Xiao-Zhong Chu

Huaiyin Normal University, Peping, Beijing, China

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Publications (5)10.22 Total impact

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    ABSTRACT: The separation of a hydrogen isotope mixture on porous materials was studied using equilibrium and breakthrough experiments. The adsorption equilibria of H2 and D2 on SBA-15 with mesopores and molecular sieves 5A, Y, and 10X with micropores were measured at 77 K using the volumetric method. The breakthrough experiments of a H2 and D2 mixture in each adsorbent bed were carried out at various conditions of flow rate and pressure. The equilibrium ratio of D2 to H2 on mesoporous molecular sieves was larger than the ratio on microporous molecular sieves (SBA-15 > 10X > Y > 5A), but the difference among the adsorbents decreased with increases in pressure. On the other hand, the order of breakthrough separation factor showed the opposite result (SBA-15 < 10X < Y < 5A). The breakthrough separation factors for zeolite 10X was approximately equal to the equilibrium ratio of D2 to H2 at the corresponding partial pressures, whereas zeolites 5A and Y showed higher breakthrough separation factors than their equilibrium ratios. In SBA-15, the separation factors from breakthrough results were even smaller than the corresponding equilibrium ratio. In the microporous adsorbent with a limited pore size (zeolite 5A in the study), the diffusion mechanism contributed to the separation of hydrogen isotope gases as one of key factors.
    International Journal of Hydrogen Energy 01/2014; 39(9):4437–4446. · 3.55 Impact Factor
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    ABSTRACT: This study investigated the antimicrobial and antioxidant activity of the extracts of the flowers, essential oil (EO) and semi-volatile fractions (SVF) of Chimonanthus praecox. The chemical composition of the EO was analysed by gas chromatography-mass spectroscopy (GC-MS) which revealed that the EO contained elemene, muurolene, caryophyllene, cadinol and spathulenol. The effective antibacterial activity of the EO suggested that its different responses on the microorganisms studied depended on the synergistic effects of the compounds contained in the EO. The effective antioxidant activity of the EO showed that the EO had a more marked antioxidant effect on scavenging O2(-)· and OH· than DPPH·, and SVF had a higher potential for scavenging DPPH· than the EO. Our data suggested that the flowers of Chimonanthus praecox had pharmaceutical benefits, and are also a potential source of natural antioxidants and biocides.
    Natural product research 08/2011; 26(14):1363-7. · 1.01 Impact Factor
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    ABSTRACT: In present work, the chemical composition of the petroleum ether extract (PE) and the ethyl ether extract (ETE) of Albizia julibrissin Durazz Pod and their biological activity were investigated, and the biodegradation relationship between with these chemical composition were discussed. The components of the two extracts were identified by GC and by GC-MS. ETE showed a higher level of antimicrobial activity than PE, which were judged by the disc diffusion method of determination of the minimal inhibitory concentration and the minimal bactericidal concentration. The antioxidant properties of the extracts were evaluated by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay, the auto-oxidation of pyrogallol test, and compared with those of the butylated hydroxytoluene (BHT). The results showed that the antioxidant activity of ETE was higher than that of PE (p < 0.01) and lower than that of BHT (p > 0.01) in the DPPH radical scavenging assay. However, in the auto-oxidation of pyrogallol test, the antioxidant activity of PE was higher than that of ETE (p < 0.01) and lower than that of BHT (p < 0.01). Because components of the A. julibrissin pod were found to have biological activity, the pod has a potential use against industrially troublesome microorganisms as a natural source of raw material for the preparation of an antioxidant and a biocide.
    International Biodeterioration & Biodegradation 01/2011; 65(1):258-264. · 2.06 Impact Factor
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    ABSTRACT: The equilibrium adsorption amounts of hydrogen isotope gas and the Brunauer−Emmett−Teller (BET) surface area were measured at 77 K with different microporous and mesoporous molecular sieves. The results indicate that good linear relationships are observed between the amount adsorbed and the BET surface area at (0.02, 0.04 0.06, 0.08, 0.10, and 0.12) MPa for microporous or mesoporous adsorbents, which provide proof of the monolayer adsorption mechanism for hydrogen isotopes at supercritical temperatures. Effects of specific surface area and pore size are more important than the surface properties of adsorbents for hydrogen isotope storage with the physical adsorption method. The equilibrium adsorption difference between hydrogen and deuterium is increased with a decrease of pressure. Moreover, the adsorption capacity of hydrogen isotopes on mesoporous molecular sieves is smaller than that on microporous molecular sieves at the same temperature, pressure, and BET surface area.
    Journal of Chemical and Engineering Data - J CHEM ENG DATA. 01/2010; 55(7).
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    ABSTRACT: The equilibrium and dynamic adsorption data of H(2) and D(2) on different micro- and mesoporous adsorbents with orderly structure including 3A, 4A, 5A, Y, and 10X zeolites; carbon CMK-3; silica SBA-15; and so forth were collected. Critical effect of the nanodimension of adsorbents on the adsorption behavior of hydrogen and its isotopes is shown. The highest adsorption capacity was observed at pore size 0.7 nm, but equal or even larger isotope difference in the equilibrium adsorption was observed at larger pore sizes, whereas the largest isotope difference in the dynamic adsorption was observed at 0.5 nm. The adsorption rate of D(2) is larger than that of H(2) in microporous adsorbents, but the sequence could be switched over in mesoporous materials. Linear relationship was observed between the adsorption capacity for hydrogen and the specific surface area of adsorbents although the adsorbents are made of different material, which provides a convincing proof of the monolayer mechanism of hydrogen adsorption. The linear plot for microporous adsorbents has a larger slope than that for mesoporous adsorbents, which is attributed to the stronger adsorption potential in micropores.
    The Journal of Physical Chemistry B 12/2006; 110(45):22596-600. · 3.61 Impact Factor