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231.
Large grain niobium has the potential of simplifying the production sequence and consequently reducing the cost of the superconducting RF cavities for ILC. To investigate the feasibility of fabrication and the possibility to achieve high gradient by large grain cavities, two 1.3GHz cavities were made of China large grain niobium and a series of vertical tests were carried out following several different
surfaces treatment procedures. Two cavities have both reached the high
gradient of more than 43MV/m repeatedly and the maximum accelerating field of 47.9MV/m has been achieved by China large grain niobium. This paper introduces the features of the fabrication and surface treatments on the large grain cavities and presents the preliminary results of the research. 相似文献
232.
T. Nakamoto M. Nakada N. M. Masaki M. Saeki T. Yamashita N. N. Krot 《Journal of Radioanalytical and Nuclear Chemistry》1999,239(2):257-261
237Np Mössbauer spectrum of the heptavalent neptunium compound [Co(NH3)6][NpO4(OH)2]·2H2O was remeasured for certification of the previous investigations. The isomer shift value of the Mössbauer spectrum showed a characteristic value for the heptavalent neptunium at 4.7K. Although the spectrum seemed to consist of two quadrupole-split peaks as previously reported byStone et al., the fitting with using two quadrupole-split peaks did not give a good agreement withStone's data. 相似文献
233.
Let α be a C ∞ curve in a homogeneous space G/H. For each point x on the curve, we consider the subspace \({S^{\alpha}_k}\) of the Lie algebra \({\mathcal{G}}\) of G consisting of the vectors generating a one parameter subgroup whose orbit through x has contact of order k with α. In this paper, we give various important properties of the sequence of subspaces \({\mathcal{G} \supset S^{\alpha}_1 \supset S^{\alpha}_2 \supset S^{\alpha}_3 \supset \cdots}\) . In particular, we give a stabilization property for certain well-behaved curves. We also describe its relationship to the isotropy subgroup with respect to the contact element of order k associated with α. 相似文献
234.
Shimoyama A Saeki A Tanimura N Tsutsui H Miyake K Suda Y Fujimoto Y Fukase K 《Chemistry (Weinheim an der Bergstrasse, Germany)》2011,17(51):14464-14474
Helicobacter pylori is a common cause of gastroduodenal inflammatory diseases such as chronic gastritis and peptic ulcers and also an important factor in gastric carcinogenesis. Recent reports have demonstrated that bacterial inflammatory processes, such as stimulation with H. pylori lipopolysaccharide (LPS), initiate atherosclerosis. To establish the structures responsible for the inflammatory response of H. pylori LPS, we synthesized various kinds of lipid A structures (i.e., triacylated lipid A and Kdo‐lipid A compounds), with or without the ethanolamine group at the 1‐phosphate moiety, by a new divergent synthetic route. Stereoselective α‐glycosylation of Kdo N‐phenyltrifluoroacetimidate was achieved by use of microfluidic methods. None of the lipid A and Kdo‐lipid A compounds were a strong inducer of IL‐1β, IL‐6, or IL‐8, suggesting that H. pylori LPS is unable to induce acute inflammation. In fact, the lipid A and Kdo‐lipid A compounds showed antagonistic activity against cytokine induction by E. coli LPS, except for the lipid A compound with the ethanolamine group, which showed very weak agonistic activity. On the other hand, these H. pylori LPS partial structures showed potent IL‐18‐ and IL‐12‐inducing activities. IL‐18 has been shown to correlate with chronic inflammation, so H. pylori LPS might be implicated in the chronic inflammatory responses induced by H. pylori. These results also indicated that H. pylori LPS can modulate the immune response: NF‐κB activation through hTLR4/MD‐2 was suppressed, whereas production of IL‐18 and IL‐12 was promoted. 相似文献
235.
Daisuke Nagao Mikio Yokoyama Shu Saeki Yoshio Kobayashi Mikio Konno 《Colloid and polymer science》2008,286(8-9):959-964
Dual functions of magnetic and fluorescent properties were created in composite particles that incorporated magnetite (Fe3O4) nanoparticles in particle cores of silica and fluorescent pyrene in particle shells of polystyrene. The Fe3O4 nanoparticles were prepared with a conventional homogeneous precipitation method and surface modified with a coupling agent of carboxyethylsilanetriol. The silica particles incorporating Fe3O4 nanoparticles were synthesized with a modified Stöber method in which the Fe3O4 nanoparticles were added to a system of tetraethylorthosilicate (TEOS)/ammonia/water/ethanol. Then, the magnetite/silica composite particles were coated with the pyrene/polystyrene shell in a soap-free emulsion polymerization, which was conducted in the presence of pyrene in a mixed solvent of water/ethanol. The composite particles prepared in the mixed solvent had both magnetic and fluorescent properties. The fluorescent spectrum of the particles with Fe3O4 was very similar to that without Fe3O4, indicating that the magnetic component within the core particles scarcely interfered with the fluorescent emission from the polymer shell. 相似文献
236.
237.
Shinki?NakamuraEmail author Naoya?Takasawa Takeshi?Saeki Yahei?Koyamada 《Optical Review》2004,11(2):68-71
We have analyzed the induced phase modulation (IPM) for ultrashort (74 fs) two-pulse propagation in a silica fiber by the extended finite-difference time-domain (FDTD) method, considering all exact Sellmeier-fitting values and nonlinear polarization PNL involving the Raman response function. We show that nonlinear polarization causes several phenomena in spectral characteristics of propagated pulses, such as self-phase modulation (SPM), self-steepening, Raman response and IPM, by the extended FDTD method. To the best of our knowledge, this is the first IPM calculation by the extended FDTD method for the simultaneous propagation of two ultrashort (74 fs) laser pulses in a silica fiber. 相似文献
238.
Sadahiro Saeki 《Journal of Fourier Analysis and Applications》1995,2(1):15-28
Let
and
Under certain conditions on
we shall prove that
converges nontangentially to
at
for
相似文献
239.
Let f:MN be a stable map between orientable 4-manifolds, whereM is closed and N is stably parallelisable. It is shown thatthe signature of M vanishes if and only if there exists a stablemap g:MN homotopic to f which has only fold and cusp singularities.This together with results of Ando and Èliaberg showsthat, in this situation, the Thom polynomials are the only obstructionsto the elimination of the singularities except for the foldsingularity. Also studied are some topological properties (includingthose of the discriminant set) of stable maps between 4-manifoldswith only Ak-type singularities. 相似文献
240.
Osamu Saeki Masamichi Takase 《Transactions of the American Mathematical Society》2002,354(12):5049-5061
We clarify the structure of the set of regular homotopy classes containing embeddings of a 3-manifold into -space inside the set of all regular homotopy classes of immersions with trivial normal bundles. As a consequence, we show that for a large class of -manifolds , the following phenomenon occurs: there exists a codimension two immersion of the -sphere whose double points cannot be eliminated by regular homotopy, but can be eliminated after taking the connected sum with a codimension two embedding of . This involves introducing and studying an equivalence relation on the set of spin structures on . Their associated -invariants also play an important role.