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排序方式: 共有1114条查询结果,搜索用时 109 毫秒
941.
Kazuya Takemoto Yoshiki Sakuma Shinichi Hirose Tatsuya Usuki Naoki Yokoyama Toshiyuki Miyazawa Motomu Takatsu Yasuhiko Arakawa 《Physica E: Low-dimensional Systems and Nanostructures》2005,26(1-4):185
We present an optical spectroscopy and photon correlation measurement at telecommunication wavelengths performed on single InAs/InP quantum dots. Two main approaches brought high optical quality: an application of a ‘double-cap’ growth method to metalorganic chemical vapor deposition, and fabrication of a small mesa structure using low-damage wet chemical etching. Sharp and discrete exciton transition lines have been observed on the single quantum dots, which widely cover the spectral range of 1.3–1.55 μm. Using a pulsed excitation source and gated single-photon detection modules, we observed a photon antibunching behavior for an isolated exciton emission line, indicating nonclassical light emission near the wavelength of 1.3 μm. 相似文献
942.
Kazuya Matsumoto Yuji Shibasaki Shinji Ando Mitsuru Ueda 《Journal of polymer science. Part A, Polymer chemistry》2005,43(1):149-156
A chemically amplified photosensitive and thermosetting polymer based on poly[2,6‐di(3‐methyl‐2‐butenyl)phenol (15 mol %)‐co‐2,6‐dimethylphenol (85 mol %)] ( 3c ) and a photoacid generator [(5‐propylsulfonyloxyimino‐5H‐thiophen‐2‐ylidene)‐(2‐methylphenyl)acetonitrile] was developed. Poly[2,6‐bis(3‐methyl‐2‐butenyl)phenol]‐co‐2,6‐dimethylphenol)] ( 3 ) with high molecular weights (number‐average molecular weight ~ 24,000) was prepared by the oxidative coupling copolymerization of 2,6‐di(3‐methyl‐2‐butenyl)phenol with 2,6‐dimethylphenol in the presence of copper(I) chloride and pyridine as the catalyst under a stream of oxygen. The structures of 3 were characterized with IR, 1H NMR, and 13C NMR spectroscopy. 3 was crosslinked by a thermal treatment at 300 °C for 1 h under N2. The 5% weight loss temperatures and glass‐transition temperatures of the cured copolymers reached around 420 °C in nitrogen and 300 °C, respectively. The average refractive index of the cured copolymer ( 3c ) film was 1.5452, from which the dielectric constant at 1 MHz was estimated to be 2.6. The resist showed a sensitivity of 35 mJ cm?2 and a contrast of 1.6 when it was exposed to 436‐nm light, postexposure‐baked at 145 °C for 5 min, and developed with toluene at 25 °C. A fine negative image featuring 8‐μm line‐and‐space patterns was obtained on a film exposed to 100 mJ cm?2 with 436‐nm light in the contact‐printed mode. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 149–156, 2005 相似文献
943.
Takahisa Anada Kazuya Koumoto Masami Mizu Ryouji Karinaga Kazuo Sakurai Seiji Shinkai 《Analytical sciences》2003,19(12):1567-1568
The limulus G test has been used as a quantitative analysis of (1-->3)-beta-D-glucans, including schizophyllan (SPG) and curdlan. The present work extended the limulus G test to detect polynucleotide/SPG complexes. The complex showed an extremely sensitive response to the test, compared with SPG itself. The minimum concentration of the complex to show the response is almost 10-times as small as that of SPG itself, indicating the possibility to detect (1-->3)-beta-D-glucans or/and polynucleotides on the pico gram/ml scale. 相似文献
944.
Satoshi Ninomiya Kazuya Ichiki Hideaki Yamada Yoshihiko Nakata Toshio Seki Takaaki Aoki Jiro Matsuo 《Rapid communications in mass spectrometry : RCM》2009,23(20):3264-3268
In this study, we present molecular depth profiling of multilayer structures composed of organic semiconductor materials such as tris(8‐hydroxyquinoline)aluminum (Alq3) and 4,4′‐bis[N‐(1‐naphthyl)‐N‐phenylamino]biphenyl (NPD). Molecular ions produced from Alq3 and NPD were measured by linear‐type time‐of‐flight (TOF) mass spectrometry under 5.5 keV Ar700 ion bombardment. The organic multilayer films were analyzed and etched with large Ar cluster ion beams, and the interfaces between the organic layers were clearly distinguished. The effect of temperature on the diffusion of these materials was also investigated by the depth profiling analysis with Ar cluster ion beams. The thermal diffusion behavior was found to depend on the specific materials, and the diffusion of Alq3 molecules was observed to start at a lower temperature than that of NPD molecules. These results prove the great potential of large gas cluster ion beams for molecular depth profiling of organic multilayer samples. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
945.
Guoqing Li Hitoshi Saito Shunji Ishio Toshiyuki Shima Koki Takanashi 《Journal of magnetism and magnetic materials》2006
Anomalous magnetization processes and non-symmetrical domain wall displacements in the minor loop of L10 FePt particulate films were investigated by magnetization measurements and in situ magnetic force microscopy. Magnetization (M) decreases dramatically on increasing the magnetic field to ∼3 kOe after which M becomes small and constant in the range of 5–20 kOe as observed in the successive measurement of minor loops. The domain wall displacement is non-symmetrical with respect to the field direction. The anomalous magnetization behavior was attributed to the non-symmetrical domain wall displacement and large magnetic field required for domain wall nucleation. Energy calculations from modeling suggest that non-symmetrical domain wall displacement is caused by the existence of metastable domains in which the domain edges are stuck to the particle boundaries. 相似文献
946.
Kazuya Tachizawa 《Journal of Fourier Analysis and Applications》2002,8(3):233-244
We give an estimate for the moments of the negative eigenvalues of elliptic operators. The estimate is a generalization of Egorov-Kondrat'ev's estimate for elliptic operators. We use the j\varphi-transform decomposition of Frazier and Jawerth and techniques of harmonic analysis. 相似文献
947.
K. Makoshi N. Shima Y. Otsuka 《Physica E: Low-dimensional Systems and Nanostructures》2005,29(3-4):656
A simple expression of the electric conductance through a nanostructure connected to two electrodes is obtained by using the phase-shift analysis. The Green function theory applicable to the nonequilibrium system is employed to formulate the electric conductance. The 0 bias limit, i.e., the linear response approximation is taken. The relation between Green functions and phase-shifts is obtained by extending the method applied to the single impurity problem in the metal. It is shown that a channel does not contribute to the conductance if its phase-shift is an integer multiple of π. Also shown is the importance of the effect due to multiple orbitals in nanostructures. Some concrete examples leading to simpler forms are given. 相似文献
948.
Tatsuro Nakagama Atsutoshi Yamaguchi Kazuya Hirasawa Koji Yoshida Katsumi Uchiyama Toshiyuki Hobo 《Analytical sciences》2002,18(1):49-53
The photo-responses of the retention and enantioseparation of several optical isomers were evaluated using an azobenzene-modified gamma-cyclodextrin stationary phase (Az gamma-CDSP) in micro-HPLC. UV light irradiation induced a decrease in the retention and the chiral selectivity for N-(3,5-dinitrobenzoyl)-1-phenylethylamine (DNBPEA) and N-(3,5-dinitrobenzoyl)-1-(1-naphtylethyl)amine (DNBNEA), while an increase was induced for dansylphenylalanine (DnsPhe) using a mixture of methanol and aqueous phosphate buffer as the mobile phase. No changes in the retention and the enantiomer separation of benzoin were observed with UV light irradiation. The retention behaviors were recovered by visible-light irradiation. It was speculated that the main factor of the change in the retention behavior was a change in the pi-pi interaction due to the azobenzene moiety of the stationary phase with photo-irradiation. Comparing the retention behavior before and after UV light irradiation, a suitable condition for obtaining a better resolution and enantiomer separation would be chosen using Az gamma-CDSP. 相似文献
949.
Kazuya Uenishi Atsushi Sudo Takeshi Endo 《Journal of polymer science. Part A, Polymer chemistry》2005,43(21):5119-5126
A new efficient and straightforward method to convert amines into siloxane‐thiol hybrid molecules was developed. The method relies on the nucleophilic addition of amines to a cyclic dithiocarbonate having siloxane moiety (DTC‐Si), and the successive ring‐opening reaction of the dithiocarbonate moiety to give the corresponding acyclic thiourethane having a thiol moiety. Based on this method, amine‐terminated poly(propylene glycol) was successfully transformed into the corresponding polyether having thiol‐terminals and siloxane groups. In the presence of moisture, the alkoxysilyl moiety underwent condensation reaction to make the polyether cured into a transparent resin having solvent‐resistance. Addition of bisphenol A diglycidyl ether (Bis A‐DGE) to the curing process resulted in two simultaneous reactions, i.e., (1) condensation of siloxane part and (2) addition reaction of the thiol terminal and the epoxide group. When this curing process was carried out on a glass surface, the siloxane part reacted with silanol group on the surface, forming a coating layer having excellent mechanical toughness graded as maximum 7H by pencil toughness test (JIS‐K5400). © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 5119–5126, 2005 相似文献
950.
Syntheses and Immunological Evaluation of Self‐Adjuvanting Clustered N‐Acetyl and N‐Propionyl Sialyl‐Tn Combined with a T‐helper Cell Epitope as Antitumor Vaccine Candidates
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Dr. Tsung‐Che Chang Dr. Yoshiyuki Manabe Prof. Dr. Yukari Fujimoto Shino Ohshima Prof. Dr. Yoshie Kametani Dr. Kazuya Kabayama Yuka Nimura Prof. Dr. Chun‐Cheng Lin Prof. Dr. Koichi Fukase 《Angewandte Chemie (International ed. in English)》2018,57(27):8219-8224
Sialyl‐Tn (STn) is a tumor‐associated carbohydrate antigen (TACA) rarely observed on healthy tissues. We synthesized two fully synthetic N‐acetyl and N‐propionyl STn trimer (triSTn) vaccines possessing a T‐helper epitope and a TLR2 agonist, since the clustered STn antigens are highly expressed on many cancer cells. Immunization of both vaccines in mice induced the anti‐triSTn IgG antibodies, which recognized triSTn‐expressing cell lines PANC‐1 and HepG2. The N‐propionyl triSTn vaccine induced the triSTn‐specific IgGs, while IgGs induced by the N‐acetyl triSTn vaccine were less specific. These results illustrated that N‐propionyl triSTn is a valuable unnatural TACA for anticancer vaccines. 相似文献