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排序方式: 共有2274条查询结果,搜索用时 15 毫秒
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Y Furuya Y Yoshida T Katayama S Yamamoto A Kawamura 《Canadian Metallurgical Quarterly》1993,31(6):1637-1640
Polymerase chain reaction (PCR) with nested primer pairs was used to diagnose scrub typhus and identify the Rickettsia tsutsugamushi serotype. The primer pairs used for PCR were designed on the basis of the nucleotide sequence of the gene that encodes the 56-kDa antigen. Serotype-specific primers were used in the second PCR amplification. Five serovariants, the Gilliam, Karp, Kato, Kawasaki, and Kuroki strains of R. tsutsugamushi, were identified by nested PCR. In addition, the serotype identified by PCR with DNA from blood clots was the same as that of the strain isolated from five patients with scrub typhus. These findings indicate that this method is useful for diagnosis and identification of the rickettsial serotype in infected patients. 相似文献
3.
On an earthspace propagation path with the low elevation angle of 10 deg, the phase between co- and crosspolar signals occasionally showed rapid and irregular fluctuations during fine weather. These fluctuations were generally significant during the daytime, and were strongly in phase with the occurrence of the copolar amplitude scintillations. This could be attributed to the combined effects of the crosspolar phase pattern of the receiving antenna and small fluctuations of the angle of arrival of the radiowaves. 相似文献
4.
J.H. Kaneko T. Tanaka S. Kawamura Y. Oshiki K. Tsuji M. Katagiri K. Ochiai T. Nishitani F. Fujita A. Homma T. Sawamura T. Iida M. Furusaka 《Diamond and Related Materials》2005,14(11-12):2027
Radiation detector was made of a high-quality CVD polycrystalline diamond composed of frost column like structure diamond grains, and induced charge distribution spectra and drift velocities were measured by using alpha particles. As a result, the CVD polycrystalline achieved maximum induced charge of 83% of HP/HT type IIa diamond. Moreover, the CVD crystal had lower charge loss on electrons compared with the HP/HT type IIa diamond. Drift velocities of electrons and holes were ve = 7.7 × 104 and vh = 7.3 × 104cm/s at an electric field of 20 kV/cm, respectively. In addition, response function measurement for 14 MeV neutrons was carried out. 相似文献
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Masafumi Itoh Osamu Sakurada Minoru Hashiba Kouichi Hiramatsu Yukio Nurishi 《Journal of Materials Science》1996,31(12):3321-3324
An average shell volume occupied in the adsorption layer on alumina by a polyacrylic acid ammonium salts molecule (PAA) defined as the average area occupied by an adsorbed PAA on alumina multiplied by the average thickness of the water layer at the limit of thickening, has been calculated from the adsorbed amount of PAA and from the flow points of alumina in the presence of PAA of different molecular weights. A steric effect of the PAA dispersant on the dispersion of alumina resulted in a flow with no yield stress. This was due to the change of the extension of PAA in the adsorption shell from a sphere to an ellipsoid with a long axis which exceeded the effective distance that the van der Waals attraction force reaches at a molecular weight for the PAA of between 10 000–20 000. 相似文献
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The authors reports the fabrication of a flip-chip InGaAsP-InAlAs superlattice avalanche photodiode using gas source molecular beam epitaxy. The incident light reaches the InGaAs photoabsorption layer through the InP substrate and an InGaAsP-InAlAs superlattice multiplication region which are transparent for wavelengths of 1.55 and 1.3 μm. The light reflection by the electrode enables the absorption layer to be as thin as 0.8 μm without significantly reducing the quantum efficiency. A maximum bandwidth of 17 GHz was obtained at a low multiplication factor because the transit time through the absorption layer is reduced 相似文献
9.
Toshimitsu Suzuki Osamu Yamada Yasuhiko Takahashi Yoshihisa Watanabe 《Fuel Processing Technology》1985,10(1):33-43
Hydroliquefaction of low-sulfur Australian coals (Wandoan and Yallourn) was studied using iron carbonyl complexes as catalyst. The addition of Fe(CO)5 (2.8 wt% Fe of coal) increased coal conversion from 48.6 to 85.2% for Wandoan coal, and from 36.7 to 69.7% for Yallourn coal in 1-methylnaphthalene at 425°C under an initial hydrogen pressure of 50 kg cm?2. When molecular sulfur was added to iron carbonyls (Fe(CO)5, Fe2(CO)9 and Fe3(CO)12), higher coal converions ( > 92%) and higher oil yields (>46%) were obtained, along with an increase in the amount of hydrogen transferred to coal from the gas phase (0.2 to 2.8%, d.a.f. coal basis). In the liquefaction studies using a hydrogen donor solvent, tetralin, Fe(CO)5S catalyst increased the amount of hydrogen absorbed from the gaseous phase and decreased the amount of naphthalene dehydrogenated from tetralin. The direct hydrogen transfer reaction from molecular hydrogen to coal fragment radicals seems to be a major reaction pathway. Organic sulfur compounds, dimethyldisulfide and benzothiophene, and inorganic FeS2 and NiS were found to be good sulfur sources to Fe(CO)5. From X-ray diffraction analyses of liquefaction residues, it is concluded that Fe(CO)5 was converted into pyrrhotite (Fe1?xS) when sulfur was present, but into Fe3O4 in the absence of sulfur. 相似文献
10.
Osamu Umezawa 《Metallurgical and Materials Transactions A》2004,35(2):543-553
To achieve higher fatigue resistance against subsurface crack generation, both the refinement of grain structure and the introduction
of mobile dislocations on various slip systems have been shown to be effective in the 32Mn-7Cr austenitic steel. A novel treatment
which consisted of cold grooved rolling and partial recrystallization was introduced to modify the microstructure. High-cycle
fatigue properties and fatigue-crack generation were investigated for both the solution-treated (ST) and the partially recrystallized
(PR) materials at 77 K. The PR material displayed higher fatigue strength than the ST material, especially in the high-cycle
regime. No subsurface crack generation was detected for the PR material; however, it appeared in the lower peak stress and/or
in the longer-life range for the ST material. Intergranular facets formed a subsurface crack initiation site in the ST material.
Since the dislocation structure that developed in the fatigued PR material assisted homogeneous and multidirectional plastic
deformation, the localized deformation and/or the stress concentration at the grain boundaries by coplanar arrays were believed
to be relieved. Therefore, intergranular cracking due to incompatibility at a grain boundary may disappear. 相似文献