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121.
The Chelyabinsk Metallurgical Combine has periodically used Kachkanar agglomerate to make conversion pig iron since 1972.
Use of this material reached a peak in 1998, when it comprised an average of 27.1% of the charge. In some months, the amount
of this material charged into the furnace reached highs of 45.6 and 74.1% on certain furnaces. The coolers on the iron notches
of furnaces 4 and 5 burned during that year, the quality of the smelting products and the condition of the ladles rapidly
deteriorated, and the smelting rate declined. No Kachkanar agglomerate was used in 2000–2001, but it was again added to the
charge in February 2002. The amount used was smaller than previously, averaging 10.7% for the shop as a whole. It was determined
that using a charge with 15% Kachkanar agglomerate has both positive and negative consequences.
N. N. Gorshkov, A. V. Denisov, and V. Kh. Barinov also participated in this study.
__________
Translated from Metallurg, No. 3, pp. 43–45, March, 2006. 相似文献
122.
Finite element analysis of problems in structural and geotechnical engineering results in linear systems where the unknowns are displacements and rotations at nodes. Although the solution of these systems can be carried out using either direct or iterative methods, in practice the matrices involved are usually very large and sparse (particularly for 3D problems) so an iterative approach is often advantageous in terms of both computational time and memory requirements. This memory saving can be further enhanced if the method used does not require assembly of the full coefficient matrix during the solution procedure. One disadvantage of iterative methods is the need to apply preconditioning to improve convergence. In this paper, we review a range of established element-based preconditioning methods for linear elastic problems and compare their performance with a new method based on preconditioning with element displacement components. This new method appears to offer a significant improvement in performance. 相似文献
123.
Simulation is useful for evaluating protocol performance and operation. However, the lack of rigor with which it's applied threatens the credibility of the published research within the manet research community. Mobile ad hoc networks (manets) allow rapid deployment because they don't depend on a fixed infrastructure. Manet nodes can participate as the source, the destination, or an intermediate router. This flexibility is attractive for military applications, disaster-response situations, and academic environments where fixed net working infrastructures might not be available. 相似文献
124.
Stievano I.S. Maio I.A. Canavero F.G. Siviero C. 《Advanced Packaging, IEEE Transactions on》2006,29(1):31-38
This paper addresses the impact of device macromodels on the accuracy of signal integrity and performance predictions for critical digital interconnecting systems. It exploits nonlinear parametric models for both single-ended and differential devices, including the effects of power supply fluctuations and receiver bit detection. The analysis demonstrates that the use of well-designed macromodels dramatically speeds up the simulation as well it preserves timing accuracy even for long bit sequences. 相似文献
125.
This paper seeks to explore a method to accurately correct geometric distortions caused during the capture of three-dimensional (3-D) integral images. Such distortions are rotational and scaling errors which, if not corrected, will cause banding and moire effects on the replayed image. The method for calculating the angle of deviation in the 3-D Integral Images is based on Hough Transform. It allows detection of the angle necessary for correction of the rotational error. Experiments have been conducted on a number of 3-D integral image samples and it has been found that the proposed method produces results with accuracy of 0.05 deg 相似文献
126.
A. Yu. Pustynnikov V. G. Ryabov D. T. Kalimullin A. N. Nechaev Ya. A. Treskov 《Chemistry and Technology of Fuels and Oils》2006,42(3):188-191
Paving-and roofing-grade asphalts were obtained at LUKOIL-Permnefteorgsintez Ltd. by mixing peroxidized asphalt and a number
of high-boiling unoxidized petroleum products in certain ratios. The asphalts obtained have improved performance characteristics:
high plasticity and low brittleness temperature.
__________
Translated from Khimiya i Tekhnologiya Topliv i Masel, No. 2, pp. 26–28, May–June, 2006. 相似文献
127.
The effects of α and β phase interactions on the room-temperature tensile and creep deformation behavior of α + β titanium
alloys with Widmanst?tten microstructures were studied using Ti-6.0 wt pct Mn and Ti-8.1 wt pct V as the model two-phase alloy
systems. This article, Part I, deals with tensile deformation. It was found that when the α phase is present as thin (<10-μm)
plates in the α + β alloys, significant twinning occurs. No significant twinning was observed in single-phase alloys with
the same chemistry and similar grain size. Additionally, the β phase of Ti-8.1 V deforms by stress-induced hexagonal martensite
(α′), while only twinning occurs in the single-phase β alloy with the same chemistry. Twinning in the α phase in association
with stress-induced martensite (SIM) in the β phase was observed for the first time in a two-phase titanium alloy. This behavior
is explained in terms of a number of factors including elastic interaction stresses between the α and β phases, coherency
between the α phase and hexagonal martensite, and β phase stability. 相似文献
128.
Y. Yin C.K. Erdonmez A. Cabot S. Hughes A.P. Alivisatos 《Advanced functional materials》2006,16(11):1389-1399
Formation of cobalt sulfide hollow nanocrystals through a mechanism similar to the Kirkendall Effect has been investigated in detail. It is found that performing the reaction at > 120 °C leads to fast formation of a single void inside each shell, whereas at room temperature multiple voids are formed within each shell, which can be attributed to strongly temperature‐dependent diffusivities for vacancies. The void formation process is dominated by outward diffusion of cobalt cations; still, the occurrence of significant inward transport of sulfur anions can be inferred as the final voids are smaller in diameter than the original cobalt nanocrystals. Comparison of volume distributions for initial and final nanostructures indicates excess apparent volume in shells, implying significant porosity and/or a defective structure. Indirect evidence for fracture of shells during growth at lower temperatures was observed in shell‐size statistics and transmission electron microscopy images of as‐grown shells. An idealized model of the diffusional process imposes two minimal requirements on material parameters for shell growth to be obtainable within a specific synthetic system. 相似文献
129.
The Magnitogorsk Metallurgical Combine has conducted a study of the effect of technological factors on the hydrogen content
of chromium-nickel-molybdenum steel after vacuum degassing. It was established that the most important factor is the hydrogen
content of the steel before the degassing operation. The study also determined the effects of the circulation coefficient,
the duration of the degassing operation, and the vacuum used in the treatment.
__________
Translated from Metallurg, No. 7, pp. 68–69, July, 2006. 相似文献
130.
Note on B-splines, wavelet scaling functions, and Gabor frames 总被引:3,自引:0,他引:3
Grochenig K. Janssen A.J.E.M. Kaiblinger N. Pfander G.E. 《IEEE transactions on information theory / Professional Technical Group on Information Theory》2003,49(12):3318-3320
Let g be a continuous, compactly supported function on such that the integer translates of g constitute a partition of unity. We show that the Gabor system (g,a,b), with window g and time-shift and frequency-shift parameters a,b>0 has no lower frame bound larger than 0 if b=2,3,... and a>0. In particular, (g,a,b) is not a Gabor frame if g is a continuous, compactly supported wavelet scaling function and if b=2,3,... and a>0. We give an example for our result for the case that g=B/sub 1/, the triangle function supported by [-1,1], by showing pictures of the canonical dual corresponding to (g,a,b) where ab=1/4 and b crosses the lines N=2,3,. 相似文献