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Deep Video Harmonization by Improving Spatial-temporal Consistency

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Machine Intelligence Research 2024年第1期21卷 46-54页

作者： Xiuwen chen Li Fang Long Ye qin Zhang Key Laboratory of Media Audio and Video Ministry of Education Communication University of ChinaBeijing 100024China

Video harmonization is an important step in video editing to achieve visual consistency by adjusting foreground appear-ances in both spatial and temporal *** methods always only harmonize on a single scale or ignore the inaccuracy of flow estimation,which leads to limited harmonization *** this work,we propose a novel architecture for video harmoniza-tion by making full use of spatiotemporal features and yield temporally consistent harmonized *** introduce multiscale harmon-ization by using nonlocal similarity on each scale to make the foreground more consistent with the *** also propose a fore-ground temporal aggregator to dynamically aggregate neighboring frames at the feature level to alleviate the effect of inaccurate estim-ated flow and ensure temporal *** experimental results demonstrate the superiority of our method over other state-of-the-art methods in both quantitative and visual comparisons.

关键词： Harmonization temporal consistency video editing video composition nonlocal similarity

The biosynthesis of alarm pheromone in the wheat aphid Rhopalosiphum padi is regulated by hormones via fatty acid metabolism

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Journal of Integrative Agriculture 2024年第7期23卷 2346-2361页

作者： chengxian Sun Yaoguo qin Julian chen Zhengxi Li Department of Entomology/Ministry of Agriculture Key Laboratory for Monitoring and Environment-friendly Control of Crop Pests College of Plant ProtectionChina Agricultural UniversityBeijing 100193China State Key Laboratory for Biology of Plant Diseases and Insect Pests Institute of Plant ProtectionChinese Academy of Agricultural SciencesBeijing 100193China

Aphids are major insect pests in agriculture and forestry *** attacks by natural enemies,many aphids release an alarm pheromone to protect their *** most aphids,the main component of the aphid alarm pheromone(AAP)is the sesquiterpene hydrocarbon(E)-β-farnesene(EβF).However,the mechanisms behind its biosynthesis and regulation remain poorly *** this study,we used the bird cherry–oat aphid Rhopalosiphum padi,which is an important wheat aphid,to investigate the regulatory mechanisms of EβF *** results showed that EβF biosynthesis occurs during the mature embryo period and the molting period of the 1st-and 2nd-instar *** provide the prerequisite material for EβF production and *** on transcriptome sequencing,RNAi analysis,hormone treatments,and quantitative measurements,we found that the biosynthesis of EβF utilizes acetyl coenzyme A produced from fatty acid degradation,which can be suppressed by juvenile hormone but it is promoted by 20-hydroxyecdysone through the modulation of fatty acid *** is the first systemic study on the modulation of EβF production in *** results of our study provide insights into the molecular regulatory mechanisms of AAP biosynthesis,as well as valuable information for designing potential aphid control strategies.

关键词： (E)-β-farnesene critical period for biosynthesis fatty acid metabolism juvenile hormone 20-hydroxyecdysone

An efficient data-driven global sensitivity analysis method of shale gas production through convolutional neural network

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Petroleum Science 2024年第4期21卷 2475-2484页

作者： Liang xue Shuai xu Jie Nie Ji qin Jiang-Xia Han Yue-Tian Liu qin-Zhuo Liao State Key Laboratory of Petroleum Resources and Engineering China University of Petroleum (Beijing) Department of Oil-Gas Field Development Engineering College of Petroleum Engineering China University of Petroleum (Beijing) Chuanqing Drilling Engineering Co.Ltd. China National Petroleum Corporation

The shale gas development process is complex in terms of its flow mechanisms and the accuracy of the production forecasting is influenced by geological parameters and engineering parameters. Therefore, to quantitatively evaluate the relative importance of model parameters on the production forecasting performance, sensitivity analysis of parameters is required. The parameters are ranked according to the sensitivity coefficients for the subsequent optimization scheme design. A data-driven global sensitivity analysis(GSA) method using convolutional neural networks(CNN) is proposed to identify the influencing parameters in shale gas production. The CNN is trained on a large dataset, validated against numerical simulations, and utilized as a surrogate model for efficient sensitivity analysis. Our approach integrates CNN with the Sobol' global sensitivity analysis method, presenting three key scenarios for sensitivity analysis: analysis of the production stage as a whole, analysis by fixed time intervals, and analysis by declining rate. The findings underscore the predominant influence of reservoir thickness and well length on shale gas production. Furthermore, the temporal sensitivity analysis reveals the dynamic shifts in parameter importance across the distinct production stages.

关键词： Shale gas Global sensitivity Convolutional neural network Data-driven

Chain Extender-induced Hydrogen Bonding Organization Determines the Morphology and Properties of Thermoplastic Polycarbonate Polyurethane

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Chinese Journal of Polymer Science 2024年第1期42卷 87-96,I0009页

作者： Yi-Lang qin Ping Zhu chen-Xi Ouyang Xia Dong Fuwai Hospital Chinese Academyof Medical Sciences&Peking Union Medical College/National Center for Cardiovascular DiseasesBejing 100037China CASKey Laboratoryof Engineering Plastics CAS Research/Education Centerfor Excellence in Molecular SciencesInstitute ofChemistryChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

Thermoplastic polycarbonate polyurethanes(PCUs) are multiblock copolymers that have been applied for medical devices for long time. Aliphatic diols are common chain extenders(CE) involved in the composition of the hard segments of PCU. However, limited knowledge was discovered about how the chemical structure of CE affects the hydrogen bonding organization within PCUs and their mechanical *** investigate this problem, a group of PCUs were synthesized respectively by extending the polymer chain with 1,4-butanediol(BDO),aminoethanol(MEA), ethanediol(EO) as three kinds of chain extenders. Tiny differences in the CE chemical structure results in remarkable variations in phase separation, condensed morphologies, thermal and mechanical properties, which are characterized by Fourier transform infrared spectrometer, atomic force microscopy, small-angle X-ray scattering, differential scanning calorimetry, and tensile tests. The microstructural evolution during unilateral deformation and the different mechanism induced by the different CEs was probed and unveil by in situ wide-and small-angle X-ray diffraction. Symmetry of CE can improve the organization of the hydrogen bonding. The coherence strength of the urethane/urea group also plays a key role by comparing the two PCUs with ethanediol and aminoethanol.

关键词： Thermoplastic polycarbonate polyurethane Chain extender Hydrogen bonding Mechanical properties

Path Tracking Controller Design of Automated Parking Systems via NMPC with an Instructible Solution

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Chinese Journal of Mechanical Engineering 2024年第3期37卷 353-367页

作者： Liang chen Zhaobo qin Manjiang Hu Yougang Bian Xiaoyan Peng State Key Laboratory of Advanced Design and Manufacturing Technology for Vehicle College of Mechanical and Vehicle EngineeringHunan UniversityChangsha 410082China Wuxi Intelligent Control Research Institute of Hunan University Wuxi 214115China

Parking difficulties have become a social issue that people have to *** parking system is practicable for quick par operations without a driver which can also greatly reduces the probability of parking *** paper proposes a Lyapunov-based nonlinear model predictive controller embedding an instructable solution which is generated by the modified rear-wheel feedback method(RF-LNMPC)in order to improve the overall path tracking accuracy in parking ***,A discrete-time RF-LNMPC considering the position and attitude of the parking vehicle is proposed to increase the success rate of automated parking ***,the RF-LNMPC problem with a multi-objective cost function is solved by the Interior-Point Optimization,of which the iterative initial values are described as the instructable solutions calculated by combining modified rear-wheel feedback to improve the performance of local optimal ***,the details on the computation of the terminal constraint and terminal cost for the linear time-varying case is *** closed-loop stability is verified via Lyapunov techniques by considering the terminal constraint and terminal cost ***,the proposed RF-LNMPC is implemented on a selfdriving Lincoln MKZ platform and the experiment results have shown improved performance in parallel and vertical parking *** Monte Carlo analysis also demonstrates good stability and repeatability of the proposed method which can be applied in practical use in the near future.

关键词： Automated parking Path tracking controller Nonlinear model predictive control Monte Carlo analysis

ARPES investigation of the electronic structure and its evolution in magnetic topological insulator MnBi2+2nTe4+3n family

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National Science Review 2024年第2期11卷 81-93页

作者： Runzhe xu Lixuan xu Zhongkai Liu Lexian Yang Yulin chen State Key Laboratory of Low Dimensional Quantum Physics Department of PhysicsTsinghua University School of Physical Science and Technology Shanghai Tech University and CAS-Shanghai Science Research Center Shanghai Tech Laboratory for Topological Physics Frontier Science Center for Quantum Information Collaborative Innovation Center of Quantum Matter Department of Physics Clarendon LaboratoryUniversity of Oxford

In the past 5 years,there has been significant research interest in the intrinsic magnetic topological insulator family compounds MnBi2+2nTe4+3n（where n=0,1,2…）.In particular,exfoliated thin films of MnBi2Te4have led to numerous experimental breakthroughs,such as the quantum anomalous Hall effect,axion insulator phase and high-Chern number quantum Hall effect without Landau ***,despite extensive efforts,the energy gap of the topological surface states due to exchange magnetic coupling,which is a key feature of the characteristic band structure of the system,remains experimentally *** electronic structure measured by using angle-resolved photoemission （ARPES） shows significant deviation from ab initio prediction and scanning tunneling spectroscopy measurements,making it challenging to understand the transport results based on the electronic *** paper reviews the measurements of the band structure of MnBi2+2nTe4+3nmagnetic topological insulators using ARPES,focusing on the evolution of their electronic structures with temperature,surface and bulk doping and film *** aim of the review is to construct a unified picture of the electronic structure of MnBi2+2nTe4+3ncompounds and explore possible control of their topological properties.

关键词： magnetic topological insulator MnBi2Te4 electronic structure angle-resolved photoemission spectroscopy

Metal complex catalysts broaden bioorthogonal reactions

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Science China Chemistry 2024年第2期67卷 428-449页

作者： Hanjie Zhang Xiaoyu qin Junping Wang Li Ma Tianfeng chen Department of Chemistry Guangdong Provincial Key Laboratory of Functional Supramolecular Coordination Materials and ApplicationsJinan UniversityGuangzhou510632China

Bioorthogonal reactions involving transition metals have diversified applications in imaging,drug development,chemical catalysis and other *** metals used to catalyze the bioorthogonal reaction mainly include ruthenium,palladium,copper,and ***,the great potential for translational applications of bioorthogonal reaction needs to be further expanded and their reaction efficiency should be ***,it is an urgent need for the development of this field to find more suitable catalysts to efficiently catalyze existing biological orthogonal reactions and expand the types of biological orthogonal ***,this review not only summarizes those transition metal complexes-based catalysts participating in bioorthogonal reaction and some bioorthogonal reactions involving transition metals inside the cells,but also sheds light into the discovery of new transition metal complexes and their future development in applications.

关键词： transition metal complexes bioorthogonal reactions biological applications

Optimal design for rubber concrete layered periodic foundations based on the analytical approximations of band gaps and mapping relations

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Earthquake Engineering and Engineering Vibration 2024年第3期23卷 593-608页

作者： Wu Qiaoyun xu Zhifeng xu Peishan Zeng Wenxuan chen xuyong School of Civil Engineering and Architecture Wuhan Institute of TechnologyWuhan 430073China State Key Laboratory for Health and Safety of Bridge Structures Wuhan 430034China Wuhan Urban Construction Group Co. Ltd.Wuhan 430022China

The seismic performance of rubber concrete-layered periodic foundations are significantly influenced by their design,in which the band gaps play a paramount *** at providing better designs for these foundations,this study first proposes and validates the analytical formulas to approximate the bounds of the first few band *** addition,the mapping relations linking the frequencies of different band gaps are ***,an optimal design method for these foundations is developed,which is validated through an engineering *** is demonstrated that ensuring the superstructure’s resonance zones are completely covered by the corresponding periodic foundation’s band gaps can achieve satisfactory vibration attenuation effects,which is a good strategy for the design of rubber concrete layered periodic foundations.

关键词： periodic foundation band gap vibration attenuation seismic isolation optimal design

Estimation of free core nutation parameters and availability of computing options

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Geodesy and Geodynamics 2024年第1期15卷 61-74页

作者： Weiwei Yang Xiaoming Cui Jianqiao xu qingchao Liu Ming qin State Key Laboratory of Geodesy and Earth's Dynamics Innovation Academy for Precision Measurement Science and TechnologyChinese Academy of SciencesWuhan 430077China University of Chinese Academy of Sciences Beijing 100049China Hubei Luojia Laboratory Wuhan 430079China

The Earth’s Free Core Nutation(FCN) causes Earth tides and forced nutation with frequencies close to the FCN that exhibit resonance ***-precision superconducting gravimeter(SG) and very long baseline interferometry(VLBI) provide good observation techniques for detecting the FCN ***,some choices in data processing and solution procedures increase the uncertainty of the FCN *** this study,we analyzed the differences and the effectiveness of weight function and ocean tide corrections in the FCN parameter detection using synthetic data,SG data from thirty-one stations,and the 10 celestial pole offset(CPO) *** results show that significant discrepancies are caused by different computing options for a single SG *** stacking method,which results in a variation of0.24-5 sidereal days(SDs) in the FCN period(T) and 10^(3)-10^(4) in the quality factor(Q) due to the selection of the weighting function and the ocean tide model(OTM),can effectively suppress this *** statistical analysis results of synthetic data shows that although different weight choices,while adjusting the proportion of diurnal tidal waves involved,do not significantly improve the accuracy of fitted FCN parameters from gravity *** study evaluated a series of OTMs using the loading correction *** fitting of FCN parameters can be improved by selecting the mean of appropriate OTMs based on the evaluation *** the estimation of the FCN parameters based on the forced nutation,it was found that the weight function P_(1) is more suitable than others,and different CPO series(after 2009) resulted in a difference of 0.4 SDs in the T and of 103 in the *** estimated the FCN parameters for SG(T=430.4±1.5 SDs and Q=1.52×10^(4)±2.5×10^(3)) and for VLBI(T=429.8±0.7 SDs,Q=1.88×10^(4)±2.1×10^(3)).

关键词： Free core nutation Superconducting gravimeter Very long baseline interferometry Weight function Ocean tide model