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121.
Yasunari Nagai 《Mathematische Zeitschrift》2008,258(2):407-426
We study the monodromy operators on the Betti cohomologies associated to a good degeneration of irreducible symplectic manifold
and we show that the unipotency of the monodromy operator on the middle cohomology is at least the half of the dimension.
This implies that the “mildest” singular fiber of a good degeneration with non-trivial monodromy of irreducible symplectic
manifolds is quite different from the generic degeneration of abelian varieties or Calabi–Yau manifolds. 相似文献
122.
Hirotsugu Ogawa Yasunari Harada Yohsuke Kyotani Toshihiro Ueda Satoru Kitazawa Kazuhisa Kandori 《Journal of carbohydrate chemistry》2013,32(4-5):729-738
Abstract Sulfo Lewisx analog containing 1-deoxynojirimycin (13) has been efficiently synthesized. Glycosidation of ethyl 2,3,4-tri-O-benzyl-1-thio-β-D-fucopyranoside (5) with O-2,6-di-O-benzoyl-3,4-isopropylidene-β-D-galactopyranosyl)-(1→4)-2,6-di-O-benzoyl-N-benzyloxycarbonyl-1,5-dideoxy-1,5-imino-D-glucitol (4), prepared from O-β-D-galactopyranosyl-(1→4)-1,5-dideoxy-1,5-imino-D-glucitol (1) via 3 steps, and subsequent acid hydrolysis of the isopropylidene group gave the desired trisaccharide diol derivative (7) in good yield. Compound 7 was easily converted into 3′-O-sulfo Lewisx analog (13) via 6 steps in high yield. 相似文献
123.
Taku Fukai Tatsuya Kobayashi Masahiro Sakaguchi Masanori Aoki Tsuyoshi Saito Eiji Fujimori Hiroki Haraguchi 《Analytical sciences》2007,23(2):207-213
The multielement determination of PM(10) (airborne particulate matter smaller than 10 microm) samples, which was collected by a high volume air sampler at the urban site of Nagoya City, was carried out by inductively coupled plasma atomic emission spectrometry (ICP-AES) and inductively coupled plasma mass spectrometry (ICP-MS). The present analytical method was validated by analyzing urban particulate matter standard reference material of NIST SRM 1648. The analytical data for ca. 30 elements in PM(10) samples collected during a period from 8 September to 9 October, 2003, were obtained in the concentration range from sub-microg g(-1) to several-10 mg g(-1), but the data for 18 elements among ca. 30 elements were available for the characterization of PM(10) samples in ambient air, because of problems caused by the filter blanks. Then, the trends concerning the distributions of diverse elements in PM(10) samples were analyzed based on the enrichment factors and size distribution factors. The lithophile and siderophile elements were distributed more than 50% in coarse particle fraction (>2.1 microm), which was derived mainly from natural sources, such as soils and crustal minerals. On the other hand, chalcophile elements were distributed more than 50% in fine particle fraction (<2.1 microm), which was derived mostly from anthropogenic emission sources. The large enrichment of chalcophile elements in PM(10) samples as well as their mining influence factors (MIFs) suggested their wide use in industrial productions. 相似文献
124.
Yasunari Noguchi Toshihisa Maruta Takeshi Yamane Nobutoshi Kiba 《Analytical sciences》2008,24(5):673-675
Using a spectrophotometric method after distillation separation is a standard test method widely employed for the determination of fluorine (F) in cement. Using a flow injection (FI) method after pyrolysis separation for quantification of fluorine in cement has recently been developed. Differences between the fluorine content values obtained by each method have been noted. This paper documents the differences between fluorine content (distillation F) measured spectrophotometrically after distillation and that (pyrolysis F) determined using the FI method after pyrolysis for fourteen commercial Portland cements and identifies a factor contributing to the differences between distillation F and pyrolysis F values. A highly significant relationship existed between distillation F and pyrolysis F values for fourteen cements (r(2) = 0.998, p < 0.001). 相似文献
125.
Indium silicate activated by terbium was found to be an efficient phosphor with CR excitation, the luminosity of which was comparable to the most luminous of other terbium-activated silicates. For the preparation of this phosphor, alkaline earth metal flourides proved to act as a good mineralizer. The best result was obtained when a mixture of 1 mol In2O3, 2.2 mol SiO2, 0.015 mol Tb4O7 and 0.05 mol BaF2 was fired at 1 400°C in air for 4 h. Other rare earth luminescent centers such as Ce, Pr, Eu, Dy, Er and Tm were examined but none showed noticeable emission. Some UV excitation properties are also described. 相似文献
126.
The 1H spin-lattice relaxation time T1 has been measured in the α-VHx. It is found that T1 in the α-phase is essential ly determined by contact hyperfine interactions, and its variation with hydrogen concentration is in accord with a rigid-band model. 相似文献
127.
Measurements of the thermal conductivity of helium and hydrogen are performed using the transient short-hot-wire method. The short hot wire is made of platinum and has a diameter of about 10 μm and a length of about 15 mm. It is attached by spot welding to platinum terminals with a diameter of 1.5 mm. The probe is inserted into the sample vessel that has a volume of 35 cm3 and an inner diameter of 30 mm. The thermal conductivity is evaluated by comparing a numerical solution of the heat conduction in and around the short wire with the experimentally obtained temperature rise of the wire. The measured thermal conductivities show good reproducibility. Also, the measured thermal conductivities agree with the reference equations within a deviation of ± 1%. 相似文献
128.
Masaru Yoshida Yosuke Kimura Jinhua Chen Masaharu Asano Yasunari Maekawa 《Radiation Physics and Chemistry》2009,78(12):1060-1066
Swift heavy 56 MeV 15N3+ ions were generated with particle fluences of 0, 3×106, 3×107, 3×108, 3×109 ions/cm2 to form a latent track zone in a 25-μm-thick film of polytetrafluoroethylene (iPTFE). Styrene (St) was then grafted onto the iPTFE films by UV-irradiation or pre-γ-irradiation, and after sulfonation iPTFE-based proton-conducting membranes were obtained, here called, iPTFE-g(UV)-PStSA and iPTFE-g(γ)-PStSA membranes, respectively, which had a straight cylindrical damage zone around the ion path. The degree of grafting was found to be about 7.5% with a particle fluence of 3×107 ions/cm2 and with either the UV-method or the γ-method. The ion-exchange capacity, proton conductivity in the thickness direction, MeOH permeability, tensile strength and elongation at break of the obtained iPTFE-g(UV)-PStSA membrane were 0.50 mmol/g, 0.06 S/cm, 0.15×10−6 cm2/s, 50 MPa and 600%, in contrast to 0.06 mmol/g, 0.06 S/cm, 0.35×10−6 cm2/s, 19 MPa and 210% for the iPTFE-g(γ)-PStSA membrane, respectively. In comparison, the Nafion 112 measured in our laboratory exhibited an ion-exchange capacity of 0.91 mmol/g, a proton conductivity of 0.06 S/cm, a MeOH permeability of 1.02×10−6 cm2/s, a tensile strength of 35 MPa and an elongation at break of 295%. It can be concluded from these data that the lower crossover of MeOH, the same proton conductibility, the lower ion-exchange capacity, and the superior mechanical properties of the UV-grafted proton-conducting membranes compared to the Nafion make them promising materials for widespread application in direct methanol fuel cells. On the other hand, the tests of mechanical strength showed that the PTFE base film is subject to degradation by the ion-beam irradiation as well as the γ-irradiation. 相似文献
129.
Tomohiro Maegawa Dr. Akira Akashi Kiichiro Yaguchi Yohei Iwasaki Masahiro Shigetsura Yasunari Monguchi Dr. Hironao Sajiki Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(28):6953-6963
An efficient and practical arene hydrogenation procedure based on the use of heterogeneous platinum group catalysts has been developed. Rh/C is the most effective catalyst for the hydrogenation of the aromatic ring, which can be conducted in iPrOH under neutral conditions and at ordinary to medium H2 pressures (<10 atm). A variety of arenes such as alkylbenzenes, benzoic acids, pyridines, furans, are hydrogenated to the corresponding cyclohexyl and heterocyclic compounds in good to excellent yields. The use of Ru/C, less expensive than Rh/C, affords an effective and practical method for the hydrogenation of arenes including phenols. Both catalysts can be reused several times after simple filtration without any significant loss of catalytic activity. 相似文献
130.
A method is presented for separating low levels of americium from large environmental samples ( $ 200 l. of sea-water, $ 100 g of sediment, 500 g of biological material, etc.) by applying an anion-exchange process in methanolic acid medium. 相似文献