High-Yield Method for the Preparation of 1,3,4,5-Tetrahydro-7-methoxy-2H-1-benzazepin-2-one with Excellent Regio- and Stereoselectivity

We have surveyed the effects of different acid catalysts, reaction times, and temperatures on the yield, regioselectivity, and stereoselectivity and calculated the ketoxime isomerization and activation energy of the title compound. A facile synthetic procedure with good yields and good regio- and stereoselectivity for Beckmann rearrangement of oxime sulfonate with ZnCl₂ in the presence of solvent is developed.     

Asymmetric Synthesis XIII: The Stereocontrolled Synthesis of (R)—α—Amino Acids via a Double Chiral Induction

The stereocontrolled synthesis of (R)—α—amino acids via a double chiral induction in alkylation of the ketimine derived from (+)—camphor and (+)—menthyl glycinate which is a chiral match pair has been studied. (R)—α—amino acids wih high optical purity 80–90% are obtained after hydrolysis of the alkylated products. We find that the chiral match which is the symergistic effect in a double chiral induction is very important to abtain the higher diastereoselectivity for the stereocontrolled synthesis.     

阳极微分脉冲伏安法测定麦迪霉素

探讨了不同pH溶液中,麦迪霉素在玻碳电极上的伏安行为。在pH=7.0的NH_4Ac溶液中,麦迪霉素有一个灵敏的氧化峰,阳极微分脉冲扫描峰电位为 0.81V(vs·SCE)。其浓度在10×10~(-7)～1.5×10~(-5)mol/L范围内与微分脉冲伏安峰电流呈线性关系,检测限为5×10~(-8)mol/L。     

尿素共沉淀法制备LiNi0.8Co0.2O2正极材料及其电化学性能

采用尿素共沉淀法合成了LiNi0.8Co0.2O2锂离子电池正极材料,研究了烧结温度、锂源摩尔配比对LiNi08Co02O2晶形结构、形貌以及电化学性能的影响.结果表明,尿素共沉淀法合成LiNi0.8Co02O2样品最佳工艺条件是800℃温度条件下烧结10 h、锂过量5;合成的样品具有较好的电化学性能,以0.2C倍率充放电时首次充放电容量分别为206.4 mAh·g-1和191.6 mAh·g-1,循环30次后容量为178.2 mAh·g-1.     

Synthesis of 1-(N-arylaminomethyl)-3-methyl-1,8-dihydrocycloheptapyrazol-8-ones

Reactions of 3-methyl-1,8-dihydrocycloheptapyrazol-8-one ( 2 ) with arylamines in the presence of formaldehyde gave 1-(N-arylaminomethyl)-3-methyl-1,8-dihydrocycloheptapyrazol-8-ones 5a-l in good yields. 1,3,5-Tris(phenyl- and 4-methoxyphenyl)hexahydro-1,3,5-triazines or bis(3-nitroanilino)methane, which were condensation products of arylamines and formaldehyde, also reacted with compound 2 to afford 5a,c,j , respectively.     

应变幅值对循环载荷下NiTi合金力学性质的影响

实验研究了应变幅值对循环载荷下NiTi合金伪弹性退化特征的影响规律,结果表明:当卸载发生在NiTi合金应力诱发马氏体相变阶段时,应变幅值对马氏体相变开始应力的退化规律影响较小,但此时应变幅值的增加会显著增大奥氏体弹性模量的退化程度,而其大变形可回复能力和阻尼特性在应变幅值大于6%时才有大幅度降低。对各参数退化程度进行定量分析,得到了NiTi合金具有较强可回复能力和阻尼性能的应变幅值范围。该研究可为NiTi合金阻尼器的设计提供参考。     

关于 Radicaltotal 环上的投射模

文中给出了Radicaltotal环上投射模的分解定理. 对一个 ~uniform 维数有限的 Totalfree 环 R, 该文证明 R 是一个总体维数≤ 1 的诺特环, 且 R上的任何投射模必同构于$ \bigoplus\limits_{i\in I}Re_{i}$, 其中每个 $e_{i}$ 均为 $R$ 的非零幂等元. 此外, 文中还给出了一些相关的例子.     

MOF-808/Bi2MoO6复合材料的构筑及其光催化性能

采用简单的两步水热法制备出了锆基金属有机骨架和钼酸铋的复合材料MOF-808/Bi₂MoO₆。通过X射线粉末衍射、傅里叶红外光谱、扫描电子显微镜、透射电子显微镜、X射线光电子能谱、紫外可见漫反射光谱、N₂吸附-脱附测试和电化学测试对所制备材料的组成、微观结构、光学性质以及光生载流子的复合效率进行了分析。与纯Bi₂MoO₆和MOF-808相比,0.5%-MOF-808/Bi₂MoO₆复合材料展示出了较高的光催化活性,在可见光照射120 min时对抗生素环丙沙星(CIP)的降解率达89.7%。通过自由基捕获实验,证明了·O₂^-是主要活性物种,基于此我们提出了可能的光催化降解机理。