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991.
本文介绍了转炉钢渣在电炉熔氧前期替代石灰造渣的理论分析及试验研究结果。认为转炉钢渣造渣不仅可以完成脱磷、脱碳的冶金效果,还可以回收金属,提高资源利用率。经济效益,社会效益显著。 相似文献
992.
Jinil Son Sangshik Kim Jehyun Lee Byunghak Choi 《Metallurgical and Materials Transactions A》2003,34(8):1617-1625
The effect of N addition on the microstructure, tensile, and corrosion behaviors of CD4MCU (Fe-25Cr-5Ni-2.8Cu-2Mo) cast duplex
stainless steel was examined in the present study. The slow strain rate tests were also conducted at a nominal strain rate
of 1 × 10−6/s in air and 3.5 pct NaCl+5 pct H2SO4 solution for studying the stress corrosion cracking (SCC) behavior. It was observed that the volume fraction of austenitic
phase in CD4MCU alloy varied from 38 to 59 pct with increasing nitrogen content from 0 to 0.27 wt. pct. The tensile behavior
of CD4MCU cast duplex stainless steels, which tended to vary significantly with different N contents, appeared to be strongly
related to the volume changes in ferritic and austenitic phases, rather than the intrinsic N effect. The improvement in the
resistance to general corrosion in 3.5 pct NaCl+5 pct H2SO4 aqueous solution was notable with 0.13 pct N addition. The further improvement was not significant with further N addition.
The resistance to SCC of CD4MCU cast duplex stainless steels in 3.5 pct NaCl+5 pct H2SO4 aqueous solution, however, increased continuously with increasing N content. The enhancement in the SCC resistance was believed
to be related to the volume fraction of globular austenitic colonies, which tended to act as barriers for the development
of initial pitting cracks in the ferritic phase into the sharp ones. 相似文献
993.
A zinc salt of a lightly sulfonated (4.5 mol %) polystyrene ionomer was used to compatibilize a 3/1 (w/w) blend of syndiotactic polystyrene and a wholly aromatic thermotropic liquid‐crystalline polymer (TLCP). The addition of the ionomer significantly reduced the dispersed TLCP domain size and improved the tensile strength, ultimate elongation, and flexural toughness of the blend. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 564–568, 2003 相似文献
994.
L Noyez JA van Son T van der Werf WN van Asten LK Lacquet 《Canadian Metallurgical Quarterly》1993,1(5):583-586
A total of 44 patients undergoing isolated aortic valve replacement received either anterograde (20 patients) or retrograde (24 patients), cold St Thomas's Hospital cardioplegia. The patients were similar with respect to age, sex, left ventricular ejection fraction, left ventricular-aortic pressure gradient, cross-clamping time and mean dose of cardioplegia. After surgery, there were no differences in enzyme release, low cardiac output syndrome, rhythm disturbances or clinical outcome between the two groups. Analysis of the postoperative haemodynamic data, however, suggests better preservation of left ventricular contractility with retrograde delivery of cardioplegic solution. 相似文献
995.
996.
In some environments, components might not always fail fully, but can degrade, and there can be multiple stages of degradation. In such cases, the efficiency of the system may decrease. After a certain stage of degradation the efficiency of the system may decrease to an unacceptable limit and can be considered as a total failure. However, the system can fail randomly from any stage. and can be repaired. Further, the repair action cannot bring the system to the good stage, but can make it operational and the failure rate of the system will, therefore, remain the same as before the failure. In this study, we present a model for predicting the reliability, availability, mean life time, and mean time to first failure of multistage degraded systems with partial repairs. In the analysis, state dependent transition rates for the degradation process, as well as repair processes, are considered. A numerical example is provided to illustrate the results. 相似文献
997.
MP Hoang SV Hirany J Parupia S Devaraj I Jialal 《Canadian Metallurgical Quarterly》1998,122(11):1005-1009
BACKGROUND: High-density lipoprotein cholesterol (HDL-C) is an independent inverse risk factor for coronary artery disease. Current methodologies for measurement of HDL-C in most clinical laboratories involve chemical precipitation-based methods. However, these methods are time-consuming, affected by high triglycerides, are not suitable for complete automation, and require a large sample size. New direct homogeneous methods are now available that do not have these constraints. DESIGN: We evaluated the performance of 2 direct homogeneous methods, Liquid N-geneous HDL-C assay (LN-HDL) and Boehringer Mannheim HDL Cholesterol assay (BM-HDL), and compared these methods against a modified Centers for Disease Control and Prevention reference method (MR-HDL) in 126 patients with normotriglyceridemia (triglycerides < 4.5 mmol/L, range 0.6-4.3 mmol/ L) and 50 patients with hypertriglyceridemia (triglycerides > or =4.5 mmol/L, range 4.5-18.8 mmol/L). RESULTS: Excellent precision profiles were exhibited by both homogeneous methods. Both LN-HDL and BM-HDL correlated well with MR-HDL in normotriglyceridemia (r = 0.98, slope = 0.93 and r = 0.97, slope = 1.0, respectively). However, compared with the modified reference method, the LN-HDL correlated better than the BM-HDL in hypertriglyceridemic samples (r = 0.97, slope = 1.0 and r = 0.91, slope = 0.9, respectively). The 1998 National Cholesterol Education Program guidelines for accuracy (bias < +/-5%) were met by LN-HDL in both normotriglyceridemic and hypertriglyceridemic samples (bias = 1.3% and 3.3%, respectively); however, BM-HDL failed to meet the National Cholesterol Education Program accuracy criteria in both triglyceride subgroups (bias = 8.2% and 11.3%, respectively). In addition, the total error for LN-HDL in both normotriglyceridemia (6.6%) and hypertriglyceridemia (8.6%) was well within the National Cholesterol Education Program guidelines for total error (< or =13%); BM-HDL exhibited a higher total error than LN-HDL in normotriglyceridemia (11.9%) and failed to meet the National Cholesterol Education Program guidelines in hypertriglyceridemia (15.0%). CONCLUSION: Although both homogeneous methods are precise, the LN-HDL assay is superior in accuracy to the BM-HDL assay when compared with the modified reference method. 相似文献
998.
A model for the bed-to-wall heat transfer under low temperature condition in a circulating fluidized bed (CFB) was developed based upon a simplified cluster renewal concept. The age of clusters in contact with the wall at different locations along the height of the CFB was estimated as the weighted average age considering their formation and disintegration. One set of experimental data on heat transfer in a 4.5-metre high, 0.15-metre diameter CFB under low temperature condition (67–77°C) was chosen for comparison with prediction of local heat transfer coefficient. The experimental observation and prediction have shown a qualitative agreement. 相似文献
999.
Payeur P. Hoang Le-Huy Gosselin C.M. 《Industrial Electronics, IEEE Transactions on》1995,42(2):147-158
A method to predict the trajectory of moving objects in a robotic environment in real-time is proposed and evaluated. The position, velocity, and acceleration of the object are estimated by several neural networks using the six most recent measurements of the object coordinates as inputs. The architecture of the neural nets and the training algorithm are presented and discussed. Simulation results obtained for both 2D and 3D cases are presented to illustrate the performance of the prediction algorithm. Real-time implementation of the neural networks is considered. Finally, the potential of the proposed trajectory prediction method in various applications is discussed 相似文献
1000.
Jei-Hwan Yoo Chang-Hyun Kim Kyu-Chan Lee Kye-Hyun Kyung Seung-Moon Yoo Jung-Hwa Lee Moon-Hae Son Jin-Man Han Bok-Moon Kang Ejaz Haq Sang-Bo Lee Jai-Hoon Sim Joung-Ho Kim Byung-Sik Moon Keum-Yong Kim Jae-Gwan Park Kyu-Phil Lee Kang-Yoon Lee Ki-Nam Kim Soo-In Cho Jong-Woo Park Hyung-Kyu Lim 《Solid-State Circuits, IEEE Journal of》1996,31(11):1635-1644
This paper describes a 32-bank 1 Gb DRAM achieving 1 Gbyte/s (500 Mb/s/DQ pin) data bandwidth and the access time from RAS of 31 ns at V cc=2.0 V and 25°C. The chip employs (1) a merged multibank architecture to minimize die area; (2) an extended small swing read operation and a single I/O line driving write scheme to reduce power consumption; (3) a self-strobing I/O schemes to achieve high bandwidth with low power dissipation; and (4) a block redundancy scheme with increased flexibility. The nonstitched chip with an area of 652 mm 2 has been fabricated using 0.16 μm four-poly, four-metal CMOS process technology 相似文献