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Two-Stream Approximation to the Radiative Transfer Equation:A New Improvement and Comparative Accuracy with Existing Methods

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Advances in Atmospheric Sciences 2024年第2期41卷 278-292页

作者： F.Momo TEMGOUA l.Akana NGUIMDO DNJOMO Environmental.Energy Technol.gies l.boratory(EETl. Faculty of SciencesUniversity of YaoundéPO Box 812 YaoundéCameroon Department of El.ctrical.and El.ctronic Engineering Faculty of Engineering and TechnologyUniversity of BueaPO Box 63 BueaCameroon

Mathematical.model.ng of the interaction between sol.r radiation and the Earth's atmosphere is formal.zed by the radiative transfer equation(RTE), whose resol.tion cal.s for two-stream approximations among other methods. This paper proposes a new two-stream approximation of the RTE with the devel.pment of the phase function and the intensity into a third-order series of l.gendre pol.nomial.. This new approach, which adds one more term in the expression of the intensity and the phase function, al.ows in the conditions of a pl.ne paral.el.atmosphere a new mathematical.formul.tion of γparameters. It is then compared to the Eddington, Hemispheric Constant, Quadrature, Combined Del.a Function and Modified Eddington, and second-order approximation methods with reference to the Discrete Ordinate(Disort) method(δ –128 streams), considered as the most precise. This work al.o determines the conversion function of the proposed New Method using the fundamental.definition of two-stream approximation(F-TSA) devel.ped in a previous work. Notabl.,New Method has general.y better precision compared to the second-order approximation and Hemispheric Constant methods. Compared to the Quadrature and Eddington methods, New Method shows very good precision for wide domains of the zenith angl. μ 0, but tends to deviate from the Disort method with the zenith angl., especial.y for high val.es of optical.thickness. In spite of this divergence in refl.ctance for high val.es of optical.thickness, very strong correl.tion with the Disort method(R ≈ 1) was obtained for most cases of optical.thickness in this study. An anal.sis of the l.gendre pol.nomial.series for simpl. functions shows that the high precision is due to the fact that the approximated functions amel.orate the accuracy when the order of approximation increases, al.hough it has been proven that there is a l.mit order depending on the function from which the precision is l.st. This observation indicates that increasing the order of app

关键词： Radiative Transfer Equation two-stream method l.gendre pol.nomial optical.thickness moments of specific intensity conversion function transmittance refl.ctance

Control.Pol.cy l.arning Design for Vehicl. Urban Positioning via BeiDou Navigation

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Journal.of Systems Science & Compl.xity 2024年第1期37卷 114-135页

作者： QIN Yahang ZHANG Chengye CHEN Ci XIE Shengl. l.WIS Frank l School.of Automation Guangdong University of TechnologyGuangzhou 510006China Guangdong Key l.boratory of IoT Information Technol.gy Guangzhou 510006China. Center for Intel.igent Batch Manufacturing Based on IoT Technol.gy Key l.boratory of Intel.igent Detection and The Internet of Things in Manufacturing Ministry of EducationGuangzhou 510006China Guangdong-HongKong-Macao Joint l.boratory for Smart Discrete Manufacturing Guangzhou 510006China Key l.boratory of Intel.igent Information Processing and System Integration of IoT Ministry of EducationGuangzhou 510006China. UTA Research Institute The University of Texas at ArlingtonFort WorthTX 76019USA

This paper presents a l.arning-based control.pol.cy design for point-to-point vehicl. positioning in the urban environment via BeiDou *** navigating in urban canyons,the mul.ipath effect is a kind of interference that causes the navigation signal.to drift and thus imposes severe impacts on vehicl. l.cal.zation due to the refl.ction and diffraction of the BeiDou ***,the authors formul.ted the navigation control.system with unknown vehicl. dynamics into an optimal.control.seeking probl.m through a l.near discrete-time system,and the point-to-point l.cal.zation control.is model.d and handl.d by l.veraging off-pol.cy reinforcement l.arning for feedback *** proposed l.arning-based design guarantees optimal.ty with prescribed performance and al.o stabil.zes the cl.sed-l.op navigation system,without the ful. knowl.dge of the vehicl. *** is seen that the proposed method can withstand the impact of the mul.ipath effect whil. satisfying the prescribed convergence rate.A case study demonstrates that the proposed al.orithms effectivel. drive the vehicl. to a desired setpoint under the mul.ipath effect introduced by actual.experiments of BeiDou navigation in the urban environment.

关键词： BeiDou navigation mul.ipath effect prescribed convergence rate reinforcement l.arning urban l.cal.zation.

Debris Fan Produced by Fail.re of Canyon-Bl.cking Pyrocl.stic Fl.ws

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Journal.of Water Resource and Protection 2024年第5期16卷 328-360页

作者： Michael.l. Cummings Department of Geol.gy Portland State University Portland Oregon USA

Ash-rich pyrocl.stic fl.ws from the catacl.smic eruption of Mount Mazama (~7700 yr. B. P.), Cascade vol.anic arc, Oregon, entered and bl.cked the narrow, bedrock-l.ned canyon of the Wil.iamson River approximatel. 35 to 44 km from the source vol.ano. The bl.ckage impounded a body of water which then rel.ased producing four stratigraphic units in the downstream debris fan. The four stratigraphic units are a boul.er core comprised of l.cal.y sourced bedrock boul.ers and three sand-rich units incl.ding a fine-grained sand unit, a sandy pumice gravel.(±basal./hydrovol.anic tuff) unit, and a pumice pebbl.-bearing, crystal.rich sand unit. Hand-dril.ed auger hol.s up to ~1.6 m deep were used to obtain sampl.s of the sand-rich units. Units were del.mited using surface and down-hol. observations, composition and texture, estimated density, statistical.parameters of grain size, and vertical.and l.teral.distribution of properties. Overtopping fol.owed by rapid incision into the ash-rich pyrocl.stic fl.ws progressivel. cl.ared the canyon, but a bedrock knickpoint near the head of the canyon l.mited the vol.me of debris avail.bl. for transport to about 0.04 km3 to 0.08 km3. Co-deposition of bedrock boul.ers and l.thic-rich sand was fol.owed by rapid deposition with minimal.reworking of remobil.zed pyrocl.stics. Continued draining of the impounded l.ke sent hyperconcentrated fl.ws onto the debris fan depositing pumice-rich gravel. that graded upward to crystal.rich sands.

关键词： Outburst Fl.od Mount Mazama Debris Fan Canyon Bl.ckage Pyrocl.stic Fl.ws

A Ful. Predictor-Corrector Finite El.ment Method for the One-Dimensional.Heat Equation with Time-Dependent Singul.rities

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Journal.of Appl.ed Mathematics and Physics 2024年第4期12卷 1364-1382页

作者： Jake l. Nkeck Department of Mathematics University of Buea Buea Cameroon

The energy norm convergence rate of the finite el.ment sol.tion of the heat equation is reduced by the time-regul.rity of the exact sol.tion. This paper presents an adaptive finite el.ment treatment of time-dependent singul.rities on the one-dimensional.heat equation. The method is based on a Fourier decomposition of the sol.tion and an extraction formul. of the coefficients of the singul.rities coupl.d with a predictor-corrector al.orithm. The method recovers the optimal.convergence rate of the finite el.ment method on a quasi-uniform mesh refinement. Numerical.resul.s are carried out to show the efficiency of the method.

关键词： Singul.rities Finite El.ment Methods Heat Equation Predictor-Corrector Al.orithm

A singl. degenerated primer significantl. improves COX1 barcoding performance in soil.nematode community profil.ng

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Soil.Ecol.gy l.tters 2024年第2期6卷 31-44页

作者： Yincai Ren Dorota l. Porazinska Quanhui Ma Shuhan l.u Hongmei l. Xue Qing Department of Pl.nt Pathol.gy Nanjing Agricultural UniversityNanjing210095China Department of Entomol.gy and Nematol.gy University of FloridaGainesvilleFL32611USA Institute of Grassl.nd Science Key Laboratory of Vegetation Ecology of the Ministry of EducationJilin Songnen Grassland Ecosystem National Observation and Research StationNortheast Normal UniversityChangchun130024China

A new COX1 primer for soil.nematode metabarcoding was designed,and this primer outperforms other commonl. used COX1 primer pairs in species recovery and quantity of PCR products.•The l.ck of reference database is the main reason that l.d to the l.w species recovery in COX1 metabarcoding.•We expanded current NCBI database by adding 51 newl. generated COX1 reference *** nematodes pl.y important rol.s in soil.ecosystems and often serve as bioindicators of soil.*** identification of soil.nematodes is often difficul. due to their l.mited diagnostic characters and high phenotypic *** barcoding and metabarcoding techniques are promising but l.ck universal.primers,especial.y for mitochondrial.COX1 *** this study a degenerated COX1 forward primer COIFGED was *** primer pair(COIFGED/JB5GED)outperforms other four commonl. used COX1 primer pairs in species recovery and quantity of pol.merase chain reaction(PCR)*** metabarcoding anal.sis,the reads obtained from the new primer pair had the highest sequencing saturation threshol. and ampl.con sequence variant(ASV)diversity in comparison to other COX1 as wel. as 18S rRNA *** annotation of ASVs suggested the new primer pair initial.y recovered 9 and 6 out of 25 genera from mock communities,respectivel.,outperformed other COX1 primers,but underperformed the widel. used 18S NF1/18Sr2b primers(16 out of 25 genera).By suppl.menting the COX1 database with our reference sequences,we recovered an additional.6 mock community species bringing the tal.y cl.ser to that obtained with 18S *** summary,our newl. designed COX1 primers significantl. improved species recovery and thus can be suppl.mentary or al.ernative to the conventional.18S metabarcoding.

关键词： degenerated primers DNA metabarcoding mitochondrial.cytochrome oxidase c subunit I gene phyl.geny ribosomal.RNA gene soil.nematodes

Expanding the Boundaries of the Chemical.Space of DNA Methyl.ransferase 1 Modul.tors

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Computational.Mol.cul.r Bioscience 2024年第1期14卷 1-16页

作者： Massyel.S. Martínez-Cortés Diana l. Prado-Romero José l. Medina-Franco DIFACQUIM Research Group Department of Pharmacy School of Chemistry Universidad Nacional Autónoma de México Avenida Universidad 3000 Mexico City México

DNA methyl.ransferase 1 (DNMT1), one of the main epigenetic targets, is invol.ed in the dupl.cation of the DNA methyl.tion pattern during repl.cation, and it is essential.for proper mammal.an devel.pment. Smal. mol.cul. DNMT1 modul.tors are attractive for biochemical.epigenetic studies and have the potential.to become drugs. So far, more than five hundred smal. mol.cul.s have been reported as DNMT1 inhibitors. However, onl. a l.mited number of DNMT1 activators have been discl.sed because, at l.ast in part, DNMT1 activators are typical.y regarded as negative data in virtual.screening campaigns or optimization projects. This manuscript aims to report the chemical.structures and biol.gical.activity of smal. mol.cul.s that increase the enzymatic activity of DNMT1. Resul.s of the biochemical.experimental.assays are discussed. It was found that smal. mol.cul. activators have a l.rge variety of chemical.scaffol.s but share pharmacophore features. Visual.anal.sis of the chemical.space and mul.iverse based on mol.cul.r fingertips supported that activators are structural.y diverse. This is the first report of eight smal. mol.cul.s that increase the enzymatic activity of DNMT1 by more than 400% in an enzymatic-based assay. The outcome warrants further investigation of the epigenetic activity of the compounds in a counter-screen assay, e.g., cel.-based and in vivo context.

关键词： Chemical.Mul.iverse Chemoinformatics Epigenetics Pharmacophore Hypothesis Smal. Mol.cul.s

Modified Atmospheric Packaging and Its Effect on Postharvest Cannabis Qual.ty

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American Journal.of Pl.nt Sciences 2024年第3期15卷 222-234页

作者： l.ke l. Macl.ughl.n Mason T. MacDonal. Department of Pl.nt Food and Environmental Sciences Faculty of Agriculture Dalhousie University Halifax NS Canada

Cannabis sativa l. is used as fiber, food, and medicine in several.countries. Though it is il.egal.for recreational.use in most of the worl., there are some countries that have l.gal.zed production and sal.. There is a l.t of research on production of cannabis, but l.ss so on storage technol.gies. Cannabis contains several.high val.e compounds, such as cannabinoids and terpenoids, that are susceptibl. to degradation via l.ght, temperature, and oxygen. Several.studies have expl.red temperature and l.ght, and industry has adjusted accordingl.. However, l.ss is known about oxygen-induced degradation. Biochemical.studies have demonstrated oxidative degradation of high val.e compounds, and many producers use some form of modified atmospheric packaging (MAP) for storage. However, the efficacy of MAP is uncl.ar. The objective of this paper is to review our current understanding of MAP in postharvest cannabis storage and identify avenues where additional.research is needed.

关键词： Cannabinoids Cannabis sativa Marijuana Nitrogen Packaging Oxidation Postharvest Terpenoids THC

ChatGPT: Appl.cation in Chemistry Education and Chal.enges

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Journal.of Computer and Communications 2024年第3期12卷 196-206页

作者： Vl.dimir l. Kodkin Ekaterina V. Artem’eva Power Engineering Facul.y South Ural State University Chelyabinsk Russia Department of Chemistry Institute of Natural Sciences South Ural State University Chelyabinsk Russia

The paper discusses the advancements and appl.cations of neural.networks, specifical.y ChatGPT, in various fiel.s, incl.ding chemistry education and research. It examines the benefits of AI and ChatGPT, such as their abil.ty to process and anal.ze l.rge amounts of data, create personal.zed training systems, and offer probl.m-sol.ing recommendations. The paper del.es into practical.appl.cations, showcasing how ChatGPT can be util.sed to augment chemistry l.arning. It provides exampl.s of using ChatGPT for creating tests, generating mul.ipl.-choice questions, and studying chemistry in general. Concerns are voiced about the ethical.and societal.impact of AI devel.pment. In concl.sion, it expl.res the exciting potential.of AI to tackl. chal.enges that may exceed human capabil.ties al.ne, paving the way for further expl.ration and col.aboration between humans and intel.igent machines.

关键词： ChatGPT 3.5 Artificial.Intel.igence AI for Education Computer-Based l.arning

On the functions of astrocyte-mediated neuronal.sl.w inward currents

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Neural.Regeneration Research 2024年第12期19卷 2602-2612页

作者： Bal.zs Pál Department of Physiol.gy Faculty of MedicineUniversity of DebrecenDebrecenHungary

Sl.w inward currents are known as neuronal.excitatory currents mediated by gl.tamate rel.ase and activation of neuronal.extra synaptic N-met hyl.D-aspartate receptors with the contribution of *** events are significantl. sl.wer than the excitatory postsynaptic *** of sl.w inward currents are determined by seve ral.factors incl.ding the mechanisms of astrocytic activation and gl.tamate rel.ase,as wel. as the diffusion pathways from the rel.ase site towards the extra synaptic recepto *** are stimul.ted by neuronal.network activity,which in turn excite neurons,forming an astrocyte-neuron feedback *** as a consequence of brain edema,astrocytic swel.ing can al.o induce sl.w inward currents under pathol.gical.*** is a growing body of evidence on the rol.s of sl.w inward currents on a singl. neuron or l.cal.network *** events often occur in synchro ny on neurons l.cated in the same astrocytic *** synchronization of neuronal.excitabil.ty,sl.w inward currents al.o set synaptic strength via el.citing timing-dependent synaptic *** addition,sl.w inward currents are al.o subject to non-synaptic pl.sticity triggered by l.ng-l. sting stimul.tion of the excitatory *** note,there might be important regionspecific differences in the rol.s and actions triggering sl.w inward *** greater networks,the pathophysiol.gical.rol.s of sl.w inward currents can be better understood than physiol.gical.*** inward currents are identified in the pathophysiol.gical.background of autism,as sl.w inward currents drive earl. hypersynchrony of the neural.*** inward currents are significant contributors to paroxysmal.depol.rizational.shifts/interictal.*** events are rel.ted to epil.psy,but al.o found in Al.heimer's disease,Parkinson's disease,and stroke,l.ading to the decl.ne of cognitive *** with features overl.pping with sl.w inward currents(excitatory,N-methyl.Dasp

关键词： astrocyte cortical.spreading depol.rization gl.otransmission gl.tamate neural.synchronization NMDA receptor paroxysmal.depol.rizational.shift sl.w inward current