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31.
Vincent Blanloeil Osamu Saeki 《Transactions of the American Mathematical Society》2002,354(10):3955-3971
Consider a closed connected oriented 3-manifold embedded in the -sphere, which is called a -knot in this paper. For two such knots, we say that their Seifert forms are spin concordant, if they are algebraically concordant with respect to a diffeomorphism between the 3-manifolds which preserves their spin structures. Then we show that two simple fibered 3-knots are geometrically concordant if and only if they have spin concordant Seifert forms, provided that they have torsion free first homology groups. Some related results are also obtained.
32.
Vapor-liquid equilibria in binary solutions of hydrocarbons (n-hexane, benzene, toluene, cyclohexane) and chlorinated methanes [carbon tetrachloride (CCl4), chloroform (CHCl3), and dichloromethane (CH2Cl2)] in polybutadiene (PBD) and polyisoprene have been determined at 23.5°C by using the piezoelectric sorption method. The weight-fraction activity coefficient of solvent (a1/w1) in cis-PBD (98% cis-1,4 addition) and random cis-trans-PBD (r-PBD, 34.3% cis-1,4 addition; 54.3% trans-1,4 addition; 11.4% vinyl-1,2 addition) are almost equal for CCI4, CHCI3, CH2CI2, benzene, and toluene solutions, while the values of a1/w1 in n-hexane and cyclohexane solutions in cis-PBD are larger than those in r-PBD solutions. The values of a1/w1 for solutions of hydrocarbons and chlorinated methanes in cis-1,4 polyisoprene (95% cis-1,4 addition) have been compared with those for cis-PBD. 相似文献
33.
For a knotted surface in -space, its generic projection into -space has branch points as its singularities, and its successive projection into -space has fold points and cusps as its singularities. In this paper, we show that for non-orientable knotted surfaces, the numbers of branch points and cusps can be minimized by isotopy.
34.
Studer A Amrein S Matsubara H Schiesser CH Doi T Kawamura T Fukuyama T Ryu I 《Chemical communications (Cambridge, England)》2003,(10):1190-1191
4-[(Trimethylstannyl)diphenylsilyl]butanoyl radical, arising from the corresponding 3-(stannylsilyl)propyl radical and CO, undergoes an SHi reaction at Si with extrusion of trimethyltin radical to give silacyclopentanone. The parent 3-(stannylsilyl)propyl radical was also found to isomerize to (3-stannylpropyl)silyl radical via a 1,4-Sn shift from Si to C with a rate constant of 9.3 x 10(4) s-1 at 80 degrees C. Ab initio and DFT MO calculations support a front-side attack mechanism. 相似文献
35.
36.
Koji Kita Sho Suzuki Tomonori Nishimura Akira Toriumi 《Applied Surface Science》2008,254(19):6100-6105
Two approaches to control high-k/Ge interface qualities were investigated. The first approach was using high-k materials that are intimate with Ge. These Ge-intimate high-k materials should have moderate reactivity with Ge to form an amorphized interface that will reduce the interface defects and will suppress the GeO desorption at the interface. The second approach was modifying the annealing processes by using a cap layer to block GeO out-diffusion. We found that Si works as the cap layer very efficiently. By combining those two approaches, we achieved fairly good high-k/Ge metal-insulator-semiconductor (MIS) characteristics with LaYO3 as the Ge-intimate high-k material, and a NiSiX electrode as the cap layer. These results provide us an important guide for controlling the high-k/Ge interface properties. 相似文献
37.
Hiroaki Aizawa Ken Hatano Hitoshi Saeki Nobuaki Honsho Tetsuo Koyama Koji Matsuoka Daiyo Terunuma 《Tetrahedron letters》2010,51(12):1545-6442
A new compound having a 2,3,4,5-tetraphenylsilole derivative on the center silicon of Dumbbell(1)6Gb3; Silole-Dumbbell(1)6Gb3 (1) was previously reported. It was found that 1 exhibited strongly increased fluorescence both in water and in a 96% acetone/water mixed solvent. The physical behavior of 1 in water and in the 96% acetone/water mixed solvent was investigated, and analyses including fluorescence quantum yields, dynamic-light-scattering (DLS), atomic-force-microscopy (AFM), and fluorescence microscopy were carried out. It was clarified that 1 dynamically formed different types of aggregates in water and in higher acetone concentrations to yield high aggregation-induced emission (AIE) effects due to the formation of micelle-like particles in water and inversion-type micelles in the acetone/water mixed solvent, respectively. 相似文献
38.
Ruili Zhang Tomonori Maeda Sho Kusaka Kei-ichiro Murai 《Journal of solid state chemistry》2010,183(3):620-623
Host lattice Ba3Si5O13−δNδ oxonitridosilicates have been synthesized by the traditional solid state reaction method. The lattice structure is based on layers of vertex-linked SiO4 tetrahedrons and Ba2+ ions, where each Ba2+ ion is coordinated by eight oxygen atoms forming distorted square antiprisms. Under an excitation wavelength of 365 nm, Ba3Si5O13−δNδ:Eu2+ and Ba3Si5O13−δNδ:Eu2+,Ce3+ show broad emission bands from about 400-620 nm, with maxima at about 480 nm and half-peak width of around 130 nm. The emission intensity is strongly enhanced by co-doping Ce3+ ions into the Ba3Si5O13−δNδ:Eu2+ phosphor, which could be explained by energy transfer. The excitation band from the near UV to the blue light region confirms the possibility that Ba3Si5O13−δNδ:Eu2+, Ce3+ could be used as a phosphor for white LEDs. 相似文献
39.
Yamauchi Y Sekiguchi K Chida K Arakawa T Nakamura S Kobayashi K Ono T Fujii T Sakano R 《Physical review letters》2011,106(17):176601
We measure the current and shot noise in a quantum dot in the Kondo regime to address the nonequilibrium properties of the Kondo effect. By systematically tuning the temperature and gate voltages to define the level positions in the quantum dot, we observe an enhancement of the shot noise as temperature decreases below the Kondo temperature, which indicates that the two-particle scattering process grows as the Kondo state evolves. Below the Kondo temperature, the Fano factor defined at finite temperature is found to exceed the expected value of unity from the noninteracting model, reaching 1.8±0.2. 相似文献
40.
Kitajima K Yoshikawa T Seo Y Ohno Y Yano Y Miki A Kanda T Kanata N Azuma T Sugimura K 《Magnetic resonance imaging》2011,29(4):579-583
Budd-Chiari syndrome (BCS) is a rare disorder caused by the obstruction of hepatic venous outflow, leading to sinusoidal congestion, ischemic injury to liver cells and portal hypertension. Long-term survival largely depends on whether hepatocellular carcinoma occurs. A recently available liver-specific contrast medium, gadolinium-ethoxybenzyl-diethylenetriamine penta-acetic acid (Gd-EOB-DTPA), reportedly has high diagnostic capability for detection of malignant liver tumors. However, there has been no report of the sue of Gd-EOB-DTPA-enhanced magnetic resonance imaging (MRI) for BCS. We present a case of chronic BCS who underwent both gadopentetate dimeglumine (Gd-DTPA) and Gd-EOB-DTPA-enhanced MRI. Hepatic congestion and edema were seen as slightly hypointense areas on Gd-EOB-DTPA-enhanced hepatobiliary-phase images, although these areas were observed as slightly hyperintense on previously obtained Gd-DTPA-enhanced delayed-phase image. Reduced uptake of Gd-EOB-DTPA by hepatocytes in the region of congestion or edema may account for this difference, which should be recognized in image interpretations. 相似文献