Comparative analysis of chemical components between barks and leaves of Eucommia ulmoides Oliver

The chemical components of the essential oils in the barks and leaves of Eucommia ulmoides Oliver were analyzed and compared by chromatograms and mass spectra technique, heuristic evolving latent projections (HELP), alternative moving window factor analysis (AMWFA) algorithms and normalization method based on the peak areas; the flavones in the barks and leaves of Eucommia ulmoides Oliver were separated on an ODS column by gradient elution carried out with the flow phase consisting of water, methanol and phosphoric acid (0.1%), and their contents were quantitatively determined by standard curve method and diode array detection (DAD) at 362 nm. The results show that 68 and 73 compounds respectively from essential oils of the barks and leaves of Eucommia ulmoides Oliver are identified, and there are 33 mutual compounds among 108 compounds determined. The total contents of these volatile components of the two samples possess 92.9% and 97.75% of the gross of the relevant essential oils, respectively; the contents of the rutin, quercetin and kaempferol in the barks and leaves of Eucommia ulmoides Oliver are 0.016 9, 0.003 6, 0.002 1 and 0.064 4, 0.030 2, 0.010 0 mg/g, respectively, and the determination recoveries are 95.2%-106.2%. The comparative analysis shows that for the barks and leaves of Eucommia ulmoides Oliver, there are significant differences in their components of the relevant essential oils and flavones.

Chemical component analysis of volatile oil in drug pair Herba Ephedrae-Ramulus Cinnamomi by GC-MS and CRM

Active volatile components in drug pair(DP)Herba Ephedrae-Ramulus Cinnamomi(HE-RC),single drug HE and RC were analyzed by gas chromatography/mass spectrometry(GC/MS),chemometric resolution method(CRM)and overall volume integration.By means of CRM,the two-dimensional data obtained from GC-MS instruments were resolved into a pure chromatogram and a mass spectrum of each chemical compound.In total,97,62,and 78 volatile chemical components in volatile oil of HE,RC,and DP HE-RC,were respectively determined qualitatively and quantitatively,accounting for 90.08%,91.62%,and 89.76% total contents of volatile oil of HE,RC,and DP HE-RC respectively.It is further demonstrated that the numbers of volatile components of DP HE-RC are almost the sum of those of two single drugs,but some relative contents of them are changed.Some new components,such as 1,6-dimethylhepta-1,3,5-triene,tetracyclo[4.2.1.1(2,5).0(9,10)]deca-3,7-diene,globulol and(E,E)-6,10,14-trimethyl-5,9,13-pentadecatrien-2-one are found in DP HE-RC because of chemical reactions and physical changes during decoction.

Analysis of volatile chemical components of Radix Paeoniae Rubra by gas chromatography-mass spectrometry and chemometric resolution

The volatile chemical components of Radix Paeoniae Rubra (RPR) were analyzed by gas chromatography-mass spectrometry with the method of heuristic evolving latent projections and overall volume integration. The results show that 38 volatile chemical components of RPR are determined, accounting for 95.21% of total contents of volatile chemical components of RPR. The main volatile chemical components of RPR are (Z, Z)-9,12-octadecadienoic acid, n-hexadecanoic acid, 2-hydroxy- benzaldehyde, 1-(2-hydroxy-4-methoxyphenyl)-ethanone, 6,6-dimethyl-bicyclo[3.1.1] heptane-2-methanol, 4,7-dimethyl-benzofuran, 4-(1-methylethenyl)-1-cyclohexene-1-carboxaldehyde, and cyclohexadecane.

Effects of combination modes of favorable growth unit of Al(OH)_3 crystals precipitating on Van der Waals and chemical bond force

The dipole moment, total energy, atomic charge, orbital population and orbital energy of four representative combination models of the favorable growth unit Al6（OH）18（H2O）6 of Al（OH）3 crystals precipitating are calculated by ab initio at RHF/STO-3G, RHF/3-21G, RHF/6-31G levels and DFT at RB3LYP/STO-3G, RB3LYP/3-21G, RB3LYP/6-31G levels with Dipole & Sphere solvent model. The effect of various combination models on Van der Waals force is analyzed using dipole moment and molecular radius, and that on chemical bond force is analyzed using total energy, orbital population and orbital energy.

Preparation and electrochemical performance of nanosized Co_3O_4 via hydrothermal method

The hydrotalcite-type cobalt compounds were prepared through oxidation of Co(OH)2 gel using NH4OH as precipitating agent and H2O2 as oxidant. These hydrotalcite-type cobalt compounds were transformed into Co3O4 through hydrothermal decomposition with nanostructural deformation. The precursor and product were characterized by Fourier-transform infrared(FT-IR) spectrum, X-ray diffractometry(XRD) and transmission electron microscopy(TEM). The electrochemical performances of as-prepared nanosized Co3O4 as anode materials in lithium-ion batteries were tested by charge-discharge test in the voltage range of 0-3.0 V. The influence of morphology of Co3O4 particle on the capacity and cycling performance was studied. The results show that the shape and size of the final product can be controlled by altering cobalt sources. The irregular cubic Co3O4 with the average particle size of about 10 nm shows the best electrochemical performance. After 10 charge-discharge cycles, the specific charge capacity retains 555 mA·h/g.

Synthesis and electrochemical characterization of layered Li[Ni_(1/3)Co_(1/3)Mn_(1/3)]O_2 cathode materialfor Li-ion batteries

Layered LiNi1/3Co1/3Mn1/3O2 materials were synthesized using a nickel-cobalt-manganese carbonate precursor obtained by chemical co-precipitation. The [Ni1/3Co1/3Mn1/3]CO3 precursor and the LiNi1/3Co1/3Mn1/3O2 powders were characterized by X-ray diffraction（XRD） and scanning electron micrograph（SEM）. The SEM analysis shows that these particles possess uniform and spherical morphology. The electrochemical properties of the (LiNi1/3-)(Co1/3Mn1/3O2) cathode material for rechargeable lithium-ion batteries such as the galvanostatic charge-discharge performance and cyclic voltammetry（CV） were measured. The results show that an initial discharge capacity of 190.29mA·h·g-1 is obtained in the voltage range of 2.54.6V and at a current rate of 0.1C at 25℃.The discharge capacity increases linearly with the increase of the upper cut-off voltage limit.

Structure and electrochemical properties of Li(Ni_(0.5)Mn_(0.5))_(1-x)TixO_2 prepared by one-step solid state reaction

The layered compound Li(Ni0.5Mn0.5)1?xTixO2 powders were prepared with Ni(OH)2,MnCO3,Li2CO3 and TiO2 by one-step solid state reaction.The effect of doping Ti on the structure and electrochemical properties was studied.The XRD results indicate that the powders with 0≤x≤0.05 have good layered structure and trace of impurity appears in the samples with x≥0.1.The SEM photographs show that the particle size distributes homogeneously and the sample with x=0.15 has larger particle size than other samples.The charge-discharge tests show that Li(Ni0.5Mn0.5)0.95Ti0.05O2 synthesized at 800 ℃ for 36 h exhibits good electrochemical properties.It firstly delivers 173 mA·h/g and maintains 90% of the initial discharge capacity after 30 cycles.The cyclic voltammetry and differential capacity vs voltage curves show that the major oxidation and reduction peaks are around 3.95 V and 3.75 V,respectively,assigned to Ni2+/Ni4+ oxidation-reduction process.A weak peak around 4.5 V is found during the oxidation process in the first cycle,which can be regarded as the main reason of the large drop of discharge capacity in the initial cycle.

Synthesis of ZnS nanoparticles by solid-liquid chemical reaction with ZnO and Na_2S under ultrasonic

A novel and simple solid-liquid chemical reaction route was proposed to synthesize ZnS nanoparticles.In the method,ZnS nanoparticles were prepared by reaction of ZnO and Na2S in water with ultrasonic radiation at low temperature.The effects of process parameters on the properties of ZnS particles were investigated.The products were characterized by X-ray diffraction(XRD), scanning electron microscopy(SEM),transmission electron microscopy(TEM),infrared spectroscopy(IR),thermogravimetrydifferential thermogravimetry(TG-DTG)and fluorescence emission spectroscopy.The results show that these particles are good crystalline zinc blende with average size of 35 nm,and possess good IR transmittance in the range of 400 to 4 000 cm1and good thermal stability in oxygen.

Studies on the Synthesis, Crystal Structure and Quantum Chemistry of Di(o-cyanobenzyl)tin Bis(quinoline-2-carboxylate)

Di（o-cyanobenzyl）tin bis（quinoline-2-carboxylate） was synthesized by the reaction of tri（o-cyanobenzyl）tin chloride with quinoline-2-carboxylic acid. The molecular structure of the compound was characterized by elemental analysis, IR, 1H NMR and X-ray diffraction. Crystal data for the compound： tficlinic, space group P1, a = 0.80734（7）, b = 1.00681（9）, c = 1.04811（9） nm, a = 81.7570（10）, β = 7.7240（10）,γ = 81.2850（10）°, V = 0.77581（12） nm3, Z = 1, Dc = 1.488 g/cm3, μ（MoKa） = 0.870 mm^-1 and F（000） = 350. The final R= 0.0204 and wR= 0.0530 for 2677 observed reflections with I 〉2σ（I）, and R = 0.0208 and wR = 0.0532 for all reflections. The molecular structure adopts a distorted octahedral geometry around the Sn atom. The title compound molecules are connected via hydrogen bonding interactions to form a 3D network structure. Quantum chemistry calculation study on the title compound has been performed by means of G98W package at the Lanl2dz basis set. The stability of the compound, orbital energies and some frontier molecular orbital composition characteristics have also been investigated.

Synthesis and electrochemical properties of SnO_2-polyaniline composite

The SnO2-polyaniline(SnO2-PAn) composite was prepared by microemulsion polymerization method using aniline,ammonium peroxodisulfate and SnO2 as starting materials.The SnO2-PAn composite was characterized by X-ray diffractometer,scanning electron microscope and electrochemical techniques.The results show that PAn in the composites is amorphous.PAn formed in the reaction is deposited preferentially on the SnO2 particles,giving a SnO2-PAn composite,in which SnO2 is coated with PAn.SnO2-PAn composite shows a reversible capacity of 657.6 mA·h/g and the capacity loss per cycle is only 0.092% after 80 cycles,suggesting that SnO2-PAn composite is a promising anode material for lithium ion batteries.

Engineering single-atom Mn on nitrogen-doped carbon to regulate lithium-peroxide reaction kinetics for rechargeable lithium-oxygen batteries

Precision engineering of catalytic sites to guide more favorable pathways for Li_(2)O_(2) nucleation and decom-position represents an enticing kinetic strategy for mitigating overpotential,enhancing discharge capac-ity,and improving recycling stability of Li-O_(2) batteries.In this work,we employ metal-organic frameworks(MOFs)derivation and ion substitution strategies to construct atomically dispersed Mn-N_(4) moieties on hierarchical porous nitrogen-doped carbon(Mn SAs-NC)with the aim of reducing the over-potential and improving the cycling stability of Li-O_(2) batteries.The porous structure provides more chan-nels for mass transfer and exposes more highly active sites for electrocatalytic reactions,thus promoting the formation and decomposition of Li_(2)O_(2).The Li-O_(2) batteries with Mn SAs-NC cathode achieve lower overpotential,higher specific capacity(14290 mA h g^(-1) at 100 mAg^(-1)),and superior cycle stability(>100 cycles at 200 mA g^(-1))compared with the Mn NPs-NC and NC.Density functional theory(DFT)cal-culations reveal that the construction of Mn-N_(4) moiety tunes the charge distribution of the pyridinic N-rich vacancy and balances the affinity of the intermediates(LiO_(2) and Li_(2)O_(2)).The initial nucleation of Li_(2)O_(2) on Mn SAs-NC favors the O_(2)-→LiO_(2)→Li_(2)O_(2) surface-adsorption pathway,which mitigates the overpoten-tials of the oxygen reduction(ORR)and oxygen evolution reaction(OER).As a result,Mn SAs-NC with Mn-N_(4) moiety effectively facilitates the Li_(2)O_(2) nucleation and enables its reversible decomposition.This work establishes a methodology for constructing carbon-based electrocatalysts with high activity and selectivity for Li-O_(2)batteries.

Synthesis, characterization and electrochemical recognition of metal ions of three new ferrocenyl derivatives containing pyridyl moiety

Three new ferrocene （Fc） based receptors with pyridyl moiety, named methyl-6- ferrocenoylacetyl-2-pyridine carboxylate （FcLl）, 1,1＇-（2,6-bispyridyl）bis-3-ferrocenyl-l,3-propanedione （FcL2）, ferrocenecarboxaldehyde-2,6-dipicolinoyhydrazone （FcL3） were synthesized, and further characterized by elemental analysis, IR spectra, UV-Vis spectra, 1H and 13C NMR. The electrochemical properties and ion sensing properties of FcL1, FcL2 and FcL3 were also investigated by means of cyclic voltammetry in ethanol solution with 0.1 mol/L LiC104 as the supporting electrolyte. The E~ values of the receptors increase with the scanning rate increasing at high scanning rate, and Ipa/Ipo approaches unity, indicating that the redox reaction is basically reversible. Their recognition performances to different metal cations such as Cd（II）, Co（II）, Cu（II）, Hg（II）, Mn（II）, Ni（II）, Zn（II） show that the FcL1 is responsive to Cu（II） with the maximum electrochemical shift of the FcL1 for Cu（II）of about 72.0 mV, whereas the FcL2 is responsive to Cu（II） and Mn（II） with shift of 102 mV and 109 mV, respectively, and the FcL3 is responsive to Hg（II） and Mn（II） with the shift of 53.0 mV and 54.0 mV, respectively. All the results show that these receptors may have potential applications in electrochemical sensor technology, material science, and molecular devices.

Synthesis and electrochemical properties of LiMn_2O_4/Li_4Ti_5O_(12) composite

LiMn2O4/Li4Ti5O12 composite was synthesized by in-situ composite technique using LiMn2O4,lithium acetate,tetrabutyl titanate as starting materials and characterized by various electrochemical methods in combination with X-ray diffractometry(XRD), infrared(IR)spectroscopy and scanning electron microscopy(SEM).The results show that Li4Ti5O12 is coated on the surface of crystalline LiMn2O4 to form LiMn2O4/Li4Ti5O12 composite.The structure of LiMn2O4 does not change due to the introduction of Li4Ti5O12.By being coated with Li4Ti5O12,the rate capability and high temperature cyclability of LiMn2O4 is improved greatly.At room temperature,the discharge capacity of LiMn2O4/Li4Ti5O12 composite is more than 108.4 mA·h/g and the capacity loss per cycle is only 0.053%after 20 cycles at 2.0C.While at 55℃,the discharge capacity of LiMn2O4/Li4Ti5O12 composite is more than 109.9 mA·h/g and the capacity loss per cycle is only 0.036%after 60 cycles at 1.0C.

Chemical component and antimicrobial activity of volatile oil of Calycopteris floribunda

The volatile oil of leaves and barks of Calycopteris floribunda was examined by gas chromatography-mass spectrometry (GC-MS). 52 volatile chemical components in leaves were identified. The antimicrobial assay of oils in the leaves and barks was carried out by disk diffusion method in vitro. The major components (mass fraction) in leaves are caryophyllene oxide (13.79%),n-hexadecanoic acid (11.91%) and β-caryophyllene (10.45%). Ten constituents are identified accounting for about 99.98% of the total volatile oil in the bark. Among these components,n-hexadecanoic acid (59.18%),linolic acid (12.70%) and butyl octyl phthalate (8.21%) are the major constituents. The oils exhibit strong antimicrobial activity and display more potent against bacteria than fungi.

Recovery of Copper（II） and Nickel（II） from Plating Wastewater by Solvent Extraction

The solvent extraction technology, was applied to recover Cu^2＋ and Ni^2＋ from plating wastewater.Lix984N was chosen as the extractant due to-its gooff extraction performance. The influence parame-ters were examlned. The results show that the separation of Cu^2＋ and Ni＂ from sulphate medium can be realized by adjusting pH value with the help of Lix984N. For extracting Cu^2＋ and Ni^2＋, the optimal pH values are 4 and 10.5, and the maximal extraction percentages are 92.9% and 93.0%, respectively .With recovered Cu^2＋ and Ni^2＋ stripped in 170g.L^ -1 and 200 g.L^-1 H2SO4 medium, the stripping percentages of Cu^2＋ and Ni^2＋ are 92.9% and 93.0%, respectively. This method is simple and can be used to recover Cu^2＋ and Ni^2＋ from plating wastewater. And a flow sheet for separation of Cu^2＋ and Ni^2＋ is presented.

Characteristics of graphite felt electrode electrochemically oxidized for vanadium redox battery application

The graphite felt was oxidized at a positive electrode potential in sulfuric acid solution.The electrochemical performance of the treated graphite felt served as electrode for vanadium redox battery was investigated with FT-IR,SEM,XPS,BET,cyclic voltammetry and testing VRB system,respectively.The results show that the molar ratio of O to C increases from 0.085 to 0.15 due to the increase of—COOH functional groups during electrochemical oxidation treatment,and the GF surface is eroded by electrochemical oxidation,resulting in the surface area increase from 0.33 m2/g to 0.49 m 2/g.The VRB with modified GF electrode exhibits excellent performance under a current density of 30 mA/cm 2 .The average current efficiency reaches 94%and average voltage efficiency reaches 85%.The improvement of electrochemical activity for the electrode is ascribed to the increase of the number of—COOH group and the special surface of GF.

Recovery of valuable metals from lepidolite by atmosphere leaching and kinetics on dissolution of lithium

The lepidolite located in Yichun, Jiangxi Province, China, was adopted to investigate the recovery of alkali metals and leaching kinetics of lithium with sulphuric acid solution under atmospheric pressure. The results show that the recoveries of alkali metals were achieved under the leaching conditions: mass ratio of lepidolite with particle size less than 180 μm to sulphuric acid 1.2, leaching temperature 411 K, liquid-solid ratio 2.5∶1, and leaching time 10 h. Under the selected conditions for leaching experiment, the leaching rates of lithium, potassium, rubidium and caesium are 94.18%, 93.70%, 91.81% and 89.22%, respectively. The X-ray diffraction analysis for leaching residue indicates that no insoluble product forms during leaching. The chemical compositions of leaching residue reveal that trace iron, manganese and calcium disappear after acid leaching. The kinetics of leaching process for lithium follows shrinking core model of mixed control and the apparent activation energy is 17.21 kJ/mol. The reaction orders with respect to sulphuric acid concentration and liquid-solid ratio are determined to be 2.85 and 1.66, respectively. A semi-empirical rate equation was obtained to describe the leaching process. The kinetic analysis shows that the leaching process is controlled by diffusion through the insoluble layer of the associated minerals.

Recovery of molybdenum and copper from porphyry ore via iso-flotability flotation

A copper-molybdenum iso-flotability flotation process has been developed to efficiently improve the recovery ofmolybdenite from Duobaoshan porphyry Cu-Mo ores.The effects of flotation approach,type of collector,feed particle sizedistribution,rougher pH value and reagent dosage on the recovery of molybdenite were evaluated systematically.The results suggestthat compared with kerosene and diesel oil,transformer oil has stronger dispersion capability in water media and better flotationselectivity for molybdenite,providing a higher molybdenum recovery under low reagent dosage.Moreover,compared with bulkflotation approach,the iso-flotability flotation approach using transformer oil as a collector can obtain superior Mo recovery(90.77%)and grade(0.80%)in the cleaner concentrate,and increase the Mo recovery and grade by over18%and5%in the final Moconcentrate,respectively.The results of commercial flotation further indicate that the iso-flotability flotation approach is a rationaland effective route to beneficiate the porphyry Cu-Mo ores.

Structural characteristics and formation mechanisms of crack-free multilayer TaC/SiC coatings on carbon-carbon composites

In order to improve high temperature(over 2 273 K)ablation resistance,TaC and TaC/SiC composite coatings were deposited on carbon-carbon composites by CVD method utilizing reactive TaCl5-C3H6-H2-Ar and TaCl5-C3H6-CH3SiCl3-H2-Ar systems respectively.The structure and morphology of these coatings were analyzed by XRD and SEM.The results show that the double carbide coatings have good chemical compatibility during preparation.Two distinctive composition gradients are developed and used to produce multilayer TaC/SiC coatings with low internal stress,free crack and good resistant to thermal shock.A transition layer consisting of either C-TaC or C-SiC formed between the coating and the C/C matrix can reduce the residual stress effectively. The processing parameters were optimized and the possible growth mechanisms for these coatings were proposed.A designing methodology to prepare high performance multilayer TaC/SiC composite coatings was developed.

Determination of contents of eight alkaloids in fruits of Macleaya cordata (Willd) R. Br. from different habitats and antioxidant activities of extracts

A reliable ultrasound-assisted extraction （UAE） method combined with HPLC-UV for quantification of eight active alkaloids in fruits of Macleaya cordata （Willd） R. Br. was developed. The optimization conditions of UAE were obtained by using Box-Behnken design of response surface methodology. Chromatography was carried out using a Kromasil C18 column by gradient elution with 0.1% phosphoric acid aqueous solution for HPLC-UV. All calibration curves showed good linear correlation coefficients （R^2〉0.999 6） and recoveries （from 97.3% to 104.9%） were acceptable. 1,1-diphenyl-2-picrylhydrazyl （DPPH） method was employed to test the antioxidant activity of the extract from the samples. The proposed method was successfully applied to quantifying eight components in nine samples of M.cordata, and significant variations of alkaloid contents and antioxidant aetivity of the samples from different habitats were demonstrated. It presents a powerful proof for the selection of the best sources to extract eight kinds of alkaloids.