集料棱角性对级配的影响

结合沥青混合料击实困难的工程实际问题,通过室内试验比较了辉绿岩和花岗岩碎石性质的差异,通过堆积密度试验分析了细集料矿料棱角性对合成矿料级配干涉状态、性质的影响。     

桥梁检测中的动静载试验研究

动静载试验是一种桥梁实际状况检验的重要方法,可科学准确地评定桥梁结构的承载能力。结合某特大桥检测的案例,从试验对象、动静载试验参数等方面,深入对动静载试验进行分析,介绍动静载试验内容,利用桥梁专业软件midas Civil建立有限元模型,进行静力分析,通过实际试验测量值和理论值做比较,分析桥梁的承载力和对桥梁综合评定。     

Logistic Regression Based Arc Fault Detection in Photovoltaic Systems Under Different Conditions

This paper investigates direct current(DC) arc fault detection in photovoltaic system. In order to avoid the risk of fire ignition caused by the arc fault in the photovoltaic power supply, it is urgent to detect the DC arc fault in the photovoltaic system. Once an arc fault is detected, the power supply should be cut off immediately. A lot of field experiments are carried out to obtain the data of arc fault current of the photovoltaic system under different current conditions. Cable length, arc gap, and the effects of different sensors are tested.These three conditions are the most significant features of this paper. Four characteristic variables from both the time domain and the frequency domain are extracted to identify the arc fault. Then the logistic regression method in the field of artificial intelligence and machine learning is originally used to analyze the experimental results of arc fault in the photovoltaic system. The function between the probability of the arc fault and the change of the characteristic variables is obtained. After validating 80 groups of experimental data under different conditions,the accuracy rate of the arc fault detection by this algorithm is proved to reach 100%.     

局部进展期中低位直肠癌单纯新辅助化疗与新辅助放化疗的疗效比较

目的 探讨局部进展期中低位直肠癌患者接受以氟尿嘧啶类药物为基础的单纯新辅助化疗(mFOLFOX6/CapeOX)与新辅助放化疗的疗效和远期预后差异,比较两组的治疗效果。方法 回顾性分析2019年1月至2021年12月在西安交通大学第一附属医院接受单纯新辅助化疗和新辅助放化疗的共118例局部进展期中低位直肠癌患者的性别、年龄、身体质量指数(BMI)等临床病理资料。分别采用t检验、Mann Whitney检验、卡方检验或Fisher精确检验比较接受单纯新辅助化疗与新辅助放化疗两组患者之间在短期疗效、淋巴结检出数目和远期预后之间的差异。采用Kaplan-Meier法计算生存率并绘制生存曲线。结果 在疗效方面,新辅助放化疗组患者获得更好的肿瘤退缩(Z=―2.05,P=0.04)和实体肿瘤疗效(Z=―2.42,P=0.015),但两组在降低临床分期方面的差异无统计学意义。新辅助放化疗组的淋巴结检出数明显降低(单纯新辅助化疗组vs.新辅助放化疗组,13.19±3.83 vs. 9.55±4.00,t=5.02,P<0.001),但两组在淋巴结阳性数和淋巴结阳性比之间的差异无统计学意义。在远期...