模型筛选及计算机分峰法在涤纶X衍射图谱分解中的应用

本文引入数学模型筛选的判别准则,从五种竞争模型中确定了涤纶无定形散射峰的表征函数;并且编制了适用于分解X射线衍射图谱的计算机分峰程序。在上述基础上分解了多种涤纶的X衍射图谱,探索了它们的结构参数,取得了较好结果。     

聚(杯芳烃-哌嗪)酰胺与2,2'-联吡啶超分子泡沫网络结构的构筑

大环番衍生物单体5,11,17,23-四叔丁基-25,27-二酰氯基-26,28-二羟基杯[4]芳烃(DC)与哌嗪通过界面聚合,制备了聚(杯芳烃-哌嗪)酰胺(D).化合物D在乙酸乙酯溶液中形成平均直径为28和164 nm的双分布囊泡形聚集体. 2,2'-联吡啶(bpy)对化合物D的交联作用可将囊泡转变为实心无规则交联网.水将交联网转变为两相界面处存在的泡沫.这个变化过程表明,化合物D在不同的诱导条件下可调整聚集状态,多重诱因使其最终形成宏观泡沫状自组装构筑.化合物D是一个集合芳香大环-小杂环,疏水-亲水、氢键供体受体、刚性-柔性及富π空腔等多种结构及自组装于一体的高分子结构,其分子链在不同诱因下改变扭曲和取向导致超分子交联网络的形成.这种可逆宏观自组装现象为自组装机理的理解及刺激-响应材料的开发提供了一种有价值的试材.     

新型丹皮酚嘧啶类化合物的合成及抗肿瘤活性

以丹皮酚为原料与1,4-二溴丁烷反应合成中间产物2-(4-溴丁烷氧基)-4-甲氧基苯乙酮(2); 2与嘧啶类化合物反应合成了11新型个丹皮酚嘧啶类化合物(4a~4k)，其结构经¹HNMR, ¹³CNMR, IR和MS（ESI）表征。采用MTT法测定目标化合物对HepG2（人肝癌细胞）、MCF-7（人乳腺癌细胞）、HCT-116（人结肠癌细胞）、A549（人肺癌细胞）和LO2（人正常肝细胞）等5种细胞的抑制活性。结果表明：部分化合物表现出一定的抗肿瘤活性，其中6-(2-氟苯基)-5-氰基-4-羟基-2-丹皮酚丁巯基嘧啶(4c)以及6-甲基-4-羟基-2-丹皮酚丁巯基嘧啶(4i)对HCT-116的IC₅₀值分别为(9.22±1.80)μg/mL、(1.32±0.71)μg/mL，优于阳性对照药顺铂。     

Studies of an LL-type 500 MHz 5-cell superconducting cavity at SINAP

A low loss- (LL) type 500 MHz 5-cell superconducting niobium prototype cavity with a large beam aperture has been developed successfully including the optimization, the deep drawing and electron beam welding, the surface treatment and the vertical testing. The performance of the fundamental mode was optimized and the higher order modes were damped by adopting an enlarged beam pipe for propagation. Surface preparation or treatment including mechanical polishing, buffered chemical polishing and high pressure rinsing with ultra-pure water and so on was carried out carefully to ensure a perfect inner surface condition. The vertical testing results show that the accelerating voltage higher than 7.5 MV was obtained while the quality factor was better than 1× 10⁹ at 4.2 K. No obvious multipacting or field emission was found during the test. However, a quench happened while increasing the field a little higher than 7.5 MV that at present limited the cavity performance.     

ICP-MS法测定氯化稀土、碳酸轻稀土中铅、锌、镍、锰、钍、铝

建立了用电感耦合等离子体质谱仪直接测定氯化稀土、碳酸轻稀土中的杂质(铅、锌、镍、锰、钍、铝)元素的新方法。对测定中试液酸度、质谱干扰和基体效应进行了详细考查。采用加入In内标元素,有效地补偿稀土基体产生的抑制效应,相对标准偏差(RSD)≤2.5%,标准加入回收率在98%～103%之间。     

在β－胡萝卜素氧化分解反应中咪唑及其衍生物的催化作用研究

使用紫外可见分光光度计研究了在以氯合四－间三甲苯基卟啉铁（Ⅲ）为催化剂，间氯代过氧化苯甲酸为氧化剂催化β－胡萝卜素氧化分解反应中咪唑及其衍生物的催化作用，分析了咪唑及其衍生物的酸碱催化及轴向配位双重作用与结构的关系，提出了反应机理，讨论了温度及咪唑类物质的浓度对反应速率的影响。     

C4H10分子的价电子的结构研究

We report here the measurements of valence electron structure for the n-butane (C4H10) using high resolution (ΔE=0.9 eV FWHM, ΔP=0.1 a.u.) (e,2e) spectrometer. The impact energy was 1200eV plus binding energy (i.e. 1206 to 1232 eV) and symmetric non-coplanar kinematics was employed. The inner-and outer-valence energy spectrum is in agreement with published Photoelectron data. The experimental momentum profiles have been compared with calculations obtained using Hartree-Fock method with the minimum basis set and a high-level basis set, and also using density functional theory (DFT) density methods with a high level basis set. The agreement between theory and experiment for shape of orbital electron momentum distributions is generally good.     

用正电子研究原生ZnO单晶中的缺陷

利用正电子寿命谱和多普勒展宽谱技术研究了原生ZnO的缺陷结构及其退火效应. 经900 ℃退火之后,正电子寿命实验显示样品中的空位型缺陷基本被消除,其体寿命为180 ps.通过比较原生和退火样品的符合多普勒展宽谱的商谱曲线,两者有相似的峰型,结合寿命谱的相关数据表明原生ZnO中不存在H原子填充Zn空位.