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October 15,2016
Volume 9,Issue 19
Pages -
Subject Area:Analytical Chemistry,Applied Mathematics,Computational Mathematics,Decision Theory

Title: Influence of SBA-15 support prepared by acid alcohol washing method on the Ni/SBA-15 catalyst for the performance of carbon dioxide reforming of methane

Authors: YANG Weiwei, HE Dehua
PP: 2051-2059
Abstract: The 5% Ni/SBA15-aaw catalyst was prepared by the conventional impregnation method with the SBA15-aaw support obtained by the acid alcohol washing method. While the 5% Ni/SBA15-cal catalyst was prepared with the SBA15-cal support obtained by the conventional calcination method (500℃, 6 h). These supports were all characterized by Fourier transform infrared (FTIR) spectroscopy and elemental analysis (EA), and the catalysts were all characterized by X-ray diffraction (XRD) and temperature programmed reduction (TPR). Besides, the catalysts were employed to catalyze the carbon dioxide reforming of methane (CRM) reaction to evaluate the catalytic performances. The results revealed that the residual P123 on SBA15-aaw support improved the dispersion of Ni on support, and ultimately generated excellent CRM reaction activity and stability.
Keywords: physical chemistry; acid alcohol washing; Ni/SBA-15; P123; carbon dioxide reforming of methane; highly-dispersed

Title: Measurement and correlation of density and viscosity of quaternary ammonium salt-phenolic compound-toluene mixtures for their separation via forming deep eutectic solvents

Authors: LIU Dongdong, REN Shuhang, JI Youan, YAO Congfei, WU Weize
PP: 2041-2050
Abstract: Densities and viscosities of deep eutectic solvents (DES) are basic data for the application of DES in separation of phenols from oil mixtures. In this work, we measured densities and viscosities of four ternary systems of quaternary ammonium salt-phenolic compound-toluene, including choline chloride (ChCl)-phenol-toluene, ChCl-o-cresol-toluene, ChCl-m-cresol-toluene, and 1-butyl-3-methylimidazolium chloride ([bmim]Cl)-phenol-toluene, which showed a potential application. Densities and viscosities of the quaternary ammonium salt-phenolic compound-toluene ternary systems were measured at temperatures from 298.15 to 368.15 K with toluene’s relative mole fractions from 0 to 0.8. The results indicate that the density declines with the increase of temperature and toluene’s relative mole fraction, the viscosity decreases with the increase of temperature and toluene’s relative mole fraction. Redlich-Kister equation was used to correlate the excess molar volume of the ternary systems with a correlation coefficient (R2) of 1. Jouyban-Acree model was used to correlate the viscosity of the ternary systems with a correlation coefficient (R2) of 0.999 998. Thermodynamic parameters (excess molar volume, partial molar volume, viscous free energy, and excess viscous free energy) were obtained via the correlated results. The results also indicate that toluene is filled in pore structure of DES formed by quaternary ammonium salt and phenol.
Keywords: physical chemistry; viscosity; density; deep eutectic solvents; quaternary ammonium salt-phenolic compound-toluene ternary system; correlation

Title: Analysis of gibberellin class plant hormones by HPLC coupled with ESI-MS

Authors: XU Linfang, ZHANG Xiaona, XIAO Rui, ZHANG Xiaoting, NIU Jiahua, LU Minghua
PP: 2035-2040
Abstract: A high performance liquid chromatography (HPLC) coupled with electrospray ionization mass spectrometry (ESI-MS) for the analysis of gibberellins was developed in this research. This method used a Hilic C18 (2.1 mm×50 mm, 2.6 μm) column, methanol:water (0.01 mol/L ammonium acetate)=80:20 (volume ratio), separation of flow rate at 0.2 mL/min, by using electrospray ionization in multiple-reaction monitoring (MRM) mode, external method for quantitative. The parent ions of GA3 and GA12 were at m/z 345.3 and 331.4, and the quantitative daughter ions were at m/z 143.0, 220.9 and 201.0, 269.2, respectively. The results showed that the established method had a good linear relationship (R2>0.99) in the 0.05-10.00 μg/mL linear range, the detection limit was 0.01 μg/mL, and the average recovery rate was between 80.00% and 120.00% in three supplemental level of 0.20, 1.50, 8.00 μg/mL with relative standard deviation (RSD) was between 0.26% and 1.90%.
Keywords: analytical chemistry; high performance liquid chromatography-electrospray ionization mass spectrometry; gibberellins; plant hormone; analytical method research

Title: Synthesis of tetraacetyl-D-fucopyranose

Authors: FANG Jing, ZHU Yangbin, CHEN Wei, LIU Yan, SUN Jiuchang, ZENG Jing, WAN Qian
PP: 2030-2034
Abstract: D-fucopyranose is an important component of many bioactive natural products. Development of efficient and practical synthetic strategy for large scale synthesis of D-fucopyranose is of great importance for the total synthesis of these natural products. Based on the optimization of reported synthetic methods, herein, we reported a 10 g-scale synthesis of tetraacetyl-D-fucopyranose in 5 steps with 53% total yield from D-galactose through sequential acetonation, sulfonation, iodination, deiodination and acetylation. Compared to the reported methods, this method has the advantages of low cost, easy manufacture and high efficiency, which offers an alternative for the large scale synthesis of D-fucopyranose.
Keywords: organic chemistry; rare sugar; D-fucopyranose; D-galactose

Title: Theoretical study on catalytic activation of carbon dioxide by carbodicarbenes

Authors: XU Zheyuan, ZHANG Qi, JIANG Yuanye, FU Yao
PP: 2023-2029
Abstract: Reduction of CO2 is a critical process in chemical transformations of CO2. In addition to transition metals, carbenes and Lewis acids/bases, carbodicarbenes have recently been demonstrated to be capable of activating CO2. In this paper, density functional theory (DFT) methods were employed to investigate the mechanism of CO2 activation by carbodicarbenes. Calculation results indicate that the activation of CO2 by carbodicarbenes proceeds via nucleophilic attack of carbodicarbene to 9-borabicyclo [3.3.1] nonane (9-BBN), hydrogen atom transfer and C—B bond cleavage. On the other hand, the adduct of carbodicarbenes and 9-BBN activates CO2 through insertion of CO2 and hydrogen atom transfer. By comparison, the hydrogen atom transfer in the later case is more kinetically difficult, making the catalytic activity of the adduct lower than that of carbodicarbenes.
Keywords: organic chemistry; carbon dioxide; density functional theory; reduction

Title: Synthesis, characterization and dielectric properities for a new metal-dithiolate-based polymer film

Authors: NIE Li, REN Xiaoming
PP: 2016-2022
Abstract: Dielectric films based on polymer have currently attracted great attention in the field of dielectric materials. A new nickel-maleonitriledithiolene polymer film was obtained in the way of solution delay flow by adding polyvinylidene fluoride (PVDF) as binder. The characteristics of morphology and structure were observed by scanning electron microscope (SEM). The results indicated the porous network structure of the polymer film. The optical properties were researched by ultraviolet-visible absorption spectroscopy. The dielectric properties of the composite film were investigated. It showed a clear dielectric relaxation process which occured at the temperature of above 383 K. The impedance spectra were further investigated to reveal that the dielectric relaxation is related to the ions conductance.
Keywords: polymer chemistry; poly(diallyldimethylammonium chloride); polyvinylidene fluoride; thin film; dielectric relaxation

Title: Ethanol gas sensor based on silicon nanostructure films

Authors: LÜ Yang, ZHANG Heqiu, HU Lizhong
PP: 2011-2015
Abstract: In this study, silicon nanostructure films were synthesized by chemical vapor transport (CVT), and their morphologies were analyzed by scanning electron microscope (SEM). The experimental results showed that the silicon nanostructure films were made up of intertwined silicon nanorods. The length of the nanorods was in the micron range, and the diameter of nanorods was about 100 nm. On this basis, we prepared an ethanol gas sensor using silicon nanostructure film, and studied its sensing characteristics to different concentrations of alcohol gas. We found that the recovery time of the sensor may be less than 1 s. What’s more, this kind of sensor is simple in fabrication process, cheap and valuable in practical application.
Keywords: semiconductor physics; silicon nanostructure film; ethanol gas sensor; chemical vapor transport; sensing characteristics

Title: Experimental measurement of Fresnel lens based on LCOS

Authors: CHI Weining, WANG Dayong, WANG Yunxin, RONG Lu, GUO Sha, MA Sijin
PP: 2003-2010
Abstract: Phase-only liquid crystal spatial light modulator based on liquid crystal on silicon (LCOS) can modulate the optical wavefront pixel by pixel through the external voltage. LCOS plays an important role in optical information process and optical computation, and replaces the traditional optical elements gradually. In this paper, based on the modulation curves under the different conditions, a phase Fresnel lens is loaded onto LCOS. The sampling requirement of the lens is satisfied, and the focal length, diffraction efficiency and imaging quality of the lens are experimentally tested respectively. The experimental results show that the phase-only liquid crystal spatial light modulator can be used in the zoom lens, which can also play the function of the mirror. Due to the programmable characteristics, focal length of LCOS can be of convenient and flexible control, which has very broad application prospects.
Keywords: optics; wavefront control; liquid crystal on silicon; phase modulation; phase Fresnel lens

Title: Optical super-resolution imaging properties of micro concave lenses

Authors: HOU Jinglei, YE Yonghong, GUO Minglei, DU Bintao
PP: 1995-2002
Abstract: The super-resolution capability of micro concave lenses (MCL) based on SU-8 photoresist with different sizes has been deeply researched. In the experiment, after removing the silica microspheres with HF which are semi-immersed in SU-8 photoresist, the MCL with different sizes have been formed. Here, the diameter of these microspheres is in the range of 3.35-15.50 μm. The results showed that the MCL could resolve 305 nm nanospheres array. We found that the imaging quality of the MCL fabricated from 4.87 μm or 7.27 μm silica microspheres semi-immersed in SU-8 photoresist was better than several other MCL. And that the thickness d of SU-8 photoresist on the sample surface which was important for MCL have been further confirmed.
Keywords: optics; micro concave lens; super-resolution; photoresist; thickness d

Title: Reflection coefficient and transmission coefficient of light propagation at absorbing medium interface

Authors: ZHANG Qiuzhang, LUO Tianshu, HUANG Liyuan, LI Meng, XU Taishan
PP: 1987-1994
Abstract: The planes of constant field amplitude and constant phase of light in the absorbing medium are defined by using the unit vectors. Using the corresponding boundary conditions, the reflection coefficient and transmission coefficient of the light through the interfaces of absorbing medium/medium and medium/absorbing medium have been obtained. The reflection coefficient and transmission coefficient are decided by the incident angle, the refractive index of medium and the complex refractive index of absorbing medium. The reflection coefficient and transmission coefficient of absorbing medium/medium are also related to the angle between the planes of constant amplitude and constant phase. Both the absorbing medium/medium and medium/absorbing medium can be simplified as medium/medium.
Keywords: optics; reflection-refraction; complex refractive index; Fresnel formula; light propagation

Title: Multiplexing microstructure optical fiber temperature sensor based on quantum dots solution filling

Authors: WANG Wenyuan, LI Xuejin, WANG Lele
PP: 1980-1986
Abstract: We propose a method for the fabrication of all-optical fiber liquid core microstructure optical fiber. Firstly, a groove is carved on the end-face of the multi-mode optical fiber by use of femtosecond laser. Secondly, the carved multi-mode optical fiber is fused to the microstructure and then the carved groove is used for filling. At last, the filled liquid is encapsulated in the holes of the microstructure optical fiber. The relationship of the fluorescent wavelength, fluorescent intensity and self-reference intensity with temperature is analyzed. With this structure, the quantum dots solution with different fluorescent wavelengths is filled into microstructure optical fiber, the multiplexing microstructure fiber temperature sensor is constructed based on quantum dots filling. Both the wavelength division multiplexing and temperature sensing characteristics of the sensor are analyzed. The proposed sensor hopefully provides new thought for multi-point measurement of optical fiber sensor.
Keywords: optics; microstructure optical fiber; quantum dots; liquid core; wavelength division multiplexing

Title: Bifurcation analysis and delayed feedback control of nonlinear finance system

Authors: YANG Jihua, ZHANG Erli, LIU Mei
PP: 1973-1979
Abstract: In this paper, the bifurcation and chaos control of nonlinear finance system were investigated. Firstly, by using the distribution theory of roots to the associate characteristic equation, we obtained the linear stable region of finance system and the conditions of ensuring the existence of Hopf bifurcation. Then we analyzed the chaos control of finance system by using delayed feedback control method. By designing appropriate feedback strength and delay, chaotic oscillation was converted into stable equilibrium or periodic orbit. Finally, some numerical simulations were carried out to support the analytic results.
Keywords: applied mathematics; stability; Hopf bifurcation; chaos; delayed feedback control

Title: Numerical analysis of several kinds of parallel difference methods for nonlinear Leland equation

Authors: ZHAO Weijuan, YANG Xiaozhong
PP: 1963-1972
Abstract: The nonlinear Leland model (nonlinear Black-Scholes option pricing model with transaction costs) occupies an important position in the option pricing and the study of numerical methods is of very important theoretical and practical significance. In this paper, we proposed a kind of high precision parallel difference method which is the improved alternating segment Crank-Nicolson (IASC-N) method. Theoretical analysis demonstrated that IASC-N method has characteristics with unique solution, unconditional stable and second order calculation precision. Finally, through numerical experiment, we compared IASC-N method, alternating segment Crank-Nicolson (ASC-N) method, and alternating segment explicit-implicit (ASE-I) method. Numerical experiments show that the calculation precision of IASC-N method is the second order, the computing efficiency of IASC-N method is taller than ASC-N method, and the computing efficiency of ASE-I method is good. By comprehensively comparing, IASC-N parallel difference method given by this paper is the most practical for solving nonlinear Leland model.
Keywords: computational mathematics; nonlinear Leland model; improved alternating segment Crank-Nicolson method; alternating segment explicit-implicit method; parallel computing; numerical experiments

Title: TOPSIS method based on new distance measure of hesitant fuzzy linguistic term set

Authors: WANG Zhongxing, CHEN Shaosong, LAN Jibin
PP: 1955-1962
Abstract: The existing distance measure of hesitant fuzzy linguistic term set (HFLTS) only considers the difference of linguistic values, but fails to take the difference of the number of linguistic values into account. Aiming at this problem, the hesitance degree of HFLTS was proposed. Based on the hesitance degree, some new distance measures and distance operators of HFLTS were defined. Then on account of new distance measure, technique for order preference by similarity to ideal solution (TOPSIS), a multiple attribute decision making method was given. Finally, a numerical example was applied into the method to verify its feasibility and effectiveness. This method can not only make full use of original data, but also reduce the loss of information.
Keywords: decision theory; technique for order preference by similarity to ideal solution; hesitance degree; new distance measure; distance operators

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