苯乙烯-4-甲基丙烯酰氧-2.2.6.6-四甲基哌啶共聚物的250兆赫~1H-核磁共振研究

本文用250兆赫~1H-核磁共振技术研究了苯乙烯(S)-4-甲基丙烯酰氧-2、2.6.6-四甲基哌啶(M)自由基引发聚合的共聚物的组分比和微结构,定量测定了以M为中心的三元组分布。由此确认该共聚体系属于一级马尔可夫链模型,并确定了单体竞聚率常数,r_M=0.32,r_S=0.60。对苯乙烯含量较多的共聚物还定量估计了以S为中心的三元组分布,与理论上计算结果有很好的一致性。     

An efficient synthesis of α-aryl β-(N-tosyl)amino phosphonate derivatives from α-diazophosphonate

The α-diazophosphonate was added to aryl (N-tosyl)imine to give β-aryl β-(N-tosyl)amino α-diazophosphonates, which were further subjected to TsOH-catalyzed diazo decomposition to yield α-aryl β-(N-tosyl)enaminophosphonates through 1,2 aryl migration. The α-aryl β-(N-tosyl)enamino phosphonates were hydrogenated to give α-aryl β-(N-tosyl)amino phosphonates.     

Sm2O3对CuO-γ-Al2O3催化剂性能的影响

在色谱微反流动法实验装置上考察了负载Ｓｍ２Ｏ３对ＣｕＯγＡｌ２Ｏ３催化剂ＣＯ氧化活性的影响，并运用Ｘ射线衍射（ＸＲＤ）、程序升温还原（ＴＰＲ）及程序升温脱附（ＴＰＤＭＳ）技术研究了Ｓｍ２Ｏ３对ＣｕＯγＡｌ２Ｏ３催化剂的物相结构、氧化还原特性及表面氧的脱附与恢复行为的影响。结果表明，负载适量的Ｓｍ２Ｏ３对ＣｕＯγＡｌ２Ｏ３催化剂表面氧的脱出与恢复有促进作用，可使部分γＡｌ２Ｏ３相变成γＡｌ２Ｏ３和θＡｌ２Ｏ３的混合型。负载适量的Ｓｍ２Ｏ３能改善催化活性，而负载过量的Ｓｍ２Ｏ３则使ＣｕＯ催化剂上ＣｕＯ的晶粒增大，从而对催化活性起了抑制作用。     

粘度法预测聚乙二醇/壳聚糖体系的相容性

甲壳素在自然界的含量很大，仅次于纤维素，是一种颇具应用潜力的天然高分子．可由甲壳素经脱酸基化制得壳聚糖．由于其分子中存在氨基，因此能溶解干酸性水溶液中，并以聚电解质的形式存在，近来用壳聚糖制得的纤维膜应用于药物、食品等的分离和纯化、污水的处理，分离效果好，且不带入任何化学杂质．在壳聚糖纤维膜制作及与纤维的混纺过程中，都要探讨它与其它相应高聚物的相容性[1]．我们以相容的壳聚糖（chitosan）／聚乙二醇（PEG）体系为例，采用粘度法讨论其分子间的相互作用，并预测它们的相容性．壳聚糖的基本结构为1实验部分1.1…     

5-氟尿嘧啶-1-乙酸合铜(Ⅱ)的合成及其与DNA的作用

The 5-fluorouracil-1-acetic acid (5FuAA) and its Cu(Ⅱ) complex (5FuAACu) were synthesized and the date for the crystal complex was obtained. The interaction of 5-fluorouracil-1-acetic acid (5FuAA) and its Cu(Ⅱ) complex (5FuAACu) with DNA was also investigated by using spectral, viscometric, electrochemical and agarose gel electrophoresis methods. The results of interaction with DNA suggest that both 5FuAA and 5FuAACu can bind to DNA in a static electricity attraction mode. But the attraction of 5FuAACu is greater than that of 5FuAA.     

Generalization of in-situ polymerization method for preparing core-shell polymeric nanospheres and hollow spheres

According to the new method of preparing core-shell nanospheres developed by our group, by using two monomers, 2-hydroxypropyl methacrylate(HPMA) and vinyl acetate(VAc), two kinds of core-shell nanospheres with poly(ɛ-caprolactone) (PCL) as the core and crosslinked poly(2-hydroxypropyl methacrylate) (PHPMA) or poly(vinyl acetate) (PVAc) as the shell were successfully prepared under similar conditions. After degrading the PCL cores of the two kinds of nanospheres by lipase, the corresponding crosslinked poly(methyl acrylic acid) hollow spheres and crosslinked poly(vinyl alcohol) hollow spheres were obtained. Results indicate that the new method we proposed for preparing core-shell polymeric nanospheres via in-situ polymerization can be generalized to a certain extent, and it is suitable for many systems provided the monomer used is soluble in water, while its corresponding polymer is insoluble in water. Translated from Chemical Journal of Chinese University, 2006, 27(9): 1762–1766 [译自: 高等学校化学学报]     

Analysis of Zoledronic Acid and Its Related Substances by Ion-Pair RP-LC

A simple high-performance liquid chromatographic method – ion-pair reversed- phase high performance liquid chromatography (RPIC) has been developed and employed for the analysis of zoledronic acid and its related substances in bulk material and commercial dosage forms. The mobile phase was a mixture of methanol (20%) and 5 mmol L^–1 phosphate buffer (80%) containing 6 mmol L^–1 tetrabutylammonium bromide, adjusted to pH 7.0 with sodium hydroxide. C₈ column was used as the stationary phase. The chromatographic conditions were optimized. The active ingredient – zoledronic acid was successfully separated from its related substances, including remained imidazol-1-yiacetic acid in the synthesis of zoledronic acid and other possible impurities of oxidation and decomposition. The excipients did not interfere with the determination of zoledronic acid in commercial dosage formulations. The method was rapid, simple, accurate and reproducible. It was not only successfully employed for the assay of zoledronic acid in bulk material and pharmaceutical dosage forms but also for the determination of its related substances.     

Anodic stripping voltammetry of sulphide at a nickel film: towards the development of a reagentless sensor

The determination of sulphide at an electrochemically generated nickel oxide layer at glassy carbon and screen-printed electrodes in acidic media has been examined and appraised. The NiO layer was found to produce a stripping-like signal to sulphide and gave a linear peak current response from 20 to 90 μM. The response was further enhanced by repetitive cycling allowing accumulation of nickel sulphide at the electrode surface such that lower micromolar levels of sulphide (i.e. 5 μM) can be determined. The response at the NiO layer to sulphide is shown to be reproducible over a period of 24 h, thereby offering the development of a disposable amperometric sensor for sulphide.     

Two Novel Alkaloids from Zanthoxylum nitidum

Two novel alkaloids, 4,5‐dihydroxy‐1‐methyl‐3‐oxo‐2‐(trichloromethyl)‐3H‐indolium chloride ( 1 ) and 4‐(2‐methoxyethyl)‐N,N‐dimethylbenzenamine ( 2 ), were isolated from the EtOH extract of the roots of Zanthoxylum nitidum. Their structures were identified on the basis of spectroscopic and mass‐spectrometric analyses.     

ATR-FTIR study of Bacillus sp. and Escherichia coli settlements on the bare and Al2O3 coated ZnSe internal reflection element

FTIR-ATR has been used for understanding the interaction between bacteria and surfaces in the adsorption progress.