预应力混凝土斜拉桥调索设计新方法

综合分析了当前各主要调索方法的流程及利弊后,指出了分阶段施工的悬臂浇筑预应力混凝土斜拉桥内力状态无法逼近一次合理成桥状态,进而提出预应力混凝土悬臂浇筑斜拉桥可不进行合理成桥状态分析,直接考虑施工阶段进行正装调索设计的新理念。     

辽长铁路膨胀土路堑试验研究

新建辽源至长春铁路是吉林省十一五重点建设项目,沿线分布有膨胀土。膨胀土工程问题是我国铁路建设中遇到的一大技术问题,对铁路建设具有特殊的危害,必须根据其特点,研究合理可行的解决办法。以DK43+200～DK44+150路堑段为研究对象,通过室内侧限压缩试验和膨胀性试验,得出影响土体膨胀能力的主要因素为其初始物理状态和其自身结构性,并在不同深度上分析了土体膨胀能力随初始物理状态和自身结构性的变化规律,最后提出了相应的工程处理措施。     

新冠病毒肺炎疫情下的船员权益保障问题

2019与2020年交替之际,一场突如其来的新冠肺炎疫情却悄然出动,迅速蔓延。疫情引起了党中央的高度重视,国家采取了史无前例的严格防控措施,打响了前所未有的、全国军民人人投身的战"疫"。疫情也引起了国际社会的严重关注.     

锌铝镁镀层钢板化学转化膜耐蚀性能研究

采用扫描电子显微镜(SEM)、能谱分析仪(EDS)研究了锌铝镁镀层钢板合金的化学转化膜形貌和元素组成。以热镀锌钢板和冷轧钢板作为比较对象,通过电化学工作站、中性盐雾试验箱对3种合金的腐蚀行为进行对比研究。结果表明,锌铝镁镀层钢板化学转化膜结晶整体呈现为长条针状,结晶排布致密,平均晶粒尺寸约为4μm,膜重达到了3.1 g/m²。锌铝镁镀层钢板的化学转化膜中Al、Mg元素含量高于热镀锌钢板和冷轧钢板。相比而言,锌铝镁镀层钢板化学转化膜的自腐蚀电位最高,为-0.889 V,腐蚀电流和腐蚀速率均最低,分别为26.94μA和2.338×10^-3μA/cm²。在经中性盐雾腐蚀200 h后,锌铝镁镀层钢板基材腐蚀程度最小,说明锌铝镁镀层钢板的耐蚀性能优于热镀锌钢板和冷轧钢板。     

The effect of information overload on the intention of consumers to adopt electric vehicles

Transportation - To encourage the pro-electric vehicle (EV) behavioral intentions of consumers, EV manufacturers should make a significant commitment to EV-related information and devise strategic...     

Experimental research on dynamic responses characteristics and influence laws of gear transmission-propulsion system under gear excitation北大核心CSCD

［Objective］In order to study the dynamic response characteristics and influence laws of a marine gear transmission-propulsion system, a series of bench tests is carried out.［Methods］First, a biaxial gear transmission-propulsion system test bench including a cross connection gear is built. Experiments to test the acceleration response of the gearbox body and propulsion shaft system are then carried out, and the influence of speed, driving mode, axial static thrust, axial dynamic excitation force from the propeller and other factors on the dynamic response characteristics of the system are compared and analyzed. ［Results］The experimental results show that the transmission law of the vibration acceleration response of the gear transmission-propulsion system is mainly at the meshing frequency and its multipliers, as well as peaks in the low frequency band of 30–80 Hz under certain working conditions. ［Conclusion］This study can provide technical support for the vibration and noise reduction design of gear transmission-propulsion systems. © 2022 Journal of Clinical Hepatology. All rights reserved.