Refine your search:     
Report No.
 - 
Search Results: Records 1-20 displayed on this page of 23

Presentation/Publication Type

Initialising ...

Refine

Journal/Book Title

Initialising ...

Meeting title

Initialising ...

First Author

Initialising ...

Keyword

Initialising ...

Language

Initialising ...

Publication Year

Initialising ...

Held year of conference

Initialising ...

Save select records

Journal Articles

Development of the minimally invasive laser therapy for endometrial lesions

Shigetomi, Hiroshi*; Oka, Kiyoshi; Oi, Hidekazu*; Furukawa, Naoto*; Yoshida, Shozo*; Kawaguchi, Ryuji*; Nagai, Akira*; Haruta, Shoji*; Yanase, Yasuhito*; Akasaka, Julia*; et al.

Nihon Reza Igakkai-Shi, 33(2), p.131 - 135, 2012/08

no abstracts in English

Journal Articles

A New method for separating the $$D$$$$_{3}$$ and $$C$$$$_{2v}$$ isomers of C$$_{78}$$

Han, A. H.*; Wakahara, Takatsugu*; Maeda, Yutaka*; Akasaka, Takeshi*; Fujitsuka, Mamoru*; Ito, Osamu*; Yamamoto, Kazunori; Kako, Masahiro*; Kobayashi, Kaoru*; Nagase, Shigeru*

New Journal of Chemistry, 33(3), p.497 - 500, 2009/03

 Times Cited Count:7 Percentile:32.59(Chemistry, Multidisciplinary)

A new chemical method can be applied to isolate the isomers of C$$_{78}$$. The photochemical cycloaddition of a mixture of C$$_{78}$$($$D$$$$_{3}$$) and C$$_{78}$$($$C$$$$_{2v}$$) with disilirane affords only the mono-adduct of the $$C$$$$_{2v}$$ isomer of C$$_{78}$$. The counter part (C$$_{78}$$($$D$$$$_{3}$$)) does not give the mono-adduct with disilirane. The $$D$$$$_{3}$$ isomer itself and the adduct of the $$C$$$$_{2v}$$ isomer of C$$_{78}$$ with disilirane was easily separated by a HPLC procedure. A facile oxidative desilylation of the adduct took place, resulting in the formation of pristine C$$_{78}$$($$C$$$$_{2v}$$). In this context, the separation and the isolation of two isomers of C$$_{78}$$($$C$$$$_{2v}$$) and C$$_{78}$$($$D$$$$_{3}$$) were successfully accomplished by using a silylation-oxidative desilylation process.

Journal Articles

Does Gd@C$$_{82}$$ have an anomalous endohedral structure? Synthesis and single crystal X-ray structure of the carbene adduct

Akasaka, Takeshi*; Kono, Takayoshi*; Takematsu, Yuji*; Nikawa, Hidefumi*; Nakahodo, Tsukasa*; Wakahara, Takatsugu*; Ishitsuka, Midori*; Tsuchiya, Takahiro*; Maeda, Yutaka*; Liu, M. T. H.*; et al.

Journal of the American Chemical Society, 130(39), p.12840 - 12841, 2008/10

 Times Cited Count:75 Percentile:84.46(Chemistry, Multidisciplinary)

We report here the results on single crystal X-ray crystallographic analysis of the Gd@C$$_{82}$$ carbene adduct (Gd@C$$_{82}$$(ad), Ad=adamantylidene). The Gd atom in Gd@C$$_{82}$$(Ad) is located at an off-centered position near a hexagonal ring in the C2v-C$$_{82}$$ cage, as found for M@C$$_{82}$$ (M = Sc and La) and La@C$$_{82}$$(Ad). Theoretical calculation also confirms the position of the Gd atom in the X-ray crystal structure.

JAEA Reports

Development of plasma stored energy feedback control and its application to high performance discharges on JT-60U

Oikawa, Toshihiro; Tsuchiya, Katsuhiko; Kurihara, Kenichi; Kawamata, Yoichi; Fukuda, Takeshi*; Fujita, Takaaki; Akasaka, Hiromi; Yonekawa, Izuru; Neyatani, Yuzuru

JAERI-Research 2003-027, 19 Pages, 2003/12

JAERI-Research-2003-027.pdf:1.14MB

no abstracts in English

Journal Articles

Bulk Synthesis and Characterization of Carbon Nanocapsules Containing Lanthanum Carbide

Yamamoto, Kazunori; Wakahara, Takatsugu*; Akasaka, Takeshi*

MA2004-01 (CD-ROM), 0 Pages, 2003/00

Carbon nanocapsules stuffed with lanthanum carbide did not degrade after exposure to air for considerable length of time, suggesting the carbide particle was completely enclosed within the carbon shell, although the carbide readily hydrolyze in moist air. In this study we present our optimization study that attempted to determine the effect of variations of the processing conditions on the morphorogy of the carbon nanocapsules.

Journal Articles

Plasma real-time control system for advanced tokamak operation scenarios in JT-60

Kurihara, Kenichi; Kawamata, Yoichi; Akiba, K.*; Miura, Yushi; Akasaka, Hiromi; Adachi, H.*; Hoshi, Y.*; Fukuda, Takeshi; Oikawa, Toshihiro

IEEE Transactions on Nuclear Science, 47(2), p.205 - 209, 2000/04

no abstracts in English

Journal Articles

Exohedral adducts of La@C$$_{82}$$

Akasaka, Takeshi*; Kato, Tatsuhisa*; Kobayashi, Kaoru*; Nagase, Shigeru*; Yamamoto, Kazunori; Funasaka, Hideyuki; Takahashi, Takeshi

Nature, 374, p.600 - 601, 1994/04

 Times Cited Count:153 Percentile:99.11(Multidisciplinary Sciences)

no abstracts in English

Journal Articles

None

; Akasaka, Naoaki; Mitsugi, Takeshi; Donomae, Takako; Ukai, Shigeharu;

ANS Winter Meeting, , 

None

Oral presentation

Protective nature of the outer graphitic cages against oxidation of the inner LaC$$_{2}$$ crystallites in nanocapsules

Yamamoto, Kazunori; Wakahara, Takatsugu*; Akasaka, Takeshi*

no journal, , 

There has been great interest in the incorporation of foreign materials into fullerene-like carbon structures (C$$_{60}$$, nanotubes, nanocapsules). Nanocapsules filled with LaC$$_{2}$$ crystallites were discovered in carbonaceous cathode deposits grown by arc discharge under an inert gas atmosphere in 1993. Although rare-earth carbides are hygroscopic and readily hydrolyze in moist air, the carbides in the capsules did not degrade even after a decade of exposure. Moreover, empty nanocapsules and nanotubes are more resistant to oxidation than other forms of carbon (such as diamond, soot, graphite, and C$$_{60}$$). Therefore higher oxidation resistance is also expected for the filled nanocapsules. In this study protective nature of the outer graphitic cages of stuffed nanocapsules was demonstrated.

Oral presentation

Oxidative properties of carbon nanocapsules encapsulated with lanthanum carbide

Yamamoto, Kazunori; Wakahara, Takatsugu*; Akasaka, Takeshi*

no journal, , 

There has been great interest in the incorporation of foreign materials into fullerene-like carbon structures. Nanocapsules filled with LaC$$_{2}$$ crystallites were discovered in carbonaceous cathode deposits grown by arc discharge. Although rare-earth carbides are hygroscopic and readily hydrolyze in moist air, the carbides in the capsules did not degrade even after a decade of exposure. Moreover, empty nanocapsules are more resistant to oxidation than other forms of carbon (such as diamond, soot, graphite, and C$$_{60}$$). Therefore higher oxidation resistance is also expected for the filled nanocapsules. In this study protective nature of the outer graphitic cages of stuffed nanocapsules was demonstrated. Nanocapsules stuffed with LaC$$_{2}$$ were heated in thermogravimetric analyser in excess air. The observation showed that all carbon nanocapsules including filled and empty nanocapsules seen in the sample were completely changed, suggesting degradation of nanocapsules at 580$$^{circ}$$C.

Oral presentation

Encapsulation of La in spherical graphitic shells by Arc discharge

Yamamoto, Kazunori; Wakahara, Takatsugu*; Akasaka, Takeshi*

no journal, , 

There has been great interest in the incorporation of foreign materials into fullerene-like multi-shell carbon cage structures such as polyhedral nanocapsules and spherical onions. Polyhedral nanocapsules filled with LaC$$_{2}$$ crystals were discovered in carbonaceous cathode deposits formed by arc-discharge evaporation and following deposition of La with carbon under an inert gas atmosphere. The transmission electron microscopy (TEM) characterization of the deposits shows that polyhedral graphitic particles generally show a hollow in the center whose shape is given by the outer faceting of the particle. On the other hand, spherical multi-shell onions filled with metals were formed by irradiation of a composite of graphitic carbon and nano-sized metal crystals at higher temperature alone. In this study spherical multi-shell onions filled with La have been found in the conventional fullerene arc soot of La synthesized at 35 Torr He.

Oral presentation

High temperature treatment of carbon fullerene soot and formation of multi-shell carbon nano-capsules filled with La carbide

Yamamoto, Kazunori; Wakahara, Takatsugu*; Akasaka, Takeshi*

no journal, , 

There has been great interest in the incorporation of foreign materials into fullerenes, nanotubes, and fullerene-like multi-shell cage structures such as polyhedral nanocapsules. Polyhedral nanocapsules containing La element were not found in the fullerene soot, which were discovered in carbonaceous cathode deposits in 1993 formed by arc-discharge evaporation and following deposition of La with carbon on the cathode surface. In this study, multi-shell single-digit nanoparticles filled with La have been found in La fullerene arc soot synthesized at 35 Torr He. Furthermore, the soot materials have been treated at temperatures between 1000 and 2200$$^{circ}$$C in vacuum. The single-digit nanoparticles have been transformed into larger multi-shell nanocapsules filled with LaC$$_{2}$$.

Oral presentation

Influence of high temperature treatments on fullerene soot and formation of multi-shell carbon nanoparticles filled with LaC$$_{2}$$

Yamamoto, Kazunori; Wakahara, Takatsugu*; Akasaka, Takeshi*

no journal, , 

There has been great interest in the incorporation of foreign materials into fullerenes, nanotubes, and fullerene-like multi-shell cage structures such as polyhedral nanocapsules. Polyhedral nanocapsules containing La element were not found in the fullerene soot, which were discovered in carbonaceous cathode deposits in 1993 formed by arc-discharge evaporation and following deposition of La with carbon on the cathode surface. In this study, multi-shell single-digit nanoparticles filled with La have been found in La fullerene arc soot synthesized at 35 Torr He. Furthermore, the soot materials have been treated at temperatures between 1000 and 2200$$^{circ}$$C in vacuum. The single-digit nanoparticles have been transformed into larger multi-shell nanocapsules filled with LaC$$_{2}$$.

Oral presentation

High temperature treatment of some specially synthesized fullerene soot and formation of lanthanum-carbide encapsulated carbon nanocapsules

Yamamoto, Kazunori; Wakahara, Takatsugu*; Akasaka, Takeshi*

no journal, , 

no abstracts in English

Oral presentation

Heat treatment effect of fullerene soot and formation of carbon nanocapsules containing LaC$$_{2}$$

Yamamoto, Kazunori; Akasaka, Takeshi*

no journal, , 

no abstracts in English

Oral presentation

Characterization of La fullerene soot and formation of LaC$$_{2}$$ containing multi-shell carbon nanocapsules by heat treatment

Yamamoto, Kazunori; Akasaka, Takeshi*

no journal, , 

La fullelene soot prepared by a conventional DC arc discharge method at low He pressure (15, 20, 35, 45 Torr) have been characterized, then used as precursors of LaC2 containing multi-shell carbon nanocapsules by our heat treatment method. The soot materials have been treated at temperatures between 1000 and 2200$$^{circ}$$C in vacuum. The soot matrrials have been characterized by TEM and thermogravimetric (TG) analysis. Multi-shell single-digit nanoparticles filled with La have been found in La fullerene arc soot synthesized at 35 and 45 Torr He, which is lower than the ordinal pressure for the fullerene and nanotube condition. On the other hand the nanoparticles have not been found in La fullerene arc soot synthesized at 15 Torr He.

Oral presentation

Raman and TEM studies of heat-treated La fullerene soot

Yamamoto, Kazunori; Shamoto, Shinichi; Akasaka, Takeshi*; Wakahara, Takatsugu*; Miyazawa, Kunichi*

no journal, , 

no abstracts in English

Oral presentation

Nano-particle formation by high temperature treatment of La-fullerene soot

Yamamoto, Kazunori; Akasaka, Takeshi*

no journal, , 

no abstracts in English

Oral presentation

Formation of LaC$$_{2}$$ containing multi-shell carbon nanocapsules by rapid heat treatment of La fullerene soot synthesized at 20 Torr He

Yamamoto, Kazunori; Akasaka, Takeshi*

no journal, , 

We previously reported that the endohedral multi-shell nanocapsules were obtained easily by vacuum heat treatment (1000-2200 $$^{circ}$$C) of La fullelene soot, which was prepared at restricted He pressure of 30-50 Torr. The pressure is much lower than preferential pressure of metallofullerene formation (100-200 Torr) and carbon nanotube formation (500 Torr). TEM observation revealed that multi-shell single-digit nanoparticles filled with La were found in La fullerene soot synthesized at 30-50 Torr He, not in that synthesized at 15, 20, 25 Torr He. Recently we have found that the endohedral multi-shell nanocapsules were obtained by rapid heat treatment of La fullelene soot synthesized at 20 and 25 Torr He. Details of rapid heat treatment and results of characterization will be discussed in our presentation.

Oral presentation

23 (Records 1-20 displayed on this page)