Zeitschrift für Naturforschung A最新文献_第9页

Red-emitting phosphors of BaSr2(PO4)2: 4 %Eu3+, 4 %A (A = Li+, Na+, K+) for white LEDs 白光led用BaSr2(PO4) 2:4 %Eu3+， 4 %A (A = Li+， Na+， K+)的红发荧光粉

Zeitschrift für Naturforschung A Pub Date : 2023-07-18 DOI: 10.1515/zna-2023-0102

Cong Liu, Junshen Xing, Zheng Liu, Wenlin Feng

引用次数: 0

Dynamics and synchronization of a novel 4D-hyperjerk autonomous chaotic system with a Van der Pol nonlinearity 具有Van der Pol非线性的新型4d超跳自主混沌系统的动力学与同步

Zeitschrift für Naturforschung A Pub Date : 2023-07-18 DOI: 10.1515/zna-2023-0063

R. Kengne, J. T. Mbé, Janvier Fotsing, A. Mezatio, Francine July Ntsafack Manekeng, R. Tchitnga

{"title":"Dynamics and synchronization of a novel 4D-hyperjerk autonomous chaotic system with a Van der Pol nonlinearity","authors":"R. Kengne, J. T. Mbé, Janvier Fotsing, A. Mezatio, Francine July Ntsafack Manekeng, R. Tchitnga","doi":"10.1515/zna-2023-0063","DOIUrl":"https://doi.org/10.1515/zna-2023-0063","url":null,"abstract":"Abstract In the literature, hyperjerk systems raised up meaningful interest due to their simple and elegant structure as well as their complex dynamical features. In this work, we propose a novel 4D autonomous hyperjerk system which the particularity resides on the type of its nonlinearity namely the Van der Pol nonlinearity. The dynamics of this hyperjerk system is assessed thanks to the well-known nonlinear dynamic tools such as time series, bifurcation diagrams, Lyapunov exponent spectrum, two-parameter phase diagram, and phase portraits. As important result, it is established that the system presents a particular phenomenon of hysteretic dynamics that leads to the coexistence of attractors. Next, through the calculation of the Hamiltonian energy, we show that this latter depends on all the variables of the novel hyperjerk system. Furthermore, basing on an adaptive backstepping method whose target is a function of the states of the error system, a new controller is designed to carry out from t = 30, complete chaotic synchronization of the identical novel hyperjerk chaotic systems. Likewise, PSpice (9.2 full version) based simulations are presented in detail to confirm the feasibility of the theoretical model. One of the key points of this work is the designing in PSpice environment of this new adaptive backstepping controller to validate both theoretical and numerical synchronization results. Finally, our experimental measurements in the laboratory are in good agreement with the numerical and analog results.","PeriodicalId":23871,"journal":{"name":"Zeitschrift für Naturforschung A","volume":"20 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84817361","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Trident-shaped monopole antenna with p-methoxy-benzylidene-p-n-butyl aniline (MBBA) nematic liquid crystal (NLC) for C- and X-band applications 三叉戟形单极天线，采用对甲氧基苄基-对正丁基苯胺(MBBA)向列液晶(NLC)，适用于C波段和x波段

Zeitschrift für Naturforschung A Pub Date : 2023-07-13 DOI: 10.1515/zna-2023-0069

Nagandla Prasad, P. Pardhasaradhi, B. Madhav, Rama Krishna Nanchara Rao Manepalli

{"title":"Trident-shaped monopole antenna with p-methoxy-benzylidene-p-n-butyl aniline (MBBA) nematic liquid crystal (NLC) for C- and X-band applications","authors":"Nagandla Prasad, P. Pardhasaradhi, B. Madhav, Rama Krishna Nanchara Rao Manepalli","doi":"10.1515/zna-2023-0069","DOIUrl":"https://doi.org/10.1515/zna-2023-0069","url":null,"abstract":"Abstract In this research article, a novel MBBA nematic liquid crystal (NLC) based circular trident-shaped antenna is proposed for both C-band and X-band microwave applications. The proposed antenna contains a trident-shaped radiating patch, which is made of copper material, and glass material is utilized as a dielectric substrate for the proposed novel MBBA-based trident shaped antenna. The dielectric substrate contains two glass plates with a thickness of 1 mm each and is separated by an air gap of 0.003 mm to fill MBBA nematic liquid crystal. So, the overall size of the proposed antenna will become 15 × 20 × 2.003 mm3. The dielectric constant of each glass plate is chosen as 5.438. However, the antenna operates at a single frequency band, when MBBA material is not present between the glass plates and produces two distinct resonant frequencies when the air gap between the glass plates is filled with MBBA NLC. Antenna radiation parameters such as gain, radiation efficiency, reflection coefficient, and radiation patterns are compared for both simulation and measurement.","PeriodicalId":23871,"journal":{"name":"Zeitschrift für Naturforschung A","volume":"44 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79028581","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Optimal system of solution using group invariance technique for shock wave in a non-ideal self-gravitating gas in rotating medium in presence of magnetic field 用群不变性技术求解磁场作用下旋转介质中非理想自重力气体激波的最优系统

Zeitschrift für Naturforschung A Pub Date : 2023-07-11 DOI: 10.1515/zna-2023-0026

G. Nath, Abhaysingh A. Maurya

{"title":"Optimal system of solution using group invariance technique for shock wave in a non-ideal self-gravitating gas in rotating medium in presence of magnetic field","authors":"G. Nath, Abhaysingh A. Maurya","doi":"10.1515/zna-2023-0026","DOIUrl":"https://doi.org/10.1515/zna-2023-0026","url":null,"abstract":"Abstract This work demonstrates the study of the optimal system of solutions for shock wave propagation in a non-ideal self-gravitating gas in rotating medium with magnetic field (axial or azimuthal) for the adiabatic flow in cylindrical geometry by applying the group invariance technique. Using the group invariance technique, we have obtained the one-dimensional (1-D) optimal system of sub-algebra for the basic governing equations. The infinitesimal group optimal classes are obtained and the similarity solution in four possible cases (two cases for perfect gas and two cases for non-ideal gas) with exponential law shock path are discussed. The numerical solution by using the Runge Kutta 4th order method is obtained and the distribution of physical variables are shown via graph. The impact of the rotational parameter, non-idealness parameter, shock Cowling number, similarity exponent and gravitational parameter on the strength of the shock and flow variables are investigated. With an increase in the shock Cowling number, non-idealness and rotational parameters, the shock strength decreases, i.e., they have decaying impact on shock wave; whereas the shock strength increases with gravitational parameter and similarity exponent. Also, the strength of the shock is reduced by considering the magnetic field to be axial instead of azimuthal.","PeriodicalId":23871,"journal":{"name":"Zeitschrift für Naturforschung A","volume":"156 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76797769","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The effect of magnetized quantum plasma on Jeans instability 磁化量子等离子体对Jeans不稳定性的影响

Zeitschrift für Naturforschung A Pub Date : 2023-07-07 DOI: 10.1515/zna-2023-0084

A. Patidar, Hemlata Joshi, Sonali Patidar, R. Pensia, Shaheen Mansuri

引用次数: 0

Design of blood plasma concentrations sensor based on a one-dimensional photonic crystal 基于一维光子晶体的血浆浓度传感器设计

Zeitschrift für Naturforschung A Pub Date : 2023-07-04 DOI: 10.1515/zna-2023-0106

F. Segovia-Chaves, Santiago Santos Beltrán, H. Vinck-Posada

引用次数: 0

Some versions of Chaplygin gas model in modified gravity framework and validity of generalized second law of thermodynamics 修正重力框架下Chaplygin气体模型的几个版本及广义热力学第二定律的有效性

Zeitschrift für Naturforschung A Pub Date : 2023-07-03 DOI: 10.1515/zna-2023-0085

Sanjeeda Sultana, E. Güdekli, S. Chattopadhyay

引用次数: 0

Excitation wavelength altered PL study of Co doped ZnO nanoparticles suitable for white LED application 适合白光LED应用的Co掺杂ZnO纳米粒子激发波长改变PL的研究

Zeitschrift für Naturforschung A Pub Date : 2023-06-30 DOI: 10.1515/zna-2023-0008

N. Lavanya, N. Deepak

{"title":"Excitation wavelength altered PL study of Co doped ZnO nanoparticles suitable for white LED application","authors":"N. Lavanya, N. Deepak","doi":"10.1515/zna-2023-0008","DOIUrl":"https://doi.org/10.1515/zna-2023-0008","url":null,"abstract":"Abstract ZnO nanoparticles doped with Co at different concentration (Zn1−xCo x O) were synthesized by sol–gel auto combustion method and are characterized by using various characterization tools. Structural study using X-ray diffraction technique (XRD) analysis showed the crystalline nature with hexagonal wurtzite geometry and the composition analysis using energy dispersive X-ray spectroscopy (EDX) confirmed the incorporation of Co in the ZnO lattice in the case of doped nanoparticles. Scanning electron-microscopy (SEM) and transmission electron microscopy (TEM) analysis showed the prepared nanoparticles as spherical, loosely agglomerated and having dimension of nanoscale. UV–vis DRS studies indicated a red shift in optical band gap with Co doping. PL spectra exhibits emission in the UV and visible region and the analysis revealed information about the presence of various types of defects in the ZnO lattice. An increase in the excitation wavelength gives intense emission in the high wavelength region for doped nanoparticles confirming the presence of divalent and monovalent oxygen as main defects. The Zn0.93Co0.07O nanoparticles records CIE coordinates lying in the white region of CIE color space at 350 nm with CCT of 5561.4 K suggesting their suitability in fabrication of white light emitting diodes.","PeriodicalId":23871,"journal":{"name":"Zeitschrift für Naturforschung A","volume":"12 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73281904","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Specific features of electromagnetic waves in degenerate two stream electron-ion plasma: self-induced magnetic field 简并两流电子-离子等离子体中电磁波的特殊特征:自感磁场

Zeitschrift für Naturforschung A Pub Date : 2023-06-26 DOI: 10.1515/zna-2023-0009

C. Rozina, M. Pervaiz, Z. Iqbal, Nourina Nadeem

{"title":"Specific features of electromagnetic waves in degenerate two stream electron-ion plasma: self-induced magnetic field","authors":"C. Rozina, M. Pervaiz, Z. Iqbal, Nourina Nadeem","doi":"10.1515/zna-2023-0009","DOIUrl":"https://doi.org/10.1515/zna-2023-0009","url":null,"abstract":"Abstract Generation and amplification of magnetic fields is a subject of interest to both laboratory and astrophysical plasmas. The counter-streaming instability or Weibel instability is a mechanism responsible for self-generating magnetic fields in plasmas. In this paper, we investigate that the non-stationary ponderomotive force of a large amplitude electromagnetic wave (EMWs) propagating through dense two stream quantum electron ion plasma, may lead to the generation of d.c. magnetic fields. It is shown that degeneracy parameters, specifically the exchange correlation potential and Fermi pressure can reduce/control the self-induced magnetic field. Next the linear propagation of EMWs through plasma under consideration has also been considered in the presence of exchange correlation potential along with other quantum effects. Linear dispersion relation, the instability conditions and growth rate have been derived. It is found that the degeneracy parameters stabilize the propagation of instability and lead to reduction of the exponentially growing magnetic field. Threshold scale length of EMWs is also obtained for the stable propagation. The present result may be account helpful to understand the seed magnetic fields in dense plasmas.","PeriodicalId":23871,"journal":{"name":"Zeitschrift für Naturforschung A","volume":"49 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77954660","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Modelling of the porous medium flow with pressure-dependent viscosity and drag coefficient 具有压力相关黏度和阻力系数的多孔介质流动模型

Zeitschrift für Naturforschung A Pub Date : 2023-06-26 DOI: 10.1515/zna-2023-0109

E. Marušić‐Paloka, Igor Pažanin

引用次数: 0