Energy spectrum of cosmic-ray neutrinos in the atmosphere

Summary The energy spectrum of cosmic-ray neutrinos in the atmosphere has been calculated for the neutrino energy from 0.2 GeV to 10⁸ GeV by taking into account the results of p-p collision, p-nucleus collision, nucleus-nucleus collision, the energy spectrum of primary cosmic rays, momentum spectrum and charge ratio of cosmic-ray muons measured by MUTRON, and the production of prompt neutrinos in the decay of charmed particles. Our result on neutrino intensity is in good agreement with the result of Osborneet al. for the horizontal direction if their muon spectrum has been corrected, and also with the result of Volkova for the vertical direction except for the lower energies. For the horizontal direction the intensity of prompt muon-neutrinos exceeds that of muonneutrinos from the conventional processes at the neutrino energy of 10⁶ GeV and also the intensity of prompt electron-neutrinos exceeds that of electron-neutrinos from the conventional processes at the energy of 10⁵ GeV. The corresponding values for the vertical direction are 10⁵ GeV and 10⁴ GeV, respectively. In the energy region from 0.3 GeV to 3 GeV, the expected value for the ratio of intensity of electron-neutrino to that of muon-neutrino is obtained as 0.42±0.08 and this is excellent agreement with the experimental value 0.36±0.13 of NUSEX group.

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Riassunto è stato calcolato lo spettro d’energia dei neutrini dei raggi cosmici nell’atmosfera per un’energia neutrinica da 0.2 a 10⁸ GeV tenendo conto dei risultati delle collisioni p-p, p-nucleo, nucleo-nucleo, dello spettro d’energia dei raggi cosmici primari, dello spettro dell’impulso e del rapporto di carica dei muoni dei raggi cosmici misurato da MUTRON e dalla produzione di neutrini pronti nel decadimento di particelle con charm. Il nostro risultato sull’intensità dei neutrini è in buon accordo con il risultato di Osborneet al. per la direzione orizzontale se il loro spettro muonico viene corretto, ed anche con il risultato di Volkova per la direzione verticale tranne che per le energie piú basse. Per la direzione orizzontale l’intensità dei neutrini muonici pronti è maggiore di quella dei neutrini muonici che derivano dai processi convenzionali ad energia neutrinica di 10⁶ GeV ed anche l’intensità dei neutrini elettronici pronti è maggiore di quella dei neutrini elettronici che derivano dai processi convenzionali all’energia di 10⁵ GeV. I valori corrispondenti per la direzione verticale sono rispettivamente 10⁵ e 10⁴ GeV. Nella regione d’energia tra 0.3 e 3 GeV, il valore atteso ottenuto per il rapporto tra l’intensità dei neutrini elettronici e quella dei neutrini muonici è 0.42±0.08 e questo è in accordo eccellente con il valore sperimentale 0.36±0.13 del gruppo NUSEX.

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Ёнергетический спектр нейтрино космических лучей в атмосфере

Резюме Вычисляется Энергетический спектр нейтрино космических лучей в атмосфере для Энергий нейтрино от 0.2 ГЭВ до 10⁸ ГЭВ, учитывая р-р соударения, р-ядерные соударения, ядерно-ядерные соударения, Энергетический спектр первичных космических лучей, импульсный спектр и зарядовое отнощение мюонов космических лучей, измеренных с помошью МUTRON, и образование нейтрино в распадах очарованных частиц. Нащ результат для интенсивности нейтрино хорощо согласуется с результатом Осборна и др. для горизонтального направления, если их мюонный спектр является правильным, а также с результатом Волковой для вертикального направления, за исключением низких Энергий. Для горизонтального направления интенсивность мгновенных мюонных нейтрино превыщает интенсивность мюон-ных нейтрино из обычных процессов при Энергиях нейтрино 10⁶ ГЭВ. Йнтенсивность мгновенных Электронных нейтрино превыщает интенсивность Электронных нейтрино из обычных процессов при Энергии 10⁵ ГЭВ. Соответствуюшие величины для вертикального направления соответственно равны 10⁵ ГЭВ и ДО⁴ ГЭВ. В области Энергий от 0.3 ГЭВ до 3 ГЭВ ожидаемая величина отнощения интенсивностей Электронных нейтрино к интенсивности мюонных нейтрино составляет 0.42±0.08. Ёта величина прекрасно согласуется с Экспериментальным результатом 0.36±0.13, полученным группой

     

Short communication: An alternative and effective catalyst for the silastannation of arylacetylenes with Me3SiSnBu3 at room temperature

The palladium‐catalyzed silastannation of acetylenes with tributyl(trimethylsilyl)stannane in the presence of triethylphosphite is reported for the first time. The reaction occurs at room temperature to give (Z)‐silyl(stannyl)ethenes in high yields. The protodemetallation of the resulting adducts with HCl–tetraethylammonium chloride is described first, which demonstrates that the reaction is governed only by the stability of a carbonium ion arising from the protonation to (Z)‐silyl(stannyl)ethenes rather than the hard and soft acid and base principle, i.e. the β‐cation stabilization effect (σ–π stabilization one) of a stannyl group in the carbonium ion is rather significant. Copyright © 2004 John Wiley & Sons, Ltd.     

Versatile In Situ Generated N‐Boc‐Imines: Application to Phase‐Transfer‐Catalyzed Asymmetric Mannich‐Type Reactions

The efficient construction of nitrogen‐containing organic compounds is a major challenge in chemical synthesis. Imines are one of the most important classes of electrophiles for this transformation. However, both the available imines and applicable nucleophiles for them are quite limited given the existing preparative methods. Described herein are imine precursors which generate reactive imines with a wide variety of substituents under mild basic conditions. This approach enables the construction of various nitrogen‐containing molecules which cannot be accessed by the traditional approach. The utility of the novel imine precursor was demonstrated in the asymmetric Mannich‐type reaction under phase‐transfer conditions.     

Electrochromic properties of polythiophene polyrotaxane film

The electrochromic properties of a polythiophene polyrotaxane film consisting of a polythiophene backbone wrapped by the tetra-cationic cyclophane, cyclobis(paraquat-p-phenylene), were characterized. A naked reference polythiophene film, i.e., polythiophene without tetra-cationic cyclophane, was also characterized. The surface morphology and thickness of the film (L) were observed by atomic force microscopy. The surface of the naked reference polythiophene film has micrometer-scale polythiophene aggregates, which causes the darker color of the film and smaller color contrast in the electrochromic process. The polythiophene polyrotaxane gives a more homogeneous and brighter colored film owing to the suppression of molecular interactions between the polythiophene chains by the tetra-cationic cyclophanes. Potential-step chronoamperometric measurement provided the area density of the oxidizable sites (Γ) and the apparent diffusion coefficient of the charge transport in the film. From linear relationship between L and Γ, the concentrations of the oxidizable sites in the polythiophene polyrotaxane and naked reference polythiophene films were calculated to be 1.3 and 2.4 mmol cm(-3), respectively. Interestingly, the polythiophene polyrotaxane film afforded a significantly larger apparent diffusion coefficient than the naked reference polythiophene film. This result suggests that the rate-determining step of the charge transport is not the electron hopping between the polythiophene chains but the transport of charge-compensating counterions from the solvent into the polythiophene. We believe that the counteranions of the tetra-cationic cyclophane provide a pathway allowing the charge-compensating counteranions to migrate from the solvent to polythiophene. The polythiophene polyrotaxane film showed faster color change than the naked reference polythiophene film in the electrochromic reaction. These results indicate that our polythiophene polyrotaxane is a better electrochromic material than the naked reference polythiophene.     

Synthesis of thiophene-capped [2]rotaxanes

Two types of thiophene-capped [2]rotaxanes, i.e., bithienyl (2T)- and bis(3,4-ethylenedioxythiophene)-yl (BEDOT)-capped [2]rotaxanes, were synthesized. The electron-deficient cyclophane of cyclobis(paraquat-p-phenylene) (CBPQT⁴⁺) was used as a macrocycle. Association constants for inclusion complexation of 2T- and BEDOT-derivatives with CBPQT⁴⁺ were obtained by ¹H NMR titration. Due to the donor-acceptor charge transfer absorption band, 2T- and BEDOT-capped [2]rotaxanes have red and green colors, respectively. On the basis of electrochemical analysis, we confirmed that only BEDOT-capped [2]rotaxane is a promising candidate for [3]rotaxane synthesis through oxidation coupling of the thiophene unit.     

Three-dimensionally arrayed and mutually connected 1.2-nm nanopores for high-performance electric double layer capacitor

Zeolite-templated carbon is a promising candidate as an electrode material for constructing an electric double layer capacitor with both high-power and high-energy densities, due to its three-dimensionally arrayed and mutually connected 1.2-nm nanopores. This carbon exhibits both very high gravimetric (140-190 F g(-1)) and volumetric (75-83 F cm(-3)) capacitances in an organic electrolyte solution. Moreover, such a high capacitance can be well retained even at a very high current up to 20 A g(-1). This extraordinary high performance is attributed to the unique pore structure.     

Interlaboratory study of DNA extraction from multiple ground samples, multiplex real-time PCR, and multiplex qualitative PCR for individual kernel detection system of genetically modified maize

In many countries, the labeling of grains, feed, and foodstuff is mandatory if the genetically modified (GM) organism content exceeds a certain level of approved GM varieties. We previously developed an individual kernel detection system consisting of grinding individual kernels, DNA extraction from the individually ground kernels, GM detection using multiplex real-time PCR, and GM event detection using multiplex qualitative PCR to analyze the precise commingling level and varieties of GM maize in real sample grains. We performed the interlaboratory study of the DNA extraction with multiple ground samples, multiplex real-time PCR detection, and multiplex qualitative PCR detection to evaluate its applicability, practicality, and ruggedness for the individual kernel detection system of GM maize. DNA extraction with multiple ground samples, multiplex real-time PCR, and multiplex qualitative PCR were evaluated by five laboratories in Japan, and all results from these laboratories were consistent with the expected results in terms of the commingling level and event analysis. Thus, the DNA extraction with multiple ground samples, multiplex real-time PCR, and multiplex qualitative PCR for the individual kernel detection system is applicable and practicable in a laboratory to regulate the commingling level of GM maize grain for GM samples, including stacked GM maize.