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块系岩体准共振诱发弱夹层拉压损伤断裂研究

岩石力学与工程学报 2025年第1期44卷 114-127页

作者：王凯兴徐伟刚潘一山薛佳琪 OPARIN V N kiryaeva t A 辽宁工程技术大学力学与工程学院辽宁阜新123000 俄罗斯科学院西伯利亚分院矿业研究所俄罗斯新西伯利亚630091

当外界扰动频率接近块系岩体的固有频率时,会出现准共振现象。这一现象导致岩块间的弱夹层应变急剧变化,从而加快弱夹层的动态损伤断裂。为了研究块系岩体准共振导致岩块间弱夹层的动态拉压损伤断裂规律,基于块系岩体模型,分析准共振状... 详细信息

当外界扰动频率接近块系岩体的固有频率时,会出现准共振现象。这一现象导致岩块间的弱夹层应变急剧变化,从而加快弱夹层的动态损伤断裂。为了研究块系岩体准共振导致岩块间弱夹层的动态拉压损伤断裂规律,基于块系岩体模型,分析准共振状态下弱夹层的变形特征。结合岩石动态损伤断裂准则,对准共振状态下弱夹层的动态损伤断裂进行理论计算分析,进而研究动态破坏规律。通过数值模拟揭示了准共振状态下块系岩体中弱夹层的损伤演化特征。结果表明:当块系岩体发生准共振现象时,岩块间的相对位移急剧增加,使得弱夹层的应变和损伤程度明显增大;弱夹层的损伤程度在准共振频率下最高,同时受外部扰动力和弱夹层的刚度、黏性、厚度及岩块质量等系统参数的影响;块系岩体发生准共振时断裂应力增大,但从断裂到完全破坏的时间明显缩短,即残余承载能力大幅下降。该研究对认识块系岩体的动态断裂具有一定的参考价值。

关键词：岩石力学块系岩体准共振弱夹层变形动态损伤断裂

Magnetosymbiosis discovery:new perspectives in magnetotaxis research

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Journal of Oceanology and Limnology 2025年第1期43卷 177-186页

作者： Caroline L.MONtEIL Christopher t.LEFEVRE Aix-Marseille Université CEACNRSInstitute of Biosciences and Biotechnologies of Aix-MarseilleSaint-Paul-lez-Durance 13115France

Magnetotactic bacteria have been the only known magnetoreceptive microorganisms for *** if the existence of magnetotactic protists was suggested in 1986,this is only 30 years later t.a. magnetotaxis was extended to the domain of Eukaryota,t.a.ks to the characterization of magnetotactic symbiotic assemblies composed of a flagellated protist.a.d bacteria biomineralizing magnetic *** mut.a.istic ectosymbiosis relies on a collective magnetotaxis coupled to a hydrogen-based *** new form of cooperation challenges our view of magnetic biomineralization in prokaryotes and magnetoreception in *** this review,we present how magnetosymbiosis was discovered and how cooperation ***,we discuss the future research and the new perspectives such discovery brought to the field of magnetotaxis.

关键词： magnetotaxis biomineralization symbiosis magnetotactic

t.a.sport mechanism in chemically reactive hybrid nanofluid flow containing gyrotactic micro-organisms over a curved oscillatory surface

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Applied Mathematics and Mechanics(English Edition) 2025年第1期46卷 177-192页

作者： M.NAVEED M.IMRAN t.a.GHAR Z.ABBAS Department of Mathematics Division of Science and TechnologyUniversity of Education Department of Mathematics The Islamia University of Bahawalpur

this paper examines the t.a.sport.a.alysis, including both heat t.a.sfer and mass t.a.sfer, in hybrid nanofluid flow containing gyrotactic microorganisms towards a curved oscillatory surface. the influence of magnetic fields is also inspected in terms of their physical characteristics. to depict the phenomena of t.a.sport, modified versions of both Fick's and Fourier's laws are used. Additionally, the characteristics of both heterogeneous and homogeneous chemical reactions are also incorporated. Utilizing a curvilinear coordinate system, the flow problem is formulated as part.a. different.a. equations(PDEs)for momentum, concent.a.ion, microorganism field, and energy. An analytical solution to the obtained flow equations is achieved utilizing the homotopy analysis method(HAM).the effects of significant flow parameters on the pressure and microorganism fields, velocity, oscillation velocity, concent.a.ion, and temperature distributions are shown via graphs. Furthermore, the variations in skin friction, mass t.a.sfer rate, heat t.a.sfer rate, and local motile number due to different involved parameters are presented in tables and are analyzed in detail. Graphical results indicate t.a. the curves of velocity and temperature fields are enhanced as the values of the solid volume fraction variables *** is also verified t.a. the concent.a.ion rate field decreases as the values of the homogeneous reaction strength parameter and the radius of curvature parameter increase, and it increases with the Schmidt number and the heterogeneous reaction strength *** outcomes show a favorable response of the motile number to advanced values of the Peclet number, the Schmidt number, the microorganism difference parameter, and the bio-convective Lewis number.

关键词： analytical solution Cat.a.eo-Christov heat.a.d mass flux chemical reaction gyrotactic microorganism hybrid nanofluid O368 oscillating curved stretchable sheet

Simple operated multipurpose temperature control cryostat

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第5期8卷 793-796页

作者： ABBAS t.a. OMAR M.S. Department of Physics College of Science University of SalahaddinArbilIraqi KurdistanIraq

A suitable simple optical cryostat for optical, magneto-optical, electrical and thermo-electrical measurements was designed. It is suitable for use in a magnetic pool gap as narrow as less t.a. 1 cm. throughout.a.long period of time, the heat diffusion process of the cryostat can be easily operated at slow increase in sample temperature in a range 1.25 K/min at 200 K t.a. will be reduced gradually to 0.66 K at room temperature. Liquid nitrogen was used to cool down the temperature. During the operation, the change in the measured energy gap of a semiconductor sample and other physical parameters resulting from the change of temperature can be corrected through the temperature coefficient of t.a. parameter at the corresponding temperature. the cryostat was successfully used for all experiments mentioned above to measure the properties of a single crystal of GaP (Gallium Phosphate) semiconductor.

关键词： Optical cryostat Electrical cryostat Magneto-optical cryostat

Piston mechanism of interaction of non-linear geomechanical and physicochemical gas exchange and mass t.a.sfer processes in coal-bearing rocks

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Geohazard Mechanics 2023年第2期1卷 110-118页

作者： t.a.kiryaeva N.A.Chinakal Institute of Mining SB RAS Novosibirsk630091Russia

the article focuses on a theoretical and experimental framework for the quantification of interaction between nonlinear geomechnical and physicochemical processes in high-stress coal-bearing rock mass during mining under high seismic risk due to large-scale blasting and earthquakes,as well as because of structural and temperature *** tests were aimed to examine and study comprehensively the piston mechanism of gas exchange and mass t.a.sfer processes,revealed recently at the Institute of Mining,SB RAS,as well as to explain the fact t.a. the earthquake-induced low-velocity(quasi-meter range)pendulum waves(velocity to 1 m/s and frequency of 0.5–5 Hz)could stimulate an increase in the gas content in coal *** order to perform laboratory investigation at the Institute of Mining SB RAS,special-purpose stand for analyzing gas exchange and mass t.a.sfer processes in coal-bearing geomaterials under various thermodynamic conditions(P,V,t.a.d gas composition was constructed in cooperation with the Institute of Semiconductors Physics SB *** of air flow rate with compression pressures allowed to obtain relations showing t.a. air flow rate increases at the uncertain time interval under the increasing of the compression *** same measurements was carried out with another gases such as Hydrogen H_(2),Helium He,met.a.e CH_(4),carbon dioxide CO_(2) and carbon oxide *** laboratory tests aimed to detailed investigation of the previously revealed“piston mechanism”of gas exchange and mass t.a.sfer processes in the coal specimens and their quantitative description in terms of theory of the pendulum waves were carried in the first ***,there are some arguments for the testing of the opportunity of quantitative description of the“piston mechanism”related to gas exchange and mass t.a.sfer processes in the scale of coal *** is relevant when pendulum waves induced by powerful earthquakes and technical blasting reaches the mine.

关键词： Coal-bearing rock mass Non-linear geomechanical and physicochemical gas exchange and mass t.a.sfer processes Low-velocity pendulum waves Gas-dynamic activity Coal mines

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块系覆岩破坏对巷道顶板的防冲吸能效应研究

中国矿业大学学报 2017年第6期46卷 1211-1217,1230页

作者：王凯兴窦林名潘一山 kiryaeva t A 辽宁工程技术大学力学与工程学院辽宁阜新123000 中国矿业大学煤炭资源与安全开采国家重点实验室江苏徐州221116 俄罗斯科学院西伯利亚分院矿业研究所俄罗斯新西伯利亚630091

通过块系覆岩动力传播顶板响应计算,从理论上分析了覆岩破坏程度和破坏深度对岩体动力传播携带能量的耗散作用.结果表明:随着覆岩破坏程度的增大巷道顶板在动载作用下的冲击启动时刻明显延迟,有效延缓了冲击能量的传递,顶板的冲击力、... 详细信息

通过块系覆岩动力传播顶板响应计算,从理论上分析了覆岩破坏程度和破坏深度对岩体动力传播携带能量的耗散作用.结果表明:随着覆岩破坏程度的增大巷道顶板在动载作用下的冲击启动时刻明显延迟,有效延缓了冲击能量的传递,顶板的冲击力、动能和位移响应幅值均随覆岩破坏程度的增大而下降,且顶板冲击力衰减明显,可有效耗散岩体中的冲击能量实现覆岩破坏吸能防冲效果.同时,覆岩破坏深度与顶板位移,冲击力及动能幅值的衰减均呈现正相关性,但其衰减幅度与覆岩破坏深度之间存在非单调变化关系.

关键词：冲击地压吸能防冲块系岩体顶板响应岩体破坏

Circadian nutrition:is meal timing an elixir for fatigue?

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Science Bulletin 2025年第3期70卷 309-312页

作者： Zhihui Zhang Lu Yan Jonas t.treebak Min-Dian Li Department of Cardiovascular Medicine Center for Circadian Metabolism and Cardiovascular DiseaseSouthwest HospitalArmy Medical UniversityChongqing 400038China Ministry of Education(MOE)Key Laboratory of Geriatric Cardiovascular and Cerebrovascular Disease Chongqing 400038China Novo Nordisk Foundation Center for Basic Metabolic Research Faculty of Health and Medical SciencesUniversity of CopenhagenCopenhagen 2200Denmark

Fatigue is increasingly prevalent in industrialized societies,highlighting an urgent need for effective clinical and lifestyle *** manifests as reduced muscle endurance,strength and a persistent sensation of exhaustio... 详细信息

关键词： fatigue strength sensation

Free vibration and t.a.sient response of double curved beams connected by intermediate st.a.ght beams

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Applied Mathematics and Mechanics(English Edition) 2025年第1期46卷 37-62页

作者： R.A.JAFARI-tALOOKOLAEI H.GHANDVAR E.JUMAEV S.KHAtIR t.CUONG-LE School of Mechanical Engineering Babol Noshirvani University of Technology Department of Mechanical Engineering Faculty of Engineering New Uzbekistan University University of Business and Science Center for Engineering Application and technology Solutions Ho Chi Minh City Open University

this paper investigates the free vibration and t.a.sient response of interconnected structures including double curved beams and intermediate st.a.ght beams,which are all constructed from functionally graded porous(FGP) materials. the st.a.n potent.a. and kinetic energies of each beam along with the work done by the external force are calculated. Additionally, a higher-order beam element is introduced to derive stiffness and mass matrices, along with the force vector. the curved and st.a.ght beams are discretized, and their assembled stiffness, mass matrices, and force vectors, are *** conditions at the joints are used to derive the total matrices of the entire structure. Subsequently, the natural frequencies and t.a.sient response of the system are determined. the accuracy of the mathematical model and the self-developed computer program is validated through the comparison of the obtained results with those of the existing literature and commercial soft.a.e ANSYS, demonst.a.ing excellent ***, a comprehensive study is conducted to investigate the effects of various parameters on the free vibration and t.a.sient response of the considered structure.

关键词： double curved beam finite element method functionally graded porous (FGP) material intermediate st.a.ght beam O313 vibration analysis

Impact of Pollutant Concent.a.ion and Particle Deposition on the Radiative Flow of Casson-Micropolar Fluid between Parallel Plates

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Computer Modeling in Engineering & Sciences 2025年第1期142卷 665-690页

作者： Ghaliah Alhamzi Badr Saad t.a.kahtani Ravi Shanker Dubey Vinut.a.Kalleshachar Neelima Nizampat.a. Department of Mathematics and Statistics College of ScienceImam Mohammad Ibn Saud Islamic University(IMSIU)Riyadh11564Saudi Arabia Department of Mathematics College of ScienceKing Saud UniversityRiyadh11989Saudi Arabia Department of Mathematics Amity School of Applied SciencesAmity University RajasthanJaipur302002RajasthanIndia Department of Studies in Mathematics Davangere UniversityDavangere577002India Department of Electronics and Communication Engineering Amrita School of EngineeringAmrita Vishwa VidyapeethamBengaluru560035India

Assessing the behaviour and concent.a.ion of waste pollutants deposited between two parallel plates is essent.a. for effective environmental *** the effectiveness of treatment methods in reducing pollution scales is made easier by analysing waste discharge *** waste discharge concent.a.ion analysis is useful for assessing how effectively wastewater treatment techniques reduce pollution *** study aims to explore the Casson micropolar fluid flow through two parallel plates with the influence of pollutant concent.a.tion and thermophoretic particle *** explore the mass and heat t.a.sport features,thermophoretic particle deposition and thermal radiation are *** governing equations are t.a.sformed into ordinary different.a. equations with the help of suitable similarity *** Runge-Kut.a.Fehlberg’s fourthfifth order technique and shooting procedure are used to solve the reduced set of equations and boundary *** integration of a neural network model based on the Levenberg-Marquardt.a.gorithm serves to improve the accuracy of predictions and optimize the analysis of *** outcomes are displayed to analyze the characteristics of the relevant dimensionless parameters in the current *** reveal t.a. concent.a.ion upsurges as the micropolar parameter *** concent.a.ion reduces with an upsurge in the thermophoretic *** upsurge in the external pollutant source variation and the local pollutant external source parameters enhances mass *** surface drag force declines for improved values of porosity and micropolar parameters.

关键词： Micropolar fluid thermal radiation porous medium thermophoretic particle deposition waste discharge concent.a.ion