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Effect of electromagnetic stirrer centered outside the mold on steel flow field of bloom continuous casting
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作者 Li-dong Xing Yan-ping Bao +1 位作者 Min Wang Yi-hong Li 《China Foundry》 SCIE CAS CSCD 2023年第5期461-468,共8页
Mold electromagnetic stirring technology for optimizing the flow of molten steel is now widely used in the continuous casting production process of high-quality steels.However,studies on the case that the center of th... Mold electromagnetic stirring technology for optimizing the flow of molten steel is now widely used in the continuous casting production process of high-quality steels.However,studies on the case that the center of the electromagnetic stirrer is located outside the mold have not been reported.Herein,the effect of the electromagnetic stirrer centered outside the mold on the steel flow field was studied in detail by means of numerical simulations.A Gauss meter was used to measure the magnetic induction intensity at different positions,currents,and frequencies.The test results were compared with the simulation results of electromagnetic stirring to calibrate and verify the accuracy of the electromagnetic model.Then,electromagnetic force was introduced into the flow field model as a source term to study its effect on the flow field under anomalous conditions.The results show that when the center of the electromagnetic stirrer is located outside the mold,the magnetic field strength is about twice as strong as that located inside the mold.This also leads to an increase in the flow velocity near the electromagnetic stirrer.As a result,the optimal electromagnetic stirring parameters(200 A,2.5 Hz)were specified when the center of the electromagnetic stirrer is located outside the mold. 展开更多
关键词 numerical modeling electromagnetic stirring fluid flow outside the mold BLOOM
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Analysis on the Applications of Remote Technical Support System in Drilling Production
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作者 ZHANGLei 《外文科技期刊数据库(文摘版)工程技术》 2022年第6期053-057,共5页
In recent years, most of the drilling engineering accidents are caused by human error of judgment, which has much to do with the fact that technical experts and leaders can't get to know the site situation immedia... In recent years, most of the drilling engineering accidents are caused by human error of judgment, which has much to do with the fact that technical experts and leaders can't get to know the site situation immediately and miss the best time to deal with downhole anomalies. Along the general direction of information-based drilling, relying on the continuous improvement of information construction and the maturing of engineering automatic warning software, in August 2016, our company was the first pilot unit of Great Wall Drilling to establish a remote technical support center. The remote real-time monitoring of drilling parameters, data entry and analysis of EISS system, engineering simulation calculation and analysis software and other modules were applied to construct a remote technical support system for drilling engineering, which achieved the control objectives of "pre-prediction", "in-process control" and "post-analysis", promoted the continuous improvement of ROP, steadily reduced the accident complexity rate, and promoted the overall speed-up and efficiency improvement of all well teams of the Company. At the same time, combining with my own work practice, the author puts forward optimization and expansion methods for the problems and development direction in the operation of the remote support system, hoping to provide reference and reference for more people in the industry. 展开更多
关键词 drilling engineering remote technical support system speed up and improve efficiency
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Quantitative detection of trace nanoplastics (down to 50 nm) via surface-enhanced Raman scattering based on the multiplex-feature coffee ring 被引量:1
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作者 Xinao Lin Fengcai Lei +5 位作者 Xiu Liang Yang Jiao Xiaofei Zhao Zhen Li Chao Zhang Jing Yu 《Opto-Electronic Advances》 2025年第6期27-39,共13页
Quantitative detection of trace small-sized nanoplastics(<100 nm)remains a significant challenge in surface-enhanced Raman scattering(SERS).To tackle this issue,we developed a hydrophobic CuO@Ag nanowire substrate ... Quantitative detection of trace small-sized nanoplastics(<100 nm)remains a significant challenge in surface-enhanced Raman scattering(SERS).To tackle this issue,we developed a hydrophobic CuO@Ag nanowire substrate and introduced a multiplex-feature analysis strategy based on the coffee ring effect.This substrate not only offers high Raman enhancement but also exhibits a high probability of detection(POD),enabling rapid and accurate identification of 50 nm polystyrene nanoplastics over a broad concentration range(1–10−10 wt%).Importantly,experimental results reveal a strong correlation between the coffee ring formation and the concentration of nanoplastic dispersion.By incorporating Raman signal intensity,coffee ring diameter,and POD as combined features,we established a machine learning-based mapping between nanoplastic concentration and coffee ring characteristics,allowing precise predictions of dispersion concentration.The mean squared error of these predictions is remarkably low,ranging from 0.21 to 0.54,representing a 19 fold improvement in accuracy compared to traditional linear regression-based methods.This strategy effectively integrates SERS with wettability modification techniques,ensuring high sensitivity and fingerprinting capabilities,while addressing the limitations of Raman signal intensity in accurately reflecting concentration changes at ultra-low levels,providing a new idea for precise SERS measurements of nanoplastics. 展开更多
关键词 quantitative detection of trace nanoplastics surface-enhanced Raman scattering coffee ring multiplexfeature analysis machine learning
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The RhSPL4-RhPRR5L module positively regulates flowering time in rose(Rosa hybrida) 被引量:1
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作者 Ziwei Huang Guoqin Liu +10 位作者 Rui Chen Hao Zhang Dan Wang Daliang Li Yixin Zhang Huijun Yan Kaixue Tang Junping Gao Nan Ma Weikun Jing Xiaofeng Zhou 《Horticultural Plant Journal》 2025年第5期1930-1942,共13页
The proper flowering time of rose(Rosa hybrida)is vital for the market value of this horticultural crop,but the mechanism regulating this trait is largely unclear.Here,we found that the transcription factor SQUAMOSA P... The proper flowering time of rose(Rosa hybrida)is vital for the market value of this horticultural crop,but the mechanism regulating this trait is largely unclear.Here,we found that the transcription factor SQUAMOSA PROMOTER BINDING PROTEIN-LIKE4(RhSPL4)positively regulates flowering time in rose.Transient silencing or overexpression transgenic rose plants of RhSPL4 exhibited delayed or early flowering,respectively.Analysis of transcriptome data from transgenic lines overexpressing RhSPL4 compared to the wild type indicated that differentially expressed genes were significantly enriched in the circadian rhythm pathway.Among the proteins encoded by these genes,RhSPL4 binds to the promoter of PSEUDO-RESPONSE REGULATOR 5-LIKE(RhPRR5L),as revealed in yeast one-hybrid,dual-Luciferase/Renilla luciferase reporter,chromatin immunoprecipitation-quantitative PCR and electrophoretic mobility shift assay.Furthermore,RhSPL4 specifically binds to the478 to441 bp region of the RhPRR5L promoter and activates its transcription.The silencing of RhPRR5L delayed flowering time in rose,resembling the phenotype of RhSPL4-silenced plants.Together,these results indicate that the RhSPL4-RhPRR5L module positively regulates flowering time in rose,laying the foundation for the genetic improvement of flowering time in this important horticultural crop. 展开更多
关键词 SQUAMOSA PROMOTER BINDING PROTEIN-LIKE 4 Flowering time Circadian clock PSEUDO-RESPONSE REGULATORS Rosa hybrida
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Low Temperature Sintering of ZnAl_(2)O_(4) Ceramics with CuO-TiO_(2)-Nb_(2)O_(5) Composite Oxide Sintering Aid
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作者 YANG Yan ZHANG Faqiang +3 位作者 MA Mingsheng WANG Yongzhe OUYANG Qi LIU Zhifu 《无机材料学报》 北大核心 2025年第6期711-718,I0009-I0011,共11页
ZnAl_(2)O_(4) and ZnAl_(2)O_(4)-based ceramics have attracted much attention from researchers due to their good microwave dielectric,thermal and mechanical properties.In this work,the influence of 5%(in mass)CuO-TiO_(... ZnAl_(2)O_(4) and ZnAl_(2)O_(4)-based ceramics have attracted much attention from researchers due to their good microwave dielectric,thermal and mechanical properties.In this work,the influence of 5%(in mass)CuO-TiO_(2)-Nb_(2)O_(5)(CTN)ternary composite oxide additives with different composition ratios on sintering behavior and properties of ZnAl_(2)O_(4) microwave dielectric ceramics was investigated.When the molar fraction ranges of Cu,Ti and Nb elements in 5%CTN additives are 0.625-0.875,0-0.250 and 0.125-0.625,respectively,sintering temperature of ZnAl_(2)O_(4) ceramics can be reduced from above 1400℃to below 1000℃.The sintering additives CN(Cu:Nb=1:1,molar ratio)and CTN(Cu:Ti:Nb=4:1:3,molar ratio)can reduce sintering temperature of ZnAl_(2)O_(4) ceramics to 975 and 1000℃,respectively,while maintaining good dielectric properties(dielectric constantε_(r)=11.36,quality factor Q׃=8245 GHz andε_(r)=9.52,Q׃=22249 GHz)and flexural strengths(200 and 161 MPa),which are expected to be applied in preparation of low temperature co-fired ceramic(LTCC)materials with copper electrodes.Low-temperature sintering of the ZnAl_(2)O_(4)+CTN system is characterized as activated sintering.Nanometer-level amorphous interfacial films containing Cu,Ti,and Nb elements are observed at the grain boundaries,which may provide fast diffusion pathways for mass transportation during the sintering process.Valence changes of Ti and Cu ions,along with changes of oxygen vacancies,are confirmed,which provides a potential mechanism for reduced sintering temperature of ZnAl_(2)O_(4) ceramics.In addition,a series of reactions occurring at the grain boundaries can activate these boundaries and further promote the sintering densification process.These results suggest a promising way to design a novel LTCC material with excellent properties based on the low temperature sintering of ceramics with the sintering aid of CuO-TiO_(2)-Nb_(2)O_(5) composite oxide. 展开更多
关键词 ZnAl_(2)O_(4) CuO-TiO_(2)-Nb_(2)O_(5) low-temperature sintering microwave dielectric ceramic low temperature co-fired ceramic
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Effects of Chamomilla Recutita Extract on Soothing Adult Acne Sequelae
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作者 Xu Qingyang Jiang Yueming Lu Wenjia 《China Detergent & Cosmetics》 2025年第1期27-34,共8页
Cutibacterium acnes were used to induce lipase production,and to establish ex-vivo skin model of inflammatory response and post-inflammatory hyperpigmentation,in purpose of exploring the mechanism of chamomilla recuti... Cutibacterium acnes were used to induce lipase production,and to establish ex-vivo skin model of inflammatory response and post-inflammatory hyperpigmentation,in purpose of exploring the mechanism of chamomilla recutita extract.Clinical study was designed to investigate the effects of chamomilla recutita extract on Chinese volunteers with sequelae of adult acne,by evaluating the severity of acne,post-acne erythema and pigmentation,skin basic physiological conditions.The results showed that chamomilla recutita extract inhibited lipase activity,cellular inflammatory response,and melanin production.In the clinical study,the acnes were relieved 173%,with a 78%lower post-acne erythema index and 202%less hyperpigmentation as compared to placebo,after applying samples containing 1%chamomilla recutita extract for 28 days.Meanwhile,chamomilla recutita extract showed instant oil control effect.The extract significantly reduced sebum secretion by 293%,increased skin moisture content by 102%,and strengthened the skin barrier by 193%after 28 days application,which provided favorable skin physiological basis for the prevention and improvement of acne vulgaris and sequelae. 展开更多
关键词 chamomilla recutita extract acne marks post-inflammatory erythema post-inflammatory hyperpigmentation
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Heavy Atom Effect on the Luminescent Properties of Multi-resonance Thermally Activated Delayed Fluorescence Emitters:Theoretical Insights
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作者 Rui Li Zhimin Wu +6 位作者 Xiaofang Li Xiaofei Wang Yuzhi Song Jianzhong Fan Guangping Zhang Chuan-Kui Wang Lili Lin 《Chinese Journal of Chemical Physics》 2025年第3期334-346,I0048-I0060,I0109,共27页
Multi-resonance thermally ac-tivated delayed fluorescence(MR-TADF)emitters are one of the most excellent materi-als for high performance or-ganic light-emitting diodes(OLEDs)with high color puri-ty benefiting from the... Multi-resonance thermally ac-tivated delayed fluorescence(MR-TADF)emitters are one of the most excellent materi-als for high performance or-ganic light-emitting diodes(OLEDs)with high color puri-ty benefiting from their nar-row full width at half maxi-mum(FWHM)and great de-vice performance.However,small spin-orbit coupling(SOC)is one of drawbacks for MR-TADF emitters and introduction of heavy atoms may be one effective solution.In this work,four MR-TADF molecules with different atoms(O,S,Se)are carried out based on the first-principles calculation,and excited state dynamics in both toluene and solid phase is investi-gated.Our calculation results indicate that heavy atoms could induce smaller adiabatic ener-gy gap and larger SOC between the first singlet excited state and the first triplet excited state,which is advantageous for the conversion of singlet and triplet excitons,and thus the generation of thermally activated delayed fluorescence(TADF).Though the reorganization energy and full width at half maximum(FWHM)of emission are increased,the influence is quite limited.Besides,the fluorescent rates are also little influenced.Our calculation results indicate that heavy atom introduction is an efficient strategy to enhance the SOC values of MR-TADF emitters without influencing other properties significantly. 展开更多
关键词 Organic light-emitting diodes Thermally activated delayed fluorescence Heavy atoms effect Spin-orbit coupling
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Bound States in the Continuum of Infinite Quality Factor in Finite Unit Cells
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作者 Hua-Wei Liang Yuan-Zhi Liu +2 位作者 Yu-Jia Zeng Yang-Jian Cai Ting-Yin Ning 《Chinese Physics Letters》 2025年第8期38-53,共16页
A theory based on the superposition principle is developed to uncover the basic physics of wave behavior in a finite grating of N unit cells.The theory reveals that bound states in the continuum(BICs)of infinite quali... A theory based on the superposition principle is developed to uncover the basic physics of wave behavior in a finite grating of N unit cells.The theory reveals that bound states in the continuum(BICs)of infinite quality factor(Q-factor)can be supported by such a grating when perfect reflection is introduced at its boundaries.If geometrical perturbations are introduced into the structure,the dark BICs transform into bright quasi-BICs with finite Q-factor,maintaining spectral characteristics nearly identical to those of quasi-BICs supported by infinite gratings.When the boundaries are replaced with high-reflectivity metallic mirrors,the Q-factor of the resonant mode is reduced to be finite;however,it can be much larger than that in the corresponding nanostructure with open boundaries and can be tuned over a large range by varying the number of unit cells or boundary conditions. 展开更多
关键词 Superposition Principle wave behavior perfect reflection Finite Unit Cells geometrical perturbations dark bics Bound States Continuum Infinite Quality Factor
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Near-infrared self-powered RuS_(2x)Se_(2-2x)alloy photodetector via chemical vapor deposition RuSe_(2)and post-sulfurization process
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作者 Jaehyeok Kim Hwi Yoon +9 位作者 Inkyu Sohn Tatsuya Nakazawa Sangyoon Lee Donghyun Kim Yusuke Ohshima Hiroki Sato Seunggi Seo Sojeong Eom Seung-Min Chung Hyungjun Kim 《Rare Metals》 2025年第6期4050-4060,共11页
Ruthenium(Ru)-based chalcogenide(S,Se)is a promising material in various fields,such as optics,photoelectrodes,and electrocatalysis,owing to its suitable bandgap for generating charge carriers under light illumination... Ruthenium(Ru)-based chalcogenide(S,Se)is a promising material in various fields,such as optics,photoelectrodes,and electrocatalysis,owing to its suitable bandgap for generating charge carriers under light illumination ranging from visible to near-infrared(NIR)and its high absorption coefficient.In this study,we report the synthesis of Ru Se_(2)thin films by chemical vapor deposition(CVD)with a bandgap matching the NIR region at 0.52 e V.Further,we demonstrated Ru S_(2x)Se_(2-2x)alloy films using the post-sulfurization process after CVD Ru Se_(2)with a tunable bandgap from 0.52 to 1.39 e V depending on sulfur composition.Remarkably,Ru S_(2x)Se_(2-2x)alloy film metal–semiconductor–metal(MSM)photodetector sulfurized at 500°C,with a 0.75 e V bandgap,exhibits enhanced broad absorption across NIR spectral ranges,suppressed dark current and high photoresponsivity in NIR wavelengths range even at zero-bias.We believe the bandgaptunable Ru S_(2x)Se_(2-2x)thin film through an efficient deposition method could be suitable for various optoelectronic applications. 展开更多
关键词 RuSe_(2) Chemical vapor deposition RuS_(2x)Se_(2-2x)alloy PHOTODETECTOR
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Influence of guidance signs on platform evacuation in suburban railway tunnel under smoke and obstacle environment
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作者 Yifan Zhuang Fan Wang +2 位作者 Yuanchun Huang Xiaomin Song Ya Rao 《High-Speed Railway》 2025年第1期1-16,共16页
Once a train stops in a tunnel section and requires emergency evacuation,the large distance between stations and long walking distances in the underground spaces of suburban railway systems pose potential risks to the... Once a train stops in a tunnel section and requires emergency evacuation,the large distance between stations and long walking distances in the underground spaces of suburban railway systems pose potential risks to the evacuation process on tunnel platforms,especially in complex environments.This study utilized Virtual Reality(VR)technology to construct a virtual experimental platform for tunnel evacuation in suburban railway systems,simulating different combinations of smoke and obstacle conditions.By requiring participants to wear VR glasses and walk on an omnidirectional treadmill for moving,as well as complete psychological questionnaires,the study reveals the influences of No Guiding(NG)signs,Wall-Guided(WG)signs,and Central axis Guidance(CG)signs on the movement abilities and psychological behaviors of participants contrastively.The results show that either smoke conditions or obstacle positions affect the mental stress of participants,and the guidance sign has a positive effect on reducing the mental stress.There is an inverse relationship between mental stress and movement abilities.WG and CG signs respectively lead participants to walk closer to walls and along the central axis,which is conducive to reducing the variation in participants’behavior characteristics when circumventing obstacles on the wall side or track side under smoke conditions,respectively.Additionally,CG signs reduce the speed fluctuations of participants before circumventing obstacles,improving the stability of the distance from the wall and speed under smoke conditions,compared to NG and WG signs.These findings contribute to understanding the evacuation psychological-behavioral-movement characteristics of pedestrians on evacuation platforms in suburban railway tunnels and provide a basis for improving the safety design of evacuation guidance signs. 展开更多
关键词 Tunnel evacuation platform Pedestrian safety VR experiment Guidance sign Suburban railway Emergency evacuation
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Effect of side group on mechanically induced conductance switching in 4,40-dipyridyl-based single-molecule junctions
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作者 Zhen Wan Chang-Feng Zheng +5 位作者 Lin Liu Yun-Long Ge Guang-Ping Zhang Shuai Qiu Hui Wang Zong-Liang Li 《Chinese Physics B》 2025年第8期678-684,共7页
The forming processes of 4,40-dipyridyl-based single-molecule junctions and mechanically induced conductance switching as well as the side-group effects are systematically investigated by applying the ab initio-based ... The forming processes of 4,40-dipyridyl-based single-molecule junctions and mechanically induced conductance switching as well as the side-group effects are systematically investigated by applying the ab initio-based adiabatic geometric optimization method and the one-dimensional transmission combined with three-dimensional correction approximation(OTCTCA)method.The numerical results show that for the 4,40-dipyridyl with a p-conjugated phenyl-phosphoryl or diphenylsilyl side group,the pyridyl vertically anchors on the second atomic layer of the pyramid-shaped Au tip electrode at small inter-electrode distances by laterally pushing the apical Au atom aside,which induces stronger pyridyl-electrode coupling and high-conductance state of the formed junctions.As the inter-electrode distance increases,the pyridyl shifts to the apical Au atom of the tip electrode.This apical Au atom introduces additional scatterings to the tunneling electrons and significantly decreases the conductance of the junctions.Furthermore,for the 4,40-dipyridyl with a phenyl-phosphoryl side group,the probability of manifesting the high-conductance state is decreased due to the oxygen atom reducing the probability of the pyridyl adsorbing on the second layer of Au tip electrode.In contrast,for the 4,40-dipyridyl with a nonconjugated cyclohexyl-phosphoryl side group,the steric hindrance from the bulky cyclohexyl group leads the molecule to preferentially form the O-Au contact,which prevents both the high conductance and mechanically induced conductance switching of the junction.Our results provide a theoretical understanding of the side-group effects on electronic transport properties of single-molecule junctions,offering an alternative explanation for the experimental observations. 展开更多
关键词 single-molecule junction electron transport properties conductance switching side-group effects
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Analysis on Electromagnetic Vibration of Synchronous Reluctance Motors under Different Drive Methods
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作者 Tiansa Chen Xiuhe Wang +3 位作者 Lingling Sun Jinyang Xu Jihao Wang Jinjun Huang 《CES Transactions on Electrical Machines and Systems》 2025年第3期300-312,共13页
Sine-wave drive and square-wave drive are two common motor control strategies.This study constructs a mathematical model capable of predicting the distribution of electromagnetic force waves in synchronous reluctance ... Sine-wave drive and square-wave drive are two common motor control strategies.This study constructs a mathematical model capable of predicting the distribution of electromagnetic force waves in synchronous reluctance motors(SynRMs)under these two drive methods,and comparatively analyzes the vibration phenomena induced by electromagnetic forces under different drive methods.It aims to provide an effective tool for predicting the distribution of electromagnetic force waves in SynRMs,while exploring the influence of drive modes on their vibration characteristics.The study focuses on a 4-pole,36-slot 5.5 kW SynRM.Based on the magnetomotive force(MMF)-permeance method,incorporating the special rotor structure and the characteristics of current harmonics under square-wave drive,an air-gap flux distribution function is established.Meanwhile,Maxwell’s stress tensor method is adopted to analyze how the air-gap flux density relates to electromagnetic excitation force waves.Subsequently,this analysis is applied to forecast the spatiotemporal distribution features of radial electromagnetic force waves.Finite element simulations are conducted to compute the modal and vibration responses of the SynRM,followed by a comparative analysis of the vibration characteristics under the two drive methods.Additionally,a 6-pole,36-slot SynRM is used for additional comparative verification.Ultimately,the effectiveness of the simulation results is verified through experiments. 展开更多
关键词 Sine-wave drive Square-wave drive Synchronous reluctance motor(SynRM) Electromagnetic excitation force Electromagnetic vibration characteristics
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Effect of Streamline Length on Aerodynamic Performance of 600 km/h Maglev Trains
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作者 Yan Li Bailong Sun +1 位作者 Tian Li Weihua Zhang 《Computer Modeling in Engineering & Sciences》 2025年第8期1957-1970,共14页
High-speed maglev trains represent a key direction for the future development of rail transportation.As operating speeds increase,they face increasingly severe aerodynamic challenges.The streamlined aerodynamic shape ... High-speed maglev trains represent a key direction for the future development of rail transportation.As operating speeds increase,they face increasingly severe aerodynamic challenges.The streamlined aerodynamic shape of a maglev train is a critical factor influencing its aerodynamic performance,and optimizing its length plays a significant role in improving the overall aerodynamic characteristics of the train.In this study,a numerical simulation model of a high-speed maglev train was established based on computational fluid dynamics(CFD)to investigate the effects of streamline length on the aerodynamic performance of the train operating on an open track.The results show that the length of the streamlined section has a pronounced impact on aerodynamic performance.When the streamline length increases from 8.3 to 14.3 m,the aerodynamic drag of the head and tail cars decreases by 16.2%and 32.1%,respectively,with reductions observed in both frictions drag and pressure drag-the latter showing the most significant decrease in the tail car.Moreover,the extended streamline length effectively suppresses flow separation on the train body surface.The intensity of the positive pressure region on the upper surface of the head car streamlined section is reduced,directly leading to a 38.2%reduction in lift.This research provides a theoretical basis for the parametric design of aerodynamic shapes for high-speed maglev trains and offers guidance and recommendations for drag and lift reduction optimization. 展开更多
关键词 High-speed maglev train aerodynamic characteristics optimization numerical simulation
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Research progress of polarized perovskite type ferroelectric materials for photocatalytic hydrogen production
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作者 Rong Yan Chunyan Du +10 位作者 Hanbo Yu Jingyi Jiang Jiao Cao Guanlong Yu Wei Dong Yulv Zou Huaiyuan Peng Yu Yang Tian Ao Tong Sun Yiyi Deng 《Journal of Energy Chemistry》 2025年第8期87-102,共16页
To address the global energy shortage,hydrogen production as a green energy source has become one of the most prominent research topics over the past decade.Novel and promising ferroelectric materials,exhibiting uniqu... To address the global energy shortage,hydrogen production as a green energy source has become one of the most prominent research topics over the past decade.Novel and promising ferroelectric materials,exhibiting unique spontaneous polarization capabilities,have shown great potential in the field of photocatalytic hydrogen evolution.Among these materials,perovskites represent a significant group of ferroelectrics,possessing both excellent ferroelectric properties and photocatalytic performance.By focusing on perovskites,we analyze the advantages of their built-in electric field for photocatalytic hydrogen evolution,integrating the domain wall structures of ferroelectrics.Furthermore,we summarize how to fully exploit the unique characteristics of ferroelectrics and highlight recent advancements in their application to photocatalytic hydrogen evolution. 展开更多
关键词 Hydrogen production FERROELECTRICS PEROVSKITE DOMAINS Built-in electric field
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A Dynamic Knowledge Base Updating Mechanism-Based Retrieval-Augmented Generation Framework for Intelligent Question-and-Answer Systems
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作者 Yu Li 《Journal of Computer and Communications》 2025年第1期41-58,共18页
In the context of power generation companies, vast amounts of specialized data and expert knowledge have been accumulated. However, challenges such as data silos and fragmented knowledge hinder the effective utilizati... In the context of power generation companies, vast amounts of specialized data and expert knowledge have been accumulated. However, challenges such as data silos and fragmented knowledge hinder the effective utilization of this information. This study proposes a novel framework for intelligent Question-and-Answer (Q&A) systems based on Retrieval-Augmented Generation (RAG) to address these issues. The system efficiently acquires domain-specific knowledge by leveraging external databases, including Relational Databases (RDBs) and graph databases, without additional fine-tuning for Large Language Models (LLMs). Crucially, the framework integrates a Dynamic Knowledge Base Updating Mechanism (DKBUM) and a Weighted Context-Aware Similarity (WCAS) method to enhance retrieval accuracy and mitigate inherent limitations of LLMs, such as hallucinations and lack of specialization. Additionally, the proposed DKBUM dynamically adjusts knowledge weights within the database, ensuring that the most recent and relevant information is utilized, while WCAS refines the alignment between queries and knowledge items by enhanced context understanding. Experimental validation demonstrates that the system can generate timely, accurate, and context-sensitive responses, making it a robust solution for managing complex business logic in specialized industries. 展开更多
关键词 Retrieval-Augmented Generation Question-and-Answer Large Language Models Dynamic Knowledge Base Updating Mechanism Weighted Context-Aware Similarity
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Symmetry-protected and Brillouin zone folding driven bound states in the continuum in dielectric nanorod arrays for efficient third harmonic generation
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作者 Wen-Jing Wang Shi-Jie Liang +2 位作者 Jia-Qi Zou Yan-Yan Huo Ting-Yin Ning 《Chinese Physics B》 2025年第3期390-398,共9页
Two types of bound states in continuum(BICs),symmetry-protected and Brillouin zone folding driven,are identified in hollow Si nanorod arrays.By modulating the direction and distance of the air holes from the center of... Two types of bound states in continuum(BICs),symmetry-protected and Brillouin zone folding driven,are identified in hollow Si nanorod arrays.By modulating the direction and distance of the air holes from the center of the nanorods,it is possible to achieve either a single quasi-BIC or three quasi-BICs.The transmission spectra exhibit ultra-narrow lines,and the quasi-BICs demonstrate ultra-high Q factors.Additionally,efficient third-harmonic generation occurs at low pump intensities.The results indicate that the proposed nanostructures of two types of BICs with a flexible modulation hold great potential applications for nonlinear photonic devices. 展开更多
关键词 bound states in the continuum Brillouin zone folding third harmonic generation
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Improving cleanliness of an H-beam steel by optimizing refining slag and calcium treatment
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作者 Wen Yang Wen-ping Liu +3 位作者 Zhi-bin Gao Si-jun Li Zhao-min Su Li-feng Zhang 《Journal of Iron and Steel Research International》 2025年第9期2784-2793,共10页
Slagging and calcium treatment are commonly used methods to control cleanliness and inclusions in steel.However,the inappropriate slagging and calcium treatment operations resulted in the generation of large-sized inc... Slagging and calcium treatment are commonly used methods to control cleanliness and inclusions in steel.However,the inappropriate slagging and calcium treatment operations resulted in the generation of large-sized inclusions and deterioration of steel cleanliness;meanwhile,changed inclusions from Al_(2)O_(3)–SiO_(2)–MnO type to Al_(2)O_(3)–SiO_(2)–CaO type after the calcium treatment during the production of an H-beam steel.Combining the thermodynamic analysis and industrial trials,measurements including reducing the basicity of refining slag to be less than 2.0 and the Al_(2)O_(3)content in slag to be less than 10 wt.%and the cancelation of calcium treatment under the total content less than 15×10^(−6)have been taken.After optimization,the content of total oxygen in tundish decreased by 24%;meanwhile,inclusions were changed from the Al_(2)O_(3)–SiO_(2)–CaO system to the Al_(2)O_(3)–SiO_(2)–MnO system with a low-melting point and a obvious decrease in the number density,area fraction,and maximum size of inclusions.It has achieved the improvement of steel cleanliness while reducing production costs. 展开更多
关键词 H-beam steel CLEANLINESS Non-metallic inclusion Refining slag Calcium treatment
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A new 2D Hindmarsh–Rose neuron,its circuit implementation,and its application in dynamic flexible job shops problem
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作者 Yao Lu Weijie Nie +2 位作者 Xu Wang Xianming Wu Qingyao Ma 《Chinese Physics B》 2025年第12期99-110,共12页
We propose a simplified version of the classic two-dimensional Hindmarsh–Rose neuron(2DHR),resulting in a new 2DHR that exhibits novel chaotic phenomena.Its dynamic characteristics are analyzed through bifurcation di... We propose a simplified version of the classic two-dimensional Hindmarsh–Rose neuron(2DHR),resulting in a new 2DHR that exhibits novel chaotic phenomena.Its dynamic characteristics are analyzed through bifurcation diagrams,Lyapunov exponent spectra,equilibrium points,and phase diagrams.Based on this system,a corresponding circuit is designed and circuit simulations are carried out,yielding results consistent with the numerical simulations.To explore practical applications of chaotic systems,2DHR is employed to improve the solution of the flexible job-shop scheduling problem with dynamic events.The research results demonstrate that applying 2DHR can significantly enhance the convergence rate of the optimization algorithm and improve the quality of the scheduling solution. 展开更多
关键词 CHAOS nervous system meta-heuristic algorithm dynamic flexible job-shop scheduling problem
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Cooperative Iteration Matching Method for Aligning Samples from Heterogeneous Industrial Datasets
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作者 LI Han SHI Guohong +1 位作者 LIU Zhao ZHU Ping 《Journal of Shanghai Jiaotong university(Science)》 2025年第2期375-384,共10页
Industrial data mining usually deals with data from different sources.These heterogeneous datasets describe the same object in different views.However,samples from some of the datasets may be lost.Then the remaining s... Industrial data mining usually deals with data from different sources.These heterogeneous datasets describe the same object in different views.However,samples from some of the datasets may be lost.Then the remaining samples do not correspond one-to-one correctly.Mismatched datasets caused by missing samples make the industrial data unavailable for further machine learning.In order to align the mismatched samples,this article presents a cooperative iteration matching method(CIMM)based on the modified dynamic time warping(DTW).The proposed method regards the sequentially accumulated industrial data as the time series.Mismatched samples are aligned by the DTW.In addition,dynamic constraints are applied to the warping distance of the DTW process to make the alignment more efficient.Then a series of models are trained with the cumulated samples iteratively.Several groups of numerical experiments on different missing patterns and missing locations are designed and analyzed to prove the effectiveness and the applicability of the proposed method. 展开更多
关键词 dynamic time warping mismatched samples sample alignment industrial data data missing
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Large Language Models With Contrastive Decoding Algorithm for Hallucination Mitigation in Low-Resource Languages
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作者 Zan Hongying Arifa Javed +2 位作者 Muhammad Abdullah Javed Rashid Muhammad Faheem 《CAAI Transactions on Intelligence Technology》 2025年第4期1104-1117,共14页
Neural machine translation(NMT)has advanced with deep learning and large-scale multilingual models,yet translating lowresource languages often lacks sufficient training data and leads to hallucinations.This often resu... Neural machine translation(NMT)has advanced with deep learning and large-scale multilingual models,yet translating lowresource languages often lacks sufficient training data and leads to hallucinations.This often results in translated content that diverges significantly from the source text.This research proposes a refined Contrastive Decoding(CD)algorithm that dynamically adjusts weights of log probabilities from strong expert and weak amateur models to mitigate hallucinations in lowresource NMT and improve translation quality.Advanced large language NMT models,including ChatGLM and LLaMA,are fine-tuned and implemented for their superior contextual understanding and cross-lingual capabilities.The refined CD algorithm evaluates multiple candidate translations using BLEU score,semantic similarity,and Named Entity Recognition accuracy.Extensive experimental results show substantial improvements in translation quality and a significant reduction in hallucination rates.Fine-tuned models achieve higher evaluation metrics compared to baseline models and state-of-the-art models.An ablation study confirms the contributions of each methodological component and highlights the effectiveness of the refined CD algorithm and advanced models in mitigating hallucinations.Notably,the refined methodology increased the BLEU score by approximately 30%compared to baseline models. 展开更多
关键词 ChatGLM contrastive decoding HALLUCINATION LLAMA LLM low resource NMT
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