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BaTiO_3晶体薄膜PLD法生长工艺参量研究

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光子学报 2014年第5期43卷 71-75页

作者：张静付秀华杨飞杨彬孙德贵长春理工大学长春130022 中国科学院长春光学精密机械与物理研究所长春130033 哈尔滨工业大学哈尔滨150001

采用脉冲激光沉积方法在单晶MgO基片上外延生长了BaTiO3晶体薄膜.为改善薄膜的结晶质量和表面粗糙度,研究并优化了生长工艺中生长温度和激光能量两个参量,并对薄膜样片实行原位退火.找到了BaTiO3薄膜在优先方向上的结晶效果,分析了结晶... 详细信息

采用脉冲激光沉积方法在单晶MgO基片上外延生长了BaTiO3晶体薄膜.为改善薄膜的结晶质量和表面粗糙度,研究并优化了生长工艺中生长温度和激光能量两个参量,并对薄膜样片实行原位退火.找到了BaTiO3薄膜在优先方向上的结晶效果,分析了结晶质量对生长温度的依赖关系和不同激光能量对结晶薄膜的表面粗糙度的影响.利用X射线衍射仪测定结晶效果与特性,原子力显微镜表征BaTiO3薄膜的结晶表面形貌与粗糙度.测试结果表明,在c轴取向生长BaTiO3薄膜,在(001)和(002)方向上都出现强度很高的尖锐衍射峰,具有较好的结晶质量和较小的表面粗糙度,原子力显微镜测定出薄膜的表面粗糙度为0.563nm.

关键词：光学薄膜光谱分析真空镀膜光学特性生长温度激光能量结晶质量表面粗糙度

Investigation of gravity influence on EOR and CO_(2) geological storage based on pore-scale simulation

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Petroleum Science 2024年第2期21卷 987-1001页

作者： Yong-Mao Hao gui-Cheng Wu Zong-Fa Li Zhong-Hui Wu Yong-Quan sun Ran Liu Xing-Xing Li Bo-Xin Pang Nan Li Key Laboratory of Unconventional Oil&Gas development(China University of Petroleum(East China)) Ministry of EducationQingdao266580ShandongChina School of Petroleum Engineering China University of Petroleum(East China)Qingdao266580ShandongChina School of Petroleum Engineering Yangtze UniversityWuhan430100HubeiChina Dongsheng Jinggong Petroleum development Group Co. LtdShengli Oilfield CompanySINOPECDongying257001ShandongChina

Gravity assistance is a critical factor influencing CO_(2)-Oil mixing and miscible flow during EOR and CO_(2)geological *** on the Navier-Stokes equation,component mass conservation equation,and fluid property-composition relationship,a mathematical model for pore-scale CO_(2) injection in oilsaturated porous media was developed in this *** model can reflect the effects of gravity assistance,component diffusion,fluid density variation,and velocity change on EOR and CO_(2) *** nonhomogeneous porous media,the gravity influence and large density difference help to minimize the velocity difference between the main flow path and the surrounding area,thus improving the oil recovery and CO_(2) *** CO_(2) injection angles and oil-CO_(2) density differences can increase the oil recovery by 22.6% and 4.2%,respectively,and increase CO_(2) storage by 37.9% and 4.7%,*** diffusion facilitates the transportation of the oil components from the low-velocity region to the main flow path,thereby reducing the oil/CO_(2) concentration difference within the porous *** diffusion can increase oil recovery and CO_(2) storage by 5.7% and 6.9%,*** addition,combined with the component diffusion,a low CO_(2) injection rate creates a more uniform spatial distribution of the oil/CO_(2) component,resulting in increases of 9.5% oil recovery and 15.7% CO_(2) storage,*** study provides theoretical support for improving the geological CO_(2) storage and EOR processes.

关键词： Gravity Flow simulation CO_(2)-oil mixing Enhanced oil recovery(EOR) Geological storage

Traffic safety helmet wear detection based on improved YOLOv5 network

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Optoelectronics Letters 2024年

作者： gui Dongdong sun Bo College of Software， Southeast University Quanzhou Equipment Research Centre， Haixi Institute， Chinese Academy of Sciences

Aiming at the problem that the current traffic safety helmet detection model can’t balance the accuracy of detection with the size of the model and the poor generalization of the model， a method based on improving YOLOv5 is proposed. By incorporating the lightweight GhostNet module into the YOLOv5 backbone network， we effectively reduce the model size. The addition of the Receptive Fields Block (RFB) module enhances feature extraction and improves the feature acquisition capability of the lightweight model. Subsequently， the high-performance lightweight convolution， GSConv， is integrated into the neck structure for further model size compression. Moreover， the baseline model’s loss function is substituted with EIoU， accelerating network convergence and enhancing detection precision. Experimental results corroborate the effectiveness of this improved algorithm in real-world traffic scenarios.

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An experimental study on effects of temperature gradient on microstructure of a 308L stainless steel manufactured by directed energy deposition

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Journal of Iron and Steel Research International 2024年第8期31卷 2031-2040页

作者： Ting Dai de-yu Gu Yu-wen Qiu Wei Guo Hui Ding Yi-wei sun School of Materials Science and Engineering Jiangsu Key Laboratory of Advanced Metallic MaterialsSoutheast UniversityNanjing 211189JiangsuChina

The effect of spatial temperature gradient on the microstructural evolution of a 308L stainless steel during the directed energy deposition(deD)process was experimentally investigated.A novel cooling system was designed and incorporated to a deD system in order to control the temperature gradient along the deposition direction during *** deposition,the workpiece was placed on a lifting platform,and as the deposition process proceeded,the platform and workpiece were gradually lowered into cooling water so that the temperature gradient along the deposition direction could be controlled and maintained stable during the deposition *** microstructure characterization results indicated that a deposition strategy with higher G and G/R values(where G is temperature gradient and R is solidification rate)produced finer cellular grains that were better aligned with the deposition direction,while a deposition strategy with lower G and G/R values produced columnar grains with larger primary arm spacing and less aligned with the deposition direction.

关键词： Additive manufacturing Directed energy deposition Stainless steel Microstructure Temperature gradient

Cavity-enhanced photoacoustic dual-comb spectroscopy

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Light(Science & Applications) 2024年第4期13卷 610-618页

作者： Zhen Wang Qinxue Nie Haojia sun Qiang Wang Simone Borri Paolo de Natale Wei Ren department of Mechanical and Automation Engineering The Chinese University of Hong KongNew TerritoriesHong Kong SARChina. State Key Laboratory of Applied Optics Changchun Institute of OpticsFine Mechanics and PhysicsChinese Academy of Sciences130033 ChangchunChina. CNRINO-Istituto Nazionale di Ottica and LENS-European Laboratory for Nonlinear Spectroscopy50019 Sesto FiorentinoItaly

Photoacoustic dual-comb spectroscopy(DCS),converting spectral information in the optical frequency domain to the audio frequency domain via multi-heterodyne beating,enables background-free spectral measurements with high resolution and broad ***,the detection sensitivity remains limited due to the low power of individual comb lines and the lack of broadband acoustic ***,we develop cavity-enhanced photoacoustic DCS,which overcomes these limitations by using a high-finesse optical cavity for the power amplification of dual-frequency combs and a broadband acoustic resonator with a flat-top frequency *** demonstrate high-resolution spectroscopic measurements of trace amounts of C2H2,NH3 and CO in the entire telecommunications *** method shows a minimum detection limit of 0.6 ppb C2H2 at the measurement time of 100 s,corresponding to the noise equivalent absorption coefficient of 7×10−10 cm−*** proposed cavityenhanced photoacoustic DCS may open new avenues for ultrasensitive,high-resolution,and multi-species gas detection with widespread applications.

关键词： individual cavity spectroscopy

Artificial synaptic simulating pain-perceptual nociceptor and brain-inspired computing based on Au/Bi_(3.2)La_(0.8)Ti_(3)O_(12)/ITO memristor

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Journal of Materiomics 2024年第6期10卷 1308-1316页

作者： Hao Chen Zhihao Shen Wen-Tao Guo Yan-Ping Jiang Wenhua Li Dan Zhang Zhenhua Tang Qi-Jun sun Xin-gui Tang School of Physics and Optoelectronic Engineering Guangdong University of TechnologyGuangzhou Higher Education Mega CenterGuangzhou510006China

Recently, memristors have garnered widespread attention as neuromorphic devices that can simulate synaptic behavior, holding promise for future commercial applications in neuromorphic computing. In this paper, we present a memristor with an Au/Bi_(3.2)La_(0.8)Ti_(3)O_(12) (BLTO)/ITO structure, demonstrating a switching ratio of nearly 103 over a duration of 104 s. It successfully simulates a range of synaptic behaviors, including long-term potentiation and depression, paired-pulse facilitation, spike-timing-dependent plasticity, spike-rate-dependent plasticity etc. Interestingly, we also employ it to simulate pain threshold, sensitization, and desensitization behaviors of pain-perceptual nociceptor (PPN). Lastly, by introducing memristor differential pairs (1T1R-1T1R), we train a neural network, effectively simplifying the learning process, reducing training time, and achieving a handwriting digit recognition accuracy of up to 97.19 %. Overall, the proposed device holds immense potential in the field of neuromorphic computing, offering possibilities for the next generation of high-performance neuromorphic computing chips.

关键词： Artificial synapse Memristor Resistive switching Pain-perceptual nociceptor Neuromorphic computing

Asymmetric Autotandem Palladium Catalysis forα,β-Unsaturated Lactones:Merging Olefin and Ester Hydrogenation

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CCS Chemistry 2024年第8期6卷 1987-1999页

作者： Lei sun Han Wang Die Bai Chang-Bin Yu Bo Wu Rong-Zhen Liao Yong-gui Zhou State Key Laboratory of Catalysis Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023Liaoning School of Chemistry and Chemical Engineering Huazhong University of Science and TechnologyWuhan 430074Hubei

Autotandem catalysis(ATC)is fascinating since a single catalyst can promote tandem reactions involving two or more mechanisms in a single reactor and is a highly desirable approach to realize multifarious transformations in organic synthetic ***,a palladium-catalyzed asymmetric autotandem hydrogenation ofα,β-unsaturated lactones is disclosed,providing chiral saturated *** this reaction,the C=C bond inα,β-unsaturated lactones was first hydrogenated to give the dihydrocoumarins with high enantioselectivity,followed by hydrogenation of the ester group with the same catalytic ***,after decreasing the reaction temperature,hydrogenation of the single C=C bond proceeded smoothly,delivering the dihydrocoumarin products with high yield and *** experiments and density functional theory calculations were carried out to elucidate the cause of this unusual asymmetric autotandem ***,the homogeneous palladium catalyst was successfully applied in the hydrogenation of esters under neutral conditions.

关键词： autotandem catalysis asymmetric hydrogenation chiral dihydrocoumarins hydrogenation of esters α β-unsaturated esters

Data-driven casting defect prediction model for sand casting based on random forest classification algorithm

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China Foundry 2024年第2期21卷 137-146页

作者： Bang Guan Dong-hong Wang Da Shu Shou-qin Zhu Xiao-yuan Ji Bao-de sun Shanghai Key Lab of Advanced High-Temperature Materials and Precision Forming School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai 200240China State Key Lab of Metal Matrix Composites Shanghai Jiao Tong UniversityShanghai 200240China Hefei Casting and Forging Factory of Anhui Heli Co. LtdHefei 230000China State Key Laboratory of Materials Processing and Die&Mould Technology Huazhong University of Science and TechnologyWuhan 430074China

The complex sand-casting process combined with the interactions between process parameters makes it difficult to control the casting quality,resulting in a high scrap rate.A strategy based on a data-driven model was proposed to reduce casting defects and improve production efficiency,which includes the random forest(RF)classification model,the feature importance analysis,and the process parameters optimization with Monte Carlo *** collected data includes four types of defects and corresponding process parameters were used to construct the RF *** results show a recall rate above 90% for all *** Gini Index was used to assess the importance of the process parameters in the formation of various defects in the RF ***,the classification model was applied to different production conditions for quality *** the case of process parameters optimization for gas porosity defects,this model serves as an experimental process in the Monte Carlo method to estimate a better temperature *** prediction model,when applied to the factory,greatly improved the efficiency of defect *** show that the scrap rate decreased from 10.16% to 6.68%.

关键词： sand casting process data-driven method classification model quality prediction feature importance

Potential evaluation of saline aquifers for the geological storage of carbon dioxide: A case study of saline aquifers in the Qian-5 member in northeastern Ordos Basin

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China Geology 2024年第1期7卷 12-25页

作者： Yan Li Peng Li Hong-jun Qu gui-wen Wang Xiao-han sun Chang Ma Tian-xing Yao Guoneng Jinjie Energy Co. Ltd.Shenmu 719319China department of Geology Northwest UniversityXi’an 710069China Carbon Neutrality College(Yulin) Northwest UniversityXi’an 710069China National&Local Joint Engineering Research Center of Carbon Capture and Storage Technology Xi’an 710069China

The well-developed coal electricity generation and coal chemical industries have led to huge carbon dioxide(CO_(2))emissions in the northeastern Ordos *** geological storage of CO_(2) in saline aquifers is an effective backup way to achieve carbon *** this case,the potential of saline aquifers for CO_(2) storage serves as a critical basis for subsequent geological storage *** study calculated the technical control capacities of CO_(2) of the saline aquifers in the fifth member of the Shiqianfeng Formation(the Qian-5 member)based on the statistical analysis of the logging and the drilling and core data from more than 200 wells in the northeastern Ordos Basin,as well as the sedimentary facies,formation lithology,and saline aquifer development patterns of the Qian-5 *** results show that(1)the reservoirs of saline aquifers in the Qian-5 member,which comprise distributary channel sand bodies of deltaic plains,feature low porosities and permeabilities;(2)The study area hosts three NNE-directed saline aquifer zones,where saline aquifers generally have a single-layer thickness of 3‒8 m and a cumulative thickness of 8‒24 m;(3)The saline aquifers of the Qian-5 member have a total technical control capacity of CO_(2) of 119.25×10^(6) *** the largest scale and the highest technical control capacity(accounting for 61%of the total technical control capacity),the Jinjie-Yulin saline aquifer zone is an important prospect area for the geological storage of CO_(2) in the saline aquifers of the Qian-5 member in the study area.

关键词： Carbon burial Carbon neutral CO_(2) storage in saline aquifer Distributary channel sand body Potential evaluation Technical control capacity CO_(2)geological storage engineering Ordos Basin