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Efficient fundamental frequency transformation for voice conversion
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作者 宋鹏 金赟 +2 位作者 包永强 赵力 邹采荣 《Journal of Southeast University(English Edition)》 EI CAS 2012年第2期140-144,共5页
In order to improve the performance of voice conversion, the fundamental frequency (F0) transformation methods are investigated, and an efficient F0 transformation algorithm is proposed. First, unlike the traditiona... In order to improve the performance of voice conversion, the fundamental frequency (F0) transformation methods are investigated, and an efficient F0 transformation algorithm is proposed. First, unlike the traditional linear transformation methods, the relationships between F0s and spectral parameters are explored. In each component of the Gaussian mixture model (GMM), the F0s are predicted from the converted spectral parameters using the support vector regression (SVR) method. Then, in order to reduce the over- smoothing caused by the statistical average of the GMM, a mixed transformation method combining SVR with the traditional mean-variance linear (MVL) conversion is presented. Meanwhile, the adaptive median filter, prevalent in image processing, is adopted to solve the discontinuity problem caused by the frame-wise transformation. Objective and subjective experiments are carried out to evaluate the performance of the proposed method. The results demonstrate that the proposed method outperforms the traditional F0 transformation methods in terms of the similarity and the quality. 展开更多
关键词 F0 prediction support vector regression meanvariance linear conversion adaptive median filter
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Effect of fluoride roasting on copper species transformation on chrysocolla surfaces and its role in enhanced sulfidation flotation
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作者 Yingqiang Ma Xin Huang +5 位作者 Yafeng Fu Zhenguo Song Sen Luo Shuanglin Zheng Feng Rao Wanzhong Yin 《International Journal of Minerals,Metallurgy and Materials》 2026年第1期165-176,共12页
It is difficult to recover chrysocolla from sulfidation flotation which is closely related to the mineral surface composition.In this study,the effects of fluoride roasting on the surface composition of chrysocolla we... It is difficult to recover chrysocolla from sulfidation flotation which is closely related to the mineral surface composition.In this study,the effects of fluoride roasting on the surface composition of chrysocolla were investigated,its impact on sulfidation flotation was explored,and the mechanisms involved in both fluoride roasting and sulfidation flotation were discussed.With CaF_(2)as the roasting reagent,Na_(2)S·9H_(2)O as the sulfidation reagent,and sodium butyl xanthate(NaBX)as the collector,the results of the flotation experiments showed that fluoride roasting improved the floatability of chrysocolla,and the recovery rate increased from 16.87%to 82.74%.X-ray diffraction analysis revealed that after fluoride roasting,approximately all the Cu on the chrysocolla surface was exposed in the form of CuO,which could provide a basis for subsequent sulfidation flotation.The microscopy and elemental analyses revealed that large quantities of"pagoda-like"grains were observed on the sulfidation surface of the fluoride-roasted chrysocolla,indicating high crystallinity particles of copper sulfide.This suggests that the effect of sulfide formation on the chrysocolla surface was more pronounced.X-ray photoelectron spectroscopy revealed that fluoride roasting increased the relative contents of sulfur and copper on the surface and that both the Cu~+and polysulfide fractions on the surface of the minerals increased.This enhances the effect of sulfidation,which is conducive to flotation recovery.Therefore,fluoride roasting improved the effect of copper species transformation and sulfidation on the surface of chysocolla,promoted the adsorption of collectors,and improved the recovery of chrysocolla from sulfidation flotation. 展开更多
关键词 sulfidation flotation CHRYSOCOLLA fluoride roasting copper species transformation enhanced sulfidation
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Tracking a High-Tech Transition--How technology is powering Guangdong’s manufacturing transformation
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作者 HU FAN 《ChinAfrica》 2026年第1期30-32,共3页
The moment a media delegation from the Republic of the Congo arrived at the Othello Kitchenware Museum on 18 November 2025,they were greeted with a vivid show of Guangdong’s industrial strength.Standing before them w... The moment a media delegation from the Republic of the Congo arrived at the Othello Kitchenware Museum on 18 November 2025,they were greeted with a vivid show of Guangdong’s industrial strength.Standing before them was not a typical exhibition hall,but a building shaped like a gleaming stainless-steel cooking pot. 展开更多
关键词 othello kitchenware museum TECHNOLOGY industrial strength high tech transition guangdong manufacturing transformation
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Characteristic changes in astrocyte properties during astrocyte-to-neuron conversion induced by NeuroD1/Ascl1/Dlx2 被引量:1
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作者 Qing He Zhen Wang +5 位作者 Yuchen Wang Mengjie Zhu Zhile Liang Kanghong Zhang Yuge Xu Gong Chen 《Neural Regeneration Research》 SCIE CAS 2025年第6期1801-1815,共15页
Direct in vivo conversion of astrocytes into functional new neurons induced by neural transcription factors has been recognized as a potential new therapeutic intervention for neural injury and degenerative disorders.... Direct in vivo conversion of astrocytes into functional new neurons induced by neural transcription factors has been recognized as a potential new therapeutic intervention for neural injury and degenerative disorders. However, a few recent studies have claimed that neural transcription factors cannot convert astrocytes into neurons, attributing the converted neurons to pre-existing neurons mis-expressing transgenes. In this study, we overexpressed three distinct neural transcription factors––NeuroD1, Ascl1, and Dlx2––in reactive astrocytes in mouse cortices subjected to stab injury, resulting in a series of significant changes in astrocyte properties. Initially, the three neural transcription factors were exclusively expressed in the nuclei of astrocytes. Over time, however, these astrocytes gradually adopted neuronal morphology, and the neural transcription factors was gradually observed in the nuclei of neuron-like cells instead of astrocytes. Furthermore,we noted that transcription factor-infected astrocytes showed a progressive decrease in the expression of astrocytic markers AQP4(astrocyte endfeet signal), CX43(gap junction signal), and S100β. Importantly, none of these changes could be attributed to transgene leakage into preexisting neurons. Therefore, our findings suggest that neural transcription factors such as NeuroD1, Ascl1, and Dlx2 can effectively convert reactive astrocytes into neurons in the adult mammalian brain. 展开更多
关键词 AQUAPORIN-4 Ascl1 ASTROCYTE cortex Dlx2 gap junction glia-to-neuron conversion neural regeneration NeuroD1 REPROGRAMMING
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基于Transformer-卷积神经网络模型实现单节点腰部康复训练动作识别任务
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作者 余圣涵 成贤锴 +1 位作者 郑跃 杨颖 《中国组织工程研究》 北大核心 2026年第16期4125-4136,共12页
背景:惯性测量单元被广泛用于人体姿态感知与动态捕捉。深度学习已逐步替代传统规则与特征工程,广泛应用于动作识别任务。卷积神经网络在提取局部动态特征方面表现良好,Transformer则在建模长时序依赖方面展现出强大能力。目的:通过基于... 背景:惯性测量单元被广泛用于人体姿态感知与动态捕捉。深度学习已逐步替代传统规则与特征工程,广泛应用于动作识别任务。卷积神经网络在提取局部动态特征方面表现良好,Transformer则在建模长时序依赖方面展现出强大能力。目的:通过基于Transformer-卷积神经网络融合模型识别方法,实现在单惯性传感器条件下的腰部康复训练动作识别任务。方法:采集6名健康受试者佩戴单个惯性传感器条件下执行腰部康复动作的加速度与角速度数据,以动作类型为数据进行标注,制作腰部康复动作数据集。通过腰部康复动作数据集对Transformer-卷积神经网络融合模型进行训练,构建动作分类模型。通过留一交叉验证评估模型准确性,并与线性判别分析、支持向量机、多层感知、经典Transformer等模型进行性能对比。结果与结论:在5类动作识别任务中,Transformer-卷积神经网络模型准确率达96.67%,F1-score为0.9669。在单传感器输入的条件下,相较于传统模型,在识别精度与泛化能力方面具有明显优势。验证了基于单惯性测量单元数据的深度模型在腰部康复动作分类任务中的实用性,为轻量化、高部署性的居家腰部康复训练系统提供基础。 展开更多
关键词 慢性腰痛 康复训练 深度学习 transformER 单节点惯性传感器 动作分类
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Conversion treatment for advanced intrahepatic cholangiocarcinoma:Opportunities and challenges 被引量:2
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作者 Jun-Jie Liu Mi Zhou +2 位作者 Tong Yuan Zhi-Yong Huang Zun-Yi Zhang 《World Journal of Gastroenterology》 2025年第15期24-41,共18页
The prevalence of intrahepatic cholangiocarcinoma(ICC)is increasing globally.Despite advancements in comprehending this intricate malignancy and formulating novel therapeutic approaches over the past few decades,the p... The prevalence of intrahepatic cholangiocarcinoma(ICC)is increasing globally.Despite advancements in comprehending this intricate malignancy and formulating novel therapeutic approaches over the past few decades,the prognosis for ICC remains poor.Owing to the high degree of malignancy and insidious onset of ICC,numerous cases are detected at intermediate or advanced stages of the disease,hence eliminating the chance for surgical intervention.Moreover,because of the highly invasive characteristics of ICC,recurrence and metastasis postresection are prevalent,leading to a 5-year survival rate of only 20%-35%following surgery.In the past decade,different methods of treatment have been investigated,including transarterial chemoembolization,transarterial radioembolization,radiotherapy,systemic therapy,and combination therapies.For certain patients with advanced ICC,conversion treatment may be utilized to facilitate surgical resection and manage disease progression.This review summarizes the definition of downstaging conversion treatment and presents the clinical experience and evidence concerning conversion treatment for advanced ICC. 展开更多
关键词 Intrahepatic cholangiocarcinoma conversion treatment DOWNSTAGING Combination therapy Chemotherapy IMMUNOTHERAPY Locoregional therapies
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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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Solvent engineering in perovskite nanocrystal colloid inks for super-fine electrohydrodynamic inkjet printing of color conversion microstructures in micro-LED displays 被引量:2
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作者 Shuli Wang Xuemin Kong +7 位作者 Siting Cai Yunshu Luo Yuxuan Gu Xiaotong Fan Guolong Chen Xiao Yang Zhong Chen Yue Lin 《Chinese Chemical Letters》 2025年第8期554-559,共6页
Super-fine electrohydrodynamic inkjet(SIJ)printing of perovskite nanocrystal(PNC)colloid ink exhibits significant potential in the fabrication of high-resolution color conversion microstructures arrays for fullcolor m... Super-fine electrohydrodynamic inkjet(SIJ)printing of perovskite nanocrystal(PNC)colloid ink exhibits significant potential in the fabrication of high-resolution color conversion microstructures arrays for fullcolor micro-LED displays.However,the impact of solvent on both the printing process and the morphology of SIJ-printed PNC color conversion microstructures remains underexplored.In this study,we prepared samples of CsPbBr3PNC colloid inks in various solvents and investigated the solvent's impact on SIJ printed PNC microstructures.Our findings reveal that the boiling point of the solvent is crucial to the SIJ printing process of PNC colloid inks.Only does the boiling point of the solvent fall in the optimal range,the regular positioned,micron-scaled,conical PNC microstructures can be successfully printed.Below this optimal range,the ink is unable to be ejected from the nozzle;while above this range,irregular positioned microstructures with nanoscale height and coffee-ring-like morphology are produced.Based on these observations,high-resolution color conversion PNC microstructures were effectively prepared using SIJ printing of PNC colloid ink dispersed in dimethylbenzene solvent. 展开更多
关键词 SOLVENT Perovskite nanocrystal Electrohydrodynamic inkjet printing Color conversion microstructures arrays Micro-LED display
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Interaction between dynamic recrystallization and phase transformation of Ti-43Al-4Nb-1Mo-0.2B alloy during hot deformation 被引量:2
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作者 Xiaofei Chen Bin Tang +5 位作者 Beibei Wei Wenxin Xu Biao Ma Jinhua Dai Guoming Zheng Jinshan Li 《Journal of Materials Science & Technology》 2025年第11期130-142,共13页
Theβsolidifiedγ-TiAl alloy holds important application value in the aerospace industry,while its com-plex phase compositions and geometric structures pose challenges to its microstructure control during the thermal-... Theβsolidifiedγ-TiAl alloy holds important application value in the aerospace industry,while its com-plex phase compositions and geometric structures pose challenges to its microstructure control during the thermal-mechanical process.The microstructure evolution of Ti-43Al-4Nb-1Mo-0.2B alloy at 1200℃/0.01 s−1 was investigated to clarify the coupling role of dynamic recrystallization(DRX)and phase transformation.The results revealed that the rate of DRX inα2+γlamellar colonies was comparatively slower than that inβo+γmixed structure,instead being accompanied by intense lamellar kinking and rotation.The initiation and development rates of DRX inα2,βo,andγphases decreased sequentially.The asynchronous DRX of the various geometric structures and phase compositions resulted in the un-even deformed microstructure,and the dynamic softening induced by lamellar kinking and rotation was replaced by strengthened DRX as strain increased.Additionally,the blockyα2 phase and the terminals ofα2 lamellae were the preferential DRX sites owing to the abundant activated slip systems.Theα2→βo transformation within lamellar colonies facilitated DRX and fragment ofα2 lamellae,while theα2→γtransformation promoted the decomposition ofα2 lamellae and DRX ofγlamellae.Moreover,the var-iedβo+γmixed structures underwent complicated evolution:(1)Theγ→βo transformation occurred at boundaries of lamellar colonies,followed by simultaneous DRX ofγlamellar terminals and neighboringβo phase;(2)DRX occurred earlier within the band-likeβo phase,with the delayed DRX in enclosedγphase;(3)DRX within theβo synapses and neighboringγphase was accelerated owing to generation of elastic stress field;(4)Dispersedβo particles triggered particle stimulated nucleation(PSN)ofγphase.Eventually,atomic diffusion along crystal defects inβo andγphases caused fracture of band-likeβo phase and formation of massiveβo particles,impeding grain boundary migration and hindering DRXed grain growth ofγphase. 展开更多
关键词 TiAl alloy Hot deformation Dynamic recrystallization Phase transformation
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Transformation of discarded biomass into value-added flexible electronic materials 被引量:1
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作者 Sijia Bao Xuenan Yang +2 位作者 Ziqi Yu Yuanbo Shi Yuan Lu 《Green Energy & Environment》 2025年第3期452-470,共19页
The development of electronic products and increased electronic waste have triggered a series of ecological problems on Earth.Meanwhile,amidst energy crises and the pursuit of carbon neutrality,the recycling of discar... The development of electronic products and increased electronic waste have triggered a series of ecological problems on Earth.Meanwhile,amidst energy crises and the pursuit of carbon neutrality,the recycling of discarded biomass has attracted the attention of many researchers.In recent years,the transformation of discarded biomass into value-added electronic products has emerged as a promising endeavor in the field of green and flexible electronics.In this review,the attempts and advancements in biomass conversion into flexible electronic materials and devices are systematically summarized.We focus on reviewing the research progress in biomass conversion into substrates,electrodes,and materials tailored for optical and thermal management.Furthermore,we explore component combinations suitable for applications in environmental monitoring and health management.Finally,we discuss the challenges in techniques and cost-effectiveness currently faced by biomass conversion into flexible electronic devices and propose improvement strategies.Drawing insights from both fundamental research and industrial applications,we offer prospects for future developments in this burgeoning field. 展开更多
关键词 Biomass conversion Flexible electronics Green process Sustainable development
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Construction of Vocational Education Quality Evaluation Index System from the Perspective of Digital Transformation Based on the Analytic Hierarchy Process of Higher Vocational Colleges in Hainan Province,China 被引量:1
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作者 Limei Fu 《Journal of Contemporary Educational Research》 2025年第1期282-289,共8页
In the context of the digital transformation of vocational education,a quality evaluation index system has been constructed.Based on a questionnaire survey conducted among higher vocational colleges and enterprises in... In the context of the digital transformation of vocational education,a quality evaluation index system has been constructed.Based on a questionnaire survey conducted among higher vocational colleges and enterprises in Hainan Province,it has been found that the quality of vocational education generally depends on the talent training program and professional construction at the macro level.At the meso level,the teacher level and teaching environment are critical,while at the micro level,the evaluation of talent training quality cannot be underestimated.Strategies for quality improvement in vocational education are proposed from the perspectives of talent training programs,major construction,teacher development,teaching environment,and talent training quality,all under the lens of digital transformation. 展开更多
关键词 Digital transformation Vocational education Evaluation index system
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Establishment of an efficient Agrobacterium rhizogenes-mediated hairy root transformation method for subtropical fruit trees 被引量:1
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作者 Mao Yin Yonghua Jiang +4 位作者 Yingjie Wen Fachao Shi Hua Huang Qian Yan Hailun Liu 《Horticultural Plant Journal》 2025年第4期1699-1702,共4页
Agrobacterium tumefaciens-mediated transformation has been widely adopted for plant genetic engineering and the study of gene function(Krenek et al.,2015).This method is prevalent in the genetic transformation of herb... Agrobacterium tumefaciens-mediated transformation has been widely adopted for plant genetic engineering and the study of gene function(Krenek et al.,2015).This method is prevalent in the genetic transformation of herbaceous plants,with notable applications in species such as Arabidopsis(Yin et al.,2024),soybean(Zhang et al.,2024),rice(Zhang et al.,2020),and Chinese cabbage(Li et al.,2021).However,its application in fruit trees is limited.This is primarily due to their long growth cycles and lack of rapid,efficient,and stable transgenic systems,which severely hinders foundational research involving plant genetic transformation(Mei et al.,2024).Furthermore,for subtropical fruit trees,the presence of recalcitrant seeds adds an extra layer of difficulty to genetic transformation(Umarani et al.,2015),as most methods rely on seed germination as a basis for transformation. 展开更多
关键词 study gene function krenek plant genetic engineering hairy root transformation fruit trees agrobacterium rhizogenes subtropical fruit trees genetic transformation chinese cabbage li
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Kinematics characteristics of unsprung mass in a double wishbone suspension based on velocity transformation 被引量:1
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作者 Yupeng Duan Jinglai Wu Yunqing Zhang 《Acta Mechanica Sinica》 2025年第2期184-203,共20页
The transformation from multibody models to lumped-parameter models is a crucial aspect of vehicle dynamics research.The velocity transformation method is adopted in this research,and the suspension multibody model is... The transformation from multibody models to lumped-parameter models is a crucial aspect of vehicle dynamics research.The velocity transformation method is adopted in this research,and the suspension multibody model is described using only one degree of freedom.It is found that the equivalent mass of the system is time-dependent during the simulation process,as observed in numerical simulations.Further symbolic calculations are conducted to derive the analytical form of the equivalent mass,and the results show that once the static parameters are determined,the equivalent mass of the suspension system is determined solely by the vertical position of the suspension upright,which reveals the kinematics characteristic of the equivalent mass of the suspension system.It is found that the equivalent mass experiences smaller changes when the suspension is compressed from the middle position,but larger changes when the suspension is extended.Furthermore,by comparing the multibody model,the lumped-parameter model with static mass,and the proposed lumped-parameter model considering the kinematics characteristic of the equivalent unsprung mass,the proposed model produces simulation results that more closely match the original multibody model than the model with static mass.The improvements in accuracy can be up to 20%under certain evaluation metrics. 展开更多
关键词 Multibody dynamics Velocity transformation SUSPENSION Model reduction Lumped-parameter model
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Unraveling the significance of cobalt on transformation kinetics,crystallography and impact toughness in high-strength steels
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作者 Yishuang Yu Jingxiao Zhao +3 位作者 Xuelin Wang Hui Guo Zhenjia Xie Chengjia Shang 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS 2025年第2期380-390,共11页
This work reveals the significant effects of cobalt(Co)on the microstructure and impact toughness of as-quenched highstrength steels by experimental characterizations and thermo-kinetic analyses.The results show that ... This work reveals the significant effects of cobalt(Co)on the microstructure and impact toughness of as-quenched highstrength steels by experimental characterizations and thermo-kinetic analyses.The results show that the Co-bearing steel exhibits finer blocks and a lower ductile-brittle transition temperature than the steel without Co.Moreover,the Co-bearing steel reveals higher transformation rates at the intermediate stage with bainite volume fraction ranging from around 0.1 to 0.6.The improved impact toughness of the Co-bearing steel results from the higher dense block boundaries dominated by the V1/V2 variant pair.Furthermore,the addition of Co induces a larger transformation driving force and a lower bainite start temperature(BS),thereby contributing to the refinement of blocks and the increase of the V1/V2 variant pair.These findings would be instructive for the composition,microstructure design,and property optimization of high-strength steels. 展开更多
关键词 high-strength steel COBALT transformation kinetics CRYSTALLOGRAPHY impact toughness
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Diamond related materials for energy storage and conversion applications
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作者 YU Si-yu WANG Xi-yan YANG Nian-jun 《新型炭材料(中英文)》 北大核心 2025年第4期973-992,共20页
Diamond combines many unique properties,including high stability,strong optical dispersion,excellent mechanical strength,and outstanding thermal conductivity.Its structure,surface groups,and electrical conductivity ar... Diamond combines many unique properties,including high stability,strong optical dispersion,excellent mechanical strength,and outstanding thermal conductivity.Its structure,surface groups,and electrical conductivity are also tunable,increasing its functional versatility.These make diamond and its related materials,such as its composites,highly promising for various applications in energy fields.This review summarizes recent advances and key achievements in energy storage and conversion,covering electrochemical energy storage(e.g.,batteries and supercapacitors),electrocatalytic energy conversion(e.g.,CO_(2)and nitrogen reduction reactions),and solar energy conversion(e.g.,photo-(electro)chemical CO_(2)and nitrogen reduction reactions,and solar cells).Current challenges and prospects related to the synthesis of diamond materials and the technologies for their energy applications are outlined and discussed. 展开更多
关键词 Diamond related materials Electrochemical energy storage Electrocatalytic energy conversion Solar energy conversion Future energy application directions
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Solar-driven methane-to-ethanol conversion by “intramolecular junction” with both high activity and selectivity 被引量:1
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作者 Qijun Tang Wenguang Tu Zhigang Zou 《Chinese Journal of Structural Chemistry》 2025年第6期6-7,共2页
Methane(CH4),the predominant component of natural gas and shale gas,is regarded as a promising carbon feedstock for chemical synthesis[1].However,considering the extreme stability of CH4 molecules,it's quite chall... Methane(CH4),the predominant component of natural gas and shale gas,is regarded as a promising carbon feedstock for chemical synthesis[1].However,considering the extreme stability of CH4 molecules,it's quite challenging in simultaneously achieving high activity and selectivity for target products under mild conditions,especially when synthesizing high-value C2t chemicals such as ethanol[2].The conversion of methane to ethanol by photocatalysis is promising for achieving transformation under ambient temperature and pressure conditions.Currently,the apparent quantum efficiency(AQE)of solar-driven methane-to-ethanol conversion is generally below 0.5%[3,4].Furthermore,the stability of photocatalysts remains inadequate,offering substantial potential for further improvement. 展开更多
关键词 natural gas shale gasis target products carbon feedstock chemical synthesis howeverconsidering intramolecular junction solar driven methane ethanol conversion
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A review of 3D graphene materials for energy storage and conversion
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作者 WU Zi-yuan XU Chi-wei +2 位作者 ZENG Jin-jue JIANG Xiang-fen WANG Xue-bin 《新型炭材料(中英文)》 北大核心 2025年第3期477-518,共42页
Three-dimensional(3D)graphene monoliths are a new carbon material,that has tremendous potential in the fields of energy conversion and storage.They can solve the limitations of two-dimensional(2D)graphene sheets,inclu... Three-dimensional(3D)graphene monoliths are a new carbon material,that has tremendous potential in the fields of energy conversion and storage.They can solve the limitations of two-dimensional(2D)graphene sheets,including interlayer restacking,high contact resistance,and insufficient pore accessibility.By constructing interconnected porous networks,3D graphenes not only retain the intrinsic advantages of 2D graphene sheets,such as high specific surface area,excellent electrical and thermal conductivities,good mechanical properties,and outstanding chemical stability,but also enable efficient mass transport of external fluid species.We summarize the fabrication methods for 3D graphenes,with a particular focus on their applications in energy-related systems.Techniques including chemical reduction assembly,chemical vapor deposition,3D printing,chemical blowing,and zinc-tiered pyrolysis have been developed to change their pore structure and elemental composition,and ways in which they can be integrated with functional components.In terms of energy conversion and storage,they have found broad use in buffering mechanical impacts,suppressing noise,photothermal conversion,electromagnetic shielding and absorption.They have also been used in electrochemical energy systems such as supercapacitors,secondary batteries,and electrocatalysis.By reviewing recent progress in structural design and new applications,we also discuss the problems these materials face,including scalable fabrication and precise pore structure control,and possible new applications. 展开更多
关键词 GRAPHENE 3D network SYNTHESIS Energy storage Energy conversion
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Soliton Solutions of a Coupled KdV System via Backlund Transformation
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作者 CAO Xifang WU Yiheng +2 位作者 LU Yi XU Wenjing XIA Yutong 《应用数学》 北大核心 2025年第1期211-216,共6页
In this paper we use Böcklund transformation to construct soliton solutions for a coupled KdV system.This system was first proposed by Wang in 2010.First we generalize the well-known Bäcklund transformation ... In this paper we use Böcklund transformation to construct soliton solutions for a coupled KdV system.This system was first proposed by Wang in 2010.First we generalize the well-known Bäcklund transformation for the KdV equation to such coupled KdV system.Then from a trivial seed solution,we construct soliton solutions.We also give a nonlinear superposition formula,which allows us to generate multi-soliton solutions. 展开更多
关键词 KdV equation Coupled KdV system B¨acklund transformation SOLITON
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Mineralogical characterization and flotation properties of rare earths in refractory iron tailings subjected to hydrogen-based mineral phase transformation 被引量:1
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作者 Jilai Ning Peng Gao +5 位作者 Yang Wang Zihao Li Shuai Yuan Yongsheng Sun Wenbo Li Zhidong Tang 《International Journal of Minerals,Metallurgy and Materials》 2025年第6期1309-1321,共13页
Hydrogen-based mineral phase transformation(HMPT)technology has demonstrated its effectiveness in separating iron and enriching rare earths from Bayan Obo refractory ores.However,further research is needed to clarify ... Hydrogen-based mineral phase transformation(HMPT)technology has demonstrated its effectiveness in separating iron and enriching rare earths from Bayan Obo refractory ores.However,further research is needed to clarify the phase composition and floatability of rare earths obtained after HMPT owing to the associated phase transformations.This study explored the mineralogical characteristics and separation behavior of rare earths in HMPT-treated iron tailings.Process mineralogy studies conducted via BGRIMM process mineralogy analysis and X-ray diffraction revealed that the main valuable minerals in the tailings included rare-earth oxides(9.15wt%),monazite(5.31wt%),and fluorite(23.52wt%).The study also examined the impact of mineral liberation and gangue mineral intergrowth on flotation performance.Flotation tests achieved a rare-earth oxide(REO)grade of 74.12wt% with a recovery of 34.17% in open-circuit flotation,whereas closed-circuit flotation resulted in a REO grade of 60.27wt% with a recovery of 73%.Transmission electron microscopy and scanning electron microscopy coupled with energy-dispersive spectroscopy revealed that monazite remained stable during the HMPT process,while bastnaesite was transformed into Ce_(7)O_(12)and CeF_(3),leading to increased collector consumption.Nonetheless,the HMPT process did not significantly affect the flotation performance of rare earths.The enrichment of fluorite in the tailings highlighted its further recovery potential.The integration of HMPT with magnetic separation and flotation presents an efficient strategy for recovering rare earths,iron,and fluorite from Bayan Obo ores. 展开更多
关键词 hydrogen-based mineral phase transformation rare-earth flotation process mineralogy study Bayan Obo refractory ores
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Preparation Cu_(x)Co_(1-x)for photocatalytic conversion of CO_(2)
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作者 WANG Jingzhou YAO Chenzhong +1 位作者 ZHANG Xisheng MA Ziwei 《燃料化学学报(中英文)》 北大核心 2025年第4期462-471,共10页
Metal nanoparticles with high surface area and high electrochemical activity exhibit excellent catalytic performance in the photocatalytic reduction of carbon dioxide(CO_(2)).However,poor stability,small specific surf... Metal nanoparticles with high surface area and high electrochemical activity exhibit excellent catalytic performance in the photocatalytic reduction of carbon dioxide(CO_(2)).However,poor stability,small specific surface area,and less active sites limits its solar energy utilization.Hydrothermal method was utilized to synthesize the bimetallic material of Cu_(x)Co_(1-x)in this work.Co was loaded onto the Cu surface due to the electrons generated by the surface plasmon resonance(SPR)effect occurring on the Cu surface.Cu_(x)Co_(1-x)exhibits high photocatalytic conversion of CO_(2)efficiency under irradiation,which mainly because the Co nanoparticles on the surface of Cu can be used as cocatalysts to enhance the photocharge transfer.Cu_(0.6)Co_(0.4)exhibits the comparatively best photocatalytic conversion efficiency of CO_(2)in the first 6 h light irradiation.The yields of CO and CH_(4)reached 35.26 and 2.71μmol/(g·h),respectively.Upon illumination,electrons were produced,with the majority of them moving towards the interface.This movement contributes to the increased lifetime of photogenerated electron-hole pairs,which in turn boosts the photocatalytic efficiency.The findings of this research provide significant insights for creating photocatalysts that are both highly effective and stable in CO_(2)reduction processes. 展开更多
关键词 photocatalytic conversion hydrothermal technique surface plasmon resonance bimetallic material photoinduced charge
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