Numerical simulation and experimental study on dissolving characteristics of layered salt rocks

Underground salt cavern reservoirs are ideal spaces for energy storage. China is rich in salt rock resources with layered lacustrine sedimentary structures. However, the dissolution mechanism of layered salt rocks remains poorly understood, resulting in significant differences between the actual measurements and the designed indices for the layered salt rock water-soluble cavity-making cycle and the cavity shape. In this work, the dissolution rates of 600 groups of layered salt rocks in China under different conditions were determined experimentally.Thus, the established artificial neural network prediction model was used to assess the effects of the contents of NaCl, Na2 SO4, and CaSO4 in the salt rocks, concentrations, dissolution angles, and flow rates on their dissolution rates by performing ANOVA and F-test. The results provide a theoretical basis for evaluating the dissolution rate of layered salt rocks under different conditions and for the numerical simulation of the layered salt rock water-soluble cavity-making process.

Preparation and Electrocatalytic Activity of Polyaniline-poly (Propylene Oxide) Modified by Pt Nanoparticles

The preparation and electrocatalytic activity of polyaniline-poly （ propylene oxide ） （ PAN-PPO ） modified by Pt particles （ Pt/ PAN-PPO ） were investigated. Pt/ PAN-PPO was characterized by scanning electron microscopy （SEM） and energy dispersive spectroscopy （ EDS ）. Pt particles on PAN-PPO were in the nanometer range, and dispersed in a three-dimensional distribution on the surface of PAN-PPO film. Compared with polyaniline and glassy carbon modified with Pt particles under the same conditions, Pt/PAN-PPO exhibited a high electrocatalytic activity for lysine oxidation.

Electrical and structural properties of diamond films implanted by various doses of oxygen ions

Oxygen-doped diamond films are prepared by implanting various dose oxygen ions into the diamond films synthesized by hot filament chemical vapour deposition, and their electrical and structural properties are investigated. Hall effect measurements show that lower dose oxygen ion implantation is beneficial to preparing n-type diamonds. The carrier concentration increases with the dose increasing, indicating that oxygen ions supply electrons to the diamonds. The results of AES spectrum indicate that oxygen ions are doped into the diamond films, and the O-implanted depth is around 0.1μm. Raman spectrum measurements indicate that the lower dose oxygen ion implantation at 10^14 cm^-2 or 10^15 cm^-2 is favourable for producing less damaged O-doDed diamond films.

Vapor-Liquid Equilibrium Measurements and Modeling for Ternary System Water ＋ Ethanol ＋ 1-Butyl-3-methylimidazolium Acetate

Vapor-liquid equilibrium(VLE) data were measured for ternary system water + ethanol + 1-butyl-3methylimidazolium acetate([bmim][OAc]),in a relatively wide range of ionic liquid(IL) mass fractions up to 0.8.Six sets of complete T-x-y data were obtained,in which the mole fraction of ethanol on IL-free basis was fixed separately at 0.1,0.2,0.4,0.6,0.8,and approximate 0.98.The non-random-two-liquid(NRTL) and electrolyte non-random-two-liquid(eNRTL) equations were used for correlation,showing similar deviations.The ternary VLE was also modeled with the correlation from two data sets,with the mole fractions of ethanol on IL-free basis being 0.1 and approximate 0.98.The VLE data were also reproduced satisfactorily.With the eNRTL model,the root-mean-square deviation for temperature is 0.79 K and that for vapor-phase mole fraction is 0.0094.The calculations are in good agreement with experimental data.The effect of the IL on the VLE behavior of the volatile components is also illustrated.

Catalytic Hydrolysis of Borohydride for Fuel Cells

Borohydrides present interesting options for the electrochemical power generation acting either as hydrogen source or anodic fuel for direct borohydride fuel cells(DBFC).In this work,Mg-Ni composite synthesized by mechanically alloying method,used as the catalyst for the hydrolysis of borohydride,has been investigated.Co-doping treatment has been carried out for the purpose of improving the hydrolysis rate further.The as-prepared and Co-doped Mg-Ni composites with low cost showed high catalytic activity to the hydrolysis of borohydride for hydrogen generation.After Co-doping,the hydrogen generation rate was around 280 ml·g-1·min-1.Borohydride would be a promising hydrogen source for fuel cells.

TiO_2/graphene nanocomposites as anode materials for high rate lithium-ion batteries

A simple strategy to prepare a hybrid of nanocomposites of anatase TiO2/graphene nanosheets(GNS)as anode materials for lithium-ion batteries was reported.The morphology and crystal structure were studied by X-ray diffraction(XRD),field emission scanning electron microscopy(FE-SEM)and transmission electron microscopy(TEM).The electrochemical performance was evaluated by galvanostatic charge–discharge tests and alternating current(AC)impedance spectroscopy.The results show that the TiO2/GNS electrode exhibit higher electrochemical performance than that of TiO2 electrode regardless of the rate.Even at 500 mA/g,the capacity of TiO2/GNS is 120.3 mAh/g,which is higher than that of TiO2 61.6 mAh/g.The high performance is attributed to the addition of graphene to improve electrical conductivity and reduce polarization.

Determination of Enantiomeric Purity of ν-Pyrrolidinyl Phenylpropanol by Capillary Electrophoresis Using β-Cyclodextrin Polymer as Chiral Selector

Enantiomer of (-pyrrolidinyl phenylpropanol was studied by capillary electrophoresis using (-cyclodextrin polymer as chiral selector. We determined the enantiomeric excess value of (-pyrrolidinyl phenylpropanol with RSD 0.48%.

Local Atomic Structure of Piperidyl Nd Dithiocarbamate

The atomic structure of a novel rare earth complex consisting of Nd and the sulfur-containing ligand pipdtc (C5H10NCS-2) has been studied with extended x-ray absorption fine structure (EXAFS} and x-ray diffraction techniques. The complex of formula Nd(pipdtc)4N(CH3)4 crystallizes in the monoclinic space group P21/n with the following lattice parameters, a = 22.685(2), b = 20.332(2), c = 17.1270(10)Å, β = 100.570(10)o, Z = 8. The calculated density is 1.47g/cm3. A new derivative method is used to remove the post-edge absorption background including the multielectron excitation effect. The EXAFS results demonstrate that there are about eight S and four O atoms around Nd with the Nd-S bond length of 2.916Å and the Nd-O bond length of 2.415Å, respectively. This implies that the powder of this complex is not stable and is easy to oxidize in air. The possible change of structure before and after oxidation is discussed.

Extraction of Lithium from Salt Lake Brine with Triisobutyl Phosphate in Ionic Liquid and Kerosene

Three ionic liquids（ILs）, namely, 1-butyl-3-methylimidazolium hexafluorophosphate, 1-butyl-3-me- thylimidazolium bis[（trifluoromethyl）sulfonyl]imide and 1-ethyl-3-methylimidazolium bis[（trifluoromethyl）sul- fonyl]imide with the triisobutyl phosphate（TIBP） and kerosene system were respectively used to extract lithium ion from salt lake brine with a high concentration ratio of magnesium and lithium experimentally. Results indicate that the highest extraction selectivity for lithium was obtained with IL 1-ethyl-3-methylimidazolium bis[（trifluoromethyl）- sulfonyl]imide. The effects of solution pH and phase ratio R（O/A） on the extractive step and the influence of acid concentration of the stripping solution and R（O/A） on the back extraction step were also investigated systematically. The single-step extraction efficiency of lithium ion was 83.71% under the optimal extraction conditions, and the single-step back extraction efficiency was 85.61% with a 1.0 mol/L HCI in 1.0 mol/L NaCI medium as stripping agent at R（O/A）=2. The liquid-liquid extraction mechanism and the complex of the ligand with lithium were proposed.

水-异丙醇-1-丁基-3-甲基咪唑氯盐三元体系气液平衡测定及模型化研究(英文)

Vapor-liquid equilibrium(VLE)data for water+2-propanol+1-butyl-3-methylimidazolium chloride([bmim]Cl)were measured.Six sets of complete T,x,y data are reported,in which the 2-propanol mole fraction on IL-free basis is fixed separately at 0.1,0.2,0.4,0.6,0.8,and approximate 0.98,while the IL mass fraction is varied from 0.1 to 0.8,in an interval of 0.1.The non-random-two-liquid(NRTL)and electrolyte non-random-two-liquid(eNRTL)equations are used to correlate the experimental data with satisfactory results.The ternary VLE behavior is also modeled with the parameters obtained by correlating two data sets,in which the mole fraction of 2-propanol on IL-free basis is approximately 0.1 and 0.98.In this way,the six sets of data are reproduced satisfactorily.With the eNRTL model,the root-mean-square deviation for temperature is 0.82 K and that for vapor-phase mole fraction is 0.0078.The influences of IL on activity coefficients and relative volatility of the volatile components are also graphically illustrated.

Synthesis and Asymmetric Enantioselective Addition of Chiral Polybinaphthyl and Polybinaphthol I.igands

Four chiral polymers P-1, P-2, P-3 and P-4 were synthesized by the polymerization of （S）-2,2＇-dioctoxy-1,1＇- binaphthyl-6,6＇-boronic acid （S-M-3） with （S）-6,6＇-dibromo-1,1＇-binaphthol （S-M-1）, （R）-6,6＇-dibromo-1,1＇- binaphthol （R-M-1）, （S）-3,3＇-diiodo-1,1＇-binaphthol （S-M-2） and （R）-3,3＇-diiodo-1,1＇-binaphthol （R-M-2） under Pd-catalyzed Suzuki reaction, respectively. All four polymers can show good solubility in some common solvents due to the nonplanarity of the polymers in the main chain backbone and flexible alkyl groups in the side chain. The analysis results indicate that specific rotation and circular dichroism （CD） spectral signals of the alternative S-S chiral polymers P-1 and P-3 are larger than those of S-R chiral polymers P-2 and P-4, but their UV-Vis and fluorescence spectra are almost similar. The results of asymmetric enantioselectivity of four polymers for diethylzinc addition to benzaldehyde indicate that catalytically active center is （R） or （S）-1, 1＇-binaphthol moieties.

In-situ synthesis of monolithic Cu-Mn-Ce/cordierite catalysts towards VOCs combustion

A monolithic series of Cu-Mn-Ce oxides supported on cordierites with different Cu/Mn/Ce molar ratios were prepared by the in-situ sol-gel method without any binder. The catalysts were characterized by scanning electron microscopy （SEM）, energy dispersive spectrometer （EDS）, X-ray diffraction （XRD）, and Brunauer-Emmett-Teller method （BET） and examined in the catalytic combustion of volatile organic compounds （VOCs）. The results showed that the well-dispersed nanometer particles of mixed oxides adhered firmly to the cordierite surface. Cu0.15Mn0.3Ce55/cordierite was identified as the most active catalyst. Compared with commercial Pd/Al2O3, Cu0.15Mn0.3Ce55/cordierite showed higher activities for the combustion of various types of VOCs, especially for oxy-derivative compounds which could be lighted off below 200 ℃.

Solid and Liquid Metastable Phase Equilibria in the Aqueous Quaternary System Li＋, Mg2＋//SO42-, Borate-H2O at 273.15 K

The metastable phase equilibria of the Li＋, Mg2＋//SO42-, borate-H2O system at 273.15 K were studied using isothermal evaporation method. The dry-salt phase diagram, water-phase diagram and the physicochemical property diagrams of the system were plotted with the metastable solubility values and physicochemical properties corresponding to density, refractive index, pH value and conductivity. The dry-salt diagram was composed of four crys- tallizing zones[lithium sulfate hydrate（Li2SO4·H2O）, epsomite（MgSO4·7H2O）, lithium metaborate octahy- drate（LiBO2.8H2O）, and hungchaoite（MgB4O7·9H2O）], five univariant curves and two invariant points （Li2SO4·H2O＋MgSO4·7H2O＋MgB4O7·9H2O and Li2SO4·H2O＋LiBO2-8H2O＋MgB4O7·9H20）. Li2B4O7 converted in- to LiBO2 in solution. Comparing the metastable phase diagram at 273.15 K and stable phase diagram at 298.15 K for the system, the crystallized area of Li2SO4·H2O and MgSO4·7H2O became large, whereas, the other phase regions became small. The J（H2O） changes regularly with increasing J（SO42-）, and the physicochemical properties change regularly with the concentration of B4O72- increasing.

Effect of mass transfer process on hydrogen adsorption on polycrystalline platinum electrode in sulfuric acid solution

The underpotential adsorption of hydrogen (HUPD) is one of the most attractive fields in surface electrochemistry and electrocatalysis. In this work, the hydrogen adsorption on polycrystalline platinum electrode experimentally as well as on single crystal Pt(110) and Pt(100) electrode theoretically were studied. The effect of forced convection on the adsorption and desorption process of hydrogen was studied through adjusting the sampling rate of the microporous sampler closing to the surface of the platinum electrode immersed in dilute sulfuric acid solution. The relationship between HUPD and surface structure sensitivity was built quantitively. The DFT simulation shows that the adsorption strength of hydrogen on Pt(100), due to the lower adsorption energy, is weaker than that on Pt(110). Moreover, the bridged position of hydrogen on Pt(100) and the short-range bridged position on Pt(110) were found to be the optimal adsorption sites. The study of forced convection on the electrode surface promotes the HUPD research from static process to a convective mode and also provides a new strategy to investigate the hydrogen adsorption in solution.

Migration equation of solute in high performance capillary zone electrophoresis

In order to reveal the relationship between migration time and solute structure aswell as electrophoretic operation conditions in high performance capillary zoneelectrophoresis (HPCZE), researchers have presented many empirical and semi-empiricalmodels. These models have two main dissatisfactory points. Firstly, a constant is im-