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Journal Articles

Sulfate complexation of element 104, Rf, in H$$_{2}$$SO$$_{4}$$/HNO$$_{3}$$ mixed solution

Li, Z.*; Toyoshima, Atsushi; Asai, Masato; Tsukada, Kazuaki; Sato, Tetsuya; Sato, Nozomi; Kikuchi, Takahiro; Nagame, Yuichiro; Sch$"a$del, M.; Pershina, V.*; et al.

Radiochimica Acta, 100(3), p.157 - 164, 2012/03

 Times Cited Count:8 Percentile:32.85(Chemistry, Inorganic & Nuclear)

Journal Articles

Fluorido complex formation of element 104, rutherfordium (Rf)

Ishii, Yasuo; Toyoshima, Atsushi; Tsukada, Kazuaki; Asai, Masato; Li, Z.*; Nagame, Yuichiro; Miyashita, Sunao*; Mori, Tomotaka*; Suganuma, Hideo*; Haba, Hiromitsu*; et al.

Bulletin of the Chemical Society of Japan, 84(9), p.903 - 911, 2011/09

 Times Cited Count:12 Percentile:50.96(Chemistry, Multidisciplinary)

The cation-exchange behavior of element 104, rutherfordium (Rf), was investigated together with its lighter group-4 homologues Zr and Hf, and the tetravalent pseudo-homologue Th in HF/HNO$$_{3}$$ mixed solution. The results demonstrate that distribution coefficients ($$K_{d}$$) of Rf in HF/0.10 M HNO$$_{3}$$ decrease with increasing concentration of the fluoride ion [F$$^{-}$$], indicating the consecutive formation of fluorido complexes of Rf. We also measured the $$K_{d}$$ values of Rf and the homologues as a function of the hydrogen ion concentration [H$$^{+}$$]. The log $$K_{d}$$ values decrease linearly with an increase of log [H$$^{+}$$] with slopes between -2.1 and -2.5. This indicates that these elements are likely to form the same chemical compounds: mixture of [MF]$$^{3+}$$ and [MF$$_{2}$$]$$^{2+}$$ (M = Rf, Zr, Hf and Th) in the studied solution. It is also ascertained that sequence in the fluoride complex formation is Zr $$sim$$ Hf $$>$$ Rf $$>$$ Th.

Journal Articles

Extraction of chromatographic behavior of Rf, Zr, and Hf in HCl solution with styrenedivinylbenzene copolymer resin modified by TOPO (trioctylphosphine oxide)

Toyoshima, Atsushi; Kasamatsu, Yoshitaka*; Tsukada, Kazuaki; Asai, Masato; Ishii, Yasuo; Tome, Hayato*; Nishinaka, Ichiro; Sato, Tetsuya; Nagame, Yuichiro; Sch$"a$del, M.; et al.

Journal of Nuclear and Radiochemical Sciences, 11(1), p.7 - 11, 2010/06

The extraction behavior of rutherfordium (Rf) into trioctylphosphine oxide (TOPO) from 2.0 - 7.0 M HCl solution was studied together with that of the homologues Zr and Hf. The extracted yields of Rf, Zr, and Hf increased with an increase of HCl concentration, and the sequence of their extraction was Zr $$>$$ Hf $$geq$$ Rf. It is suggested that the stability of the RfCl$$_{4}$$$$cdot$$2(TOPO) complex is lower than that of the corresponding species of the homologues.

Journal Articles

Anionic fluoro complex of element 105, Db

Kasamatsu, Yoshitaka*; Toyoshima, Atsushi; Asai, Masato; Tsukada, Kazuaki; Li, Z.; Ishii, Yasuo; Tome, Hayato*; Sato, Tetsuya; Kikuchi, Takahiro; Nishinaka, Ichiro; et al.

Chemistry Letters, 38(11), p.1084 - 1085, 2009/10

 Times Cited Count:13 Percentile:48.46(Chemistry, Multidisciplinary)

We report on the characteristic anion-exchange behavior of the superheavy element dubnium (Db) with atomic number Z = 105 in HF/HNO$$_{3}$$ solution at the fluoride ion concentration [F$$^{-}$$] = 0.003 M. The result clearly demonstrates that the fluoro complex formation of Db is significantly different from that of the group-5 homologue Ta in the 6th period of the periodic table while the behavior of Db is similar to that of the lighter homologue Nb in the 5th period.

Journal Articles

$$^{225}$$Ac metallofullerene; Toward $$^{225}$$Ac nanogenerator in fullerene

Akiyama, Kazuhiko*; Haba, Hiromitsu*; Sueki, Keisuke*; Tsukada, Kazuaki; Asai, Masato; Toyoshima, Atsushi; Nagame, Yuichiro; Katada, Motomi*

Chemistry Letters, 38(10), p.978 - 979, 2009/09

 Times Cited Count:7 Percentile:62.27(Chemistry, Multidisciplinary)

We report on the successful production of a metallofullerene encapsulating the radioactive tracer $$^{225}$$Ac and on its electronic properties studied by radiochromatography. Considering the number of $$pi$$-electrons on the fullerene cage estimated from an HPLC retention time on the 5PBB column and the general oxidation state of Ac (+3), a chemical species of the dominant chromatographic peak is suggested to be Ac@C$$_{82}$$.

Journal Articles

Oxidation of element 102, nobelium, with flow electrolytic column chromatography on an atom-at-a-time scale

Toyoshima, Atsushi; Kasamatsu, Yoshitaka*; Tsukada, Kazuaki; Asai, Masato; Kitatsuji, Yoshihiro; Ishii, Yasuo; Tome, Hayato; Nishinaka, Ichiro; Haba, Hiromitsu*; Oe, Kazuhiro*; et al.

Journal of the American Chemical Society, 131(26), p.9180 - 9181, 2009/07

 Times Cited Count:8 Percentile:59.46(Chemistry, Multidisciplinary)

We report here on the successful oxidation of element 102, nobelium (No), on an atom-at-a-time scale in 0.1 M $$alpha$$-hydroxyisobutyric acid ($$alpha$$-HIB) solution using newly developed flow electrolytic column chromatography. It is found that the most stable No$$^{2+}$$ is oxidized to No$$^{3+}$$ within 3 min and that the oxidized No complex with $$alpha$$-HIB holds the trivalent state in the column above the applied potential of 1.0 V.

Journal Articles

Chloride complexation of Zr and Hf in HCl investigated by extended X-ray absorption fine structure spectroscopy; Toward characterization of chloride complexation of element 104, rutherfordium (Rf)

Haba, Hiromitsu*; Akiyama, Kazuhiko*; Tsukada, Kazuaki; Asai, Masato; Toyoshima, Atsushi; Yaita, Tsuyoshi; Hirata, Masaru; Sueki, Keisuke*; Nagame, Yuichiro

Bulletin of the Chemical Society of Japan, 82(6), p.698 - 703, 2009/06

 Times Cited Count:9 Percentile:56.91(Chemistry, Multidisciplinary)

Chloride complexation of the group-4 elements Zr and Hf in 8.0-11.9 M HCl is investigated by Extended X-ray Absorption Fine Structure (EXAFS) spectroscopy to characterize chloro complexes of the transactinide element, rutherfordium (Rf). The complexes of Zr and Hf successively vary with the concentration of HCl from a hydrated complex [M(H$$_{2}$$O) $$_{8}$$]$$^{4+}$$ at 8.0 M to a hexachloro complex [MCl$$_{6}$$]$$^{2-}$$ at 11.9 M (M = Zr and Hf). The present structural changes of the Zr and Hf complexes well reflect the previously studied anion-exchange behavior of Zr and Hf in HCl. From both the EXAFS and anion-exchange results, we suggest that Rf forms the same complexes as those of Zr and Hf in HCl, and that the complexation strength of the hexachloro complexes of the group-4 elements, [MCl$$_{6}$$] $$^{2-}$$ (M = Zr, Hf, and Rf), is in the sequence of Rf $$>$$ Zr $$>$$ Hf.

Journal Articles

A Metallofullerene that encapsulates $$^{225}$$Ac

Akiyama, Kazuhiko*; Haba, Hiromitsu*; Tsukada, Kazuaki; Asai, Masato; Toyoshima, Atsushi; Sueki, Keisuke*; Nagame, Yuichiro; Katada, Motomi*

Journal of Radioanalytical and Nuclear Chemistry, 280(2), p.329 - 331, 2009/05

 Times Cited Count:7 Percentile:45.86(Chemistry, Analytical)

The properties of a metallofullerene that encapsulates $$^{225}$$Ac were studied by radio-chromatographic methods. The results of chromatography on a Buckyclutcher column suggest that there are some metallofullerene isomers of AcC$$_{82}$$. The identical HPLC retention time of the major AcC$$_{82}$$ peak with that of La@C$$_{82}$$ indicates that the structure of one of the AcC$$_{82}$$ isomers is the same as La@C$$_{82}$$.

Journal Articles

Adsorption of Nb, Ta and Pa on anion-exchanger in HF and HF/HNO$$_{3}$$ solutions; Model experiments for the chemical study of Db

Kasamatsu, Yoshitaka; Toyoshima, Atsushi; Haba, Hiromitsu*; Tome, Hayato*; Tsukada, Kazuaki; Akiyama, Kazuhiko*; Yoshimura, Takashi*; Nagame, Yuichiro

Journal of Radioanalytical and Nuclear Chemistry, 279(2), p.371 - 376, 2009/02

 Times Cited Count:11 Percentile:31.4(Chemistry, Analytical)

Anion-exchange behavior of the group-5 elements Nb and Ta, and their pseudo homologue Pa in HF and HF/HNO$$_{3}$$ solutions was investigated by a batch method to find suitable conditions for the anion-exchange experiment of element 105 (Dubnium, Db). We determined distribution coefficients of those elements on the anion-exchange resin as a function of the F$$^{-}$$ and NO$$_{3}$$$$^{-}$$ concentrations. Clearly different anion-exchange behavior was observed among these elements. Based on the results, we discuss the fluoro-complex formation of each element and suggest experimental conditions for the study of fluoride complexation of Db.

Journal Articles

Adsorption of Db and its homologues Nb and Ta, and the pseudo-homologue Pa on anion-exchange resin in HF solution

Tsukada, Kazuaki; Haba, Hiromitsu*; Asai, Masato; Toyoshima, Atsushi; Akiyama, Kazuhiko*; Kasamatsu, Yoshitaka; Nishinaka, Ichiro; Ichikawa, Shinichi; Yasuda, Kenichiro; Miyamoto, Yutaka; et al.

Radiochimica Acta, 97(2), p.83 - 89, 2009/02

 Times Cited Count:19 Percentile:15.82(Chemistry, Inorganic & Nuclear)

Anion-exchange chromatography of element 105, dubnium (Db), produced in the $$^{248}$$Cm($$^{19}$$F, 5n)$$^{262}$$Db reaction is investigated together with the homologues Nb and Ta, and the pseudo-homologue Pa in 13.9 M hydrofluoric acid (HF) solution. The distribution coefficient (K$$_{d}$$) of Db on an anion-exchange resin is successfully determined by running cycles of the 1702 chromatographic column separations. The result clearly indicates that the adsorption of Db on the resin is significantly different from that of the homologues and that the adsorption of anionic fluoro complexes of these elements decreases in the sequence of Ta $$approx$$ Nb $$>$$ Db $$geq$$ Pa.

Journal Articles

Fluoride complexation of element 104, rutherfordium (Rf), investigated by cation-exchange chromatography

Ishii, Yasuo; Toyoshima, Atsushi; Tsukada, Kazuaki; Asai, Masato; Tome, Hayato; Nishinaka, Ichiro; Nagame, Yuichiro; Miyashita, Sunao*; Mori, Tomotaka*; Suganuma, Hideo*; et al.

Chemistry Letters, 37(3), p.288 - 289, 2008/03

 Times Cited Count:17 Percentile:43.4(Chemistry, Multidisciplinary)

We have investigated cation-exchange behavior of Rf together with the lighter homologues of the group-4 elements Zr and Hf, and the tetravalent pseudo-homologue Th, in HF/HNO$$_{3}$$ solution using Automated Ion exchange separation apparatus coupled with the Detection system for Alpha spectroscopy (AIDA). The ${it K}$ $$_{d}$$ values of Zr, Hf, Th and Rf in HF/0.1 M HNO$$_{3}$$ were decreased with increasing the concentration of the fluoride ion [F$$^{-}$$], indicating the formation of the fluoride complexes. The sequence of the fluoride complexation strength is Zr $$sim$$ Hf $$>$$ Rf $$>$$ Th.

Journal Articles

Hexafluoro complex of rutherfordium in mixed HF/HNO$$_{3}$$ solutions

Toyoshima, Atsushi; Haba, Hiromitsu*; Tsukada, Kazuaki; Asai, Masato; Akiyama, Kazuhiko*; Goto, Shinichi*; Ishii, Yasuo; Nishinaka, Ichiro; Sato, Tetsuya; Nagame, Yuichiro; et al.

Radiochimica Acta, 96(3), p.125 - 134, 2008/03

 Times Cited Count:23 Percentile:13(Chemistry, Inorganic & Nuclear)

Formation of an anionic fluoride-complex of element 104, rutherfordium (Rf) produced in the $$^{248}$$Cm($$^{18}$$O,5n)$$^{261}$$Rf reaction was studied by an anion-exchange method based on an atom-at-a-time scale. It was found that the hexafluoro complex of Rf, [RfF$$_{6}$$]$$^{2-}$$, was formed in the studied fluoride ion concentrations of 0.0005 - 0.013 M. Formation of [RfF$$_{6}$$]$$^{2-}$$ was significantly different from that of the homologues Zr and Hf, [ZrF$$_{6}$$]$$^{2-}$$ and [HfF$$_{6}$$]$$^{2-}$$; the evaluated formation constant of [RfF$$_{6}$$]$$^{2-}$$ is at least one-order of magnitude smaller than those of [ZrF$$_{6}$$]$$^{2-}$$ and [HfF$$_{6}$$]$$^{2-}$$.

Journal Articles

The H-Invitational Database (H-InvDB); A Comprehensive annotation resource for human genes and transcripts

Yamasaki, Chisato*; Murakami, Katsuhiko*; Fujii, Yasuyuki*; Sato, Yoshiharu*; Harada, Erimi*; Takeda, Junichi*; Taniya, Takayuki*; Sakate, Ryuichi*; Kikugawa, Shingo*; Shimada, Makoto*; et al.

Nucleic Acids Research, 36(Database), p.D793 - D799, 2008/01

 Times Cited Count:50 Percentile:21.34(Biochemistry & Molecular Biology)

Here we report the new features and improvements in our latest release of the H-Invitational Database, a comprehensive annotation resource for human genes and transcripts. H-InvDB, originally developed as an integrated database of the human transcriptome based on extensive annotation of large sets of fulllength cDNA (FLcDNA) clones, now provides annotation for 120 558 human mRNAs extracted from the International Nucleotide Sequence Databases (INSD), in addition to 54 978 human FLcDNAs, in the latest release H-InvDB. We mapped those human transcripts onto the human genome sequences (NCBI build 36.1) and determined 34 699 human gene clusters, which could define 34 057 protein-coding and 642 non-protein-coding loci; 858 transcribed loci overlapped with predicted pseudogenes.

Journal Articles

Current status of the control system for J-PARC accelerator complex

Yoshikawa, Hiroshi; Sakaki, Hironao; Sako, Hiroyuki; Takahashi, Hiroki; Shen, G.; Kato, Yuko; Ito, Yuichi; Ikeda, Hiroshi*; Ishiyama, Tatsuya*; Tsuchiya, Hitoshi*; et al.

Proceedings of International Conference on Accelerator and Large Experimental Physics Control Systems (ICALEPCS '07) (CD-ROM), p.62 - 64, 2007/10

J-PARC is a large scale facility of the proton accelerators for the multi-purpose of scientific researches in Japan. This facility consists of three accelerators and three experimental stations. Now, J-PARC is under construction, and LINAC is operated for one year, 3GeV synchrotron has just started the commissioning in this October the 1st. The completion of this facility will be next summer. The control system of accelerators established fundamental performance for the initial commissioning. The most important requirement to the control system of this facility is to minimize the activation of accelerator devices. In this paper, we show that the performances of each layer of this control system have been achieved in the initial stage.

Journal Articles

Extraction behavior of rutherfordium into tributylphosphate from hydrochloric acid

Haba, Hiromitsu*; Tsukada, Kazuaki; Asai, Masato; Toyoshima, Atsushi; Ishii, Yasuo; Tome, Hayato; Sato, Tetsuya; Nishinaka, Ichiro; Ichikawa, Takatoshi; Ichikawa, Shinichi; et al.

Radiochimica Acta, 95(1), p.1 - 6, 2007/01

 Times Cited Count:14 Percentile:24.72(Chemistry, Inorganic & Nuclear)

no abstracts in English

Journal Articles

Simultaneous observation of volatility of Zr, Hf, and Rf chlorides

Sato, Tetsuya; Tsukada, Kazuaki; Asai, Masato; Akiyama, Kazuhiko*; Haba, Hiromitsu*; Toyoshima, Atsushi; Ono, Sawako*; Hirai, Toshiyuki*; Goto, Shinichi*; Ichikawa, Shinichi; et al.

Journal of Nuclear and Radiochemical Sciences, 6(2), p.N1 - N3, 2005/12

$$^{85}$$Zr, $$^{169}$$Hf, and $$^{261}$$Rf were produced simultaneously from $$^{rm nat}$$Ge($$^{18}$$, ${it x}$n), $$^{rm nat}$$Gd($$^{18}$$O, ${it x}$n), and $$^{248}$$Cm($$^{18}$$O, 5n) reactions, respectively, and the volatility of their chlorides was examined using an isothermal gas chromatographic system. The observed gas chromatogram indicated that ZrCl$$_4$$, HfCl$$_4$$, and RfCl$$_4$$ had almost similar volatility.

Journal Articles

Experimental identification of spin-parities and single-particle configurations in $$^{257}$$No and its $$alpha$$-decay daughter $$^{253}$$Fm

Asai, Masato; Tsukada, Kazuaki; Sakama, Minoru*; Ichikawa, Shinichi; Ishii, Tetsuro; Nagame, Yuichiro; Nishinaka, Ichiro; Akiyama, Kazuhiko; Osa, Akihiko; Oura, Yasuji*; et al.

Physical Review Letters, 95(10), p.102502_1 - 102502_4, 2005/09

 Times Cited Count:56 Percentile:11.75(Physics, Multidisciplinary)

Excited states in $$^{253}$$Fm fed by the $$alpha$$ decay of $$^{257}$$No have been established through $$alpha$$-$$gamma$$ and $$alpha$$-electron coincidence spectroscopy using a gas-jet transport system and an on-line isotope separator. The spin-parity of the 124.1 keV level in $$^{253}$$Fm has been identified on the basis of the measured internal conversion coefficients. The $$nu 3/2^{+}[622]$$ configuration has been assigned to the ground state of $$^{257}$$No as well as to the 124.1 keV level. It was found that the ground state configuration of $$^{257}$$No is different from that of lighter $$N=155$$ isotones.

Journal Articles

Formation of fullerene(C$$_{60}$$) by laser ablation in superfluid helium at 1.5K

Aratono, Yasuyuki; Wada, Akira*; Akiyama, Kazuhiko; Kitazawa, Shinichi; Hojo, Kiichi; Naramoto, Hiroshi*

Chemical Physics Letters, 408(4-6), p.247 - 251, 2005/06

 Times Cited Count:1 Percentile:96.37(Chemistry, Physical)

C$$_{60}$$ fulleren was detected in the deposit produced by the laser ablation in superfluid helium at 1.5K. From the mass spectrometry, it was found that the ratio, $$^{12}$$C$$_{60}$$/$$^{12}$$C$$_{59}$$$$^{13}$$C, differs from statistical one calculated by Poisson distribution for natural graphite. Assuming the recombination of atomic carbons to C$$_{2}$$ molecules as an initial stage for C$$_{60}$$ formation, the different isotopic ratio of C$$_{60}$$ from Poisson statistics was ascribed to the tunneling recombination between $$^{12}$$C and $$^{13}$$C atoms in the bubble state.

Journal Articles

Chemical studies on rutherfordium (Rf) at JAERI

Nagame, Yuichiro; Tsukada, Kazuaki; Asai, Masato; Toyoshima, Atsushi; Akiyama, Kazuhiko; Ishii, Yasuo; Sato, Tetsuya; Hirata, Masaru; Nishinaka, Ichiro; Ichikawa, Shinichi; et al.

Radiochimica Acta, 93(9-10), p.519 - 526, 2005/00

 Times Cited Count:26 Percentile:11.69(Chemistry, Inorganic & Nuclear)

no abstracts in English

Journal Articles

Elution curve of Rutherfordium (Rf) in anion-exchange chromatography with hydrofluoric acid solution

Toyoshima, Atsushi; Haba, Hiromitsu*; Tsukada, Kazuaki; Asai, Masato; Akiyama, Kazuhiko; Nishinaka, Ichiro; Nagame, Yuichiro; Saika, Daisuke*; Matsuo, Keishi*; Sato, Wataru*; et al.

Journal of Nuclear and Radiochemical Sciences, 5(2), p.45 - 48, 2004/12

no abstracts in English

66 (Records 1-20 displayed on this page)