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Numerical study of the circular opening effect on mechanical behaviour of rock under confinement

Journal of Rock Mechanics and Geotechnical Engineering 2019年第6期11卷 1201-1210页

作者： y.l.gui J.l.Shang J.J.Ma Z.y.Zhao school of engineering newcastle universitynewcastle upon tynene17ruunited kingdom school of civil and environmental engineering nanyang technological university639798singapore school of civil engineering sun yat-sen universityguangzhou510275china

Opening holes in rock including their size and distribution can affect the performance of rock-related structures.A good understanding on this will contribute to,for example,rock cavern design,and construction,tunnelling,and mining *** improve the understanding,a comprehensive investigation of the opening hole effect on the rock mechanical behaviour under biaxial loading condition is carried out by virtue of a hybrid continuum-discrete element *** specimens with both single hole and multi-hole of various radii are investigated and compared with the cases subjected to uniaxial *** is demonstrated that the confining pressure can increase both the stiffness and strength due to delaying the crack initiation and *** increase due to the confining pressure is more evident for the compressive *** single hole specimens with 0.75 mm radius hole,the increase ratio of the compressive strength is a linear increasing function with width and the increase ratio ranges from 2.15 for the specimen with 3.5 mm width to 2.45 for 10 mm *** the single hole specimen with 10 mm width,the increase ratio starts at 2.13 for the specimen with 0.75 mm radius hole,ascending to the peak of 2.37 for the specimen with 1 mm radius hole,followed by a decline to 2.2 for the specimen with 1.25 mm radius ***,for the multi-hole specimens,the increase ratio varies from 1.66 to *** addition,to verify the influence of confining pressure magnitude on the performance of the rock specimens,totalling 10 confining pressure levels are applied and *** simulation results show that even though there are opening holes in the specimens,the simulated compressive strength generally follows the generalised Hoek-Brown model.

关键词： Rock with opening Simulation Biaxial loading Strength Stiffness

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Observation of acoustic hybrid topological phases induced by the p-d orbital interactions

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Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 132-139页

作者： Xiao Xiang Feng Gao yu-gui Peng Peng Wu Zong-lin li Xue-Feng Zhu School of Physics and Innovation Institute Huazhong University of Science and Technology

In spinless systems,growing attention has recently been attracted to synthetic gauge fields,which redefine the fundamental crystal symmetries by utilizing the projective algebraic ***,synthetic gauge fields have been commonly investigated in single orbital systems,and explorations on hybrid orbitals remain elusive in ***,we report the experimental observation of hybrid topological phases induced by hybrid synthetic gauge flux,which is formed by the interaction between p and d orbitals embedded in acoustic *** breaking the translation symmetries of lxand/or ly,we unambiguously demonstrate the first-order M?bius edge states and higher-order corner *** work establishes a platform for seeking exotic topological phases induced by hybrid-orbitals interactions and initializing the framework of hybrid-orbitalsrelated topological *** applications can be anticipated in scenarios such as high-quality sensing and robust wave trapping due to the stepwise energy distribution of the hybrid topological phase.

关键词： topological insulator synthetic gauge field projective symmetry corner states

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Cortical hem signaling center: functions, development, and potential implications for evolution and brain disorders

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Neural Regeneration Research 2025年第4期20卷 1079-1080页

作者： Victor V.Chizhikov Igor y.Iskusnykh Department of Anatomy and Neurobiology University of Tennessee Health Science CenterMemphisTNUSA

Development of the telencephalon relies upon several signaling centers-localized cellular populations that supply secreted factors to pattern the cortical *** such signaling center is the cortical hem,which arises during embryonic development at the telencephalic dorsal midline,adjacent to the choroid plexus and hippocampal primordium(Figure 1A).While the cortical hem has also been described in reptiles and birds,most of our knowledge about the developmental roles of the cortical hem is derived from the analysis in *** cortical hem produces several types of secreted molecules,including wingless-related integration site(Wnt)and bone morphogenetic(Bmp)*** cortical hem is particularly important for the development of the hippocampus,which is involved in learning and memory,and the neocortex,which is the most complex brain region that mediates multiple types of behavior and higher cognitive functions(Mangale et al.,2008;Dal-Valle-Anton and Borrell,2022).

关键词： epithelium Figure center

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书信交往与苏门的发展历程——以苏轼与四学士为中心

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海南大学学报（人文社会科学版） 2025年第1期43卷 16-25页

作者：李贵王兴武上海师范大学人文学院上海200234

由苏轼主盟的“苏门”在哲宗元祐年间大放异彩,是两宋影响最大的文学群体之一。在长达四十三年的时间里,书信是苏轼与“四学士”等人最主要的交往媒介。这些书信在苏门的发展历程中发挥了不可替代的重要作用。苏门文人在书信中求教讨论... 详细信息

由苏轼主盟的“苏门”在哲宗元祐年间大放异彩,是两宋影响最大的文学群体之一。在长达四十三年的时间里,书信是苏轼与“四学士”等人最主要的交往媒介。这些书信在苏门的发展历程中发挥了不可替代的重要作用。苏门文人在书信中求教讨论、品题称扬、交流信息、劝勉慰藉、宣泄情感、传承斯文,在此过程中建构起集体认同,培养了深厚情谊,写下了传世佳作。苏轼和四学士的来往书信,在平易自然的表达中见出作者们真实的情感和隐秘的心迹,在温暖的人际关系中见出人性的真善美,具有高度的文学价值和史学价值。探讨苏门书信交往的细节和意义,有助于深化对宋代文学史和社会文化史的认识。

关键词：苏门苏轼苏门四学士书信交往

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Symmetric Equations for Evaluating Maximum Torsion Stress of Rectangular Beams in Compliant Mechanisms

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Chinese Journal of Mechanical Engineering 2018年第1期31卷 34-40页

作者： gui-Min Chen larry l.Howell State Key laboratory for Manufacturing Systems Engineering Xi'an Jiaotong University Department of Mechanical Engineering Brigham Young University

There are several design equations available for calculating the torsional compliance and the maximum torsion stress of a rectangular cross-section beam, but most depend on the relative magnitude of the two dimensions of the crosssection(i.e., the thickness and the width). After reviewing the available equations, two thickness-to-width ratio Independent equations that are symmetric with respect to the two dimensions are obtained for evaluating the maximum torsion stress of rectangular cross-section beams. Based on the resulting equations, outside lamina emergent torsional joints are analyzed and some useful design Insights are obtained. These equations, together with the previous work on symmetric equations for calculating torsional compliance, provide a convenient and effective way for designing and optimizing torsional beams in compliant mechanisms.

关键词： Compliant mechanism Maximum torsion stress Rectangular beam lamina emergent joint

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Assembly and Electrochemical Study of Transition Metal Substituted Polyoxometalates SiW_(11)NiO_(39)^(6-) and SiW_(11)MnO_(39)^(6-) on 4-Aminothio-phenol Modified Glassy Carbon Electrode

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Chemical Research in Chinese Universities 2005年第4期21卷 401-405页

作者： lügui-qin DUJin-yan HUChang-wen InstituteforChemicalPhysics DepartmentofChemistryBeijingInstituteofTechnologyBeijing100081P.R.China InstituteforChemicalPhysics DepartmentofChemistryBeijingInstituteofTechnologyBeijing100081P.R.China／／ChemistryDepartmentAnhuiNormalUniversityWuhu241000P.R.China

Via layer-by-layer assembly, the polyoxometalates of Keggin type, SiW_ 11O_ 39Ni(H_2O) 6-(SiNiW_ 11) and {SiW_ 11O_ 39Mn(H_2O) 6-}(SiMnW_ 11) were first immobilized on a 4-aminothiophenol(4-ATP) modified glassy carbon electrode surface. The electrochemical behavior of these polyoxometalates was investigated. They exhibited some special properties in the films, which are different from those in a homogeneous aqueous solution. Their reaction mechanism in a multilayer film is proposed. The electrocatalytic behavior of these multilayer film electrodes for the reduction of BrO-_3 and NO-_2 were comparatively studied.

关键词： Polyoxometalate layer-by-layer assembly Electrochemical behavior Electrocatalytic reduction BrO_3^- NO_2^-

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Interest of D-dimer level,severity of COVID-19 and cost of management in Gabon

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World Journal of Critical Care Medicine 2025年第1期14卷 91-99页

作者： Berthe A Iroungou Arnaud Nze O Helga M Kandet y Neil-Michel longo-Pendy Nina D Mezogho-Obame Annicet-Clotaire Dikoumba guignali l Mangouka UnitéMixte de Recherche Centre International de Recherches Médicales de Franceville et le Service de SantéMilitaireLibreville 20404EstuaireGabon AP-HP Health Economics Research UnitHtel Dieu HospitalParis 75004Ilede-FranceFrance laboratory Hôpital D'Instruction des Armées D'AkandaLibreville 20404EstuaireGabo Unitéde Recherche enÉcologie de la Santé Centre Interdisciplinaire de Recherches Médicales de FrancevilleFranceville 769Gabon laboratory Hôpital D'Instruction des Armées Omar Bongo OndimbaLibreville 20404EstuaireGabon Department of Medecine Polyvalente Hôpital D'Instruction des Armées Omar Bongo OndimbaLibreville 20404EstuaireGabon

BACKGROUND Coronavirus disease 2019(COVID-19)is strongly associated with an increased risk of thrombotic events,including severe outcomes such as pulmonary *** D-dimer levels are a critical biomarker for assessing this *** Gabon,early implementation of anticoagulation therapy and D-dimer testing has been crucial in managing *** study hypothesizes that elevated Ddimer levels are linked to increased COVID-19 *** To determine the impact of D-dimer levels on COVID-19 severity and their role in guiding clinical *** This retrospective study analyzed COVID-19 patients admitted to two hospitals in Gabon between March 2020 and December *** study included patients with confirmed COVID-19 diagnoses and available D-dimer measurements at *** on demographics,clinical outcomes,D-dimer levels,and healthcare costs were ***-19 severity was classified as non-severe(outpatients)or severe(inpatients).A multivariable logistic regression model was used to assess the relationship between D-dimer levels and disease severity,with adjusted odds ratios(OR)and 95%*** A total of 3004 patients were included,with a mean age of 50.17 years,and the majority were female(53.43%).Elevated D-dimer levels were found in 65.81%of patients,and 57.21%of these experienced severe *** analysis showed that patients with elevated D-dimer levels had 3.33 times higher odds of severe COVID-19(OR=3.33,95%CI:2.84-3.92,Pltivariable analysis,adjusted for age,sex,and year of *** financial analysis revealed a substantial burden,particularly for uninsured *** D-dimer predicts COVID-19 severity and guides treatment,but the high cost of anticoagulant therapy highlights the need for policies ensuring affordable access in resource-limited settings like Gabon.

关键词： D-dimers COVID-19 Management Disease severity Healthcare costs Gabon

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Solvothermal Syntheses and Crystal Structures of Two New Nonmetal Borates:C_4H_(10)N_2·B_6O_8(OH)_2 and (NH_3CH_2CH_2NH_3)B_5O_8(OH)

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Chinese Journal of Structural Chemistry 2007年第3期26卷 257-262页

作者： lü gui-Qin yANG Xin lI Min SHI Heng-Zhen School of Science Beijing Institute of Technology Beijing 100081 China Institute of Applied Catalysis Yantai University Yantai 264005 China Department of Chemistry Zhoukou Normal University Zhoukou 46600 1 China

Two new borate compounds, C4H10N2·B6O8（OH）2 and （NH3CH2CH2NH3）B5O8 （OH）2, have been solvothermally synthesized and structurally characterized by single-crystal X-ray diffraction, IR, elemental analysis and thermal analysis. Compound 1 crystallizes in the monoclinic system, space group P21/c, with a = 8.3318（17）, b = 6.2118（12）, c = 12.479（3） A, β = 108.96（3）°, V = 610.8（2） A^3, Mr = 313.02, Z = 2, 13,.= 1.702 g/cm^,/J = 0.150 mm^-1, F（000） = 320, R = 0.0387 and wR = 0.0924. Its layered structure is linked by infinite covalently coordinated neutral sheets with 3,20-membered window system, which are built up from alternative B6O8（OH）2 subunits donated by two piperzazine nitrogen donors. 2 crystallizes in monoclinic, space group Co, with a = 6.7207（13）, b = 11.481 （2）, c = 12.564（3）A,β = 95.25（3）°, V = 965.4（3） A^3, Mr = 261.18, Z = 4, Dc = 1.797 g/cm^3,/t = 0.164 mm^-1, F（000） = 536, R = 0.0396 and wR = 0.0752. Its oxoborate structure is generated from the sheets of 3,9-membered boron rings bonded diamine molecules through electrostatic and H-bonding interactions to form a two-dimensional layered network.

关键词： solvothermal synthesis crystal structure borate

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Isothermal reduction of titanomagnetite concentrates containing coal

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International Journal of Minerals,Metallurgy and Materials 2014年第2期21卷 131-137页

作者： Tu Hu Xue-wei lü Chen-guang Bai gui-bao Qiu College of Materials Science and Engineering Chongqing University Faculty of Metallurgical and Energy Engineering Kunming University of Science and Technology

The isothermal reduction of the Panzhihua titanomagnetite concentrates （PTC） briquette containing coal under argon atmosphere was investigated by thermogravimetry in an electric resistance furnace within the temperature range of 1250-1350°C. The samples reduced in argon at 1350°C for different time were examined by X-ray diffraction （XRD） analysis. Model-fitting and model-free methods were used to evaluate the apparent activation energy of the reduction reaction. It is found that the reduction rate is very fast at the early stage, and then, at a later stage, the reduction rate becomes slow and decreases gradually to the end of the reduction. It is also observed that the reduction of PTC by coal depends greatly on the temperature. At high temperatures, the reduction degree reaches high values faster and the final value achieved is higher than at low temperatures. The final phase composition of the reduced PTC-coal briquette consists in iron and fer-rous-pseudobrookite （FeTi2O5）, while Fe2.75Ti0.25O4, Fe2.5Ti0.5O4, Fe2.25Ti0.75O4, ilmenite （FeTiO3） and wustite （FeO） are intermediate products. The reaction rate is controlled by the phase boundary reaction for reduction degree less than 0.2 with an apparent activation energy of about 68 kJ·mol-1 and by three-dimensional diffusion for reduction degree greater than 0.75 with an apparent activation energy of about 134 kJ·mol-1. For the reduction degree in the range of 0.2-0.75, the reaction rate is under mixed control, and the activation energy increases with the increase of the reduction degree.

关键词： titanomagnetite carbothermal reduction thermogravimetric analysis kinetics

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Beginning from the end:the presynaptic terminal as a pathomechanism hub in frontotemporal dementia and amyotrophic lateral sclerosis

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Neural Regeneration Research 2025年第11期20卷 3217-3218页

作者： laura Huggon Emma l.Clayton UK Dementia Research Institute at King’s College london LondonUK Department of Basic and Clinical Neuroscience Institute of Psychiatry Psychology&NeuroscienceKing’s College LondonLondonUK

Frontotemporal dementia and amyotrophic lateral sclerosis:Frontotemporal dementia(F T D)and amyo t rophic lateral sclerosis(AlS)are neurodegenerative diseases with significant overlapping *** these neurodegenerative diseases affect different neuronal populations(with FTD affecting neurons of the frontal and temporal lobes,and AlS affecting upper and lower motor neurons),these two diseases are complexly *** and AlS exist on a disease spectrum,with shared genetic causes,clinical presentations,and pathologies.

关键词： diseases amyotrophic sclerosis

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