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A Generalized Array Factor for Time-Modulated Hexagonal Based Antenna Array Geometry With Novel Trapezoidal

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IEEE/CAA Journal of Automatica Sinica 2024年第9期11卷 1967-1972页

作者： Gopi ram Department of Electronics and Communication Engineering National Institute of TechnologyWarangal 506004India

The concept of the time-modulated array has been emerging as an alternative to the complex phase shifters,which lowers the cost of the array feeding network due to the utilization of radio frequency(RF)*** various forms of hexagonal antenna array geometries can be used for applications like surveillance tracking in phased array radar and wireless communication *** work proposes the generalized array factor(AF)for the hexagonal antenna array geometry based on time *** time modulation in generalized hexagonal geometry can maintain the fixed static amplitude excitation,giving more flexibility over ***,a novel trapezoidal switching function is also proposed and applied to the generalized array factor to enable future researchers to use this array factor in the field of advancement to observe how switching schemes like trapezoidal and rectangular affect the array pattern's side lobe level(SLL).The generalized equation can be utilized for the analysis and synthesis of radiation characteristics of the time-modulated hexagonal array(TMHA),time-modulated concentric hexagonal array(TMCHA),time-modulated hexagonal cylindrical array(TMHCA),and time-modulated hexagonal concentric cylindrical array(TMHCCA).The numerical result illustrates the generation of AF of time-modulated hexagonal structures and also shows that the trapezoidal switching sequence outperforms the rectangular switch using the cat swarm optimization(CSO)approach.

关键词： Hexagonal array geometry radiation pattern time-modulation trapezoidal pulse

Solution of the Center Problem for a Class of Polynomial Differential Systems

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Acta Mathematica Sinica,English Series 2024年第7期40卷 1685-1696页

作者： Chang Jian Liu Jaume Llibre Rafael ramírez Valentín ramírez School of Mathematics(Zhuhai) Sun Yat-sen UniversityZhuhai519086P.R.China Departament de Matemàtiques Universitat Autònoma de Barcelona08193BellaterraBarcelonaCataloniaSpain Departament d’Enginyeria Informàtica i Matemàtiques Universitat Rovira i VirgiliAvinguda dels Paiïsos Catalans 2643007TarragonaCataloniaSpain

Consider the polynomial differential system of degree m of the form x=-y(1+μ(a_(2)x-a_(1)y))+x(v(a_(1)x+a_(2)y)+Ω_(m-1)(x,y)),y=x(1+μ(a_(2)x-a_(1)y))+y(v(a_(1)x+a_(2)y)+Ω_(m-1)(x,y)),whereμandνare real numbers such that(μ^(2)+v^(2))(μ+v(m-2))(a_(1)^(2)+a_(2)^(2))≠m>2 andΩ_(m−1)(x,y)is a homogenous polynomial of degree m−1.A conjecture,stated in *** Equations 2019,suggests that whenν=1,this differential system has a weak center at the origin if and only if after a convenient linear change of variable(x,y)→(X,Y)the system is invariant under the transformation(X,Y,t)→(−X,Y,−t).For every degree m we prove the extension of this conjecture to any value ofνexcept for a finite set of values ofμ.

关键词： Center problem polynomial differential system

Seedling potential of trees species along the elevational gradient in temperate hill forest of central Nepal

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Journal of Mountain Science 2024年第4期21卷 1329-1344页

作者： DANI ram Sharan BANIYA Chitra Bahadur Central Department of botany Tribhuvan UniversityKirtipur 44618Nepal

Regeneration status of tree species along elevation gradient in temperate hill forest was not understood *** research examined the tree diversity and its regeneration patterns along an elevation gradient in temperate hill forest,central *** were collected from 300 sample plots within vertical elevation bands of 10,ranging from 1365 to 2450 m asl.A random sampling method was used for data collection in three seasons,winter,pre-monsoon and post monsoon *** at breast height(DBH)was used to broadly categorize the plant individual into trees,saplings and *** tree species richness ranged from 12 to 25 with density of 350 to 1200 individuals per *** richness of tree and sapling showed statistically significant unimodal pattern,which peaked at *** showed a strong and positive linear correlation with the seedling density(Deviance=0.99,pseedling(10.6%)≤mature(10.9%).Among tested environmental variables,elevation and annual mean rainfall were the most influential factors in the regeneration of tree species.

关键词： Regeneration potential Chandragiri hill Altitudinal gradient Species diversity Tree species richness

Development of novel 5-FU modified siRNA against BCL-2 with enhanced efficacy and vehicle-free cellular uptake

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Genes & Diseases 2024年第1期11卷 23-25页

作者： Andrew Fesler Ga-ram Hwang Jingfang Ju Department of Pathology Renaissance School of MedicineStony Brook UniversityStony BrookNY 11794USA The Northport Veteran's Administration Medical Center NorthportNY 11768USA Curamir Therapeutics Inc. WoburnMA 01801USA

One of the major obstacles for nucleic acid-based medicine is cellular uptake due to the concern of efficiencyand potential toxicity of the *** this work,we developed a novel approach to eliminate the need for a vehicle to allow for the cellular uptake of siRNA-based therapy with a unique modification strategy that also further enhances therapeutic *** discovery may be of great importance for the development of siRNA-based therapeutics as cellular uptake remains a critical *** this study,we have tested the potential of this modification strategy for siRNA using a siRNA that targets B-cell lymphoma-2(BCL-2).

关键词： eliminate uptake modified

Gluing Affine Vortices

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Acta Mathematica Sinica,English Series 2024年第1期40卷 250-312页

作者： Guang bo XU Department of Mathematics Rutgers UniversityHill Center-Busch Campus 110 Frelinghuysen RoadPiscatawayNJ 08854-8019USA

We provide an analytical construction of the gluing map for stable affine vortices over the upper half plane with the Lagrangian boundary *** result is a necessary ingredient in studies of the relation between gauged ... 详细信息

关键词： Affine vortices gauged linear sigma model adiabatic limit symplectic reduction

Design of multifunctional polymeric binders in silicon anodes for lithium‐ion batteries

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Carbon Energy 2024年第4期6卷 140-163页

作者： Masytha Nuzula ramdhiny Ju‐won Jeon Department of Chemistry Kookmin UniversitySeoulRepublic of Korea Correspondence

Silicon(Si)is a promising anode material for lithium‐ion batteries(LIBs)owing to its tremendously high theoretical storage capacity(4200 mAh g−1),which has the potential to elevate the energy of ***,Si anodes exhibit severe volume change during lithiation/delithiation processes,resulting in anode pulverization and delamination with detrimental growth of solid electrolyte interface *** a result,the cycling stability of Si anodes is insufficient for commercialization in *** binders can play critical roles in Si anodes by affecting their cycling stability,although they occupy a small portion of the *** review introduces crucial factors influencing polymeric binders'properties and the electrochemical performance of Si *** particular,we emphasize the structure–property relationships of binders in the context of molecular design strategy,functional groups,types of interactions,and functionalities of ***,binders with additional functionalities,such as electrical conductivity and self‐healability,are extensively discussed,with an emphasis on the binder design principle.

关键词： conductivity lithium‐ion batteries molecular interactions polymeric binders self‐healability Si anodes

Catalysis by subsurface metal atoms in Al(001) through electron transfer

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National Science Review 2024年第4期11卷 12-13页

作者： bo Sun Ding Ma Beijing National Laboratory for Molecular Science New Cornerstone Science Laboratory College of Chemistry and Molecular Engineering Peking University

Heterogeneous catalysis plays a crucial role in the chemical industry, which has evolved from the investigation of chemisorption to an electronic structure[1]. Diverse strategies, such as alloying,doping, and confining, have been applied to enhance the catalytic properties of active sites through electronic modulation. The electron transfer between active sites and substrates profoundly influences catalytic activity [2].

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A Generalized Array Factor for Time-Modulated Hexagonal Based Antenna Array Geometry With Novel Trapezoidal Switching

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IEEE/CAA Journal of Automatica Sinica 2024年第09期 1967-1972页

作者： Gopi ram IEEE the Department of Electronics and Communication Engineering National Institute of Technology

The concept of the time-modulated array has been emerging as an alternative to the complex phase shifters, which lowers the cost of the array feeding network due to the utilization of radio frequency(RF) switches. The various forms of hexagonal antenna array geometries can be used for applications like surveillance tracking in phased array radar and wireless communication systems. This work proposes the generalized array factor(AF) for the hexagonal antenna array geometry based on time modulation. The time modulation in generalized hexagonal geometry can maintain the fixed static amplitude excitation, giving more flexibility over time. Furthermore, a novel trapezoidal switching function is also proposed and applied to the generalized array factor to enable future researchers to use this array factor in the field of advancement to observe how switching schemes like trapezoidal and rectangular affect the array pattern's side lobe level(SLL). The generalized equation can be utilized for the analysis and synthesis of radiation characteristics of the time-modulated hexagonal array(TMHA), time-modulated concentric hexagonal array(TMCHA), time-modulated hexagonal cylindrical array(TMHCA), and time-modulated hexagonal concentric cylindrical array(TMHCCA). The numerical result illustrates the generation of AF of time-modulated hexagonal structures and also shows that the trapezoidal switching sequence outperforms the rectangular switch using the cat swarm optimization(CSO)approach.

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Simple preparation of C(CS)/g-C_(3)N_(4)/Co carbon aerogel and its catalytic performance for ammonium perchlorate

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Defence Technology（防务技术） 2024年第3期33卷 186-196页

作者： Yujie Yan bo Jin Rufang Peng State Key Laboratory of Environment-friendly Energy Materials School of Materials Science and EngineeringSouthwest University of Science and TechnologyMianyang621010China

Biomass chitosan(CS)was used as a template,graphitic phase carbon nitride(g-C_(3)N_(4))with high nitrogen content and certain catalytic activity was used as a dopant,and nano-transition metal cobalt(Co)was used as a catalytic center *** carbon aerogel(C(CS)/g-C_(3)N_(4)/Co)with a three-dimensional network-like structure was prepared by assembling the three materials through experimental operations such as freeze-drying and high-temperature *** was demonstrated by scanning and transmission characterization that the CS in the carbon aerogel could provide more active sites for the cobalt nanoparticles,and the doping of graphite-phase carbon nitride as a template dispersed the cobalt nanoparticles and changed the conductivity of the *** investigate the catalytic effect of carbon aerogel on ammonium perchlorate(AP),it was investigated by differential thermal analyzer and TG thermal *** carbon aerogel was very effective in catalyzing AP,and the 10 wt% content of the catalyst reduced the AP pyrolysis peak from 703.9 to 595.5 *** to further investigate the synergistic effect of the three materials,further carbon aerogels such as C(CS)/Co,g-C_(3)N_(4)/Co were prepared and applied to catalyze AP,and the same ratio reduced the AP pyrolysis peak by 98.1℃ and 97.7℃.This result indicates a synergistic effect of the assembly of the three materials.

关键词： g-C_(3)N_(4) Chitosan Co Ammonium perchlorate Pyrolysis kinetics