表面改性纳米BaTiO3杂化聚酰亚胺薄膜的合成及其热性能

以3,3’,4,4’-联苯四酸二酐和4,4’-二氨基二苯醚为原料,通过原位聚合和流延成膜法制备了不同纳米BaTiO3含量的聚酰亚胺(PI)/BaTiO3杂化膜。采用不同的硅烷偶联剂对纳米BaTiO3进行表面改性,发现γ-巯丙基三乙氧基硅烷(KH590)的改性效果较好。大部分杂化膜在质量损失5%的温度都较纯膜有不同程度的升高,最多升高了18℃,说明PI/BaTiO3杂化膜较纯膜具有更好的耐热性能,且热分解温度均高于520℃。     

超高效液相色谱-串联质谱法测定化妆品还原液内的4-氨基联苯

建立了超高效液相色谱-串联质谱(UPLC-MS/MS)检测化妆品还原液中4-氨基联苯的方法.化妆品试样经过连二亚硫酸钠化学还原后,离心、PCX固相萃取小柱提取富集、净化,并经氨化甲醇洗脱、氮吹至近干,定容后通过UPLC-MS/MS仪检测,分离柱为Waters Acquity BEH C18柱;流动相为0.3％乙腈-甲酸水溶液;流速0.5mL/min.5种不同基质中4-氨基联苯在5～250 ng/mL浓度范围内呈良好的线性关系,线性回归系数r2均大于0.999,检测限均为1 ng/mL.5种不同基质中4-氨基联苯的回收率为80.9％～92.6％,相对标准偏差(RSD)为0.51％～3.76％(n=3).     

类胡萝卜素的分子光谱研究

类胡萝卜素是含有9个CC共轭双键的短链多烯类生物分子. 特殊的分子结构, 使其不仅在光采集, 光防护, 防癌, 抗癌等生物学领域有重要应用, 而且在分子导线, 光开关, 滤光器等光电器件研制中也有重要的非生物学应用. 本文对它的分子光谱进行研究和总结, 结果表明, 类胡萝卜素具有宽带荧光, 将其用于荧光增强受激拉曼散射可以获得宽带受激拉曼散射; 电子能隙随温度降低而收缩, 电子吸收光谱红移, 这特性使它能研制优质半导体元件; 极大的拉曼活性和三阶非线性系数, CC键基频拉曼散射截面可以比普通分子大10个数量级, 和频、倍频拉曼散射强度也很高, 低温下与基频强度比可达0.5. 类胡萝卜素分子的这些光谱特性对多烯类分子结构、性能研究及其在非生物学中的应用有重要参数价值.     

不同pH条件下木质素磺酸钠的静电逐层自组装研究

以来源于造纸废液中的木质素磺酸钠(SL)为研究对象,利用静电逐层自组装技术,与聚二烯丙基二甲基氯化铵(PDAC)交替吸附,制备木质素磺酸钠的自组装多层吸附膜.研究了不同pH值条件下木质素磺酸钠在固体表面的静电吸附规律.木质素磺酸钠的自组装过程用紫外-可见光吸收光谱来监控,而自组装膜的表面形貌用原子力显微镜来观察.研究表明,SL与PDAC多层吸附膜的紫外-可见光吸收光谱强度随层数增加而线性增长,说明SL/PDAC多层吸附膜的厚度增长是以逐层自组装的方式进行的.木质素磺酸钠浸渍溶液的pH值对多层吸附膜的厚度和表面形貌产生重要的影响.在所研究的pH范围内,pH值越低,越有利于生成吸光度高的自组装膜,而得到的自组装膜的表面粗糙度越大。     

Eddy current septum magnets for injection and extraction at SSRF

There are 6 in-vacuum eddy current septum magnets used for booster injection, extraction, and storage ring injection in SSRF. Special attention was paid to coils and their support designs because of the shock force they bear in the magnetic fields and the high heat which is hard to be dissipated in vacuum environment. For the storage ring magnets, good transverse homogeneity in the gap was achieved by careful design, precise machining and accurate assembly; and an extremely low leakage field on the stored beam is another key feature thanks to the high permeability Mu metal. Magnetic field measurement was conducted with both a point coil and a long integral coil, and the results agree well with the OPERA-2d/3d simulations. An inner tube is added to keep the continuity of impedance for the circulating beam with two RF finger flanges at each end. There is no vacuum separation between the inner tube and the magnet chamber. Sputter ion pumps integrated with NEG are used to acquire the UHV for the chamber.     

单束激光脉冲俘获及放大机理的理论分析与数值模拟研究

本文提出用固体靶前放置薄膜靶来实现激光场放大的新方案, 研究了针对单束激光脉冲条件的俘获及放大机理. 理论模型与数值模拟均表明入射激光能量可以部分地以驻波形式驻留在靶间区域并得到有效放大. 研究表明在入射激光光压、俘获激光光压和电荷分离场的共同作用下, 薄膜靶电子层压缩和膨胀是能量积累存在反复振荡过程的直接原因, 经过振荡后激光脉冲得到稳定俘获.     

城市干化污泥循环流化床燃烧过程中NO和N2O的排放特性

在15 kW循环流化床实验台上进行了城市干化污泥的燃烧实验,研究了污泥含水率、燃烧温度、过量空气系数、二次风比率等因素对NO和N₂O排放特性的影响。实验结果表明:污泥含水率从4.5%增加至17.5%时,NO排放浓度明显降低,N₂O排放浓度明显升高;燃烧温度升高,NO排放浓度呈上升趋势,N₂O排放浓度则呈下降趋势;增大过量空气系数会促进NO和N₂O的生成;提高二次风比率可以降低NO和N₂O的排放浓度。城市干化污泥在循环流化床燃烧过程中NO和N₂O的排放浓度高于污泥与煤混烧时的排放浓度,但燃料N向NO和N₂O的转化率低于与煤混烧过程。     

变参数随机服务系统最优设计

利用排队理论，建立了一个到达率递增、服务率不变、服务台数量递减的变参数随机服务系统最优设计模型。给出了满足投资有限，在一定时期内设备使用率和用户服务质量满足给定的要求，使用寿命达到设计的服务系统最优设计方案。     

Exploring the Critical Sensitivity in Small-World Networks

Catastrophic phenomena such as earthquakes, avalanches, and critical points in the stock market are hard to predict. Recently, Xia et al. [Pure Appl. Geophys. 159 (2002)2491] showed that a geometrical system near catastrophic rupture presents a general critical sensitivity: the system becomes significantly sensitive near the catastrophe transition. Here we report that the phenomenon of critical sensitivity also exists in small-world network systems. With the increase of the small-world rewiring probability p, from the regular network p=0 to the random one p=1, the system performs more sensitively before the critical point while remaining in better organization through the evolutional progress, and the prediction threshold P8 performs more in advance. The concept of critical sensitivity can be applied to other complex network systems.