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排序方式: 共有813条查询结果,搜索用时 15 毫秒
91.
H Yoshii M Sato S Yamamoto M Motegi S Okusawa M Kitano A Nagashima M Doi K Takuma K Kato N Aikawa 《Canadian Metallurgical Quarterly》1998,45(1):45-50; discussion 50-1
BACKGROUND: In the assessment of blunt abdominal trauma, the reliability of ultrasonography (US) in identifying individual organ injuries remains uncertain, in spite of its usefulness in detecting hemoperitoneum. This study was designed to evaluate the overall diagnostic value of US, including identification of individual organ injuries. METHODS: The accuracy of US in the detection of intra-abdominal injuries and the identification of individual organ injuries was evaluated in 1,239 patients seen during a 15-year period. Accuracy was based on detection of intraperitoneal fluid, free air, or irregular parenchymal lesions. RESULTS: For the detection of injuries, US was 94.6% sensitive, 95.1% specific, and 94.9% accurate. Individual organ injuries were identified with sensitivities of 92.4, 90.0, 92.2, 71.4, and 34.7% for the liver, spleen, kidneys, pancreas, and intestine, respectively. CONCLUSION: US is reliable for the detection of injuries and the identification of solid-organ injuries despite its poor sensitivity for intestinal injuries. 相似文献
92.
Synthesis of nitrogen (N) doped zinc oxide (ZnO) has been attempted by a serial operation of co-grinding the mixture of ZnO and urea (CO(NH2)2), followed by calcining the ground product at 400 °C. The prepared ZnO sample has been characterized by X-ray diffraction (XRD) analysis, infrared spectroscopy (IR), Raman spectroscopy. All spectra from these techniques are completely different from those of the hand ground mixture sample, confirming the mechanochemical effect of N-doping. The prepared N-doped ZnO sample exhibits light absorbance in the visible light wavelength region, and has high photo-catalytic ability in an anti-bacterial test. 相似文献
93.
94.
G.E. Abdelrahman Shohei Kawabe Fumio Tatsuoka Yoshimichi Tsukamoto 《Soils and Foundations》2008,48(4):479-494
The rate-dependency of the stress-strain behavior of EPS (Expanded Polystyrene) geofoam with densities of 19.3 and 28.0 kg/m3 was investigated by performing unconventional unconfined compression tests. A set of monotonic loading (ML) tests were performed at different constant values of vertical (axial) strain rate, εv. The εv value was stepwise changed many times and several sustained loading (SL) tests were performed during otherwise ML at a constant εv in other tests. A number of SL tests were performed during global unload and reload cycles to infer the stress-strain relation when εv=0. The elastic properties were evaluated by applying minute unload/reload cycles during otherwise ML. The rate-dependent stress-strain behaviour observed in these tests was described by an elasto-viscoplastic model (i.e., a non-linear three-component model), for which the vertical (axial) stress, σv, consists of inviscid and viscous components, σvf and σvv, while εv consists of elastic and irreversible components, εve and εvir. It is shown that the viscous property of EPS geofoam is of Isotach type in that, under the loading conditions where εvir is always positive, the current σvv value is a unique function of instantaneous εvir and εvir, therefore the strength increases with εv. This viscous property was quantified based on the test results and incorporated into the model. The rate-dependent stress-strain behaviour, including the creep behaviour, observed in the experiment is simulated very well by the proposed model. In particular, the fact that the creep strain becomes significant when the sustained σv value becomes larger than the inviscid yield vertical stress is well simulated. 相似文献
95.
A very-low-noise 0.5 ?m-gate GaAs f.e.t. is realised by using intentional side etching of an Au/Ti double layer as the Schottky-gate metal. At 12 GHz, the minimum noise figure is 2.1 dB, with 7.6 dB associated gain at a bias of VD = 4 V, ID= 10 mA. Maximum stable gain is 14 dB at VD = 4 V, ID = 30 mA. 相似文献
96.
97.
Tool wear prediction and economics in machining stepped parts 总被引:1,自引:0,他引:1
Kazunori Nagasaka Fumio Hashimoto 《International Journal of Machine Tools and Manufacture》1988,28(4):569-576
For analysing economics of machining cylindrical stepped parts, tool life must be predicted. In this paper, tool life tests, to obtain tool life changing cutting speed before the tool reaches tool life criterion under a constant speed, are performed and the tool life is calculated. Using the results of the calculations machining economics of various forms of stepped parts for the constant spindle rpm method and the constant cutting speed method, are analysed. 相似文献
98.
Y Noguchi S Takashima J Ikezoe M Yoshii T Koide T Kozuka 《Canadian Metallurgical Quarterly》1993,34(6):625-630
MR images of the neck were prospectively studied in 19 patients with hyperparathyroidism. Fast low angle shot (FLASH) sequence was performed in addition to T1- and T2-weighted spin echo (SE) sequences. FLASH images were obtained with 320/12/20 degrees (TR/TE/flip angle) using presaturation technique. TE of 12 ms was chosen to eliminate high signal of fat tissue. In the evaluation of detectability, a combination of T1-weighted SE and FLASH images (T1WI + FLASH) was compared with a combination of T1- and T2-weighted SE images (T1WI + T2WI). MR imaging correctly depicted 20 of 30 abnormal glands on both T1WI + FLASH and T1WI + T2WI. FLASH imaging effectively eliminated high signal of fat tissue. Nineteen abnormal glands demonstrated higher signal than surrounding tissues on FLASH images, whereas 12 glands were high-intense on T2-weighted SE images. We conclude that FLASH imaging provides improved tissue contrast and anatomic delineation and, thus, may replace T2-weighted SE imaging in the neck. 相似文献
99.
Hojin Ryu Eiki Kasai Kazumasa Sugiyama Fumio Saito Yoshio Waseda Hiromichi Ohta 《Particulate Science and Technology》1993,11(3):157-164
The present paper describes the effect of grinding a kaolinite/aiuminum-trihydroxide mixture using a planetary ball mill on the structure of the ground product and the mean thermal expansion coefficients of samples sintered from the unground and ground mixtures. The size reduction of the mixture predominates in the early stage of grinding and the obtained fine particles aggregate subsequently with an increase in grinding time. The crystal structure of the mixture is collapsed easily into a disordered one, of which amount increases with an increase in grinding time. Only mullite phase was detected in the sintered body of the ground products at relatively lower temperature 1523K except for anatase as an inherent impurity, whereas corundum, cristobalite and Al-Si spinel phases besides mullite were formed in the sintered body of the unground mixture. The thermal expansion coefficients of sintered bodies of the 120 minutes-ground mixture are considerably lower than those of the unground mixture by about 10%. Consequently, the planetary milling enables us to improve the uniform mixing state at the atomic scale resulting in direct formation of mullite with high purity at relatively low temperature with a lower thermal expansion coefficient of the sintered body. 相似文献
100.
The laminate method for studying the permeability and diffusivity of moistened cellophane to gases is described and the humidity dependence of the transport parameters for H2, He, and Ne is presented. In the relative humidity region of about 0% to 60%, a small increase in the permeability was observed, which is caused by a comparatively small increase in the diffusivity owing to the plasticizing effect of sorbed water and a decrease in the solubility. On the other hand, an extremely large increase in the permeability observed in the relative humidity region above 60% is mainly based on the diffusion coefficient of gas enhanced by the swelling effect of sorbed water. The presence of a minimum in the solubility–relative humidity curves has been confirmed and is discussed. 相似文献