检索结果-南通市图书馆

Arsenic uptake, accumulation and phytofiltration by duckweed (Spirodela polyrhiza L.)

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2011年第4期23卷 601-606页

作者： Xin Zhang Ying Hu yunxia liu Baodong Chen State key Laboratory of Urban and Regional Ecology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China

This study investigates arsenic （As） accumulation and tolerance of duckweed Spirodela polyrhiza L. and its potential for As phytofiltration. S. polyrhiza was able to survive in high concentration of As（V） solution. The EC 50 values （± SE） based on the external As（V） were （181.66 ± 20.12） μmol/L. It accumulated （999 ± 95） mg As/kg dw when exposed in 320 μmol/L As（V） solution for one week, and was able to take up appropriately 400 mg As/kg dw in tissues without a significant biomass loss. The EC 50 values （the effective concentration of As（V） in the nutrient solution that caused a 50% inhibition on biomass production） was （866 ± 68） mg/kg dw for the tissues, indicating that S. polyrhiza had a high capability of As accumulation and tolerance. The uptake kinetic parameters V max was （55.33 ± 2.24） nmol/（g dw·min） and K m was （0.144 ± 0.011） mmol/L. Within 72 hr, S. polyrhiza decreased As concentration in the solution from 190 to 113 ng/mL with a removal rate of 41%. The study suggested that this floating aquatic plant has some potential for As phytofiltration in contaminated water bodies or paddy soils.

关键词： arsenic duckweed phytofiltration Spirodela polyrhiza L.

Health risk assessment of heavy metals in soils and vegetables from wastewater irrigated area,Beijing-Tianjin city cluster,China

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2012年第4期24卷 690-698页

作者： Yanchun Wang Min Qiao yunxia liu Yongguan Zhu State Key Laboratory of Reginal and Urban Ecology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China Beijing Institute of Landscape Architecture Beijing 100102China Key Laboratory of Urban Environment Health Institute of Urban EnvironmentChinese Academy of ScienceXiamen 361021China

The possible health risks of heavy metals contamination to local population through food chain were evaluated in Beijing and Tianjin city cluster, China, where have a long history of sewage irrigation. The transfer factors （TF） for heavy metals from soil to vegetables for six elements including Cu, Zn, Pb, Cr, As and Cd were calculated and the pollution load indexes （PLI） were also assessed. Results indicate that only Cd exceeded the maximum acceptable limit in these sites. So far, the heavy metal concentrations in soils and vegetables were all below the permissible limits set by the Ministry of Environmental Protection of China and World Health Organization. The transfer factors of six heavy metals showed the trend as Cd 〉 Zn 〉 Cu 〉 Pb 〉 As 〉 Cr, which were dependent on the vegetable species. The estimated dietary intakes of Cu, Zn, Pb, Cr, As and Cd were far below the tolerable limits and the target hazard quotient （THQ） values were less than 1, which suggested that the health risks of heavy metals exposure through consuming vegetables were generally assumed to be safe.

关键词： heavy metals soil transfer factor human health risk wastewater irrigation

Combined effects of chromium and arsenic on rice seedlings(Oryza sativa L.) growth in a solution culture supplied with or without P fertilizer

在线全文

学校读者我要写书评

暂无评论

Science China(Life Sciences) 2010年第12期53卷 1459-1466页

作者： HUANG YiZong HU Ying liu yunxia Research Center for Eco-Environmental Sciences Chinese Academy of SciencesBeijing 100085China

The growths of two rice genotypes(Jin23A and CDR22) under the coexistence of As and Cr in solution culture with and without P were *** result showed that rice shoot dry weight decreased due to the complex contaminatio... 详细信息

关键词： Complex contamination of As and Cr P Fe rice

Energy-based adaptive orthogonal FRIT and its application in image denoising

在线全文

学校读者我要写书评

暂无评论

Science in China(Series F) 2007年第2期50卷 212-226页

作者： liu yunxia PENG YuHua QU HuaiJing YIN Yong School of Information Science and Engineering Shandong University Jinan 250100 China Shandong Tumor Hospital Jinan 250117 China

Efficient representation of linear singularities is discussed in this paper. We analyzed the relationship between the ＂wrap around＂ effect and the distribution of FRAT （Finite Radon Transform） coefficients first, and then based on study of some properties of the columnwisely FRAT reconstruction procedure, we proposed an energy-based adaptive orthogonal FRIT scheme （EFRIT）. Experiments using nonlinear approximation show its superiority in energy concentration over both Discrete Wavelet Transform （DWT） and Finite Ridgelet Transform （FRIT）. Furthermore, we have modeled the denoising problem and proposed a novel threshold selecting method. Experiments carried out on images containing strong linear singularities and texture components with varying levels of addictive white Gaussian noise show that our method achieves prominent improvement in terms of both SNR and visual quality as compared with that of DWT and FRIT.

关键词： orthogonal transform FRIT image denoising threshold

Cation-πinteractions regulate electrocatalytic water oxidation over iridium single atoms supported on conjugated polymers

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第6期67卷 2063-2069页

作者： Jing Bai yunxia liu Ziwei Ma Shouhan Zhang Guojie Chao Haiping Lin Elke Debroye Longsheng Zhang Tianxi liu Key Laboratory of Synthetic and Biological Colloids Ministry of EducationSchool of Chemical and Material EngineeringJiangnan UniversityWuxi214122China School of Chemistry and Chemical Engineering Northwestern Polytechnical UniversityXi’an710072China School of Physics and Information Technology Shanxi Normal UniversityXi’an710062China Department of Chemistry KU LeuvenCelestijnenlaan 200FLeuven3001Belgium

Designing cost-effective and high-performing metal catalysts is significant for many renewable energy conversion *** metal loading without sacrificing activity and durability is highly desired for the catalyst design,especially for those reactions where the noble metals deliver the best catalyzing ***-atom catalysts(SACs)with maximal metalatom utilization,homogeneous and tailorable active sites have emerged as promising catalyst candidates,where the local coordination structures of the metal atoms in SACs largely determine the reaction *** design strategies of constructing strong metal-support interactions can stabilize the individual metal atoms in SACs,but present obstacles to provide a flexible manipulation platform for elaborately tailoring the coordination structures to achieve performance optimization towards a specifically targeted ***,for the proof-of-concept study,we report a novel design of SAC with iridium(Ir)single atoms supported on conjugated polymer,in which the adsorption energies of reaction intermediates on Ir atoms and the reaction kinetics towards acidic water oxidation can be readily optimized through modulating the formed cation-πinteractions that can be tailored by adjusting the molecular structures of conjugated *** strategy establishes a general route to develop targeted SACs for various catalytic reactions.

关键词： conjugated polymers single-atom catalysts cation-πinteractions oxygen evolution reaction

Growth and metal uptake of energy sugarcane (Saccharum spp.) in different metal mine tailings with soil amendments

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2014年第5期26卷 1080-1089页

作者： Xin Zhang Yongguan Zhu Yuebin Zhang yunxia liu Shaochun liu Jiawen Guo Rudan Li Songlin Wu Baodong Chen State key Laboratory of Urban and Regional Ecology Research Center for Eco-Environmental SciencesChinese Academy of Sciences Key Lab of Urban Environment and Health Institute of Urban EnvironmentChinese Academy of Sciences Sugarcane Research Institute Yunnan Academy of Agricultural Sciences

A pot experiment was conducted to investigate the feasibility of growing energy sugarcane （Sac- charum spp.） in three different metal mine railings （Cu, Sn and Pb/Zn tailings） amended with uncontaminated soil at different mixing ratios. The results indicated that sugarcane was highly tolerant to tailing environments. Amendments of 20% soil to Sn tailings and 30% soil to Cu tailings could increase the biomass of cane-stem for use as the raw material for bioethanol production. Heavy metals were mostly retained in roots, which indicated that sugarcane was useful for the stabilization of the tailings. Bagasse and juice, as the most valuable parts to produce bioethanol, only accounted for 0.6%- 3% and 0.6%-7% of the total metal content. Our study supported the potential use of sugarcane for tailing phytostabilization and bioenergy production.

关键词： bioenergy crop sugarcane metal mine tailings phytoremediation

The triggering of catalysis via structural engineering at atomic level: Direct propane dehydrogenation on Fe-N_(3)P-C

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2023年第3期34卷 442-446页

作者： Wenyi Bian Xueli Shen Huang Tan Xing Fan yunxia liu Haiping Lin Youyong Li Institute of Functional Nano&Soft Materials(FUNSOM) Jiangsu Key Laboratory for Carbon-Based Functional Materials&DevicesSoochow UniversitySuzhou 215123China School of Physics and Information Technology Shaanxi Normal UniversityXi’an 710062China Macao Institute of Materials Science and Engineering Macao University of Science and TechnologyMacaoChina

The on-purpose direct propane dehydrogenation(PDH) has received extensive attention to meet the everincreasing demand of *** this work,by means of density functional theory(DFT) calculations,we systematically studied the intrinsic coordinating effect of Fe single-atom catalysts in ***,the N and P dual-coordinated single Fe(Fe-N_(3)P-C) significantly outperform the Fe-N_(4-)C site in catalysis and exhibit desired activity and selectivity at industrial PDH *** mechanistic origin of different performance on Fe-N_(3)P-C and Fe-N_(4-)C has been ascribed to the geometric *** be specific,the in-plane configuration of Fe-N_(4) site exhibits low H affinity,which results in poor activity in C-H bond *** contrast,the out-of-plane structure of Fe-N_(3)P-C site exhibits moderate H affinity,which not only promote the C-H bond scission but also offer a platform for obtaining appropriate H diffusion rate which ensures the high selectivity of propylene and the regeneration of *** work demonstrates promising applications of dual-coordinated single-atom catalysts for highly selective propane dehydrogenation.

关键词： Non-oxidative propane dehydrogenation Propylene selectivity Single-atom catalysis Heteroatom-doped graphene Fe catalyst

A mechanistic study of selective propane dehydrogenations on MoS_(2) supported single Fe atoms

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2023年第2期34卷 542-545页

作者： Yingke Yang Ruru Song Xing Fan yunxia liu Ningning Kong Haiping Lin Youyong Li Institute of Functional Nano&Soft Materials(FUNSOM) Jiangsu Key Laboratory for Carbon-Based Functional Materials&DevicesSoochow UniversitySuzhou 215123China School of Physics and Information Technology Shaanxi Normal UniversityXi'an 710119China Macao Institute of Materials Science and Engineering Macao University of Science and TechnologyMacao SAR 999078China

On-purpose propane dehydrogenation(PDH) has emerged as a profitable alternative to the traditional cracking of oil products for propylene production. By means of density functional theory(DFT) calculations, the present work demonstrates that Fe atoms may atomically disperse on MoS_(2)(Fe_(1)/MoS_(2)) and serve as a promising single-atom catalyst(SAC) for PDH. The catalytic activity of Fe_(1)/MoS_(2)is attributed to the highly exposed d orbitals of single Fe atoms, while the propylene selectivity is originated from the kinetic inhibition of propylene dehydrogenation resulting from fast propenyl hydrogenation. The unique catalytic selectivity of Fe_(1)/MoS_(2)may inspire further investigations of on-purpose dehydrogenations of propane on SACs.

关键词： Propane dehydrogenation(PDH) Density functional theory(DFT) Single-atom catalysts(SACs) Kinetic inhibition Propylene selectivity

Combined toxicity of copper and cadmium to six rice genotypes (Oryza sativa L.)

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2009年第5期21卷 647-653页

作者： HUANG Yizong, HU Ying, liu yunxia Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China. [a]Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China

Accumulations of copper （Cu） and cadmium （Cd） in six rice cultivars （94D-22, 94D-54, 94D-64, Gui630, YY-1, and KY1360） were evaluated through exposure to heavy metal contamination （100 mg/kg Cu, 1.0 mg/kg Cd, and 100 mg/kg Cu ＋ 1.0 mg/kg Cd） in a greenhouse. The dry weights of shoot and root, concentrations of Cu and Cd in plant tissues and the Cu, Cd, P, Fe concentrations in the root surface iron plaques were analyzed eight weeks later after treatment. The results indicated that the plant biomass was mainly determined by rice genotypes, not Cu and Cd content in soil. Separated treatment with Cu/Cd increased each metal level in shoot, root and iron plaques. Soil Cu enhanced Cd accumulation in tissues. In contrast, Cu concentrations in shoot and root was unaffected by soil Cd. Compared to single metal contamination, combined treatment increased Cd content by 110.6%, 77.0%, and 45.2% in shoot, and by 112.7%, 51.2% and 18.4% in root for Gui630, YY-1, and KY1360, respectively. The content level of Cu or Cd in root surface iron plaques was not affected by their soil content. Cu promoted Fe accumulation in iron plaques, while Cd has no effect on P and Fe accumulation in it. The translocation of Cu and Cd from iron plaques to root and shoot was also discussed. These results might be beneficial in selecting cultivars with low heavy metal accumulation and designing strategies for soil bioremediation.

关键词： Cu Cd combined contamination soil uptake accumulation root surface iron plaques