期刊文献+
共找到80,388篇文章
< 1 2 250 >
每页显示 20 50 100
A High-Order Modulation Signal ClassificationMethod Based on a Fourier Analysis NetworkIntegrated with an Attention Mechanism
1
作者 Yuepeng Li Xiaogang Tang +2 位作者 Binquan Zhang Lu Wang Hao Huan 《Journal of Beijing Institute of Technology》 2025年第4期350-361,共12页
In modern wireless communication and electromagnetic control,automatic modulationclassification(AMC)of orthogonal frequency division multiplexing(OFDM)signals plays animportant role.However,under Doppler frequency shi... In modern wireless communication and electromagnetic control,automatic modulationclassification(AMC)of orthogonal frequency division multiplexing(OFDM)signals plays animportant role.However,under Doppler frequency shift and complex multipath channel conditions,extracting discriminative features from high-order modulation signals and ensuring model inter-pretability remain challenging.To address these issues,this paper proposes a Fourier attention net-work(FAttNet),which combines an attention mechanism with a Fourier analysis network(FAN).Specifically,the method directly converts the input signal to the frequency domain using the FAN,thereby obtaining frequency features that reflect the periodic variations in amplitude and phase.Abuilt-in attention mechanism then automatically calculates the weights for each frequency band,focusing on the most discriminative components.This approach improves both classification accu-racy and model interpretability.Experimental validation was conducted via high-order modulationsimulation using an RF testbed.The results show that under three different Doppler frequencyshifts and complex multipath channel conditions,with a signal-to-noise ratio of 10 dB,the classifi-cation accuracy can reach 89.1%,90.4%and 90%,all of which are superior to the current main-stream methods.The proposed approach offers practical value for dynamic spectrum access and sig-nal security detection,and it makes important theoretical contributions to the application of deeplearning in complex electromagnetic signal recognition. 展开更多
关键词 orthogonal frequency division multiplexing high order modulated signal automaticmodulation classification Fourier analysis network
在线阅读 下载PDF
Design of Serially Concatenated Two-Level Polar Coded Modulation System with Low-Complexity
2
作者 Zhou Lin Liao Guojun +3 位作者 Xu Lei An Ran Xie Xianzhong Wang Xi 《China Communications》 2025年第1期102-110,共9页
Multilevel coding(MLC)is a commonly used polar coded modulation scheme,but challenging to implement in engineering due to its high complexity and long decoding delay for high-order modulations.To address these limitat... Multilevel coding(MLC)is a commonly used polar coded modulation scheme,but challenging to implement in engineering due to its high complexity and long decoding delay for high-order modulations.To address these limitations,a novel two-level serially concatenated MLC scheme,in which the bitlevels with similar reliability are bundled and transmitted together,is proposed.The proposed scheme hierarchically protects the two bit-level sets:the bitlevel sets at the higher level are sufficiently reliable and do not require excessive resources for protection,whereas only the bit-level sets at the lower level are encoded by polar codes.The proposed scheme has the advantages of low power consumption,low delay and high reliability.Moreover,an optimized constellation signal labeling rule that can enhance the performance is proposed.Finally,the superiority of the proposed scheme is validated through the theoretical analysis and simulation results.Compared with the bit interleaving coding modulation(BICM)scheme,under 256-quadrature amplitude modulation(QAM),the proposed scheme attains a performance gain of 1.0 dB while reducing the decoding complexity by 54.55%. 展开更多
关键词 bit-interleaved coded modulation high-order modulation multilevel coding polar codes
在线阅读 下载PDF
Spin-dependent amplitude and phase modulation with multifold interferences via single-layer diatomic all-silicon metasurfaces 被引量:2
3
作者 Hui Li Chenhui Zhao +6 位作者 Jie Li Hang Xu Wenhui Xu Qi Tan Chunyu Song Yun Shen Jianquan Yao 《Opto-Electronic Science》 2025年第3期2-15,共14页
Diatomic metasurfaces designed for interferometric mechanisms possess significant potential for the multidimensional manipulation of electromagnetic waves,including control over amplitude,phase,frequency,and polarizat... Diatomic metasurfaces designed for interferometric mechanisms possess significant potential for the multidimensional manipulation of electromagnetic waves,including control over amplitude,phase,frequency,and polarization.Geometric phase profiles with spin-selective properties are commonly associated with wavefront modulation,allowing the implementation of conjugate strategies within orthogonal circularly polarized channels.Simultaneous control of these characteristics in a single-layered diatomic metasurface will be an apparent technological extension.Here,spin-selective modulation of terahertz(THz)beams is realized by assembling a pair of meta-atoms with birefringent effects.The distinct modulation functions arise from geometric phase profiles characterized by multiple rotational properties,which introduce independent parametric factors that elucidate their physical significance.By arranging the key parameters,the proposed design strategy can be employed to realize independent amplitude and phase manipulation.A series of THz metasurface samples with specific modulation functions are characterized,experimentally demonstrating the accuracy of on-demand manipulation.This research paves the way for all-silicon meta-optics that may have great potential in imaging,sensing and detection. 展开更多
关键词 diatomic metasurface geometric phase complex amplitude modulation spin-selective
在线阅读 下载PDF
Bioinspired smart dual-layer hydrogels system with synchronous solar and thermal radiation modulation for energy-saving all-season temperature regulation 被引量:1
4
作者 Meng-Chen Huang Chao-Hua Xue +8 位作者 Zhongxue Bai Jun Cheng Yong-Gang Wu Chao-Qun Ma Li Wan Long Xie Hui-Di Wang Bing-Ying Liu Xiao-Jing Guo 《Journal of Energy Chemistry》 2025年第2期175-190,I0005,共17页
All-season thermal management with zero energy consumption and emissions is more crucial to global decarbonization over traditional energy-intensive cooling/heating systems.However,the static single thermal management... All-season thermal management with zero energy consumption and emissions is more crucial to global decarbonization over traditional energy-intensive cooling/heating systems.However,the static single thermal management for cooling or heating fails to self-regulate the temperature in dynamic seasonal temperature condition.Herein,inspired by the dual-temperature regulation function of the fur color changes on the backs and abdomens of penguins,a smart thermal management composite hydrogel(PNA@H-PM Gel)system was subtly created though an"on-demand"dual-layer structure design strategy.The PNA@H-PM Gel system features synchronous solar and thermal radiation modulation as well as tunable phase transition temperatures to meet the variable seasonal thermal requirements and energy-saving demands via self-adaptive radiative cooling and solar heating regulation.Furthermore,this system demonstrates superb modulations of both the solar reflectance(ΔR=0.74)and thermal emissivity(ΔE=0.52)in response to ambient temperature changes,highlighting efficient temperature regulation with average radiative cooling and solar heating effects of 9.6℃in summer and 6.1℃in winter,respectively.Moreover,compared to standard building baselines,the PNA@H-PM Gel presents a more substantial energy-saving cooling/heating potentials for energy-efficient buildings across various regions and climates.This novel solution,inspired by penguins in the real world,will offer a fresh approach for producing intelligent,energy-saving thermal management materials,and serve for temperature regulation under dynamic climate conditions and even throughout all seasons. 展开更多
关键词 Thermochromic hydrogel Self-adaptive thermal management Radiative cooling Spectral modulation ENERGY-SAVING
在线阅读 下载PDF
Ion-modulation optoelectronic neuromorphic devices:mechanisms,characteristics,and applications 被引量:1
5
作者 Xiaohan Meng Runsheng Gao +1 位作者 Xiaojian Zhu Run-Wei Li 《Journal of Semiconductors》 2025年第2期24-36,共13页
The traditional von Neumann architecture faces inherent limitations due to the separation of memory and computa-tion,leading to high energy consumption,significant latency,and reduced operational efficiency.Neuromorph... The traditional von Neumann architecture faces inherent limitations due to the separation of memory and computa-tion,leading to high energy consumption,significant latency,and reduced operational efficiency.Neuromorphic computing,inspired by the architecture of the human brain,offers a promising alternative by integrating memory and computational func-tions,enabling parallel,high-speed,and energy-efficient information processing.Among various neuromorphic technologies,ion-modulated optoelectronic devices have garnered attention due to their excellent ionic tunability and the availability of multi-dimensional control strategies.This review provides a comprehensive overview of recent progress in ion-modulation optoelec-tronic neuromorphic devices.It elucidates the key mechanisms underlying ionic modulation of light fields,including ion migra-tion dynamics and capture and release of charge through ions.Furthermore,the synthesis of active materials and the proper-ties of these devices are analyzed in detail.The review also highlights the application of ion-modulation optoelectronic devices in artificial vision systems,neuromorphic computing,and other bionic fields.Finally,the existing challenges and future direc-tions for the development of optoelectronic neuromorphic devices are discussed,providing critical insights for advancing this promising field. 展开更多
关键词 ion migration optoelectronic modulation optoelectronic device neuromorphic computing artificial vision system
在线阅读 下载PDF
Defect Engineering with Rational Dopants Modulation for High‑Temperature Energy Harvesting in Lead‑Free Piezoceramics
6
作者 Kaibiao Xi Jianzhe Guo +2 位作者 Mupeng Zheng Mankang Zhu Yudong Hou 《Nano-Micro Letters》 SCIE EI CAS 2025年第3期87-101,共15页
High temperature piezoelectric energy harvester(HTPEH)is an important solution to replace chemical battery to achieve independent power supply of HT wireless sensors.However,simultaneously excellent performances,inclu... High temperature piezoelectric energy harvester(HTPEH)is an important solution to replace chemical battery to achieve independent power supply of HT wireless sensors.However,simultaneously excellent performances,including high figure of merit(FOM),insulation resistivity(ρ)and depolarization temperature(Td)are indispensable but hard to achieve in lead-free piezoceramics,especially operating at 250°C has not been reported before.Herein,well-balanced performances are achieved in BiFeO3–BaTiO3 ceramics via innovative defect engineering with respect to delicate manganese doping.Due to the synergistic effect of enhancing electrostrictive coefficient by polarization configuration optimization,regulating iron ion oxidation state by high valence manganese ion and stabilizing domain orientation by defect dipole,comprehensive excellent electrical performances(Td=340°C,ρ250°C>10^(7)Ωcm and FOM_(250°C)=4905×10^(–15)m^(2)N^(−1))are realized at the solid solubility limit of manganese ions.The HT-PEHs assembled using the rationally designed piezoceramic can allow for fast charging of commercial electrolytic capacitor at 250°C with high energy conversion efficiency(η=11.43%).These characteristics demonstrate that defect engineering tailored BF-BT can satisfy high-end HT-PEHs requirements,paving a new way in developing selfpowered wireless sensors working in HT environments. 展开更多
关键词 Lead-free piezoceramic Defect engineering Dopants modulation High-temperature Piezoelectric energy harvester
在线阅读 下载PDF
Increase in the variability of terrestrial carbon uptake in response to enhanced future ENSO modulation
7
作者 Younong Li Li Dan +2 位作者 Jing Peng Qidong Yang Fuqiang Yang 《Atmospheric and Oceanic Science Letters》 2025年第1期32-38,共7页
El Niño-Southern Oscillation(ENSO)is a major driver of climate change in middle and low latitudes and thus strongly influences the terrestrial carbon cycle through land-air interaction.Both the ENSO modulation an... El Niño-Southern Oscillation(ENSO)is a major driver of climate change in middle and low latitudes and thus strongly influences the terrestrial carbon cycle through land-air interaction.Both the ENSO modulation and carbon flux variability are projected to increase in the future,but their connection still needs further investigation.To investigate the impact of future ENSO modulation on carbon flux variability,this study used 10 CMIP6 earth system models to analyze ENSO modulation and carbon flux variability in middle and low latitudes,and their relationship,under different scenarios simulated by CMIP6 models.The results show a high consistency in the simulations,with both ENSO modulation and carbon flux variability showing an increasing trend in the future.The higher the emissions scenario,especially SSP5-8.5 compared to SSP2-4.5,the greater the increase in variability.Carbon flux variability in the middle and low latitudes under SSP2-4.5 increases by 30.9%compared to historical levels during 1951-2000,while under SSP5-8.5 it increases by 58.2%.Further analysis suggests that ENSO influences mid-and low-latitude carbon flux variability primarily through temperature.This occurrence may potentially be attributed to the increased responsiveness of gross primary productivity towards regional temperature fluctuations,combined with the intensified influence of ENSO on land surface temperatures. 展开更多
关键词 Carbon variability ENSO modulation CMIP6 models
在线阅读 下载PDF
Cation and anion modulation activates lattice oxygen for enhanced oxygen evolution 被引量:1
8
作者 Mingxing Chen Zihe Du +8 位作者 Nian Liu Huijie Li Jing Qi Enbo Shangguan Jing Li Jiahao Cao Shujiao Yang Wei Zhang Rui Cao 《Chinese Journal of Catalysis》 2025年第2期282-291,共10页
Oxygen evolution reaction(OER)is often regarded as a crucial bottleneck in the field of renewable energy storage and conversion.To further accelerate the sluggish kinetics of OER,a cation and anion modulation strategy... Oxygen evolution reaction(OER)is often regarded as a crucial bottleneck in the field of renewable energy storage and conversion.To further accelerate the sluggish kinetics of OER,a cation and anion modulation strategy is reported here,which has been proven to be effective in preparing highly active electrocatalyst.For example,the cobalt,sulfur,and phosphorus modulated nickel hydroxide(denoted as NiCoPSOH)only needs an overpotential of 232 mV to reach a current density of 20 mA cm^(–2),demonstrating excellent OER performances.The cation and anion modulation facilitates the generation of high-valent Ni species,which would activate the lattice oxygen and switch the OER reaction pathway from conventional adsorbate evolution mechanism to lattice oxygen mechanism(LOM),as evidenced by the results of electrochemical measurements,Raman spectroscopy and differential electrochemical mass spectrometry.The LOM pathway of NiCoPSOH is further verified by the theoretical calculations,including the upshift of O 2p band center,the weakened Ni–O bond and the lowest energy barrier of rate-limiting step.Thus,the anion and cation modulated catalyst NiCoPSOH could effectively accelerate the sluggish OER kinetics.Our work provides a new insight into the cation and anion modulation,and broadens the possibility for the rational design of highly active electrocatalysts. 展开更多
关键词 Oxygen evolution reaction ELECTROCATALYSIS Lattice oxygen mechanism High-valent metal species Cation and anion modulation
在线阅读 下载PDF
Crystallization Modulation and Holistic Passivation Enables Efficient Two‑Terminal Perovskite/CuIn(Ga)Se_(2)Tandem Solar Cells
9
作者 Cong Geng Kuanxiang Zhang +7 位作者 Changhua Wang Chung Hsien Wu Jiwen Jiang Fei Long Liyuan Han Qifeng Han Yi‑Bing Cheng Yong Peng 《Nano-Micro Letters》 SCIE EI CAS 2025年第1期205-215,共11页
Two-terminal(2-T)perovskite(PVK)/CuIn(Ga)Se_(2)(CIGS)tandem solar cells(TSCs)have been considered as an ideal tandem cell because of their best bandgap matching regarding to Shockley–Queisser(S–Q)limits.However,the ... Two-terminal(2-T)perovskite(PVK)/CuIn(Ga)Se_(2)(CIGS)tandem solar cells(TSCs)have been considered as an ideal tandem cell because of their best bandgap matching regarding to Shockley–Queisser(S–Q)limits.However,the nature of the irregular rough morphology of commercial CIGS prevents people from improving tandem device performances.In this paper,D-homoserine lactone hydrochloride is proven to improve coverage of PVK materials on irregular rough CIGS surfaces and also passivate bulk defects by modulating the growth of PVK crystals.In addition,the minority carriers near the PVK/C60 interface and the incompletely passivated trap states caused interface recombination.A surface reconstruction with 2-thiopheneethylammonium iodide and N,N-dimethylformamide assisted passivates the defect sites located at the surface and grain boundaries.Meanwhile,LiF is used to create this field effect,repelling hole carriers away from the PVK and C60 interface and thus reducing recombination.As a result,a 2-T PVK/CIGS tandem yielded a power conversion efficiency of 24.6%(0.16 cm^(2)),one of the highest results for 2-T PVK/CIGS TSCs to our knowledge.This validation underscores the potential of our methodology in achieving superior performance in PVK/CIGS tandem solar cells. 展开更多
关键词 PVK/CIGS TSCs Irregular rough surfaces modulating the growth PVK/C60 interface recombination
在线阅读 下载PDF
Frequency shifts of high-order harmonics from ZnO crystals by chirped laser pulses
10
作者 Yu Zhao Xiao-Jin Liu +3 位作者 Shuang Wang Xiao-Xin Huo Yun-He Xing Jun Zhang 《Chinese Physics B》 2025年第3期340-346,共7页
We investigate theoretically the effects of chirped laser pulses on high-order harmonic generation(HHG)from solids.We find that the harmonic spectra display redshifts for the driving laser pulses with negative chirp a... We investigate theoretically the effects of chirped laser pulses on high-order harmonic generation(HHG)from solids.We find that the harmonic spectra display redshifts for the driving laser pulses with negative chirp and blueshifts for those with positive chirp,which is due to the change in the instantaneous frequency of the driving laser for different chirped pulses.The analysis of crystal-momentum-resolved(k-resolved)HHG reveals that the frequency shifts are equal for the harmonics generated by different crystal momentum channels.The frequency shifts in the cutoff region are larger than those in the plateau region.With the increase of the absolute value of the chirp parameters,the frequency shifts of HHG become more significant,leading to the shifts from odd-to even-order harmonics.We also demonstrate that the frequency shifts of harmonic spectra are related to the duration of the chirped laser field,but are insensitive to the laser intensity and dephasing time. 展开更多
关键词 high-order harmonic generation ZnO crystal chirped laser pulse spectral shift
原文传递
Accessing polyarene-fused ten-membered lactams via oxidative N-heterocyclic carbene(NHC)-catalyzed high-order[7+3]annulation
11
作者 Chen-Chang Cui Shao-Qing Shi +4 位作者 Lu-Yao Wang Feng Lin Man-Su Tu Wen-Juan Hao Bo Jiang 《Chinese Chemical Letters》 2025年第6期479-483,共5页
A new oxidative N-heterocyclic carbene(NHC)-catalyzed high-order[7+3]annulation reaction ofγ-indolyl phenols as 1,7-dinucleophiles andα,β-alkynals with the aid of Sc(OTf)_(3)is reported,enabling the highly regiosel... A new oxidative N-heterocyclic carbene(NHC)-catalyzed high-order[7+3]annulation reaction ofγ-indolyl phenols as 1,7-dinucleophiles andα,β-alkynals with the aid of Sc(OTf)_(3)is reported,enabling the highly regioselective access to unprecedented polyarene-fused ten-membered lactams bearing a bridged aryl-aryl-indole scaffold in moderate to good yields.This protocol demonstrates a broad substrate scope,good compatibility with substituents and complete regioselectivity,providing an organocatalytic modular synthetic strategy for creating medium-sized lactams. 展开更多
关键词 NHC-catalysis high-order annulation Regioselectivity Medium-sized lactams γ-Indolyl phenols
原文传递
Unveiling the role of high-order anharmonicity in thermal expansion: A first-principles perspective
12
作者 Tianxu Zhang Kun Zhou +5 位作者 Yingjian Li Chenhao Yi Muhammad Faizan Yuhao Fu Xinjiang Wang Lijun Zhang 《Chinese Physics B》 2025年第4期212-219,共8页
Thermal expansion is crucial for various industrial processes and is increasingly the focus of research endeavors aimed at improving material performance.However,it is the continuous advancements in first-principles c... Thermal expansion is crucial for various industrial processes and is increasingly the focus of research endeavors aimed at improving material performance.However,it is the continuous advancements in first-principles calculations that have enabled researchers to understand the microscopic origins of thermal expansion.In this study,we propose a coefficient of thermal expansion(CTE)calculation scheme based on self-consistent phonon theory,incorporating the fourth-order anharmonicity.We selected four structures(Si,CaZrF_(6),SrTiO_(3),NaBr)to investigate high-order anharmonicity’s impact on their CTEs,based on bonding types.The results indicate that our method goes beyond the second-order quasi-harmonic approximation and the third-order perturbation theory,aligning closely with experimental data.Furthermore,we observed that an increase in the ionicity of the structures leads to a more pronounced influence of high-order anharmonicity on CTE,with this effect primarily manifesting in variations of the Grüneisen parameter.Our research provides a theoretical foundation for accurately predicting and regulating the thermal expansion behavior of materials. 展开更多
关键词 high-order anharmonicity Grüneisen parameter thermal expansion first-principles calculations
原文传递
Correction:Initiating Binary Metal Oxides Microcubes Electromagnetic Wave Absorber Toward Ultrabroad Absorption Bandwidth Through Interfacial and Defects Modulation
13
作者 Fushan Li Nannan Wu +8 位作者 Hideo Kimura Yuan Wang Ben Bin Xu Ding Wang Yifan Li Hassan Algadi Zhanhu Guo Wei Du Chuanxin Hou 《Nano-Micro Letters》 2025年第11期530-533,共4页
Following publication of the original article[1],the authors found that they pasted the same data when drawing XRD for sample NCO-1 and NCO-2 in Fig.2a,however,the XRD of all four samples in the manuscript was tested,... Following publication of the original article[1],the authors found that they pasted the same data when drawing XRD for sample NCO-1 and NCO-2 in Fig.2a,however,the XRD of all four samples in the manuscript was tested,and XRD raw data were kept and can be offered.The correct Fig.2 has been provided in this Correction. 展开更多
关键词 binary metal oxides ultrabroad absorption bandwidth electromagnetic wave absorber interfacial modulation defects modulation XRD microcubes
在线阅读 下载PDF
A High-Order Scalar Auxiliary Variable Approach for Nonlinear Parabolic Integro-Differential Equations
14
作者 YAN Li-na ZHANG Gen-gen HUANG Qiong-ao 《Chinese Quarterly Journal of Mathematics》 2025年第3期262-270,共9页
An efficient and accurate scalar auxiliary variable(SAV)scheme for numerically solving nonlinear parabolic integro-differential equation(PIDE)is developed in this paper.The original equation is first transformed into ... An efficient and accurate scalar auxiliary variable(SAV)scheme for numerically solving nonlinear parabolic integro-differential equation(PIDE)is developed in this paper.The original equation is first transformed into an equivalent system,and the k-order backward differentiation formula(BDF k)and central difference formula are used to discretize the temporal and spatial derivatives,respectively.Different from the traditional discrete method that adopts full implicit or full explicit for the nonlinear integral terms,the proposed scheme is based on the SAV idea and can be treated semi-implicitly,taking into account both accuracy and effectiveness.Numerical results are presented to demonstrate the high-order convergence(up to fourth-order)of the developed schemes and it is computationally efficient in long-time computations. 展开更多
关键词 Parabolic integro-differential equation Scalar auxiliary variable Fredholm equation high-order BDF scheme
在线阅读 下载PDF
Generalized Quadrature Spatial Modulation for STAR-RIS Aided NOMA Networks
15
作者 Guo Yonghao Dang Shuping +3 位作者 Li Jun Shang Wenli Hou Jia Huang Yu 《China Communications》 2025年第4期1-12,共12页
The simultaneously transmitting and reflecting reconfigurable intelligent surface(STAR-RIS)is regarded as a promising paradigm for enhancing the connectivity and reliability of non-orthogonal multiple access(NOMA)netw... The simultaneously transmitting and reflecting reconfigurable intelligent surface(STAR-RIS)is regarded as a promising paradigm for enhancing the connectivity and reliability of non-orthogonal multiple access(NOMA)networks.However,the transmission of STAR-RIS enhanced NOMA networks performance is severely limited due to the inter-user interference(IUI)on multi-user detections.To mitigate this drawback,we propose a generalized quadrature spatial modulation(GQSM)aided STAR-RIS in conjunction with the NOMA scheme,termed STARRIS-NOMA-GQSM,to improve the performance of the corresponding NGMA network.By STAR-RISNOMA-GQSM,the information bits for all users in transmission and reflection zones are transmitted via orthogonal signal domains to eliminate the IUI so as to greatly improve the system performance.The lowcomplexity detection and upper-bounded bit error rate(BER)of STAR-RIS-NOMA-GQSM are both studied to evaluate its feasibility and performance.Moreover,by further utilizing index modulation(IM),we propose an enhanced STAR-RIS-NOMA-GQSM scheme,termed E-STAR-RIS-NOMA-GQSM,to enhance the transmission rate by dynamically adjusting reflection patterns in both transmission and reflection zones.Simulation results show that the proposed original and enhanced scheme significantly outperform the conventional STAR-RIS-NOMA and also confirm the precision of the theoretical analysis of the upper-bounded BER. 展开更多
关键词 index modulation NOMA STAR-RIS
在线阅读 下载PDF
Multi-frequency formation mechanism and modulation strategy of self-priming enhanced submerged pulsed waterjet
16
作者 Haojie Jia Yanwei Liu +6 位作者 Weiqin Zuo Hongkai Han Ping Chang Mohammad Waqar Ali Asad Guozhong Hu Jian Miao Hani SMitri 《International Journal of Mining Science and Technology》 2025年第2期175-189,共15页
Under submerged conditions, compared with traditional self-excited oscillating pulsed waterjets(SOPWs), annular fluid-enhanced self-excited oscillating pulsed waterjets(AFESOPWs) exhibit a higher surge pressure throug... Under submerged conditions, compared with traditional self-excited oscillating pulsed waterjets(SOPWs), annular fluid-enhanced self-excited oscillating pulsed waterjets(AFESOPWs) exhibit a higher surge pressure through self-priming. However, their pressure frequency and cavitation characteristics remain unclear, resulting in an inability to fully utilize resonance and cavitation erosion to break coal and rock. In this study, high-frequency pressure testing, high-speed photography, and large eddy simulation(LES) are used to investigate the distribution of the pressure frequency band, evolution law of the cavitation cloud, and its regulation mechanism of a continuous waterjet, SOPW, and AFESOPW. The results indicated that the excitation of the plunger pump, shearing layer vortex, and bubble collapse corresponded to the three high-amplitude frequency bands of the waterjet pressure. AFESOPWs have an additional self-priming frequency that can produce a larger amplitude under a synergistic effect with the second high-amplitude frequency band. A better cavitation effect was produced after self-priming the annulus fluid, and the shedding frequency of the cavitation clouds of the three types of waterjets was linearly related to the cavitation number. The peak pressure of the waterjet and cavitation erosion effect can be improved by modulating the waterjet pressure oscillation frequency and cavitation shedding frequency. 展开更多
关键词 MULTI-FREQUENCY modulation SELF-PRIMING Submerged waterjet CAVITATION
在线阅读 下载PDF
Adhesion of 2D Materials: Measurement and Modulation
17
作者 Na Li Hongrong Wu +1 位作者 Changwei Sun Junhua Zhao 《Acta Mechanica Solida Sinica》 2025年第2期252-274,共23页
Two-dimensional(2D)materials are promising for next-generation electronic devices and systems due to their unique physical properties.The interfacial adhesion plays a vital role not only in the synthesis,transfer and ... Two-dimensional(2D)materials are promising for next-generation electronic devices and systems due to their unique physical properties.The interfacial adhesion plays a vital role not only in the synthesis,transfer and manipulation of 2D materials but also in the manufacture,integration and performance of the functional devices.However,the atomic thickness and limited lateral dimensions of 2D materials make the accurate measurement and modulation of their interfacial adhesion energy challenging.In this review,the recent advances in the measurement and modulation of the interfacial adhesion properties of 2D materials are systematically combed.Experimental methods and relative theoretical models for the adhesion measurement of 2D materials are summarized,with their scope of application and limitations discussed.The measured adhesion energies between 2D materials and various substrates are described in categories,where the typical adhesion modulation strategies of 2D materials are also introduced.Finally,the remaining challenges and opportunities for the interfacial adhesion measurement and modulation of 2D materials are presented.This paper provides guidance for addressing the adhesion issues in devices and systems involving 2D materials. 展开更多
关键词 2D materials ADHESION MEASUREMENT modulation
原文传递
Periodic modulation of adiabatic dynamics in non-reciprocal Landau-Zener systems
18
作者 Rong Chang Sheng-Chang Li 《Chinese Physics B》 2025年第3期259-264,共6页
The control of adiabatic dynamics is essential for quantum manipulation.We investigate the effects of both periodic modulating field and linear sweeping field on adiabatic dynamics based on a non-reciprocal Landau-Zen... The control of adiabatic dynamics is essential for quantum manipulation.We investigate the effects of both periodic modulating field and linear sweeping field on adiabatic dynamics based on a non-reciprocal Landau-Zener model with periodic modulation.We obtain adiabatic phase diagrams in the(ω,δ)parameter space,where the adiabatic region is bounded by the modulating frequencyωgreater than a critical valueω_(c) and the non-reciprocal parameterδless than one.The results show that the adiabaticity of the system is not sensitive to the modulating amplitude.We find that the critical modulating frequency can be expressed as a power function of the modulating period number or the sweeping rate.Our findings suggest that one can change the adiabatic region or improve the adiabaticity by adjusting the parameters of both the modulating and the sweeping fields,which provides an effective means to flexibly control the adiabatic dynamics of non-reciprocal systems. 展开更多
关键词 ADIABATICITY non-reciprocity Landau-Zener tunneling periodic modulation
原文传递
High-order harmonic generation of methane in an elliptically polarized field
19
作者 Shu-Shan Zhou Yu-Long Li +6 位作者 Zhi-Xue Zhao Man Xing Nan Xu Hao Wang Jun Wang Xi Zhao Mu-Hong Hu 《Chinese Physics B》 2025年第6期125-130,共6页
We performed real-time and real-space numerical simulations of high-order harmonic generation in the threedimensional structured molecule methane(CH_(4)) using time-dependent density functional theory. By irradiating ... We performed real-time and real-space numerical simulations of high-order harmonic generation in the threedimensional structured molecule methane(CH_(4)) using time-dependent density functional theory. By irradiating the methane molecule with an elliptically polarized laser pulse polarized in the x–y plane, we observed significant even-order harmonic emission in the z-direction. By analyzing the electron dynamics in the electric field and the multi-orbital effects of the molecule, we revealed that electron recombination near specific atoms in methane is the primary source of highorder harmonic generation in the z-direction. Furthermore, we identified the dominant molecular orbitals responsible for the enhancement of harmonics in this direction and demonstrated the critical role played by multi-orbital effects in this process. 展开更多
关键词 high-order harmonic generation elliptically polarized field time-dependent density functional theory
原文传递
Single-sideband modulation for dynamically reconfigurable multiwavelength interferometry
20
作者 Leonard Voßgrag Annelie Schiller +4 位作者 Tobias Seyler Markus Fratz Alexander Bertz Daniel Carl Ingo Breunig 《Advanced Photonics Nexus》 2025年第4期119-127,共9页
Single-wavelength interferometry achieves high resolution for smooth surfaces but struggles with rough industrially relevant ones due to limited unambiguous measuring range and speckle effects.Multiwavelength interfer... Single-wavelength interferometry achieves high resolution for smooth surfaces but struggles with rough industrially relevant ones due to limited unambiguous measuring range and speckle effects.Multiwavelength interferometry addresses these challenges using synthetic wavelengths,enabling a balance between extended measurement range and resolution by combining several synthetic wavelengths.This approach holds immense potential for diverse industrial applications,yet it remains largely untapped due to the lack of suitable light sources.Existing solutions are constrained by limited flexibility in synthetic-wavelength generation and slow switching speeds.We demonstrate a light source for multiwavelength interferometry based on electro-optic single-sideband modulation.It reliably generates synthetic wavelengths with arbitrary values from centimeters to meters and switching time below 30 ms.This breakthrough paves the way for dynamic reconfigurable multiwavelength interferometry capable of adapting to complex surfaces and operating efficiently even outside laboratory settings.These capabilities unlock the full potential of multiwavelength interferometry,offering unprecedented flexibility and speed for industrial and technological applications. 展开更多
关键词 digital holography electro-optic modulation INTERFEROMETRY
在线阅读 下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部