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991.
Coppel LG Neuman M Edström P 《Journal of the Optical Society of America. A, Optics, image science, and vision》2012,29(4):574-578
Expressions relating the bispectral reflectance of a stack of n fluorescing layers to each individual layer's reflectance and transmittance are derived. This theoretical framework is used together with recently proposed extensions of the Kubelka-Munk model to study the fluorescence from layered turbid media. For one layer over a reflecting background, the model is shown to give the same results as a previous model. The extension to n layers with different optical properties allows simulating the bispectral reflectance from a pad of layered turbid media. The applicability of the model is exemplified with an optimization of fluorophore distribution in layered turbid media. 相似文献
992.
E. Čižmár M. Ozerov Y. Skourski S. A. Zvyagin J. A. Schlueter J. L. Manson J. Wosnitza 《Journal of Low Temperature Physics》2010,159(1-2):92-95
We report on pulsed-field magnetization studies of the quasi-two-dimensional spin system [Cu(pyz)2(HF2)]PF6. The magnetization saturates at $B_{C}^{ab}=37.5$ T and $B_{C}^{c}=33.8$ T for in-plane and out-of-plane orientations of the applied magnetic field, respectively. In addition, the angular dependence of the g-factor studied by electron-spin resonance reveals orbital overlap in the ab plane suggesting a quasi-two-dimensional square-lattice network of Cu spins. It is argued that the high-field behavior is governed by the two-dimensional nature of the spin correlations due to the large anisotropy of the exchange couplings. 相似文献
993.
E. Tel A. Kaplan A. Aydın S. Özkorucuklu H. Büyükuslu G. Yıldırım 《Journal of Fusion Energy》2010,29(4):312-316
Although there have been significant research and development studies on the inertial and magnetic fusion reactor technology,
there is still a long way to go to penetrate commercial fusion reactors to the energy market. Tritium self-sufficiency must
be maintained for a commercial power plant. For self-sustaining (D-T) fusion driver tritium breeding ratio should be greater
than 1.05. So, working out the systematics of (n,t) reaction cross sections and triton emission differential data are important for the given reaction taking place on various
nuclei at different energies. In this study, (n,xt) reactions for some target nuclei as 16O, 27Al, 59Co and 209Bi have been investigated up to 45 MeV incident neutron energy. In the calculations of the triton emission spectra, the pre-equilibrium
and equilibrium effects have been used. The calculated results have been compared with the experimental data taken from the
literature. 相似文献
994.
Repeated dehydriding-hydriding cycles of ball-milled nanocrystalline MgH2 was carried out in a Sieverts’-type apparatus. In order to characterize the microstructural changes during a complete MgH2 → Mg → MgH2 transformation, the fourth desorption and subsequent absorption were interrupted at different hydrogenation stages. Convolutional multiple whole profile fitting procedure of the corresponding X-ray diffractograms was applied to reveal the evolution of microstructural parameters during the sorption cycle, such as average coherent domain size and crystallite size distribution. Complementary analysis of lattice parameters was also carried out. In this paper we demonstrate that analysing solely the evolution of microstructural parameters during cycling leads to similar rate-controlling mechanisms obtained by sorption kinetic measurements. 相似文献
995.
Numerical simulations are carried out to study the performance of two schemes of power output control applicable to solar chimney power plants. Either the volume flow or the turbine pressure drop is used as independent control variable. Values found in the literature for the optimum ratio of turbine pressure drop to pressure potential vary between 2/3 and 0.97. It is shown that the optimum ratio is not constant during the whole day and it is dependent of the heat transfer coefficients applied to the collector. This study is a contribution towards understanding solar chimney power plant performance and control and may be useful in the design of solar chimney turbines. 相似文献
996.
Stina Svensson Gunilla Borgefors Ingela Nystrm 《Journal of Visual Communication and Image Representation》1999,10(4):379
In many applications thinning of objects is of great interest. We here present a skeletonization algorithm that is based on the idea of iteratively thinning the distance transform of an object layer by layer until either an anchor-point is reached or the connectivity breaks. Our algorithm is general in the sense that any metric and any connectivity can be used. Also, it is based on ideas that are not specific for 2D. The properties of the resulting skeletons are evaluated according to the “Lee–Lam–Suen properties.” 相似文献
997.
Magnus Hanson Anders Grd Pavel Krakhmalev Sture Hogmark Jens Bergstrm 《Lubrication Science》2008,14(3):147-158
Two test methods often used to simulate the tribological performance of forming tool materials are compared in this investigation through an evaluation of the friction and wear properties of four tool steels in dry sliding. One test (slider‐on‐flat‐surface (SOFS)) utilises a vertical disc sliding on a horizontal flat test surface, and the other (load scanner (LS) tests) utilises two crossed cylindrical rods. The test conditions were selected as equal as possible for the two tests, and the following conclusions are made. Somewhat unexpectedly, the friction and wear results differed substantially between the two tests. The SOFS test showed a better potential to evaluate wear resistance since one test sample is in continuous contact with the other. The LS test can generate higher contact pressures since the two rods contact each other in an unworn condition throughout the whole test stroke. LS indicate that two hard and smooth tool steels tested against each other generally give low friction and good galling resistance. The two hard couples tested sustained the highest loads without any detectable surface damage. For the same combinations of hard steels, SOFS gave a higher friction due to the wear of the disc. The carbides in the disc material resist wear better than the matrix and will consequently wear the disc by abrasion, which adds to the friction. The above conclusions are drawn from a rather limited examination using only one set of test parameters. In fact, the two tests are both very flexible as to the way they can be used, and they both have advantages and limitations in tribological studies. They should rather be considered complementary than competitive. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
998.
Hatice Begüm Murathan Gülay Özkan Meryem Sena Akkuş Derya Öncel Özgür Göksel Özkan 《International Journal of Hydrogen Energy》2018,43(23):10728-10733
The aim of this study is to enable high hydrogen production yield from catalytic methanolysis of ammonia borane (AB) in the presence of a cordierite type ceramic monolithic. The monolithic channel surfaces were coated with Al2O3 by wash-coating method and then this layer was impregnated with 1 wt%Pd-2 wt%Co bimetallic catalyst. SEM-EDX and multi-point BET analysis were used in order to characterize the catalyst. The experimental studies were conducted in a continuous flow type reactor, which was used for the first time in this study. The reactions were carried on low temperature (40 °C), and with various AB feed concentrations and flow rates. It was found that the highest hydrogen production yield (88.5%) was obtained from AB flow rate of 3.3 mL/min, and AB feed concentration of 0.1 wt%. It was concluded that Pd-Co/Al2O3 coated monolithic, which is a stable, active and low-cost catalyst, was a very promising catalyst for on-board hydrogen production from the methanolysis of ammonia borane. 相似文献
999.
In this paper we describe how behavioral responses of carbon dioxide (CO2) tax increases are accounted for in tax revenue estimation in Sweden. The rationale for developing a method for this is a mix between that a CO2 tax is a primary climate policy tool aiming to reduce CO2 emissions and that the CO2 tax generates sizable tax revenues. 相似文献
1000.
Can Tuncay Ak&inodot nn Ayhan Bekleyen Mü cahit Y&inodot ld&inodot r&inodot m 《建筑学研究前沿(英文版)》2016,5(3):360
The traditional houses of the residential areas in and around Siirt in the southeastern region of Turkey are notable because of their interesting forms. The most successful examples are the "truncated pyramidal-shaped houses" that have existed for centuries and are unique to the locality; however, these forms are demolished rapidly. In this study, the structures of small- scale settlements in Siirt province and its environs have been evaluated to highlight the cultural aspects of the region. The subject of this research is to investigate the design principles of the rural houses constructed in vernacular style to raise international awareness of the need to preserve vernacular architecture. Surviving examples have been examined in terms of multiple case approach by their forms, spatial compositions, changes in their forms over time, their layouts in urban and rural areas, the construction techniques used to produce them from material production through implementation, the composition of the living space and its uses, their differences or similarities to other houses in the region and their aesthetic details. The research reveals that the design principles of traditional rural architecture offer the use of local material and techniques in a unique way that promote highlights to the future. 相似文献