上海光源储存环线性模型校正

上海光源是我国刚刚建成的一台第三代中能同步辐射光源。为使得上海光源能够严格工作在设计状态下, 在调试过程中进行了一系列线性模型的校正, 主要包括闭轨校正、 基于束流准直（BBA）校正、 LOCO参数校正和线性耦合校正。经过反复的线性模型校正以后, 上海光源储存环的闭轨畸变均方根误差在水平和垂直两个方向可以分别控制到50和60 μm的水平, 包络函数畸变和色散函数畸变都可以控制到小于1%的状态, 工作点和束流发射度基本上校正到了设计值。线性耦合校正能够方便地将储存环的耦合度从0.02%调节到2%左右。调试结果表明, 上海光源采取的这一套线性模型校正方法, 能够有效地将上海光源的工作状态校正到设计状态, 并且为其他模式的调节奠定了基础。In the commissioning stage of Shanghai Synchrotron Radiation Facility(SSRF) storage ring, several methods were used to correct the linear optics. Beam Based Alignment(BBA) was used for BPM\|Quadrupole offsets measurement; Response matrix was used for orbit correction; LOCO was used for linear optics fitting, and quadrupoles strength were adjusted to correction the beta function; coupling was measured and corrected by skew quadrupoles. After correction, closed orbit are reduced to 50/60 μm in hortizontal and vertical plane; β beating and dispersion errors are less than 1%; betatron tune and emmittance are closed to the design value; betatron coupling also can be adjusted from 0.02% to 2%. These methods have been proved to be useful for storage ring calibrations, with the help of these methods, SSRF storage ring can be tuned to the design model and other model easily.     

8-epi-Liphagal的合成研究

四环杂萜类天然产物Liphagal含有新奇的[6-7-5-6]四环骨架, 是磷酸肌醇3-激酶(PI3K)的有效抑制剂之一, 可以选择性抑制细胞增殖和促进细胞死亡, 在治疗炎症、免疫紊乱、癌症以及心血管疾病中有潜在的医用价值. 从廉价的2,4,5-三甲氧基苯甲醛出发, 通过Wittig反应、Cu催化的环化反应、选择性氢化、分子内Friedel-Crafts反应, 以直线步骤最长7步, 8.72%的总收率实现了8-epi-Liphagal高级中间体10的合成.     

基于指数加权-核在线序列极限学习机的混沌系统动态重构研究

利用指数加权在线核序列极限学习机(exponential weighted online sequential extreme learning machine with kernel, EW-KOSELM)辨识算法,开展了针对混沌动力学系统的动态重构研究. EW-KOSELM算法将核递归最小二乘(kernel recursive least squares, KRLS)算法直接延伸至在线ELM (extreme learning machine)框架中,通过引入遗忘因子削弱了旧数据的影响,并基于"固定预算(fixed-budget, FB)"内存技术,应对在线核学习算法所固有的规模不断增长的计算困难.将所提辨识算法应用于Duffing-Ueda振子的混沌动力学系统数值仿真实例中,对基于FB-EW-KOSELM的辨识模型与原系统的动态性能进行了定性与定量的分析校验,定性校验准则是基于对比辨识模型与原系统吸引子(轨迹嵌入)、庞加莱映射、分岔图、极限环完成的,定量校验准则包括对比辨识模型与原系统的李雅普诺夫指数与关联维.进一步将其分别应用于来自测量蔡氏电路产生双涡卷吸引子与螺旋吸引子的实测数据实验及某一实际混沌电路所产生的时间序列中,对于具有低信噪比的实测电压或电流数据还需进行了小波降噪预处理.通过分析辨识模型重构吸引子,实验结果表明,FB-EW-KOSELM算法具有良好的动态重构性能,能精确地再生出展示混沌动态行为的过程非线性模型,且具有与原混沌系统非常接近的动态不变性指标.     

Optimal sorting method and application to SSRF booster dipoles

As the dipoles of SSRF booster are powered in series, the magnet field error varies from magnet to magnet and results in bad beam quality. Sorting and installing magnets according to the measured field errors so that the errors on different magnets are partially compensated with each other, has been the easiest way in many cases to reduce the detrimental effects of the errors without introducing complications. Based on the magnet field measurement results, we investigated and implemented the sorting of dipoles using a method mixed by local cancellation and simulated annealing, and it's found to be quite effective.     

超临界CO2协助多单体接枝改性聚丙烯

利用超临界CO2作为溶胀剂和携带剂,使小分子单体马来酸酐和苯乙烯单体(MAH与St)及引发剂过氧化苯甲酰(BPO)插嵌进入聚丙烯(PP)基质中,然后在100℃条件下反应4 h得到接枝产物。研究了不同超临界CO2条件及引发剂浓度对接枝率的影响,固定超临界流体压力,改变温度,42℃为最佳温度,接枝率达到2.2%;固定温度,改变压力,10 MPa为最佳条件,接枝率为2.3%。对样品的FT-IR和SEM分析表明,共单体确实接枝到了PP分子链上,而DSC分析表明,随着接枝率的提高,材料的熔点(Tm)及表观结晶度(Ca)下降。这可能是接枝破坏了PP链结构的规整性,同时扩大了分子链间的距离所致。     

离子液体和KGM修饰电极上的直接电化学

将血红蛋白固定在用室温离子液体和魔芋葡甘聚糖(KGM)水凝胶修饰的玻碳电极上,其循环伏安扫描显示一对可逆的氧化还原电流峰,克式量电位(-0.38V,vs.SCE)随溶液pH值的增大而负移,呈良好的线性关系,斜率为51 mV/pH,表明在离子液体和KGM共同修饰的电极上包埋在魔芋葡甘聚糖水凝胶中的血红蛋白发生了直接可逆的电子传递反应,并伴随有一质子的迁移过程.此外,还考察了该血红蛋白修饰电极对O2还原反应的电催化性能.     

Lie-form invariance of nonholonomic mechanical systems

The Lie-form invariance of a nonholonomic mechanical system is studied. The definition and criterion of the Lie-form invariance of the nonholonomic mechanical system are given. The Hojman conserved quantity and a new type of conserved quantity are obtained from the Lie-form invariance. An example is given to illustrate the application of the results.     

Lie-form invariance of non-holonomic systems with unilateral constraints

In this paper the Lie-form invariance of the non-holonomic systems with unilateral constraints is studied. The definition and the criterion of the Lie-form invariance of the system are given. The generalized Hojman conserved quantity and a new type of conserved quantity deduced from the Lie-form invariance are obtained. Finally, an example is presented to illustrate the application of the results.     

相称长周期光栅及其在增益谱平坦化中的应用

用耦合模方法和传输矩阵法相结合对周期光栅的传播光谱特性进行了研究。提出了用相移长周期光栅使双峰的谱线平坦化。理论证明,实现这样的平坦化是可行的。     

烧结反应对液相法制得FeWO_4微米晶光催化性能的改性（英文）

通过简单的液相法制得FeWO_4微米晶,FeWO_4微米晶于310℃、空气气氛条件下烧结,研究了烧结反应对FeWO_4微米晶光催化性质的影响。烧结前后的样品通过X射线粉末衍射、扫描电子显微镜、透射电子显微镜、N2吸附-脱附、热重分析、红外分析和紫外-可见等分析方法加以表征。光催化实验证明烧结后其在降解罗丹明B溶液中表现出了较高活性,说明烧结反应有利于提高FeWO_4的吸附与光催化性能。