盐生盐杆菌生长过程热动力学研究

用 LKB2 2 77生物活性检测系统测定了盐生盐杆菌 R1、J7、S9以及 R1和 J7的融合子 F9生长的产热功率曲线 .根据曲线的特征 ,建立了古生菌生长过程的热动力学方程 :ln[P· ( 1 -P/Pm) r- 1 ]=ln[P0 · ( 1 -P0 /Pm) r- 1 ]+k· t.由此求得了盐生盐杆菌的生长速率常数 ,并对此模型和融合子 F9的生长进行了讨论 .该热动力学方程描述了一系列非理想的细菌生长过程的产热功率曲线 ,并将其与经典的指数式生长模型和 lo-gistic模型进行了比较 ,它具有更广泛的适用性 .首次报道了微量热技术在古生菌中的应用     

Improved hygrothermal durability of flax/polypropylene composites after chemical treatments through a hybrid approach

There are growing research interests in flax fibers due to their renewable ‘green’ origin and high strength. However, these natural fibers easily absorb moisture and have poor adhesion with polymer matrix leading to low interfacial strength for the composites. A hybrid chemical treatment technique combining alkali (sodium hydroxide) and silane treatments is adopted in the current study to modify flax fibers for improved performances of flax/polypropylene composites. Changes in chemical composition, microstructure, wettability, surface morphology, crystallinity and tensile properties of single flax fiber before and after chemical treatments were comprehensively characterized using techniques including SEM, FTIR, AFM, XRD, micro-fiber tester, etc. It was found that hemicellulose and lignin at the fiber surface were removed due to alkali treatment, which helped to reduce moisture absorption of the composites. Alkali-treated flax fibers were later subjected to silane treatment, which helped to improve the compatibility between flax fiber and polypropylene matrix. After alkali-silane hybrid chemical treatment, moisture absorption of the composites was further decreased. At the same time, the interfacial bonding strength between flax and polypropylene is significantly enhanced. All these results validate the great advantage of the hybrid chemical treatment approach for flax/polypropylene composites, which has the potential to promote the application of chemical treatment techniques in the plant fiber composite industry.

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七-O-乙酰基-β-乳糖异硫氰酸酯的合成、表征及电化学研究

本文合成了并培养出了七-O-乙酰基—β—乳糖异硫氰酸酯的单晶，用X射线衍射分析了其晶体结构。结果表明，晶体为正交晶系，P2₁2₁2₁空间群，a＝1．23282(7)，b＝1．80012(10)，c＝1.85230(10) nm，α＝β＝γ＝90°，V＝4．1107(4) nm³，Z＝4。电化学实验观测到单链DNA和双链DNA对该化合物的峰电流均有明显降低作用，表明化合物与DNA发生了静电作用。     

1,3,3a,5-四苯基-3a,4,5,11-四氢-3H,6H-1,2,4-三唑并[4,3-d][1,5]苯并二氮杂(艹卓)的合成及晶体结构

通过2,4-二苯基-2,3-二氢-1H-1,5-苯并二氮杂(艹卓)与苯甲酰氯苯腙的[2+3]环加成反应制备了标题化合物,用X射线单晶衍射仪测定了其晶体结构.晶体属正交晶系,空间群为Fdd2.晶胞参数:a=1.762 8(4)nm,b=5.751 2(12)nm,c=1.022 7 nm,V=10.368(5)nm3,Z=16,Dc=1.262 g·cm-3,μ=0.075 mm-1,F(000)=4 160,1 139个可观测衍射点,R-0.046 1,Rw=0.056 0.     

冠醚B15C5萃取分离锂同位素的阴离子效应

本文研究了B15C5冠醚萃取锂盐时,不同阴离子对体系的同位素分离效应的影响。结果表明,阴离子在冠醚萃取过程中不仅对萃取络合物的稳定性有显著影响,而且阴离子半径及软度越大时,萃取体系的锂同位素分离系数(α_(LI))也越大。     

Immobilization of Glucose Oxidase on Cellulose／Cellulose Acetate Membrane and its Detection by Scanning Electrochemical Microscope （SECM）

Cellulose/cellulose acetate membranes were prepared and functionalized by introducingamino group on it, and then immobilized the glucose oxidase (Gox) on the functionalizd membrane.SECM was applied for the detection of enzyme activity immobilized on the membrane.Immobilized biomolecules on such membranes was combined with analysis apparatus and can beused in bioassays.     

Alkaloids from stems of Ervatamia yunnanensis

Six indole alkaloids were isolated from the stems of Ervatamia yunnanensis. Among them, yunnanensine (I) is new. The other five are known alkaloids, namely: 19,20-E-vallesamine (II), 19s-heyneanine (HI), ibogaine (IV), ibogamine (V), coronaridine (VI). The structural elucidation of the alkaloids was based on spectral means.     

Synthesis and Kinetic Study on the Chromium(III) Complex [Cr(ASA)(en)2]Cl·2H2O

In order to explore the transfer mechanism of chromium(III) in mammals, a novel complex [Cr(ASA)(en)₂]Cl· 2H₂O, bis(ethylenediamine‐ κ ² N,N′)(4‐aminosalicylic acid‐ κ ² O,O′) chromium(III) monochloride dihydrate was synthesized (4‐aminosalicylic acid=H₂ASA, ethylenediamine=en). The crystal structure belongs to orthorhombic system with the space group P2₁2₁2₁ by means of X‐ray diffraction. The characteristic for transfer of Cr³⁺ from the compound to the low‐molecular‐mass chelator EDTA and the iron‐binding protein apoovotransferrin (apoOTf) was followed by UV‐visible (UV‐Vis) and fluorescence spectra in 0.01 mol·L^?1 Hepes at pH 7.4. The second order rate constants were calculated. Those spectra in conjunction were used to obtain more accurate information about the interaction of chromium complex with apoOTf. The experimental results indicate that Cr³⁺ can be transferred from the complex to apoOTf with the retention of the 4‐aminosalicylic acid acting as a synergistic anion.