探究开放式计算机基础实验教学

本文通过探究开放式计算机基础实验教学,从实验内容、实验过程、实验空间及学习方式等方面,采取激发学生的学习兴趣的措施,调动学生学习的主动性和积极性,培养学生自主学习的能力和创新能力,解决目前计算机基础实验教学存在的弊端。     

数字逻辑虚拟实验教学研究

本文阐述了将虚拟现实及网络技术应用到数字逻辑实验教学中的理论过程。并详细介绍了运用Flash、插件等多媒体编程技术建设数字逻辑虚拟实验室的详细过程。同时,对未来计算机实验教学的发展方向进行了讨论。     

基于在线评判系统的程序设计教学

本文介绍了以在线评判系统为平台的程序设计教学模式,这一教学模式将教师与学生、课堂教学与实验教学、课内学习与课外学习融为一体,既减轻了教师低层次重复性工作量,又能吸引学生主动学习、主动实验,从而切实提高学生的程序设计能力。     

计算机本科专业软件实习工厂的构建研究

本文针对目前中国计算机专业本科教育中生产实习受客观因素所限,造成学生实验动手和科技创新能力不足的问题,提出利用软件实习工厂进行生产实习的方法,将生产实习投入到一个实际项目的开发与建设上,真实模拟软件公司的生产过程,并探讨其建设的总体设计思想和结构模型。     

Strength prediction of sheet to tube single sided resistance spot welding

Single-Sided Spot Welding (SSSW) procedure is considered as a feasible method to join hydroformed or closed section parts to others in vehicle productions. A ‘doughnut’ shaped or ring nugget can be formed between the two workpieces during this process. The strengths of conventional button spot welds can be determined by the attributes of weldments and many functions that link weld diameter, sheet thickness and material properties to weld strength have been established. For welds of sheet to tube joining, the strength prediction model is greatly different from that of conventional welds for the completely different nugget form. In this study, computer experiments were conduced using the concept of design of experiments (DOE) and the method of finite element used to simulate the tensile-shear tests. The stress and strain distribution contour clouds during tensile-shear process were analyzed and quantitative relationship models were established to link a weld’s geometric and material properties to its tensile-shear strength. The results can give a simple judgment whether a ring spot weld was good only by its appearance.     

Experimental calculation of mixed-mode notch stress intensity factors for anisotropic materials

This study developed a least-squares method to find the notch stress intensity factors (SIFs) of anisotropic materials using image-correlation experiments without the requirement of smooth procedures. Complex displacement functions are deduced into a least-squares form, and then displacements from the image-correlation experiments are substituted into the least-squares equation to evaluate the notch SIFs for anisotropic materials. Experimental results compared with the H-integral and finite element analyses show that the SIFs evaluated from the current method are acceptably accurate if more than five displacement terms are included. Moreover, the least-squares SIFs are not sensitive to the maximum or minimum radius of the area from which data is included, so experimental data very near the notch tip is not necessary.     

地下水中乙醇汽油溶解组分运移与生物降解的研究

为了解乙醇混合汽油主要溶解组分在地下水中的迁移,开展了含水砂槽多孔介质的投注试验,投注物是含有溴化物、乙醇和汽油的混合溶液。试验结果表明：水动力弥散和混合电子受体条件下的土著微生物降解是乙醇和单环芳香烃(BTEX)自然衰减的主要过程。乙醇迁移没有滞后性(阻滞系数为1.0),在生物作用参与下随迁移距离增加而逐渐消失;但乙醇对生化氧量的高需求延迟了甲苯和乙苯的生物降解。苯与甲苯的阻滞系数为1.18,乙苯和二甲苯的阻滞系数为1.28;苯的晕体延伸最长,持续时间最长。基于守恒示踪剂溴离子的浓度校正,乙醇与BTEX的一级降解速率存在明显的大小顺序,即乙醇>甲苯>乙苯>间、对二甲苯>邻二甲苯／苯,与它们的迁移晕体长度大小顺序(即苯>间、对二甲苯／邻二甲苯>乙苯>甲苯／乙醇)具有相反的对应关系。这表明改善乙醇生物降解条件和加速其生物降解速率,是BTEX污染修复的一个有效策略。     

瓦斯爆炸气体成分实验研究

通过瓦斯爆炸实验,分析了瓦斯爆炸后的各种气体成分;总结了不同体积分数的瓦斯爆炸后CO,CO2,H2气体的体积分数变化规律。研究结果能够为瓦斯爆炸事故调查提供依据,对减少瓦斯爆炸事故中的伤亡具有重要意义。     

不同炮孔密集系数下矿岩爆破能量分布

通过数值试验分析了密集系数m的变化所引起的矿岩爆破能量分布的变化。两孔之间至自由面的矿岩爆破能量分布为振荡形,m值不同,其振荡形状不同,总体趋势是m越大,其振荡形状越低,而且,m越大,两孔之间矿岩不能破碎的岩埂也越大。之外,试验也揭示了两孔之间至自由面的矿岩爆破破碎是由反射波引起的。     

模具表面球冠状微凸体形貌的激光加工

为了减少磨损,延长模具的使用寿命,在模具表面应用激光毛化处理。采用200W灯抽运Nd:YAG激光器,进行系统的激光毛化工艺试验,得出脉冲激光参量对模具表面微观形貌主要几何参量的影响规律,最终获得了预期的几何形貌。并分别测量和分析了毛化模具表面硬度和金相组织状况。结果表明,微凸体表面硬度比基体材料的表面硬度提高了30%~40%,提高了模具表面的耐磨性。