Regio- and diastereoselective Reformatsky reaction of chiral fluoroalkyl α,β-unsaturated N-tert-butanesulfinyl ketimines: Efficient asymmetric synthesis of β-fluoroalkyl β-vinyl β-amino esters

Highly regio- and diastereoselective Reformatsky reaction of stable, chiral fluoroalkyl α,β-unsaturated N-tert-butanesulfinyl ketimines was developed, which provided an efficient method for the asymmetric synthesis of structurally diverse β-tetrasubstituted β-fluoroalkyl β-vinyl β-amino esters in good yields and with excellent diastereoselectivities (dr up to 96:4).     

Polyphenolic compounds from Malus hupehensis and their free radical scavenging effects

One new 4-chromanone glycoside, 5-O-β-d-glucopyranoside-4-chromanone (1), together with 21 known polyphenols, was isolated from the leaves of Malus hupehensis. Their structures were elucidated on the basis of extensive spectroscopic methods including NMR (1D and 2D), mass (ESIMS and HRESIMS), IR, and by comparison with the data reported in the literature. Some of the isolated compounds were screened for antioxidant activity. Compounds 18 and 14 exhibited significant antioxidant activities with SC₅₀ values 2.73 and 2.91 μg/mL, respectively, while 17, 19, 11, 7, 20, 22, 12 and 13 exhibited moderate activities with SC₅₀ values ranging from 5.24–11.86 μg/mL. The HPLC fingerprint profiles of the leaves and fruits extracts were also analysed, which showed that the constituents were almost the same in both the extracts except for the content of phlorizin which was present in higher amount in the leaves.     

红霉素生产废水的树脂吸附法处理研究

采用XDA-1大孔吸附树脂对琥乙红霉素和红霉素碱两种生产废水分别进行动态吸附处理,研究影响吸附的一些因素.结果显示,在室温、原废水pH和较低流速条件下,经处理后废水的COD降低72%～88%;经丙酮解吸后再从解吸液蒸馏回收99%的醋酸丁酯,从琥乙红霉素废水中还可回收大约0.4kg/m3的红霉素粗品.     

Preparation and Characterization of Mesoporous Ce0.5Zr0.5O2 Mixed Oxide

Mesoporous （MSU） Ce0.5Zr0.5O2 mixed oxide with a high specific surface area has been synthesized under weak acidic condition in the presence of an anionic surfactant, sodium dodecylbenzenesulfonate. The effect of the pH value on the formation of mesostructure and the thermal stability of the material has been evaluated. The products were characterized by transmission electron microscopy, powder X-ray diffraction and nitrogen adsorption-desorption measurements. The results showed that the as-prepared Ce0.5Zr0.5O2 mixed oxide possessed a specific surface area of 163.3 m^2·g^-1, which had a cubic fluorite-type structure and possessed specific surface areas of 148.4 and 62.4 m^2·g^-1 after calcination at 500 and 800 ℃ for 2 h, respectively. The material showed excellent thermal stability.     

多元醇: 新一代的能源平台？

 在基于生物质的新能源战略中,多元醇正在成为新一代的能源平台. 从纤维素出发,通过热裂解、催化裂化和酸水解加氢等反应能制得多元醇,再以多元醇为原料在较温和的条件下通过水汽重整和费托合成等方法合成燃料、化学品和氢气. 本文综述了多元醇经水汽重整制燃料油和化学品或经光解制氢气的进展,介绍了纤维素类生物质资源经催化氢化和水解加氢制多元醇的研究进展. 虽然简单地套用现有的工业技术就可以转化纤维素,但这些方法在效率、能耗、规模和环保等方面还存在诸多问题,有效提高纤维素利用率的新思路仍在期待之中. 虽然采用精心设计的工艺路线可以有效地转化多元醇,但离“简约、节能、方便可行和环境友好”的要求仍有一定的差距,“一步法”或“一锅法”在未来可能是催化学家仍需持续努力的方向.     

Synthesis and Characterization of a Novel Acrylonitrile Copolymer Containing Glucose Pendants

In this work,a novel sugar-containing copolymer was synthesized by the copolymerization of α-allyl glucoside(AG) with acryloniutrile(AN).The copolymers were characterized by NMR Spectroscopy.It was found that acrylonitrile-based copolymers containing as high as 22wt.% of α-allyl glucoside can be synthesized by the free radical solution copolymerization of the two monomers in DMSO with AIBN as initiator.     

锂盐-锍镍试金-等离子质谱法测定黑色页岩中铂族元素

建立锍镍试金-等离子质谱法测定黑色页岩中铂族元素(PGEs)的方法。在不减少称样量的前提下,结合黑色页岩成分特点,调整试金配料,利用硝酸钾的氧化性,解决形成锍扣难的问题;利用四硼酸锂的助融性,使盐酸溶解锍扣后黑色沉淀量大幅度降低,用等离子质谱法测定黑色页岩中铂族元素。PGEs的线性相关系数均不小于0.9995。Pt,Pd,Rh,Ir,Ru的检出限分别为0.30,0.36,0.032,0.028,0.041 ng/g。用该方法测定实际样品,测定值与参考值一致,测定结果的相对标准偏差为1.2%~10.6%(n=10)。该方法满足地质矿产实验室测试质量管理规范(DZ/T 0130-2006)的要求,可用于黑色页岩中铂族元素的测定。     

DPA(TCNQ)2的烧孔阈值电压对脉宽的依赖关系

合成了一种新的二元电荷转移复合物DPA(TCNQ)2（二丙胺-7,7,8,8-四氰基对亚甲基苯醌)，并得到了其单晶ab面的STM高分辨图像，表面晶格常数与体相晶格常数的XRD数据完全一致.用STM成功地写入了5×5的信息点阵，并在5.1 μm×5.1 μm的面积上写入更大规模的信息点阵，写入的可靠性和稳定性都很高.实验发现，烧孔阈值电压强烈依赖于脉宽,这一现象不支持场致蒸发的机理.理论分析表明，它支持热化学烧孔的机理.     

固定化脂肪酶催化合成6,6'-海藻糖月桂酸酯

 以吸附在硅藻土上的假丝酵母（Candidasp．1619）脂肪酶为催\r\n化剂，在无溶剂体系中，研究了月桂酸与海藻糖的酯化反应．结果表明\r\n，反应温度为47℃，pH为7．0，月桂酸与海藻糖的摩尔比大于6时酯化\r\n反应的转化率较高．在3．2mmol（0．64g）月桂酸、0．2mmol（0．07\r\n6g，即53μl浓度为1．43g／ml的糖溶液）海藻糖和200mg固定化脂肪酶\r\n（1000U）组成的反应体系中，于47℃振荡反应36h，以海藻糖月桂酸双\r\n酯计算，酯化程度达95％以上．用有机溶剂提取的反应产物经薄层色谱\r\n提纯后进行13CNMR分析，结果表明，产物主要是6，6’－海藻糖月桂酸\r\n酯，其纯度为90％～95％．     

助剂钾对二氧化碳加氢反应活性及产物分布的影响

报导助剂Ｋ对Ａｌ２Ｏ３，ＴｉＯ２，ＺｒＯ２担载Ｆｅ催化剂，用于ＣＯ２加氢合成Ｃ２＋烃的催化活性及产物分布的影响。与不含Ｋ的催化剂相比，Ｋ的存在导致Ｆｅ／Ｋ－Ａｌ２Ｏ３的催化活性及Ｃ＾２＋烃选择性明显提高，但使Ｆｅ／Ｋ－ＴｉＯ２的催化活性及Ｃ２＋烃选择性显著下降，而对Ｆｅ／Ｋ－ＺｒＯ２，这种影响并不显著。Ｋ的明显有利于低碳烯烃的生存。