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971.
We consider the Penrose–Fife phase field model [Thermodynamically consistent models of phase-field type for the kinetics of phase transitions, Physica D 43 (1990) 44–62] with homogeneous Neumann boundary condition to the nonlinear heat flux q=∇(1/θ), i.e., q=0 on the boundary, where θ>0 is the temperature. There is a unique H1 solution globally in time with the non-empty, connected, compact ω-limit set composed of stationary solutions, and the linearized stable stationary solution is dynamically stable. 相似文献
972.
M. Mihara T. Izumikawa H. Ueno K. Matsuta D. Nishimura T. Nagatomo T. Moriguchi Y. Ito D. Nagae M. Fukuda A. Yoshimi K. Yamada M. Takechi Y. Ichikawa S. Momota Y. Hirayama T. Ohtsubo S. Suzuki T. Kubo Y. Namiki A. Ozawa Y. Ishibashi H. Oishi K. Suzuki I. Hachiuma K. Namihira D. Horikawa T. Minamisono T. Yamaguchi T. Kuboki T. Suzuki K. Satoh Y. Kobayashi K. Asahi K. Matsukawa K. Shirai 《Hyperfine Interactions》2010,197(1-3):143-147
The β-NMR study of short-lived nucleus 58Cu (I π ?=?1?+?, T 1/2?=?3.2 s) in Si has been performed. Spin polarization of 58Cu induced by the charge exchange reaction of 58Ni was observed in Si at 15 K. The 58Cu magnetic moment $|\upmu[^{58}\mbox{Cu}]| = (0.46 \pm 0.03)\upmu_{\rm N}$ deduced from the β-NMR spectrum is consistent with the previous results on the laser spectroscopy. The present result shows that the 58Cu nucleus is promising as a new nuclear probe for the microscopic study of Cu impurities in Si. 相似文献
973.
Ichikawa A Sugimoto Y Tanaka S 《Proceedings of the Japan Academy. Series B, Physical and biological sciences》2010,86(8):848-866
Histamine and prostaglandins (PGs) play a variety of physiological roles as autacoids, which function in the vicinity of their sources and maintain local homeostasis in the body. They stimulate target cells by acting on their specific receptors, which are coupled to trimeric G proteins. For the precise understanding of the physiological roles of histamine and PGs, it is necessary to clarify the molecular mechanisms involved in their synthesis as well as their receptor-mediated responses. We cloned the cDNAs for mouse L-histidine decarboxylase (HDC) and 6 mouse prostanoid receptors (4 PGE(2) receptors, PGF receptor, and PGI receptor). We then characterized the expression patterns and functions of these genes. Furthermore, we established gene-targeted mouse strains for HDC and PG receptors to explore the novel pathophysiological roles of histamine and PGs. We have here summarized our research, which should contribute to progress in the molecular biology of HDC and PG receptors. 相似文献
974.
Masaaki Hori Harushi Mori Shigeki Aoki Osamu Abe Tomohiko Masumoto Satoshi Kunimatsu Kuni Ohtomo Hiroyuki Kabasawa Nobuyuki Shiraga Tsutomu Araki 《Magnetic resonance imaging》2010
Object
Although three-dimensional (3D), high-spatial resolution susceptibility-weighted imaging (SWI) appears to be valuable in the evaluation of central nervous system gliomas, several evaluation methods are proposed in the literature. The purpose of this study was to evaluate the use of 3D SWI for grading intracranial gliomas with various analysis methods.Materials and Methods
Twenty-three patients suspected of having gliomas participated in this study. SWI was performed in addition to conventional MR sequences. In 15 cases, post-gadolinium enhanced SWI was also obtained. Imaging evaluation criteria were conventional grade, hypointensity ratio in the tumor-dominant structure of hypointensity on SWI (hemorrhage or vascular structure) and presence of abnormal enhancement surrounding the tumor.Results
Mean grading scores of conventional grade showed no statistically significant difference among WHO grades. Mean grading scores of hypointensity ratios in the tumor were higher for WHO Grades 3 and 4 than for lower grade tumors (P=.05, Mann–Whitney U test). Hemorrhagic foci were more frequently seen in the higher grade tumor. Post-contrast susceptibility-weighted images of five of 11 WHO Grade 3 and 4 cases showed bright enhancement surrounding the tumor, suggesting a breakdown of the blood–brain barrier.Conclusions
SWI at 3 T may be a useful method to analyze the structural characteristics of gliomas and to evaluate pathology in vivo. Assessment of hypointensity ratios in the glioma was the most preferable method in grading glioma. However, more studies, specifically concerning a suitable method for image analysis, are needed to establish SWI at 3 T as a useful tool in clinical routine. 相似文献975.
Lei Wang Yanpeng Qi Dongliang Wang Xianping Zhang Zhaoshun Gao Zhiyu Zhang Yanwei Ma Satoshi Awaji Gen Nishijima Kazuo Watanabe 《Physica C: Superconductivity and its Applications》2010,470(2):183-186
We report the achievement of transport critical currents in Sr0.6K0.4Fe2As2 wires and tapes with a Tc = 34 K. The wires and tapes were fabricated through an in situ powder-in-tube process. Silver was used as a chemical addition as well as a sheath material. All the wire and tape samples have shown the ability to transport superconducting current. Critical current density Jc was enhanced upon silver addition, and at 4.2 K, a largest Jc of ~1200 A/cm2 (Ic = 9 A) was achieved for 20% silver added tapes, which is the highest in iron-based wires and tapes so far. The Jc is almost field independent between 1 T and 10 T, exhibiting a strong vortex pinning. Such a high transport critical current density is attributed to the weak reaction between the silver sheath and the superconducting core, as well as an improved connectivity between grains. We also identify a weak-link behavior from the apparent drop of Jc at low fields and a hysteretic phenomenon. Finally, we found that compared to Fe, Ta and Nb tubes, Ag was the best sheath material for the fabrication of high-performance 122 type pnictide wires and tapes. 相似文献
976.
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option. 相似文献
977.
Ryojun Ito 《The Ramanujan Journal》2018,45(2):433-449
We consider certain CM elliptic curves which are related to Fermat curves, and express the values of L-functions at \(s=2\) in terms of special values of generalized hypergeometric functions. We compare them and a similar result of Rogers–Zudilin with Otsubo’s regulator formulas, and give a new proof of the Beilinson conjectures originally due to Bloch. 相似文献
978.
Satoshi Kuriki Yasuhide Numata 《Annals of the Institute of Statistical Mathematics》2010,62(4):645-672
We provide formulas for the moments of the real and complex noncentral Wishart distributions of general degrees. The obtained
formulas for the real and complex cases are described in terms of the undirected and directed graphs, respectively. By considering
degenerate cases, we give explicit formulas for the moments of bivariate chi-square distributions and 2 × 2 Wishart distributions
by enumerating the graphs. Noting that the Laguerre polynomials can be considered to be moments of a noncentral chi-square
distributions formally, we demonstrate a combinatorial interpretation of the coefficients of the Laguerre polynomials. 相似文献
979.
[Structure: see text] tert-Butyl hypoiodite (t-BuOI) was found to be a powerful reagent for the cyclization of N-alkenylamides leading to a variety of N-heterocycles under extremely mild conditions. When N-alkenylsulfonamides were employed in the reaction, three- to six-membered saturated N-heterocycles were obtained in good to excellent yields with complete stereoselectivity. The method was applicable to the cyclization of alkenylbenzamide derivatives to afford N-, O- or N-, S-heterocycles. 相似文献
980.
[reaction: see text] This paper describes the selective formation of a cyclic tetramer from a readily synthesized metalloporphyrin with two self-complementary quadruple hydrogen-bonding units. The extremely strong quadruple hydrogen-bonding unit, 2-ureido-4[1H]-pyrimidinone, enabled the formation of a stable cyclic tetramer based on a tetraphenylporphyrin derivative over a wide concentration range. This hydrogen-bonded tetramer is a new functional unit for use in a higher-ordered architecture of a supramolecular porphyrin assembly. 相似文献