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Experimental,Numerical,and Analytical Studies on the Bending of Mechanically Lined Pipe

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China Ocean Engineering 2024年第2期38卷 221-232页

作者： WEI wen-bin YUAN Lin ZHOU jia-sheng LIU zheng State Key Laboratory of Hydraulic Engineering Simulation and Safety Tianjin UniversityTianjin 300072China School of Civil Engineering Tianjin UniversityTianjin 300072China School of Mechanical Engineering Tianjin UniversityTianjin 300072China

Mechanically lined pipe(MLP)is often used for offshore oil and gas transport because of its low cost and corrosion *** installation and operation,the pipe may undergo severe bending deformation,which causes the liner to separate from the outer pipe and buckles,affecting the stability of the whole *** this paper,the buckling response of MLP subjected to bending is investigated to clarify its bending characteristics by employing both experiments,numerical simulation,as theoretical *** types of MLPs were manufactured with GB 45 carbon steel(SLP)and Al 6061(ALP)used as the outer pipe material,*** hydraulic expansion and bending experiments of small-scale MLPs are *** addition to the ovalized shape of the cross-section for the SLP specimens,the copper liner was found to wrinkle on the compressive *** contrast,the liner of ALP remains intact without developing any wrinkling and collapse *** addition,a dedicated numerical framework and theoretical models were also *** was found both the manufacturing and bending responses of the MLP can be well reproduced,and the predicted maximum moment and critical curvatures are in good agreement with the experimental results.

关键词： lined pipe bending nonlinear ring theory buckling plasticity

Experimental observation of spontaneous symmetry breaking in a quantum phase transition

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Science China(Physics,Mechanics & Astronomy) 2024年第2期67卷 34-39页

作者： wen Ning Ri-Hua zheng jia-Hao Lu Fan Wu Zhen-Biao Yang Shi-Biao zheng Fujian Key Laboratory of Quantum Information and Quantum Optics College of Physics and Information EngineeringFuzhou UniversityFuzhou 350108China Hefei National Laboratory Hefei 230088China

Spontaneous symmetry breaking(SSB)plays a central role in understanding a large variety of phenomena associated with phase transitions,such as superfluid and *** far,the transition from a symmetric vacuum to a macroscopically ordered phase has been substantially *** process bridging these two distinct phases is critical to understanding how a classical world emerges from a quantum phase transition,but so far remains unexplored in *** here report an experimental demonstration of such a process with a quantum Rabi model engineered with a superconducting *** move the system from the normal phase to the superradiant phase featuring two symmetry-breaking field components,one of which is observed to emerge as the classical *** results demonstrate that the environment-induced decoherence plays a critical role in the SSB.

关键词： quantum phase transition Rabi model spontaneous symmetry breaking superconducting circuit Schrodinger cat states

Ceramic-based meta-material absorber with high-temperature stability

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Rare Metals 2024年第9期43卷 4433-4440页

作者： Xing-Cong Chen Wei-jia Luo Run-Ni Zhao Yong-zheng wen Ji Zhou State Key Laboratory of New Ceramics and Fine Processing School of Materials Science and EngineeringTsinghua UniversityBeijing 100084China

With the continuous exploration of uncharted and extreme environments,enhanced temperature robustness of passive devices has become particularly *** this study,a ceramic-based meta-material absorber with exceptional temperature stability is developed using a fusion design approach that combines rare metal-based tungsten bronze structural ceramics and ***,the absorbance of the meta-material array based on Mie resonance exceeds 49.0%in both waveguides and free space,approaching the theoretical *** to impedance analysis,the absorption performance can be distinctly correlated with the dielectric loss(Q_(f)).Notably,the high-temperature robustness is verified to still be effective at 400℃.These advancements in our design allow for the use of monolithic materials in fabricating temperature-stable perfect absorbers,providing greater freedom in the dielectric performance and expanding their potential applications,including in space exploration and 5G millimeter-wave scenarios.

关键词： Temperature robustness Meta-material absorber Microwave absorption Rare metal-based ceramics Miniaturization

Effect of Land Use on Soil Erosion and Nutrients in Dianchi Lake Watershed, China

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Pedosphere 2015年第1期25卷 103-111页

作者： NIU Xiao-Yin WANG Yan-Hua YANG Hao zheng jia-wen ZOU Jun XU Mei-Na WU Shan-Shan XIE Biao College of Geography Sciences Nanjing Normal University College of Resource and Environmental Engineering Shandong University of Technology

Soil erosion and loss of soil nutrients have been a crucial environment threat in Southwest China. The land use and its impact on soil qualities continue to be highlighted. The present study was conducted to compare soil erosion under four land use types(i.e.,forestland, abandoned farmland, tillage, and grassland) and their effects on soil organic carbon(SOC), total nitrogen(TN) and total phosphorus(TP) in the Shuanglong catchment of the Dianchi Lake watershed, China. There were large variations in the erosion rate and the nutrient distributions across the four land use types. The erosion rates estimated by137 Cs averaged 2 133 t km-2year-1under tillage and abandoned farmland over the erosion rate of non-cultivated sites, and the grasslands showed a net deposition. For all sites, the nutrient contents basically decreased with the soil depth. Compared with tillage and abandoned farmland, grassland had the highest SOC and TN contents within 0–40 cm soil layer, followed by forestland. The significant correlations between137 Cs, SOC and TN were observed. The nutrient loss caused by erosion in tillage was the highest. These results suggested that grassland and forestland would be beneficial for SOC and TN sequestration over a long-term period because of their ability to reduce the loss of nutrients by soil erosion. Our study demonstrated that reduction of nutrient loss in the red soil area could be made through well-managed vegetation restoration measures.

关键词： 137Cs nutrient loss soil organic carbon total nitrogen total phosphorus vegetation restoration

Dynamic simulation analysis of molten salt reactor-coupled air-steam combined cycle power generation system

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Nuclear Science and Techniques 2024年第2期35卷 222-233页

作者： Jing-Lei Huang Guo-Bin jia Li-Feng Han wen-Qian Liu Li Huang zheng-Han Yang Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China University of Chinese Academy of Sciences Beijing 100049China

A nonlinear dynamic simulation model based on coordinated control of speed and flow rate for the molten salt reactor and combined cycle systems is proposed here to ensure the coordination and stability between the molten salt reactor and power *** model considers the impact of thermal properties of fluid variation on accuracy and has been validated with *** study reveals the capability of the control system to compensate for anomalous situations and maintain shaft stability in the event of perturbations occurring in high-temperature molten salt tank outlet ***,the control system’s impact on the system’s dynamic characteristics under molten salt disturbance is also *** results reveal that after the disturbance occurs,the controlled system benefits from the action of the control,and the overshoot and disturbance amplitude are positively correlated,while the system power and frequency eventually return to the initial *** simulation model provides a basis for utilizing molten salt reactors for power generation and maintaining grid stability.

关键词： Molten salt reactor Combined cycle Dynamic characteristic Control

Iron-based layered double hydroxide packed with metal-organic frameworks for enhanced overall water-splitting electrocatalysis

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Tungsten 2024年第4期6卷 859-868页

作者： Long Chen Yun Luo Zhi-Peng Yu Yi-Kun Cheng Yang zheng Li He jia-Hao Xiong wen-wen Kong Key Laboratory for Green Process of Chemical Engineering of Xinjiang Bingtuan School of Chemistry and Chemical Engineering Shihezi University Institute of Scientific Research Luzhou North Chemistry Industry Co.Ltd International Iberian Nanotechnology Laboratory (INL) CAS Key Laboratory of Functional Materials and Devices for Special Environments Xinjiang Key Laboratory of Electronic Information Materials and Devices Center of Materials Science and Optoelectronics Engineering Xinjiang Technical Institute of Physics and Chemistry of CAS

Designing hybrid materials with numerous catalytic active sites,high specific surface area,and interfacial interactions is an effective strategy to improve electrocatalytic *** this work,iron-based metal organic frameworks（Fe-MOFs）@（Co,Ni）Fe-layered double hydroxide（LDH） is successfully constructed using the similar "MOF growing on LDH" strategy for oxygen evolution reaction and hydrogen evolution reaction in the alkaline *** synthesized hybrid materials in this particular way show excellent electrochemical overall water-splitting performance with the cell voltage of 1.62 V at10 mA·cm-2in the alkaline environment due to the optimized adsorption/desorption properties of metal ions on oxygencontaining species and interfacial effects of hybrid ***-MOFs@（Co,Ni）Fe-LDH also exhibits excellent hydrogen and oxygen production efficiency of 370 and 175 μL·min-1,*** work draws on an effective approach to the fabrication of MOF@LDH structures and provides new insights into overall water-splitting in alkaline conditions.

关键词： Electrocatalysis Interfacial interactions Layered double hydroxide Metal–organic frameworks (MOFs) Water splitting

Black hole evaporation and its remnants with the generalized uncertainty principle including a linear term

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Communications in Theoretical Physics 2024年第2期76卷 125-136页

作者： Bo Yu zheng-wen Long College of Physics Guizhou UniversityGuiyang550025China

In recent years,researchers have investigated the evaporation of Schwarzschild black holes using various forms of the generalized uncertainty principle(GUP),metric quantum correction,and noncommutative geometry,***,there are differences between the GUP correction and the other two methods in terms of describing the later stages of black hole ***,some studies argue that the GUP with a negative parameter cannot effectively correct black hole evaporation,while others contend that the positivity or negativity of the GUP parameters should not affect the correction *** the above into consideration,we reconsider black hole evaporation with the generalized uncertainty principle including a linear term(LGUP),and examine the case of negative *** results indicate that the evaporation behavior of both Schwarzschild black holes and Reissner–Nordstr?m black holes,under LGUP correction,is consistent with the results of metric quantum correction and non-commutative ***,the negative parameter LGUP can also effectively correct for black hole evaporation.

关键词： black hole evaporation generalized uncertainty principle negative parameter

The rate dependence of the dielectric strength of dielectric elastomers

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International Journal of Smart and Nano Materials 2024年第1期15卷 110-126页

作者： Xianghe zheng jianyou Zhou Pan jia zheng Zhong School of Science Harbin Institute of TechnologyShenzhenChina

Elastomers are widely used in electronics and electrical devices,either as insulators or *** insulation and actuation performance of elastomers are highly suscepti-ble to their dielectric *** the factors that influ-encethedielectricstrength ofelastomers,material viscoelasticity is an important factor that needs further *** the material viscoelasticity is often character-ized by rate-dependent behaviors,we present two different sample configurations to experimentally examine the electrical and mechanical rate dependence of the dielectric strength of VHB 4905 *** pre-stretch ratio of 4,the improve-ment of the dielectric strength is about 30%from voltage ramp of 50 V/s to 800 V/***,with an in-house biaxial test platform,the effect of the stretching rate on the dielectric strength is examined for the first *** improvement of the dielectric strength is about 35%from stretching rate of 0.1 mm/s to 5 mm/***,a dielectric strength predictor based on configurational stress is adopted to describe the experimental *** to the predictor,the loading rate affects the dielectric strength of the elastomer mainly by influencing the evolution of the inelastic deformation.

关键词： Dielectric strength dielectric elastomers material viscoelasticity rate-dependence configurational stress

Effect of Pre-strain on Microstructure and Stamping Performance of High-strength Low-alloy Steel

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Journal of Wuhan University of Technology(Materials Science) 2024年第3期39卷 774-780页

作者：刘坡 wen Zhicheng LIU zheng 许峰 School of Mechanical Engineering Guilin University of Aerospace TechnologyGuilin 541004China School of Automotive Engineer-ing Changshu Institute of TechnologyChangshu 215500China

In this study,pre-strain ranging from 0 to 0.12 was applied through uniaxial tension on high-strength low-alloy(HSLA)specimens with four kinds of grain *** of pre-strain and grain size on me-chanical property was investigated through tensile *** of the pre-strained and tensile tested samples were analyzed,*** 30.8°v-bending and following flattening,as well as Erichson cupping tests,were performed on the pre-strained *** show the elongation ratio of grain and dislocation density increases with *** platform is removed when pre-strain is larger than 0.06 while yielding plateau period decreases with pre-strain less than 0.06 due to reduction of pinning *** 30.8°v-bending and the following flattening tests are successfully accomplished on all the pre-strained samples with different grain *** in grain size,along with increase in pre-strain,causes increase in strength and decrease in elongation rate as well as cupping ***-strain causes very slight effect on bending ability,much less than that on mechanical property and cupping test *** impact of the pre-strain and grain size on HSLA steel deformability is inconspicuous.

关键词： strain hardening dislocation texture bending erichson cupping test