Guangzhou Quality Supervision and Testing Institute

Guangzhou, China

Guangzhou Quality Supervision and Testing Institute

Guangzhou, China
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Dong H.,South China University of Technology | Xiao K.,South China University of Technology | Xian Y.,Guangzhou Quality Supervision and Testing Institute | Wu Y.,Guangzhou Quality Supervision and Testing Institute
Food Chemistry | Year: 2018

The present work aims to systematically demonstrate the authenticity of honeys with non-extractable proteins for the first time, by means of EA-IRMS and LC-IRMS. Fifty-three pure honeys of various botanical and geographical origins were studied and a criterion on the basis of the stable carbon isotope ratio characterization of total honey and the main sugars was established for pure honeys. Parameters such as δ13C values of total honey and the main sugars were well utilized to identify honeys with non-extractable proteins. Thirty-five honeys from which protein could not be extracted were all identified as adulterated with C-4 sugars or C-3 sugars. The use of isotopic compositions and some systematic differences permit the honeys with non-extractable proteins to be reliably identified. The findings obtained in this work could supplement the AOAC 998.12 C-4 sugar method, with regard to honeys from which protein cannot be extracted. © 2017 Elsevier Ltd


Feng H.-L.,Sun Yat Sen University | Wu W.-Q.,Sun Yat Sen University | Rao H.-S.,Sun Yat Sen University | Wan Q.,Guangzhou Quality Supervision and Testing Institute | And 3 more authors.
ACS Applied Materials and Interfaces | Year: 2015

The development of a novel nanoarray photoanode with a heterostructure on a transparent conducting oxide substrate provides a promising scheme to fabricate efficient energy conversion devices. Herein, we successfully synthesize the vertically aligned hierarchical TiO2 nanowire/ZnO nanorod or TiO2 nanowire/ZnO nanosheet hybrid arrays, which are proven to be excellent anode candidates for superior light utilization. Consequently, the quantum-dot-sensitized solar cells based on such hybrid arrays exhibit an impressive power conversion efficiency (PCE) under AM 1.5G one sun illumination with improved short-circuit current density (JSC) and fill factor compared to pristine TiO2 nanowire arrays. Combined with the chemical-bath-deposited Cu2S counter electrode, the eventual PCE can be further optimized to as high as 4.57% for CdS/CdSe co-sensitized quantum dot solar cells. © 2015 American Chemical Society.


Wu W.-Q.,Sun Yat Sen University | Rao H.-S.,Sun Yat Sen University | Feng H.-L.,Sun Yat Sen University | Guo X.-D.,Guangzhou Quality Supervision and Testing Institute | And 2 more authors.
Journal of Power Sources | Year: 2014

The present work establishes a facile process for one-step hydrothermal growth of vertically aligned anatase cactus-like branched TiO2 (CBT) arrays on a transparent conducting oxide (TCO) substrate. Various CBT morphologies are obtained by adjusting the potassium titanium oxide oxalate (PTO) reactant concentration (from 0.05 M to 0.15 M) and this yields a morphologically-controllable branched TiO2 arrays geometry. The CBT arrays consist of a vertically oriented nanowire (NW) or nanosheet (NS) stem and a host of short nanorod (NR) branches. The hierarchical CBT arrays demonstrate their excellent candidatures as photoanodes, which are capable of exhibiting high light-harvesting efficiency in dye-sensitized solar cells (DSSCs). Consequently, DSSCs based on 7 μm long optimized CBT arrays (0.05 M PTO), which are assembled with high density and high aspect-ratio NR branches, exhibit an impressive power conversion efficiency of 6.43% under AM 1.5G one sun illumination. The high performance can be attributed to the prominent light-harvesting efficiency, resulting from larger surface area and superior light-scattering capability. © 2014 Elsevier B.V. All rights reserved.


Yang H.,CAS Guangzhou Institute of Geochemistry | Yang H.,University of Chinese Academy of Sciences | An T.,CAS Guangzhou Institute of Geochemistry | Li G.,CAS Guangzhou Institute of Geochemistry | And 6 more authors.
Journal of Hazardous Materials | Year: 2010

This study investigated the photocatalytic degradation of three β-blockers in TiO2 suspensions. The disappearance of the compounds followed pseudo-first-order kinetics according to the Langmuir-Hinshelwood model and the rate constants were 0.075, 0.072 and 0.182min-1 for atenolol, metoprolol and propranolol, respectively. After 240min irradiation, the reaction intermediates were completely mineralized to CO2 and the nitrogen was predominantly as NH4 +. The influence of initial pH and β-blocker concentration on the kinetics was also studied. From adsorption studies it appears that the photocatalytic degradation occurred mainly on the surface of TiO2. Further studies indicated that surface reaction with OH radical was principally responsible for the degradation of these three β-blockers. The major degradation intermediates were identified by HPLC/MS analysis. Cleavage of the side chain and the addition of the hydroxyl group to the parent compounds were found to be the two main degradation pathways for all three β-blockers. © 2010 Elsevier B.V.


Zhao R.R.,South China Normal University | Zhu L.C.,South China Normal University | Huang Z.Z.,Guangzhou Quality Supervision and Testing Institute | Liang J.Z.,Guangzhou Quality Supervision and Testing Institute | And 2 more authors.
Ionics | Year: 2013

LiFePO4/C composites were synthesized by carbothermal reduction method using commercial FePO4 and Tween#80-assisted synthesized nano-FePO4 as starting materials, glucose as reducing agent, and also carbon source. The FePO4 intermediates were characterized by X-ray diffraction and scanning electron microscopy. A suitable mole ratio of Li to Fe was investigated, and the performances of samples synthesized under different temperatures were studied. It seems that the residual carbon content, which determine the electrochemical polarization of the cathode composites, greatly depend on the synthesis temperature when carbothermal reduction method was used. The electrochemical measurements showed that the discharge capacity first increase and then decrease with the rise of temperature. The optimal sample synthesized at 600 °C for 10 h using homemade FePO4 as iron source exhibit 142 mAh g-1 at 0. 2 C and a capacity retention rate of 98. 8 % after 50 cycles. © 2012 Springer-Verlag.


Zhu J.,Guangzhou Quality Supervision and Testing Institute | He G.,Guangxi University | Liang L.,Guangxi University | Wan Q.,Guangzhou Quality Supervision and Testing Institute | Shen P.K.,Guangxi University
Electrochimica Acta | Year: 2015

A novel and facile strategy has been developed to synthesize nitrogen and phosphorus-dual-doped carbon nanotube (N,P-CNT) array and used as Pt support for fuel cell application. In this strategy, the N,P-CNT array with well-designed nanostructure is directly grown on the cheap Ni foam using self-generated cylindrical Ni2P as catalysts. The N,P-CNT with open ends and a large hollow channel provides large number of reactive sites in inner walls with access to reactants compared with conventional bamboo-shape nitrogen-doped carbon nanotubes (N-CNTs). The N,P-CNTs which possess abundant disordered nanostructures and reaction active sites can ingeniously anchor Pt with no need of pretreatment. The highly distributed Pt nanoparticles provide well Pt utilization and strengthen interaction between N,P-CNTs and Pt nanoparticles. The synthesized Pt/N,P-CNTs catalyst shows much better electrocatalytic performance for oxygen reduction reaction in comparison with Pt/CNTs, Pt/N-CNTs and commercial Pt/C catalysts. At 0.9 V vs. RHE in 0.1 mol L-1 HClO4, the Pt mass activity of Pt/CNTs and Pt/N-CNTs are 93.5 and 165.4 mAmg-1 Pt, while, the Pt/N,P-CNTs catalyst shows a mass activity of 285.3 mA mg-1 Pt, which is 3.1 and 1.7 times as high as that of Pt/CNTs and Pt/N-CNTs, respectively. © 2015 Elsevier Ltd. All rights reserved.


Hu J.,CAS Guangzhou Institute of Chemistry | Rong T.,Guangzhou Quality Supervision and Testing Institute | Rong M.-Z.,CAS Guangzhou Institute of Chemistry | Zhang M.-Q.,CAS Guangzhou Institute of Chemistry
Acta Polymerica Sinica | Year: 2014

The castor oil was converted into maleic acid ester (i. e. maleated castor oil, MACO) by the reaction with maleic anhydride. Afterwards, the resultant MACO was free-radically copolymerized with reactive diluents (styrene, St) and cured to form foam plastics through conventional foaming technique. By changing MACO/St ratio, mechanical properties and aerobic biodegradability of MACO foams can be easily adjusted. To understand the biodegradation mechanism of the castor oil based plastic foam, various characterization techniques were employed in a systematic way. Compost tests in laboratory soil combined with molecular characterizations demonstrated that the bio-foam has acquired excellent biodegradability. Destruction of the network structure of the castor oil based polymer resulted from fission of ester groups due to attack of microorganisms. The final product of compost tests proved to be carbon dioxide. Inoculation of fungi on the castor oil based polymer further revealed that the vegetable oil acted as carbon source of growth of aspergillus niger. Under the catalysis of lipase, castor oil, MACO and its foam were hydrolyzed to produce fatty acids. The results of different degradation tests matched each other, which not only confirmed biodegradability of MACO plastics, but also preliminarily revealed molecular mechanism of the biodegradation process.


Zhu J.,Guangzhou Quality Supervision and Testing Institute | He G.,Guangxi University | Shen P.K.,Guangxi University
Journal of Power Sources | Year: 2014

An ion-exchange method has been developed to synthesize Co2P on graphitized carbon and further deposit Pt nanoparticles for the first time. Various methods have been used to characterize the property of the Pt deposited on Co2P/C (Pt-Co2P/C). It shows an improved catalytic activity and stability for methanol electrooxidation. The electrochemical testing proves that the Pt-Co2P/C catalyst has nearly four times the catalytic activity and 120 mV more negative onset potential compared with commercial Pt/C. The reason of the highly enhanced electrocatalytic activity and poisoning resistance of the Pt-Co2P/C catalyst is discussed. © 2014 Elsevier B.V. All rights reserved.


Pan Z.-K.,Guangzhou Quality Supervision and Testing Institute | Lin W.-X.,South China University of Technology | Chu Q.-X.,South China University of Technology
IEEE Transactions on Antennas and Propagation | Year: 2014

A compact single-feed circularly-polarized (CP) wide beam microstrip antenna is proposed for CNSS application. The antenna is designed with a double-layer structure, comprising a circular patch with two rectangular stubs along the diameter direction and a parasitic ring right above it. The resonance frequency and the CP characteristics are mainly controlled by the circular patch and the rectangular stubs, respectively. The vertical HPBW (half power beam width) could be widened by the parasitic ring. Experimental results show that the measured vertical HPBW is approximately 140°and the measured out-of-roundness for the horizontal radiation pattern is only 1.1 dB. Besides, it could maintain good low-profile characteristics. © 2014 IEEE.


Wu Z.,Guangzhou Quality Supervision and Testing Institute | He Z.,Guangzhou Quality Supervision and Testing Institute | Guo M.,Guangzhou Quality Supervision and Testing Institute
Applied Mechanics and Materials | Year: 2012

The HPLC method has been developed for the determination of nine food additives (acesulfame-potassium, benzoic acid, sodium saccharin, sorbic acid, dehydroacetic acid, aspartame, methylparaben, ethylparaben, propylparaben) in condiments. Samples were precipitated, tested by the reverse-phase high performance liquid chromatography instrument with photodiode array detector. All the compounds exhibited good linear relationship with the correlation coefficient from 0.9991 to 0.9998. The recoveries were range from 87.1% to 108.5 % with the RSD values from 1.61 % to 5.13 % at the spiked levels from 5 mg/kg to 250 mg/kg. The detection limits of the method were from 0.3 mg/kg to 2.0 mg/kg. It is a convenient, accurate and effective method to determine these additives in condiment.

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