A symmetric substructuring method for analyzing the natural frequencies of conical origami structures

Conical origami structures are characterized by their substantial out-of-plane stiffness and energy-absorptioncapacity.Previous investigations have commonly focused on the static characteristics of these lightweight struc-tures.However,the efficient analysis of the natural vibrations of these structures is pivotal for designing conicalorigami structures with programmable stiffness and mass.In this paper,we propose a novel method to analyzethe natural vibrations of such structures by combining a symmetric substructuring method(SSM)and a gener-alized eigenvalue analysis.SSM exploits the inherent symmetry of the structure to decompose it into a finiteset of repetitive substructures.In doing so,we reduce the dimensions of matrices and improve computationalefficiency by adopting the stiffness and mass matrices of the substructures in the generalized eigenvalue analysis.Finite element simulations of pin-jointed models are used to validate the computational results of the proposedapproach.Moreover,the parametric analysis of the structures demonstrates the influences of the number of seg-ments along the circumference and the radius of the cone on the structural mass and natural frequencies of thestructures.Furthermore,we present a comparison between six-fold and four-fold conical origami structures anddiscuss the influence of various geometric parameters on their natural frequencies.This study provides a strategyfor efficiently analyzing the natural vibration of symmetric origami structures and has the potential to contributeto the efficient design and customization of origami metastructures with programmable stiffness.

The “Dead Universe” Theory: Natural Separation of Galaxies Driven by the Remnants of a Supermassive Dead Universe

This article explores the dead universe theory as a novel interpretation for the origin and evolution of the universe, suggesting that our cosmos may have originated from the remnants of a preceding universe. This perspective challenges the conventional Big Bang theory, particularly concerning dark matter, the expansion of the universe, and the interpretation of phenomena such as gravitational waves.

Investigating the tourism image of mountain scenic spots in China through the lens of tourist perception

A favorable tourism image of high-quality mountain scenic spots(HQMSS)is crucial for tourism prosperity and sustainability.This paper establishes a framework for investigating the tourism image based on cognitive-emotion theory and uses natural language processing(NLP)tools to clarify the cognition,emotion,and overall tourist image of the HQMSS in China from the perspective of tourist perception.This paper examines the multi-dimensional spatial differentiation of China's overall image,including province,scenic spot scales,as well as the spatial pattern of the overall comprehensive tourism image.Strategies for comprehensively improving HQMSS's tourism image are also formulated.The results show that:(1)The cognitive image of Chinese HQMSS is categorized into core and marginal images,and the core images such as scenery and cable car are the expression of the uniqueness of mountainous scenic spots.Additionally,the cognitive image is classified into six dimensions:tourism environment,tourism supporting facilities,tourism experience,tourism price,tourism service,and tourism safety.(2)Positive emotions are the dominant mood type of HQMSS in China,followed by neutral emotions,with negative emotions being the least frequent.Emotional images vary across dimensions,with tourism environment and tourism experience evoking relatively higher emotion.(3)The spatial pattern of HQMSS for each dimension at the national,provincial,and scenic scales is diversifying.This article provides a multidimensional perspective for investigating the tourism image of mountainous scenic spots,proposes targeted recommendations to improve the overall image of HQMSS in China,and can greatly contribute to the sustainable development of mountain tourism.

Fundamental Issues Towards Unified Design Theory of Recycled and Natural Aggregate Concrete Components

In the past 20 years,recycled aggregate concrete(RAC),as a type of low-carbon concrete,has become a worldwide focus of research.However,the design methodology for RAC structural components remains a challenge.Consequently,demands for a unified design of natural aggregate concrete(NAC)and RAC components have been presented.Accordingly,this study analyses the necessity of a unified design theory and provides an in-depth demonstration of the strength determination,compressive constitutive relationship,and design method of concrete components.The coefficient of variation of RAC strength is found to be generally higher than that of NAC strength.The compressive and tensile strengths of RAC can be defined and determined using the same method as that used for NAC.The uniaxial compressive constitutive relationship between NAC and RAC has a unified mathematical expression.However,the elastic modulus of RAC decreases,and its brittleness exhibits an increasing trend compared with that of NAC.Finally,to unify the design formulae of RAC and NAC components for bearing capacity,modification factors for RAC components are proposed considering safety and reliability.Additionally,the feasibility of the proposed unified time-dependent design theory is demonstrated in terms of conceptual design and structural measures considering the effects of strength degradation and reinforcement corrosion.It is believed that this study enriches and develops the basic theory of concrete structures.

A theoretical insight about co-pyrolysis reaction of natural gas and coal

The co-pyrolysis of natural gas and coal is a promising way for the production of acetylene due to its high efficiency for energy and hydrogen utilization.This work investigated the thermodynamics for the copyrolysis reaction of natural gas and coal using density functional theory.The favorable reaction conditions are presented in the form of phase diagrams.The calculation results show that the extra amount of methane may benefit the production of acetylene in the co-pyrolysis reaction,and the C/H ratio of 1:1,temperature around 3000 K and pressure at 0.1 MPa are most favorable.The results would provide basic data for related industrial process for the production of acetylene.

Globalization Under the Spells of Breakdowns in Supply Chains, Regime Change, Regime Formation, and Alliance Restructuring: How Much Is Left for Public Goods?

In a paper conceived about five years ago(“Globalization and Public Goods:Too Big to Tackle?”)roughly a dozen factors were linked to explain important causal paths from globalization to the potential output of public goods.The Russian invasion of Ukraine,the corona epidemic,and the increased hegemonic rivalry between China and the U.S.interrupted or even destroyed many of the linkages between globalization and potential public good production.About five important detrimental paths involved in the meantime.In the present article we aim at linking what is left from the previous level of globalization or emerging to form a new and simplified causal model for likely linkages between truncated or(re-)emerging globalization,and the deadly needed output of public goods.These linkages refer to rules of climate control,go to trade linkages and arbitrary tariffs and trade interventions.Regime change,regime formation,and alliance restructuring address aspects of domestic rule and international stability.Selectorate theory,regime type,and exit options for political elites provide key explanatory factors in explaining globalization and public goods productions,or their decay.Where possible we use some data and transformation experiences corroborating our arguments.In other instances need for further empirical macro research will become clear.

The Thought of the Oneness Between Man and Nature in Walden

From the view of the ecological theory, this paper tries to analyze that Thoreau uses Chinese traditional philosophical thought--- the oneness of man and nature to deal with the relationship of human beings and the nature in Walden.

Free vibration analysis of functionally graded material beams based on Levinson beam theory

Free vibration response of functionally graded material （FGM） beams is studied based on the Levinson beam theory （LBT）. Equations of motion of an FGM beam are derived by directly integrating the stress-form equations of elasticity along the beam depth with the inertial resultant forces related to the included coupling and higherorder shear strain. Assuming harmonic response, governing equations of the free vibration of the FGM beam are reduced to a standard system of second-order ordinary differential equations associated with boundary conditions in terms of shape functions related to axial and transverse displacements and the rotational angle. By a shooting method to solve the two-point boundary value problem of the three coupled ordinary differential equations, free vibration response of thick FGM beams is obtained numerically. Particularly, for a beam with simply supported edges, the natural frequency of an FGM Levinson beam is analytically derived in terms of the natural frequency of a corresponding homogenous Euler-Bernoulli beam. As the material properties are assumed to vary through the depth according to the power-law functions, the numerical results of frequencies are presented to examine the effects of the material gradient parameter, the length-to-depth ratio, and the boundary conditions on the vibration response.

Quantization of light energy directly from classical electromagnetic theory in vacuum

It is currently believed that light quantum or the quantization of light energy is beyond classical physics, and the picture of wave-particle duality, which was criticized by Einstein but has attracted a number of experimental researches, is necessary for the description of light. It is shown in this paper, however, that the quantization of light energy in vacuum, which is the same as that in quantum electrodynamics, can be derived directly from the classical electromagnetic theory through the consideration of statistics based on classical physics. Therefore, the quantization of energy is an intrinsic property of light as a classical electromagnetic wave and has no need of being related to particles.

THEORY AND PRACTICE FOR COMPILING THE ATLAS OF NATURAL DISASTERS IN CHINA

This article inquires into theoretical and practical problems on compilation of an atlas of regional natural disasters. (1) The basic theory of compiling an atlas of regional disasters has been founded on the combination of the sciences of disasters, cartography and regional geogrphy. The content structure of a regional disaster atlas should be composed of at least the following five parts:hazard-formative environments and hazard-affected bodies,hazards, disaster effects, monitoring and warning system for natural disasters, and countermeasures for natural disaster reduction. (2) Contents of cartographic design of a regional disaster atlas should be composed of at least the following five parts: base map system, cartographic representation, Symbol System, color system, map edition and map layout system. (3) Based on theory and cartographic design of compiling an atlas of regional disaster, the Atlas of Natural Disater in China, which reveals objectively the temporal and spaial pattern of regional natural disasters of China,has been compiled and published.

Community Regeneration Based on CPTED Theory: A Case Study of Rosengard Residential Area in Sweden

With urban development and social transformation, residential areas in some western countries have been faced with safety problems and community deterioration. In order to solve these problems through community planning, Crime Prevention through Environmental Design(CPTED) theory had been applied to practice. Rosengard residential area in Malmo, Sweden was a typical example of underclass community with physical and social problems. However, regeneration programme based on CPTED theory aimed to change the community from a problematical area to a safe and attractive neighborhood. Multidimensional analysis was carried out to illustrate the relationship between environmental improvement and security from community image, traffic system, territoriality and natural surveillance perspectives. This study could be considered as a referential approach for community construction and regeneration in China.

An R(x)-orthonormal theory for the vibration performance of a non-smooth symmetric composite beam with complex interface

A composite beam is symmetric if both the material property and support are symmetric with respect to the middle point. In order to study the free vibration performance of the symmetric composite beams with different complex nonsmooth/discontinuous interfaces, we develop an R(x)-orthonormal theory, where R(x) is an integrable flexural rigidity function. The R(x)-orthonormal bases in the linear space of boundary functions are constructed, of which the second-order derivatives of the boundary functions are asked to be orthonormal with respect to the weight function R(x). When the vibration modes of the symmetric composite beam are expressed in terms of the R(x)-orthonormal bases we can derive an eigenvalue problem endowed with a special structure of the coefficient matrix A :=[aij ],aij= 0 if i + j is odd. Based on the special structure we can prove two new theorems, which indicate that the characteristic equation of A can be decomposed into the product of the characteristic equations of two sub-matrices with dimensions half lower. Hence, we can sequentially solve the natural frequencies in closed-form owing to the specialty of A. We use this powerful new theory to analyze the free vibration performance and the vibration modes of symmetric composite beams with three different interfaces.

On the Natures of English Passive Construction Based on Theta Theory

The study of English passive construction has always been one of the hot topics in the literature of Generative Grammar. Although many attempts have been made, the study of this structure is still not systematic enough especially in terms of its essential natures. The present study is designed to give a full explanation of natures of English passive construction from the perspective of theta theory, which can provide English learners with a deeper understanding of passive structure.

BASIC EQUATIONS, THEORY AND PRINCIPLE OF COMPUTATIONAL STOCK MARKET (Ⅲ)—BASIC THEORIES

By basic equations, two basic theories are presented: 1.Theory of stock's value v *(t)=v *(0) exp (ar * 2t); 2. Theory of conservation of stock's energy. Let stock's energy be defined as a quadratic function of stock's price v and its derivative , =Av 2+ Bv+C 2+Dv, under the constraint of basic equation, the problem was reduced to a problem of constrained optimization along optimal path. Using Lagrange multiplier and Euler equation of variation method, it can be proved that keeps conservation for any v,. The application of these equations and theories on judgement and analysis of tendency of stock market are given, and the judgement is checked to be correct by the recorded tendency of Shenzhen and Shanghai stock markets.

A Theory of Evolving Natural Constants Based on the Unification of General Theory of Relativity and Dirac’s Large Number Hypothesis

Talcing Dirac's large number hypothesis as true, we have shown [Commun.Theor. Phys. (Beijing, China) 42 (2004) 703] the inconsistency of applying Einstein's theory ofgeneral relativity with fixed gravitation constant G to cosmology, and a modified theory for varyingG is found, which reduces to Einstein's theory outside the gravitating body for phenomena of shortduration in small distances, thereby agrees with all the crucial tests formerly supportingEinstein's theory. The modified theory, when applied to the usual homogeneous cosmological model,gives rise to a variable cosmological tensor term determined by the derivatives of G, in place ofthe cosmological constant term usually introduced ad hoc. Without any free parameter thetheoretical Hubble's relation obtained from the modified theory seems not in contradiction toobservations, as Dr. Wang's preliminary analysis of the recent data indicates [Commun. Theor. Phys.(Beijing, China) 42 (2004) 703]. As a complement to Commun. Theor. Phys. (Beijing, China) 42 (2004)703 we shall study in this paper the modification of electromagnetism due to Dirac's large numberhypothesis in more detail to show that the approximation of geometric optics still leads to nullgeodesies for the path of light, and that the general relation between the luminosity distance andthe proper geometric distance is still valid in our theory as in Einstein's theory, and give theequations for homogeneous cosmological model involving matter plus electromagnetic radiation.Finally we consider the impact of the modification to quantum mechanics and statistical mechanics,and arrive at a systematic theory of evolving natural constants including Planck's h as well asBoltzmann's k_B by finding out their cosmologically combined counterparts with factors ofappropriate powers of G that may remain truly constant to cosmologically long time.

A graph theory model using human nature structure

A graph theory model of the human nature structure( GMH) for machine vision and image/graphics processing is described in this paper. Independent from the motion and deformation of contours,the human nature structure( HNS) embodies the most basic movement characteristics of the body. The human body can be divided into basic units like head,torso,and limbs. Using these basic units,a graph theory model for the HNS can be constructed. GMH provides a basic model for human posture processing,and the outline in the perspective projection plane is the body contour of an image. In addition,the GMH can be applied to articulated motion and deformable objects,e. g.,in the design and analysis of body posture,by modifying mapping parameters of the GMH.

Photoionization Study of Cl II, Ar II and Kr II Ions Using the Modified Atomic Orbital Theory

Resonance energies of the Cl II-[3s23p3(2D5/2)]nd and [3s23p3(2P3/2)]nd, Ar II-3s23p4(1D2)ns, nd and of the Kr II [4s24p4(1D2)]ns, nd and 4s24p4(3P2,3P1)]ns, 4s24p4(3D2)]ns, nd and 4s24p4(3D2, 1S0)]ns, nd Rydberg series are reported. Natural widths of the Ar II-[3s23p4(1D2)]ns, nd series are also reported. Calculations are done in the framework of the Modified Atomic Orbital Theory (MAOT). Excellent agreements are obtained with available theoretical and experimental data. High lying accurate resonance energies up to n = 40 are tabulated. The possibility to use the MAOT formalism report rapidly with an excellent accuracy the position of the excitation resonances as well as their width within simple analytical formulae is demonstrated.

Problems and Countermeasures of Bike-Sharing System in China Based on the theory of Public Goods

Under the new normal of China’s economic development,bike-sharing,a new product of the“Internet+”era,opens the door to a novel lifestyle for the society,and is in the stage of rapid development.Nevertheless,with the explosive growth of the number of bicycles,some new problems gradually come out,such as disorderly parking,serious damage and waste of resources,which in turn restrict its further development.Based on the theory of public goods,this article studies the quasi-public goods attributes and problems of bike-sharing,as well as provides feasible measures for its long-term development,so as to realize the co-governance and sharing among enterprises,consumers and government.

Envisioning the Profile of Chinese Culture——from the Perspective of the Social Value Theory

For a few decades China has undergone an enduring, drastic and complicated transformation. The structure and form of Chinese culture has been profoundly shaped and re-shaped during this process. With careful analysis of the history and the actualities, this paper presents a sketch of Chinese culture that highlights three significant traits; an elegant temperament featuring both classicality and novelty, an intrinsic value focusing on nature and freedom, and an encompassing structure marked by harmonious diversity. A new Chinese culture has already revealed her profile against the sunglow at the dawn of the new era. Beautiful and promising as it is, Chinese people believe that she deserves being heartily applauded, warmly welcomed, and boldly embraced.

Theory of pleiotropic action of biologically active compounds and medicines—Basic principles and practical application

This article represents the main positions of the theory of pleiotropic action of biologically active compounds (BACs) and medicines, which has been designed by the author based on her own experimental researches. The term “pleiotropy” means the ability of the BACs and medicines to implement more than one mechanism of action resulting in the specific biological (pharmacological) effect. The interaction of these mechanisms forms a distinct pattern of biological response (pleiotropic pattern), which reflects the change in his character with the increased dose (concentration)-dependent efficacy of BACs and medicines. The article consists of description of different pleiotropic patterns established in experiments on the model of reactive oxygen species (ROS) generation by macrophages dependent on activity of specialized enzyme called Nox2-NAD(P)H oxidase (Nox2, EC 1.6.3.1). Moreover, it consists of explanation of pharmacodynamic nature of pleiotropic patterns by means of application Chou-Talalay median effect equalization and combination index (CI) theory. The novel theory explains unsolved until now universal aspects of activity BACs and medicines, such as slope angles of “dose-effect” dependences in the conditions relevant in vivo, and it is of fundamental interest. However, it has applications in experimental pharmacology, as it allows defining the choice of the individual compounds and combinations, modulating the trust effect selectively and efficiently. This knowledge opens up new approaches to medicines discovery and evaluation, their rational dosing and combining.