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111.
The availability of an X-ray absorption technique employing a very low power X-ray tube was examined to extend measurable range for photographic film dosimetry. The X-ray tube having titanium target was operated at 8 kV and 0.2 microA to emit Ti KX-rays of moderate intensity. The degree of the Ti KX-ray absorption, defined as similar to photographic density, was measured for the two kinds of badge film, Fuji gamma-ray badge film and Kodak personal monitoring film, type 2 exposed for 60Co or 137Cs gamma-rays and developed by the respective standard procedures. The experimental results show that the dosimetric range of 0.01-100 R for the Fuji film and 0.03-1,000 R for the Kodak film may be easily measured by 1 minute counting with the relative statistical error (sigma) of 10%. 相似文献
112.
Mean-field theory applied to superconductors with one-dimensional band in the presence of both the homogeneous magnetic field H0 and the antiferromagnetic field HQ, the second-order phase transition temperature is investigated for the arbitrary angle θ between H0 and HQ. It is found that the remarkable superconducting region in the case of θ = 0 is retained only for small θ and that the spatially dependent order parameter coexists with the spatially uniform order parameter except for θ = τ/2. 相似文献
113.
DMSO or DMF as a solvent strongly accelerated the thiocarboxylation of amines and alcohols with carbon monoxide and sulfur. Under mild conditions (1 atm, 20 °C), this thiocarboxylation of amines assisted by DMSO with carbon monoxide and sulfur has been developed into a practical and convenient synthetic method for S-alkyl thiocarbamates in good to excellent yields, including EPTC, thiobencarb, orbencarb, and molinate (herbicides). DMF also showed the similar solvent effect. NMP slightly decreased the effect for the thiocarboxylation of amines, and the yield of S-alkyl thiocarbamate was lowered in DMAc. Surprisingly, no formation of S-alkyl thiocarbamate was observed at the use of the other solvents, such as THF, hexane, toluene, AcOEt, MeCN, MeOH, and H2O. The present solvent-assisted thiocarboxylation with carbon monoxide and sulfur could be also applied to a new synthesis of S-alkyl O-alkyl carbonothioates from alcohols under mild conditions (1 atm, 20 °C) in DMF using DBU (1,8-diazabicyclo[5.4.0]undec-7-ene). 相似文献
114.
Five new polyketides, biselides A (1), B (2), C (3), D (4), and E (5), were isolated from the Okinawan ascidian Didemnidae sp. Their structures were determined by spectroscopic analysis. Biselides A (1), B (2), and C (3) showed cytotoxicity against human cancer cells NCI-H460 and MDA-MB-231. 相似文献
115.
Chiba J Takeshima S Mishima K Maeda H Nanai Y Mizuno K Inouye M 《Chemistry (Weinheim an der Bergstrasse, Germany)》2007,13(29):8124-8130
DNA-like fluorescent oligomers composed of alkynyl beta-D-ribofuranosides bearing pyrene, perylene, and anthracene as a fluorophore were synthesized by solid-phase DNA synthesis. The fluorescent oligomers possess the defined number and order of the fluorophores. In these oligomers, the adjacent fluorophores efficiently interact with each other by hydrophobic interactions in their electronic ground states in a face-to-face fashion. The predominant excimer emissions were observed from not only the homooligomers (pyrene-pyrene and perylene-perylene systems) but also the heterooligomers (pyrene-perylene, pyrene-anthracene, and perylene-anthracene systems) in aqueous media. 相似文献
116.
117.
Sakuma F Chiba J En'yo H Fukao Y Funahashi H Hamagaki H Ieiri M Ishino M Kanda H Kitaguchi M Mihara S Miwa K Miyashita T Murakami T Muto R Nakura T Naruki M Ozawa K Sasaki O Sekimoto M Tabaru T Tanaka KH Togawa M Yamada S Yokkaichi S Yoshimura Y;KEK-PS E Collaboration 《Physical review letters》2007,98(15):152302
The invariant mass spectra of phi-->K+K- are measured in 12 GeV p+A reactions in order to search for the in-medium modification of phi mesons. The observed K+K- spectra are well reproduced by the relativistic Breit-Wigner function with a combinatorial background shape in three betagamma regions between 1.0 and 3.5. The nuclear mass number dependence of the yields of the K+K- decay channel is compared to the simultaneously measured e+e- decay channel for carbon and copper targets. We parameterize the production yields as sigma(A)=sigma0Aalpha and obtain alphaphi-->K+K- -alphaphi-->e+e- to be 0.14+/-0.12. Limits are obtained for the partial decay widths of the phi mesons in nuclear matter. 相似文献
118.
Zhang LM Zhang ZP Adachi I Aihara H Aulchenko V Aushev T Bakich AM Balagura V Barberio E Bay A Belous K Bitenc U Bondar A Bozek A Bracko M Brodzicka J Browder TE Chang P Chao Y Chen A Chen KF Chen WT Cheon BG Chiang CC Cho IS Choi Y Choi YK Dalseno J Danilov M Dash M Drutskoy A Eidelman S Epifanov D Fratina S Gabyshev N Gokhroo G Golob B Ha H Haba J Hara T Hastings NC Hayasaka K Hayashii H Hazumi M Heffernan D Hokuue T Hoshi Y Hou WS Hsiung YB Hyun HJ Iijima T Ikado K Inami K Ishikawa A 《Physical review letters》2007,99(13):131803
We report a measurement of D0-D(0) mixing parameters in D(0) --> K(s)(0) pi(+) pi(-) decays using a time-dependent Dalitz-plot analysis. We first assume CP conservation and subsequently allow for CP violation. The results are based on 540 fb(-1) of data accumulated with the Belle detector at the KEKB e(+)e(-) collider. Assuming negligible CP violation, we measure the mixing parameters x = (0.80 +/- 0.29(-0.07-0.14)(+0.09+0.10))% and y = (0.33+/-0.24(-0.12-0.08)(+0.08+0.06))%, where the errors are statistical, experimental systematic, and systematic due to the Dalitz decay model, respectively. Allowing for CP violation, we obtain the CP-violating parameters |q / p| = 0.86(-0.29-0.03)(+0.30+0.06) +/- 0.08 and arg(q/p) = (-14(-18-3-4)(+16+5+2)) degrees . 相似文献
119.
Fratina S Abe K Abe K Adachi I Aihara H Anipko D Arinstein K Aushev T Bakich AM Barberio E Bay A Belous K Bitenc U Bizjak I Bondar A Bozek A Bracko M Brodzicka J Browder TE Chang MC Chang P Chao Y Chen A Chen KF Chen WT Cheon BG Chistov R Choi Y Choi YK Cole S Dalseno J Dash M Drutskoy A Eidelman S Go A Golob B Gorisek A Ha H Haba J Hara K Hazumi M Heffernan D Hokuue T Hoshi Y Hou WS Iijima T Inami K Ishikawa A Ishino H Itoh R Iwasaki M Iwasaki Y Kaji H Kang JH Katayama N Kawai H Kawasaki T 《Physical review letters》2007,98(22):221802
We report measurements of the branching fraction and CP violation parameters in B(0)-->D+ D- decays. The results are based on a data sample that contains 535 x 10(6) BB pairs collected at the Upsilon(4S) resonance, with the Belle detector at the KEKB asymmetric-energy e+e- collider. We obtain [1.97+/-0.20(stat) +/- 0.20(syst)] x 10(-4) for the branching fraction of B0-->D+D-. The measured values of the CP violation parameters are S=-1.13+/-0.37+/-0.09, A=0.91+/-0.23+/-0.06, where the first error is statistical and the second is systematic. We find evidence of CP violation in B0-->D+D- at the 4.1sigma confidence level. While the value of S is consistent with expectations from other measurements, the value of the parameter A favors large direct CP violation at the 3.2sigma confidence level, in contradiction to standard model expectations. 相似文献
120.
Lin SW Chang P Abe K Abe K Adachi I Aihara H Anipko D Arinstein K Aulchenko V Aushev T Aziz T Bakich AM Barberio E Bay A Bedny I Belous K Bitenc U Bizjak I Blyth S Bondar A Bozek A Bracko M Chao Y Chen A Chen KF Chen WT Cheon BG Chistov R Choi SK Choi Y Choi YK Dalseno J Dash M Dragic J Eidelman S Fratina S Gabyshev N Gershon T Go A Gokhroo G Golob B Ha H Haba J Hara T Hayasaka K Hayashii H Hazumi M Heffernan D Hoshi Y Hou S Hou WS Hsiung YB Iijima T Ikado K Imoto A Inami K Ishikawa A Ishino H 《Physical review letters》2007,98(18):181804
Using 449x10(6) BB[over ] pairs collected with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider, we observe clear signals for B(+)-->K[over ](0)K(+) and B(0)-->K[over ](0)K(0) decays with 5.3sigma and 6.0sigma significance, respectively. We measure the branching fractions B(B(+)-->K[over ](0)K(+))=(1.22(-0.28-0.16)(+0.32+0.13))x10(-6) and B(B(0)-->K[over ](0)K(0))=(0.87(-0.20)(+0.25)+/-0.09)x10(-6), and partial-rate asymmetries A(CP)(B(+)-->K[over ](0)K(+))=0.13(-0.24)(+0.23)+/-0.02 and A(CP)(B(0)-->K[over ](0)K(0))=-0.58(-0.66)(+0.73)+/-0.04. From a simultaneous fit, we also obtain B(B(+)-->K(0)pi(+))=(22.8(-0.7)(+0.8)+/-1.3)x10(-6) and A(CP)(B(+)-->K(0)pi(+))=0.03+/-0.03+/-0.01. The first and second error in the branching fractions and the partial-rate asymmetries are statistical and systematic, respectively. No signal is observed for B(0)-->K(+)K(-) decays, and for this branching fraction, we set an upper limit of 4.1x10(-7) at the 90% confidence level. 相似文献