Effects of surfactants on enzyme-containing reversed micellar system

With the development of colloid interface and enzyme technologies,enzyme-containing reversed micellar system has been receiving much attention in bioseparation and bioconversion. Because of its high efficiency,it has brought new opportunities for the development of molecular biotechnology. Reversed micelles represent nano-sized aqueous droplets stabilized by surfactant amphiphiles inside the bulk organic solvents. The entrapped enzymes have enhanced activities under those conditions as suited in the lipid b...     

Vibration control of the finite L-shaped beam structures based on the active and reactive power flow

This paper analyzes the physical meaning of the active and reactive power flow in the finite L-shaped beams and studies the active vibration control of the structures based on the active and reactive power flow.The traveling wave approach is used to calculate the structural dynamic responses.Because the error of control force is inevitable in practical applications,the effects of the error of control force on the control results are studied.The study indicates that the error of control force has pronounced ...     

Chemical composition of PM_(2.5) during winter in Tianjin,China

PM2.5 samples for 24 h were collected during winter in Tianjin,China. The ambient mass concentration and chemical composition of the PM2.5 were determined. Ionic species were analyzed by ion chromatog-raphy,while carbonaceous species were determined with the IMPROVE thermal optical reectance(TOR) method,and inorganic elements were measured by inductively coupled plasma-atomic emission spec-trometer. The daily PM2.5 mass concentrations ranged from 48.2 to 319.2 g/m3 with an arithmetic average of 144.6 g/m3. ...     

Energy Decay for the Cauchy Problem of the Linear Wave Equation of Variable Coeffcients with Dissipation

Decay of the energy for the Cauchy problem of the wave equation of variable coeffcients with a dissipation is considered.It is shown that whether a dissipation can be localized near infinity depends on the curvature properties of a Riemannian metric given by the variable coeffcients.In particular,some criteria on curvature of the Riemannian manifold for a dissipation to be localized are given.     

Photocatalytic degradation of rhodamine B by dye-sensitized TiO_2 under visible-light irradiation

Perylene tetracarboxylic diimide (PTCDI),widely used in organic photovoltaic devices,is an n-type semiconductor with strong absorption in the visible-light spectrum.There has been almost no study of the PTCDI-sensitized TiO2 composite used to photocatalytically degrade pollutants.In this study,PTCDIand copper phthalocyanine tetrasulfonic acid (CuPcTs)-sensitized TiO2 composites were prepared using a hydrothermal method.The morphologies and structures of the two composites were characterized by X-ray diffrac...     

Homogeneous modification of carbon nanotubes with cellulose acetate

An efficient strategy that comprised shorten,chain extension,active groups introducing and homogeneous reaction tactics,was adopted to modify multiwalled carbon nanotubes(MWNTs) with cellulose acetate(CA).Specially,by utilizing 2,4,6-trichloro- 1,3,5-triazine,a reactive intermediate of the MWNTs(MWNT-triazine) was obtained.Suitable solubility of the MWNT-triazine helps make the homogeneous modification become reality.Detailed characterizations further verified that reaction between chloride atoms in the ...     

FeCl_3·6H_2O Catalyzed Reaction of Aromatic Aldehydes with 5, 5-Dimethyl-1, 3-cyclohexandione in Ionic Liquids

Room temperature ionic liquids with low melting point (<100℃) salts represent a new class of non-molecular, ionic solvents. Especially those based on the 1-N-alkyl-3- methylimidazolium cations, have shown great promise as an attractive alternative to conventional solvents for catalytic reactions1. On the other hand, FeCl3·6H2O was considered to be an environmentally benign Lewis acid and has been used successfully in several kinds of organic reactions2. Recently we have focused our interes…     

TREATMENT OF SORBIC ACID MANUFACTURING WASTEWATER BY HYPERCROSSLINKED POLYMERIC ADSORBENT (NDA-150)

1. INTRODUCTION The chemical name of sorbic acid is 2,4-hexadienoic acid. Toxicity of sorbic acid is less than any other preservative, which is internationally acknowledged. Sorbic acid can participate in mans metabolism and can be easily oxidized, then …     

QSAR Studies on the COX-2 Inhibition by 3,4-Diarylcycloxazolones Based on MEDV Descriptor

Selective inhibition of cyclooxygenase-2 (COX-2) might avoid the side effects of current available nonsteroidal antiinflammatory drugs while retaining their therapeutic efficacy. A novel variable selection and modeling method based on prediction is developed to construct the quantitative structure-activity relationships (QSAR) between the molecular electronegativity distance vector (MEDV) based on 13 atomic types and the biological activities of a set of selective cyclooxygenase-2 inhibitory molecules, 3,4-diarylcycloxazolones (DAA) plus indomethacin,naproxen, and celecoxib. Using multiple linear regression, a 5-variable linear model is developed with the calibrated correlation coefficient of 0.9271 and root mean square error of 0.17 in modeling stage and the validated correlation coefficient of 0.9030 and root mean square error of 0.20 in leave-one-out validation step, respectively. To further test the predictive ability of the model, 20 DAA compounds are picked up to construct a training set which is used to build a QSAR model and then the model is employed to predict the biological activities of the balance compounds. The predicted correlation coefficient and root mean square error are 0.9332 and 0.19, respectively.     

大孔吸附树脂对邻甲酚的吸附行为研究

研究了大孔吸附树脂NDA—909吸附水溶液中邻甲酚的热力学特征，并与Amberlite XAD—4树脂进行了比较．通过吸附动力学实验，初步探讨了初始温度对吸附过程的影响。结果表明，NDA—909对邻甲酚的吸附符合Freundlich经验公式，表现为放热的物理吸附过程．此外吸附速率受颗粒内扩散和其它类型扩散的共同控制。