检索结果-南通市图书馆

A New Fractional Model for the Falling Body Problem

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics Letters 2017年第2期34卷 1-3页

作者： A.ebaid B.Masaedeh e.e1-Zahar Department of Mathematics Faculty of ScienceTabuk UniversityP.O.Box 741Tabuk 71491Kingdom of Saudi Arabia Department of Mathematics Faculty of Sciences and HumanitiesPrince Sattam Bin Abdulaziz UniversityA1kharj11942Kingdom of Saudi Arabia Department of Basic engineering Science Faculty of EngineeringShebin El-Kom32511Menofia UniversityEgypt

Recently, a conformable fractional derivative has been proposed to calculate the derivative of non-integer order of time functions. It has been shown that this new fractional derivative definition obeys many advantages over the preceding definitions. For mathematical models in applied sciences and to preserve the dimensionality of the physical quantities, an auxiliary parameter （~r） which has the dimension of seconds should be implemented in the fractional derivative definition. We obtain analytic solutions for the resulting conformable fractional differential equations describing the vertical velocity and the height of the falling body. It is shown that the dimensions of velocity and height are always correct without any restrictions on the auxiliary parameter cr which contradicts with the results in the literature when applying the Caputo definition to the same problem. This may open the door for many future works either to describe the role of such an auxiliary parameter or to derive a more suitable definition for the fractional derivative.

关键词： A New Fractional Model for the Falling Body Problem

Advances and challenges in diagnosing and managing adult autoimmune enteropathy

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2025年第2期31卷 128-131页

作者： Grigorios Christodoulidis Sara e Agko Marina N Kouliou Konstantinos e Koumarelas Dimitris Zacharoulis Department of General Surgery University Hospital of LarissaLarissa 41110Greece Department of Intensive Care Unit Asklepios Paulinen Clinic WiesbadenWiesbaden 65197Germany Department of emergency Medicine General Hospital of LarissaLarissa 41221Greece Department of Surgery University Hospital of LarissaLarissa 41334Greece

Autoimmune enteropathy(AIe)is a rare immune mediated disorder primarily affecting children,characterized by chronic diarrhea,malabsorption,vomiting,weight loss and villous *** has also been observed in adults presenting diagnostic and treatment challenges due to its overlap with other gastrointestinal disorders such as celiac *** diagnostic criteria for AIe include small bowel villous atrophy,lack of response to dietary restrictions,presence of anti-enterocyte antibodies,and predisposition to autoimmunity without severe *** criteria emphasize characteristic histological findings and exclusion of other causes of villous *** is associated with various autoimmune disorders and can present with overlapping features with Celiac disease,including villous atrophy but without significant intraepithelial *** primarily involves immunosuppression using corticosteroids,calcineurin inhibitors,and anti-tumor necrosis factor therapy,alongside nutri-tional *** the challenges,understanding AIe’s diverse manifest-ations and improving diagnostic criteria are essential for effective management and improved patient *** research is needed to elucidate the pathogenesis,disease progression and long-term outcomes of AIe.

关键词： Autoimmune enteropathy Diagnosis Prognosis Adult autoimmune enter-opathy and challenges Autoimmune enteropathy and treatment Autoimmune enteropathy and diagnostic criteria Pathophysiology of autoimmune enteropathy

Near-threshold K^*(892)^+ meson production in the interaction of π−mesons with nuclei

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics C 2020年第11期44卷 168-178页

作者： e.Ya.Paryev Institute for Nuclear Research Russian Academy of SciencesMoscow 117312Russia Institute for Theoretical and experimental Physics Moscow 117218Russia

We study the inclusive production of strange vector K^∗(892)^+ mesons in π−A reactions at near-threshold laboratory incident pion momenta of 1.4-2.0 GeV/c via a nuclear spectral function *** approach accounts for incoherent primary π−meson-proton π−p→K^∗(892)^+Σ^− production processes as well as the influence of the scalar K^∗(892)^+-nucleus potential(or the K^∗(892)^+ in-medium mass shift)on these *** calculate the absolute differential and total cross sections for the production of K∗(892)+mesons from carbon and tungsten nuclei at laboratory angles of 0∘-45∘and at the aforementioned momenta in five scenarios for the aforenoted *** show that the K^∗(892)^+ momentum distributions and their excitation functions(absolute and relative)possess a high sensitivity to changes in the in-medium K^∗(892)^+ mass shift in the low-momentum region of 0.1-0.6 GeV/***,the measurement of such observables in a dedicated experiment at the GSI pion beam facility in the near-threshold momentum domain will allow us to get valuable information on the K^∗(892)^+ in-medium properties.

关键词： pion-nucleus reactions strange vector meson production in-medium effects

Possibility of observation of hidden-bottom pentaquark resonances in bottomonium photoproduction on protons and nuclei near threshold

在线全文

学校读者我要写书评

暂无评论

Chinese Physics C 2020年第10期44卷 87-97页

作者： e.Ya.Paryev Institute for Nuclear Research Russian Academy of SciencesMoscow 117312Russia Institute for Theoretical and experimental Physics Moscow 117218Russia

We study theΥ(1S)meson photoproduction on protons and nuclei at near-threshold center-of-mass energies below 11.4 GeV(or at the corresponding photon laboratory energies eγbelow 68.8 GeV).We calculate the absolute excitation functions for the nonresonant and resonant photoproduction ofΥ(1S)mesons off protons at incident photon laboratory energies of 63-68 GeV by considering direct(γp→Υ(1S)p)and two-step(γp→P^+b(11080)→Υ(1S)p,γp→P^+b(11125)→Υ(1S)p,γp→P^+b(11130)→Υ(1S)p)Υ(1S)production channels within different scenarios for the nonresonant total cross section of the elementary reactionγp→Υ(1S)p and for branching ratios of the decays P^+b(11080)→Υ(1S)p,P^+b(11125)→Υ(1S)p,and P^+b(11130)→Υ(1S)*** also calculate an analogous function for the photoproduction ofΥ(1S)mesons on the 12C and 208Pb target nuclei in the near-threshold center-of-mass beam energy region of 9.0-11.4 GeV by considering the respective incoherent direct(γN→Υ(1S)N)and two-step(γp→P^+b(11080)→Υ(1S)p,γp→P^+b(11125)→Υ(1S)p,γp→P^+b(11130)→Υ(1S)p andγn→P^0b(11080)→Υ(1S)n,γn→P^0b(11125)→Υ(1S)n,γn→P^0b(11130)→Υ(1S)n)Υ(1S))production processes using a nuclear spectral function *** demonstrate that a detailed scan of theΥ(1S)total photoproduction cross section on proton and nuclear targets in the near-threshold energy region in future high-precision experiments at the proposed high-luminosity electron-ion colliders eIC and eicC in the US and China should provide a definite result for or against the existence of the nonstrange hidden-bottom pentaquark statesP^+bi and P^0bi(i=1,2,3)as well as clarify their decay rates.

关键词： photon-nucleus reactions bottomonium production hidden-bottom pentaquarks

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

CLASSIFICATIONS OF DUPIN HYPeRSURFACeS IN LIe SPHeRe GeOMeTRY

在线全文

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

Hydrologic Time Scale:A Fundamental Stream Characteristic

在线全文

学校读者我要写书评

暂无评论

Journal of earth Science 2022年第5期33卷 1291-1297页

作者： Robert e.Criss Department of earth and Planetary Sciences Washington University in St.LouisSt.LouisMO63130USA

A new,fundamental catchment attribute called the hydrologic time scaleτgoverns the rate of delivery of runoff to a particular site,and is equal to∫Qdt/∫|dQ|,where Q is discharge and t is *** value ofτfor any gauged site is readily calculated from tabulated discharge data by replacing the integrals with *** quantity,coupled with the square root of catchment area,√A,form a coordinate pair that embodies the characteristic time and length scales for any catchment,which govern its flow *** fitting constants used in several unit hydrograph models are simple multiples ofτ,so knowledge ofτallows rapid calibration of these models for the particular site,facilitating flow prediction from rainfall *** ofτreflect many different landscape attributes,but for multiple sub-basins in watersheds with homogeneous land use and lithologic conditions,they correlate linearly with √*** ratio √A/τprovides a characteristic velocity that is high for channelized,floodprone rivers,for flashy urban streams with high impervious cover,and for sites downstream of hydropower *** with low velocities are resistant to flooding,as their landscapes have a greater ability to delay the delivery of runoff by retention,detention,and infiltration into the groundwater system.

关键词： unit hydrograph time constant flash floods impervious cover urban streams flashiness hydrogeology

The effect of the concentration of plastic waste on the formation of reaction products of the Ti-PeT system

在线全文

学校读者我要写书评

暂无评论

Green Chemical engineering 2024年第3期5卷 374-382页

作者： Aleksey e.Matveev Tomsk Scientific Center of the Siberian Branch of the Russian Academy of Sciences 634055TomskAkademicheskii Prospekt 10/4Russia

The paper presents research results of the synthesis,phase composition,and structure of products obtained by highly exothermic reactions between Ti and C10H8O4mixture components,depending on the plastic waste concentration and Ti powder dispersiveness,density of initial samples,and synthesis *** dependence of the phase composition and structure of the synthesis products on the concentration of the polymer(plastic)component in the initial Ti-PeT(C10H8O4)system was *** the plastic waste content is 20 wt%to 25 wt%,synthesis products contain TiC0.5O0.5-TiC0.6-0.75particle *** growth in the polyethylene terephthalate content from 30 wt%to 45 wt%leads to the formation of synthesis products consisting of titanium carbide(TiC0.6-1.0).The gaseous byproduct composition of the exothermic reaction is investigated for the Ti--C10H8O4mixture *** is found that the gaseous by-product mostly contains hydrogen and carbon monoxide as well as impurities of different hydrocarbons(methane,acetylene,ethane,ethene)and carbon *** maximum adiabatic temperature of the gas combustion temperature is 2080℃,which demonstrates the possibility of using gas as a fuel for energy generation *** on the data obtained,it is possible to create a basis for a new plastic waste technology to fabricate carbide-containing materials.

关键词： Plastic waste Titanium carbide Green technology Hydrogen synthesis

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