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Intelligent geochemical interpretation of mass chromatograms:Based on convolution neural network

Petroleum Science 2024年第2期21卷 752-764页

作者： Kai-Ming Su Jun-Gang lu jian Yu Zi-Xing lu Shi-Jia Chen Hubei Key Laboratory of Petroleum Geochemistry and Environment Wuhan430100HubeiChina College of Resources and Environment Yangtze UniversityWuhan430100HubeiChina School of Geoscience and Technology Southwest Petroleum UniversityChengdu610500SichuanChina Changqing Oilfield Company PetroChinaXi'an710021ShaanxiChina

Gas chromatography-mass spectrometry(GC-MS)is an extremely important analytical technique that is widely used in organic *** is the only approach to capture biomarker features of organic matter and provides the key evidence for oil-source correlation and thermal maturity ***,the conventional way of processing and interpreting the mass chromatogram is both timeconsuming and labor-intensive,which increases the research cost and restrains extensive applications of this *** overcome this limitation,a correlation model is developed based on the convolution neural network(CNN)to link the mass chromatogram and biomarker features of samples from the Triassic Yanchang Formation,Ordos Basin,*** this way,the mass chromatogram can be automatically *** research first performs dimensionality reduction for 15 biomarker parameters via the factor analysis and then quantifies the biomarker features using two indexes(*** and PMI)that represent the organic matter thermal maturity and parent material type,***,training,interpretation,and validation are performed multiple times using different CNN models to optimize the model structure and hyper-parameter setting,with the mass chromatogram used as the input and the obtained MI and PMI values for supervision(label).The optimized model presents high accuracy in automatically interpreting the mass chromatogram,with R2values typically above 0.85 and0.80 for the thermal maturity and parent material interpretation results,*** significance of this research is twofold:(i)developing an efficient technique for geochemical research;(ii)more importantly,demonstrating the potential of artificial intelligence in organic geochemistry and providing vital references for future related studies.

关键词： Organic geochemistry Biomarker Mass chromatographic analysis Automated interpretation Convolution neural network Machine learning

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Two-layer Lagrange-based relay network topology and trajectory design for solar system explorations

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Science China(Information Sciences) 2024年第6期67卷 342-358页

作者： Jun CAO jian JIAO Hao LIU Rongxing lu Qinyu ZHANG Guangdong Provincial Key Laboratory of Aerospace Communication and Networking Technology Harbin Institute of Technology (Shenzhen) Faculty of Computer Science (FCS) University of New Brunswick

Exploration targeting outer planets and even the edge of the solar system is an emerging direction for the deep-space exploration in the next decades. To address this challenge, a novel two-layer Lagrangebased relay network topology is proposed in this study. Specifically, we utilize the Sun-Mars and Sun-Saturn Lagrange points(LPs) L4 and L5 to build a two-layer backbone relay network, which ensures continuous and high-efficiency communication capability for the exploration of the solar system. Furthermore, we utilize the planetary gravity assist and design the transfer trajectory of backbone relays with the help of planetary celestial body motion equations and Kepler's laws. Moreover, we conduct link budget analysis for multihop relay transmission under Gamma-Gamma distribution, shadowed Rician fading, and additive white Gaussian noise channels in several typical exploration scenarios and validate that the LP relays can effectively support future deep-space exploration missions.

关键词： deep-space communication Lagrangian points backbone relay network transfer trajectory relay selection

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The joint knowledge reasoning model based on knowledge representation learning for aviation assembly domain

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Science China(Technological Sciences) 2024年第1期67卷 143-156页

作者： LIU PeiFeng QIAN lu lu Hu XUE Lei zhao XingWei TAO Bo State Key Laboratory of Digital Manufacturing Equipment and Technology Department of MechanicalHuazhong University of Science and TechnologyWuhan 430074China School of Transportation and Logistics Engineering Wuhan University of Technology(WHUT)Wuhan 430063China Shanghai Aircraft Manufacturing Co. Ltd.Shanghai 201324China

Knowledge graph technology is widely applied in the domain of general knowledge reasoning with an excellent *** fine-grained professional fields,professional knowledge graphs can provide more accurate information in practical industrial *** on an aviation assembly domain-specific knowledge graph,the article constructs a joint knowledge reasoning model,which combines a named entity recognition model and a subgraph embedding learning *** performing knowledge reasoning tasks,the two models vectorize entities,relationships and entity attributes in the same space,so as to share parameters and optimize learning *** knowledge reasoning model,which provides intelligent question answering services,is able to reduce the assembly error rate and improve the assembly *** system can accurately solve general knowledge reasoning problems in the assembly process in actual industrial scenarios of general assembly and component assembly under interference-free ***,this paper compares the proposed knowledge reasoning model based on knowledge representation learning and the question-answering system based on large-scale pre-trained *** the application scenario of system functional testing in general assembly,the joint model attains an accuracy rate of 95%,outperforming GPT with 78%accuracy and enhanced representation through knowledge integration with 71%accuracy.

关键词： intelligent manufacturing knowledge graph aviation assembly knowledge representation knowledge-based question an-swering

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A toroidal SAW gyroscope with focused IDTs for sensitivity enhancement

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Microsystems & Nanoengineering 2024年第2期10卷 47-56页

作者： lu Tian Haitao zhao Qiang Shen Honglong Chang Ministry of Education Key Laboratory of Micro and Nano Systems for Aerospace School of Mechanical EngineeringNorthwestern Polytechnical UniversityXi’an710072China

A surface acoustic wave(SAW)gyroscope measures the rate of rotational angular velocity by exploiting a phenomenon known as the SAW gyroscope *** a gyroscope is a great candidate for application in harsh environments because of the simplification of the suspension vibration mechanism necessary for traditional microelectromechanical system(MEMS)***,for the first time,we propose a novel toroidal standing-wave-mode SAW gyroscope using focused interdigitated transducers(FIDTs).Unlike traditional SAW gyroscopes that use linear IDTs to generate surface acoustic waves,which cause beam deflection and result in energy dissipation,this study uses FIDTs to concentrate the SAW energy based on structural features,resulting in better focusing performance and increased SAW *** experimental results reveal that the sensitivity of the structure is 1.51µV/(°/s),and the bias instability is 0.77°/s,which are improved by an order of magnitude compared to those of a traditional SAW ***,the FIDT component can enhance the performance of the SAW gyroscope,demonstrating its superiority for angular velocity *** work provides new insights into improving the sensitivity and performance of SAW gyroscopes.

关键词： angular deflection gyroscope

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Characteristics of orthorhombic anisotropic seismic response induced by horizontal in situ stress in vertical transversely isotropic media

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Science China Earth Sciences 2024年第7期67卷 2291-2310页

作者： Xinpeng PAN Chengxu lu Zhizhe zhao jianxin LIU School of Geoscience and Info-Physics Central South UniversityChangsha 410083China Hunan Key Labraory of Nonferrous Resources and Geological Disaster Exploration Central South University Changsha 410083China Key Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring(Central South University) Ministry of EducationChangsha 410083China PowerChina Zhongnan Engineering Corporation Limited Changsha 410014China

Sedimentary strata typically exhibit the characteristics of transverse isotropy(VTI)with a vertical axis of ***,fractures in sedimentary strata tend to produce anisotropic closure due to horizontal in situ stress,resulting in pronounced orthorhombic anisotropy in VTI media under such stress conditions and influencing the propagation behavior of seismic *** studies have primarily focused on the elastic wave velocity anisotropy induced by applied stress in isotropic background media,neglecting the impact of VTI background media on the anisotropy induced by horizontal in situ stress and the response characteristics of seismic wave *** address these gaps,we first establish the effective elastic stiffness tensor of VTI media under horizontal in situ stress using nonlinear acoustoelastic ***,we derive the accurate and linearized approximate equations for P-wave seismic reflectivity of VTI media under horizontal in situ stress,based on wave equations and scattering theory,***,we compare and analyze the characteristics of orthorhombic anisotropic seismic response induced by horizontal in situ stress at various types of elastic reflection *** results demonstrate that the linearized approximation of the seismic reflection response characteristics closely aligns with the accurate equations under conditions of small stress below 10 MPa,effectively capturing the azimuth-dependent orthorhombic anisotropy induced by horizontal in situ stress in VTI *** results of this study also provide a novel theoretical approach and valuable insights into the seismic prediction of in situ stress.

关键词： Horizontal in situ stress Nonlinear acoustoelastic theory Linear slip theory Orthorhombic anisotropy Stress seismic prediction

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Dynamic response of sandwich panel attached with a double mass-spring-damping system to shallow-buried explosion:Analytical modeling

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Science China(Technological Sciences) 2024年第2期67卷 568-586页

作者： ZHANG Dujiang zhao ZhenYu GAO HuiYao lu Tianjian State Key Laboratory of Mechanics and Control for Aerospace Structures Nanjing University of Aeronautics and AstronauticsNanjing 210016China MIIT Key Laboratory of Multifunctional Lightweight Materials and Structures(MLMS) Nanjing University of Aeronautics and AstronauticsNanjing 210016China

How to ensure the safety of occupants has become a challenge for protective design of armored vehicles against intensive blast *** this study,for armored vehicles subjected to shallow-buried explosions,an analytical model was established to characterize the dynamic performance of an all-metallic sandwich floorboard attached with a double mass-spring-damping system(mimicking seat and occupant),with the former consisting of a front face,a core and a rear *** validation,numerical simulations with the method of finite elements(FE)were *** agreement between analytical predictions and numerical results was *** analytical model was then employed to quantify the effects of explosive mass,yield stress of material make,configurational parameters of sandwich panel,spring stiffness,and damping coefficient on dynamic response of the sandwich panel and double mass-spring-damping *** increasing explosive mass and decreasing yield stress of material make,the peak displacements of rear face,seat and occupant were all found to *** core relative density was increased,these peak displacements also increased when the ratio of face thickness to core height was relatively *** the ratio of face thickness to core height led to increased peak accelerations of seat and *** peak displacement of rear face was insensitive to the increase of either spring stiffness or damping coefficient,while the peak acceleration of occupant increased with increasing spring *** increasing the damping coefficient between the rear face and seat or that between the seat and occupant or both,the peak acceleration of occupant *** occupant safety duly considered,the proposed analytical model provides useful guidance for designing high-performance protective structures for armored vehicles subjected to intensive blast loadings.

关键词： analytical model shallow-buried explosion sandwich panel occupant safety mass-spring-damping system

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Construction technology for deep tunnels crossing superhigh-temperature fault zones with high water surges

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Frontiers of Structural and Civil Engineering 2024年第8期18卷 1267-1280页

作者： Yong zhao Tingyu ZHU Li YU Ming lu Sichuan–Xizang Railway Co. Ltd.Linzhi 860000China School of Civil Engineering Southwest Jiaotong UniversityChengdu 610036China

The harsh environment in tunnels with high geothermal temperatures and humidity can adversely impact machinery,personnel,and *** main causes of specific problems are the unknown mechanisms of local geothermal formation,inappropriate temperature control measures,and insufficient systematic *** this study,three work sections relating to a high geothermal tunnel are:the tunnel face,middle-of-tunnel section,and outside-oftunnel section.A cooling strategy is proposed to offer technical support in achieving comprehensive cooling,overall as well as for each of the ***,a comprehensive geological survey explores the mechanism and exact location of the heat ***,grouting and centralized drainage measures are used to control the heat release of hot *** ventilation,ice chillers and other applicable measures are used to control the ambient ***,a monitoring and early warning system is established to prevent *** cooling strategy has been applied in the field with good results.

关键词： high geothermal tunnels cooling strategy comprehensive cooling measures safety and security

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An ultrafast rechargeable hybrid potassium dual-ion capacitor based on carbon quantum dot@ultrathin carbon film cathode

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Rare Metals 2024年第10期43卷 5070-5081页

作者： zhao-Meng Liu Da Wang Shang-Zhuo Li Qing-Song Lai Dong-Run Yang lu-Kang zhao jian-Jia Mu Xuan-Chen Wang Xuan-Wen Gao Wen-Bin luo Institute for Energy Electrochemistry and Urban Mines Metallurgy School of MetallurgyNortheastern University Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education) Nankai University

Ultrafast rechargeable hybrid potassium dualion capacitors （HPDICs） were designed by employing carbon quantum dot@ultrathin carbon film （CQD@CF） as the cathode *** designed CQD@CF is selfassembled by a simple catalytic graphitization route followed by an acid leaching *** special composite features a large adsorption interface,a remarkable anion hybrid storage capability and outstanding structure *** electrochemical performance of CQD@CF composite is fully tapped in a half-cell system at the operating voltage between 1.4 and 4.5 V,achieving an admirable specific discharge capacity of 128.5 mAh·g-1a 50 mA·g-1,an ultra-high capacity retention ratio of 97.97% after cycling 5000 times at 1000 mA·g-1and a 96.10%high capacity retention ratio after cycling 40,000 times at 5000 mA·g-1,***,with the support of ex situ TEM and XPS,the structural stability principle and anionic hybrid storage mechanism of CQD@CF electrode are investigated *** the full-cell system,HPDICs with the CQD@CF as cathode and nanographite powder as anode also present a 141.5 Wh·kg-1high energy density,a 5850 W·kg-1power density and a super-long cycle stability (90.2% capacity retention ratio after cycling 30,000 times at 5000 mA·g-1).

关键词： Anion hybrid storage mechanism Carbon quantum dots Potassium dual ion capacitor Ultrafast rechargeable Ultrathin carbon film

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Exploring the impacts of major events on the systemic risk of the international energy market

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Petroleum Science 2024年第2期21卷 1444-1457页

作者： Ming-Tao zhao Su-Wan lu Lian-Biao Cui School of Statistics and Applied Mathematics Anhui University of Finance and EconomicsBengbu233030AnhuiChina Anhui Province Key Laboratory of Philosophy and Social Science of Low-Carbon Development and Carbon Finance Anhui University of Finance and EconomicsBengbu233030AnhuiChina

This study examines the systemic risk caused by major events in the international energy market(IEM)and proposes a management strategy to mitigate it. Using the tail-event driven network(TENET)method, this study constructed a tail-risk spillover network(TRSN) of IEM and simulated the dynamic spillover tail-risk process through the cascading failure mechanism. The study found that renewable energy markets contributed more to systemic risk during the Paris Agreement and the COVID-19pandemic, while fossil energy markets played a larger role during the Russia-Ukraine conflict. This study identifies systemically important markets(SM) and critical tail-risk spillover paths as potential sources of systemic risk. The research confirms that cutting off the IEM risk spillover path can greatly reduce systemic risk and the influence of SM. This study offers insights into the management of systemic risk in IEM and provides policy recommendations to reduce the impact of shock events.

关键词： International energy market Tail-risk spillover Cascading failure mechanism Systemic risk management

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Reorientation and obstacle avoidance control of free-floating modular robots using sinusoidal oscillator

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Chinese Journal of Aeronautics 2024年第6期37卷 262-275页

作者： Zhiyuan YANG Mingzhu LAI jian QI Ning zhao Xin SUI Jie zhao Yanhe ZHU State Key Laboratory of Robotics and System Harbin Institute of TechnologyHarbin 150001China School of Mathematics and Statistics Hainan Normal UniversityHaikou 571158China

This paper presents that a serpentine curve-based controller can solve locomotion control problems for articulated space robots with extensive flight phases,such as obstacle avoidance during free floating or attitude adjustment before *** proposed algorithm achieves articulated robots to use closed paths in the joint space to accomplish the above *** snakes,which can shuttle through gaps and adjust their landing posture by swinging their body during gliding in jungle environments,inspired the design of two *** first maneuver generates a rotation of the system by varying the moment of inertia between the joints of the robot,with the magnitude of the net rotation depending on the controller *** maneuver can be repeated to allow the robot to reach arbitrary *** second maneuver involves periodic undulations,allowing the robot to avoid collisions when the trajectory of the global Center of Mass(CM)passes through the *** maneuvers are based on the improved serpenoid curve,which can adapt to redundant systems consisting of different numbers of ***,the simulation illustrates that combining the two maneuvers can help a free-floating chain-type robot traverse complex *** proposed algorithm can be used with similar articulated robot models.

关键词： Collision avoidance Modularrobots Reorientation Free-floating space robots Nonholonomic systems Biologically inspired controllers Serpenoid curve

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