使用X光透镜和位置灵敏正比计数器的高能量分辨微束XRF谱仪

报导一种新型微束X荧光分析谱仪,它由导管X光透镜和使用位置灵敏正比计数管的波长色散谱仪组成.谱仪具有高空间分辨,高能量分辨和高灵敏度的特点.从实验上研究了影响谱仪能量分辨的各种因素及用于稀土元素L线分析的可能性.实验结果表明谱仪使用X光透镜形成的X光微束的最小束径对Mo-Kα线为30μm,谱仪对Ti-Kα线的能量分辨为4.4 eV,对稀土元素L线的最低探测极限达到10-10g.     

Development of the CAS-LIBB single-particlemicrobeam for localizedirradiation of living cells

The use of microirradiation techniques in radiationbiology dates back to the work of Zirkle and his col-leagues in 1950’s[1,2]. However, biological effects of arandom single particle traversal in living materials re-mained highly unknown since they could not be simulatedby conventional broad-field radiation exposures. In recentyears, there has been a resurgence of interest in sin-gle-particle/single-cell microbeams[3—12]. The biologicalinterest in the single-particle microbeam stems from the…     

压电粘弹性微梁的粘附分析

以处于粘附状态下的压电粘弹性微梁为研究对象，通过引入参数剥离数表示其粘附特征，分析了压电电压、粘弹性参数和几何参数对处于粘附状态下压电粘弹性微梁剥离数的影响.结果表明，压电电压能有效提高微梁的剥离数，这给通过压电电压修复已处于粘附状态的压电微梁提供了理论依据和参考.同时，微梁的几何参数对微梁的剥离数也有着重要影响，这对微梁的设计造成了一定的限制.     

红宝石激光微束照射黑腹果蝇(Drosophila melanogaster)的辐射生物学 Ⅱ 对各发育阶段的时间、死亡率及性比的影响

本实验继前次实验后,利用红宝石激光微束辐照显微操作技术,进一步研究了激光微束对黑腹果蝇奋发育阶段所需时间及死亡率的影响;同时,分析了F_1代、F_2代的性别比例。证明激光微束辐照确有延长果蝇生育期和致死的作用,经t测验,达显著水平。但对F_1代性比无影响,对F_2代性比略有影响。     

非线性弹性Timoshenko梁的动力学问题及应用

提出了几何非线物理线性的Timoshenko梁的构造函数,应用Hamilton原理于导出了非线性动力学偏微分-积分方程组.无量纲化后在其平凡解附近展成线性偏微分方程,并以悬臂梁为例与Bernoulli-Euler的初等假设理论进行了比较,讨论了长细比对梁的动力学特性的影响,分析了结构实验动态参数与两种理论值的关系.     

Chromosome microdissection by laser microbeam, chromosomal fragment isolation and amplificationin vitro in barley (Hordeum vulgare L.)

A method for microdissection, isolation and amplification of plant chromosomal fragments using laser microbeam and a glass microneedle was established. Firstly, 7H chromosome of barley (Hordeum vulgare L.) was dissected by Nd: YAG laserbeam with suitable parameters and the fragment comprising a satellite was isolated with a glass microneedle which was fixed on a micromanipulator. Then, the chromosomal fragment DNA was amplified by LA_PCR (linker adaptor PCR) for two rounds. The size of the DNA fragments of PCR products varied from 500-3 000 bp and the PCR products originated from the genome of barley were verified by Southern hybridization. Compared with previous reports, there are some advantages in this research. The performance is easier, the dissection is more precise and the cost is low. It also permits efficient amplification with only one single chromosome fragment. Laser microbeam_glass microneedle method may be useful in the microdissection of special chromosome regions, especially in plants with middle or small chromosomes.     

微束激光对单细胞诱变机制研究

本文报道用微束激光对家蚕进行外源染色质的转移获得成功,观察到转移的染色质基因在受体中的当代形态性状表达.并论述短脉冲微束激光照射家蚕受精卵大细胞转移外源基因的同时,引起变异的主要机制.     

活体旁效应的研究进展及单束定点辐照线虫的方法学研究

辐射旁效应的发现对传统的以线性外推方式建立起来的辐射防护学提出了挑战,其研究已成为辐射生物学领域的热点.十几年来,通过离体细胞的体外实验,旁效应的现象及其机制已逐渐被人们所了解。近年来,随着单粒子微束装置的发展,人们的研究重点逐渐从细胞水平转向更为复杂的组织水平和个体水平.文中对国内外有关辐射旁效应的活体研究进行了综述,并且建立了一个实验体系来研究线虫个体水平上的辐射长程传导效应.     

Introduction of pokeweed antiviral protein cDNA intoBrassica napus and acquisition of transgenic plants resistant to viruses

Using cotyledonary petioles as explants, the PAP cDNA controlled by wound-inducible promoter has been introduced intoBrassica napus by coculture withAgrobacterium tumefaciens and laser microbeam puncture respectively. Regenerated plants resistant to gentamycin have been selected out. PCR amplification and Southern blotting analysis indicated that PAP cDNA together with wound-inducible promoter had been integrated intoBrassica genome with transformation frequencies of 2.0% and 1.7% for two transformation methods respectively. The test of virus challenge showed that these transgenicBrassica plants were resistant in different degrees to mechanically inoculated TuMV.     

矿车运输系统动态特性建模与仿真分析

建立了矿车及铁轨耦合振动模型。在时域及频域内分析了矿车及铁轨的振动特性。模型中,矿车被等效为两自由度弹簧-质量-阻尼系统,铁轨被等效为铺设在连续弹性道床上的伯努利-欧拉梁,矿车与铁轨的振动相互耦合。由仿真结果可知,矿车发生振动时,振幅与其运行速度有关,所以其速度应小于3m/s;由于铁轨中部的振幅大于其端部的振幅,所以在铁轨的中部安装限位装置有利于控制铁轨的振动。