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Regulating microstructure and composition by carbonizing in-situ grown metal-organic frameworks on cotton fabrics for boosting electromagnetic wave absorption

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Nano Research 2024年第8期17卷 7290-7300页

作者： Jie Jin hongsen Long hu Liu Yan Guo Tiantian Bai Ben Bin Xu mohammed A.Amin hua Qiu m.ham.d h.helal Chuntai Liu Changyu Shen zeinhom m.El-Bahy Zhanhu Guo State Key Laboratory of Structural Analysis Optimization and CAE Software for Industrial EquipmentNational Engineering Research Center for Advanced Polymer Processing TechnologyZhengzhou UniversityZhengzhou 450002China China State Key Laboratory of Powder metallurgy Central South UniversityChangsha 410000China School of Electronic Engineering North China University of Water Resources and Electric PowerZhengzhou 450046China Complex Conditions of high-end Tire Technology Innovation Center Shuguang Rubber Industry Research&Design Institute Co.LtdGuilin 541004China Integrated Composites Lab Department of Mechanical and Civil EngineeringNorthumbria UniversityNewcastle Upon TyneNE18STUK department of Chemistry College of ScienceTaif UniversityP.O.Box 11099Taif 21944Saudi Arabia Shaanxi Key Laboratory of macromolecular Science and Technology School of Chemistry and Chemical EngineeringNorthwestern Polytechnical UniversityXi’an 710072China department of Chemistry Faculty of Arts and ScienceNorthern Border UniversityRafha 73213Saudi Arabia department of Chemistry Faculty of ScienceAl-Azhar UniversityNasr City 11884CairoEgypt

high-temperature carbonized metal-organic frameworks(mOFs)derivatives have demonstrated their superiority for promising electromagnetic wave(EmW)absorbers,but they still suffer from limited EmW absorption capacity and narrow *** the advantage of microstructure and chemical composition regulation for the design of EmW absorber,hierarchical heterostructured moS_(2)/CoS_(2)-Co_(3)O_(4)@cabonized cotton fabric(CF)(mCC@CCF)is prepared by growing ZIF-67 mOFs onto CF surface,chemical etching,and *** from the dual loss mechanism of magnetic-dielectric multicomponent carbonized mOFs,chemical etching and carbonization process can effectively introduce abundant micro-gap structure that can result in better impedance matching and stronger absorption capacity via internal reflection,doped heteroatoms(mo,N,S)to supply additional dipolar polarization loss,and numerous heterointerfaces among moS_(2),CoS_(2),Co_(3)O_(4),and CCF that produce promoted conduction loss and interfacial polarization ***,a minimal reflection loss of−52.87 dB and a broadest effective absorption bandwidth of 6.88 Ghz were achieved via tunning the sample thickness and filler loading,showing excellent EmW absorption *** research is of great value for guiding the research on mOFs derivatives based EmW absorbing materials.

关键词： metal-organic frameworks hierarchical structure chemical etching sulfurization electromagnetic wave absorption

The multi-impurity system in CdSe nanoplatelets:electronic structure and thermodynamic properties

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Communications in Theoretical Physics 2024年第3期76卷 165-173页

作者： d A Baghdasaryan V A harutynyan E m Kazaryan h A Sarkisyan Russian-Armenian University H Emin 1230051YerevanArmenia Institute of Applied Problems of Physics 25 Nersisyan St0014YerevanArmenia

This paper theoretically studies the impurity states and the effects of impurity concentration and configuration on the optical,electrical,and statistical properties of CdSe nanoplatelets(NPLs).An image charge-based model of electron-impurity interaction is *** charge-carrier energy spectra and corresponding wave functions depending on the impurity number and configuration are *** electron binding energies are calculated for different NPL *** is shown that the image charge-based interaction potential that arises due to the dielectric constants mismatch is much stronger than the interaction potential that does not take such a mismatch into ***,it is demonstrated that the binding energies are increasing with the number of *** calculate the canonical partition function using the energy levels of the electron,which in turn is used to obtain the mean energy,heat capacity,and entropy of the non-interacting electron *** thermodynamic properties of the non-interacting electron gas that depend on the geometric parameters of the NPL,impurity number,configuration,and temperature are studied.

关键词： nanoplateletes thermodynamic properties impurity states

Tilted global solar irradiance in Bahrain: an experimental study

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CLEAN ENERGY 2024年第2期8卷 27-34页

作者： Vasilikos, N. Georgantopoulou, C. Alajaimi, h. Almajed, S. h. Ahmed, m. mathioulakis, d. Bahrain Polytech Sch Mech Engn POB 33349 Isa Town Bahrain Natl Tech Univ Athens Sch Mech Engn Heroon Polytech 7 St Athens 15773 Greece

In the present work, tilted global solar irradiance data are presented and analysed, measured for a period of 1 year on the campus of Bahrain Polytechnic, Kingdom of Bahrain, from both a fixed photovoltaic panel and a moving one via a two-axis solar tracker. The fixed panel faces south with an angle of 26 degrees with respect to the horizontal, coinciding with the local geographical latitude. The second panel is moved by two motors, controlled by a global positioning system and suitable software so that the Sun's rays are perpendicular to the panel surface. A pyranometer is installed on each panel, recording the tilted global solar irradiance, stored by using a data logger. The analysis of the data obtained shows a 33% solar energy gain on an annual basis for the moving panel (2780 versus 2088 kWh/m2 on the fixed panel). more importantly, in June, when the energy demand in Bahrain is elevated due to the increased residential cooling loads, the solar energy received by the moving panel is 54.7% higher compared with that of the fixed panel. On a percentage basis, the increase in solar energy from the moving panel is profound in the early morning and late evening hours. moreover, the reduction in the solar energy received by the fixed panel from may to June does not appear in the moving panel because of the adjustable orientation of the latter. Throughout the year, the mean daily solar power varies between 0.37 and 0.56 kW/m2 for the fixed panel, and 0.45 and 0.70 kW/m2 for the moving panel. In winter, solar energy fluctuations are elevated due to erratic weather conditions that present a peak standard deviation of 28% of the corresponding mean. The data presented are useful for potential solar investments in Gulf countries. Tilted global solar irradiance data are measured and analysed for a period of 1 year on the campus of Bahrain Polytechnic, Kingdom of Bahrain, from both a fixed photovoltaic panel and a moving one via a two-axis solar tracker. Graphical Abstract

关键词： tilted solar irradiance renewable energy solar tracking photovoltaic Gulf Cooperation Council Countries SUN TRACKING ENERGY SYSTEmS PANELS WORLd

Comparison of Treatment Efficacy of different Number of Botulinum Toxin Type A Injection Sites for Crow's Feet Lines: A Single-Center Retrospective Clinical Study in Vietnam

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International Journal of dermatology and Venereology 2024年第3期7卷 131-136页

作者： Nguyen Quang m. Le Thi m. duong Phuc h. Vu Thai h. Le huu d. department of Stem Cell Research and Application National Hospital of Dermatology and Venereology Hanoi 100000 Viet Nam department of healthcare Activity direction National Hospital of Dermatology and Venereology Hanoi 100000 Viet Nam department of dermatology Hanoi Medical University Hanoi 100000 Viet Nam

Objective: Botulinum toxin type A is frequently used to treat crow's feet lines. however, the optimal dose and injection sites are still controversial. The objective of this study was to compare the efficacy of different botulinum toxin type A injection patterns for the treatment of crow's feet. methods: This single-center, retrospective, clinical study was conducted at the National hospital of dermatology and Venereology from July 2020 to december 2020. data on 60 patients with crow's feet were collected and divided into 2 groups (3- or 4-point intramuscular injection) according to the intramuscular injection technique the patients received. The treatment efficacy was assessed based on the changes in the Crow's Feet Grading Scale score at 1, 4, and 16 weeks after treatment. Repeated measures analysis of variance was used for the assessment of changes in scores over time between the two groups. Results: After treatment, the average Crow's Feet Grading Scale score was significantly decreased compared with the pretreatment score at all timepoints (1, 4, and 16 weeks) in both states (dynamic: For 3-point intramuscular injection technique, 1 week: 1.90 ± 0.71 vs. 2.97 ± 0.56; 4 weeks: 1.87 ± 0.68 vs. 2.97 ± 0.56; 16 weeks: 2.60 ± 0.67 vs. 2.97 ± 0.56. For 4-point intramuscular injection technique, 1 week: 1.73 ± 0.83 vs. 3.03 ± 0.49; 4 weeks: 1.73 ± 0.74 vs. 3.03 ± 0.49; 16 weeks: 2.57 ± 0.68 vs. 3.03 ± 0.49, all P d static: For 3-point intramuscular injection technique, 1 week: 1.20 ± 0.89 vs. 2.20 ± 0.85; 4 weeks: 1.20 ± 0.89 vs. 2.20 ± 0.85; 16 weeks: 1.87 ± 0.97 vs. 2.20 ± 0.85; For 4-point intramuscular injection technique, 1 week: 1.50 ± 0.86 vs. 2.30 ± 0.84; 4 weeks: 1.33 ± 0.84 vs. 2.30 ± 0.84; 16 weeks: 1.87 ± 0.97 vs. 2.30 ± 0.84. All P he average subjective patient-rated satisfaction scores after treatment were significantly higher in the 4-point injection group than in the 3-point injection group (P = 0.028). The adverse events were pos

关键词： botulinum toxin type A crow's feet lines dose injection site

Greatly enhanced corrosion/wear resistances of epoxy coating for mg alloy through a synergistic effect between functionalized graphene and insulated blocking layer

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Journal of magnesium and Alloys 2024年第1期12卷 332-344页

作者： Z.Y.Xue X.J.Li J.h.Chu m.m.Li d.N.Zou L.B.Tong School of metallurgical Engineering Xi’an University of Architecture and TechnologyXi’an 710055China State Key Laboratory of Advanced design and manufacturing for Vehicle Body Hunan UniversityChangsha 410082China

The poor corrosion and wear resistances of mg alloys seriously limit their potential applications in various *** conventional epoxy coating easily forms many intrinsic defects during the solidification process,which cannot provide sufficient *** the current study,we design a double-layer epoxy composite coating on mg alloy with enhanced anti-corrosion/wear properties,via the spin-assisted assembly *** outer layer is functionalized graphene(FG)in waterborne epoxy resin(WEP)and the inner layer is Ce-based conversion(Ce)*** FG sheets can be homogeneously dispersed within the epoxy matrix to fill the intrinsic defects and improve the barrier *** Ce film connects the outer layer with the substrate,showing the transition *** corrosion rate of Ce/WEP/FG composite coating is 2131 times lower than that of bare mg alloy,and the wear rate is decreased by~90%.The improved corrosion resistance is attributed to the labyrinth effect(hindering the penetration of corrosive medium)and the obstruction of galvanic coupling *** synergistic effect derived from the FG sheet and blocking layer exhibits great potential in realizing the improvement of multi-functional integration,which will open up a new avenue for the development of novel composite protection coatings of mg alloys.

关键词： mg alloy Functionalized graphene Epoxy coating Corrosion/wear resistance Blocking layer

Role of marine natural products in the development of antiviral agents against SARS‑CoV‑2:potential and prospects

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marine Life Science & Technology 2024年第2期6卷 280-297页

作者： d.P.Nagahawatta N.m.Liyanage Thilina U.Jayawardena h.h.A.C.K.Jayawardhana Seong‑hun Jeong hyung‑Jun Kwon You‑Jin Jeon department of marine Life Sciences Jeju National UniversityJeju 690-756Republic of Korea department of Chemistry Biochemistry and PhysicsUniversitédu QuébecàTrois-RivièresTrois-RivièresQC G8Z 4M3Canada marine Science Institute Jeju National UniversityJeju 63333Republic of Korea Functional Biomaterial Research Center Korea Research Institute of Bioscience and BiotechnologyJeongeup-siRepublic of Korea

A novel coronavirus,known as severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),has surfaced and caused global concern owing to its ***-CoV-2 is the causative agent of coronavirus disease 2019;however,it was only discovered at the end of the year and was considered a pandemic by the World health ***,the develop-ment of novel potent inhibitors against SARS-CoV-2 and future outbreaks is urgently *** naturally occurring bioactive substances have been studied in the clinical setting for diverse *** intricate infection and replication mechanism of SARS-CoV-2 offers diverse therapeutic drug targets for developing antiviral medicines by employing natural products that are safer than synthetic *** natural products(mNPs)have received increased attention in the development of novel drugs owing to their high diversity and ***,this review article investigates the infection and replication mechanisms,including the function of the SARS-CoV-2 genome and ***,we highlighted anti-SARS-CoV-2 therapeutic intervention efforts utilizing mNPs and predicted SARS-CoV-2 inhibitor design.

关键词： SARS-CoV-2 marine natural products drug targets Inhibitors

Numerical calculation of Z-scan measurements for nonlinear media with large phase shift

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Optoelectronics Letters 2024年第3期20卷 177-182页

作者： m.d.Zidan A.Allahham department of Physics Atomic Energy Commission of SyriaP.O.Box 6091DamascusSyria

We have reported the characteristics of a Z-scan for the poly(azaneylylidene-acylene)(dAZA) polymer, as nonlinear medium with a large nonlinear phase shift using continuous-wave(CW) laser beam. It has been verified that the Fresnel diffraction model is applicable for analyses of Z-scan measurements with dAZA polymer at high laser power. It was found that Z-scan curves with peak-to-valley features appear as the applied light intensity increases in the case of a large nonlinear phase shift. The Z-scan experiments were carried out using a CW laser to verify the theoretical calculations in the case of a large nonlinear phase shift model. Our results show good agreements between the experimental data and the proposed theoretical models.

关键词： nonlinear phase media

Exploring one material for dual applications:A red-emitting mg2GeO4:Eu3+ nanophosphor for future generation energy efficient WLEds and dosimetric applications

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Journal of Rare Earths 2024年第10期42卷 1835-1845页

作者： Akshay Arjun G.P.darshan S.C.Sharma h.Nagabhushana d.V.Sunitha h.B.Premkumar department of Physics Faculty of Mathematical and Physical SciencesM.S.Ramaiah University of Applied Sciences Jain University C.N.R.Rao Centre for Advanced materials Tumkur University School of Applied Sciences (Physics) REVA University

The envisaged design and developme nt of individual mate rials to excavate a broader spectrum of desired properties and offer multiple applications are highly *** this in mind,a series of forsterite-structured mg2GeO4:Eu3+（1 mol%-9 mol%） nanophosphors was synthesized via a solution combustion method using oxalyl dihydrazide as a *** X-ray diffraction patterns confirm the orthorhombic crystal system with a Puma space *** results clearly show irregularly shaped cluster-like structures with aggregation of the *** diffuse reflectance spectra,the optical energy band gap of the mg2GeO4:Eu3+（1 mol%-9 mol%） nanophosphors was estimated and obtained to be～4.12-4.32 *** photoluminescence emission spectra exhibit intense peaks at ～579,589,610,661,and 707 nm,which are due to characteristic5d0→7F0,5d0→7F1,5do→7F2,5d0→7F3and5d0→7F4transitions of Eu3+ions,*** Commission International de L'Eclairage color coordinates are gradually tuned from pale red（0.5980,0.4012） to a pure red（0.6385,0.3611） *** glow peaks showcase excellent super-linear response at low doses of γ-irradiations,indicating that the prepared phosphor can be used in thermoluminescent personal dosimetry which is a biological tissue *** aforementioned results demonstrate that the prepared mg2GeO4:Eu3+（1 mol%-9 mol%） nanophosphors are considered an excellent candidate for dual applications,i.e.,red component in future generation white-light-emitting diodes（WLEds） and personal dosimetric applications.

关键词： dosimetry Nanophosphors Photoluminescence Photometric properties Rare earths Thermoluminescence

Enhancement of coercivity,permeability,and dielectric properties of Co_(0.2)Zn_(0.3)Ni_(0.5)Eu_(x)Fe_(2-x)O_(4) ferrites for memory and high frequency devices

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Journal of Rare Earths 2024年第6期42卷 1128-1135,I0005页

作者： I.Sardar m.d.hossain m.S.Sikder m.N.I.Khan m.R.Rahman Physics discipline Khulna UniversityKhulna9208Bangladesh department of Physics Khulna University of Engineering&TechnologyKhulna9203Bangladesh department ofComputer Science and Engineering Northern University of Business&Technology KhulnaKhulna9100Bangladesh material Science division Atomic Energy CentreDhaka1000Bangladesh

Spinel cubic ferrites have huge applications in me mory and high frequency *** the improvement of these modern devices,the magnetic coercivity,permeability,and dielectric properties of a ferrite are the important *** article focuses on improving the magnetic coercivity,magnetic permeability,and dielectric properties of Co_(0.2)Zn_(0.3)Ni_(0.5)Eu_(x)Fe_(2-x)O_(4) ferrites,where x=0.00,0.06,and *** X-ray diffraction(XRd),Fourier transform infrared spectroscopy(FTIR),field emission scanning electron microscopy(FESEm),energy dispersive X-ray(EdX),vibrating sample magnetometer(VSm),and an impedance analyzer were used to characterize the structural,magnetic,and dielectric properties of the *** XRd patterns indicate the formation of spinel cubic structure of the samples with a secondary peak(EuFeO_(3))for Eu doped *** densities and porosities of the samples follow an inverse trend,where the doped samples’lattice parameters are increased with the increment of rare earth Eu *** FTIR analysis also proves the spinel cubic phase of the *** average grain size of the ferrites is obtained via FESEm images,and it is increased from 121 to 198 *** analysis confirms that doping of the Eu content also changes other hysteresis loop properties of Co_(0.2)Zn_(0.3)Ni_(0.5)Eu_(x)Fe_(2-x)O_(4) ***,the coercivity of the Eu doped samples is greater than that of the mother alloy(x=0.00).The EdX study shows that there is no impurity contamination in the *** permeability and dielectric measurements show an improved quality factor of the Eu-doped samples with low magnetic and dielectric *** dependent resistivity and impedance analysis also show the improved *** the observed properties of the samples,all the investigated ferrites might be strong candidates for potential applications in memory devices,magnetic sensors,and high frequency applications.

关键词： Ferrites Raree arths Coercivity Permeability EdX Resistivity