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51.
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Mizue Munekata Seiichi Kimura Hiroaki Kurishima Jinsuke Tanaka Sohei Yamamoto Hiroyuki Yoshikawa Kazuyoshi Matsuzaki Hideki Ohba 《热科学学报(英文版)》2008,17(1):56-60
Recently, development of high technology has been required for the formation of thin uniform film in manufacturing processes of semiconductor as the semiconductor instruments become more sophisticated. Spin coating is usually used for spreading photoresist on a wafer surface. However, since rotating speed of the disk is very high in spin coating, the dropped photoresist scarers outward and reattaches on the film surface. A catch cup is set up outside the wafer in spin coating, and scattered photoresist mist is removed from the wafer edge by the exhaust flow generated at the gap between the wafer edge and the catch cup. In the dry process of a spin coating, it is a serious concern that the film thickness increases near the wafer edge in the case of low rotating speed. The purpose of this study is to make clear the effect of the catch cup geometry on the 3D boundary layer flow over the wafer surface and the drying rate of liquid film. 相似文献
53.
The purpose of this study is to establish the high-accurate prediction method of particle separation in a cyclone separator. Numerical simulation of the swirling flows in a cyclone separator is performed by using a large eddy simulation (LES) based on a Smagorinsky model. The validity of the simulation and the complicated flow characteristics are discussed by comparison with experimental results. Moreover, particle motions are treated by a Lagrangian method and are calculated with a one-way method. A performance for particle separation is predicted from the results of the particle tracing. As results of our investigation, the influences of the inserted height of the outlet pipe on the performance for particle separation of cyclone separator are shown. 相似文献
54.
Lipid A of Gram-negative bacteria is known to represent a central role for the immunological activity of endotoxin. Chemical structure and biosynthetic pathways as well as specific receptors on phagocytic cells had been clarified by the beginning of the 21st century. Although the lipid A of enterobacteria including Escherichia coli share a common structure, other Gram-negative bacteria belonging to various classes of the phylum Proteobacteria and other taxonomical groups show wide variety of lipid A structure with relatively decreased endotoxic activity compared to that of E. coli. The structural diversity is produced from the difference of chain length of 3-hydroxy fatty acids and non-hydroxy fatty acids linked to their hydroxyl groups. In some bacteria, glucosamine in the backbone is substituted by another amino sugar, or phosphate groups bound to the backbone are modified. The variation of structure is also introduced by the enzymes that can modify electrostatic charges or acylation profiles of lipid A during or after its synthesis. Furthermore, lipid A structure can be artificially modified or engineered by the disruption and introduction of biosynthetic genes especially those of acyltransferases. These technologies may produce novel vaccine adjuvants or antagonistic drugs derived from endotoxin in the future. 相似文献
55.
A data set of the coefficient of vertical subgrade reaction for a plate diameter of 30 cm, KP.FWD, measured by Portable Falling Weight Deflectometer tests in full-scale compaction tests on sandy soil using various types of compaction machines was analysed. Based on this analysis and the previous analysis of a CBR data set from another full-scale compaction test series, a set of conclusions could be drawn. The soil stiffness indexes (SSIs), CBR and KP.FWD, can be expressed by, respectively, an empirical equation multiplying a function of ρd and another of Sr, where CBR and KP.FWD decrease significantly as Sr increases. As such, ρd values cannot be estimated from SSI alone. By fixing the field ρd – w compaction curve by keeping the soil type and the field compaction energy level, CELf, to those in the field compaction tests in which the SSI – ρd – Sr correlation has been calibrated, field compacted ρd & w states can be estimated by measuring the SSI values. Then, by the upper-bound and lower-bound control of SSI, the field compacted states approach the specified target, where, typically, ρd = the maximum dry density for CELf and Sr = the optimum degree of saturation, (Sr)opt. A method to incorporate this indirect but fast SSI-based compaction control into the conventional ρd & w-based compaction control is proposed. 相似文献
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In this article, leading research and development activities of shearing in Japan are reviewed. Main contents are elucidation of shearing mechanism, theoretical analysis, tool life, burr-free blanking, precision shearing, bar cropping, pipe cutting, slitting, shearing of non-metallic materials, tool making, shearing of extremely thin sheets, etc. 相似文献
58.
Kazuyoshi Tanaka Tsuneaki Koike Katsuya Ueda Katsushisa Ohzeki Tokio Yamabe Shizukuni Yata 《Synthetic Metals》1985,11(2):61-73
The electronic structures of polyacenacene (PAA) and its geometrical isomer, polyphenanthrophenanthrene (PPhP) have been studied using the tight-binding SCF-CO (self consistent field-crystal orbital) method with respect to a design of one-dimensional (1D) graphite. The geometry of each polymer is optimized from the energetic point of view. It has been found that from the analysis of the electronic structure of its optimized geometry, PAA favours the structure without the carbon-carbon bond alternations, yielding no band gap. In this sense, PAA is a typical 1D-graphite. On the other hand, it is predicted that the magnitude of the band gap of PPhP in its optimized geometry is almost equal to that of trans-polyacetylene. 相似文献
59.
Iron aluminides exhibit good resistance to high-temperature sulfidizing and oxidizing environments and potential for structural applications at high temperatures under corrosive environments. In this study, Fe-Al intermetallic compound was prepared by multi-layered roll-bonding of elemental Fe and Al foils. The process consisted of the accumulative roll-bonding (ARB) for making a laminated Fe/Al sheet and the subsequent heat treatment promoting a solid phase reaction in the laminated Fe/Al sheet. The microstructures produced at each processing stage were characterized by optical microscopy and scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectroscopy (EDS). Vickers microhardness testing was used for hardness determination. A homogeneous intermetallic compound of Fe3Al or FeAl could be obtained after the subsequent heat treatment for 1.8 ks at 973 K and for 10.8 ks at 1123 or 1173 K. 相似文献
60.