Unleashing the Power of Information Theory: Enhancing Accuracy in Modeling Physical Phenomena

When building a model of a physical phenomenon or process, scientists face an inevitable compromise between the simplicity of the model (qualitative-quantitative set of variables) and its accuracy. For hundreds of years, the visual simplicity of a law testified to the genius and depth of the physical thinking of the scientist who proposed it. Currently, the desire for a deeper physical understanding of the surrounding world and newly discovered physical phenomena motivates researchers to increase the number of variables considered in a model. This direction leads to an increased probability of choosing an inaccurate or even erroneous model. This study describes a method for estimating the limit of measurement accuracy, taking into account the stage of model building in terms of storage, transmission, processing and use of information by the observer. This limit, due to the finite amount of information stored in the model, allows you to select the optimal number of variables for the best reproduction of the observed object and calculate the exact values of the threshold discrepancy between the model and the phenomenon under study in measurement theory. We consider two examples: measurement of the speed of sound and measurement of physical constants.

Cu含量对Al-1Mg-0.6Si-xCu合金板材韧性及弯曲性能的影响

采用室温拉伸、Kahn撕裂以及弯曲实验,结合数字图像分析法和扫描透射电镜等手段,探究了Cu含量对Al-1Mg-0.6Si-xCu合金板材韧性及弯曲性能的影响。结果表明:随着Cu含量的增加,合金的伸长率、均匀伸长率、均匀断裂能和单位面积裂纹形核功逐渐增加,合金的弯曲性能变好,均匀阶段韧性提升,而合金的失稳伸长率、失稳断裂能及单位面积裂纹扩展功下降,合金失稳阶段韧性变差。随着Cu含量的增加,Al-1Mg-0.6Si-xCu合金中强化相β″的密度增加,且在0.5-Cu合金中出现Q′相和L相,晶内析出相密度增加,使得合金在形变过程中消耗的能量增加;晶界析出相间距增加,从而提高合金的韧性及弯曲性能。

Effect of external and internal cues on core muscle activation during the Sahrmann five-level core stability test

BACKGROUND Pain in the back or pelvis or fear of back pain may affect the timing or cocontraction of the core muscles.In both static and dynamic movements,the Sahrmann core stability test provides an assessment of core muscle activation and a person's ability to stabilize the lumbopelvic complex.Preparatory cues and images can be used to increase the activation of these muscles.To attain optimal movement patterns,it will be necessary to determine what cueing will give the most effective results for core stability.AIM To investigate the effects of external and internal cues on core muscle activation during the Sahrmann five-level core stability test.METHODS Total 68 participants(21.83±3.47 years)were randomly allocated to an external(n=35)or internal cue group(n=33).Participants performed the Sahrmann fivelevel core stability test without a cue as baseline and the five-level stability exercises with an internal or external cue.External cue group received a pressure biofeedback unit(PBU),and the internal cue group received an audio cue.A Delsys Trigno^(TM)surface electromyography unit was used for muscle activation from the rectus abdominis,external oblique,and transverse abdominis/internal oblique muscles.RESULTS Linear mixed effects model analysis showed that cueing had a significant effect on core muscle activation(P=0.001);however,there was no significant difference between cue types(internal or external)(P=0.130).CONCLUSION Both external and internal cueing have significant effects on core muscle activation during the Sahrmann five-level core stability test and the PBU does not create higher muscle activation than internal cueing.

The Study-to-work Transition of Chinese International Students: Navigating a Future in the Global Labour Market

In the global competition for talents,the massive inflow of Chinese students into the UK has drawn great attention.However,only a few studies examine students’interactions with socioeconomic structures in their study-to-work transition.This study used Higher Education Statistics AgencyHESA,22data and interview data collected from Chinese postgraduate students,and it aims to:investigate structural factors that influence post-study migration patterns of Chinese students;and explore how Chinese students interact with wider social structures.This study found that different configurations between students"goals,""actions,"and"reflexivity"would lead to different employment outcomes.Three different study-to-work transition strategies were identified:"proceeding without a fixed plan";"reaching a compromise";and"knowing goals and approaching goals".Findings suggest that the transition between study and work is more complex than what is described in human capital and push-pull approaches.A better understanding of students’decision-making processes would help higher education institutions in preparing graduates for careers in the global labour market.

SIS在某海外燃煤电站主保护系统的应用

在某海外大型燃煤电站项目中,为了切实提高机组主保护的可靠性,SIS在锅炉和汽轮机主保护中得以应用,其具有优异的稳定性、可靠性、良好的人机接口及其与DCS的兼容性,为同类型机组主保护配置选型或升级改造提供了新的选择。

Work in Cooperation for A New Chapter in the Cause of International Human Rights——Speech by Yang Jiechi,Vice Minister of Foreign Affairs of the People's Republic of China at the Inaugural Session of the United Nations Human Rights Council

Mr Chairman, I would like to start by congratulating you, on behalf of the Chinese Govern- ment, on your assumption of the Chair of the inaugural session of the Human Rights Council. I have every confidence that under your able leadership this session will be successful.

The 2 ℃ Global Temperature Target and the Evolution of the Long-TermGoal of Addressing Climate Change-From the United Nations FrameworkConvention on Climate Change to the Paris Agreement

The Paris Agreement proposed to keep the increase in global average temperature to well below 2 ℃ abovepre-industrial levels and to pursue efforts to limit the temperature increase to 1.5 ℃ above pre-industriallevels. It was thus the first international treaty to endow the 2 ℃ global temperature target with legal effect.The qualitative expression of the ultimate objective in Article 2 of the United Nations Framework Conventionon Climate Change （UNFCCC） has now evolved into the numerical temperature rise target in Article 2 of theParis Agreement. Starting with the Second Assessment Report （SAR） of the Intergovernmental Panel on Cli-mate Change （IPCC）, an important task for subsequent assessments has been to provide scientific informa-tion to help determine the quantified long-term goal for UNFCCC negotiation. However, due to involvementin the value judgment within the scope of non-scientific assessment, the IPCC has never scientifically af-firmed the unacceptable extent of global temperature rise. The setting of the long-term goal for addressingclimate change has been a long process, and the 2 ℃ global temperature target is the political consensuson the basis of scientific assessment. This article analyzes the evolution of the long-term global goal foraddressing climate change and its impact on scientific assessment, negotiation processes, and global low-carbon development, from aspects of the origin of the target, the series of assessments carried out by the 1PCCfocusing on Article 2 of the UNFCCC, and the promotion of the global temperature goal at the political level.

Structure and internal stress of Au films deposited on SiO_2/Si(100) and mica by dc sputtering

Au films with a thickness of about 300 nm were deposited on SiO_2/Si(100) andmica substrates by dc sputtering. X-ray diffraction spectroscopy and field emission scanningelectron microscopy were used to analyze the structure and internal stress of the Au films. Thefirms grown on SiO_2/Si(100) show a preferential orientation of [111] in the growth direction.However the films grown on mica have mixture crystalline orientations of [111], [200], [220] and[311] in the growth direction and the orientations of [200] and [311] are slightly more than thoseof [111] and [220]. An internal stress in the films grown on SiO_2/Si(100) is tensile. For Au filmsgrown on mica the internal stresses in the [111]- and [311]-orientation grains are compressive whilethose in the [200]- and [220]-orientation grains are tensile. Au films grown SiO_2/Si(100) havesome very large grains with a size of about 400 nm and have a wider grain size distribution comparedwith those grown on mica.

Electroluminescence of Si Nanocrystal-Doped SiO2

We perform a comparative st udy on the electroluminescence （EL） and photoluminescence （PL） of Si nanocrystaldoped SiO2 （nc-Si：SiO2） and SiO2, and clarify whether the contribution from Si nanocrystals in the EL of nc-Si：SiO2 truly exists. The results unambiguously indicate the presence of EL of Si nanocrystals. The difference of peak positions between the EL and PL spectra are discussed. It is found that the normal method of passivation to enhance the PL of Si nanocrystals is not equally effective for the EL, hence new methods need to be explored to promote the EL of Si nanocrystals.

Abstracts from International Journal of Minerals, Metallurgy and Materials

Crystallization behavior of F-free mold fluxes ZHANG Zuotai,WEN Guanghua,and ZHANG Yingyi Abstract The time-temperature-transformation(TTT) diagrams of F-free mold fluxes were constructed using single hot thermocouple technique(SHTT) and confocal scanning laser

High Accuracy When Measuring Physical Constants: From the Perspective of the Information-Theoretic Approach

The practical value of high-precision models of the studied physical phenomena and technological processes is a decisive factor in science and technology. Currently, numerous methods and criteria for optimizing models have been proposed. However, the classification of measurement uncertainties due to the number of variables taken into account and their qualitative choice is still not given sufficient attention. The goal is to develop a new criterion suitable for any groups of experimental data obtained as a result of applying various measurement methods. Using the “information-theoretic method”, we propose two procedures for analyzing experimental results using a quantitative indicator to calculate the relative uncertainty of the measurement model, which, in turn, determines the legitimacy of the declared value of a physical constant. The presented procedure is used to analyze the results of measurements of the Boltzmann constant, Planck constant, Hubble constant and gravitational constant.

Investigation of the Nanostructures Formation in the Irradiated by γ-Quanta Single-Crystal Silicon with Ultrasonic Method

It’s determined that a phasic dynamics of deformation strengthening of single-crystal silicon irradiated by γ-quanta (with energy ~1.27 MeV) in the range of radiation absorbed doses from 102 up to 109 rad by the internal friction measurement with widely known ultrasonic resonance method. We have detected appearance the maximum on the dependence of internal friction (Q-1) from dose at 5 × 105 rad in the specimens of p - Si with a density of the dislocations more than 103 cm-2. The instability of the dislocation structures has been established in the range of doses from 106 up to 109 rad, due to the formation and accumulation in the crystal lattice of the point like and the continuous radiation defects. On the time dependence of Q-1(t) per 1.5 - 2 hours after irradiation, the maximum has been established which position depends on dose of radiation. The monotonic decrease of Q-1(t) dependence was observed at the increase of the observation time after stopping of the specimen irradiation, which is connected with decreasing of the radiation defects densities as the result of their annihilation.

国际单位制(SI)词头发展简史

梳理了自1964年以来国际单位制(SI)词头的发展简史,特别关注了2022年第27届国际计量大会(CGPM)通过的关于扩展SI词头的决议,并对未来进行了简要展望。

On Intrinsic Rotation of Bodies

Spontaneous rotation of matter is investigated. The results provide further evidence in support of earlier indications of a wave-only reality in which the quantum energy packet exists in the form of a conjugate wave—particle doublet. It reveals that matter, be it wave or particle, is a harmonic oscillator defined with full spectrum of the usual mechanical properties of simple harmonic motion SHM. Notably, the quantum energy packet’s stress field correlates with radius to generate intrinsic torque, it motivates spontaneous rotation at all levels of the cosmic mass scale from the electron to the universe;its atomic and natural units are and respectively for matter’s wave (bosonic) and particulate (fermionic) forms. The proton’s observational internal pressure Pa reported recently by Burkert et al. deviates markedly from the theoretical value ~1022 Pa, the difference attributes to challenges with existing energy measurement procedures. Velocities of electron waveform in random thermal motion evaluated with the new approach agree remarkably well with values obtained with kinetic-molecular theory KT;much more importantly, the analysis reveals existence, at standard conditions, of electron waveform’s hyper-luminal root-mean-square velocity, , if verified, this finding might inform on-going neutrino research. The evidence suggests that effects formalized in the theories of thermodynamics and kinetics trace to mobile torque fields.

Major historical events affecting the accounting profession： An overview

The accounting result from science and technology innovation and the development of productivity, with management modes and financial reforms as its opportunity and the operation of international capital, as well as economic integration helping improve it. An invention, a president, the occurrence of an organization, a historical lesson may directly or indirectly change accounting regulations, and even trigger an accounting revolution. We will put a variety of significant impacts on an accounting, so as to get a fundamental understanding of the close relationship between such events and accounting events, including innovation of accounting theory, and accounting practice; we adopted the ＂table-style＂ form of papers, with many self-evident and intuitive tables, we compile a series of major historical events reasonably. Only in accordance with evolution of objective environment, can we design proper accounting practice, and thus innovate and develop accounting.

Quantifying and Simplifying the 1997 UNWC’s Guidelines to Mitigate Hegemony in Transboundary Watercourse Negotiations

The 1997 United Nations Convention on the Law of the Non-navigational Uses of International Watercourses (UNWC) contains a negotiation framework for transboundary water rights. However, it is a subjective document open to a wide range of possibilities and interpretations. Water Rights Allocations (WRAs) as described by Dinar and Nigatu (2013) and Dinar and Tsur (2017) provide a limited number of quantifiable allocation possibilities based on the UNWC. It is suggested that this methodology streamlines the negotiation process and reduces the effects of hydro hegemony. These methodologies are explored and applied through a case study on the Orontes River Basin.

新国际单位制对电磁计量体系的影响

从2019年5月起,以4个基本物理常数为基础的新国际单位制正式实施,全面实现了用基本物理常数定义基本单位、基本单位的量子化以及量子基准取代实物基准,开启了计量单位独立复现、不再依赖于国际计量局的全新局面。论述了新SI体系下电学计量体系相比于1990电学计量体系的变化,探讨了国际单位制变革所引发的电磁测量活动。

美国对自决原则的立场演变分析

自决原则兴起于两次世界大战期间,是二战后确立的国际规则体系的主要内容之一,但在冷战特别是后冷战时期面临着日益严峻的冲击和挑战。本文以两次世界大战期间、二战结束初期、非殖民化及冷战时期、后冷战时期等国际秩序发生重大变动的四个时期为基础,结合自决原则兴起、制度化、扩散和重塑等不同阶段,分析美国在霸权的不同时期对待自决原则的立场和行动差异。在自决理念的兴起阶段,虽然美国与苏联都是该理念的重要倡导者,但是威尔逊与列宁所倡导的自决理念存在重大的差异,包括自决理论的政治和意识形态起源的不同,以及对实施自决的态度差异。这决定了两次世界大战期间美国对自决原则支持的限度,也加速了美国在价值和利益层面与世界非殖民化进程的背离。自决原则在二战后的制度化及扩散阶段,美国与苏联及广大新独立国家围绕自决原则的内涵及适用性展开了激烈争论,美国公开反对新独立国家保障经济、社会和文化发展权利,以及实现经济自决的诉求。美国对自决原则最直接的挑战体现在它对该原则的修正主义立场和行动,一是将自决意识形态化和工具化,二是以“人权高于主权”对自决原则进行重塑。与美国鼓吹“以规则为基础的国际秩序”而将自身塑造为国际规则的创建者和领导者的形象不同,美国并非自决原则的唯一倡导者,而是规范争论者;既非自决原则的一贯遵守者,而是修正主义者。美国对自决原则的结果性逻辑决定了它的立场和行动。

电学计量中的量子标准与自然常数

介绍了库仑定律和安培定律在电学单位制中发挥的作用,依据机械功率与电功率等效的原理,选择电流单位安培(A)作为基本物理单位,并介绍了实用单位制和电学实物计量标准。阐述了三种电学计量的量子标准原理和溯源到自然常数的途径,分析了真空磁导率在安培定律公式中发挥的作用,探讨了电学量子三角形与欧姆定律兼容的问题。指出基本电荷量常数不是简单地从约瑟夫森常数K_(J-90)和冯·克里青常数R_(H-90)推导而来,而是由精细结构常数公式计算出来的,能量守恒原理是单位制中的第一性原理,是力学和电学计量单位的纽带。提出量子点之间的位移电流对单电子隧道泵有一定的影响,真空磁导率不再是理想的常数,真空磁导率的变化将成为后来理论界研究的重点。