Time filter

Source Type

Wang L.H.,Tianjin Modern Vocational Technology College | Liu H.,Tianjin Modern Vocational Technology College
Polish Journal of Chemical Technology | Year: 2015

A carbon-based solid acid catalyst was prepared by the sulfonation of carbonized seed shells of Jatropha curcas (J. curcas L.). The structure of amorphous carbon consisting of polycyclic aromatic carbon sheets attached a high density of acidic SO3H groups (2.0 mmol · g-1) was identified with scanning electron microscopy (SEM), fourier transform infrared (FTIR) spectroscopy, powder X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) . The performance of the solid acid catalyst was evaluated for biodiesel production in the esterification of oleic acid with methanol. 95.7% yield of biodiesel was obtained after 2 h reaction and the conversions with reused catalyst varied in the range of 95.7% to 95.1%, showing better activity and stability than commercial catalyst amberlyst-46. It was also observed that the prepared catalyst showed enhanced activity in the transesterification of triolein with methanol when compared with other solid acid catalysts. A synergistic effect results from the high density of SO3H groups and the good access of reactants to the acidic sites can be used to explain the excellent catalytic activity, as well as the strong affinity between the hydrophilic reactants and the neutral OH groups bonded to the polycyclic aromatic carbon rings.

Sun H.,Tianjin Modern Vocational Technology College | Liu M.-Q.,China Institute of Technology | Zhang B.-J.,Xuzhou Institute of Technology
Inorganica Chimica Acta | Year: 2016

Two dysprosium compounds with the formula [Dy(TTA)2L] (1) and [Dy2(dbm)2(L)2(CH3OH)2]·2.6CH3OH·0.4CH2Cl2 (2) (TTA = 2-thenoyltrifluoroacetone, dbm = 1,3-diphenyl-1,3-propanedione and HL = N-(methylene-8-hydroxyquinoline)-pyridylhydrazone) based on a multidentate 8-hydroxyquinoline Schiff base have been synthesized, structurally and magnetically characterized. The X-ray structural analysis exhibits that 1 is a mononuclear structure, while 2 is a μ2-O bridged dinuclear complex. Magnetic measurements indicated that different magnetic relaxation behaviors were clearly observed in 1 and 2 under zero-dc field, with the effective barriers (ΔE/kB) of 67.8 K for 1 and 2.67 K for 2. © 2016 Elsevier B.V.

PubMed | Nankai Hospital of Tianjin City, Tianjin University, Tianjin Modern Vocational Technology College and Tianjin Polytechnic University
Type: | Journal: Analytical and bioanalytical chemistry | Year: 2016

Highly efficient extraction of peptides from serum is critical for finding serum biomarkers using mass spectrometry, which still remains a great challenge. Currently,a bottom-up proteomics approach has been applied to discover serum biomarkers. However, the approach was labor intensive, time and cost consuming, and cannot meet the requirements for clinical application. In this work, Fe

Liu Y.,Tianjin University of Technology and Education | Zheng H.-X.,Tianjin University of Technology and Education | Wu G.-X.,Tianjin Modern Vocational Technology College
2012 10th International Symposium on Antennas, Propagation and EM Theory, ISAPE 2012 | Year: 2012

To simulate elastic wave propagating in different solid medium, a three dimensional model has been developed Based on Yee's algorithm, the staggered grid of the stressvelocity equations for the model has been set up, and the finite-difference form of it has been derived. The perfectly matched layer (PML) absorbing boundary is discussed, and the finite-difference scheme of the PML boundary conditions is implemented. Active simulation of the interaction of elastic wave with layered medium and cubic object has been finished, respectively. Numerical experiments have proved the effectiveness of the proposed method. © 2012 IEEE.

Wang H.-S.,China Pharmaceutical University | Wei J.-P.,Tianjin Modern Vocational Technology College
Nanoscale | Year: 2015

The major scientific challenge of enantiomeric separation is to develop simple, rapid, and sensitive routine analytical methods. Generally, enantio-resolution is still based on "three-point interaction" theory, which indicates that homochiral sites are needed for enantio-selective interaction. However, in recent years, advanced materials with precise homochiral fabrication at the nanoscale have been synthesized, and have shown great potential in development of high-throughput enantio-resolution methods. This tutorial review summarizes fabrication and applications of homochiral materials for enantio-selective recognition and separation. These materials, which include intrinsic and restructured chiral metal surfaces, plasmonic nanostructures, coordination polymers, organic polymer sensors, and molecularly imprinted polymers, have been applied as sensors or chiral stationary phases (CSPs) for efficient enantio-resolution. This journal is © The Royal Society of Chemistry.

Li F.,Tianjin University of Commerce | Song W.,Tianjin University of Commerce | Wei J.,Tianjin Modern Vocational Technology College | Liu C.,Arizona State University | Yu C.,Tianjin University of Commerce
International Biodeterioration and Biodegradation | Year: 2016

Phenol is a widespread environmental pollutant due to their broad usage and applications, and presence in many industrial effluents. To date, bacterial degradation of phenol remains to be the preferred method for its removal and remediation. Although the degradation pathway has been extensively studied, the variations in the level of expression of the key enzymes during catabolism are still not quantitatively understood. An explicit quantitative expression helps us know the degradation process in detail. It is important and valuable for us to further understand mechanisms underlying phenol degradation. In this study, we used iTRAQ-based comparative proteomics analysis approach to determine variations in expression and regulation of key enzymes in Arthrobacter during phenol degradation. We propose that the phenol biodegradation pathway is mainly determined by 5 pivotal enzymes, which belonged to 3-oxoadipate pathway and tricarboxylic acid cycle. Arthrobacter mainly degrades phenol through 3-oxoadipate pathway, which makes the pathway of this strain for degrading the toxic compound clearer. These findings provide new insights into phenol biodegradation process and would help us understand the step by step stages of this metabolic pathway. © 2016 Elsevier Ltd.

Liu M.L.,Tianjin Modern Vocational Technology College | Gu W.,Nankai University | Liu X.,Nankai University
Russian Journal of Coordination Chemistry/Koordinatsionnaya Khimiya | Year: 2014

Two new ionic complexes built on polyoxometalate anions of [CoW12O40]6- and Ln3+ (Ln = Ce, Nd) cations, namely [Ce(CoW12O40)(NMP)2(H2O)6][Ce(NMP)(H2O)8] · 3H2O · NMP (I) and [Nd(CoW12O40)(NMP)2(H2O)6][Nd(NMP)(H2O)8] · 7H2O (II) (NMP = N-methyl-2-pyrrolidone) have been synthesized. Single crystal X-ray crystallographic analyses (CIF files CCDC nos. 704837 (I) and 689561 (II)) revealed that the structures of two complexes were similar, which crystallize in the P21/n monoclinic space group. Complexes I and II were both ionic clusters and the coordination numbers of Ln3+ (Ln = Ce, Nd) were nine. The unit cell parameters for I: a = 17.551(4), b = 17.783(4), c = 26.729(5) Å, β = 101.33(3)°, V = 8180(3) Å3, Z = 4. The unit cell parameters for II: a = 17.571(3), b = 17.750(3), c = 28.989(9) Å, β = 115.42(2)°, V = 8166(3) Å3, Z = 4. Complex I was characterized by TG analysis. Variable-temperature magnetic susceptibility measurements showed that there exists a weak antiferromagnetic interaction of complex II. © 2014 Pleiades Publishing, Ltd.

Wu S.-X.,Tianjin University of Science and Technology | Wu S.-X.,Tianjin Modern Vocational Technology College | Sha Z.-L.,Tianjin University of Science and Technology
Huaxue Gongcheng/Chemical Engineering (China) | Year: 2013

The continuous crystallization process of KCl-H2O system in a 10 L Draft Tube Baffle (DTB) crystallizer was studied by Computational Fluid Dynamics (CFD). The model of multiphase flow and the population balance equations coupling solution was used with one continuous phase and five different sizes crystals of the dispersed phase. The flow field and solid suspension were studied under different feed velocities and feed mass concentration considering the conditions of crystal growth and nucleation, and the influence of the operation conditions on the crystallization process was analyzed based on the characteristic parameters of fluid dynamics characteristics, supersaturation distribution and crystals size distribution, etc. The simulation results show that the feed velocity and feed mass concentration have an obvious effect on supersaturation distribution and crystal size distribution, while little effect on the flow field.

Wang H.-S.,China Pharmaceutical University | Feng X.-Y.,China Pharmaceutical University | Wei J.-P.,Tianjin Modern Vocational Technology College
Journal of Chromatography A | Year: 2015

Novel biocompatible chiral monolithic stationary phase was prepared by reverse and direct atom transfer radical polymerization (ATRP) methods. By taking advantages of the controlled/living property of ATRP method, the chiral monolith was prepared by reverse ATRP (RATRP) firstly. An attractive feature of RATRP is the prepared polymer containing a terminal radically transferable atom that can initiate another post-polymerization reaction by direct ATRP. Then, the biocompatible poly(hydroxyethyl methacrylate) (PHEMA) was grafted on the surface of the chiral monolith by direct ATRP as a diffusion barrier for proteins. This biocompatible chiral monolith was successfully used as restricted access stationary phase for determination of enantiomers in biological samples with direct injection by high-performance liquid chromatography (HPLC). © 2015 Elsevier B.V.

Fu W.,Tianjin Modern Vocational Technology College
Applied Mechanics and Materials | Year: 2014

This paper established a food safety supervision system on the basis of foreign advanced food safety management mode and methods, combining with China's specific national conditions, and strengthen food quality and safety control system, in order to speed up the process of development with international standard is the key problem. Based on the advanced management experience of developed country, this paper put forward a scientific, efficient and dynamic supervision system of food safety. © (2014) Trans Tech Publications, Switzerland.

Loading Tianjin Modern Vocational Technology College collaborators
Loading Tianjin Modern Vocational Technology College collaborators