bluuebunny/crossref_metadata_2025 huggingface dataset:
Smart Materials
Authors: Awadelkarim Osama O. , Suliman Samia A.
Published: November 2024

In this article, we give the reader a brief introduction to a selected number of smart materials and structures. These materials include semiconductors and related structures, superconductors, piezoelectric materials, and shape memory materials. These materials are discussed in terms of their electrical, mechanical, optical, and chemical properties and possible engineering applications in the fields of nanoelectronics, nano/microelectromechanical systems, optoelectronics, and communication.
Magnetic Field Measurement
Authors: Stecher Manfred
Published: November 2024

The measurement of electromagnetic (EM) fields is relevant for various purposes: for scientific and technical applications, for radio propagation, for electromagnetic compatibility (EMC) tests (i.e., testing of the immunity of electronic equipment to electromagnetic emissions aiming at the protection of radio reception from radio interference), and for safety reasons (i.e., the protection of persons from excessive field strengths). For radio propagation and EMC measurements, below about 30MHz a distinction is made between electric and magnetic components of the EM field to be measured. In the area of human safety, this distinction is continued to even higher frequencies.
Feedforward Amplifiers
Authors: Gardner P.
Published: November 2024

A feedforward amplifier is a transmitter subsystem in which feedforward linearization is used to correct for the effects of nonlinearities in the gain and phase response of a basic amplifier.

Such nonlinearities have the effect of generating intermodulation products in multicarrier systems, and spectral regrowth in systems that use bandlimited, nonconstant envelope modulation. Odd‐order intermodulation is a particular problem in communication systems because it can generate spurious signals very close in frequency to the wanted signals, often in adjacent communication channels. Similarly, spectral regrowth is a problem because it generates unwanted noise or crosstalk in adjacent frequency bands, violating the tough out‐of‐band emissions specifications imposed by modern communication standards. The problems can be reduced, in principle, by the use of separate amplifiers for each channel, and/or linear class A amplifiers backed off well below saturation, but these measures make transmitters highly inefficient.

A better compromise between efficiency and linearity can be achieved by using artificial linearization techniques. This article describes one such technique: feedforward linearization. The basic principle of operation is described, the practical limitations are discussed, and comparisons with other linearization techniques are also made. Some advanced techniques are also introduced, including dual‐loop feedforward amplifiers and adaptive feedforward.
Microwave Filters
Authors: Zhu Lei
Published: November 2024

This article summarizes the fundamentals of microwave filters with varied frequency‐selective characteristics such as lowpass, bandpass, highpass, and bandstop. On the basis of the ladder network of a lowpass prototype filter, a well‐known synthesis design approach is described to realize the lowpass frequency response in terms of the preselected insertion loss functions and then determine the element values of this network under the Butterworth and Chebyshev function responses. By executing the frequency transformation from the normalized to actual microwave frequency ranges, various lumped‐element microwave filters are first constructed with both series and shunt elements. Next, the immittance inverters are introduced and utilized to eliminate either series or shunt elements, thus alleviating the complexity in filter implementation. In addition to a series of useful design formulas and tables provided with brief explanations, a variety of practical microwave filters are made up using transmission‐line and waveguide elements and their principles are discussed with regard to their equivalent cascaded networks.
Microwave Isolators
Authors: Dunn Vernon E.
Published: November 2024

Isolators are used extensively in microwave equipment to prevent interaction between other components of the system. This article describes the principles of operation of the most common types of microwave isolators and typical operating characteristics of these isolators.
Microwave Oscillators
Authors: Choi Jonghoon , Mortazawi Amir
Published: November 2024

Microwave applications such as communications and radars require stable, efficient, and low‐noise microwave oscillators. For this purpose, microwave oscillators are characterized by their frequency of operation, output power, phase noise, long‐term stability, and DC‐to‐RF efficiency. This article discusses the small‐signal and large‐signal designs of microwave oscillators, based on the negative‐resistance model. Also, the injection‐locking phenomenon is introduced and analyzed employing the equivalent‐circuit model of injection‐locked oscillators. The phase noise of microwave oscillators is explained using Leeson's model. Several practical oscillators are examined. Finally, the state‐of‐the art result for various microwave integrated oscillators is presented.
Monolithic Microwave Integrated Circuits (MMICs)
Authors: Bahl Inder J.
Published: November 2024

Advanced military and microwave systems are demanding increased integration, reliability, radiation hardness, compact size, and lower cost when produced in large volume, whereas the microwave commercial market, including wireless communications, mandates low‐cost circuits. Monolithic microwave integrated circuit (MMIC) technology provides an economically viable approach to meeting these needs. This article deals with MMIC fabrication, substrates, matching networks, active devices, and monolithic design of microwave components and circuits, including device modeling and EM simulations. Typical monolithic microwave circuits and their performance, and MMIC packaging are also discussed.
Slotlines
Authors: Lee Chung-Yi , Itoh Tatsuo
Published: November 2024

This article introduces one type of high‐frequency transmission line called the slotline. The configuration, terminology, analysis, and applications are discussed in subsequent sections. A slotline is an uniplanar wave‐guiding structure proposed by Cohn in 1968. We will use the spectral domain approach to analyze the slotline. The propagation constant and the characteristic impedance are obtained from this rigorous analysis. Slotlines can be built using the same fabrication process for the microstrip line and the coplanar waveguide (CPW). Slotline discontinuities, coaxialto‐slotline, microstrip‐to‐slotline, and CPW‐to‐slotline transitions are investigated in this article.
Smith Chart
Authors: Schwab Leonard M.
Published: November 2024

The Smith chart was routinely used to solve difficult transmission‐line matching problems in a variety of broadcasting, microwave, circuit design, and telecommunication applications. While it has since evolved almost exclusively into a software format, the original paper forms remain a convenient detailed medium for print output of finished work from software implementations of Smith's graphical method.

The essential objective in using the Smith chart is stated simply. An impedance (or equivalent admittance) locus over a frequency range is systematically repositioned on the chart in well‐defined ways by the progressive effects of series or shunt elements, thereby placing the passband portion of the impedance vector in the central area of the chart and the stopband portion at the outer periphery of the chart. The circuit elements commonly used include distributed elements such as transmission lines and quarter‐wave stubs, discrete elements such as inductors and capacitors, and any combination of these and related elements. Resistance elements are seldom intentionally used.
Surface Acoustic Wave Delay Lines
Authors: Reindl Leonhard M. , Ruppel Clemens C.W.
Published: November 2024

Surface acoustic wave (SAW ) delay lines are special microwave components that have been used for electronic analog signal processing since the early 1970s. A tremendous variety of devices and systems for consumer, commercial, and military applications have been developed, running now at an annual rate of some hundred million U.S. dollars. SAW filters, especially linear and nonlinear delay lines, as well as reflective delay lines play a key role in the radiofrequency (RF ) and intermediate‐frequency (IF ) stages of many electronic systems such as radar systems, spread‐spectrum telecommunication systems, and wireless passive sensor systems. The objective of this article is to provide an overview of the latest developments in SAW delay lines and to identify novel emerging applications, especially in the field of wireless communications and sensing. The pertinent key issues for the successful design and mass fabrication of SAW devices are addressed and the underlying operating principles are discussed.
Altimeters
Authors: Eren Halit
Published: November 2024

Alimeters are instruments that measure altitude or elevation objects above or below a given level. There are three types of alimeters: pressure altimeters that make use of properties of atmosphere, radio and radar altimeters that are based on electromagnetic wave propagation, and optical altimeters that use optical properties of light and lasers. All these basic altimeters find extensive applications in industry, aviation, military, navigational aids, land surveying, remote sensing, recreations, and sports.

Modern barometric altimeters are manufactured mostly as integrated circuit (IC) pressure transducers. Therefore primary signal processing such as linearization, error corrections, and gain adjustment are made within the chip. Altimeters based on electromagnetic principles transmit electromagnetic energy and detects of the reflected energy from an object. An example of these altimeters is the single‐frequency radar system that broadcasts a pulsed tone signal directly downward the object and processes the returned signals with elaborate electronic circuits for high sensitivity and resolution. Altimeters based on microwave energy transmission can be used for other purposes such as imaging, scanning, mapping, oceanographic studies, and weather forecasting. Laser altimeters operate similar to the radar altimeters by processing time differences between the transmitted and received signals. Typical examples of such altimeters are the LIDAR (light detection and ranging) and the SLA (shuttle laser altimeter) and RASCAL (
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A popular system that can be used as altimeter is the Global Positioning System (GPS), which constitutes 24 satellites orbiting around Earth. Each satellite transmits electromagnetic energy carrying unique codes and information. Information picked up receivers is used to determine positions of objects in three dimensions.
Radar Polarimetry
Authors: Sletten Mark A. , Mc Laughlin David J.
Published: November 2024

This article summarizes the fundamentals of radar polarimetry and gives examples of related applications and research. The mathematical foundation is described first. This discussion includes explanations of the various ways in which polarized and partially polarized electromagnetic waves can be described and how formalisms are used to express the polarimetric scattering properties of objects and surfaces. The scattering, Mueller, covariance, and coherency matrices embody these formalisms. Some practical aspects of polarimetric radar design are then discussed, and the article concludes by summarizing applications of polarimetry and areas of active research, including scattering studies, image classification, contrast enhancement, meteorology, and topographic mapping.
Thin Film Resistors
Authors: Collins F. M. , Anderson W. A. , Ma E. M.
Published: November 2024

In this article, we will discuss the historical background and technological evolution of thin film resistors. We will also review resistor technology design concepts, including requirements for (1) the range of resistance values, (2) their precision, and (3) the physical size in terms of power or voltage demands, materials used in production, finished formats, performance characteristics, and some advantages of integrated thin film resistor production.
SiC Device Technologies
Authors: Östling M. , Koo S.-M. , Domeij M. , Danielsson E. , Zetterling C.-M.
Published: November 2024

Silicon carbide (SiC) devices have drawn considerable attention for use in various applications due to the interesting materials properties of SiC. Commercial products are now available for high‐voltage and high‐frequency applications. Prototype devices show promising performance, whereas materials issues are still a hinder for economically viable production of large‐area devices with high yield. This article reviews the more recent progress in SiC devices and process technology and presents the state‐of‐the‐art SiC devices as well as new application areas such as ferroelectric field‐effect transistors (FeFETs).
Television Broadcast Transmission Standards
Authors: Godber Alan S. , Redford James R.
Published: November 2024

Since the invention of television, images and sound have been captured, processed, transmitted, received, and displayed using analog technology, where the picture and sound elements are represented by signals that are proportional to the image amplitude and sound volume. In more recent years, as solid‐state technology has developed, spurred primarily by the development of computers, digital technology has gradually been introduced into the handling of the television signal, both for image and sound. Many portions of television systems are now hybrid combinations of analog and digital, and it is expected that eventually all television equipment will be fully digital, except for the transducers, cameras, and microphones (whose inputs are analog) and the television displays and loudspeakers (whose outputs are analog).
Blueprints for the scientific society of the future: how FEBS and other scientific societies will have changed 60 years from now
Authors: Ali Yussuf
Published: November 2024

The Federation of European Biochemical Societies (FEBS) was founded in 1964 to bring together the scientific societies of Europe and neighbouring regions and to provide a platform for scientific exchange. Today, FEBS is an organisation of more than 30 000 members across 39 biochemistry and molecular biology societies that promotes excellence in the life sciences in Europe and beyond. To mark the 60th anniversary of FEBS, FEBS Letters celebrated with a writing contest focussed on participants' visions of scientific societies in the year 2084. Here, we present the winning essay, in which Yussuf Ali (Jagiellonian University, Poland) considers a future in which FEBS transcends not only geographical boundaries, but also interdisciplinary, technological and financial boundaries.
Adversarial Machine Learning
Authors: Arce Pablo G. , Insua David R.
Published: November 2024

This paper introduces key concepts in adversarial machine learning (ML). Its aim is to deliver ML approaches that are more robust against adversarial attempts to alter their performance. We cover the cases of classification, regression, unsupervised, and reinforcement learning. The three core topics in the field (attacks, defenses, and workflows) are briefly discussed.
A predictive model for Gamma Knife intermediate dose spill: R50%Analytic‐GK
Authors: Cordrey Ivan L. , Kucuk Sare , Ramsey Chester , Bowling Joseph , Desai Dharmin D.
Published: November 2024

Purpose

Minimizing intermediate dose spill in stereotactic radiosurgery (SRS) for brain treatment is crucial. Intermediate dose spill correlates with the exposure of normal brain tissue to high doses, which increases the risk of radionecrosis. R50%, defined as the volume of the 50% of prescription isodose cloud/planning target volume, is one metric for intermediate dose spill. A predictive model for R50% in linear accelerator VMAT‐delivered SRS has been developed Desai et al. (2020) and is called R50%Analytic. This study extends the R50%Analytic model to Gamma Knife (GK) delivered SRS, resulting in the R50%Analytic‐GK model.

Methods

Phantom calculations were performed on 11 spherical target volumes ranging from 0.001  to 44 cm3 to develop the R50%Analytic‐GK model. R50%Analytic‐GK was tested against clinical data from 18 brain metastasis cases with one to 11 targets treated on GK Icon and planned in GammaPlan with lightning dose optimizer. Thirty‐five targets with volumes between 0.011  and 27.4 cm3 were analyzed by extracting the R50% achieved clinically (R50%Clinical) for comparison to the predicted intermediate dose spill from R50%Analytic‐GK.

Results

The predicted R50%Analytic‐GK values generally represent a lower bound for the R50%Clinical values as the model would predict. The Difference, R50%Clinical − R50%Analytic‐GK, has a median value of 0.92, which quantifies the lower bound nature of R50%Analytic‐GK. The model reflected the character of intermediate dose spill for the clinical cases. A few outliers were likely due to specific planning complexities.

Conclusion

The R50%Analytic‐GK model for intermediate dose spill successfully extends the theoretical framework of R50%Analytic to GK‐delivered SRS. It provides a method to predict the intermediate dose spill for GK Icon treatments. This model can aid in assessing SRS treatment plans by providing a benchmark for the intermediate dose spill for comparison.
InAs on Insulator: A New Platform for Cryogenic Hybrid Superconducting Electronics
Authors: Paghi Alessandro , Trupiano Giacomo , De Simoni Giorgio , Arif Omer , Sorba Lucia , Giazotto Francesco
Published: November 2024

Superconducting circuits based on hybrid InAs Josephson Junctions (JJs) play a starring role in the design of fast and ultra‐low power consumption solid‐state quantum electronics and exploring novel physical phenomena. Conventionally, 3D substrates, 2D quantum wells (QWs), and 1D nanowires (NWs) made of InAs are employed to create superconducting circuits with hybrid JJs. Each platform has its advantages and disadvantages. Here, the InAs‐on‐insulator (InAsOI) is proposed as a groundbreaking platform for developing superconducting electronics. An epilayer of semiconducting InAs with different electron densities is grown onto an InAlAs metamorphic buffer, efficiently used as a cryogenic insulator to decouple adjacent devices electrically. JJs with various lengths and widths are fabricated employing Al as a superconductor and InAs with different electron densities. A switching current density of 7.3 µA µm−1, a critical voltage of 50‐to‐80 µV, and a critical temperature equal to that of the superconductor used are achieved. For all the JJs, the switching current follows a Fraunhofer‐like pattern with the out‐of‐plane magnetic field. These achievements enable the use of InAsOI to design and fabricate surface‐exposed Josephson Field Effect Transistors with high critical current densities and superior gating properties.
Optimizing Local Configuration of Interphase Copper Oxide by Ru Atoms Incorporation for High‐Efficient Nitrate Reduction to Ammonia
Authors: Lin Yunxiang , Wang Ying , Xu Ying , Liu Hengjie , Liu Xue , Shan Lei , Wu Chuanqiang , Yang Li , Song Li
Published: November 2024

The electrochemical reduction of nitrate offers an environmentally friendly and sustainable development strategy to mitigate nitrate pollution and further facilitate value‐added ammonia synthesis. Here, interphase Cu2+1O (regarded as Cu2O with metal excess defects) featured by abundant Cu0 and Cuδ+ sites with Ru single atoms incorporation (marked as RuSA@Cu2+1O) are synthesized by fast Joule heating method for efficient nitrate reduction to ammonia. The X‐ray absorption spectroscopy found that the incorporation of Ru atoms can effectively tune the local electronic structure of Cu2+1O substrate with charge polarization. The as‐prepared RuSA@Cu2+1O exhibits a remarkable Faradaic efficiency (FE) of 98.02% and an ammonia yield of 0.81 mmol h−1 cm−2 at the potential of ‐0.4 V (vs RHE). In situ, attenuated total reflection surface‐enhanced infrared absorption spectroscopy and theoretical investigations further confirm that Ru incorporation promotes the rapid transfer of the hydrogenation process. This study not only presents a feasible approach for fabricating interphase catalysts through fast Joule heating synthesis, but also offers insights into effectively regulating the local electronic structure of electrocatalysts for boosted reaction process.
Multifunctional Silanol‐Based Film‐Forming Additive for Stable Zn Anode
Authors: Xiao Qinghua , He Sidan , Liu Pengbo , Ge Mengya , Li Yunsong , Zhu Yuxuan , Lin Yuxiao , Wang Chao , Wang Qinghong
Published: November 2024

Aqueous zinc ion batteries (AZIBs) have garnered significant attention due to their advantages, including high safety, a straightforward manufacturing process, abundant resource availability, and high theoretical capacity. Nevertheless, the industrial application of AZIBs is impeded by the undesirable growth of dendrites and side reactions on the Zn anode. In this study, [3‐(trimethoxysilyl) propyl] urea (3TMS) is utilized as an electrolyte additive to develop a solid/electrolyte interphase (SEI) film on the surface of Zn anode. The in situ formed SEI layer not only prevents side reactions form the direct contact of Zn anode with water but also induces preferential Zn deposition along the (002) crystal plane, suppressing dendrite growth. These synergistic functions enable the Zn anode with ultralong cycle life of over 6000 h at the current density of 1 mA cm−2 with the areal capacity of 1 mAh cm−2, as well as high coulombic efficiency of 99.34% after 750 cycles. Moreover, the Zn//V2O5 full cells with 3TMS additive display a high specific capacity of 114.4 mAh g−1 at a current density of 0.5 A g−1 after 1000 cycles. This work provides a simple yet feasible approach to develop stable Zn anode toward high‐performance AZIBs.
KBaScSi3O9:Eu2+ Glass‐Ceramics as Single‐Phase High‐Power White Emitters
Authors: Kuang Yuhang , Jin Jiance , Liu Gaochao , Chen Weibin , Xia Zhiguo
Published: November 2024

Single‐phase white‐light emitters in the lighting technology overcome the challenges of re‐absorption and color shift. However, achieving the broadband white emission in single‐phase phosphor remains a challenge. Here, crystallized KBaScSi3O9:Eu2+ (KBSSO:Eu2+) glass‐ceramics (GC) with abundant cationic sites have been developed and an ultra‐broad emission band ranging from 460 to 800 nm have been found, in which the asymmetric green emission is ascribed to the Eu2+ ions in [KO8] and [BaO7] polyhedra, while the red emission centered at 620 nm is originated from Eu2+ ions in [ScO6] sites. The optimized GC‐converted white LED (WLED) exhibits a high color rendering index (Ra = 89.8) and low correlated color temperature (CCT = 4241 K). Moreover, the encapsulant‐free GCc‐WLED can operate continuously under high drive currents. This work paves the way for the design and future development of single‐phase high‐power white light sources.
Near‐Infrared Two‐Photon J‐Aggregation‐Induced Organic Fluorescent Dots with Large Stokes‐Shift for Ratiometric Imaging of Hypochlorous Acid in Living Cells and Brains of AD Mice
Authors: Huang Rui , Zhang Ziwei , Shi Zhen , Yang Yumeng , Sun Junyong , Gao Feng
Published: November 2024

Alzheimer's disease (AD) is characterized by multiple toxicity from various biomarkers, and it is very important to monitor the fluctuation of biomarker level in brain tissues to track its early onset, illness progression, and therapeutic effect. Hypochlorous acid (HOCl) is confirmed to be a reliable biomarker to extend the scope of diagnosis. However, the practical applications of the developed conjugated small molecule fluorescent probes for detecting HOCl are often restricted to a large extent by their low solubility, aggregation‐caused quenching (ACQ), unsatisfactory fluorescence brightness, small Strokes‐shift, and lack of self‐correcting ratiometric emitters. In this study, a J‐aggregation‐induced organic fluorescent dot (PBT dots), is reported which is facilely developed by co‐assembling newly designed organic molecule PBT with polymer DSPE‐PEG, for ClO− imaging in living brain‐derived Endothelial (bEnd.3) cells and brain tissues of AD mice. The developed two‐photon PBT dots show NIR emission at 715 nm, large Stokes‐shift of 245 nm, quick response within 2 s, ratiometric sensing properties, and favorable blood‐brain barrier (BBB) penetrate ability. The results demonstrate that HOCl level is elevated in AD mouse brain, and PBT dot holds promise as an imaging probe to understand and reveal AD pathologies.
Atomic‐Level Electric Polarization in Entropy‐Driven Perovskites for Boosting Dielectric Response
Authors: Xiong Xuhui , Liu Zhengwang , Zhang Ruixuan , Yang Liting , Liang Guisheng , Zhou Xiaodi , Li Bangxin , Zhang Huibin , Lv Hualiang , Che Renchao
Published: November 2024

Dielectric oxides with robust relaxation responses are fundamental for electronic devices utilized in energy absorption, conversion, and storage. However, the structural origins governing the dielectric response remain elusive due to the involvement of atomically complex compositional and structural environments. Herein, configurational entropy is introduced as a regulatory factor to precisely control the structural heterogeneity in representative perovskite dielectric oxides. Through advanced structural and electric field visualization studies, a novel quantitative relationship is established between atomic‐level structural disorder‐induced electric field polarization and macroscopic dielectric properties. The results indicate that the degree of atomic delocalization in perovskite oxides exhibits a near‐parabolic trend with increasing entropy, reaching a maximum in medium‐entropy perovskite. Correspondingly, the atomic electric field vectors display significant asymmetrical distribution, thus greatly enhancing angstrom‐scale electric field polarization. Then, it is experimentally proven that entropy‐driven electric polarization can improve the dielectric relaxation behavior characterized by broader frequency and stronger intensity of electromagnetic energy absorption, with improvements of approximately 160% and 413% compared to structurally homogeneous control. This study unveils the quantitative correlation between angstrom‐scale electric field polarization and dielectric response in perovskite oxides, offering a novel perspective for exploring the structure–property relationship in dielectric materials.
Ketocyanine‐Based Materials for Near Infrared‐to‐Visible Thermochromism
Authors: López Alex Julià , Pérez Noel Muñoz , Magerramov Ruslan , Puyol Mar , Crugeira Ferran , Miltsov Sergey , Ruiz‐Molina Daniel , Roscini Claudio
Published: November 2024

Thermochromic materials with tunable optical absorption over the NIR and visible spectral regions, and exhibiting colorless‐to‐colored transitions, are of interest in relevant applications such as invisible security inks or solar light‐energy management. Despite so, the most common commercial thermochromic materials, based on phase‐change‐material mixtures of spirocompounds (leuco‐dyes), allow narrow spectral modulation within the UV/vis regions and mostly produce colored‐to‐colorless transition, hampering their applicability beyond novelty products. In contrast, materials intrinsically thermochromic in the NIR, require time‐consuming syntheses for their spectral and transition temperature tunability. Herein these challenges are overcome by replacing conventional leuco‐dyes with Ketocyanines that exhibit strong color sensitivity on external multifactor, i.e. polarity, aggregation state, and pH, through different intermolecular interaction mechanisms, allowing fine and straightforward spectral tunability. Their absorption can be further shifted to the NIR region (λmax = 870 nm) by increasing the number of methine units, giving access to the desired colorless‐to‐colored transition (Δλ = 280 nm), via negative thermochromism. The preserved transitions of the microstructured mixtures are of interest for future thermochromic inks. Finally, their acid/base vapors response makes these multistimuli responsive materials highly attractive for applications such as anti‐counterfeiting, bioimaging, and optical information storage for food packaging.
Spin‐Orbit Coupled Trapped Exciton–Polariton Condensates in Perovskite Microcavity
Authors: Shang Qiuyu , Deng Xinyi , Song Jiepeng , Liang Yin , Lu Heng , Gong Yiyang , Chen Shulin , Gao Peng , Zhan Xiaowei , Liu Xinfeng , Zhang Qing
Published: November 2024

Lead halide perovskites exhibit superior properties compared to classical III–V semiconductor quantum wells for room‐temperature polaritonic applications, particularly owing to the significant crystalline anisotropy. This anisotropy results in a sizeable split in condensate energy, which can profoundly influence polariton interactions and spin relaxation pathways. Besides, trapped exciton‐polariton (TEP) exhibits a quantized energy landscape, which is essential for modulating polaritonic logical circuits. Herein, spin‐orbit coupled TEP lasing is demonstrated in birefringent perovskite. Cascade condensate processes between orthogonally polarized polariton branches happen considering the dominance of reservoir exciton–polariton or polariton–polariton scattering within each stage. Such condensation adequately is verified via the input‐output “S” curve, the narrowed linewidth, the energy blueshift, and the real space spatial coherence of the orthogonally polarized modes. This trapped anisotropic condensate holds great promise for room‐temperature polaritonic and spintronics.
Observing Deformation‐Induced Backscattering in Flexible Valley‐Hall Topological Metasurfaces
Authors: Ma Qian , Chen Long , Qin Shi Long , Gao Xinxin , Zhang Yi , Liu Shuo , You Jian Wei , Cui Tie Jun
Published: November 2024

Topological metasurfaces based on the quantum valley Hall effect have garnered attention for their ability to enable novel physical phenomena. However, the propagation characteristics of flexible topological metasurfaces under bending and folding remain underexplored, leaving open questions about the behaviors of topological edge states in these configurations. This study investigates edge‐state propagation and frequency response in topological insulator metasurfaces under varying degrees of circular bending and dihedral folding. A flexible topological insulator is designed, fabricated, and tested with a passband between 4.4 and −4.6 GHz, monitoring how its transmission passband changes as the curvature radius decreases from 400 to 100 mm. Simulations and experimental measurements reveal how the transmission frequency response and near‐field distribution evolve as the metasurface undergoes folding from 90° to 30°. Results show that both the topological passband and transmission gradually vary with reduced folding angles, while arc‐shaped bending minimally affects the propagation path, though the passband narrows slightly with increased curvature. To illustrate the impact, metasurface communication performance between planar and folded configurations (90° to 30°) is compared, observing a notable performance drop after folding. This study aims to enhance the understanding of edge‐state properties in topological systems under deformation and promote further advancements in flexible topological devices.
Efficient Near‐Infrared Luminescence in Cr3+ Activated β‐Alumina Structure Phosphor via Multiple‐Sites Occupancy
Authors: Li Kai , Wang Dandan , Wu Dan , Dong Xiaoling , Wang Yue , Liu Yifan , Zheng Guojun , Zhou Wenping , Zhang Liangliang
Published: November 2024

Broadband near‐infrared (NIR) phosphors play vital roles in the research and development of compact NIR light sources. Herein, improved NIR luminescence properties have been achieved in β‐alumina structure Ba0.2La0.55Mg0.55Al2.45Ga8O17.25 (BLMAG):Cr3+ phosphor by cation co‐substitution strategy, which controls the local crystal environment for site‐selective occupancy of Cr3+ emitters. With the increase of La3+‐Mg2+ couples in host lattice, the NIR emission peak can be tuned from 712 to 746 nm under 405 nm excitation with a high internal (external) quantum efficiency of 97% (42.6%) and superior thermal stability of 90% @150 °C. The structural refinement and spectral analysis indicate that the broadband NIR emission drives from the Cr3+ occupying multiple luminescence centers in the lattice. Moreover, the as‐prepared phosphor‐converted light‐emitting diode (pc‐LED), using the optimized BLMAG:0.10Cr3+ phosphor, achieves an NIR output power of 72.9 mW at 150 mA with photoelectric conversion efficiency of 15.4%. The spectra well matched to the absorption of photosensitive pigment PFR appear promising in plant growth, the captured doll as well as the penetration experiments also illustrate the application in night vision and biosensing.
Hydrogel‐Based Dynamic Structural Color with Optical Janus Effect for Imaging Encryption/Concealment
Authors: Liu Lanlan , Feng Chenyu , Bo Guohao , Wang Jing , Zhang Hanying , Shao Huguang , Zhang Jian , Zhang Xuefeng
Published: November 2024

Structural colors are widely used due to their eco‐friendliness, stability, and precise controllability. However, achieving dynamic structural colors typically requires complex fabrication processes and high‐quality material preparation. Here, a simple bilayer structure containing hydrogel micropattern and semi‐transparent ultrathin aluminum film is proposed that achieves the dynamic structural color with Janus effect. Combining experimental research and theoretical analysis, it is found that by merely controlling the electron‐beam exposure dose, the colors, and patterns with these hydrogel‐based Janus structures can be precisely and rationally designed. Additionally, the thickness and swellability of the hydrogel micropattern can be individually regulated, enabling imaging encryption/concealment with the optical Janus effect. The stability and cyclic performance of this structure are verified. The environmental sensitivity, real‐time adjustability, and stability of this hydrogel‐based Janus structural color make it suitable for applications such as secure information transmission and intelligent anti‐counterfeiting labels.
Prephase‐Based Reconfigurable Joint Amplitude‐Phase Control Metasurface for Multifunctional Scattering Manipulation
Authors: Duan Kun , Fan Chenxi , Chen Ke , Jiang Tian , Zhao Junming , Feng Yijun
Published: November 2024

Reconfigurable metasurfaces have gained significant attention due to their flexible capabilities in manipulating electromagnetic (EM) waves. In particular, amplitude and phase both play crucial roles in the wavefront regulation. However, most reported reconfigurable metasurfaces focus either on amplitude‐only or phase‐only control within a single polarization, thereby limiting their functionalities and applications. In this work, a design approach of dual‐polarization independently reconfigurable joint amplitude‐phase control metasurface is proposed. By increasing the bias voltage of the integrated p–i–n diode within the unit cell, the reflection magnitude can be continuously tuned from reflection to absorption and then switched back to reflection, allowing for a about 180° phase difference in the states. The nearly consistent and independent EM responses remain in the dual linear polarization. Furthermore, the geometric dimensions of the unit cell are adjusted to design two prephased unit cells with an approximately 90° phase difference, for enhancing the degree of freedom through metasurface array configuration. The scattering manipulation capabilities are demonstrated through full‐wave simulations and experiments, including polarization conversion, single‐beam and multi‐beam generation, modulation of scattering beam intensity, and more. The proposed metasurface can pave the way for new opportunities in scattering manipulation and enable advanced concepts for next‐generation multifunctional devices.
Converting Perovskite Nanocrystals to PbS Quantum Dots Toward Short‐Wave Infrared Photodetectors
Authors: Zhang Wenjie , Fang Fan , Zhong Huaying , Huang Lili , Tang Haodong , Chen Xi , Hao Junjie , Zhang Lei , Cao Leifeng , Tang Jun , Zheng Keyu , Müller‐Buschbaum Peter , Chen Wei
Published: November 2024

PbS quantum dots (QDs) are particularly promising in low‐cost short‐wave infrared (SWIR) photodetection and imaging applications. Herein, a novel method is introduced defined as the perovskite conversion method (PCM) fabricating PbS QDs by using perovskite nanocrystals (PeNCs) as the lead precursor. The elemental substitution mechanism for PbS QDs from PeNCs is proposed, and it is confirmed that PCM‐QDs are exhibiting a smaller trap density due to a natural perovskite passivated surface condition compared to QDs prepared via conventional hot injection method (HIM). Grazing‐incidence small‐angle X‐ray scattering (GISAXS) results indicate that a short‐range disorder of the QDs can lead to a long‐range disorder configuration in the inner structure of PCM‐QD superlattice, which leads to a compact configuration in the QD solid film facilitating charge carrier transport in devices. In a photoconductor‐typed SWIR photodetector (PD) comparison, PCM‐QD PDs exhibit a high responsivity of 468 A W−1 and detectivities of 2.1 × 1012 Jones, which are almost three times higher than the values in HIM‐QDs PDs. Moreover, PCM‐QD PDs further show a higher response speed and one magnitude order higher loss frequency than PCM‐QD PDs. PCM is promising in the fabrication of high‐quality QDs for advanced optoelectronic applications.
A Hybrid Haptic Device Integrating Pneumatic and Electromagnetic Actuators for Realistic Tactile Signal Feedback
Authors: Ryu Youngjun , Park Joowon , Hong Jeongbin , Kee Hyeonwoo , Park Sukho
Published: November 2024

The accurate and realistic transmission of tactile signals is essential for the advancement of haptic devices. Challenges arise due to the simultaneous presence of high‐frequency tactile signals, such as surface textures, and low‐frequency tactile signals, like shape or hardness, when interacting with real objects. This complexity is evident when trying to transmit various signals in existing studies such as single‐actuator, multimodal, and hybrid haptic devices. This article introduces a novel hybrid haptic device that is soft and wearable, integrating pneumatic and electromagnetic actuators to improve the accuracy of tactile signal transmission. The pneumatic actuator handles low‐frequency components, while the electromagnetic actuator is responsible for high‐frequency components, each aligning with their specific mechanical properties. A series of experiments validate the mechanical properties of our proposed device, demonstrating its significant potential in enhancing the accuracy and realism of tactile signal transmission.
Nanocarriers Made of Natural Fatty Acids: Modulation of Their Release Profiles through Photo‐Crosslinking
Authors: Zhang Dong , Meng Yuxuan , Hao Min , Xia Younan
Published: November 2024

Natural fatty acids are attractive carrier materials for drug delivery, but their rapid dissolution and degradation in vivo calls for new strategies to enhance their stability. Here we report a simple and versatile method capable of photo‐crosslinking carriers made of natural fatty acids for drug delivery under controlled release. By optimizing the crosslinking density, the nanoscale carriers show a high drug loading efficiency, together with a stable network structure for minimal degradation in a body fluid mimic. Fluorescence microscopy analysis also reveals the exceptional intracellular stability of the crosslinked network, resulting in negligible cytotoxicity toward A549 cells up to 24 h when loaded with a potent anticancer drug. We further extend this strategy to microscale carriers fabricated using electrospray. Upon photo‐crosslinking, the carriers show a retarded release of nerve growth factor, resulting in slower neurite outgrowth from dorsal root ganglion. This work holds promise for addressing the efficacy and safety issues critical to nanomedicine and related applications.
Titanium Mxene: A Promising Material for Next‐Generation Optical Biosensors and Machine Learning Integration
Authors: Aravind Athulya , Dhinasekaran Durgalakshmi , Rajendran Ajay Rakkesh
Published: November 2024

Nano biosensors based on MXenes have been emerging as a promising tool in the detection of biomarkers, for the discrimination of diseases and in the detection of environmental pollutants. Their potential in sensing applications has also drawn a lot of attention to their unique qualities such as their high conductivity, huge surface area, outstanding hydrophilicity, biocompatibility, and simplicity of surface functionalization. The development of scalable synthesis techniques is essential to the large‐scale manufacturing and broad application of MXene‐based sensors. Furthermore, the stability of the MXene layers in diverse environmental circumstances continues to be a difficulty for their practical application. To increase the dependability and precision of MXene‐based sensors, their selectivity must be increased through functionalization and tuning. With innovative technologies like machine learning, MXene biosensor is now taken advantage of new opportunities. Personalized healthcare solutions, remote data analysis, and real‐time monitoring are all possible when MXene sensors and AI algorithms work together. Herein, the optical properties, synthesis approaches, role of MXene biosensors in machine learning, its significant challenges and future prospects of MXene‐based nano(bio)sensors are deliberated.
Dehydrogenative Coupling for Synthesis of Quinazolin‐4(3H)‐ones via Tandem Reaction using Ruthenium(II)‐Phenyl‐Azo‐Naphthaldoxime: An Experimental and Theoretical Investigation
Authors: Halder Supriyo , Naskar Srijita , Jana Debashis , Kanrar Gopal , Mandal Shyama Charan , Roy Subhadip , Bharadwaj Nishchal , Pramanik Kausikisankar , Ganguly Sanjib
Published: November 2024

The bidentate N, N, donor phenyl‐azo‐naphthaldoxime NpLH, 1 was used to synthesize the ruthenium(II) complex trans‐[Ru(NpL)(CO)Cl(PPh3)2], 2. It has been characterized by SCXRD, electrochemical and spectral studies. Computational analysis indicates that the low‐lying π*‐LUMO of the complex has substantial azo‐character of coordinated ligand. This property has been exploited to form an efficient electron transfer pre‐catalyst to effectuate dehydrogenative functionalization of a large number of benzyl alcohols to quinazolin‐4(3H)‐ones via condensation with diverse o‐amino benzamides as well as N‐substituted benzamides under aerobic conditions (57 entries). A reaction mechanism has been projected via isolation of intermediates and certain control experiments. Furthermore, it has been substantiated by theoretical scrutiny using density functional theory (DFT) calculation. The catalytic cycle involves stepwise hydrogen atom transfer (HAT) from benzyl alcohols to the Nazo atoms of the coordinated ligand with subsequent removal of the H‐atoms from the Nazo atoms to regenerate the active catalyst.
Surface Reconstructed Ni0.95Pt0.05/Si Photoelectrodes for Bias‐free Hydrogen Evolution Coupled with 5‐hydroxymethylfurfural Oxidation
Authors: Zhang Haoyue , Li Shengyang , Xu Jing , Ru Changzhou , Yu Jiacheng , Luo Jun , Mu LiXuan , Shi Wensheng , She Guangwei
Published: November 2024

Coupling hydrogen evolution reaction (HER) with biomass valorization using a photoelectrochemical (PEC) system presents a promising approach for effectively converting solar energy to chemical energy. A crucial biomass valorization reaction is the production of value‐added 2,5‐furandicarboxylic acid (FDCA) via 5‐Hydroxymethylfurfural (HMF) oxidation reaction (HMFOR). To achieve efficient FDCA production, we demonstrate an effective photoanode strategy that combines metal silicidation, dopant segregation, and surface reconstruction to create a bimetallic silicide Ni0.95Pt0.05Si/n‐Si photoanode. The oxide‐free Ni0.95Pt0.05Si/n‐Si interface prepared by the metal‐silicidation process ensures efficient interfacial charge transport, while dopant segregation enhances the Schottky barrier height and photovoltage, and surface reconstruction dramatically improves the catalytic activity of the photoanode surface. The as‐prepared Ni0.95Pt0.05Si/n‐Si photoanode exhibited excellent PEC performance for HMFOR with high conversion of HMF (97.2 %) and yield of FDCA (80.3 %) under illumination. Furthermore, by integrating a surface reconstructed Ni0.95Pt0.05Si/n‐Si photoanode with a Ni0.95Pt0.05Si/p‐Si photocathode, a dual‐photoelectrode system was constructed capable of simultaneous production of FDCA and H2, which achieves high photocurrent density of 5 mA cm−2 at zero bias under illumination. This study offers an auspicious prospect for high cost‐effectiveness conversion from solar energy to industrial monomers.
Uses and Abuses of ‘Not Wanting Peace’ in the Context of the Israel/Palestine Conflict
Authors: Goodman Simon , Tiripelli Giuliana , Kambashi Ngosa
Published: November 2024

Since its inception, peace has eluded the modern state of Israel and while peace can be presented as an ideal aim, talk about peace has been shown to justify further conflict and harm in and beyond Israel and Palestine. The current analysis focuses specifically on online activity, where the aim of peace is shunned as it is deemed to be not wanted. A discursive analysis of interaction on the social media website Twitter (now X) shows that (1) opponents are presented as not wanting peace, often on the grounds that (2) Palestinians, or Muslims/Arab people more generally are too hateful to want peace, which means that Palestinians can be blamed for this lack of peace. Occasionally Israelis are also presented in this way. This argument (3) presents peace as something for Israel to offer and for Palestinians to accept or not, where they are deemed responsible if they do not accept terms that are presented to them. Together, these findings show that there is a move away from the interactional requirement to be in favour of peace, where not wanting peace can be used to support ongoing violence and conflict and, in this case, justify the status‐quo of ongoing violence and oppression of Palestinian people.
Impact of Geographical Distribution on Chemical Composition and Biological Potential of Juniperus communis L. Essential Oil: A Case Study From Western Himalayas
Authors: Vashisath Sachin , Kaundal Rishabh , Kumar Aman , Bhardwaj Rishabh , Shesh Singh Pragati , Bhatt Abhishek , Pati Aparna Maitra , Kumar Dinesh
Published: November 2024

The current study was focused to assess the impact of geographical distribution (1325–3200 m, asl) on essential oils (EOs) yield, chemical composition, and biological activities of Juniperus communis leaves. Soil mineral content was also analyzed to understand its impact on chemical composition. EO yield variations were observed (0.22%–0.48%), with highest in J. communis collected from Thatri Dhaar (JCTH) (0.48%) sample. Further, refractive index, specific gravity, and optical rotation of EOs revealed notable differences among the samples. Six trace elements in soils were found, with iron being the most abundant at all locations. Total phenolic and flavonoid content indicated significant variations, with highest total phenolic content (TPC) in JCTH (6.100 ± 0.649 mg GAE/g) sample, whereas total flavonoid content (TFC) was in J. communis collected from Mooring (JCM) (1.126 ± 0.004 mgRE/g) sample. GC and GC/MS‐based metabolite profiling had shown overall thirty metabolites, including terpenes and monoterpene hydrocarbons. Free radical scavenging assays showed strong antioxidant activity of JCCI and JCTH samples (IC50‐ABTS = 4.222 ± 0.166 µg/mL and IC50‐DPPH = 3.211 ± 0.307 µg/mL, respectively). Moreover, EOs significantly inhibit α‐glucosidase and α‐amylase enzymes, Gram‐positive and Grnegative bacterial strains. These findings suggested its promising biological potential. Furthermore, identified metabolites‐based statistical analysis (principal component analysis [PCA] and hierarchical clustering analysis [HCA]) highlighted similarities and discriminations of geographically impacted samples. This research will be helpful to understand the metabolite composition and their accumulation under different environmental conditions.