Transesterification of palm oil to biodiesel using Brφnsted acidic ionic liquid as high-efficient and eco-friendly catalyst

The transesterification of palm oil and methanol catalyzed by Br?nsted acidic ionic liquids was investigated. Four eco-friendly Br?nsted acidic ionic liquids were prepared and their structures were characterized by NMR, FT-IR and TG–DTG. The results demonstrated that [CyN_(1,1)PrSO_3H][p-TSA] was more efficient than the other ionic liquids and chosen as catalyst for further research. The influences of various reaction parameters on the conversion of palm oil to biodiesel were performed, and the orthogonal test was investigated to seek the optimum reaction conditions, which were illustrated as follows: methanol to oil mole ratio of 24:1, catalyst dosage of 3.0 wt% of oil, reaction temperature of 120 °C, reaction time of 150 min, and the biodiesel yield achieved 98.4%. In addition, kinetic study was established for the conversion process, with activation energy and preexponential factor of 122.93 k J·mol^(-1) and 1.83 × 10^(15), respectively. Meanwhile, seven-time recycling runs of ionic liquid were completed with ignorable loss of its catalyst activity. The refined biodiesel met the biodiesel standard EN 14214.

Determination of gouty arthritis' biomarkers in human urine using reversed-phase high-performance liquid chromatography

Creatinine, uric acid, hypoxanthine and xanthine are important diagnostic biomarkers in human urine for gouty arthritis or renal disease diacrisis. A simple method for simultaneous determination of these biomarkers in urine based on reversed-phase high-performance liquid chromatography （RP-HPLC） with ultraviolet （UV） detector was proposed. After pretreatment by dilution, centrifugation and filtration, the biomarkers in urine samples were separated by ODS-BP column by elution with methanol/50 mM NaH2PO4 buffer solution at pH 5.26 （5：95）. Good linearity between peak areas and concentrations of standards was obtained for the biomarkers with correlation coefficients in the range of 0.9957-0.9993. The proposed analytical method has satisfactory repeatability （the recovery of data in a range of creatinine, uric acid, hypoxanthine and xanthine was 93.49-97.90%, 95.38-96.45%, 112.46-115.78%and 90.82-97.13%with standard deviation of o5%, respectively） and the limits of detection （LODs, S/N Z 3） for creatinine, uric acid, hypoxanthine, and xanthine were 0.010, 0.025, 0.050 and 0.025 mg/L, respectively. The established method was proved to be simple, accurate, sensitive and reliable for the quantitation of gouty arthritis＇ biomarkers in human urine samples. The ratio of creatinine to uric acid was found to be a possible factor for assessment of gouty arthritis.

Application of Bronsted acid ionic liquids as green catalyst in the synthesis of 2-propanol with reactive distillation

Five Br?nsted acidic ionic liquids(ILs) were prepared and characterized by FT-IR,~1H NMR and ^(13)C NMR. Their catalytic activities for the synthesis of 2-propanol(IPOH) via transesterification of isopropyl acetate(IPAc) with methanol(Me OH) were investigated. Among all the tested ILs, [Ps-mim]HSO_4 performed best and was used as catalyst for further studies. The reaction kinetics were carried out to correlate the parameters in a homogeneous second order kinetic model. It has been found that there is close agreement between the calculated and experimental values. The high-pressure batch reactive distillation experimental apparatus was set up in order to enhance the conversion of IPAc. A high conversion of IPAc of 99.4% was obtained under the optimal reaction conditions. The catalyst [Ps-mim]HSO_4 can be recycled easily by a rotary evaporator and reused without any further treatment. The catalyst had been repeatedly used for four times and no obvious changes in the structure of catalyst could be observed.

Application and Mechanism of ZnSb2O4 and ZnSb2O6 in the Photocatalytic Degradation of Tetracycline Hydrochloride

The photocatalytic performances in the photocatalytic degradation of tetracycline hydrochloride(TC) of ZnSb2O4 and ZnSb2O6 synthesized by hydrothermal method were explored.The effects of synthesis conditions including reaction temperature, reaction time, precursor solution pH, and the amount of hydrazine hydrate on the photocatalytic activity were discussed.The ZnSb2O4 and ZnSb2O6 photocatalysts prepared under optimal conditions exhibited similar photocatalytic activities for the degradation of TC. However, the areal photoctalytic activity of ZnSb2O4 was 12 times higher than that of ZnSb2O6 because of their different electronic and geometric structures. The photocatalytic degradation mechanisms of TC over ZnSb2O4 and ZnSb2O6 were proposed. Our work will facilitate the development of composite oxides consisting of p-block metal ions as new semiconductor photocatalysts.

Game Analysis and Countermeasures on Increasing Prices of Agricultural Products under Triple Supply Chain

From the perspective of supply chain of agricultural products,by establishing Stackelberg game model based on triple supply chain,this paper researches the price formation and profit distribution mechanism of agricultural products under circumstance of non-cooperation and cooperation.The results show the main factors responsible for the hiking of prices of agricultural products as follows:the cost of agricultural products climbs incessantly;the circulation cost hovers at high level;the factor inputs of agricultural products are short;inflation pressure is incessantly mounting;the profit distribution of supply chain is irrational.Finally,corresponding countermeasures are put forward.

Preparation of Different Lights Irradiated ZnSe/GSH QDs and Their Interaction with BSA

Using L-glutathione(GSH) as a capping agent,Zn Se/GSH quantum dots(QDs) were prepared under microwave irradiation and irradiated under dark, ultraviolet light and incandescent light, respectively. The properties and interaction of different lights irradiated ZnSe/GSH QDs and bovine serum albumin(BSA) were studied systematically. The fluorescence(FL) spectra results reveal that the quenching mechanism are all the static quenching in nature. The quenching constant(Ksv) and binding constant(K) value of different irradiated Zn Se/GSH QDs and BSA all increased with the change of light types from dark to incandescent light and UV light. The number of binding site(n) is close to 1 at different temperatures. The lighting types influence the enthalpy and entropy changes. The Fourier transform infrared(FTIR) spectra indicate that the light induced GSH ligand will facilitate photocatalytic oxidation on the surface of ZnSe/GSH QDs. The circular dichroism(CD)results show that the α-helicity content of BSA decreases from 60.34%, 59.31%, to 58.79% under UV lighting,incandescent lighting and dark conditions. The interaction results of different lights illuminated ZnSe/GSH QDs with BSA by CD spectra method matches well with that by FL and FTIR spectra. That is, the interaction of ZnSe/GSH QDs and BSA from strong to weak is UV light, incandescent light and dark in sequence.

Solving a class of burning disturbed problem with shock layers

A class of combustion problem with shock layers is considered.A modified perturbation method is presented.Using this simple and valid technique,we construct the boundary and the shock layers solution to the problem,and the asymptotic behavior of the solution is discussed.The modifying perturbation method is shown to be a valid method.

Synthesis,Structure and Photoluminescence of (CH_3-4,4'-H_2bipy)-(HgCl_4) with CH_3-4,4'-H_2bipy Generated in Situ

A novel viologen（4,4＇bipyridinium）-based complex （CH3-4,4＇-H2bipy）（HgCl4） （1）,in which the CH3-4,4＇-H2bipy （MQ2＋） was generated in situ,has been synthesized via hydrothermal reaction and structurally characterized. Complex 1 crystallizes in the space group P21/c of monoclinic system with four formula units in a cell：a = 8.1848（6）,b = 21.809（2）,c = 9.0285（6） ,β = 107.377（1）°,V = 1538.0（2） 3,C11H11Cl4HgN2,Mr = 513.61,Dc = 2.218 g/cm3,S = 1.009,μ（MoKα） = 10.685 mm-1,F（000） = 956,R = 0.0360 and wR = 0.0812. The crystal structure analysis reveals that the title complex features an isolated structure based on a CH3-4,4＇-H2bipy moiety and a mercury atom terminally bound by four chlorine atoms. Photoluminescence investigation reveals a strong emission in blue region,which may originate from π→π＊ charge-transfer interaction of the CH3-4,4＇-H2bipy moiety.

THE ESTIMATION OF SOLUTION OF THE BOUNDARY VALUE PROBLEM OF THE SYSTEMS FOR QUASI-LINEAR ORDINARY DIFFERENTIAL EQUATIONS

This paper deals with the singular perturbation of the boundary value problem of the systems for quasi-linear ordinary differential equationswhere x,f, y , h, A, B and C all belong to Rn , and g is an n×n matrix function. Under suitable conditions we prove the existence of the solutions by diagonalization and the fixed point theorem and also estimate the remainder.

Approximate solving method of shock for nonlinear disturbed coupled Schrdinger system

A class of nonlinear disturbed coupled SchrSdinger systems is studied. The specific technique is used to relate the exact and approximate solutions. The correspond- ing typical coupled system is considered. An exact shock travelling solution is obtained by a mapping method. The travelling asymptotic solutions of the disturbed coupled SchrSdinger system are then found with an approximate method.

Synthesis and Crystal Structure of a New Cadmium(Ⅱ) Coordination Polymer with Ethylenediaminetetraacetic Acid

A new cadmium（Ⅱ） coordination polymer,namely,[KCd2（edta）I]n（1,H4edta = ethylenediaminetetraacetic acid）,has been prepared and structurally characterized by single-crystal X-ray diffraction.Crystallographic data for 1：C10H12Cd2IKN2O8,Mr = 679.02,monoclinic,space group P21/n,a = 9.870（5）,b = 8.989（4）,c = 19.082（10） ,β = 104.581（10）o,V = 1638.5（13） 3,Z = 4,Dc = 2.753 g/cm3,μ = 4.776 mm-1,F（000） = 1272,the final R = 0.0473 and wR = 0.1311 for 2846 observed reflections with I 〉 2σ（I）.Polymer 1 features a 2-D layered structure,in which each edta4-ligand chelates/bridges five adjacent six-/seven-coordinated Cd（Ⅱ） centers with all ten donors（eight oxygen and two nitrogen） involved with coordination.Additional iodide I-ions as counterions are bound to the Cd（Ⅱ） centers in a terminal mode and the potassium K＋ ions are located in the layers and surrounded by O and I atoms from neighboring environment.The thermal stability of 1 has been discussed.

Hydrothermal Synthesis and Structure of One New Vanadoarsenate [Zn(dien)(Hdien)]_2[As_6V_(15)O_(42)(H_2O)]·4H_2O

One new arsenic-vanadium cluster, [Zn（dien）（Hdien）]2[As6V15O42（H2O）]·4H2O （1, dien = diethylenetriamine）, has been hydrothermally synthesized and characterized by IR, elemental analysis, TGA, magnetic property and single-crystal X-ray diffraction analysis. Crystal data for 1： monoclinic, space group P21/n, a = 13.959（3）, b = 22.428（5）, c = 22.831（5） A^°, β = 90.733（4）°, Z = 4. X-ray crystallographic study showed that compound 1 is constructed from [As6V15O42（H2O）]^6- polyoxoanions linked together by novel [Zn（dien）（Hdien）]^3＋ complex fragments via hydrogen bonds into a three-dimensional network. Variable temperature susceptibility measurement demonstrates the presence of antiferromagnetic interaction between V^IV cations in 1.

Hydrothermal Synthesis and Structure of One New Polyoxotungsate [Ni(trien)]_4[Ni_4(H_2O)_2(HPW_9O_(34))_2]·4H_2O

One new sandwich-type tetra-nickel substituted polyoxotungsate,[Ni（trien）]4-[Ni4（H2O）2（HPW9O34）2]·4H2O（1,trien=triethylenetetramine）,has been hydrothermally synthesized and characterized by IR,elemental analysis,TGA,and single-crystal X-ray diffraction analysis.Crystal data for 1：triclinic,space group P with a=13.279（3）,b=13.816（3）,c=14.494（4）,α=95.403（1）,β=113.173（4）,γ=93.809（3）o,V=2418.0（10）3,Z=1 and Dc=3.861 g/cm3.X-ray crystallographic study shows that compound 1 is a relatively rare inorganic-organic hybrid polyoxo tungstate constructed from sandwich Ni-substituted polyoxo-anions and nickel complexes.

pH-Dependent Assembly of Molecular Capsule,2D and 3D Coordination Polymers

Three lanthanum/4-sulfocalix[4]arene complexes,namely,H2[（H4CAS）La（H2O）7]2· H2[（H4CAS）La（H2O）7]2·2C2H5OH·12H2O（1）,[H（H4CAS）La（H2O）5]·5H2O（2）and [（H4CAS）La-（H2O）4（NO3）La（H2O）5]·7H2O（3）,have been synthesized at different pH conditions.Complex 1,which exhibits the structure of ＂molecular capsule＂ containing the guest of C2H5OH molecule,is formed at pH = 1.At pH = 2～3,a two-dimensional（2D）coordination polymer of 2 is formed.Further increase of the pH value to 5 leads to the three-dimensional（3D）coordination polymer of 3.Crystal data for 1：monoclinic,space group P21/n,a = 10.8743（16）,b = 25.957（4）,c = 15.863（2）,β = 94.763（2）°,V = 4462.1（11）3,Mr = 1160.87,Z = 4,F（000）= 2376,R = 0.0370 and wR = 0.0936;Crystal data for 2：tetragonal,space group P4/n,a = 11.6593（16）,c = 14.069（4）,V = 1912.5（6）3,Mr = 1114.81,Z = 2,F（000）= 1136,R = 0.0849 and wR = 0.1906;and those for 3：triclinic,space group P1,a = 10.4588（16）,b = 14.995（2）,c = 16.699（3）,α = 65.446（3）,β = 83.487（3）,γ = 73.305（3）°,V = 2281.6（6）3,Mr = 1367.76,Z = 2,F（000）= 1368,R = 0.0423 and wR = 0.1183.

Perturbed Solving Method for Interdecadal Sea-air Oscillator Model

A coupled system of the interdecadal sea-air oscillator model is studied.The El Nio-southern oscillation(ENSO) atmospheric physics oscillation is an abnormal phenomenon involved in the tropical Pacific ocean-atmosphere interactions.The oscillator model is involved with the variations of both the eastern and western Pacific anomaly pat-terns.This paper proposes an ENSO atmospheric physics model using a method of the perturbation theory.The aim is to create an asymptotic solving method for the ENSO model.Employing the perturbed method,the asymptotic solution of corresponding problem is obtained,and the asymptotic behaviour of the solution is studied.Thus we can obtain the prognoses of the sea surface temperature anomaly and related physical quantities.

Singularly perturbed solution for weakly nonlinear equations with two parameters

A class of singularly perturbed boundary value problems of weakly non linear equation for fourth order on the interval [a, b] with two parameters is considered. Under suitable conditions, firstly, the reduced solution and formal outer solution are constructed using the expansion method of power series. Secondly, using the transformation of stretched variable, the first boundary layer corrective term near x = a is constructed which possesses exponential attenuation behavior. Then, using the stronger transformation of stretched variable, the second boundary layer corrective term near x = a is constructed, wtfich also possesses exponential attenuation behavior. The thickness of second boundary layer is smaller than the first one and forms a cover layer near x = a. Finally, using the theory of differential inequalities, the existence, uniform validity in the whole interval [a, b] and asymptotic behavior of solution for the original boundary value problem are proved. Satisfying results are obtained.

ZnO-chitosan/Rectorite Nanocomposite Exhibiting High Photocatalytic Activities under Visible-light Irradiation

Chitosan(CS),hydrated zinc acetate,and rectorite(REC) were used as raw materials to prepare CS-embedded zinc oxide(ZnO) nanoparticle by a chemical precipitation process.Hydrogen-bonded REC-loaded ZnO-CS nanoparticle was to form ZnO-CS/REC nanocomposite photocatalyst,its morphology and structure were analyzed by means of FTIR,XRD,TGA,SEM,and TEM.The effects of the catalyst dosage,methyl orange(MO) initial concentration and solution pH on photocatalytic performance were also discussed.The experimental results show that the ZnO-CS/REC nanocomposite has a particle size of 100 nm with good dispersion and uniformity.Under irradiation of visible light,0.6 g/L photocatalyst was used to degrade MO in solution for 90 min at pH 6,then the MO solution(10 mg/L) was decolored by more than 99%,indicating that the ZnO-CS/REC nanocomposite exhibited highly photocatalytic degradation activity.Therefore,the photodegradation kinetic mechanism of MO in aqueous solution is presumed.

印第安人:来自亚洲还是土生土长于美洲?

印第安人来自哪里?这曾经是一个世界文化问题,研究这一问题,牵涉到许多学科。本文从考古人类学,考古文化学、地理学、语言学以及国外高新科技的研究成果等方面,指出印第安人是通过不同途径到达美洲的亚洲人的后裔。

Photoluminescent,Theoretical and X-ray Investigations on an Iron-nicotinato Cluster

An unprecedented oxo-centered, trinuclear iron nicotinato cluster, [Fe30o （C6NO2Hs）6（H20）3][Fe（H30）2C16]＇12H20＂6Br （1）, has been prepared via hydrothermal reac- tions and structurally characterized by X-ray diffraction. Compound 1 crystallizes in the R-3c space group of rhombohedral system with a = 21.763（4）, c = 24.361（3） A, V = 9992（3） A3, C36H66Br6C16Fe4N6030, Mr = 1978.51, De. = 11973 g/cms, S = 1.006,/（MoKa） = 4.778 mm-1, F（000） = 5880, Z = 6, R = 0.0591 and wR = 0.1054. The title complex features an isolated structure, based on one discrete [Fe30（C6NO2H5）6（H20）3]7＋ cation, one [Fe（H30）2C16]- anion, twelve lattice water molecules and six isolated bromine anions. These isolated moieties are interconnected via hydrogen bonds to yield a three-dimensional （3-D） supramolecular network. Photoluminescent investigation reveals that the title complex exhibits an emission in the purple region. Theoretical study reveals that the emission is attributed to the metal to ligand charge-transfer （MLCT） interaction.

3D Multilayered Turtle Shell Models for Image Steganography

By embedding secret data into cover images,image steganography can produce non-discriminable stego-images.The turtle shell model for data hiding is an excellent method that uses a reference matrix to make a good balance between image quality and embedding capacity.However,increasing the embedding capacity by extending the area of basic structures of the turtle shell model usually leads to severe degradation of image quality.In this research,we innovatively extend the basic structure of the turtle shell model into a three-dimensional(3D)space.Some intrinsic properties of the original turtle shell model are well preserved in the 3D version.Theoretic analysis shows that the new proposed models have good performance both in the image quality and in the complexity of the reference matrix.Our experimental results justify the theoretic conclusions.