Daoyong Zhang

National Taiwan University, T’ai-pei, Taipei, Taiwan

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Publications (52)99.03 Total impact

  • Shuzhi Wang, Xiangliang Pan, Daoyong Zhang
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    ABSTRACT: The knowledge of the effects of Sb(V) on the physiological characteristics of cyanobacteria was still limited. In the present study, responses of photosystem I and II (PSI and PSII), cyclic electron flow (CEF), and interphotosystem electron transport of Microcystis aeruginosa to 5-100 mg/l Sb(V) were synchronously measured using the Dual-PAM-100. 5 mg/l Sb (V) significantly inhibited PSII activity, but had no significant effects on PSI activity. At higher concentrations of Sb(V), the quantum yield and electron transport of PSI were less affected compared to PSII. The ratio of Y(II)/Y(I) significantly decreased with increasing Sb(V) concentration. It decreased from 0.7 for control to 0.4 for 100 mg/l Sb(V)-treated cells, indicating that the change of the distribution of quantum yields between two photosystems and more serious inhibition of PSII under stress of Sb(V) compared to PSI. CEF was activated associated with the inhibition of linear electron flow after exposure to Sb(V). The contribution of Y(CEF) to the quantum yield and activity of PSI increased with increasing Sb(V) concentrations. The cyclic electron transport rate made a significant contribution to electron transport rate of PSI, especially at high Sb(V) concentration (100 mg/l) and high illumination (above 555 μmol photons/m(2)/s). The stimulation of CEF was essential for the higher tolerance of PSI than PSII to Sb(V).
    Current microbiology. 08/2014;
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    ABSTRACT: Responses of photosystem I and II activities of Microcystis aeruginosa to various concentrations of Cu(2+) were simultaneously examined using a Dual-PAM-100 fluorometer. Cell growth and contents of chlorophyll a were significantly inhibited by Cu(2+). Photosystem II activity [Y(II)] and electron transport [rETRmax(II)] were significantly altered by Cu(2+). The quantum yield of photosystem II [Y(II)] decreased by 29 % at 100 μg L(-1) Cu(2+) compared to control. On the contrary, photosystem I was stable under Cu(2+) stress and showed an obvious increase of quantum yield [Y(I)] and electron transport [rETRmax(I)] due to activation of cyclic electron flow (CEF). Yield of cyclic electron flow [Y(CEF)] was enhanced by 17 % at 100 μg L(-1) Cu(2+) compared to control. The contribution of linear electron flow to photosystem I [Y(II)/Y(I)] decreased with increasing Cu(2+) concentration. Yield of cyclic electron flow [Y(CEF)] was negatively correlated with the maximal photosystem II photochemical efficiency (F v/F m). In summary, photosystem II was the major target sites of toxicity of Cu(2+), while photosystem I activity was enhanced under Cu(2+) stress.
    Biological Trace Element Research 06/2014; · 1.31 Impact Factor
  • Daoyong Zhang, Xiangliang Pan, Duu-Jong Lee
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    ABSTRACT: In total, 34 urban street dust samples were collected in Taipei City. Concentrations of potential harmful metals Cr, Pb, Hg, Ni, Cd, Zn, Cu, and Sr and metalloids As and Sb in street dust samples were measured and their sources and potential health risks to humans were evaluated. Traffic emissions were the main source of the potential harmful metals and metalloids in street dust samples from Taipei. Exposure routes for all studied potential harmful metals and metalloids, except for that of Hg, follow ingestion > dermal contact > inhalation. Children are at higher health risk than adults. The As, Sb, Cr, and Pb concentrations in Taipei have adverse non-cancer health effects on residential children. Carcinogenic risk of As exposure for children and adults in Taipei were higher than the threshold value (10−6–10−4). The study highlights the determinant role of anthropogenic factors in the formation of street dust.
    Journal of the Taiwan Institute of Chemical Engineers 01/2014; · 2.08 Impact Factor
  • Pesticide Biochemistry and Physiology 01/2014; · 2.11 Impact Factor
  • Chunnuan Deng, Xiangliang Pan, Daoyong Zhang
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    ABSTRACT: Pollution with antibiotics poses a great risk to aquatic ecosystems. Although some toxic effects of antibiotics on photosystem II (PSII) have been documented, their toxicity to photosystem I (PSI) is still unclear. In this study, effects of ofloxacin on activities of both PSI and PSII of Microcystis aeruginosa (Kützing) Kützing were investigated. Exposure to 0.1 mg L−1 ofloxacin led to increases in contents of chlorophyll a and carotenoids and photosynthetic activity of M. aeruginosa. PSI activity and its electron transport were not affected by 0.1 mg L−1 ofloxacin. When M. aeruginosa was exposed to ≥10 mg L−1 ofloxacin, the electron transport rates of PSI and PSII, the yield of cyclic electron flow (CEF) and the contribution of linear electron flow (LEF) to PSI decreased whereas Y(NA) (limitation of donor side of PSI) and Y(NO) (the quantum yield of non-regulated energy dissipation in PSII) significantly increased. CEF had a significant contribution to alleviating the inhibitory effect of ofloxacin on PSI of M. aeruginosa treated with low concentrations of ofloxacin. The protective role CEF for tolerance of PSI to the toxicity of ofloxacin decreased with increasing ofloxacin concentration.
    Journal of Bioscience and Bioengineering 01/2014; · 1.74 Impact Factor
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    ABSTRACT: Anaerobic Fe(II) Oxidizing Denitrifiers (AFODN), a type of newly found Fe(II)-oxidizing bacteria, play an important role in iron and nitrogen cycling. In the present study, a novel AFODN strain PXL1 was isolated from anaerobic activated sludge. Phylogenetic analysis of 16S rRNA gene sequence revealed similarity between this strain and Citrobactor freundii. The strain reduced 30% of nitrate and oxidized 85% of Fe(II) over 72 h with an initial Fe(II) concentration of 3.4 mM and nitrate concentration of 9.5 mM. Oxidation of iron was dependent on the reduction of nitrate to nitrite in the absence of other electron donors or acceptors. Nitrate reduction and Fe(II) oxidation followed first-order reaction kinetics. Iron oxides accumulated in the culture were analyzed by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) spectroscopy and scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS). The strain recovered deposited oxidized Fe in the form of amorphous Fe oxides.
    Geomicrobiology 01/2014; 31(2). · 1.61 Impact Factor
  • Daoyong Zhang, Duu-Jong Lee, Xiangliang Pan
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    ABSTRACT: Urumqi City is the farthest metropolis from an ocean in the world. This communication measured the concentrations of eight potentially harmful metals Cr, Pb, Hg, Ni, Cd, Zn, Cu, and Sr and metalloids As and Sb in the street dusts collected from Urumqi City and compared them with those noted in Taipei City. Although the geological environments of Taipei and Urumqi differ markedly; however, the potential harmful metals and metalloids studied are surprisingly similar in their distributions in these two cities. Particularly, As is a common pollutant that poses severe health risks to residents in both cities. Hence, the anthropogenic rather than geogenic factors pre-dominate the formation and distributions of street dusts. This finding suggests common control strategy may be applicable to different metropolis on the confinement of adverse health effects by the street dusts.
    Journal of the Taiwan Institute of Chemical Engineers 01/2014; · 2.08 Impact Factor
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    ABSTRACT: This study characterized the interactions of goethite, EPS from cyanobacterium Chroococcus sp. and Hg(II) using excitation emission matrix (EEM) spectra and adsorption isotherms. Three protein-like fluorescence peaks were noted to quench in the presence of Hg(II). The estimated conditional stability constant (logKa) and the binding constant (logKb) of the studied EPS-Hg(II) systems ranged 3.84-4.24 and 6.99-7.69, respectively. The proteins in EPS formed stable complex with Hg(II). The presence of proteins of Chroococcus sp. enhanced the adsorption capacity of Hg(II) on goethite; therefore, the goethite-EPS soil is a larger Hg(II) sink than goethite alone soil. Biosorption significantly affects the mobility of Hg(II) in goethite soils.
    Bioresource Technology 12/2013; · 5.04 Impact Factor
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    Shuzhi Wang, Daoyong Zhang, Xiangliang Pan
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    ABSTRACT: In presenting the calculation of the quantum yield of photosystem I, Y(I), the authors erroneously presented the wrong equation: Equation (4), page 232. The right equation of Y(I) is (Pm'-P)/Pm, where ‘-P’ was missed in the previous version.
    Chemosphere 11/2013; · 3.14 Impact Factor
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    ABSTRACT: Here we demonstrate a calcifying ureolytic bacterium Bacillus sp. CS8 for the bioremediation of chromate (Cr(VI)) from chromium slag based on microbially induced calcite precipitation (MICP). A consolidated structure like bricks was prepared from chromium slags using bacterial cells, and five stage Cr(VI) sequential extraction was carried out to know their distribution pattern. Cr(VI) mobility was found to significantly be decreased in the exchangeable fraction of Cr slag and subsequently, the Cr(VI) concentration was markedly increased in carbonated fraction after bioremediation. It was found that such Cr slag bricks developed high compressive strength with low permeability. Further, leaching behavior of Cr(VI) in the Cr slag was studied by column tests and remarkable decrease in Cr(VI) concentration was noticed after bioremediation. Cr slags from columns were characterized by SEM-EDS confirming MICP process in bioremediation. The incorporation of Cr(VI) into the calcite surface forms a strong complex that leads to obstruction in Cr(VI) release into the environment. As China is facing chromium slag accidents at the regular time intervals, the technology discussed in the present study promises to provide effective and economical treatment of such sites across the country, however, it can be used globally.
    Chemosphere 08/2013; · 3.14 Impact Factor
  • Daoyong Zhang, Chunnuan Deng, Xiangliang Pan
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    ABSTRACT: This study demonstrated that excess Ca(2+) increased the toxicity of Hg(2+) to PSII of cyanobacterium Synechocystis sp. using fast rise chlorophyll fluorescence test. Excess Ca(2+) increased the inhibitory effect of Hg(2+) on O2 evolution. Exposure to Hg(2+) caused increase in functional antenna size (ABS/RC), trapping rate of reaction center (TR0/RC), dissipated energy flux per reaction center (DI0/RC) and maximum quantum yield of non-photochemical deexcitation ( [Formula: see text] ), indicating that some reaction centers were transformed to dissipation sinks under Hg(2+) stress. Hg(2+) stress slowed down electron transport on both donor side and acceptor side and caused accumulation of P680(+). Excess Ca(2+) intensified all the Hg(2+) toxic effects on PSII function and led to dysfunction of PSII. The number of reaction centers that were transformed into dissipation sinks increased with increasing Ca(2+) concentration.
    Ecotoxicology and Environmental Safety 08/2013; · 2.20 Impact Factor
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    ABSTRACT: Antimony (Sb(V)) in Sb mine drainage has adverse effects on the receiving water environments. This study for the first time demonstrated the feasibility of using sulfate-reducing bacteria (SRB) to convert sulfate ions in SMD into sulfides that reduce Sb(V) to Sb(III) and to form complex with Sb(III) as precipitate. The principal compound in the precipitate was stibnite (Sb2S3) at pH 7 and pH 9. The Sb(V) removal mechanism is sulfate-reduction and sulfide oxidization-precipitation, different from the conventional SRB-precipitation processes for heavy metals. The Sb(V)/sulfate ratio is noted an essential parameter affecting the Sb removal efficiency from SMD.
    Bioresource Technology 08/2013; · 5.04 Impact Factor
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    ABSTRACT: Mercury (Hg) is one of the top toxic metals in environment and it poses a great risk to organisms. This study aimed to elucidate the toxic effects of Hg(2+) on energy conversion of photosystem I (PSI) and photosystem II (PSII), membrane potential and proton gradient of Microsorium pteropus (an aquatic plant species). Contents of chlorophyll a, chlorophyll b and carotenoids, quantum yield and electron transfer of PSI and PSII of M. pteropus exposed to various concentrations of Hg(2+) were measured. With increasing Hg(2+) concentration, quantum yield and electron transport of PSI [Y(I) and ETR(I)] and PSII [Y(II) and ETR(II)] decreased whereas limitation of donor side of PSI [Y(ND)] increased. At ⩾165μgL(-1) Hg(2+), quantum yield of non-light-induced non-photochemical fluorescence quenching in PSII [Y(NO)] significantly increased but quantum yield of light-induced non-photochemical fluorescence quenching [Y(NPQ)] decreased. Membrane potential (Δψ) and proton gradient (ΔpH) of M. pteropus were reduced significantly at 330μg L(-1) Hg(2+) compared to control. Mercury exposure affected multiple sites in PSII and PSI of M. pteropus.
    Journal of photochemistry and photobiology. B, Biology 07/2013; 127C:1-7. · 3.11 Impact Factor
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    Shuzhi Wang, Daoyong Zhang, Xiangliang Pan
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    ABSTRACT: Cadmium (Cd) shows high toxicity to aquatic microalgae. Many studies showed that Cd inhibited activities of photosystem II (PSII) but the effects of heavy metals on photosystem I (PSI) and cyclic electron flow (CEF) were still controversial and unclear. The effects of CdCl2 on the activities of PSI, PSII and CEF in Chlorella pyrenoidosa was measured simultaneously in the present study. In presence of 200μM of Cd, ultrastructure of some cells was strongly modified. Cd exposure led to decrease of the activities of photosynthetic oxygen evolution and respiration. PSII was more sensitive to Cd treatment than PSI. Cd treatment showed significant inhibition on the photochemical quantum yield and electron transport rate of PSII. Cd increased the quantum yield of non-light-induced non-photochemical fluorescence quenching, indicating the damage of PSII. The activity of PSI showed tolerance to Cd treatment with concentration less than 100μM in the experiment. Linear electron flow (LEF) made significant contribution to the photochemical quantum yield of PSI of the untreated cells, but decreased with increasing Cd concentration. The contribution of CEF to the yield of PSI increased with increasing Cd concentration. The activation of CEF after exposure to Cd played an essential role for the protection of PSI.
    Chemosphere 05/2013; · 3.14 Impact Factor
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    ABSTRACT: Antimony (Sb) pollution has been of a great environmental concern in some areas in China. Sb enters human body via drinking water, inhalation and food chain, unavoidably interacts with human serum albumin (HSA) in blood plasma, and consequently does harm to human health. The harmful effects of Sb on human health depend on the Sb species and their binding ability to HSA. In the present study, binding of three forms of Sb with HSA was investigated by excitation-emission matrix (EEM) spectroscopy. All of antimony potassium tartrate, antimony trichloride and potassium pyroantimonate quenched fluorescence of HSA. Values of conditional stability constant Ka (×105/M) for Sb and HSA systems were 8.13–9.12 for antimony potassium tartrate, 2.51–4.27 for antimony trichloride and 3.63–9.77 for potassium pyroantimonate. The binding constant Kb (×104/M) values of HSA with antimony potassium tartrate, antimony trichloride and potassium pyroantimonate were 0.02–0.07, 3.55–5.01, and 0.07–1.08, respectively. There was one independent class of binding site for antimony trichloride towards HSA. There was more than one Sb binding site and negative cooperativity between multiple binding sites for potassium pyroantimonate and antimony potassium tartrate towards HSA. The binding ability of HSA to complex Sb followed the order: antimony trichloride>potassium pyroantimonate>antimony potassium tartrate.
    Journal of Luminescence 04/2013; 136:80–85. · 2.14 Impact Factor
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    ABSTRACT: Chromium (Cr) is a toxic metal that poses a great threat to aquatic ecosystems. Information is limited on coinstantaneous responses of photosystems I (PSI) and II (PSII) to Cr(VI) stress due to lack of instruments that can simultaneously measure PSI and PSII activities. In the present study, responses of quantum yields of energy conversion and electron transport rates of PSI and PSII in Microcystis aeruginosa cells to Cr(VI) stress were simultaneously analyzed by a DUAL-PAM-100 system. Quantum yield of cyclic electron flow (CEF) under Cr(VI) stress and its physiological role in alleviating toxicity of Cr(VI) were also analyzed. At 5mgL(-1) Cr(VI), quantum yield and electron transport rate of PSII decreased significantly, and light-induced non-photochemical fluorescence quenching lost. Cr(VI) also inhibited efficiency of PSII to use energy under high light more than of PSI. PSII showed lower maximal electron transport rate and light adaptability than PSI. Electron transport rate of PSI was higher and decreased less than that of PSII, implying less sensitivity of PSI to high light and Cr(VI). Energy dissipation through non-light-induced non-photochemical fluorescence quenching increased with increasing Cr(VI) concentration. CEF was stimulated under Cr(VI) treatment and made a significant contribution to quantum yield and electron transport of PSI, which was essential for protection of PSI from stresses of Cr(VI) and high light.
    Ecotoxicology and Environmental Safety 12/2012; · 2.20 Impact Factor
  • Daoyong Zhang, Duu-Jong Lee, Xiangliang Pan
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    ABSTRACT: Extracellular polymeric substances (EPS) existed ubiquitously in biological systems affect the mobility and availability of heavy metals in the environments. The adsorption-desorption behaviors of Hg(II) and Sb(V) on EPS were investigated. The sorption rates follow Sb(V)>Hg(II), and the desorption rates follow reverse order. Applications of ethylene diamine tetraacetic acid (EDTA), Ca(II) and pH shocks affect desorption rates and desorbed quantities of Hg(II) from EPS-Hg complex. Temperature shock minimally affects the desorption rate of Hg(II). Conversely, the EPS-Sb complex is stable subjected to EDTA, Ca(II), temperature or pH shocks. The excitation-emission matrix (EEM) fluorescence spectroscopy and fast-Fourier (FT-IR) analysis showed that Hg(II) and Sb(V) principally interacted with polysaccharides and protein-like compounds in the EPS, respectively. The EPS-Hg complex presents a time bomb that may release high levels of Hg(II) in short time period under environmental shocks.
    Bioresource Technology 10/2012; 128C:711-715. · 5.04 Impact Factor
  • Varenyam Achal, Xiangliang Pan, Daoyong Zhang
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    ABSTRACT: Contamination of aquifers or sediments by radioactive strontium ((90)Sr) is a significant environmental problem. In the present study, microbially induced calcite precipitation (MICP) was evaluated for its potential to remediate strontium from aquifer quartz sand. A Sr resistant urease producing Halomonas sp. was characterized for its potential role in bioremediation. The bacterial strain removed 80% of Sr from soluble-exchangeable fraction of aquifer quartz sand. X-ray diffraction detected calcite, vaterite and aragonite along with calcite-strontianite (SrCO(3)) solid solution in bioremediated sample with indications that Sr was incorporated into the calcite. Scanning electron micrography coupled with energy-dispersive X-ray further confirmed MICP process in remediation. The study showed that MICP sequesters soluble strontium as biominerals and could play an important role in strontium bioremediation from both ecological and greener point of view.
    Chemosphere 07/2012; 89(6):764-8. · 3.14 Impact Factor
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    Shuzhi Wang, Daoyong Zhang, Xiangliang Pan
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    ABSTRACT: Effects of arsenic on growth, pigments content, oxygen evolution and photosystem II (PSII) activity of Microcystis aeruginosa were investigated in the present study. Various concentrations of As(III) did not show significant effects on growth and total carotenoids content within 24 h of treatment. After 48 h of treatment, 10 mg L(-1) As(III) significantly inhibited the growth and synthesis of carotenoids of M. aeruginosa, while As(III) at concentrations ranging from 0 to 1 mg L(-1) showed no significant inhibition. Chlorophyll a synthesis, oxygen evolution and chlorophyll fluorescence were more sensitive to As(III) exposure than carotenoid synthesis and growth. Chlorophyll a content, fast fluorescence rise transients and fluorescence decay kinetics appeared to be affected after the cells were exposed to 1 and 10 mg L(-1) As(III) for more than 24 h. Treatment with 10 mg L(-1) As(III) for 24 h or longer led to flattening of the fluorescence transient and drastic decrease of amplitude of fast phase of QA- reoxidation kinetics. Exposure to As(III) mainly inhibited the quantum yield for primary photochemistry, density of reaction centers and photosynthesis performance index, and increased the dissipated energy. The decrease in amplitude of the fast and middle phases further revealed that once electron transfer from QA- to QB was inhibited by As(III), more QA- was reoxidized via S2(QAQB)- charge recombination. As(III) stress may result in an increased stability of the S2QB- and S2QA- recombination.
    Ecotoxicology and Environmental Safety 07/2012; 84:104-11. · 2.20 Impact Factor
  • Daoyong Zhang, Duu-Jong Lee, Xiangliang Pan
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    ABSTRACT: The Cu(II) binding properties of loosely bound extracellular polymeric substances (LBEPSs) and tightly bound EPSs (TBEPSs) extracted from biofilm samples at two apparent molecular weight (AMW) ranges, >14 kDa and 1–14 kDa, were investigated using three-dimensional excitation–emission matrix (EEM) fluorescence spectroscopy. The protein-like and aromatic protein fluorescence peaks were identified in EEM fluorescence spectra as peaks A and B, respectively. The intensities of peaks A and B were generally quenched when Cu(II) was bound with LBEPSs or TBEPSs with AMWs > 14 kDa at various pH levels. Conversely, for 1–14 kDa EPSs, fluorescence intensities of peaks A and B were not quenched when Cu(II) was bound with LBEPSs at pH 4 or with both LBEPSs and TBEPSs at pH 8. The Stern–Volmer constant (log Ksv) for the Cu(II)–LBEPSs and Cu(II)–TBEPSs binding processes were 2.38–4.37. The capability of EPSs to bind with Cu(II) increased as pH increased. At pH > 4, the protein-like substances and aromatic proteins in TBEPSs had greater Cu(II) binding capability than LBEPSs. Additionally, the EPSs with AMWs > 14 kDa had stronger binding capability with Cu(II) than EPSs with AMWs of 1–14 kDa. The difference in Cu binding behavior of LBEPS and TBEPS significantly affect the mobility, bioavailability, and toxicity of Cu in aquatic environments.
    Journal of the Taiwan Institute of Chemical Engineers 05/2012; 43(3):450–454. · 2.08 Impact Factor

Publication Stats

162 Citations
99.03 Total Impact Points

Institutions

  • 2011–2014
    • National Taiwan University
      • Department of Chemical Engineering
      T’ai-pei, Taipei, Taiwan
  • 2006–2014
    • Chinese Academy of Sciences
      • • Xinjiang Institute of Ecology and Geography
      • • State Key Laboratory of Environmental Geochemistry
      • • Institute of Geochemistry
      Peping, Beijing, China
  • 2007–2013
    • Northeast Institute of Geography and Agroecology
      • • Xinjiang Institute of Ecology and Geography
      • • Key Laboratory of Biogeography and Bioresource in Arid Land
      • • Institute of Geochemistry
      Beijing, Beijing Shi, China