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圆管拉拔配模两种计算方法的比较和分析 总被引:2,自引:1,他引:1
本文通过理论推导证明了在一定条件下等比递减计算法实质上就是等差递减计算法,两者具有内在联系。实例计算也证明了这一点。本文还对这两种计算法进行了分析比较,认为等差法(KD-KS计算法)优于等比法(如ZBL法),前者可为优化圆管拉拔配模规程创造有利条件。 相似文献
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利用变形系数编制轧制和拉拔变形规程 总被引:3,自引:2,他引:3
介绍了“K计算法”。它是近年来作者发表的KD—KS计算法、KD计算法和KH计算法等研究成果的总结.并对于它们作了理沦上分析和阐明。它适用于编制轧制板带的压下规程和拉拔管捧线的配模规程,可为计算机编制并优化变形规程.特别是轧制板带的压下规程,创造条件和前提。 相似文献
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用厚度减缩系数KH计算法编制有色金属板带材的压下规程。经12例的计算、对比,结果表明:KH计算法是可行的,运算操作简便。 相似文献
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阐述了高梯度磁选设备磁系设计计算传统的方法有线性积分法、回路磁通法、并联磁路法、经验计算法等,指出新型的数值计算法有有限差分法、有限元法和边界单元法。 相似文献
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中小铜管盘拉配模规程两种计算方法比较 总被引:2,自引:1,他引:1
通过两个实例,计算表明K计算法和径差法均是可行的;两者在Di和Si两组数列中,道次最大相对差异为2.52%。但前者计算简便,所需已知数据少,并且具有灵活性,能适应较为复杂多变的实际生产情况。所推荐的K计算法,也适用于编制板带材轧制压下规程。 相似文献
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TC11钛合金相变点的测定与分析 总被引:1,自引:0,他引:1
采用计算法、差示扫描量热法和连续升温金相法3种手段计算和测定了TC11两相钛合金(α+β)/β相变点。计算法由于各元素及杂质元素含量对相变点的影响值是在一个含量范围内的计算值,因此计算的相变点与实测值是接近的;差示扫描量热法由于钛合金和坩埚的化学反应,产生相变滞后现象,导致所测相变温度过高;而连续升温金相法由于淬火温度间隔选择较小,测量的准确性较高,因此更能准确测量TC11钛合金相变温度。通过连续升温金相法,观察不同淬火温度的试样在光学显微镜下的显微组织变化,发现升温过程中初生α相完全消失的温度,从而确定了TC11钛合金的相变点为1035℃。并分析了不同钛合金之间相变点差异的原因。 相似文献
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圆管拉拔工艺流程设计计算方法 总被引:11,自引:5,他引:6
本文推荐的设计计算圆管拉拔工艺流程的KD-KS方法,能方便地对道次减径量和减壁量进行搭配,以利控制成品管的性能。KD-KS方法适用性广,特别适用于由成品管尺寸选择中间管坯尺寸。 相似文献
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Assesses the utility of the Center for Epidemiologic Studies–Depression Scale (CES–D) for identifying symptoms of depression among a sample of Korean immigrants in Canada. Evidence that supports the content, construct, and concurrent validity of a Korean version of this instrument (the CES–D—K) is presented, and the authors recommend that the CES–D—K be used in both cross-cultural and intranational investigations involving Korean populations. It is recommended, however, that the Positive Affect items be deleted when computing CES–D—K scores to avoid overestimating the number of Korean immigrants manifesting high levels of psychological distress. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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熊春华 《中国稀土学报(英文版)》2008,26(2):258-263
The sorption behavior and mechanism of a Macroporous weak acid resin, (D155 resin,) for Gd(Ⅲ) were investigated. The statically saturated sorption capacity is 283 mg/g resin at 298 K in HAc-NaAc medium. The Gd(Ⅲ) adsorbed on macroporous weak acid resin, (D155 resin,) could be reductively eluted with the mixed solution of HCl and NaCl, and the elution percentage was as high as 100%. The resin could be regenerated and reused without remarkable decrease in sorption capacity. The apparent sorption rate constant was k298=1.98×10^5 s^-1. The apparent activation energy was Ea=2.78 kJ/mol. The sorption behavior of D155 resin for Gd(Ⅲ) obeyed the Langmuir isotherm. The thermodynamic sorption parameters were △H=33.0 kJ/mol,△S=192 J/mol/K, and △G298=-24.3 kJ/mol. The sorption mechanism of D155 resin for Gd(Ⅲ) was examined by using chemical method and IR spectrometry. The coordination compound was formed between oxygen atoms in the functional group of D155 resin and Gd (Ⅲ). 相似文献
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用KD KS 方法设计圆管拉拔配模时经验参数ΔD 和ΔS 的值 ,已能将经验和理论结合起来进行选取 ;并对计算结果“不到位” ,提出了 4种修正方法。ΔD 对ΔD .max 和ΔS 对ΔS .max的比值是ΔD 和ΔS 取值是否合理的判据。ΔD 值和ΔS 值的选取 ,除了要使计算结果“到位” ,还应该考虑圆管的材质和工艺条件及其要求 相似文献
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为提高某石灰岩地下矿山房柱法开采安全性及矿石回收率,结合材料力学、结构力学及K.B鲁别涅依他公式的计算结果,运用Matlab软件对隔离矿柱厚度及矿房跨度进行数据拟合。结果表明,隔离矿柱安全厚度随矿房跨度的增加而非线性地增加。随后,运用ANSYS及FLAC3D软件进行三维数值模拟及优化,结果表明,当下分层矿房跨度为15 m,间柱宽度为13 m时,最佳隔离矿柱厚度为12 m。 相似文献
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Ching-Chuan Huang Cheng-Chen Tsai Yu-Hong Chen 《Canadian Metallurgical Quarterly》2002,128(10):836-848
This paper describes an extension of a new three-dimensional (3D) stability analysis method, including formulation, comparative studies, and examples of new application. The new method uses “two-directional force and moment equilibrium” in the stability analysis of 3D potential failure mass with arbitrary shapes. The use of this new method has resulted in a novel situation wherein the direction of the resultant shear force (or direction of sliding) generated on the potential failure surface can now be calculated instead of the guesswork assumptions that were formerly made. It is also demonstrated that this new method eliminates the labor-intensive work for establishing local coordinate systems performed in conventional 3D analysis. Consequently, this new method facilitates a computer-aided 3D search for the critical failure surfaces in slope areas. 相似文献
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核一级部件的断裂韧度要求反映在ASME和RCC-M规范中,即KIR-(T-RTNDT)基准曲线。KIP包括KIa,KId和KIc^J。KIc^J的测试国内外已有标准方法,而KIa的测试只有美国公布了正工标准,KId的测试国内外没有标准方法可循。因此,为研究核电材料断裂韧度,首先建立了相应的测试方法,在此基础上试验了国产核一级容器钢508-3的动、静态断裂韧度KIa,KId,KIc,获得了不同温度下的数据,并与ASME和RCC-M规范中的基准曲线作了比较。结果表明,国产508-3钢的动、静态断裂韧度能满足核一级部件的要求。 相似文献