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On the “Onion Husk” Algorithm for Approximate Solution of the Traveling Salesman Problem

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Journal of Applied Mathematics and Physics 2024年第4期12卷 1557-1570页

作者： Mikhail e. Abramyan Nikolai i. Krainiukov Boris F. Melnikov Faculty of Computational Mathematics and Cybernetics Shenzhen MSU-BIT University Shenzhen China Department of Algebra and Discrete Mathematics Southern Federal University Rostov-on-Don Russian Federation

The paper describes some implementation aspects of an algorithm for approximate solution of the traveling salesman problem based on the construction of convex closed contours on the initial set of points (“cities”) and their subsequent combination into a closed path (the so-called contour algorithm or “onion husk” algorithm). A number of heuristics related to the different stages of the algorithm are considered, and various variants of the algorithm based on these heuristics are analyzed. Sets of randomly generated points of different sizes (from 4 to 90 and from 500 to 10,000) were used to test the algorithms. The numerical results obtained are compared with the results of two well-known combinatorial optimization algorithms, namely the algorithm based on the branch and bound method and the simulated annealing algorithm. .

关键词： Branch and Bound Method Contour Algorithm “Onion Husk” Algorithm Simulated Annealing Method Traveling Salesman Problem

Advances in spinal cord injury:insights from non-human primates

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Neural Regeneration Research 2024年第11期19卷 2354-2364页

作者： Gaetan Poulen Florence e.Perrin University of Montpellier INSERMEPHEMontpellierFrance Department of Neurosurgery Gui de Chauliac HospitalMontpellier University Medical CenterMontpellierFrance institut Universitaire de France(iUF) ParisFrance

Spinal cord injury results in significant sensorimotor deficits,currently,there is no curative treatment for the symptoms induced by spinal cord *** and pre-clinical research on spinal cord injury relies on the development and characterization of appropriate animal *** models should replicate the symptoms observed in human,allowing for the exploration of functional deficits and investigation into various aspects of physiopathology of spinal cord ***-human primates,due to their close phylogenetic association with humans,share more neuroanatomical,genetic,and physiological similarities with humans than ***,the responses to spinal cord injury in nonhuman primates most likely resemble the responses to traumatism in *** this review,we will discuss nonhuman primate models of spinal cord injury,focusing on in vivo assessments,including behavioral tests,magnetic resonance imaging,and electrical activity recordings,as well as ex vivo histological ***,we will present therapeutic strategies developed in non-human primates and discuss the unique specificities of non-human primate models of spinal cord injury.

关键词： behavior cellular analysis non-human primates spinal cord injury tissue analysis

On Differential equations of integrable Billiard Tables

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Acta Mathematica Sinica,english Series 2024年第1期40卷 417-424页

作者： Vladimir DRAGOViC Andrey e.MiRONOV Department of Mathematical Sciences The University of Texas at DallasRichardson TXUSA Mathematical institute SANU BelgradeSerbia Novosibirsk State University NovosibirskRussia Sobolev institute of Mathematics of the Siberian Branch of the Russian Academy of Sciences NovosibirskRussia

We introduce a method to find differential equations for functions which define tables,such that associated billiard systems admit a local first *** illustrate this method in three situations:the case of(locally)integrable wire billiards,for finding surfaces in R^(3)with a first integral of degree one in velocities,and for finding a piece-wise smooth surface in R^(3)homeomorphic to a torus,being a table of a billiard admitting two additional first integrals.

关键词： Polynomial first integrals wire billiards piece-wise smooth surfaces

Aulacaspis yasumatsui infestations accelerate Cycas leaf litter decomposition and nutrient release

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Pedosphere 2024年第3期34卷 681-684页

作者： Thomas e.MARLeR Bagong Kaalaman Botanikal institute 15 Rizal StreetBarangay MalabañasAngeles City 2009(Philippines)

Dear editor,Numerous aspects of ecosystem ecology are influenced by insects(Prasad,2022).Herbivory of plant organs by insects may influence the biogeochemistry of forests by changing the speed of litter decomposition(Schowalter,2022).Cycas micronesica *** is the only native gymnosperm in the Mariana *** once-abundant tree experienced no known lethal threats prior to the 2003 invasion of Guam by the scale Aulacaspis yasumatsui Takagi(Marler,2012).This insular case study has been the subject of abundant research(Marler et al.,2021).Changes to leaf litter chemistry improved litter quality following *** infestations(Marler and Dongol,2016),but the prediction of increased decomposition speed has not been confirmed with experimental incubations.

关键词： litter fir release

First-principles calculation on the electronic structures, phonon dynamics, and electrical conductivities of Pb_(10)(PO_(4))_(6O) and Pb_(9)Cu(PO_(4))_(6O) compounds

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Journal of Materials Science & Technology 2024年第6期173卷 218-224页

作者： L.Y.Hao e.G.Fu State Key Laboratory of Nuclear Physics and Technology Department of Technical PhysicsSchool of PhysicsPeking UniversityBeijing 100871China

Superconducting materials with high critical temperature have the potential to revolutionize many fields,including military,electronic communications,and power ***,scientists around the world have been tirelessly working with the ultimate goal of achieving high-temperature *** 2023,a preprint by Lee et *** South Korea claimed the discovery of ultra-high-temperature superconductivity with a critical temperature of up to 423 K in Cu-doped lead-apatite(LK-99)(arXiv:2307.12008,arXiv:2307.12037),which caused a worldwide sensation and ***,the electronic structures,phonon dynamics,and electrical conductivities of LK-99 and its parent compound lead-apatite have been calculated using first-principles *** results show that the lead-apatite compound and the LK-99 compound are insulator and half-metal *** flat band characteristic is consistent with previous *** electrical conductivity of the LK-99 compound shows two extreme points,and the electrical conductivity along the C-axis increases significantly after 400 *** phonon dispersion spectra of the compounds were investigated,demonstrating their dynamic instability.

关键词： Superconductivity LK-99 Lead-apatite First-principles calculation

Octopamine enhances learning

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National Science Review 2024年第06期11卷 82-83页

作者： Yvette e.Fisher Department of Molecular and Cell Biology and Helen Wills Neuroscience institute University of California

Across the animal kingdom, diverse monoamines actuate and modulate neural circuit function. However, measuring the rapid dynamics of these neuromodulators at cellular resolution has historically presented significant ... 详细信息

关键词： DOPAMiNe TYRAMiNe FLieS

Commentary on "Association of daily sitting time and leisure-time physical activity with body fat among ***"

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Journal of Sport and Health Science 2024年第2期13卷 127-129页

作者： Barbara e.Ainsworth School of exercise and Health Shanghai University of SportShanghai 200438China

in their study,association of daily sitting time and leisure-time physical activity (LTPA) with body fat among ***,Liao et al.^(1) analyzed data from the 2011-2018 National Health and examination Survey to examine associations between h/day sitting,meeting (or not meeting) the *** Activity Guidelines of≥150 min/week of moderate-and vigorous-intensity LTPA,and combinations of sitting time and LTPA on totaland trunk percent body fat (BF%).

关键词： U.S. adult among

Particle Size Optimization of Thermochemical Salt Hydrates for High energy Density Thermal Storage

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energy & environmental Materials 2024年第2期7卷 326-333页

作者： Andrew Martin Drew Lilley Raνi Prasher Sumanjeet Kaur energy Technologies Area Lawrence Berkeley National LaboratoryBerkeleyCA 94720USA Department of Mechanical engineering UC BerkeleyBerkeleyCA 94720USA

Thermal energy storage(TeS)solutions offer opportunities to reduce energy consumption,greenhouse gas emissions,and ***,they can help reduce the peak load and address the intermittency of renewable energy sources by time shifting the load,which are critical toward zero energy *** materials(TCMs)as a class of TeS undergo a solid-gas reversible chemical reaction with water vapor to store and release energy with high storage capacities(600 kWh m^(-3))and negligible self-discharge that makes them uniquely suited as compact,stand-alone units for daily or seasonal ***,TCMs suffer from instabilities at the material(salt particles)and reactor level(packed beds of salt),resulting in poor multi-cycle efficiency and high-levelized cost of *** this study,a model is developed to predict the pulverization limit or Rcrit of various salt hydrates during thermal *** is critical as it provides design rules to make mechanically stable TCM composites as well as enables the use of more energy-efficient manufacturing process(solid-state mixing)to make the *** model is experimentally validated on multiple TCM salt hydrates with different water content,and effect of Rcrit on hydration and dehydration kinetics is also investigated.

关键词： high energy density hydration kinetics long-term cycling thermal energy storage thermochemical materials

ionogels and eutectogels for stable and long-term eeG and eMG signal acquisition

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Materials Futures 2024年第3期3卷 95-110页

作者： Asmita Veronica Hnin Yin Yin Nyein i-Ming Hsing Department of Chemical and Biological engineering The Hong Kong University of Science and TechnologyClear Water BayHong Kong Special Administrative Region of ChinaPeople’s Republic of China

Neurological injuries and disorders have a significant impact on individuals’quality of life,often resulting in motor and sensory *** assess motor performance and monitor neurological disorders,non-invasive techniques such as electroencephalography(eeG)and electromyography(eMG)are commonly *** employed wet electrodes with conductive gels are limited by lengthy skin preparation time and allergic *** dry electrodes and hydrogel-based electrodes can mitigate these issues,their applicability for long-term monitoring is *** electrodes are susceptible to motion artifacts,whereas hydrogel-based electrodes face challenges related to water-induced ***,ionogels and eutectogels derived from ionic liquids and deep eutectic solvents have gained immense popularity due to their non-volatility,ionic conductivity,thermal stability,and ***,in particular,exhibit superior *** characteristics make them suitable alternatives for the development of safer,robust,and reliable eeG and eMG ***,research specifically focused on their application for eeG and eMG signal acquisition remains *** article explores the electrode requirements and material advancements in eeG and eMG sensing,with a focus on highlighting the benefits that ionogels and eutectogels offer over conventional *** sheds light on the current limitations of these materials and proposes areas for further improvement in this *** potential of these gel-based materials to achieve a seamless interface for high-quality and long-term electrophysiological signal acquisition is *** the unique properties of ionogels and eutectogels holds promise for future advancements in eeG and eMG electrode materials,leading to improved monitoring systems and enhanced patient outcomes.

关键词： ionogel eutectogel electrode electroencephalography electromyography