Brazilian Journal of Physics最新文献_第10页

Relation Between Electron Yield and Temperature: Exploring a Novel Route to Measure the Nanoscale Temperature 电子产率与温度的关系:探索纳米尺度温度测量的新途径

IF 1.6 4区物理与天体物理

Brazilian Journal of Physics Pub Date : 2023-03-08 DOI: 10.1007/s13538-023-01280-2

Peng Zhang, Zhiyao Ma, Dengmei Li

{"title":"Relation Between Electron Yield and Temperature: Exploring a Novel Route to Measure the Nanoscale Temperature","authors":"Peng Zhang, Zhiyao Ma, Dengmei Li","doi":"10.1007/s13538-023-01280-2","DOIUrl":"10.1007/s13538-023-01280-2","url":null,"abstract":"<div><p>Scanning electron microscope (SEM) is widely used in imaging rather than for thermometry. Here, the temperature-dependent electron emission for four different semi-infinite materials (beryllium (Be), magnesium (Mg), copper (Cu) and gold (Au)) was investigated through a simulation approach. Various electron yields (secondary electron (SE), backscattering electron (BSE) and total electron (TE)) were recorded with different temperatures of samples at various primary electron (PE) energies. It was found that the temperature-dependent electron yield curve varies with the atomic number and the PE energy. Possible mechanisms were systematically analyzed based on the theory of electron-solid interaction. In addition, this work also investigates the temperature effect on the system of one Be nanosphere (Be-NS) and one Au nanosphere (Au-NS) on a Be substrate. The temperature-dependent electron emission on this system presents obvious differences between that in these semi-infinite materials. This work poses a potential possibility of measuring the nanoscale temperature through acquiring the temperature-dependent electron yield by a standard SEM.</p></div>","PeriodicalId":499,"journal":{"name":"Brazilian Journal of Physics","volume":"53 3","pages":""},"PeriodicalIF":1.6,"publicationDate":"2023-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4349582","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Invertibility as a Witness of Markovianity of the Quantum Dynamical Maps 可逆性作为量子动力映射马尔可夫性的证明

IF 1.6 4区物理与天体物理

Brazilian Journal of Physics Pub Date : 2023-03-07 DOI: 10.1007/s13538-023-01274-0

Jasmina Jeknić-Dugić, Momir Arsenijević, Miroljub Dugić

引用次数: 2

Biomedical Image Encryption with a Novel Memristive Chua Oscillator Embedded in a Microcontroller 一种嵌入微控制器的新型记忆蔡氏振荡器的生物医学图像加密

IF 1.6 4区物理与天体物理

Brazilian Journal of Physics Pub Date : 2023-03-03 DOI: 10.1007/s13538-023-01268-y

Gabin Jeatsa Kitio, Alain Djomo Fanda, Idriss Rochinel Kemlenack Feulefack, Justin Roger Mboupda Pone, Romanic Kengne, Alain Tiedeu

{"title":"Biomedical Image Encryption with a Novel Memristive Chua Oscillator Embedded in a Microcontroller","authors":"Gabin Jeatsa Kitio, Alain Djomo Fanda, Idriss Rochinel Kemlenack Feulefack, Justin Roger Mboupda Pone, Romanic Kengne, Alain Tiedeu","doi":"10.1007/s13538-023-01268-y","DOIUrl":"10.1007/s13538-023-01268-y","url":null,"abstract":"<div><p>In this paper, a chaos-based encryption/decryption scheme using a novel memristive Chua oscillator to protect medical images is presented. The novel Chua oscillator is constructed by using the active voltage memristor in the nonlinear branch of the Chua oscillator. The chaotic dynamics behaviors are investigated using 1-D, 2-D bifurcation diagrams, time traces, basin of attractions, and largest Lyapunov exponent plot. The study reveals that the novel memristive Chua oscillator exhibits versatile transitions to chaos with interesting dynamics like multistability, spiking, and bursting oscillations just to name a few. These remarkable features are experimentally confirmed by a laboratory microcontroller-based setup. Thereafter, a chaos-based cryptography algorithm designed for biomedical images is built using pseudorandom number generated from the oscillator. The robustness and security tests undergone by the algorithm yielded high sensitivity on the encryption keys and resisted noise contamination as well as data loss. These results are encouraging and prove that the chaos-based cryptosystem built with the memristive Chua circuit–generated pseudorandom number is suitable for securing images in a healthcare system.</p></div>","PeriodicalId":499,"journal":{"name":"Brazilian Journal of Physics","volume":"53 3","pages":""},"PeriodicalIF":1.6,"publicationDate":"2023-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4132918","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Influence of the Director-Density Coupling on the Orientational Dynamics in the Isotropic Phase of Nematic Liquid Crystals 向列相液晶各向同性相中Director-Density耦合对取向动力学的影响

IF 1.6 4区物理与天体物理

Brazilian Journal of Physics Pub Date : 2023-03-03 DOI: 10.1007/s13538-023-01276-y

Carlindo Vitoriano

{"title":"Influence of the Director-Density Coupling on the Orientational Dynamics in the Isotropic Phase of Nematic Liquid Crystals","authors":"Carlindo Vitoriano","doi":"10.1007/s13538-023-01276-y","DOIUrl":"10.1007/s13538-023-01276-y","url":null,"abstract":"<div><p>The dynamics of how the order parameter <span>(Q_{alpha beta })</span> of the nematic-isotropic phase transition relaxes to zero in the isotropic phase is divided into two time scales, one slow and the other fast. The slow time scale is associated to the final portion of the curve <i>G</i>(<i>t</i>), the orientational correlation function, which decays exponentially in accordance with the Landau-de Gennes prediction. The initial portion of the curve <i>G</i>(<i>t</i>), on the other side, exhibits a power-law decay given by <span>(t^{-alpha })</span>, where <span>(alpha)</span> is a temperature-independent exponent. In contrast to the slow dynamics, the fast one is yet barely understood. In this paper, a new approach for the nematodynamics in the isotropic phase is developed in order to include an energetic coupling between mass density gradients and <span>(Q_{alpha beta })</span>. The important result here is the appearance of a new viscosity parameter <span>(zeta ')</span> that is crucial to derive the power-law behavior of <i>G</i>(<i>t</i>). We also explain why the fast dynamics is strongly coupled with density fluctuations and dominated by large momentum contributions.</p></div>","PeriodicalId":499,"journal":{"name":"Brazilian Journal of Physics","volume":"53 3","pages":""},"PeriodicalIF":1.6,"publicationDate":"2023-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s13538-023-01276-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4132919","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Refinement of the Crystal Structure of Low-Carbon Polycrystalline AISI 420 Martensitic Steel (C = 0.15%) 低碳多晶AISI 420马氏体钢(C = 0.15%)晶体结构的细化

IF 1.6 4区物理与天体物理

Brazilian Journal of Physics Pub Date : 2023-03-03 DOI: 10.1007/s13538-023-01269-x

Vinicius Danilo Nonato Bezzon, Mariane Gonçalves de Miranda Salustre, Julia Boni Vaneli, Alex Arbey Lopera Sepúlveda, Elson Silva Galvão, Marcos Tadeu D´Azeredo Orlando

引用次数: 0

Transmission Dynamics of COVID-19 with Saturated Treatment: A Case Study of Spain 饱和处理下新冠肺炎传播动态——以西班牙为例

IF 1.6 4区物理与天体物理

Brazilian Journal of Physics Pub Date : 2023-02-28 DOI: 10.1007/s13538-023-01267-z

Jayanta Kumar Ghosh, Pritam Saha, Md Kamrujjaman, Uttam Ghosh

{"title":"Transmission Dynamics of COVID-19 with Saturated Treatment: A Case Study of Spain","authors":"Jayanta Kumar Ghosh, Pritam Saha, Md Kamrujjaman, Uttam Ghosh","doi":"10.1007/s13538-023-01267-z","DOIUrl":"10.1007/s13538-023-01267-z","url":null,"abstract":"<div><p>In this paper, an epidemic compartmental model with saturated type treatment function is presented to investigate the transmission dynamics of COVID-19 with a case study of Spain (in Europe). We obtain the basic reproduction number of the model which plays a very important role in disease spreading. We show that if the basic reproduction number is less than unity then the disease-free equilibrium point is locally asymptotically stable, but making the basic reproduction number less than unity is not sufficient to eradicate COVID-19 infection which is shown through backward bifurcation. The model is validated with the real COVID-19 data of Spain (in Europe), Algeria (in Africa), and India (in Asia) and also estimated important model parameters in all cases. The effect of an important model parameter for controlling the disease spreading is also investigated for the infection scenario of Spain only. We establish that the asymptomatic class plays a very important role for spreading this pandemic disease. The effective reproduction number has been estimated which varies in time in Spain. Finally, the model is reformulated as an optimal control problem which shows that the social distancing due to adapting a partial lockdown by some countries is highly effective for controlling COVID-19.</p></div>","PeriodicalId":499,"journal":{"name":"Brazilian Journal of Physics","volume":"53 3","pages":""},"PeriodicalIF":1.6,"publicationDate":"2023-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5075976","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Cold Plasma as a Competent Approach to Treat Solid Fiber of Ichnocarpus frutescens: PIXE, XRD, Raman, FT-IR, and SEM Analysis 冷等离子体作为处理石竹固体纤维的有效方法:PIXE, XRD, Raman, FT-IR和SEM分析

IF 1.6 4区物理与天体物理

Brazilian Journal of Physics Pub Date : 2023-02-17 DOI: 10.1007/s13538-023-01256-2

Subrajeet Rout, Biswajit Mallick, Chhatrapati Parida

{"title":"Cold Plasma as a Competent Approach to Treat Solid Fiber of Ichnocarpus frutescens: PIXE, XRD, Raman, FT-IR, and SEM Analysis","authors":"Subrajeet Rout, Biswajit Mallick, Chhatrapati Parida","doi":"10.1007/s13538-023-01256-2","DOIUrl":"10.1007/s13538-023-01256-2","url":null,"abstract":"<div><p>The impact of cold air plasma on cellulosic Ichnocarpus frutescens is investigated, with varied irradiation periods of 1.5, 3, and 4.5 min, at 1 kV. Before plasma irradiation, the IFS fiber was extracted from the plant’s stem using 4% dil. NaOH solution. The impact of plasma irradiation on fibers was evaluated using PIXE, XRD, Raman, FT-IR, and SEM. Proton-induced X-ray emission (PIXE) analysis reveals that IFS fiber holds Si, S, P, Cl, K, Ca, Sc, Ti, V, Mn, Fe, Cu, and Zn, each with unique therapeutic qualities. The high concentrations of K, Ca, and Sc were estimated to be 419,310 ± 488, 256,665 ± 2408, and 363,210 ± 423 ppm, respectively, exploring applications in biomedical terrain. XRD analysis revealed the increase in the percentage of crystalline when IFS fiber was irradiated with cold plasma for 1.5 min. However, with an increase in the irradiation time, the percentage of crystalline decreases. The values of microstrain, FWHM, crystallite size, azimuth angle, and helix angle were evaluated for each irradiated IFS sample and the change in these parameters indicates molecular interaction between IFS fiber and plasma. Presence of amide (R-NH<sub>2</sub>), halogens, hydrocarbons, and carbonyl groups in the plasma-exposed IFS fiber were established from FT-IR and Raman spectra. The presence of amine (NH<sub>2</sub>) and nitrile (NO<sub>3</sub>) groups indicates the molecular interaction of plasma with IFS fiber. SEM of both pristine and plasma-irradiated IFS fiber revealed the presence of defects caused by irradiation. The results will aid in utilizing IFS fiber as potential reinforcement in composite materials.</p></div>","PeriodicalId":499,"journal":{"name":"Brazilian Journal of Physics","volume":"53 2","pages":""},"PeriodicalIF":1.6,"publicationDate":"2023-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s13538-023-01256-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4971206","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A Fractal Model with Biological Significance for the Scaling Linguistic Diversity-Area 一种具有生物学意义的分形语言多样性区域尺度模型

IF 1.6 4区物理与天体物理

Brazilian Journal of Physics Pub Date : 2023-02-14 DOI: 10.1007/s13538-023-01263-3

M. R. F. Santos, M. A. F. Gomes

引用次数: 0

Properties of (Glass, Pb)/MgSe Interfaces Designed as Terahertz Band Filters 太赫兹滤波器(玻璃，铅)/MgSe界面特性研究

IF 1.6 4区物理与天体物理

Brazilian Journal of Physics Pub Date : 2023-02-11 DOI: 10.1007/s13538-023-01260-6

A. F. Qasrawi, Lara O. Abu Samen, Samah S. Atari

{"title":"Properties of (Glass, Pb)/MgSe Interfaces Designed as Terahertz Band Filters","authors":"A. F. Qasrawi, Lara O. Abu Samen, Samah S. Atari","doi":"10.1007/s13538-023-01260-6","DOIUrl":"10.1007/s13538-023-01260-6","url":null,"abstract":"<div><p>Herein, thin films of MgSe (300 nm) are deposited onto glass and semitransparent Pb (150 nm) substrates by the thermal evaporation technique under a vacuum pressure of 10<sup>−5</sup> mbar. The films are structurally, morphologically, compositionally, and optically characterized. It is found that Pb substrates induced the formation of single phase of MgSe against a mixture of MgSe and MgSe<sub>2</sub>. Lead substrates improved the light absorbability in the infrared (IR) range of light. Pb substrates also red-shifted and blue-shifted the direct and indirect band gap of MgSe by 0.62 eV and 0.10 eV, respectively. The dielectric dispersion analyses have shown that Pb substrates are more effective in the visible and IR ranges of light. When Pb/MgSe films are treated as band filters, they showed wide range of tunability of the terahertz cutoff frequency. The Pb/MgSe interfaces are found good candidates as terahertz band filters sensitive to IR-850 nm lasers which are used in communication technology. Optical oscillators of this wavelength performed within scattering time of 0.50 fs and exhibited drift mobility of 4.69 cm<sup>2</sup>/Vs. In addition, Drude-Lorentz analyses which targeted finding optoelectronic information about Pb/MgSe have shown the ability of using Pb/MgSe interfaces in thin film transistors, ultraviolet photo-detection, and terahertz technologies.\u0000</p></div>","PeriodicalId":499,"journal":{"name":"Brazilian Journal of Physics","volume":"53 2","pages":""},"PeriodicalIF":1.6,"publicationDate":"2023-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4754026","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Photothermal Antibacterial Activity of Gold Nanorods Stabilized by Phospholipid 磷脂稳定金纳米棒光热抗菌活性研究

IF 1.6 4区物理与天体物理

Brazilian Journal of Physics Pub Date : 2023-02-09 DOI: 10.1007/s13538-023-01265-1

Hasan Hamedani, Hasan Kariminezhad, Hossein Amani

{"title":"Photothermal Antibacterial Activity of Gold Nanorods Stabilized by Phospholipid","authors":"Hasan Hamedani, Hasan Kariminezhad, Hossein Amani","doi":"10.1007/s13538-023-01265-1","DOIUrl":"10.1007/s13538-023-01265-1","url":null,"abstract":"<div><h2>Abstract\u0000</h2><div><p>In this paper, thermal stability of phospholipid-decorated gold nanorods and their photothermal activity against <i>Staphylococcus epidermidis</i> were experimentally studied. For this aim, cetyl trimethyl ammonium bromide (CTAB) stabilized gold nanostructures were first synthesized, and then the chemical bilayers were exchanged with phospholipid (DMPC). The effects of this replacement on the shape and spectral properties of gold nanorods were analyzed by UV–vis and FTIR as well as transmission electron microscopy (TEM). In addition, thermal heating at 95 ± 2 °C caused CTAB-decorated gold nanorods to decompose in less than half an hour, whereas the phospholipid-modified gold nanorods maintained their spectral characteristics for up to 5 h. Furthermore, while the minimum inhibitory concentration (MIC) for CTAB-AuNRs was obtained equal to 5 μg/ml, DMPC-AuNRs did not indicate significant toxicity in concentrations below 20 μg/ml. The photothermal-induced bactericidal activity of DMPC-gold nanorods was investigated through illumination by a laser with the wavelength of 808 nm. It was demonstrated that treating <i>Staphylococcus epidermidis</i> with the nontoxic concentration of phospholipid-stabilized gold nanorod suspension followed by the laser beam exposure for 15 min resulted in a 4.6 log reduction in the bacterial viable count.</p></div></div>","PeriodicalId":499,"journal":{"name":"Brazilian Journal of Physics","volume":"53 2","pages":""},"PeriodicalIF":1.6,"publicationDate":"2023-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4376978","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1