溶胶-凝胶法制备分子筛／γ-Al2O3对Mn^2＋的吸附性能研究

采用溶胶-凝胶法制备分子筛／γ-Al2O3复合材料，以高碘酸钾分光光度法为检测手段，考察了分子筛／γ-AL2O3在静态条件下对Mn^2＋的吸附性能。结果表昵，pH值在7～8时，分子筛／γ-Al2O3对Mn^2＋有较好的吸附性能，吸附符合Langmuir吸附模型，吸附容量可达29mg／g，产生复合效应。     

K_2CO_3/γ-Al_2O_3催化菜籽油酯交换合成生物柴油

采用等体积浸渍法制备了负载型固体碱K2CO3/γ-Al2O3催化剂,并将其用于催化菜籽油与甲醇酯交换反应合成生物柴油。考察了催化剂制备条件和反应条件对生物柴油收率的影响。实验结果表明,采用K2CO3负载量(质量分数)为20%、在600℃下焙烧5h的K2CO3/γ-Al2O3催化剂,当催化剂与菜籽油的质量比为0.03,甲醇与菜籽油的摩尔比为12∶1,在60℃下反应1h后,生物柴油的收率高达93.6%。用X射线衍射、比表面积测定等手段对催化剂的结构进行了表征,表征结果显示,催化剂的活性与其晶相和比表面积密切相关。     

Preparation of well uniform-sized and monodisperse ZnS nanoballs by γ-irradiation method

Well uniform-sized and monodisperse ZnS nanoballs with an average diameter about 120 nm were synthesized through γ-irradiation route by controlling appropriate irradiation time under ambient pressure and at room temperature. The products are characterized by field emission scanning electron micrograph (FESEM), transmission electron microscope (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectrometry (XPS). The influencing factors for the uniform-sized ZnS nanoballs e.g. irradiation time (dose), and pressure were also primarily investigated.     

喹啉、吲哚对二苯并噻吩在NiMoS/γ-Al2O3上加氢脱硫反应的影响

 在固定床高压微反装置中考察了喹啉和吲哚对二苯并噻吩(DBT)在NiMoS/γ-Al₂O₃催化剂上加氢脱硫(HDS)反应活性及反应路径的影响.结果表明,喹啉和吲哚对DBT的加氢脱硫反应具有抑制作用. 少量的喹啉和吲哚即可强烈抑制DBT加氢脱硫反应的加氢路径; 而当含氮化合物加入量高时,才能较为显著地抑制DBT加氢脱硫反应的氢解路径. 在相同的条件下, 喹啉对加氢脱硫反应的抑制能力比吲哚强. 产物分析结果表明, 氮化物对DBT加氢脱硫反应的抑制作用与其分子结构和加氢脱氮反应中间产物的种类紧密相关.     

Culinary plants,herbs and spices – A rich source of PPARγ ligands

Obesity and the related disorders, diabetes, hypertension and hyperlipidemia have reached epidemic proportions world-wide. The influence of 70 plants, herbs and spices on peroxisome proliferators-activated receptor (PPAR)γ activation or antagonism, a drug target for metabolic syndrome, was investigated. Approximately 50 different plant extracts bound PPARγ in competitive ligand binding assay, including pomegranate, apple, clove, cinnamon, thyme, green coffee, bilberry and bay leaves. Five plant extracts transactivated PPARγ in chimeric GAL4-PPARγ-LBD system: nutmeg, licorice, black pepper, holy basil and sage. Interestingly, nearly all plant extracts antagonized rosiglitazone-mediated coactivator recruitment in time resolved fluorescence resonance energy transfer coactivator assay. The five transactivating extracts may function as selective PPARγ modulators (SPPARγMs), and the other extracts seem to be moderate antagonists or undetectable/weak SPPARγMs. As SPPARγMs improve insulin resistance without weight gain and PPARγ antagonists exert antiobesity action, a combination of these plants in diet could reduce obesity and the incidence of metabolic syndrome.     

三种聚合物光纤γ射线辐照光谱特性实验研究

分析了聚合物光纤在辐照环境下的物理化学变化，实验研究了聚甲基丙烯酸甲脂（PMMA）.聚碳酸脂（PC）、聚苯乙烯（PS）三种光纤在不同剂量的γ射线辐照下的辐照损伤效应，测量了三种聚合物光纤在可见光波段的辐照光谱。测量结果表明，光纤的辐照损伤和恢复都有波长相关性，在0.1kGy和1kGy辐照剂量时，三种光纤的透过率光谱趋势类似，整个可见光波段透过率光谱都较平坦；在5kGy和10kGy辐照剂量时，测得的辐照光谱在不同波长段出现峰值，辐照剂量越高剂量率越大，光谱的峰值效果越明显，透过率起伏越多，透过率峰值也向长波段偏移     

振动剪切诱导茂金属全同立构聚丙烯生长γ晶

采用普通注射成型(CIM)和振动保压注射成型(OPIM)两种方法制备茂金属全同立构聚丙烯(m-iPP)试样。利用二维广角X射线衍射(2D-WAXD)和差示扫描量热法(DSC)分别表征试样从表层到芯层的晶体结构和热行为。结果表明:(1)γ晶的相对含量是温度场控制和剪切场诱导共同作用的结果。慢的冷却速率有利于γ晶形成,剪切取向一定程度抑制分子链的折叠有利于γ晶形成;(2)DSC与2D-WAXD的试验结果有很好的一致性。     

Surface modification of superparamagnetic iron nanoparticles with calcium salt of poly(γ-glutamic acid) as coating material

Surface-modified magnetite nanoparticles (MNPs) were synthesized by co-precipitation of aqueous solution of ferrous and ferric salts (molar ratio 1:2) upon adding a base followed by calcium salt of poly(γ-glutamic acid) (Ca-γ-PGA) for uniform coating on the surface of MNPs. Both uncoated and Ca-γ-PGA-coated MNPs were characterized using various techniques including Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM), thermogravimetric analysis (TGA) and vibrating sample magnetometric (VSM) studies. Compared with bare MNPs, the IR spectra of coated MNPs showed characteristic peaks of γ-PGA, implying the γ-PGA coating on MNPs did occur. The TEM images depicted an average size of 8-10 nm for bare MNPs and 14 nm for coated MNPs, with their shape being spherical in nature. In the presence of applied magnetic field, a superparamagnetic behavior was observed at room temperature for both bare and Ca-γ-PGA-coated MNPs, with no magnetism left upon magnetic-field removal.     

Changes in γ-aminobutyric acid content and related enzyme activities in Jindou 25 soybean (Glycine max L.) seeds during germination

In order to accumulate γ-aminobutyric acid (GABA), soybean seeds (cultivar Jindou 25) were germinated for 102 h at different temperatures (19, 25 and 32 °C). The content of GABA, glutamic acid and the activity of the glutamate decarboxylase (GAD) and GABA transaminase (GABA-T) in soybeans during germination were investigated. The results showed that the germination temperature and germination time had great influences on GABA content and the related enzyme activities in soybean seeds. As compared to raw soybeans, an increase in the content of GABA and glutamic acid was observed, as well as GAD activity in soybeans during germination, while germination at 32 °C was better for accumulating GABA in soybeans. The GABA-T activity first decreased and then increased at 19 °C and 25 °C, on the contrary, it first increased and then decreased sharply during germination at 32 °C. These results indicate that the increase of GABA content can be attributed to the changes of GAD and GABA-T activities rather than enough glutamic acid resulting from the degradation of protein during germination of Jindou 25 seeds. However, more assays need to be further performed with more soybean cultivars.     

pH值对铁系催化剂结构的影响

以FeSO4·7H2O为铁源,以氨水为沉淀剂,通过沉淀-空气氧化法,在不同pH值条件下制备了一系列铁系催化剂;采用X射线衍射、低温N2吸附、扫描电镜和透射电镜等技术对催化剂进行了表征.通过800℃焙烧3h考察了催化剂的含水量.结果表明,不同pH值制备的催化剂主体晶相和微观结构有较大差异,其中pH值为7.0时,催化剂主体晶相为γ-FeOOH,微观形态为板条状,其比表面积最高,平均孔径最小,催化剂中含水量最高.