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Deep learning characterization of rock conditions based on tunnel boring machine data

Underground Space 2023年第5期12卷 89-101页

作者： Xu Li Min Yao Ji-dong yuan yu-jie Wang peng-yu Li Key Laboratory of Urban Underground Engineering of Ministry of Education Beijing Jiaotong UniversityBeijing 100044China School of Computer and Information Technology Beijing Jiaotong UniversityBeijing 100044China China Institute of Water Resources and Hydropower Research Beijing 100048China China Railway Engineering Equipment Group Co. Ltd.Zhengzhou 450000China

Rock condition perception based on tunnel boring machine(TBM)data is of great importance for not only ensuring tunnel boring safety but also improving construction *** prediction of TBM boring responses(i.e.,torque and total thrust of the cutterhead)largely determines the reliability of rock condition *** this paper,a new architecture of a two-dimensional convolutional neural network(2D-CNN)with a dual-input strategy is proposed to predict the TBM *** TBM Lot 3 of the Yinsong project in Jilin province,China,is taken as the case study in this *** types of models that follow different learning strategies are compared:one is defined as the point model,which only learns data of the stable phase,and the other is defined as the line model,which learns data from both the loading and stable boring *** line model is further improved by the weighted loss function *** results indicate that the strategy of learning data from both the loading phase and stable boring phase and increasing the weight of samples from the stable phase is shown to be optimal in predicting TBM boring *** terms of learning strategies,the line model can learn the influence of active control parameters on passive response parameters,but the point model *** terms of machine learning algorithms,2D-CNN has the best performance,with R2 values of 0.865 and 0.923 for torque and total thrust,*** proposed line model can overcome the problem that the traditional model failed to learn the influence of control *** a model can provide a solid base for the timely optimization of the control parameters in TBM boring process.

关键词： TBM Rock condition perception 2D-CNN Weighted loss function Line model

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Structural and electrical properties of HCl–polyaniline–Ag composites synthesized by polymerization using Ag-coated (NH_4)_2S_2O_8 powder

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International Journal of Minerals,Metallurgy and Materials 2018年第11期25卷 1329-1334页

作者： You Zhou yu-he Zhang Jun-sheng Ma Ming-peng yu Hong Qiu School of Mathematics and Physics University of Science and Technology Beijing

Ag nanoparticles were sputter-deposited on ammonium persulfate((NH_4)_2S_2O_8) powder to obtain(NH_4)_2S_2O_8-Ag powder, which was used to synthesize the HCl-doped polyaniline-Ag(HCl-PANI-Ag) composite via a polymerization procedure. The Ag nanoparticles were dispersed in the HCl-PANI matrix, and their sizes mainly ranged from 3 to 6 nm. The Ag nanoparticles did not affect the structure of emeraldine salt in the composite, and they increased the ordered crystalline regions in the HCl-PANI matrix. The HCl-PANI-Ag composite had a conductivity of(6.8 ± 0.1) S/cm, which is about four times larger than that of the HCl-PANI. The charge transport mechanism in the composite is explained by the three-dimensional Mott variable-range hopping(3D-Mott-VRH).

关键词： hydrochloric-acid-doped polyaniline silver nanoparticles composite structure conductivity

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Soil phosphorus fractions and their availability over natural succession from clear-cut of a mixed broadleaved and Korean pine forest in northeast China

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Journal of Forestry Research 2022年第1期33卷 253-260页

作者： peng yu Xin Zhang Huiyan Gu Jianping Pan Xiangwei Chen Northeast Forestry University Harbin 150040People’s Republic of China Academy of Forest and Grassland Inventory and Planning National Forestry and Grassland AdministrationBeijing 100714People’s Republic of China

To assess phosphorus(P)status of forest soil under naturally restored vegetation,P fractions in the 10-cm soil layer were quantified at different successional stages on the clear-cut site of mixed broadleaved and Korean pine *** communities of shrub,softwood broad-leaved forest,softwood and hardwood broad-leaved forest,and hardwood broad-leaved forest represented different successional stages.A soil sample from a primary broad-leaved and Korean pine stand was the control.A sequential P fractionation scheme extracted empirically defined pools of P and path analysis used to partition the direct and indirect contribution of soil P fractions to available *** results show that available P increased significantly with long-term succession,while both sodium bicarbonate-extractable P(NaHCO_(3)-P)and sodium hydroxide-extractable P(NaOHP)fractions were reduced in early successional stages and increased in late *** to the primary forest,concentrations of P fractions in the four stages significantly decreased except for HCl-P,indicating that soil P supplements over the long-term did not return to primary forest *** results of related analysis also showed that NaHCO_(3)-P_(i)levels were significantly related to available *** to the path analysis coefficient,NaHCO_(3)-P_(i)exhibited the highest effect on available P among eight P fractions;the indirect effects of other P fractions via NaHCO_(3)-P_(i)were larger than those with other P ***,this study suggests that soil P bioavailability gradually improved during natural vegetation restoration on clear-cut sites mainly through the increase of NaHCO_(3)-P,where phosphorous is immediately available,and subsequently available phosphorus Na OH-P.

关键词： Vegetation succession Available phosphorus Phosphorus fractions Correlation analysis Path analysis

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On the comparison of particle regeneration technique and volume adaptive scheme in the compressible flow based on smoothed particle hydrodynamics

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Journal of Hydrodynamics 2022年第3期34卷 408-421页

作者： Ming-Kang Li Shuai Zhang yu-Xiang peng A-Man Zhang College of Shipbuilding Engineering Harbin Engineering UniversityHarbin150001China Nanhai Institute of Harbin Engineering University Sanya572024China School of Marine Engineering and Technology Sun Yat-sen UniversityZhuhai519082China

The collapse of a cavitation bubble is an interesting topic and it has many applications in the engineering *** to its compressible nature,the modelling of a cavitation bubble is not easy by the Lagrangian method,like the smoothed particle hydrodynamics(SPH),as there is large variation of particle ***,there are two kinds of method that have been proposed to deal with this problem:the particle regeneration technique(PRT)and the volume adaptive scheme(VAS).They have all been validated via several numerical tests of compressible flow in the past *** is based on totally different concept,the ultimate simulation results and properties may ***,we intend to compare these two methods based on the Riemann-based SPH solver with monotone upwind-centered scheme for conservation laws(MUSCL)reconstruction via several numerical *** characteristics of these two methods are discussed and the applicable scope for them are also commented for further usage.

关键词： Compressible flow smoothed particle hydrodynamics(SPH) particle regeneration technique(PRT) volume adaptive scheme(VAS)

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Dip-coating processed sponge-based electrodes for stretchable Zn-MnO2 batteries

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Nano Research 2018年第3期11卷 1554-1562页

作者： Hong-Wu Zhu Jin Ge yu-Can peng Hao-yu Zhao Lu-An Shi Shu-Hong yu Division of Nanomaterials & Chemistry Hefei National Laboratory for Physical Sciences at the Microscale Collaborative Innovation Center of Suzhou Nano Science and Technology Department of Chemistry CAS Centre for Excellence in Nanoscience Hefei Science Centre of CAS University of Science and Technology of China Hefei 230026 China

Stretchable electronics are in high demand for next-generation wearable devices, but their fabrication is still challenging. Stretchable conductors, flexible pressure sensors, and foldable light-emitting diodes （LEDs） have been reported; however, the fabrication of stable stretchable batteries, as power suppliers for wearable devices, is significantly behind the development of other stretchable electronics. Several stretchable lithium-ion batteries and primary batteries have been fabricated, but their low capacities and complicated manufacturing processes are obstacles for practical applications. Herein, we report a stretchable zinc/manganese-oxide （Zn-MnO2） full battery based on a silver-nanowire- coated sponge prepared via a facile dip-coating process. The spongy electrode, with a three-dimensional （3D） binary network structure, provided not only high conductivity and stretchability, but also enabled a high mass loading of electrochemically active materials （Zn and MnO2 particles）. The fabricated Zn-MnO2 battery exhibited an areal capacity as high as 3.6 mAh·cm^-2 and could accommodate tensile strains of up to 100% while retaining 89% of its original capacity. The facile solution-based strategy of dip-coating active materials onto a cheap sponge-based stretchable current collector opens up a new avenue for fabricating stretchable batteries.

关键词： stretchable battery,Zn-MnO2 batter silver nanowires,sponge,binary network structure

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Prenatal amoxicillin exposure induces developmental toxicity in fetal mice and its characteristics

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Journal of Environmental Sciences 2024年第3期137卷 287-301页

作者： Yongguo Dai yu peng Wen Hu Yi Liu Hui Wang Department of Pharmacology Wuhan University School of Basic Medical SciencesWuhan 430071China Department of Pharmacy Zhongnan Hospital of Wuhan UniversityWuhan 430071China Hubei Provincial Key Laboratory of Developmentally Originated Disease Wuhan 430071China

Amoxicillin,a widely used antibiotic in human and veterinary pharmaceuticals,is now considered as an“emerging contaminant”because it exists widespreadly in the environment and brings a series of adverse ***,systematic studies about the developmental toxicity of amoxicillin are still *** explored the potential effects of amoxicillin exposure on pregnancy outcomes,maternal/fetal serum phenotypes,and fetal multiple organ development in mice,at different doses(75,150,300 mg/(kg·day))during late-pregnancy,or at a dose of 300 mg/(kg·day)during different stages(mid-/latepregnancy)and courses(single-/multi-course).Results showed that prenatal amoxicillin exposure(PAmE)had no significant infuence on the body weights of dams,but it could inhibit the physical development and reduce the survival rate of fetuses,especially during the ***,PAmE altered multiple maternal/fetal serum phenotypes,especially in *** multi-organ function results showed that PAmE inhibited testicular/adrenal steroid synthesis,long bone/cartilage and hippocampal development,and enhanced ovarian steroid synthesis and hepatic glycogenesis/lipogenesis,and the order of severity might be gonad(testis,ovary)>liver>*** analysis found that PAmE-induced multiorgan developmental and functional alterations had differences in stages,courses and fetal gender,and the most obvious changes might be in high-dose,late-pregnancy and multicourse,but there was no typical rule of a dose-response *** conclusion,this study confirmed that PAmE could cause abnormal development and multi-organ function alterations,which deepens our understanding of the risk of PAmE and provides an experimental basis for further exploration of the long-term harm.

关键词： Amoxicillin Prenatal exposure Fetal development Organ function Developmental toxicity

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Chattering analysis for discrete sliding mode control ofdistributed control systems

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Journal of Systems Engineering and Electronics 2016年第5期27卷 1096-1107页

作者： litong ren shousheng xie yu zhang jingbo peng ledi zhang Aeronautics and Astronautics Engineering College Air Force Engineering University Xi’an 710038 China

The chattering characteristic of sliding mode control isanalyzed when it is applied in distributed control systems （DCSs）.For a DCS with random time delay and packet dropout, a discreteswitching system model with time varying sampling period isconstructed based on the time delay system method. The reachinglaw based sliding mode controller is applied in the proposedsystem. The exponential stability condition in the form of linearmatrix inequality is figured out based on the multi-Lyaponov functionmethod. Then, the chattering characteristic is analyzed for theswitching system, and a chattering region related with time varyingsampling period and external disturbance is proposed. Finally, numericalexamples are given to illustrate the validity of the analysisresult.

关键词： distributed control system sliding mode control,switching system chattering analysis.

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Microstructure recognition of steels by machine learning based on visual attention mechanism

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Journal of Iron and Steel Research International 2024年第4期31卷 909-923页

作者： Xing-yu Chen Lin Cheng Cheng-yang Hu yu-peng Zhang Kai-ming Wu The State Key Laboratory of Refractories and Metallurgy Hubei Province Key Laboratory of Systems Science on Metallurgical ProcessingInternational Research Institute for Steel TechnologyCollaborative Center on Advanced SteelsWuhan University of Science and TechnologyWuhan 430081HubeiChina Metals Valley and Band(Foshan)Metallic Composite Materials Co. Ltd.Foshan 528000GuangdongChina

U-Net has achieved good performance with the small-scale datasets through skip connections to merge the features of the low-level layers and high-level layers and has been widely utilized in biomedical image segmentation as well as recent microstructure image segregation of the *** representative visual attention mechanism modules,named as squeeze-and-excitation networks,convolutional block attention module,and extended calibration algorithm,were intro-duced into the traditional U-Net architecture to further improve the prediction *** is found that compared with the original U-Net architecture,the evaluation index of the improved U-Net architecture has been significantly improved for the microstructure segmentation of the steels with the ferrite/martensite composite microstructure and pearlite/ferrite composite microstructure and the complex martensite/austenite island/bainite microstructure,which demonstrates the advantages of the utilization of the visual attention mechanism in the microstructure *** reasons for the accuracy improvement were discussed based on the feature maps analysis.

关键词： Microstructure recognition-Steel Machine learning Visual attention mechanism Visualization

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Joined AZ31B Magnesium Alloys with Ag Interlayer by Ultrasonic-Induced Transient Liquid Phase Bonding in Air

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Acta Metallurgica Sinica(English Letters) 2024年第7期37卷 1177-1185页

作者： Qian Wang peng yu Haoran Lin Chongzhi Guo Xiaoqiang Hu Ganjiang Innovation Academy Chinese Academy of SciencesGanzhou341119China School of Rare Earths University of Science and Technology of ChinaHefei230026China Shenyang 7D New Materials Equipment Co.LTD. Shenyang110076China Shenyang National Laboratory of Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang110016China

AZ31B magnesium alloys are commonly used in lightweight structures of automobile and aerospace *** this work,the ultrasonic-induced transient liquid phase bonding technique is deployed to joint AZ31B magnesium alloys at 490℃ with Ag interlayer in the *** effect of ultrasonic vibration on microstructure and mechanical properties of welding seam is *** vibration duration increases,the width of the welding seam increases firstly and then *** the ultrasound vibration sustained for one second,the eutectic reaction occurred in the contacting interface between Ag interlayer and the base metal AZ31B,resulting in formation of liquid phase and metallurgical *** the ultrasound vibration sustained for seven second,the width of the welding seam increased to a maximum of about 303.1μm and the average shear bond strength of the welding joint attained the peak value of about 66.87 *** the ultrasound vibration sustained over seven seconds,the liquid phase is gradually squeezed out and the width of the welding seam decreases.α-Mg and AgMg_(3) can be observed in the welding *** analysis shows thatα-Mg has a certain strengthening *** whole process of appearance,growth and integration ofα-Mg is analyzed.

关键词： Ultrasonic bonding Magnesium alloy Silver Microstructure Intermetallic compound

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Evolution of fermion resonance in thick brane

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Communications in Theoretical Physics 2024年第12期76卷 129-139页

作者： Chun-Chun Zhu Qin Tan yu-peng Zhang yu-Xiao Liu Institute of Theoretical Physics & Research Center of Gravitation Lanzhou University Key Laboratory of Quantum Theory and Applications of Mo E Lanzhou University Lanzhou Center for Theoretical Physics & Key Laboratory of Theoretical Physics of Gansu Province Lanzhou University

In this work, we investigate the numerical evolution of massive Kaluza–Klein(KK) modes of a Dirac field on a thick brane. We deduce the Dirac equation in five-dimensional spacetime, and obtain the time-dependent evolution equation and Schr?dinger-like equation of the extradimensional component. We use the Dirac KK resonances as the initial data and study the corresponding dynamics. By monitoring the decay law of the left-and right-chiral KK resonances, we compute the corresponding lifetimes and find that there could exist long-lived KK modes on the brane. Especially, for the lightest KK resonance with a large coupling parameter and a large three momentum, it will have an extremely long lifetime.

关键词： braneworld dynamic evolution fermion resonance

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