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Journal of Energy Chemistry 2024年第10期97卷 738-746页

作者： Siyun Qi Chuanchuan Li Gang Chen Mingwen Zhao school of Physics and Electronics Shandong Normal University Qingdao industrial Energy Storage Research Institute Qingdao Institute of Bioenergy and Bioprocess Technology Chinese Academy of Sciences school of Physics & State Key Laboratory of Crystal Materials Shandong University

Single-atom catalysts（SACs） hold great promise in addressing the sluggish kinetics of the sulfur reduction reaction（SRR） in lithium-sulfur（Li-S） batteries for their unique catalytic activity and maximum atom *** these SACs must be dispersed on solid substrates,the underlying support is usually limited to carbon materials that have a poor ability to modulate the coordination environment and electronic structures of single atoms,and consequently their catalytic activity toward the SRR is *** we propose two-dimensional（2D） graphene/electride heterostructu res as substrates to enhance the catalytic activities of SACs for Li-S batteries.2D electrides featuring the anionic electron gas on their surface enable efficient electron transfer to SACs,which alters their electronic structures,resulting in the shifts of the d orbital and Fermi *** unique electronic structure decreases the filling of antibonding states such that the bonding with adsorbates at active sites is *** demonstrate the enhanced catalytic performance of SACs in terms of the Gibbs free energy of SRR and Li2S *** addition,a universal descriptor for the rapid screening of SACs is established by a linear regression fitting *** work provides a new design strategy to modulate SAC activity through electrides for Li-S batteries.

关键词： Charge transfers DFT calculations Electrides Kinetics Universal descriptors

Hydrolysis mechanism of YbB_(2)C_(2)and the microstructure of the carbon derived from the hydrolysis reaction

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Journal of Materials Science & Technology 2024年第4期171卷 209-221页

作者： Zhihui Li Hao Zhang Jixin Chen Jiemin Wang Xiaohui Wang Jinxing Yang Chao Zhang Zerong Zhang Hongyang Liu Fei Huang Meishuan Li Fei Li Shenyang national Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China school of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China Shanghai Key Laboratory for high Temperature Materials and Precision Forming School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai 200240China

Carbide-derived carbon(CDC)materials have gained great attention due to the excellent properties for various potential ***,graphite crystal is formed during a room-temperature hydrolysis pro-cess of layered compound YbB_(2)C_(2).The formation mechanism can be demonstrated by a YbB_(2)C_(2)molecular cell:Yb^(3+)acts as a cathode where H_(2)O molecule is reduced to H atom and OH^(−)ion,while(B_(2)C_(2))^(3−)acts as an anode where OH−ion is oxidized to O ***,YbB_(2)C_(2)molecular cell begins to disintegrate,i.e.,Yb^(3+)ion,B and C atoms dissociate from the molecular *** as-produced C atoms combine to form graphite *** initial graphite crystal is a cabbage-like microsphere,and then it gradually disintegrates and transforms into layered *** addition,YbB_(6),Yb_(3)(OH)_(3)n(BO_(3))_((3-n))sol,hydrogen,hydrocarbons,and carbon oxides form *** method provides a general and inexpensive route to obtain carbide-derived graphite crystal.

关键词： Carbide-derived carbon YbB_(2)C_(2) Hydrolysis Molecular cell First-principles calculations

Holevo bound independent of weight matrices for estimating two parameters of a qubit

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Chinese Physics B 2024年第2期33卷 137-143页

作者：牛畅郁司夏 Department of Modern Physics&Hefei national Research Center for Physical sciences at the Microscale and school of Physical sciences University of Science and Technology of ChinaHefei 230026China Hefei national Laboratory University of Science and Technology of ChinaHefei 230088China

Holevo bound plays an important role in quantum metrology as it sets the ultimate limit for multi-parameter estimations,which can be asymptotically *** for some trivial cases,the Holevo bound is implicitly defined and formulated with the help of weight *** we report the first instance of an intrinsic Holevo bound,namely,without any reference to weight matrices,in a nontrivial ***,we prove that the Holevo bound for estimating two parameters of a qubit is equivalent to the joint constraint imposed by two quantum Cramér–Rao bounds corresponding to symmetric and right logarithmic *** weightless form of Holevo bound enables us to determine the precise range of independent entries of the mean-square error matrix,i.e.,two variances and one covariance that quantify the precisions of the estimation,as illustrated by different estimation *** result sheds some new light on the relations between the Holevo bound and quantum Cramer–Rao *** generalizations are discussed.

关键词： quantum metrology quantum Fisher information Holevo bound quantum multi-parameter estimation

Comparative Study of the Types of Photovoltaic Panels Used in Solar Pumping Systems in Dry Tropical Zones: Case of Adamawa Region in Cameroon

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Open Journal of Energy Efficiency 2024年第3期13卷 79-87页

作者： Boussaibo Andre Waoudowa Kande Veronique Ndjiya Ngasop Stephane Gautier Kitmo Department of Electrical Engineering University Institute of Ngaoundr Ngaoundr Cameroon Department of Electrical Energy and Automation National School of Agro-Industrial Sciences Ngaoundr Cameroon Department of Physics University of Ngaoundr Ngaoundr Cameroon

In the dry tropical zone where access to water is increasingly difficult for populations, solar pumping units are increasingly installed to provide water to population. In the local market, there are essentially two types of solar panels, namely monocrystalline and polycrystalline. However, the part of the local market is more dominated by the polycrystalline panel. In this work, comparative studies are carried out in order to characterize the two types of solar panels with regard to local constraints. Tests were carried out over the course of the sun to establish the performance of each type. The panels used have the same electrical characteristics and are connected to loads with same characteristics. Under the set operating conditions, the monocrystalline panel presents more performance than the polycrystalline panel. Although the local market is dominated by the polycrystalline panel, dust deposition tests on the surface of the panels show that the performance of the polycrystalline panel is more affected compared to the performance of the monocrystalline panel.

关键词： Solar Pumping Monocrystalline Cell Polycrystalline Cell Dry tropical Zone Dustdeposit

Electronic transport evolution across the successive structural transitions in Ni_(50-x)Fe_xTi_(50) shape memory alloys

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Chinese Physics B 2024年第7期33卷 529-536页

作者：何萍杨金颖任秋飒王彬彬吴光恒刘恩克 Beijing national Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China school of Physical sciences University of Chinese Academy of SciencesBeijing 100049China school of Materials Science and Engineering University of Science and Technology of BeijingBeijing 100083China

TiNi-based shape memory alloys have been extensively investigated due to their significant applications,but a comprehensive understanding of the evolution of electronic structure and electrical transport in a system with martensitic transformations(MT) is still *** this work,we focused on the electronic transport behavior of three phases in Ni_(50-x)Fe_xTi_(50)across the MT.A phase diagram of Ni_(50-x)Fe_xTi_(50) was established based on x-ray diffraction,calorimetric,magnetic,and electrical *** reveal the driving force of MT,phonon softening was revealed using first-principles ***,the transverse and longitudinal transport behavior changed significantly across the phase transition,which can be attributed to the reconstruction of electronic *** work promotes the understanding of phase transitions and demonstrates the sensitivity of electron transport to phase transition.

关键词： martensitic transformation electronic behavior transport properties first-principles calculations

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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 ***,structural evolutions under external pres-sures are required to analyze the *** 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 *** materials become ferromagnetic with Curie temperature of 105 K after further 20%K *** title material undergoes an isostruc-tural phase transition at around 19 *** 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 *** with the bond stretch,interlayer As-As distances become shorter and the As-As dimers form after the phase *** 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

Research on intelligent search-and-secure technology in accelerator hazardous areas based on machine vision

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Nuclear Science and Techniques 2024年第4期35卷 96-107页

作者： Ying-Lin Ma Yao Wang Hong-Mei Shi Hui-Jie Zhang school of Traffic and Transportation Beijing Jiaotong UniversityBeijing 100044China school of Mechanical Electronic and Control EngineeringBeijing Jiaotong UniversityBeijing 100044China Institute of high Energy Physics Chinese Academy of SciencesBeijing 100049China

Prompt radiation emitted during accelerator operation poses a significant health risk,necessitating a thorough search and securing of hazardous areas prior to ***,manual sweep methods are ***,the limitations of manual sweeps have become increasingly evident with the implementation of large-scale *** leveraging advancements in machine vision technology,the automatic identification of stranded personnel in controlled areas through camera imagery presents a viable solution for efficient search and *** the criticality of personal safety for stranded individuals,search and security processes must be sufficiently *** ensure comprehensive coverage,180°camera groups were strategically positioned on both sides of the accelerator tunnel to eliminate blind spots within the monitoring *** YOLOV8 network model was modified to enable the detection of small targets,such as hands and feet,as well as larger targets formed by individuals near the ***,the system incorporates a pedestrian recognition model that detects human body parts,and an information fusion strategy is used to integrate the detected head,hands,and feet with the identified pedestrians as a cohesive *** strategy enhanced the capability of the model to identify pedestrians obstructed by equipment,resulting in a notable improvement in the recall ***,recall rates of 0.915 and 0.82were obtained for Datasets 1 and 2,*** there was a slight decrease in accuracy,it aligned with the intended purpose of the search-and-secure software *** tests conducted within an accelerator tunnel demonstrated the effectiveness of this approach in achieving reliable recognition outcomes.

关键词： Search and secure Machine vision Camera Human body parts recognition Particle accelerator Hazardous area

Investigation of electrostatically tunable adhesion and instability of flying head slider

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Friction 2024年第3期12卷 462-473页

作者： Fan ZHANG Yu WANG Yueqiang HU Mingquan ZHANG Baotong LI school of Mechanical Engineering Xi’an Jiaotong UniversityXi’an 710049China national Engineering Research Center for high Efficiency Grinding College of Mechanical and Vehicle EngineeringHunan UniversityChangsha 410082China

The interfacial adhesion between microstructures is inevitable in a micro-electro-mechanical system(e.g.,hard disk drive(HDD)),which may lead to complicated microtribodynamics *** research has investigated the effect of surface potential on the interfacial adhesion and microtribodynamics of the head–disk interface(HDI)in an HDD.A dynamic continuum surface force model,where the electrowetting is considered,is proposed to evaluate the interfacial interaction,and then employed into a two-degree-of-freedom(2DOF)model to theoretically analyze the potential influence mechanism on the *** results confirm that the elimination of potential can effectively repress the adhesion retention,which is further proved by the measured slider response with a laser Doppler vibrometer(LDV).Moreover,the effect of the potential on the adhesion-induced instability is also analyzed through the phase *** tells that the critical stable flying height can be lowered with the elimination of potential.

关键词： electric field(EF) retention instability adhesion

Long-term Evolution of Solar Activity and Prediction of the Following Solar Cycles

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Research in Astronomy and Astrophysics 2024年第3期24卷 194-204页

作者： Pei-Xin Luo Bao-Lin Tan national Astronomical Observatories Chinese Academy of SciencesBeijing 100101China school of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 100049China

Solar activities have a great impact on modern high-tech systems,such as human aerospace activities,satellite communication and navigation,deep space exploration,and related scientific ***,studying the long-term evolution trend of solar activity and accurately predicting the future solar cycles are highly *** on the wavelet transform and empirical function fitting of the longest recorded data of the annual average relative sunspot number(ASN)series of 323 yr to date,this work decisively verifies the existence of the solar century cycles and confirms that its length is about 104.0 yr,and the magnitude has a slightly increasing trend on the timescale of several hundred *** on this long-term evolutionary trend,we predict solar cycles 25 and26 by using phase similar prediction *** for solar cycle 25,its maximum ASN will be about146.7±33.40,obviously stronger than solar cycle *** peak year will occur approximately in 2024,and the period will be about 11±1 *** for solar cycle 26,it will start around 2030,and reach its maximum between2035 and 2036,with maximum ASN of about 133.0±3.200,and period of about 10 yr.

关键词： Sun activity-Sun evolution-(Sun) sunspots-methods data analysis

Implications of the Stellar Mass Density of high-z Massive Galaxies from JWST on Warm Dark Matter

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Research in Astronomy and Astrophysics 2024年第1期24卷 128-134页

作者： Hengjie Lin Yan Gong Bin Yue Xuelei Chen national Astronomical Observatories Chinese Academy of SciencesBeijing 100101China University of Chinese Academy of sciences Beijing 100049China Science Center for China Space Station Telescope National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China Department of Physics College of SciencesNortheastern UniversityShenyang 110819China Center for high Energy Physics Peking UniversityBeijing 100871China

A significant excess of the stellar mass density at high redshift has been discovered from the early data release of James Webb Space Telescope(JWST),and it may require a high star formation ***,this will lead to large number density of ionizing photons in the epoch of reionization(EoR),so that the reionization history will be changed,which can arise tension with the current EoR *** dark matter(WDM),via the free streaming effect,can suppress the formation of small-scale structure as well as low-mass *** provides an effective way to decrease the ionizing photons when considering a large star formation efficiency in high-z massive galaxies without altering the cosmic reionization *** the other hand,the constraints on the properties of WDM can be derived from the JWST *** this work,we study WDM as a possible solution to reconcile the JWST stellar mass density of high-z massive galaxies and reionization *** find that,the JWST high-z comoving cumulative stellar mass density alone has no significant preference for either CDM or WDM *** using the observational data of other stellar mass density measurements and reionization history,we obtain that the WDM particle mass with mw=0.51_(-0.12)^(+0.22) keV and star formation efficiency parameter f_(*)^(0)> 0.39 in 2σ confidence level can match both the JWST high-z comoving cumulative stellar mass density and the reionization history.

关键词： Cosmology (cosmology:)dark matter (cosmology:)large-scale structure of universe