Production of direct single electrons in proton-nucleus collisions at 13 GeV/c

Direct production of single electrons in proton-nucleus collisions at 13 GeV/c has been measured. A rising $\text{e}\text{π}$ ratio with decreasing p_T above the 10^?4 level is observed for low p_T single electrons. The source of the rising $\text{e}\text{π}$ ratio at low $\text{e}\text{π}$ ratio at low p_T is discussed in connection with the low mass dielectron continuum below the ? mass region.     

Estimate of Fukushima-derived radiocaesium in the North Pacific Ocean in summer 2012

Distributions of radiocaesium (¹³⁴Cs and ¹³⁷Cs) derived from the Tokyo Electric Power Company (TEPCO) Fukushima Dai-ichi Nuclear Power Plant (FNPP1) accident in the North Pacific Ocean in the summer of 2012 were investigated. We have estimated the radiocaesium inventory in the surface layer using the optimal interpolation analysis and the subducted amount into the central mode water (CMW) by using vertical profiles of FNPP1-¹³⁴Cs and mass balance analysis as the first approach. The inventory of the ¹³⁴Cs in the surface layer in the North Pacific Ocean in August–December 2012 was estimated at 5.1?±?0.9 PBq on 1 October 2012, which corresponds to 8.6?±?1.5 PBq when it was decay corrected to the date of the FNPP1 accident, 11 March 2011. It was revealed that 56?±?10% of the released ¹³⁴Cs into the North Pacific Ocean, which was estimated at 15.3?±?2.6 PBq, transported eastward in the surface layer in 2012. The amount of ¹³⁴Cs subducted in the CMW was estimated to be 2.5?±?0.9 PBq based on the mass balance among the three domains of the surface layer, subtropical mode water, and CMW.     

Fructose/dioxygen biofuel cell based on direct electron transfer-type bioelectrocatalysis

One-compartment biofuel cells without separators have been constructed, in which d-fructose dehydrogenase (FDH) from Gluconobacter sp. and laccase from Trametes sp. (TsLAC) work as catalysts of direct electron transfer (DET)-type bioelectrocatalysis in the two-electron oxidation of d-fructose and four-electron reduction of dioxygen as fuels, respectively. FDH adsorbs strongly and stably on Ketjen black (KB) particles that have been modified on carbon papers (CP) and produces the catalytic current with the maximum density of about 4 mA cm(-2) without mediators at pH 5. The catalytic wave of the d-fructose oxidation is controlled by the enzyme kinetics. The location and the shape of the catalytic waves suggest strongly that the electron is directly transferred to the KB particles from the heme c site in FDH, of which the formal potential has been determined to be 39 mV vs. Ag|AgCl|sat. KCl. Electrochemistry of three kinds of multi-copper oxidases has also been investigated and TsLAC has been selected as the best one of the DET-type bioelectrocatalyst for the four-electron reduction of dioxygen in view of the thermodynamics and kinetics at pH 5. In the DET-type bioelectrocatalysis, the electron from electrodes seems to be transferred to the type I copper site of multi-copper oxidases. TsLAC adsorbed on carbon aerogel (CG) particles with an average pore size of 22 nm, that have been modified on CP electrodes, produces the catalytic reduction current of dioxygen with a density of about 4 mA cm(-2), which is governed by the mass transfer of the dissolved dioxygen. The FDH-adsorbed KB-modified CP electrodes and the TsLAC-adsorbed CG-modified CP electrodes have been combined to construct one-compartment biofuel cells without separators. The open-circuit voltage was 790 mV. The maximum current density of 2.8 mA cm(-2) and the maximum power density of 850 microW cm(-2) have been achieved at 410 mV of the cell voltage under stirring.     

Photoswitchable,DNA‐Binding Helical Peptides Assembled with Two Independently Designed Sequences for Photoregulation and DNA Recognition

Diarylethene‐bridged peptides were developed to photoregulate biomolecular interactions. The peptides are made up of diarylethene‐bridged and DNA‐binding regions at their N‐ and C termini, respectively. The two regions could be independently designed and combined as desired. The α‐helicities of the peptides were photoregulated in on/off or off/on manners, and the manner depended on the positions of two ornithine (Orn) residues for cross‐linking reaction at the diarylethene‐bridged region. In the case of the on/off manner, when the diarylethene structure adopted the open form on the peptides, the peptides folded into stable α‐helices. Upon UV irradiation, the diarylethene moiety isomerized to its closed form to destabilize the helical structures. Quartz crystal microbalance (QCM) analysis showed that the open isomer strongly associated with a target DNA, as compared with the closed one. When the closed‐form peptide existing in the DNA complex was irradiated with a fluorescent lamp in the middle of the QCM monitoring, the frequency change (ΔF) was enhanced by the diarylethene photoisomerization.     

The Proron threshold states in21MG relevant to the rp-process

More than ten new levels have been identified just above the proton threshold in²¹Mg. The lowest s-wave resonant state assumed previously for the calculation of the stellar reaction rate in the rp-process is found to be a bound state, suggesting a serious change for the early stage of the rp-process.     

寻找超高能宇宙线源——西藏广延空气簇射实验

总结了１９９０年６月到１９９３年１０月期间西藏空气簇射阵列的观测结果。寻找了来自于蟹状星云、Ｘ射线双星、脉冲星、活动星系核和其它活动天体的能量为１０ＴｅＶγ射线连续发射，没有发现连续稳定发射的迹象，但给出了每个源的流强上限。在阵列所观测的天区寻找了１０ＴｅＶ的γ暴，结果没有发现能量１０ＴｅＶ的γ暴，最后也给出了发现此种γ暴的上限。应用该阵列，明显地观测到了能量为１０ＴｅＶ的宇宙线流强的太阳和月亮阴影。观测了朝向和远离太阳的行星际空间磁场对宇宙线阴影的影响，这是行星际磁场对阴影位移影响的第一次直接观测。研究并发现在实验期间，太阳阴影的位置每年都在变化。同时观测在此期间，朝向和远离方向的宇宙线阴影的不同变化。另外，应用该实验的数据，给出了所谓的“膝”区的原初宇宙线能谱。