排序方式: 共有16条查询结果,搜索用时 15 毫秒
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Yutaka Ado Yukie Suzuki Toshio Tadokoro Kazuo Kimura Hirotoshi Samejima 《Applied biochemistry and biotechnology》1979,4(1):43-55
A number of fermentative methods for the production of various important nucleotides from their precursors have been developed in Japan, and some of these nucleotides have been industrially produced for more than a decade. For the production of these nucleotides, required ATP is usually supplied to the fermentation media either exogenously or by the naturally occurring ATP regenerating system involved in microbial cells. In this paper, the authors describe an attempt to immobilize ATP-regenerating microbial cells and then utilize such immobilized cells for the continuous production of various nucleotides. 相似文献
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We present direct experimental observation of exciton-phonon bound states in the photoluminescence excitation spectra of isolated single-walled carbon nanotubes (SWNT) in aqueous suspension. The photoluminescence excitation spectra from several distinct SWNTs show the presence of at least one sideband related to the tangential modes, lying 0.2 eV above the main absorption or emission peak. Both the energy position and line shapes of the sidebands are in excellent agreement with recent calculations [Phys. Rev. Lett. 94, 027402 (2005)] that predict the existence of exciton-phonon bound states, a sizable spectral weight transfer to these exciton-phonon complexes, and that the amount of this transfer depends on the specific nanotube structure and diameter. 相似文献
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Abe T Sato C Ushirogochi H Sato K Takasaki T Isoda T Mihira A Yamamura I Hayashi K Kumagai T Tamai S Shiro M Venkatesan AM Mansour TS 《The Journal of organic chemistry》2004,69(18):5850-5860
A novel and mild method was established to synthesize 6-methylidene penem compounds. This method entails a MgBr(2)/Et(3)N-promoted aldol-type condensation on 6-bromopenem 12 with an appropriately substituted aldehyde to yield the intermediate acetylated bromohydrin, which was smoothly converted to the final product with simultaneous deprotection of C3 carboxylic acid ester using activated zinc dust and phosphate buffer at pH 6.5. This process provides a useful variation of C-C bond formation method for penem derivatives and also serves as a practical synthetic method to prepare 6-exomethylenepenem derivatives without racemization at the C5 position. 相似文献
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Araujo PT Doorn SK Kilina S Tretiak S Einarsson E Maruyama S Chacham H Pimenta MA Jorio A 《Physical review letters》2007,98(6):067401
We have studied the optical transition energies of single-wall carbon nanotubes over broad diameter (0.7-2.3 nm) and energy (1.26-2.71 eV) ranges, using their radial breathing mode Raman spectra. We establish the diameter and chiral angle dependence of the poorly studied third and fourth optical transitions in semiconducting tubes. Comparative analysis between the higher lying transitions and the first and second transitions show two different diameter scalings. Quantum mechanical calculations explain the result showing strongly bound excitons in the first and second transitions and a delocalized electron wave function in the third transition. 相似文献
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Mitsuharu Tabuchi Satoshi Tsutsui Christian Masquelier Ryoji Kanno Kazuaki Ado Ichiro Matsubara Saburo Nasu Hiroyuki Kageyama 《Journal of solid state chemistry》1998,140(2):1550
The magnetic properties of several LiFeO2polymorphs (different cation arrangements in a cubic close-packed oxygen structure) have been examined by magnetic susceptibility measurements and Mössbauer spectroscopy. Samples with relatively low ferromagnetic impurity levels have been obtained by hydrothermal reaction of FeCl3·6H2O or FeOOH with LiOH·H2O and subsequent annealing in air.α-NaFeO2with no detectable ferromagnetic impurity has been obtained by hydrothermal reaction ofα-FeOOH and NaOH. Whileα-NaFeO2revealed only one anomaly at 11 K (Néel point) in the magnetic susceptibility–temperature curves, each LiFeO2sample shows two anomalies (40–50 and 90–280 K). Mössbauer data confirm that iron is present in the high-spin 3+ state according to the values of the internal field at 4.2 K and isomer shifts at 300 K. The relationship between the cation arrangements and the Néel temperature is discussed for LiFeO2. 相似文献
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The Synthesis of 2,3,4,5-1H-Tetrahydroimidazo[2,1-b]quinazolin-2,5-diones and analogous 2,3,4,5-1H-Tetrahydroimidazo[1,2-a]thieno[2,3-d] (or [3,2-d])-pyrimidin-2,5-diones The syntheses of various imidazo [2, 1-b]quinazolinediones and their thiophene analogs are described. 相似文献
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Matsushita Y Suzuki J Izumi Y Matsuoka K Takahashi S Aoyama Y Mihira T Takano A 《The Journal of chemical physics》2010,133(19):194901
The effect of molecular weight distribution of ABC linear terpolymers on the formation of periodic structures was investigated. Three poly(isoprene-b-styrene-b-2-vinylpridine) triblockterpolymers with molecular weights of 26k, 96k, and 150k were blended variously. Three-phase, four-layer lamellar structures were observed when polydispersity index (PDI) was low, but it has been found that simple lamellar structure with flat surface transforms into an undulated lamellar one, where two interfaces, i.e., I/S and S/P, are both undulated, and they are synchronizing each other if PDI exceeds the critical value. This new structure could be formed due to the periodic and "weak" localization of three chains along the domain interfaces, which produces periodic surfaces with nonconstant mean curvatures. With further increase of PDI, the blend macroscopically phase-separated into different microphase-separated structures. 相似文献
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