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101.
Dr. Yuriy Pihosh Jin Uemura Dr. Ivan Turkevych Dr. Kazuma Mawatari Dr. Yutaka Kazoe Dr. Adelina Smirnova Prof. Takehiko Kitamori 《Angewandte Chemie (International ed. in English)》2017,56(28):8130-8133
Autonomous micro/nano mechanical, chemical, and biomedical sensors require persistent power sources scaled to their size. Realization of autonomous micro-power sources is a challenging task, as it requires combination of wireless energy supply, conversion, storage, and delivery to the sensor. Herein, we realized a solar-light-driven power source that consists of a micro fuel cell (μFC) and a photocatalytic micro fuel generator (μFG) integrated on a single microfluidic chip. The μFG produces hydrogen by photocatalytic water splitting under solar light. The hydrogen fuel is then consumed by the μFC to generate electricity. Importantly, the by-product water returns back to the photocatalytic μFG via recirculation loop without losses. Both devices rely on novel phenomena in extended-nano-fluidic channels that ensure ultra-fast proton transport. As a proof of concept, we demonstrate that μFG/μFC source achieves remarkable energy density of ca. 17.2 mWh cm−2 at room temperature. 相似文献
102.
103.
Satoshi Aoki Takayuki Hibi Hidefumi Ohsugi Akimichi Takemura 《Annals of the Institute of Statistical Mathematics》2010,62(2):299-321
We consider testing independence in group-wise selections with some restrictions on combinations of choices. We present models for frequency data of selections for which it is easy to perform conditional tests by Markov chain Monte Carlo (MCMC) methods. When the restrictions on the combinations can be described in terms of a Segre–Veronese configuration, an explicit form of a Gröbner basis consisting of binomials of degree two is readily available for performing a Markov chain. We illustrate our setting with the National Center Test for university entrance examinations in Japan. We also apply our method to testing independence hypotheses involving genotypes at more than one locus or haplotypes of alleles on the same chromosome. 相似文献
104.
Hisayuki Hara Akimichi Takemura Ruriko Yoshida 《Journal of multivariate analysis》2010,101(4):909-925
In this paper we consider exact tests of a multiple logistic regression with categorical covariates via Markov bases. In many applications of multiple logistic regression, the sample size is positive for each combination of levels of the covariates. In this case we do not need a whole Markov basis, which guarantees connectivity of all fibers. We first give an explicit Markov basis for multiple Poisson regression. By the Lawrence lifting of this basis, in the case of bivariate logistic regression, we show a simple subset of the Markov basis which connects all fibers with a positive sample size for each combination of levels of covariates. 相似文献
105.
Kazuma Tsuboi 《Tetrahedron letters》2010,51(14):1876-1072
A second-generation total synthesis of (−)-diversifolin has been achieved by a more straightforward strategy, involving a highly stereochemistry-dependent 10-membered ring-closing metathesis and a stereoselective dihydroxylation/lactone transposition sequence. Compared to our previous synthesis, the present synthesis is improved in the yield of the key intermediate 2 (20% in 12 steps from diol 8). 相似文献
106.
Kazuma Gotoh Tetsuo Asaji Hiroyuki Ishida 《Acta Crystallographica. Section C, Structural Chemistry》2010,66(3):o114-o118
The crystal structures of two solid phases of the title compound, C4H5N2+·C6HCl2O4−·H2O, have been determined at 225 and 120 K. In the high‐temperature phase, stable above 198 K, the transition temperature of which has been determined by 35Cl nuclear quadrupole resonance and differential thermal analysis measurements, the three components are held together by O—H...O, N...H...O, C—H...O and C—H...Cl hydrogen bonds, forming a centrosymmetric 2+2+2 aggregate. In the N...H...O hydrogen bond formed between the pyrimidin‐1‐ium cation and the water molecule, the H atom is disordered over two positions, resulting in two states, viz. pyrimidin‐1‐ium–water and pyrimidine–oxonium. In the low‐temperature phase, the title compound crystallizes in the same monoclinic space group and has a similar molecular packing, but the 2+2+2 aggregate loses the centrosymmetry, resulting in a doubling of the unit cell and two crystallographically independent molecules for each component in the asymmetric unit. The H atom in one N...H...O hydrogen bond between the pyrimidin‐1‐ium cation and the water molecule is disordered, while the H atom in the other hydrogen bond is found to be ordered at the N‐atom site with a long N—H distance [1.10 (3) Å]. 相似文献
107.
H. Hasegawa K. Nakagawa M. Azizur Rahman M. Takemura T. Maki K. Naito M. Mamunur Rahman 《Chromatographia》2015,78(1-2):65-72
108.
We successfully fabricated thin films of organic–inorganic layered perovskite-type compound (AEHBA)2PbCl4, where AEHBA stands for N-(2-aminoethyl)-2-hydroxybenzamide, a blue fluorescent dye that shows excited state intramolecular proton transfer (ESIPT) reaction. The formation of its highly ordered structure was readily achieved by the spin-coating of N,N-dimethylformamide solution dissolving PbCl2 and the AEHBA hydrogen chloride salt. X-ray diffraction analysis of the films revealed that organic AEHBA and inorganic PbCl4 perovskite layers were alternately stacked parallel to the substrate. In the absorption spectrum, exciton formation within the perovskite layers was confirmed by the appearance of a characteristic sharp band, while the photoluminescence spectrum showed a large Stokes-shifted band of AEHBA, indicating that it underwent an ESIPT. 相似文献
109.
Hiroyuki Takemura Teruo Shinmyozu Hirokazu Miura Islam Ullah Khan Takahiko Inazu 《Journal of inclusion phenomena and macrocyclic chemistry》1994,19(1-4):193-206
Side arm modifications of hexahomotriazacalix[3]arene (1) were achieved by simple synthetic methods. Compound5 has picolyl side arms and liquid-liquid extraction experiments showed that the alkali cation affinity of5 is much stronger than that of1. A chiral group was also introduced into the azacalixarene structure. Calix[4]arene was converted into dihomoazacalix[4]arene (2) in 8% yield. Clathrate formation of2 with various solvents is described. MM3 calculations were carried out onp-substituted analogs of2. The self-filled structure, in which the benzyl side arm is placed in its cavity, is the most stable structure when thep-positions of the aromatic rings carry small substituents. Strong hydrogen bonds between nitrogen and phenolic hydroxyl groups in dihomoazacalix[4]arene (2) were observed at low temperatures. The1H-NMR signals of phenolic hydroxyl groups appeared as six singlets in the range of 9.817.1 ppm at –70°C.This paper is dedicated to the commemorative issue on the 50th anniversary of calixarenes. 相似文献
110.
Tetsuo Iwagawa Miho MiyazakiHiroaki Okamura Munehiro NakataniMatsumi Doe Kaoru Takemura 《Tetrahedron letters》2003,44(12):2533-2535
Three novel bis(indole) alkaloids with an unprecedented skeleton have been isolated from a stony coral, Tubastraea sp. These indoles could biogenetically be derived from two molecules of aplysinopsin via a Diels-Alder reaction. 相似文献