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251.
M. Tsuboi J. Inatani T. Kasuga R. Kawabe A. Sakamoto H. Iwashita K. Miyazawa 《International Journal of Infrared and Millimeter Waves》1987,8(1):1-11
A 40 GHz band SIS mixer receiver has been built using Nb/Al–AlOx/Nb array junctions and a 4.3 K closed cycle helium refrigerator. The minimum conversion loss of the mixer is 2±1 dB and the single sideband receiver noise temperature (TRX (SSB)) is as low as 110±10 K at 36 GHz. TRX (SSB) is almost constant in the IF bandwidth of 600 MHz. The mixer saturation level is as high as 15 nW, which is comparable to the injected LO power.Nobeyama Radio Observatory (NRO), a branch of the Tokyo Astronomical Observatory, University of Tokyo, is a cosmic radio observing facility open for outside users. 相似文献
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253.
Summary In order to simplify the thermal decomposition process of the amalgam on a silver net packed in a quartz tube during the determination of total mercury in tissue samples by flameless atomic-absorption, we attempted to make a handmade trapping and heating apparatus which is simpler and cheaper than the conventional apparatus. The proposed simple analytical technique for the analysis of total mercury by moving only the quartz tube inside the handmade electric furnace side to side by hand may be usefully applied to the microanalysis of total mercury at nanogram levels in very small amounts of tissue samples.
Vereinfachung der thermischen Zersetzung von Silberamalgam bei der Bestimmung von Gesamtquecksilber in Gewebeproben durch flammenlose AAS相似文献
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255.
Yasufumi Takahashi Yu Kobayashi Ziqian Wang Yoshikazu Ito Masato Ota Hiroki Ida Akichika Kumatani Keisuke Miyazawa Takeshi Fujita Hitoshi Shiku Yuri E. Korchev Yasumitsu Miyata Takeshi Fukuma Mingwei Chen Tomokazu Matsue 《Angewandte Chemie (International ed. in English)》2020,59(9):3601-3608
High‐resolution scanning electrochemical cell microscopy (SECCM) is used to image and quantitatively analyze the hydrogen evolution reaction (HER) catalytically active sites of 1H‐MoS2 nanosheets, MoS2, and WS2 heteronanosheets. Using a 20 nm radius nanopipette and hopping mode scanning, the resolution of SECCM was beyond the optical microscopy limit and visualized a small triangular MoS2 nanosheet with a side length of ca. 130 nm. The electrochemical cell provides local cyclic voltammograms with a nanoscale spatial resolution for visualizing HER active sites as electrochemical images. The HER activity difference of edge, terrace, and heterojunction of MoS2 and WS2 were revealed. The SECCM imaging directly visualized the relationship of HER activity and number of MoS2 nanosheet layers and unveiled the heterogeneous aging state of MoS2 nanosheets. SECCM can be used for improving local HER activities by producing sulfur vacancies using electrochemical reaction at the selected region. 相似文献
256.
Mamoru Miyazawa Takashi Tokuhashi Akiyoshi Horibata Takatoshi Nakamura Yu Onozaki Nobuhito Kurono Hisanori Senboku Masao Tokuda Takeshi Ohkuma Kazuhiko Orito 《Journal of heterocyclic chemistry》2013,50(Z1):E48-E54
A variety of alkoxy‐substituted benzolactams with a berbine or yohimbane skeleton were prepared from 1‐benzyl‐1,2,3,4‐tetrahydroisoquinolines or 1‐benzyl‐1,2,3,4‐tetrahydro‐β‐carbolines by a phosphine‐free Pd(II)‐catalyzed direct aromatic carbonylation in a Pd(OAc)2‐Cu(OAc)2 catalytic system. The site selectivity was compared with that of the carbonylation with Pd(OAc)2 or Pd(OAc)2·2 PPh3, respectively. 相似文献
257.
Shinsuke MarumotoMitsuo Miyazawa 《Tetrahedron》2011,67(2):495-500
Microbial transformation of coumarin, psoralen, and xanthyletin was performed with the fungus Glomerella cingulata. The main reaction pathways involved reduction at α,β-unsaturated δ-lactone ring on coumarin analogue. Coumarin was metabolized by G. cingulata to give the corresponding reduced acid, hydrocoumaric acid. In the biotransformation of psoralen, two reduced metabolites, 6,7-furano-hydrocoumaric acid, and 6,7-furano-o-hydrocoumaryl alcohol were isolated from the incubation of psoralen. Xanthyletin was converted to reduced products 9,9-dimethyl-6,7-pyrano-hydrocoumaric acid and 9,9-dimethyl-6,7-pyrano-o-hydrocoumaryl alcohol by G. cingulata. The structures of the new compounds were characterized using spectroscopic techniques. In addition, all of compounds including methyl ester derivatives of the metabolites were tested for the β-secretase (BACE1) inhibitory activity in vitro. 6,7-Furano-hydrocoumaric acid methyl ester was shown to possess BACE1 inhibitory activity, and an IC50 value was 0.84 ± 0.06 mM. 相似文献
258.
P.M. Shirage K. Kihou K. Miyazawa C.H. Lee H. Kito Y. Yoshida H. Eisaki Y. Tanaka A. Iyo 《Physica C: Superconductivity and its Applications》2010,470(20):986-988
We report the iron isotope effect on a transition temperature (Tc) in an optimally-doped (Ba,K)Fe2As2 (Tc = 38 K) and SmFeAsO1−y (Tc = 54 K) superconductors. In order to obtain the reliable isotope shift in Tc, twin samples with different iron isotope mass are synthesized in the same conditions (simultaneously) under high-pressure. We have found that (Ba,K)Fe2As2 shows an inverse iron isotope effect αFe = −0.18 ± 0.03 while SmFeAsO1−y shows a small iron isotope effect αFe = −0.02 ± 0.01, where the isotope exponent α is defined by Tc ∼ M−α (M is the isotopic mass). The results show that αFe changes in the iron-based superconductors depending on the system. The distinct iron isotope effects imply the exotic coupling mechanism in the iron-based superconductors. 相似文献
259.
Journal of Statistical Physics - We consider a single-server GI / GI / 1 queueing system with feedback. We assume the service time distribution to be... 相似文献
260.
Yajiao Hao Lin Yu Keisuke Miyazawa Shengrui Zhang Mo Liu Zhongqi Yu Jun Liu Yang Yu Song Li Shujue Xu Takeshi Fukuma Sean Xiao-An Zhang Minjie Li 《Angewandte Chemie (International ed. in English)》2023,62(22):e202302365
Synthesis of highly stable two-dimensional single-layer assemblies (SLAs) is a key challenge in supramolecular science, especially those with long-range molecular order and well-defined morphology. Here, thin (thickness <2 nm) triangular AuI-thiolate SLAs with high thermo-, solvato- and mechano- stability have been synthesized via a double-ligand co-assembly strategy. Furthermore, the SLAs show assembly-level elastic and anisotropic deformation responses to external stimuli as a result of the long-range anisotropic molecular packing, which provides SLAs with new application potentials in bio-mimic nanomechanics. 相似文献