溶剂型环氧—酚醛—聚酰胺树脂掺混清漆

应用溶解度参数相近相溶原理，通过环氧树脂、酚醛树酯和聚酰胺三种树脂均相溶液适当掺混，研制成综合性能优良的溶剂型环氧－酚醛－聚酰胺清漆。讨论了该清漆的溶剂选择、配方代化、固化反应机理和红外光谱表征。列举了该清漆的性能测试结果。     

3β-乙酰氧基-15β，16β-亚甲基雄甾-5-烯-17-酮的合成

在二甲亚砜、四氢呋喃或1，4-二氧杂环己烷溶剂中，当温度为12～30℃时，碘化三甲氧硫锤鎓（((CH3)3S^ OI^-)与氢化钠(NaH)作用1h生成甲基硫氧叶立德，再与3β-乙酰氧基雄甾-5，15-二烯-17-酮(Ⅱ)反应，产物经分离得到环丙化产物3β-乙酰氧基-15β，16β-亚甲基雄甾-5-烯-17-酮；探讨了反应物配比、反应温度、溶剂种类、加料方式对环丙化反应的影响．当反应温度为12℃，n((CH3)3S^ OI^-)：n(NaH)2：n(Ⅱ)=1．10：1．05：1．00，加料方式为叶立德溶液加入到甾体溶液中，溶剂为二甲亚砜和四氢呋喃(体积比为4：1)时，用重结晶法分离得产物，产率为80．5％．测试了产物的比位移值Rf、熔点、旋光度，并采用IR，MS和^1HNMR等对产物进行了表征．     

电场作用下沸腾气泡行为实验

为了进一步探讨电场对沸腾传热强化机理,以水为实验工质,实验研究了电场作用下沸腾单个气泡的行为特性。通过直接加热法产生单个沸腾气泡,并利用高速摄像机拍摄观察了不同热流密度和电场强度组合工况下气泡的生长过程,并对该过程中对电场作用下气泡的脱离形态、周期和长径比等行为特性变化进行了相关定性分析,根据实验结果和相关定性分析,进一步合理阐释了电水动力学强化沸腾传热机理。结果表明:外加电场工况后,电场对沸腾气泡的脱离形态有显著的影响,气泡沿场强方向拉伸变形且场强越大,拉伸变形越明显;气泡的脱离长径比随着电场强度和热流密度的增大而变大;气泡的脱离周期随着电场强度和热流密度的增大而减小。这表明电场和热场协同作用有助于减小气泡的停留时间来减小热源于流体之间的热阻,进一步说明电场和热场对沸腾强化传热有一定的影响。     

Synthesis, oxygenation and catalytic performance of manganese complex with p-aminomethyl benzoic acid Schiffbase

The amino acid Schiff base complex (Sal-AMBA-Mn) was prepared with p-amino-methylbenzoic acid, salicylaldehyde and Mn(OAc)2·4H2O. Its structures was characterized with IR and UV spectra. Oxygenation mechanism of the complex in N, N-dimethylformamide solution was investigated. The results show that lower temperature is in favor of the oxygenation, and energy, enthalpy and entropy are -3.8 kJ/mol, -4.2 J/mol and -161.44 J/(mol·K), respectively. In the presence of the manganese complex, dehydroepiandrosterone acetate is effectively oxidized by molecular oxygen and the corresponding enone 7-ketodehydroepiandrosterone acetate is obtained. The yield is 62.1% when the oxidation is carried out under the reaction conditions of 60 ℃, 2 MPa of O2 pressure, C5H5N as a solvent and molar ratio of the substrate to the complex of 1:10.     

Asymmetric synthesis of 3β-acetoxy-17,17-ethylendioxy-15β,16β-methylene-5-androsten-7β-ol

3β-acetoxy-17,17-ethylendioxy-15β,16β-methylene-5-androsten-7β-ol( Ⅰ ) was prepared by 3 steps from 3β-acetoxy-15β,16β-methylene-5-androsten-17-one ( Ⅱ ) with overall yield of 52.7%. Thus, interaction of ethylene glycol and material ( Ⅱ ) gave 3β-acetoxy- 17,17-ethylendioxy-15β,16β-methylene-5-androsten ( Ⅲ ) which was subsequently oxidated and stereoselectively reduced to produce compound( Ⅰ ). The normal influencing factors, such as the types of oxidants and reductives, the mole ratio of reactants, the reaction temperature, and the addition ways of reactants, in oxidation and reduction were discussed. The results show that the oxidation rate order is CrO3-C5 H5 N (1: 1, mole fraction)＞CrO3-C5H5 N(1: 2)＞ (C5H5NH)2 Cr2O7 in terms of the oxidant, the yield of the oxidation becomes higher with increasing the oxidant stoichiometry and raising the reaction temperature. And the optimum condition is that the reaction temperature is at 30 ℃, and n(Ⅲ)/n(CrO3-C5H5N(1: 2))=1: 20. The yield of the -7β alcohol order with Li[Al(OC(CH3)3)3H] (e. G. 78. 6%) is more than that with NaBH4 (e. G. 14. 5%) in terms of the reductive agent and the reduction rate decreases in the course of reaction. The compound (Ⅰ) is characterized by 1R and MS.     

Preparation of cobalt-modified magnetite and its magnetic properties

Magnetite was modified by reaction with alkaline solution containing Co^2 and Fe^2 to obtain a cobalt ferrite layer on the surface of particles. The influences of modification conditions on the properties were investigated. The as-prepared particles were characterized by X-ray diffraction(XRD) and transmission electron microscope(TEM). The results show that pH value influences the particles composition directly, the desirable CoFe2O4 is obtained as pH value is 12. The coercivity of particles increases with the increase of cobalt content, and the cobalt efficiency reaches a maximum value at cobalt content of 2.71% (mass fraction). With cobalt modification, the magnetite particles have the similar lattice constant and structure to that without cobalt modification, and the squareness ratio is almost 0.5. The increase of the coercivity is attributed to the uniaxial magnetic anisotropy and magnetocrystalline anisotropy of cobalt-ferrite itself.     

硫铁矿烧渣制备静电复印显影剂用Fe3O4

硫铁矿烧渣是生产硫酸时产生的固体废弃物。硫铁矿烧渣经硫酸浸出,用机械活化的硫铁矿还原,过滤得到硫酸亚铁溶液。以此溶液为原料,采用空气氧化法制备显影剂用Fe3O4。研究了FeSO4浓度、碱种类、pH值、空气流量和温度对产品性能的影响,用XRD、SEM、粒度分析和磁性能测试等手段对产品进行了表征。结果表明,在最佳工艺条件下得到了球形Fe3O4,粒度分布范围为0.1～0.5μm,磁饱和强度为96.2Am2/kg,矫顽力为10.7kA/m,满足静电复印显影剂对磁粉的要求。     

Kinetics of Fe_3O_4 formation by air oxidation

1　INTRODUCTIONFe3O4 hasanumberofnovelpropertiesandper formances ,itsuniquemagnetic ,thermalandtribolog icalpropertiesmakeitanewtypeofmaterialspromis inginvariousapplicationssuchaspigment,toner ,in formationstorage ,ferrofluids ,bioprocessing ,elec tronicsandcatalyst[1,2 ] .Owingtothewideapplica tion ,majorityofresearchersfocusedontheprepara tionmethodsofmagnetite[310 ] ,however ,themech anismandkineticsofFe3O4 formationwerescarcelystudied .Thekineticsandmechanismofoxyhydrox idesformatio…     

溶剂型环氧—聚酰胺树脂清漆

应用溶解度参数理论,通过对环氧树脂、聚酰胺树脂均相溶液适当混合,研制出综合性能优良的溶剂型环氧－聚酰胺清漆。讨论了清漆的溶剂选择、固化反应机理和红外光谱表征。列举了清漆性能的测试结果。     

r-TiO2可见光催化H2O2降解阿特拉津

以金红石型TiO2(r-TiO2)为光催化剂,以内分泌干扰物阿特拉津作模型污染物,研究了r-TiO2可见光催化H2O2降解阿特拉津的反应特性.表明r-TiO2能可见光催化H2O2降解阿特拉津,反应180 min,阿特拉津的降解率达60%;通过对反应体系的荧光光谱分析显示,阿特拉津的降解涉及羟基自由基(·OH)的产生与参与;往反应体系加入自由基抑制剂(Na2CO3或NaHCO3)时,显著降低金红石TiO2的降解效率;阿特拉津的降解反应主要发生在溶液里.