基于磁场测量的变电站接地网结构判断实验

通过磁场检测方法,在没有接地网的具体位置和结构的情况下,通过测量地表面磁感应强度的分布,确定接地网结构.该方法把教学和科研相结合,培养了学生的创新能力,提高了学生的综合素质.     

秘鲁M_w≥6.9地震趋势判断与时空对称规律

选取秘鲁地区1970年以来M_w≥6.9的地震数据,根据可公度性理论,提取秘鲁强震的可公度信息,采用蝴蝶结构图、可公度网络结构图和震中迁移方法,探索该地区强震活动的时空对称性,同时对可能触发地震的天文现象与地震灾害的发生进行相关分析,进一步验证趋势判断结果,发现相关规律.研究结果表明:1970年以来秘鲁M_w≥6.9地震具有可公度性,2019年在秘鲁北部(73°W,11°S附近)发生中深源地震的信号较强;太阳活动、地球自转、月球运动与秘鲁地震的发生具有一定相关性,秘鲁M_w≥6.9地震发生在太阳活动峰值年、下降段的占77.78%,发生在太阳活动双周期的占66.67%,发生在地球自转变化率较大年份的占60%,朔月前后是地震频发期(占44.44%),朔月、下弦月前后地震发生次数达83.33%.     

FAILURE MODE AND CONSTITUTIVE MODEL OF PLAIN HIGH-STRENGTH HIGH-PERFORMANCE CONCRETE UNDER BIAXIAL COMPRESSION AFTER EXPOSURE TO HIGH TEMPERATURES

An orthotropic constitutive relationship with temperature parameters for plain highstrength high-performance concrete （HSHPC） under biaxial compression is developed. It is based on the experiments performed for characterizing the strength and deformation behavior at two strength levels of HSHPC at 7 different stress ratios including a=σs ： σ3=0.00：-1,-0.20：-1,-0.30 ： -1,-0.40：-1,-0.50：-1,-0.75：-1,-1.00：-1, after the exposure to normal and high temperatures of 20, 200, 300, 400, 500 and 600℃, and using a large static-dynamic true triaxial machine. The biaxial tests were performed on 100 mm×100 mm×100 mm cubic specimens, and friction-reducing pads were used consisting of three layers of plastic membrane with glycerine in-between for the compressive loading plane. Based on the experimental results, failure modes of HSHPC specimens were described. The principal static compressive strengths, strains at the peak stress and stress-strain curves were measured; and the influence of the temperature and stress ratios on them was also analyzed. The experimental results showed that the uniaxial compressive strength of plain HSHPC after exposure to high temperatures does not decrease dramatically with the increase of temperature. The ratio of the biaxial to its uniaxial compressive strength depends on the stress ratios and brittleness-stiffness of HSHPC after exposure to different temperature levels. Comparison of the stress-strain results obtained from the theoretical model and the experimental data indicates good agreement.     

电势-pH图在判断高锰酸钾反应产物中的应用

针对无机化学实验的性质实验模块中，关于溶液酸碱度对高锰酸钾与亚硫酸钠间氧化还原反应产物的影响，以及反应放置一段时间后化学现象发生变化等问题，利用能斯特方程推导出相关电对的电极电势随pH变化表达式，通过电势-pH图讨论了Mn体系相关物质在水中的热力学稳定性和存在形式，讨论了在不同酸度下KMnO₄作为氧化剂，与Na₂SO₃反应生成不同产物的原因，并从理论上探讨了放置一段时间后，在特定的酸碱性条件下因某种反应物过量等因素而观察到产物继续会转化成MnO₂、Mn(OH)₂等的可能性。     

基于概率判断函数的分类探讨——以玻璃分类为例

分类问题在基因、化学、地质等领域都有着广泛的应用,在数据满足正态分布的前提下,利用一元正态分布函数的概率密度函数比值构造概率判断函数,建立数学模型,在默认阈值为α=0.5的前提下,对未知类型进行判断,并通过不同阈值下的正负谬误做误差估计,确定最优的阈值.以高钾类、铅钡类玻璃的风化、无风化四种数据为研究对象,利用概率判断函数对模型进行验证.结果表明,模型能准确的对待测的高钾类、铅钡类样本进行分类.在误差分析方面,通过改变阈值进行灵敏度分析,对于高钾类、铅钡类无风化问题,当阈值α=0.65时,误差最小.