An excellent new resolving agent for the diastereomeric resolution of rac-mandelic acid

Chiral mandelic acid (S)-1, which is an important precursor for stereoselective transformations and a versatile intermediate for pharmaceuticals, was resolved with the Pope and Peachey method. Enantiopure 1-amino-3-phenoxypropan-2-ol (S)-2, a key intermediate for pharmaceuticals, was used to resolve rac-mandelic acid rac-1 successfully for the first time. The less soluble salt (S)-1·(S)-2·H₂O could be obtained in 77% yield and 98% de (E 75%) using (S)-2 and LiOH in water. The crystal structure of the less soluble salt (S)-1·(S)-2·H₂O showed that the water molecule played a key role in forming the crystals.     

A Convenient Synthesis of α-Hydroxyiminoacetonitriles From Aldoximes

Aromatic α-hydroxyiminoacetonitriles can be conveniently prepared by a facile one-pot procedure in high yields involving chlorination of the corresponding aldoximes with tert-butyl hypochlorite followed by reaction with alkali cyanide.     

单分散SnO2中空微纳米球的制备和性质

模板法是制备无机中空微纳米球的重要方法之一. 本文以苯乙烯为单体, 通过乳液聚合得到粒径约为620 nm的单分散聚苯乙烯(PS)微球. 以磺化后的聚苯乙烯(PSS)微球为模板, 利用阴阳离子静电吸附作用, 将PSS与前驱体SnSO₄中的Sn²⁺结合. 通过Sn²⁺在乙醇-水介质中的水解作用得到核-壳复合结构, 再经高温煅烧, 得到SnO₂中空微纳米球. 实验对前驱体的浓度、表面活性剂的用量、反应时间及模板选择等方面做了研究,通过扫描电镜(SEM)、X 射线衍射(XRD)、红外(IR) 光谱、热重分析(TGA)、H₂ 程序升温还原(H₂-TPR)、Brunauer-Emmett-Teller (BET)比表面积等技术深入探究SnO₂中空微纳米球的结构, 并对比中空SnO₂与实心粒子的氧化还原特性. BET和H₂-TPR显示将SnO₂制备成微纳米空心球后其比表面积增大, 表面氧空位明显增多, 氧化活性明显提高. 从IR 及XRD推断核-壳结构形成机理, 进而优化出简单合理的实验方案, 获得表面光滑、结构致密, 包覆厚度可控的SnO₂中空微纳米球.     

Unconventional Origin and Hybrid System for Construction of Pyrrolopyrrole Moiety in Kosinostatin Biosynthesis

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Local Quark-Hadron Duality and Magnetic Form Factors of Bound Proton

We discuss the consequence of local duality for elastic scattering, and derive a model-independent equation between structure functions at x～1 and elastic electromagnetic form factors. Then the electromagnetic form factors of proton are discussed using the quark-hadro.n duality theory. We also debate the form factor of proton in a bound state.It may be an effective approach to study the form factor of proton in media.     

Study on the Regioselective Cleavage of Acetyl of Glycoside in Mild Condition

It is very important to selectively protect or deprotect functional groups in organic synthesis, [1] especially in sugar chemistry where many hydroxyl groups of sugars need to be protected or deprotected selectively in mild condition.     

Aliquat 336功能化壳聚糖螯合吸附剂对溶液中Y(Ⅲ)的富集分离

采用静态吸附法研究了Aliquat 336功能化壳聚糖螯合吸附剂对溶液中Y(Ⅲ)的富集分离。溶液的pH值对Y(Ⅲ)的吸附有较大影响,Y(Ⅲ)初始浓度为90 mg/L,温度为20℃,pH=4.9时,Y(Ⅲ)的吸附量达到大;Y(Ⅲ)的吸附符合准二级动力学模型和Langmuir等温吸附模型;随着温度的升高,Y(Ⅲ)的吸附量减少,吸附过程为放热反应过程。XPS结果表明,Y(Ⅲ)的吸附机理为阴阳离子均参与了Y(Ⅲ)的吸附,提高了Y(Ⅲ)的分离选择性和吸附量。以废弃土荧光粉中土为例,讨论了在实际体系中对Y和其它土的富集和分析分离,显示了本方法潜在的应用价值。     

透皮无创血糖监测技术中的关键电化学问题研究

本研究分析并解决了在透皮无创血糖监测技术中的几个关键电化学问题.针对葡萄糖传感器的线性范围,提出使用新的校正方程标定葡萄糖传感器,使得传感器的线性范围增加到原来的20倍以上.针对透皮无创血糖监测中特有的"有限空间",建立了新的扩散模型进行分析,确立了适于无创血糖检测的采样时刻.针对传感器长时间血糖监测中电极损耗,提出"电极掩膜"的概念,避免了传感器电极的失效.在解决以上关键问题后,得出了较好的动物实验数据.以有创检测值为对照,97个无创血糖值中,70.10%的数据属临床准确,29.90%的数据为临床相对准确.本研究为透皮无创血糖监测技术的实现和优化奠定了基础.     

新型β-氨基醇类高碳糖的合成及波谱研究

用C10高碳糖合成了具有潜在生物活性的C10高碳糖氨基醇类化合物及其中间体,并对所合成化合物的IR、ESI-MS/MS、1H NMR和13C NMR图谱进行归属,确证了化合物的结构.     

A Diquark-Quark Model with Its Use in Nucleon Form Factorst

The nucleon electromagnetic form factors are investigated within a simple diquark-quark model using the light-front formalism. In this model, baryon is described as a bound state of one quark and one clustering diquark. The calculational results are compared with the experimental ones. We also regard the quarks in a baryon as pointlike constituent quarks.