巻号一覧
2015 巻 (2015)
- 270 号 p. 225-
- 269 号 p. 181-
- 268 号 p. 131-
- 267 号 p. 77-
- 266 号 p. 1-
2015 巻, 267 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
- >
- >|
解説
-
Wilhelm Frohs, Felix Roeßner原稿種別: Review Paper
2015 年 2015 巻 267 号 p. 77-83
発行日: 2015/04/01
公開日: 2015/05/01
ジャーナル フリーPetroleum-based needle coke will be losing its dominance for the production of graphite electrodes, due to the growing production capacities in the field of coal tar pitch (CTP)-based needle coke types. Up to now, CTP needle coke does not harmonize with the conditions prevailing in modern lengthwise graphitization furnaces. The reason is the volumetric expansion during graphitization—the so called puffing—caused by the removal of gaseous nitrogen. Earlier research activity has failed to depress (or even prevent) the nitrogen puffing of CTP needle coke to a similar level as found with petroleum needle coke standards. This paper gives a brief review of the research carried out in the past. It evaluates several measures to depress nitrogen puffing and reports recently obtained results. It is expected that a chemical inhibition of nitrogen puffing is not possible on an industrial scale. However, solutions are seen in physical measures—like thermal reduction of the nitrogen content and in tailoring the coke morphology by the thermal processes involved in its production.抄録全体を表示PDF形式でダウンロード (1350K) -
Masayuki Kawaguchi原稿種別: Review Paper
2015 年 2015 巻 267 号 p. 84-93
発行日: 2015/04/01
公開日: 2015/05/01
ジャーナル フリーCarbon-based materials containing heteroatoms, such as boron and nitrogen, are called heteroatom-substituted carbon alloys. Preparation and applications of heteroatom-substituted carbon alloys, particularly materials composed of boron, carbon and nitrogen (B/C/N materials), and carbon and nitrogen (C/N materials) are summarized in this review. Examples of potential applications of the materials to energy conversion and storage systems, such as secondary batteries, capacitors and photocatalysts are described. B/C/N materials can be intercalated with sodium (Na) to form a first stage intercalation compound, which can be used as the anode of Na ion batteries. C/N materials used as the electrode of capacitors have higher volumetric capacities than commercially-used activated carbon, and show photocatalytic behavior as an electrode for the production of hydrogen by the electrolysis of water. Important roles of boron and nitrogen in B/C/N and C/N materials are also discussed.抄録全体を表示PDF形式でダウンロード (2783K)
論文
-
瀧上 眞知子, 馬場 伸弥, 尾崎 純一原稿種別: 論文
2015 年 2015 巻 267 号 p. 94-100
発行日: 2015/04/01
公開日: 2015/05/01
ジャーナル フリーCarbon catalysts for the oxygen reduction reaction (ORR) were prepared from mixtures of humic acid and cobalt compounds. To examine the effects of cobalt and nitrogen on the ORR, cobalt phthalocyanine (CoPc), cobalt chloride (CoCl2) and phthalocyanine (H2Pc) were mixed with the humic acid and carbonized at 800 °C. The carbons were washed with hydrochloric acid to remove metals on the surface of the carbons. The carbon prepared by mixing HA, CoCl2 and H2Pc (HA-CoCl2-H2Pc) had the highest ORR activity, while the carbons, HA-CoPc and HA-H2Pc, had lower ORR activities. HA-CoCl2 had moderate activity. The results imply that both of cobalt and nitrogen are important to obtain ORR catalysts with higher activities. A uniform distribution of Co atoms in the precursor is also important to obtain carbon alloy catalysts with higher ORR activities.抄録全体を表示PDF形式でダウンロード (1515K)
ノート
-
根本 康成, 天野 佳正, 町田 基, 今関 文夫原稿種別: ノート
2015 年 2015 巻 267 号 p. 101-104
発行日: 2015/04/01
公開日: 2015/05/01
ジャーナル フリーIt has been found that activated carbon oxidized with a solution prepared by dissolving (NH4)2S2O8 in 1.0 M sulfuric acid has a very large number of functional groups and increases the adsorption of metal ions. However, the oxidation simultaneously produces a decrease in surface area and causes the activated carbon to have a fragile structure. This study examined the effects of nitric acid, sodium sulfate and sulfuric acid as (NH4)2S2O8 solvents used for the oxidation of activated carbons on Ni(II) adsorption, oxygen content, functional groups and surface area. The results showed that 1.0 M solvents introduce more carboxy groups than 0.1 M solvents and a 1.0 M sodium sulfate solution produces a high adsorption capacity without decreasing the surface area drastically.抄録全体を表示PDF形式でダウンロード (483K)
解説
-
斎藤 幸恵原稿種別: 解説
2015 年 2015 巻 267 号 p. 105-112
発行日: 2015/04/01
公開日: 2015/05/01
ジャーナル 認証ありScrewed-stacked cone carbon (SSCC) is produced by the pyrolysis of certain organic compounds and appears to be columnar or whisker-like in shape and formed of continuous helical hexagonal carbon layers. The rotation angle between adjacent layers is commonly 21.7° or 27.8°. It has been found that SSCCs show birefringence and vertical orientation in a magnetic field. Although they are a kind of ordered turbostratic carbon, they intercalate sulfuric acid and can be subsequently expanded like graphite by heating. Further studies will elucidate their mechanical and electric properties and how they depend on the continuous non-planar graphitic features.抄録全体を表示PDF形式でダウンロード (4066K)
資料
-
藤本 宏之原稿種別: 資料
2015 年 2015 巻 267 号 p. 113-117
発行日: 2015/04/01
公開日: 2015/05/01
ジャーナル 認証ありThe structural parameters of coke and mesocarbon microbeads were measured using three diffractometers with different angular resolutions based on the standard X-ray diffraction measurement procedure for carbon (Gakushin method). There was no observable difference in the values of the lattice constants, a0 and c0, obtained using the three instruments. However, because the half width of the profile is affected by the angular resolution there were differences in the measured crystallite size.抄録全体を表示PDF形式でダウンロード (1151K)
学位論文紹介
-
工藤 泰彦原稿種別: 学位論文紹介
2015 年 2015 巻 267 号 p. 118-119
発行日: 2015/04/01
公開日: 2015/05/01
ジャーナル 認証あり2004年にグラフェンの簡便な単離法が報告されて以来，Fermi準位近傍の特異な電子構造に起因する電子物性の研究が広く行われてきた。一方，グラフェンの端における電子構造はその幾何構造に依存し，特にジグザグ型の端では副格子対称性の破れに起因する非結合性の局在電子状態（エッジ状態）がFermi準位に現れる。本学位論文ではこのエッジ状態の発現に注目し，グラフェンに端を導入した場合の電子散乱現象の検討，X線吸収分光法によるエッジ状態の証明と，グラフェン端の構造の化学的制御法について取り組んだ。
本学位論文は7つの章で構成される。第1章では化学に関する様々な課題の中からグラフェン，そしてグラフェン端に着目することの意義と目的を俯瞰的に述べた。第2章ではグラフェンの特異な電子構造と電子輸送現象，そしてナノグラフェンのエッジ状態について基礎的な理論をまとめた。第3章では最近のグラフェンの実験的研究の進展について述べた。清浄なグラフェンの電子構造に由来する特異な物性と，不純物や欠陥などによる効果が検討されてきたことをまとめ，一方でナノグラフェンを用いたエッジ状態の研究の経緯を述べた。その上で，グラフェンにエッジ状態を発現させ，端の化学構造を制御することでエッジ状態に由来する物性を解明する必要があるという本論文の課題の意義を述べた。第4章では端を導入したグラフェンの電子散乱特性を磁場中の電子輸送とRaman分光の測定結果に基づき議論した。試料中の主要な散乱源が荷電不純物なのかグラフェン端なのかを検証し，エッジ状態の寄与が期待される後者の試料構造を指摘した。第5章では第4章の結論に基づき作製した試料においてX線吸収端微細構造(NEXAFS)の測定によりエッジ状態の存在を確かめた。さらに，欠陥量を著しく増やし表面をアモルファス化させたときのπ*ピークとエッジ状態ピークの変化の相違を，遮蔽効果と伝導電子密度の観点から説明した。第6章ではグラフェン端の任意の官能基化方法の構築を目的に，その始点として水素化処理方法について検討した。第7章では本学位論文の総括と将来展望を述べた。本稿では，本成果の主要部である第4章から第6章について記述する。抄録全体を表示PDF形式でダウンロード (357K)
- |<
- <
- 1
- >
- >|