Function Of State Research Articles

Conformal field theory approach to parton fractional quantum Hall trial wave functions

We show that all lowest Landau-level projected and unprojected chiral parton type fractional quantum Hall ground and edge-state trial wave functions, which take the form of products of integer quantum Hall wave functions, can be expressed as conformal field theory (CFT) correlation functions, where we can associate a chiral algebra to each parton state such that the CFT defined by the algebra is the “smallest” such CFT that can generate the corresponding ground and edge-state trial wave functions (assuming that the corresponding chiral algebra does indeed define a physically “sensible” CFT). A field-theoretic generalization of Laughlin's plasma analogy, known as generalized screening, is formulated for these states. If this holds, along with an additional assumption, we argue that the inner products of edge-state trial wave functions, for parton states where the “densest” trial wave function is unique, can be expressed as matrix elements of an exponentiated local action operator of the CFT, generalizing the result of Dubail [], which implies the equality between edge-state and entanglement level counting to state counting in the corresponding CFT. We numerically test this result in the case of the unprojected ν=2/5 composite fermion state and the bosonic ν=1ϕ22 parton state. We discuss how Read's arguments [] still apply, implying that conformal blocks of the CFT defined by the corresponding chiral algebra are valid quasihole trial wave functions, with the adiabatic braiding statistics given by the monodromy of these functions, assuming the existence of a quasiparticle trapping Hamiltonian. Generalizations of these constructions are discussed, with particular attention given to simple current constructions. It is shown that all chiral composite fermion wave functions can be expressed as CFT correlation functions without explicit symmetrization or antisymmetrization and that the ground, edge, and certain quasihole trial wave functions of the ϕnm parton states can be expressed as the conformal blocks of the U(1)⊗SU(n)m WZW models. Finally, we discuss the relation of the ϕ2k series with the Read-Rezayi series, where several examples of quasihole braiding statistics calculations are given. Published by the American Physical Society 2024

Efficient reliability assessment of slope stability with insightful sensitivity analysis concerning the safety factor

The limit state functions (LSFs) of slope stability are nonlinear, implicit, or derived from numerical simulations, and additional surrogate models are usually used for its reliability problems. Alternatively, an efficient numerical procedure using a variant of the HLRF-BFGS algorithm is proposed to address this issue without additional surrogate models. This proposed procedure simultaneously conducts reliability assessment and sensitivity analysis concerning the safety factor by suggested calculations of partial derivatives using the finite difference method (FDM). Two highly nonlinear numerical examples are presented to validate its convergence and to investigate the step length of the FDM. Results show that the proposed procedure can get considerable accuracy while the HLRF algorithm cannot converge, and its required iterations are about 30% and 81% less than those of the limited step-size iteration algorithm. In addition, a step length not greater than 0.1 is suggested after investigations. Application to a classical two-layered slope is illustrated. Reliability results show that the proposed procedure can get the same accuracy as those of surrogate models after only 5 iterative steps. Sensitivity results show that the cohesion of the upper soil is the only sensitivity factor, and the most possible potential slide surface lies in the upper soil.

Reliability analysis of rolling bearings considering failure mode correlations

AbstractAs an essential mechanical component, a rolling bearing can exhibit multiple failure modes that may occur independently or in correlation with one another. A reliability analysis method that meticulously accounts for the interdependencies among various bearing failure modes is presented in this paper. The examination of wear and fatigue failure mechanisms in rolling bearings is carried out using the Physics of Failure (PoF) approach. By considering the influence of uncertain variables, the limit state functions for individual failure modes are formulated through the application of stress‐strength interference theory. In the context of wear failure, the limit state function is derived using working clearance as the characteristic quantity. On the other hand, the limit state function for fatigue failure is constructed with a focus on fatigue damage accumulation. The Copula function is used to characterize the relationship between wear failure and fatigue failure, and a reliability calculation model for rolling bearings is developed, considering the correlation between these failure modes. Ultimately, the proposed method is utilized to assess the reliability of bearings under two different sets of test conditions. The feasibility of this method is confirmed through test data, demonstrating its effectiveness in predicting bearing reliability. Through the application of this method, engineers can optimize bearing size parameters, select appropriate initial clearances, and enhance the reliability design of bearing.

Studies of the barrier function of the acid-base state of the skin using a potentiometric method

Studies of the barrier function of the acid-base state of the skin using a potentiometric method

Implementation of the Su-Schrieffer-Heeger Model in the Self-Assembly Si-In Atomic Chains on the Si(553)-Au Surface.

Indium-decorated Si atomic chains on a stepped Si(553)-Au substrate are proposed as an extended Su-Schrieffer-Heeger (SSH) model, revealing topological end states. An appropriate amount of In atoms on the Si(553)-Au surface induce the self-assembly formation of trimer SSH chains, where the chain unit cell comprises one In atom and two Si atoms, confirmed by scanning tunneling microscopy images and density functional calculations. The electronic structure of the system, examined through scanning tunneling spectroscopy, manifests three electron bands within the Si-In chain, accompanied by additional midgap topological states exclusively appearing at the chain's end atoms. To elucidate the emergence of these topological states, a tight-binding model for a finite-length-extended SSH chain is proposed. Analysis of the energy spectra, density of states functions, and eigenfunctions demonstrates the topological nature of these self-assembled atomic chains.

The Problem with NIST Thermodynamics Tables in Continuum Mechanics.

Thermodynamics is a fundamental topic of continuum mechanics and biomechanics, with a wide range of applications to physiological and biological processes. This study addresses two fundamental limitations of current thermodynamic treatments. First, thermodynamics tables distributed online by the U.S. National Institute of Standards and Technology report properties of fluids as a function of absolute temperature T and absolute pressure P. These properties include mass density ρ, specific internal energy u, enthalpy h=u+P/ρ and entropy s. However, formulations of jump conditions across phase boundaries derived from Newton's second law of motion and the first law of thermodynamics employ the gauge pressure p=P-Pr, where Pr is an arbitrarily selected referential absolute pressure. Interchanging p with P is not innocuous as it alters tabulated NIST values for u, while keeping h and s unchanged. Using p for functions of state and governing equations solves the problem with using NIST entries for the specific internal energy u in standard thermodynamics tables, and analyses of phase transformation in continuum mechanics. Second, constitutive models for the free energy of fluids, such as water and air, are not typically provided in standard thermodynamics treatments. This study proposes a set of constitutive models and validates them against suitably modified NIST data.

Negative Differential Resistance in Conical Nanopore Iontronic Memristors.

Emerging ion transport dynamics with memory effects at nanoscale solution-substrate interfaces offers a unique opportunity to overcome the bottlenecks in traditional computational architectures, trade-offs in selectivity and throughput in separation, and electrochemical energy conversions. Negative differential resistance (NDR), a decrease in conductance with increasing potential, constitutes a new function from the perspective of time-dependent instead of steady-state nanoscale electrokinetic ion transport but remains unexplored in ionotronics to develop higher-order complexity and advanced capabilities. Herein, NDR is introduced in hysteretic and rectified ion transport through single conical nanopipettes (NPs) as ionic memristors. Deterministic and chaotic behaviors are controlled via an electric field as the sole stimulus. The NDR arises fundamentally from the availability and redistribution of the ionic charges during the hysteretic and rectified transport at asymmetric nanointerfaces. The elucidated mechanism is generalizable, and the drastically simplified operations enable tunable state-switching dynamics with higher-order complexity besides the first-order synaptic functions in multiple excitatory and inhibitory states.

Ultra-high ON/OFF Ratio with Low Set Voltage for a Pt-Nb2O5-Pt Resistivity Switching Device

The limited ON/OFF ratio constrains the quantity of available resistance states and the multi-level storage capability, a high ON/OFF ratio (>103) is essential for implementing multi-level storage in a resistive device. Through annealing processes for Nb2O5 films prepared by magnetron sputtering, we successfully achieved an ultra-high ON/OFF ratio of 106 and a four-order higher resistance compared to conventional binary oxide resistive random-access memory. Results confirm that annealing can effectively modulate the content of oxygen vacancies within the resistance-switching layer and the formation path of oxygen vacancies. At the same time, we observed a gradual decrease in the set voltage of the device with increasing annealing temperature, which is beneficial for the low power consumption characteristics. Therefore, appropriate annealing is a novel and effective approach to optimize device performances for better information storage applications, and its core mechanism is to modulate the concentration of Vo for constructing fixed conductive paths.

The mechanistic origins of heterogeneous void growth during ductile failure

In 1969, Rice and Tracey proposed that the rate of void growth during ductile failure is a strong function of the hydrostatic stress state. Numerous in-situ x-ray computed tomography (XCT) studies demonstrated that the average rate of void growth is well-predicted by modified versions of the Rice-Tracey equation. However, recent in-situ XCT studies of void growth demonstrated that individual voids grow in highly heterogeneous manners in a way that is not predicted by Rice-Tracey or similar models. Model-based studies using crystal plasticity finite element (CP-FE) suggest that local effects of grain orientation play a strong role during void growth, but we lack experimental data to test this hypothesis. The present study leverages recent advances in laboratory-based diffraction contrast tomography (Lab-DCT) and in-situ XCT to systematically examine the effects of grain orientation on void growth experimentally in an Al-2219 alloy. CP-FE modeling was used to assess the local stress states associated with voids and their influence on void growth rates. These data indicate that void growth is not simply controlled by the local hydrostatic stress or stress triaxiality. Additionally, no clear relationship between void growth rates and grain orientation were observed. Instead, void growth rates were highly stochastic in ways that could not be directly linked to the local stress or strain states. The combination of experimental and modeling data suggests that our current assumptions regarding the mechanisms of void growth are flawed and that additional factors, which may include the local dislocation density, affect the rate of void growth.

Multiple heating loads participate in the system power regulation control strategy

With the addition of a high proportion of new energy and power electronic equipment, the power system has shown characteristics such as low inertia and significant energy output fluctuation, which has brought great challenges to power/frequency regulation and control of the power system. Therefore, this article uses the inertia characteristics of heat energy on the load side and exerts reasonable start-stop control to play a positive and beneficial role in the power regulation of the power system. Firstly, the room temperature variation process was transformed into a lumped parameter equivalent model. A lumped parameter heat transfer model of a single typical load was built in Simulink, and its dynamic characteristics were analyzed by symbolic calculation. Based on this, a time-domain simulation was carried out to explore the influence of the law of system parameters and external input on the change of system state quantity. Based on time domain simulation, the behavior of the heating load is analyzed. Then, the effects of typical and multiple loads on system power regulation at different outdoor temperatures are studied. It is found that when the average outdoor temperature decreases, the sustainable time of system power upturn will increase, and the sustainable time of downturn will decrease. The power curve of multiple loads simultaneously is more stable, and the adjustment ability is stronger. The reasonable and flexible control method of load switch setting, namely the coherent characteristic load power regulation strategy, realizes the sustainable power optimization of the load to the system in the specified period.

Impact of blue-shifted effective joint density of electronic states on the photoluminescence of nanostructured silicon

Light emission from nanostructured silicon has triggered tremendous research interest for three decades. Yet, the exact mechanism of photoluminescence from silicon-based nano-systems is still not completely understood. It is generally believed that quantum confinement and surface chemistry play a combined role in determining the luminescence characteristics on nano silicon. In this work, we show that the evolution of electron-hole effective joint density of states, resulting from the relaxation of k-selection rule, can account for the much-observed temperature dependent shift of the luminescence spectra of nanostructured silicon. Deconvolution of the emission characteristics reveals three distinct radiative recombination channels that can be attributed to band-to-band, band-to-trap and trap-to-trap transitions. At temperatures below ∼200 K, the peak due to band-to-band transition exhibit a nearly linear blue shift with increasing temperature while at higher temperatures this trend is reversed. The rate of variation of emission peak energy with temperature is also found to be dependent on average crystallite size. These results are explained in terms of shift in the effective joint density of state function of photogenerated electron-hole pairs. The shift provides experimental evidence of the pseudo-direct transitions in the quantum-confined nanostructure of silicon.

The Triple Product Rule and the Subtleties of the Mathematical Tools Used in Thermodynamics

We have clarified several formulas from mathematics and physics. Specifically, we have shown that several standard concepts from thermodynamics, which have been recently investigated and rejected in some papers, continue to be valid. Thus, we have studied the triple product rule, the first law of thermodynamics, Mayer's relation, work, function of state, the relationship between the coefficient of thermal expansion, coefficient of isothermal compressibility and thermal coefficient of pressure. We have used multivariable calculus and properties of Jacobians and other mathematical tools. Likewise, we have provided several didactic examples concerning the interpretation of thermodynamical and mathematical formulas. We have concluded that the basement of several thermodynamical formulas is correct but full of subtleties. Thus, those formulas continue to be valid despite some claims in the recent literature.

The Concentration of Emergency Competencies During the COVID-19 Pandemic in Hungary: A Lack of Effective Control

The COVID-19 pandemic has posed a major challenge not only to the effectiveness of health crisis management by national governments but also to the democratic functioning of states. This article describes how the institutional guarantees of the democratic exercise of power in Hungary malfunctioned. The operation of Parliament and local self-governments as representative bodies, the Constitutional Court, the Ombudsperson, and the courts as control- and judicial-type institutions will be analysed vis-à-vis the Hungarian Government's action. The study thus aims to reveal how the systematic challenges and diminishing role of local self-governments in collaborative crisis management are not an outstanding and isolated problem, but part of the systematic autocratic regime change in Hungary accelerated by the COVID-19-related special legal order.

Space-time entropy, space of singularities and gravity origin: A case study

A new definition of entropy is introduced using a model that simulates an expanding space-time compatible with the fundamental principle of cosmology. The entropy is obtained by mean of a state function that measures the variation of the space-time normal curvature, from a highly compressed space to a lower compressed space. The defined entropy leads to work out a new understanding of the earliest conditions that last for a period estimated to 380,000 years after the Big Bang. It leads to understand via a short period of inflation the process that generates the uniform distribution of matter and energy at the surface of the last scattering. It involves gravitational singularities in a process of gradual decompression propitious to the incubation of matter recombination, and it allows to trace back gravity origin.

The photocatalytic potential of single-atom Ag with tungsten-based two-dimensional transition metal dichalcogenides substrate for harmful gas removal

Tungsten-based two-dimensional transition metal dichalcogenides (TMDs) is a promising non-precious metal catalyst that can be applied to drive photocatalytic removal of harmful gases. However, the photocatalytic performance of these promising tungsten-based TMDs is limited by low carrier separation efficiency. In order to promote the separation efficiency of photogenerated carriers, it is a useful strategy to introduce a trace amount of precious metal Ag into tungsten-based TMDs. Due to the presence of precious metal Ag, the separation efficiency of photogenerated carrier is significantly improved. The photocatalytic removal potential of single-atom Ag with tungsten-based TMDs substrate for harmful gases was demonstrated in this work. Specifically, the effects of trace Ag atom and its load on the light absorption spectra, work function, band structure and density of states of tungsten-based TMDs were discussed by first principles calculations, among which tungsten-based TMDs substrate included 2 H-WS2, 2 H-WSe2 and 2 H-WTe2. It was found that Ag@2 H-WS2 and Ag@2 H-WSe2 possess strong light absorption capacity, low electron escape work and suitable band structure for photocatalysis. Through cohesive energy, formation energy and molecular dynamics, it was found that Ag@2 H-WSe2 possesses excellent stability, while Ag@2 H-WS2 may be unstable. Thus, Ag@2 H-WSe2 was identified as a new photocatalyst with broad application prospects. Finally, taking NH3, H2S, NO2 and SO2 as model harmful gases, it was proved that Ag@2 H-WSe2 can effectively photocatalyze the removal of harmful gases by differential charge density, projected density of states and energy barrier calculations. The above calculations indicates that Ag@2 H-WSe2 exhibits excellent photocatalytic activity and stability, and is a promising photocatalyst.

Disaster, Societal Responses, and State Legitimacy in Crisis in Vietnam

This article examines the role of celebrity activism in post-disaster politics in the context of state authoritarianism in Vietnam. In late 2020, a chain of violent tropical storms hit Vietnam’s central highland region – host to hundreds of hydropower dams – triggering severe landslides and floods that devastated human lives and local livelihoods. Drawing on data gathered through social media, online platforms, and interviews with non-governmental organisations and private sector actors, this article shows how the rupture of these disaster events facilitated socio-political openings in state–society relations that might otherwise have remained closed. It explores these political contestations, attributions of blame, and the competing recovery efforts that emerged between government actors, celebrities, and citizens. Public debates over the natural and political catalysts of the disaster revealed major structural and governance problems for the state, which allowed voluntary charity work by a celebrity to supplement state functions during the disaster. Considered illegal under state law, the article shows how support from the public and lower tiers of government for private charity work challenged state legitimacy. Under pressure from within and from citizens, the central government had to amend its policies to accommodate voluntary disaster relief – to restore its flagging legitimacy.

Optimal vaccination and treatment policies with constrained inequalities to study limited vaccination resources for a multistrain reaction–diffusion [formula omitted] model of COVID-19

The availability of an effective vaccine is a major challenge in COVID-19 vaccination campaigns. In this article, we propose a comprehensive strategy incorporating distributed controls via vaccination and treatment while considering the limitations of available resources expressed as inequalities constrained. Our approach utilizes a spatiotemporal model that includes multiple strains of the virus and considers spatial heterogeneity, providing a more accurate representation of disease transmission. By using a generalized two-strain ODE model, we effectively capture the evolution of COVID-19, including various strains and variants. To validate our model, we establish the positivity and boundedness of the system’s solution. Through the exploration of vaccination and treatment controls. Our study aims to reduce the spread of the disease between strains and identify optimal values that minimize the number of infected individuals and associated costs. This work provides useful insights into effective strategies for controlling the COVID-19 epidemic, even with limited vaccination resources. Furthermore, we demonstrate the existence of controls and describe their characterizations in terms of state and adjoint functions. The penalty method is used to treat the inequalities constrained. More importantly, our numerical simulation shows that adequate vaccination resources and simultaneous treatment can effectively reduce and even eliminate the spread of COVID-19.

Adaptive Cruise Control Based on Safe Deep Reinforcement Learning.

Adaptive cruise control (ACC) enables efficient, safe, and intelligent vehicle control by autonomously adjusting speed and ensuring a safe following distance from the vehicle in front. This paper proposes a novel adaptive cruise system, namely the Safety-First Reinforcement Learning Adaptive Cruise Control (SFRL-ACC). This system aims to leverage the model-free nature and high real-time inference efficiency of Deep Reinforcement Learning (DRL) to overcome the challenges of modeling difficulties and lower computational efficiency faced by current optimization control-based ACC methods while simultaneously maintaining safety advantages and optimizing ride comfort. Firstly, we transform the ACC problem into a safe DRL formulation Constrained Markov Decision Process (CMDP) by carefully designing state, action, reward, and cost functions. Subsequently, we propose the Projected Constrained Policy Optimization (PCPO)-based ACC Algorithm SFRL-ACC, which is specifically tailored to solve the CMDP problem. PCPO incorporates safety constraints that further restrict the trust region formed by the Kullback-Leibler (KL) divergence, facilitating DRL policy updates that maximize performance while keeping safety costs within their limit bounds. Finally, we train an SFRL-ACC policy and compare its computation time, traffic efficiency, ride comfort, and safety with state-of-the-art MPC-based ACC control methods. The experimental results prove the superiority of the proposed method in the aforementioned performance aspects.

Dynamics of Open States and Promoter Functioning in the appY_red and appY_green Genetic Constructions Based on the pPF1 Plasmid.

Although the role of dynamic factors in DNA function still remains unclear, research in this direction is a rapidly developing area of molecular biology. In this work, the genetic constructions appY_red and appY_green, based on the plasmid pPF1 and containing a fragment of Escherichia coli (E. coli) DNA with predicted promoter-like regions, are considered complex dynamic systems in which local sites of double helix unwinding, called open states, can arise and propagate. The purpose of the article is to show the existence of a connection between the dynamics of open states and the functioning of predicted promoters. We experimentally verified the functionality of the predicted promoters using a reporter vector. Using a reverse transcription reaction, transcription start sites were identified indicating the presence of two divergent promoters, one on each strand. In mathematical studies, a dynamic model was used that described open states as one-soliton solutions (kinks) of a system of nonlinear partial differential equations, and the influence of the torque Mτ on the dynamics of kinks was taken into account. Fluorescence analysis of colonies of E. coli cells transformed with plasmid constructions showed that one of the two promoters is stronger than the other and that the strength of the promoters depends on the orientation of the fragment under study in the plasmid. On the other hand, using mathematical modeling, the energy profiles of genetic constructions were calculated and the kink trajectories were constructed. In addition, by studying the effect of torsion moment in model studies, we found threshold torque values at which the behavior of kinks changes dramatically: from oscillatory to translational motion. The minimum values of torsion moment required to initiate the transcription process were also assessed. A comparative analysis of the results of experimental data and model calculations showed a good correlation between the preferred starting points and the direction of transcription, which in turn confirmed the existence of a relationship between the dynamics of open states and the functioning of promoters.

Development and Validation of Treatment Expectation Scale for Patients with Liver Cancer

IntroductionLiver cancer is one of the most common tumors in the world. Patients with liver cancer usually face substantial physical, psychological, and social burdens, which has a great demand and expectation to ease the burden in all aspects. This study aimed to develop and validate a scale evaluating treatment expectations for patients with liver cancer (TES-LC).Material and methodsThe study was conducted in three phases. In the first stage, we used literature reviews and semi-structured interviews to generate the items to be included in the questionnaire TES-LC (version 1). In the second stage, two rounds of the Delphi expert consultation method were used to modify the first version to form TES-LC (version 2). In the third stage, projects were selected through project analysis and exploratory factor analysis to create TES-LC (version 3); version 3 was tested for reliability and validity to generate version 4.ResultsThe final version of the TES-LC contains 19 items in 5 dimensions: disease symptoms, practical needs, psychological state, emotional satisfaction, and social function. Five common factors were extracted through exploratory factor analysis, explaining 60.11% of the variance. In the validation factor analysis, the fitting effect of the five-factor model was satisfactory after modification. The TES-LC had good internal consistency, with a Cronbach's alpha coefficient of 0.911 for the total scale.ConclusionsThe TES-LC developed in this study has good reliability and validity and can provide a standardized tool for measuring treatment expectancy in patients with liver cancer, which is of good clinical utility.