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排序方式: 共有161条查询结果,搜索用时 21 毫秒
101.
Ahn MH Aoki S Ashie Y Bhang H Boyd S Casper D Choi JH Fukuda S Fukuda Y Gran R Hara T Hasegawa M Hasegawa T Hayashi K Hayato Y Hill J Ichikawa AK Ikeda A Inagaki T Ishida T Ishii T Ishitsuka M Itow Y Iwashita T Jang HI Jang JS Jeon EJ Joo KK Jung CK Kajita T Kameda J Kaneyuki K Kato I Kearns E Kibayashi A Kielczewska D Kim BJ Kim CO Kim JY Kim SB Kobayashi K Kobayashi T Koshio Y Kropp WR Learned JG Lim SH Lim IT Maesaka H Maruyama T Matsuno S Mauger C Mcgrew C Minamino A Mine S Miura M Miyano K 《Physical review letters》2004,93(5):051801
We present a search for electron neutrino appearance from accelerator-produced muon neutrinos in the K2K long-baseline neutrino experiment. One candidate event is found in the data corresponding to an exposure of 4.8 x 10(19) protons on target. The expected background in the absence of neutrino oscillations is estimated to be 2.4+/-0.6 events and is dominated by misidentification of events from neutral current pi(0) production. We exclude the nu(micro) to nu(e) oscillations at 90% C.L. for the effective mixing angle in the 2-flavor approximation of sin((2)2theta(microe)( approximately 1/2sin((2)2theta(13))>0.15 at Deltam(2)(microe)=2.8 x 10(-3) eV(2), the best-fit value of the nu(micro) disappearance analysis in K2K. The most stringent limit of sin((2)2theta(microe)<0.09 is obtained at Deltam(2)(microe)=6 x 10(-3) eV(2). 相似文献
102.
Yu Horiuchi Shinya Mine Madoka Moriyasu Masakazu Anpo Tae-Ho Kim Masaya Matsuoka 《Research on Chemical Intermediates》2017,43(9):5123-5136
This work spotlights the formation behavior of visible light-responsive tantalum oxynitride (TaON) thin film photocatalysts under high substrate temperature in radiofrequency reactive magnetron sputtering deposition. The results emanating from the optimization of the sputtering conditions demonstrated that sputtered N atoms with high kinetic energy generated by controlling target–substrate distances and total pressures in the sputtering chamber were necessary to grow TaON phase even under N2-rich atmosphere. Based on these findings, TaON thin film photocatalysts were successfully synthesized by single-step sputtering under a high substrate temperature of 1073 K before heat treatment. The optimal thickness of TaON thin film photocatalysts was extrapolated to be 450 nm by photoelectrochemical measurements under visible light irradiation (λ > 450 nm), in which distinct photocurrents corresponding to water oxidation were observed. Moreover, the photoelectrochemical activity was able to be improved by postsynthetic heat treatment in gaseous NH3 and loading with IrO2 nanocolloids as cocatalysts. This finding would be because the thin film photocatalyst after heat treatment in NH3 under appropriate conditions possessed better crystallinity and moderate donor density. The optimized TaON thin film photocatalysts with IrO2 nanocolloids also exhibited photocatalytic activity for H2 evolution from aqueous medium containing methanol as a sacrificial electron donor under visible light irradiation (λ > 450 nm). 相似文献
103.
Ab initio and density functional theory calculations with aug-cc-pVDZ and aug-cc-pVTZ basis sets have been performed on the HCl-CH3SH dimer and HCl-(CH3SH)2 and (HCl)2-CH3SH trimers. Structures, energetics, and infrared frequencies are calculated. The results are discussed in terms of the cooperativity effect which is a characteristic of H-bonded systems and compared to oxygen-containing analogs of the same trimers, HCl-(CH3OH)2 and (HCl)2-CH3OH, which have been published recently. 相似文献
104.
Allylic onium salts with different hetero‐atoms and various substituent groups at the allylic double bond have been shown to be very efficient initiators for cationic polymerization. When attacked by a radical, they become radical cations, which are highly unstable species, and undergo fragmentation into smaller radical cations called onium radical cations. The reaction mechanism involves radical formation, addition and fragmentation. In our previous work, radical initiators generated in the same way and under the same conditions are studied experimentally for their ability to affect the polymerization efficiency. Here, the factors affecting the polymerization efficiency are discussed theoretically using semi‐empirical quantum mechanical techniques. The type of radical species, substituent group at the allylic side, the heteroatom at the onium side and the onium group itself are analyzed separately. For this purpose, the geometries of different onium radical cations to be fragmented are optimized and the strength of the C–heteroatom bond to be broken and the size of the radical cations after fragmentation are considered. 相似文献
105.
Tau neutrinos favored over sterile neutrinos in atmospheric muon neutrino oscillations 总被引:1,自引:0,他引:1
Fukuda S Fukuda Y Ishitsuka M Kajita T Kameda J Kaneyuki K Kobayashi K Koshio Y Miura M Moriyama S Nakahata M Nakayama S Obayashi Y Okada A Okumura K Sakurai N Shiozawa M Suzuki Y Takeuchi H Takeuchi Y Toshito T Totsuka Y Yamada S Earl M Habig A Kearns E Messier MD Scholberg K Stone JL Sulak LR Walter CW Goldhaber M Barszczak T Casper D Gajewski W Kropp WR Mine S Price LR Smy M Sobel HW Vagins MR Ganezer KS Keig WE Ellsworth RW Tasaka S Kibayashi A Learned JG Matsuno S Takemori D 《Physical review letters》2000,85(19):3999-4003
The previously published atmospheric neutrino data did not distinguish whether muon neutrinos were oscillating into tau neutrinos or sterile neutrinos, as both hypotheses fit the data. Using data recorded in 1100 live days of the Super-Kamiokande detector, we use three complementary data samples to study the difference in zenith angle distribution due to neutral currents and matter effects. We find no evidence favoring sterile neutrinos, and reject the hypothesis at the 99% confidence level. On the other hand, we find that oscillation between muon and tau neutrinos suffices to explain all the results in hand. 相似文献
106.
A. W. Nowosselowa O. I. Worobjewa T. Akiyama und Y. Mine 《Fresenius' Journal of Analytical Chemistry》1939,117(7-8):270
Ohne Zusammenfassung 相似文献
107.
Ince M Hausmann A Martínez-Díaz MV Guldi DM Torres T 《Chemical communications (Cambridge, England)》2012,48(34):4058-4060
A novel supramolecular electron donor-acceptor hybrid (2·1) and an electron donor-acceptor conjugate (3), both exhibiting a remarkably shifted Q band in the NIR region of the solar spectrum, were prepared. Irradiation of the supramolecular ensemble 2·1 within the visible range leads to a nanosecond lived radical-ion pair state Zn-azulenocyanine˙(+)-C(60)˙(-). 相似文献
108.
Balcı FM Uras-Aytemiz N Gómez PC Escribano R 《Physical chemistry chemical physics : PCCP》2011,13(40):18145-18153
The structure and spectroscopic properties of clusters of HNO(3)·HCl·(H(2)O)(n), with n = 1 to 6, have been calculated at the MP2/aug-cc-pVDZ level of theory. Altogether 22 different clusters have been found as stable structures, with minima in their potential energy surfaces. The clusters can be grouped in families with the same number of water molecules, and with close aggregation energies within each family. The addition of each new water molecule increments the aggregation energy of the clusters by a nearly constant value of 76.2 ± 0.1 Hartree. The proton transfer parameter and the coordination number of HNO(3) and HCl in each cluster have been evaluated, and the wavenumber shifts for the X(-)-H(+) vibration from the corresponding mode in the isolated molecules have also been predicted. These values allow classification of the acidic species in the clusters into three types, characterized by the strength of the hydrogen bond and the degree of ionization. A correspondence is found between the coordination number of HNO(3) and the magnitude of the X(-)-H(+) vibrational shift. 相似文献
109.
Abdulhadi Baykal Hüseyin Kavas Zehra Durmu? Mine Demir Sinan Kazan Ramazan Topkaya Muhammet S. Toprak 《Central European Journal of Chemistry》2010,8(3):633-638
We report on the synthesis of Mn3O4 nanoparticles (NPs) using a novel sonochemical method without requiring any pH adjustment. Synthesized material was identified
as tetragonal hausmannite crystal structure model of Mn3O4 from XRD analysis. Crystallite size was estimated from x-ray line profile fitting to be 17±5 nm. FTIR analysis revealed stretching
vibrations of metal ions in tetrahedral and octahedral coordination confirming the crystal structure. TEM analysis revealed
a dominantly cubic morphology of NPs with an average size of ∼20 nm. Magnetic evaluation revealed a blocking temperature,
T
B of 40 K above which the material behaves paramagnetic. Asymmetric coercive field is attributed to the interaction between
ferromagnetic Mn3O4 and antiferromagnetic Mn oxide at the surface of nanoparticles.
相似文献
110.
通过对富含树皮体的煤和半丝质体的煤进行液化研究和结构分析,探讨其液化产品的产率与结构参数之间的关系。富含树皮体的煤的氢含量和挥发分含量均高,H/C原子比也很高。13C-核磁共振分析表明,所有用煤都以芳香族碳为主。WEST样品的芳碳率最高,LP、CG和DHB样品中CH2基团碳含量高于CH3基团碳含量,且CH2基团碳含量高于其他三个样品。而P858样品中CH3基团碳含量高于CH2基团碳含量。液化结果表明,LP、CG和DHB有高的液化转化率和油收率。煤液化的油收率和煤结构中的CH2基团碳含量以及转化率和煤的芳碳率之间都存在明显的相关关系。因此,13C-核磁共振技术可以用来预测煤液化产品的收率。 相似文献