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141.
Zach Evenson Tobias Schmitt Mathias Nicola Isabella Gallino Ralf Busch 《Acta Materialia》2012,60(12):4712-4719
The molten viscous behavior of Vitreloy 106, 106a, 105 and 101 bulk metallic glass-forming alloys was investigated at temperatures above Tliq. Couette concentric cylinder viscometry was used to determine the isothermal and continuous cooling melt viscosities. Isothermal three point beam bending measurements of the viscosity in the vicinity of Tg revealed a kinetically stronger liquid at low temperatures than at high temperatures, near Tliq. This behavior is revealed to be the result of a fragile to strong transition in the undercooled liquid, possibly due to polyamorphism. 相似文献
142.
The influence of reaction conditions (temperature, catalyst type, catalyst concentration – represented as molar ratio catalyst/acetone nc/na) on the composition of the product formed from the reaction of acetone and hydrogen peroxide (30%) under acid catalysis was studied. 3,3,6,6,9,9‐Hexamethyl‐1,2,4,5,7,8‐hexoxonane (TATP) was found to be the major product when the content of the catalyst in the reaction mixture is low (nc/na ≤ 0.5). A single side product (peak 10.2) in an amount ranging from 1.5 to 8% of the total peak area was present in all the prepared samples. Three other side products were found when catalyzing by hydrochloric and nitric acids. Temperature and catalyst type did not have a significant influence on the composition of the product at low catalyst concentration. Increasing the catalyst concentration led to the formation of 3,3,6,6‐tetramethyl‐1,2,4,5‐tetroxane (DADP) either as a co‐product of TATP or as an exclusive product depending on the concentration of the catalyst. 相似文献
143.
A two-dimensional finite element model is developed to study the reaction kinetics and heat transfer during the self-propagating high-temperature synthesis of La0.6 Sr0.4 MnO3 , a cathode and interconnect material used in solid oxide fuel cells. The activation energy of La0.6 Sr0.4 MnO3 formation was calculated from experimental temperature history. The calculated spatial-temporal temperature profile, heat generation rate, reaction conversion, and flow pattern of surrounding gas during the reaction are reported in this work. Hot spots are found at the corner near the ignition point shortly after the ignition. The model provided a simple and reliable way to design a large-scale production of La0.6 Sr0.4 MnO3 . 相似文献
144.
Miks A Novak J Novak P 《Journal of the Optical Society of America. A, Optics, image science, and vision》2006,23(4):894-901
Measurements of very small phase changes in optical measurement techniques are usually performed with interferometric methods that are based on evaluation of interference patterns, which correspond to a phase change of the investigated wave field. If values of the phase change are small, it is difficult to determine accurately the phase values, and one needs very expensive measurement systems. We present a simple method for evaluation of small phase variations that uses the interference of polychromatic light. The phase change affects the color of the interference pattern, and the color of the interference pattern corresponds to a specific phase change that can be evaluated using colorimetric analysis. We describe and analyze our colorimetric phase evaluation method. The proposed method offers accurate results, and it may be suitable for practical utilization in the optical industry. 相似文献
145.
We propose a method for increasing the contour resolution of static ground targets and to overcome the diffraction limit of an optical system installed on top of a satellite. The resolution improvement is obtained by using a sequence of low-resolution images taken from different angles realized by the movement of the satellite platform. The superresolving process is obtained by the generation of relative movement between the inspected object and the a priori known high-resolution background. The relative movement is caused because the images are taken from different angles. The captured set of low-resolution images are decoded by the a priori known high-resolution background obtained from a set of reference images taken only once by a high-resolution camera. The proposed concept is demonstrated via Matlab simulation and laboratory experiments. 相似文献
146.
Formulas for a minimum of wave aberration variance and a maximum of the Strehl ratio in the optimal image point are derived using the third- and fifth-order aberration theory. Moreover, relations for the calculation of the optimal value of f-number of the optical system were derived, which enabled us to theoretically analyze real optical systems and their image quality. The optimal f-number corresponds to such a value of f-number when the image quality of a real optical system is comparable to an aberration-free optical system. This value may also serve as an auxiliary criterion of the image quality of the optical system, for example, in photography. 相似文献
147.
Within this work an 11-bit integrated Successive Approximation Register (SAR) Analog-to-Digital Converter (ADC) based on a combined capacitor and resistor network is presented. Utilizing this approach, the chip area is
reduced by the factor of 24 compared to conventional solutions without any interpolation and it occupies only 0.3 mm2. Furthermore, the equivalent capacitance is decreased by connecting two capacitors in series, whereby the matching and the
power consumption are improved. The measured Differential Non-Linearity (DNL) and the Integral Non-Linearity (INL) are below 0.3 and 0.5 LSBs, respectively. The calculated Effective Number Of Bits (ENOB) accounts to 10.72 bits. The chip is produced in 0.6 μm CMOS technology. 相似文献
148.
Janette Bobalova Jiri Salplachta Josef Chmelik 《Journal of the Institute of Brewing》2008,114(1):22-26
The protein composition of barley partly determines its quality in terms of malting and brewing. For this reason, the water‐soluble proteins of two different barley cultivars were investigated by gel electrophoresis and matrix‐assisted laser desorption/ionization mass spectrometry. Mass spectra were obtained directly from barley extracts by using three matrices. According to the quality of the measured spectra, it was possible to establish which matrix was the most suitable for the analysis of water‐soluble proteins from barley. We found that the protein patterns did not differ significantly between Jersey and Tolar varieties. However, our results showed the influence of the malting process on the posttranslational modification of some water‐soluble barley proteins. These proteins also survive the brewing process and they are very important for the formation and stability of beer foam. Several barley proteins were also identified by proteomic analysis. 相似文献
149.
3 RESULTS AND DISCUSSION
3.1 Testing the MAG antimycotic effectivity by micro titration method
This method was used only for the yeasts Candida albicans and Candida parapsilosis. 相似文献