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A Fast Algorithm of Scalar Multiplication Based on Side-Channel Atomicity
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作者 郝玉洁 殷石 《China Communications》 SCIE CSCD 2011年第2期134-139,共6页
Simple power analysis is the most devastating attack on the security of elliptic curve scalar multiplication and can probably retrieve the secret key. In this paper,we analyze the formulas of point doubling and additi... Simple power analysis is the most devastating attack on the security of elliptic curve scalar multiplication and can probably retrieve the secret key. In this paper,we analyze the formulas of point doubling and addition on Jacobi-quartic Curve in projective coordination. In addition,a fast and secure side-channel atomic scalar multiplication algorithm is proposed using the side-channel atomic block. Compared with the previous methods,the new algorithm is more efficient. For 192 bits scalar using NAF recoding,the efficiency of the new algorithm is increased by about 6.7%~23% if S/M=0.8 or 12.7%~33.2% if S/M=0.6. 展开更多
关键词 jacobi-quartic curve scalar multipli-cation simple power analysis side-channel atomicity
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Clarifying atomicity-activity relations of platinum clusters for oxygen reduction reaction
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作者 Qingdan Ding Shiyu Dai Wei Ma 《Science China Materials》 2025年第6期1847-1855,共9页
Platinum clusters(Pt_(n))are extensively used as electrocatalysts for oxygen reduction reaction(ORR)because they provide excellent performance together with a reduced Pt requirement.However,the precise synthesis and a... Platinum clusters(Pt_(n))are extensively used as electrocatalysts for oxygen reduction reaction(ORR)because they provide excellent performance together with a reduced Pt requirement.However,the precise synthesis and atomic-level insights into the structure-activity relationship of Pt_(n) remain a great challenge.Here,we present a combinatorial synthesis and analysis method to investigate the atomicity-activity relationships of Pt_(n) at the individual level.We employ single nanoparticle collision electrochemistry to facilitate the in-situ electrodeposition of a single precisely tunable Pt_(n) on the graphene quantum dot support,followed by instantaneous measurement of the intrinsic ORR activity of the resulting Pt_(n).By relying on highly sensitive electrochemical measurements,our investigations clarify the atomicity-specific ORR activity of Pt_(n),which is attributed to their distinct geometric and electronic structures at varying cluster sizes.Significantly,Pt_(n) with low atomicity,especially below 20,can reach extraordinarily high ORR activities due to atom-by-atom arrangement.Our work provides a simple and efficient method for investigating the atomicity-activity relationships of other nanoclusters under real reaction conditions,enabling a better design of the electrocatalysts at the atomic level. 展开更多
关键词 atomicity-activity relation atomically precise Pt nanoclusters oxygen reduction reaction
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Mixed Quasi-martingale Hardy Spaces
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作者 ZHANG Chuanzhou LI Shimeng HE Zhibin 《应用数学》 北大核心 2026年第1期221-231,共11页
In this article,we conduct a study on mixed quasi-martingale Hardy spaces that are defined by means of the mixed L_(p)-norm.By utilizing Doob’s inequalities,we explore the atomic decomposition and quasi-martingale in... In this article,we conduct a study on mixed quasi-martingale Hardy spaces that are defined by means of the mixed L_(p)-norm.By utilizing Doob’s inequalities,we explore the atomic decomposition and quasi-martingale inequalities of mixed quasi-martingale Hardy spaces.Moreover,we furnish sufficient conditions for the boundedness ofσ-sublinear operators in these spaces.These findings extend the existing conclusions regarding mixed quasi-martingale Hardy spaces defined with the help of the mixed L_(p)-norm. 展开更多
关键词 Mixed quasi-martingale Hardy space Atomic Decomposition σ-sublinear operator
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Direct Generation of an Array with 78400 Optical Tweezers Using a Single Metasurface
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作者 Yuqing Wang Yuxuan Liao +9 位作者 Tao Zhang Ye Tian Yujia Wu Wenjun Zhang Wei Zhang Yidong Huang Hui Zhai Wenlan Chen Xue Feng Zhongchi Zhang 《Chinese Physics Letters》 2026年第1期129-133,共5页
Scalability remains a major challenge in building practical fault-tolerant quantum computers.Currently,the largest number of qubits achieved across leading quantum platforms ranges from hundreds to thousands.In atom a... Scalability remains a major challenge in building practical fault-tolerant quantum computers.Currently,the largest number of qubits achieved across leading quantum platforms ranges from hundreds to thousands.In atom arrays,scalability is primarily constrained by the capacity to generate large numbers of optical tweezers,and conventional techniques using acousto-optic deflectors or spatial light modulators struggle to produce arrays much beyond∼10,000 tweezers.Moreover,these methods require additional microscope objectives to focus the light into micrometer-sized spots,which further complicates system integration and scalability.Here,we demonstrate the experimental generation of an optical tweezer array containing 280×280 spots using a metasurface,nearly an order of magnitude more than most existing systems.The metasurface leverages a large number of subwavelength phase-control pixels to engineer the wavefront of the incident light,enabling both large-scale tweezer generation and direct focusing into micron-scale spots without the need for a microscope.This result shifts the scalability bottleneck for atom arrays from the tweezer generation hardware to the available laser power.Furthermore,the array shows excellent intensity uniformity exceeding 90%,making it suitable for homogeneous single-atom loading and paving the way for trapping arrays of more than 10,000 atoms in the near future. 展开更多
关键词 quantum computing optical tweezersand quantum platforms optical tweezers atom arraysscalability atom arrays SCALABILITY spatial light modulators
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Atomic density disturbance rejection in atomic gyroscopes via faraday polarimetric decoupling
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作者 Zehua Liu Yifan Yan +5 位作者 Haoying Pang Xinhui Liu Jixi Lu Xusheng Lei Zhuo Wang Wei Quan 《Defence Technology(防务技术)》 2026年第1期1-10,共10页
Atomic spin gyroscopes are promising candidates for next-generation inertial navigation due to extremely high theoretical precision,relatively small size among atomic gyroscopes,and promising potential for miniaturiza... Atomic spin gyroscopes are promising candidates for next-generation inertial navigation due to extremely high theoretical precision,relatively small size among atomic gyroscopes,and promising potential for miniaturization.In particular,the spin-exchange relaxation-free(SERF)atomic gyroscope relies on optical pumping to polarize atoms,enabling rotation sensing through the Faraday optical rotation angle(FORA).However,fluctuations in atomic density introduce systematic errors in FORA measurements,limiting long-term stability.We present a data-driven decoupling method that isolates atomic density fluctuations from the FORA signal by modeling spatially resolved light absorption in the vapor cell.The model accounts for the spatial distribution of spin polarization in the pump-light interaction volume,density-dependent relaxation rates,wall-induced relaxation,and polarization diffusion,and is implemented within a finite-element framework.Compared to the conventional Lambert-Beer law,which assumes one-dimensional homogeneity,our approach captures the full threedimensional density and polarization distribution,significantly improving the accuracy of light absorption modeling.The resulting absorption-density maps are used to train a feedforward neural network,yielding a high-precision estimator for atomic density fluctuations.This estimator enables the construction of a decoupling equation that separates the density contribution from the FORA signal.Experimental validation shows that this method improves the bias instability atσ(100 s)of the gyroscope was improved by 73.1%compared to traditional platinum-resistance-based stabilization.The proposed framework is general and can be extended to other optical pumping-based sensors,such as optically pumped magnetometers. 展开更多
关键词 Atomic gyroscope SERF gyroscope Atomic density Optically pumped sensors
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Optimizing Magnetic Performance and Microstructure of CoPt Nanoparticles by Sol-Gel Synthesis
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作者 WANG Xinchi WANG Wei +2 位作者 LIU Shuai WANG Yun LI Baohe 《Journal of Wuhan University of Technology(Materials Science)》 2026年第1期8-14,共7页
We prepared Co_(x)Pt_(100-x)(x=40,45,50,55,60)nanoparticles by the sol-gel method.The phase composition and crystal structure,morphology and microstructure,and magnetic properties of the samples were characterized and... We prepared Co_(x)Pt_(100-x)(x=40,45,50,55,60)nanoparticles by the sol-gel method.The phase composition and crystal structure,morphology and microstructure,and magnetic properties of the samples were characterized and tested using X-ray diffraction(XRD),transmission electron microscopy(TEM),and vibrating sample magnetometer(VSM),respectively.The results demonstrate that the coercivity of CoPt nanoparticles can be effectively controlled by adjusting the atomic ratio of Co and Pt in the samples.Among the compositions studied,the Co_(45)Pt_(55)sample synthesized by the sol-gel method exhibits smaller grain size and a coercivity as high as 6.65×10^(5) A/m is achieved.The morphology and microstructure of the nanoparticles were analyzed by TEM images,indicating that a slight excess of Pt can effectively enhance the coercivity of CoPt nanoparticles. 展开更多
关键词 COPT sol-gel method atomic ratio magnetic nanoparticles COERCIVITY
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Single Fe atom anchored by N vacancy of C_(3)N_(4) activates PMS for efficient degradation of refractory organics:The key role of non-radical pathway through 1O_(2) and Fe(IV)=O
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作者 Shenghui Tu Lu Sun +5 位作者 Hongxiang Zhang Jiaqi Xie Leizhen Shen Wenming Liu Guobo Li Honggen Peng 《Journal of Environmental Sciences》 2026年第1期339-348,共10页
Fenton-like technology based on peroxymonosulfate activation has shown great potential in refractory organics degradation.In this work,single Fe atom catalysts were synthesized through facile ball milling and exhibite... Fenton-like technology based on peroxymonosulfate activation has shown great potential in refractory organics degradation.In this work,single Fe atom catalysts were synthesized through facile ball milling and exhibited very high performance in peroxymonosulfate activation.The Fe single-atom filled an N vacancy on the triazine ring edge of C_(3)N_(4),as confirmed through X-ray absorption fine structure,density functional calculation and elec-tron paramagnetic resonance.The SAFe_(0.4)–C_(3)N_(4)/PMS system could completely remove phenol(20 mg/L)within 10 min and its first-order kinetic constant was 12.3 times that of the Fe_(3)O_(4)/PMS system.Under different ini-tial pH levels and in various anionic environments,SAFe_(0.4)–C_(3)N_(4) still demonstrated excellent catalytic activity,achieving a removal rate of over 90%for phenol within 12 min.In addition,SAFe_(0.4)–C_(3)N_(4) exhibited outstanding selectivity in reaction systems with different pollutants,showing excellent degradation effects on electron-rich pollutants only.Hydroxyl radicals(•OH),singlet oxygen(1O_(2))and high-valent iron oxide(Fe(Ⅳ)=O)were de-tected in the SAFe_(0.4)–C_(3)N_(4)/PMS system through free radical capture experiments.Further experiments on the quenching of active species and a methyl phenyl sulfoxide probe confirmed that 1O_(2) and Fe(Ⅳ)=O played dom-inant roles.Additionally,the change in the current response after adding PMS and phenol in succession proved that a direct electron transfer path between organic matter and the catalyst surface was unlikely to exist in the SAFe_(0.4)–C_(3)N_(4)/PMS/Phenol degradation system.This study provides a new demonstration of the catalytic mech-anism of single-atom catalysts. 展开更多
关键词 Refractory organics PMS activation Single atom Singlet oxygen High-valent iron Carbon nitride
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Electron-Deficient Type Electride Li_(4)Al under High Pressure:Bonding Properties and Superconductivity
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作者 Daoyuan Zhang Yanliang Wei +3 位作者 Chenlong Xie Yilong Pan Zhao Liu Tian Cui 《Chinese Physics Letters》 2026年第1期142-155,共14页
High-pressure electrides,characterized by the presence of interstitial quasi-atoms(ISQs),possess unique electronic structures and physical properties,such as diverse dimensions of electride states exhibiting different... High-pressure electrides,characterized by the presence of interstitial quasi-atoms(ISQs),possess unique electronic structures and physical properties,such as diverse dimensions of electride states exhibiting different superconductivity,which has attracted significant attention.Here,we report a new electron-deficient type of electride Li_(4)Al and identify its phase transition progress with pressurization,where the internal driving force behind phase transitions,bonding characteristics,and superconducting behaviors have been revealed based on first-principles density functional theory.Through analysis of the bonding properties of electride Li_(4)Al,we demonstrate that the ISQs exhibiting increasingly covalent characteristics between Al ions play a critical role in driving the phase transition.Our electron–phonon coupling calculations indicate that all phases exhibit superconducting behaviors.Importantly,we prove that the ISQs behave as free electrons and demonstrate that the factor governing T_(c) is primarily derived from Li-p-hybridized electronic states with ISQ compositions.These electronic states are scattered by low-frequency phonons arising from mixed vibrations of Li and Al affected by ISQs to enhance electron–phonon coupling.Our study largely expands the research scope of electrides,provides new insight for understanding phase transitions,and elucidates the effects of ISQs on superconducting behavior. 展开更多
关键词 low frequency phonons bonding properties Li Al phase transition electride interstitial quasi atoms SUPERCONDUCTIVITY electron phonon coupling
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Production of ^(287,288)Mc isotopes in the ^(48)Ca+^(243)Am reaction at China Accelerator Facility for Superheavy Elements
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作者 X.Y.Huang Z.Y.Zhang +38 位作者 J.G.Wang L.Ma C.L.Yang M.H.Huang X.L.Wu Z.G.Gan H.B.Yang M.M.Zhang Y.L.Tian Y.S.Wang J.Y.Wang Y.H.Qiang G.Xie S.Y.Xu Z.Zhao Z.C.Li L.C.Sun L.Zhu X.Zhang H.Zhou F.Guan Z.H.Li W.X.Huang Z.Qin Y.Wang X.J.Yin Y.F.Cui Z.W.Lu Y.He L.T.Sun Z.Z.Ren S.G.Zhou V.K.Utyonkov A.A.Voinov Yu.S.Tsyganov A.N.Polyakov D.I.Solovyev N.D.Kovrizhnykh M.V.Shumeiko 《Chinese Physics Letters》 2026年第1期9-16,共8页
We report the results of the experiment on synthesizing ^(287,288)Mc isotopes (Z=115) using the fusionevaporation reaction ^(243)Am(^(48)Ca,4n,3n)^(287,288)Mc at the Spectrometer for Heavy Atoms and Nuclear Structure-... We report the results of the experiment on synthesizing ^(287,288)Mc isotopes (Z=115) using the fusionevaporation reaction ^(243)Am(^(48)Ca,4n,3n)^(287,288)Mc at the Spectrometer for Heavy Atoms and Nuclear Structure-2(SHANS2),a gas-filled recoil separator located at the China Accelerator Facility for Superheavy Elements(CAFE2).In total,20 decay chains are attributed to ^(288)Mc and 1 decay chain is assigned to ^(287)Mc.The measured oa-decay properties of ^(287,288)Mc as well as its descendants are consistent with the known data.No additional decay chains originating from the 2n or 5n reaction channels were detected.The excitation function of the ^(243)Am(^(48)Ca,3n)^(288)Mc reaction was measured at the cross-section level of picobarn,which indicates the promising capability for the study of heavy and superheavy nuclei at the facility. 展开更多
关键词 spectrometer heavy atoms fusionevaporation reaction China Accelerator Facility Superheavy Elements PRODUCTION decay chains ISOTOPES ca am reaction mc
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Non-reciprocal Synchronization in Thermal Rydberg Ensembles
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作者 Yunlong Xue Zhengyang Bai 《Chinese Physics Letters》 2026年第1期26-30,共5页
Optical non-reciprocity is a fundamental phenomenon in photonics.It is crucial for developing devices that rely on directional signal control,such as optical isolators and circulators.However,most research in this fie... Optical non-reciprocity is a fundamental phenomenon in photonics.It is crucial for developing devices that rely on directional signal control,such as optical isolators and circulators.However,most research in this field has focused on systems in equilibrium or steady states.In this work,we demonstrate a room-temperature Rydberg atomic platform where the unidirectional propagation of light acts as a switch to mediate time-crystalline-like collective oscillations through atomic synchronization. 展开更多
关键词 atomic synchronization non reciprocal synchronization optical non reciprocity optical isolators thermal Rydberg ensembles directional signal controlsuch time crystalline oscillations unidirectional propagation light
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P,N co-doped hollow carbon nanospheres prepared by micellar copolymerization for increased hydrogen evolution in alkaline water 被引量:1
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作者 HAN Yi-meng XIONG Hao +2 位作者 YANG Jia-ying WANG Jian-gan XU Fei 《新型炭材料(中英文)》 北大核心 2025年第1期211-221,共11页
The design of cost-effective and efficient metal-free carbon-based catalysts for the hydrogen evolution reaction(HER)is of great significance for increasing the production of clean hydrogen by the electrolysis of alka... The design of cost-effective and efficient metal-free carbon-based catalysts for the hydrogen evolution reaction(HER)is of great significance for increasing the production of clean hydrogen by the electrolysis of alkaline water.Precise control of the electronic structure by heteroatom doping has proven to be efficient for increasing catalytic activity.Nevertheless,both the structural characteristics and the underlying mechanism are not well understood,especially for doping with two different atoms,thus limiting the use of these catalysts.We report the production of phosphorus and nitrogen co-doped hollow carbon nanospheres(HCNs)by the copolymerization of pyrrole and aniline at a Triton X-100 micelle-interface,followed by doping with phytic acid and carbonization.The unique pore structure and defect-rich framework of the HCNs expose numerous active sites.Crucially,the combined effect of graphitic nitrogen and phosphorus-carbon bonds modulate the local electronic structure of adjacent C atoms and facilitates electron transfer.As a res-ult,the HCN carbonized at 1100°C exhibited superior HER activity and an outstanding stability(70 h at a current density of 10 mA cm^(−2))in alkaline water,because of the large number of graphitic nitrogen and phosphorus-carbon bonds. 展开更多
关键词 Alkaline hydrogen evolution ELECTROCATALYSTS Hollow carbon nanospheres Dual atoms doping Combined effect
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Cu-Catalyzed Regioselective Heteroarylation of C(sp^(3))—H Bond Induce by Sulfonyl Group 被引量:1
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作者 Liu Huiying Wu Zhongtian +1 位作者 Li Haotian Wu Xinxin 《有机化学》 北大核心 2025年第1期297-306,共10页
The regioselective carbon-hydrogen bond functionalization reaction in atom-and step-economy holds significant potential for the late-stage elaboration of complex molecules and natural products.In recent years,the hydr... The regioselective carbon-hydrogen bond functionalization reaction in atom-and step-economy holds significant potential for the late-stage elaboration of complex molecules and natural products.In recent years,the hydrogen atom transfer strategy involving radicals has garnered considerable attention from chemists due to its high chemoselectivity and regioselectivity.However,owing to the marginal differences in bond dissociation energies(BDEs)among C(sp^(3))—H bonds,hydrogen atom transfer reactions mediated by alkyl radicals remain less-developed.A copper-catalyzed sulfone-induced regioselective C(sp^(3))—H bond heteroarylation reaction was reported.This strategy utilizes theα-alkyl radical of sulfone as an intramolecular hydrogen abstraction reagent,enabling the regioselective formation of carbon-nitrogen bonds under copper catalysis. 展开更多
关键词 radical reaction hydrogen atom transfer C—H bond functionalization heteroarylation
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Boosting bidirectional sulfur conversion enabled by introducing boron-doped atoms and phosphorus vacancies in Ni_(2)P for lithium-sulfur batteries 被引量:2
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作者 Lin Peng Yu Bai +3 位作者 Hang Li Meixiu Qu Zhenhua Wang Kening Sun 《Journal of Energy Chemistry》 2025年第1期760-769,共10页
Lithium-sulfur (Li-S) batteries have gained great attention due to the high theoretical energy density and low cost,yet their further commercialization has been obstructed by the notorious shuttle effect and sluggish ... Lithium-sulfur (Li-S) batteries have gained great attention due to the high theoretical energy density and low cost,yet their further commercialization has been obstructed by the notorious shuttle effect and sluggish redox dynamics.Herein,we supply a strategy to optimize the electron structure of Ni_(2)P by concurrently introducing B-doped atoms and P vacancies in Ni_(2)P (Vp-B-Ni_(2)P),thereby enhancing the bidirectional sulfur conversion.The study indicates that the simultaneous introduction of B-doped atoms and P vacancies in Ni_(2)P causes the redistribution of electron around Ni atoms,bringing about the upward shift of d-band center of Ni atoms and effective d-p orbital hybridization between Ni atoms and sulfur species,thus strengthening the chemical anchoring for lithium polysulfides (LiPSs) as well as expediting the bidirectional conversion kinetics of sulfur species.Meanwhile,theoretical calculations reveal that the incorporation of B-doped atoms and P vacancies in Ni_(2)P selectively promotes Li2S dissolution and nucleation processes.Thus,the Li-S batteries with Vp-B-Ni_(2)P-separators present outstanding rate ability of 777 m A h g^(-1)at 5 C and high areal capacity of 8.03 mA h cm^(-2)under E/S of 5μL mg^(-1)and sulfur loading of 7.20 mg cm^(-2).This work elucidates that introducing heteroatom and vacancy in metal phosphide collaboratively regulates the electron structure to accelerate bidirectional sulfur conversion. 展开更多
关键词 B-doped atoms P vacancies Nickel phosphide Bidirectional sulfur conversion Lithium-sulfur batteries
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Perspectives on metal-organic framework-derived microwave absorption materials 被引量:2
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作者 Meng-Qi Wang Mao-Sheng Cao 《Journal of Materials Science & Technology》 2025年第11期37-52,共16页
Exploring efficient microwave absorbing materials(MAMs)has gradually become a hot topic in recent years because it is crucial in both civil and military fields.Metal-organic framework(MOF)has great potential due to it... Exploring efficient microwave absorbing materials(MAMs)has gradually become a hot topic in recent years because it is crucial in both civil and military fields.Metal-organic framework(MOF)has great potential due to its unique composition and bonding mode,which has advantages such as large specific surface area,high porosity,adjustable structure,and designable composition.Herein,MOF-derived MAMs are highlighted based on morphology and structure.The synthesis strategies of MOF-derived MAMs of different dimensions are discussed.On this basis,the structure-activity relationships can be deeply explored through the precise control of material structure and property by atomic engineering.Finally,perspectives are given for the existing problems of MOF-derived MAMs,which will open a new horizon and promote the development of MAMs. 展开更多
关键词 Metal-organic framework Atomic engineering Microwave absorption
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Biomass-derived single atom catalysts with phosphorus-coordinated Fe-N_(3)P configuration for efficient oxygen reduction reaction 被引量:2
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作者 Peng-Peng Guo Abrar Qadir +6 位作者 Chao Xu Kun-Zu Yang Yong-Zhi Su Xin Liu Ping-Jie Wei Qinggang He Jin-Gang Liu 《Green Energy & Environment》 2025年第5期1064-1072,共9页
Exploiting non-precious metal catalysts with excellent oxygen reduction reaction(ORR)performance for energy devices is paramount essential for the green and sustainable society development.Herein,low-cost,high-perform... Exploiting non-precious metal catalysts with excellent oxygen reduction reaction(ORR)performance for energy devices is paramount essential for the green and sustainable society development.Herein,low-cost,high-performance biomass-derived ORR catalysts with an asymmetric Fe-N_(3)P configuration was prepared by a simple pyrolysis-etching technique,where carboxymethyl cellulose(CMC)was used as the carbon source,urea and 1,10-phenanthroline iron complex(FePhen)as additives,and Na_(3)PO_(4)as the phosphorus dopant and a pore-forming agent.The CMC-derived FeNPC catalyst displayed a large specific area(BET:1235 m^(2)g^(-1))with atomically dispersed Fe-N_(3)P active sites,which exhibited superior ORR activity and stability in alkaline solution(E_(1/2)=0.90 V vs.RHE)and Zn-air batteries(P_(max)=149 mW cm^(-2))to commercial Pt/C catalyst(E_(1/2)=0.87 V,P_(max)=118 mW cm^(-2))under similar experimental conditions.This work provides a feasible and costeffective route toward highly efficient ORR catalysts and their application to Zn-air batteries for energy conversion. 展开更多
关键词 Oxygen reduction reaction Biomass-derived electrocatalyst Single atom catalyst Phosphorus dopant Zn-air battery
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Atomic-scale investigation on the evolution of T_(1) precipitates in an aged Al-Cu-Li-Mg-Ag alloy 被引量:1
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作者 Xinyue Zhao Juan Ding +2 位作者 Daihong Xiao Lanping Huang Wensheng Liu 《Journal of Materials Science & Technology》 2025年第6期139-148,共10页
The T_(1)(Al_(2) CuLi)phase is one of the most effective strengthening nanoscale-precipitate in Al-Cu alloys with Li.However,its formation and evolution still need to be further clarified during aging due to the compl... The T_(1)(Al_(2) CuLi)phase is one of the most effective strengthening nanoscale-precipitate in Al-Cu alloys with Li.However,its formation and evolution still need to be further clarified during aging due to the complex precipitation sequences.Here,a detailed investigation has been carried out on the atomic struc-tural evolution of T_(1) precipitate in an aged Al-Cu-Li-Mg-Ag alloy using state-of-the-art Cs-corrected high-angle annular dark field(HAADF)-coupled with integrated differential phase contrast(iDPC)-scanning transmission electron microscopy(STEM)and energy-dispersive X-ray spectroscopy(EDXS)techniques.An intermediate T_(1)’phase between T_(1p) and T_(1) phase,with a crystal structure and orientation rela-tionship consistent with T_(1),but exhibiting different atomic occupancy and chemical composition was found.We observed the atomic structural transformation from T_(1p) to T_(1)’phase(fcc→hcp),involving only 1/12<112>Al shear component.DFT calculation results validated our proposed structural models and the precipitation sequence.Besides,the distributions of minor solute elements(Ag,Mg,and Zn)in the pre-cipitates exhibited significant differences.These findings may contribute to a further understanding of the nucleation mechanism of T_(1) precipitate. 展开更多
关键词 PRECIPITATE Chemical composition Atomic structure Aluminium alloy STEM
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Effects of pressure oscillations on impinging-jet atomization and spray combustion in liquid rocket engines 被引量:1
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作者 Zhili PENG Bo ZHONG +1 位作者 Xiaodong CHEN Longfei LI 《Chinese Journal of Aeronautics》 2025年第4期25-43,共19页
Combustion dynamics are a critical factor in determining the performance and reliabilityof a chemical propulsion engine.The underlying processes include liquid atomization,evaporation,mixing,and chemical reactions.Thi... Combustion dynamics are a critical factor in determining the performance and reliabilityof a chemical propulsion engine.The underlying processes include liquid atomization,evaporation,mixing,and chemical reactions.This paper presents a high-fidelity numerical study of liquidatomization and spray combustion under high-pressure conditions,emphasizing the effects of pres-sure oscillations on the flow evolution and combustion dynamics.The theoretical framework isbased on the three-dimensional conservation equations for multiphase flows and turbulent combus-tion.The numerical solution is achieved using a coupling method of volume-of-fluid and Lagran-gian particle tracking.The Zhuang-Kadota-Sutton(ZKS)high-pressure evaporation model andthe eddy breakup-Arrhenius combustion model are employed.Simulations are conducted for amodel combustion chamber with impinging-jet injectors using liquid oxygen and kerosene as pro-pellants.Both conditions with and without inlet and outlet pressure oscillations are considered.Thefindings reveal that pressure oscillations amplify flow fluctuations and can be characterized usingkey physical parameters such as droplet evaporation,chemical reaction,and chamber pressure.The spectral analysis uncovers the axial variations of the dominant and secondary frequenciesand their amplitudes in terms of the characteristic physical quantities.This research helps establisha methodology for exploring the coupling effect of liquid atomization and spray combustion.It alsoprovides practical insights into their responses to pressure oscillations during the occurrence ofcombustion instability.This information can be used to enhance the design and operation ofliquid-fueled propulsion engines. 展开更多
关键词 Liquid atomization Spray combustion Pressure oscillations High-pressure evaporation Combustion instability
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Transition Metal Carbonitride MXenes Anchored with Pt Sub-Nanometer Clusters to Achieve High-Performance Hydrogen Evolution Reaction at All pH Range 被引量:1
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作者 Zhihao Lei Sajjad Ali +18 位作者 CI Sathish MuhammadIbrar Ahmed Jiangtao Qu Rongkun Zheng Shibo Xi Xiaojiang Yu MBHBreese Chao Liu Jizhen Zhang Shuai Qi Xinwei Guan Vibin Perumalsamy Mohammed Fawaz Jae-Hun Yang Mohamed Bououdina Kazunari Domen Ajayan Vinu Liang Qiao Jiabao Yi 《Nano-Micro Letters》 2025年第5期525-539,共15页
Transition metal carbides,known as MXenes,particularly Ti_(3)C_(2)T_(x),have been extensively explored as promising materials for electrochemical reactions.However,transition metal carbonitride MXenes with high nitrog... Transition metal carbides,known as MXenes,particularly Ti_(3)C_(2)T_(x),have been extensively explored as promising materials for electrochemical reactions.However,transition metal carbonitride MXenes with high nitrogen content for electrochemical reactions are rarely reported.In this work,transition metal carbonitride MXenes incorporated with Pt-based electrocatalysts,ranging from single atoms to sub-nanometer dimensions,are explored for hydrogen evolution reaction(HER).The fabricated Pt clusters/MXene catalyst exhibits superior HER performance compared to the single-atom-incorporated MXene and commercial Pt/C catalyst in both acidic and alkaline electrolytes.The optimized sample shows low overpotentials of 28,65,and 154 mV at a current densities of 10,100,and 500 m A cm^(-2),a small Tafel slope of 29 m V dec^(-1),a high mass activity of 1203 mA mgPt^(-1)and an excellent turnover frequency of 6.1 s^(-1)in the acidic electrolyte.Density functional theory calculations indicate that this high performance can be attributed to the enhanced active sites,increased surface functional groups,faster charge transfer dynamics,and stronger electronic interaction between Pt and MXene,resulting in optimized hydrogen absorption/desorption toward better HER.This work demonstrates that MXenes with a high content of nitrogen may be promising candidates for various catalytic reactions by incorporating single atoms or clusters. 展开更多
关键词 MXene Hydrogen evolution reaction Single atom Two-dimensional nanosheets Density functional theory
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High-voltage MIM-type aluminum electrolytic capacitors 被引量:1
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作者 Yuan Guo Shixin Wang +5 位作者 Xianfeng Du Xinkuan Zang Zhongshuai Liang Jun Xiong Ruizhi Wang Zhuo Li 《Journal of Energy Chemistry》 2025年第5期79-90,共12页
Metal-insulator-metal aluminium electrolytic capacitors(MIM-AECs)combine high capacity-density and high breakdown field strength of solid AECs with high-frequency responsibility,wide workingtemperature window and wate... Metal-insulator-metal aluminium electrolytic capacitors(MIM-AECs)combine high capacity-density and high breakdown field strength of solid AECs with high-frequency responsibility,wide workingtemperature window and waterproof properties of MIM nanocapacitors.However,interfacial atomic diffusion poses a major obstacle,preventing the high-voltage MIM-AECs exploitation and thereby hampering their potential and advantages in high-power and high-energy-density applications.Here,an innovative high-voltage MIM-AECs were fabricated.The AlPO_(4)buffer layer is formed on AlO(OH)/AAO/Al surface by using H_(3)PO_(4)treatment,then a stable van der Waals(vdW)SnO_(2)/AlPO_(4)/AAO/Al multilayer was constructed via atomic layer deposition(ALD)technology.Due to higher diffusion barrier and lower carrier migration of SnO_(2)/AlPO_(4)/AAO interfaces,Sn atom diffusion is inhibited and carrier acceleration by electric field is weakened,guaranteeing high breakdown field strength of dielectric AAO and avoiding local breakdown risks.Through partial etching to hydrated AlO(OH)by H_(3)PO_(4)treatment,the tunnel was further opened up to facilitate subsequent ALD-SnO_(2)entry,thus obtaining a high SnO_(2)coverage.The SnO_(2)/AlPO_(4)/AAO/Al capacitors show a comprehensive performance in high-voltage(260 V),hightemperature(335℃),high-humidity(100%RH)and high-frequency response(100 k Hz),outperforming commercial solid-state AECs,and high-energy density(8.6μWh/cm^(2)),markedly exceeding previously reported MIM capacitors.The work lays the foundation for next-generation capacitors with highvoltage,high-frequency,high-temperature and high-humidity resistance. 展开更多
关键词 MIM nanocapacitor Electrolytic capacitor Buffer layer Atomic layer deposition High voltage
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High-performance KNN-based piezoelectric ceramics for buzzer application 被引量:1
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作者 Cheng Xiong Bosen Li +2 位作者 Zhongxin Liao Yan Qiu Daqiang Gao 《Chinese Physics B》 2025年第4期591-596,共6页
Piezoelectric ceramic materials are important components of piezoelectric buzzers,where the parameter of inverse piezoelectric coefficient(d_(33)^(*))plays a decisive role in the performance of the buzzer.Here,we repo... Piezoelectric ceramic materials are important components of piezoelectric buzzers,where the parameter of inverse piezoelectric coefficient(d_(33)^(*))plays a decisive role in the performance of the buzzer.Here,we report the manufacture and performance of a lead-free ceramic-based(0.96(K_(0.5)Na_(0.5))(Nb_(0.96)Sb_(0.04))O_(3)-0.04(Bi_(0.5)Na_(0.5))ZrO_(3)-1 mol%Al_(2)O_(3),abbreviated as KNNS-BNZ-1 mol%Al_(2)O_(3))piezoelectric buzzer and compare it with commercial(PbZr_(0.5)Ti_(0.5)O_(3),abbreviated as PZT)ceramics.Briefly,KNN-based ceramics have a typical perovskite structure and piezoelectric properties of d_(33)=480 pC/N,k_(p)=0.62 and d_(33)^(*)=830 pm/V,compared to d_(33)=500 pC/N,k_(p)=0.6 and d_(33)^(*)=918 pm/V of the commercial PZT-4 ceramics.Our results show that the KNNS-BNZ-1 mol%Al_(2)O_(3)ceramics have a similar sound pressure level performance over the testing frequency range to commercial PZT ceramics(which is even better in the 3-4 kHz range).These findings highlight the great application potential of KNN-based piezoelectric ceramics. 展开更多
关键词 lead-free piezoelectric ceramics phase structure engineering BUZZER ATOMIZER
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