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Pandemic modeling with the game of life 用生命游戏制作大流行病模型
IF 0.9 4区 教育学 Q3 EDUCATION, SCIENTIFIC DISCIPLINES Pub Date : 2023-12-01 DOI: 10.1119/5.0166146
David Faux, Thesha Thavaraja, Alana Croucher
The generalized semi-classical game of life (gSCGOL) is a cellular automaton in which qubits evolve through repeated applications of birth, death, and survival operators. gSCGOL is used to model human–virus interactions during the COVID-19 pandemic by using cell “liveness” to be equivalent to the human population that is vulnerable to the disease. A match to the United Kingdom (UK) daily 7-day average COVID-19 deaths was achieved by daily changes to a parameter V representing the vulnerability of the population to the virus. The model predicts that the first COVID-19 virus entered the UK on December 22, 2019 with an uncertainty of ±1 days. The changes in the vulnerability V elucidate the human response to the unfolding pandemic during 2020, quantifying the impact of the lockdown, the relaxation of restrictions, and the opening and closing of schools. The model predicts that starting the first UK national lockdown one week earlier would have led to 40% fewer COVID-19-related deaths, equivalent to 17 000 lives.
广义半经典生命博弈(gSCGOL)是一个元胞自动机,其中量子比特通过重复应用出生、死亡和生存算子而进化。gSCGOL用于模拟COVID-19大流行期间人-病毒相互作用,方法是将细胞“活性”等同于易受疾病影响的人群。通过对代表人口对该病毒脆弱性的参数V进行每日更改,实现了与英国每日7天平均COVID-19死亡人数的匹配。该模型预测,首个COVID-19病毒于2019年12月22日进入英国,不确定性为±1天。脆弱性V的变化阐明了2020年期间人类对正在展开的大流行的反应,量化了封锁、放松限制以及学校开放和关闭的影响。该模型预测,提前一周开始英国第一次全国封锁将导致与covid -19相关的死亡人数减少40%,相当于1.7万人的生命。
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引用次数: 0
Molecular spectroscopy as a laboratory experiment: Measurement of important parameters of sodium diatomic molecules 作为实验室实验的分子光谱学:测量钠二原子分子的重要参数
IF 0.9 4区 教育学 Q3 EDUCATION, SCIENTIFIC DISCIPLINES Pub Date : 2023-12-01 DOI: 10.1119/5.0123126
Md Shakil Bin Kashem, Morgan Davies, Lok Pant, S. B. Bayram
We present an inexpensive sodium molecular spectroscopy experiment for use in an advanced undergraduate laboratory course in physics or chemistry. The molecules were excited predominantly from the ground X1Σg+(v″ = 15) state to the B1Πu(v′ = 6) state using a commercially available 532-nm broadband diode laser. The laser-induced molecular fluorescence was measured using a miniature fiber-coupled spectrometer at a resolution of 0.5 nm. The spectral peak assignments were done by comparing the observed spectrum with the calculated Franck–Condon values. Important molecular constants such as fundamental frequency, anharmonicity, bond strength, and dissociation energy of the ground electronic state were determined by using the Birge–Sponer extrapolation method. The presence of highly visible blue glowing molecules along the green laser beam creates an engaging laboratory experience. Emphasis is placed on students developing their understanding of the molecular structure, practicing molecular spectroscopic techniques, and applying knowledge of light–matter interactions to a physical system.
我们提出了一个廉价的钠分子光谱实验,用于物理或化学的高级本科实验课程。利用市售的532纳米宽带二极管激光器,将分子主要从地面X1Σg+(v″= 15)态激发到B1Πu(v ' = 6)态。采用分辨率为0.5 nm的微型光纤耦合光谱仪测量激光诱导的分子荧光。通过将观测光谱与计算的frank - condon值进行比较,确定了光谱峰的归属。利用Birge-Sponer外推法确定了重要的分子常数,如基态的基频、非谐波、键强度和离解能。沿着绿色激光束的高度可见的蓝色发光分子的存在创造了一种引人入胜的实验室体验。重点是培养学生对分子结构的理解,实践分子光谱技术,并将光与物质相互作用的知识应用于物理系统。
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引用次数: 0
Paediatric Parotid Abscess: A Rare Presentation. 小儿腮腺脓肿:罕见的表现。
IF 0.8 4区 教育学 Q3 EDUCATION, SCIENTIFIC DISCIPLINES Pub Date : 2023-12-01 Epub Date: 2023-07-06 DOI: 10.1007/s12070-023-04030-7
Sounak Patra, Sauradeep Das, Prachurya Tamuli, Suvamoy Chakraborty

Acute parotitis in children is a common occurrence with predisposing factors including ductal dysfunction, poor oral hygiene or dental infections, immunosuppression, dehydration, or a pre-existing Warthin's tumour. Bacterial or viral infections of the intra-parotid and peri-parotid lymph nodes or the parotid gland parenchyma results in inflammatory followed by suppurative changes which leads to formation of parotid abscess. Surgical drainage is necessary in parotid abscesses not responding to conservative management. Surgical intervention is invasive and has associated risks of injury to the facial nerve and poor cosmetic outcome. We present a case of parotid abscess in a 9-year-old female child which required surgical drainage. In literature, parotid gland abscess arising from a preceeding dental infection in paediatric age group is an uncommon occurence and limited number of cases have been documented. The first line of imaging is ultrasonographic examination of the parotid gland which adds on to the clinical examination. In combination with color doppler, sonography is of immense assistance for diagnosis and evaluation of therapeutic efficacy and also helps guide aspiration or incision and drainage.

儿童急性腮腺炎是一种常见的疾病,其诱发因素包括导管功能障碍、口腔卫生不良或牙齿感染、免疫抑制、脱水或先前存在的沃辛肿瘤。细菌或病毒感染的腮腺内和腮腺周围淋巴结或腮腺实质导致炎症,随后化脓性改变,导致腮腺脓肿的形成。对于保守治疗无效的腮腺脓肿,手术引流是必要的。手术干预是侵入性的,有损伤面神经和不良美容效果的相关风险。我们报告一个9岁女童腮腺脓肿的病例,需要手术引流。在文献中,由先前的牙齿感染引起的腮腺脓肿在儿科年龄组中是罕见的,并且记录的病例数量有限。第一道影像学检查是腮腺的超声检查,它是临床检查的补充。超声与彩色多普勒结合,对诊断和评价治疗效果有很大的帮助,也有助于指导抽吸或切开引流。
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引用次数: 0
Metastable states in a 1D quantum system 一维量子系统中的嬗变态
IF 0.9 4区 教育学 Q3 EDUCATION, SCIENTIFIC DISCIPLINES Pub Date : 2023-12-01 DOI: 10.1119/5.0124407
J. Goff, Don C. Colladay
One-dimensional (1D) systems in which metastable states exist are physically important, but they are usually not discussed quantitatively in textbooks. This paper presents a relatively simple 1D system involving a piecewise-constant potential for which metastable states can be easily calculated using a computer algebraic system. The metastable-state wave functions are computed and plotted for various particle energies. The Breit–Wigner approximation is used to fit the resulting resonant structure in the transmission coefficient. Connections are made between the initial analysis and poles of the scattering matrix that corresponds to the potential.
存在亚稳态的一维系统在物理上是重要的,但在教科书中通常没有进行定量讨论。本文提出了一个相对简单的一维系统,涉及一个分段常数势,它的亚稳态可以很容易地用计算机代数系统计算出来。计算并绘制了不同粒子能量的亚稳态波函数。采用Breit-Wigner近似来拟合透射系数中的谐振结构。在初始分析和对应于势的散射矩阵的极点之间建立了联系。
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引用次数: 0
Pendulum waves: A model of Thomae's function 钟摆波托马函数模型
IF 0.9 4区 教育学 Q3 EDUCATION, SCIENTIFIC DISCIPLINES Pub Date : 2023-12-01 DOI: 10.1119/5.0131936
Xiangdong Feng, Changhong Lu, Jurgen Schulte, Zengxu Shan, Gentong Liu
The pendulum wave apparatus exhibits cyclic pendulum patterns, including wave-like motion and pendulums alignments. This work presents a complete analytical solution to the times and numbers of pendulum alignment, which is shown to be a subset of Thomae's function. Based on the properties of this function and basic number theory, a comprehensive analysis of pendulum patterns is presented.
摆波装置表现出循环摆摆模式,包括波状运动和钟摆排列。本文给出了钟摆对准次数和次数的完整解析解,并证明了它是托马函数的一个子集。根据该函数的性质和基本数论,对摆型进行了全面的分析。
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引用次数: 0
Using lock-in detection to build a barcode scanner 使用锁定检测构建条形码扫描器
IF 0.9 4区 教育学 Q3 EDUCATION, SCIENTIFIC DISCIPLINES Pub Date : 2023-12-01 DOI: 10.1119/5.0151621
Riley E. Alexander, Maya M. DiFrischia, Margaret J. Doubman, Stefany Fabian Dubon, Lily Goltz, Yuqian Li, Rebecca A. Long, Genevieve Love, Nina Martinez Diers, Matangi Melpakkam, Catie Robinson, Elizabeth M. Tompkins, Avalon L. B. Vanis, Xinrui Wang, Mallory Yu, Sarah E. Spielman, Michael W. Noel
Lock-in detection is a widely used experimental technique in which a weak signal is measured by modulating it at a particular frequency. Then, by detecting an experimental output at that frequency, the desired signal can be isolated from much larger-amplitude noise. Here, we report on the implementation and optimization of a homemade laser barcode scanner based on the lock-in technique. Our setup is comprised of components that are readily available in an undergraduate instructional laboratory. The successful transcription of the barcode into a digital signal was achieved, and this digital signal was collected with a simple computer and processed to reveal the encoded number.
锁相检测是一种广泛使用的实验技术,通过在特定频率调制微弱信号来测量微弱信号。然后,通过检测该频率的实验输出,可以将所需的信号从更大幅度的噪声中分离出来。本文报道了一种基于锁定技术的自制激光条码扫描器的实现和优化。我们的设置是由组件组成,很容易在一个本科教学实验室。成功地将条形码转录成数字信号,然后用一台简单的计算机收集该数字信号并进行处理以显示编码的数字。
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引用次数: 0
Nonlinear oscillator acceleration and period variation with amplitude 非线性振荡器加速度和周期随振幅的变化
IF 0.9 4区 教育学 Q3 EDUCATION, SCIENTIFIC DISCIPLINES Pub Date : 2023-12-01 DOI: 10.1119/5.0139124
Peter F. Hinrichsen
A classic nonlinear spring mass oscillator, the nonlinearity of which could be varied by changing the initial stretching of the spring, was used to investigate how the amplitude dependence of the period and the harmonic content depended on the nonlinearity. The oscillations were measured with a photogate and a MEMS accelerometer, allowing both the oscillation period and the Fourier components of the motion to be precisely determined. The results were in good agreement with theory.
利用一个经典的非线性弹簧质量振子,研究了周期的幅值依赖性和谐波含量对非线性的依赖关系,该振子的非线性可以通过改变弹簧的初始拉伸量来改变。振荡用光门和MEMS加速度计测量,可以精确地确定振荡周期和运动的傅立叶分量。结果与理论很好地吻合。
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引用次数: 0
Comment on “Avoid propagation of typos with numerical methods” [Am. J. Phys. 89(1), 9 (2021)] 关于 "用数值方法避免错别字传播 "的评论 [Am. J. Phys. 89(1), 9 (2021)]
IF 0.9 4区 教育学 Q3 EDUCATION, SCIENTIFIC DISCIPLINES Pub Date : 2023-12-01 DOI: 10.1119/5.0167881
B. C. Reed
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引用次数: 0
S-matrices for simple quantum systems 简单量子系统的s矩阵
4区 教育学 Q3 EDUCATION, SCIENTIFIC DISCIPLINES Pub Date : 2023-11-01 DOI: 10.1119/5.0078607
Leo de Wit
Scattering processes are a standard topic covered in introductory courses on quantum mechanics and particle physics. Unfortunately, a full mathematical treatment tends to be overwhelming for undergraduate students. This article introduces some toy models that are easy to comprehend but still contain the essential features of quantum theory. We define a Hilbert space with state vectors and use creation/annihilation operators to construct transition matrices and S-matrices. We show how perturbation theory gives rise to Feynman diagrams and Feynman rules. We also discuss how we can use symmetry and group theory to restrict what interactions are possible.
散射过程是量子力学和粒子物理入门课程中的一个标准主题。不幸的是,一个完整的数学处理往往是压倒性的本科生。本文介绍了一些易于理解但仍包含量子理论基本特征的玩具模型。我们定义了一个具有状态向量的Hilbert空间,并使用产生/湮灭算子构造了转移矩阵和s矩阵。我们展示了摄动理论如何产生费曼图和费曼规则。我们还讨论了如何使用对称性和群论来限制可能的相互作用。
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引用次数: 0
Oblique angle collisions between three or more billiard balls 三个或更多台球之间的斜角碰撞
4区 教育学 Q3 EDUCATION, SCIENTIFIC DISCIPLINES Pub Date : 2023-11-01 DOI: 10.1119/5.0119656
Rod Cross
Oblique angle collisions between two balls or two disks have been addressed by many authors. This paper describes oblique angle collisions between three or four billiard balls. Measurements and calculations are presented for cases where one ball is incident obliquely on two or three identical balls, which are in contact and initially at rest. Conservation laws alone are not sufficient to predict the outcome. Adding information about the impact forces on each ball (and ignoring friction forces) provides good theoretical agreement with experimental results.
两个球或两个盘之间的斜角碰撞已被许多作者解决。本文描述了三个或四个台球之间的斜角碰撞。给出了一个球斜入射到两个或三个相同的球上的测量和计算,这两个球接触并最初处于静止状态。仅靠守恒定律不足以预测结果。加入关于每个球的冲击力的信息(忽略摩擦力)提供了与实验结果良好的理论一致性。
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American Journal of Physics
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