新型螺环六氢山酮素-氧化吲哚-苯并呋喃酮类拼接物的合成及其抗白血病细胞增殖活性

以色酮-氧化吲哚合成子与3-烯基苯并呋喃酮为原料,在催化剂1,8-二氮杂二环十一碳-7-烯作用下,在二氯甲烷中发生Michael/Michael加成关环反应,合成了6个未见文献报道的螺环六氢山酮素-氧化吲哚-苯并呋喃酮类拼接物(3a^3f),产率75%~87%,dr值3/1~5/1,其结构经1H NMR,13C NMR和HR-MS(ESI-TOF)表征。采用MTT法研究了3a^3f对人白血病细胞(K562)的体外抗增殖活性。结果表明:化合物3c,3e和3f对K562增殖有一定的抑制活性。     

Determination of the apparent standard potential of the Dy/Dy(Ⅲ) system in the LiCl-KCl eutectic

The apparent standard potential of Dy/Dy(III) system in the LiCl-KCl eutectic has been determined by the logarithmic analysis of the semi-integrals of voltammograms, logarithmic analysis of chronopotentiograms and the open circuit potentiometry. The dysprosium equilibrium potentiab for various concentration of dysprosium chloride in the LiCl-KCl eutectic melt between 400-500℃ were first determined experimentally, and the apparent standard potential of this system and its temperature dependance have been calculated.     

Application of Cyclopentadiene and its Derivatives in Natural Product Synthesis

Approaches toward the synthesis of iridoids and 9-isocyanopupukeanane starting from cy-clopentadiene are discussed.     

环化聚合的研究——聚合温度对甲基丙烯酸酐聚合反应机构的影响

前报关于对称非共轭双烯的环化聚合反应机构我们提出了单分子与双分子结合考虑的反应机构,由此而推得环化聚合组分方程为 -(d[M]/d[m])=A+(B/[M])A,B为反应速度常数的函数,本文报导甲基丙烯酸酐(MAN)在不同温度下进行环化聚合的研究进一步验证上述方程。当分别在60,40及25°聚合时,以d[M]/d[m]对1/[M]作图,都得到了直线,它们的截距分别为2.90,2.15及1.70。若只考虑单分子环化机构则截距将总是1,而不可能随聚合温度不同而改变,因此证实了前文所提出的方程及机构。本文并求得了在60,40及25°聚合时的双分子反应与单分子反应速度(双/单)的比值分别大于 2.7[M],2.0[M]及 1.4[M]。随聚合温度下降,双/单比值也下降,故当温度更低及在较稀单体浓度下聚合时,才有可能主要按单分子环化机构进行。本文还求得双分子环化反应活化能(E_(1c))较单分子环化反应活化能(E_c)高约3.7千卡/克分子,因而对为什么聚合温度升高时聚合体环化率也将升高作出解释。     

KINETICS AND MECHANISM OF PHOTOINDUCED POLYMERIZATION BY α,α-DIMETHOXY-α-PHENYL ACETOPHENONE

α,α-dimethoxy-α-Phenyl acetophenone (DMPA) is an efficient and thermally stable photoinitiator. Here its spectral characteristics in the transient state were shown. The transient species were identified as a benzoyl radical and a dimethoxyi benzyl radical that played a primary initiation role in polymerization. The kinetics and mechanism of the bulk polymerization of MMA were investigated. The exponent of DMPA concentration and k_p/k_1~(1/2) value were found to be 0.5 and 0.066 mol(-1/2)l~(1/2)s~(-1/2), respectively. The existence of oxygen led to obtain the polymer with higher molecular weight, which can be attributed to the occurrence of the subsequent polymerization induced by active polymer end group. In the photocrosslinking reaction, the dependence of DMPA content on initial rate has been found. A principal reason is that the sample contained higher percentage of DMPA has higher light-absorbed efficiency. In solid film, higher concentration of DMPA is permitted to be used because there is little excited state self-quenching effect in the rigid medium.     

分子印迹聚合物膜修饰电极的制备及在香草醛测量中的应用

以香草醛为模板分子,采用光引发聚合法和电化学聚合法分别在电极表面合成了香草醛印迹聚合物,探讨了两种方法的印迹、洗脱及电极再生机理。研究了香草醛在两种电极上的吸附行为,结果表明两种电极均可对香草醛进行吸附富集并进行线性扫描伏安法测定。两种电极均有很好的选择性、稳定性,且各有特点。     

Two-dimensional coupled vibration and equivalent circuit of longitudinal-longitudinal orthogonal composite vibration direction converter

With the advantages of transmitting energy from multiple directions to one direction and transforming vibration from one source to multiple directions, the two-dimensional vibra?tion direction converter has important applications in power ultrasonic technology. However, for the complexity of using the wave equation to design and analysis the two-dimensional vibration direction converter, a concise equivalent circuit for the converter is investigated. By introducing the two-dimensional mechanical coupling coefficient and the longitudinal force transform coef?ficient, and using the electromechanical analogy principle, the equivalent circuit and resonance frequency equation of the two-dimensional vibration direction converter vibrating in anti-phase and in-phase two-dimensional coupled vibration are deduced. The resonance frequencies of the vibration direction converters of two different materials are calculated by using the proposed frequency equation, which are in agreement with the results from the finite element method and the experimental test. It provides a concise method for the design and applications of such ultrasonic vibration system.     

3种现场快速水质检测仪的性价对比

选择了市场上口碑好、占有率高的3款便携式水质现场应急检测设备,通过准确度、精密度、检测时长及价格等指标,以权重积分法对3款仪器进行了比选,结果表明德国MN公司的PF-12型便携式多参数分光光度计的综合性能最优.     

单斜与锐钛矿双晶相TiO2/MWNTs复合材料的制备及其可见光光催化活性

以超强耐酸碱的表面活性剂-丁基封端脂肪醇聚氧乙烯醚作为晶型调节剂,利用钛酸丁酯和氢氧化钠的水热反应制备了单斜相与锐钛矿相双晶相TiO₂/多壁碳纳米管(简称MWNTs)复合材料,并考察了复合材料的可见光光催化活性。结果显示:MWNTs的加入可调控TiO₂的晶相组成,增强TiO₂的光催化活性,其中含5%MWNTs的样品具有较高的催化降解效率;随煅烧温度的升高,样品的光催化活性大幅提升。其机理归因于(1)促进单斜相和锐钛矿相双晶相结构的形成;(2)碳纳米管优良的导电作用及碳纳米管/TiO₂间的异质结效应;(3)高温下碳纳米管分解产生的碳元素掺杂作用。     

新型杯[4]冠醚衍生物聚合单体的合成

从对叔丁基杯[4]芳烃出发,对其下沿的酚羟基进行修饰,先后在1,3-和2-酚羟基位点引入冠醚环和乙基;最后在NaH/THF中与3-溴丙烯酸丙酯反应制得聚合单体——新型杯[4]冠醚衍生物,其结构经1H NMR和MS表征。