微光图象光子计数器象管光子增益测试研究

本文介绍了微光图象光子计数器象管的主要构成及其与常规二代微光象增强器的区别.在论述单通道光子计数技术原理的基础上,提出了微光图象光子计数器象管的主要参数-光子增益的测试原理和方法,建立了测试系统.对微光图象光子计数器象管的光子增益进行了实测,并将测试结果与常规二代微光象增强器的亮度增益进行了比较,给出了光子增益的估算公式.     

单模光纤共焦扫描显微系统研究

本文探讨一种使用单模光纤同时作为点源与点探测器的激光共焦扫描显微系统。该系统具有与传统共焦扫描相同的功能，但更容易操作，结构更简单，系统更稳定，文中给出系统的原理设计方案，并对其光学特性进行分析。     

YBa_2Cu_3O_y中对Y位与Cu(Ⅰ)位取代导致的空穴浓度变化

本文研究Co对Cu(I)和Ca对Y作取代时,YBa_2Cu_3O,系统中的空穴浓度、晶体结构和超导临界温度随掺杂量的变化关系及其起源。结果表明,上述取代对体系中的Cu-O平面上的空穴浓度P_(sh)都有重要影响,但其作用和方式是不同的。前一种取代主要是通过对空穴的复合和增强对空穴的局域化而使P_(sh)下降:后者则具有明显的退局域化作用,从而使得P_(sh)上升。当两种取代同时进行时,局域化作用不再是影响P_(sh)的因素,P_(sh)的增加来源于体系的总的空穴浓度的增加。还就超导电性与P_(sh)的关系作讨论。     

微波热辐射仪信息检测乳腺癌的研究

微波热辐射仪信息检测乳腺癌的研究李也周，阎瑞民（武汉大学计算中心武汉４３００７２）（广州军区武汉总医院武汉４３００７１）李而周，向勋贤（湖北省肿瘤医院武汉４３００７０）（华中理工大学无线电系武汉４３００７４）关键词微波诊断，乳腺癌，热辐射分类号Ｒ７３...     

灰色多层次综合评判在柳树材性分析中的应用

用灰色关联度与层次分析（ＡＨＰ）法选出了柳树作矿柱和造纸用材不同无性系的优良品种，其结果是：作造纸用材Ｊ９０３＞Ｊ７９９＞Ｊ１７２＞Ｊ３０８＞Ｊ７９５＞Ｊ８０２，作矿柱用材Ｊ９０３＞Ｊ７９９＞Ｊ３０８＞Ｊ１７２＞Ｊ７９５＞Ｊ８０２，为木材工业的发展进一步提供了信息和科学根据。     

一类非自共轭非线性Schro(?)dinger方程组的有限差分法

近年来,在很多物理问题中都遇到了非线性Schrodinger方程。由于它具有孤立子解和类似于KDV方程的许多性质,因此对其解的适定性研究和数值解法也越来越引起人们的重视,这方面的工作可见[1—5]。然而上述工作中所考虑的方程都是自共轭的,但在一维晶体和α-螺旋生物分子所产生的激子中出现了一类非自共轭的非线性Schrodinger方程,[6]研究了这类非线性Schrodinger方程组的适定性。由于在方程组中出现了非自     

Rb谱灯的同位素滤光

用扫描式Fabry-Perot平涉仪测量了经内充缓冲气体的Rb~(85)滤光泡滤光后的Rb~(87)D_1线谱线轮廓,考察了不同的缓冲气体种类和压力、滤光泡长度及Rb~(87)谱灯光强对滤光效果的影响,指出在Rb~(85)滤光泡内充以适当的混合气体,可以增强滤光效果,从而提高光抽运汽泡型Rb频标性能。     

Single-Walled Carbon Nanotubes Acting as Controllable Transport Channels

The motion and equilibrium distribution of water molecules adsorbed inside neutral and negatively charged singlewalled carbon nanotubes (SWNTs) have been studied using molecular dynamics simulations (MDSs) at room temperature based on CHARMM (Chemistry at HARvard Molecular Mechanics) potential parameters. We find that water molecules have a conspicuous electropism phenomenon and regular tubule patterns inside and outside the charged tube wall. The analyses of the motion behaviour of water molecules in the radial and axial directions show that by charging the SWNT, the adsorption efficiency is greatly enhanced, and the electric field produced by the charged SWNTs prevents water molecules from flowing out of the nanotube. However, water molecules can travel through the neutral SWNT in a fluctuating manner. This indicates that by electrically charging and uncharging the SWNTs, one can control the adsorption and transport behaviour of polar molecules in SWNTs for using as a stable storage medium or long transport channels. The transport velocity can be tailored by changing the charge on the SWNTs, which may have a further application as modulatable transport channels.     

Geometrical Structure Effect on Localization Length of Carbon Nanotubes

The localization length and density of states of carbon nanotubes are evaluated within the tight-binding approximation. By comparison with the corresponding results for the square lattice tubes, it is found that the hexagonal structure affects strongly the behaviour of the density of states and localization lengths of carbon nanotubes.