软光刻技术制备液晶显示用定向层

以偶氮聚合物光致表面起伏光栅为模板,制备聚二甲基硅氧烷(PDMS)弹性印章,再以可溶性聚酰亚胺(PI)为“墨水”,在石英玻璃上压印出具有规则起伏结构的PI薄膜.由此制备的PI薄膜显示出很好的使液晶分子定向排列的效果.此方法成本低、效率高,是一种实用的液晶定向层薄膜制备方法.     

聚合物 分散液晶体系的相分离结构对温度依赖性的研究

在不同温度下采用紫外光引发相分离法制备了聚合物分散液晶样品．用光学显微镜及扫描电镜研究了样品的相分离结构．采用对样品施加电压观察其微结构轮廓，或测量液晶微粒相变点的简单方法研究了聚合温度对相分离结果的影响．结果表明，在一定温度范围内，随着温度的增高，液晶微粒的平均尺寸趋于减小，而且形成的液晶微粒也逐渐变纯．作者给出了这些测试结果并进行了讨论．     

A Novel Method for Quantification of Circulating DNA in Serum by Capillary Zone Electrophoresis

In this paper, we first presented a novel method for quantification of circulating DNA in human serum based on capillary zone electrophoresis with laser-induced fluorescence detection (CZE-LIF). The serum was digested by proteinase to release free DNA, and then CZE-LIF system was used for the quantification of total circulating DNA. This method was successfully used to quantify the circulating DNA levels in sera from healthy individuals and certain cancer patients.We found the significantly elevated circulating DNA levels in certain prostate cancer patients. Our results demonstrated that CZE-LIF system has good linearity, excellent sensitivity (0.5 ng/mL DNA),satisfactory reproducibility (RSDs in one day and between days were both less than 5%) and reliability, and is well suitable to the quantification of the circulating DNA in human serum or plasma.     

甲醇氨化反应中交联皂石的催化行为

层柱材料是具有规则孔结构且其表面酸性及孔结构可调变的固体酸催化剂.本文合成了皂石,并用十三聚铝羟基络离子(Al_(13))与其交联,在醇氨化反应中研究了此层柱材料孔结构及表面酸性与催化性能间的关系.     

铂电极上异黄樟油和胡椒醛电氧化的SERS研究

采用循环伏安(CV)法和原位表面增强拉曼光谱(SERS)技术, 研究了非水体系中反应物异黄樟油和目标产物胡椒醛在粗糙铂电极上的电氧化行为, 发现胡椒醛在电位≥1.50 V时将进一步氧化, 而且从分子水平证实, 在胡椒醛的氧化电位(≥1.50 V) 下, 波长为632.8 nm的激光对胡椒醛的氧化有助催化作用. 由异黄樟油直接电氧化合成胡椒醛的电位(E)应控制在1.20 V相似文献   

3,9-咔唑聚合物基态和激发态性质的理论研究

用密度泛函B3LYP方法对3,9-咔唑低聚物[(3,9-carbazole)n(n=1,2,3,4,6,8)]体系进行了全优化, 计算得到电离能、电子亲合势、空穴抽取能及电子抽取能等相关能量, 用ZINDO和TD-DFT方法计算得到吸收光谱; 分析了各种能量的变化及光谱规律. 用外推法由低聚物分子的各种性质与聚合度n相联系得到高聚物的性质, 将所得结果与2,7-咔唑(2,7-carbazole)及类似聚合物进行了比较分析. 结果表明, 3,9位聚合的咔唑整体共轭程度降低, 光谱蓝移, 其IP值和聚芴相近, 可以作为空穴接受材料应用于多层电子荧光器件的空穴传输层. 用CIS方法进行优化得到部分分子的S1激发态结构, 用ZINDO和TD-DFT方法得到对应的发射光谱.     

Optimizing the quadruple-potential waveform for the pulsed amperometric detection of neomycin

Determination of neomycin is important for quality control of the pharmaceutical preparation. A quadruple-potential waveform used for pulsed amperometric detection of neomycin was investigated. The waveform cleans the electrode by application of a potential more negative than the potential limit to avoid the formation of gold oxide during applying positive potential to clean gold electrode, thus decreasing the dissolution resulting recession of the gold working electrode within gold oxide formation/reduction cycles in the triple-potential waveform. Waveform parameters were optimized to maximize the signal-to-noise ratio (S/N). The detection limit of neomycin B is lower than 0.01 microg/ml. The linearity of framycetin (plotted as peak area of neomycin B) ranges from 0.05 to 100 microg/ml with correlation coefficient 0.9998. R.S.D. (n = 60) of the peak area of neomycin B is lower than 2%. The quadruple-potential waveform shows low detection limits and long-term reproducibility.     

利用室温固态反应制备球霰石型CaCO3粒子

合成形态、大小及结构可人为调控的无机材料是现代材料科学的重要研究方向[1]. 借助于各类有机添加剂及模板剂的调控作用, 可利用溶液合成方法制备出形貌与结构受到有效调控的无机粒子[2,3]. 室温固态化学反应已被成功地应用于多种无机纳米粒子[4]及纳米线[5]的合成, 并显示出高效、节能、无污染和操作简便等优点, 因而在材料合成领域具有应用前景[6].     

Synthesis and photochromic properties of molecules containing [e]-annelated dihydropyrenes. Two and three way pi-switches based on the dimethyldihydropyrene-metacyclophanediene valence isomerization

The syntheses of several new simple negative, a simple positive, and multiple negative photochromes containing the dihydropyrene-cyclophanediene photochromic system are described. The photo-openings of the negative photochromes, the [e]-annelated benzo (7), naphtho (9), anthro (11), furano (19), and triphenyleno (15) derivatives of the parent 2,7-di-tert-butyl-trans-10b,10c-dimethyl-dihydropyrene (5), as well as its 4,5-dibromo derivative (13), are described to give the corresponding cyclophanedienes, as well as their photoclosures and thermal closures back to the dihydropyrenes. These are compared to the results obtained for the positive photochrome dibenzo[e,l]dihydropyrene (21) and to the bis(dihydropyreno)chrysene (44) and the (dihydropyrenobenzo)(benzo)metacyclophanediene (47) photochromes, which have more than one photochromic switch present and thus have more than a simple "on-off" state. Thermodynamic data are obtained for the thermal closing reactions. The anthrodihydropyrene (12) has the fastest thermal closing (tau(1/2) = 20 min), while the furanodihydropyrene (19') has the slowest (tau(1/2) = 63 h) at 46 degrees C. An electrochemical readout of the state of the switch is demonstrated for the benzodihydropyrene (7).     

Influence of vanadium doping on the behavior of YBa_2Cu_3O_7-y

YBa2Cu3-xVxO7-y(x=0, 0.1, 0.2, 0.3, 0.4, 0.5 and 0.6) superconductors have been prepared. X-ray diffraction shows that the system remains orthorhombic for all compositions studied, but for x > 0.4 V2O5 was detected as an impurity phase. Substitution of V5+ for Cu2+ occurs in the Cu(2) sites on the Cu(2)-O planes. The introduction of the high valence element, vanadium, produces the extra free-electrons. These electrons recombine with the positive carrier of the system. It makes depression of the mobility and the Hall number of YBa2Cu3-xVxO7-v and also results in a depression of TC.