大学预科化学课程教学探讨

本针对大学预科班学生的特点，从大学预科化学课程的基本目的和要求出发，讨论大学预科化学课程教学中应注意的问题．     

关于生物高分子元素活性中心分布规律的第四统计力学理论标度的研究(Ⅱ)——心血管中药的生命动力元素按原子序数分布的规律与群子参数间关系

首次采用第四统计力学群子理论对心血管中药中生命动力元素的分布规律进行了系统的研究 ,结果表明心血管中药的生命动力元素按原子序数分布呈现出如下四种分布规律，即不同中药有轻度元素分布、较轻度元素分布、较重度元素分布和重度元素分布 ,并且每一种分布根据R₂ /R₁的值又可分为两个分支。本文还首次阐述了群子统计参数R₁、R₂ 、R₂ /R₁及R₁·R₂ 在中药生命动力元素分布中的物理内涵。这些研究为进一步定量地研究中药的性味和药效之间的关系提供了必要的依据。     

Land vehicle positioning using GPS and dead reckoning

To ensure reliable land vehicle positioning, the Global Positioning System (GPS) is one of the best techniques commonly used in present-day positioning systems. However, GPS signals are not available if line of sight with the satellites is lost. In this respect, the addition of the Dead Reckoning (DR) method to complement the GPS unit would enhance the reliability of land vehicle positioning system. For implementing the DR method, the magnetic sensor and accelerometer are used for obtaining heading and velocity or distance information. Calibration of two sensors' dynamic model and DR algorithm are also introduced in this paper. The test result utilizing the GPS and DR methods is analyzed in this paper. It utilize spositioning information from GPS receiver when GPSsignal is available, otherwise DR is started to compensate GPS outage with the GPS output as the original point. The results showed that the error in east and north produced by the DR algorithm for a short time interval can be limitedwithin an acceptable range.     

In-vehicle GPS/DR navigation system development and test results in Singapore

This paper introduces the in-car navigation system prototype development and test results under the context of Singapore. In the system, integrated GPS/DR is used for continuous vehicle positioning. A digital road network map database is built for the whole Singapore. The database is designed to support map matching, route determination, and route guidance functions. The prototype system demonstrates GPS positioning of the vehicle in real-time, tracking the vehicle onto a digital map with fix updates every one or two seconds.With the map matched vehicle location on the map, voice and/or text guidance is provide to the driver. The vehicle position can also be transferred to control centre through communication data link for the purpose of fleet management.     

A carbon- and oxygen-isotope record of recent environ- mental change from Qinghai Lake, NE Tibetan Plateau

An understanding of natural climatic variability is essential for evaluating anthropogenic impacts on recent and future climate[1—3]. Due to the lack of lengthy instrumental records, such an understanding must be gained from natural archives of climate change. Palaeolimnological indicators of past lake levels may provide a sensitive record of changes in effective precipitation in closed basins. This approach is particularly relevant on the Tibetan Plateau, where instrumental records are very…     

泥石流危险性动量分区方法与应用

运用泥石流运动数值模拟和GIS相结合的方法模拟泥石流出山口后的运动全过程, 求得泥石流流速和流深分布, 确定泥石流过程中泛滥范围内任一点的最大动量, 建立了泥石流危险性动量分区模型Z = Khv. 根据考察和实验资料对委内瑞拉首都加拉加斯的Chacaito沟百年一遇泥石流运动过程进行了模拟, 利用动量分区方法划分出泥石流危险区.     

连续系统振动特征值摄动问题的统一解法

将离散系统振动分析中的通用的矩阵摄动法推广到连续系统。采用弹性结构理论算子，对连续系统的振动特征值摄动问题进行统一描述。根据特征函数子空间缩聚法和正交分解的基本原理，推导了统一的摄动公式。该方法能同时有效地处理孤立、重及密集特征值3种不同情况。以薄膜振动和变厚度薄板弯曲振动的特征值问题为例，阐明了方法的实际应用。     

两种线分维及线分维与面分维间关系

分别用二次电子扫描线法和垂直抛面法对不同回火制度的３０ＳｉＭｎＣｒＮｉＭｏＢ钢的冲击断口表面的分维数进行了数量。通过研究发现：平行裂纹扩展方向的分维更适合于描述材料韧性的变化。