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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

Atomically Substitutional Engineering of Transition Metal Dichalcogenide Layers for Enhancing Tailored Properties and Superior Applications

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Nano-Micro Letters 2024年第5期16卷 248-284页

作者： Zhaosu Liu Si Yin Tee Guijian Guan Ming‑Yong Han institute of molecular Plus Tianjin UniversityTianjin 300072People’s Republic of China institute of Materials Research and Engineering A*STARSingapore 138634Singapore

Transition metal dichalcogenides(TMDs)are a promising class of layered materials in the post-graphene era,with extensive research attention due to their diverse alternative elements and fascinating semiconductor behavior.Binary MX2 layers with different metal and/or chalcogen elements have similar structural parameters but varied optoelectronic properties,providing opportunities for atomically substitutional engineering via partial alteration of metal or/and chalcogenide atoms to produce ternary or quaternary TMDs.The resulting multinary TMD layers still maintain structural integrity and homogeneity while achieving tunable(opto)electronic properties across a full range of composition with arbitrary ratios of introduced metal or chalcogen to original counterparts(0–100%).Atomic substitution in TMD layers offers new adjustable degrees of freedom for tailoring crystal phase,band alignment/structure,carrier density,and surface reactive activity,enabling novel and promising applications.This review comprehensively elaborates on atomically substitutional engineering in TMD layers,including theoretical foundations,synthetic strategies,tailored properties,and superior applications.The emerging type of ternary TMDs,Janus TMDs,is presented specifically to highlight their typical compounds,fabrication methods,and potential applications.Finally,opportunities and challenges for further development of multinary TMDs are envisioned to expedite the evolution of this pivotal field.

关键词： Transition metal dichalcogenides Atomic substitution Tailored structure Tunable bandgap Enhanced applications

Theoretical investigation of excited dipole bound states of alkali-containing diatomic anions

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Chinese Physics B 2024年第5期33卷 389-393页

作者：连艺肖利丹边丽丽徐海峰闫冰 institute of Atomic and molecular Physics Jilin UniversityChangchun 130012China

Information about electronic excited states of molecular anions plays an important role in investigating electron attachment and detachment processes.Here we present a high-level theoretical study of the electronic structures of 12 alkali-metal-containing diatomic anions MX-(MX = LiH,LiF,LiCl,NaF,NaCl,NaBr,RbCl,KCl,KBr,RbI,KI and CsI).The equation-of-motion electron-attachment coupled-cluster singles and doubles(EOM-EA-CCSD) method is used to calculate the electron binding energies(EBEs) of 10 electronic excited states of each of the 12 molecule anions.With addition of different s-/p-/d-type diffusion functions in the basis set,we have identified possible excited dipole bound states(DBSs) of each anion.With the investigation of EBEs on the 12 MXs with dipole moment(DM) up to 12.1 D,we evaluate the dependence of the number of anionic excited DBSs on molecular DM.The results indicate that there are at least two or three DBSs of anions with a molecular DM larger than 7 D and a molecule with DM > 10 D can sustain a π-DBS of the anion.Our study has some implications for the excited DBS electronic states of alkali-metal-containing diatomic molecules.

关键词： anions dipole bound states alkali-metal-containing diatomic molecules

Recent progress on rapid diagnosis of COVID-19 by point-of-care testing platforms

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Chinese Chemical Letters 2024年第3期35卷 66-75页

作者： Ya-Nan Tang Dingding Jiang Xuejun Wang Yunqi Liu Dacheng Wei State Key Laboratory of molecular Engineering of Polymers Department of Macromolecular ScienceFudan UniversityShanghai 200433China institute of molecular Materials and Devices Fudan UniversityShanghai 200433China

The outbreak of COVID-19 has drawn great attention around the world.SARS-CoV-2 is a highly infectious virus with occult transmission by many mutations and a long incubation period.In particular,the emergence of asymptomatic infections has made the epidemic even more severe.Therefore,early diagnosis and timely management of suspected cases are essential measures to control the spread of the virus.Developing simple,portable,and accurate diagnostic techniques for SARS-CoV-2 is the key to epidemic prevention.The advantages of point-of-care testing technology make it play an increasingly important role in viral detection and screening.This review summarizes the point-of-care testing platforms developed by nucleic acid detection,immunological detection,and nanomaterial-based biosensors detection.Furthermore,this paper provides a prospect for designing future highly accurate,cheap,and convenient SARS-CoV-2 diagnostic technology.

关键词： COVID-19 Point-of-care testing platforms Nucleic acid detection Asymptomatic infection Biosensors

Mitogenome-based phylogeny of mosquitoes(Diptera:Culicidae)

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Insect Science 2024年第2期31卷 599-612页

作者： De-Hong Chen Shu-Lin He Wen-Bo Fu Zhen-Tian Yan Yun-Jian Hu Huan Yuan Ming-Bin Wang Bin Chen Chongqing Key Laboratory of Vector Insects Institute of Entomology and Molecular BiologyChongqing Normal UniversityChongqingChina

Mosquitoes are of great medical significance as vectors of many deadly diseases.Mitogenomes have been widely used in phylogenetic studies,but mitogenome knowledge within the family Culicidae is limited,and Culicidae phylogeny is far from resolved.In this study,we surveyed the mitogenomes of 149 Culicidae species,including 7 newly sequenced species.Comparative analysis of 149 mosquito mitogenomes shows gene composition and order to be identical to that of an ancestral insect,and the AT bias,length variation,and codon usage are all consistent with that of other reported Dipteran mitogenomes.Phylogenetic analyses based on the DNA sequences of the 13 protein-coding genes from the 149 species robustly support the monophyly of the subfamily Anophelinae and the tribes Aedini,Culicini,Mansonini,Sabethini,and Toxorhynchitini.To resolve ambiguous relationships between clades within the subfamily Culicinae,we performed topological tests and show that Aedini is a sister to Culicini and that Uranotaenini is a sister to(Mansonini)+(Toxorhynchitini+Sabethini).In addition,we estimated divergence times using a Bayesian relaxation clock based on the sequence data and 3 fossil calibration points.The results show mosquitoes diverged during the Early Jurassic with massive Culicinae radiations during the Cretaceous,coincident with the emergence of angiosperms and the burst of mammals and birds.Overall,this study,which uses the largest number of Culicidae mitogenomes sequenced to date,comprehensively reveals the mitogenome characteristics and mitogenome-based phylogeny and divergence times of Culicidae,providing information for further studies on the mitogenome,phylogeny,evolution,and taxonomic revision of Culicidae.

关键词： characterization Culicidae evolution mitogenomes mosquitoes phylogeny

Advances of graphdiyne-supported metal catalysts in thermocatalytic reactions

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Nano Research 2024年第4期17卷 2223-2233页

作者： Jia Yu Yida Yang Yuliang Li Changyan Cao Weiguo Song Beijing National Laboratory for molecular Sciences CAS Research/Education Center for Excellence in Molecular SciencesLaboratory of Molecular Nanostructures and NanotechnologyInstitute of ChemistryChinese Academy of SciencesBeijing 100190China School of Chemical Sciences University of Chinese Academy of SciencesBeijing 100049China Beijing National Laboratory for molecular Sciences CAS Research/Education Center for Excellence in Molecular SciencesLaboratory of organic solidsInstitute of ChemistryChinese Academy of SciencesBeijing 100190China

Supported metal catalysts are widely used in the modern chemical industry.The electronic interaction between supports and active components is of great significance for heterogeneous catalysis.Graphdiyne(GDY),a new type of carbon allotrope with sp-hybridized carbon atoms,πconjugate structure,and electron transmission capability,is a promising candidate as catalyst support.Recent years have witnessed the rapid progress of GDY-supported metal catalysts for different catalysis reactions.Considering that most processes in the current chemical industry are thermocatalytic reactions,we herein give an overview about the advances and particular characteristics of GDY-supported catalysts in these reactions.The geometric structure and electronic properties of GDY are first introduced.Then,the synthesis methods for GDY-supported metal catalysts and their applications in thermocatalytic reactions are discussed,in which the effect of electronic interaction on catalytic performance is highlighted.Finally,the current challenges and future directions of GDY-supported metal catalysts for thermocatalysis are proposed.It is expected that this review will enrich our understanding of the advances of GDY as a superior support for metal catalysts in thermocatalytic reactions.

关键词： graphdiyne metal catalysts thermocatalytic reactions heterogeneous catalysis

Direct Observation on H-Elimination Enhancement from C_(2)H_(4) through Non-Adiabatic Process by Femtosecond Laser Induced Coulomb Explosion

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Chinese Physics Letters 2024年第5期41卷 17-22页

作者：金无维王春成赵晓戈杨译章任殿相刘泽槿李孝开罗嗣佐丁大军 institute of Atomic and molecular Physics Jilin UniversityChangchun 130012China Jilin Provincial Key Laboratory of Applied Atomic and molecular Spectroscopy Jilin UniversityChangchun 130012China

Ethylene, the simplest model of a carbon-carbon double bond system, is pivotal in numerous chemical and biological processes. By employing intense infrared laser pump-probe techniques alongside coincidence measurements, we investigate the ultrafast non-adiabatic dynamics involved in the breakage of carbon-carbon double bonds and hydrogen elimination in dissociation of ethylene. Our study entails analyzing the dynamic kinetic energy release spectra to assess three bond-breaking scenarios, movements of nuclei, and structural changes around the carbon atoms. This allows us to evaluate the relaxation dynamics and characteristics of various dissociative states. Notably, we observe a significant rise in the yield of fragments resulting from C–H bond breakage with the delay time extended, suggesting non-adiabatic coupling through conical intersections from C–C bond breakage as a probable cause.

关键词： pump Femto adiabatic

Effect of sample temperature on femtosecond laser ablation of copper

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Chinese Physics B 2024年第2期33卷 377-385页

作者：党伟杰陈雨桐陈安民金明星 institute of Atomic and molecular Physics Jilin UniversityChangchun 130012China Jilin Provincial Key Laboratory of Applied Atomic and molecular Spectroscopy Jilin UniversityChangchun 130012China

We conduct an experimental study supported by theoretical analysis of single laser ablating copper to investigate the interactions between laser and material at different sample temperatures,and predict the changes of ablation morphology and lattice temperature.For investigating the effect of sample temperature on femtosecond laser processing,we conduct experiments on and simulate the thermal behavior of femtosecond laser irradiating copper by using a two-temperature model.The simulation results show that both electron peak temperature and the relaxation time needed to reach equilibrium increase as initial sample temperature rises.When the sample temperature rises from 300 K to 600 K,the maximum lattice temperature of the copper surface increases by about 6500 K under femtosecond laser irradiation,and the ablation depth increases by 20%.The simulated ablation depths follow the same general trend as the experimental values.This work provides some theoretical basis and technical support for developing femtosecond laser processing in the field of metal materials.

关键词： femtosecond laser two-temperature model sample temperature ablation depth

Optimization of extreme ultraviolet vortex beam based on high harmonic generation

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Chinese Physics B 2024年第5期33卷 459-464页

作者：肖礴赵逸文程方晶王革文姜威王一琛胡杰梁红静马日 institute of Atomic and molecular Physics Jilin UniversityChangchun 130012China College of Science Jilin Institute of Chemical TechnologyJilin 132022China

In high harmonic generation(HHG),Laguerre–Gaussian(LG) beams are used to generate extreme ultraviolet(XUV)vortices with well-defined orbital angular momentum(OAM),which have potential applications in fields such as microscopy and spectroscopy.An experimental study on the HHG driven by vortex and Gaussian beams is conducted in this work.It is found that the intensity of vortex harmonics is positively correlated with the laser energy and gas pressure.The structure and intensity distribution of the vortex harmonics exhibit significant dependence on the relative position between the gas jet and the laser focus.The ring-like structures observed in the vortex harmonics,and the interference of quantum paths provide an explanation for the distinct structural characteristics.Moreover,by adjusting the relative position between the jet and laser focus,it is possible to discern the contributions from different quantum paths.The optimization of the HH vortex field is applicable to the XUV,which opens up a new way for exploiting the potential in optical spin or manipulating electrons by using the photon with tunable orbital angular momentum.

关键词： high harmonic generation phase matching extreme ultraviolet vortex beam quantum path interference