt Johannes Wagner Laurence Devillers Laurence Vidrascu Vered Aharonson Loic Kessous Noam Amir 《Computer Speech and Language》2011,25(1):4-28
In this article, we describe and interpret a set of acoustic and linguistic features that characterise emotional/emotion-related user states – confined to the one database processed: four classes in a German corpus of children interacting with a pet robot. To this end, we collected a very large feature vector consisting of more than 4000 features extracted at different sites. We performed extensive feature selection (Sequential Forward Floating Search) for seven acoustic and four linguistic types of features, ending up in a small number of ‘most important’ features which we try to interpret by discussing the impact of different feature and extraction types. We establish different measures of impact and discuss the mutual influence of acoustics and linguistics. 相似文献
94.
Numerical modeling and performance evaluation of multi-tubular sodium alanate hydride finned reactor
Maha Bhouri Jacques Goyette Bruce J. Hardy Donald L. Anton 《International Journal of Hydrogen Energy》2012
The optimization of the hydrogen loading process in a multi-tubular sodium alanate hydride reactor equipped with longitudinal fins is investigated numerically. The effect of the number, thickness and tip clearance of the fins on the hydrogen charging rate is assessed, so that the fin optimal geometric properties are determined by the compromise between the hydrogen loading rate and the fin contribution to the weight and the volume of the storage system. Simulation results have shown that the hydrogen loading rate corresponding to this optimized configuration is 41% greater than the case without fins if we suppose a perfect interconnectivity between the fin tips and the internal walls of the hydride tubes. Otherwise, the amount of stored hydrogen decreases drastically. The loading of hydrogen under high charging pressures results in higher hydrogen loading rates and there is an interaction between the geometric and operating parameters leading to the optimized amount of stored hydrogen. 相似文献
95.
Anton Trník Igor Štubňa Jana Moravčíková 《International Journal of Thermophysics》2009,30(4):1323-1328
The sound velocity of Sedlec kaolin during heating from 20 °C to 1100 °C was investigated by modulated force thermomechanical
analysis (mf-TMA). In the interval from 20 °C to 250 °C, the sound velocity increases which can be explained by liberation
of the water molecules from pores and micropores. Dehydroxylation (450 °C to 650 °C) presents itself with a decrease of the
sound velocity. After dehydroxylation, a two-step increase of the sound velocity was observed. The first step of the increase
of the sound velocity is due to solid-state sintering at low temperatures. The second step starts at 950 °C as a consequence
of the collapse of the metakaolinite structure. After the maximum, a steep increase of the sound velocity follows as a result
of solid-state sintering. 相似文献
96.
It is becoming increasingly clear that the agricultural sector will have to find an additional raison d'être beyond the production of food alone. One of the new services that agriculture can provide is contributing to the environmental quality of rural areas. In this respect a great burden of expectation is placed on organic farming. Here we examine how organic farming can contribute to the quality of specific regional landscapes. We do this with the help of a new instrument, the phenology of the landscape, which measures the contributions made by organic and conventional farming to the succession of colours and shapes during the seasons. This seasonal development plays an important role in people's appreciation of the landscape. The study shows that seasonal development is more recognizable on organic farms than on conventional farms, and that seasonal development is a scientifically‐usable criterion for evaluating the environmental quality of farms. 相似文献
97.
Dividing-wall column (DWC) is considered nowadays the new champion in distillation, as it can bring substantial reduction in the capital invested as well as savings in the operating costs. This work presents the simulation results of energy efficient control and dynamics of a dividing-wall column (DWC). In order to allow a fair comparison of the results with previously published references, the case-study considered here is the industrially relevant ternary separation of the mixture benzene-toluene-xylene (BTX) in a DWC. Rigorous simulations were carried out in Aspen Plus and Aspen Dynamics. Several conventional control structures based on PID control loops (DB/LSV, DV/LSB, LB/DSV, LV/DSB) were used as a control basis. These control structures were enhanced by adding an extra loop controlling the heavy component composition in the top of the prefractionator, by using the liquid split as an additional manipulated variable, thus implicitly achieving minimization of energy requirements. The results of the dynamic simulations show relatively short settling times and low overshooting especially for the DB/LSV and LB/DSV control structures. Moreover, the energy efficient control proposed in this work allows the operation of DWC with minimum energy requirements or maximum purity of products. 相似文献
98.
Miks A 《Journal of the Optical Society of America. A, Optics, image science, and vision》2002,19(9):1867-1871
New parameters for calculation of third-order aberration coefficients (Seidel aberration coefficients) are introduced. The formulas for Seidel aberration coefficients are linear in these new variables. With these new variables it is possible to calculate the shape and the refractive index of the glass of the individual lenses of the optical system, which was not possible before. 相似文献
99.
The optical constants of thin films of CsI, KI, and KBr and the quantum efficiency (QE) of planar photocathodes made with these alkali halides in the 53.6-174.4-nm spectral range are presented. The optical constants were obtained from measurements of the reflectance as a function of incidence angle. The effect of film heating and exposure to UV irradiation on the optical properties and on the QE of the three alkali halides was investigated. KBr was found to be the most stable material for both heating and UV irradiation. KI appeared to be close to temperature stable, whereas UV exposure affected its optical constants. CsI optical constants changed after 420 K heating and after UV exposure. The changes in the optical constants were related to the QE changes, and a certain correlation between both variations was determined. However, it was also demonstrated that the QE changes cannot be explained solely by the changes in optical constants. 相似文献
100.
Back JW Notenboom V de Koning LJ Muijsers AO Sixma TK de Koster CG de Jong L 《Analytical chemistry》2002,74(17):4417-4422
A new method is presented to screen proteolytic mass maps of cross-linked protein complexes for the presence of cross-linked peptides and for the verification of proposed structures. On the basis of the incorporation of 18O from isotopically enriched water into the C-termini of proteolytic peptides, cross-linked peptides are readily distinguished in mass spectra by a characteristic 8 amu shift. This is due to the incorporation of two 18O atoms in each C-terminus, so that normal and surface-labeled peptides shift 4 amu and cross-linked peptides containing two C-termini will shift 8 amu compared with their unlabeled counterparts. The method is fast, sensitive, and reliable and can be combined with any available cross-linking reagent and a wide range of proteolytic agents. As proof of principle, we successfully applied the method to a complex of two DNA repair proteins (Rad18-Rad6) and identified the interaction domain. 相似文献