检索结果-南通市图书馆

A high-Order Localized Artificial diffusivity Scheme for discontinuity Capturing on 1d drift-Flux Models for Gas-Liquid Flows

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Advances in Applied Mathematics and Mechanics 2024年第1期16卷 47-74页

作者： Adyllyson h.Nascimento Eugenio S.Rosa department of Energy School of Mechanical EngineeringUniversity of CampinasCampinasBrazil

A computational code is developed for the numerical solution of onedimensional transient gas-liquid flows using drift-flux models,in isothermal and also with phase change *** these two-phase models,classical upwind schemes such as Roe-and Godunov-type schemes are generally difficult to derive and expensive to use,since there are no treatable analytic expressions for the Jacobian matrix,eigenvalues and eigenvectors of the system of *** the other hand,the highorder compact finite difference scheme becomes an attractive alternative on these occasions,as it does not make use of any wave propagation information from the system of *** present paper extends the localized artificial diffusivity method for high-order compact finite difference schemes to solve two-phase flows with *** numerical method has simple formulation,straightforward implementation,low computational cost and,most importantly,*** numerical methodology proposed is validated by solving several numerical examples given in the *** simulations are sixth-order accurate and it is shown that the proposed numerical method provides accurate approximations of shock waves and contact *** is an essential property for simulations of realistic mass transport problems relevant to operations in the petroleum industry。

关键词： Compressible two-phase flows drift-flux model localized artificial diffusivity highorder numerical methods

Late Neoproterozoic to early Cambrian high-grade metamorphism from Mikir hills(Assam-Meghalaya gneissic Complex,northeast India):Implications for eastern Gondwana assembly

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Geoscience Frontiers 2024年第5期15卷 256-282页

作者： Rahul Nag h.hrushikesh Nathan Cogné N.Prabhakar department of Earth Sciences Indian Institute of Technology BombayPowaiMumbaiMaharastra 400076India Geological Survey of India Northeastern RegionGuwahatiAssam 781005India Géosciences Rennes UMR6118CNRS Universitéde RennesFrance

Mikir hills region,which represents the eastern segment of the Assam-Meghalaya Gneissic Complex(AMGC)in northeast India,constitutes part of the Eastern *** Mikir hills preserves multiple metamorphic and magmatic events ranging from Early Mesoproterozoic to Early *** of these events,documenting the late Neoproterozoic to early Cambrian tectonothermal events is helpful in correlating the continental blocks of Eastern *** present an integrated study involving field relations,petrology,P-T history and zircon-monazite geochronology of hitherto poorly studied pelitic and quartzo-feldspathic gneisses from the Mikir hills *** gneisses have experienced at least three deformation events(d_(1),d_(2) and d_(3))with dominant foliation indicated by ENE-WSW striking and shallow-moderately dipping(hism in pelitic and quartzo-feldspathic gneisses is characterized by garnet(core)-K-feldspar-sillimanite-plagioclase-bio tite-rutile-quartz-ilmenite-melt and garnet-plagioclase-K-feldspar-biotite-quartz-ilmenite-melt assemblages,*** application of thermobarometric methods constrains the peak P-T conditions of 7.5-8.4 kbar at 674-778℃and 6.7-7.4 kbar at 601-618℃for pelitic and quartzofeldspathic gneisses,*** results are consistent with the values estimated using phase equilibria modelling and melt reintegration *** results of pseudosection modelling suggests a clockwise P-T path for pelitic gneisses involving migmatisation during peak metamorphism followed by near isothermal decompression from 8.0 to 8.6 kbar at 768-780℃to 4.0-5.0 kbar at 720-765℃.In contrast,quartzo-feldspathic gneisses preserved slightly lower peak P-T conditions at 3.8-4.6 kbar and 590-650℃.The U-Pb zircon dating of migmatised pelitic and quartzo-feldspathic gneisses yielded concordant ages of 1647±11 Ma and 1590±7 Ma,*** dates represent the inherited igneous protolith components,possibly

关键词： Gondwana Assam-Meghalaya Gneissic Complex Migmatisation Neoproterozoic Geochronology P-T-t history

Superplasticity of fine-grained Mg-10Li alloy prepared by severe plastic deformation and understanding its deformation mechanisms

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2024年第1期12卷 316-331页

作者： h.T.Jeong S.W.Lee W.J.Kim department of Materials Science and Engineering Hongik UniversityMapo-guSangsu-dong 72-1Seoul 121-791Republic of Korea

The superplastic behavior and associated deformation mechanisms of a fine-grained Mg-10.1 Li-0.8Al-0.6Zn alloy(LAZ1011)with a grain size of 3.2μm,primarily composed of the BCCβphase and a small amount of the hCPαphase,were examined in a temperature range of 473 K to 623 *** microstructural refinement of this alloy was achieved by employing high-ratio differential speed *** best superplasticity was achieved at 523 K and at strain rates of 10^(-4)-5×10^(-4)s^(-1),where tensile elongations of 550±600%were *** the heating and holding stage of the tensile samples prior to tensile loading,a significant increase in grain size was observed at temperatures above 573 ***,it was important to consider this effect when analyzing and understanding the superplastic deformation behavior and *** the investigated strain rate range,the superplastic flow at low strain rates was governed by lattice diffusion-controlled grain boundary sliding,while at high strain rates,lattice diffusion-controlled dislocation climb creep was the rate-controlling deformation *** was concluded that solute drag creep is unlikely to *** the late stages of deformation at 523 K,it was observed that grain boundary sliding led to the agglomeration of theαphase,resulting in significant strain *** mechanism maps were constructed forβ-Mg-Li alloys in the form of 2d and 3d formats as a function of strain rate,stress,temperature,and grain size,using the constitutive equations for various deformation mechanisms derived based on the data of the current tests.

关键词： Magnesium-lithium alloy Superplasticity Severe plastic deformation Grain size Grain growth

Validation of the TOPAS Monte-Carlo Code of the Off-Field dose of a 6 MV Synergy Linac

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Journal of Biosciences and Medicines 2024年第7期12卷 38-54页

作者： Kodjo Joel Fabrice N’Guessan Ibrahima Sakho Bogbé d. L. h. Gogon department of Physics and Chemistry Faculty of Sciences and Technology Iba Der Thiam University of This This Senegal International Cancer Center of dakar Dakar Senegal department of Physics Faculty of Sciences and Technology Flix Houphouet Boigny University of Abidjan Abidjan Cte dIvoire

The risk of radiation-induced second cancer and the late tissue loss due to Off-field doses in radiotherapy remain a serious concern. Monte Carlo (MC) simulation is currently one of the most accurate methods for calculating these doses. MC simulation model based on the Particle Simulation Tool (TOPAS) has been developed to simulate the off-field dose of an Elekta Synergy linear accelerator (Linac) emitting 6 MV photons. Measurements were taken in a water phantom using an ionization chamber to validate this model. The Percentage depth dose (Pdd) at the depth of 0.0, 5.0, 10.0 and 15.0 cm from the beam axis for a 10 × 10 cm2 field size was measured and simulated. Off-field dose profiles at the depth of 1.5 (dmax), 5.0 and 10.0 cm for field sizes of 5 × 5, 10 × 10, 15 × 15, and 20 × 20 cm2 respectively were measured and simulated. Comparison of measured and simulated off-field dose values showed a good agreement. The average gamma passing rate of the Pdds and profiles curves for off-field doses were 87.5% and 98.11% respectively. The local dose difference based on the Pdd curve between the measured and simulated was less than 6.0 % for all locations. For all field size considered in this study, the average difference between profile curves for off-field dose measured and simulated was 9.1%. Pdds and Profiles curves for off-field dose simulation uncertainties were less than 2.0% and 1.0% respectively. TOPAS-MC simulation model developed is a good representation of our 6 MV Linac Elekta Synergy for assessing off-field dose, which would be the primary cause of some secondary cancers.

关键词： Radiotherapy Off-Field dose Secondary Cancer TOPAS-MC Simulation dosimetry

Cognition on oxidation behavior of Ni-based superalloy Gh4742 when exposed to water vapor

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2024年第7期174卷 15-22页

作者： h.Xu S.F.Yang E.h.Wang C.Y.Guo Y.S.Liu X.M.hou Y.L.Zhang State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China Institute for Carbon Neutrality University of Science and Technology BeijingBeijing 100083China

The oxidation behavior of Ni-based superalloy Gh4742 exposed to water vapor was investigated at 900-1100℃for 50 h in Ar+20%h_(2)O,with Ar+20%O_(2)included for *** presence of h_(2)O is adverse to formation of continuous Cr_(2)O_(3)oxide layer but contributes to generation of big *** on this,Ni^(2+)and Co^(2+)are more easily to diffuse towards the outermost oxide layer(OOL),forming non-protective Ni-and Co-rich oxides with high *** leads to a higher weight gain in Ar+20%h_(2)O than that in Ar+20%O_(2).At elevated temperatures,the spallation of oxide scale occurs while the consumption of Cr is reduced in Ar+20%h_(2)O,and the contents of Ni-and Co-rich oxides at this moment are reduced in the *** oxidation mechanism was also discussed.

关键词： Gh4742 Superalloy h_(2)O diffusion Oxidation Mechanism

Efficient guiding and focusing of intense laser pulse using periodic thin slits

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Matter and Radiation at Extremes 2024年第4期9卷 29-39页

作者： L.Xu T.W.huang K.Jiang C.N.Wu h.Peng P.C.hen R.Li h.B.Zhuo C.T.Zhou Shenzhen Key Laboratory of Ultraintense Laser and Advanced Material Technology Center for Intense Laser ApplicationTechnologyand College of Engineering PhysicsShenzhen Technology UniversityShenzhen 518118People’s Republic of China

Slits have been widely used in laser-plasma interactions as plasma optical components for generating high-harmonic light and controlling laser-driven particle ***,we propose and demonstrate that periodic thin slits can be regarded as a new breed of optical elements for efficient focusing and guiding of intense laser *** fundamental physics of intense laser interaction with thin slits is studied,and it is revealed that relativistic effects can lead to enhanced laser focusing far beyond the pure diffractive focusing *** addition,the interaction of an intense laser pulse with periodic thin slits makes it feasible to achieve multifold enhancement in both laser intensity and energy transfer efficiency compared with conventional *** results provide a novel method for manipulating ultra-intense laser pulses and should be of interest for many laser-based applications.

关键词： laser pulse intense

Facies development and sedimentology of the Middle Miocene carbonates of the Raghama Formation, northeastern Saudi Arabia

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Geochimica 2024年第1期43卷 87-96页

作者： Mansour h.Al-hashim Abdelbaset S.El-Sorogy Meshal Wadani department of Geology and Geophysics College of ScienceKing Saud University2455Riyadh 11451Saudi Arabia

Ragahama Formation comprises a siliciclastic continental deposits followed by marine carbonates, representing prograding alluvial fans from adjacent high hinterlands seaward into lagoons and fringing reef environments. The present work aimed to document the facies development and sedimentology of the Raghama carbonates exposed along the eastern coastal plain of the Red Sea, northwestern Saudi Arabia. Four stratigraphic sections were measured and sampled(d1–d4) and thin sections and major and trace element analyses were prepared and applied for petrographic and geochemical approaches. The carbonates were subdivided into three successive fore-reef, reef-core, and back-reef depositional facies. Sandy stromatolitic boundstone, microbial laminites, dolomitic ooidal grainstone, bioclastic coralline algal wackestone, sandy bioclastic wackestone, and coral boundstones were the reported microfacies types. Petrographic analysis reveals that the studied carbonates were affected by dissolution, dolomitization, and aggrading recrystallization, which affects both the original micrite matrix and grains or acts as fracture and veinlet filling leading to widespread vuggy and moldic porosity. No evidence of physical compaction, suggesting rapid lithification and recrystallization during early diagenesis and prior to substantial burial and intensive flushing by meteoric waters. Most of the original microstructure of corals were leached and destructed. This is indicated by the higher depletion in Sr and Ca levels and increase in Mg,Na, Fe, and Mn levels, especially in section d1, in comparison with the worldwide carbonates.

关键词： Raghama Formation Miocene diagenesis Geochemistry Saudi Arabia

Blockade of Rho-associated kinase prevents inhibition of axon regeneration of peripheral nerves induced by anti-ganglioside antibodies

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2024年第4期19卷 895-899页

作者： Andrés Berardo Cristian R.Bacaglio Bárbara B.Báez Rubén Sambuelli Kazim A.Sheikh Pablo h.h.Lopez Laboratorio de Neurobiología Instituto de Investigación Médica Mercedes y Martin Ferreyra(INIMEC)-Consejo Nacional de Investigaciones Cientificas y Técnicas(CONICET)Universidad Nacional de Córdoba departamento de Química Biológica-Centro de Investigaciones en Química Biológica de Córdoba(CIQUIBIC)-Consejo Nacional de Investigaciones Cientificas y Técnicas(CONICET) Facultad de Cs.QuímicasUniversidad Nacional de Córdoba Servicio de Anatomía Patológica Clínica Universitaria Reina FabiolaUniversidad Católica de Córdoba department of Neurology University of Texas Medical School at Houston

Anti-ganglioside antibodies are associated with delayed/poor clinical recovery in Guillain-Barrèsyndrome,mostly related to halted axon ***-linking of cell surface gangliosides by anti-ganglioside antibodies triggers inhibition of nerve repair in in vitro and in vivo paradigms of axon *** effects involve the activation of the small GTPase Rho A/ROCK signaling pathways,which negatively modulate growth cone cytoskeleton,similarly to well stablished inhibitors of axon regeneration described so *** aim of this work was to perform a proof of concept study to demonstrate the effectiveness of Y-27632,a selective pharmacological inhibitor of ROCK,in a mouse model of axon regeneration of peripheral nerves,where the passive immunization with a monoclonal antibody targeting gangliosides Gd1a and GT1b was previously reported to exert a potent inhibitory effect on regeneration of both myelinated and unmyelinated *** results demonstrate a differential sensitivity of myelinated and unmyelinated axons to the pro-regenerative effect of *** with a total dosage of 9 mg/kg of Y-27632 resulted in a complete prevention of anti-Gd1a/GT1b monoclonal antibody-mediated inhibition of axon regeneration of unmyelinated fibers to skin and the functional recovery of mechanical cutaneous *** contrast,the same dose showed toxic effects on the regeneration of myelinated ***,scale down of the dosage of Y-27632 to 5 mg/kg resulted in a significant although not complete recovery of regenerated myelinated axons exposed to anti-Gd1a/GT1b monoclonal antibody in the absence of toxicity in animals exposed to only ***,these findings confirm the in vivo participation of Rho A/ROCK signaling pathways in the molecular mechanisms associated with the inhibition of axon regeneration induced by anti-Gd1a/GT1b monoclonal *** findings open the possibility of therapeutic pharmacological intervention targeting Rho A/R

关键词： anti-ganglioside antibodies anti-glycan antibodies axon regeneration ganglioside Guillain-Barrésyndrome nerve repair ROCK Y-27632

Mental health status among COvid-19 patients survivors of critical illness in Saudi Arabia:A 6-month follow-up questionnaire study

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2024年第15期12卷 2560-2567页

作者： Abdullah M Alhammad Namareq F Aldardeer Abdulaziz Alqahtani Mohammad h Aljawadi Bushra Alnefaie Raghad Alonazi Mansour Almuqbil Abdulrahman Alsaadon Rakan M Alqahtani Rashid Alballaa Bader Alshehri Mohammed I Alarifi Fahad d Alosaimi department of Clinical Pharmacy College of PharmacyKing Saud UniversityRiyadh 12372Saudi Arabia department of Pharmacy Services King Faisal Specialist Hospital and Research CentreJeddah 21499Saudi Arabia Corporate department of Pharmacy Services King Saud University Medical CityRiyadh 12372Saudi Arabia College of Pharmacy King Saud UniversityRiyadh 12372Saudi Arabia department of Critical Care Medicine College of MedicineKing Saud UniversityRiyadh 12372Saudi Arabia department of Psychiatry College of MedicineKing Saud UniversityRiyadh 12372Saudi Arabia

BACKGROUNd Psychological assessment after intensive care unit(ICU)discharge is increasingly used to assess patients'cognitive and psychological ***,few studies have examined those who recovered from coronavirus disease 2019(COvid-19).There is a paucity of data from the Middle East assessing the post-ICU discharge mental health status of patients who had *** To evaluate anxiety and depression among patients who had severe *** This is a prospective single-center follow-up questionnaire-based study of adults who were admitted to the ICU or under ICU consultation for>24 h for *** patients were contacted via *** patient’s anxiety and depression six months after ICU discharge were assessed using the hospital Anxiety and depression Scale(hAdS).The primary outcome was the mean hAdS *** secondary outcomes were risk factors of anxiety and/or *** Patients who were admitted to the ICU because of COvid-19 were screened(n=518).Of these,48 completed the *** mean age was 56.3±17.2 *** patients(62.5%)were *** main comorbidities were endocrine(n=24,50%)and cardiovascular(n=21,43.8%)*** mean overall hAdS score for anxiety and depression at 6 months post-ICU discharge was 11.4(Sd±8.5).A hAdS score of>7 for anxiety and depression was detected in 15 patients(30%)and 18 patients(36%),*** from the multivariable ordered logistic regression demonstrated that vasopressor use was associated with the development of anxiety and depression[odds ratio(OR)39.06,95% confidence interval:1.309-1165.8;Phs after ICU discharge,30% of patients who had COvid-19 demonstrated a hAdS score that confirmed anxiety and *** compare the psychological status of patients following an ICU admission(with vs without COvid-19),further studies are warranted.

关键词： COvid-19 Critically ill Anxiety depression hAdS Saudi Arabia