基于PXI总线的阵列探测器数据获取系统

描述了一种适用于阵列探测器的数据获取系统。系统基于PXI总线, 采用标准NIM插件作为前端电子学。系统软件采用C/C++语言编写, 在线分析通过调用ROOT类库实现, 系统运行在Linux操作系统下。多次测试结果表明, 系统稳定可靠, 单个ADC通道可以处理的最大事例率为40 kHz。A data acquisition system for array detectors is described. The system is based on PXI bus with standard NIM modules used as front\|end electronics. The system software is written in C/C++ language with its online analysis modules realized by ROOT class library. Several runs of the system under Linux show that it is reliable and is capable of handling event rates up to 40 k events/s for 1 ADC channel.     

PS_(3000)-b-PAA_(5000)球形胶束温度效应的原位小角X射线散射技术研究

应用小角X射线散射技术(SAXS)对两亲嵌段共聚物聚苯乙烯聚丙烯酸(PS-b-PAA)胶束形貌的温度影响进行了原位表征.SAXS结果表明:随着水含量的增加,粒子尺寸相应增加;对于水含量10%的PS_(3000)-b-PAA_(5000)胶束溶液,发现了明显的SAXS双峰现象;双峰的位置不随着温度的变化而改变,但是peak 1和peak 2的相对强度随着温度发生了减弱和增强的交错变化;相邻的SAXS双峰说明在PS_(3000)-b-PAA_(5000)胶束溶液中最初形成的粒子尺寸并不是均匀的,主要分为尺寸极其相近的两种球形粒子;随着温度的升高,粒径大小不同的两种粒子存在着一种消融和生长的过程,并且保持着一个相同的归一化动态平衡速率.     

A novel hyperchaotic system and its circuit implementation

A four-dimensional hyperchaotic system with five parameters is proposed. Its dynamical properties such as dissipativity, equilibrium points, Lyapunov exponent, Lyapunov dimension, bifurcation diagrams and Poincare maps are analyzed theoretically and numerically. Theoretical analyses and simulation tests indicate that the new system's dynamics behavior can be periodic attractor, chaotic attractor and hyperchaotic attractor as the parameter varies. Finally, the circuit of this new hyperchaotic system is designed and realized by Multisim software. The simulation results confirm that the chaotic system is different from the existing chaotic systems and is a novel hyperchaotic system. The system is recommendable for many engineering applications such as information processing, cryptology, secure communications, etc.     

火焰原子吸收光谱法测定马氏珠母贝与企鹅珍珠贝中的重金属镉

通过HNO3-HClO4混合酸消解样品,采用火焰原子吸收光谱法测定马氏珠母贝与企鹅珍珠贝中镉的含量.在最佳试验条件下,线性范围为0.05-1.00μg/mL,相关系数r=0.9998,检出限为0.00686μg/mL,测定结果的相对标准偏差均小于3％(n=6),加标回收率结果在96.77％-103.89％之间.该方法简便、快速,灵敏度高,准确性好,结果令人满意.     

PTCDA/P-Si光电探测器欧姆接触层的XPS测试分析

在光电探测器PTCDA/P-Si芯片的有机层表面,成功制作出了比接触电阻为4.5×10-5Ω·cm2的低阻欧姆接触层。利用X射线光电子能谱(XPS)对Al/Ni/ITO的欧姆接触层界面的电子状态进行了测试和分析。结果表明,ITO中的In3d及Sn3d各出现两个分裂能级的谱峰,它们是In和Sn原子处于氧化环境的结合能。Ni2p有两个谱峰Ni2p(1)及Ni2p(2),低结合能位置Ni2p(1)对应于Ni原子被X射线激发产生的谱峰,说明NiITO之间没有发生化学反应,Ni层阻止了Al层被氧化成Al2O3;高结合能Ni2p(2)谱峰说明已形成了Al3Ni冶金相,有利于低阻欧姆接触层的形成。     

褶合光谱法考察羟自由基清除剂对紫外照射致DNA变异的作用

采用褶合光谱法考察了紫外线UV A ,UV B ,UV C导致的DNA变异 ,并以褶合光谱差谱值的形式量化表达DNA细微突变的程度。DNA受UV A ,UV B ,UV C作用后 ,差谱值依次增大 ,表明变异程度增大 ;添加二甲亚砜、甘露醇等羟自由基清除剂以后 ,在UV A ,UV B ,UV C作用下 ,差谱值有不同程度的降低 ,呈现一定的抑制变异作用。尽管DNA的变异程度有所区别 ,但它们的差谱点分布区域相似 ,提示UV A ,UV B ,UV C导致的DNA变异类型可能相似 ,两种羟自由基清除剂抑制DNA变异的作用机制也可能相似     

Comparison on the mixture rules of sound velocities used in characterizing biomedium components

In this paper, several mixtrue rules of sound velocity and their useful ness in characterizing the components of biomedium are analysed. It is pointed out that for characterizing the components of biomedium, the rules are compatible with each other under certain conditions, and the errors between each rule and real sound velocity are diffferent. It concludes that there is no general rule suitable for various media among above mentioned rules.     

Ti扩散铌酸锂光波导特性的热固定技术

在Ti扩散铌酸锂光波导中,因光致折变效应而导致光波导特性漂移.在光波相干性的导波光学器件中,光致折变效应的影响尤为严重.本文报道了稳定光致折变效应的热固定技术实验结果;并提出在光波导特性的热固定过程中,不是H~+离子起主导作用这一看法.     

Nuclear statistical equilibrium at core-collapse supernova

A new improved nuclear partition function is employed to calculate the nuclear statistical equilibrium (NSE) in core-collapse supernova environment. The results show that the change of nucleus abundance is slight even though the temperature is higher than 10$^{11}$\,K when shock propagates, which indicates that the effect of the nuclear partition function is not so important as shown in the previous calculations, but it can also be considered in detailed simulation if it is sensitive to weak interaction rates in core-collapse supernova.