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Asymmetrically ligated single atomic nickel sites for efficient hydrogen peroxide electrosynthesis

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Nano Research 2024年第3期17卷 1094-1100页

作者： Xusheng cheng Jinwen Hu Wenzhe Shang Jingya Guo Cuncun xin Songlin Zhang Suchan Song Wei liu Yantao Shi State Key laboratory of Fine Chemicals Frontier Science Center for Smart MaterialsSchool of ChemistryDalian University of TechnologyDalian 116024China

Atomic transition-metal-nitrogen-carbon electrocatalysts hold great promise as alternatives to benchmark Pt in the oxygen reduction *** pristine metal centers with quasi square-planar D_(4h) configuration,however,still suffer from unfavorable energetics and thereby strong activity/selectivity trade-off during the catalytic *** we present a ligand-field engineering of single-atom Ni-N-C catalysts to boost the sluggish kinetics via rationally constructing prototypical asymmetrically ligated Ni-N_(3)O_(1) *** as-obtained Ni-supported multi-walled carbon nanotubes with molten salt-treated(defined as Ni/CNS)catalyst delivered an excellent H_(2)O_(2) selectivity(>90%)within a wide potential window(0.2–0.7 V *** hydrogen electrode(RHE))and robust stability(for 10 h)in alkaline *** electron paramagnetic resonance and theoretical analysis rationalize this finding and demonstrate that the broken symmetry facilitates the electron transfer of a σ* to O–O orbital as compared to the Ni-N_(4) counterpart,playing an indispensable role in efficient O_(2) activation.

关键词： broken D4h single nickel sites oxygen reduction H_(2)O_(2)production

Quantum phase transition of the Jaynes-Cummings model

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Science China(Physics,Mechanics & Astronomy) 2024年第1期67卷 1-9页

作者： cheng liu Jin-Feng Huang Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education Key Laboratory for Matter Microstructure and Function of Hunan ProvinceDepartment of Physics and Synergetic Innovation Center for Quantum Effects and ApplicationsInstitute of Interdisciplinary StudiesHunan Normal UniversityChangsha 410081China

Herein,we propose an experimentally feasible scheme to show the quantum phase transition of the Jaynes-Cummings(JC)model by modulating the transition frequency of a two-level system in a quantum Rabi model with strong *** tuning the modulation frequency and amplitude,the ratio of the effective coupling strength of the rotating terms to the effective cavity(atomic transition)frequency can enter the deep-strong coupling regime,while the counter-rotating terms can be ***,a deep-strong JC model is *** ratio of the coupling strength to resonance frequencies in the deep-strong JC model is two orders of magnitude larger than the corresponding ratio in the original quantum Rabi *** scheme can be employed in atom-cavity resonance and off-resonance cases,and it is valid over a broad *** nonzero average cavity photons of the ground state indicate the emergence of a quantum phase ***,we demonstrate the dependence of the phase diagram on the atom-cavity detuning and modulation *** the parameters used in our scheme are within the reach of current experimental *** scheme provides a new mechanism for investigating the critical phenomena of finite-sized systems without requiring classical field limits,thereby opening a door for studying fundamental quantum phenomena occurring in the ultrastrong and even deep-strong coupling regimes.

关键词： Jaynes-Cummings model quantum phase transition frequency modulation

Modification of the CuO electronic structure for enhanced selective electrochemical CO_(2) reduction to ethylene

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Nano Research 2024年第8期17卷 7194-7202页

作者： xin Wu Zhuang Tong Yunliang liu Yaxi Li Yuanyuan cheng Jingwen Yu Peng Cao Chunqiang Zhuang Qiuzhong Shi Naiyun liu Xiang liu Hongyu Liang Haitao Li Institute for Energy Research School of Energy and Power EngineeringJiangsu UniversityZhenjiang 212013China Faculty of Materials and Manufacturing Beijing University of TechnologyBeijing 100124China Institute of Medicine&Chemical Engineering Zhenjiang CollegeZhenjiang 212013China Institute of Advanced Manufacturing and Modern Equipment Technology School of Mechanical EngineeringJiangsu UniversityZhenjiang 212013China

Electrochemical carbon dioxide reduction reaction(CO_(2)RR)can produce value-added hydrocarbons from renewable electricity,providing a sustainable and promising approach to meet dual-carbon targets and alleviate the energy ***,it is still challenging to improve the selectivity and stability of the products,especially the C^(2+) *** we propose to modulate the electronic structure of copper oxide(CuO)through lattice strain construction by zinc(Zn)doping to improve the selectivity of the catalyst to *** performance and in situ characterization analyses show that the compressive strain generated within the CuO lattice and the electronic structure modulation by Zn doping enhances the adsorption of the key intermediate*CO,thereby increasing the intrinsic activity of CO_(2)RR and inhibiting the hydrogen precipitation *** the best catalysts had significantly improved ethylene selectivity of 60.5%and partial current density of 500 mA·cm^(–2),and the highest C^(2+) Faraday efficiency of 71.47%.This paper provides a simple idea to study the modulation of CO_(2)RR properties by heteroatom doped and lattice strain.

关键词： CO_(2) reduction heteroatom-doped lattice strain ethylene selectivity

Effect of succinic acid on morphology transformation of the anhydrous magnesium carbonate particles prepared by magnesium chloride hexahydrate and urea

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Particuology 2024年第7期90卷 209-217页

作者： Song liu Guojun cheng Zhongfeng Tang School of Materials Science and Engineering Anhui University of Science and TechnologyHuainan232001China Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China Anhui Province Key Laboratory of Environment-friendly Polymer Materials Anhui UniversityHefei230601China

The homogeneous and controllable morphology of anhydrous magnesium carbonate(MgCO_(3))particles with excellent properties is difficult to obtain because of a variety of synthetic *** effect of succinic acid as a crystal modifier on the particle morphology transformation of anhydrous MgCO_(3)was investigated by the hydrothermal *** effect of the addition of succinic acid on the particles was similar to that of temperature *** morphology of particles with a folded diamond-like shape was gradually uniform,and the particle size was between 3.3 and 7.5μ*** MgCO_(3)particles prepared at pH 9 could easily agglomerate,and the average particle size increased from diamond-like to cube-like as the reaction time *** interaction between succinic acid and magnesium ions at different concentrations was the main factor responsible for the morphological *** pH,temperature,and time affected the molecular motion rate and crystal growth.

关键词： MgCO_(3) MgCl_(2)·6H_(2)O Urea Succinic acid Morphology

Evaluation of water management on arsenic methylation and volatilization in arsenic-contaminated soils strengthened by bioaugmentation and biostimulation

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Journal of Environmental Sciences 2024年第3期137卷 515-526页

作者： Peng Chen Yi liu Guo-xin Sun State Key Laboratory of Urban and Regional Ecology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China Key Laboratory of Aquatic Botany and Watershed Ecology Wuhan Botanical GardenChinese Academy of SciencesWuhan 430074China University of Chinese Academy of Sciences Beijing 100049China

Arsenic(As) fate in paddy fields has been one of the most significant current issues due to the strong As accumulation potential of rice plants under fooded conditions. However,no attempt was done to explore As methylation and volatilization under non-fooded conditions. Herein, we investigated the effects of water management on As methylation and volatilization in three arsenic-contaminated soils enhanced by biostimulation with strawderived organic matter and bioaugmentation with genetic engineered Pseudomonas putida KT2440(GE P. putida). Under fooded conditions, the application of biochar(BC), rice straw(RS)and their combination(BC+RS) increased total As in porewater. However, these effects were greatly attenuated under non-fooded conditions. Compared with RS amendment alone, the combination of GE P. putida and RS further promoted the As methylation and volatilization,and the promotion percentage under non-fooded conditions were significantly higher than that under fooded conditions. The combined GE P. putida and RS showed the highest efficiency in As methylation(88 μg/L) and volatilization(415.4 μg/(kg·year)) in the non-fooded soil with moderate As contamination. Finally, stepwise multiple linear regression analysis presented that methylated As, DOC and p H in porewater were the most important factors contributing to As volatilization. Overall, our findings suggest that combination of bioaugmentation with GE P. putida and biostimulation with RS/BC+RS is a potential strategy for bioremediation of arsenic-contaminated soils by enhancing As methylation and volatilization under non-fooded conditions.

关键词： Arsenic methylation Arsenic volatilization Water management Straw incorporation Bioaugmentation

Spacelike Framed Curves with Lightlike Components and Singularities of Their Evolutes and Focal Surfaces in Minkowski 3-space

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Acta Mathematica Sinica,English Series 2024年第6期40卷 1521-1532页

作者： Peng cheng LI Dong He PEI xin ZHAO School of Mathematics and Statistics Northeast Normal UniversityChangchun 130024P.R.China Department of Mathematics Harbin Institute of TechnologyWeihai 264209P.R.China School of Mathematics and Statistics Qingdao UniversityQingdao 266071P.R.China

In this paper,we define the evolute and focal surface of a spacelike framed curve with lightlike components in Minkowski *** is a generalization of the previous results of regular spacelike curves,since singularities are allowed in the original spacelike curves studied by spacelike framed curves with lightlike ***,we show a new geometric invariant to characterise singularities of the focal ***,the classification theorem and recognition theorem for the singularities of the focal surface in generic are also given.

关键词： Evolutes focal surfaces spacelike framed curves singularities

Facile synthesis of high-brightness green-emitting carbon dots with narrow bandwidth towards backlight display

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Chinese Chemical Letters 2024年第5期35卷 277-282页

作者： Rui cheng Tingting Zhang xin Huang Jian Yu State Key Laboratory of Materials-Oriented Chemical Engineering College of Chemical EngineeringNanjing Tech UniversityNanjing 210009China

High-performance carbon dots(CDs)allowing the application in high-end display devices are highly desirable and usually limited by the absence of simple and easy synthesis *** this work,we exploited an easy-to-implement strategy for the one-step synthesis of green-emitting CDs(G-CDs)with superb optical *** G-CDs were synthesized using m-phenylenediamine(m-PD)as a single precursor,and the reaction reacted at 180℃for 12 h The resultant G-CDs exhibit high-purity and excitationindependent green fluorescence with the photoluminescence(PL)peak located at 516 nm,full width at half maximum(FWHM)of 46 nm,and PL quantum yield(QY)of∼80%under the 470nm excitation *** G-CDs and corresponding composite film prepared with polyvinyl butyral(G-CDs@PVB)exhibit good PL stability after undergoing long-time storage for one year and 360 h exposure under 460nm blue *** G-CDs@PVB film was used as color-conversion materials in green-emitting light-emitting diode(LED)application,exhibiting a Commission internationale de l’Eclairage(CIE)chromaticity coordinate of(0.21,0.44).The film was also used in CD-based liquid crystal display(CD-LCD)application,achieving a color gamut value of 85%.This work will offer a working basis for the synthesis of high-performance CDs as well as their application in displays.

关键词： Carbon dots One-step synthesis Narrow bandwidth High quantum yield Display

Trend of ambient seismic noise attenuation tomography:Theory and applications

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Science China Earth Sciences 2024年第10期67卷 3326-3330页

作者： xin liu Zhanwen LI Department of Earth Sciences University of Hong KongHong Kong 999077China

1. Introduction Ambient seismic noise is an approximately uniform wave field generated by persistent and high-energy noise sources such as Earth's inherent vibrations and oceanic noise propagating within Earth's interior and multiple scattering. This noise wave field is widely distributed in subsurface structure and carries information about mechanical and physicochemical property of fault fracture zones.

关键词： seismic Earth fault

Multiple Nanoparticles Coupling Strategy for Enhancing Optical Filter Performance of Spectral Splitter Used in Photovoltaic/Thermal System

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Journal of Thermal Science 2024年第1期33卷 368-382页

作者： LIANG Huaxu HUANG xin WANG Fuqiang cheng Ziming DONG Yan School of Energy Science and Engineering Harbin Institute of TechnologyHarbin 150001China School of New Energy Harbin Institute of Technology at WeihaiWeihai 264209China School of Materials Science and Engineering Nanyang Technological UniversitySingapore 639798Singapore

Selective absorptive nanofluid can pre-absorb certain sunlight wavelength that cannot be used by PV and transmits remaining sunlight to the surface of PV,which can decouple PV from the thermal receiver *** order to improve the harvesting of electricity and high-temperature thermal nanofluid,it is important to design an optimal optical filter window(transmit sunlight with wavelengths of 732-1067 nm to the surface of the photovoltaic cell and absorb the remaining sunlight).However,designing optimal optical filter is facing following challenges:(1) inherently narrow selective absorptivity property of single nanoparticle;(2) simplified numerical calculation method calculating transmittance;(3) ignoring the shape of the *** this study,the idea of using multiple nanoparticles coupling effect to design an optical filter is proposed,which can superimpose the narrow absorption bandwidth of different nanoparticles to obtain a wide absorption bandwidth of the whole *** addition,an improved transmission method considering light-matter interaction at air/vessel and liquid/vessel interfaces is adopted to compute the *** results calculated by improved transmission method are more accurate than widely used traditional Lambert-Beer law,which is verified by experimental ***,the effect of nanoparticle shape on spectral transmittance is also investigated,which shows that spiny Ag can approximately extend absorbance from 400 nm to 600 nm compared to nanosphere ***,the results show that optical filter efficiency of nanofluids with multiple nanoparticles coupling(Ag,spiny Ag,ZnO,ITO) can reached up to 35%.

关键词： solar energy PV/T nanofluid optimal optical filter radiative transfer spectral splitting