Co3O4纳米花的合成及其磁性

通过水热和热处理的方法，制备了产物Co3O4纳米花. 用X射线粉末衍射、场发射扫锚电镜、透射电镜和红外光谱等手段对产物进行了表征. 结果表明，产物纳米花是由大量的Co3O4纳米须组成，纳 米须的直径为20?40 nm，长度为100?500 nm，具有纳米孔结构，比表面积约为34.61 m2/g. 磁性测量表明，在零场冷却条件下，产物主要表现为反铁磁性；在加场冷却条件下，闭锁温度约为34K时，产物主要表现为铁磁性．     

利用密度泛函理论研究BnNi(n≤5)小团簇的结构和磁性

基于第一性原理，用密度泛函理论中的广义梯度近似方法，获得了B_nNi(n≤5)小团簇在不同自旋多重度下的几何构型，确定了最低能量结构，并计算了相应的频率、平均结合能和磁性. 结果表明：B_nNi(n≤5)小团簇最低能量结构的自旋多重度分别为2，1，2，1，2；Ni掺入B团簇后增大了其结合能；Ni原子磁矩和团簇总磁矩随团簇尺寸增大而呈现振荡趋势. 关键词： nNi小团簇')" href="#">B_nNi小团簇 自旋多重度 磁性     

Transport Properties of Binary Clusters

We present first-principles studies on the transport properties of small sificon and aluminium clusters： Al2, Si2, Al4 and AlSi sandwiched between two Al （100） electrodes. The variation of the equilibrium conductance as a function of contact distance for these two-probe systems is probed. Our results show that the transport properties are dependent on both the specific nanostructure and the separation distance between the central molecule and the electrodes. For equilibrium transport properties, the clusters with the similar structure show similar transmission spectra at large distances, the small difference can be explained by the electron filling. For current-voltage characteristics, all the clusters show the metallic behaviour at lower bias, however very different non-linear behaviour can be observed at higher bias. For AlSi and Al2, when the distance between the central cluster and the electrodes is 3.5 A, large negative differential resistance （NDR） can be found in the bias range 0.8V～1.4V.     

高功率DPSL声光调Q脉宽压窄的影响因素研究

利用调Q速率方程,从工作物质的增益和谐振腔的损耗之间的内在关系出发,论述了谐振腔内多个可变参数对激光器输出脉冲宽度的影响。用实验给予了验证。在实验中,采用高效的光耦合泵浦腔,对35个20W连续激光二极管阵列侧面泵浦的声光调Q Nd∶YAG固体激光器进行了研究,激光工作物质的尺寸为Φ4mm×115mm,使用熔石英声光Q开关,在泵浦电流I=22.2A时,获得了重复频率10kHz,脉冲宽度45.8ns,平均功率112W的1064nm调Q激光脉冲输出。光-光转换效率为21.3%,电-光转换效率为8.5%。     

基于文丘里管和涡轮流量计的液液两相流测量

本文研究了运用单相流量计组合进行液液两相流参数测量的方法.该方法首先通过静态混合器将液液两相流混合成为均相流,然后利用文丘里管获得两相流差压,利用涡轮流量计获得两相流总体积流量,最后通过液液两相流测量模型获得液液两相流总体积流量、总质量流量、混合密度以及分相流量.初步实验结果表明该方法是可行的,在总体积流量1～6 m3/h,油含率15%～85%的范围内,可有效地测量液液两相流的总体积流量、总质量流量和两相流混合密度,测量相对误差在5%以内,但液液两相流分相流量测量相对误差较大,仍需进一步研究.     

Lie Symmetries and Conserved Quantities for Super-Long Elastic Slender Rod

DNA is a nucleic acid molecule with double-helical structures that are special symmetrical structures attracting great attention of numerous researchers. The super-long elastic slender rod, an important structural model of DNA and other long-train molecules, is a useful tool in analysing the symmetrical properties and the stabilities of DNA. We study the Lie symmetries of a super-long elastic slender rod by using the methods of infinitesimal transformation. Based on Kirchhoff＇s analogue, generalized Hamilton canonical equations are analysed. The infinitesimal transformations with respect to the radian coordinate, the generalized coordinate, and the quasimomentum of the model are introduced. The Lie symmetries and conserved quantities of the model are presented.     

Laser Micro-beam Manipulation System for Cells

This paper introduces a laser micro-beam system for cells manipulation. The laser micro-beam system comprises a laser scissors and a laser tweezers, which are focused by a Nd∶YAG laser and a He-Ne laser through a microscope objective, respectively. Not only the overall design of the laser micro-beam system is discussed, but also the design and choice of the critical components. A laser micro-beam system was constructed and anticipated experiment results were gained. Yeast cells can be successfully manipulated with the laser tweezers. Chromosomes can be successfully incised with the laser scissors.     

光的时间相干性及傅里叶变换光谱分析实验系统的研制

光的时间相干性及傅里叶变换光谱分析实验系统可以实时采集和分析各种光源在迈克耳孙干涉仪上产生的干涉条纹信号，并进行傅里叶变换以分析光源的频谱。系统运用多媒体声音和动画演示技术，达到生动形象的现场教学效果。     

汞原子激发电位和电离电位的测量

一引言原子内部能量量子化这一概念,在物理教学中无疑是很重要的。因而定量地、形象地反映原子能级的存在,在近代物理实验中就成为不可缺少的课题。早在1914年J·Franck和G.Hertz就用电子碰撞原子的方法,使后者从低能级激发到高能级,从而证明了原子能级的存在,为原子的Bohr理论提供了直接的实验证据。此即著名的Franck—Hertz实     

相对论介子束缚态的一些普遍性质

本文从B-S方程出发讨论相对论介子束缚态的一些普遍性质,包括0^--1^-介子的对称性,0^--1^-介子质量分裂等。结果表明,标量(1)或静矢(γ₄)相互作用可满足0^--1^-对称性;在相对论情形下,由单胶子交换矢量(γ_μ)势所引起的0^--1^-质量分裂,将以质量平方形式出现;在重夸克(层子)模型中,只有以赝标(γ₅)为主的相互作用,可近似地满足0^--1^-对称性,并可能给出合理的质量谱,BargmannWigner型波函数存在着严重困难。