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Nuclear Science and Techniques 2018年第10期29卷 200-209页

作者： m.i.sayyed F.Akman i.H.Geccbesler H.O.Tekin Department of Physics University of TabukTabuk 009662Saudi Arabia Department of Electronic Communication Technology Vocational School of Technical SciencesBingo¨l University12000 Bingo¨lTurkey Department of Occupational Health and Safety Faculty of Health ScienceLaboratory of Natural Product ResearchBingo¨l University12000 Bingo¨lTurkey Department of Radiotherapy Uskdar University34662 I stanbulTurkey

The mass attenuation coefficients(l/q) for different parts(root, flower, stem, and leaf) of three medicinal aromatic plants(Teucrium chamaedrys L. subsp. sinuatum,Rheum ribes, and Chrysophthalmum montanum) were measured using an ^(241)Am photon source in a stable geometry and calculated using the monte Carlo N-Particle Transport Code System-extended(mCNPX) code and the WinXCOm program. The experimental and theoretical mCNPX and WinXCOm values exhibited good *** measured mass attenuation coefficient values were then used to compute the effective atomic number(Z_(eff))and electron density(N_E) of the samples. The results reveal that S1-S(stem of Teucrium chamaedrys L. subsp. sinuatum) has the highest values of l/q and Zeff.

关键词： medicinal Aromatic plant mCNPX code mass attenuation coefficient Photon WinXCOm

Sm^(3+) ions doped Sm_(2)Si_(2)O_(7)-based glass ceramics:Crystallization,luminescence and energy transfer process through heat treatment

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Journal of Rare Earths 2023年第8期41卷 1144-1152,I0001页

作者： m.monisha m.S.murari Dalal Abdullah Aloraini Aljawhara H.Almuqrin m.i.sayyed Karunakara Naregundi Sudha D.Kamath Department of Physics Manipal Institute of TechnologyManipal Academy of Higher EducationManipal576104India Scientific Officer DST-PURSE ProgramMangalore UniversityMangalagangotriKarnataka574199India Department of Physics College of SciencePrincess Nourah Bint Abdulrahman UniversityP.O.Box 84428Riyadh11671Saudi Arabia Department of Physics Faculty of ScienceIsra UniversityAmmanJordan Centre for Application of Radioisotopes and Radiation Technology(CARRT) Mangalore UniversityMangalagangotriKarnataka574199India Centre for Advanced Research in Environmental Radioactivity(CARER) Mangalore UniversityMangalagangotriKarnataka574199India

Sm^(3+) ions incorporated Sm_(2)Si_(2)O_(7) crystalline phase formed in the aluminoborosilicate glass matrix synthesized via melting quenching technique followed by heat-treatment process is reported *** preliminary confirmation on the obtained glass ceramics was made through X-ray diffration(XRD) *** of non-bridging oxygens(NBOs) in the glass network and the modes of vibrations of network units we re analyzed through Fourier transform infrared spectroscopy(FTiR) *** morphology of heat-treated samples at varying temperatures was determined via a field emission scanning electron microscope(FESEm).The absorption studies on heat-treated samples signify the low bandgap values and high Urbach energy values due to improved crystallinity in the glass ***-Ofelt intensity parameters identified for visible absorption transitions follow the trend of Ω_(4)>Ω_(2)>Ω_(6).Excitation and emission studies on heat-treated samples show improvement in their intensities compared to the unheated base *** thermal quenching is observed at higher temperatures(540 and 580℃ for 3 h) of heat-treated *** based on luminescence spectra including radiative transition probability,stimulated emission cross-section and branching ratio show good results for glass ceramics prior to precursor *** lifetimes of Sm^(3+) ions(milliseconds) in the level ^(4)G_(5/2) are seen for glass *** coordinates suggest the reddish-orange emissions from prepared glass ***,Sm^(3+) doped Sm_(2)Si_(2)O_(7) glass ceramics are favorable materials for solid-state lighting and laser applications.

关键词： Sm^(3+)ions Glass ceramics Luminescence spectra Stimulated emission cross-section Rare earths

Shielding effectiveness of boron-containing ores in Liaoning province of China against gamma rays and thermal neutrons

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Nuclear Science and Techniques 2018年第4期29卷 155-162页

作者： meng-Ge Dong Xiang-Xin Xue V.P.Singh He Yang Zhe-Fu Li m.i.sayyed Department of Resource and Environment School of Metallurgy Northeastern University Shenyang 110819China Department of Physics Karnatak UniversityDharwad 580003 India Shanghai institute of Applied Physics Shanghai 201800China Physics Department University of Tabuk Tabuk Saudi Arabia

in this study, the mass attenuation coefficient of boron-containing ores in the Liaoning province of China was calculated using Win XCOm software to investigate the shielding effectiveness of these ores against gamma rays. The mass attenuation coefficients were also calculated using mCNP-4 B code and compared with Win XCOm results; consequently, a good consistency between the results of Win XCOm and mCNP-4 B was observed. Furthermore, the G-P fitting method was used to evaluate the values of exposure buildup factor(EBF) in the energy range of 0.015–15 me V up to 40 mean free paths. Among the selected ores, boron-bearing iron concentrate ore(m3)was determined to be the best gamma ray shielding ore owing to its higher values of mass attenuation coefficient and equivalent atomic number and lower value of ***, American Evaluated Nuclear Data File(ENDF/B-Vii) was used to analyze the shielding effectivenessagainst thermal neutrons. it was determined that Szaibelyite(m2) is the best thermal neutron shielding *** study would be useful for demonstrating the potential of boron-containing ores for applications in the field of nuclear engineering and technology.

关键词： Exposure buildup factors Gamma ray Neutron Boron-containing ores G-P fitting method

influence of erbium on structural,and charged particles,photons,and neutrons shielding properties of Ba_(1-x)Er_(x)SnO_(3) perovskite ceramics

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Journal of Rare Earths 2024年第4期42卷 724-732页

作者： m.K.h.Hamad Nidal Dwaikat m.H.A.mhareb m.i.sayyed R.m.Hamad Y.S.m.Alajerami m.A.Almessiere Gameel Saleh Ahmad Hussein Alomari K.A.Ziq Department of Basic Sciences School of Social and Basics SciencesAl Hussein Technical UniversityKing Abdullah II St 242Amman11831Jordan Department of Physics College of Engineering and PhysicsInterdisciplinary Research Center for Advanced MaterialsKing Fahd University of Petroleum&MineralsDhahran31261Saudi Arabia Department of Physics College of ScienceImam Abdulrahman Bin Faisal UniversityP.O.Box 1982Dammam31441Saudi Arabia Basic and Applied Scientific Research Center Imam Abdulrahman Bin Faisal UniversityP0.Box 1982Dammam31441Saudi Arabia Department of Physics Faculty of ScienceIsra UniversityAmman11622Jordan Department of Nuclear medicine Research Institute for Research and Medical Consultations(IRMC)Imam Abdulrahman Bin Faisal UniversityPo.Box 1982Dammam31441Saudi Arabia medical imaging Department Applied Medical Sciences FacultyAl Azhar University-Gaza CityPo.Box 1277Palestine Department of Biophysics Institute for Research and Medical Consultations(IRMC)Imam Abdulrahman Bin Faisal UniversityPo.Box1982Dammam 31441Saudi Arabia Department of Biomedical Engineering College of EngineeringImam Abdulrahman Bin Faisal UniversityPo.Box 1982Dammam31441Saudi Energy&minerals Regulatory Commission Amman11821Jordan

Five perovskite ceramics samples of Ba_(1-x)Er_(x)SnO_(3) with x=0.00,0.05,0.10,0.15,and 0.20 were synthesized using the conventional solid-state reaction *** prepared samples were characterized by X-ray diffraction(XRD),Fourier transforms infrared(FTiR),and UV-Vis *** shielding properties against ionizing radiation were also *** XRD analysis shows the perovskite cubic structure as the major phase in all *** FTiR reveals a distinctive band around 614-620 cm^(-1) ascribed to the antisymmetric O-Sn-O ***-Vis spectroscopy was used to determine the bandgap according to diffuse reflectance,and the results display a fixed enhancement in the bandgap from 3.2 to 3.3 eV for all ***-ray shielding properties of the synthesized samples were experimentally measured and compared with XCOm computational *** relative differences(Δ,%)between experimental and theo retical values are low and fall within the 0.446%-7.10%*** addition of Er leads to the enhanced density,neutron,and gamma shielding *** contrast,charged particles’shielding parameters gradually reduce with rising Er *** results suggest that Ba_(1-x)Er_(x)SnO_(3) samples can be used in different radiation shielding applications.

关键词： Perovskite Ceramics Gamma ray shielding mass stopping power Rare earths

Arctic sea-ice extent: No record minimum in 2023 or recent years

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Atmospheric and Oceanic Science Letters 2025年第1期18卷 52-55页

作者： Ola m.Johannessen Tor i.Olaussen Nansen Scientific Society BergenNorway Nansen Environmental and Remote Sensing Center BergenNorway

Arctic sea-ice extent reaches its minimum each year in September. On 11 September 2023 the minimum was 4.969 million square kilometers(***^(2)). This was not a record low, which occurred in 2012, when the minimum was 4.175 ***^(2), 0.794 ***^(2) less than the minimum in 2023. However, the ice extent had decreased by 0.432 ***^(2) compared with 2022. Nevertheless, the summer melting in 2023 was remarkably less than expected when considering the strong heat waves in the atmosphere and ocean, with record temperatures set around the world. in general, there is a high correlation between the long-term decrease in sea-ice extent and the increasing CO_(2) in the atmosphere, where the increase of CO_(2) in recent decades explains about 80% of the decrease in sea ice in September, while the remainder is caused by natural variability.

关键词： Sea ice Arctic minimum ice Climate

Flood basalt hosted palaeosols:Potential palaeoclimatic indicators of global climate change

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Geoscience Frontiers 2014年第6期5卷 791-799页

作者： m.R.G.sayyed Department of Geology Poona College (University of Pune)CampPune 411 001MaharashtraIndia

Since continental sediments （in addition to the marine geological record） offer important means of deciphering environmental changes, the sediments hosted by the successive flows of the continental flood basalt provinces of the world should be treasure houses in gathering the palaeoclimatic data. Palaeosols developed on top of basalt flows are potentially ideal for palaeoenvironmental reconstructions because it is easy to determine their protolith geochemistry and also they define a definite time interval. The present paper summarizes the nature of the basalt-hosted palaeosols formed on the flood basalts provinces from different parts of the ~lobe havin~ different ages.

关键词： Continental flood basalts Palaeosols Weathering Palaeoclimates Global change

Superconducting parameter determination for (Co0.5Zn0.5Fe2O4)x/Cu0.5Tl0.5-1223 composite

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Journal of Advanced Ceramics 2016年第3期5卷 210-218页

作者： m.mE.BARAKAT N.AL-sayyed R.AWAD A.i.ABOU-ALY Physics Department Faculty of Science Alexandria University Alexandria Egypt Physics Department Faculty of Science Beirut Arab University Beirut Lebanon

The addition of magnetic Co0.5Zn0.5Fe2O4 nanoparticles to the superconducting Cu0.5Tl0.5-1223 phase has been used to investigate the electrical resistivity behavior of the composite above the superconducting transition temperature T c. This was studied according to the opening of spin gap and fluctuation conductivity. The results indicated that the pseudogap temperature (T*) and superconducting fluctuation temperature (T scf) change by increasing the addition of Co0.5Zn0.5Fe2O4 nanoparticles. it was found that T* is related to hole carrier concentration P and it also depends on the antiferromagnetic fluctuation affected by magnetic nanoparticles. The excess-conductivity analysis showed four different fluctuation regions started from high temperature up to T c, and they were denoted by short wave (sw), two-dimensional (2D), three-dimensional (3D), and critical (cr) fluctuations. The crossover temperature between 3D and 2D (T 3D–2D) in the mean field region was decreased by increasing the addition of Co0.5Zn0.5Fe2O4 nanoparticles, in accordance with the decrease in T scf with x. The coherence length at 0 K along c-axis ξ c(0), effective layer thickness of the 2D system d, and inter-layer coupling strength J were estimated as a function of Co0.5Zn0.5Fe2O4 nanoparticle addition. moreover, the thermodynamics, lower and upper critical magnetic fields, as well as critical current density have been calculated from the Ginzburg number N G. it was found that the low concentration of Co0.5Zn0.5Fe2O4 nanoparticles up to x = 0.08 wt% improves the superconducting parameters of Cu0.5Tl0.5-1223 phase. On the contrary, these parameters were deteriorated for (Co0.5Zn0.5Fe2O4) x /Cu0.5Tl0.5-1223 composite with x > 0.08 wt%.

关键词： Co0.5Zn0.5Fe2O4 nanoparticles Cu0.5Tl0.5-1223 phase pseudogap temperature fluctuation conductivity

Comparison of experimental and theoretical radiation shielding parameters of several environmentally friendly materials

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Nuclear Science and Techniques 2019年第7期30卷 54-61页

作者： F. Akman1 O. Agar m. R. Kacal m. i. sayyed Vocational School of Technical Sciences Department of Electronic Communication Technology Bingol University 12000 Bingol Turkey Department of Physics Karamanoglu Mehmetbey University Karaman Turkey Department of Physics Arts and Sciences Faculty Giresun University 28100 Giresun Turkey Department of Physics Faculty of Science University of Tabuk Tabuk Saudi Arabia

in this study, the gamma radiation shielding features of several environmentally friendly materials were investigated. For this purpose, several attenuation parameters, such as the mass attenuation coefficient (l=q), radiation protection efficiency (RPE), and effective atomic number (Zeff) were determined experimentally and compared with numerical data obtained using WinXCom software. in the measurements, the emitted gamma photons were counted by a gamma spectrometer equipped with an HPGe detector using 22Na, 54mn, 57Co, 60Co, 133Ba, and 137Cs radioactive point sources in the energy region of 81–1333 keV. The obtained results indicate that the l=q and RPE values of the samples decrease with an increase in photon energy. The experimental values are in good agreement with those obtained using WinXCom software. The RPE and Zeff results show that among the studied materials, the NaY0.77Yb0.20Er0.03F4 sample has the best gamma radiation shielding effectiveness.

关键词： Greener products Radiation shielding Attenuation coefficient WinXCom Radiation protection efficiency

Comparison of effective parameters for copper powder production via electrorefining and electrowinning cells and improvement using DOE methods

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international Journal of minerals,metallurgy and materials 2011年第6期18卷 731-740页

作者： Ebrahim Akbarzadeh sayyed Esmaeil Shakib Department of materials Science and metallurgical Engineering Shahid Bahonar University of Kerman

The influences of cupric ion concentration （5-35 g/L）,current density （500-2000 A/m2）,circulation rate of the electrolyte solution （15-120 mL/min）,and temperature （25-60℃） on the physical and chemical properties of copper powders obtained in electrolysis cells were *** industrial processes,electrorefining （ER） cells with a synthetic electrolyte and electrowinning （EW） cells with an original solution of coppermineral leaching,were utilized to produce copper ***,the statistical full factorial method of design of experiments （DOE） was employed to investigate the interaction or the main effects of *** results show that increasing the copper concentration and temperature can increase the grain size,apparent density,and electrical energy *** the other hand,increasing the current density and circulation rate of the electrolyte can decrease *** production process is optimized via DOE to control the interactive and main effects to produce copper powders with favorable properties.

关键词： copper powders electrorefining electrowinning grain size apparent density

The sexually dimorphic expression of glutamate transporters and their implication in pain after spinal cord injury

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Neural Regeneration Research 2025年第11期20卷 3317-3329页

作者： Jennifer m.Colón-mercado Aranza i.Torrado-Tapias iris K.Salgado Jose m.Santiago Samuel E.Ocasio Rivera Dina P.Bracho-Rincon Luis H.Pagan Rivera Jorge D.miranda Department of Physiology University of Puerto RicoMedical Sciences CampusSan JuanPRUSA National institutes of Health National Human Genome Research InstituteBethesdaMDUSA Universidad Central del Caribe School of MedicineBayamónPRUSA University of Puerto Rico Carolina CampusCarolinaPRUSA institute of Neurobiology San JuanPRUSA

in addition to the loss of motor function,~60% of patients develop pain after spinal cord *** cellular-molecular mechanisms are not well understood,but the data suggests that plasticity within the rostral,epicenter,and caudal penumbra of the injury site initiates a cellularmolecular interplay that acts as a rewiring mechanism leading to central neuropathic *** can lead to the formation of new connections triggering abnormal sensory *** excitatory glutamate transporters are responsible for the reuptake of extracellular glutamate which makes them a critical target to prevent neuronal hyperexcitability and *** previous studies showed a sexually dimorphic therapeutic window for spinal cord injury after treatment with the selective estrogen receptor modulator *** this study,we investigated the anti-allodynic effects of tamoxifen in male and female rats with spinal cord *** hypothesized that tamoxifen exerts anti-allodynic effects by increasing the expression of glutamate transporters,leading to reduced hyperexcitability of the secondary neuron or by decreasing aberrant *** and female rats received a moderate contusion to the thoracic spinal cord followed by subcutaneous slow-release treatment of tamoxifen or matrix pellets as a control(placebo).We used von Frey monofilaments and the“up-down method”to evaluate mechanical *** treatment decreased allodynia only in female rats with spinal cord injury revealing a sexdependent *** expression profile of glutamatergic transporters(excitatory amino acid transporter 1/glutamate aspartate transporter and excitatory amino acid transporter 2/glutamate transporter-1)revealed a sexual dimorphism in the rostral,epicenter,and caudal areas of the spinal cord with a pattern of expression primarily on *** rodents showed a significantly higher level of excitatory amino acid transporter-1 expression while male rodents showed increased

关键词： allodynia central neuropathic pain EAAT-1/GLAST EAAT-2/GLT-1 glutamate transporters selective estrogen receptor modulator sexual dimorphism spinal cord injury trauma