铁路轨道线形智能分段

轨道实测线形分段是不平顺检测计算的首要步骤。针对当前铁路线形分段主要依据正矢或曲率的现状,提出一种基于轨道姿态角的线形分段方法;即将GNSS/INS组合测量系统提供的轨道姿态角信息和轨道各元线形固有的几何特征结合起来进行分段。对比实测数据分段结果和轨道设计文件,平面和纵断面线形分界点里程识别误差均不大于6 m,证明该线形分段方法行之有效。     

水电机组故障诊断系统中的模糊诊断技术研究

介绍了在水电机组故障诊断系统中采用的模糊诊断技术,构造了故障诊断的模糊关系矩阵.此模糊知识已成功地应用于实际水电厂的故障诊断系统中,在故障诊断系统的使用过程中得到进一步的充实和验证.在整个系统的多年运行中,此诊断方法成功地诊断出如转子不对中、尾水管偏心涡带等机组运行问题,为电厂的维修与管理提供了有价值的依据与参考。应用效果表明,使用模糊诊断方法于水电机组故障诊断中是有效的,模糊关系矩阵也在故障诊断系统的使用过程中得到进一步的充实和验证.     

Global stability of endemic equilibrium point of basic virus infection model with application to HBV infection

In this paper, the authors first show that if R ₀ ≤ 1, the infection free steady state is globally attractive by using approaches different from those given by Min, et al.(2008). Then the authors prove that if R ₀ > 1, the endemic steady state is also globally attractive. Finally, based on a patient’s clinical HBV DNA data of anti-HBV infection with drug lamivudine, the authors establish an ABVIM. The numerical simulations of the ABVIM are good in agreement with the clinical data.     

Multi-period Bank Hedging with Interest Rate Futures

In this paper, a model for multi-period bank hedging with interest rate futures is set up. Formulas for the optimal dynamic multi-period bank and static bank hedge ratio are derived. The described model offers the potential benefits of： （1） although these formulas are developed for the case of direct sheet balance multi-period hedging, the framework used is sufficiently flexible so that these formulas can be applied to bank loan or deposit multi-period hedging situations respectively. （2） Periodic modification and updating of the interest rate futures position, as suggested by interest rates, throughout the bank hedging horizons. （3） This paper examines a situation in which the return of loan, the interest rate of deposit and the equity capital of bank, and interest rate futures prices are cointergrated, Multi-period bank hedging formulas are derived under three-dimensional stochastic volatility model. However, empirical research is required for validating this model.     

Research on X-efficiency Measure of Chinese Ports

Considering the current situation of Chinese ports and from the port company's point of view, this brief figured out the main factors influencing Chinese port X-efficiency and established the X-efficiency measure model with help of stochastic frontier method, which filled the theoretical gap of port X-efficiency research. On that basis, this brief studied the data of 13 typical port-listed-companies such as Shenchiwan A that stood for the five biggest port clusters in China. The result proved some main factors influencing Chinese port X-efficiency such as the internal incentive system of port-listed companies. Finally, suggestions for improving the Chinese ports X-efficiency were proposed, such as reforming the staff incentive system and company ownership system.     

长庆气田中区马五14储层流体识别及天然气富集规律研究

鄂尔多斯盆地长庆气田中区马五14储层分为气层、低产水层、中高产纯水层、气水同层、干层五种产层类型,建立了相对应的测井综合判识标准.剖析了马五14气藏的成藏条件,认为燕山中期的构造运动系天然气运移聚集的转折点,后期天然气由西向东运移而聚集在上倾方向致密遮挡带下的圈闭内.研究了马五14储层气、水分布特征及天然气富集规律.     

广义Hardy-Hilbert积分算子不等式

本文所建立的广义Hardy-Hilbert积分算子不等式,是著名的Hilbert不等式的实质性改进和推广,所求出的该算子的范数统一证明了Hilbert不等式各种参数推广中的最佳常数.     

高中数学教学现状的调查与思考

新课改在教学内容、教学理念、教学方式等方面都有很大变化。然而,面对这么多的新内容、新理念、新模式,教师能否适应呢?教学效果能否保证?通过问卷调查,同时,结合个别访谈、召开小型座谈会和深入课堂听课等方式进行调研发现新课改推进中还存在不少问题:教师、学生普遍反映负担重;新理念难以接受;新模式难以实施。     

非共沸混合工质热泵节能特性的试验研究

本文对非共沸混合工质(以下简称NARB工质)热泵节能特性进行了试验研究,分析了温度、压力和充注浓度对热泵的性能系数、容量控制和热负荷等特性的影响。实验表明:混合工质比纯工质具有明显节能效果,这种效果随着混合工质中低沸点工质浓度的增加而加强,但受实际装置所限,存在着一个最佳浓度和压力选择问题。本文还对三元混合工质进行了实验研究,并与二元工质进行了对比分析。     

船用6160A型柴油机曲轴断裂强度分析和实验

根据线弹性断裂力学和光弹性实验方法,对6160A型柴油机曲轴（球墨铸铁QT60－2）的三维应力状态、断裂力学参数进行了分析和实验研究,以预报带裂纹曲轴安全可靠性和寿命,为船舶检验周期提供新的理论和实验依据．