上海光源数字化低电平控制系统的硬件设计与实现

 设计了上海光源高频低电平控制系统,它是以数字化技术为基础,采用上下变频和IQ调制解调技术,实现幅度、频率和相位的反馈控制。上海光源储存环的束流设计流强为300 mA,为了抑制由此带来的Robinson不稳定性和纵向零模束流振荡,加入了高频直接反馈和零模束流反馈环路。从上下变频技术、IQ调制解调技术、时钟分配及锁相技术等方面对上海光源数字化低电平系统的硬件设计及其实现进行了阐述,给出了该系统试验、高功率下运行的测试结果,实现了设计要求的幅度控制精度±1%、频率控制精度 ±10 Hz和相位控制精度± 1°的技术指标。     

在现场可编程门阵列中的高频反馈数字化算法

 介绍了高频反馈的基本原理,并依据此原理,提出了在现场可编程门阵列中采用数字算法实现高频反馈的方案,即采用旋转矩阵实现反馈环路中的增益调节和相位调节,然后再与标准信号进行矢量运算。同时,在上海光源的高频系统上进行了相关的实验,测量得到的环路延时为1.2 μs;当加入高频反馈前后,观测到超导高频腔的带宽由3.3 kHz增加到了4.8 kHz,Q值由150 550降到104 130。     

基于特征点跟踪的数字稳像算法

针对图像平移和旋转的数字电子稳像问题,提出了一种新的稳像算法。采用K-R法(Kitchen-Rosenfeld)提取图像特征,根据Similarity变换模型进行运动估计,将图像平移和旋转模型转化为仅绕中心点旋转的单一旋转模型,降低了模型的复杂度和计算量。实验证明,这种算法具有很好的稳像效果。     

Highly efficient Nd:YAG/LBO laser at 473 nm under direct 885-nm diode laser pumping

<正>In diode pumped Nd:YAG lasers,the quantum defect is the most important parameter determining the thermal load of the laser crystal,which can be dramatically reduced by pumping directly into the upper laser level.A compact folded three-mirror cavity with a length of 105 mm is optimized to obtain a highly efficient 473-nm laser.When the absorbed pump power(with 15.8-W incident pump power) at 885 nm into Nd:YAG is 10 W,a continuous-wave 473-nm blue laser as high as 2.34 W is achieved by LBO intra-cavity frequency doubled.The optical-to-optical conversion efficiency is 14.8%.To the best of our knowledge, this is the highest efficiency at 473 nm by an intra-cavity doubled frequency Nd:YAG laser.     

三苄基锡氨荒酸酯的合成与表征

合成了15个新的三苄基锡氨荒酸酯,利用元素分析,紫外光谱,红外光谱,核磁共振氢谱以及热分析表征了它们的结构,确定了氨荒酸是以双硫形式与锡原子配位。生物活性测试结果表明,这类化合物具有一定的杀菌活性。     

TiO2/SiO2的制备及其光催化降解敌敌畏

二氧化钛;溶胶-凝胶法;表面复合物;TiO2/SiO2的制备及其光催化降解敌敌畏     

吡啶基羧酸苄基锡配合物的红外光谱

研究了７ 种吡啶基羧酸苄基锡配合物的红外光谱, 归属了它们的主要红外吸收峰, 探讨了它们随化学结构而变化的规律, 确定了吡啶基羧酸与锡原子的配位形式。     

丁基锡炔基膦酸酯的合成

本文合成了１０个新的二（三）丁基锡炔基膦酸酯「（ｎ－（Ｃ４Ｈ９）ｎＳｎ」ｎ－１Ｏ２Ｐ（Ｏ）Ｃ≡ＣＲ（ｎ＝２,３;Ｒ＝ｎ－Ｃ５Ｈ１１,ｎ－Ｃ６Ｈ１３,Ｐｈ,ＣＨ２ＯＭｅ,ＣＨ２ＯＥｔ）通过元素分析,ＩＲ和＾１Ｈ ＮＭＲ确证了其结构。     

硫酸铜催化合成二元酸系列酯

以硫酸铜为催化剂,合成了２０种二元酸系列酯,结果表明,该催化剂具有活性好、操作简便、无三度污染、酯收率高、可多次重复使用等优点。经正交试验得出已下酯较佳的合成工艺条件。     

Bending of a circular cylinder containing a crack

The study of bending of cracked circular cylinders is of more significance. The bending of cylinders containing radical crack or cracks was discussed by refs. [1]–[4] and that of concentrically craked circular cylinders was studied by [5]. Continuing [6] and using complex variable methods in elasticity, this paper deals with the bending problems of a circular cylinder, containing an internal linear crack at any position under an acting force perpendicular to the crack. The general forms of displacements, stresses, and stressintensity factors, expressed in terms of series, are obtained and to this bending problems with small Ah are presented good approximate formulas for the stress-intensity factors whose variations with the center of the crack are analysed. Finally, the twist angle per unit length and the center of bending for the radically cracked circular cylinder, one of whose crack-tips is located at the origin, have been computed and the results are almost the same as that calculated in [1].