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Mechanical and hydraulic properties of carbonate rock:The critical role of porosity

journal of Rock Mechanics and Geotechnical Engineering 2023年第4期15卷 814-825页

作者： Kam ng j.Carlos Santamarina Department of Civil and Architectural Engineering and Construction Management University of WyomingLaramieWY82071USA Physical Science and Engineering Division King Abdullah University of Science and TechnologyThuwal23955-6900Saudi Arabia

Carbonate rocks are extensively used in civil infrastructure and play a critical role in geoenergy geoengineering,either as hydrocarbon reservoirs or potential repositories for CO_(2)geological *** genesis and diagenetic overprint determine the properties of carbonate *** study combines recent data gathered from Madison Limestone and an extensive dataset compiled from published sources to analyze the hydraulic and mechanical properties of limestone carbonate *** models and data analyses recognize the inherently granular genesis of carbonate rocks and explain the strong dependency of physical properties on *** asymptotically-correct power model in terms of(1-Ф/Ф*)a is a good approximation to global trends of unconfined stiffness E and unconfined compressive strength UCS,cohesive intercept in Mohr-Coulomb failure envelopes,and the brittle-toductile transition *** power model is the analytical solution for the mechanical properties of percolating granular *** adopted a limiting granular porosityФ*=0.5 for all models,which was consistent with the loosest packing of monosize *** fitted power model has exponent(α=2)in agreement with percolation theory and highlights the sensitivity of mechanical properties to *** and models confirm a porosity-independent ratio between unconfined stiffness and strength,and the ratio follows a log-normal distribution with mean(E/UCS)≈*** high angle of internal shear strength measured for carbonate rocks reflects delayed contact failure with increased confinement,and it is not sensitive to *** spans more than six orders of *** size controls pore size and determines the reference permeability k^(*)at the limiting porosityФ*=*** a given grain size from fine to coarse-grained dominant carbonates,permeability is very sensitive to changes in porosity,suggesting preferential changes in the internal pore network during compaction.

关键词： Rock porosity Carbonate permeability Rock unconfined stiffness Unconfined compressive strength(UCS)

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Geochemical studies of hybrid granite from Madugulapalli area, Eastern Dharwar Craton, Southern India: Implications for crustal mixing

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Acta Geochimica 2023年第1期42卷 9-23页

作者： Nagamma j Ratnakar j Ajay kumar A Ashok ch State Mines and Geology Department 508001 NalgondaIndia Department of Geology Osmania University500007 HyderabadIndia CSIR-National Geophysical Research Institute 500007 UppalHyderabadIndia

Magma produced by melting of continental crust and mantle at the Archean-Proterozoic boundary are compositionally variable and chemical compositions provide evidence for the mixing of two sources. Understanding the composition of hybrid magma is essential for determining the comparative infl uence of crust and mantle sources during orogenesis. The hybrid granites are less documented in Indian cratons, especially less in Dharwar Craton. Here we present petrographic and whole-rock geochemical data of Madgulapalli granitic rocks situated in the NE part of the Eastern Dharwar Craton(EDC), to elucidate their petrogenesis and role in crust formation. The Madugulapalli granites(MPG) are composed chiefl y of plagioclase, quartz, and alkali feldspar with associated biotite showing alteration and inter-granular textures. Geochemically, they are metaluminous to peraluminous in nature with calc-alkaline hybrid granite. The hybrid granites exhibit both negative and positive europium anomalies;the lower Rb/Sr, Rb, Sr, and higher Sr/Y,(Dy/Yb)N ratios suggest that the interaction of older rocks with residual garnet source melted at high pressures. We hypothesize that hybrid granites are formed by interaction(e.g., metasomatism, mingling, or mixing) between parental magmas and pre-existing rocks with the infl uence of sanukitoid melts(heat source) in a subduction environment. The genesis of the hybrid granites demonstrates the mixing coupled with diff erentiation in the petrogeny’s residue system in a syn-collision setting followed by continental crust stability in EDC during the Neoarchean period.

关键词： Madugulapalli granite Hybrid granite Crustal mixing Subduction

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Modeling the high-energy emission from the gamma-ray binary 1FGL j1018.6–5856

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Research in Astronomy and Astrophysics 2021年第8期21卷 46-58页

作者： A-Ming chen chowing ng jumpei Takata Yun-Wei Yu School of physics Huazhong University of Science and TechnologyWuhan 430074China Department of Physics The University of Hong KongPokfulam RoadHong KongChina College of Physical Science and Technology Central China Normal UniversityWuhan 430079China

1FGL j1018.6–5856 is a high mass gamma-ray binary containing a compact object orbiting around a massive star with a period of 16.544 *** the compact object is a pulsar,non-thermal emissions are likely produced by electrons accelerated at the termination shock,and may also originate from the magnetosphere and the un-shocked wind of the *** this paper,we investigate the non-thermal emissions from the wind and the shock with different viewing geometries and study the multi-wavelength emissions from 1FGL j1018.6–*** present the analysis results of the Fermi/LAT using nearly 10 years of *** phase-resolved spectra indicate that the Ge V emissions comprise a rather steady component that does not vary with orbital motion and a modulated component that shows flux maximum around inferior *** ke V/Te V light curves of 1FGL j1018.6–5856 also exhibit a sharp peak around inferior conjunction,which are attributed to the boosted emission from the shock,while the broad sinusoidal modulations could be originating from the deflected shock tail at a larger *** modulations of Ge V flux are likely caused by the boosted synchrotron emission from the shock and the IC emission from the unshocked pulsar wind,while the steady component comes from the outer gap of the pulsar ***,we discuss the similarities and differences of 1FGL j1018.6–5856 with other binaries,like LS 5039.

关键词： binaries:close gamma rays:stars X-rays:binaries radiation mechanisms:non-thermal

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Embolization of brain arteriovenous malformations with squid co-polymer embolic material:Initial experience

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journal of Interventional Medicine 2023年第4期6卷 175-178页

作者： Li Shyan ch'ng Zulkifli Zaki Ahmad Sobri Muda Radiology Department Faculty of Medicine UiTMSungai BulohMalaysia Radiology Department Hospital Sungai BulohSungai BulohMalaysia Radiology Department HSAASFaculty of Medicine and Health SciencesUniversiti Putra MalaysiaMalaysia Radiology Department Faculty of Medicine UiTM Sungai Buloh47000Malaysia

Objective:To analyze the safety and effectiveness of the ethylene-vinyl alcohol copolymer(EVOH)liquid embolic agent Squid(Emboflu,Switzerland)for the treatment of brain arteriovenous *** and procedures:Between April 2015 and july 2017,46 embolization treatments for brain arteriovenous malformations(BAVM)were performed in 25 patients using two Squid formulations(18 and 12).Six female and 19 male patients with a mean age of 34 years(range,9–62 years)were included.A total of 46 procedures were *** BAVMs were classified as Spetzler-Martin gradeⅡin 4 procedures,Ⅲin 27 procedures,and 1V in 15 *** the 25 patients,15 presented with hemorrhage,5 with seizures,and 5 with headache and *** BAVMs were located in the temporal lobe in 5 patients,parietal lobe in 7 patients,frontal lobe in 3 patients,posterior fossa in 6 patients,basal ganglia in 3 patients,and parasagittal lobe in 1 ***:The obliteration rate of the BAVMs ranged from 10%to 100%,with a mean of 33%.Most patients underwent their first or second embolization *** patients(8%)developed intracranial bleeding post procedure,with one death(2%).One patient(2%)experienced a seizure during the procedure;however,no intracranial bleeding was *** patients(15%)experienced perforations during catheter *** case(2%)of fractured catheter was recorded,but no significant complications were *** average volume of copolymer injected was 0.6 ml per *** procedures used the Squid-12 formulation,29 procedures used the Squid-18 formulation,and 3 procedures used a combination of Squid-12 and-18 ***:Squid is a safe and effective embolic agent for treating BAVMs.

关键词： Brain arteriovenous malformation Embolization Ethylene vinyl alcohol copolymer SQUID

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On pancreatic cancer screening by magnetic resonance imaging with the recent evidence by Del chiaro and colleagues

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chinese journal of Cancer Research 2015年第4期27卷 417-422页

作者： Yì-Xiáng j.Wáng jing-Shan Gong Romaric Loffroy Department of Imaging and Interventional Radiology Faculty of Medicine The Chinese University of Hong Kong Prince of Wales Hospital Department of Radiology Shenzhen People’s Hospital Second Clinical Medicine College of jinan University Department of Vascular Oncologic and Interventional Radiology Le2i UMR CNRS 6306 University of Dijon School of Medicine Bocage Teaching Hospital

Pancreatic cancer is a lethal disease because incidence and mortality rates are nearly *** 5-year survival rate in Western countries is 4%,the lowest among all types of cancer（1）.In china,pancreatic cancer is the sixth leading cause of death from malignant disease,with an overall cumulative 5-year survival rate of 1%to 3%（2,3）.

关键词： screening mortality intraductal cumulative lethal identical mucinous incidence familial pancreas

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Apples to oranges:environmentally derived,dynamic regulation of serotonin neuron subpopulations in adulthood?

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Neural Regeneration Research 2025年第9期20卷 2596-2597页

作者： christopher j.O’Connell Matthew j.Robson Department of Genetics College of MedicineHarvard UniversityBostonMAUSA james L.Winkle College of Pharmacy Division of Pharmaceutical SciencesUniversity of CincinnatiCincinnatiOHUSA Neuroscience Graduate Program College of MedicineUniversity of CincinnatiCincinnatiOHUSA

Traumatic brain injury(TBI)is a public health problem with an undue economic burden that impacts nearly every age,ethnic,and gender group across the globe(Capizzi et al.,2020).TBIs are often sustained during a dynamic range of exposures to energetic environmental forces and as such outcomes are typically heterogeneous regarding severity and pathology(Capizzi et al.,2020).

关键词： sustained orange dynamic

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COUPLED VIBRATION OF STRUCTURAL THIN-WALLED CORES

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Acta Mechanica Solida Sinica 2000年第1期13卷 81-88页

作者： Shiu cho ng j.S.Kuang Department of Civil Engineering Hong Kong University of Science and Technology

This paper presents an analysis of the coupled vibration of asymmetric core structures in tall buildings. The governing equation of free vibration and its corresponding eigenvalue problem, which is a set of equations for laterally flexural vibrations in two different directions coupled by a warping-St. Venant torsional vibration, are derived. Based on the Calerkin method, a generalized approximate method is developed for the analysis of coupled vibration and thus proposed for determining the natural frequencies and mode shapes of the structure in triply-coupled vibration. The results of the proposed method for the example structure show good agreement with those of the FEM analysis. The proposed method has been shown to provide a simple and rapid, yet accurate, means for coupled vibration analysis of core structures.

关键词： coupled vibration analysis asymmetric core structure Galerkin method natural frequency mode shape

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Ranking parameters in urban energy models for various building forms and climates using sensitivity analysis

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Building Simulation 2023年第9期16卷 1587-1600页

作者： Aysegul Demir Dilsiz Kaitlynn ng jérôme Kämpf Zoltan Nagy Department of Civil and Architectural Engineering and Construction Management University of WyomingLaramie WYUSA Intelligent Environments Lab Department of CivilArchitectural and Environmental EngineeringThe University of Texas at AustinAustin TXUSA Energy Informatics Group Idiap Research Institute1920 MartignySwitzerland

Urban Building Energy Modelling(UBEM)allows us to simulate buildings’energy performances at a larger ***,creating a reliable urban-scale energy model of new or existing urban areas can be difficult since the model requires overly detailed input data,which is not necessarily publicly *** calibration is a necessary step to reduce the uncertainties and simulation results in order to develop a reliable and accurate *** to the concerns over computational resources and the time needed for calibration,a sensitivity analysis is often required to identify the key parameters with the most substantial impact before the calibration is deployed in ***,we study the sensitivity of uncertain input parameters that affect the annual heating and cooling energy demand by employing an urban-scale energy model,*** goal is to determine the relative influence of each set of input parameters and their interactions on heating and cooling loads for various building forms under different ***,we conduct a global sensitivity analysis for annual cooling and heating consumption under different climate *** upon this,we investigate the changes in input sensitivity to different building forms,focusing on the indices with the largest Total-order ***,we determine First-order indices and Total-order effects of each input parameter included in the urban building energy *** also provide tables,showing the important parameters on the annual cooling and heating demand for each climate and each building *** find that if the desired calibration process require to decrease the number of the inputs to save the computational time and cost,calibrating 5 parameters;temperature set-point,infiltration rate,floor U-value,*** U-value and roof U-value would impact the results over 55%for any climate and any building form.

关键词： global sensitivity analysis Sobol’method urban energy modeling building stocks energy modelling parameter screening Sobol’indices sustainable urban planning

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A NOVEL THEORY OF EFFECTIVE MEchANICAL PROPERTIES OF CLOSED-CELL FOAM MATERIALS

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Acta Mechanica Solida Sinica 2013年第6期26卷 559-569页

作者： Yuli Ma Xianyue Su R.Pyrz j.ch.Rauhe The State Key Laboratory for Turbulence and Complex Systems (LTCS) and Department of Mechanics and Aerospace Engineering College of EngineeringPeking University chinalco Research Institute of Science and Technology Department of Mechanical and Manufacturing Engineering Aalborg University

In this paper a new theory of effective mechanical properties of foam materials is proposed. A cell volume distribution coefficient is introduced to modify the original Gibson-Ashby equations of effective mechanical properties of foam materials. The constants that influence the effective modulus are replaced by the coeff^cient. Based on the modified distribution coefficient, the yield stress is also recalculated. Using X-ray microtomography, the internal structures of dif- ferent samples of polypropylene-nanoclay foam are obtained. The cell volume distributions of these samples are derived from the experiment by image analysis and the fitting curves are plot- ted. The distribution coefficient is acquired using the parameters from the theoretical model of the distribution curves. The results of the improved theory are compared with the experimental values and show good fitting quality. It was found that the precision of the improved theory is high and the cell volume distribution has an impact on the effective mechanical properties that would lead to the optimization of the synthesis procedure.

关键词： closed-cell foam cell volume distribution distribution coefficient Young's modulus yield stress distribution function

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The role of AVDR in linear cascade testing

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航空动力学报 2007年第6期22卷 933-944页

作者： Wing F.ng Department of Mechanical Engineering Virginia Polytechnic Instituteand State University

Linear cascade testing plays an important role in the research and development of turbomachinery and is widely used over the *** ideal cascade model of a turbomachinery blade row is *** actual linear cascade testing,the flow through the test section converges due to the development of the boundary layer and secondary flow along the sidewall surfaces of the test *** velocity density ratio(AVDR) is adopted to account for the deviation of the tested cascade flow from the ideal 2D *** numerous published cascade works,the influence of AVDR on cascade performance is seen to be complicated with many affecting factors,such as those related to cascade/blade geometry and flow ***,controlling AVDR is limited by the facility ***,real blade-to-blade flow in turbomachines is usually associated with AVDR greater than unity due to limited span of blades between the hub and shroud such that cascade testing without reducing AVDR could be favored *** these facets add complexity and diversification to the *** current paper reviews previous studies and results on *** understanding on the role of AVDR and recommendations on how to deal with it in linear cascade testing are provided.

关键词：线性叶栅试验轴向速度密度比空气流动叶栅特性

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