Dynamic Vapochromic Behaviors of Organic Crystals Based on the Open–Close Motions of S‐Shaped Donor–Acceptor Folding Units

The first vapochromic organic crystals are described with respect to their preparation, color change, adsorption/desorption properties, crystal structures, and color‐change mechanism. Non‐solvatochromic, 1,4,5,8‐naphthalene‐tetracarboxylic diimide (NDI) derivatives 1 a bearing two pyrrole imine (PI) tethers have been used as a motif for the crystal packing template. Red‐purple vapochromic solid 3 was prepared by evacuation of orange crystals 2 (equivalent to 1 a ?2 MeOH), obtained by recrystallization of 1 a from MeOH. Solid 3 showed high‐adsorption ability and unprecedented vapor‐dependent color changes upon exposure to a variety of organic vapors, whereas light brown amorphous solid 1 a , did not show vapo‐ or solvatochromic behavior toward any organic solvent. The strong adsorption capability of 3 was confirmed by TGA experiments and adsorption/desorption isotherms. Analysis of the solid‐state UV/Vis analysis revealed that the vapor‐dependent color changes of 3 were owed to the specific interference of solvent vapors with its broad CT absorbance at λ=450–650 nm. Packing structures of 1 a in orange crystals 2 , red‐purple solid 3 , and regenerated orange solid 2 were unequivocally established by single crystal and synchrotron powder X‐ray diffraction, respectively. Molecular structures and arrays of 1 a in these materials indicated that 1) unit 1 a had an S‐shaped folded conformation in 2 and 3 by intramolecular donor–acceptor interactions between NDI and two PI units; 2) inclusion of the guest vapor into the S‐shaped template decreased the intramolecular PI‐NDI interactions, accompanied by increasing intermolecular NDI‐NDI and PI‐PI interactions; and 3) such flexible, open–close motions of the S‐shaped template could be repeated during reversible adsorption/desorption processes without degradation of crystal packing. The adsorption properties and mechanism of molecular shape‐dependent vapochromic behavior of 3 are discussed with reference to experimental results, crystallographic data, and theoretical calculations.     

Dynamic properties of combustion instability in a lean premixed gas-turbine combustor

We experimentally investigate the dynamic behavior of the combustion instability in a lean premixed gas-turbine combustor from the viewpoint of nonlinear dynamics. A nonlinear time series analysis in combination with a surrogate data method clearly reveals that as the equivalence ratio increases, the dynamic behavior of the combustion instability undergoes a significant transition from stochastic fluctuation to periodic oscillation through low-dimensional chaotic oscillation. We also show that a nonlinear forecasting method is useful for predicting the short-term dynamic behavior of the combustion instability in a lean premixed gas-turbine combustor, which has not been addressed in the fields of combustion science and physics.     

THE NUMERICAL STABILITY OF THE θ-METHOD FOR DELAYDIFFERENTIAL EQUATIONS WITH MANY VARIABLEDELAYS

1.IntroductionInthispaper,wewillinvestigatethenumericalsolutionsofthefollowinginitialvalueproblemsforDDEswithmanyvariabledelayswherea,bl,b2,...,bmandcoEC,0相似文献   

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

     

Efficient synthesis of diborylalkenes from alkenes and diboron by a new PSiP-pincer palladium-catalyzed dehydrogenative borylation

The efficient synthesis of various diborylalkenes such as 1,1-, trans-1,2-, and cyclic 1,2-diborylalkenes from alkenes and diboron was achieved for the first time. Selective preparation of di- and monoborylalkenes was also realized by the appropriate choice of reaction conditions. The reaction was found to proceed via a new mechanism of dehydrogenative borylation through a monoborylpalladium complex bearing an anionic PSiP-pincer ligand as a key intermediate, which realized the efficient borylation without sacrificial hydroboration or hydrogenation of the alkene.     

Measurement of Reflected and Scattered Light for Monitoring Fluctuation of Structures

A laser spectroscopic technique for studying fluctuations of structural objects is presented, together with some results of our investigations including an observation of forced vibration of a refrigerator, intrinsic vibrations of buildings, and appearance of a fluctuation in rotational speed due to fatigue. An alternative detection technique which uses the scattered light for monitoring in place of the mirror-reflected beam is also presented. A leak of water out of a pipeline was detected with this method.

The results obtained with this laser spectroscopic technique should form a useful collection of data regarding fluctuation analysis of various objects.     

Family of symplectic implicit Runge-Kutta formulae

A family of formulae for the sympletic IRK method is investigated. Specifically, focus is given to general solutions for formula parameters of IRK under the symplectic and the order conditions. Examples of such formulae are constructed for up to three stages.     

The catalytic hydrogenolysis of benzylamine derivatives

The hydrogenolysis of optically active ethyl 2-amino-2-phenylpropionate (I), its N-methyl (II), and N,N-dimethyl (III) derivatives was studied using Raney Ni and Pd as the catalysts. The Raney Ni catalysed hydrogenolysis of II and III, as well as the reaction catalysed by Pd, occurred predominantly with inversion of configuration; this is not in accord with the hydrogenolysis of corresponding benzyl alcohols. This difference can be ascribed to the difference of the affinity for Ni between N and O atoms. The “SN_Ni” process may be inhibited in the Raney Ni catalysed hydrogenolysis of II and III since the amino group acts as a self-catalyst poison, and the “S_N2” process appears to be preferable to the “S_Ni” one. The predominance of the configurationally inversion was also observed in the Pd catalysed hydrogenolysis of I. These results over Pd are reasonable in reflecting that the N atom has not so high affinity for Pd. The hydrogenolysis of a quarternary ammonium bromide of I was also reported.