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Amplitude-Squared Squeezing in a Kerr-Nonlinear Blackbody

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Communications in Theoretical Physics 2007年第5期47卷 933-936页

作者： WU Zi-Xia cheng Ze zhang yan-Min cheng Zheng-Ze Department of Physics Huazhong University of Science and Technology Wuhan 430074 China

We find that amplitude-squared squeezing of the photon field is present in a new blackbody, namely, a Kerr- nonlinear blackbody. The squeezing effect decreases as temperature T increases. The amount of the amplitude-squared squeezing in a Kerr-nonlinear blackbody is much larger than the corresponding squeezing in normal blackbody, and the degree of amplitude-squared squeezing is much larger than the amplitude squeezing for the same range of parameters in a Kerr-nonlinear blackbody.

关键词： Kerr-nonlinear blackbody amplitude-squared squeezing nonpolariton

“Capture-activation-recapture” mechanism-guided design of double-atom catalysts for electrocatalytic nitrogen reduction

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Journal of Energy Chemistry 2024年第9期96卷 437-447页

作者： cheng He Shiqi yan Wenxue zhang State Key Laboratory for Mechanical Behavior of Materials School of Materials Science and EngineeringXi’an Jiaotong UniversityXi’an 710049ShaanxiChina School of Materials Science and Engineering Chang’an UniversityXi’an 710064ShaanxiChina

Compared with the traditional industrial nitrogen fixation, electrocatalytic methods, especially those utilizing double-atom catalysts containing nonmetals, can give good consideration to the economy and environmental protection. However, the existing “acceptance-donation” mechanism is only applicable to bimetallic catalysts and nonmetallic double-atom catalysts containing boron atoms. Herein, a novel “capture-activation-recapture” mechanism for metal-nonmetal double-atom catalyst is proposed to solve the problem by adjusting the coordination environments of nonmetallic atoms and utilizing the activation effect of metal atoms on nitrogen. Based on this mechanism, the nitrogen reduction reaction (NRR) activity of 48 structures is calculated by density functional theory calculation, and four candidates are selected as outstanding electrocatalytic nitrogen reduction catalysts: Si-Fe@NG (U_(L) = –0.14 V), Si-Co@NG (U_(L)= –0.15 V), Si-Mo@BP1 (U_(L) = 0 V), and Si-Re@BP1 (U_(L) = –0.02 V). The analyses of electronic properties further confirm “capture-activation-recapture” mechanism and suggest that the difference in valence electron distribution between metal and Si atoms triggers the activation of N≡N bonds. In addition, a machine learning approach is utilized to generate an expression and an intrinsic descriptor that considers the coordination environment to predict the limiting potential. This study offers profound insight into the synergistic mechanism of TM and Si for NRR and guidance in the design of novel double-atom nitrogen fixation catalysts.

关键词： "Capture-activation-recapture"mechanism Double-atom catalyst Nitrogen reduction reaction Density functional theory

Three-dimensional regulation of transcription

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Protein & Cell 2015年第4期6卷 241-253页

作者： Jun Cao Zhengyu Luo Qingyu cheng Qianlan Xu yan zhang Fei Wang yan Wu Xiaoyuan Song CAS Key Laboratory of Brain Function and Disease and School of Life Sciences University of Science and Technology ofChina Hefei 230027 China

Cells can adapt to environment and development by reconstructing their transcriptional networks to regulate diverse cellular processes without altering the underly- ing DNA sequences. These alterations, namely epige- netic changes, occur during cell division, differentiation and cell death. Numerous evidences demonstrate that epigenetic changes are governed by various types of determinants, including DNA methylation patterns, his- tone posttranslational modification signatures, histone variants, chromatin remodeling, and recently discovered chromosome conformation characteristics and non- coding RNAs （ncRNAs）. Here, we highlight recent efforts on how the two latter epigenetic factors participate in the sophisticated transcriptional process and describe emerging techniques which permit us to uncover and gain insights into the fascinating genomic regulation.

关键词： transcriptional regulation long non-coding RNAs three-dimensional chromosome interactions,epigenetic changes

Bioinspired designs in active metal-based batteries

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Nano Research 2024年第2期17卷 587-601页

作者： Fan zhang Ting Liao cheng yan Ziqi Sun School of Chemistry and Physics Queensland University of TechnologyGeorge StreetBrisbaneQLD 4000Australia School of Mechanical Medical and Process Engineering Queensland University of TechnologyGeorge StreetBrisbaneQLD 4000Australia QUT Centre for Materials Science Queensland University of TechnologyGeorge StreetBrisbaneQLD 4000Australia

Active metal-based batteries are drawing increased attention because of their inherent high energy density and specific *** grand challenges,such as dendrite growth,electrode degradation,rapid performance fading,etc.,have limited their practical ***,which involves taking cues from the structures and functions of the natural world,can lead to a wealth of conceptually fresh approaches to regulator the metal ion transportation to achieve a dendrite-free metal plating,thwart the side-reaction reactions,and retard the structural distortions,for a more reliable and secure operation of active metal-based *** this review,we concentrate on the fabrication and application of bioinspired designs in active metal-based batteries with enhanced performance,along with discussion on the challenges and opportunities associated with this promising *** anticipate that this review can offer some insights into the development of functional materials by learning from nature and provide some approaches for the innovations of either the battery structures or the energy materials for metal-based batteries.

关键词： bioinspired materials energy storage devices metal-based batteries

Spin asymmetry and dipole moments inτ-pair production with ultraperipheral heavy ion collisions

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Science China(Physics,Mechanics & Astronomy) 2024年第8期67卷 15-21页

作者： Dingyu Shao Bin yan Shu-Run Yuan cheng zhang Department of Physics Center for Field Theory and Particle PhysicsFudan UniversityShanghai 200433China Key Laboratory of Nuclear Physics and Ion-beam Application(MOE) Fudan UniversityShanghai 200433China Shanghai Research Center for Theoretical Nuclear Physics National Natural Science Foundation of China(NSFC)and Fudan UniversityShanghai 200438China Institute of High Energy Physics Chinese Academy of SciencesBeijing 100049China School of Physics Peking UniversityBeijing 100871China

The anomalous magnetic(MDM)and electric(EDM)dipole moments of theτlepton serve as crucial indicators of new physics beyond the standard *** azimuthal angular asymmetry as a novel tool in ultraperipheral collisions(UPCs),we attain unparalleled precision in the study of these key *** by the highly linear polarization of coherent photons,this method uniquely enables both the MDM and EDM to contribute to the cos 2φangular distribution in similar ***,our approach substantially narrows the parameter space,excluding more than half of it compared to expected UPC-based measurements reliant solely on the total *** method not only provides improved constraints but also minimizes the need for additional theoretical assumptions,and offers a novel avenue to probe the EDM effects.

关键词： ultraperipheral collisions magnetic and electric dipole moments spin asymmetry

The abundance,distribution,and enrichment mechanism of harmful trace elements in coals from Guizhou,Southwestern China

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Acta Geochimica 2024年第5期43卷 889-903页

作者： Hui Hou Wei cheng Ruidong yang yan zhang College of Mining Guizhou UniversityGuiyangChina National and Local Joint Laboratory of Engineering for Effective Utilization of RegionalMineral Resources from Karst Areas GuiyangChina Guizhou Key Laboratory of Comprehensive Utilization of Non-Metallic Mineral Resources GuiyangChina College of Resource and Environment Engineering Guizhou UniversityGuiyangChina

Coal seams can enrich a variety of harmful trace elements under specific geological *** spatial distribution of harmful trace elements in coal is extremely uneven,and the distribution characteristics of each element content are *** harmful elements released in the process of coal mining and utilization will cause serious harm to the environment and the human *** is of great resource significance to study the geochemistry of coal that affects the enrichment and distribution characteristics of harmful trace *** on the domestic and foreign literature on coal geochemistry in Guizhou published by previous investigators,this study counted 1097 sample data from 23 major coal-producing counties in Guizhou Province,systematically summarized the relevant research results of harmful trace elements in the coal of Guizhou,and revealed the overall distribution and enrichment characteristics of harmful trace elements in the coal of *** results show that the average contents of Cd,Pb,Se,Cu,Mo,U,V,As,Hg,and Cr in coal of Guizhou are higher than those in Chinese coal and world coal.A variety of harmful trace elements in the coal of Guizhou have high background values,especially in Liupanshui,Xingyi and Qianbei *** enrichment of various harmful trace elements in the Late Permian coal in Guizhou is mainly related to the combined action of various geological and geochemical *** supply of terrigenous debris and sedimentary environment may be the basic background of the enrichment of harmful elements in western Guizhou,while low-temperature hydrothermal activity and volcanic ash deposition may be the main reasons for the enrichment of harmful elements in southwestern Guizhou.

关键词： Harmful trace elements Distribution characteristics Enrichment law Geological and geochemical features Guizhou

A Novel Disturbance Observer Based Fixed-Time Sliding Mode Control for Robotic Manipulators With Global Fast Convergence

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IEEE/CAA Journal of Automatica Sinica 2024年第3期11卷 661-672页

作者： Dan zhang Jiabin Hu Jun cheng Zheng-Guang Wu Huaicheng yan IEEE Zhejiang University of Technology Guangxi Normal University Zhejiang University the East China University of Science and Technology

This paper proposes a new global fixed-time sliding mode control strategy for the trajectory tracking control of uncertain robotic ***,a fixed-time disturbance observer(FTDO) is designed to deal with the adverse effects of model uncertainties and external disturbances in the manipulator *** an adaptive scheme is used and the adaptive FTDO(AFTDO) is developed,so that the priori knowledge of the lumped disturbance is not ***,a new non-singular fast terminal sliding mode(NFTSM) surface is designed by using an arctan function,which helps to overcome the singularity problem and enhance the robustness of the *** on the estimation of the lumped disturbance by the AFTDO,a fixed-time non-singular fast terminal sliding mode controller(FTNFTSMC)is developed to guarantee the trajectory tracking errors converge to zero within a fixed *** settling time is independent of the initial state of the *** addition,the stability of the AFTDO and FTNFTSMC is strictly proved by using Lyapunov ***,the fixed-time NFESM(FTNFTSM) algorithm is validated on a 2-link manipulator and comparisons with other existing sliding mode controllers(SMCs) are *** comparative results confirm that the FTNFTSMC has superior control performance.

关键词： Disturbance observer(DO) fixed-time non-singular sliding mode control robotic manipulator trajectory tracking

The impact of water quality on the formation of halogenated benzoquinones and the adsorption efficiency by activated carbon

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Journal of Environmental Sciences 2024年第1期135卷 693-702页

作者： Yongjing Wang Song Gao Xinyu yan Songtao Wang Ruolin zhang yan Zhou Lianhai Ren cheng Li State Environmental Protection Key Laboratory of Food Chain Pollution Control Beijing Technology and Business UniversityBeijing 100048China Institute of Scientific and Technical Information of China Beijing 100038China Institute of Quality Standard and Testing Technology Beijing Academy of Agriculture and Forestry SciencesBeijing 100097China Key Laboratory of Cleaner Production and Integrated Resource Utilization of China National Light Industry Beijing Technology and Business UniversityBeijing 100048China

Halogenated benzoquinones(HBQs)could cause bladder cancer,but there were few related studies on the generation and *** this study,the impact of different precursors,pH,bromide concentration,and algae-derived organic matters on the formation of HBQs and the removal efficiency by activated carbon were *** was found that the chlorination of bisphenol A produced the most 2,6-dichloro-1,4-benzoquinone(2,6-DCBQ),reaching 14.86μg/L at 1 hr,followed by tyrosine,2-chlorophenol,P-hydroxybenzoic acid,trichlorophenol,and *** production of 2,6-DCBQ increased first and then decreased from 0 to 36 hr(chlorination doses 0-20 mg/L),indicating that HBQs were unstable in ***(THMs)were detected during chlorination,and the concentration increased with prolongation of reaction time.2,6-DCBQ production decreased and 2,6-dibromo-1,4-benzoquinone(2,6-DBBQ)production increased with increment bromide concentration and the bromide promoted the formation of *** production of 2,6-DCBQ decreased with increase of pH,and the maximum production was 141.38μg/L at pH of *** aeruginosa,Chlorella algae cells,and intracellular organic matters(IOM)could be chlorinated as potential precursors for *** most amount of 2,6-DCBQ was generated from algae cells of Microcystis aeruginosa,followed by Chlorella algae cells,Microcystis aeruginosa IOM,and Chlorella *** study compared the removal efficiency of HBQs by granular activated carbon(GAC)and columnar activated carbon(CAC)under different carbon doses and initial concentrations of *** was found that the removal efficiency by GAC(80.1%)was higher than that by CAC(51.8%),indicating that GAC has better control for HBQs.

关键词： HBQS DBPS Drinking water Algae derived organic matters Activated carbon

Superhydrophobic Co/Fe sulfide nanoparticles and single-atoms doped carbon nanosheets composite air cathode for high-performance zinc-air batteries

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Journal of Energy Chemistry 2024年第9期96卷 568-577页

作者： yan Tan Yijie Wang Aoshuang Li Xiucai Jiang Yuzhong zhang Chuanwei cheng Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology School of Physics Science and EngineeringTongji UniversityShanghai 200092China

Development of a high-performance bifunctional catalyst is essential for the actual implementation of zinc-air batteries in practical ***,a bifunctional cathode of Co_(3)S_(4)/FeS heterogeneous nanoparticles embedded in Co/Fe single-atom-loaded nitrogen-doped carbon nanosheets is ***-iron sulfides and single atomic sites with Co-N_(4)/Fe-N_(4)configurations are confirmed to coexist on the carbon matrix by EXAFS spectroscopy.3D self-supported super-hydrophobic multiphase composite cathode provides abundant active sites and facilitates gas–liquid-solid three-phase interface reactions,resulting in excellent electrocatalytic activity and batteries performance,i.e.,an OER overpotential(η_(10))of 260 mV,a half-wave potential(E_(1/2))of 0.872 V for ORR,aΔE of 0.618 V,and a discharge power density of 170 mW cm^(−2),a specific capacity of 816.3 mAh g^(−1).DFT analysis shows multiphase coupling of sulfide heterojunction through single-atomic metal doped carbon nanosheets reduces offset on center of electronic density of states before and after oxygen adsorption,and spin density of adsorbed oxygen with same spin orientation,leading to weakened charge/spin interactions between adsorbed oxygen and substrate,and a lowered oxygen adsorption energy to accelerate OER/ORR.

关键词： Zn-air battery Superhydrophobic interface Metal sulfide Heterostructure Spin density