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A decomposition of light’s spin angular momentum density

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Light(Science & Applications) 2024年第8期13卷 1578-1589页

作者： Alex j.Vernon Sebastian Golat Claire Rigouzzo Eugene A.Lim Francisco j.Rodríguez-Fortuño Department of Physics King’s College LondonStrandLondon WC2R 2LSUK London Centre for Nanotechnology LondonUK

Light carries intrinsic spin angular momentum(SAM)when the electric or magnetic field vector rotates over time.A familiar vector equation calculates the direction of light’s SAM density using the right-hand rule with reference to the electric and magnetic polarisation *** Maxwell’s equations,this vector equation can be decomposed into a sum of two distinct terms,akin to the well-known Poynting vector decomposition into orbital and spin *** present the first general study of this spin decomposition,showing that the two terms,which we call canonical and Poynting spin,are chiral analogies to the canonical and spin momenta of light in its interaction with *** canonical momentum,canonical spin is directly *** canonical and Poynting spin incorporate spatial variation of the electric and magnetic fields and are influenced by optical *** decomposition allows us to show that a linearly polarised vortex beam,which has no total SAM,can nevertheless exert longitudinal chiral pressure due to equal and opposite canonical and Poynting spins.

关键词： canonical momentum angular

Europium recovery process by means of polymeric nanoparticles functionalized with acrylic acid,curcumin and fumaramide

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journal of Rare Earths 2024年第10期42卷 1950-1959页

作者： P.A.Martínez-Montoya j.M del Río A.de j.Morales-Ramirez M.Corea Escuela Superior de Ingeniería Química e Industrias Extractivas ESIQIE-IPNDepartamento de Ingeniería Metalúrgica UPALM S/N Col.LindavistaGustao A.MaderoCDMXC.P.07738Mexico Escuela Superior de Ingenieria Química e Industrias Extractivas ESIQIE-IPNLaboratorio de Investigación en Polímeros y NanomaterialesUPALM S/N Col.LindavistaGustavoA.MaderoCDMXC.P.07738Mexico Centra de Investigación e Innovación Tecnológica CIITEC-IPNCda.de CECATIs/nSanta CatarinaAzcapotzalcoC.P.02250CDMXMexico

Polymeric nanoparticles of poly(methyl methacrylate)were obtained by emulsion polymerization techniques in a proce ss of two *** particles were functionalized with acrylic acid,curcumin,and fumaramide and three series of polymeric particles were *** incorporation of functional groups was confirmed by Fourier transform-infrared spectrosocopy(FT-IR)and ultraviolet-visible(UV-Vis)*** spherical morphology of particles with an average diameter of 100 nm was observed by scartning electron microscopy(SEM).The polymeric materials were used for recovery of[Eu]from synthetic *** nanoparticles show excellent chelation capacity to trap rare-earth ions,because they recover more than 85%of[Eu]at pH of *** images of SEM after extraction process show arrays between particles with larger average particle sizes to 1.5 *** addition,the particles have a good stripping capacity,exceeding 50%of it,maintaining their homogeneity in morphology and good stability in dispersion for the recovery and stripping processes.A pseudo-second model order is obtained for the extraction and stripping processes while the best results of stripping process are obtained at pH of 6.

关键词： [Eu]recovery Chelating effect Extraction process Stripping process Emulsion polymerization Rare earths

Stability analysis of a time-delayed Van der Pol–Helmholtz–Duffing oscillator in fractal space with a non-perturbative approach

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Communications in Theoretical Physics 2024年第4期76卷 22-31页

作者： Yusry o El-Dib Department of Mathematics Faculty of EducationAin Shams UniversityRoxyCairoEgypt

The time-delayed fractal Van der Pol–Helmholtz–Duffing(VPHD)oscillator is the subject of this paper,which explores its mechanisms and highlights its stability *** time-delayed technologies are currently garnering significant attention,the focus of this research remains crucially relevant.A non-perturbative approach is employed to refine and set the stage for the system under *** innovative methodologies introduced yield an equivalent linear differential equation,mirroring the inherent nonlinearities of the ***,the incorporation of quadratic nonlinearity into the frequency formula represents a cutting-edge *** analytical solution's validity is corroborated using a numerical *** conditions are ascertained through the residual Galerkin ***,it is observed that the delay parameter,in the context of the fractal system,reverses its stabilizing influence,impacting both the amplitude of delayed velocity and the *** analytical solution's precision is underscored by its close alignment with numerical ***,the study reveals that fractal characteristics emulate damping *** its applicability across diverse nonlinear dynamical systems,this non-perturbative approach emerges as a promising avenue for future research.

关键词： Van der Pol-Helmholtz-Duffing oscillator fractal space time-delay non-perturbative approach stability analysis El-Dib's frequency formula

Sensing nanoscale electromagnetic forces when the heat is on

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National Science Review 2024年第7期11卷 64-65页

作者： Eric o.Potma Department of Chemistry University of California

In scanning probe microscopy(SPM),a sharp tip scans across a sample to produce an image with nanometer-scale resolution or better. SPM contrast is derived from the physical interplay between the tip and the sample. A special class of SPM techniques measures forces when the tip–sample junction is illuminated by an external light source. Photo-induced forces can be sensitive to the optical properties of the sample, thus enabling nanoscale imaging with spectroscopic,material-specific contrast.

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Apples to oranges:environmentally derived,dynamic regulation of serotonin neuron subpopulations in adulthood?

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Neural Regeneration Research 2025年第9期20卷 2596-2597页

作者： Christopher j.o’Connell Matthew j.Robson Department of Genetics College of MedicineHarvard UniversityBostonMAUSA james L.Winkle College of Pharmacy Division of Pharmaceutical SciencesUniversity of CincinnatiCincinnatiOHUSA Neuroscience Graduate Program College of MedicineUniversity of CincinnatiCincinnatiOHUSA

Traumatic brain injury(TBI)is a public health problem with an undue economic burden that impacts nearly every age,ethnic,and gender group across the globe(Capizzi et al.,2020).TBIs are often sustained during a dynamic range of exposures to energetic environmental forces and as such outcomes are typically heterogeneous regarding severity and pathology(Capizzi et al.,2020).

关键词： sustained orange dynamic

Perturbations in the earthworm metabolite profile during a two-week exposure to metformin

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Emerging Contaminants 2024年第3期10卷 221-229页

作者： j.D.Gillis G.W.Price S.o.Prasher Department of Bioresource Engineering McGill UniversityFaculty of Agricultural and Environmental SciencesMacdonald-Stewart Building MS1-02721111 Lakeshore RoadSainte-Anne-de-BellevueQuebecH9X 3V9Canada Department of Engineering Dalhousie UniversityFaculty of Agriculture39 Cox RoadPO Box 550TruroNova ScotiaB2N 5E3Canada

Metformin is among the most prescribed pharmaceuticals in many countries,and as a result has shown up in biosolids derived from municipal wastewater treatment that are destined for land *** humans taking metformin,the effects include reduced glucose uptake in the intestine,a reduction in gluconeogenesis,increased oxidation of fatty acids,and reduced fatty acid *** effects of metformin on soil-dwelling organisms are not well *** study tested the effects of metformin exposure(0,10,40,160,640μg g^(-1))on the earthworm(***)at four time points(6 h,2 d,7 d,and 14 d)using GC-MS to reveal sub-lethal effects and elucidate potential modes of action for *** were no mortalities observed,and earthworms exposed to the highest concentrations(160 and 640μg g^(-1))gained weight relative to the control on days 7 and *** reductions on day 7 were observed for glucose and malic acid(consistent with a reduction in gluconeogenesis),and for palmitic and margaric acid(consistent with increased oxidation and reduced synthesis of fatty acids).Lactic acid ranked first and second among canonicals 1 and 2 respectively and led to significant differences in discriminant scores across concentration and *** levels increased to equal or greater than the control on day 14,likely caused by reduced exposure as metformin is reported to be readily transformed by microorganisms under aerobic *** observations were consistent with the known effects of metformin in humans,and suggests that a similar mode of action exists in earthworms.

关键词： Metabolites Toxicity Earthworms Metformin GC-MS

SMILE soft X-ray Imager flight model CCD370 pre-flight device characterisation

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Earth and Planetary Physics 2024年第1期8卷 25-38页

作者： S.Parsons D.j.Hall o.Hetherington T.W.Buggey T.Arnold M.W.j.Hubbard A.Holland Centre for Electronic Imaging the Open UniversityMilton KeynesMK76AAUK

Throughout the SMILE mission the satellite will be bombarded by radiation which gradually damages the focal plane devices and degrades their *** order to understand the changes of the CCD370s within the soft X-ray Imager,an initial characterisation of the devices has been carried out to give a baseline performance *** CCDs have been characterised,the two flight devices and the flight spa *** has been carried out at the open University in a bespo ke cleanroom measure ment *** results show that there is a cluster of bright pixels in the flight spa re which increases in size with tempe *** at the nominal ope rating tempe rature(-120℃) it is within the procure ment ***,the devices meet the specifications when ope rating at -120℃ in 6 × 6 binned frame transfer science *** se rial charge transfer inefficiency degrades with temperature in full frame *** any charge losses are recovered when binning/frame transfer is implemented.

关键词： CCD soft X-ray imager characterisation SMILE

on the analytical solution of transient friction in channel flows

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Applied Mathematics and Mechanics(English Edition) 2024年第8期45卷 1447-1466页

作者： F.j.GARCíA-GARCíA P.FARINAS-ALVARINo Department of Naval&Industrial Engineering Polytechnic School of EngineeringUniversity of A CorunaCampus Industrial de FerrolFerrol 15403A CorunaSpain Integraciones Técnicas de Seguridad S.A.Pol.Ind.Espiritu SantoC/Nobel15Cambre 15650A CorunaSpain

The transient friction in channel mean flows is the sum of two contributions,i.e.,the underlying laminar flow(ULF)and the purely turbulent component(PTC),and the contributions are analyzed separately by theoretical *** is found that,the transient friction may be higher or remarkably lower than that in equal-Reynolds number steady-state *** universal time constant for plane-parallel laminar flows is reported,and the role of the time constant in a turbulent mean flow is *** is shown that the time constant is related to the turbulence's frozen ***,a study of the logarithmic layer during the transient flow is accomplished,which shows that the logarithmic layer is destroyed.

关键词： transient friction transient flow unsteady channel flow

Nutritional epigenetics education improves diet and attitude of parents of children with autism or attention deficit/hyperactivity disorder

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World journal of Psychiatry 2024年第1期14卷 159-178页

作者： Renee j Dufault Katherine M Adler David o Carpenter Steven G Gilbert Raquel A Crider College of Graduate Health Studies A.T.Still UniversityKirksvilleMO 63501United States Department of Research Food Ingredient and Health Research InstituteNaalehuHI 96772United States Department of Health Sciences University of New HavenWest HavenCT 06516United States Institute for Health and the Environment School of Public HealthState University of New YorkAlbanyNY 12222United States Department of Research Institute of Neurotoxicology and Neurological DisordersSeattleWA 98105United States Department of Statistics Food Ingredient and Health Research InstituteNaalehuHI 96772United States

BACKGRoUND Unhealthy maternal diet leads to heavy metal exposures from the consumption of ultra-processed foods that may impact gene behavior across generations,creating conditions for the neurodevelopmental disorders known as autism and attention deficit/hyperactivity disorder(ADHD).Children with these disorders have difficulty metabolizing and excreting heavy metals from their bloodstream,and the severity of their symptoms correlates with the heavy metal levels measured in their *** may play a key role in helping parents reduce their ultra-processed food and dietary heavy metal intake by providing access to effective nutritional epigenetics *** To test the efficacy of nutritional epigenetics instruction in reducing parental ultra-processed food *** The study utilized a semi-randomized test and control group pretest-posttest pilot study design with participants recruited from parents having a learning-disabled child with autism or ***-two parents who met the inclusion criteria were randomly selected to serve in the test(n=11)or control(n=11)*** test group participated in the six-week online nutritional epigenetics tutorial,while the control group did *** efficacy of the nutritional epigenetics instruction was determined by measuring changes in parent diet and attitude using data derived from an online diet survey administered to the participants during the pre and post intervention *** intake scores were derived for both ultra-processed and whole/organic *** sample t-tests were conducted to determine any differences in mean diet scores within each *** There was a significant difference in the diet scores of the test group between the pre-and post-intervention *** parents in the test group significantly reduced their intake of ultra-processed foods with a preintervention diet score of 70(mean=5.385,SD=2.534)and a post-intervention diet score of 113(mean=8.692,SD=1.750)and the

关键词： Epigenomics Parenteral nutrition Autism Attention deficit/hyperactivity disorder Ultra-processed foods Heavy metals