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901.
902.
Reflectance, transmittance and absorbance spectra were observed of Hydrobryum japonicum, a kind of Aquatic angiosperm, over the wavelength range from 300 to 780 nm. Three remarkable peaks were observed at 380, 430, and at 680 nm in the absorbance
curve, which were assigned to the two pigments flavonoid and chlorophyll. The functions of these pigments of making photosynthesis
inevitable for the botanical activity and of protecting the plant from the heat given by the sunlight were discussed. 相似文献
903.
Structure Determination of an AgI‐Mediated Cytosine–Cytosine Base Pair within DNA Duplex in Solution with 1H/15N/109Ag NMR Spectroscopy 下载免费PDF全文
Dr. Takenori Dairaku Dr. Kyoko Furuita Dr. Hajime Sato Dr. Jakub Šebera Dr. Katsuyuki Nakashima Dr. Jiro Kondo Daichi Yamanaka Prof. Yoshinori Kondo Dr. Itaru Okamoto Prof. Akira Ono Dr. Vladimír Sychrovský Dr. Chojiro Kojima Prof. Yoshiyuki Tanaka 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(37):13028-13031
The structure of an AgI‐mediated cytosine–cytosine base pair, C–AgI–C, was determined with NMR spectroscopy in solution. The observation of 1‐bond 15N‐109Ag J‐coupling (1J(15N,109Ag): 83 and 84 Hz) recorded within the C–AgI–C base pair evidenced the N3–AgI–N3 linkage in C–AgI–C. The triplet resonances of the N4 atoms in C–AgI–C demonstrated that each exocyclic N4 atom exists as an amino group (?NH2), and any isomerization and/or N4–AgI bonding can be excluded. The 3D structure of AgI–DNA complex determined with NOEs was classified as a B‐form conformation with a notable propeller twist of C–AgI–C (?18.3±3.0°). The 109Ag NMR chemical shift of C‐AgI‐C was recorded for cytidine/AgI complex (δ(109Ag): 442 ppm) to completed full NMR characterization of the metal linkage. The structural interpretation of NMR data with quantum mechanical calculations corroborated the structure of the C–AgI–C base pair. 相似文献
904.
T. Okamoto J. Kano S. Nakamura A. Fuwa T. Otoyama Y. Nakazaki H. Hashimoto J. Takada M. Ito N. Ikeda 《Hyperfine Interactions》2013,219(1-3):147-152
57Fe Mössbauer spectroscopy was performed on two types of Fe oxide nanoparticles supported on a typical ferroelectric, BaTiO3. It was found that the valence state of FeO nanoparticles changed to a mixed 2+/3+ state at high temperature where BaTiO3 shows paraelectric behaviour. We attribute this phenomenon to the fluctuation of electric dipoles which realizes carrier injection into the Fe oxides. This is the first report which discusses a dynamical valence state of transition metal oxides supported on ferroelectrics. 相似文献
905.
906.
Twelve new compounds, namely, five melanothyrsins A–E (1α-angeloyloxyeremophilenolides), normelanothyrsin A (1α-angeloyloxynoreremophilenone), and six other eremophilane-type compounds, have been isolated from Ligularia melanothyrsa Hand.-Mazz. (Asteraceae), collected in the Sichuan Province of China. Six of the compounds have a 1α-angeloyloxy moiety, while the other six have no functional group at the C-1 position. The absolute configuration was also determined using CD spectra. This is the first chemical study of compounds isolated from this species. 相似文献
907.
The chain length dependence involving a chiral memory effect of 2,6-pyridylene ethynylene oligomers ‘meta-ethynylpyridines’ was investigated. The meta-ethynylpyridine oligomers associated with octyl β-d-glucopyranoside form a helical complex giving induced CD; the induced chirality could be memorized with the help of Cu(OTf)2 as an additive. Contrary to our expectations, the study of the length dependence revealed that the 12-meric oligomer showed a more sustainable chiral memory effect than those observed in both of the shorter 6-meric and longer 18-meric oligomers. 相似文献
908.
Understanding the Origins of Nucleophilic Hydride Reactivity of a Sodium Hydride–Iodide Composite 下载免费PDF全文
Zonghan Hong Derek Yiren Ong Dr. Subas Kumar Muduli Dr. Pei Chui Too Guo Hao Chan Dr. Ya Lin Tnay Prof. Shunsuke Chiba Dr. Yusuke Nishiyama Prof. Hajime Hirao Prof. Han Sen Soo 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(21):7108-7114
Sodium hydride (NaH) has been commonly used as a Brønsted base in chemical syntheses, while it has rarely been employed to add hydride (H?) to unsaturated electrophiles. We previously developed a procedure to activate NaH through the addition of a soluble iodide source and found that the new NaH–NaI composite can effect even stereoselective nucleophilic hydride reductions of nitriles, imines, and carbonyl compounds. In this work, we report that mixing NaH with NaI or LiI in tetrahydrofuran (THF) as a solvent provides a new inorganic composite, which consists of NaI interspersed with activated NaH, as revealed by powder X‐ray diffraction, and both solid‐state NMR and X‐ray photoelectron spectroscopies. DFT calculations imply that this remarkably simple inorganic composite, which is comprised of NaH and NaI, gains nucleophilic hydridic character similar to covalent hydrides, resulting in unprecedented and unique hydride donor chemical reactivity. 相似文献
909.
Hisashi Miyazaki Hiroaki Takiguchi Masami Aono Yoichi Okamoto 《Journal of Non》2012,358(17):2103-2106
Multilayered a-Ge/Au was investigated to realize low-temperature formation of poly-Ge films on insulator. Increasing Au layer thicknesses, peak intensity of crystalline Ge–Ge TO mode increased and amorphous Ge–Ge TO mode decreased. When Au composition ratio is high, the samples are crystallized under eutectic temperature. Annealing temperature at 673 K, all samples with Au layer are crystallized. Crystalline Ge has no strain evaluated by X-ray diffraction and Raman scattering spectroscopy. However, the Au is compressed or expanded in the films with various annealing temperature. It is thought that this phenomenon changes depending on the size of the space in the film. The behavior of electrical resistivity is changed at eutectic temperature. 相似文献
910.