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排序方式: 共有2115条查询结果,搜索用时 15 毫秒
81.
Y. Takei R. Fujimoto Y. Ishisaki U. Morita K. Tanaka T. Koga K. Mitsuda T. Ohashi N. Y. Yamasaki N. Iyomoto T. Ichitsubo K. Sato T. Fujimori T. Oshima K. Futamoto K. Shinozaki T. Morooka S. Nakayama K. Yoshida N. Takai K. Chinone 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》2004,520(1-3):340-343
We are developing transition edge sensor (TES) microcalorimeter arrays for future Japanese astronomy missions. Although 6.6 eV energy resolution for 5.9 keV and 74 μs decay time are achieved, our energy resolution was limited by the excess noise of unknown origin. The dominant noise showed 1/R dependence and it only appeared when the current through the TES, I, is larger than 10 μA. This is explained if we assume a constant voltage noise source with a level of 2(4kTCRn)1/2. We also investigated the influence of I on the TES performance and found the TES sensitivity is reduced when the ratio of current to the critical current I/IC is large. It can explain the reduction of observed when operated without a magnetic shield. We also found a strong correlation between IC and or the baseline width. Thus, we conclude that IC is an essential parameter for the TES performance. 相似文献
82.
Yoshitaka Shingaya Tomonobu Nakayama Masakazu Aono 《Science and Technology of Advanced Materials》2004,5(5-6):647
Nanorods of substoichiometric tungsten oxide (WOx) were grown on W(001) substrates. Two methods for the growth of nanorods were used: oxidation of the substrate under appropriate conditions and the deposition of tungsten oxide from a tungsten foil heated in the presence of oxygen. The grown nanorods were observed using a scanning electron microscope and an atomic force microscope. The diameters of the nanorods were 5–20 nm. The nanorods were slightly inclined from the directions parallel or normal to the surface. The inclination of nanorods was explained in terms of the epitaxial relationship between WO3 crystals and the W(001) substrate. The WO3 crystals formed at the initial stage of growth act as the nuclei of WOx nanorods. We observed selective enhancement of the growth in a certain epitaxial direction depending on the method of growth, and an array of WOx nanorods was produced on the W(001) substrate. 相似文献
83.
Ring shear tests were conducted on five samples of different nature with a modified Imperial College type ring shear machine. The three different testing methods used, (1) individual sample testing for each normal stress, (2) increasing load multistage ring shear test, and (3) reducing load multistage ring shear test, all showed similar effective residual internal friction angle for the samples, irrespective of testing method. However, effective residual shear intercept was different according to the testing methodology. The internal friction angle did not vary, particularly after the first minimum point in the stress displacement curve, although the residual shear intercept decreased with increase in the displacement. The thickness of the shearing zone increased along with the displacement. The remolded peak shear strength for saturated conditions at field dry density varied with the consolidation history. Measurement of remolded peak shear strength was possible in a single sample using the increasing load multistage ring shear test at normal consolidation. The equilibrium water content of the sample after the ring shear test was nearly equal to the plastic limit. 相似文献
84.
Hideaki Takeda 《New Generation Computing》2004,22(4):395-413
In this article, I describe the basic technologies for Semantic Web and relationship between Semantic Web and Knowledge Representation
in Artificial Intelligence. Semantic Web is planned as an extension of the current web in order to help cooperation between
computers and humans, i.e., computers and humans are expected to understand each other in the knowledge level. I first describe
the vision of the Semantic Web, then introduce the current Semantic Web technologies, i.e., RDF, RDFS, and OWL. I describe
relationship between the trend of Semantic Web and Knowledge Representation, and clarify challenges and difficulties of Semantic
Web from the point of view of Knowledge Representation.
Hideaki Takeda: He is a professor at National Institute of Informatics (NII) and a professor in Department of Informatics at the Graduate
University of Advanced Studies (Sokendai). He received his Ph.D. from the University of Tokyo in 1991. His research interest
in computer science includes ontology engineering, community informatics and knowledge sharing systems. 相似文献
85.
We present a new memory access optimization for Java to perform aggressive code motion for speculatively optimizing memory accesses by applying partial redundancy elimination (PRE) techniques. First, to reduce as many barriers as possible and to enhance code motion, we perform alias analysis to identify all the regions in which each object reference is not aliased. Secondly, we find all the possible barriers. Finally, we perform code motions in three steps. For the first step, we apply a non‐speculative PRE algorithm to move load instructions and their following instructions in the backwards direction of the control flow graph. For the second step, we apply a speculative PRE algorithm to move some of them aggressively before the conditional branches. For the third step, we apply our modified version of a non‐speculative PRE algorithm to move store instructions in the forward direction of the control flow graph and to even move some of them after the merge points. We implemented our new algorithm in our production‐level Java just‐in‐time compiler. Our experimental results show that our speculative algorithm improves the average (maximum) performance by 13.1% (90.7%) for jBYTEmark and 1.4% (4.4%) for SPECjvm98 over the fastest algorithm previously described, while it increases the average (maximum) compilation time by 0.9% (2.9%) for both benchmark suites. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
86.
Nakayama Y 《Ultramicroscopy》2002,91(1-4):49-56
We have developed well-controlled processes for the growth and manipulation of carbon nanotubes. The relatively thin multiwalled nanotubes were prepared with high purity by arc discharge with a high gas temperature. In the manipulation of nanotubes, the first crucial process is to prepare a nanotube array, so-called nanotube cartridge. We have found the alternated current electrophoresis of nanotubes by which nanotubes are aligned at the knife-edge of a disposal razor. The second important process is to transfer a nanotube from the nanotube cartridge onto a substrate in a scanning electron microscope. Using this method, we have developed nanotube probes and nanotube tweezers that operate in a scanning probe microscope (SPM). The nanotube probes have been applied for observation of biological samples and industrial samples to clarify their advantages. The nanotube tweezers have been demonstrated for their motion in scanning electron microscope and operated to carry a nanomaterial in a SPM. 相似文献
87.
Iakoubovskii K Mitsuishi K Nakayama Y Furuya K 《Microscopy research and technique》2008,71(8):626-631
Measurements of thickness using electron energy loss spectroscopy (EELS) are revised. Absolute thickness values can be quickly and accurately determined with the Kramers-Kronig sum method. The EELS data analysis is even much easier with the log-ratio method, however, absolute calibration of this method requires knowledge of the mean free path of inelastic electron scattering lambda. The latter has been measured here in a wide range of solids and a scaling law lambda approximately rho(-0.3) versus mass density rho has been revealed. EELS measurements critically depend on the excitation and collection angles. This dependence has been studied experimentally and theoretically and an efficient model has been formulated. 相似文献
88.
A DNA–cyclodextrin–silica composite was prepared by the sol–gel method. This composite possessed the bi-functions of double-stranded DNA, such as intercalation into DNA, and cyclodextrin, such as inclusion into its intramolecular cavity. Therefore, we demonstrated the accumulation of harmful compounds from an aqueous multi-component solution using a DNA–cyclodextrin–silica composite column. As a result, the DNA–cyclodextrin–silica composite column can effectively accumulate not only planar structure-containing harmful compounds, such as dioxin and polychlorobiphenyl (PCB) derivatives, but also non-planar structure containing compounds, such as bisphenol A and diethylstilbestrol, from an aqueous multi-component solution. The accumulated amount of these harmful compounds was more than 90%. Additionally, the DNA–cyclodextrin–silica composite column was recycled by the application of methanol. Therefore, the DNA–cyclodextrin–silica composite may have the potential to be used as an environmental material for the accumulation of harmful compounds from industrial or experimental waste. 相似文献
89.
Yutaka Kawahara Atsushi Nakayama Masatoshi Shioya Masaki Tsuji Hideki Yamane Tadahisa Iwata 《Journal of Materials Science》2012,47(4):1887-1892
Structure of poly(dioxanone) (PPDX) fibers produced through a two-step melt-spinning process with an additional short-period
annealing above the melting temperature of PPDX was investigated and the effect of annealing on the degradation behavior was
discussed. The morphological study carried out by etching the fibers using a phosphate or permanganate solution suggested
that the fibers take a skin–core structure, and both the skin layer and the core region consist of a bundle of microfibrils.
The micro-beam X-ray diffraction analysis revealed that the short-period annealing in the production process only slightly
promotes the crystallization in the skin layer but contributes to increasing the packing of amorphous chains near the skin,
which seems to be the controlling factor of the hydrolytic degradation behavior of the fibers. 相似文献
90.
Kunihiro Ogata Tokio Umino Tsuyoshi Nakayama Eiichi Ono Toshiaki Tsuji 《Advanced Robotics》2017,31(6):303-310
Development of clothing in consideration of the shape and body function of a person with spinal cord injury is an important task. Then, a dummy robot with a deformation mechanism was developed in this study for evaluating the comfortable level of clothings. Specifically, a trunk joint mechanism and an abdominal mechanism that can realize various deformations of the abdominal area and various trunk poses were developed. The trunk joint mechanism was implemented in order to simulate the seated posture of persons with spinal cord injury. The abdominal deformation mechanism was implemented using linear actuators and rotating servomotors in order to simulate abdominal obesity of persons with spinal cord injury. Further, a tactile sensor system was developed for measuring the clothing pressure on the abdominal area and evaluating the comfort or discomfort of clothing. 相似文献