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排序方式: 共有947条查询结果,搜索用时 31 毫秒
31.
Z. Jing N. Matsuoka F. Jin N. Yamasaki K. Suzuki T. Hashida 《Journal of Materials Science》2006,41(5):1579-1584
Solidification of Coal Fly-ash (CFA) has been carried out using a hydrothermal processing method. In the hydrothermal processing,
the CFA was first compacted in a mold at 20 - 50 MPa, and then hydrothermally cured in an autoclave. The hydrothermal curing
was performed at 150 – 250°C for 15 – 60 h. The experimental results showed that NaOH solution, Ca(OH)2 content, compaction pressure, autoclave curing temperature and time significantly affected the strength of solidified bodies.
The most important strength-producing constituent in the solidified bodies produced with CFA was tobermorite, or tobermorite-like
calcium silicate hydrate. When the CaO/SiO2 ratio of the starting material was close to 0.83, tobermorite readily formed and the formed tobermorite enhanced the strength
of solidified bodies. The tensile strength determined by the Brazilian test reached more than 10 MPa under the hydrothermal
processing. As such, the hydrothermal processing method may provide a high potential for recycling CFA on a large scale. 相似文献
32.
H.Kyogoku S.Komatsu M.Shinzawa H.Nakayama T.Matsuoka 《粉末冶金技术》2005,23(2):95-99
本文的目的是研究粉末性能对粉末注射成形奥氏体不锈钢的力学性能(特别是疲劳和冲击强度)的影响。试样用混有聚酰氨粘结剂系的水雾化(WA)和气雾化(GA)粉末制成。注射坯在空气中脱粘,而后在不同温度、不同保温时间下真空烧结。粉末性能对烧结体的密度、显微组织和力学性能有显著影响。孔和析出物显示出Ostward时效,而孔和析出物的长大满足Lifshitz-Wagner方程。WA和GA粉末试样的疲劳极限分别约为300MPa和310MPa。它们的疲劳强度略低于常规锻材。烧结体的冲击值随密度增加线性增大。 相似文献
33.
Nakamoto Y Sakata M Sumiya H Shimizu K Irifune T Matsuoka T Ohishi Y 《The Review of scientific instruments》2011,82(6):066104
Nano-polycrystalline diamonds (NPDs) consist of nanosized diamond grains oriented in random directions. They have high toughness and isotropic mechanical properties. A NPD has neither the cleavage feature nor the anisotropy of hardness peculiar to single-crystal diamonds. Therefore, it is thought to be useful as a diamond anvil. We previously reported the usefulness of a NPD as an anvil for high-pressure development. In this study, some additional high-pressure generating tests using diamond anvils of various shapes prepared from NPDs were conducted to investigate the advantage of using NPDs for anvil applications. The results revealed that the achievable pressure value of a NPD anvil with a culet size of more than 300 μm is about 1.5 to 2 times higher than that of single-crystal diamond anvils, indicating that NPD anvils have considerable potential for large-volume diamond anvils with large culet sizes. 相似文献
34.
Thermal Spray Using a High-Frequency Pulse Detonation Combustor Operated in the Liquid-Purge Mode 总被引:1,自引:0,他引:1
T. Endo R. Obayashi T. Tajiri K. Kimura Y. Morohashi T. Johzaki K. Matsuoka T. Hanafusa S. Mizunari 《Journal of Thermal Spray Technology》2016,25(3):494-508
Experiments on thermal spray by pulsed detonations at 150 Hz were conducted. Two types of pulse detonation combustors were used, one operated in the inert gas purge (GAP) mode and the other in the liquid-purge (LIP) mode. In both modes, all gases were supplied in the valveless mode. The GAP mode is free of moving components, although the explosive mixture is unavoidably diluted with the inert gas used for the purge of the hot burned gas. In the LIP mode, pure fuel-oxygen combustion can be realized, although a liquid-droplet injector must be actuated cyclically. The objective of this work was to demonstrate a higher spraying temperature in the LIP mode. First, the temperature of CoNiCrAlY particles heated by pulsed detonations was measured. As a result, the spraying temperature in the LIP mode was higher than that in the GAP mode by about 1000 K. Second, the temperature of yttria-stabilized zirconia (YSZ) particles, whose melting point was almost 2800 °C, heated by pulsed detonations in the LIP mode was measured. As a result, the YSZ particles were heated up to about 2500 °C. Finally, a thermal spray experiment using YSZ particles was conducted, and a coating with low porosity was successfully deposited. 相似文献
35.
36.
Toshiki Ozaki Tatsuya KotoTam V. Nguyen Hideyuki NakanishiTomohisa Norisuye Qui Tran-Cong-Miyata 《Polymer》2014
Influence of the Trommsdorff–Norrish (T–N) effect on the phase separation of methyl methacrylate (MMA)/poly(ethyl acrylate) (PEA) mixtures undergoing photo-polymerization was examined by a combination of several experimental techniques. By FT-IR spectroscopy, it was found that the polymerization conversion explosively increases at the onset of this T–N effect. The characteristic irradiation time τ at which this effect occurs, strongly depends on the light intensity and gradually shifts to early time as the irradiation intensity increases. The shrinkage of the mixture observed in situ by laser-scanning confocal microscopy exhibits a transition at a particular irradiation time which is slightly longer than the characteristic time τ. By gel permeation chromatography (GPC), it was found that the molecular weight of the resulting PMMA was almost unchanged before τ and suddenly increases about an order of magnitude after the onset of the auto-acceleration effect. Finally, the characteristic length scales of the morphology also quickly increase with irradiation time and are eventually frozen by this T–N effect. These experimental results indicate that the Trommsdorff–Norrish effect plays an important role in the kinetic processes of polymerization-induced phase separation, suggesting an efficient tool to control the morphology of the polymerizing mixture. 相似文献
37.
38.
For some adhesive joints where the main difference is the degree of contact at the interface, failure occurs not at the interface, but some distance away in the polymer itself. This cohesive mode of failure in the polymer was always found to be the case in our studies of cupric oxide to branched polyethylene interfaces, even where the joint was so weak that the peeled surface seemed clean of the polymer to the naked eye. It was observed that the strength of the joint was associated with the coarseness of the texture of the peeled surface of the polymer. With a differential scanning calorimetry technique we have shown that the coarseness of the surface texture and therefore the strength of the joint, is a direct function of the amount of polymer involved in plastic deformation. The strength criteria for the adhesive joint of this kind is thus the energy of deformation and not the maximum tensile stress that the material can withstand. 相似文献
39.
Yunosuke Abe Toshiki Aoki Hongge Jia Shingo Hadano Takeshi Namikoshi Yuriko Kakihana Lijia Liu Yu Zang Masahiro Teraguchi Takashi Kaneko 《Polymer》2012,53(11):2129-2133
A soluble and stable one-handed helical conjugated polymer without the coexistence of any other chiral moieties was successfully synthesized by asymmetric-induced polymerization of a chiral monomer having two hydroxyl groups followed by desubstitution of the chiral groups in a solid membrane state. The reason for the success was the polymer reaction was carried out in the membrane state. This is an alternative method to obtain such a unique chiral polymer which was obtained only by the helix-sense-selective polymerization (HSSP) we reported before. In addition the efficiency of the chiral induction was higher than that of the HSSP. It is interesting that the “Membrane state” acted like as if a protecting group. 相似文献
40.
Rapid pyrolysis was conducted in a drop tube reactor using seven coals under various operating conditions. In addition to dense char, porous chars (network char and cenospheric char) were formed by the rapid pyrolysis under certain conditions. Porous char was mainly composed of film-like carbon and skeleton carbon. The pyrolyzed coal char particles were characterized in detail. Morphology and bulk density of porous char were quite different from the dense char formed under the same conditions, but elemental composition and BET surface area were similar to each other. CO2 gasification reactivity of porous char was lower than dense char in the later gasification stage, and this was ascribed to the low reactivity of skeleton carbon. 相似文献