Search Results

You are looking at 1 - 10 of 39 items for

  • Author or Editor: Q. Yang x
  • Refine by Access: All Content x
Clear All Modify Search

Novel magnetic solid-phase extraction using carboxylated multiwalled carbon nanotubes was proposed with ultra high-performance liquid chromatography–tandem mass spectrometry for the determination of silodosin in biological samples. The effects of various experimental parameters including adsorbent amount, pH, adsorption time, desorption conditions, and adsorbent reusability were systematically validated. Under the optimized conditions, the calibration curve was linear within the concentration range of 1.0–800 ng mL−1 with the correlation coefficient of 0.9997 and the lower limit of detection was 0.3 ng mL−1. The extraction recoveries were over 90.0% with relative standard deviation (RSD) of less than 5.0%. All these results suggested that magnetic extraction method can be used for enrichment and quantification of silodosin in biological samples.

Open access

Study of the immobilization of226Ra

I. Cement solidification of226Ra waste

Journal of Radioanalytical and Nuclear Chemistry
Authors: R. Wang, X. Yang, and Q. Wu

Abstract  

A study of the immobilization for226Ra waste has been carried out. Cement-based concrete was used as a matrix for the solidification of radium waste. The experimental results show that the cement mixture with water/cement between 0.46–0.54 has higher strengh (above 20 MPa), and the compressive strength was not reduced by addition of 1% barite or the radium waste (RaSO4) into the concrete solid.

Restricted access

Two Mn(II) chloride complexes containing guest molecules

Solvothermal syntheses, crystal structures and thermal decomposition

Journal of Thermal Analysis and Calorimetry
Authors: Q. Yang, S. Chen, and S. Gao

Abstract  

Two phenanthroline-manganese inclusion complexes with [MnCl(H2O)(phen)2]+ core have been synthesized and characterized by single crystal X-ray diffraction, elemental analyses, IR spectra, thermogravimetric analyses. Uncoordinated 2-mercaptothiazole (tzdtH) and 2-mercaptobenzothiazole (bztzH) as guest molecules are included in the complexes with formulas [MnCl(H2O)(phen)2]Cl·tzdtH (1) and {[MnCl(H2O)(phen)2]Cl}2·bztzH (2). X-ray structural analyses for complexes revealed that the complex 1 is triclinic, space group P1 with a=9.724(1) Å, b=11.858(1) Å, c=12.644(2) Å; β=89.056(2)°; Z=2, D c=1.513 Mg m−3, F(000)=638 and the complex 2 is triclinic, space group P1 with a=9.861(1) Å, b=11.476(1) Å; c=12.908(3) Å; β=84.991(2)°; Z=1, D c=1.511 Mg m−3, F(000)=600. Two complexes exhibit high stability up to 650°C. The molar specific heat capacities for the two complexes 1 and 2 can be estimated as being 96.175±0.332 and 72.505±0.364 J mol−1 K−1 at 298.15 K by RD496-III microcalorimeter, respectively.

Restricted access

Abstract  

Five new complexes M(Hmna)2 [M=Mn(II) (1), Co(II) (2), Ni(II) (3), Cu(II) (4) and Zn(II) (5), H2mna=2-mercaptonicotinic acid] have been synthesized and characterized by elemental analyses, IR spectra, thermogravimetric analyses. In addition, molar specific heat capacities and enthalpy changes of reactions were determined by a microcalorimeter at 298.15 K. All the complexes exhibited similar IR spectra, the sulfur and oxygen atoms from monoanionic Hmna ligand coordinated to M2+ in a bidentate fashion. The thermal stability of M(Hmna)2 complexes varied in the sequence 1>2>3>4>5. The complexes were stable up to about 300°C and decomposed to oxides at higher temperatures. The molar specific heat capacities of the complexes were determined in the range between 106.452±0.399 and 145.920±0.423 J mol−1 K−1. The enthalpy changes of reactions, Δr H m θ, were determined from 18.28±0.05 to 52.59±0.07 kJ mol−1 for complexes 1–5, indicating that the thermodynamic stability of M(Hmna)2 increased in the sequence from Mn2+ to Zn2+.

Restricted access

Abstract  

Fourteen new complexes with the general formula of Ln(Hmna)3·nH2O (n=2 for Ln=La-Ho and n=1 for Er-Lu, H2mna=2-mercaptonicotinic acid) were synthesized and characterized by elemental analyses, IR spectra and thermogravimetric analyses. In addition, molar specific heat capacities were determined by a microcalorimeter at 298.15 K. The IR spectra of the prepared complexes revealed that carboxyl groups of the ligands coordinated with Ln(III) ions in bidentate chelating mode. Hydrated complexes lost water molecules during heating in one step and then the anhydrous complexes decomposed directly to oxides Ln2O3, CeO2, Pr6O11 and Tb4O7. The values of molar specific heat capacities for fourteen solid complexes were plotted against the atomic numbers of lanthanide, which presented as ‘tripartite effect’. It suggested a certain amount of covalent character existed in the bond of Ln3+ and ligands, according with nephelauxetic effect of 4f electrons of rare earth ions.

Restricted access

Some wild species of the genus Oryza such as O. rufipogon and O. longistaminata show a high level of resistance to pests and diseases including rice blast (caused by Magnaporthe grisea). To transfer blast resistance from wild species into cultivatedvarieties (O. sativa), interspecific hybrids were produced and anther culture was used toaccelerate the procedure of resistance breeding. Anther culture efficiency depended onboth the medium and the genotype of the cultivated varieties and the wild species. Afterinoculation with a mixture of six strains with wide spectrum virulence, all the F1 hybridswere resistant to blast; the F2 plants segregated, from high resistance to susceptibility, anda similar result was obtained for the H1 and H2 plants. At the H3 stage, blast resistancetended to be stable and almost 100% of inoculated H5 plants were highly resistant to riceblast. For agronomic characteristics, the F2 and H1 showed segregation, but no significantdifferences were seen between the cultivated parents and the H2 to H5 generations. Theresults demonstrate that blast resistance genes can be transferred from wild rice speciesinto cultivated varieties through crossing and anther culture, and the H5 can be used asstable lines in future breeding programmes.

Restricted access

Abstract  

Poly(AN—co—St) (PAS) and poly(AN—St—MMA)(PASM) were synthetized by emulsion polymerisation. The glass transition temperatures (Tg) of the copolymers and the relationship between Tg and the components of the copolymers were investigated by differential scanning calorimetry. The results show that Tg for the AN—St bipolymers has apeak value in the range 115–118°C at a content of 50 mass% St. When methyl methacrylate was added, the Tg of the terpolymer was decreased by about 2–6°C.The thermostability and the activation energy E of degradation were determined by thermogravimetric analysis.

Restricted access

Abstract  

Soybean oil based polyols (5-OH polyol, 10-OH polyol and 15-OH polyol) were synthetised from epoxidized soybean oil. The melting peak of polyols and the relationship between melting peak and the number-average functionality of hydroxyl in polyols were investigated by differential scanning calorimetry (DSC). The thermal decomposition of polyols and some of their thermal properties by thermogravimetry (TG) and derivative thermogravimetry (DTG) were also studied. The thermal stability of polyols in a nitrogen atmosphere was very close hence they had a same baseplate of triglyceride for polyols. The extrapolated onset temperature of polyols in their thermal mass loss, first step had a decreasing order: 5-OH polyol>10-OH polyol>15-OH polyol due to the difficulty in forming multiple elements ring of them had the same order. The thermal behavior of polyols under non-isothermal conditions using Friedman’s differential isoconversional method with different heating rates indicated that the 5-OH polyol had the lowest activation energy in thermal decomposition amongst these polyols according to the same fractional mass loss because of the weakest intramolecular oligomerization. The 15-OH polyol was prior to reach the mass loss region because the six-member ring is more stable than the three-member ring from 10-OH polyol and more easily formed.

Restricted access

Abstract  

Solid complexes of M(His)2Cl2 nH2O (M=Mn, Co, Ni, Cu) of MnCl26H2O, CoCl26H2O, NiCl26H2O, CuCl22H2O and L-α-histidine (His) have been prepared in 95% ethanol solution and characterized by elemental analyses, chemical analyses, IR and TG-DTG. The constant-volume combustion energies of the complexes have been determined by a rotating-bomb calorimeter. And the standard enthalpies of formation of the complexes have been calculated as well.

Restricted access

Abstract  

New solid complex of nitrilotriacetic acid and bismuth trichloride was synthesized by a solid phase reaction of nitrilotriacetic acid and bismuth trichloride at room temperature. The composition of the sample is BiCl3[N(CH2COOH)3]2.5. The crystal structure of the complex belongs to triclinic system with the lattice parameters: α=0.7849 nm, β=0.9821 nm, χ=2.0021 nm, α=96.50, β=98.76 and γ=90.49. The far-infrared spectra show the bonding between the Bi ion and N atom of nitrilotriacetic acid. The thermal analysis also demonstrates the complex formation between the bismuth ion and nitrilotriacetic acid. The gaseous pyrolysis product and the final residue in the thermal decomposition process are determined to check the thermal decomposition reaction.

Restricted access