关于HPM和PME结合的研究

目的探讨HPM和PME结合的可行性。方法通过对HPM和PME的比较，以数学学习心理为依据，结合数学史对数学教学的既有研究，从数学学习层面分析数学史对数学教育的作用。结果数学史通过影响认知因素及非认知因素参与并推动数学学习活动，由此影响数学学习活动的全过程。结论与PME相结合，是HPM被数学教育界认可的一个走向。     

注重数学思想方法 培养学生数学素质

根据目前初中数学教学中所存在的问题，本文表明了数学思想方法对培养学生数学意识，提高数学素质的作用。分析了义务制教材中数学思想方法的体现以及掌握数学思想方法与学习数学知识的关系。结合现代心理学认知学派的观点，揭示了数学思想方法对构建数学认知结构的心理学意义，并提出了数学思想方法的基本程式和教学策略．     

A Physical Approach to the Construction of Cognition and to Cognitive Evolution

It is shown that the method of operationaldefinition of theoretical terms applied inphysics may well support constructivist ideasin cognitive sciences when extended toobservational terms. This leads to unexpectedresults for the notion of reality, inductionand for the problem why mathematics is sosuccessful in physics.A theory of cognitive operators is proposedwhich are implemented somewhere in our brainand which transform certain states of oursensory apparatus into what we call perceptionsin the same sense as measurement devicestransform the interaction with the object intomeasurement results. Then, perceivedregularities, as well as the laws of nature wewould derive from them can be seen asinvariants of the cognitive operators concernedand are by this human specific constructsrather than ontologically independent elements.(e.g., the law of energy conservation can bederived from the homogeneity of time and bythis depends on our mental time metricgenerator). So, reality in so far it isrepresented by the laws of nature has no longeran independent ontological status. This isopposed to Campbell's `natural selectionepistemology'. From this it is shown that thereholds an incompleteness theorem for physicallaws similar to Gödels incompletenesstheorem for mathematical axioms, i.e., there isno definitive or object `theory of everything'.This constructivist approaches to cognitionwill allow a coherent and consistent model ofboth cognitive and organic evolution. Whereasthe classical view sees the two evolutionrather dichotomously (for ex.: most scientistssee cognitive evolution converging towards adefinitive world picture, whereas organicevolution obviously has no specific focus (the`pride of creation').     

(Controller Area Network) bus is a kind

utomation. The technical features and operating principal of CAN bus were presented in this paper briefly. At the same time, we used CAN bus to monitor DC power on-line and design the systematic structure. The operating process of the system was also intro     

C3I系统综合电台车EMC分析及模拟论证

通过对C3I系统综合电台车的电磁兼容性(EMC)分析,建立了其电磁兼容性分析的工程模型,并利用计算机软件实现了其电磁兼容性分析的模拟,最后深入分析了计算机模拟的结果,指出在实际运用中只要选择合理的天线间距和频率间距,同车安装和同址配置使用就可以满足电磁兼容性要求,从而对C3I系统综合电台车的装配和使用提出了合理而有效的论证.     

重新认识算法思维方式

通过“数学思想发展的源泉”，“算法思维方式”及２１世纪数学教育改革”等三个方面论述了算法思维方式在数学发展中的作用以及在数学教育中的增减算法思维能力的意义。     

微波晶体检波二极管分段定标方法的研究

提出了微波晶体检波二极管的分段定标方法．该方法利用线性回归法将测量系统中驻波幅度自波节至波腹进行分段定标，得到每段的检波律．在微波参数测量中，CAT(Computer Aided Test)系统根据实际测试幅度查找相对应的检波律，然后进行相应的参数计算，从而有效地减小了在微波测量中由于晶体检波器而引起的误差，提高了测量精度．     

学生认知能力的评估

在分析学生各种能力的基础上，建立一个基于知识结构的学生认知状态的评估方法。该方法包括领域概念模型、学生的认知能力和部分能力的具体描述以及认知能力的评估方法（包括测试试题和评估）。该方法的特别是从知识结构的角度定性描述学生的认知能力。     

数字下变频器HSP50214B在软件无线电中的应用

介绍了数字下变频器HSP50214B的内部结构及其在软件无线电中的应用．首先阐述了HSP50214B模块具有的数字混频、滤波、自动增益控制等功能，通过解调AM信号的一个实例，设计了一个DSP与下变频器的电路，并给出了下变频器部分控制字，展示了下变频器在软件无线电中强大的功能和良好的可编程性。     

Radio wave propagation effects produced by chemical releases in the ionosphere

As an effective means to actively modify the ionosphere,chemical release can produce artificial ionospheric holes as a consequence of ionization depletion,which can greatly impact on radio wave propagation.In this paper,on the basis of the pre-study results on ionospheric disturbances produced by some representative chemical releases,the radio waves propagation effects of ionospheric holes that are produced by two different release species,water(H2O) and sulfur hexafluoride(SF6),had been investigated and simulated by the three-dimensional(3-D) numerical ray tracing.The results show that ① the appearance of various artificial ionospheric holes can lead to certain decrease of critical frequency in the ionosphere,and ② when the wave frequency exceeds the critical frequency,the rays should be multiple reflections or penetrate through the ionospheric hole and focus afterwards with the focus altitude elevated for higher frequencies.This work may provide the necessary theoretical support for chemical release experiments and the evaluation of radio wave propagation effects.