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881.
V. S. Kucheryavyi 《Power Technology and Engineering (formerly Hydrotechnical Construction)》1985,19(9):463-466
Conclusions After the almost 2-yr operation of the gate apparatus since the start of reconstruction of friction units of the vanes, we can make a preliminary evaluation of the effectiveness of the works:There is practically no leakage of water through the gate vanes to the turbine cover, which led to a complete unloading of the drainage pumps on the turbine cover and the efficiency of operating the gate apparatus increased considerably.Repair of the gate apparatus is not required during maintenance.There is no vibration of the gate vanes, since the gaps in the friction units of the journals of the gate vanes are minimum and stable.The operating personnel objectively evaluate highly the work of the gate apparatus of the turbine after reconstruction and will continue this work on the remaining turbines.Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 9, pp. 12–14, September, 1985. 相似文献
882.
Results are reported from the production of two trial heats of alloy steel in which the cast slabs were cooled in a thermostatted chamber and in a dense stack. It is shown that cooling slabs in such a chamber makes it possible to reduce the hydrogen content of the steel 30% compared to slabs that are cooled while stacked. 相似文献
883.
S.T.V. Parthasaradhi R. Derakhshani L.A. Hornak S.A.C. Schuckers 《IEEE transactions on systems, man and cybernetics. Part C, Applications and reviews》2005,35(3):335-343
Fingerprint scanners may be susceptible to spoofing using artificial materials, or in the worst case, dismembered fingers. An anti-spoofing method based on liveness detection has been developed for use in fingerprint scanners. This method quantifies a specific temporal perspiration pattern present in fingerprints acquired from live claimants. The enhanced perspiration detection algorithm presented here improves our previous work by including other fingerprint scanner technologies; using a larger, more diverse data set; and a shorter time window. Several classification methods were tested in order to separate live and spoof fingerprint images. The dataset included fingerprint images from 33 live subjects, 33 spoofs created with dental material and Play-Doh, and fourteen cadaver fingers. Each method had a different performance with respect to each scanner and time window. However, all the classifiers achieved approximately 90% classification rate for all scanners, using the reduced time window and the more comprehensive training and test sets. 相似文献
884.
N. M. Shchetinin L. T. Kochelaeva V. A. Iveleva G. V. Kuz'mina N. S. Kireeva 《Glass and Ceramics》1991,48(1):5-7
Translated from Steklo i Keramika, No. 1, pp. 6–7, January, 1991. 相似文献
885.
Umashankar K.R. Nimmagadda S. Taflove A. 《Antennas and Propagation, IEEE Transactions on》1992,40(8):867-877
Apparent computational difficulties with the direct integral equation and method of moments have prompted an alternative numerical solution procedure based on the spatial decomposition technique. Using rigorous electromagnetic equivalence, the spatial decomposition technique virtually divides an electrically large object into a multiplicity of subzones. It permits the maximum size of the method of moments system matrix that needs to be inverted to be strictly limited, regardless of the electrical size of the large scattering object being modeled. The requirement on the computer resources is O (N ), where N is the number of spatial subzones and each subzone is electrically small, spanning on the order of a few wavelengths. Numerical examples are reported along with comparative data and relative error estimation to expose the applicability and limitations of the spatial decomposition technique for the two-dimensional scattering study of electrically large conducting and dielectric objects 相似文献
886.
The devolatilization and volatile combustion of a single coal particle in spouted and spout-fluid beds have been studied. The results showed that the flame extinction time increases with the particle diameter, and decreases with the bed temperature. When the bed temperature and the air flow rate were fixed, the operation modes (spouted or spout-fluid bed) showed less effect on the mean flame extinction time. A mathematical model of the spouted bed mode for preignition and postignition periods has also been developed assuming the devolatilization rate to be controlled by heat transfer and multireaction pyrolysis kinetics based on volatile products. Ignition, heat transfer back from the volatile flame to the particle surface, variation in flame temperature, and the hydrodynamics of SB are taken into account. The model predictions, with some adjusting parameters, were in good agreement with experimental results. 相似文献
887.
888.
889.
G. A. Isaak'yan V. Ya. Alekseev A. I. Ivanov N. I. Karmalitsyn A. E. Kochin T. E. Sazonova S. V. Sepman I. F. Uchevatkin V. I. Fominykh 《Atomic Energy》1992,73(5):903-907
Mendeleev All-Union Metrology Research Institute. Translated from Atomnaya Énergiya, Vol. 73, No. 5, pp. 393–397, November 1992. 相似文献
890.
An algorithm is presented for computing degrees of sequence conservation found among aligned amino acid sequences. Sequence identities are calculated for each position of an alignment and average identity values of neighboring positions are figured. The average identity value of the whole alignment is chosen as a limit to discriminate between well and less conserved sequence sections. A second algorithm is given to calculate the degree of divergence of individual sequences compared to the other sequences of the alignment. The approach is easy to use on microcomputers and gives an exact picture of sequence identities and differences in order to determine, first, protein regions of high functional or structural importance among homologous proteins, and, second, significant differences of single sequences that may contribute to individual properties of the analysed protein. The method is illustrated by an example analysing a sequence alignment of higher plant nitrate reductases. 相似文献