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Core level excitation spectra of La and Mn ions in LaMnO3

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chinese Physics B 2024年第3期33卷 327-332页

作者：李福建程新路张红 institute of Atomic and Molecular Physics Sichuan UniversityChengdu 610065Chin

Manganese-based perovskite is popular for research on ferromagnetic materials,and its spectroscopic studies are essential for understanding its electronic structure,dielectric,electrical,and magnetic properties.In this paper,the M-edge spectra of La ions and the M-edge,L-edge,and K-edge spectra of Mn ions in LaMnO3 are calculated by considering both the free-ion multiplet calculation and the crystal field effects.We analyze spectral shapes,identify peak origins,and estimate the oxidation states of La and Mn ions in LaMnO3 theoretically.It is concluded that La ions in LaMnO3 predominantly exist in the trivalent state,while Mn ions exist primarily in the trivalent state with a minor presence of tetravalent ions.Furthermore,the calculated spectra are in better conformity with the experimental spectra when the proportion of Mn3+is 90%and Mn4+is 10%.This article enhances our comprehension of the oxidation states of La and Mn within the crystal and also provides a valuable guidance for spectroscopic investigations of other manganates.

关键词： lanthanum manganate the core level excitation spectra free-ion multiplet calculation oxidation state

Molecule aging induced by electron attacking

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Journal of Energy Chemistry 2024年第6期93卷 519-525,I0013页

作者： Ping Song Yining Dong Xue Gong Mingbo Ruan Baoxin Ni Xuanhao Mei Kun Jiang Weilin Xu State Key Laboratory of Electroanalytical Chemistry and Jilin Province Key Laboratory of Low Carbon Chemical Power Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022JilinChina School of Applied Chemistry and Engineering University of Science and Technology of Chin1Hefei 230026AnhuiChina Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials Collaborative Innovation Center of Chemistry for Energy MaterialsDepartment of ChemistryFudan UniversityShanghai 200438China

Here we propose a new concept of"molecule aging":with some special treatment,a molecule could be"aged"by losing some unknown tiny particles or pieces from atoms in the molecule,Such"aging"or loss of unknown tiny particles does not change apparently its molecular structure or chemical composition,but some physicochemical properties could be changed irreversibly.We further confirm such"molecule aging"via a long-term electron attacking to age water(H_(2)O)molecules.The IR spectra show no structural difference between the fresh water and the aged one,while the NMR spectra show that the electron attacking can decrease the size of water clusters.Such facts indicate that the electron attacking indeed can"affect"the structure of water molecule slightly but without damaging to its basic molecule frame.Further exploration reveals that the hydrogen evolution reaction(HER)activity of the aged water molecule is lower than the fresh water on the same Pt/C electrocatalyst.The density functional theory calculations indicate that the shortened O-H bond in H_(2)O indeed can present lower HER activity,so the observed size decrease of water clusters from NMR probably could be attributed to the shortening of O-H bond in water molecules.Such results indicate significantly that the molecule aging can produce materials with new functions for new possible applications.

关键词： Aging of molecules Electron attacking Full width at half maxima Hydrogen evolution reaction

Enhanced charge separation by incomplete calcination modified co-doped TiO_(2)nanoparticle for isothiazolinone photocatalytic degradation

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Nano Research 2024年第6期17卷 4834-4843页

作者： Zhiren Guo Xiao Zhang Xinyuan Li Chang Cui Zilei Zhang Hansheng Li Dongxiang Zhang Jinying Li Xiyan Xu Jiatao Zhang School of Chemistry and Chemical Engineering Beijing Institute of TechnologyBeijing 102488China Department of Chemistry MSU-BIT UniversityShenzhen 517182Chin

Photocatalytic oxidation techniques are promising for degradation of the highly ecotoxic and refractory isothiazolinone bactericides in relevant industrial wastewaters.However,low charge separation and directional transport efficiency under solar light radiation restrain their practical application.Here,we report a nanostructured photocatalyst doped with Gd and B in TiO_(2)with carbon incorporation and defect formation through incomplete calcination.The specific surface area,grain size,and hydrophilicity of TiO_(2)are improved,which is beneficial for the interfacial reaction between the photocatalyst and pollutants.The reduction of the bandgap,the broadening of the photo-absorption range,and the retarded electron-hole recombination promote the photocatalytic performance due to the improved oxygen vacancies based on the electron distribution modification.The difference in partial density of states(ΔPDOS)between the current catalyst and raw TiO_(2)indicates that the co-doping of Gd and B with incomplete calcination changes the electronic hybridization of conduction band and valence band near the Fermi level,and affects the band gap energy.It improved charge separation and directional transport efficiency and benefited the formation of main active species,including•OH and O_(2)•−,for the pollutant decomposition.The rate of photocatalytic removal of benzisothiazolinone(BIT)by the current photocatalyst reaches 1.25 h^(−1),being 4.31 times that of TiO_(2).The current work offers a constructive approach to the design and synthesis of nanostructured photocatalysts for the photocatalytic degradation of refractory organic pollutants.

关键词： TiO_(2)nanoparticle charge separation oxygen vacancies electron distribution modification photocatalytic degradation

Efficient C-N coupling in electrocatalytic urea generation on copper carbonate hydroxide electrocatalysts

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Journal of Energy Chemistry 2024年第6期93卷 289-298,I0008页

作者： Yinuo Wang Yian Wang Qinglan Zhao Hongming Xu Shangqian Zhu Fei Yang Ernest P.Delmo Xiaoyi Qiu Chi Song Juhee Jang Tiehuai Li Ping Gao MDanny Gu Minhua Shao Advanced Materials Thrust The Hong Kong University of Science and Technology(Guangzhou)Guangzhou 511400GuangdongChina Department of Chemical and Biological Engineering The Hong Kong University of Science and TechnologyClear Water BayKowloonHong KongChina Department of Materials Science and Engineering Southern University of Science and Technology of Chin11088 Xueyuan BoulevardShenzhen 518055GuangdongChina Energy institute and Chinese National Engineering Research Center for Control&Treatment of Heavy Metal PollutionThe Hong Kong University of Science and TechnologyKowloonHong KongChina Department of Chemistry City University of Hong KongTat Chee AvenueKowloonHong KongChina

Urea generation through electrochemical CO_(2) and NO_(3)~-co-reduction reaction(CO_(2)NO_(3)RR)is still limited by either the low selectivity or yield rate of urea.Herein,we report copper carbonate hydroxide(Cu_2(OH)_2CO_(3))as an efficient CO_(2)NO_(3)RR electrocatalyst with an impressive urea Faradaic efficiency of45.2%±2.1%and a high yield rate of 1564.5±145.2μg h~(-1)mg_(cat)~(-1).More importantly,H_(2) evolution is fully inhibited on this electrocatalyst over a wide potential range between-0.3 and-0.8 V versus reversible hydrogen electrode.Our thermodynamic simulation reveals that the first C-N coupling follows a unique pathway on Cu_2(OH)_2CO_(3) by combining the two intermediates,~*COOH and~*NHO.This work demonstrates that high selectivity and yield rate of urea can be simultaneously achieved on simple Cu-based electrocatalysts in CO_(2)NO_(3)RR,and provide guidance for rational design of more advanced catalysts.

关键词： Copper carbonate hydroxide Co-reduction Urea generation C-N coupling DFT calculation

Recent advances in photoelectrochemistry-coupled dual-modal biosensors:From constructions to biosensing applications

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Nano Research 2024年第6期17卷 5512-5528页

作者： Yuxiang Dong Weisa Wang Changqing Ye Yanlin Song School of Materials Science and Engineering Suzhou University of Science and TechnologySuzhou 215009China Key Laboratory of Green Printing Institute of ChemistryChinese Academy of SciencesBeijing 100190Chin

Precise and sensitive bioanalysis has been the major and urgent pursuit in pathologic diagnosis,food safety,environment monitoring,and drug evaluation.Photoelectrochemical(PEC)bioanalysis,as one of the most promising detection technologies,has rapidly expanded within the field of analysis.However,most of reported PEC analysis approaches still suffer from weak external anti-interference ability,high background,and the risk of false positive or negative errors due to their inherent single-signal readout.To overcome these shortcomings,new PEC-coupled dual-modal analysis approaches have been developed,where a dual-response signal can be derived through two completely different mechanisms and independent signal transduction pathways.This review introduces the basic principles of PEC biosensing and enumerates and classifies the substrate or probe selections,constructions,and applications of PEC-coupled dual-modal biosensors.Furthermore,the challenges and developmental prospects of PEC-coupled dual-mode sensing technologies are evaluated and discussed.We hope that this review will provide valuable insights into the latest advancements and practical applications of dual-mode PEC bioanalysis,which will be of great interest to those seeking to stay informed in this field.

关键词： photoelectrochemistry biosensor electrochemistry colorimetry electrochemiluminescence fluorescence dual-mode detection

Anomalous bond lengthening in compressed magnetic doped semiconductor Ba(Zn_(0.95)Mn_(0.05))_(2)As_(2)

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Journal of Semiconductors 2024年第4期45卷 36-41页

作者： Fei Sun Yi Peng Guoqiang Zhao Xiancheng Wang Zheng Deng Changqing Jin institute of Physics Chinese Academy of SciencesBeijing 100190China School of Physics University of Chinese Academy of SciencesBeijing 101408China Center for High Pressure Science and Technology Advanced Research Beijing 100094Chin

Applying pressure has been evidenced as an effective method to control the properties of semiconductors,owing to its capability to modify the band configuration around Fermi energy.Correspondingly,structural evolutions under external pres-sures are required to analyze the mechanisms.Herein high-pressure structure of a magnetic doped semiconductor Ba(Zn_(0.95)Mn_(0.05))_(2)As_(2)is studied with combination of in-situ synchrotron X-ray diffractions and diamond anvil cells.The materials become ferromagnetic with Curie temperature of 105 K after further 20%K doping.The title material undergoes an isostruc-tural phase transition at around 19 GPa.Below the transition pressure,it is remarkable to find lengthening of Zn/Mn-As bond within Zn/MnAs layers,since chemical bonds are generally shortened with applying pressures.Accompanied with the bond stretch,interlayer As-As distances become shorter and the As-As dimers form after the phase transition.With further compres-sion,Zn/Mn-As bond becomes shortened due to the recovery of isotropic compression on the Zn/MnAs layers.

关键词： magnetic semiconductor high-pressure in-situ X-ray diffraction phase transition

RKKY interaction in helical higher-order topological insulators

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chinese Physics B 2024年第7期33卷 587-593页

作者：金莎李健李清旭朱家骥 School of Science Chongqing University of Posts and TelecommunicationsChongqing 400065China institute for Advanced Sciences Chongqing University of Posts and TelecommunicationsChongqing 400065China Southwest Center for Theoretical Physics Chongqing UniversityChongqing 401331Chin

We theoretically investigate the Ruderman–Kittel–Kasuya–Yosida(RKKY) interaction in helical higher-order topological insulators(HOTIs), revealing distinct behaviors mediated by hinge and Dirac-type bulk carriers. Our findings show that hinge-mediated interactions consist of Heisenberg, Ising, and Dzyaloshinskii–Moriya(DM) terms, exhibiting a decay with impurity spacing z and oscillations with Fermi energy εF. These interactions demonstrate ferromagnetic behaviors for the Heisenberg and Ising terms and alternating behavior for the DM term. In contrast, bulk-mediated interactions include Heisenberg, twisted Ising, and DM terms, with a conventional cubic oscillating decay. This study highlights the nuanced interplay between hinge and bulk RKKY interactions in HOTIs, offering insights into designs of next-generation quantum devices based on HOTIs.

关键词： magnetic impurity interactions magnetic ordering spintronics topological phases

Study of the multi-physics field-coupled model of the two-stage electrostatic precipitator

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Building Simulation 2024年第3期17卷 387-398页

作者： Wenjia Hao Yu Guo Yukun Wang Tao Yu Hao Gao Zhengwei Long Tianjin Key Laboratory of Indoor Air Environmental Quality Control School of Environmental Science and EngineeringTianjin UniversityWeijin Road 92Tianjin300072China Wuhan Second Ship Design and Research institute WuhanChin

The two-stage electrostatic precipitator is widely used to purify oil mist particles.However,there is limited research on the influences of relative humidity,particle deposition characteristics,and the generation of gaseous pollutants.Therefore,this paper established a numerical model of the electrostatic oil mist purifier and applied it to a two-stage electrostatic precipitator.Then the model was used to investigate the corona discharge characteristics under different relative humidity conditions in the charged zone,the particle deposition characteristics,the purification efficiency,the ozone concentration distribution,and the oil vapor concentration distribution in the collection zone.The results indicate that,with a constant temperature,the corona current decreases as relative humidity increase,and there is a quadratic relationship between relative humidity and current.The variation in relative humidity has little impact on the purification efficiency.The maximum ozone concentration occurs near the electrode line,and its concentration is influenced by the discharge current and inlet airflow velocity.The oil vapor concentration reaches its maximum value at the side plates,with a value of 19 ppb,while it reaches the minimum value at the collecting zone electrode plate,with a value of 2 ppb.The temperature is the main factor affecting the volatilization of the oil film,with higher temperatures resulting in higher oil vapor.

关键词： two-stage ESPs particle deposition corona discharge oil vapor

Identification and distribution of 13003 landslides in the northwest margin of Qinghai-Tibet Plateau based on human-computer interaction remote sensing interpretation

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china Geology 2024年第2期7卷 171-187页

作者： Wei Wang Yuan-dong Huang Chong Xu Xiao-yi Shao Lei Li Li-ye Feng Hui-ran Gao Yu-long Cui Shuai Wu Zhi-qiang Yang Kai Ma National institute of Natural Hazards Ministry of Emergency Management of ChinaBeijing 100085China Key Laboratory of Compound and Chained Natural Hazards Dynamics Ministry of Emergency Management of Chin12eijing 100085China School of Emergency Management Science and Engineering University of Chinese Academy of SciencesBeijing 100049China School of Soil and Water Conservation Beijing Forestry UniversityBeijing 100083China School of Civil Engineering and Architecture Anhui University of Science and TechnologyHuainan 232001China No.3 Bureau of china Metallurgical Geology Bureau Taiyuan 030031China

The periphery of the Qinghai-Tibet Plateau is renowned for its susceptibility to landslides.However,the northwestern margin of this region,characterised by limited human activities and challenging transportation,remains insufficiently explored concerning landslide occurrence and dispersion.With the planning and construction of the Xinjiang-Tibet Railway,a comprehensive investigation into disastrous landslides in this area is essential for effective disaster preparedness and mitigation strategies.By using the human-computer interaction interpretation approach,the authors established a landslide database encompassing 13003 landslides,collectively spanning an area of 3351.24 km^(2)(36°N-40°N,73°E-78°E).The database incorporates diverse topographical and environmental parameters,including regional elevation,slope angle,slope aspect,distance to faults,distance to roads,distance to rivers,annual precipitation,and stratum.The statistical characteristics of number and area of landslides,landslide number density(LND),and landslide area percentage(LAP)are analyzed.The authors found that a predominant concentration of landslide origins within high slope angle regions,with the highest incidence observed in intervals characterised by average slopes of 20°to 30°,maximum slope angle above 80°,along with orientations towards the north(N),northeast(NE),and southwest(SW).Additionally,elevations above 4.5 km,distance to rivers below 1 km,rainfall between 20-30 mm and 30-40 mm emerge as particularly susceptible to landslide development.The study area’s geological composition primarily comprises Mesozoic and Upper Paleozoic outcrops.Both fault and human engineering activities have different degrees of influence on landslide development.Furthermore,the significance of the landslide database,the relationship between landslide distribution and environmental factors,and the geometric and morphological characteristics of landslides are discussed.The landslide H/L ratios in the study area are mainly concentrated between 0.4 and 0.64.It mea

关键词： Landslides Human-computer interaction interpretation Landslide database Spatial distribution Earthquake Rainfall Human engineering activity Qinghai-Tibet Plateau Geological hazards survey engineering