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City level CO_(2) and local air pollutants co-control performance evaluation: A case study of 113 key envir on mental protection cities in China

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Advances in Climate Change Research 2022年第1期13卷 118-130页

作者： Qing-Yong ZHANG bo-Feng CAI Mu-Dan WANG jun-xia WANG You-Kai XING Guang-xia DONG Zhen ZHANG xian-Qiang MAO School of Environment Beijing Normal University'Beijing 100875China Center for Climate Change and Environmental Policy Chinese Academy of Environmental PlanningBeijing 100012China China National Environmental Monitoring Centre Beijing 100012China Ministry of Transport Transport Planning and Research InstituteLaboratory of Transport Pollution Control and Monitoring TechnologyBeijing 100028China

‘Co-control',or synergistically reducing CO_(2)and local air polluta nt emissions,is an important strategy for cities to achieve'low carb on'and'blue sky'***,there were few studies to evaluate and compare the level of co-control of CO_(2) and local air pollutants in cities *** present study proposed qualitative and quantitative methods to evaluate the level of co-control of CO_(2)and three local air pollutant(SO_(2).NOX,and particulate matter PM)emissions in key environmental protection cities in China over two periods(2012-2015 and 2015-2018).Statistical analysis found that,though three local air pollutant emissions positively correlated with CO_(2) emission,no significantly positive correlation was found between local air pollutants emission reductions and CO_(2) emission reductions,indicating that co-control effects were poor in *** using the co-control effect coordinate system,qualitative evaluation showed that less than half of the sample cities could achieve co-control of the total amount of CO_(2) and local air *** employing the indicator of emission reduction equivalence(EReq),quantitative evaluation showed that the co-control level of the sample cities improved in 2015-2018 compared with *** regression analysis showed that,reducing coal consumption and economic development significantly enhanced the co-control performance of the observed *** present case study proved that the proposed methods for evaluation and comparison of the city co-control performance works well,and can be used in other countries and regions to promote global cities racing to carbon and local air pollutants co-control.

关键词： Co-control CO_(2)emission reduction Local air pollutant emission reduction:Performance evaluation Key environmental protection cities

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New mechanistic pathways for CO oxidation catalyzed by single-atom catalysts： Supported and doped Au1/ThO2

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Nano Research 2016年第12期9卷 3868-3880页

作者： bo Long Yan Tang jun Li Department of Chemistry and Laboratory of Organic Optoelectronics & Molecular Engineering of the Ministry of Education Tsinghua University Beijing 100084 China College of Information Engineering Guizhou Minzu University Guiyang 550025 China

Single-atom catalysts are of great interest and importance for designing new high-performance low-cost catalysts. We investigated CO oxidation catalyzed by single gold atoms supported on thoria （Au/ThO2） and doped ThO2 using density functional theory with Hubbard-type on-site Coulomb interaction （DFT ＋ U）. The calculation results show that the Au-doped THO2（111） catalyst exhibits remarkable catalytic activity for CO oxidation via the Eley-Rideal mechanism in three steps, where the rate-determining step is decomposition of the OCOO＋ intermediate with an energy barrier of 0.58 eV. Moreover, our results also reveal a new mechanism of CO oxidation on a gold adatom supported by THO2（111）, where O2 is adsorbed only at the Th site on the surface, and the gas-phase CO then reacts directly with the activated O2＋ to form CO2, which is the rate-limiting step, with a barrier of 0.46 eV. It is found that CO oxidation can occur without CO and O2 coadsorption on Au, which was previously considered a key intermediate. Therefore, these results provide new insights into CO oxidation on isolated gold atoms supported by the 5f-element compound THO2（111）. This mechanism can help clarify the catalytic cycle of CO oxidation, support the design of high- performance low-cost catalysts, and elucidate the redox properties of actinide oxides.

关键词： CO oxidation single gold catalysis catalytic mechanism actinide oxides

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Solid Solute Regularity of La Atom inα-Fe Supercell by First-principles

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Journal of Iron and Steel Research International 2016年第11期23卷 1213-1218页

作者： Cai-xia WANG Jian YANG Sha LIU xiao-lei XING Ji-bo WANG Xue-jun REN Qing-xiang YANG State Key Laboratory of Metastable Materials Science and Technology Yanshan University School of Materials Science and Engineering University of Science and Technology Beijing School of Engineering Liverpool John Moores University

The structure stability, elastic property and electronic structure of a-Fe supercell with La atom were inves- tigated by first-principles, in which, generalized gradient approximation （GGA） with the Perdew Burke Ernzerhof （PBE） was used as exchange-correlation functional, a-Fe supercells with La atom include a-Fe supercell with La atom in octahedral interstitial solid solute （La-OISS）, that with La atom in tetrahedral interstitial solid solute （La-TISS） and that with La atom in substitutional solid solute （La-SSS）. The results show that the La-SSS a-Fe supercell is more stable than La-OISS one. The resistance to volume change, reversible deformation and stiffness of La-OISS a-Fe supercell are stronger than those of La-SSS one. Moreover, the degrees of anisotropy and ionization in La-SSS a-Fe supercell are both stronger than those in La-OISS one. The bonding strength between La atom and Fe atom in La-SSS a-Fe supercell is larger than that in La-OISS one.

关键词： La atom a-Fe supercell solid solution first-principles bonding strength

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On Strong Embeddability and Finite Decomposition Complexity

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Acta Mathematica Sinica,English Series 2017年第3期33卷 403-418页

作者： jun xia xian Jin WANG College of Mathematics and Statistics Chongqing University Chongqing 401331 P. R. China

The strong embeddability is a notion of metric geometry, which is an intermediate property lying between coarse embeddability and property A. In this paper, we study the permanence properties of strong embeddability for metric spaces. We show that strong embeddability is coarsely invariant and it is closed under taking subspaces, direct products, direct limits and finite unions. Furthermore, we show that a metric space is strongly embeddable if and only if it has weak finite decomposition complexity with respect to strong embeddability.

关键词： Metric geometry strong embeddability coarse invariance permanence properties finitedecomposition complexity

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Structure,nitridation efficiency and magnetic properties of SmFe powders and its nitrides

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Rare Metals 2023年第6期42卷 1983-1988页

作者： xiao-xia Chen Yang Luo Zhou Hu Wen-Long Yan Ning-Tao Quan Shuo Lu Dun-bo Yu Jia-jun Xie National Engineering Research Center for Rare Earth Grirem Advanced Materials Co.Ltd.Beijing100088China

The effect of annealing temperature(TA) at600-900℃ on structure and magnetic properties of the melt-spun Sm_(8.6)Fe_(85.9)Co_(4.3)Zr_(1.2) alloys and its nitrides was *** show that the melt-spun powder is TbCu7-type SmFe_(9) single phase.X-ray diffractometer(XRD) Rietveld refinement shows that the lattice parameter a increases,c and c/a decrease with the increase in T_(A) at600-700℃.This is due to the tendency of nitrogen entering into the 3f site(1/2,0,0) during the nitridation process,which is good for the magnetic *** phase transforms from TbCu7-type SmFe_(9) to Th_(2)Zn_(17)-type Sm_(2)Fe_(17) at above 800 *** electron microscopy(SEM) images show that the amount of surface defects of melt-spun powder which are harmful for magnetic properties decreases at first and then increases as TA *** coercivity(H_(cj)) and maximum magnetic energy product((BH)_(max)) of its nitrides increase first and then decrease as a function of *** the remanence(B_(r))always shows a *** optimal magnetic properties of H_(cj)=748 kA·m^(-1),B_(r)=0.92 T,(BH)_(max)=118 kJ·m^(-3) are obtained by annealing at 675℃ for 2 h and then nitriding at 460℃ for 10 h.

关键词： Melt-spun alloy Annealing temperature Magnetic property XRD Rietveld refinement

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Effects of the Rainfall-Triggered Lisse Effect on the Stability of Loess Slopes

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Journal of Earth Science 2024年第4期35卷 1254-1262页

作者： Zhizhou Yang Donghui Cheng jun xia School of Water and Environment Chang’an UniversityXi’an710054China Key Laboratory of Subsurface Hydrology and Ecological Effects in Arid Region of the Ministry of Education Chang’an UniversityXi’an710054China Key Laboratory of Eco-Hydrology and Water Security in Arid and Semi-Arid Regions of the Ministry of Water Resources Chang’an UniversityXi’an710054China Key Laboratory of Water Cycle&Related Land Surface Processes Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing100101China State Key Laboratory of Water Resources&Hydropower Engineering Sciences Wuhan UniversityWuhan430000China

This paper coupled a water-air two-phase hydrodynamic(WATPH)model with the Iverson’s method to analyze the influence of the Lisse effect on the fast groundwater pressure(P_(w))response and the slope ***,the sensitivities of the driving force and loess soil parameters were *** showed that the WATPH model simulated the height and rise of the depth to the water table reasonably *** depth to water table before rainfall(H0)had a significant impact on the Lisse effect and the slope *** the H_(0) was less than approximately 1 m,the rainfall triggered a significant Lisse effect and decreased the slope factor of safety(F_(s)).When the rainfall intensity(R_(i))was higher than the saturated hydraulic conductivity(K_(s)),the Lisse effect and the F_(s) slightly changed with the increase of the R_(i),and the slope tended to be unstable with continuous *** increasing K_(s),the Lisse effect noticeably increased,and the minimum F_(s) quickly *** analysis of the normalized sensitivity coefficient revealed that H_(0) had a dramatic impact on the Lisse effect and loess slope *** different R_(i) and K_(s) values had prominent influences on the Lisse effect and slight impacts on F_(s).

关键词： Lisse effect landslides safety factor rainfall

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Low power LNA using the MOSFETs in moderate inversion

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The Journal of China Universities of Posts and Telecommunications 2011年第3期18卷 120-123页

作者： xia Wen-bo ZHANG xiao-lin School of Electronic Information Engineering Beihang University Beijing 100191 China

This paper presents an integrated complementary metal oxide semiconductor （CMOS） low power low noise amplifier （LNA） for global positioning system （GPS） receivers. To achieve low power dissipation, the MOS transistors in the proposed LNA are biased in moderate inversion region. It is implemented by SMIC 180 nm 1P6M CMOS process. The experiment results show that a gain of 12.14 dB@l.57 GHz is achieved with low noise figure （NF） of 1.62 dB. The power consumption of the circuit is 1.5 mW at supply voltage of 1.8 V. The ratio of gain to dc power consumption is 8 dB/mW. The size of the LNA is only 980 μm ×720 μm including the pads.

关键词： CMOS GPS LNA moderate inversion radio frequency (RF)

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Lattice Strain Induced by Ion Implantation in AlGaAs/AlGaInAs Quantum Well Samples

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Chinese Physics Letters 2002年第4期19卷 599-601页

作者： Liu Pi-jun, xia Yue-Yuan Department of Physics Shandong University

Si^+ ions of 350 keV have been implanted into AlGaAs/AlGaInAs quantum well samples in the dose range from 5×10^13cm^-2to 5×10^14cm^-2. The Raman spectra and high resolution x-ray diffraction (HRXRD) were measured from these implanted samples as well as the non-implanted sample. In the implanted layers the average strain which was evaluated by HRXRD increases with the implantation doses and varies from 0.0011 to 0.0029. The quantum well interface intermixing effect and compositional modification are also observed from HRXRD. At the higher doses, an abnormal annealing procedure takes place and it partly removes damage, but the strain remains almost unchanged in the epilayers.

关键词： Aluminum gallium arsenide

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Green Monomer of CO_(2) and Alkyne-based Four-component Tandem Polymerization toward Regio-and Stereoregular Poly(aminoacrylate)s

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Chinese Journal of Polymer Science 2021年第1期39卷 51-59,I0006页

作者： bo Song An-jun Qin Ben Zhong Tang State Key Laboratory of Luminescent Materials and Devices Guangdong Provincial Key Laboratory of Luminescence from Molecular AggregatesCenter for Aggregation-Induced EmissionSouth China University of TechnologyGuangzhou 510640China Department of Chemistry Hong Kong Branch of Chinese National Engineering Research Centre for Tissue Restoration and ReconstructionInstitute for Advanced StudyDepartment of Chemical and Biological EngineeringThe Hong Kong University of Science&TechnologyHong KongChina

Green monomers, such as carbon dioxide(CO_(2)), are closely related to our daily life and highly desirable to be transferred to functional polymers with diverse structures and versatile properties because they are abundant, cheap, nontoxic, renewable, and sustainable. However, the polymerizations based on these green monomers are to be further developed. In this work, a facile CO_(2) and alkyne-based one-pot, two-step, fourcomponent tandem polymerization was successfully established. The polymerization of CO_(2), diynes, alkyl dihalides, and primary/secondary amines can proceed under mild reaction conditions and regio-and stereoregular poly(aminoacrylate)s with good solubility and thermal stability were obtained in high yields(up to 95%). Notably, distinctly different stereoregularity of resultant poly(aminoacrylate)s was realized via using primary or secondary amines. Using the former would readily generate polymers with 100% Z-isomers, whereas the latter furnished products with over 95% E-isomers. Through different monomer combination, the polymers with tunable structures and properties were ***, the tetraphenylethene units containing poly(aminoacrylate)s, showing the unique aggregation-induced emission characteristics,could function as a fluorescent probe for sensitive explosive detection. Thus, this work not only develops a facile CO_(2) and alkyne-based multicomponent tandem polymerization but also provides a valuable strategy to fine-tune the polymer structures and properties, which could be potentially applied in diverse areas.

关键词： Carbon dioxide Multicomponent tandem polymerization Aggregation-induced emission Green monomer

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Fast Quantification of the Mixture of Polycyclic Aromatic Hydrocarbons Using Surface-Enhanced Raman Spectroscopy Combined with PLS-GA-BP Network

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Journal of Ocean University of China 2021年第6期20卷 1451-1458页

作者： YAN xia SHI xiaofeng MA jun Optics and Optoelectronics Laboratory of Qingdao Ocean University of ChinaQingdao 266100China

To realize the fast and accurate quantitative analysis of the mixture of polycyclic aromatic hydrocarbons(PAHs),surface-enhanced Raman spectroscopy(SERS)coupled with multivariate calibrations were *** this study,three kinds of calibration algorithms were used to quantitative analysis of the mixture of naphthalene(Nap),phenanthrene(Phe),and pyrene(Pyr).Firstly,partial least squares(PLS)algorithm was used to select characteristic variables,then the global search capability of genetic algorithm(GA)was used for the determining of the initial weights and thresholds of back propagation(BP)neural network so that local minima was *** PLS-GA-BP model exhibited superiority to quantify PAHs mixture,which achieved R2=0.9975,0.9710,0.9643,ARE=10.07%,19.28%,16.72%and RMSE=13.10,5.40,5.10 nmol L−1 for Nap,Phe,Pyr(in the PAHs mixture)concentration prediction *** forecast error,ARE and RMSE have been reduced more than 50%and 60%respectively compared with the whole spectral BP *** study indicates that accurate quantitative spectroscopic analysis of the mixture of PAHs samples can be achieved through the combination of SERS technique and PLS-GA-BP algorithm.

关键词： polycyclic aromatic hydrocarbons(PAHs) surface enhanced Raman spectral(SERS) back propagation(BP)algorithm multi-component quantitative analysis

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