修正的Pickands估计样本点分割的自助估计方法

在本文中,我们着重研究了极值指数的修正的Pickands型估计的样本点分割方法．我们在渐近二阶矩最小的准则下,利用子样本自助法给出了修正的Pickands型估计的样本点分割方法,从理论上证明了该估计的大样本性质,说明了这种分割在渐近二阶矩最小的准则下是渐近最优分割,同时提出了自适应的样本点分割的自助算法．     

茜素红S催化动力学光度法测定痕量铜(Ⅱ)及机理探究

研究了在pH 5.0的柠檬酸-NaOH缓冲介质中,以邻菲口罗啉(phen)作活化剂,痕量Cu(Ⅱ)对H2O2氧化茜素红S(ARS)的褪色反应存在明显的催化作用,由此建立了测定痕量Cu(Ⅱ)的催化动力学光度法。应用了正交试验法确定最佳条件,测定了有关动力学参数。该方法的检出限为6.3×10-9g/mL,线性范围为0~0.8μg/mL,应用于茶叶、自来水等水样中痕量铜的测定。同时,对反应机理进行了探究。     

催化裂解过程分子尺度的反应动力学模拟： 原料油分子尺度的模拟

以工业实测数据为基础,运用结构导向集总方法构造分子,对催化裂解原料油进行了分子尺度上的蒙特卡罗模拟.结果表明,Monte Carlo方法可以在分子尺度上实现对催化裂解原料很好的模拟.两种工况下原料的平均分子量、饱和烃、芳烃、胶质沥青、碳、氢、硫、氮含量等性质的计算值与实际值吻合,且由此产生的分子矩阵将为后续反应网络的建立打下基础.     

LB膜中的缺陷畴区及其诱导形成环形草酸钙图形

利用存在缺陷的LB膜来模拟受损伤的肾上皮细胞膜诱导肾结石矿物草酸钙(CaOxa)晶体生长. 经2.5 mmol·L-1的草酸钾溶液对二棕榈酰磷脂酰胆碱(DPPC)的LB膜进行处理后, 可强化LB膜中液态扩张相(LE)和液态凝聚相(LC)之间的结构差异, 原子力显微镜(AFM)证实了圈状缺陷的存在. 以LB膜的圈状缺陷为模板, 诱导了一水草酸钙(COM)晶体环状图案. 相比之下, 未经草酸钾处理的LB膜只诱导生成零散的六边形COM晶体.     

New Cyclolignan Esters and Their Antidiabetic Activitity from the Root of Rhus semialata

Rhus semialata is one of five Rhus species (Anacardiaceae), distributed in the island of Taiwan. In the early days,the pericarp of R. semialata was commonly used as a substitute of salt by indigenous mountain people. The root of it is also a folk herb for treating diarrhea, spermatorrhea and malaria.[1,2] This paper describes the isolation and structural elucidation of new cyclolignan esters 3 and 4, and two known compounds: cyclolariciresinol (1) and lynoiresinol (2) isolated from the n-butanol extract of R. semialata.     

A New Cerebroside, Asperiamide A, from Marine Fungus Asperillus sp.

Cerebrosides and ceramides[1] have been isolated from a number of marine organisms such as sea stars, sea anemones, gorgonians, sponges, tunicates, dinoflagellates, and green algae. Some cerebroside and ceramides exhibited cytotoxic, antitumor,[2,3] immunostimulatory,[4] antifungal,[5] and antiviral[6] activites. In the search for bioactive components,two water soluble constituents, asperiamide A and adenosine, were isolated from the marine fungus Asperillus sp. The current report describes the structural elucidation of a new compound, aspefiamide A (1) and a known one, adenosine (2).     

荧光素和苯磺酰氯间反应机理研究

在N,N-二甲基甲酰胺存在下,荧光素和苯磺酰氯间的反应经历串联两步:首先荧光素被苯磺酰氯酯化,然后生成的氯离子亲核进攻芳碳,取代苯磺酰氧基,后者是良好的离去基团。反应的结果是氯取了荧光素的酚羟基,反应机理由本工作找到的关键中间体证实。     

聚苯胺／聚氯乙烯和聚苯胺聚甲基丙烯酸甲酯复合物薄膜三阶非线性光学效应

聚苯胺／聚氯乙烯和聚苯胺聚甲基丙烯酸甲酯复合物薄膜三阶非线性光学效应欧阳萌，龚克成（华南理工大学高分子材料系广州５１０６４１）莫党，王惠，林位株（中山大学物理系广州５１０２７５）关键词聚苯胺复合物，光学透过率，三阶非线性光学效应对于具有共轭双键结构的...     

7,8-亚甲二氧基-4-氧代-3,4-二氢嘧啶并[4,5-b]喹啉衍生物的合成

为了寻找具有药理活性的喹啉衍生物, 我们合成了五个新的喹啉衍生物和十一个7,8--亚甲二氧基-4-氧代-3,4-二氢嘧啶并[4,5-b]喹啉衍生物. 这些化合物的结构均经核磁共振光谱, 红外光谱和元素分析予以证实 .     

一种新型含三苯胺的喹啉衍生物及其金属配合物的合成与表征

A new 8-hydroxyquinoline derivative(5)was synthesized and characterized by ESI-MS,~1H NMR spectroscopy,elemental analysis and IR spectroscopy.The photophysical properties of compounds 5,6 and 7 were also deteminedby UV-vis and FL spectroscopy.The vibrational frequency of ligand 5 predicted by using B3LYP method is in goodagreement with experimentally determined values.The compositions of the corresponding copper(Ⅱ)and zinc(Ⅱ)complexes were confirmed to be Cu(C_(29)H_(21)N_2O)_2·H_2O(6)and Zn(C_(29)H_(21)N_2O)_2·H_2O(7)by elementary analysis,thermogravimetry analysis and IR spectroscopy.