Fate of secondary effluent dissolved organic matter during soil-aquifer treatment

The reduction of mass and trihalomethane formation potential (THMFP) of dissolved organic matter (DOM) and its fractions from secondary effluent during laboratory-scale soil-aquifer treatment (SAT) soil columns were studied. Reduction in dissolved organic carbon (DOC), absorbance of ultraviolet light at 254 nm (UV-254), biodegradable dissolved organic carbon (BDOC) and nonbiodegradable dis- solved organic carbon (NBDOC) for the bulk DOM averaged 72.35%, 53.98%, 97.49% and 35.33% across the soil columns, respectively. Using XAD-8 and XAD-4 resins, DOM was fractionated into 3 fractions: hydrophobic acid (HPO-A), transphilic acid (TPI-A) and hydrophilic fraction (HPI). HPO-A was removed by 61.06%, TPI-A by 54.86% and HPI by 74.95% as DOC as a consequence of the laboratory-scale SAT, respectively. The reduction of THMFP from HPO-A, TPI-A and HPI was 27.24%, 26.24% and 36.08%, respectively. Proton nuclear magnetic resonance (1H-NMR) spectra revealed that the HPO-A isolated from the secondary effluent contained more aromatic functional groups than the corresponding TPI-A. Fourier-transform infrared (FT-IR) spectrum analysis illustrated that TPI-A had decreased hydrocarbon and increased aromatics content in the SAT columns. Specific ultraviolet light absorbance (SUVA) and specific THMFP for each DOM fraction increased across the soil columns and HPI exhibited greater increase in both than HPO-A and TPI-A. The most problematic THM precursor was found to be HPO-A with its high quantity present in recharged water and high chlorine reactivity.     

Pell方程x^2-[（mn）^2±4n]y^2=1的最小解

运用计算连分数的方法，给出Pell方程x^2-Dy^2=1当D=（mn）^2±4n（m,n）为正整数）时的最小解的计算公式。     

求解Pe11方程的算法与程序设计

本文给出n~(1/2)的次分数的递推算法与其渐近分数的高精度算法,完成求解Pell方程的Turbo　 C程序设计.     

异长叶烯甲基甲酸酯香料合成研究

以江西马尾松重质松节油为主要原料,经精馏、异构化和Prins反应合成了异长叶烯甲基甲酸酯香料。得率达到47.66％。并对反应机理和产物结构进行了探讨。     

势函数 v(r) =α_1r~(10) α_2 r~4 α_3 r~2 β_2 r~(-4) β_1r~(-6)的径向 schr dinger方程的精确解

采用连续分数法 ,得到势函数为 v ( r) =α1r10 α2 r4 α3r2 β2 r- 4 β1r- 6 的径向schr dinger方程的精确解 ,并作适当的讨论     

湍流浸没射流反应区结构的数值计算

介绍HC1气体以湍流浸没喷入NH_3水溶液容器内而发生化学反应的反应区结构的数值计算。通过化学平衡的计算,求得以混合分数为基础的状态关系;采用局部均相流动模型(LHF)、κ-ε-g湍流模型、截尾正态分布模型和法夫雷(Favre)均化的榆运方程组,得到反应区内空隙率、温度、气体穿透距离和各组分的浓度等参数值。     

Ferric chloride-catalyzed decarboxylative alkylation of β-keto acids with benzylic alcohols

β-Keto acids are unstable to heat,acids,and bases,and have rarely been employed as carbon nucleophiles for the formation of carbon-carbon bonds.In this context,an efficient decarboxylative alkylation reaction of β-keto acids with benzylic alcohols has been developed,for the first time,through sequential cleavage of carbon-oxygen and carbon-carbon bonds.In the presence of 10 mol% of ferric chloride,a range of β-keto acids smoothly undergo decarboxylative alkylation with benzylic alcohols to give structurally diverse unsymmetric ketones in moderate to excellent yields and with extremely high regioselectivity.Preliminary mechanistic studies indicate that the reaction proceeds through an SN1 alkylation followed by decarboxylation.     

Chitin synthetase activity and inhibition in different insect microsomal preparations

Summary To facilitate massive screening and for structure-activity relationship studies of chitin synthesis inhibitors, methods to obtain the chitin synthetase (CS) containing microsomal fraction from the postmitochondrial supernatant were examined. Compared with fractionation by differential centrifugation, the CaCl₂ precipitate yielded the most active CS preparation. Acidification (pH 5.6) and polyethylene glycol 8000 (5%) treatments resulted in relatively low CS activity. Inhibitory effects were detected with polyoxin-D and 1-geranyl-2-methyl benzimidazole, a novel CS inhibitor, but not with benzoylphenyl ureas.     

无限型符号动力系统的一个几何解释

可列无穷个符号的符号序列空间Σ∞与区间Ｉ＝［０，ｌ］上的所有无理数构成的子空间Ｗ同胚，而Σ∞上的位移映射σ则与Ｗ上的高斯映射ｇ拓扑共轭．     

藤梨正丁醇部位化学成分的研究

采用薄层色谱,正相、反相硅胶,葡聚糖凝胶,半制备高效液相柱对中药藤梨的正丁醇部位进行了分离研究.得到8个化合物,分别为:2-β-D-葡萄糖-1,3,7-三羟基-酮(1),7-O-[β-D-吡喃木糖-(1-6)-β-D-吡喃葡萄糖苷]-1,8-二羟基-3-甲氧基-酮(2),3-O-[β-D-吡喃鼠李糖-(1-6)-β-D-吡喃葡萄糖]-5,7,4′-三羟基黄酮(3),6-C-葡萄糖-5,7,3′,4′-四羟基黄酮(4),6-C-葡萄糖-5,7,4′-三羟基黄酮(5),1-O-[β-D-吡喃木糖-(1-6)-β-D-吡喃葡萄糖苷]-8-羟基-3,7-二甲氧基-酮(6),3-O-[β-D-吡喃鼠李糖-(1-6)-β-D-吡喃半乳糖]-5,7,3′,4′-四羟基黄酮(7),7-O-[β-D-吡喃鼠李糖-(1-6)-β-D-吡喃葡萄糖]-5,3′-二羟基-4′-甲氧基二氢黄酮(8).所有的化合物都是首次从该植物分离得到.