火焰原子吸收法快速分析硫酸中铅镉铜锌

文中直接取硫酸样品3ml于装有约10ml水的25ml比色管中,加入碘化钾溶液2ml,用水稀至刻度。加入甲基异丁酮5ml,萃取lmin,分层后,在有机相中测定铅、镉、铜含量;在水相中测定锌含量。方法的加标回收率为98.9％～103％,精密度1.8％～4.3％,标准曲线法和标准加入法结果相近,倍比试验结果亦相吻合,方法快速简便、准确,适合于工业中的快速分析。     

Study of a molecular imprinting polymer coated BAW bio-mimic sensor and its application to the determination of caffeine in human serum and urine

A bio-mimic bulk acoustic wave (BAW) sensor was fabricated by coating the caffeine (CAF) template molecular imprinting polymer (MIP). This sensor exhibited high selectivity and a sensitive mass response to CAF. The response range of the sensor was between 5.0 x 10(-9) and 1.0 x 10(-4) M with a detection limit of 5.0 x 10(-9) M at pH 8.0. Recoveries were 96.1-105.6%. Influencing factors were investigated in detail and optimized. When employed to detect real samples, the proposed method proved to be a convenient method with the advantages of high sensitivity, good selectivity and ease of handling.     

Palladium-catalyzed, stereoselective rearrangement of a tetracyclic allyl cyclopropane under arylation

The first example of a pi,sigma domino-Heck reaction under concomitant rearrangement of the tetracyclic allylcyclopropane endo,exo-bishomobarrelene (5) is reported; the stereoselective reaction proceeds via an intramolecular insertion of a primarily-formed carbopalladation intermediate into a strained cyclopropane C-C sigma-bond, giving 9.     

Fast electron transfer repair of oxidizing OH adduct of dGMP by chlorogenic acid

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Fe-Co-Ni合金纳米线有序阵列的模板合成与磁性

以二次阳极氧化的氧化铝膜为模板，用电化学沉积的方法成功地合成了Fe-Co-Ni三组份有序纳米线阵列.扫描电子显微镜（SEM）和透射电子显微镜(TEM)观察表明纳米线表面光滑、有序、高长径比；磁性测量表明,其矫顽力较同组份的膜材料有较大的提高.将样品在惰性气体氛围中不同温度下退火，随着退火温度增加，其纵向矫顽力有一个极值，而对应的横向矫顽力没有类似的变化，关于这一现象的机理,本文进行了初步的讨论. 图5参15     

Comparative study of electrochemically directed assembly versus conventional self-assembly of thioacetyl-terminated oligo(phenylene ethynylene)s on gold and platinum surfaces

The assembly of thioacetyl-terminated oligo(phenylene ethynylene)s (OPEs) on Au and Pt surfaces under an electric potential (electrochemical assembly, EA) was compared to assembly at an open circuit (conventional self-assembly, CSA). Cyclic voltammetry and ellipsometry were used to characterize the adsorption kinetics of self-assembled monolayers formed by these two techniques. The adsorption rate of the EA was remarkably faster at positive potentials but slower at negative potentials than that of the CSA, The EA at 400 mV proceeded about 800 times faster than the CSA when exposed to the same solution concentrations. The adsorption rates of both EA and CSA were found to be dependent on the molecular structures of OPEs. OPEs containing electron-donating groups assemble faster than those with electron-withdrawing groups. The amount of time that the thioacetyl-terminated OPE is in the presence of the base, for removal of the acetyl group to generate the thiolate, is called the deprotection time. Deprotection times play a critical role in achieving the maximum difference in adsorption rates between the EA and the CSA. The assembly must be initiated no later than 5 min after the basic deprotection is commenced so that the thiolate concentration remains low. The difference in the adsorption rates between EA and CSA might enable selective deposition of certain OPEs onto specific electrodes.     

A study of carboxylic-modified mesoporous silica in controlled delivery for drug famotidine

A series of pure silica MSU and carboxylic-modified MSU materials were prepared. The formation of mesoporous silica materials with terminal carboxylic groups on pore surface was performed by the acid-catalyzed hydrolysis of cyano to carboxylic. Then their potential applications in controlled drug delivery carriers were investigated. Drug famotidine was selected as a model molecule out of the consideration of the terminal amino groups in its molecule. The adsorption experiments show significant adsorption of famotidine on the carboxylic-modified MSU materials. And, the functionalization level of carboxylic groups has been found to be the key factor affecting the adsorption capacities of the modified MSU materials for famotidine. Subsequently, three kinds of release fluids, including simulated gastric medium, simulated intestinal medium, and simulated body fluid, were used to test the famotidine release rate from the carboxylic-modified MSU material. Obvious delayed effect has been observed for the famotidine release from the carboxylic-modified mesoporous silica material under the in vitro assays.     

负载型非晶态Cu/SiO2催化剂的非晶性质

以超细ＳｉＯ２为载体，用ＫＢＨ４还原Ｃｕ＾２＋盐溶液制备了非负载型Ｃｕ和负载型Ｃｕ／ＳｉＯ２催化剂，ＸＲＤ，ＴＥＭ和电子衍射分析结果表明，负载型Ｃｕ／ＳｉＯ２为完全非晶态，而非负载型Ｃｕ中存在着少量晶态Ｃｕ，ＤＳＣ结果表明，非晶态Ｃｕ／ＳｉＯ２的热稳定性明显高于非负载型Ｃｕ，说明超细ＳｉＯ２具有稳定非晶结构的作用，ＸＰＳ结果表明，还原产物中的铜原子呈Ｃｕ状态，ＩＣＰ分析结果表明，样品中的Ｂ含量均低     

苯、甲苯、一氯代苯对含水卵磷脂液晶结构影响的SAXS研究

苯及其衍生物甲苯,一氯代苯都是重要的有机试剂和化工原料,也是对人体有害的有机物。为了了解这些有机试剂对处于生物液晶态的生物膜毒害的机理,我们以含水卵磷脂组成的液晶体系作为人工模型用小角X射线散射(SAXS)方法探讨这些有机试剂对它们结构的影响。关于苯或其它非极性有机介质与含水卵磷脂形成液晶体系及其结构模型前人有一些报导。     

流动注射—化学发光法测定苯甲醛

依据苯甲醛增强没食子酸－过氧化氢－氢氧化钠体系化学发光的性质，建立了苯甲醛的流动注射化学发光分析法。