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111.
Ohno O Chiba T Todoroki S Yoshimura H Maru N Maekawa K Imagawa H Yamada K Wakamiya A Suenaga K Uemura D 《Chemical communications (Cambridge, England)》2011,47(46):12453-12455
Novel sesquiterpene alkaloids, halichonines A (1), B (2), and C (3), were identified from the marine sponge Halichondria okadai Kadota. By spectroscopic analyses and synthesis, their structures were revealed to include a 6,6-bicyclic ring system and two prenylated amine moieties. In addition, 2 induced apoptosis in HL60 human leukemia cells. 相似文献
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We have investigated the pressure-induced Raman spectral changes of 1-ethyl-3-methylimidazolium tetrafluoroborate ([emim][BF4]). We found that [emim][BF4] did not crystallize up to 1.2 GPa. The Raman CH stretching spectra arising from the CH3 groups of the ethyl-chain and the CH3 group adjacent to the imidazolium-ring in [emim]+ cation largely changed against pressure. Moreover, the Raman intensity of the CH2 (N) bending band arising from the alkyl-chain drastically changes with increasing pressure, but that of the imidazolium-ring in-plane bending band arising from the imidazolium-ring is independent of pressure. Our results show that the environment around the alkyl-chain of [emim][BF4] is largely perturbed rather than that around the imidazolium-ring upon compression. 相似文献
114.
Toshihiro Yoshimura Yusuke Tamenori Nozomu Iwasaki Hiroshi Hasegawa Atsushi Suzuki Hodaka Kawahata 《Journal of synchrotron radiation》2013,20(5):734-740
Magnesium K‐edge X‐ray absorption near‐edge structure (XANES) spectra have been investigated to develop a systematic understanding of a suite of Mg‐bearing geological materials such as silicate and carbonate minerals, sediments, rocks and chemical reagents. For the model compounds the Mg XANES was found to vary widely between compounds and to provide a fingerprint for the form of Mg involved in geologic materials. The energy positions and resonance features obtained from these spectra can be used to specify the dominant molecular host site of Mg, thus shedding light on Mg partitioning and isotope fractionation in geologic materials and providing a valuable complement to existing knowledge of Mg geochemistry. 相似文献
115.
H. Wada H. Nakamura E. Fukami K. Yoshimura M. Shiga Y. Nakamura 《Journal of magnetism and magnetic materials》1987,70(1-3):17-19
The thermal expansion and low temperature and low temperature specific heat were measured for Y1−xScxMn2. The results are discussed in terms of spin fluctuations and compared with those of Y(Mn1−xAlx)2, which show al local moment character. It is revealed that Y1−xScxMn2 is a typical nearly antiferromagnet in which giant spin fluctuations are thermally excited. 相似文献
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Hiroshi Kageyama Takashi Watanabe Yoshihiro Tsujimoto Atsushi Kitada Yuji Sumida Kazuyoshi Kanamori Kazuyoshi Yoshimura Naoaki Hayashi Shigetoshi Muranaka Mikio Takano Monica Ceretti Werner Paulus Clemens Ritter Gilles Andr 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2008,120(31):5824-5829
119.
Terrestrial carbonate deposits with a banded layer structure can be good tools for the extraction of past environmental information on global and local scales using trace element concentrations and stable isotope ratios. The absolute age dating is most important for the reconstruction of an environmental chronicle. The measurements of fluorescent annual bandings in stalagmites using a microscopic spectrofluorometer with an XY-stage can be a convenient dating method and are especially effective for young samples whose absolute age is very difficult to be determined by other methods. The number of annual bandings was objectively counted using a personal computer. The optimal conditions for the measurements are discussed. The annual banding in stalagmites is caused by the seasonal differences in the fulvic acid concentrations in the dripping water which forms speleothems. 相似文献
120.
We propose to explain two observed anomalies that suggest extension of the minimal gauge scheme, the eμ production in the e+e? reaction and the anomalous y-distribution in reactions, as being caused by a single object, a heavy muon. With more accurate neutrino data this explanation can readily be distinguished from that of a new quark production. 相似文献