红树来源真菌Daldinia eschscholtzii HJ004发酵产物中三个新的次级代谢产物（英文）

从红树来源真菌Daldinia eschscholtzii HJ004中分离得到3个新化合物以及8个已知化合物.通过高分辨质谱、一维和二维核磁共振波谱以及X射线单晶衍射数据确定了8-乙基-7-羟基-5-羧基-2,3-二甲基色酮(1)的结构.通过电子圆二色谱(ECD)量子化学计算以及圆二色谱(CD)数据与文献进行比较,确定了felinone C (2)和螺旋霉素G (3)的绝对构型.利用总抗氧化能力检测试剂盒(ABTS快速法)测试了所得11个化合物的自由基清除能力,其中4个化合物表现出显著的抗氧化活性,IC50值的范围为5.57～195.03μmol/L,强于阳性对照水溶性维生素E(trolox)的抗氧化活性(IC50=292.12μmol/L),具有开发为抗氧剂的潜力.     

光电门技术在重力加速度测量中的应用

根据简谐振动的特点，构建出一个简易的弹簧振子简谐振动实验装置，利用光电门技术测量弹簧振子做简谐振动的周期，同时结合最小二乘法处理实验数据，计算出重力加速度.研究发现利用该装置测量的重力加速度，结果准确度高，稳定性好，易于推广.     

Observation of Charge Density Wave in Layered Hexagonal Cu1.89Te Single Crystal

We report comprehensive transport, electron microscopy and Raman spectroscopy studies on transition-metal chalcogenides Cu_1.89Te single crystals. The metallic Cu_1.89Te displays successive metal-semiconductor transitions at low temperatures and almost ideal linear MR when magnetic field up to 33 T. Through the electron diffraction patterns, the stable room-temperature phase is identified as a 3 × 3 × 2 modulated superstructure based on the Nowotny hexagonal structure. The su...     

Anderson结构稀土钼铬多金属氧酸盐的合成与表征

A new kind of Anderson-type chromium-molybdates containing the rare earth elements are synthesized， which have the general molecular formula of (NH₄)₆[CrMo₅Ln(OH₂)₂O₂₄H₆]·xH₂O (Ln=La，Ce，Pr，Nd，Sm，Gd and Yb). The components of these heteropoly complexes are determined by chemical elemental analysis， ICP and TG-DTA. And IR， UV， ESR，XPS and ¹H NMR are also applied to characterize the complexes as well. The results indicate that the structures of these complexes are Anderson B type and the rare earth elements are in the inner sphere of the heteropoly salts. The thermal stabilities of these complexes studied by TG-DTA show that the range of pyrolysis temperature is between 490℃ and 500℃.