An Economical Magnetocardiogram System Based on High-To SQUIDs

An economical magnetocardiogram （MCG） system is built in our laboratory. It mainly consists of a MCG data acquisition stage equipped with two high-To superconducting quantum interference device （SQUID） magnetometers, a data processing stage with digital filtering and a one-layer μ-metal magnetically shielded room in conjunction with a high-Tc SQUID based active compensation. Experimental results show that a noise level of pico-tesla in MCG profiles, which is necessary for clinical applications, may be achieved with the system. Moreover, stable and convenient operations of the system are demonstrated with simulating MCG measurements.     

Synthesis of ZnAl2O4/α-Al2O3 complex substrates and growth of GaN films

With the solid phase reaction between pulsed-laser-deposited (PLD) ZnOfilm and α-Al2O3 substrate, ZnAl2O4/α-Al2O3 complex substrates were synthesized. X-ray diffraction (XRD) spectra show that as the reaction proceeds, ZnAl2O4 changes from the initial (111)-oriented single crystal to poly-crystal, and then to inadequate (111) orientation. Corresponding scanning electron microscope (SEM)images indicate that the surface morphology of ZnAl2O4 transforms from uniform islands to stick structures, and then to bulgy-line structures. In addition, XRDspectra present that ZnAl2O4 prepared at low temperature is unstable at the environment of higher temperature. On the as-obtained ZnAl2O4/α-Al2O3 substrates, GaN films were grown without any nitride buffer using light-radiation heating low-pressure MOCVD (LRH-LP-MOCVD). XRD spectra indicate that GaN film on this kind of complex substrate changes from c-axis single crystal to poly-crystal as ZnAl2O4 layer is thickened. For the single crystal GaN, its full width at half maximum (FWHM) of X-ray rocking curve is 0.4°. Results indicate that islands on thin ZnAl2O4 layer can promote nucleation at initial stage of GaN growth, which leadsto the (0001)-oriented GaN film.     

捕虫神刀手——螳螂

1.螳螂是螳螂目昆虫的通称,又称刀螂。它分布广泛,全世界有2000多种,我国已知的有100多种,常见的如大刀螂、斑小螳螂等。螳螂神态温柔,骨子里却是不折不扣的“虫国杀手”。     

浅论《数学实验》课程的基础课地位

本论述了大学本科的《教学实验》课的基础课地位以及它的教学指导思想，阐述了它与相关的其它课程的关系及课程本身的一些特点。     

对一种屏蔽常用输入消息病毒的剖析

通过剖析一种屏蔽常用输入消息病毒的制作过程,来学习windows对消息响应机制的编程方法,了解运用Hook技术对鼠标和键盘消息进行拦截的方法,熟悉动态连接库的制作,以及了解对注册表的使用技术。     

燃料电池汽车用氢气品质可靠性研究项目的系统分析

本文以燃料电池汽车用氢气品质可靠性研究项目为案例，从系统环境、目标、资源、管理角度对该项目进行了解剖分析，从中认识项目成功的重要因素。     

饱和烷烃第二维里系数与分子的拓扑

本文采用图论方法对饱和烷烃第二维里系数B与分子结构的关系进行了探讨,结果发现烷烃第二维里系数与Wiener指数具有较好的相关性,并建立了它们之间的一个定量关系。对C_2～C_8共39个饱和烷烃B的计算表明,计算值与文献值的一致性是令人满意的。本文不仅拓展了Wiener指数的应用领域,而且也有助于深入理解第二维里系数的物理意义。     

南屯矿63_上10面综采放顶煤开采覆岩移动变形破坏特征研究

本文根据使用新技术──双回路注（放）水系统在６３上１０工作面综采放顶煤开采覆岩破坏的探测结果，结合其它采矿方法的实测结果，应用断裂力学理论，研究了放顶煤开采覆岩移动变形破坏特征，为矿井安全生产提供了依据。     

著名科学家

1、郭守敬 (1231-1316),我国元朝著名科学家,顺德邢台(今属河北)人。他在天文观测、数学运算和水利建设等方面都做出了杰出的贡献。