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排序方式: 共有516条查询结果,搜索用时 15 毫秒
71.
Y Ohnishi S Tajima A Ishibashi T Inazumi T Sasaki H Sakamoto 《Canadian Metallurgical Quarterly》1998,139(1):141-144
Fourier transform infrared and Raman (FT-IR and FT-Raman) microspectroscopy were used to study materials found in human tissue. Individual cases involving cholesterol, calcium stearate, and a polystyrenesulfonate ion exchange resin demonstrate the utility of the spectroscopic data. Characteristic spectral bands for these materials were compared with those of authentic chemical species to confirm their identities. The role of vibrational spectroscopy in pathologic diagnoses is discussed. 相似文献
72.
J.-H. Chung T. Egami R. J. McQueeney M. Yethiraj M. Arai T. Yokoo H. A. Mook Y. Endoh S. Tajima C. Frost F. Dogan 《Journal of Superconductivity and Novel Magnetism》2002,15(5):327-330
We measured the phonon dispersions of YBa2Cu3O6.15 and YBa2Cu3O6.95 by time-of-flight inelastic neutron scattering. The in-plane bond-stretching modes in the metallic phase showed a distinct a-b plane anisotropy beyond what is expected for structural origin. Such anisotropy in the longitudinal optical modes, which is absent in the TO, suggests strong in-plane anisotropy in the underlying electronic structure. Apical oxygen bond-stretching modes showed a large frequency change between the insulating and the metallic phases. This large softening also is beyond structural origin, and suggests the effect of local electronic environment. 相似文献
73.
The amounts of nucleotide variation within and between allelic classes were studied. The expectation and variance of the number of segregating sites and the expectation of the average number of pairwise differences among a sample of DNA sequences were obtained by using the theory of gene genealogy with no recombination. When the ancestral allelic class is unknown, it was found that the amount of variation within an allelic class increases with its frequency in the sample, while the amount of variation between two allelic classes is the largest when the two allelic classes exist equally. On the other hand, if we know the ancestral allelic class, as the frequency of the mutant allelic class increases, the amounts of variation within the mutant allelic class and between two allelic classes increase and the amount of variation within the ancestral allelic class decreases. As an example, we analyzed the polymorphism in the ND5 gene of Drosophila melanogaster and constructed the common ancestral sequence with high confidence, suggesting that the pattern of polymorphism within species gives useful information to know the ancestral sequence of the species. 相似文献
74.
M Karvonen M Pitk?niemi J Pitk?niemi K Kohtam?ki N Tajima J Tuomilehto 《Canadian Metallurgical Quarterly》1997,13(4):275-291
Myocarditis is thought to be commonly caused by various viruses, and accumulating evidence links viral myocarditis with the eventual development of dilated cardiomyopathy. Recently, the importance of hepatitis C virus infection was noted in patients with dilated and hypertrophic cardiomyopathy. Cytokines are being increasingly recognized as an important factor in the pathogenesis and pathophysiology of myocarditis and cardiomyopathy. Elevated levels of circulating cytokines have been reported in patients with heart failure, and various cytokines have been shown to depress myocardial contractility in vitro and in vivo. A number of reports have shown that cytokines generated by activated immune cells cause an increase in nitric oxide (NO) via induction of NO synthase. Increased generation of NO may induce negative inotropism and myocardial damage. This review discusses the etiology and pathogenesis of myocarditis and cardiomyopathy from this point of view. 相似文献
75.
The transverse magnetoresistance of α-(BEDT-TTF)2KHg(SCN)4 was investigated with the magnetic field rotated within a conducting ac-plane. It was found that the magnetic-field-orientation dependence of the magnetoresistance in the weak-field limit, ΔR(B,θ), has the form ΔR(B,θ) = B2(psin2(θ − θmin) + qcos2(θ − θmin), where θ is the angle betweeen a-axis and magnetic field direction and (p, q, θmin) are temperature-dependent parameters. By examining the results based on the classical theory of magnetoresistance, it was concluded that the electrical anisotropy within be-plane is 3.5 4.5 and 2.5 3.0 above and below the phase transition at 10 K, respectively. 相似文献
76.
Chlorine concentration profiles in silica fibres were studied by X-ray microanalysis and consideration of the chemical reactions concerned with chlorine in the fibre fabrication process. The chlorine content was proportional to the doped element contents. The Cl/Ge content ratio was larger than the Cl/Si or Cl/P content ratio. 相似文献
77.
Y Tanaka S Tajima K Imai K Tsujiguchi K Ueda K Yabu 《Canadian Metallurgical Quarterly》1996,17(4):209-216
We report five cases of adipo-lymphatico venous transfer (ALVT) performed to treat unilateral obstructive lymphedema of the lower extremity. ALVT is a surgical procedure that utilizes the long saphenous vein and its surrounding lymphatic tissue from the unaffected limb for the treatment of lymphedema. Since ALVT does not necessitate anastomoses of lymphatic vessels, it can be performed regardless of the severity and duration of lymphedema, and stable long-term results can be obtained when the transferred lymphatic tissue shows viability. 相似文献
78.
Zhou J. Tajima K. Nakajima K. Kurokawa K. Matsui T. Fukai C. Sankawa I. 《Electronics letters》2005,41(7):403-405
A photonic crystal fibre (PCF) with polarisation mode dispersion (PMD) of 0.03 ps/rkm was obtained by unidirectional twist. The work was also successful in reducing the PMD of the PCF to 10% of its initial value by periodic bidirectional twisting without loss increasing and structural deformation. 相似文献
79.
Raman amplification characteristics at 850 nm in a silica-based photonic crystal fiber 总被引:1,自引:0,他引:1
K. Nakajima C. Fukai K. Kurokawa K. Tajima T. Matsui I. Sankawa 《Photonics Technology Letters, IEEE》2006,18(3):451-453
We achieve a 2.5-dB improvement in the power penalty in a 10-Gb/s-based distributed Raman amplification transmission at 850 nm using a silica-based low-loss photonic crystal fiber (PCF). The experimental results agree well with a signal-to-noise ratio improvement model. The model indicates the negligible influence of double Rayleigh backscattering in the fabricated PCF. 相似文献
80.
H Tajima Y Hayashi T Maehara T Morohoshi T Imada T Amano J Kondoh 《Canadian Metallurgical Quarterly》1998,28(10):1078-1080
Endobronchial hamartomas are only rarely encountered. They cause irreversible lung damage due to bronchial obstruction if not diagnosed early and treated properly. Among the various treatments for this rare disease, a surgical resection remains the most popular. We herein report a case of a 53-year-old man presenting with an endobronchial hamartoma which was successfully excised by laser irradiation via a rigid bronchoscope, along with a review of 113 patients with this disease reported in the literature. 相似文献