葛根素对血管性痴呆大鼠海马中低氧诱导因子-1α和红细胞生成素表达的影响

目的观察葛根素对血管性痴呆(VD)大鼠海马中低氧诱导因子-1α和红细胞生成素表达的影响并探讨其可能机制。方法采用大鼠双侧颈总动脉永久性阻断法(2-VO)建立VD的动物模型,SD大鼠随机分为假手术组、2-VO组和葛根素组,每组又分为1周、3周、6周、2月(n=6)四个时间点;应用Y型水迷宫实验测定动物的学习记忆能力,采用免疫组化法检测大鼠海马CA1区HIF-1α和EPO蛋白的表达。结果①2-VO组和葛根素组大鼠游全程时间和误入盲端次数均显著增加,但各时间点葛根素组大鼠的学习记忆成绩均显著优于2-VO组。②各时间点,2-VO组和葛根素组大鼠海马CA1区HIF-1α和EPO的表达均较假手术组明显增高,但葛根素组两种蛋白的表达均较2-VO组明显降低。结论葛根素可提高缺血脑组织细胞内氧浓度,改善学习记忆功能,对VD具有确切的保护作用。     

低速运动条件下的磁传感器定位方法

为了提高磁传感器定位技术的实用性,将时分复用技术应用于磁传感器的定位中,有效解决了运动磁传感器的定位问题,提出了基于磁场模值的标量定位方法,解决了背景磁异常对磁传感器定位精度的影响,并理论分析和实验验证了所提方法的可行性,实验结果表明,定位距离在3 m内时误差在厘米级别,并有望随实验条件的改善而提高,且该方法定位的灵敏度非常高。     

AgNi15触头电性能试验研究

本文采用试验的方法,研究了模压烧结和模压烧结挤压两种不同工艺生产的Ag Ni15触头材料在抗熔焊、抗电损和分断能力方面所表现出来的差异。通过在特定样机上的试验,证实了不同的生产工艺对触头材料的电性能有一定的影响,并从理论上分析了造成影响的原因。     

Simulation of hydrodynamic performance of drag and double reverse propeller podded propulsors

The unsteady performance of drag and double reverse propeller podded propulsors in open water was numerically simulated using a computational fluid dynamics (CFD) method. A moving mesh method was used to more realistically simulate propulsor working conditions, and the thrust, torque, and lateral force coefficients of both propulsors were compared and analyzed. Forces acting on different parts of the propulsors along with the flow field distribution of steady and unsteady results at different advance coefficients were compared. Moreover, the change of the lateral force and the difference between the abovementioned two methods were mainly analyzed. It was shown that the thrust and torque results of both methods were similar, with the lateral force results having the highest deviation     

Comparing prediction methods for maritime accidents

ABSTRACT

The purpose of maritime accident prediction is to reasonably forecast an accident occurring in the future. In determining the level of maritime traffic management safety, it is important to analyze development trends of existing traffic conditions. Common prediction methods for maritime accidents include regression analysis, grey system models (GM) and exponential smoothing. In this study, a brief introduction is provided that discusses the aforementioned prediction models, including the associated methods and characteristics of each analysis, which form the basis for an attempt to apply a residual error correction model designed to optimize the grey system model. Based on the results, in which the model is verified using two different types of maritime accident data (linear smooth type and random-fluctuation type, respectively), the prediction accuracy and the applicability were validated. A discussion is then presented on how to apply the Markov model as a way to optimize the grey system model. This method, which proved to be correct in terms of prediction accuracy and applicability, is explored through empirical analysis. Although the accuracy of the residual error correction model is usually higher than the accuracy of the original GM (1,1), the effect of the Markov correction model is not always superior to the original GM (1,1). In addition, the accuracy of the former model depends on the characteristics of the original data, the status partition and the determination method for the status transition matrix.     

重装备牵引车集装箱运输应用研究

为促进我军汽车部队集装箱与重装备的运输能力的发展,提出将重装备牵引车应用到集装箱运输中。在分析重装备运输车应用到集装箱运输中的必要性的基础上,对照外包物流公司运输,介绍了其成本—效益分析方法和量化方法,并以进藏冻肉冷藏集装箱铁公联运试点为例、对成本、效益进行了估算,验证了该运输方式的经济性和可行性。     

驾驶特性对交通安全的影响分析

本文基于对人类行为模式的研究,并以此作为参考,将驾驶员的信息处理过程划分为感知、判断、操纵三个阶段。分析感知特性、判断特性、操作特性对交通安全的影响。     

山区高速公路长大下坡路段避险车道 设置位置研究

本文在分析了避险车道现状问题和安全影响因素的基础上,通过货车在雅西高速公路上的制动鼓温度变化实车试验,建立货车在山区高速公路长大下坡路段行驶时的制动鼓温度变化模型,然后在试验的基础上建立一套适用于山区高速公路的避险车道设置位置理论计算方法,以此来确定避险车道的设置位置和设置间距.     

汽车机械变速器润滑油温升测试系统开发

为测试微型车机械变速器最高工作油温,设计了共直流母线能量回馈电封闭式变速器温升检测试验台。介绍了该试验台的结构、测试原理、通信方式、数据采集过程以及上、下位机的编程软件。温升检测结果表明,在高转速、无外界强制散热的情况下,该试验台可准确测试变速器工作油温,检测效率高,且负载发电机在温升试验空转时可以实现发电功能。     

里程延长型电动汽车实现方法探究

为了延长电动汽车的续驶里程,在动力系统中加入了动力辅助单元(APU)。介绍了不同的APU组成和相应的控制策略、延长里程的方式和相应的实验结果并得出结论,证明该方法的有效性与实用性。