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排序方式: 共有8786条查询结果,搜索用时 15 毫秒
1.
Yan R.-H. Lee K.F. Jeon D.Y. Kim Y.O. Park B.G. Pinto M.R. Rafferty C.S. Tennant D.M. Westerwick E.H. Chin G.M. Morris M.D. Early K. Mulgrew P. Mansfield W.M. Watts R.K. Voshchenkov A.M. Bokor J. Swartz R.G. Ourmazd A. 《Electron Device Letters, IEEE》1992,13(5):256-258
The authors report the implementation of deep-submicrometer Si MOSFETs that at room temperature have a unity-current-gain cutoff frequency (f T) of 89 GHz, for a drain-to-source bias of 1.5 V, a gate-to-source bias of 1 V, a gate oxide thickness of 40 Å, and a channel length of 0.15 μm. The fabrication procedure is mostly conventional, except for the e-beam defined gates. The speed performance is achieved through an intrinsic transit time of only 1.8 ps across the active device region 相似文献
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Improving the efficiency of induction motors, which are the most energy consuming electric machines in the world, saves much energy. The efficiency can be increased by improving cooling performance as well as by using better materials or by improving electromagnetic performance with better design. This paper presents the relationship between the efficiency or the losses and the temperature of coils with experiments as well as simulations by changing parameters such as the load and the flow rate of cooling air. The losses and the efficiency are calculated from an equivalent circuit method as well as experiments. Coil temperatures variation affects much on the efficiency. The internal cooling method is better than that of external cooling for the coil temperature reduction. Several cooling methods are compared focusing on the fan efficiency and performance, from which the values of the efficiencies of the motors are expected. The fan efficiency as well as the fan performance should be considered for the optimum fan design to increase the total efficiency of a motor. The simulations are validated by the comparison with the experiments 相似文献
4.
Sera from 82 cases of leptospirosis (confirmed by micro-agglutination tests or IFAT) and 108 patients with other diseases were investigated using the microcapsule agglutination test (MCAT) for leptospirosis. The overall sensitivity (90.2%), specificity (96.3%), positive predictive value (94.9%), negative predictive value (92.9%), and accuracy of the MCAT (93.7%) were encouraging. MCAT is simple, can be performed by unskilled personnel with minimum laboratory facilities, and produces results in 3 h. MCAT would be a reliable serodiagnostic test for rapidly screening individuals for leptospirosis, in various geographical areas of Thailand. 相似文献
5.
E Legius H Cuppens H Dierick K Van Zandt R Dom JP Fryns G Evers-Kiebooms M Decruyenaere K Demyttenaere P Marynen 《Canadian Metallurgical Quarterly》1994,2(1):44-50
Pantoprazole is a specific inhibitor of the H+/K(+)-ATPase of the gastric parietal cell. The dose-dependency of a range of pantoprazole pharmacokinetic characteristics was studied. Twelve healthy male subjects were given 10, 20, 40 and 80 mg pantoprazole intravenously according to a randomized, single blind, 4-period change-over scheme. The area under the concentration vs time curve (AUC) and the maximum serum concentration (Cmax) showed a linear increase in line with the dose. Apparent volume of distribution (Vd area), clearance (Cl) and terminal half-life (t1/2) were independent of the dose. The dose-independent elimination of pantoprazole was attributed to the lack of interaction of the drug with cytochrome P450. In clinical practice, a good predictable response, as well as a low potential for interaction with other drugs might be expected. 相似文献
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JP Guignard 《Canadian Metallurgical Quarterly》1993,50(3):187-189
8.
Chankil Lee Youngsik Jeon Kwangil Yeon 《Electronics letters》1998,34(1):37-39
The final closed-form expression for bit error probability (BEP) is presented for a DS-CDMA system using a maximal ratio combining (MRC) diversity over a Rician fading channel. The accuracy of the BEP estimate evaluated by this expression is verified by comparison with a semi-analytic simulation result. The effect that diversity order has on the BEP is also considered for typical multipath delay profiles with different Rician ratios 相似文献
9.
Y Panis J Belghiti D Valla JP Benhamou F Fékété 《Canadian Metallurgical Quarterly》1994,115(3):276-281
BACKGROUND: In Budd-Chiari syndrome (BCS) treated by portosystemic shunt, postoperative shunt thrombosis is associated with high morbidity and mortality rates. The aim of this study was to determine factors associated with shunt thrombosis. METHODS: From 1985 to 1991, 25 patients underwent portosystemic shunt for BCS. According to the patency of the shunt during the postoperative period and follow-up, patients were divided into two groups including 17 patients with patent shunt and 8 (32%) with shunt thrombosis. RESULTS: In patients with patent shunt, actuarial survival rate at 5 years was 87% versus 38% in patients with shunt thrombosis (p < 0.05). Duration of symptoms before operation was higher in patients with shunt thrombosis than in patients with patent shunt (315 +/- 483 vs 109 +/- 168 days, p < 0.05). In patients with patent shunt, extensive fibrosis or cirrhosis was observed in 3 of 17 (18%) versus in 5 of 8 (63%) of patients with shunt thrombosis (p < 0.05). Shunt thrombosis was observed in 3 of 3 patients (100%) with the combination of myeloproliferative disorder, duration of symptoms more than 100 days, and cirrhosis versus 0 of 6 (0%) patients without this combination (p < 0.05). CONCLUSIONS: In acute form of BCS (with short history of the disease and absence of extensive fibrosis or cirrhosis), early portal decompression is mandatory, with low risk of shunt thrombosis and good long-term results. In chronic form of BCS, the risk of shunt thrombosis is high and long-term results are bad; in these patients, orthotopic liver transplantation must be considered. 相似文献
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