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排序方式: 共有675条查询结果,搜索用时 15 毫秒
31.
There has been continuous progress at the High Energy Accelerator Research Organization (KEK) in R&D on vacuum beam ducts adaptable to future high-current particle storage rings. Here we proposed copper beam ducts with antechambers to deal with the severe issues attributed to the high beam currents. The proposed antechamber scheme can withstand intense synchrotron radiation (SR), provide a beam duct with low beam impedance, and effectively reduce the electron cloud effect (ECE) in positron/proton rings. Several trial models were manufactured by a pressing or cold-drawn method, and assembled with electron beam welding. Special vacuum components, such as connection flanges, distributed pumps, and gate valves, were customized for the beam ducts. TiN coating on the inner surface of the beam duct was also investigated as a mitigating measure for the ECE. Trial models of the copper beam ducts were installed into the KEK B-factory (KEKB), and their performances were evaluated using real positron and electron beams. 相似文献
32.
Seiichi Takami Yasuhiro Shirai Toyohiro Chikyow Yutaka Wakayama 《Thin solid films》2009,518(2):692-694
We have proposed the synthesis of organic molecular nanowires using porous alumina as a template. We also proposed the use of a magnetic field to control the molecular packing structure in the nanowires. In this paper, we developed the method to evaluate the electronic properties of the nanowire of a phthalocyanine derivative that was synthesized using porous alumina as a template. The developed method facilitates the study in the organic molecular nanowires that were synthesized using templates and helps their use in future electronic devices. 相似文献
33.
M Igarashi N Hosoda Y Bando K Shimanuki W Sunaoshi H Shirai H Miura 《Canadian Metallurgical Quarterly》1992,12(5):335-340
An anticarbamazepine antibody was detected in the serum of a patient with severe carbamazepine-induced serum sickness. We found that the patient's T cells and IgG antibody recognized an epitope which appeared in subjects showing an allergic reaction, as well as that in subjects who showed no allergic reaction, after long-term carbamazepine therapy. These results show that an anti-carbamazepine immune response does not occur in the majority of subjects who undergo long-term carbamazepine therapy without developing allergic symptoms, although the immunodominant haptenic epitope of carbamazepine is present in their sera. 相似文献
34.
H Tsushima S Kawata S Tamura N Ito Y Shirai S Kiso Y Imai H Shimomukai Y Nomura Y Matsuda Y Matsuzawa 《Canadian Metallurgical Quarterly》1996,110(2):375-382
BACKGROUND & AIMS: Contribution of transforming growth factor beta 1 (TGF-beta 1) to tumor progression has been suggested. However, little is known about the role of TGF-beta 1 in colorectal cancer. Plasma TGF-beta 1 levels and its expression were analyzed in patients with colorectal cancer. METHODS: Plasma TGF-beta 1 levels were measured in 22 patients with colorectal cancer using a TGF-beta 1 enzyme-linked immunosorbent assay. Expression of TGF-beta 1 messenger RNA and immunohistochemical distribution of the protein in colorectal cancer tissues were examined. RESULTS: Plasma TGF-beta 1 levels in patients with colorectal cancer (14.8 +/- 8.4 ng/mL) were significantly higher than in normal controls (1.9 +/- 1.4; n = 22) (P < 0.001). After curative surgical resection, plasma TGF-beta 1 levels decreased in examined patients from 11.9 +/- 6.7 to 3.8 +/- 1.2 ng/mL (P < 0.01). TGF-beta 1 messenger RNA was about 2 1/2 times more abundant in colorectal cancer tissues than in control (P < 0.01). TGF-beta 1 was detected in the cytoplasm of colorectal cancer cells immunohistochemically. Both TGF-beta 1 messenger RNA expression in colorectal adenocarcinoma tissues and its plasma levels were associated with tumor stage of Dukes' classification (P < 0.05). CONCLUSIONS: These results suggest that plasma TGF-beta 1 levels may reflect overexpression of the gene in colon cancer tissues and are associated with disease progression. 相似文献
35.
Mode analysis of spreading of partially coherent beams propagating through atmospheric turbulence 总被引:11,自引:0,他引:11
Shirai T Dogariu A Wolf E 《Journal of the Optical Society of America. A, Optics, image science, and vision》2003,20(6):1094-1102
The spreading of partially coherent beams propagating through atmospheric turbulence is studied by use of the coherent-mode representation of the beams. Specifically, we consider partially coherent Gaussian Schell-model beams entering the atmosphere, and we examine the spreading of each coherent mode, represented by a Hermite-Gaussian function, on propagation. We find that in atmospheric turbulence the relative spreading of higher-order modes is smaller than that of lower-order modes, whereas the relative spreading of all order modes is the same as in free space. This modal behavior successfully explains why under certain circumstances partially coherent beams are less affected by atmospheric turbulence than are fully spatially coherent laser beams. 相似文献
36.
We have investigated an optimal annealing process in order to enhance 1.55 μm light emission from semiconducting β-FeSi2 and found that two steps annealing at 600 °C and 800 °C is effective to its enhancement. Rutherford backscattering spectroscopy and SEM observations revealed that pronounced surface segregation of Fe atoms during annealing at 600 °C caused surface precipitate of β-FeSi2. The enhancement of light emission is attributed spatial isolation of the surface β-FeSi2 (light emitting layer) from damaged and defective layers with nonradiative recombination centers. 相似文献
37.
Eiji Shirai 《Circuits and Systems II: Express Briefs, IEEE Transactions on》2007,54(2):166-170
This brief describes a design technique for multistage preamplifiers of the type commonly used in high-performance comparators. Following the examination of multistage preamplifier responses in both the spectral and time domains, and a consideration 1/f noise attenuation in topologies employing offset storage capacitors, a procedure for optimizing both the number of stages and the offset storage capacitance is presented. As a demonstration vehicle, a comparator with a 13-Msample/s conversion rate and 200-muV minimum input resolution is designed for realization in a 0.4-mum CMOS technology under the constraint of a power dissipation of 250 muW when operating from a 2.5-V supply. In this design, the effective input signal is 33 muV for the minimum input resolution of 200 muV due to signal corruption from circuit noise and residual error from incomplete settling 相似文献
38.
Yoshihito Honsho Atsushi Asano Shu Seki Takeyoshi Sunagawa Akinori Saeki 《Synthetic Metals》2009,159(9-10):843-846
Intra-molecular mobility of positive charge carriers in poly(n-hexyl-[S]-2-methylbutylsilane) (PHMBS) films doped with N,N′-bis(2,5-di-tert-buthylphenyl)-3,4,9,10-perylenedicarboximide (PDI) is studied by time-resolved microwave conductivity (TRMC) measurements. PHMBS with optically active side chains has a rod-like tightly locked Si catenation with unlikely long persistence length compared with conventional dialkyl-substituted polysilanes. It was found that PDI is a suitable electron acceptor for PHMBS as it provides the high product of photo carrier generation yield ? as ~0.08% under an excitation at 355 nm. The efficient electron transfer reaction from PHMBS to PDI gives clear conductivity transients ascribed to the positive charges on the Si catenation of PHMBS by TRMC measurements. The estimated value of isotropic mobility along the tightly locked Si catenation is 0.36 cm2 V?1 s?1, suggesting the presence of mobile holes on the backbones of PHMBS. 相似文献
39.
Joji Ohshita Yosuke Tada Atsutaka Kunai Yutaka Harima Yoshihito Kunugi 《Synthetic Metals》2009,159(3-4):214-217
Hole-injection properties of annealed poly(alkoxy- and alkylthiophene) films in OLEDs were studied. Among them, annealed poly(3,3′-dihexyloxy-2,2′-bithiophene) (aPHOBT) film exhibited good hole-injection properties and a triple-layered OLED with the structure ITO/aPHOBT/PVK/Alq3/Mg–Ag (device I) showed much higher performance than a double-layered device without the aPHOBT layer (device II, ITO/PVK/Alq3/Mg–Ag). Device I was slightly inferior to a device having a PEDOT–PSS layer as the hole injector (device III, ITO/PEDOT– PSS/PVK/Alq3/Mg–Ag) in the low-intermediate region of the applied voltage (6–11 V), but gave comparable luminance to III when the applied voltage exceeded 11 V. 相似文献
40.
2-n-Butylaminonaphthazarin (2) absorbs at 499 and 532 nm in ethanol but at 539 and 577 nm in alkali solution, while 2, 6-bis(n-butylamino)naphthazarin (3) absorbs at 461, 500 and 540 nm in ethanol but at 511 and 545 nm in alkali solution, with only a small bathochromic shift of 5 nm. The absorption curve of 3 was changed by addition of alkali and the λDmax at around 461 nm completely disappeared. In the case of 2-bromo-3, 6-bis(n-butylamino)naphthazarin (4), tautomerism between the 1, 4-quinone and 1, 5-quinone forms was observed and the isosbestic point was observed at 480 nm. Dye 2 easily deprotonated to give the 1, 4-dianion, but dyes 3 and 4 existed as tautomeric mixtures in solution and shifted to 1, 5-quinone forms in alkali solution. 相似文献