8—氮鸟嘌呤的极谱伏安行为

用循环伏安法（ＣＶ）、电流采样极诸法（ＳＣＰ，即ＴＡＳＴ）、常规脉冲极谱法（ＮＰＰ）、微分脉冲极谱法（ＤＰＰ）、线性扫描伏安法（ＬＳＶ）、Ｏｓｔｅｒｙｏｕｎｇ方波伏安法（ＯＳＷＶ）和计时库仑法（ＣＣ）等电化学技术研究了抗癌药物８－氮鸟嘌呤（８－ａｚａｇｕａｎｉｎｅ，ｇｕａｎａｚｏｌｏ，简称８－ＡＧ）的极谱伏安行为．在 ０． １ｍｏｌ／Ｌ Ｈ２ＳＯ４底液中，８－ＡＧ有一良好的还原峰，峰电位（Ｅｐ）在－０． ９５Ｖ（ｖｓ．Ａｇ／ＡｇＣｌ，下同）附近，８－ＡＧ浓度在４×１０－６～８×１０－４ｍｏｌ／Ｌ范围内．峰高与浓度有良好的线性关系，线性相关系数ｒ＝０．９９９９～０．９９１０，检出限为１× １０－６ｍｏｌ／Ｌ．实验证明了该峰具有吸附性．本文提出了电极反应机理，它包括：酸性介质中８－ＡＧ的质子化、质子化的８－ＡＧ在汞电极上吸附以及完全不可逆的两电子还原过程．同时用量子化学计算方法（全略微分重叠法即ＣＮＤＯ／２）对８－ＡＧ和鸟嘌呤的各原子的净电荷以及Ｗｉｂｅｒｇ键级进行了计算，从理论上解释了８－ＡＧ的电化学还原机理。     

1—酰基—4—氯环己烷与取代芳烃的区域与立体选择性反应

从环己烯合成了１－酰基－４－氯环己烷，发现在其在ＡｌＣｌ３催化与苯，氯苯，溴苯等优先生成反式１－芳基－４－酰基环己烷，与联苯反应时选择性较差。     

Reactivity of organolanthanide and organolithium complexes containing the guanidinate ligands toward isocyanate or carbodiimide: synthesis and crystal structures

The direct reactions of (C5H5)2LnCl with LiN=C(NMe2)2 proceeded at room temperature in THF under pure nitrogen to yield the lanthanocene guanidinate complexes [(C5H5)2Ln(mu-eta1:eta2-N=C(NMe2)2)]2 (Ln = Gd (1), Er (2)). Treatment of phenyl isocyanate with complexes 1 and 2 results in monoinsertion of phenyl isocyanate into the Ln-N(mu-Gua) bond to yield the corresponding insertion products [(C5H5)2Ln(mu-eta1:eta2-OC(N=C(NMe2)2)NPh)]2 (Ln = Gd (3), Er (4)), presenting the first example of unsaturated organic small molecule insertion into the metal-guanidinate ligand bond. Further investigations indicate that N,N'-diisopropylcarbodiimide does not react with complexes 1 and 2 under the same conditions; however, it readily inserts into the lithium-guanidinate ligand bond of LiN=C(NMe2)2. As a synthon of the insertion product Li[(iPrN)2C(N=C(NMe2)2)], its reaction with (C5H5)2LnCl gives the novel organolanthanide complexes containing the guanidinoacetamidinate ligand, (C5H5)2Ln[(iPrN)2C(N=C(NMe2)2)] (Ln = Yb (5), Er (6), Dy (7)). All complexes were characterized by elemental analysis and spectroscopic properties. The structures of complexes 1, 3, 5 and 7 were determined through X-ray single-crystal diffraction analysis.     

(4,4′,4″,4″′-四硝基)·酞菁合钴(Ⅱ)化学修饰电极对抗坏血酸的电催化氧化

合成了一种钴的酞菁配合物,以玻碳为基体、用化学吸附法制备了它的化学修饰电极。用CV法研究了该化学修饰电极对抗坏血酸氧化的电催化作用。结果表明,该化学修饰电极对抗坏血酸的氧化有一定的电催化作用,且电催化活性的稳定性高,抗坏血酸的电催化氧化峰电流和其浓度之间有良好的线性关系。     

二(2,4,4-三甲基戊基)膦酸-上胺205-正庚烷乳状液膜分离钪(Ⅲ)、铁(Ⅲ)和镥(Ⅲ)

本文研究了二（2，4，4-三甲基戊基）膦酸（Cyanex272）-上胺205-正庚烷乳状液膜分离Sc（Ⅲ）、Fe（Ⅲ）和Lu（Ⅲ）。考察了外相酸度、表面活性剂浓度、流动载体浓度及内相盐酸浓度对Sc（Ⅲ）迁移的影响。并探讨了该液膜体系分离Sc（Ⅲ）、Fe（Ⅲ）和Lu（Ⅲ）的可能性，结果表明，该体系对于稀土矿中Sc（Ⅲ）的分离与分析有良好的应用前景。     

ELECTROCHEMICAL POLYMERIZATION OF ANILINE IN PHOSPHORIC ACID AND THE PROPERTIES OF POLYANILINE

The behavior of the electrochemical polymerization of aniline in a weak acid, phosphoric acid, is very similar to that in strong acids, i.e. its polymerization rate increases quickly with the electrolysis time. The FTIR spectra of polyaniline samples synthesized in phosphoric acid indicate that the counter ion H2PO4^- is present in both the oxidized form and the reduced form of polyaniline. The counter ion plays an important role in adjusting the pH value at the electrode surface of polyaniline during the oxidation and reduction processes. As a result, a pair of redox peaks still appear in cyclic voltammograms of polyaniline in a solution of sodium sulfate of pH 5.5 and in a solution of NaH2PO4 of pH 7.0,respectively, at low potential scan rate; and the color of polyaniline film also changes with applied potential at pH 7.0. Thus,the pH region for the electrochemical activity and the electrochromism of polyaniline is extended to pH 5.5 for a solution of sodium sulfate and to pH 7.0 for a solution of NaH2PO4. The conductivity of polyaniline is 3.3 S cm^-1, depending on the concentration of phosphoric acid used in the stage of polymerization of aniline. The result of elemental analysis of polyaniline is presented here.     

An efficient synthesis of a hexasaccharide—the repeating unit of the exopolysaccharide from Cryptococcus neoformans serovar A

A general method for the synthesis of 2-xylose or glucuronic acid branched (1→3)-linked mannose oligosaccharides has been developed. As a typical example, the synthesis of the methyl glycoside of β-d-GlcpA-(1→2)-α-d-Manp-(1→3)-[β-d-Xylp-(1→2)-]α-d-Manp-(1→3)-[β-d-Xylp-(1→2)-]α-d-Manp, the repeating unit of the exopolysaccharide from Cryptococcus neoformans serovar A, was achieved in a regio- and stereoselective manner.     

以学生为中心的物理化学远程教学初探

During the fight against the new coronavirus epidemic, the "Physical Chemistry" team of Beijing Normal University used various network platforms and tools, such as MOOC of China University, Rain Classroom and WeChat Group in the teaching process. The exploration and practice of online learning of "Physical Chemistry" is carried out based on MOOC teaching, with student learning as the center and teacher guidance as the support. Taking the most difficult chapter of "fundamentals for statistical thermodynamic" as an example, we designed a complex teaching program that includes previews, watching MOOC videos in class, real-time online exercises, teachers' answers, and after-class reflection and questioning. The students were encouraged to learn independently through the reserved information, designed activities and assignments. Practice shows that the online course has cultivated the students' self-management ability, trained their critical thinking skills, and achieved good teaching results.     

Co—Mo／MgO—Al2O3水煤气耐硫变换催化剂失活的研究

利用Ｘ－射线衍射，扫描电镜，拉曼光谱，等离子发射光谱和比表面测定等方法研究了不同状态下失活及新鲜催化剂的结构，杂种类及含量。结果表明，超温使催化剂晶化明显，制备方法对催化剂结构有直接影响，再生使其强度降低，条形催化剂比较容易粉化，无机杂质是次要的失活原因。     

TiO2 sol-gel derived amperometric biosensor for H2O2 on the electropolymerized phenazine methosulfate modified electrode

A novel hydrogen peroxide biosensor was developed based on the immobilization of horseradish peroxidase (HRP) in a TiO(2) sol-gel matrix on an electropolymerized phenazine methosulfate (PMS) modified electrode surface. Such membranes are of interest due to their high surface area, biological compatibility, and ease of fabrication. HRP entrapped in the TiO(2) matix was stable and retained its activity to a large extent. Cyclic voltammetry and amperometric measurements were employed to demonstrate the feasibility of electron transfer between immobilized HRP and the glassy carbon electrode via electropolymerized PMS. The influence of various experimental parameters such as operating potential, pH, temperature, and stability was investigated for optimum analytical performance. The biosensor provided a wide linear calibration range from 4.0x10(-6) M to 1.0x10(-3) M, with a detection limit of 8.0x10(-7) M at a signal-to-noise ratio of 3. The sensor retained 80% of its original activity after two months of operation.