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131.
H Mizuta K Kubota M Shiraishi Y Otsuka N Nagamoto K Takagi 《Canadian Metallurgical Quarterly》1995,77(6):890-894
We describe the results of conservative treatment for complete midsubstance tears of the anterior cruciate ligament (ACL) in 18 skeletally immature patients, followed for a minimum of 36 months. Six patients had an ACL reconstruction during the follow-up period and were assessed immediately before their operation. The average time from initial injury to evaluation was 51 months. All patients had symptoms when reviewed. The modified Lysholm knee score showed one excellent result, one good, eight fair, and eight poor with a mean score of 64.3. Only one patient had returned to her preinjury level of athletics. Secondary meniscal tears were confirmed in six patients, and three more had the clinical signs of a tear at follow-up. Radiological evidence of degenerative changes was found in 11 of the 18 patients. We conclude that the results of non-operative treatment for ACL injuries in this age group are poor and not acceptable. 相似文献
132.
Suganuma K. Sakai T. Keun-Soo Kim Takagi Y. Sugimoto J. Ueshima M. 《Electronics Packaging Manufacturing, IEEE Transactions on》2002,25(4):257-261
Thermal stability of the circuit boards with a quad flat package (QFP) soldered with Sn-58wt%Bi-(0, 0.5 and 1.0) wt% Ag and their microstructural features were evaluated. The addition of 1.0 wt% Ag causes the formation of large primary Ag/sub 3/Sn precipitates in the solder while no primary Ag/sub 3/Sn is found in Sn-57Bi-0.5Ag. Thermo-Calc calculation indicates that the lowest limit content for the formation of primary Ag/sub 3/Sn is about 0.8 wt%. Heat-exposure below 100/spl deg/C has no serious degradation on the joint structure for all solders. Heat-exposure at 125/spl deg/C caused serious degradation in joint strength for all alloys. The contamination of Pb from Sn-Pb surface plating on the components reduces the interface tolerance by forming ternary Sn-Pb-Bi phase melting at low temperature. Thermal fatigue between -20 and 80/spl deg/C does not have any significant influence on joint structure. 相似文献
133.
Mechanical properties of amorphous alloy compacts prepared by different consolidation techniques 总被引:2,自引:0,他引:2
M. Takagi Y. Kawamura T. Imura J. Nishigaki H. Saka 《Journal of Materials Science》1992,27(3):817-824
Amorphous alloy compacts of Fe78B13Si9 prepared by three different techniques (explosive consolidation, high hydrostatic pressure consolidation and warm extrusion) were deformed in compression between 573 and 723 K at a strain rate ranging from 8.3×10–5–4.2×10–4s–1. Explosively consolidated compacts had high strength ranging from 1.9–2.5 GPa below 623 K and could be plastically deformed to a strain of more than 50% at 673 K while preserving the amorphous state. Amorphous alloy compacts prepared by high hydrostatic pressure consolidation showed lower compressive strength. Those produced by warm extrusion were anisotropic in strength, the highest strength being as high as 2.74 GPa. It was also found that the geometry of the starting powders had a profound effect on the strength of the product compacts. Compacts prepared from flaky powders were stronger than those prepared from spherical ones. It is concluded that the mechanical properties of the amorphous alloy compacts depend on the consolidation technique, powder geometry and surface conditions of the powders, especially existence of oxide films. 相似文献
134.
135.
Keizo Uematsu Masaki Takagi Tsunehiro Honda Nozomu Uchida Katsuichi Saito 《Journal of the American Ceramic Society》1989,72(8):1476-1478
Hydroxyapatite powder was synthesized and formed into a compact in an aqueous medium using a filter-cake method. The compact was hot isostatically pressed at 700° to 1000°C and 100 MPa for 2 h. Fully dense, transparent materials were obtained above 800°C. Both forming and densification methods were found to be important in obtaining transparent materials. 相似文献
136.
A new type of GaAs lateral bipolar transistor has been developed by introducing an n-i-p-i-n structure where the electric field is applied perpendicular to the direction of carrier injection in order for the carriers to be separated. The diffusion length is increased owing to the increase of lifetime due to the spatial separation of injected carriers, resulting in the increase of current gain. 相似文献
137.
Amorphous carbon materials for lithium ion battery anodes which contain a small amount of Li2CO3 were prepared by three methods. The obtained materials were characterized using X-ray diffraction (XRD) analysis, Raman spectroscopy and CO2 adsorption experiments. Although the XRD profiles and Raman spectra of these materials were similar to those of carbon materials synthesized with no addition, the amount of CO2 adsorbed was largely decreased by Li2CO3 addition. These results suggest that the micropores in these materials were plugged and/or filled with Li2 CO3. Galvanostatic lithium charging and discharging experiments showed that the irreversible capacity of the material can be significantly decreased by Li2CO3 addition, which is thought to be due to the plugging of the pore inlets by Li2CO3. Moreover, it was also found that the reversible capacities of the materials can be increased by adjusting both the amount of Li2CO3 addition and carbonization temperature. 相似文献
138.
Nukaiyama Y. Takagi I. Ishihara H. Kudo A. Makino Y. Hosokawa N. 《Power Delivery, IEEE Transactions on》1994,9(4):1885-1891
Gas analysis provides a promising means for a diagnosis of gas-insulated equipment. Although many studies have been concentrated on SF6 gas decomposition, they were mostly related to the faults in GIS systems and not directly applicable to gas-insulated transformers, which have much more complicated material structure. An experimental survey on decomposition by-products at various abnormal conditions was carried out by use of simulation models to develop a diagnostic method for gas-insulated transformers based on gas and ion chromatograph analyses. Major components characteristic in each abnormality, such as SO2 on metal overheat, SO2F 2 on partial discharges, etc. were identified by the experiments 相似文献
139.
140.
A method for the stereospecific analysis of triacyl-sn-glycerols by high-performance liquid chromatography (HPLC) on a chiral column is described. Triacyl-sn-glycerols were partially degraded with ethyl magnesium bromide, and the monoacylglycerols produced were separated as 1- and
2-monoacylglycerol fractions by thin-layer chromatography on boric acid-impregnated silica gel plates. The 1-monoacylglycerols
were resolved intosn-1 andsn-3 monoacylglycerol fractions by HPLC on a chiral column (Sumichiral OA-4100) after derivatization with 3,5-dinitrophenyl
isocyanate. Fatty acid methyl esters obtained from the original triacyl-sn-glycerols, 1- and 2-monoacylglycerol fractions, andsn-1 andsn-3 monoacylglycerol fractions were analyzed by gas chromatography on open-tubular columns. Stereospecific acyl distributions
in triacyl-sn-glycerols were calculated from the data. The acyl distributions of several oils were obtained. The method is rapid, simple
and gave reproducible results. 相似文献