非圆截面环流器FY-1实验(Ⅰ)——被动运行部分

本文简略地描述了FY-1装置结构、等离子体基本参数的测量和等离子体位形的调试,初步考察了硬X射线产额与工作气压的关系。实验分析表明,FY-1装置已形成的等离子体环流放电属于逃逸放电。在场成形线圈作被动运行时,通过改变其回路连接方式和外串电感值,可适当调节等离子体平衡位置和位形。MHD平衡计算与实验测量拟合结果表明,等离子体截面可调节为不同截面积和拉长比(k=1.1—1.4)的椭圆。     

平行共轴线圈的磁场特征研究与实验设计

通过计算机及相关的传感器和数据采集接口辅助,研究了平行共轴双线圈间距分别为0.5R,R,1.5R时,轴线方向磁场强度的分布规律及特征.从平行共轴双线圈间距为R的亥姆霍兹线圈所形成的均匀磁场出发,结合理论推导,自己设计并组装了三线圈实验装置,实现了平行共轴三线圈均匀磁场区域扩大、强度增强的实验设计,在一定程度上弥补了传统亥姆霍兹线圈磁场测量的不足并有助于对其深入的理解和研究.     

高温超导线圈在大电流下稳定性的数值仿真

在电力应用中,超导磁体可能会因为线圈工作于过流状态而失超,也可能会因为交流损耗而导致失超.为此,我们模拟了一个磁体在大电流过载下的稳定性情况.我们使用了一个建立在热传导方程和麦克斯韦方程基础上的差分数值计算方法来得出磁体内部的温度分布.我们对各种不同的电流冲击情况进行了考察,我们的模型可以使磁体设计者在实际制作之前能够估计一个比较安全的操作电流水平,有着广泛的实用价值.     

硅基半导体芯片激光红外显微成像系统研究

为了解决可见光显微成像技术无法实现硅基芯片内部结构观测的问题,根据1 064nm的红外激光对硅材料具有一定穿透深度的特性,设计了一种硅基半导体芯片激光红外显微成像系统.该系统采用数值孔径为0.42的长工作距显微物镜,通过音圈电机振动多模石英光纤消除散斑噪音,由系统观察CD-RW盘片道间距,表明系统分辨率可达到1.6μm,接近理论值,实现了对芯片厚度为70μm的静态随机存储器内部结构显微成像的观测.     

高场磁共振成像1H/31P双调谐射频线圈研究进展

在众多可产生磁共振现象的原子核中,¹H核凭借其在生物体中含量高、磁共振信号强的优势,成为磁共振成像的主要研究对象．但其它杂核在生命科学相关研究中同样具有不可替代的独特性,如³¹P核广泛参与了生物体内的能量代谢过程,是非质子成像研究领域的重要内容．MRI向更高场强的发展使得杂核成像逐渐普及,其核心部件是高质量的¹H/³¹P双调谐射频线圈．本文总结了与¹H/³¹P双调谐射频线圈相关的研究与应用,展示了9.4 T下小鼠脑的质子磁共振成像及磁共振磷谱,并讨论了高场¹H/³¹P双调谐射频线圈的潜在应用价值．     

Flow-induced vibration in two-phase flow with wire coil inserts

Information of flow-induced vibration (FIV) in two-phase flow with wire coil inserts at atmospheric pressure, is presented in this study. FIV was measured in an upward vertical tube for four different wire coil inserts using an air–water mixture as process fluid. Vibration increased along with mass flux and quality. The narrower wire coils produced more vibration. The FIV prediction correlation for two-phase flow with wire coil inserts was experimentally developed with coefficient correlation value of 0.956.     

Synthesis and characterization of fluorene‐based rod–coil liquid crystal polymers

A series of fluorene‐based rod–coil liquid crystal polymers with different lengths of the coil segments on backbones were designed and synthesized by a palladium‐catalyzed Suzuki coupling‐reaction. The thermal stability, the UV–Vis absorption and fluorescence spectra in chloroform solution and thin film, the electrochemical properties, thermal behavior, and morphology of these rod–coil polymers were investigated. The thermal stability of these polymers steadily decreased on increasing the length of the coil segments on the backbone; their optical and electrochemical properties did not exhibit noticeable dependence on the weight fraction of the coil segments. However, the shoulder emission and the full width at the half‐maximum (FWHM) in PL spectra of the films increased, whereas the oxidation onset potentials and the corresponding HOMO energy levels decreased with the increase in the weight fraction of the coil segments, which was assigned to microphase separation and formation of folded chain conformation as the weight fraction of the coil segments increased. These polymers displayed a characteristic liquid crystalline texture. The variation of the weight fraction of the coil segments obviously affected the thermal behavior and morphology of these rod–coil polymers. Copyright © 2008 John Wiley & Sons, Ltd.     

低场核磁共振短死时间射频线圈与射频开关的设计

本文以核磁共振（NMR）射频线圈振铃信号产生原理为对象进行分析研究,提出了一种适用于低场环境下由环状间隙腔线圈与螺线管线圈构成的收发分离式短死时间射频线圈设计方案,采用优化调谐匹配网络提高发射效率;根据射频线圈方案需求设计了快速切换的射频开关及驱动．在此基础上依据仿真结果制作了短死时间射频线圈,并应用于自主研制的低场9.51 MHz便携式NMR谱仪系统,进行NMR实验,结果显示可将收发切换时间缩短至10 μs以内,验证了该设计方案的可行性．     

Counter-current chromatographic separation of nucleic acid constituents with a hydrophilic solvent system

Nucleic acid constituents such as nucleobases, nucleosides and nucleotides were separated by counter-current chromatography using type J coil planet centrifuge. The separation was performed with a hydrophilic solvent system composed of 1-propanol/800 mM potassium phosphate buffer (pH 7.4) (1:1, v/v) by eluting the lower aqueous phase at a flow-rate of 0.5 ml/min. Eight selected nucleic acid constituents (4.0 mg, 0.5 mg of each), uridine monophosphate (UMP), adenosine monophosphate (AMP), deoxyadenosine monophosphate (dAMP), uridine, urasile, deoxy uridine, adenosine and adenine were well resolved within 160 min.     

翻转线圈系统在波荡器积分场测量中的应用

 为了更有效地测量用于上海同步辐射光源波荡器的积分场误差,在已有的伸展线磁测系统的基础上研制了一套翻转线圈磁测系统,该系统的运动控制、数据采集和数据分析处理均可自动完成。在利用这套磁测系统测量3.4×10^-6 T·m磁场积分时获得高于1×10^-6 T·m的测量精度,初步的实验结果表明这套波荡器积分磁场测量系统具有测量精度好、速度快的特点,与已有的伸展线磁测系统、平移线圈磁测系统和霍尔点测系统相比,它更适合于测量波荡器的一、二次场积分和多极场分量。