Rheological behavior of powder in a rotational viscometer

Summary The bahavior of granular materials in theMac Michael type viscometer was studied. The deflection angle of the bob decreased with the increase of the rate of rotation of the cup in the cases of these materials contrary to those of liquids. The powder bed in the gap of the viscometer is divided into twp cylindrical parts, the inner one with flowing layers of particles and the other moving with the cup as a bulk. The existence of these two parts is considered responsible for the extraordinary behavior of powder in the viscometer. The coefficient of kinetic friction of powder layers was obtained by applyingBenarie's analysis to our results.     

Effects of benzyl ether type dendrons as hole-harvesting antennas, and shielding for the neutralization of stilbene core radical cations with chloride ion during two-photon ionization of stilbene dendrimers having stilbene core and benzyl ether type dendrons

The two-photon ionization (TPI) process (308 and 266 nm) of stilbene dendrimers having a stilbene core and benzyl ether type dendrons has been investigated in an acetonitrile and 1,2-dichloroethane mixture (3:1) in order to elucidate the dendrimer effects. The quantum yield of the formation of stilbene core radical cation during the 308-nm TPI was independent of the dendron generation of the dendrimers, whereas a generation dependence of the quantum yield of the radical cation was observed during the 266-nm TPI, where both the stilbene core and benzyl ether type dendron were ionized, suggesting that the subsequent hole transfer occurs from the dendron to the stilbene core, and that the dendron acts as a hole-harvesting antenna. The neutralization rate of the stilbene core radical cation with the chloride ion, generated from the dissociative electron capture by 1,2-dichloroethane, decreased with the increase in the dendrimer generation, suggesting that the dendron is an effective shield of the stilbene core radical cation against the chloride ion.     

Total synthesis and determination of the stereochemistry of 2-amino-3-cyclopropylbutanoic acid,a novel plant growth regulator isolated from the mushroom Amanita castanopsidis Hongo

The unknown stereostructure of 2-amino-3-cyclopropylbutanoic acid 1, a novel plant growth regulator isolated from the mushroom Amanita castanopsidis Hongo, was determined to be (2S,3S)-2 through its racemic and enantioselective syntheses employing the chelate-enolate Claisen rearrangement as a key step.     

Excess-electron injection and transfer in terthiophene-modified DNA: terthiophene as a photosensitizing electron donor for thymine, cytosine, and adenine

Excess-electron transfer (EET) in DNA has attracted wide attention owing to its close relation to DNA repair and nanowires. To clarify the dynamics of EET in DNA, a photosensitizing electron donor that can donate an excess electron to a variety of DNA sequences has to be developed. Herein, a terthiophene (3T) derivative was used as the photosensitizing electron donor. From the dyad systems in which 3T was connected to a single nucleobase, it was revealed that (1) 3T* donates an excess electron efficiently to thymine, cytosine, and adenine, despite adenine being a well-known hole conductor. The free-energy dependence of the electron-transfer rate was explained on the basis of the Marcus theory. From the DNA hairpins, it became clear that (1) 3T* can donate an excess electron not only to the adjacent nucleobase but also to the neighbor one nucleobase further along and so on. From the charge-injection rate, the possibilities of smaller β?value and/or charge delocalization were discussed. In addition, EET through consecutive cytosine nucleobases was suggested.     

FTIR and 1H NMR Spectral Study of 3-(Substituted Benzamido)-5,6,7,8-Tetrahydro-5,8-methanoiso-quinolines And Related Compounds

The title benzamide derivatives were synthesized. FTIR spectra of the benzamides having substituents p-NH₂, p-OCH₃, p-CH₃ 3, p-F, H 5,p-CI, p-CF₃, p-CN, p-NO₂ 9 and m-Cl 10 and their related compounds were measured in dilute n-heptane, CCl₄, CHCl₃ and CH₂Cl₂ solutions. ¹H NMR spectra of the benzamides were also measured in CDCl₃ solution. Substituent effects on these spectra were investigated. The results were theoretically considered together with CNDO/2 calculation ones. Conformational analysis of 5 was carried out by the AMl method, and the results were compared with the X-ray structural data of 3, 5, 9 and 10. The intermolecular hydrogen bondings in crystals of the benzamides were examined based on the frequency shifts of their C=0 stretching vibration bands.     

ON THE HYSTERESIS-FREE RESPONSE OF ANTIFERROELECTRIC SMECTICS—THE CASE OF MESOPHASES WITH LONG PERIOD -

Abstract

In order to elucidate the hysteresis-free response (V-shaped response) observed at a transmittance of light in antiferroelectric smectic materials, the dynamical responses of the order parameters to an electric field are studied on the basis of an extended ANNNI model with J ₃ < 0. It is shown that the V-shaped responses appear at mesophases with long period near the ferroelectric phase in low frequency range.     

Palladium-catalyzed direct ortho-alkynylation of aromatic carboxylic acid derivatives

The palladium-catalyzed direct alkynylation of C-H bonds in aromatic carboxylic acid derivatives is described. The use of 8-aminoquinoline as a directing group facilitates the alkynylation of an electronically diverse range of C(sp(2))-H bonds.     

基于光纤列阵薄膜传感的客流计数系统研究

为实现客流计数自动化,开发了一种基于新型高分子薄膜型光纤列阵感压的客流计数系统.感压原理建立在光散射强度与高分子材料密度变动的对应关系上,系统以脚底压力分布"质心"的时空变化为信息特征,该时空变化特征反映了乘客上下车时维持动态平衡的一般规律.由此设计了多种行为模式的客流跟踪、辨向和计数方法.统计实验结果表明,该客流计数系统可实现实时测试,准确率达95%以上.