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Modeling Patch Characteristics of Farmland Loss for Site Assessment in Urban Fringe of Beijing, China

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Chinese Geographical Science 2013年第3期23卷 365-377页

作者： liu xiaona ZHANG Weiwei LI Hong SUN Danfeng College of Resources and Environmental Sciences China Agricultural University Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Institute of System Comprehensive Development Beijing Academy of Agriculture and Forest Science

Farmland protection and delimitation in the urban fringe considers not only natural factors but also the spatial characters and site factors. Taking Daxing District, Beijing in China as a case study, this paper used landscape ecology and power-law methods to ana- lyze and evaluate farmland loss during the period of 2004~2007 based on the interpretation results of SPOT5 remote sensing images in 2004 and 2007. At the patch level, we selected four landscape indices, namely patch size, shape index, the nearest neighbor distance between farmland and construction land （including residential land and other construction land）, and cropping type, to evaluate the risk of farmland loss and establish a farmland site analysis indicator system. The results showed that patch size and shape index have a sig- nificant positive correlation with farmland loss, whereas the distance to construction land has a clear negative correlation with farmland loss. As regards cropping type, fallow farmland is much easier for non-agriculUlral use than cultivated farmland. The relative transition ratio among vegetable land, fallow farmland and cultivated farmland is 1 ： 5.6 ： 1. The patch size of lost farmland follows a power-law distribution, indicating that not only small parcels but also large parcels can be lost. Patch size less than 4 ha or more than 15 ha is in high loss risk, between 4 ha and 10 ha in medium loss risk, and larger than 10 ha and less than 15 ha in low risk. Farmland with a more regular shape has a higher likelihood of loss. Patch shape index less than 2.0 is in high loss risk, between 2.0 and 3.0 in medium loss risk, and larger than 3.0 in low risk. Construction land has a varying impact on farmland loss, the residential land effeeted distance is 1000 m, and that of the other construction land is 2000 m. This analysis showed the relationships between site factors and farmland loss, and the analysis framework can provide support and reference for farmland protection and delimi

关键词： farmland loss loss risk site analysis logistic regression analysis power-law distribution

Adsorption of Pb(Ⅱ)in Water by Niobate/Titanate Nanoflakes

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Journal of Wuhan University of Technology(Materials Science) 2020年第4期35卷 726-732页

作者： DING Qingwei SUI Rui liu xiaona QIAN Tianwei College of Environment and Safety Taiyuan University of Science and TechnologyTaiyuan 030024China College of EnvironmentalScience and Engineering Taiyuan University of TechnologyJinzhong 030600China

A niobate/titanat nanoflakes(Nb/TiNFs)composite was synthesized via the hydrothermal method and used to remove Pb(Ⅱ)from ***,TEM,and SEM results indicate that Nb/TiNFs appear as nanoflakes,of which the primary crystal phase is ***/TiNFs show rapid adsorption kinetics and the result fits well with the pseudo-second order *** key mechanism of adsorption is ion-exchange between metal and-ONa/*** to the Langmuir isotherm model,the maximum capacity of Pb(Ⅱ)is 488.323 mg·g^-*** relatively low RL values indicate that Nb/TiNFs exhibit favorable adsorption of Pb(Ⅱ).Nb/TiNFs indicate high adsorption capacity over a broad pH ***-existing inorganic ions(Na+and Ca^2+)have a slight inhibition effect on adsorption,and HA moderately inhibits the adsorption of Pb(Ⅱ)on Nb/*** of the simple method of synthesis and high removal efficiency for heavy metals,Nb/TiNFs are a promising material in remediation of heavy metal polluted water.

关键词： Nb/TiNFs Pb(Ⅱ) adsorption ion-exchange

Peracetic acid catalytic activation using Co_(3)O_(4) nanocluster decorated graphitic carbon nitride for cefapirin degradation in water

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Science China(Technological Sciences) 2024年第10期67卷 3103-3115页

作者： YIN ShiMei GAO YiXuan CHEN Long LI Fan liu xiaona QI Fei liu Wen Beijing Key Lab for Source Control Technology of Water Pollution College of Environmental Science and EngineeringBeijing Forestry UniversityBeijing 100083China Key Laboratory of Water and Sediment Sciences(Ministry of Education) College of Environmental Sciences and EngineeringPeking UniversityBeijing 100871China School of Environmental Science and Engineering Taiyuan University of TechnologyTaiyuan 030024China State Environmental Protection Key Laboratory of All Material Fluxes in River Ecosystems Peking UniversityBeijing 100871China Beijing National Laboratory for Molecular Sciences Peking UniversityBeijing 100871China

This study innovated cobalt-based catalytic nanocomposites(CCNs)for the heterogeneous activation of peracetic acid(PAA),a green and efficient advanced oxidation process for removing antibiotics from *** Co_(3)O_(4) catalysts exhibit limited activity due to stable electronic *** overcome this,CCNs were synthesized using a one-step condensation method,incorporating a size control strategy that anchors Co_(3)O_(4) nanoclusters within 4‒5 nm onto six-fold cavity of g-C3N4,simultaneously modifying the coordination environment of *** alteration significantly enhances the adsorption energy of PAA and catalytic activity compared to commercial Co_(3)O_(4).The improved performance of CCN2,in particular,is attributed to a shift in the cobalt d band center towards the Fermi level,facilitating electron delocalization and transfer,enhancing Co‒O bonding,and accelerating PAA ***2’s superior activity,with a cefapirin(CFP)degradation kinetic rate constant(k1=0.760 min^(−1))~11 times that of PAA direct oxidation(k1=0.070 min^(−1))and~5 times that of commercial Co_(3)O_(4)/PAA system(k1=0.164 min^(−1)),is due to its ability to generate dominant reactive species for antibiotic degradation,including alkoxy radicals(CH3C(=O)OO•),high valence metal(Co^(Ⅳ)(=O)^(2+)),and singlet oxygen(^(1)O_(2)),with the latter two being crucial for the degradation *** degradation of CFP involved three mechanisms,including direct oxidation by PAA,decarboxylation,and open-ring reactions at nitrogen *** research provides insights into developing high-activity catalysts for efficient PAA activation and antibiotic removal,leveraging the strategy of shifting the transition metal d band center.

关键词： peracetic acid Co_(3)O_(4)nanocluster high valence metal singlet oxygen cefapirin

Tuning band structure of graphitic carbon nitride for efficient degradation of sulfamethazine: Atmospheric condition and theoretical calculation

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Chinese Chemical Letters 2022年第3期33卷 1385-1389页

作者： Yue liu Long Chen xiaona liu Tianwei Qian Meng Yao Wen liu Haodong Ji College of Environmental Science and Engineering Taiyuan University of TechnologyJinzhong 030600China The Key Laboratory of Water and Sediment Science Ministry of EducationCollege of Environment Science and EngineeringPeking UniversityBeijing 100871China State Environmental Protection Key Laboratory of All Material Fluxes in River Ecosystems Peking UniversityBeijing 100871China

Numerous approaches have been used to modify graphitic carbon nitride (g-C_(3)N_(4)) for improving its photocatalytic activity. In this study, we demonstrated a facial post-calcination method for modified graphitic carbon nitride (g-C_(3)N_(4)-Ar/Air) to direct tuning band structure, i.e., bandgap and positions of conduction band (CB)/valence band (VB), through the control of atmospheric condition without involving any additional elements or metals or semiconductors. The synthesized g-C_(3)N_(4)-Ar/Air could efficiently degrade sulfamethazine (SMT) under simulated solar light, i.e., 99.0% removal of SMT with rate constant k1 = 2.696 h-1 within 1.5 h (4.9 times than pristine g-C_(3)N_(4)). Material characterizations indicated that the damaged/partial-collapsed structure and decreased nanosheet-interlayer distance for g-C_(3)N_(4)-Ar/Air resulted in the shift of band structure due to the denser stacking of pristine g-C_(3)N_(4) through oxidative exfoliation and planarization by air calcination. In addition, the bandgap of g-C_(3)N_(4)-Ar/Air was slightly shrunk from 2.82 eV (pristine g-C_(3)N_(4)) to 2.79 eV, and the CB was significantly upshifted from -0.44 eV (pristine g-C_(3)N_(4)) to -0.81 eV, suggesting the powerful ability for donating the electrons for O_(2) to form ^(·)O_(2)^(-). Fukui index (f -) based on theoretical calculation indicated that the sites of SMT molecule with high values, i.e., N9, C4 and C6, preferred to be attacked by ^(·)O_(2)^(-) and ^(·)OH, which is confirmed by the intermediates’ analysis. The tuning method for graphitic carbon nitride provides a simple approach to regulate the charge carrier lifetime then facilitate the utilization efficiency of solar light, which exhibits great potential in efficient removal of emerging organic contaminants from wastewater.

关键词： Graphitic carbon nitride Pharmaceuticals Photocatalysis Atmospheric condition DFT calculation

Experimental and Molecular Simulation of Volumetric Properties of Methyl Nonanoate,n-Dodecane,and Their Binary Mixtures

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Chemical Research in Chinese Universities 2019年第2期35卷 299-303页

作者： ZANG Dongyun ZHAO Guanjia liu xiaona YIN Jianguo MA Suxia College of Electrical and Power Engineering Taiyuan University of TechnologyTaiyuan 030024P.R.China

Densities of methyl nonanoate,n-dodecane,and their binary mixtures were investigated to provide the necessary data for their engineering applications as promising fuels and fuel *** the present work,densities were measured under atmospheric pressure at 293.15—463.15 *** density data for the binary mixtures were fitted into a forai of excess molar *** excess molar volumes were mostly positive,and the maximum value was obtained at molar fractions of n-dodecane between 0.5 and *** simulations of specified systems were carried out by using four kinds of force fields,and the suitable force fields for describing the volume properties of the system were AMBER96 and *** relative deviations for these two force fields between the simulated and the experimental data were well within±4%,which meets the general engineering requirement.

关键词： Methyl nonanoate n-Dodecane Density Molecular dynamics

Isolable Bis-BN-Based Analogues of Müller's Hydrocarbon

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Chinese Journal of Chemistry 2023年第23期41卷 3211-3215页

作者： Sha Xu Zhuofeng Xie Yuyang Dai xiaona liu Qidi Bao Chunmeng liu Yuanting Su College of Chemistry Chemical Engineering and Materials ScienceSoochow UniversitySuzhouJiangsu215123 China School of Radiation Medicine and Protection Soochow UniversitySuzhouJiangsu215123 China

Müller's hydrocarbon and its analogues are classical examples of Kekulé diradicaloids and have gained great ***,because of their high reactivities,their isolation and structural characterizations are still ***,we report the isolation of two bis-BN-based analogues of Müller's hydrocarbon (1 and 2) as crystalline solids in moderate *** results and theoretical studies demonstrated that compound 1 possessing the terminal 1,3,2-diazaboryl groups is an open-shell singlet diradicaloid,which is in contrast to the closed-shell singlet ground states of the bis-BN-based analogues of Thiele's and Chichibabin's hydrocarbons with the same terminal groups,illustrating the strong influence of the central linkers on the ground ***,the replacement of the terminal 1,3,2-diazaboryl groups in 1 with the bis(2,4,6-triisopropylphenyl)boryl groups affords 2 with higher diradical character and a smaller singlet-triplet energy gap.

关键词： Radicals Müller's hydrocarbon Boron Structure elucidation Electronic structure

Enhancing capacitive deionization performance and cyclic stability of nitrogen-doped activated carbon by the electro-oxidation of anode materials

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Chinese Journal of Chemical Engineering 2024年第5期69卷 23-33页

作者： xiaona liu Baohua Zhao Yanyun Hu Luyue Huang Jingxiang Ma Shuqiao Xu Zhonglin Xia Xiaoying Ma Shuangchen Ma School of Environmental Science and Engineering North China Electric Power UniversityBaoding 071003China Huadian Zhengzhou Machinery Design and Research Institute Co. LtdZhengzhou 450002China Huadian Inner Mongolia Energy Co. Ltd.Baotou Power Generation BranchBaotou 014013China

Electrode materials with high desalination capacity and long-term cyclic stability are the focus of capacitive deionization(CDI) community. Understanding the causes of performance decay in traditional carbons is crucial to design a high-performance material. Based on this, here, nitrogen-doped activated carbon(NAC) was prepared by pyrolyzing the blend of activated carbon powder(ACP) and melamine for the positive electrode of asymmetric CDI. By comparing the indicators changes such as conductivity, salt adsorption capacity, pH, and charge efficiency of the symmetrical ACP-ACP device to the asymmetric ACP-NAC device under different CDI cycles, as well as the changes of the electrochemical properties of anode and cathode materials after long-term operation, the reasons for the decline of the stability of the CDI performance were revealed. It was found that the carboxyl functional groups generated by the electro-oxidation of anode carbon materials make the anode zero-charge potential(E_(pzc)) shift positively,which results in the uneven distribution of potential windows of CDI units and affects the adsorption capacity. Furthermore, by understanding the electron density on C atoms surrounding the N atoms, we attribute the increased cyclic stability to the enhanced negativity of the charge of carbon atoms adjacent to quaternary-N and pyridinic-oxide-N.

关键词： Anodic oxidation Capacitive deionization Cyclic stability N-doping

Cultivars and oil extraction techniques affect Cd/Pb contents and health risks in oil of rapeseed grown on Cd/Pb-contaminated farmland

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Frontiers of Environmental Science & Engineering 2023年第7期17卷 119-131页

作者： Junmei Guo Yuexing Wei Junxing Yang Tongbin Chen Guodi Zheng Tianwei Qian xiaona liu Xiaofei Meng Mengke He College of Environmental Science and Engineering Taiyuan University of TechnologyJinzhong 030600China Center for Environmental Remediation Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China

Substitute planting with rapeseed offers promise for safely using large areas of Cd/Pb-contaminated ***/Pb distributions during rapeseed oil production were investigated and health risks posed by the oil were *** were performed using three cultivars(Brassica rapa SYH and ZS100 and Brassica napus QY-1)and four oil extraction techniques(mechanical and low-temperature pressing and n-hexane and subcritical low-temperature butane extraction).The amounts of Cd and Pb in oil were 0.73%-8.44%and 3.14%-11.76%,respectively,of the amounts in rapeseed and were strongly affected by the cultivar and oil extraction *** heavy metal(HM)concentrations were lower in solvent-extracted oil(particularly subcritical low-temperature butane extracted oil,in which HMs were not detected)than mechanically pressed *** Cd and Pb transfer indices were lower(meaning larger proportions of HMs were retained by the rapeseed meal)for *** than *** was attributed to a high HM binding protein content of *** *** risks to humans were assessed using a probabilistic risk assessment *** carcinogenic risk was mainly(97.1%-99.9%)caused by Cd and poses more concern than non-carcinogenic *** health risks are posed by mechanically pressed than solvent-extracted oil,and higher carcinogenic risks are posed to people living in rural areas than urban *** planting with *** and extracting oil with organic solvent(preferably subcritical low-temperature butane)are optimal for safely utilizing Cd/Pb-contaminated *** should be paid to the health risks posed by Cd in oil to rural populations.

关键词： Rapeseed oil Oil extraction technologies Human health risk assessment Cd/Pb-contaminated farmland Substitute planting

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基于PCA-DEA的中国区域生态效率研究

山西科技 2019年第1期34卷 33-36,42页

作者：刘小娜山西大学经济与管理学院山西太原030006

近年来,关于经济发展与环境污染、资源消费关系的研究有很多。利用我国除西藏、港澳台外的30个省、直辖市、自治区2016年的国内生产总值(GDP)衡量经济发展,用废水、废气和固体废弃物的排放量衡量环境污染,用能源消费量、用水量、电力消... 详细信息

近年来,关于经济发展与环境污染、资源消费关系的研究有很多。利用我国除西藏、港澳台外的30个省、直辖市、自治区2016年的国内生产总值(GDP)衡量经济发展,用废水、废气和固体废弃物的排放量衡量环境污染,用能源消费量、用水量、电力消费量衡量资源消费,研究经济发展与资源环境的关系。由于投入指标相对于产出指标过多,不利于进行数据包络分析,先利用主成分分析法对投入指标进行了降维处理,然后用DEA模型进行相关分析,并提出了相应的对策建议。

关键词：主成分分析数据包络分析经济发展资源环境