bluuebunny/crossref_metadata_2025_split huggingface dataset:
Power Combiners and Dividers
Authors: Bialkowski Marek E. , Tsai Feng-Chi E. 
Published: November 2024

AbstractThe article provides an extensive review on the topic of microwave and millimeter‐wave power combiners and dividers. Because many power combining and dividing structures can be used interchangeably, the review focuses on power combiners. It commences with an introduction of power combining principles and grouping of power combiners into suitable categories. The main categories considered here include circuit‐level (both resonant and nonresonant type) and space‐level power combiners. Next, operation and fundamental characteristics of circuit and space‐level combiners, which have been presented in the microwave literature, are thoroughly explained. In the subsequent sections, analysis methods for power combiner/divider structures are described. They concern both circuit and electromagnetic field approaches. The use of state‐of‐the art computer software for the analysis of power combining/dividing structures is also covered. The last section of the article is concerned with applications of power combiner/dividers in modern communication and radar systems. Examples of most impressive power combiners of solid‐state devices, in terms of an achieved output power level or highest frequency of operation, are presented. The review concludes with remarks on recent progress in the field of space‐level combiners.
Resonators
Authors: Ahn Hee-Ran 
Published: November 2024

AbstractResonators are important components in microwave communication circuits. They create filters and select frequencies in oscillators, amplifiers, tuners, and so on. Fields inside a resonator store energy at the resonance frequency where equal storage of electric and magnetic energies occurs. The input impedance at resonance is purely real because the reactance is proportional to the difference between electric and magnetic energy storage.In this article, series and parallel resonance circuits will be discussed and then the representative resonators that are commonly used in practical cases will be explained.
Skin Effect
Authors: Olyslager Frank , de Zutter Daniël 
Published: November 2024

AbstractThe skin effect is the property that electromagnetic waves penetrate only a small distance into a conductor. The fields and induced currents decay exponentially with the distance from the surface. The distance over which the fields and induced currents decrease by a factor ofeis the skin depth. The ratio of the voltage drop along the surface of the conductor to the current flowing in the conductor and causing this voltage drop is the surface impedance. Expressions for the skin depth and the surface impedance are in the first instance derived for a plane conductor interface. The results for a plane conductor are also applicable for a curved conductor as long as the radius of curvature is large compared to the wavelength. For a conductor with a finite thickness an expression for the surface impedance is derived that takes into account the finite thickness of the conductor. The roughness of the conductor surface increases the surface resistance. This increase is quantified by an empirical law. The concept of the surface impedance allows an efficient inclusion of conductors with finite conductivity in numerical electromagnetic simulation techniques such as integral equation techniques, finite‐element techniques, and finite‐difference time‐domain techniques.
Radar Applications
Authors: Tsihrintzis George A. 
Published: November 2024

AbstractRadar (radiodetection andranging) systems attempt to infer information about remotely located objects from reflections of deliberately generated electromagnetic waves at radio‐ and microwave frequencies. Typically, the information sought is detection of the presence of target objects in the midst of clutter, recognition (classification) of targets, and estimation of target parameters such as range distance from the radar antenna), bearing (azimuth and elevation), orientation, velocity, acceleration, or backscattering cross section (reflectivity) distribution. Today's radar systems perform these tasks for multiple targets simultaneously, at the finest possible target resolution and with the highest possible accuracy. Additionally, the domain of utilization of radar techniques has expanded beyond the traditional aircraft detection and ranging application. Indeed, modern radar applications include search, tracking, and navigation radar for spread targets, high‐resolution aerial imaging radar, weather observation radar, and ground‐ and foliage‐penetrating radar. To achieve their expanded tasks, modern radar systems combine high‐quality hardware with sophisticated signal design and processing algorithm development and implementation based on statistical descriptions of both the target characteristics and the clutter distributions.
Digital Radio
Authors: Aalo Valentine A. 
Published: November 2024

Abstract
This article presents an overview of digital radiocommunications with emphasis on wireless personal communications.
The main objective of wireless personal communication is to allow the user access to the capabilities of the global network at any time and without regards to location and mobility.
Digital radio, used extensively in second‐generation and the evolving third‐generation systems, considerably improves the quality of the cellular system and enhances the services available to the mobile subscribers.
Feedback Amplifiers
Authors: Schubert Thomas F. 
Published: November 2024

AbstractThis article considers the benefits of negative feedback on amplifier design: stabilization of gain, reduction of nonlinear distortion, increased bandwidth, and selective modification of input and output resistance. Basic definitions are followed by a general discussion of the properties of a feedback system. Amplifiers are divided into four categories of feedback topology, and the specific properties of each topological type are determined. The drawbacks of feedback, reduction of gain, and the possibility of oscillation are also considered. Several compensation methods to improve amplifier stability are discussed.
RF Circuit Noise
Authors: Marshall Leach W. 
Published: November 2024

Abstract

The
V
n
−
I
n
noise model of an amplifier is described. The model is used to define signal‐to‐noise ratio and noise factor. The optimum source impedance that minimizes the noise factor is derived. The effect of matching networks on noise factor is described. Two lossless matching network examples illustrate how the source impedance can be transformed to minimize the noise factor. The use of Smith chart noise circles and gain circles to evaluate amplifier performance is described and illustrated by an example. Measurement of noise factor and a method of determining amplifier noise parameters from noise factor measurements are described.
Evaluating the origin and spread of spotted lanternfly (Lycorma delicatula) in Japan
Authors: Kamiyama Matthew T. , Takahashi Michihiko , Broadley Hannah J. , Gómez‐Marco Francesc , Hoddle Mark S. , Matsuura Kenji 
Published: November 2024

AbstractSpotted lanternfly Lycorma delicatula is an emergent invasive agricultural pest native to China, and has invaded the Republic of Korea ([i.e., South Korea] first detected 2006), Japan (2009), and the United States of America (2014). Previous reports from the Republic of Korea and the United States on L. delicatula detail rapid population expansion and severe feeding damage to crop and non‐crop host plants following its invasion. In contrast, populations in Japan initially spread slowly and remained isolated to two prefectures (Ishikawa and Fukui) for 8 years post‐invasion without any reports of agricultural damage. Here we update the current known distribution of L. delicatula in Japan through field surveys and complete a comprehensive review of formally published literature and community scientist reports. Recently L. delicatula has expanded its range in Japan with six new prefectural detections in the last 2 years. Phylogenetic analyses were performed using whole mitochondrial genome sequences of specimens collected across Japan to elucidate the genetic makeup and potential source areas of these populations. Phylogenetic analyses suggest the putative area of origin of Japanese L. delicatula populations is the north‐central region of China, as opposed to the invasive populations in the Republic of Korea and in the United States, which both originate from the eastern region of China. Results presented here provide a better understanding of the factors influencing the invasion dynamics of L. delicatula, which could enable development of improved biosecurity, monitoring, and incursion management programs for this pest.
Commissioning of a commercial treatment planning system for scanned carbon‐ion radiotherapy
Authors: Sun Wei , Wang Weiwei , Huang Zhijie , Zhao Jingfang 
Published: November 2024

AbstractPurposeTo commission the RayStation (RS) TPS (treatment planning system) for scanned CIRT (carbon‐ion radiotherapy) utilizing pencil beam algorithms (PBv4.2).MethodsThe beam model commissioning entailed employing 1D single beams and 2D monoenergetic fields to validate spot profiles with films, assess beam range using Peakfinder measurements, and evaluate fragment spectra through dose‐averaged linear energy transfer (LETd) calculations. 3D dose distributions were verified in homogeneous phantoms for both absorbed and relative biological effectiveness (RBE)‐weighted doses, and further assessed in double wedge and anthropomorphic phantoms for absorbed dose only. Finally, RBE‐weighted dose verification and patient‐specific quality assurance were conducted using 58 beams from 20 clinically treated patient plans.ResultsThe results demonstrated good agreement in absolute dose distribution between TPS calculations and measurements, with mean dose discrepancies within 3%. However, deviations were slightly higher (> 1%) for the cases involving the range shifter (RaShi) compared to those without the RaShi (< 1%). Beam range, depth dose distribution, and lateral profiles of spread‐out Bragg peaks (SOBPs) closely matched between RS TPS calculations and measurements. Some discrepancies (less than 0.5 mm) were observed at field edges and in penumbra regions due to limitations in simulating asymmetrical spots, but within clinical tolerance. After model tuning, RBE‐weighted dose calculations in RS TPS were in agreement with those from the clinically used TPS, except for variations exceeding 3% observed at energies exceeding 408.07 MeV/u, primarily attributed to fragment spectra differences.ConclusionOverall, this study validated the RS TPS for calculating absorbed doses against measurements and RBE‐weighted doses against a clinically used TPS. The results suggested that the RS TPS could be utilized for CIRT treatment planning, except for energies exceeding 408.07 MeV/u.
Diarylethene Molecular Clocks for Dual‐Mode Time‐Dependent Data Encryption
Authors: Liu Jie , Liang Baoshuai , Dong Yu , Wu Huacan , Zhang Chuang , Pei Haizhou , Zuo Mengdi , Yu Xiaolan , Zheng Shiya , Feng Shiyu , Huang Weiguo 
Published: November 2024

AbstractDeveloping dynamic encryption materials with time‐dependent outputs has gained importance in the digital age. While many studies have introduced phosphorescent, polymeric, and/or self‐assembled materials for this purpose, challenges such as poor handleability, short readout duration, and single‐mode output persist. To address these issues, designed three photochromic molecules—DAE‐B, DAE‐NH, and DAE‐N with different photoisomerization rates are designed. Under 254 nm irradiation, DAE‐B and DAE‐NH appear magenta per cyclization, while DAE‐N emits orange fluorescence. Notably, DAE‐B and DAE‐NH are visible under both visible light and UV light (254 and 365 nm), whereas DAE‐N is visible only under UV light. Leveraging these properties, a time‐dependent dynamic encryption system using DAE‐B and DAE‐NH is developed, where the correct message is accessible only at a specific time, while wrong information would appear at other time points. Additionally, by integrating DAE‐B, DAE‐NH, and DAE‐N into QR codes (quick‐response code), and combining this with the scanning sequence, time, and wavelength, a dual‐mode, 3D encryption system that operates under both visible and UV light is created. This innovation not only advances time‐based encryption techniques but also contributes to the development of molecular clock‐based encryption materials.
Synergistic Redox Dual‐Site Strategy to Boost Photosynthesis of Hydrogen Peroxide
Authors: Zhang Rongao , Xu Haonan , Huang Zixiang , Zhang Jing , Liu Limin , Ma Zhentao , Zhang Zhilin , Wang Kun , Liu Peigen , Liu Huarong , Zheng Xusheng 
Published: November 2024

AbstractGraphitized carbon nitride (C3N4)‐based photocatalysts provide a prospective approach for producing hydrogen peroxide (H2O2) in artificial photosynthesis. However, their activity is constrained by the sluggish water oxidation reaction (WOR) process, which hampers the supply of protons and electrons necessary for the oxygen reduction reaction. Here, this work demonstrates a synergistic redox dual‐site strategy via co‐modified with 3,4,9,10‐perylenetetracarboxylic acid diimide (PDI) and Pt single atoms in C3N4 support, which achieves an exceptional H2O2 yield of 802 µmol g−1 h−1 and a selectivity of 91.8% without sacrificial agents. Mechanistic studies reveal that Pt single atoms act as photogenerated electron‐rich sites to effectively activate O2 to form superoxide radicals, and PDI promotes WOR driving force to provide abundant protons. The optimized reduction and oxidation half‐reactions improve the proton‐coupled electron transfer process, thereby enhancing the selective photosynthesis of H2O2. This work underscores the importance of finely controlling half‐reactions in photocatalytic processes to promote efficient and synergistic overall reactions.
Red Multi‐Resonant Thermally Activated Delayed Fluorescence Emitters as Bioimaging Agents
Authors: Si Changfeng , Primrose William L. , Xu Yan , Hudson Zachary M. , Zysman‐Colman Eli 
Published: November 2024

AbstractMulti‐resonant thermally activated delayed fluorescence (MR‐TADF) emitters have attracted strong interest for organic electroluminescent devices due to their high photoluminescence quantum yield (ΦPL) and narrowband emission. These properties are also crucial for high‐performance biological probes, especially red emitters. Orange and red MR‐TADF emitters, PhDPA‐DiKTa and MeODPA‐DiKTa, are designed by decorating the DiKTa core with di([1,1′‐biphenyl]‐4‐yl)amine and bis(4‐methoxyphenyl)amine, respectively. As 5 wt.% doped films in 1,3‐di(9H‐carbazol‐9‐yl)benzene (mCP), PhDPA‐DiKTa emits at λPL of 617 nm, while MeODPA‐DiKTa emits at λPL of 655 nm. Both show delayed fluorescence, with delayed lifetimes, τd, of 658.4 and 249.2 µs, respectively. Water‐dispersible glassy organic dots (g‐Odots) based on these materials are prepared by encapsulating them and mCP host into an amphiphilic DSPE‐PEG2k polymer. Both families of g‐Odots showed a deeper red emission and enhanced ΦPL compared to the corresponding 5 wt.% doped films in mCP (λPL = 618 nm, ΦPL = 77% for PhDPA‐DiKTa g‐Odots, λPL = 663 nm, ΦPL = 38% for MeODPA‐DiKTa g‐Odots). The TADF character of the emitters is conserved in the g‐ODots, with τd of 203.9 µs for PhDPA‐DiKTa g‐Odots and 131.6 µs for MeODPA‐DiKTa g‐Odots. These MR‐TADF g‐Odots are successfully demonstrated as biological imaging probes of HeLa cells.
Understanding and Circumventing Failure Mechanisms in Chalcogenide Optical Phase Change Material Ge2Sb2Se4Te
Authors: Popescu Cosmin Constantin , Aryana Kiumars , Mills Brian , Lee Tae Woo , Martin‐Monier Louis , Ranno Luigi , Sia Jia Xu Brian , Dao Khoi Phuong , Bae Hyung‐Bin , Liberman Vladimir , Vitale Steven A. , Kang Myungkoo , Richardson Kathleen A. , Ríos Ocampo Carlos A. , Calahan Dennis , Zhang Yifei , Humphreys William M. , Kim Hyun Jung , Gu Tian , Hu Juejun 
Published: November 2024

AbstractChalcogenide optical phase change materials (PCMs) have garnered significant interest for their growing applications in programmable photonics, optical analog computing, active metasurfaces, and beyond. Limited endurance or cycling lifetime is however increasingly becoming a bottleneck toward their practical deployment for these applications. To address this issue, a systematic study elucidating the cycling failure mechanisms of Ge2Sb2Se4Te (GSST) is performed, a common optical PCM tailored for infrared photonic applications, in an electrothermal switching configuration commensurate with their applications in on‐chip photonic devices. Further a set of design rules building on insights into the failure mechanisms is proposed, and successfully implemented them to boost the endurance of the Ge2Sb2Se4Te (GSST) device to over 67 000 cycles.
Theoretical and Experimental Optimization of P2‐Type Sodium‐Ion Battery Cathodes via Li, Mg, and Ni Co‐Doping: A Path to Enhanced Capacity and Stability
Authors: Cho Man‐Jae , Yaqoob Najma , Yu Jun Ho , Köster Konstantin , Kim A‐Yeon , Jung Hun‐Gi , Ihm Kyuwook , Lee Kug‐Seung , Avdeev Maxim , Kim Hyungsub , Kaghazchi Payam , Myung Seung‐Taek 
Published: November 2024

AbstractUnderstanding the oxygen‐redox reactions within Mn‐rich layered cathode materials is an important strategy to improve the capacity of sodium‐ion batteries (SIBs) while satisfying the demand for low cost and the use of abundant resources. Nonetheless, the P2‐type Nay[AxMn1‐x]O2 compositions (where A = electro‐inactive elements) exhibit poor capacity retention and low operation voltage along with a broad voltage hysteresis. In addition, Nay[TMxMn1‐x]O2 (where TM = transition metal) still suffers from low capacity in the absence of anion redox activity. This investigation introduces Li, Mg, and Ni into the P2‐layered NaxMnO2 matrix to explore diverse compositional dynamics engineered by density functional theory and ab initio molecular dynamics. The P2‐Na0.7[Li0.1Mg0.05Ni0.15Mn0.7]O2 configuration is optimized, exhibiting enhanced structural and electrochemical stabilities. Operando X‐ray diffraction analyses affirm the preservation of the P2 structure throughout de/sodiation, and comprehensive structural analyses unraveled the complex charge‐compensation mechanisms facilitated by Ni2+/Ni4+, Mn3+/Mn4+, and O2−/(O2)n− redox pairs. Neutron diffraction and nuclear magnetic resonance techniques elucidate the Li migration phenomena within the TM and sodium layers. This research underscores the pivotal role of Li, Mg, and Ni co‐doping in the development of cathode materials, paving the way for SIBs with enhanced electrochemical performance.
Alcohol Self‐Aggregation: the Preferred Configurations of the Ethanol Trimer
Authors: Indira Murugachandran S. , Peña Isabel , Mokhtar Lamsabhi Al , Yáñez Manuel , Eugenia Sanz M. 
Published: November 2024

AbstractAn atomic‐level knowledge of the aggregation of archetypal molecular systems is essential to accurately model supramolecular structures and the transition from gas to liquid phase. The structures and forces involved in ethanol aggregation have been investigated using microwave spectroscopy and extensive quantum chemical calculations. Four isomers of the ethanol trimer have been observed and identified based on comparisons between experimental and predicted spectroscopic parameters, and considering collisional relaxation in the supersonic expansion. All observed isomers exhibit O−H
O hydrogen bonds between the hydroxyl groups forming a six‐membered ring. Additionally, secondary C−H
O hydrogen bonds and H
H dispersion contacts participate in the stabilization of the complexes with remarkably similar energy contributions. Structures where there is a mixture of gauche and trans conformations of ethanol are favored, with gauche conformations being predominant and no evidence of homochirality synchronization. Our results underscore the critical changes involved in aggregation as the size of the system increases and shed light on the unique properties and behavior of ethanol in chemical and biological systems.
Selection of Plastic‐Binding DNA Aptamers for Microplastics Detection
Authors: Zandieh Mohamad , Luo Xin , Zhao Yu , Feng Chuanliang , Liu Juewen 
Published: November 2024

AbstractPlastics are critical materials for modern technological applications, yet environmental contamination by microplastics has become a growing concern. In this study, DNA aptamers were isolated for two of the most abundant plastic materials: polyvinylchloride (PVC) and polystyrene (PS). These aptamers contain approximately 90 % cytosine and thymine but only 10 % purine content. Among them, the PVC‐1 aptamer binds to PVC with a six‐fold higher capacity than a random sequenced DNA. Among the tested plastic materials, PVC and PS exhibited the highest specific binding capacity. Using fluorophore‐labeled PVC‐1 aptamer, PS/PVC microplastics as low as 1 mg were detected, and the aptamer was selective for microplastics over other environmentally relevant materials, such as silica. Molecular dynamics simulations indicated that the aptamer attempted to maximize contact with the plastic surface for adsorption. This plastic‐binding aptamer is expected to find applications in environmental monitoring and has fundamental implications for surface‐binding aptamers.
Detecting Interactions in High‐Dimensional Data Using Cross Leverage Scores
Authors: Teschke Sven , Ickstadt Katja , Munteanu Alexander 
Published: November 2024

ABSTRACTWe develop a variable selection method for interactions in regression models on large data in the context of genetics. The method is intended for investigating the influence of single‐nucleotide polymorphisms (SNPs) and their interactions on health outcomes, which is a problem. We introduce cross leverage scores (CLSs) to detect interactions of variables while maintaining interpretability. Using this method, it is not necessary to consider every possible interaction between variables individually, which would be very time‐consuming even for moderate amounts of variables. Instead, we calculate the CLS for each variable and obtain a measure of importance for this variable. Calculating the scores remains time‐consuming for large data sets. The key idea for scaling to large data is to divide the data into smaller random batches or consecutive windows of variables. This avoids complex and time‐consuming computations on high‐dimensional matrices by performing the computations only for small subsets of the data, which is less costly. We compare these methods to provable approximations of CLS based on sketching, which aims at summarizing data succinctly. In a simulation study, we show that the CLSs are directly linked to the importance of a variable in the sense of an interaction effect. We further show that the approximation approaches are appropriate for performing the calculations efficiently on arbitrarily large data while preserving the interaction detection effect of the CLS. This underlines their scalability to genome wide data. In addition, we evaluate the methods on real data from the HapMap project.