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Mechanical properties and fracture surface roughness of thermally damaged granite under dynamic splitting

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Deep Underground Science and Engineering 2024年第1期3卷 103-116页

作者： Yijin qian peng Jia Songze Mao Jialiang Lu School of Resources and Civil Engineering Northeastern UniversityShenyangChina

In order to understand the mechanical properties and the fracture surface roughness characteristics of thermally damaged granite under dynamic splitting,dynamic Brazilian splitting tests were conducted on granite samples after thermal treatment at 25,200,400,and 600℃.Results show that the dynamic peak splitting strength of thermally damaged granite samples increases with increasing strain rate,showing obvious strain‐rate *** increasing temperature,thermally induced cracks in granite transform from intergranular cracks to intragranular cracks,and to a transgranular crack *** induced damages reduce the dynamic peak splitting strength and the maximum absorbed energy while increasing the peak radial *** fracture mode of the thermally damaged granite under dynamic loads is mode Ⅱ splitting *** using the axial roughness index Z2 a,the distribution ranges of the wedge‐shaped failure zones and the tensile failure zones in the fracture surfaces under dynamic Brazilian splitting can be effectively *** radial roughness index Z_(2)^(r)is sensitive to the strain rate and *** shows a linear correlation with the peak splitting strength and the maximum absorbed energy and a linear negative correlation with the peak radial strain.Z_(2)^(r)can be used to quantitatively estimate the dynamic parameters based on the models proposed.

关键词： dynamic splitting fracture surface roughness granite strain rate thermal treatment

Infrared imaging of magnetic octupole domains in non-collinear antiferromagnets

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National Science Review 2024年第06期11卷 197-205页

作者： peng Wang Wei Xia Jinhui Shen yulong Chen Wenzhi peng Jiachen Zhang Haolin Pan Xuhao yu Zheng Liu Yang Gao qian Niu Zhian Xu Hongtao Yang Yanfeng Guo Dazhi Hou International Center for Quantum Design of Functional Materials(ICQD) School of Emerging TechnologyUniversity of Science and Technology of China College of Mathematics and Physics Qingdao University of Science and Technology School of Physical Science and Technology Shanghai Tech University Shanghai Tech Laboratory for Topological Physics Shanghai Tech University Department of Physics University of Science and Technology of China CAS Key Laboratory of Strongly-Coupled Quantum Matter Physics University of Science and Technology of China Xi'an Institute of Optics and Precision Mechanics of Chinese Academy of Sciences

Magnetic structure plays a pivotal role in the functionality of antiferromagnets（AFMs）, which not only can be employed to encode digital data but also yields novel phenomena. Despite its growing significance,visualizing the antiferromagnetic domain structure remains a challenge, particularly for non-collinear AFMs. Currently, the observation of magnetic domains in non-collinear antiferromagnetic materials is feasible only in Mn3Sn, underscoring the limitations of existing techniques that necessitate distinct methods for in-plane and out-of-plane magnetic domain imaging. In this study, we present a versatile method for imaging the antiferromagnetic domain structure in a series of non-collinear antiferromagnetic materials by utilizing the anomalous Ettingshausen effect（AEE）, which resolves both the magnetic octupole moments parallel and perpendicular to the sample surface. Temperature modulation due to AEE originating from different magnetic domains is measured by lock-in thermography, revealing distinct behaviors of octupole domains in different antiferromagnets. This work delivers an efficient technique for the visualization of magnetic domains in non-collinear AFMs, which enables comprehensive study of the magnetization process at the microscopic level and paves the way for potential advancements in applications.

关键词： non-collinear antiferromagnet domain structure infrared imaging anomalous Ettingshausen effect

Temperature trends and its elevation-dependent warming over the Qilian Mountains

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Journal of Mountain Science 2024年第2期21卷 500-510页

作者： ZHAO peng HE Zhibin MA Dengke WANG Wen qian Lihui School of Computer Science Huainan Normal UniversityHuainan 232038China Linze Inland River Basin Research Station Key Laboratory of Inland River Basin ScienceNorthwest Institute of Eco-Environment and ResourceChinese Academy of SciencesLanzhou 730000China University of Chinese Academy of Sciences Beijing 100049China

Understanding temperature variability especially elevation dependent warming(EDW)in high-elevation mountain regions is critical for assessing the impacts of climate change on water resources including glacier melt,degradation of soils,and active layer *** means that temperature is warming faster with the increase of *** this study,we used observed temperature data during 1979-2017 from 23 meteorological stations in the Qilian Mountains(QLM)to analyze temperature trend with Mann-Kendall(MK)test and Sen’s slope *** showed that the warming trends for the annual temperature followed the order of T_min>T_mean>T_max and with a shift both occurred in *** and summer temperature have a higher increasing trend than that in autumn and winter.T_mean shifts occurred in 1996 for spring and summer,in 1997 for autumn and winter.T_max shifts occurred in 1997 for spring and 1996 for summer.T_min shifts occurred in 1997 for spring,summer and winter as well as in 1999 for *** mean diurnal temperature range(DTR)shows a significant decreasing trend(-0.18°C/10a)from 1979 to *** mean DTR shows a significant decreasing trend(-0.26°C/10a)from 1979 to 2017 with a shift occurred in *** removing longitude and latitude factors,we can learn that the warming enhancement rate of average annual temperature is 0.0673°C/km/10a,indicating that the temperature warming trend is accelerating with the continuous increase of *** increase rate of elevation temperature is 0.0371°C/km/10a in spring,0.0457°C/km/10a in summer,0.0707°C/km/10a in autumn,and 0.0606°C/km/10a in winter,which indicates that there is a clear EDW in the *** main causes of warming in the Qilian Mountains are human activities,cloudiness,ice-snow feedback and El Nino phenomenon.

关键词： Climate change Qilian Mountains Warming rates DTR Elevation-dependent warming

Effects of combustion temperature on the optical properties of brown carbon from biomass burning

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Journal of Environmental Sciences 2024年第3期137卷 302-309页

作者： peng Gao Rule Deng Song Jia yue Li Xuefei Wang qian Xing School of Chemistry Sciences University of Chinese Academy of SciencesBeijing 100049China College of Chemistry and Materials Engineering Beijing Technology and Business UniversityBeijing 100048China

Biomass burning has been known as one of main sources of Brown Carbon(BrC)in *** this study,by controlling the combustion temperature at 250℃,350℃,and 450℃,the methanol soluble organic carbon(MSOC)and methanol insoluble carbon(MISC)from pine wood burning was collected by ***–Vis,excitation emission matrix(EEM),TEM and FTIR spectra were applied to investigate the properties of BrC *** MSOC at 250℃ and 350℃,all the spectral profiles of UV–Vis absorption and excitation emission matrix are almost the same,while the EEM of MSOC at 450℃ are different from that of the other *** MISC fuorescence was observed only in the case of 450℃.In the FTIR spectra,with the temperature increasing the peaks associated to the oxygen-contained functions was weakened,indicating the formation of the fuorophores with larger conjugated system,especially aromatic *** results show that biomass combustion at low temperature produces more oxygen-riched BrC,which possesses relatively lower light absorption,while at high temperature produces more aromatics hydrocarbons with relatively strong light *** results of this work are helpful to trace the source of brown carbon and optimize biomass energy utilization.

关键词： Biomass burning Combustion temperature Methanol-soluble brown carbon EEM Impinger

Promising prognostic value of ATP binding cassette transporters and their correlation with tumor-infiltrating immune cells in lung adenocarcinoma

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Genes & Diseases 2024年第5期11卷 91-93页

作者： Linzi Wei qian yu Xueying Yang Department of Thoracic Surgery The Fourth Affiliated Hospital of China Medical UniversityShenyangLiaoning 110032China

Lung cancer(LC)is a prevalent and fatal malignancy,with high incidence and mortality rates.1 ATP binding cassette(ABC)transporters,a superfamily of integral membrane proteins,use ATP hydrolysis to facilitate substrate transport across cellular membranes.2 The pivotal role of ABC transporters in tumorigenesis was initially established by Mochida,3 who demonstrated that the loss of ABCB1 suppresses intestinal polyp formation and tumor progression in *** investigations have reported correlations between ABC transporters and the tumor microenvironment and cancer immunotherapy response,suggesting their modulatory effects on tumor progression and immunotherapy.

关键词： mortality adenocarcinoma Lung

Assessment and control of the mine tremor disaster induced by the energy accumulation and dispersion of thick-hard roofs

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International Journal of Mining Science and Technology 2024年第7期34卷 925-941页

作者： Bin yu Mingxian peng Yang Tai Shuai Guo State Key Laboratory of Coal Mine Disaster Dynamics and Control Chongqing UniversityChongqing 400044China School of Resources and Safety Engineering Chongqing UniversityChongqing 400044China School of Mines China University of Mining and TechnologyXuzhou 221116China

In order to solve the problem that current theory models cannot accurately describe thick-hard roof(THR)elastic energy and assess the mine tremor disasters,a theoretical method,a Timoshenko beam theory on Winkler foundation was adopted to establish the THR’s periodic breaking *** superposition principle was used for this complex model to derive the calculation formulas of the elastic energy and impact load on hydraulic ***,the influence of roof thickness h,cantilever length L_(1),and load q on THR’s elastic energy and impact load was ***,the effect of mine tremor disasters was ***,it is revealed that:(1)The THR’s elastic energy U exhibits power-law variations,with the fitted relationships U=0.0096L_(1)^(3.5866^),U=5943.9h^(-1.935),and U=21.049q^(2).(2)The impact load on hydraulic supports F_(ZJ) increases linearly with an increase in the cantilever length,thickness,and applied *** fitted relationships are F_(ZJ)=1067.3L_(1)+6361.1,F_(ZJ)=125.89h+15100,and F_(ZJ)=10420q+3912.6.(3)Ground hydraulic fracturing and liquid explosive deep-hole blasting techniques effectively reduce the THR’s cantilever length at periodic breakages,thus eliminating mine tremor disasters.

关键词： Dynamic disaster Energy Hard and thick roof Timoshenko beam

Improved spatio-temporal alignment measurement method for hull deformation

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Journal of Systems Engineering and Electronics 2024年第2期35卷 485-494页

作者： XU Dongsheng yu yuanjin ZHANG Xiaoli peng Xiafu School of Automation Beijing Institute of TechnologyBeijing 100081China School of Aerospace Engineering Xiamen UniversityXiamen 361005China

In this paper,an improved spatio-temporal alignment measurement method is presented to address the inertial matching measurement of hull deformation under the coexistence of time delay and large misalignment *** misalignment angle and time delay often occur simultaneously and bring great challenges to the accurate measurement of hull deformation in space and *** proposed method utilizes coarse alignment with large misalignment angle and time delay estimation of inertial measurement unit modeling to establish a brand-new spatiotemporal aligned hull deformation measurement *** addition,two-step loop control is designed to ensure the accurate description of dynamic deformation angle and static deformation angle by the time-space alignment method of hull *** experiments illustrate that the proposed method can effectively measure the hull deformation angle when time delay and large misalignment angle coexist.

关键词： inertial measurement spatio-temporal alignment hull deformation

Nonlinear metamaterial enabled aeroelastic vibration reduction of a supersonic cantilever wing plate

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Applied Mathematics and Mechanics(English Edition) 2024年第10期45卷 1749-1772页

作者： peng SHENG Xin FANG Dianlong yu Jihong WEN Laboratory of Science and Technology on Integrated Logistics Support College of Intelligence Science and TechnologyNational University of Defense TechnologyChangsha 410073China

The violent vibration of supersonic wings threatens aircraft *** paper proposes the strongly nonlinear acoustic metamaterial(NAM)method to mitigate aeroelastic vibration in supersonic wing *** employ the cantilever plate to simulate the practical behavior of a *** aeroelastic vibration model of the NAM cantilever plate is established based on the mode superposition method and a modified third-order piston *** aerodynamic properties are systematically studied using both the timedomain integration and frequency-domain harmonic balance *** presenting the flutter and post-flutter behaviors of the NAM wing,we emphasize more on the preflutter broadband vibration that is prevalent in *** results show that the NAM method can reduce the low-frequency and broadband pre-flutter steady vibration by 50%-90%,while the post-flutter vibration is reduced by over 95%,and the critical flutter velocity is also slightly *** clarified,the significant reduction arises from the bandgap,chaotic band,and nonlinear resonances of the NAM *** reduction effect is robust across a broad range of parameters,with optimal performance achieved with only 10%attached *** work offers a novel approach for reducing aeroelastic vibration in aircraft,and it expands the study of nonlinear acoustic/elastic metamaterials.

关键词： nonlinear acoustic metamaterial(NAM) hypersonic aeroelastic vibration vibration reduction fluid-structure interaction

Therapeutic advances in atrial fibrillation based on animal models

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2024年第2期25卷 135-152页

作者： qian GONG Xuan LE pengcheng yu Lenan ZHUANG Institute of Genetics and Reproduction College of Animal SciencesZhejiang UniversityHangzhou310058China Key Laboratory of Cardiovascular Intervention and Regenerative Medicine of Zhejiang Province Department of CardiologySir Run Run Shaw HospitalSchool of MedicineZhejiang UniversityHangzhou310016China

Atrial fibrillation(AF)is the most prevalent sustained cardiac arrhythmia among humans,with its incidence increasing significantly with *** the high frequency of AF in clinical practice,its etiology and management remain *** develop effective treatment strategies,it is imperative to comprehend the underlying mechanisms of AF;therefore,the establishment of animal models of AF is vital to explore its *** spontaneous AF is rare in most animal species,several large animal models,particularly those of pigs,dogs,and horses,have proven as invaluable in recent years in advancing our knowledge of AF pathogenesis and developing novel therapeutic *** review aims to provide a comprehensive discussion of various animal models of AF,with an emphasis on the unique features of each model and its utility in AF research and *** data summarized in this review provide valuable insights into the mechanisms of AF and can be used to evaluate the efficacy and safety of novel therapeutic interventions.

关键词： Atrial fibrillation Animal model Therapeutic