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131.
Hasegawa Y Takahashi K Kume S Nishihara H 《Chemical communications (Cambridge, England)》2011,47(24):6846-6848
Iron(II) complexes of Z- and E-2,6-di(1H-pyrazol-1-yl)-4-styrylpyridine (Z-2 and E-2, respectively) exhibited visible light photoisomerization from Z-2 to E-2, both in solution and in solid phases. Z-2 occupied the high-spin state over the full temperature range examined, whereas E-2 displayed a spin crossover phenomenon between 100 K and 300 K. 相似文献
132.
133.
Nakashima Y Suzuki S Yamazaki M Inoue Y Fukatsu Y Yamamoto A 《Analytical sciences》2011,27(9):889-892
A quantitative analysis was developed for eight acidic and neutral preservatives in foods and daily necessities using the inline dialysis-IC combined with hydrophobic anion-exchange separation. The eight preservatives were dialyzed by inline dialysis and separated on a hydrophobic anion exchange column. Under the optimized separation conditions, the detection limits (S/N = 3) for the eight preservatives were from 0.08 to 0.66 mg L(-1), moreover, a good linearity (R(2) > 0.998) for each preservative was obtained in the range to 100 mg L(-1). Although the dialysis rate of the neutral preservatives was not so high, a good repeatability (RSD, n = 8) of less than 1.5% for the eight preservatives was obtained. The inline dialysis-IC method was applied to the determination of the preservatives in foods and daily necessities. The preservatives were quantified without any interference. The proposed method will be useful for the determination of the preservatives in foods and daily necessities containing high concentration matrices. 相似文献
134.
Hiromasa?NishikioriEmail author Yosuke?Fukasawa Yuta?Yokosuka Tsuneo?Fujii 《Research on Chemical Intermediates》2011,37(8):869-881
N-doped TiO2 has been prepared by use of sol–gel systems containing titanium alkoxide, with nitric acid as the nitrogen source. The time
needed for gelation of the systems was drastically reduced by ultrasonic irradiation. The peaks assigned to the nitrate and
nitrous ions were observed by FT-IR measurement during the sol–gel reaction. The N-doping was confirmed by the observation
of N–O peaks in the XPS spectrum of the sample heated at 400 °C. The nitrate ion acted as an oxidizer of the ethanol solvent
and titanium species. The TiO2 became doped with nitrogen oxide species as a result of reduction of nitrate ion incorporated into the dried gel samples.
These results indicated that the added nitric acid was reduced during the sol–gel transition and heating process, and the
resulting NO species were situated in the titania networks. The UV and visible photocatalytic activity of the samples was
confirmed by the degradation of trichloroethylene. 相似文献
135.
Harada J Ueki K Anada M Kawazoe Y Ogawa K 《Chemistry (Weinheim an der Bergstrasse, Germany)》2011,17(50):14111-14119
Solid-state photochromism of benzopyrans and naphthopyrans (chromenes) was investigated in the temperature range between 300 and 80 K. Variable-temperature diffuse reflectance spectroscopy of microcrystalline powders showed that the extent of photocoloration was greatly enhanced at low temperatures. All the chromenes examined exhibited solid-state photochromism at low temperatures, even when they showed little or no photocoloration at room temperature. The solid-state photochromic properties of the chromenes were quite similar to those reported for analogous photochromic compounds of spiropyrans and spirooxazines, which indicates that these classes of compounds are generally photochromic even in the solid state. Photobleaching reactions of the colored merocyanine forms proceeded at low temperatures through the formation of a colorless intermediate, instead of directly resuming the original closed form. In addition to two stable planar merocyanine forms, which are usually observed in the photochromic reactions in solution, photoreactions at low temperatures allowed us to observe unstable colored species, which were tentatively assigned as nonplanar cisoid forms, and were stabilized in the solid state at low temperatures. 相似文献
136.
S Kitaura K Kurotobi M Sato Y Takano T Umeyama H Imahori 《Chemical communications (Cambridge, England)》2012,48(68):8550-8552
The effects of fullerene bisadduct regioisomers on solar cell performance have been examined for the first time and the two substituent positions on C(60) have been found to have a large impact on the solar cell performance. 相似文献
137.
To elucidate the thermoelectric properties at high temperatures, the electrical conductivity and Seebeck coefficient were measured at temperatures between 423 K and 973 K for perovskite-type ceramics of BaBi1?xSbxO3 solid solutions with x=0.0–0.5. All the ceramics exhibit p-type semiconducting behaviors and electrical conduction is attributed to hopping of small polaronic holes localized on the pentavalent cations. Substitution of Bi with Sb causes the electrical conductivity σ and cell volume to decrease, but the Seebeck coefficient S to increase, suggesting that the Sb atoms are doped as Sb5+ and replace Bi5+, reducing 6s holes conduction from Bi5+(6s0) to Bi3+ (6s2). The thermoelectric power factor S 2σ has values of 6×10?8–3×10?5 W m?1 K?2 in the measured temperature range, and is maximized for an Sb-undoped BaBiO3?δ, but decreases upon Sb doping due to the decreased σ values. 相似文献
138.
Qixin Guo Hajime Akiyama Yuta Mikuriya Katsuhiko Saito Tooru Tanaka Mitsuhiro Nishio 《Journal of Crystal Growth》2012,341(1):7-11
ZnTe layers were grown on (111) GaAs substrates by metalorganic vapor phase epitaxy using dimethylzinc and diethyltelluride as the source materials. X-ray diffraction analysis revealed that epitaxial ZnTe layers can be obtained on (111) GaAs substrates. X-ray rocking curves, Raman spectroscopy, and photoluminescence measurements showed that the crystal quality of ZnTe layers depends on the substrate temperature during the growth. A high-crystalline quality (111) ZnTe heteroepitaxial layer with strong near-band-edge emission at 550 nm was obtained at a substrate temperature of 440 °C. 相似文献
139.
Dr. Yasutaka Suzuki Yuta Tenma Yukihiro Nishioka Prof. Dr. Jun Kawamata 《化学:亚洲杂志》2012,7(6):1170-1179
Nonlinear optical (NLO) responses from organic dyes can be maximized when the dyes are aligned in appropriate manners in bulk materials. The use of restricted nanospaces provided by interlayer spacing of inorganic layered materials is a promising strategy for imposing suitable molecular alignments for NLO materials on dyes. The hybrid materials thus obtained exhibit salient NLO responses owing to the improved molecular orientation. In some cases, extension of the π‐electron system as a consequence of improved molecular planarity, obtained by the intercalation of a dye into the 2‐dimensional interlayer space of an inorganic layered material, is also observed as a factor that enhances NLO responses of chromophores at the molecular level. This review focuses on recent progress in the strategies for controlling the molecular orientation of NLO‐phores by employing clay minerals, which are one of the typical inorganic layered materials. In addition, development of a means for fabricating composites that satisfy the properties of an optical material, such as a sufficient size and thickness, a flat surface, and low light‐scattering characteristics is required to utilize the superior NLO properties observed for clay/dye hybrid materials for practical applications. A novel means for obtaining such a hybrid material is also outlined. 相似文献
140.
In information theory, lossless compression of general data is based on an explicit assumption of a stochastic generative model on target data. However, in lossless image compression, researchers have mainly focused on the coding procedure that outputs the coded sequence from the input image, and the assumption of the stochastic generative model is implicit. In these studies, there is a difficulty in discussing the difference between the expected code length and the entropy of the stochastic generative model. We solve this difficulty for a class of images, in which they have non-stationarity among segments. In this paper, we propose a novel stochastic generative model of images by redefining the implicit stochastic generative model in a previous coding procedure. Our model is based on the quadtree so that it effectively represents the variable block size segmentation of images. Then, we construct the Bayes code optimal for the proposed stochastic generative model. It requires the summation of all possible quadtrees weighted by their posterior. In general, its computational cost increases exponentially for the image size. However, we introduce an efficient algorithm to calculate it in the polynomial order of the image size without loss of optimality. As a result, the derived algorithm has a better average coding rate than that of JBIG. 相似文献