Java程序设计教材规划探讨

从可持续发展的教育思想出发,分别从知识体系与实践内容组织两方面提出Java程序设计教材参考规划,目的是培养高素质的可持续发展的编程人才.     

从毕业设计谈力学教学问题

针对学生毕业设计论文反映出来的问题,指出了力学教学中存在的一些不足;针对目前教学改革的形式,分析了力学教学面临的新情况,提出了切实可行的方法和措施.     

二次动压巷道支护设计与参数优化

采用正交数值试验和灰色理论中的关联度分析,进行阳泉矿区二次采场巷道的分析与支护参数优化决策.选择13因素3水平的正交试验方案,进行27次试验,分析了不同应力状态和支护参数的巷道稳定性与变形特征.在计算中采用巷道稳定性和变形收敛率等多种评价指标,进行了局部优化;考虑支护成本和施工难易等因素,采用灰色理论,进行最佳方案的关联度分析.该研究已应用于阳泉矿区二次采场巷道支护设计,并取得较满意的支护效果.     

基于参数识别应用Backstepping design控制Lue′s混沌吸引子

混沌控制在最近十几年的研究中已经取得了长足的进展，形成了许多比较成熟而且有效的控制技术和方法，如：OGY控制、线性状态空间反馈等．但对于带有未知参数的系统，前面提到的方法常常无法达到预期的控制．通过构造识别函数识别Lue′s混沌系统的未知参数，然后应用Backstepping design控制Lue′s混沌吸引子，将Lue′s混沌吸引子控制刮一个稳定的周期轨道，通过数据模拟证明了该控制方法的有效性．     

Basic rules for rheologic forging process of semisolid alloy

Semisolid mold forging is a major type of semisolid processing, which is different from neither traditional mold forging nor traditional permanent casting. However, processing defects are often seen in work pieces because of lacking available rules for the process design and control. Some basic rules for the process design and control, simply named the shortest flowing length, pressure filling and the minimum uplifting mold pressure, are advanced in the paper based on amount of researches and experiments. The equations to determine the major process parameters are given out such as the filling pressure, forming pressure and locking mold pressure for the process design and control. The rules and equations are experimentally proved available and applicable by several actual work pieces produced by the semisolid forging process.     

Optimization of butanol production from corn straw hydrolysate by <Emphasis Type="Italic">Clostridium acetobutylicum</Emphasis> using response surface method

Butanol is a new kind of very potential biofuels.Enzymatic hydrolysis of corn stalk was utilized in this study to produce butanol by Clostridium acetobutylicum CICC 8008.Plackett-Burman (P-B) design and Central Composite Design (CCD) were adopted to screen crucial factors during fermentation as well as the optimization of experimental conditions.The result demonstrated that among the seven factors,namely,Yeast extract,(NH 4) 2 SO 4,KH 2 PO 4,MgSO 4,FeSO 4,CuSO 4 and CaCO 3,only CaCO 3 was selected as the most critical factor.The optimization experiment results for CaCO 3 usage,temperature and reaction time by CCD were determined to be 5.04 g/L,35°C and 70 h,respectively.A corresponding mathematical model was established to predict the fermentation experiment and maximum butanol yield of 6.57 g/L was acquired.The result of verification experiment under the optimum conditions showed that 6.20 g/L was the maximum butanol yield.This demonstrated that statistical method was a powerful tool for the optimization of butanol production from enzymatic hydrolysis of corn stalk.     

基于PRO/E的连续采煤机滚筒的参数化设计

依据连续采煤机截割滚筒整体结构和装配关系,利用Pro/Engineer强大的参数化造型技术及其提供的二次开发模块Pro/Toolkit,建立了连续采煤机截割滚筒参数化设计系统.该设计可避免产品设计过程中不必要的重复性工作,提高了设计的质量、水平以及工作效率,为深入开展连续采煤机截割滚筒的仿真研究奠定了基础.     

Abrasive resistance of metastable V–Cr–Mn–Ni spheroidal carbide cast irons using the factorial design method

Full factorial design was used to evaluate the two-body abrasive resistance of 3wt%C–4wt%Mn–1.5wt%Ni spheroidal carbide cast irons with varying vanadium (5.0wt%–10.0wt%) and chromium (up to 9.0wt%) contents. The alloys were quenched at 920℃. The regression equation of wear rate as a function of V and Cr contents was proposed. This regression equation shows that the wear rate decreases with increasing V content because of the growth of spheroidal VC carbide amount. Cr influences the overall response in a complex manner both by reducing the wear rate owing to eutectic carbides (M₇C₃) and by increasing the wear rate though stabilizing austenite to deformation-induced martensite transformation. This transformation is recognized as an important factor in increasing the abrasive response of the alloys. By analyzing the regression equation, the optimal content ranges are found to be 7.5wt%–10.0wt% for V and 2.5wt%–4.5wt% for Cr, which corresponds to the alloys containing 9vol%–15vol% spheroidal VC carbides, 8vol%–16vol% M₇C₃, and a metastable austenite/martensite matrix. The wear resistance is 1.9–2.3 times that of the traditional 12wt% V–13wt% Mn spheroidal carbide cast iron.     

自建 Tg. C57-ras V1. 0 小鼠模型与日本 Tg. rasH2小鼠遗传学及其杂交 1 代生物学特性比较

摘要:目的 比较自主建立的 Tg. C57-ras 小鼠与日本 Tg. rasH2 小鼠模型的遗传学及 Tg. C57-ras 转基因小鼠与BALB / c 小鼠的杂交 1 代小鼠(简称 CB6F1-NIFDC) 与日本 Tg. rasH2 转基因小鼠模型杂交 1 代小鼠(简称 CB6F1-CIEA)的生物学特性,为国内药物安全评价机构提供致癌性模型的多元化选择。 方法 对两种模型的遗传学及生物学特性进行比较,包括模型构建方法、转录水平、蛋白水平、生长曲线、血液生理数据等。 结果 遗传学特性:两种模型均采用转基因方法构建,转入 c-Ha-ras 基因序列无实质差异,拷贝数仅相差一个;两种模型的不同脏器在mRNA 水平基因表达具有相似性;日本模型肺组织的蛋白水平稍高于自主建立模型,但无统计学差异。 生物学特性:根据文献分析两种模型杂交 1 代的生长曲线有差异,但在致癌实验周期内两模型体质量差别不大;血液生理指标有部分差异。 结论 通过遗传学及生物学特性比较,自建模型可作为临床前药物致癌性评价的候选模型。