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71.
Putzke C Coldea AI Guillamón I Vignolles D McCollam A Leboeuf D Watson MD Mazin II Kasahara S Terashima T Shibauchi T Matsuda Y Carrington A 《Physical review letters》2012,108(4):047002
We report a de Haas-van Alphen oscillation study of the 111 iron pnictide superconductors LiFeAs with T(c) ≈ 18 K and LiFeP with T(c) ≈ 5 K. We find that for both compounds the Fermi surface topology is in good agreement with density functional band-structure calculations and has almost nested electron and hole bands. The effective masses generally show significant enhancement, up to ~3 for LiFeP and ~5 for LiFeAs. However, one hole Fermi surface in LiFeP shows a very small enhancement, as compared with its other sheets. This difference probably results from k-dependent coupling to spin fluctuations and may be the origin of the different nodal and nodeless superconducting gap structures in LiFeP and LiFeAs, respectively. 相似文献
72.
Assem N Hili R He Z Kasahara T Inman BL Decker S Yudin AK 《The Journal of organic chemistry》2012,77(13):5613-5623
Unprotected aziridine aldehydes belong to the amphoteric class of molecules by virtue of their dual nucleophilicity/electrophilicity. The dimeric nature of these molecules, brought together by a weak and reversible aminal "connection", was found to be an important element of reactivity control. We present evidence that reversible dimer dissociation is instrumental in aziridine aldehyde transformations. We anticipate further developments that will unveil other synthetic consequences of remote control of selectivity through forging reversible covalent interactions. 相似文献
73.
Katsuaki Shirai Christian Bayer Andreas Voigt Thorsten Pfister Lars Büttner Jürgen Czarske 《European Journal of Mechanics - B/Fluids》2008,27(5):567-578
This paper reports on the measurements of the near-wall turbulence statistics in a fully developed channel flow. The flow measurements were carried out with a novel laser Doppler velocity profile sensor with a high spatial resolution. The sensor provides both the information of velocity and position of individual tracer particles inside the measurement volume. Hence, it yields the velocity profile inside the measurement volume, in principle, without the sensor being mechanically traversed. Two sensor systems were realized with different techniques. Typically the sensor has a relative accuracy of velocity measurement of 10−3 and the spatial resolution of a few micrometers inside the measurement volume of about 500 μm long. The streamwise velocity was measured with two independent sensor systems at three different Reynolds number conditions. The resulting turbulence statistics show a good agreement with available data of direct numerical simulations up to fourth order moment. This demonstrates the velocity profile sensor to be one of the promising techniques for turbulent flow research with the advantage of a spatial resolution more than one magnitude higher than a conventional laser Doppler technique. 相似文献
74.
Tadashi Wadayama Toru Hada Koichiro Wakasugi Masao Kasahara 《Designs, Codes and Cryptography》2001,23(1):23-34
The paper presents lower and upper bounds on the maximumnonlinearity for an n-input m-output Booleanfunction. We show a systematic construction method for a highlynonlinear Boolean function based on binary linear codes whichcontain the first order Reed-Muller code as a subcode. We alsopresent a method to prove the nonexistence of some nonlinearBoolean functions by using nonexistence results on binary linearcodes. Such construction and nonexistence results can be regardedas lower and upper bounds on the maximum nonlinearity. For somen and m, these bounds are tighter than theconventional bounds. The techniques employed here indicate astrong connection between binary linear codes and nonlinear n-input m-output Boolean functions. 相似文献
75.
Ryuya Yokoo Keisuke Goto Jiro Kasahara Venkat Athmanathan James Braun Guillermo Paniagua Terrence R. Meyer Akira Kawasaki Ken Matsuoka Akiko Matsuo Ikkoh Funaki 《Proceedings of the Combustion Institute》2021,38(3):3759-3768
The internal flow structures of detonation wave were experimentally analyzed in an optically accessible hollow rotating detonation combustor with multiple chamber lengths. The cylindrical RDC has a glass chamber wall, 20 mm in diameter, which allowed us to capture the combustion self-luminescence. A chamber 70 mm in length was first tested using C2H4O2 and H2–O2 as propellants. Images with a strong self-luminescence region near the bottom were obtained, confirming the small extent of the region where most of the heat release occurs as found in our previous research. Based on the visualization experiments, we tested RDCs with shorter chamber walls of 40 and 20 mm. The detonation wave was also observed in the shorter chambers, and its velocity was not affected by the difference in chamber length. Thrust performance was also maintained compared to the longer chamber, and the short cylindrical RDC had the same specific impulse tendency as the cylindrical (hollow) or annular 70-mm chamber RDC. Finally, we calculated the pressure distributions of various chamber lengths, and found they were also consistent with the measured pressure at the bottom and exit. We concluded that the short-chamber cylindrical RDC with equal length and diameter maintained thrust performance similar to the longer annular RDC, further expanding the potential of compact RDCs. 相似文献
76.
Y Takeda K Urakawa A Sakamoto T Nakano Y Sugawara Y Ohsugi M Morita T Kasahara 《Chemical & pharmaceutical bulletin》1992,40(1):177-181
The regulatory effects of lobenzarit disodium (CCA), a therapeutic agent for treating rheumatoid arthritis (RA), on polyclonal immunoglobulin production by human lymphocytes were investigated in vitro. CCA inhibited the production of immunoglobulin in all the classes examined at a clinically relevant concentration. Moreover, it inhibited the immunoglobulin production as well as lymphocyte proliferation even when purified B lymphocytes preactivated by Staphylococcus aureus COWAN I were cultured with recombinant lymphokines such as IL2 and IL6. These results suggest that CCA acts directly on B lymphocytes. The analysis at each of two different stages of B lymphocyte activation lineage, i.e., the primary activation stage and a stage of proliferation and differentiation to antibody secreting cells, has indicated that CCA inhibits the proliferation-differentiation stage of B lymphocytes. CCA does not inhibit B lymphocytes at the primary activation stage; actually, it augments them, resulting in the subsequent enhancement of immunoglobulin production. 相似文献
77.
总结了1990年6月到1993年10月期间西藏空气簇射阵列的观测结果。寻找了来自于蟹状星云、X射线双星、脉冲星、活动星系核和其它活动天体的能量为10TeVγ射线连续发射,没有发现连续稳定发射的迹象,但给出了每个源的流强上限。在阵列所观测的天区寻找了10TeV的γ暴,结果没有发现能量10TeV的γ暴,最后也给出了发现此种γ暴的上限。应用该阵列,明显地观测到了能量为10TeV的宇宙线流强的太阳和月亮阴影。观测了朝向和远离太阳的行星际空间磁场对宇宙线阴影的影响,这是行星际磁场对阴影位移影响的第一次直接观测。研究并发现在实验期间,太阳阴影的位置每年都在变化。同时观测在此期间,朝向和远离方向的宇宙线阴影的不同变化。另外,应用该实验的数据,给出了所谓的“膝”区的原初宇宙线能谱。 相似文献
78.
Mizuho Sugiuchi Dr. Yukatsu Shichibu Prof. Katsuaki Konishi 《Angewandte Chemie (International ed. in English)》2018,57(26):7855-7859
2,3‐bis(diphenylphosphino)butane enantiomers (chiraphos, L) used as chiral auxiliaries results in the preferential formation of an unprecedented Au24 framework with inherent chirality. The crystal structure of [Au24L6Cl4]2+ ( 1 ) has a square antiprism‐like octagold core twinned by two helicene‐like hexagold motifs, where the inherent chirality is associated with the helical arrangement. The clusters carrying (R,R)‐ and (S,S)‐ diphosphines had right‐ and left‐handed strands, respectively. Circular dichroism spectra showed peaks in the visible to near‐IR region, some of which did not coincide with absorption bands, suggesting the enantiomeric Au24 frameworks possess unique chiroptical properties. The Au24 frameworks were thermally robust, which could be attributed to the superatomic concept (18 e? system) and the steric constraint effects of the bridging ligand units. 相似文献
79.
Longley NP Bode CR Border PM Courant H DeMuth DM Gray RN Johns K Kasahara SM Lowe MJ Marshak ML Miller WH Mualem L Peterson EA Roback DM Ruddick K Schmid DJ Schub MH Shupe MA Vassiliev V Villaume G Werkema SJ Ayres DS Fields TH Gallagher HM Goodman MC Lopez FV May EN Price LE Seidlein RV Thron JL Trost H Uretsky JL Allison WW Barr GD Brooks CB Cobb JH Giller GL Stassinakis A Thomson MA West N Wielgosz U Alner GJ Cockerill DJ Cotton RJ Garcia-Garcia C Litchfield PJ Pearce GF Ewen B Kafka T 《Physical review D: Particles and fields》1995,52(5):2760-2765
80.