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排序方式: 共有410条查询结果,搜索用时 15 毫秒
121.
Ohtani Yuta Kumano Keita Saneshige Mami Takami Kei Hoshi Hajime 《Journal of Solid State Electrochemistry》2021,25(7):2107-2113
Journal of Solid State Electrochemistry - Despite their potential for use as a low-cost energy-conversion device, dye-sensitized solar cells (DSSCs) have not been widely utilized because they apply... 相似文献
122.
Yuki Minamoto Yuta Kondo Kosuke Osawa Yuji Harada Masayasu Shimura Mamoru Tanahashi 《Proceedings of the Combustion Institute》2021,38(4):5519-5527
Direct numerical simulations of homogeneous charge compression ignition combustion are performed to investigate the behaviour of the wall heat flux, Φ, under engine relevant conditions. In laminar conditions, there are four distinctive stages where Φ evolution is affected by low-temperature chemistry (LTC), resulting in multiple local maxima with a lagged maximum value in Φ evolution. These effects are also observed in turbulence conditions locally. However, they no longer appear in the mean Φ evolution clearly, although some weak non-monotonicity in Φ due to the LTC are observed. The locality of the LTC effects may need to be addressed for near-wall pollutant prediction in future. 相似文献
123.
Yuta Ogawa Erika Takiguchi Masashi Mamada Daisuke Kumaki Shizuo Tokito Hiroshi Katagiri 《Tetrahedron letters》2017,58(10):963-967
Two novel bent-shaped thienoacenes, naphtho[2,3-b]naphtho[2′,3′:4,5]thieno[3,2-d]thiophene (bent-DNTT) and anthra[2,3-b]anthra[2′,3′:4,5]thieno[3,2-d]thiophene (bent-DATT) were synthesized from thieno[2,3-b]thiophene and their corresponding aromatic anhydrides by three steps: Friedel–Crafts acylation, acid-promoted cyclization, and reductive aromatization. The structural curvature improved the solubility of these thienoacenes in organic solvents. The bent-DNTT based FET device was fabricated by the spin-coating method. The device exhibited p-type characteristics with a mobility of 5.1 × 10?5 cm2 V?1 s?1. Its thin-film structure was fully characterized as an edge-on orientation with large intermolecular orbital coupling. 相似文献
124.
Yuta Kamiya Fumikazu Ikemori 《International journal of environmental analytical chemistry》2015,95(12):1157-1168
Chlorinated polycyclic aromatic hydrocarbons (ClPAHs) have been discovered to represent ubiquitous environmental pollutants in the last decade. In the present study, sample pre-treatment and ionisation conditions associated with the gas chromatography/mass spectrometry (GC/MS) analysis of ClPAHs were evaluated. The optimal pre-treatment of ambient air particulate samples was achieved using fractionation over silica gel with 10% dichloromethane in n-hexane as the eluent. The optimised condition of GC/MS with electron impact ionisation permitted analysis of all target ClPAHs. Not all target ClPAHs were detected using GC/MS with negative chemical ionisation, although this technique exhibited greater sensitivity for several of the compounds compared to electron impact ionisation. The analytical method was applied to the survey of ClPAHs in atmospheric particulate matter obtained close to an industrial site and in a standard sample of tunnel dust. Fourteen and eighteen species of ClPAHs were detected in the industrial air samples and tunnel dust, respectively, confirming the capability of the method. The compositions of ClPAHs were significantly different between air samples and tunnel dust. It suggests that alternative emission sources rather than vehicle exhaust could play a significant role in the air. 相似文献
125.
Total Synthesis,Stereochemical Reassignment,and Biological Evaluation of (−)‐Lyngbyaloside B
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Prof. Dr. Haruhiko Fuwa Yuta Okuaki Naoya Yamagata Prof. Dr. Makoto Sasaki 《Angewandte Chemie (International ed. in English)》2015,54(3):868-873
(?)‐Lyngbyaloside B is a 14‐membered macrolide glycoside isolated from the marine cyanobacterium Lyngbya sp. as a cytotoxic substance by Moore and co‐workers. The first total synthesis of (?)‐lyngbyaloside B and the reassignment of its stereostructure is described. The synthesis features an Abiko–Masamune aldol reaction, a vinylogous Mukaiyama aldol reaction, and a macrocyclization involving an acyl ketene intermediate for the construction of the macrocyclic backbone, which contains an acylated tertiary alcohol. The antiproliferative activity of selected compounds against a small panel of human cancer cell lines is also reported. 相似文献
126.
Takumi Nakanishi Yuta Hori Shuqi Wu Hiroyasu Sato Atsushi Okazawa Prof. Norimichi Kojima Yusuke Horie Hajime Okajima Prof. Akira Sakamoto Yoshihito Shiota Prof. Kazunari Yoshizawa Prof. Osamu Sato 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(35):14891-14897
A proton–electron coupling system, exhibiting unique bistability or multistability of the protonated state, is an attractive target for developing new switchable materials based on proton dynamics. Herein, we present an iron(II) hydrazone crystalline compound, which displays the stepwise transition and bistability of proton transfer at the crystal level. These phenomena are realized through the coupling with spin transition. Although the multi-step transition with hysteresis has been observed in various systems, the corresponding behavior of proton transfer has not been reported in crystalline systems; thus, the described iron(II) complex is the first example. Furthermore, because proton transfer occurs only in one of the two ligands and π electrons redistribute in it, the dipole moment of the iron(II) complexes changes with the proton transfer, wherein the total dipole moment in the crystal was canceled out owing to the antiferroelectric-like arrangement. 相似文献
127.
A microbubble generator with a cylindrical hollow ultrasonic horn (HUSH), gas flow path, and an orifice inside it can produce high ultrasonic pressure around the generated microbubbles. We used this microbubble generator with a HUSH as a sonochemical reactor for the degradation of indigo carmine and evaluated the sonochemical reaction by simply inserting the horn end into a liquid. The experimental results revealed that the ultrasonic irradiation around ultrasonically generated microbubbles effectively degraded indigo carmine in water. In addition, degradation experiments performed by varying the ultrasonic power and gas flow rates indicated that a continuous gas supply and ultrasonic pressure were required for generating the microbubbles, without the generation of millimeter-scale bubbles, to enhance the sonochemical reaction in water. 相似文献
128.
The oxidative intramolecular bromo-amination of various N-alkenyl sulfonamides and N-alkenoxyl sulfonamides via umpolung of alkali metal bromides occurred exo-selectively to generate cyclic bromoamides in high yields with good diastereoselectivities. This method provided the desired products without elaborating the stoichiometric amount of corresponding organic waste. 相似文献
129.
130.
Ueda M Kondoh E Ito Y Shono H Kakiuchi M Ichii Y Kimura T Miyoshi T Naito T Miyata O 《Organic & biomolecular chemistry》2011,9(7):2062-2064
Direct generation of a benzyl radical by C-H bond activation of toluenes and the addition reaction of the resulting radical to an electron deficient olefin were developed. The reaction of dimethyl fumarate with toluene in the presence of Et(3)B as a radical initiator at reflux afforded 2-benzylsuccinic acid dimethyl ester in good yield. 相似文献