巻号一覧
2004 巻 (2004)
- 215 号 p. 221-
- 214 号 p. 179-
- 213 号 p. 123-
- 212 号 p. 69-
- 211 号 p. 4-
2004 巻, 213 号
選択された号の論文の7件中1～7を表示しています
- |<
- <
- 1
- >
- >|
-
藤本 宏之, 白石 稔2004 年 2004 巻 213 号 p. 123-127
発行日: 2004/06/15
公開日: 2010/06/28
ジャーナル フリーThe theory for Fourier transform of X-ray diffraction intensity proposed by Hirsch was applied to the microstructure analysis of mesocarbon microbeads. The precision of the result of Fourier transform was improved by the consideration of measurement and integration conditions, and the distribution of the interlayer-spacing of carbon was roughly estimated.抄録全体を表示PDF形式でダウンロード (869K) -
奥山 圭一, 加藤 純郎, 山田 哲哉, 座古 勝2004 年 2004 巻 213 号 p. 128-133
発行日: 2004/06/15
公開日: 2010/06/28
ジャーナル フリーThe outer wall of reentry vehicles is covered with heat shield materials in order to protect them from severe aerodynamic heating. An ablator is a type of heat shield material effective for reentry vehicles. In particularly an ablator made of Phenolic carbon fiber-reinforced plastics (CFRP) is known to possess superior resistance against severe aerodynamic heating. Phenolic CFRP is pyrolyzed and carbonized by aerodynamic heating and is recessed by oxidation. Like graphite, carbonized Phenolic CFRP manifests distinctly different oxidation characteristics in the rate and the diffusion-controlled regions. Its surface recession in both the regions can be expressed by Metzger's equation. However, the recession behavior predicted by Metzger's equation is inaccurate, because the thermal properties of graphite are used as inputting the equation, regardless of the difference in the thermal characteristics of graphite and carbonized Phenolic CFRP. Accurate prediction of the recession of carbonized Phenolic CFRP requires a precise estimation of its activation energy E, collision-frequency coefficient ko and diffusion-controlled mass transfer constant Co. These parameters were precisely determined in this study, and it was shown that substitution these parameters enabled the accurate prediction of the recession behavior of carbonized Phenolic CFRP.抄録全体を表示PDF形式でダウンロード (1240K) -
奥山 圭一, 座古 勝2004 年 2004 巻 213 号 p. 134-139
発行日: 2004/06/15
公開日: 2010/06/28
ジャーナル フリーAn ablator system, made of a completely carbonized two-layer phenolic CFRP, is able to withstand severe aerodynamic heating during reentry. The surface heat shield material of the two-layer type ablator is made by a technique in which chopped prepreg pieces are compressed at a high temperature. The use of the two-layer type ablator is an epoch-making concept that can attain lighter weight compared with the ablator system using the conventional phenolic CFRP, which surely leaves the non-pyrolyzed layer (virgin layer) to function as a structural member. The chopped cloth ablator is recessed in the chemical reaction between the material surface and oxygen. Although this chopped cloth ablator expands by thermal movement, it gets shrunk by carbonization. After all, the characteristic of the change in temperature of the chopped cloth ablator thickness is unknown. Therefore, it is difficult to estimate the exact stress of the chopped cloth ablator. In this study, the expansion (or shrinking) of the chopped cloth ablator is clarified from the difference in measured isobaric specific heat Cp, and the isochoric specific heat Cv. Cv of the chopped cloth ablator can be predicted using the Einstein frequency v. The measured temperature characteristic of the chopped cloth ablator's thickness was well in agreement with the value estimated based on the difference in Cp, and Cv.抄録全体を表示PDF形式でダウンロード (1016K) -
大関 克知, 大崎 由恵, ゴールマン ボリス, 篠原 邦夫2004 年 2004 巻 213 号 p. 140-143
発行日: 2004/06/15
公開日: 2010/06/28
ジャーナル フリーThe relationship was experimentally investigated between void-size distribution of anode film made of natural graphite particles for lithium-ion batteries and high rate discharge capability. The high rate discharge capability improved, as the modal void diameter increased. Thus, it was considered that lithium-ion diffuses in the electrolyte liquid penetrating through the voids among the particles in the electrode film due to the gradient of lithium-ion concentration. While, the modal diameter of voids increased for graphite powders of higher tapping density. Therefore, it was found that the tapping density was a useful indicator for the graphite particles to yield the film of high rate discharge capability in practical use.抄録全体を表示PDF形式でダウンロード (2600K) -
藤本 宏之, 白石 稔2004 年 2004 巻 213 号 p. 144-150
発行日: 2004/06/15
公開日: 2010/06/28
ジャーナル フリーThe analysis method for the distribution of carbon layer size proposed by Diamond was modified by being combined with the newly developed techniques in the field of X-ray crystallography, so that it was applicable for every carbon material. Each step of the method was examined in detail. As a result, the analysis precision and reliability were enhanced, and the 11 band profile, including the background and impurity peak profiles, was fitted fairly well.抄録全体を表示PDF形式でダウンロード (1473K) -
大谷 朝男2004 年 2004 巻 213 号 p. 151-157
発行日: 2004/06/15
公開日: 2010/06/28
ジャーナル フリーPolymer blend technique as a method to design nanocarbons is described comprehensively. The principal idea of the technique is initially explained, and then some nanocarbons prepared until now are introduced: they are carbon nanofibers, carbon nanotubes, carbon nanospheres, carbon nanoballoons and so on. A high potentiality of the technique is further emphasized through showing two unique shaped carbons which were prepared by tricky methods. Finally merits and demerits of the technique are summarized.抄録全体を表示PDF形式でダウンロード (11450K) -
丸山 茂夫, 澁田 靖2004 年 2004 巻 213 号 p. 158-165
発行日: 2004/06/15
公開日: 2010/06/28
ジャーナル フリーFormation process of single-walled carbon nanotubes (SWNTs) by the catalytic chemical vapor deposition method is studied by molecular dynamics simulations. The random deposition process of carbon atoms to a nano-scale metal catalyst is realized with the multi-body potentials based on density functional theory calculations of small metal-carbon and metal-metal clusters A nanotube cap structure is generated when pieces of the hexagonal network structure emerges from the metal-carbon binary cluster and then coalesces. Furthermore, the tendency of graphitization of carbon atoms is compared for Ni, Co, Fe metal clusters. The Co cluster has a pseudo crystal structure where metal atoms are regularly allocated and embedded in the hexagonal carbon network. On the other hand, carbon atoms cover the entire surface of the Fe cluster. This implies stronger interaction between the graphitic lattice and Co atoms, hence higher graphitization ability. Finally, the mechanism of chirality determination by the stability of nanotube cap structure is discussed in order to explain the recent experimental finding that the near-armchair nanotubes are more dominantly produced for small diameter nanotubes.抄録全体を表示PDF形式でダウンロード (7614K)
- |<
- <
- 1
- >
- >|