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exploring the mass gap:Black holes in green pea galaxies

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Science China(Physics,Mechanics & Astronomy) 2024年第10期67卷 170-171页

作者： James e.rhoads School of earth and Space exploration Arizona State UniversityTempeAZ 85287USA

We know about black holes primarily on two mass scales(e.g.,see Figure 22 of ref.[1]).Supermassive black holes inhabit the centers of galaxies,where they sometimes power active galactic nuclei(AGN).Their populations can be probed through AGN surveys,tidal disruption event surveys,and(in the closest galaxies)stellar and gas dynamics in the innermost regions where the black hole dominates the gravitational potential.

关键词： galaxies tidal galactic

Control system design for a pressure-tube-type supercritical water-cooled nuclear reactor via a higher order sliding mode method

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Nuclear Science and Techniques 2024年第1期35卷 145-154页

作者： M.Hajipour G.r.Ansarifar Department of Nuclear engineering Faculty of PhysicsUniversity of IsfahanIsfahan 81746-73441Iran

Nuclear power plants exhibit non-linear and time-variable ***,designing a control system that sets the reactor power and forces it to follow the desired load is complicated.A supercritical water reactor(SCWr)is a fourth-generation conceptual *** an SCWr,the non-linear dynamics of the reactor require a controller capable of control-ling the *** this study,a pressure-tube-type SCWr was controlled during reactor power maneuvering with a higher order sliding mode,and the reactor outgoing steam temperature and pressure were controlled *** an SCWr,the temperature,pressure,and power must be maintained at a setpoint(desired value)during power *** point kinetics equations with three groups of delayed neutrons were used in the ***-order and classic sliding mode controllers were separately manufactured to control the plant and were compared with the PI controllers speci-fied in previous *** controlled parameters were reactor power,steam temperature,and ***,for these parameters,the PI controller had certain instabilities in the presence of *** classic sliding mode controller had a higher accuracy and stability;however its main drawback was the chattering *** was highly accurate and stable and had a small computational *** reality,it followed the desired values without oscillations and chattering.

关键词： Supercritical water nuclear reactor Higher order sliding mode controller Steam temperature Steam pressure Point kinetics model

Learning the optimal power flow:environment design matters

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energy and AI 2024年第3期17卷 432-443页

作者： Thomas Wolgast Astrid Nieße Carl von Ossietzky Universität Oldenburg Department of Computing ScienceDigitalized Energy SystemsAmmerländer Heerstraße 114-118Oldenburg26129Germany

To solve the optimal power flow(OPF)problem,reinforcement learning(rL)emerges as a promising new ***,the rL-OPF literature is strongly divided regarding the exact formulation of the OPF problem as an rL *** this work,we collect and implement diverse environment design decisions from the literature regarding training data,observation space,episode definition,and reward function *** an experimental analysis,we show the significant impact of these environment design options on rL-OPF training ***,we derive some first recommendations regarding the choice of these design *** created environment framework is fully open-source and can serve as a benchmark for future research in the rL-OPF field.

关键词： reinforcement learning Optimal power flow environment design economic Dispatch Voltage control reactive power market

Sex-specific life-history trait expression in hybrids of a cave- and surface-dwelling fish (Poecilia mexicana, Poecilidae)

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Current Zoology 2024年第4期70卷 421-429页

作者： rüdiger riesch Luis r.Arriaga Ingo Schlupp Department of Biological Sciences Royal Holloway University of LondonEghamTW20 OEXUK CeFe CNRSUnivMontpellierEPHEIRDMontpellierFrance Department of Biology University of OklahomaNormanOK 73019USA

evaluating the fitness of hybrids can provide important insights into genetic differences between species or diverging *** focused on surface-and cave-ecotypes of the widespread Atlantic molly Poecilia mexicana and raised F1 hybrids of reciprocal crosses to sexual maturity in a common-garden *** were reared in a fully factorial 2 x 2 design consisting of lighting(light ***)and resource availability(high *** food).We quantified survival,ability to realize their full reproductive potential(i.e.,completed maturation for males and 3 consecutive births for females)and essential life-history *** to the performance of pure cave and surface fish from a previous experiment,F1s had the highest death rate and the lowest proportion of fish that reached their full reproductive *** also uncovered an intriguing pattern of sex-specific phenotype expression,because male hybrids expressed cave molly life histories,while female hybrids expressed surface molly life *** results provide evidence for strong selection against hybrids in the cave molly system,but also sug-gest a complex pattern of sex-specific(opposing)dominance,with certain surface molly genes being dominant in female hybrids and certain cavemollygenes beingdominant in malehybrids.

关键词： dominance life-history evolution local adaptation postzygotic isolation selection against hybrids.

Integrated Zoology calls for papers:special issue on wildlife diseases and parasitology

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Integrative Zoology 2024年第3期19卷 424-425页

作者： Nubia e.MATTA Wenhua XIONG Department of Biology Universidad Nacional de ColombiaBogotaColombia International Society of Zoological Sciences BeijingChina Institute of Zoology Chinese Academy of SciencesBeijingChina

The VI International Conference on Malaria and Other Blood Parasites of Wildlife and the III International Symposium of the Wildlife Diseases research Network are scheduled to be held in Medellín,Colombia,from November 26 to 30 of 2024(https://***/lLW79).It will be hosted by the University of Antioquia’s Department of Biology and the Universidad Nacional de Colombia Department of Biology.

关键词： Blood Malaria diseases

Optimization of random Feature Method in the High-Precision regime

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Communications on Applied Mathematics and Computation 2024年第2期6卷 1490-1517页

作者： Jingrun Chen Weinan e Yifei Sun School of Mathematical Sciences and Suzhou Institute for Advanced research Suzhou 215006JiangsuChina University of Science and Technology of China Hefei 230026AnhuiChina Center for Machine Learning research and School of Mathematical Sciences Peking UniversityBeijing 100871China AI for Science Institute Beijing 100084China School of Mathematical Sciences Soochow UniversitySuzhou 215006JiangsuChina

Machine learning has been widely used for solving partial differential equations(PDes)in recent years,among which the random feature method(rFM)exhibits spectral accuracy and can compete with traditional solvers in terms of both accuracy and ***,the optimization problem in the rFM is more difficult to solve than those that arise in traditional *** the broader machine-learning research,which frequently targets tasks within the low-precision regime,our study focuses on the high-precision regime crucial for solving *** this work,we study this problem from the following aspects:(i)we analyze the coeffcient matrix that arises in the rFM by studying the distribution of singular values;(ii)we investigate whether the continuous training causes the overfitting issue;(ii)we test direct and iterative methods as well as randomized methods for solving the optimization *** on these results,we find that direct methods are superior to other methods if memory is not an issue,while iterative methods typically have low accuracy and can be improved by preconditioning to some extent.

关键词： random feature method(rFM) Partial differential equation(PDe) Least-squares problem Direct method Iterative method

Olfactory immune response to SArS-CoV-2

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Cellular & Molecular Immunology 2024年第2期21卷 134-143页

作者： Sebastian A.Wellford e.Ashley Moseman Department of Integrative Immunobiology Duke University School of MedicineDurhamNCUSA

Numerous pathogens can infect the olfactory tract,yet the pandemic caused by SArS-CoV-2 has strongly emphasized the importance of the olfactory mucosa as an immune *** in the nasal passages,the olfactory mucosa is directly exposed to the environment to sense airborne odorants;however,this also means it can serve as a direct route of entry from the outside world into the *** a result,olfactotropic infections can have serious consequences,including dysfunction of the olfactory system,CNS invasion,dissemination to the lower respiratory tract,and transmission between *** research has shown that a distinctive immune response is needed to protect this neuronal and mucosal tissue.A better understanding of innate,adaptive,and structural immune barriers in the olfactory mucosa is needed to develop effective therapeutics and vaccines against olfactotropic microbes such as ***,we summarize the ramifications of SArS-CoV-2 infection of the olfactory mucosa,review the subsequent immune response,and discuss important areas of future research for olfactory immunity to infectious disease.

关键词： Mucosal immunology Neuroimmunology Infectious Disease Sars-CoV-2

exploring the associations between skeletal muscle echogenicity and physical function in aging adults:A systematic review with meta-analyses

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Journal of Sport and Health Science 2024年第6期13卷 820-840页

作者： Dustin J.Oranchuk Stephan G.Bodkin Katie L.Boncella Michael O.harris-Love Muscle Morphology Mechanicsand Performance LaboratoryDepartment of Physical Medicine and RehabilitationUniversity of Colorado Anschutz Medical CampusAuroraCO 80045USA Department of Physical Therapy

Background:Assessment and quantification of skeletal muscle within the aging population is vital for diagnosis,treatment,and injury/disease *** clinical availability of assessing muscle quality through diagnostic ultrasound presents an opportunity to be utilized as a screening tool for function-limiting ***,relationships between muscle echogenicity and clinical functional assessments require authoritative ***,we aimed to(a) synthesize the literature to assess the relationships between skeletal muscle echogenicity and physical function in older adults(≥60 years),(b) perform pooled analyses of relationships between skeletal muscle echogenicity and physical function,and(c) perform sub-analyses to determine between-muscle ***:CINAHL,embase,MeDLINe,PubMed,and Web of Science databases were systematically searched to identify articles relating skeletal muscle echogenicity to physical function in older ***-of-bias assessments were conducted along with funnel plot ***-analyses with and without sub-analyses for individual muscles were performed utilizing Fisher's Z transformation for the most common measures of physical ***'s Z was back-transformed to Pearson's r for ***:Fifty-one articles(n=5095,female=~2759,male=~2301,72.5± 5.8 years,mean±SD(1 study did not provide sex descriptors))were extracted for review,with previously unpublished data obtained from the authors of 13 *** rectus femoris(n=34) and isometric knee extension strength(n=22) were the most accessed muscle and physical qualities,*** relationship between quadriceps echogenicity and knee extensor strength was moderate(n=2924,r=-0.36(95% confidence interval:-0.38 to-0.32),p er meta-analyses(grip strength,walking speed,sit-to-stand,timed up-and-go) resulting in slightly weaker correlations(r:-0.34 to-0.23,all p es determined minimal differences in predicti

关键词： Correlations echo intensity elderly Intramuscular fat Strength

Assessment of rainwater Quality in Warri and environ, Southern Nigeria for Domestic Purposes

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Journal of Geoscience and environment Protection 2024年第6期12卷 255-268页

作者： Iwekumo e. Agbozu Tobore r. Maminor Uwem Bassey Department of environmental Management and Toxicology Federal University of Petroleum Resources Effurun Nigeria Department of Science Laboratory Technology Delta State University Abraka Nigeria

The study aimed at assessing the physiochemical characteristics of rainwater in Warri and it environ was investigated. Pb, Zn, Cd, Cu and Cr concentrations in rainwater from roof and non-roof sources were determined using Atomic Absorption Spectrophotometry. Three geospatial locations comprising Jakpa, Udu, and Ubeji were selected based on prevailing anthropogenic activities. The rainwater samples were systematically collected from (aluminum) roof and non-roof sources for the months of April, June, and August and October 2022, treated and analyzed in the laboratory for sixteen physicochemical parameters. results were statistically analyzed using ANOVA, and T-test for the determination of the level of relationships and variations across geospatial locations. Significant correlations (r = 0.72) exist between Cr in rainwater from roof and non-roof sources. Implying point-source contaminations and may be emanating from the influence of roof materials. Furthermore, high concentrations of Cd and Pb in roof source above WHO standards were mostly in Jakpa and Ubeji. Calculated Health risk Index (HrI) for children and adult is greater than 1. The results showed that most samples from the locations are considered not safe (HrI > 1) especially for Cd, which means that there are potential health risks consuming rainwater from Jakpa, Udu and Ubeji. Therefore, there is need for prompt sensitization program to dissuade people from directly drinking rainwater from these locations.

关键词： Water Quality Health risks rainwater Heavy Metals Warri environs