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Ting L.,Jinan University | Haiyan J.,Guangdong Province Material Testing Center | Cuiyun C.,Jinan University | Yinzhou C.,Jinan University
Chemical Journal on Internet | Year: 2010

A new biflavonoid, 5,7,4',5"-tetrahydroxy-7"-metroxy-[3-O-4'"] biflavone along with four known biflavonoids and one known phenolic acid was isolated from the herb of Selaginella uncinata(Desv.) Spring. Their structures were elucidated by spectroscopic methods.


Shi G.,China University of Geosciences | Shi G.,American Museum of Natural History | Harlow G.E.,American Museum of Natural History | Wang J.,China University of Geosciences | And 4 more authors.
European Journal of Mineralogy | Year: 2012

The jadeitite from Myanmar is the most important commercial source on Earth, and its mineralogy perhaps the most diverse. More than thirty mineral species, including jadeite, omphacite, kosmochlor, Cr-bearing jadeite-omphacite, albite, celsian, banalsite, hyalophane, nyböite, eckermannite, magnesiokatophorite, glaucophane, richterite, winchite, analcime, natrolite, thomsonite-Ca, pectolite, vesuvianite, titanite, grossular, uvarovite, allanite, phlogopite, cymrite, zircon, graphite, quartz, diaspore, kaolinite, pyrite, galena, chromite, and ilmenite have been documented from these jadeitites and related rocks, which we review and update. Phlogopite, natrolite, thomsonite-Sr, titanite and ilmenite are newly reported here. Amphiboles, kosmochlor and omphacite formed closely related to the paragenetic sequence in the presence of jadeite; however, uvarovite is formed by replacement of chromite and does not require the presence of jadeite. At least two stages of jadeitization have been identified for Myanmar jadeitite. Late-stage zeolites, pectolite and hyalophane, banalsite, titanite and some celsian formed at lower P and T. The spectrum of minerals in Myanmar jadeitite indicates that the jadeite-forming fluids were rich in Na, Al, Ba, Sr, and Ca. Moreover, the variety of replacement textures suggests that most rocks in the serpentinite mélanges were subject to infiltration and potential replacement by jadeitite or reaction with jadeitite. Serpentinite was replaced by sodic to sodic-calcic amphibole, chromite in ultramafic rock by kosmochlor and Cr-bearing jadeite, and the clinopyroxene in mafic rock by omphacite. Relict ilmenite replaced by titanite in omphacitite is evidence for metasomatism of mafic rock. Sodium-rich fluids were likely dominant throughout jadeitite crystallization and metasomatic reactions. A general mineralogical comparison of jadeitites world-wide indicates both similarities and distinctions; these could be used for interpreting sources of the jadeite jade, particularly in archaeology. © 2012 E. Schweizerbart'sche Verlagsbuchhandlung.


Xiong Q.,Sichuan University | Chen W.,Sichuan University | Zhu X.,Sichuan University | Hang X.,Sichuan University | And 2 more authors.
Lizi Jiaohuan Yu Xifu/Ion Exchange and Adsorption | Year: 2012

The adsorption behavior of Pb2+ on Thiol-functionalized bentonite (TFB) was studied using batch technique under a function of contact time, pH, ionic strength and temperature. And then the kinetics and thermodynamics of the adsorption process was studied in detail. The results showed that the removal efficiency of Pb2+ by TFB could reach 85.4%, when the initial concentration of Pb2+ was 200mg/L, the liquid/solid ratio was 5g/L, pH was 6.0, concentration of KNO3 was 0.1mol/L and adsorption time was 60min at room temperature. The adsorption of Pb2+ on TFB followed pseudo-second-order kinetic model well. On the other hand, the adsorption of Pb2+ on TFB followed Langmuir and Dubinin-Radushkevich (D-R) isotherm models well. Based on the fitting results of Langmuir model, the adsorption was regarded as monolayer adsorption and taken place at the functional groups/binding sites on the surface of the adsorbent. And from the D-R isotherm model, adsorption energy E was between 8kJ/mol and 16kJ/mol, which indicated that the adsorption of Pb2+ was chemisorption process. The thermodynamic parameters (the Gibbs free energy, entropy and enthalpy) of the adsorption were discussed at different temperatures and the results demonstrated that the adsorption process was spontaneous and exothermic.


Guo Q.,Sun Yat Sen University | Guo Q.,Guangdong Province Material Testing Center | Zhao W.,Sun Yat Sen University | Chen J.,CAS Guangzhou Institute of Geochemistry | Wang B.,CAS Guangzhou Institute of Geochemistry
Acta Petrologica Sinica | Year: 2012

A lot exsolution structures have been observed in the Songduo eclogites, southern Tibet. EDS analyzing in the EPMA shows that the exsolutions in garnet are rutile, and the exsolutions in omphacite are a K-rich mineral and quartz. The calculation of the garnet-omphacite-phengite geobarothermometer shows that the peak-metamorphic P-T conditions of the Songduo eclogites are close to the transformation line between quartz-coesite. Thus, the exsolutions of minerals indicate that the Songduo eclogites likely experienced UHP metamorphism, which provides an important evidence for formation P-T conditions of the Songduo eclogites.


Chen W.,Chengdu University of Technology | Chen W.,University of Electronic Science and Technology of China | Xiong Q.-X.,Chengdu University of Technology | Pang X.-F.,University of Electronic Science and Technology of China | And 4 more authors.
Guang Pu Xue Yu Guang Pu Fen Xi/Spectroscopy and Spectral Analysis | Year: 2013

A comparative analysis of the functional groups and surface structure of the Ca-bentonite (RB) and thiol-modified bentonite (TMB) were characterized by means of FTIR and SEM. The absorptive property of Pb2+ on TMB and RB and its influential factors was studied and the conditions for the adsorption were optimized by using FAAS method. Then the conditions for desorption of Pb2+ from the TMB by using simulated acid rain were studied and the contrast analysis of absorptive stability of Pb2+ on TMB and RB was given. The results showed that the adsorption rate of Pb2+ by TMB could reach more than 98%, when the initial Pb2+ concentration was 100 mg·L-1, the liquid-solid ratio was 5 g·L-1, pH was 6.0, KNO3 ionic strength was 0.1 mol·L-1 and adsorption period was 60 min at 25°C. The saturated adsorption capacity of TMB was 67.27 mg·g-1; it's much more than that of RB (9.667 mg·g-1). The adsorption of Pb2+ on TMB follows Langmuir and Freundlich isotherm models well. Desorption experiments of Pb2+ from TMB with simulated acid rain (pH 3.50) were done, and the desorption rate was 0. The results showed that TMB has a strong adsorption and fixation capacity for Pb2+; it is adapted to lead contaminated soil for chemical remediation.


Li Y.,Guangdong Province Material Testing Center | Liu W.,Guangdong Province Material Testing Center | Chen F.,Guangdong Province Material Testing Center | Zhao Q.,Guangdong Province Material Testing Center
Chinese Journal of Environmental Engineering | Year: 2013

Based on Ca-bentonite, a novel kind of thiol-functionalized bentonite was obtained. And a study was conducted to compare this material with other 17 kinds of modified bentonite and Ca-bentonite for heavy metal adsorption properties. The results showed that the adsorption capacity of thiol-functionalized bentonite for Cd2+ is the best, which is 30% higher than the others, and its saturated adsorption capacity for Cd2+ is up to 52.1 mg/g. The influences of all the 19 kinds of materials on the adsorption characteristics of Cd2+, Pb2+ and Ni2+ were studied in competitive adsorption condition. As shown by the experimental results, the adsorption capacity of thiol-functionalized bentonite for Pb2+ is obviously better than the others, and middle level for Ni2+ in all the studied materials. In addition, the adsorption capacity of thiol-functionalized bentonite for Cd2+, Pb2+ and Ni2+ has the least influence by competitive adsorption. Therefore, the thiol-functionalized bentonite is the most ideal adsorbent for heavy metal ions of all the studied materials.


Zhao Q.-X.,Chengdu University of Technology | Zhao Q.-X.,Laurentian University | Zhao Q.-X.,Guangdong Province Material Testing Center | Chen Y.-W.,Laurentian University | And 2 more authors.
Analytica Chimica Acta | Year: 2010

A low volume microwave digestion (LVMWD) procedure has been developed to have all forms of selenium (Se) compounds in biological samples decomposed to Se (IV) and allow total Se be directly determined by hydride generation-atomic fluorescence spectrometry (HG-AFS), or voltammetrically. Between 0.3 and 0.4mL of mixed digestion reagents consisting of concentrated (15.4M) HNO3-(18.5M) H2SO4 (v:v=10:1) and >5 to <40mg sample were found ideal systems with an optimized MW digestion program. Total Se in five certified reference materials was accurately determined. The results obtained by the conventional and LVMWD techniques agreed well. By avoiding pre-reduction step, this method, suitable for a wide range of biological samples, fully takes the advantages of HG-AFS or voltammetric techniques for their high sensitivity, high tolerance to matrix-related interference and accessibility in instrumentation. LVMWD not only enhances the sample output by 3 times and reduces the operational cost and acid wastes, but also makes the small sample analysis possible for many environmental and medical related research objectives. The digestion pathways of Se containing organic samples are also discussed based on the experimental results. © 2010 Elsevier B.V.


Lei T.,Jinan University | Zhang L.,Jinan University | Jiang H.-Y.,Guangdong Province Material Testing Center | Hu Y.,Jinan University | And 2 more authors.
Journal of Asian Natural Products Research | Year: 2011

Two new compounds, along with two known compounds, were isolated from the barks of Parabarium huaitingii, and their structures were determined as 5α-pregn-6-ene-3β,17α,20(S)-triol-20-O-β-D- digitoxopyranoside (1), cymaropyranurolactone 4-O-β-D-digitalopyranosyl-(1 → 4)-O-β-D-cymaropyranosyl-(1 → 4)-O-β-D-oleandropyranosyl-( 1 → 4)-O-β-D-cymaropyranoside (2), 3β,17α,20(S)- trihydroxy-5α-pregn-6-ene (3), and 5a-pregn-6-ene-3β,17α,20(S)- triol-3-O-β-D-digitalopyranoside (4) by spectroscopic methods. © 2011 Taylor & Francis.


Zhao Q.-X.,Chengdu University of Technology | Zhao Q.-X.,Laurentian University | Zhao Q.-X.,Guangdong Province Material Testing Center | Chen Y.-W.,Laurentian University | And 4 more authors.
Journal of Sulfur Chemistry | Year: 2010

High-purity (99.8%1.1) trimethylselenonium iodide (TMSeI) was synthesized from dimethyl selenide and methyl iodide. Its chemical structure was confirmed using the spectroscopic methods of nuclear magnetic resonance, Fourier transform infrared and electrospray ionization-mass spectrometry. Some thermodynamic properties of the pure TMSeI were studied with differential scanning calorimetry, and its decomposition point and entropy were determined to be 157.7C and 100.7kJ mol-1, respectively. The chromatographic and UV absorption behavior of the trimethylselenonium cation was also studied and the photochemical and chemical stability of TMSe+ and its decomposition products under varying microwave digestion conditions were examined. Some peculiar, yet interesting chemical properties on the stability of the compound were revealed. This is the first time that the chemical properties of this compound are comprehensively studied by various techniques and from different angles. The high purity of the synthesized compound allows it to be used as a primary standard compound in analytical method development and in basic and environmentally related studies. © 2010 Taylor & Francis.

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