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Numerical simulation of square shaped particle sedimentation

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particuology 2024年第1期84卷 107-116页

作者： Govind Sharma Bahni ray Department of Mechanical Engineering Indian Institute of Technology DelhiHauz KhasNew Delhi110016India

Direct numerical simulations of square particle sedimentation in a viscous incompressible fluid are presented to examine the effects of sharp edges for various particle-to-fluid density ratios and different initial inclination *** settling process exhibits four different motion regimes;non-oscillatory,non-uniform centered oscillatory,uniform off-centered oscillatory,and non-uniform off-centered(irregular)*** moderate density ratios,we observe that the rotational motion of settling square particle varies with the initial inclination *** employ Dynamic Time Warping and Fast Fourier Transform to analyze translational and angular *** systems are described using phase-space plots,and a chaotic phenomenon is observed at a higher density ratio.

关键词： Sedimentation Distributed Lagrangian multiplier phase synchronization Oscillations

TALYS calculation and a short review of the experimental status of proton capture studies on p-nuclei:A guide to future investigation

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Chinese physics C 2024年第6期48卷 102-111页

作者： Indrani ray Argha Deb physics Department Jadavpur UniversityKolkata-700032India

TALYS calculations were performed to obtain the theoretical proton capture cross-sections on the p-nuclei.A short review on the status of related experimental studies was also *** basic properties such as Q-values,Coulomb barrier,Gamow peak,Gamow Window,and decay properties of the parent and daughter nuclei were *** experimental parameters,e.g.,beam energy,beam current,targets,and detectors,used in experimental investigations reported in the literature,were *** results of the TALYS calculations in the Gamow region were compared with the corresponding experimental values wherever *** study is expected to facilitate the planning of future experiments.

关键词： p-nuclei proton capture cross-section gamma ray Gamow energy TALYS TENDL kADoNis

Geochemistry of volcanic glass from Mahanadi offshore region,eastern continental margin of India:Constraints on the contribution of latest Toba super-eruption

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Acta Oceanologica Sinica 2024年第2期43卷 111-119页

作者： Muralidhar kocherla Durbar ray Manavalan Satyanarayanan Hilda Joao Virsen Gaikwad pB Ramamurty CSIR-National Institute of Oceanography Dona Paula 403004GoaIndia CSIR-National Geophysical Research Institute Uppal RoadHyderabad 500007India

The tephra layers in multiple sediment cores from the offshore region of the Mahanadi basin in the northern Bay of Bengal were investigated for possible volcanic sources. The glass shards from those tephra layers were studied for size distribution, texture, and elemental geochemistry to establish chronostratigraphic markers for regional and global Quaternary correlation. The textural features of fine-grained(silty) volcanic glasses suggest the distal source of these tephra deposits. Major element composition with elevated SiO_(2) contents ranging between75%–76% and dominance of k_(2)O(> 4.5%) over CaO(petrographic composition of tephra from the Toba volcano. The bulk trace element compositions of the same glass shards were comparable with those reported in the youngest Toba tephra reported elsewhere. Likewise, the LREE-dominated chondrite normalized REE profiles of tephra from the Mahanadi basin closely resemble the characteristic REE patterns in Toba ash from other parts of the Indian Ocean and thus confirmed the contribution of the youngest Toba super-eruption for this ash layers.

关键词： Mahanadi basin Bay of Bengal volcanic glass glass morphology glass-chemistry

Functional cure of chronic hepatitis B-hope or hype?

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World Journal of Hepatology 2024年第9期16卷 1199-1205页

作者： Gautam ray Gastroenterology Unit Department of MedicineB.R.Singh HospitalKolkata 700014West BengalIndia

Chronic hepatitis B constitutes a substantial disease burden *** steps advocated by the World Health Organization in 2016 to eradicate hepatitis B by 2030 has failed to achieve significant progress,especially with respect to immu-nization coverage and linkage to *** lack of governmental and public awar-eness regarding the long-term implications of hepatitis B burden cause under-funding of developmental *** presently approved treatment modalities have limited efficacy in complete viral eradication,hence the need for newer molecules to achieve functional cure(sustained undetectable hepatitis B surface antigen(HBsAg)and hepatitis B virus DNA in peripheral blood after a finite period of therapy).However,preliminary results from trials of novel therapies show their inadequacy to achieve this end by themselves but better performance with a low baseline serum HBsAg with nucleos(t)ide analogues(NA)treatment which need to be combined with/without pegylated interferon as an *** therapy is limited by cost and adverse events and need to show incremental benefit over the standard of care(long-term NA therapy)with respect to efficacy and drug toxicities,making the development process ***,while such therapies continue to be tested,strategies should still focus on prevention of transmission by non-pharmaceutical measures,vaccination and increasing linkage to care.

关键词： Hepatitis B Drugs Clinical trial Therapy Novel therapies Functional cure

A new method for deriving broad-band polar motion geodetic excitations

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Geodesy and Geodynamics 2024年第5期15卷 453-464页

作者： Wei Chen Jiesi Luo Jim ray Jiancheng Li Hubei Luojia Laboratory School of Geodesy and GeomaticsWuhan UniversityWuhan 430079China National Oceanic and Atmospheric Administration Silver SpringMDUSA Central South University Changsha 410083China

While the geodetic excitationχ(t)of polar motion p(t)is essential to improve our understanding of global mass redistributions and relative motions with respect to the terrestrial frame,the widely adopted method to deriveχ(t)from p(t)has biases in both amplitude and phase *** study has developed a new simple but more accurate method based on the combination of the frequency-and time-domain Liouville's equation(FTLE).The FTLE method has been validated not only with 6-h sampled synthetic excitation series but also with daily and 6-h sampled polar motion measurements as well asχ(t)produced by the interactive webpage tool of the International Earth Rotation and Reference Systems Service(IERS).Numerical comparisons demonstrate thatχ(t)derived from the FTLE method has superior performances in both the time and frequency domains with respect to that obtained from the widely adopted method or the IERS webpage tool,provided that the input p(t)series has a length around or more than 25 years,which presents no practical limitations since the necessary polar motion data are readily *** FTLE code is provided in the form of Mat Lab function.

关键词： Earth rotation polar motion Geodetic excitation Liouville's equation Mat Lab

painlevéintegrability,auto-Bäcklund transformations,new abundant analytic solutions including multi-soliton solutions for time-dependent extended kdV8 equation in nonlinear physics

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Journal of Ocean Engineering and Science 2024年第5期9卷 489-507页

作者： Shailendra Singh S.Saha ray National Institute of Technology Department of MathematicsRourkela 769008India

In this paper,a new eighth-order(1+1)-dimensional time-dependent extended kdV equation has been *** considered equation is being found completely integrable by using the painlevéanalysis ***,three auto-Bäcklund transformations have been generated by truncating the painlevéseries at a constant *** auto-Bäcklund transformations have been used to derive various analytic solution families for the newly developed *** solutions include the kink-antikink soliton,kink-soliton,antikink-soliton,periodic-soliton,complex kink-soliton and complex periodic-soliton ***-soliton solutions including N-soliton solution,have been obtained by using the simplified Hirota’s method for the considered *** the results are being expressed graphically to signify the physical importance of the considered equation.

关键词： Higher-order kdV equation painlevéanalysis Auto-Bäcklund transformation Simplified Hirota method

population Dynamics in an Advective Environment

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Communications on Applied Mathematics and Computation 2024年第1期6卷 399-430页

作者： king-Yeung Lam ray Lee Yuan Lou Department of Mathematics The Ohio State UniversityColumbusOH43210USA School of Mathematical Sciences CMA-Shanghai and MOE-LSCShanghai Jiao Tong UniversityShanghai200240China

We consider a one-dimensional reaction-diffusion equation describing single-and two-species population dynamics in an advective environment,based on the modeling frameworks proposed by Lutscher et *** *** analyze the effect of rate of loss of individuals at both the upstream and downstream *** the single-species case,we prove the existence of the critical domain size and provide explicit formulas in terms of model *** further derive qualitative properties of the critical domain size and show that,in some cases,the critical domain size is either strictly decreasing over all diffusion rates,or monotonically increasing after first decreasing to a *** also consider competition between species differing only in their diffusion *** two species having large diffusion rates,we give a sufficient condition to determine whether the faster or slower diffuser wins the *** also briefly discuss applications of these results to competition in species whose spatial niche is affected by shifting isotherms caused by climate change.

关键词： Reaction-diffusion-advection Critical domain size Competition Climate change

Emission colour tuning in kLnF_(4):Yb^(3+),Er^(3+)/Ho^(3+)phosphor

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Journal of Rare Earths 2024年第1期42卷 57-65,I0002页

作者： Janani k Gayathri E Vijayatha V Ramasubramanian S Thiyagarajan p Department of Science and Humanities Nehru Institute of TechnologyKaliapuramThirumalayampalayamCoimbatoreIndia Department of Sciences Amrita School of Physical SciencesAmrita Vishwa VidyapeethamCoimbatoreIndia Department of physics Anna UniversityChennaiIndia

kLnF_(4):Yb^(3+),Er^(3+)/Ho^(3+)(Ln=Y,Yb,Gd)phosphors were prepared by solid-state reaction *** each of the Yb^(3+)/Er^(3+)and Yb^(3+)/Ho^(3+)co-doped phosphors independently,phase confirmation and morphological examination were accomplished using the X-ray diffraction technique and scanning electron microscope analysis.X-ray photoelectron spectroscopy analysis shows the charge state and existence of lanthanides and *** luminescence emissions of green and red colour were detected for the synthesized *** changes in the upconverted emission intensities and colour output pertaining to the change of the lanthanide host matrix along with dopants were investigated for the prepared *** the upconversion luminescence,erbium-doped samples exhibit a predominance of red emission while holmium-doped samples display a prevalence of green *** rare-earth Er/Ho doped kYbF4shows strong red emission compared to other ***_(4):Yb,Er/Ho exhibits relatively significant green upconve rsion emissions,while Yb,Er-doped kGdF_(4)host displays a 10-fold increase in green/red emission ratio with an increase in the input power of 20-780 *** photoluminescence studies and decay curve analysis were carried out using UV light excitation for the developed phosphors.A higher lifetime of 2.2 ms was measured for the downshifting red emission in the Ho doped kYbF_(4)*** study suggests a potential for colour tunability in the upconversion and downshifting emissions through host modifications to the fluoride phosphor.

关键词： Rare earths Energy transfer upconversion Downshifting Colour coordinates

Wireless Sensing: A New Sixth Sense to Deciphering our World

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Wireless Sensing: A New Sixth Sense to Deciphering our World