6G New Multiple Access Technology

As a basic technology at physical layer of mobile communications,non-orthogonal multiple access has been attracting wide attention across the academia and the industry.During the standardization of the fifth-generation(5G)of mobile communications,3GPP conducted preliminary study on non-orthogonal multiple access without reaching the consensus to standardize the technology.

Multiscale Characteristics and Connection Mechanisms of Attraction Networks:A Trajectory Data Mining Approach Leveraging Geotagged Data

Urban tourism is considered a complex system,and multiscale exploration of the organizational patterns of attraction networks has become a topical issue in urban tourism,so exploring the multiscale characteristics and connection mechanisms of attraction networks is important for understanding the linkages between attractions and even the future destination planning.This paper uses geotagging data to compare the links between attractions in Beijing,China during four different periods:the pre-Olympic period(2004–2007),the Olympic Games and subsequent‘heat period’(2008–2013),the post-Olympic period(2014–2019),and the COVID-19(Corona Virus Disease 2019)pandemic period(2020–2021).The aim is to better understand the evolution and patterns of attraction networks at different scales in Beijing and to provide insights for tourism planning in the destination.The results show that the macro,meso-,and microscales network characteristics of attraction networks have inherent logical relationships that can explain the commonalities and differences in the development process of tourism networks.The macroscale attraction network degree Matthew effect is significant in the four different periods and exhibits a morphological monocentric structure,suggesting that new entrants are more likely to be associated with attractions that already have high value.The mesoscale links attractions according to the common purpose of tourists,and the results of the community segmentation of the attraction networks in the four different periods suggest that the functional polycentric structure describes their clustering effect,and the weak links between clusters result from attractions bound by incomplete information and distance,and the functional polycentric structure with a generally more efficient network of clusters.The pattern structure at the microscale reveals the topological transformation relationship of the regional collaboration pattern,and the attraction network structure in the four different periods has a very similar importance profile structure suggesting that the attraction network has the same construction rules and evolution mechanism,which aids in understanding the attraction network pattern at both macro and micro scales.Important approaches and practical implications for planners and managers are presented.

The Substructure of Elementary Particles Demonstrated by the I-Theory

Present studies in physics assume that elementary particles are the building blocks of all matter, and that they are zero-dimensional objects which do not occupy space. The new I-Theory predicts that elementary particles do indeed have a substructure, three dimensions, and occupy space, being composed of fundamental particles called I-particles. In this article we identify the substructural pattern of elementary particles and define the quanta of energy that form each elementary particle. We demonstrate that the substructure comprises two classes of quanta which we call “attraction quanta” and “repulsion quanta”. We create a model that defines the rest-mass energy of each elementary particle and can predict new particles. Lastly, in order to incorporate this knowledge into the contemporary models of science, a revised periodic table is proposed.

Electrostatic Attraction and Repulsion Explained and Modelled Mathematically Using Classical Physics—A Detailed Mechanism Based on Particle Wave Functions

The phenomenon of electrical attraction and repulsion between charged particles is well known, and described mathematically by Coulomb’s Law, yet until now there has been no explanation for why this occurs. There has been no mechanistic explanation that reveals what causes the charged particles to accelerate, either towards or away from each other. This paper gives a detailed explanation of the phenomena of electrical attraction and repulsion based on my previous work that determined the exact wave-function solutions for both the Electron and the Positron. It is revealed that the effects are caused by wave interactions between the wave functions that result in Electromagnetic reflections of parts of the particle’s wave functions, causing a change in their momenta.

Mathematical Wave Functions and 3D Finite Element Modelling of the Electron and Positron

The wave/particle duality of particles in Physics is well known. Particles have properties that uniquely characterize them from one another, such as mass, charge and spin. Charged particles have associated Electric and Magnetic fields. Also, every moving particle has a De Broglie wavelength determined by its mass and velocity. This paper shows that all of these properties of a particle can be derived from a single wave function equation for that particle. Wave functions for the Electron and the Positron are presented and principles are provided that can be used to calculate the wave functions of all the fundamental particles in Physics. Fundamental particles such as electrons and positrons are considered to be point particles in the Standard Model of Physics and are not considered to have a structure. This paper demonstrates that they do indeed have structure and that this structure extends into the space around the particle’s center (in fact, they have infinite extent), but with rapidly diminishing energy density with the distance from that center. The particles are formed from Electromagnetic standing waves, which are stable solutions to the Schrödinger and Classical wave equations. This stable structure therefore accounts for both the wave and particle nature of these particles. In fact, all of their properties such as mass, spin and electric charge, can be accounted for from this structure. These particle properties appear to originate from a single point at the center of the wave function structure, in the same sort of way that the Shell theorem of gravity causes the gravity of a body to appear to all originate from a central point. This paper represents the first two fully characterized fundamental particles, with a complete description of their structure and properties, built up from the underlying Electromagnetic waves that comprise these and all fundamental particles.

Mesenchymal stem cell-derived apoptotic bodies alleviate alveolar bone destruction by regulating osteoclast differentiation and function

Periodontitis is caused by overactive osteoclast activity that results in the loss of periodontal supporting tissue and mesenchymal stem cells(MSCs)are essential for periodontal regeneration.However,the hypoxic periodontal microenvironment during periodontitis induces the apoptosis of MSCs.Apoptotic bodies(ABs)are the major product of apoptotic cells and have been attracting increased attention as potential mediators for periodontitis treatment,thus we investigated the effects of ABs derived from MSCs on periodontitis.MSCs were derived from bone marrows of mice and were cultured under hypoxic conditions for 72 h,after which ABs were isolated from the culture supernatant using a multi-filtration system.The results demonstrate that ABs derived from MSCs inhibited osteoclast differentiation and alveolar bone resorption.miRNA array analysis showed that miR-223-3p is highly enriched in those ABs and is critical for their therapeutic effects.Targetscan and luciferase activity results confirmed that Itgb1 is targeted by miR-223-3p,which interferes with the function of osteoclasts.Additionally,DC-STAMP is a key regulator that mediates membrane infusion.ABs and pre-osteoclasts expressed high levels of DC-STAMP on their membranes,which mediates the engulfment of ABs by pre-osteoclasts.ABs with knock-down of DC-STAMP failed to be engulfed by pre-osteoclasts.Collectively,MSC-derived ABs are targeted to be engulfed by pre-osteoclasts via DC-STAMP,which rescued alveolar bone loss by transferring miR-223-3p to osteoclasts,which in turn led to the attenuation of their differentiation and bone resorption.These results suggest that MSC-derived ABs are promising therapeutic agents for the treatment of periodontitis.

Route to Stabilize Cubic Gauche Polynitrogen to Ambient Conditions via Surface Saturation by Hydrogen

Cubic gauche polynitrogen(cg-N)is an attractive high-energy density material.However,high-pressure synthesized cg-N will decompose at low pressure and cannot exist under ambient conditions.Here,the stabilities of cg-N surfaces with and without saturations at different pressures and temperatures are systematically investigated based on first-principles calculations and molecular dynamics simulations.Pristine surfaces at 0 GPa are very brittle and will decompose at 300 K,especially(110)surface will collapse completely just after structural relaxation,whereas the decompositions of surfaces can be suppressed by applying pressure,indicating that surface instability causes the cg-N decomposition at low pressure.Due to the saturation of dangling bonds and transferring electrons to the surfaces,saturation with H can stabilize surfaces under ambient conditions,while it is impossible for OH saturation to occur solely from obtaining electrons from surfaces.This suggests that polynitrogen is more stable in an acidic environment or when the surface is saturated with less electronegative adsorbates.

Signatures of Temperature-Driven Lifshitz Transition in Semimetal Hafnium Ditelluride

Temperature-driven change of Fermi surface has been attracting attention recently as it is fundamental and essential to understand a metallic system.We report the magnetotransport anomalies in the semimetal HfTe_(2) single crystals.The magnetoresistance behavior at high temperatures obeys Kohler's rule which can lead to the field-induced resistivity upturn behavior as observed.When the temperature is decreased to around 30 K,Kohler's rule becomes inapplicable,indicating the change of the Fermi surface in HfTe_(2).The Hall analyses and extended Kohler's plot reveal abrupt change of carrier densities and mobilities near 30 K.These results suggest that the chemical potential may shift as the temperature increases and the shift causes an electron pocket to vanish.Our work of the temperature-driven Lifshitz transition in HfTe_(2) is relevant to understanding of the transport anomalies and exotic physical properties in transition-metal dichalcogenides.

What is attractive rural landscape?Differences in the social and expert assessment of the changes in the rural landscape of the Carpathian region in Poland with regard to the need of its protection

Contemporary villages of the mountain region are subject to uncontrolled structural and spatial transformations,which cause deformation of centuries-old spatial systems of high cultural and natural value.The aim of the study is to confront the opinions of the inhabitants and experts regarding the condition of the cultural landscape of the villages in south-eastern Poland.This area belongs to the Carpathian region of Central Europe.The historical and economic conditions of the studied region,related to the functioning in the post-war period,and then its breakdown and the development of the free market economy,constitute an interesting background for the proposed research.Local communities still remembering the period of difficulties related to the period of systemic transformations,are currently experiencing a relative prosperity,many difficulties related to the period of systemic transformations,are currently experiencing a relative prosperity,which is also expressed in a completely new,previously unknown way of managing the landscape.Investments implemented in villages are associated by the inhabitants with the improvement of the standards and quality of life.They assess them rather positively.An expert assessment of these landscape transformations indicates their negative dimension and the risk of losing timeless values.The discrepancy in the assessment of experts and local residents creates difficulties in the protection of the rural landscape.Therefore,high-quality visual landscape features among rural residents is necessary from the point of view of its multi-faceted and effective protection.Local initiatives and actions in the field of industry policy should play a significant role in this respect by consolidating the images of a harmonious landscape in the public awareness.

Optical Pulling Force in Non-Paraxial Bessel Tractor Beam Generated with Polarization-Insensitive Metasurface

Tractor beams,able to produce optical pulling forces(OPFs)on particles,are attracting increasing attention.Here,non-paraxial Bessel tractor beams are generated using polarization-insensitive metasurfaces.OPFs are found to exert on dielectric particles with specific radii at the axes of the beams.The strengths of the OPFs depend on the radii of the particles,which provides the possibility of sorting particles with different sizes.For the OPFs,the radius ranges of particles vary with the polarization states or topological charges of the incident beams.The change of polarizations can provide a switch between the pulling and pushing forces,which offers a new way to realize dynamic manipulation of particles.The change of topological charges leads to disjoint radii ranges for the OPFs exerting on particles,which provides the possibility of selective optical separation.Moreover,we study the behaviors of particles in the tractor beams.The simulation results reveal that linearly or circularly polarized tractor beams can pull particles a sufficient distance towards the light source,which verifies the feasibility of separating particles.

Highly Anisotropic Magnetism and Nearly Isotropic Magnetocaloric Effect in Mn_(3)Sn_(2)Single Crystals

Mn_(3)Sn_(2)has been proposed as an ideal material for magnetic refrigeration.It undergoes two successive ferromagnetic transitions(T_(C1)=262 K and T_(C2)=227 K)and one antiferromagnetic transition(TN=192 K).Herein we report,for the first time,the preparation of single crystals of Mn_(3)Sn_(2)from Bi flux.The resultant anisotropic magnetic properties and magnetocaloric effect are investigated along the three principal crystallographic directions of the crystal.Significant anisotropy of magnetic susceptibility and multiple field-induced metamagnetic transitions were found at low fields,whereas the magnetocaloric effect was found to be almost isotropic and larger than that of the polycrystalline one.The maximum magnetic entropy change amounts to-ΔSM=4.01 J·kg^(-1)·K^(-1)near T_(C1)under a magnetic field change of μ_(0)ΔH=5 T along the c-axis,with the corresponding refrigerant capacity of 1750 mJ·cm^(-3).Combined with a much wider cooling temperature span(~80 K),our results demonstrate Mn_(3)Sn_(2)single crystal to be an attractive candidate working material for active magnetic refrigeration at low temperatures.

Existence of hidden attractors in nonlinear hydro-turbine governing systems and its stability analysis

This work studies the stability and hidden dynamics of the nonlinear hydro-turbine governing system with an output limiting link,and propose a new six-dimensional system,which exhibits some hidden attractors.The parameter switching algorithm is used to numerically study the dynamic behaviors of the system.Moreover,it is investigated that for some parameters the system with a stable equilibrium point can generate strange hidden attractors.A self-excited attractor with the change of its parameters is also recognized.In addition,numerical simulations are carried out to analyze the dynamic behaviors of the proposed system by using the Lyapunov exponent spectra,Lyapunov dimensions,bifurcation diagrams,phase space orbits,and basins of attraction.Consequently,the findings in this work show that the basins of hidden attractors are tiny for which the standard computational procedure for localization is unavailable.These simulation results are conducive to better understanding of hidden chaotic attractors in higher-dimensional dynamical systems,and are also of great significance in revealing chaotic oscillations such as uncontrolled speed adjustment in the operation of hydropower station due to small changes of initial values.

Effect of thickness on magnetic properties of single domain GdBCO bulk superconductors

To study the influence of thickness on the magnetic properties of ReBCO(Re = Y, Gd, Sm, Nd, etc.) bulk superconductors, a single domain gadolinium barium copper oxide(GdBCO) bulk superconductor fabricated by the Re + 011 top seeded infiltration growth(Re + 011 TSIG) method was continuously sliced along the bottom to obtain samples of different thickness. The levitation force and attractive force of these samples were tested at 77 K in the zero-field-cooled(ZFC)state. It is found that as the sample thickness decreases, the levitation force decreases gradually whereas the attractive force increases. This is related to the varied ability to resist the penetration of magnetic field occasioned by varying sample thickness, which are deeply revealed by combining with the characteristics of the non-ideal type-II superconductor. Further,the levitation force exhibits a trend of slow initial change followed by rapid change, which may be attributed to the growth of the sample. Measurement of the trapped field shows that a similar distribution of trapped field at the top and bottom surfaces can be achieved by removing some materials from the bottom of the bulk. These results provide a reference for meeting the actual requirements of ReBCO bulks of different thicknesses and greatly contribute to practical designs and applications.

Efficient Numerical Scheme for Solving Large System of Nonlinear Equations

A fifth-order family of an iterative method for solving systems of nonlinear equations and highly nonlinear boundary value problems has been developed in this paper.Convergence analysis demonstrates that the local order of convergence of the numerical method is five.The computer algebra system CAS-Maple,Mathematica,or MATLAB was the primary tool for dealing with difficult problems since it allows for the handling and manipulation of complex mathematical equations and other mathematical objects.Several numerical examples are provided to demonstrate the properties of the proposed rapidly convergent algorithms.A dynamic evaluation of the presented methods is also presented utilizing basins of attraction to analyze their convergence behavior.Aside from visualizing iterative processes,this methodology provides useful information on iterations,such as the number of diverging-converging points and the average number of iterations as a function of initial points.Solving numerous highly nonlinear boundary value problems and large nonlinear systems of equations of higher dimensions demonstrate the performance,efficiency,precision,and applicability of a newly presented technique.

Eleven“Opinion Editorials”were published

Opinion Editorials(Op-Ed)was introduced in 2017 as a new category,and is attracting the attention of the international polar community.One scientist from School of Environment,Education and Development,the University of Manchester gave the comments that this is a most welcome initiative.

Eleven “Opinion Editorials” were published since its introduction

Opinion Editorials(Op-Ed)was introduced in 2017 as a new category,and is attracting the attention of the international polar community.One scientist from School of Environment,Education and Development,the University of Manchester gave the comments that this is a most welcome initiative.Op-Ed can be a statement of the opinion of a named author or authors,with a maximum of 1500 words(a maximum length of 2 printed pages).It will provide a forum for comment on the status and/or deficiencies on any aspect of polar science,reflect on recent innovation or progress,promote internationally collaborative polar science projects,etc.It will be directly reviewed by EICs with final decision without peer review by expert referrers.Up to now,eleven Op-Eds have already been published on APS.

Eleven“Opinion Editorials”were published since its introduction

Opinion Editorials(Op-Ed)was introduced in 2017 as a new category,and is attracting the attention of the international polar community.One scientist from School of Environment,Education and Development,the University of Manchester gave the comments that this is a most welcome initiative.

世界经济:坐观变起,行至险地

The world economy is no longer running or developing on the trajectory and pattern of economic globalization in good times;instead,it is facing unprecedented interlocking problems and profound adjustments.In 2020,in the face of the global economic recession of-3.1%due to the outbreak of the COVID-19 pandemic,there was no loss of confidence such as there is today.At the time,countries were confident that they would come together to tide over the difficulties related to the pandemic.After bottoming out in 2020,the global economy rebounded to 6%growth in 2021.However,it fell back to 3.2%in2022,attracting more attention than ever before.

The First CISCE:Connecting the World for A Shared Future

The first China International Supply Chain Expo(CISCE)concluded in Beijing on 30,November.The five-day event attracted many participants,with a total of 515 Chinese and foreign enterprises and institutions joining the event.There were also approximately 360 exchange activities,attracting about 150,000 visitors.A total of 23 achievements such as research reports,pieces of propaganda,and standards were released.Estimates show that a total of more than 200 cooperation agreements and tentative agreements were signed during the five-day event,with a total value of more than 150 billion yuan.The CISCE has brought about tangible benefits for the world supply chain cooperation.

Empirical Likelihood Statistical Inference for Compound Poisson Vector Processes under Infinite Covariance Matrix

The paper discusses the statistical inference problem of the compound Poisson vector process(CPVP)in the domain of attraction of normal law but with infinite covariance matrix.The empirical likelihood(EL)method to construct confidence regions for the mean vector has been proposed.It is a generalization from the finite second-order moments to the infinite second-order moments in the domain of attraction of normal law.The log-empirical likelihood ratio statistic for the average number of the CPVP converges to F distribution in distribution when the population is in the domain of attraction of normal law but has infinite covariance matrix.Some simulation results are proposed to illustrate the method of the paper.