葛根素-7-磷酸二乙酯的NMR研究

葛根素是从常用中药野葛根中分离提取出来的一种具有很强生物活性的异黄酮碳苷类化合物,设计并合成了一种新的化合物葛根素-7-磷酸二乙酯. 在常温下,这种新的化合物在NMR谱上有两组相关的信号峰,即在溶液中以两种不同的构象存在. 本文利用HSQC和HMBC等多种二维核磁共振技术对这种化合物的NMR谱进行了全归属.     

Generalized-Type Synchronization of Hyperchaotic Oscillators Using a Vector Signal

In this paper, a systematic and powerful scheme is proposed to address a generalized-type synchronization of a class of continuous-time systems, which includes generalized lag synchronization, generalized anticipated synchronization, and generalized synchronization. The presented scheme is used to investigate the generalized-type synchronization of the 4D hyperchaotic oscillator and the hyperchaotic oscillator with gyrators. Numerical simulations are used to verify the effectiveness of the proposed scheme. The scheme is more powerful than the scalar signal scheme due to Grassi and Mascolo.     

四齿四棱草根部环肽化合物的分离及鉴定

通过正相和反相硅胶柱层析,从四齿四棱草根部的乙醇提取物中分离纯化出4个环肽化合物,经波谱分析等鉴定了其结构,其中2个新化合物的结构分别为cyclo(-N-Pro¹-Pro²-Phe¹-Phe²-Leu¹-Ser-Thr-Leu²-CO)(1,四棱草肽C)和cyclo(-N-Pro¹-Pro²-His-Gly-Val-Asn-Ile-Trp-CO)(2,四棱草肽D).     

NMR研究溶液中正十四烷基硫酸钠/正十四烷基聚氧乙烯醚(3)表面活性剂之间的相互作用

采用¹HNMR弛豫、自扩散系数和二维相敏(2DNOESY)实验研究了正十四烷基硫酸钠[n-CH₃(CH₂)₁₃OSO₃Na(STS)]和正十四烷基聚氧乙烯醚(3)[n-CH₃(CH₂)₁₃O(C₂H₄O)₃H(C₁₄E₃)]在溶液中的自聚集以及二者混合后的相互作用.结果表明,STS与C₁₄E₃混合后存在相互作用,并形成混合胶束;弛豫实验表明,混合胶束中STS疏水链质子运动更加受阻,C₁₄E₃的α-(4″)和β-CH₂(3″)处链堆积紧密.C₁₄E₃的亲水端(CH₂CH₂0)₃链卷曲紧贴在疏水壳表面外链堆积较紧密处.自扩散系数测量表明,混合胶束比单一阴离子表面活性剂形成的胶束大.单一非离子型胶束和混合胶束的亲水端(CH₂CH₂0)₃(5″)链构成相应较软和松散的外壳.单一C₁₄E₃在极性溶剂氯仿溶液中,质子运动比在水中自由度大,但2DNOESY谱中出现了少量分子间的交叉峰,也可能形成了一些小的聚集体.     

混沌系统的变量变化率反馈控制方法研究

设计了一种控制连续非线性系统中混沌的新方法--变量变化率脉冲反馈(VRPF)方法.介绍了VRPF方法的控制原理以及反馈系数和脉冲间隔的选择技巧.将此方法应用到BZ反应3D模型系统混沌的控制中,计算机仿真模拟显示,通过恰当地选择反馈系数和脉冲间隔,可以将系统稳定在1p、2p、3p、4p、…、2n×3mp (n、m为整数)这样不同的周期轨道,从而使系统的功率谱也由混沌态时的连续谱转变为具有分立单峰的分立谱.此外,仿真模拟还发现VRPF方法具有极宽的控制域.     

An approximation of the first passage probability of systems under nonstationary random excitation

An approximate method is presented for obtaining analytical solutions for the conditional first passage probability of systems under modulated white noise excitation. As the method is based on VanMarcke＇s approximation, with normalization of the response introduced, the expected decay rates can be evaluated from the second-moment statistics instead of the correlation functions or spectrum density functions of the response of considered structures. Explicit solutions to the second-moment statistics of the response are given. Accuracy, efficiency and usage of the proposed method are demonstrated by the first passage analysis of single-degree-of-freedom （SDOF） linear systems under two special types of modulated white noise excitations.     

苯酰胺类D2受体显像剂的共平面效应

苯酰胺类化合物是多巴胺Ｄ2受体的拮抗剂,它不仅与Ｄ2受体的亲和力高,而且产生的锥体外副反应极轻,是一类很有应用潜力的抗精神病药物.放射性同位素(123Ｉ等)标记的苯酰胺类化合物可作为多巴胺Ｄ2受体显像剂用于临床诊断疾病.近年来,相继报导了一系列高亲和力的该类化合物,其中,123ＩＩＢＺＭ等已用于临床诊断疾病[1].本文在前文[2]苯酰胺类Ｄ2受体显像剂结构效应的研究基础上,利用ＳＹＢＹＬ6.4软件,研究了该类化合物分子的不同构象以及空间结构与结合活性之间的关系,证实了前文提出的由于分子内氢键形成六元共平面假想Ａ环、Ｂ环等是影响…     

气相色谱法测定爱迪注射液中的斑蟊素

 研究了斑蟊素在几种萃取体系中的分配行为,测定了它的分配系数。选定二氯甲烷为萃取剂,在相比为1∶10时,只需一次萃取便可以使斑蟊素定量富集。选用OV-17填充柱、外标法定量。方法的分离效果令人满意,检测限低,结果的准确性和精密度良好。     

立体专一合成1-O-酰基-β-D-吡喃半乳糖酯

用相转移催化法合成了一系列1-O-酰基-β-D-吡喃半乳糖酯类化合物,IR,H NMR和MS分析结果证明产物为β构型,反应具有立体专一性.     

3D-QSAR Studies of Dimethoxyphenoxyphenoxy pyrimidines and Analogues

1　 INTRODUCTIONPhotosynthesis is special and important physiology and biochemistry phe-nomenon for plant,so itisnecessary to selectphotosynthesis as a herbicidal targetinorder to get nontoxic pesticides. Recently,a number of 6 - ( 4- phenoxyphenoxy)pyrimidines and triazines which showed a strong Hill reaction inhibition were synthe-sized and their herbicidal activity was measured〔1〕. General structural formulas ofthese compounds are shown in Table1 .In this paper,we examined the three…