基于WBS-RBS的机场建设工程施工过程风险管理研究

根据郑州新郑国际机场二期建设工程总体施工部署和现场环境,以工程进度控制为主线,以关键线路为控制点,采用WBS-RBS法对本工程的风险因素进行识别,得到关键风险源清单。整理获取风险因素并编制成调研问卷,采用问卷调查法对风险因素进行度量,确定各项风险因素的重要性均值。通过计算关键风险源的发生概率与风险损失,对施工风险进行评估,得出主要风险的等级,制订风险控制方案,保证项目的顺利实施。

PD-1抑制剂联合抗血管生成药物及化疗二线治疗晚期肺腺癌的临床对比分析

目的本研究拟探讨程序性死亡受体1(Programmed cell death 1,PD-1)抑制剂联合抗血管生成药物及化疗二线治疗晚期肺腺癌的临床对比分析。方法回顾性分析河北北方学院附属第一医院2017年1月1日—2020年12月31日期间收治的99例晚期肺腺癌患者临床资料,根据不同治疗方法将患者分为单纯化疗组(n=35)、化疗联合抗血管生成药物组(n=34)和化疗联合抗血管生成药物联合免疫治疗组(n=30)。比较三组患者治疗后的临床疗效及不良反应发生情况。结果三组的疾病控制率(Disease control rate,DCR)分别为48.6%、55.9%和80.0%,差异有统计学意义(P=0.028);客观缓解率(Objective response rate,ORR)分别为11.4%、8.8%和23.3%,差异无统计学意义(P=0.273)。三组中位无进展生存期(Progression-free survival,PFS)分别为2.4个月、4.3个月和6.2个月,差异有统计学意义(P<0.001)。治疗期间三组最常见的不良反应有白细胞减少、恶心呕吐、转氨酶升高、乏力等,大多为1~2级。单因素分析显示临床分期是影响PFS的独立因素。在考虑分组因素情况下,多因素Cox回归分析显示脑转移是PFS的独立影响因素。结论三组对比分析显示二线应用PD-1抑制剂联合抗血管生成药物及化疗治疗晚期肺腺癌的疗效确切且安全性良好。

Intelligent Vehicle Electrical Power Supply System with Central Coordinated Protection

The current research of vehicle electrical power supply system mainly focuses on electric vehicles（EV） and hybrid electric vehicles（HEV）.The vehicle electrical power supply system used in traditional fuel vehicles is rather simple and imperfect;electrical/electronic devices（EEDs） applied in vehicles are usually directly connected with the vehicle＇s battery.With increasing numbers of EEDs being applied in traditional fuel vehicles,vehicle electrical power supply systems should be optimized and improved so that they can work more safely and more effectively.In this paper,a new vehicle electrical power supply system for traditional fuel vehicles,which accounts for all electrical/electronic devices and complex work conditions,is proposed based on a smart electrical/electronic device（SEED） system.Working as an independent intelligent electrical power supply network,the proposed system is isolated from the electrical control module and communication network,and access to the vehicle system is made through a bus interface.This results in a clean controller power supply with no electromagnetic interference.A new practical battery state of charge（So C） estimation method is also proposed to achieve more accurate So C estimation for lead-acid batteries in traditional fuel vehicles so that the intelligent power system can monitor the status of the battery for an over-current state in each power channel.Optimized protection methods are also used to ensure power supply safety.Experiments and tests on a traditional fuel vehicle are performed,and the results reveal that the battery So C is calculated quickly and sufficiently accurately for battery over-discharge protection.Over-current protection is achieved,and the entire vehicle＇s power utilization is optimized.For traditional fuel vehicles,the proposed vehicle electrical power supply system is comprehensive and has a unified system architecture,enhancing system reliability and security.

残余奥氏体对铁路货车轴承性能的影响

通过对比国内外评价轴承热处理组织指标的差别,说明残余奥氏体含量与金相组织级别之间的关系。阐述残余奥氏体的作用、形成机理,分析残余奥氏体对铁路货车轴承接触疲劳寿命、力学性能和尺寸稳定性的影响。提出将轴承残余奥氏体含量控制在10%~20%为宜,检测位置为成品轴承滚动表面下0.2 mm处。

Acoustic performance prediction of Helmholtz resonator with conical neck

There is no accurate analytical approach for the acoustic performance prediction of Helmholtz resonator with conical neck,which has broad band acoustic attenuation performance in the low frequency range.To predict the acoustic performance of the resonator accurately,a general theory model based on the one-dimensional analysis approach with acoustic length corrections is developed.The segmentation method is used to calculate the acoustic parameters for sound propagation in conical tubes.And then,an approximate formula is deduced to give accurate correction lengths for conical tubes with difierent geometries.The deviations of the resonance frequency between the transmission loss results obtained by the general theory with acoustic lengths correction and the results from the finite element method and experiments are less than 2 Hz,which is much better than the results from one-dimensional approach without corrections.The results show that the method of acoustic length correction for the conical neck greatly improved the accuracy of the one-dimensional analysis approach,and it will be quick and accurate to predict the sound attenuation property of Helmholtz resonator with conical neck.

JJC型接触网检修车制造难点及控制措施

西安公司在2016年引进了某公司开发的JJC型接触网检修车,通过对该车进行结构分析,将车架内梁制作、车架变形控制、蒙皮控制、顶棚钢结构焊缝渗漏检测等作为制造难点,通过采用各种工艺措施,保证了该车的制造质量。