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41.
42.
Hou Xiaoying Xu Yunbo Wu Di State Key Laboratory of Rolling Automation Northeastern University Shenyang China 《稀有金属材料与工程》2011,(Z3)
The effects of final air cooling temperature on the microstructure and mechanical properties of hot rolled 0.2C-1.9Mn-0.5Si-0.08P TRIP steel were studied by utilizing OM, SEM, TEM and tensile tests. Experimental results showed that in the multiphase microstructure of the investigated steel when the finish rolling temperature was about 820 ℃ and the final air cooling temperature was in the range of 630-700 ℃, the grain size of most of ferrite was finer (about 4 μm) and which had higher dislocation density, t... 相似文献
43.
The X 37CrMoV5 1 KU hot working steel has been quenched and tempered, overcarburised, nitrided and nitrocarburised. The surface layers constituted after the thermochemical treatments were characterised by means of X‐ray diffraction (XRD) analyses, optical and scanning electron microscope (SEM) observations, micro‐ and macrohardness indentations. The electrochemical behaviour was evaluated in two different aggressive environments: 0.1 M Na2SO4 and 0.1 M NaCl solutions. While the overcarburised and the nitrocarburised samples exhibit a poor electrochemical behaviour, the presence of a nitrided surface layer enhances the corrosion resistance. This is attributable to the protective action of the nitrided layer that hinders the anodic dissolution reaction of the matrix, whereas the presence of complex carbides in the overcarburised or nitrocarburised samples causes the preferential dissolution of the ferritic matrix due to galvanic coupling phenomena. Finally, the poor corrosion resistance exhibited by the nitrocarburised sample can be ascribed to the presence of a large amount of ferrite together with little ε solid solution in the surface layer. 相似文献
44.
热轧带肋钢筋拉伸试验结果的不确定度评定 总被引:1,自引:0,他引:1
凌霄 《理化检验(物理分册)》2011,(11):694-696,716
根据钢筋检验及评定标准,对3件热轧带肋钢筋用直接评定法进行了强度检验结果的不确定度评定,给出了合成及扩展不确定度的评定结果。 相似文献
45.
In this investigation, hot compression tests were performed at 900 °C ? 1100 °C and strain rate of 0.001 ? 0.1 s?1 to study hot deformation behavior and flow stress model of 4130 steel. Based on the classical stress–dislocation relations and the kinematics of the dynamic recrystallization, the flow stress constitutive equations of the work hardening‐dynamical recovery period and dynamical recrystallization period were established for 4130 steel, respectively. The validity of the model was demonstrated by comparing the experimental data with the numerical results. The agreement of this comparison is quite reasonable. 相似文献
46.
47.
A laboratory evaluation of a novel hot water cabinet for the decontamination of sides of beef 总被引:2,自引:0,他引:2
A hot water cabinet based on an idealized distributor design for the decontamination of sides of beef is described and a laboratory evaluation of this novel cabinet is reported.
Beef sides were inoculated with E. coli and exposed to mean water temperatures at the surface tissue ( Tf ) of 83.5, 74.2, 66.0 and 44.5°C for 10 or 20 s. Mean log10 reductions of bacteria for 10-s exposures were 2.23, 1.40, 0.91 and 0.2. For 20 s, reductions were 2.98, 2.14, 1.17 and 0.1. There was a significant ( P < 0.05) linear relationship between log reductions and T f which varied with exposure time. At a T f of 83.5°C with exposure times greater than 20 s, carcass bloom was judged to be permanently and adversely affected. At shorter times or with lower temperatures this did not occur.
Evaporative heat losses were well correlated with the pressure driving force ( r = 0.89) and gravity driving force ( r = 0.92) for air interchange between the cabinet and its surrounds.
The running cost using the distributor cabinet was one-third of that of an existing spray cabinet when compared at the maximum reduction of log 1.3 (95%) achieved by the spray cabinet. An additional advantage of the distributor cabinet is its constructional simplicity. 相似文献
Beef sides were inoculated with E. coli and exposed to mean water temperatures at the surface tissue ( T
Evaporative heat losses were well correlated with the pressure driving force ( r = 0.89) and gravity driving force ( r = 0.92) for air interchange between the cabinet and its surrounds.
The running cost using the distributor cabinet was one-third of that of an existing spray cabinet when compared at the maximum reduction of log 1.3 (95%) achieved by the spray cabinet. An additional advantage of the distributor cabinet is its constructional simplicity. 相似文献
48.
比较有无AlN插入层AlGaN/GaN HEMTs在直流偏置应力条件下的电流崩塌程度,研究AlN插入层对电流崩塌的影响.从测试结果看,无AlN插入层的AlGaN/GaN HEMTs有更显著的电流崩塌程度,表明AlN插入层对电流崩塌效应有显著的抑制作用.模拟的AlGaN/GaN能带结构表明,AlN插入层能显著提高AlGaN导带底能级,增加异质结的带隙差.带隙差的增加有利于减小电子遂穿几率,加强沟道二维电子气的量子限制,从而抑制电流崩塌效应. 相似文献
49.
文章简述了光电印制电路板中聚合物光波导层的制作应该遵循的原则,介绍了光波导层的主要成型工艺,包括反应离子蚀刻、平版影印、激光烧蚀和加热模压等方法。 相似文献
50.
In the very large scale integration (VLSI) technology, the need for high density and high performance integrated circuit (IC)
chip demands advanced processing techniques that often result in the generation of high energy particles and photons. Frequently,
the radiation damage are introduced by these energetic particles and photons during device processing. The radiation damage
created by x-ray irradiation, which can often occur during metal sputtering process, has been shown to potentially enhance
hot-carrier instability if the neutral traps which act as electron or hole traps in the silicon dioxide is not annealed out.
In this paper, we investigate the effects of annealing using different hydrogen contents and temperatures on the device characteristics
and hot carrier instability of 0.5 μm CMOS devices after 1500 mJ/cm2 synchrotron x-ray irradiation. Three different annealing conditions were employed; 400° C H2, 450° C H2, and 400° C H2 + N2. It is found that for all three different hydrogen anneals the normal characteristics of irradiated CMOS devices can be effectively
recovered. The hot-carrier instability of bothp- andn-channel MOSFETs are significantly enhanced after x-ray irradiation due to the creation of neutral traps and positively charged
oxide traps. After high H2 (100%) concentration anneals at 450° C, the hot-carrier instability in irradiatedn-channel devices is greatly reduced and comparable to the non-irradiated devices. Although the hot-carrier instability inp-channel devices is also significantly reduced after annealing, the threshold voltage shifts are still enhanced as compared
to the devices without exposure to x-ray irradiation during maximum gate current stress. For those non-irradiated, but hydrogen-annealedp-channel devices, the hot-carrier instability was observed to be worse than the non-irradiated device without hydrogen annealing. 相似文献