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Deformation Behavior and Mechanisms of fcc High-Entropy Alloys:Insights from Neutron Diffraction
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作者 Zhao Yanchun Yao Yatao +9 位作者 Zhang Fan Huang Yan Zhang Yibo Lu Zhichao Zhang Qi Fu Xiaoling Wang Anding Zhang Fei Song Wenli Ma Dong 《稀有金属材料与工程》 北大核心 2026年第3期655-664,共10页
The multi-principal element characteristic of high-entropy alloys has revolutionized the conventional alloy design concept of single-principal element,endowing them with excellent mechanical properties.However,owing t... The multi-principal element characteristic of high-entropy alloys has revolutionized the conventional alloy design concept of single-principal element,endowing them with excellent mechanical properties.However,owing to this multi-principal element nature,high-entropy alloys exhibit complex deformation behavior dominated by alternating and coupled deformation mechanisms.Therefore,elucidating these intricate deformation mechanisms remains a key challenge in current research.Neutron diffraction(ND)techniques offer distinct advantages over traditional microscopic methods for characterizing such complex deformation behavior.The strong penetration capability of neutrons enables in-situ,real-time,and non-destructive detection of structural evolution in most centimeter-level bulk samples under complex environments,and ND allows precise characterization of lattice site occupations for light elements,such as C and O,and neighboring elements.This review discussed the principles of ND,experiment procedures,and data analysis.Combining with recent advances in the research about face-centered cubic high-entropy alloy,typical examples of using ND to investigate the deformation behavior were summarized,ultimately revealing deformation mechanisms dominated by dislocations,stacking faults,twinning,and phase transformations. 展开更多
关键词 high-entropy alloys neutron diffraction face centered-cubic structure deformation mechanism
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Independent sampling and padding for Rayleigh-Sommerfeld diffraction based on scaled convolution approach
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作者 YANG Chen FU Xi-hong +1 位作者 FU Xin-peng BAYANHESHIG 《中国光学(中英文)》 北大核心 2026年第2期367-381,共15页
We propose a novel fast numerical calculation method for the Rayleigh-Sommerfeld diffraction integral,which is developed based on the existing scaled convolution method.This approach enables fast cal-culations for gen... We propose a novel fast numerical calculation method for the Rayleigh-Sommerfeld diffraction integral,which is developed based on the existing scaled convolution method.This approach enables fast cal-culations for general cases of off-axis scenarios where the sampling intervals and numbers of the input and observation planes are unequal.Additionally,it allows for arbitrary adjustment of the sampling interval of the impulse response function,facilitating a manual trade-off between computational load and accuracy.The er-rors associated with this method,which is equivalent to interpolation,primarily arise from the discontinuities of the sampling matrix of the impulse response function on its boundaries of periodic extension.To address this issue,we propose the concept of the padding function and its construction method,and evaluate its ef-fectiveness in enhancing computational accuracy.The feasibility of the proposed method is verified by nu-merical simulation and compared with the direct integration DI-method in a simplified scenario.It shows that the proposed method has good computational accuracy for the general case where the sampling interval of the input and observation plane is not equal under non-near-field diffraction,and when the diffraction distance is large,although the computational accuracy of the proposed method cannot exceed that of the DI-method,the computational amount can be significantly reduced with almost no effect on the computational accuracy.This method provides a general numerical calculation scheme of diffraction in the non-near field case for areas such as computational holography. 展开更多
关键词 Rayleigh-Sommerfeld diffraction scaled convolution padding function
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Illusion Optics via Phase-Gradient Metasurfaces
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作者 Zhaoyao Pan Jinpeng Yang Yadong Xu 《Chinese Physics Letters》 2026年第1期31-36,共6页
Optical phase-gradient metasurfaces have garnered significant attention for enabling flexible light manipulation,with applications across diverse domains.In this work,we will demonstrate that the metasurfaces with pha... Optical phase-gradient metasurfaces have garnered significant attention for enabling flexible light manipulation,with applications across diverse domains.In this work,we will demonstrate that the metasurfaces with phase gradient modulation can be used to achieve illusion optics,featuring the advantages of simple geometric structure and feasible implementation compared with the well-known transformation optics method.The underlying mechanism is the anomalous diffraction law caused by the phase gradient,which provides a theoretical basis for freely manipulating the propagation path of light.By considering a specific example,we will demonstrate that the phase gradient can transform spatial coordinates in real space into illusion space,thereby converting a plane in real space into a curved surface structure in illusion space to achieve the illusion effect.This approach provides a viable alternative to transformation optics for designing illusion devices. 展开更多
关键词 transformation optics anomalous diffraction law illusion opticsfeaturing flexible light manipulationwith illusion optics anomalous diffraction phase gradient modulation phase gradient metasurfaces
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Cross-scale multiplane holograms with decoupled input-output sampling for vehicle display
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作者 Xiaohang Sheng Shaodong Zhou +5 位作者 Dong Zhao Li Ding Kun Huang Guanxue Wang Songlin Zhuang Qingqing Cheng 《Advanced Photonics Nexus》 2026年第1期101-110,共10页
Head-up displays(HUDs)are emerging as key components of intelligent vehicles,requiring wide-depth,large-area,and high-efficiency dynamic imaging,which remains difficult to realize with traditional refractive optics.Co... Head-up displays(HUDs)are emerging as key components of intelligent vehicles,requiring wide-depth,large-area,and high-efficiency dynamic imaging,which remains difficult to realize with traditional refractive optics.Computer-generated holography(CGH)with diffraction optics offers a promising solution to these technical demands.However,CGH optimization based on the fast Fourier transform(FFT)faces limitations such as zero-padding redundancy,coupled sampling intervals,and incompatible near-and farfield propagation models.Here,we report a holography-based multiplane HUD using a matrix multiplication(MM)-assisted diffraction algorithm that restructures the Fresnel integral into two sequential matrix operations,thus eliminating zero-padding and enabling fully decoupled sampling between object and image planes.Compared with FFT-based angular spectrum methods,the MM approach significantly improves computational speed and memory efficiency for hologram design,which is validated by demonstrating dual-plane holography with a size ratio exceeding 100:1 and unified reconstruction across Fresnel and Fraunhofer regimes within a single computation.A prototype HUD system is demonstrated successfully to exhibit multiple-plane holographic virtual images that can be mixed with real-world objects at three independent planes.The technique might be one of the potential candidates for next-generation intelligent vehicle displays. 展开更多
关键词 computer-generated holography diffraction theory matrix multiplication head-up display multi-plane imaging
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Revision of the absolute configurations of Pallavicinia diterpenoids and further discovery of their Diels-Alder cycloadducts
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作者 Jiao-Zhen Zhang Cheng-Min Zhang +7 位作者 Yong-Jie Wang Pei-Lin Wu Rui-Feng Liu Ye Li Ming-Zhu Zhu Shuang-Zhi Yuan Ze-Jun Xu Hong-Xiang Lou 《Chinese Chemical Letters》 2026年第1期394-398,共5页
Owing to their intricate molecular frameworks and copious chiral centers,the structural identification and configurational assignment of natural products are challenging tasks.Comprehensive spectral data analysis is c... Owing to their intricate molecular frameworks and copious chiral centers,the structural identification and configurational assignment of natural products are challenging tasks.Comprehensive spectral data analysis is crucial for the confirmation of absolute configurations.Ignoring critical parameters will lead to false structure,which may confuse the total synthesis and drug development.Herein,the configurations of seven heterogeneous Pallavicinia diterpenoids(PDs) isolated from Pallavicinia liverworts are revised using a combination of single-crystal X-ray diffraction and electronic circular dichroism(ECD) calculations.Meanwhile,identification of five unprecedented PD heterodimers PD-dimers A-E(18-22) along with eleven previously undescribed PDs(5-9,13-17,23) obtained by the reinvestigation of the Chinese liverwort Pallavicinia subciliata have resulted in corrections and support the revised conclusions. 展开更多
关键词 REVISION Absolute configurations Pallavicinia diterpenoids LIVERWORT Single-crystal X-ray diffraction Electronic circular dichroism calculations
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Contrastive learning for data-efficient substrate deoxidation monitoring in edge-side adaptive molecular beam epitaxy systems
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作者 Yuehao Li Chao Shen +6 位作者 Wenkang Zhan Bo Xu Yazhou Yang Xu Zhang Hongchang Wang Chao Zhao Haifang Jian 《Journal of Semiconductors》 2026年第3期28-37,共10页
Accurate temperature control and effective oxide removal are essential for achieving high-quality epitaxial growth in molecular beam epitaxy(MBE).However,traditional methods often rely on manual identification of refl... Accurate temperature control and effective oxide removal are essential for achieving high-quality epitaxial growth in molecular beam epitaxy(MBE).However,traditional methods often rely on manual identification of reflection high-energy electron diffraction(RHEED)patterns.This process is heavily influenced by the grower’s experience,leading to issues with reproducibility and limiting the potential for automation.In this report,we propose an unsupervised learning framework for realtime RHEED analysis during the deoxidation process.By incorporating temporal similarity constraints into contrastive learning,our model generates smooth and interpretable feature trajectories that illustrate transitions in the deoxidation state,thus eliminating the need for manual labeling.The model,pre-trained using grouped contrastive loss,shows significant improvement in RHEED feature boundary discrimination and localization of critical regions.We evaluated its generalizability through two transfer learning strategies:calibration-free clustering and few-shot fine-tuning.The pre-trained model achieved a clustering accuracy of 88.1%for GaAs deoxidation samples without additional labels and reached an accuracy of 94.3%to 95.5%after fine-tuning with just five sample pairs across GaAs,Ge,and InAs substrates.This framework is optimized for resource-constrained edge devices,allowing for real-time,plug-and-play integration with existing MBE systems and swift adaptation across various materials and equipment.This work paves the way for greater automation and improved reproducibility in semiconductor manufacturing. 展开更多
关键词 contrastive learning molecular beam epitaxy real-time control reflection high-energy electron diffraction
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Optical temporal interference model for investigation and manipulation of non-integer high-order harmonic generation
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作者 Zhao-Yue Meng Yun Pan +1 位作者 Jun-Ping Wang Xi Zhao 《Chinese Physics B》 2026年第2期433-441,共9页
High-precision optical frequency measurement serves as a cornerstone of modern science and technology,enabling advancements in fields ranging from fundamental physics to quantum information technologies.Obtaining prec... High-precision optical frequency measurement serves as a cornerstone of modern science and technology,enabling advancements in fields ranging from fundamental physics to quantum information technologies.Obtaining precise photon frequencies,especially in the ultraviolet or even extreme ultraviolet regimes,is a key goal in both light–matter interaction experiments and engineering applications.High-order harmonic generation(HHG)is an ideal light source for producing such photons.In this work,we propose an optical temporal interference model(OTIM)that establishes an analogy with multi-slit Fraunhofer diffraction(MSFD)to manipulate fine-frequency photon generation by exploiting the temporal coherence of HHG processes.Our model provides a unified physical framework for three distinct non-integer HHG generation schemes:single-pulse,shaped-pulse,and laser pulse train approaches,which correspond to single-MSFD-like,double-MSFD-like,and multi-MSFD-like processes,respectively.Arbitrary non-integer HHG photons can be obtained using our scheme.Our approach provides a new perspective for accurately measuring and controlling photon frequencies in fields such as frequency comb technology,interferometry,and atomic clocks. 展开更多
关键词 high-order harmonic generation optical temporal interference multi-slit Fraunhofer diffraction
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A comprehensive understanding of the structural evolution and capacity contribution of fast-charging NCM cathodes
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作者 Chao Wang Yuying Zhang +7 位作者 Zhenzhong Li Jianwen Wang Huiyan Zeng Jiajun Chen Yitao Liu Mengxian Li Shaofei Wang Chunzhen Yang 《Journal of Energy Chemistry》 2026年第3期183-193,共11页
Achieving extreme fast charging(XFC,-6 C)capability remains a challenge for Li ion batteries in electric vehicle applications.This work employs time-resolved X-ray diffraction(XRD)to investigate the structural evoluti... Achieving extreme fast charging(XFC,-6 C)capability remains a challenge for Li ion batteries in electric vehicle applications.This work employs time-resolved X-ray diffraction(XRD)to investigate the structural evolution and capacity contributions of a series of LiNi_(x)Co_(y)Mn_(z)O_(2)(x+y+z=1,NCM)cathodes under XFC conditions.All NCM cathodes(NCM-92,NCM-83,and NCM-622)deliver -60%of their capacities with less than 2%unit cell volume expansion during the H1-H2 phase transition,but the subsequent H2-H3 phase transition exhibits significant compositional and rate dependence.The NCM-92 cathode shows a maximum d-spacing shrinkage of-5.3%at 6 C,which is larger than that of NCM-83(-4.1%)and NCM-622(-0.05%).Furthermore,NCM-92 follows a“phase heterogeneity”pathway for its structural evolution above 4.2 V,distinct from the“solid-solution”pathway observed in NCM-83 and NCM-622.This phase heterogeneity is evidenced by the splitting of the(003)diffraction peak and a decrease in intensity during the H2-H3 phase transition,indicating the formation of lithium-rich/depleted domains.These findings establish a direct correlation between cathode composition,structural dynamics,and XFC performance,highlighting a critical trade-off between structural stability and fast-charging capability in nickel-rich layered oxides. 展开更多
关键词 Extreme fast charge(XFC)batteries Time-resolved X-ray diffraction(XRD) Structural evolutions Rate performance
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Crystal Structure Solution of Radiation-Sensitive Porous Framework CL30 by Low-Dose Cryo 3D Electron Diffraction
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作者 Ke Wang Dapeng Sun +5 位作者 Penghe Li Zhiyuan Mao Yi Luo Hongxia Wang Hongyi Xu Yumei Wang 《Chinese Physics Letters》 2026年第3期294-299,共6页
To overcome the limitations of traditional single-crystal X-ray diffraction(SCXRD)for microcrystalline materials and the peak-overlapping issue of powder X-ray diffraction(PXRD),this study employed cryogenic continuou... To overcome the limitations of traditional single-crystal X-ray diffraction(SCXRD)for microcrystalline materials and the peak-overlapping issue of powder X-ray diffraction(PXRD),this study employed cryogenic continuous rotation electron diffraction(cryo-cRED)with a low-dose strategy to determine the crystal structure of CL30,a novel silicogermanate framework.It is confirmed that CL30 crystallizes in the C2/m space group and has layered topology composed of discontinuous zigzag chains connected by double four-membered ring(d4r)units,with fluoride anions(F^(-))occluded in the d4r units.In CL30,charge balance involves organic structure-directing agent(OSDA)cations,occluded F^(-),and terminal oxygen sites whose protonation state cannot be established from the present three dimensional(3D)ED data.F^(-)encapsulated in the d4r units contributes to charge compensation as the counter-anion to OSDA cations,rather than only balancing the framework charge.Although the refinement indices(R_(1)=0.29,wR_(2)=0.71)exceeded typical small-molecule crystallography standards,the structural model remained highly reliable,as supported by geometric restraints and validation.In electron diffraction,elevated R_(1) values are commonly attributed to the intrinsic factors of the technique,such as dynamic scattering,detector noise from scintillator-based detectors,and TEM stage instability(large spheres of confusion).This study introduces a new structural prototype to the silicogermanate family and establishes a feasible workflow for determining the structures of radiation-sensitive microcrystalline porous materials. 展开更多
关键词 discontinuous zigzag chains low dose cryo d electron diffraction c m space group crystal structure radiation sensitive porous framework silicogermanate layered topology silicogermanate frameworkit
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Insight into the Fe-rich phases strengthening mechanisms of non-heat-treatable Al-Mg-Mn-Fe-Cu alloys 被引量:2
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作者 Yuliang Zhao Weixiang He +9 位作者 Feiyu Zhao Chenghao Song Weiwen Zhang Dongfu Song Yue Tang Zhenzhong Sun Wen Yin Yanling Xue Runxia Li Ricardo Fernandez 《Journal of Materials Science & Technology》 2025年第2期232-246,共15页
This paper examines the effect of Fe addition on the microstructure characterized by scanning electron microscopy/electron backscattered diffraction,neutron diffraction,and synchrotron X-ray tomography and the mechani... This paper examines the effect of Fe addition on the microstructure characterized by scanning electron microscopy/electron backscattered diffraction,neutron diffraction,and synchrotron X-ray tomography and the mechanical properties of Al-Mg-Mn-Fe-Cu alloys.The findings reveal that the microstructures of the alloys consisted of an Al matrix,Al_(6)(FeMn),and Al_(2)CuMg phase particles.The addition of Fe significantly increased the yield strength(YS),and ultimate tensile strength(UTS)of the alloys,while reducing elongation.The transformation of the 3D morphology of the Al_(6)(FeMn)phase from separated and fine particles with Chinese-script morphology to interconnected rod-like structure as Fe content increased from 0.1%to 0.8%.This strengthening effect was attributed to the slip lines being blocked at the vicinity of the inter-connected Fe-rich phase,leading to grain rotation and dislocation density increment around the Fe-rich phase,ultimately improving the strength of the alloys.However,the Fe-rich phases and Al_(2)CuMg phases were found to be prone to cracking under tensile stress,resulting in decreased elongation of the alloys.This study provides a potential application in the design and manufacturing of new non-heat-treatable Al alloys for the automotive industry. 展开更多
关键词 Al alloy Fe-rich phase Synchrotron X-ray tomography Neutron diffraction In-situ EBSD Strengthening
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Chaeglobol A,an unusual octocyclic sterol with antifungal activity from the marine-derived fungus Chaetomium globosum HBU-45 被引量:2
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作者 Yun-Feng Liu Hui-Fang Du +4 位作者 Ya-Hui Zhang Zhi-Qin Liu Xiao-Qian Qi Du-Qiang Luo Fei Cao 《Chinese Chemical Letters》 2025年第3期407-410,共4页
Chemical investigation of the marine-derived fungus Chaetomium globosum HBU-45 led to the discovery of chaeglobol A(1).Its structure was determined by spectroscopic analysis,computational electronic circular dichroism... Chemical investigation of the marine-derived fungus Chaetomium globosum HBU-45 led to the discovery of chaeglobol A(1).Its structure was determined by spectroscopic analysis,computational electronic circular dichroism(ECD)/optical rotatory dispersion(ORD)methods,and X-ray crystallography.Compound 1 represents a new skeleton with an uncommon 6/6/6/5/6/5/6/5 octacyclic system,which is presumably biosynthesized via a[4+2]cycloaddition and an enzymatic cyclization.Chaeglobol A(1)exhibited inhibitory activity against B.dothidea by destroying cell membrane integrity and causing oxidative damage within the cells. 展开更多
关键词 Marine-derived fungus Chaetomium globosum Octocyclic sterol Antifungal activity Single-crystal X-ray diffraction
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Controllable two-dimensional asymmetric diffraction grating via vortex light in a semiconductor double quantum wells system 被引量:1
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作者 Kunpeng Zhao Duo Zhang +1 位作者 Junbing Guo Jiaqian Li 《Communications in Theoretical Physics》 2025年第8期49-58,共10页
We present a theoretical scheme to realize two-dimensional(2D)asymmetric diffraction grating in a five-level inverted Y-type asymmetric double semiconductor quantum wells(SQWs)structure with resonant tunneling.The SQW... We present a theoretical scheme to realize two-dimensional(2D)asymmetric diffraction grating in a five-level inverted Y-type asymmetric double semiconductor quantum wells(SQWs)structure with resonant tunneling.The SQW structure interacts with a weak probe laser field,a spatially independent 2D standing-wave(SW)field,and a Laguerre–Gaussian(LG)vortex field,respectively.The results indicate that the diffraction patterns are highly sensitive to amplitude modulation and phase modulation.Because of the existence of vortex light,it is possible to realize asymmetric high-order diffraction in the SQW structure,and then a 2D asymmetric grating is established.By adjusting the detunings of the probe field,vortex field,and SW field,as well as the interaction length,diffraction intensity,and direction of the 2D asymmetric electromagnetically induced grating(EIG)can be controlled effectively.In addition,the number of orbital angular momenta(OAM)and beam waist parameter can be used to modulate the diffraction intensity and energy transfer of the probe light in different regions.High-order diffraction intensity is enhanced and high-efficiency 2D asymmetric diffraction grating with different diffraction patterns is obtained in the scheme.Such 2D asymmetric diffraction grating may be beneficial to the research of optical communication and innovative semiconductor quantum devices. 展开更多
关键词 asymmetric diffraction grating standing-wave field laguerre-gaussian vortex field diffraction property semiconductor quantum well
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Out-of-plane ordered quaternary borides M'_(4)VSiB_(2) (M'=Nb and Mo): Experimental and theoretical investigations 被引量:1
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作者 He Chong Chaobo Wang +9 位作者 Zhaohui Chen Ni Zhao Hongyun Guo Xiaobai Ma Dongfeng Chen Kai Sun Wenyun Yang Jinbo Yang Qiang Wang Weibin Cui 《Journal of Materials Science & Technology》 2025年第25期234-240,共7页
Two novel out-of-plane ordered quaternary borides M'_(4)VSiB_(2) (M'=Nb and Mo) have been synthesized. The out-of-plane ordered characteristic has been confirmed by the X-ray diffraction, the neutron powder di... Two novel out-of-plane ordered quaternary borides M'_(4)VSiB_(2) (M'=Nb and Mo) have been synthesized. The out-of-plane ordered characteristic has been confirmed by the X-ray diffraction, the neutron powder diffraction and the scanning transmission electron microscopy with high-angle angular dark field images. By adjusting the stoichiometric ratio of Mo and V, the 16l site preferentially occupied by relatively larger atom and 4c site by relatively smaller atom have been confirmed. The further first-principle calculation demonstrates the dynamical and thermodynamical stability of Mo_(4)VSiB_(2) o-T2 phase. This work confirms the transition metal occupation strategy of o-T2 phase and enriches the out-of-plane ordered laminated borides family. 展开更多
关键词 Neutron powder diffraction o-T2 phase Out-of-plane chemical ordered Nanolaminated boride
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Effect of preprocessing on performances of machine learning-based mineral composition analysis on gas hydrate sediments,Ulleung Basin,East Sea 被引量:1
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作者 Hongkeun Jin Ju Young Park +3 位作者 Sun Young Park Byeong-Kook Son Baehyun Min Kyungbook Lee 《Petroleum Science》 2025年第1期151-162,共12页
Gas hydrate(GH)is an unconventional resource estimated at 1000-120,000 trillion m^(3)worldwide.Research on GH is ongoing to determine its geological and flow characteristics for commercial produc-tion.After two large-... Gas hydrate(GH)is an unconventional resource estimated at 1000-120,000 trillion m^(3)worldwide.Research on GH is ongoing to determine its geological and flow characteristics for commercial produc-tion.After two large-scale drilling expeditions to study the GH-bearing zone in the Ulleung Basin,the mineral composition of 488 sediment samples was analyzed using X-ray diffraction(XRD).Because the analysis is costly and dependent on experts,a machine learning model was developed to predict the mineral composition using XRD intensity profiles as input data.However,the model’s performance was limited because of improper preprocessing of the intensity profile.Because preprocessing was applied to each feature,the intensity trend was not preserved even though this factor is the most important when analyzing mineral composition.In this study,the profile was preprocessed for each sample using min-max scaling because relative intensity is critical for mineral analysis.For 49 test data among the 488 data,the convolutional neural network(CNN)model improved the average absolute error and coefficient of determination by 41%and 46%,respectively,than those of CNN model with feature-based pre-processing.This study confirms that combining preprocessing for each sample with CNN is the most efficient approach for analyzing XRD data.The developed model can be used for the compositional analysis of sediment samples from the Ulleung Basin and the Korea Plateau.In addition,the overall procedure can be applied to any XRD data of sediments worldwide. 展开更多
关键词 Sample-based preprocessing X-ray diffraction(XRD) Machine learning Mineral composition Gas hydrate(GH) Ulleung basin
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Effect of post weld heat treatment on grain boundary character distribution and corrosion resistance of friction stir welded armourgrade nickel and molybdenum-free high-nitrogen austenitic stainless steel 被引量:1
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作者 Arun Kumar Gurrala Raffi Mohammed G Madhusudhan Reddy 《Defence Technology(防务技术)》 2025年第9期246-261,共16页
This study examines the effects of friction stir welding(FSW)and post-weld heat treatment(PWHT)on the grain boundary character distribution and corrosion resistance of cross sectional(top and bottom)regions of nickel-... This study examines the effects of friction stir welding(FSW)and post-weld heat treatment(PWHT)on the grain boundary character distribution and corrosion resistance of cross sectional(top and bottom)regions of nickel-and molybdenum-free high-nitrogen austenitic stainless steel(HNASS).FSW at 400 rpm and 30 mm/min resulted in finer grains(4.18μm)and higher coincident site lattice(CSL)boundaries(32.3%)at the top of the stir zone(SZ)due to dynamic recrystallization(DRX).PWHT at 900℃for 1 h led to grain coarsening(12.91μm the bottom SZ)but enhanced CSL boundaries from 24.6%to 30.2%,improving grain boundary stability.PWHT reduced the kernel average misorientation(KAM)by 14.9%in the SZ-top layer and 20.4%in the SZ-bottom layer,accompanied by a 25%decrease in hardness in the SZ-top layer and 26.7%in the SZ-bottom layer,indicating strain recovery and reduced dislocation density.Potentiodynamic polarization tests(PDP)showed a 18%increase in pitting potential and a 76%reduction in corrosion rate after PWHT.The improvement in corrosion resistance is attributed to the increase inΣ3 twin boundaries,which enhance grain boundary stability and reduce susceptibility to localized corrosion.These findings highlight the role of PWHT in refining the microstructure and strengthening corrosion resistance,making HNASS a promising material for demanding applications. 展开更多
关键词 Nickel and molybdenum free high-nitrogen austenitic stainless steel Friction stir welding Post-weld heat treatment Electron backscattered diffraction Microstructural gradients Pitting corrosion resistance Coincident site lattice Grain boundary characteristic distribution
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Improvement of Lattice Parameter Accuracy in Single Crystal XRD Based on a Laser-Induced X-Ray Source
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作者 LIU Jin WANG Qiannan LI Jiangtao 《高压物理学报》 北大核心 2025年第4期9-15,共7页
The lattice parameter,measured with sufficient accuracy,can be utilized to evaluate the quality of single crystals and to determine the equation of state for materials.We propose an iterative method for obtaining more... The lattice parameter,measured with sufficient accuracy,can be utilized to evaluate the quality of single crystals and to determine the equation of state for materials.We propose an iterative method for obtaining more precise lattice parameters using the interaction points for the pseudo-Kossel pattern obtained from laser-induced X-ray diffraction(XRD).This method has been validated by the analysis of an XRD experiment conducted on iron single crystals.Furthermore,the method was used to calculate the compression ratio and rotated angle of an LiF sample under high pressure loading.This technique provides a robust tool for in-situ characterization of structural changes in single crystals under extreme conditions.It has significant implications for studying the equation of state and phase transitions. 展开更多
关键词 lattice parameter measurement accuracy single crystal X-ray diffraction iterative algorithm high pressure ratio of compression
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Microscopic characterization and analysis of nickel-plated steel coatings
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作者 GU Jiaqing LI Xiujun DENG Zhaojun 《Baosteel Technical Research》 2025年第1期17-27,共11页
Employing experimental equipment and techniques,such as electron backscatter diffraction,transmission Kikuchi diffraction,and transmission electron microscopy,the microstructure,phase structure,and orientation relatio... Employing experimental equipment and techniques,such as electron backscatter diffraction,transmission Kikuchi diffraction,and transmission electron microscopy,the microstructure,phase structure,and orientation relationships of 0.6μm electroplated nickel(Ni)steel following annealing at 580-650℃for 15-30 hours were investigated.A comprehensive analysis was conducted to gain insights into the complex changes in the material's properties due to the annealing process.The results reveal that prolonged annealing led to considerable long-range diffusion of surface Ni atoms into the substrate of the 0.6μm Ni-plated steel.This diffusion process resulted in the formation of an alloy diffusion layer,approximately 4μm in thickness,which altered the material's microstructural characteristics.The extent of diffusion and its effect on the microstructure and structure were meticulously quantified.At the annealing temperature,the diffused Ni in the substrate,acting as an austenite-stabilizing element,expanded the austenite phase region.The alloy layer at this temperature predominantly consisted of the face-centered cubic(FCC)-structuredγ(Fe,Ni)solid solution.Upon cooling to room temperature,the alloy diffusion layer evolved into a dual-layer composite structure.The upper layer mainly comprised the FCC-structuredγ(Fe,Ni)solid solution,interspersed with a minor FCC compound superstructure phase.The lower layer underwent a diffusionless phase transformation during cooling,which led to the formation of the body-centered tetragonal/body-centered cubic-structured martensite.This phase,which is known for its high hardness and numerous variants,maintained the classic Kurdjumov-Sachs orientation relationship with the upper FCC parent phase,and it satisfied the close-packed plane{111}γ//{110}α′and close-packed direction<110>γ//<111>α′.A detailed analysis of the different phases within the alloy layer and their phase transitions was presented,offering an in-depth understanding of the material's characteristics. 展开更多
关键词 nickel-plated steel electron backscatter diffraction transmission Kikuchi diffraction transmission electron microscopy SUPERSTRUCTURE
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Diffraction classification imaging using coordinate attention enhanced DenseNet
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作者 Tong-Jie Sheng Jing-Tao Zhao +2 位作者 Su-Ping Peng Zong-Nan Chen Jie Yang 《Petroleum Science》 2025年第6期2353-2383,共31页
In oil and gas exploration,small-scale karst cavities and faults are important targets.The former often serve as reservoir space for carbonate reservoirs,while the latter often provide migration pathways for oil and g... In oil and gas exploration,small-scale karst cavities and faults are important targets.The former often serve as reservoir space for carbonate reservoirs,while the latter often provide migration pathways for oil and gas.Due to these differences,the classification and identification of karst cavities and faults are of great significance for reservoir development.Traditional seismic attributes and diffraction imaging techniques can effectively identify discontinuities in seismic images,but these techniques do not distinguish whether these discontinuities are karst cavities,faults,or other structures.It poses a challenge for seismic interpretation to accurately locate and classify karst cavities or faults within the seismic attribute maps and diffraction imaging profiles.In seismic data,the scattering waves are associated with small-scale scatters like karst cavities,while diffracted waves are seismic responses from discontinuous structures such as faults,reflector edges and fractures.In order to achieve classification and identification of small-scale karst cavities and faults in seismic images,we propose a diffraction classification imaging method which classifies diffracted and scattered waves in the azimuth-dip angle image matrix using a modified DenseNet.We introduce a coordinate attention module into DenseNet,enabling more precise extraction of dynamic and azimuthal features of diffracted and scattered waves in the azimuth-dip angle image matrix.Leveraging these extracted features,the modified DenseNet can produce reliable probabilities for diffracted/scattered waves,achieving high-accuracy automatic classification of cavities and faults based on diffraction imaging.The proposed method achieves 96%classification accuracy on the synthetic dataset.The field data experiment demonstrates that the proposed method can accurately classify small-scale faults and scatterers,further enhancing the resolution of diffraction imaging in complex geologic structures,and contributing to the localization of karstic fracture-cavern reservoirs. 展开更多
关键词 Diffraction imaging Diffraction classification Azimuth-dip angle image matrix Coordinate attention DenseNet
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Second Harmonic-Induced Ultrafast Wrinkle Formation in Two-Dimensional Material
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作者 Xiaodong Wang Yongzhao Zhang +3 位作者 Shuaishuai Sun Jun Li Shaobo Cheng Huaixin Yang 《Chinese Physics Letters》 2025年第4期73-84,共12页
The precise control of wrinkles and strain gradients in nanofilm is of significant interest due to their profound influence on electronic band structures and spin states.Here,we employ ultrafast electron diffraction(U... The precise control of wrinkles and strain gradients in nanofilm is of significant interest due to their profound influence on electronic band structures and spin states.Here,we employ ultrafast electron diffraction(UED)to study the picosecond-scale dynamics of laser-induced bending in 2H-MoTe2 thin films. 展开更多
关键词 second harmonic ultrafast electron diffraction ued laser induced bending picosecond dynamics control wrinkles strain gradients ultrafast wrinkling two dimensional materials ultrafast electron diffraction
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Effect of wood vinegar on the release of calcium,magnesium,and phosphorus from calcareous soils in different land uses
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作者 Soheila Sadat HASHEMI 《Journal of Arid Land》 2025年第5期680-695,共16页
The release of essential nutrients from soil minerals for plant growth in calcareous soils,facilitated by organic extractants,is critical in semi-arid areas,particularly for elements affected by high soil pH.This stud... The release of essential nutrients from soil minerals for plant growth in calcareous soils,facilitated by organic extractants,is critical in semi-arid areas,particularly for elements affected by high soil pH.This study aims to investigate the release of calcium(Ca),magnesium(Mg),and phosphorus(P)through the application of wood vinegar extract in surface calcareous soils in Borojerd City,Lorestan Province,Iran.The experiment was conducted using a completely randomized design with three replications.The treatments included soils from three different land uses:vineyard,wheat field,and rangeland,each treated with 1.00%wood vinegar solution.Cumulative measurements of the specified elements were recorded over 10 consecutive 0.5 h intervals.The release data were analyzed using four various kinetic models(Elovich equation,parabolic diffusion law,power function equation,and zero-order kinetics).The highest concentrations recorded were for Ca(39,500.00 mg/kg),Mg(5880.00 mg/kg),and P(5.00 mg/kg)in grape cultivation.The findings revealed a significant difference in Ca release between grape cultivation and rangeland(P<0.01),while the Mg release showed a significant difference between both grape cultivation and rangeland and wheat cultivation(P<0.01).Additionally,the cumulative release of P showed significant differences between grape cultivation and both wheat and rangeland(P<0.01).The results indicated that the zero-order kinetics provided the best fit for the data(R^(2)=0.99).The maximum initial release amount was observed in grape cultivation when applying the zero-order kinetics,while the highest release rate was achieved using the parabolic diffusion law across three applications.Wood vinegar had the capacity to degrade various clay minerals,including vermiculite,smectite,palygorskite,and,to some extent,illite,resulting in the release of associated elements.Consequently,it can be concluded that wood vinegar can be effectively utilized in grape cultivation as an agent for reducing soil acidity,thereby enhancing the availability of soil nutrients and decreasing reliance on chemical fertilizers. 展开更多
关键词 X-ray diffraction kinetics analysis VINEYARD wheat field RANGELAND VERMICULITE
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