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排序方式: 共有1156条查询结果,搜索用时 31 毫秒
31.
Wakabayashi K Matsumura T Nakayama Y Koshi M 《The Review of scientific instruments》2011,82(2):026112
We performed miniature flyer impact experiments to investigate the relationship between the apparent (u(a)) and actual (u(A)) particle velocities measured by a velocity interferometer in single-crystal lithium fluoride (LiF) that was shock-compressed along the [100] axis. The miniature flyer was accelerated to velocities in the range 652.5-1937.6 m/s by a tabletop pulsed laser. An empirical relationship of u(a) = (1.2749 ± 0.0102)u(A) was obtained. The obtained relationship agreed well with the results of a previous study within the experimental errors and its uncertainty was less than ±1%. This result indicates that the present experimental technique is effective for measuring the relationship between u(a) and u(A) of shocked transparent materials with a comparable accuracy to conventional methods. 相似文献
32.
Hiroshi Mukawa Katsuyuki Akutsu Ikuo Matsumura Satoshi Nakano Takuji Yoshida Mieko Kuwahara Kazuma Aiki 《Journal of the Society for Information Display》2009,17(3):185-193
Abstract— A full‐color eyewear display with over 85% see‐through transmittance with a 16° horizontal field of view was developed. Very low color crosstalk, less than 0.008 Δu′v′ uniformity, and 120% NTSC color gamut were achieved. Waveguides with two in‐ and out‐coupling reflection volume hologram elements enabled a simple configuration that has an optical engine beside the user's temples. The reflection volume hologram elements used on the waveguides realized a small thickness of 1.4 mm for each waveguide, and an out‐coupling reflection volume hologram used as an optical combiner contributed a high see‐through transmittance of 85% due to its wavelength selectivity. However, there are technical challenges in achieving a reasonable screen size and quality color images with optics that utilize holographic waveguides because holograms have large chromatic dispersions compared to conventional optical elements such as lenses and mirrors. Approaches to overcome these issues are described. 相似文献
33.
This paper proposes a new spatial query called a reverse direction-based surrounder (RDBS) query, which retrieves a user who is seeing a point of interest (POI) as one of their direction-based surrounders (DBSs). According to a user, one POI can be dominated by a second POI if the POIs are directionally close and the first POI is farther from the user than the second is. Two POIs are directionally close if their included angle with respect to the user is smaller than an angular threshold ??. If a POI cannot be dominated by another POI, it is a DBS of the user. We also propose an extended query called competitor RDBS query. POIs that share the same RDBSs with another POI are defined as competitors of that POI. We design algorithms to answer the RDBS queries and competitor queries. The experimental results show that the proposed algorithms can answer the queries efficiently. 相似文献
34.
Fengrong LI Takuya IIDA Yoshiharu ISHIKAWA 《Frontiers of Computer Science in China》2008,2(3):257-267
In recent years, peer-to-peer (P2P) technologies are used for flexible and scalable information exchange in the Internet,
but there exist problems to be solved for reliable information exchange. It is important to trace how data circulates between
peers and how data modifications are performed during the circulation before reaching the destination for enhancing the reliability
of exchanged information. However, such lineage tracing is not easy in current P2P networks, since data replications and modifications
are performed independently by autonomous peers—this creates a lack of reliability among the records exchanged. In this paper,
we propose a framework for traceable record exchange in a P2P network. By managing historical information in distributed peers,
we make the modification and exchange histories of records traceable. One of the features of our work is that the database
technologies are utilized for realizing the framework. Histories are maintained in a relational database in each peer, and
tracing queries are written in the datalog query language and executed in a P2P network by cooperating peers. This paper describes
the concept of the framework and overviews the approach to query processing. 相似文献
35.
36.
A method for determining the authenticity of subterranean termite trail pheromones is suggested and utilized to verify the presence of trail pheromones inReticulitermes virginicus, R. flavipes, andR. tibialis. In addition, a possible trail pheromone has been demonstrated forCoptotermes formosanus. A choice bioassay method shows that the above trail pheromones are species specific. 相似文献
37.
Ichiro Takano Yoshiharu Arai Michiko Sasaki Yoshio Sawada Kaori Yamada Takayoshi Yagasaki Yuji Kimura 《Vacuum》2006,80(7):788-792
Biodegradable plastics can be used as conventional plastics, while on disposal they decompose to water and carbon dioxide by microorganisms existing in natural environment. Products using biodegradable plastics have recently been developed in many companies pursuing ecology. In this study, surface modification of biodegradable plastics was carried out by inert ion beams for improvement of photo deterioration under an ultraviolet ray. The hardness of biodegradable plastics tended generally to decrease with irradiation of an ultraviolet ray. In this method, the hardness of ion-bombarded biodegradable plastics was kept at an initial value under an ultraviolet ray, because the modified layer by ion bombardment intercepted an ultraviolet ray. The hardness of He+ ion-bombarded biodegradable plastics showed larger value than that of Ar+ ion bombardment. He+ ion bombardment at ion energy of 10 keV produced the suitable property with both of high transmittance of a visible ray and high interception of an ultraviolet ray in a surface layer of biodegradable plastics. 相似文献
38.
Multidimensional Cube Packing 总被引:1,自引:0,他引:1
Yoshiharu Kohayakawa Flavio Keidi Miyazawa Prabhakar Raghavan Yoshiko Wakabayashi 《Algorithmica》2004,40(3):173-187
We consider the d-dimensional cube packing problem (d-CPP): given a list L of d-dimensional
cubes and (an unlimited quantity of) d-dimensional unit-capacity cubes, called bins, find a packing of L into
the minimum number of bins. We present two approximation algorithms for d-CPP, for fixed d. The first
algorithm has an asymptotic performance bound that can be made arbitrarily close to 2 – (1/2)d . The second
algorithm is an improvement of the first and has an asymptotic performance bound that can be made arbitrarily
close to 2 – (2/3)d . To our knowledge, these results improve the bounds known so far for d = 2 and d = 3, and
are the first results with bounds that are not exponential in the dimension. 相似文献
39.
40.
Yu Takanashi Yuki OrikasaMasato Mogi Masatsugu OishiHaruno Murayama Kenji SatoHisao Yamashige Daiko TakamatsuTakahiro Fujimoto Hajime TanidaHajime Arai Toshiaki OhtaEiichiro Matsubara Yoshiharu UchimotoZempachi Ogumi 《Journal of power sources》2011,196(24):10679-10685
Solid electrolyte interface (SEI) films formed on Li1−xCoO2 electrodes were observed with hard X-ray photoelectron spectroscopy (HX-PES). This paper particularly focuses on film thickness estimation using HX-PES with theoretical calculation. The validity of the calculation was proven by experiments using model SEI films. The native film formed on a LiCoO2 composite electrode was estimated to be LiF with its thickness of 5 nm. Formation of Co (II) species on top of LiCoO2 was also indicated. Storage of the electrode at 60 °C brought about considerable film growth (30-40 nm) with carbonate compounds formation. SEI film changes during charging of the LiCoO2 electrode were also examined. The main component in the film was deduced to be LiF or a kind of fluorite, with its thickness decreased during charging. The SEI formation mechanisms are also elucidated. 相似文献