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141.
Manabu Shimada Heru Setyawan Yutaka Hayashi Nobuki Kashihara Kikuo Okuyama Sugeng Winardi 《Aerosol science and technology》2013,47(5):408-414
The effects of gas flow rate on particle formation and film deposition during the preparation of silica thin film using a TEOS/O2 plasma were investigated. Particle formation and growth are suppressed with increasing gas flow rates. The film deposition rate increases with increasing gas flow rate, reaches a maximum value, and eventually decreases again. However, the uniformity of the film tends to degrade at high gas flow rates. At a high gas flow rate, some particles trapped in the sheath near the grounded electrode pass through the sheath to reach the substrate and are then embedded in the growing film. A self-consistent sheath model combined with particle force balance based on charge fluctuation was developed to explain these experimental findings qualitatively. The model reveals that charge fluctuation is a key factor for the particle to overcome the potential barrier of the negatively charged particles to pass through the sheath, eventually reaching the substrate. The model further shows that the probability of a particle being deposited on the substrate is higher for increased gas flow rates, which correctly predicts the experimentally observed trend. 相似文献
142.
Naka R. Watanabe K. Kawarabayashi J. Uritani A. Iguchi T. Hayashi N. Kojima N. Yoshida T. Kaneko J. Takeuchi H. Kakuta T. 《IEEE transactions on nuclear science》2001,48(6):2348-2351
The purpose of this study is to develop a radiation distribution monitor using a normal plastic optical fiber. The monitor has a long operating length and can obtain continuous radiation distributions. A principle of the position sensing is based on a time-of-flight technique. The monitor is sensitive to beta rays or charged particles, gamma rays, and fast neutrons. The spatial resolutions for beta-rays ( 90Sr-90Y), gamma-rays (137Cs), and D-T neutrons are 30, 37, and 13 cm, respectively. The detection efficiencies for the beta-rays, gamma-rays, and D-T neutrons are 0.11%, 1.6×10 -5% and 1.2×10-4%, respectively. The effective attenuation length of the detection efficiency is 18 m. In this paper, we describe the basic characteristics of this monitor 相似文献
143.
Fast Labelling of Natural Scenes Using Enhanced Knowledge 总被引:1,自引:0,他引:1
Hiroki Hayashi Mineichi Kudo Jun Toyama Masaru Shimbo 《Pattern Analysis & Applications》2001,4(1):20-27
A new technique for labelling natural scenes is proposed. This technique labels disjoint regions on an image of a natural
scene on the basis of knowledge about the relationship among objects. The proposed technique consists of three stages: (1)
segmentation, (2) initial labelling, and (3) label improvement. One of the most promising previous techniques uses simulated
annealing to find the solution, while our technique uses local hill-climbing with enhanced knowledge for speeding up the processing.
Local hill-climbing is known to be easy to be captured by a local minimum. We solved this problem by enhancing the knowledge
being used as constraints for the search. Our knowledge represents 1-to-n relationships among regions, pair-wise relationships of regions, and relative locations of the regions to the image. In addition,
we introduced two region features: an entropy in intensity; and a linearity of contours of each region. The linearity evaluation
aims to distinguish artificial objects from natural objects. The validity of the technique is supported by some experiments.
These experiments showed that the proposed technique is much faster with the almost same accurate. 相似文献
144.
Summary
Dynamic light scattering measurements have been made on 14 samples of a polymacromonomer consisting of polystyrene with 15
styrene side-chain units in cyclohexane at 34.5°C (the theta point) to determine the translational diffusion coefficient D as a function of molecular weight. The dependence of D on the main-chain length is analyzed on the basis of the wormlike chain by taking into account the end effect arising from
side chains near the main-chain ends. The model parameters describing this dependence, i.e., the Kuhn segment length (11.5
± 1.5 nm), the linear mass density (5600 ± 700 nm−1), the diameter (5.2 ± 0.5 nm), and the end-effect parameter δ (2.5 ± 0.3 nm), are close to those determined previously from
<S
2>z (the z-average mean-square radius of gyration) and [η] (the intrinsic viscosity), leading to the conclusion that the wormlike chain
model is capable of consistently explaining <S
2>z, [η], and D of the polymacromonomer in the Θ solvent.
Received: 8 February 2000/Accepted: 18 February 2000 相似文献
145.
Kensuke Miyahara Saburo Matsuoka Tohru Hayashi 《Metallurgical and Materials Transactions A》2001,32(3):761-768
A nanoindentation hardness testing system, including an atomic-force microscope (AFM)-based nanoindentation tester and a calibration
method using electrolytically polished single-crystal metals as references, was proposed. This was applied to a study of the
mechanical properties of fine-grained ferritic steel (grain size of 1.2 μm) and coarse-grained ferritic steel (30 μm). An
empirical function giving the macroscopic hardness for all four reference metals from the nanoindentation force curves was
established. The converted Vickers hardness (HV*) of the coarse-grained steel is almost independent of the indent size. The
fine-grained steel shows only HV* 130 with an indent of only 100 nm, compared with a macroscopic hardness of HV 210. The difference,
HV 80, is considered to reflect the amount of grain-boundary strengthening. The critical indent size for the hardness transition
seems to be around 1 μm, comparable to the grain size of the specimen. This result supports the explanation of grainboundary
strengthening. It is also consistent with Pickering’s work on low-carbon steel, as the estimated locking parameter (k of 2.6×105 N/m3/2) in the Hall-Petch relationship is in good agreement with his value of 2.4×105 N/m3/2. 相似文献
146.
Masaru Ogura Susumu Kage Masayoshi Hayashi Masahiko Matsukata Eiichi Kikuchi 《Applied catalysis. B, Environmental》2000,27(4):L213-L216
Effect of second components on the catalytic performance of Pd/H-ZSM-5 zeolite (Pd: 0.4 wt.%) was evaluated by a durability test of NO reduction with CH4 at a relatively high temperature of 500°C in the presence of water vapor for a prolonged period. The Pd/H-ZSM-5 showed high stable activity for this reaction without H2O in the reactant feed, while immediate and irreversible deactivation was observed in the presence of H2O, resulting in no activity after 7 h. The second components such as Co, Rh, Ag, Ce, and Fe introduced individually to the Pd/H-ZSM-5 enhanced the durability, and in particular the addition of 3.3 wt.% Co led to a stable NO conversion for more than 40 h in the presence of H2O. 相似文献
147.
Keiichi Honda Nanao Hayashi Fumiko Abe Tatsuo Yamauchi 《Journal of chemical ecology》1997,23(7):1703-1713
A giant danaid butterfly, Idea leuconoe, specializes on apocynaceous plants such as Parsonsia laevigata, which has been reported to contain pyrrolizidine alkaloids. Females of I. leuconoe deposited eggs in response to methanolic extract of P. laevigata, and subsequent bioassay-guided fractionation of the extract revealed that phytochemicals crucial for host recognition by ovipositing females are Parsonsia-specific macrocyclic pyrrolizidine alkaloids including parsonsianine, parsonsianidine, and 17-methylparsonsianidine. Parsonine, another P. laevigata pyrrolizidine component with a keto-dihydropyrrolizine moiety that is closely related in structure to male pheromones of the butterfly, and several nonhost pyrrolizidine alkaloids were entirely inactive. We interpret these data as strong evidence for an ancestral association through herbivory between danaid butterflies and pyrrolizidine alkaloids. 相似文献
148.
To identify the differences in the knowledge production between disciplines, we analyzed the relation between the average
paper length and impact factor of 100 journals from 5 disciplines. We found negative correlation between the average length
and the impact factor in the natural sciences, but not in the social sciences. We also analyzed the structures of paper and
the citation patterns. These analyses are expanded to the comparison between Mode 1 and Mode 2. All results showed the natural
sciences articles could emphasize the differences from previous studies and be diffused effectively by the short standardized
style of paper.
This research is partly funded by International Program in Special Coordinating Funds for Promoting S&T from Science and Technology
Agency of Japan. 相似文献
149.
150.
A study was made of a centrifugal pressure nozzle with large orifice diameter (8-10 nun) for producing dry milk in capacity of 2-3 tons per hour to develop some performance data on spray distribution, drop size distribution, and capacity with changing spray drying conditions such as nozzle pressure, orifice diameter and spray angle. Experimental results were shown as follows. (1) A centrifugal pressure nozzle of large capacity such as 5,000- 5,500 l/hr at 150 kg/cm2 spray pressure and 110°s ray angle was designed by using the nozzle parameter Si/dedi√di/di. (2) Atomization characteristics were greatly affected by the ratio of orifice diameter (de) to the length (L) of the nozzle core. The smaller the ratio, around 0.125, the better are the atomizing effects. (3) The large orifice can be used at least 3,000 hr in the spray drying operation for milk without any wear in the orifice although it is only made of stainless steel. As a result, a spray dryer of large capacity for dry milk has been operated by a mono nozzle with a large orifice without any trouble for a long time 相似文献