微拟球藻脂肪热解及对全组分制备生物油的影响

以酸水解法从微拟球藻中提取的粗脂肪为原料,在管式裂解炉中考察不同热解温度下脂肪单组分的热解规律及对微拟球藻全组分各相产率及生物油性能的影响。利用热重分析仪分别考察粗脂肪及全组分的热失重特性,并求出相应的动力学参数。结果表明,脂肪热解能够提高全组分热解有机相产率并改善油品性能。随着温度的升高,粗脂肪与全组分热解后的有机相产率及油品性能的变化趋势相同,且生物油性能均在600℃时达到最佳。经热解,粗脂肪中含氧化合物含量降低,脂肪烃含量显著增加。对比全组分热解,粗脂肪热解后的油品脱氧率及氢、碳元素比例更高,因而增加全组分中脂肪的含量能够促进油品性能的进一步提高。对粗脂肪及全组分的热重数据进行计算,发现两者均满足二级化学反应机理,粗脂肪、全组分的活化能与指前因子分别为64.34 k J/mol与2.94×105min-1,48.13 k J/mol与2.96×103min-1。     

Polyimides derived from bismethylolimides. II. Polyamine-imides from bismethylolimides and diamines

Compounds in the N-methylolimide group reacted smoothly with amines in the presence of water to yield the corresponding condensation products. Polycondensations of bismethylolimides, N,N′-bismethylolpyromellitic diimide, and N,N′-bismethylolbenzophenonetetracarboxylic diimide, with amines such as aromatic diamines, piperazine, and n-butylamine, were carried out in DMAc that contained 1% water to produce linear polyamine-imides. The polyamine-imides assumed various colors, from very pale yellow to deep purple, and had inherent viscosities in the 0.07–0.37-dl/g range. Most of these polymers were soluble in polar solvents such as DMAc and DMSO. The thermal stability of the polymers was examined by thermogravimetric analysis; decomposition started at 210–350°C and weight residue at 500°C was 22–85% in air.     

Studies on constituents from Chamaecyparis pisifera and antibacterial activity of diterpenes.

In the course of our research for biologically active constituents from coniferous plants, a chromone derivative (1) and an abietane derivative (2) were isolated along with several diterpenes from Chamaecyparis pisifera. Structures of the new compounds were determined to be 5,7-dihydroxy-2-(1-acetyl-2-methoxycarbonylethyl)-chromone and rel-(8R,10R,20S)-8,10,20-trihydroxy-9(10-->20)-abeo-abieta-9,13-dien-12-one by means of spectral methods including two-dimensional NMR experiments. Some of these abietane-type compounds isolated from this plants showed antibacterial activitv against the gram-positive bacteria Staphylococcus aureus and Bacillus subtilis.     

Studies on quinones. XII. Cycloketalization of michael adducts from hydroxyquinones

The reaction of 2-hydroxy-3-(1-phenyl-3-oxobutyl)-1,4-naphthoquinone ( 1 ) with either acidic methanol or a mixture of trimethyl orthoformate, methanol and ammonium chloride resulted in the formation of the p-quinonic cycloketals: trans- and cis-4-phenyl-2-methyl-2-methoxy-3,4-dihydro-2H-naphtho[2,3-b]pyran-5,10-dione ( 2a,2b ). Cyclization of the Michael adducts 6, 10 and 11 , which are structurally related to 1 , with trimethyl orthoformate-methanol-ammonium chloride gave the corresponding p-quinonic cycloketals 7, 12 and 13 . The structures of the regioisomers 2a and 2b are proposed based on the spectral properties of compound 7 and by analysis of its proton nmr spectra.     

Adsorption of cations from formic acid solutions on strong acid cation-exchange resin. Separation of zirconium from thorium and from gallium

The adsorption of Pb(II), Cu(II), Bi(III), Cd(II), Mn(II), Co(II), Ga(III), Y(III), Zr(IV) and Th(IV) from aqueous solutions of formic acid on cation-exchanger Dowex 50W-X8 has been studied. Electrophoretic measurements have also been made. Possible separations are suggested and discussed. Zirconium may be quantitatively separated from thorium and from gallium.     

Bioactive constituents from Chinese natural medicines. XV. Inhibitory effect on aldose reductase and structures of Saussureosides A and B from Saussurea medusa

The 80% aqueous acetone extract from the whole plant of Saussurea medusa MAXIM. was found to inhibit rat lens aldose reductase (IC50=1.4 microg/ml). From this extract, flavonoids, lignans, and quinic acid derivatives were isolated together with two new ionone glycosides, saussureosides A and B. Their absolute stereostructures were elucidated on the basis of chemical and physicochemical evidence including the application of modified Mosher's method. In addition, some isolates were found to show an inhibitory effect on aldose reductase.     

Alternating Copolymers from Alkyleneimines. I. Copolymers from Ethyleneimine and Dicarboxylic Anhydrides

Ethyleneimine and dicarboxylic anhydrides were copolymerized to alternating copolymers which possess an ester-amide in the repeating unit. The structure of copolymer was Identified by IR, NMR, and elemental analysis. On taking the structure of copolymer, the nucleophllic reactivity of ethyleneimine, and the electrophilic nature of dicarboxylic anhydride Into consideration, a reaction mechanism was elucidated. It Involves ring opening and a stepwise addition reaction in alternating manner, in that one monomer undergoes ring opening and chain propagation exclusively through the interaction with another monomer that is already present at the polymer chain end. The copolymers obtained from halogen containing dicarboxylic anhydrides are useful as fire-retarding additives for plastics and also as thermosetting resin precursor when anhydrides are partially replaced by maleic anhydride.     

Studies on pyrazines. 35. An improved synthesis of bromopyrazines from hydroxypyrazines

The synthesis of bromopyrazines from hydroxypyrazines was successfully effected by the procedure via trimethylsilyloxypyrazines, the sequence of which proceeds under mild conditions and does not require the isolation of intermediate.     

Spectral investigations on melanterite mineral from France.

EPR, Optical and IR spectral studies on a naturally occurring mineral melanterite are carried out at room temperature. EPR studies indicate the presence of Cu(II) ion in tetragonally distorted octahedral site and hyperfine lines could not be resolved due to higher concentration of the paramagnetic impurity in the mineral. Optical absorption spectrum is a characteristic of Fe(II) and Cu(II) ions. Crystal field parameters are evaluated. IR spectrum confirms the presence of water and sulphate ions.