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Probing the Equation of State of Dense Nuclear Matter by Heavy Ion Collision Experiments 通过重离子碰撞实验探测致密核物质的状态方程
Pub Date : 2024-09-05 DOI: 10.3390/sym16091162
Peter Senger
The investigation of the nuclear matter equation of state (EOS) beyond saturation density has been a fundamental goal of heavy ion collision experiments for more than 40 years. First constraints on the EOS of symmetric nuclear matter at high densities were extracted from heavy ion data measured at AGS and GSI. At GSI, symmetry energy has also been investigated in nuclear collisions. These results of laboratory measurements are complemented by the analysis of recent astrophysical observations regarding the mass and radius of neutron stars and gravitational waves from neutron star merger events. The research programs of upcoming laboratory experiments include the study of the EOS at neutron star core densities and will also shed light on the elementary degrees of freedom of dense QCD matter. The status of the CBM experiment at FAIR and the perspective regarding the studies of the EOS of symmetric and asymmetric dense nuclear matter will be presented.
40 多年来,研究超过饱和密度的核物质状态方程(EOS)一直是重离子碰撞实验的基本目标。从 AGS 和 GSI 测量的重离子数据中首次提取了高密度对称核物质状态方程的约束条件。在 GSI,也对核碰撞中的对称能进行了研究。对最近有关中子星的质量和半径以及中子星合并事件产生的引力波的天体物理观测分析,补充了这些实验室测量结果。即将进行的实验室实验的研究计划包括研究中子星内核密度的 EOS,还将揭示致密 QCD 物质的基本自由度。将介绍在 FAIR 进行的 CBM 实验的现状以及对称和非对称致密核物质 EOS 研究的前景。
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引用次数: 0
Interval-Valued Linguistic q-Rung Orthopair Fuzzy TODIM with Unknown Attribute Weight Information 具有未知属性权重信息的区间值语言 q-Rung Orthopair 模糊 TODIM
Pub Date : 2024-09-05 DOI: 10.3390/sym16091161
Yushu Zhang, Fangcheng Tang, Zeyuan Song, Jun Wang
It is widely known that symmetry does exist in management systems, such as economics, management, and even daily life. In addition, effective and qualified decision-making methods can enhance the performance and symmetry of management systems. Hence, this paper focuses on a decision-making method. Linguistic interval-valued q-rung orthopair fuzzy sets (LIVq-ROFSs) have recently been proposed as being effective in describing decision-makers’ evaluation values in complex situations. This paper proposes a novel multi-attribute group decision-making (MAGDM) method with LIVq-ROFSs to handle realistic decision-making problems. The main contributions of this study are three-fold. First, a new method for determining the weight information of attributes based on decision makers’ evaluation values is proposed. Second, the classical TODIM is extended into LIVq-ROFSs and a new decision-making method is proposed. Third, our proposed MAGDM method is applied to a real decision-making problem to reveal its effectiveness.
众所周知,对称性确实存在于经济、管理甚至日常生活等管理系统中。此外,有效和合格的决策方法可以提高管理系统的性能和对称性。因此,本文重点探讨一种决策方法。最近有人提出了语言区间值q-rung正对模糊集(LIVq-ROFSs),认为它能有效地描述决策者在复杂情况下的评价值。本文提出了一种使用 LIVq-ROFSs 的新型多属性群体决策(MAGDM)方法,用于处理现实决策问题。本研究的主要贡献有三方面。首先,提出了一种基于决策者评价值确定属性权重信息的新方法。其次,将经典的 TODIM 扩展到 LIVq-ROFSs 中,并提出了一种新的决策方法。第三,将我们提出的 MAGDM 方法应用于实际决策问题,以揭示其有效性。
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引用次数: 0
Uncertain Time Series Analysis for the Confirmed Case of Brucellosis in China 中国布鲁氏菌病确诊病例的不确定时间序列分析
Pub Date : 2024-09-05 DOI: 10.3390/sym16091160
Shanshan Zhang, Yaxuan Zhang, Waichon Lio, Rui Kang
Brucellosis, as an infectious disease that affects both humans and livestock, poses a serious threat to human health and has a severe impact on economic development. Essentially, brucellosis transmission is a kind of study in biological systems, and the epistemic uncertainty existing in the data of confirmed brucellosis cases in China is realized as significant uncertainty that needs to be addressed. Therefore, this paper proposes an uncertain time series model to explore the confirmed brucellosis cases in China. Then, some methods based on uncertain statistics and symmetry of the biological system are applied, including order estimation, parameter estimation, residual analysis, uncertain hypothesis test, and forecast. The proposed model is practically applied to the data of confirmed brucellosis cases in China from January 2017 to December 2020, and the results show that the uncertain model fits the observed data better than the probabilistic model due to the frequency instability inherent in the data of confirmed brucellosis cases. Based on the proposed model and statistical method, this paper develops an approach to rapidly forecast the number of confirmed brucellosis cases in small sample scenarios, which can contribute to epidemic control in real application.
布鲁氏菌病是人畜共患的传染病,严重威胁人类健康,影响经济发展。从本质上讲,布鲁氏菌病的传播是一种生物系统研究,而中国布鲁氏菌病确诊病例数据中存在的认识不确定性是亟待解决的重大不确定性问题。因此,本文提出了一个不确定时间序列模型来探讨中国布鲁氏菌病确诊病例。然后,应用基于不确定统计和生物系统对称性的一些方法,包括阶次估计、参数估计、残差分析、不确定假设检验和预测。将提出的模型实际应用于 2017 年 1 月至 2020 年 12 月中国布鲁氏菌病确诊病例数据,结果表明,由于布鲁氏菌病确诊病例数据本身存在频率不稳定性,不确定模型比概率模型更适合观测数据。基于所提出的模型和统计方法,本文提出了一种在小样本情况下快速预测布鲁氏菌病确诊病例数的方法,可在实际应用中为疫情控制做出贡献。
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引用次数: 0
The Formulae and Symmetry Property of Bernstein Type Polynomials Related to Special Numbers and Functions 与特殊数和函数有关的伯恩斯坦型多项式的公式和对称性
Pub Date : 2024-09-05 DOI: 10.3390/sym16091159
Ayse Yilmaz Ceylan, Buket Simsek
The aim of this paper is to derive formulae for the generating functions of the Bernstein type polynomials. We give a PDE equation for this generating function. By using this equation, we give recurrence relations for the Bernstein polynomials. Using generating functions, we also derive some identities including a symmetry property for the Bernstein type polynomials. We give some relations among the Bernstein type polynomials, Bernoulli numbers, Stirling numbers, Dahee numbers, the Legendre polynomials, and the coefficients of the classical superoscillatory function associated with the weak measurements. We introduce some integral formulae for these polynomials. By using these integral formulae, we derive some new combinatorial sums involving the Bernoulli numbers and the combinatorial numbers. Moreover, we define Bezier type curves in terms of these polynomials.
本文旨在推导伯恩斯坦型多项式的生成函数公式。我们给出了该生成函数的 PDE 方程。利用这个方程,我们给出了伯恩斯坦多项式的递推关系。利用生成函数,我们还推导出了伯恩斯坦型多项式的一些特性,包括对称性。我们给出了伯恩斯坦多项式、伯努利数、斯特林数、大黑数、勒让德多项式以及与弱测量相关的经典超振荡函数系数之间的一些关系。我们介绍了这些多项式的一些积分公式。利用这些积分公式,我们推导出一些涉及伯努利数和组合数的新组合和。此外,我们还用这些多项式定义了贝塞尔型曲线。
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引用次数: 0
Integrability of the Multi-Species Asymmetric Simple Exclusion Processes with Long-Range Jumps on ℤ 在ℤ上具有长程跳跃的多物种非对称简单排斥过程的积分性
Pub Date : 2024-09-05 DOI: 10.3390/sym16091164
Eunghyun Lee
Let us consider a two-sided multi-species stochastic particle model with finitely many particles on Z, defined as follows. Suppose that each particle is labelled by a positive integer l, and waits a random time exponentially distributed with rate 1. It then chooses the right direction to jump with probability p, or the left direction with probability q=1−p. If the particle chooses the right direction, it jumps to the nearest site occupied by a particle l′
让我们考虑一个在 Z 上有有限多个粒子的双面多物种随机粒子模型,其定义如下。假设每个粒子都用一个正整数 l 标记,并等待速率为 1 的指数分布的随机时间。然后,它以 p 的概率选择向右跳,或以 q=1-p 的概率选择向左跳。如果粒子选择向右跳,它就会跳到离它最近的、被粒子 l′
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引用次数: 0
Revisiting the Two-Dimensional Hydrogen Atom: Azimuthal Wavefunctions for Illustrating s, p, d, and f Orbitals 重新审视二维氢原子:用于说明 s、p、d 和 f 轨道的方位波函数
Pub Date : 2024-09-05 DOI: 10.3390/sym16091163
Phatlada Sathongpaen, Suphawich Jindanate, Attapon Amthong
The two-dimensional (2D) hydrogen atom is a fundamental atomic model that is important for various technologies based on 2D materials. Here, the atomic model is revisited to enhance understanding of the hydrogen wavefunctions. Unlike in previous studies, we propose an alternative expression of azimuthal wavefunctions, which are the eigenstates of the square of angular momentum and exhibit rotational symmetry. Remarkably, our expression leads to the rotation and oscillation along the azimuthal direction of the probability densities, which do not appear in the conventional wavefunctions. These behaviors are validated by the numerical results obtained through the 2D finite difference approach. Variation in oscillator strengths due to the rotation of wavefunctions is observed in our proposed 2D hydrogen wavefunctions, whereas those due to the conventional wavefunctions remain constant. More importantly, the proposed wavefunctions’ advantage is illustrating the orbital shapes of the planar hydrogen states, whose orientation is labeled here using Cartesian representation for the first time. This study can be applied to visualize the orbital characteristics of the states in quantum confinement with a radial potential.
二维(2D)氢原子是一个基本原子模型,对于基于二维材料的各种技术非常重要。在此,我们重新审视了这一原子模型,以加深对氢原子波函数的理解。与以往的研究不同,我们提出了方位角波函数的另一种表达方式,它是角动量平方的特征状态,具有旋转对称性。值得注意的是,我们的表达式导致了概率密度沿方位角方向的旋转和振荡,这在传统波函数中是没有的。通过二维有限差分方法获得的数值结果验证了这些行为。在我们提出的二维氢波函数中,可以观察到波函数旋转导致的振荡器强度变化,而传统波函数导致的振荡器强度变化则保持不变。更重要的是,所提出的波函数的优势在于说明了平面氢态的轨道形状,这里首次使用笛卡尔表示法标注了氢态的方向。这项研究可用于观察具有径向势能的量子约束态的轨道特征。
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引用次数: 0
Automorphism Groups in Polyhedral Graphs 多面体图中的自形群
Pub Date : 2024-09-05 DOI: 10.3390/sym16091157
Modjtaba Ghorbani, Razie Alidehi-Ravandi, Matthias Dehmer
The study delves into the relationship between symmetry groups and automorphism groups in polyhedral graphs, emphasizing their interconnected nature and their significance in understanding the symmetries and structural properties of fullerenes. It highlights the visual importance of symmetry and its applications in architecture, as well as the mathematical structure of the automorphism group, which captures all of the symmetries of a graph. The paper also discusses the significance of groups in Abstract Algebra and their relevance to understanding the behavior of mathematical systems. Overall, the findings offer an inclusive understanding of the relationship between symmetry groups and automorphism groups, paving the way for further research in this area.
该研究深入探讨了多面体图中对称群和自形群之间的关系,强调了它们之间的相互联系,以及它们在理解富勒烯的对称性和结构特性方面的重要意义。论文强调了对称在视觉上的重要性及其在建筑中的应用,以及自形群的数学结构,自形群捕捉了图形的所有对称性。论文还讨论了抽象代数中群的重要性及其与理解数学系统行为的相关性。总之,研究结果提供了对对称群和自形群之间关系的包容性理解,为这一领域的进一步研究铺平了道路。
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引用次数: 0
Ar+ Ion Irradiation Response of LPBF AlSi10Mg Alloy in As-Built and KOBO-Processed Conditions 原样和 KOBO 加工条件下 LPBF AlSi10Mg 合金的 Ar+ 离子辐照响应
Pub Date : 2024-09-05 DOI: 10.3390/sym16091158
Przemysław Snopiński, Marek Barlak, Katarzyna Nowakowska-Langier
In recent years, revolutionary improvements in the properties of certain FCC metals have been achieved by increasing the proportion of twin-related, highly symmetric grain boundaries. Various thermomechanical routes of grain boundary engineering (GBE) processing have been employed to enhance the fraction of low ΣCSL grain boundaries, thereby improving the radiation tolerance of many polycrystalline materials. This improvement is due to symmetric twin boundaries acting as effective sinks for defects caused by radiation, thus enhancing the material’s performance. In this study, the LPBF AlSi10Mg alloy was post-processed via the KOBO extrusion method. Subsequently, the samples were subjected to irradiation with Ar+ ions at an ion fluence of 5 × 1017 cm−2. The microstructures of the samples were thoroughly investigated using electron backscatter diffraction (EBSD), transmission electron microscopy (TEM), and high-resolution TEM (HRTEM). The results showed that KOBO processing led to the formation of an ultrafine-grained microstructure with a mean grain size of 0.8 µm. Moreover, it was revealed that the microstructure of the KOBO-processed sample exhibited an increased fraction of low-ΣCSL boundaries. Specifically, the fraction of Σ11 boundaries increased from approximately 2% to 8%. Post-irradiation microstructural analysis revealed improved radiation tolerance in the KOBO-processed sample, indicating a beneficial influence of the increased grain boundary fraction and low-ΣCSL boundary fraction on the irradiation resistance of the AlSi10Mg alloy. This research provides valuable insights for the development of customized microstructures with enhanced radiation tolerance, which has significant implications for the advancement of materials in nuclear and aerospace applications.
近年来,通过增加孪生、高度对称晶界的比例,某些催化裂化金属的性能得到了革命性的改善。人们采用各种晶界工程 (GBE) 热机械加工方法来提高低 ΣCSL 晶界的比例,从而改善了许多多晶材料的辐射耐受性。这种改善是由于对称孪晶边界可有效吸收辐射造成的缺陷,从而提高材料的性能。在这项研究中,通过 KOBO 挤压法对 LPBF AlSi10Mg 合金进行了后处理。随后,用 Ar+ 离子以 5 × 1017 cm-2 的离子通量对样品进行辐照。使用电子反向散射衍射(EBSD)、透射电子显微镜(TEM)和高分辨率 TEM(HRTEM)对样品的微观结构进行了深入研究。结果表明,KOBO 工艺形成了平均晶粒尺寸为 0.8 微米的超细晶粒微观结构。此外,还发现 KOBO 加工样品的微观结构中,低 ΣCSL 边界的比例有所增加。具体来说,Σ11 边界的比例从大约 2% 增加到 8%。辐照后的微观结构分析表明,KOBO 加工样品的耐辐照性有所提高,这表明晶界部分和低ΣCSL 界部分的增加对 AlSi10Mg 合金的耐辐照性产生了有利影响。这项研究为开发具有更强辐照耐受性的定制微结构提供了有价值的见解,对促进核材料和航空航天材料的应用具有重要意义。
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引用次数: 0
A Convolutional Neural Network with Hyperparameter Tuning for Packet Payload-Based Network Intrusion Detection 基于数据包有效载荷的网络入侵检测的超参数调整卷积神经网络
Pub Date : 2024-09-04 DOI: 10.3390/sym16091151
Ammar Boulaiche, Sofiane Haddad, Ali Lemouari
In the last few years, the use of convolutional neural networks (CNNs) in intrusion detection domains has attracted more and more attention. However, their results in this domain have not lived up to expectations compared to the results obtained in other domains, such as image classification and video analysis. This is mainly due to the datasets used, which contain preprocessed features that are not compatible with convolutional neural networks, as they do not allow a full exploit of all the information embedded in the original network traffic. With the aim of overcoming these issues, we propose in this paper a new efficient convolutional neural network model for network intrusion detection based on raw traffic data (pcap files) rather than preprocessed data stored in CSV files. The novelty of this paper lies in the proposal of a new method for adapting the raw network traffic data to the most suitable format for CNN models, which allows us to fully exploit the strengths of CNNs in terms of pattern recognition and spatial analysis, leading to more accurate and effective results. Additionally, to further improve its detection performance, the structure and hyperparameters of our proposed CNN-based model are automatically adjusted using the self-adaptive differential evolution (SADE) metaheuristic, in which symmetry plays an essential role in balancing the different phases of the algorithm, so that each phase can contribute in an equal and efficient way to finding optimal solutions. This helps to make the overall performance more robust and efficient when solving optimization problems. The experimental results on three datasets, KDD-99, UNSW-NB15, and CIC-IDS2017, show a strong symmetry between the frequency values implemented in the images built for each network traffic and the different attack classes. This was confirmed by a good predictive accuracy that goes well beyond similar competing models in the literature.
最近几年,卷积神经网络(CNN)在入侵检测领域的应用吸引了越来越多的关注。然而,与图像分类和视频分析等其他领域的结果相比,卷积神经网络在这一领域的结果并不尽如人意。这主要是由于所使用的数据集包含的预处理特征与卷积神经网络不兼容,因为它们无法充分利用原始网络流量中蕴含的所有信息。为了克服这些问题,我们在本文中提出了一种新的高效卷积神经网络模型,用于基于原始流量数据(pcap 文件)而非存储在 CSV 文件中的预处理数据的网络入侵检测。本文的新颖之处在于提出了一种新方法,可将原始网络流量数据调整为最适合 CNN 模型的格式,从而充分发挥 CNN 在模式识别和空间分析方面的优势,获得更准确、更有效的结果。此外,为了进一步提高其检测性能,我们提出的基于 CNN 的模型的结构和超参数使用自适应微分进化(SADE)元启发式进行自动调整,其中对称性在平衡算法的不同阶段方面发挥着至关重要的作用,从而使每个阶段都能以平等、高效的方式为找到最优解做出贡献。这有助于使算法在解决优化问题时的整体性能更稳健、更高效。在 KDD-99、UNSW-NB15 和 CIC-IDS2017 三个数据集上的实验结果表明,为每个网络流量和不同攻击类别构建的图像中的频率值之间具有很强的对称性。良好的预测准确性也证实了这一点,远远超出了文献中类似的竞争模型。
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引用次数: 0
Enzymatic Deracemization of Fluorinated Arylcarboxylic Acids: Chiral Enzymatic Analysis and Absolute Stereochemistry Using Chiral HPLC 氟代芳基羧酸的酶法脱羧化:利用手性高效液相色谱进行手性酶分析和绝对立体化学分析
Pub Date : 2024-09-04 DOI: 10.3390/sym16091150
Oleg I. Kolodiazhnyi, Anastasiia O. Kolodiazhna, Oleh Faiziiev, Yuliia Gurova
The hydrolase-catalyzed kinetic resolution of fluorinated racemates of 3-arylcarboxylic acids is described. Hydrolysis of ethyl esters of fluorinated acids by esterases and hydrolases in all cases resulted in the formation of hydrolyzed (S)-carboxylic acids and unreacted (R)-esters in high yields and high enantiomeric purity. The influence of separation conditions on the efficiency and enantioselectivity of biocatalytic conversion was also studied. The reactions were carried out under normal conditions (stirring with a magnetic stirrer at room temperature) and microwave irradiation in the presence of hydrolases. Amano PS showed excellent selectivity and good yields in the hydrolysis of fluorinated aromatic compounds. The absolute configuration of the resulting compounds was based on biokinetic studies and the use of chiral HPLC. A molecular modeling of the kinetic resolution of carboxylic acid esters was carried out.
介绍了水解酶催化的 3-芳基羧酸氟化外消旋体的动力学解析。在所有情况下,酯酶和水解酶水解含氟酸的乙酯都能以高产率和高对映体纯度生成水解的(S)-羧酸和未反应的(R)-酯。此外,还研究了分离条件对生物催化转化效率和对映体选择性的影响。反应是在水解酶存在的正常条件(室温下用磁力搅拌器搅拌)和微波辐照下进行的。Amano PS 在水解含氟芳香族化合物时表现出优异的选择性和良好的产率。根据生物动力学研究和使用手性高效液相色谱法确定了所得化合物的绝对构型。对羧酸酯的动力学解析进行了分子建模。
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引用次数: 0
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