检索结果-南通市图书馆

维普期刊数据库

Governance in the exploration of global and regional determinants of ICT development

在线全文

学校读者我要写书评

暂无评论

International Journal of Innovation studies 2024年第2期8卷 132-153页

作者： Charles s.saba simplice A.Asongu Nicholas Ngepah Yolande e.Ngoungou school of economics College of Business and EconomicsUniversity of JohannesburgJohannesburgSouth Africa Department of econornic&Data science New Uzbekistan University54 Mustaili AvenueTashkent100007Uzbekistan University of Yaounde 2 SoaCameroon

The present study assesses how governance affects information and communication technology(IcT)at the global level contingent on macroeconomic policy factors such as trade,foreign direct investment(FDI),manufacturing value added,and agricultural value *** study focuses on 183 countries from 2003 to 2021,and the empirical evidence is based on the generalized method of moments(GMM).The following main findings are *** the full sample,governance unconditionally promotes ICT development,while trade openness(industrial added value)moderates governance to promote(dampen)ICT *** sub-saharan Africa,only trade openness effectively moderates governance to induce an overall positive effect on ICT,while in the Middle east and North Africa(MeNA)region,all policy variables moderate governance for an overall positive incidence on ICT sector *** findings for the MeNA region are confirmed in the europe and Central Asia(eCA)region,with the exception of the moderating role of industrial added value,which engenders an overall negative *** the east and south Asia and the Pacific(esAP)countries,one overall positive incidence is apparent in the role of trade openness,while net negative effects are established from the moderating roles of industrial added value and agricultural added *** the American sub-sample,a positive(negative)net effect is apparent from the role of industrial added value(trade)in moderating the incidence of gover-nance on ICT sector ***,policy implications are discussed.

关键词： ICT Governance Trade FDI Industry Agriculture

simplified seismic scenario analysis of existing masonry buildings accounting for local site effects

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of structural and Civil engineering 2024年第2期18卷 309-318页

作者： Ayşe e.ÖZsOYÖZBAY Işıl sANRI KARAPINAR Zehra N.KUTLU İsmail e.KILIÇ Department of Civil engineering Maltepe UniversityIstanbul 34857Turkey school of engineering and Construction Oryx Universal CollegeDoha 12253Qatar

This study discusses the effects of local sites and hazard amplification on the seismic vulnerability assessment of existing masonry *** this context,a rapid seismic evaluation procedure was implemented on an old masonry building stock in the historical center Galata,located inİstanbul,to determine the seismic risk priority of the built *** scenarios were generated for all soil classes,different moment magnitudes,and source-to-site distances to obtain more accurate results for the seismic vulnerability assessment of the studied building ***,damage distributions estimated under nine different scenarios with/without site effects were compared and illustrated in maps to discuss changes in vulnerability owing to amplification *** this study,by re-examining the rapid seismic evaluation procedure by including geo-hazard-based assessment,the importance of site effects on the vulnerability and risk assessment of built heritage was *** proposed framework integrating field data and local site effects is believed to advance the current applications for vulnerability assessment of masonry buildings and provide an improvement in the application of rapid seismic assessment procedures with more reliable results.

关键词： masonry buildings seismic vulnerability assessment cultural heritage local site effect

Unravelling COVID-19 waves in Rio de Janeiro city:Qualitative insights from nonlinear dynamic analysis

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Infectious Disease Modelling 2024年第2期9卷 314-328页

作者： Adriane s.Reis Laurita dos santos Américo Cunha Jr Thaís C.R.O.Konstantyner elbert e.N.Macao Institute of science and Technology Federal University of São PauloSão Josédos CamposSPBrazil Physics Institute University of São PauloSão PauloSPBrazil scientific and Technological Institute Universidade BrasilSão PauloSPBrazil Department of Applied Mathematics Rio de Janeiro State UniversityRio de JaneiroRJBrazil Paulista school of Medicine Federal University of São PauloSão PauloSPBrazil

since the COVID-19 pandemic was first reported in 2019,it has rapidly spread around the *** countries implemented several measures to try to control the virus *** healthcare system and consequently the general quality of life population in the cities have all been significantly impacted by the Coronavirus *** different waves of contagious were responsible for the increase in the number of cases that,unfortunately,many times lead to *** this paper,we aim to characterize the dynamics of the six waves of cases and deaths caused by COVID-19 in Rio de Janeiro city using techniques such as the Poincaréplot,approximate entropy,second-order difference plot,and central tendency *** results reveal that by examining the structure and patterns of the time series,using a set of non-linear techniques we can gain a better understanding of the role of multiple waves of COVID-19,also,we can identify underlying dynamics of disease spreading and extract meaningful information about the dynamical behavior of epidemiological time *** findings can help to closely approximate the dynamics of virus spread and obtain a correlation between the different stages of the disease,allowing us to identify and categorize the stages due to different virus variants that are reflected in the time series.

关键词： COVID-19 Nonlinear analysis Poincaréplot Central tendency measure

CLAssIFICATIONs OF DUPIN HYPeRsURFACes IN LIe sPHeRe GeOMeTRY

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 Mathematica scientia 2024年第1期44卷 1-36页

作者： Thomas e.CeCIL Department of Mathematics and Computer science College of the Holy CrossWorcesterMA01610USA

This is a survey of local and global classification results concerning Dupin hypersurfaces in s^(n)(or R^(n))that have been obtained in the context of Lie sphere *** emphasis is on results that relate Dupin hypersurfaces to isoparametric hypersurfaces in *** with these classification results,many important concepts from Lie sphere geometry,such as curvature spheres,Lie curvatures,and Legendre lifts of submanifolds of s^(n)(or R^(n)),are described in *** paper also contains several important constructions of Dupin hypersurfaces with certain special properties.

关键词： Dupin hypersurfaces isoparametric hypersurfaces Lie sphere geometry Lie sphere transformations Lie curvatures

维普期刊数据库

Investigating the impact of the universal function of the nuclear proximity potential in heavy-ion fusion cross sections

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2024年第5期76卷 86-93页

作者： R Gharaei e sarvari Department of Physics Sciences FacultyHakim Sabzevari UniversityPO Box 397SabzevarIran Department of Physics Faculty of ScienceFerdowsi University of MashhadPO Box 91775-1436MashhadIran science Faculty Department of PhysicsTarbiat Modares UniversityTehranIran

The fusion barriers and cross sections of 15 colliding systems with 320≤Z_(1)Z_(2)≤1512 are investigated in detail to understand the influence of the universal function of proximity potential formalism in the heavy-ion fusion *** realize this goal,we select three versions of the phenomenological proximity potentials,including Prox.77,Zhang 2013,and Guo 2013,to calculate the nucleus-nucleus *** experimental fusion cross sections for the selected reactions are analyzed using the standard coupled-channel calculations,including couplings to the low-lying 2^(+)and 3^(-)states in the target and *** calculated results show that the universal functions of the Guo 2013 and Prox.77 models provide the lowest and highest fusion barriers,*** addition,it is found that the height of the fusion barriers is enhanced by increasing the mass number of the projectile from light to heavy *** highest sensitivity to the mass number of the projectile belongs to the results of Prox.77.A discussion is also presented on the influence of the universal function on the radial behavior of the interaction potential in the allowed region for overlapping *** results reveal that the best fit to the experimental data of the fusion cross sections for the reactions involving light and medium nuclei is obtained using the universal function of the Zhang 2013 *** the heavier systems,the results of the Guo 2013 model at sub-barrier energies provide a good description of the available data.

关键词： fusion reactions proximity-type potentials universal function coupled-channel calculations

维普期刊数据库

Are hydrides under high-pressure-high-temperature superconductors?

在线全文

学校读者我要写书评

暂无评论

National science Review 2024年第7期11卷 9-12页

作者： J.e.Hirsch Department of Physics University of California

Contrary to the current consensus, I argue that the existing evidence for high-temperature superconductivity in hydrides under high pressure is not compelling. I suggest that the focus of the field should urgently shift to establish unequivocally experimentally whether or not superconductivity in pressurized hydrides exists, instead of continuing to search for new materials that might show elusive signals of unproven superconductivity at ever higher temperatures. The implications of a negative finding for the theoretical understanding of superconductivity are discussed.

关键词： Hydrides

enhancing high-temperature oxidation resistance(at 1000 °C) of nickel superalloy obtained by laser powder bed fusion via reactive electric spark treatment

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Transactions of Nonferrous Metals society of China 2024年

作者： s.K.MUKANOV M.I.PeTRZHIK A.e.KUDRYAsHOV e.A.NAUMOVA F.A.BAsKOV P.A.LOGINOV e.A.LeVAsHOV National University of science and Technology MIsIs

The high-temperature oxidation resistance of the nickel superalloy grown by the Laser Powder Bed Fusion (LPBF) has been significantly increased as a result of in-situ formation of a thermal barrier layer (α-Al2O3+ CaMoO4) during oxidative annealing of surface layers modified by electric spark treatment (esT). The reactive esT of the LPBF-built items based on nickel eP741NP alloy was carried out with low-melting Al-12%si， Al-6%Ca-0.6%si and Al-7%Ca-1%Mn electrodes. It was found that at esT done by Al-7%Ca-1%Mn electrode an intermetallic (β-NiAl + γ’-Ni3Al) 15 microns thick layer reinforced by spherical oxide (CaMe)O nanoparticles was formed. Formation of that structure increases the wear resistance of LPBF nickel superalloy by 4.5 times. Further oxidative annealing at 1000 °C lead to a formation of continuous two-layered coating with an inner layer of α-Al2O3and an outer layer of CaMoO4， which together act as an effective barrier preventing the diffusion of oxygen into the volume of the superalloy.

关键词：

effect of eu3+,Bi3+,and Li+ doping on luminescent property of GdNbO4

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Rare earths 2024年第1期42卷 66-75页

作者： s.W.Wi Y.s.Lee Department of Physics and Integrative Institute of Basic sciences Soongsil University

We investigated the emission properties of eu3+-doped GdNbO4-based oxide phosphors,aiming at improving the eu3+emission by codoping of Bi3+and Li+.eu3+singly doped,eu3+and Bi3+doubly doped,and eu3+,Bi3+,and Li+triply doped GdNbO4were prepared using a high-temperature solid-state reaction *** red-orange emissions from eu3+in the singly doped samples are significantly improved by the codoping of Bi3+,mainly due to the energy transfer from Bi3+to eu3+.The additional codoping of Li+is found to increase the eu3+emission *** improvement might be attributed to the increase in the photoluminescent quantum yield originating from larger grain sizes and better crystallinity.A detailed analysis of the X-ray diffraction pattern and the asymmetric ratio estimated from the photoluminescence spectra show that the local lattice environment around eu3+in GdNbO4does not change significantly with the codoping of Bi3+and Li+.Our results indicate that Li+doping is a promising way to improve the emission properties of rare-earth ion-doped GdNbO4phosphors.

关键词： eu 3+ GdNbO 4 Codoping of Li + Photoluminescence sensitizer Rare earths

Mast cell activation syndrome:An up-to-date review of literature

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

World Journal of Clinical Pediatrics 2024年第2期13卷 104-113页

作者： ÖnerÖzdemir Gökçe Kasımoğlu Ayşegül Bak Hüseyin sütlüoğlu süreyya savaşan Department of Pediatric Allergy and Immunology Sakarya UniversitySakaryaAdapazarı54100Türkiye Department of Pediatrics Sakarya UniversitySakaryaAdapazarı54100Türkiye Department of Pediatrics Kocaeli City HospitalKocaeli 50123Türkiye Department of Pediatrics Children’s Hospital of MichiganHematology/OncologyCentral Michigan University College of MedicineMount PleasantMI 48859United States Barbara Ann Karmanos Cancer Institute Wayne State UniversityDetroitMI 12345United States

Mast cells are a subtype of white blood cells and are involved in the immune *** cells contain many chemical substances called mediators,which are involved in the allergic *** fact that mast cells play a role in many events that require urgent intervention,especially anaphylaxis,has led to a more detailed study of these *** diseases also caused by dysfunctions of mast cells have been examined in many *** instance,mast cell activation syndrome is known as an augmented number of cells due to decreased cell death,resulting in clinical symptoms affecting many *** main common symptoms include flushing,hypotension,urticaria,angioedema,headache,vomiting and *** the underlying mechanism is not yet clearly known,we aim to review the literature in a broad perspective and bring together the existing knowledge in the light of the literature due to the diversity of its involvement in the body and the fact that it is a little known syndrome.

关键词： Mast cell Mast cell activation syndrome Tryptase Histamine