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New method for multibody dynamics based on unknown constraint force

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Science China(Technological Sciences) 2024年第3期67卷 791-808页

作者： tian Ying jia YingHong ZHANG Jun School of Astronautics Beihang UniversityBeijing 100191China Beijing Institute of Control Engineering Beijing 100190China National Laboratory of Space Intelligent Control Beijing 100190China

This paper presents a new method for the dynamics of multibody systems based on unknown constraint force. The method can uniformly solve multibody systems with typical configurations, including the system with rigid-flexible coupling, the system in tree topology, and the system with loop constraints. Unlike common methods, the proposed method can model the loop system without “cutting off” loop constraints, leading to the exact same modelling process as the tree-like system performs. Based on graph theory, a topological record matrix M_(rec) is proposed to capture the arbitrary system configuration. Moreover, constraint forces are selected as the key variables in semi-recursive framework. With the recursive kinematics relationship between adjacent bodies, the constraint force equation is further assembled to achieve the full-state system solution. The numerical simulations demonstrate the accuracy of the proposed method.

关键词： multibody system dynamic modelling rigid-flexible coupling unknown constraint force graph theory semi-recursive algorithm

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Ore Geology,H-O-C Isotopes and 40Ar-39Ar Dating of the Wutonggou Iron Deposit,Eastern tianshan,NW China:Implications for the Source,Timing,and Genesis of Hydrothermal Mineralization in a Sedimentary Iron Deposit

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Journal of Earth Science 2024年第4期35卷 1170-1185页

作者： Chun-long Wang Yi-tian Wang State Key Laboratory of Geological Processes and Mineral Resources Collaborative Innovation Center for Exploration of Strategic Mineral ResourcesSchool of Earth ResourcesChina University of GeosciencesWuhan430074China MNR Key Laboratory of Metallogeny and Mineral Assessment Institute of Mineral ResourcesChinese Academy of Geological SciencesBeijing100037China

The Wutonggou iron deposit is located in the well-known iron metallogenic belt in the eastern tianshan,NW China,and has been regarded as a sedimentary iron *** hydrothermal overprinting could play indispensable roles in the formation of high-grade iron ores in sedimentary iron deposits,previous studies mainly focused on sedimentary-related iron mineralization,while the nature and contribution of hydrothermal fluids are poorly ***,an integrated study of ore geology,H-O-C isotopes and^(40)Ar-^(39)Ar dating,is conducted on the Wutonggou deposit,in order to reveal the features,source,and timing of hydrothermal *** studied deposit includes two mining sections namely the jianshan and ***δ^(18)O values of early magnetite from the jianshan section range from+3.0‰to+5.8‰that nearly consistent with classic magmatic magnetite,while increase to 6.3‰-8.0‰in the late *** from the two sections shows comparable H-O isotopic compositions and identical fractionation trends,and is plotted in or periphery to the primary magmatic water *** from the two sections are broadly similar in carbon and oxygen isotopic compositions,and siderite from the Wutonggou section is plotted in the same ***,comparable stable isotopic compositions and evolution trends indicate similar magmatic fluids contributed hydrothermal iron mineralization in the two mining ***,water-rock interactions of varying degrees generated distinct mineralization styles in the jianshan and Wutonggou sections,and caused the isotopic fractionation in late *** extracted from a hydrothermal siderite ore yielded a^(40)Ar-^(39)Ar plateau age of 299.5±2.0 Ma,indicates the timing of hydrothermal iron mineralization is corresponding to the emplacement of vicinity *** together,the hydrothermal mineralization in the Wutonggou iron deposit was the product of remobilization and upgrading of early sedimentary iron ores,a

关键词： iron deposits H-O-C isotopes 40Ar-39Ar dating sedimentary iron deposits Wutonggou iron deposit eastern tianshan

Mechanism Exploration of Euphorbia fischeriana Steud. for Liver Cancer Based on Aspartic Acid Identification in Metabolomics

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Chinese Journal of Integrative Medicine 2024年第6期30卷 507-514页

作者： ZHAO Jing tian Xin-chen ZHANG jia-qi HUANG Chen SUN Yan QIAO Sen jiaNG Shu-long Clinical Medical Laboratory Center Jining First People’s HospitalJiningShandong Province272000China Cheeloo College of Medicine Shandong UniversityJinan250000China

Objective:To investigate the anti-liver cancer effects and aspartic acid(Asp)-related action mechanism of Euphorbia fischeriana Steud.(LD).Methods:The mice model of liver cancer was established by injection of H22 *** 5 days,mice were randomly divided into model group,sorafenib group(20 mg/kg),LD high-dose(LDH,1.36 g/kg) group,LD medium-dose(LDM,0.68 g/kg) group,and LD low-dose(LDL,0.34 g/kg)group,10 mice each *** were intragastrically administered to the mice once daily for 10 days,*** weight,tumor size and tumor weight were *** index was *** changes of liver cancer tissues were evaluated by hematoxylin and eosin staining and TUNEL *** chromatography-mass spectrometer was used to analyze different metabolites between the model and LDH ***:After LD treatment,tumor weight,tumor size and hepatic index were reduced compared with the model *** and karyorrhexis of tumor cells were ***,61 differential metabolites(18 up-regulated,43 down-regulated) were affirmed and 20 pathways of KEGG(P<0.05) were *** addition,Bel-7402,HepG2 and H22 cell viabilities were significantly increased after adding Asp into the *** then,the cell proliferation effect induced by Asp was ameliorated by ***:The anti-liver cancer efficacy of LD extract was validated in H22 mice model,and inhibition of Asp level might be the underlying mechanism.

关键词： liver cancer Euphorbia fischeriana Steud. aspartic acid metabolomics

Design of acceleration control schedule for adaptive cycle engine based on direct simulation model

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Chinese Journal of Aeronautics 2024年第6期37卷 307-318页

作者： Keran SONG Linyuan jia Yuchun CHEN tian TAN School of Power and Energy Northwestern Polytechnical UniversityXi’an 710072China

To design the optimum acceleration control schedule for the Adaptive Cycle Engine(ACE)in the full flight envelope,this paper establishes a direct simulation model of the ACE transient *** this model,geometric parameters are used to replace the component state *** corresponding relationship between geometric parameters and component state parameters is determined by sensitivity *** geometric variables are controlled when the geometric adjustment speed exceeds the limit,and at the same time the corresponding component state parameters are *** gradient optimization algorism is used to optimize the ground acceleration process of ACE,and the control schedule in terms of operating point of compression components and corrected acceleration rate is used as the full-envelope acceleration control schedule based on the similarity *** acceleration control schedules of the triple-bypass mode and the double-bypass mode are designed in this *** acceleration processes under various flight conditions are simulated using the acceleration control *** with the acceleration process with the linear geometric adjustment schedule,the acceleration performance of ACE is improved by the acceleration control schedule,with the impulse of the acceleration process of the triple-bypass mode being increased by 8.7%-12.3% and the impulse of the double-bypass mode acceleration process being increased by 11.8%-14.1%.

关键词： Adaptive Cycle Engine(ACE) Direct simulation method Acceleration Control schedule Full flight envelope

Torsional deformation-induced gradient hierarchical structure in a 304 stainless steel

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Journal of Iron and Steel Research International 2021年第6期28卷 722-728页

作者： jia-long tian Guang Hu Wei Wang Yi-yin Shan Zhou-hua jiang School of Metallurgy Northeastern UniversityShenyang 110819LiaoningChina Institute of Metal Research Chinese Academy of SciencesShenyang 110016LiaoningChina Shenyang RongRong Science and Technology Co. Ltd.Shenyang 110000LiaoningChina State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang 110819LiaoningChina

After applying torsion to cylindrical 304 stainless steel samples,a gradient structure along the radial direction was *** was found that the volume fraction of a0-martensite increased gradually from the center to the surface of *** possibility of deformation-induced martensitic transformation was analyzed theoretically,whose conclusions were consistent with the experimental *** was found that torsional deformation could produce abundant deformation twin and deformation-induced martensite,which could affect the tensile property of steel *** existence of deformation and martensite during torsion could increase the strength but deteriorate the ductility dramatically during the tensile test,which should be attributed to the weakening of work hardening *** a result of severe deformation,both strain-induced and stress-induced martensite have been ***,two types of martensitic transformation mechanisms during torsional deformation were discussed.

关键词： Gradient material Torsional deformation Thermodynamic calculation 304 stainless steel Martensitic transformation

Unveiling the Re,Cr,and I diffusion in saturated compacted bentonite using machine-learning methods

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Nuclear Science and Techniques 2024年第6期35卷 65-77页

作者： Zheng-Ye Feng Jun-Lei tian Tao Wu Guo-Jun Wei Zhi-long Li Xiao-Qiong Shi Yong-jia Wang Qing-Feng Li Department of Engineering Huzhou UniversityHuzhou 313000China Institute of Theoretical Physics Shanxi UniversityTaiyuan 030006China College of Physics Science and Technology Shenyang Normal UniversityShenyang 110034China

The safety assessment of high-level radioactive waste repositories requires a high predictive accuracy for radionuclide diffusion and a comprehensive understanding of the diffusion *** this study,a through-diffusion method and six machine-learning methods were employed to investigate the diffusion of ReO_(4)^(−),HCrO_(4)^(−),and I−in saturated compacted bentonite under different salinities and compacted dry *** machine-learning models were trained using two *** dataset contained six input features and 293 instances obtained from the diffusion database system of the Japan Atomic Energy Agency(JAEA-DDB)and 15 *** other dataset,comprising 15,000 pseudo-instances,was produced using a multi-porosity model and contained eight input *** results indicate that the former dataset yielded a higher predictive accuracy than the *** gradient-boosting exhibited a higher prediction accuracy(R2=0.92)and lower error(MSE=0.01)than the other machine-learning *** addition,Shapley Additive Explanations,Feature Importance,and Partial Dependence Plot analysis results indicate that the rock capacity factor and compacted dry density had the two most significant effects on predicting the effective diffusion coefficient,thereby offering valuable insights.

关键词： Machine learning Effective diffusion coefficient Through-diffusion experiment Multi-porosity model Global analysis

Constructing the metabolic network of wheat kernels based on structure-guided chemical modification and multi-omics data

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Journal of Genetics and Genomics 2024年第7期51卷 714-722页

作者： Zhitao tian Jingqi jia Bo Yin Wei Chen National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research(Wuhan) Huazhong Agricultural UniversityWuhanHubei 430070China Hubei Hongshan Laboratory WuhanHubei 430070China

Metabolic network construction plays a pivotal role in unraveling the regulatory mechanism of biological activities,although it often proves to be challenging and labor-intensive,particularly with non-model *** this study,we develop a computational approach that employs reaction models based on the structure-guided chemical modification and related compounds to construct a metabolic network in *** construction results in a comprehensive structure-guided network,including 625 identified metabolites and additional 333 putative reactions compared with the Kyoto Encyclopedia of Genes and Genomes *** a combination of gene annotation,reaction classification,structure similarity,and correlations from transcriptome and metabolome analysis,a total of 229 potential genes related to these reactions are identified within this *** validate the network,the functionality of a hydroxycinnamoyltransferase(TraesCS3D01G314900)for the synthesis of polyphenols and a rhamnosyltransferase(TraesCS2D01G078700)for the modification of flavonoids are verified through in vitro enzymatic studies and wheat mutant tests,*** research thus supports the utility of structure-guided chemical modification as an effective tool in identifying causal candidate genes for constructing metabolic networks and further in metabolomic genetic studies.

关键词： Metabolic network Chemical modification Genetic study Wheat kernel Multi-omics

Learning the imaging mechanism directly from optical microscopy observations

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Photonics Research 2024年第1期12卷 7-26页

作者： ZE-HAO WANG long-KUN SHAN TONG-tian WENG tian-long CHEN XIANG-DONG CHEN ZHANG-YANG WANG GUANG-CAN GUO FANG-WEN SUN CAS Key Laboratory of Quantum Information University of Science and Technology of ChinaHefei 230026China CAS Center for Excellence in Quantum Information and Quantum Physics University of Science and Technology of ChinaHefei 230026China University of Texas at Austin AustinTexas 78705USA Hefei National Laboratory University of Science and Technology of ChinaHefei 230088China

The optical microscopy image plays an important role in scientific research through the direct visualization of the nanoworld,where the imaging mechanism is described as the convolution of the point spread function(PSF)and *** on a priori knowledge of the PSF or equivalent PSF,it is possible to achieve more precise exploration of the ***,it is an outstanding challenge to directly extract the PSF from microscopy ***,with the help of self-supervised learning,we propose a physics-informed masked autoencoder(PiMAE)that enables a learnable estimation of the PSF and emitters directly from the raw microscopy *** demonstrate our method in synthetic data and real-world experiments with significant accuracy and noise *** outperforms DeepSTORM and the Richardson–Lucy algorithm in synthetic data tasks with an average improvement of 19.6%and 50.7%(35 tasks),respectively,as measured by the normalized root mean square error(NRMSE)*** is achieved without prior knowledge of the PSF,in contrast to the supervised approach used by DeepSTORM and the known PSF assumption in the Richardson–Lucy *** method,PiMAE,provides a feasible scheme for achieving the hidden imaging mechanism in optical microscopy and has the potential to learn hidden mechanisms in many more systems.

关键词： optical emitter mechanism

Anderson Acceleration of Gradient Methods with Energy for Optimization Problems

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Communications on Applied Mathematics and Computation 2024年第2期6卷 1299-1318页

作者： Hailiang Liu jia-Hao He Xuping tian Department of Mathematics Iowa State UniversityAmesIAUSA Department of Agricultural and Biosystems Engineering Iowa State UniversityAmesIAUSA

Anderson acceleration(AA)is an extrapolation technique designed to speed up fixed-point *** optimization problems,we propose a novel algorithm by combining the AA with the energy adaptive gradient method(AEGD)[arXiv:2010.05109].The feasibility of our algorithm is ensured in light of the convergence theory for AEGD,though it is not a fixed-point *** provide rigorous convergence rates of AA for gradient descent(GD)by an acceleration factor of the gain at each implementation of *** experimental results show that the proposed AA-AEGD algorithm requires little tuning of hyperparameters and exhibits superior fast convergence.

关键词： Anderson acceleration(AA) Gradient descent(GD) Energy stability