高速双边缘光纤光栅波长解调技术

提出一种双边缘结构对光纤光栅传感进行波长解调的方案,利用被测光谱通过不同光谱特性的滤波器时输出不同光强的比值确定被测光的波长.该系统在解调时不存在任何机械移动部分,比扫描式的解调方法测量速度更快,运行时更稳定、更精确.     

ICP-MS测定动物肝脏中铅、镉和砷

利用电感耦合等离子体-质谱法(ICP-MS)同时测定动物肝脏中铅、镉、砷3种元素.样品经聚四氟乙烯高压消化罐消解后,以锗、铟、铋作为内标物质,补偿基体效应,直接用ICP-MS同时测定这3种元素,结果令人满意.该法线性范围宽,分析速度快,准确度和精密度均符合分析测试要求.     

FAAS法测钙时磷酸根离子的干扰及消除研究

研究了用火焰原子吸收光谱法测钙时PO3- 4对钙的测定的干扰情况以及用有关方法消除PO3-4对钙干扰的效果.用La(NO3)3和EDTA单独消除PO3-4的干扰进行了实验研究,同时对有关问题作了讨论.对测定各种样品中的钙时消除PO3-4的干扰有一定的指导意义.     

表面活性剂对均相沉淀法制备单晶Ce2O(CO3)2￠H2O微粉形貌及 形成机理的影响

在尿素及硝酸铈的混合溶液中分别加入表面活性剂CTAB、 PEG19000、OP-10,利用均相沉淀法合成了不同形貌的CeO2超细前驱体Ce2O(COa)2·H2O,采用X射线衍射及透射电子显微镜等测试手段,对产品的物相和形貌进行了表征．实验结果表明,所得产品均为斜方晶系的单晶Ce2O(CO3)2·H2O,且表面活性剂的加入使晶体的晶化程度明显提高;添加不同的表面活性剂得到不同形貌尺寸的产物: 阳离子型表面活性剂CTAB对Ce2O(CO3)2·H2O晶体的形貌影响不大,所得产物尺寸变小,且分散性得到一定的改善;非离子型表面活性剂对所得产物的形貌影响显著．加入PEG19000和OP-10分别得到了形状排列有序的、尺寸较均匀的、较规则无团聚的微米棒及具有紧密结合中心的发散状的花样微粒．不同形貌前驱体的形成与晶粒形成生长机理的改变有关．     

Self-Assembly of Micro-Parts onto Si Substrates at Liquid-Liquid Interface

We report a new approach for the self-assembly of cuboid micro-parts onto Si substrates to construct three-dimensional microstructures. To perform assembly, the Si substrates are prepared with a deep cavity array as binding sites. An aggregate composed of hundreds of uniformly aligned micro-parts is formed at the C10F18-H2O interface. The micro-parts are arranged by passing the substrate through the aggregate of micro-parts, thus the micro-parts are left on the substrate, and then the substrate is vibrated ultrasonically in the solution, making it possible for the micro-parts to fall into the cavities on the substrate. Finally the substrate is pulled out of the solution after assembly. This technique could give a high yield of up to 70%, providing a new method for micro-assembly.     

Fast fat-suppressed reduced field-of-view temperature mapping using 2DRF excitation pulses

The purpose of this study is to develop a fast and accurate temperature mapping method capable of both fat suppression and reduced field-of-view (rFOV) imaging, using a two-dimensional spatially-selective RF (2DRF) pulse. Temperature measurement errors caused by fat signals were assessed, through simulations. An 11×1140μs echo-planar 2DRF pulse was developed and incorporated into a gradient-echo sequence. Temperature measurements were obtained during focused ultrasound (FUS) heating of a fat-water phantom. Experiments both with and without the use of a 2DRF pulse were performed at 3T, and the accuracy of the resulting temperature measurements were compared over a range of TE values. Significant inconsistencies in terms of measured temperature values were observed when using a regular slice-selective RF excitation pulse. In contrast, the proposed 2DRF excitation pulse suppressed fat signals by more than 90%, allowing good temperature consistency regardless of TE settings. Temporal resolution was also improved, from 12 frames per minute (fpm) with the regular pulse to 28 frames per minute with the rFOV excitation. This technique appears promising toward the MR monitoring of temperature in moving adipose organs, during thermal therapies.     

Design and end chamfer simulation of PEFP beam line curved dipole magnets

The design, fabrication and field measurement of 11 DC curved dipole magnets for the PEFP Beam Line have been completed. In this paper, a design method for a complex end chamfer using OPERA-3D is proposed. The conventional method for estimating chamfer shape is extended and applied to a curved dipole magnet by a coordinate transformation. Using the interface with CAD software, the complex end chamfer is modeled and fully determined by 3D simulation to meet the field uniformity requirement. The magnetic field measurement results are in good agreement with the simulation. The design considerations, field simulation results, end chamfer development process and measurement results are presented in detail.     

聚变反应时间历程的双峰结构测量

利用新研制的聚变反应速率测量系统,在神光Ⅲ原型装置上测量了间接驱动时充DT气体的玻璃球壳内爆靶丸的聚变反应速率的时间历程,获得了DT中子产额约为1010时的聚变反应速率随时间的变化过程,发现了聚变中子发射在时间上的双峰结构。利用辐射流体程序对聚变中子在时间上的双峰结构进行了数值模拟,发现双峰结构分别由冲击压缩过程和惯性压缩过程产生,靶丸壳层厚度不同时产生的聚变中子发射双峰强度比变化可能是由靶丸的初始表面调制度不同所致。通过理论模拟与实验结果的对比,验证了中子聚变反应历程的双峰结构。     

非线性发展方程的Riemann theta 函数等几种新解

为了构造非线性发展方程的复合型无穷序列精确解, 获得了第二种椭圆方程的Riemann theta 函数等几种新解.在此基础上,利用第二种椭圆方程与Riccati方程的Bäcklund变换和解的非线性叠加公式, 借助符号计算系统 Mathematica, 以mKdV方程为应用实例, 构造了该方程的复合型无穷序列新精确解.这里包括Riemann theta 函数、Jacobi椭圆函数、双曲函数、 三角函数和有理函数,通过几种形式构成的复合型无穷序列新精确解. 关键词： 第二种椭圆方程 Riccati方程 非线性发展方程 Riemann theta 函数无穷序列解     

1,8-二羟基-3-甲基-苯并［d,e］蒽酮的2D NMR研究

从中药芦荟(Aloe vera)中分离得到一个蒽酮类新化合物. 通过UV、IR、HREI-M S、¹H NMR和¹³C NMR及2D NMR(¹H-¹H COSY、HMBC、HMQC和J -resolved)方法， 鉴定其结构为：1,8- 二羟基-3-甲基-苯并［d,e］蒽酮. 文章的侧重点在于讨论该化合物的¹H和¹³C NMR信号的全归属.