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排序方式: 共有1813条查询结果,搜索用时 656 毫秒
1.
Dr. Yogesh Kumar Maurya Dr. Pingchun Wei Takahide Shimada Dr. Kazuhisa Yamasumi Dr. Shigeki Mori Prof. Dr. Ko Furukawa Dr. Hajime Kusaba Prof. Dr. Tatsumi Ishihara Prof. Dr. Yongshu Xie Dr. Masatoshi Ishida Prof. Dr. Hiroyuki Furuta 《化学:亚洲杂志》2021,16(7):743-747
A facile synthetic strategy towards conformationally stable chiral chromophores based on dimeric porphyrinoids has been established. A peculiar class of face-to-face intramolecularly interlocked corrole dimers were formed by the oxidative C−C coupling linked at the inner carbon sites upon simple treatment of copper(II) ions. Their intrinsic electronic structures were modulated by the peripheral corrole ring annulations, which lead to distinct optical properties and redox profiles. The stereogenic carbon centers implemented in the confused corrole skeleton provided a rationale for designing novel chiral materials. 相似文献
2.
HIRONOBU Ishihara 《Geometriae Dedicata》1997,67(3):309-336
Several classification results for ample vector bundles of rank 2 on Hirzebruch surfaces, and on Del Pezzo surfaces, are obtained. In particular, we classify rank 2 ample vector bundles with c2 less than seven on Hirzebruch surfaces, and with c2 less than four on Del Pezzo surfaces. 相似文献
3.
We study the nonrelativistic limit of the Cauchy problem for the nonlinear Klein-Gordon equation and prove that any finite
energy solution converges to the corresponding solution of the nonlinear Schr?dinger equation in the energy space, after the
infinite oscillation in time is removed. We also derive the optimal rate of convergence in .
Received: 13 July 2000 / Published online: 1 February 2002 相似文献
4.
Shuzo Kuwano Manabu Ishihara 《The Journal of microwave power and electromagnetic energy》2007,40(3):155-164
The finite-difference time-domain (FDTD) simulations of specific absorption rate (SAR) in a human head exposed to microwaves have, to date, been carried out on models of the head only. This was because it was believed that the body effects on the average SAR of the head could be ignored at high frequencies of around 1 GHz. That opinion, however, was based on inappropriate calculation conditions and is therefore unreliable. In this paper, we have re-examined the body effects on the SAR distributions in a realistic homogeneous model of the adult head exposed to microwaves. We found that the SAR on the eye surface of the head-only model exposed to E-polarized waves was 31% smaller than that of the whole-body model at 900 MHz, and 43% larger at 1.5 GHz. For a size that can practically be considered whole-body, it is necessary to have the top of the head to the belly for 900 MHz and to the chest area for 1.5 GHz. The previously unclear body effects of H-polarized waves were assumed to be less than those of E-polarized waves, suggesting that the chest area would be sufficient for both frequencies. 相似文献
5.
Hiroyasu Nishiguchi Hiroshi Yamada Masaru Ogura Tatsumi Ishihara Yusaku Takita 《Research on Chemical Intermediates》2003,29(7-9):755-760
The oxygen storage capacity of CeO2, Ce0.9Pr0.1O2, Pt?Rh/CeO2 and Pt?Rh/Ce0.9Pr0.1O2 was investigated by conventional GC pulse method and transient pulse techniques. It is shown that incorporation of PrOy into CeO2 matrix strongly promotes oxygen storage capacity (OSC) measured using the transient pulse technique. The improvement of OSC at low temperature is observed in Pt?Rh loaded onto CeO2 and Ce?Pr catalysts. 相似文献
6.
Tohru OishiHiroshi Tsuchikawa Michio Murata Manabu YoshidaMasaaki Morisawa 《Tetrahedron letters》2003,44(34):6387-6389
A chemoattractant candidate named sperm-activating and attracting factor (SAAF) from the eggs of ascidian Ciona intestinalis, was synthesized from chenodeoxycholic acid in 16 steps. The present synthesis led to the unambiguous structure determination of SAAF to be (3R,4R,7R,25S)-3,4,7,26-tetrahydroxycholestane-3,26-disulfate. The synthetic pure specimen was also used to confirm the dual sperm-activating and attracting activity. 相似文献
7.
Yasuyuki Itoh Tohru Sugawara 《Journal of Infrared, Millimeter and Terahertz Waves》1996,17(2):465-475
This paper describes a quasi-optical method for the conversion of modes transmitted through highly oversized circular waveguides. A waveguide-mode is radiated once from a waveguide cut in the form of a radiation beam, which is then properly shaped by two curved mirrors and directed back into the waveguide. The curved mirror shapes are iteratively and automatically determined for given propagation distances using the design technique for phase correction mirrors. The proposed method gives favorable results in designing a waveguide expander/reducer, a TE01-TE02 mode converter, and a TE01-HE11 mode converter. 相似文献
8.
Weighted Strichartz estimates with homogeneous weights with critical exponents are proved for the wave equation without a support restriction on the forcing term. The method of proof is based on expansion by spherical harmonics and on the Sobolev space over the unit sphere, by which the required estimates are reduced to the radial case. As an application of the weighted Strichartz estimates, the existence and uniqueness of self‐similar solutions to nonlinear wave equations are proved on up to five space dimensions. © 2006 Wiley Periodicals, Inc. 相似文献
9.
Nakamura M. Ishihara N. Akazawa Y. Kimura H. 《Solid-State Circuits, IEEE Journal of》1995,30(9):991-997
An instantaneous response CMOS optical-receiver IC is described with wide input dynamic range and high sensitivity. In a TCM (time compression multiplexing)-TDMA (time division multiple access) fiber-optic subscriber system, a receiver should be able to handle burst-data packets with different amplitude. This requires quick response and a wide dynamic range. Instantaneous response is achieved with a new feed-forward auto-bias adjustment technique. In addition, multistaged offset compensation provides a wide dynamic range without any external elements and adjustments. Using these design techniques, an optical receiver IC was fabricated in a standard 0.8-μm CMOS technology. The receiver has a wide dynamic range of more than 25 dB for burst-mode optical input at 29 Mb/s. It has high transimpedance gain of 150 dBΩ and high sensitivity of -42 dBm with stable operation for FET threshold voltage and power supply voltage fluctuation 相似文献
10.
Toyoda M Ishihara M Yamaguchi S Ito H Matsuo T Roll R Rosenbauer H 《Journal of mass spectrometry : JMS》2000,35(2):163-167
A new type of multi-turn time-of-flight mass spectrometer was constructed, consisting of four cylindrical electric sectors and 28 electric quadrupole lenses, the size of the vacuum chamber being 60 x 70 x 20 cm. It was demonstrated that the mass resolution can be increased according to the number of cycles of the ions through the ion optical system. 相似文献