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排序方式: 共有1423条查询结果,搜索用时 31 毫秒
91.
S. J. L. Billinge E. S. Božin M. Gutmann H. Takagi 《Journal of Superconductivity and Novel Magnetism》2000,13(5):713-722
We present local structural evidence for the existence of charge inhomogeneities at low temperature in underdoped and optimally doped La2?x Sr x CuO4. The inhomogeneities disappear for x ≥ 0.2. The evidence for the charge inhomogeneities comes from an anomalous increase in the inplane Cu–O bond length distribution in the underdoped samples as well as evidence for CuO6 octahedral tilt inhomogeneities in the intermediate range structure. Preliminary analysis of the temperature dependence of this phenomenon indicates that the inhomogeneities set in at temperatures in the range 60 K < T co < 130 K, which depends on doping. 相似文献
92.
We have developed a new specific detection system for polyamines, separated by high-performance liquid chromatography, to replace the usual o-phthalaldehyde (OPA) postlabeling method. This system utilizes a chemiluminescent reaction to determine the amount of hydrogen peroxide generated through the enzymatic oxidation of polyamines. With this method, as little as 5 pmol of putrescine could be accurately determined (S/N = 4), and linearity between the amount of this polyamine and the relative chemiluminescence intensity was observed up to 500 pmol. In the cases of cadaverine, spermidine, and spermine, the linearity continued to 1 nmol. The within-assay coefficients of variation for these four polyamines ranged between 0.97% and 2.03%. As compared with the OPA method, the new method is highly specific for polyamines due to the high specificity of the enzyme used. Another advantage of the new method is the direct determination of polyamines in urine samples that contain various compounds that interfere with the OPA method. 相似文献
93.
The ultrasonic speeds and densities of poly(dimethylsiloxane), viscosity grades 30 and 50×10–4 m · s–1 at 298.15 K, were measured at 298.15, 303.15, and 308.15 K. The measurements were carried out using new apparatuses, one for measurement of the speed under pressures up to 200 MPa and another for measurement of the density under pressures up to 100 MPa. The former is constructed with a sing-around technique of the fixed-path type operated at a frequency of 2 MHz, and the latter is a dynamic bellows piezometer. The probable uncertainty in the present results is within ±0.23% for speed and ±0.19% for density for all the experimental conditions. The ultrasonic speed in these fluids at first increases rapidly with pressure and then indicates a mild rise in the highpressure region. Similar pressure effects are observed for the density. The relationship between the speed and the density satisfied a first-order function well. The isentropic compressibility, derived from the speed and density, also showed a large pressure effect. The values and its pressure effects seemed almost independent of the viscosity of poly(dimethylsiloxane). 相似文献
94.
Mitsuru Kudo Akira Takeuchi Yousuke Nozaki Hisahito Endo Jiro Sumita 《Electrical Engineering in Japan》2009,167(4):16-23
Recently, there has been an increase in concern about the global environment. Interest is growing in developing an energy network by which new energy systems such as photovoltaic and fuel cells generate power locally and electrical power and heat are controlled with a communication network. We developed the power generation forecast method for photovoltaic power systems in an energy network. The method makes use of weather information and regression analysis. We carried out forecasting power output of the photovoltaic power system installed in Expo 2005, Aichi Japan. As a result of comparing measurements with prediction values, the average prediction error per day was about 26% of the measured power. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 167(4): 16–23, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20755 相似文献
95.
OBJECTIVES: We investigated the long-term prognosis of completely asymptomatic adult patients with hypertrophic cardiomyopathy (HC). Diagnosis of HC was suspected because of an abnormal electrocardiogram and/or cardiac murmur and confirmed by echocardiography and/or left ventricular angiography, and hemodynamic investigation. BACKGROUND: Hypertrophic cardiomyopathy shows marked heterogeneity in clinical expression and prognosis. The prognosis of asymptomatic patients with HC has not been fully defined. METHODS: Of 128 consecutive adult patients with HC, 58 asymptomatic patients (Group 1, mean age 42.8 years) and 70 symptomatic patients (Group 2, mean age 50.4 years) were studied to assess cardiac mortality. Mean follow-up periods were 11.0 years for Group 1 and 9.1 years for Group 2. RESULTS: At presentation, Group 1 patients were younger and had smaller left atrial dimensions than did Group 2 patients. The annual cardiac mortality rate and the rate for sudden death alone in Group 1 were significantly lower than in Group 2 (0.9% vs. 1.9%, p < 0.05, 0.1% vs. 1.4%, p < 0.05, respectively). Although about one-third of the survivors in Group 1 had cardiac symptoms at their most recent evaluation, only one patient died suddenly compared with eight in Group 2. The annual mortality rate due to heart failure was similar in each group. Only a syncopal episode was associated with both cardiac death and sudden death for both groups combined. CONCLUSIONS: The cardiac mortality rate for completely asymptomatic adult patients with HC was very low, significantly lower than that of symptomatic patients, and there was a disproportionately low incidence of sudden death. 相似文献
96.
97.
Dynamic Characteristics Analysis of Two‐DOF Oscillatory Actuator and Experimental Verification of Prototype
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Yoshimoto Takamichi Katsuhiro Hirata Yasuyoshi Asai Kenji Ueyama Eiichiro Hashimoto Takahiro Takagi 《Electrical Engineering in Japan》2014,186(1):58-65
Recently, linear oscillatory actuators have been used in a wide range of applications. In particular, small linear oscillatory actuators are expected to be used in haptic devices by being extended to provide multi‐degree‐of‐freedom motion with arbitrary acceleration. In this paper, we propose a compact two‐DOF oscillatory actuator that can move in various directions on a plane. The static and dynamic characteristics of the actuator are determined by the 3D finite element method. The effectiveness of this method is shown through a comparison of the measured results with the experimental results from a prototype. © 2013 Wiley Periodicals, Inc. Electr Eng Jpn, 186(1): 58–65, 2014; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.22312 相似文献
98.
High performance liquid chromatographic separation of monoacylglycerol enantiomers as di-3,5-dinitrophenylurethane derivatives
was carried out on a chiral stationary phase, N-(S)-2-(4-chlorophenyl)isovaleroyl-D-phenylglycine chemically bonded tov-aminopropyl silanized silica. Complete separation of the urethane derivatives of racemic monoacylglycerols with saturated
acyl groups of C12−C18 was achieved using a stainless steel column (25 cm long) packed with the 5μ particles, an isocratic elution at ambient temperature
with a mixture of hexane/ethylene dichloride/ethanol as a mobile phase, and a UV detector. Thesn-1 enantiomers were eluted ahead of the correspondingsn-3 enantiomers. Complete separation of thesn-2 isomers from the corresponding enantiomers and partial separation of the enantiomer homologues differing by two acyl carbons
also were observed. 相似文献
99.
I Takagi K Yamada T Sato T Hanaichi T Iwamoto L Jin 《Journal of electron microscopy》1990,39(1):67-68
The penetration and stainability of modified Sato's lead staining solution containing calcined lead citrate were studied. Modified Sato's lead solution was preserved for 1 week and for 2 years, each at room temperature and at 4 degrees C. Specimens were stained with these solutions to measure the stainability. After 2-min staining, specimens were stained to the depth of 1.0-1.2 microns even when there had been 2-year preservation of the staining solution. This modified solution could be preserved for a long time and good penetration and stainability could still be obtained. This solution is also suitable for the observation of semithin sections. 相似文献
100.
BACKGROUND AND PURPOSE: The pathogenesis of periventricular hyperintensity (PVH) is still uncertain. We investigated the relationship between PVH and risk factors for cerebrovascular diseases, especially extracranial carotid artery stenosis (ECAS). METHODS: We studied PVH and ECAS in 323 subjects between 1991 and 1994. Using 1.5-T MRI scan images, we measured PVH quantitatively at eight points and evaluated cerebral infarction. Duplex carotid sonography was performed on the carotid arteries bilaterally and used to divide the severity of ECAS into five grades. Risk factors for cerebrovascular diseases and atherosclerotic complications were assessed from the clinical history. RESULTS: Age was significantly correlated with the size of frontal and whole PVH (P < .01). Frontal PVH was significantly more severe in subjects with hypertension (P < .05). Frontal, occipital, and whole PVH were significantly more severe in subjects with a history of cerebrovascular accident (P < .01). Other risk factors and atherosclerotic complications were not correlated with PVH. There were no significant differences in the severity of PVH among the five groups of ECAS. The severity of PVH in each region was not related to ECAS. There was no significant difference in the age of patients in relation to the five grades of ECAS. However, PVH was significantly more severe in subjects with lacunar infarction or infarction of the deep border zone (P < .05). There was no relationship between PVH and cortical infarction or infarction of the cortical border zone. CONCLUSIONS: PVH correlated with age, hypertension, and past history of cerebrovascular disease but not with ECAS. PVH was significantly more severe in lacunar infarction and infarction of the deep border zone. These results suggest that small-vessel disease may underlie the pathogenesis and development of PVH. 相似文献