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Journal of Environmental Sciences 2014年第2期26卷 398-403页

作者： Qing Yu Anzhou Ma Mengmeng Cui Xuliang Zhuang Guoqiang Zhuang research center for Eco-Environmental Sciences Chinese Academy of Sciences

Immigrant bacteria located on leaf surfaces are important to the health of plants as well as to people who consume fresh fruits and vegetables. However, the spatial distribution and organization of these immigrant bacteria on leaf surfaces are still poorly understood. To examine the spatial organization of these strains, two bacterial strains on tobacco leaves：（1） an indigenous strain, Pseudomonas stutzeri Nov. Y2011 labeled with green fluorescent protein, and （2） an immigrant strain Pantoea agglomerans labeled with cyan fluorescent protein isolated from pear, were studied. Under moist conditions, P. agglomerans cells quickly disappeared from direct observation by laser- scanning confocal microscopy, although elution results indicated that large amounts of live cells were still present on the leaves. Following exposure to desiccation stress, particles of cyan fluorescent protein-labeled P. agglomerans were visible within cracked aggregates of P. stutzeri Nov. Y2011. Detailed observation of sectioned aggregates showed that colonies of immigrant P. agglomerans were embedded within aggregates of P. stutzeri Nov. Y2011. Furthermore, carbon-resource partitioning studies suggested that these two species could coexist without significant nutritional competition. This is the first observation of an immigrant bacterium embedding within aggregates of indigenous bacteria on leaves to evade harsh conditions in the phyllosphere.

关键词： phyllosphere spatial organization epiphytes survival manner

Remarkable promotion effect of trace sulfation on OMS-2nanorod catalysts for the catalytic combustion of ethanol

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Journal of Environmental Sciences 2015年第9期27卷 69-75页

作者： Jie Zhang Changbin Zhang Hong He research center for Eco-Environmental Sciences Chinese Academy of Sciences

OMS-2 nanorod catalysts were synthesized by a hydrothermal redox reaction method using Mn SO4（OMS-2-SO4） and Mn（CH3COO）2（OMS-2-AC） as precursors. SO4^2--doped OMS-2-AC catalysts with different SO4^2-concentrations were prepared next by adding（NH4）2SO4solution into OMS-2-AC samples to investigate the effect of the anion SO4^2-on the OMS-2-AC catalyst. All catalysts were then tested for the catalytic oxidation of ethanol. The OMS-2-SO4 catalyst synthesized demonstrated much better activity than OMS-2-AC. The SO4^2-doping greatly influenced the activity of the OMS-2-AC catalyst, with a dramatic promotion of activity for suitable concentration of SO4^2-（SO4/catalyst = 0.5% W/W）. The samples were characterized by X-ray diffraction（XRD）, field emission scanning electron microscopy（FE-SEM）, transmission electron microscopy（TEM）, X-ray photoelectron spectroscopy（XPS）,inductively coupled plasma optical emission spectroscopy（ICP-OES）, NH3-TPD and H2-TPR techniques. The results showed that the presence of a suitable amount of SO4^2-species in the OMS-2-AC catalyst could decrease the Mn–O bond strength and also enhance the lattice oxygen and acid site concentrations, which then effectively promoted the catalytic activity of OMS-2-AC toward ethanol oxidation. Thus it was confirmed that the better catalytic performance of OMS-2-SO4 compared to OMS-2-AC is due to the presence of some residual SO4^2-species in OMS-2-SO4 samples.

关键词： Manganese oxide Octahedral molecular sieves(OMS-2) Catalytic oxidation VOCs Lattice oxygen

Seasonal and diurnal variations of atmospheric peroxyacetyl nitrate, peroxypropionyl nitrate, and carbon tetrachloride in Beijing

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Journal of Environmental Sciences 2014年第1期26卷 65-74页

作者： Gen Zhang Yujing Mu Junfeng Liu Chenglong Zhang Yuanyuan Zhang Yujie Zhang Hongxing Zhang research center for Eco-Environmental Sciences Chinese Academy of Sciences

Atmospheric peroxyacetyl nitrate （PAN）, peroxypropionyl nitrate （PPN）, and carbon tetrachloride （CCl4） were measured from September 2010 to August 2011 in Beijing. PAN exhibited low values from mid-autumn to early spring （October to March） with monthly average concentrations ranging from 0.28 to 0.73 ppbV, and increased from early spring to summer （March to August）, ranging from 1.37-3.79 ppbV. The monthly variation of PPN was similar to PAN, with low values （below detection limit to 0.18 ppbV） from mid-autumn to early spring, and a monthly maximum in September （1.14 ppbV）. The monthly variation of CCl4 was tightly related to the variation of temperature, exhibiting a minimum in winter （69.3 pptV） and a maximum of 180.6 pptV in summer. Due to weak solar intensity and short duration, PAN and O3 showed no distinct diurnal patterns from morning to night during winter, whereas for other seasons, they both exhibited maximal values in the late afternoon （ca. 15：00 to 16：00 local time） and minimal values during early morning and midnight. Good linear correlations between PAN and PPN were found in autumn （R = 0.91）, spring （R = 0.94）, and summer （R = 0.81）, with slopes of 0.130, 0.222, and 0.133, respectively, suggesting that anthropogenic hydrocarbons dominated the photochemical formation of PANs in Beijing. Positive correlation between PAN and O3 in summer with the low slopes （AO3/APAN） ranging from 9.92 to 18.0 indicated serious air pollution in Beijing, and strong negative correlation in winter reflected strong O3 consumption by NO titration and less thermal decompositin of PAN.

关键词： atmospheric peroxyacetyl nitrate peroxypropionyl nitrate carbon tetrachloride Beijing atmosphere

Temperature effect on photolysis decomposing of perfluorooctanoic acid

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Journal of Environmental Sciences 2016年第4期28卷 126-133页

作者： Tiliang Zhang Gang Pan Qin Zhou research center for Eco-Environmental Sciences Chinese Academy of Sciences

Perfluorooctanoic acid（PFOA）is recalcitrant to degrade and ***,the effect of temperature on the photolytic decomposition of PFOA was *** decomposition of PFOA was enhanced from 34% to 99% in 60 min of exposure when the temperature was increased from 25 to 85℃ under UV light（201–600 nm）.The limited degree of decomposition at 25℃ was due to low quantum yield,which was increased by a factor of 12 at 85℃.Under the imposed conditions,the defluorination ratio increased from 8% at 25℃ to 50% at85℃ in 60 *** of perfluorinated carboxylic acids（PFCAs,C7–C5）,PFCAs（C4–C3）and TFA（trifluoroacetic acid,C2）accelerated and attained a maximum within 30 to 90 min at 85℃.However,these reactions did not occur at 25℃ despite extended irradiation to180 *** was decomposed in a step-wise process by surrendering one *** each cyclical process,increased temperature enhanced the quantum yields of irradiation and reactions between water molecules and intermediates *** energy consumption for removing eachμmol of PFOA was reduced from 82.5 k J at 25℃ to 10.9 k J at 85℃ using *** coupled with heat achieved high rates of PFOA degradation and defluorination.

关键词： Perfluorooctanoic acid PFOA Photolysis Temperature effect

Characteristics and anthropogenic sources of carbonyl sulfide in Beijing

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Journal of Environmental Sciences 2015年第2期27卷 163-170页

作者： Ye Cheng Chenglong Zhang Yuanyuan Zhang Hongxing Zhang Xu Sun Yujing Mu research center for Eco-Environmental Sciences Chinese Academy of Sciences

Atmospheric mixing ratios of carbonyl sulfide（COS） in Beijing were intensively measured from March 2011 to June 2013. COS mixing ratios exhibited distinct seasonal variation, with a maximum average value of 849 ± 477 pptv in winter and a minimal value of 372 ± 115 pptv in summer. The seasonal variation of COS was mainly ascribed to the combined effects of vegetation uptake and anthropogenic emissions. Two types of significant linear correlations（R2〉 0.66） were found between COS and CO during the periods from May to June and from October to March, with slopes（ΔCOS/ΔCO） of 0.72 and 0.14 pptv/ppbv, respectively. Based on the emission ratios of COS/CO from various sources, the dominant anthropogenic sources of COS in Beijing were found to be vehicle tire wear in summer and coal burning in winter. The total anthropogenic emission of COS in Beijing was roughly estimated as 0.53 ± 0.02 Gg/year based on the local CO emission inventory and the ΔCOS/ΔCO ratios.

关键词： Carbonyl sulfide Anthropogenic sources Vehicle tire wire Coal combustion Carbon monoxide

Influence of zeta potential on the flocculation of cyanobacteria cells using chitosan modified soil

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Journal of Environmental Sciences 2015年第2期27卷 47-53页

作者： Liang Li Honggang Zhang Gang Pan research center for Eco-Environmental Sciences Chinese Academy of Sciences

Using chitosan modified soil to flocculate and sediment algal cells has been considered as a promising strategy to combat cyanobacteria blooms in natural waters. However, the flocculation efficiency often varies with algal cells with different zeta potential（ZP） attributed to different growth phases or water conditions. This article investigated the relationship between ZP of Microcystis aeruginosa and its influence to the flocculation efficiency using chitosan modified soil. Results suggested that the optimal removal efficiency was obtained when the ZP was between- 20.7 and- 6.7 m V with a removal efficiency of more than 80% in 30 min and large floc size of 〉 350 μm. When the algal cells were more negatively charged than- 20.7 m V, the effect of chitosan modified soil was depressed（〈 60%） due to the insufficient charge density of chitosan to neutralize and destabilize the algal suspension. When the algal cells were less negative than- 6.7 m V or even positively charged, a small floc size（〈 120 μm） was formed, which may be difficult to sink under natural water conditions. Therefore, manipulation of ZP provided a viable tool to improve the flocculation efficiency of chitosan modified soil and an important guidance for practical engineering of cyanobacteria bloom control.

关键词： Cyanobacteria blooms Flocculation Chitosan Modified soil Zeta potential

Effect of pretreatment on Pd/Al_2O_3catalyst for catalytic oxidation of o-xylene at low temperature

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Journal of Environmental Sciences 2013年第6期25卷 1206-1212页

作者： Shaoyong Huang Changbin Zhang Hong He research center for Eco-Environmental Sciences Chinese Academy of Sciences

The effect of pretreatment on Pd/Al2O3 catalysts for the catalytic oxidation of o-xylene at low temperature was studied by changing the pretreatment and testing conditions. The fresh and pretreated Pd/Al2O3 catalysts were characterized by transmission electron microscopy （TEM）, X-ray photoelectron spectroscopy （XPS） and X-ray diffraction （XRD）. The results showed that the pretreatment dramatically changed the Pd/PdO ratio and then significantly affected the Pd/Al2O3 activity; while the pretreatment had not much influence on Pd particle size. The Pd/Al2O3 pre-reduced at 300~C/400~C, which has fully reduced Pd species, showed the highest activity; while the fresh Pd/Al2O3, which has fully oxidized Pd species, presented the worst performance, indicating the Pd chemical state plays an important role in the catalytic activity for the o-xylene oxidation. It is concluded that metallic Pd is the active species on the Pd/Al2O3 catalyst for the catalytic oxidation of o-xylene at low temperature.

关键词： Pd/Al2O3 o-xylene catalytic oxidation noble metal VOC

Fabrication of carbon-supported Al2O3 nanoparticles via spontaneous cross-linking to enhance selective hydrogenation of furfural

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Journal of Energy Chemistry 2025年第1期100卷 612-620页

作者： Weiwei Yu Xinbao Zhang Hongyu Chen Yanan Wang Shaoguo Li Fucun Chen Zhenni Liu Xiujie Li Xiangxue Zhu State Key Laboratory of Catalysis Dalian Institute of Chemical Physics Chinese Academy of Sciences

Selective hydrogenation of furfural to furfuryl alcohol is a great challenge in the hydrogenation field due to thermodynamic preference for hydrogenation of C=C over C=***,a novel Al2O3/C-u hybrid catalyst,composed of N-modified dendritic carbon networks supporting Al2O3nanoparticles,was successfully prepared via carbonizing the freeze-dried gel from spontaneous cross-linking of alginate,Al3+and *** obtained carbon-supported Al2O3hybrid catalyst has a high ratio （31%） of Al species in pentahedral-coordinated *** introduction of urea enhances the surface N content,the ratio of pyrrolic N,and specific surface area of catalyst,leading to improved adsorption capacity of C=O and the accessibility of active *** the furfural hydrogenation reaction with isopropyl alcohol as hydrogen donor,Al2O3/C-u catalyst achieved a 90%conversion of furfural with 98.0% selectivity to furfuryl alcohol,outperforming that of commercial γ-***,Al2O3/C-u demonstrates excellent catalytic stability in the recycling tests attributed to the synergistic effect of abundant weak Lewis acid sites and the anchoring effect of the carbon network on *** work provides an innovative and facile strategy for fabrication of carbon-supported Al2O3hybrid catalysts with rich AlVspecies,serving as a high selective hydrogenation catalyst through MPV reaction route.

关键词： Selective hydrogenation Furfural Furfuryl alcohol Cross-linking MPV route

Determining wind field and electric field by a barium release experiment in the ionosphere

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Science China Earth Sciences 2015年第7期58卷 1210-1215页

作者： XIE LiangHai LI Lei WANG JingDong TAO Ran center for Space Science and Applied research Chinese Academy of Sciences

Barium release experiment is an effective way to study the near-earth environment, in which artificial plasma cloud is created via ionization of neutral gases released from a rocket or a satellite. The first barium release experiment in China was success- fully carried out by a sounding rocket at a height of about 190 km on April 5, 2013. The observed barium cloud images show that the neutral cloud follows a damping motion, whose velocity decreases exponentially and finally tends towards the wind velocity of the background. But for the ion cloud, the motion is controlled mainly by the Lorentz force and a ExB drift happens This work is devoted to calculating the wind and electric field of the background by analyzing the observed images from dif- ferent stations. It turns out that the wind has a magnitude of 51.28 m/s, which is mainly in the northeast direction but also has an appreciable vertical component; the ion cloud has a drift velocity of 71.38 m/s, with a large vertical velocity component be- sides the horizontal components, then the electric field is obtained from the drift velocity as 2.49 mV/m. It is interesting that the wind field shows a better agreement with GITM model than the other empirical or theoretical models, and the GITM model can also give a good prediction for the ion velocity observed by us, which is consistent with the ISR observation at Jicamarca as well.

关键词： active experiment barium release ionospheric electric field wind field

Low CO content hydrogen production from oxidative steam reforming of ethanol over CuO-CeO_2 catalysts at low-temperature

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Journal of Energy Chemistry 2013年第6期22卷 861-868页

作者： Xue Han Yunbo Yu Hong He Jiaojiao Zhao research center for Eco-Environmental Sciences Chinese Academy of Sciences

CuO-CeO2 catalysts were prepared by a urea precipitation method for the oxidative steam reforming of ethanol at *** catalytic performance was evaluated and the catalysts were characterized by inductively coupled plasma atomic emission spectroscopy,X-ray diffraction,temperature-programmed reduction,field emission scanning electron microscopy and thermo-gravimetric *** CuOCeO2 catalysts,H2 with low CO content was produced in the whole tested temperature range of 250–450 *** non-noble metal catalyst 20CuCe showed higher H2production rate than 1%Rh/CeO2 catalyst at 300–400 C and the advantage was more obvious after 20 h testing at400 *** results further confirmed that CuO-CeO2 catalysts may be suitable candidates for low temperature hydrogen production from ethanol.

关键词： CuO-CeO2 catalyst hydrogen production oxidative steam reforming low-temperature