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31.
We study quantum effects in a system of S = 1/2 spins with two–, three and four–spin exchange interactions on the triangular lattice, a possible model of the nuclear magnetism of solid
3
He layers. The ground state phases found in our previous work are studied by using the linear spin–wave theory. The uuud state shows a very flat spin–wave dispersion, which suggests that this state, though locally stable, will not survive non–linear quantum effects. The tetrahedral state, which has long–range order of a scalar chirality, is found to be stable against spin wave fluctuations. The ground state energies of different phases are compared. Results of numerical analysis of finite size clusters are also presented. 相似文献
32.
Highly mutagenic water of the Katsura River, Kyoto, and moderately mutagenic water of the Asahi River, Okayama, were used to evaluate the efficacy of three concentration techniques, the blue-chitin column, the blue-rayon hanging, and the XAD-2 column. These two river waters have been shown to exhibit high mutagenicity in the assay with Salmonella typhimurium TA98 with metabolic activation. With this assay as a measure, two water samples from the Katsura, collected on different dates, and a sample from the Asahi were submitted to the column concentration techniques, blue-chitin and XAD-2. Blue-chitin was more efficient than XAD-2 for all of these samples: e.g., for one Katsura sample, the mutagenicity found was 913 +/- 53 (mean +/- SD, n = 3) revertants/500 ml with blue-chitin, and 419 +/- 129 (n = 3)/500 ml with XAD-2. Blue rayon (0.5 g) hung in the Asahi for 24 h gave 563 +/- 74 (n = 3) revertants, while the water spot-sampled at the start of the hanging showed 253 +/- 10 (n = 3) revertants per 5 liter with the blue-chitin column technique. We conclude that for quantitative measurement of the "Salmonella TA98 +/- S9' mutagens in these rivers, the blue-chitin column is more efficient and accurate than the XAD-2 column and that for judging the presence of mutagens, the blue-rayon hanging is the most sensitive and convenient among the three methods examined. 相似文献
33.
Hiroki Yamaguchi Tsuneo Hanawa Oto Yamamoto Yu Matsuda Yasuhiro Egami Tomohide Niimi 《Microfluidics and nanofluidics》2011,11(1):57-64
The tangential momentum accommodation coefficient (TMAC) was investigated experimentally from the mass flow rate through a
single microtube under the slip flow and the early part of the transition regime. The measurements were carried out by the
constant-volume method under the mean Knudsen number smaller than 0.3, which is based on the mean pressure of the inlet and
the outlet of the microtube, to apply the second-order slip boundary condition. To measure TMACs on various materials, quite
large microtube was employed, which require the reduction in leakage. TMAC was obtained from the slip coefficient determined
by the relation of the mass flow rate to the mean Knudsen number. The obtained mass flow rate was well explained by the theoretical
equation. TMACs of deactivated-fused silica with argon, nitrogen, and oxygen were measured, showing the tangential momentum
was not accommodated completely to the surface, and the values showed good agreement with previous studies. From the comparison
between microtubes with different inner diameter, it is showed that TMAC is determined mainly by gas species and surface material. 相似文献
34.
Yusuke Fukui Yosuke Honda Yasuhiro Yamauchi Michiko Okafuji Masahiro Sakai Mikihiko Nishitani Yusuke Takata 《Journal of the Society for Information Display》2010,18(12):1090-1094
Abstract— MgO thin film is currently used as a surface protective layer for dielectric materials because MgO has a high resistance during ion sputtering and exhibits effective secondary electron emission. The secondary‐electron‐emission coefficient γ of MgO is high for Ne ions; however, it is low for Xe ions. The Xe content of the discharge gas of PDPs needs to be raised in order to increase the luminous efficiency. Thus, the development of high‐γ materials replacing MgO is required. The discharge properties and chemical surface stability of SrO containing Zr (SrZrO) as the candidate high‐γ protective layer for noble PDPs have been characterized. SrZrO films have superior chemical stability, especially the resistance to carbonation because of the existence of a few adsorption sites due to their amorphous structure. The firing voltage is 60 V lower than that of MgO films for a discharge gas of Ne/Xe = 85/15 at 60 kPa. 相似文献
35.
Ding Zhongming Takuma Kawamura Naohisa Sakamoto Koji Koyamada 《Simulation Modelling Practice and Theory》2010,18(8):1172-1183
In this paper, we describe an improved particle-based volume rendering (PBVR) technique for previewing a large irregular volume dataset using the CUDA architecture. This technique allows for opaque and emissive particles to render translucent volumes without visibility sorting. Our GPU acceleration of PBVR provides the multi-volume rendering feature while remaining compatible with both regular and irregular volumes. We also reduce the memory cost required for storing all sub-pixel values by proposing a pixel repetition technique for a large sub-pixel level. By adjusting the repetition level, we achieved a very smooth level of detail (LOD) control for trading quality for speed. Our work demonstrates a full-detail rendering rate from 5 to 10 fps for irregular volume data with mega-scale cell numbers on an NVIDIA GeForce 8800GTS. 相似文献
36.
Ryo Tsujimoto Genki Terauchi Hisao Sasaki Shingo X. Sakamoto Shuhei Sawayama Shuji Sasa 《International journal of remote sensing》2016,37(24):5843-5863
Damage to seagrass and seaweed beds caused by the huge tsunami of the Great East Japan Earthquake on 11 March 2011 was investigated in Matsushima Bay, Miyagi Prefecture, Japan, by comparing satellite images taken before the tsunami in November 2009 and after the tsunami in May 2011. The results showed that the tsunami destroyed 220 ha of seagrass and seaweed beds, from 320 ha in 2009 to 100 ha just after the tsunami. Zostera marina beds on the sandy and muddy bottom were rather severely damaged compared with brown seaweed beds of Sargassum horneri on the rocky substrate. Substrates of the beds and directions of the tsunami seem to be responsible for the magnitude of the damage to the beds. Maps of the spatial distributions of the beds before and after the tsunami can provide information for the restoration of seagrass and seaweed beds as natural infrastructures of coastal fisheries resources. 相似文献
37.
Morihiro Nakamura Yuki Koyama Daisuke Sakamoto Takeo Igarashi 《Computer Graphics Forum》2016,35(7):323-332
We present an interactive design system for designing free‐formed bamboo‐copters, where novices can easily design free‐formed, even asymmetric bamboo‐copters that successfully fly. The designed bamboo‐copters can be fabricated using digital fabrication equipment, such as a laser cutter. Our system provides two useful functions for facilitating this design activity. First, it visualizes a simulated flight trajectory of the current bamboo‐copter design, which is updated in real time during the user's editing. Second, it provides an optimization function that automatically tweaks the current bamboo‐copter design such that the spin quality—how stably it spins—and the flight quality—how high and long it flies—are enhanced. To enable these functions, we present non‐trivial extensions over existing techniques for designing free‐formed model airplanes [ UKSI14 ], including a wing discretization method tailored to free‐formed bamboo‐copters and an optimization scheme for achieving stable bamboo‐copters considering both spin and flight qualities. 相似文献
38.
Makoto Sakamoto Kaoru Kajisa Naoko Tomozoe Takao Ito Hiroshi Furutani Michio Kono Satoshi Ikeda 《Artificial Life and Robotics》2008,13(1):61-64
In 1997, C.R. Dyer and A. Rosenfeld introduced an acceptor on a two-dimensional pattern (or tape), called the pyramid cellular acceptor, and demonstrated that many useful recognition tasks are executed by pyramid cellular acceptors in time proportional to the
logarithm of the diameter of the input. They also introduced a bottom-up pyramid cellular acceptor which is a restricted version of the pyramid cellular acceptor, and proposed some interesting open problems of the bottom-up
pyramid cellular acceptors. On the other hand, we think that the study of threedimensional automata has been meaningful as
the computational model of three-dimensional information processing such as computer vision, robotics, and so forth. In this
paper, we investigate about bottom-up pyramid cellular acceptors with three-dimensional layers, and show their some accepting
powers.
This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January
31–February 2, 2008 相似文献
39.
重复控制系统中非周期扰动的抑制 总被引:3,自引:0,他引:3
为了改善重复控制系统中的扰动抑制性能,提出一种基于曲率模型的扰动估计新方法.该方法的主要特点是扰动的估计值直接与重复控制规则结合也不影响重复控制系统的稳定性.仿真结果显示该方法可以有效地抑制扰动. 相似文献
40.