bluuebunny/crossref_metadata_2025 huggingface dataset:
Nonlinear random wave field in shallow water: variable Korteweg-de Vries framework
Authors: Sergeeva A. , Pelinovsky E. , Talipova T.
Published: February 2011

Abstract. The transformation of a random wave field in shallow water of variable depth is analyzed within the framework of the variable-coefficient Korteweg-de Vries equation. The characteristic wave height varies with depth according to Green's law, and this follows rigorously from the theoretical model. The skewness and kurtosis are computed, and it is shown that they increase when the depth decreases, and simultaneously the wave state deviates from the Gaussian. The probability of large-amplitude (rogue) waves increases within the transition zone. The characteristics of this process depend on the wave steepness, which is characterized in terms of the Ursell parameter. The results obtained show that the number of rogue waves may deviate significantly from the value expected for a flat bottom of a given depth. If the random wave field is represented as a soliton gas, the probabilities of soliton amplitudes increase to a high-amplitude range and the number of large-amplitude (rogue) solitons increases when the water shallows.
Atmospheric gravity waves in the Red Sea: a new hotspot
Authors: Magalhaes J. M. , Araújo I. B. , da Silva J. C. B. , Grimshaw R. H. J. , Davis K. , Pineda J.
Published: February 2011

Abstract. The region of the Middle East around the Red Sea (between 32° E and 44° E longitude and 12° N and 28° N latitude) is a currently undocumented hotspot for atmospheric gravity waves (AGWs). Satellite imagery shows evidence that this region is prone to relatively high occurrence of AGWs compared to other areas in the world, and reveals the spatial characteristics of these waves. The favorable conditions for wave propagation in this region are illustrated with three typical cases of AGWs propagating in the lower troposphere over the sea. Using weakly nonlinear long wave theory and the observed characteristic wavelengths we obtain phase speeds which are consistent with those observed and typical for AGWs, with the Korteweg-de Vries theory performing slightly better than Benjamin-Davis-Acrivos-Ono theory as far as phase speeds are concerned. ERS-SAR and Envisat-ASAR satellite data analysis between 1993 and 2008 reveals signatures consistent with horizontally propagating large-scale internal waves. These signatures cover the entire Red Sea and are more frequently observed between April and September, although they also occur during the rest of the year. The region's (seasonal) propagation conditions for AGWs, based upon average vertical atmospheric stratification profiles suggest that many of the signatures identified in the satellite images are atmospheric internal waves.
Re-evaluation of the Mentelle Basin, a polyphase rifted margin basin, offshore south-west Australia: new insights from integrated regional seismic datasets
Authors: Maloney D. , Sargent C. , Direen N. G. , Hobbs R. W. , Gröcke D. R.
Published: February 2011

Abstract. Vintage 2-D (two dimensional) seismic reflection surveys from the sparsely explored Mentelle Basin (western Australian margin) have been re-processed and integrated with recent high quality seismic survey, and stratigraphic borehole data. Interpretation of these data sets allows the internal geometry of the Mentelle Basin fill and depositional history to be reanalysed with a greater degree of confidence. Basin stratigraphy can be subdivided into several seismically defined megasequences, separated by major unconformities related to both the Valanginian breakup between India-Madagascar and Australia-Antarctica, and tectonically-driven switches in deposition through the Albian. Resting on the Valanginian unconformity are several kilometre-scale mounded structures that formed during late Jurassic to early Cretaceous extension. These have previously been interpreted as volcanic edifices, although direct evidence of volcanic feeder systems is lacking. An alternative interpretation is that these features may be carbonate build-ups. The latter interpretation carries significant climatic ramifications, since carbonate build-ups would have formed at high palaeolatitude, ~60° S. Soon after breakup, initial subsidence resulted in a shallow marine environment and Barremian-Aptian silty-sandy mudstones were deposited. As subsidence continued, thick Albian ferruginous black clays were deposited. Internally, black clay megasequences show previously unresolved unconformities, onlapping and downlapping packages, which reflect a complex depositional, rifting and subsidence history, at odds with their previous interpretation as open marine sediments. Southwestwards migration of the Kerguelen hotspot led to thermal contraction and subsidence to the present day water depth (~3000 m). This was accompanied by Turonian-Santonian deposition of massive chalk beds, which are unconformably overlain by pelagic Palaeocene-Holocene sediments. This substantial unconformity is related to the diachronous breakup and onset of slow spreading between Australia and Antarctica, which may have led to the reactivation and inversion of basement faults, followed by rapid seafloor spreading from the middle Eocene to the present.
Exploring the impact of altitude on congenital heart defects in Saudi Arabia
Authors: Sandridge Amy L. , Greer William , Al-Menieir Maha , Al Rowais Abdullah
Published: February 2011

Congenital heart defects (CHD) have a complex etiology in which environmental factors play a key role. High altitude has already been established as a risk factor. Data from the CHD Registry in Riyadh were used to explore the impact of altitude throughout the Kingdom, including the mountain ranges of the south-west; 2,787 Saudi Arabian CHD cases were studied from 104 different cities and villages. Altitude was estimated using a geographical information system. The CHD “burden” was estimated by normalizing the number of CHD cases according to the city population. Cities at both the highest and the lowest altitudes displayed an increased CHD burden, indicating that CHD burden in Saudi Arabia is impacted by at least two different environmental factors — high altitude and coastal proximity. There is also an indication of a separate south-western influence which may reflect a unique cultural or genetic factor.
Mechanisms for collaboration and influence: the role of IFLA and other international library-related organizations
Authors: Byrne Alex
Published: February 2011

Collaboration and influence lie at the heart of non-governmental organizations because they are created by people and their organizations which want to achieve some shared goals. Collaboration needs to be fostered at many levels including that among individuals, between member organizations, and with external bodies. Library organizations need to build structures of collaboration to provide a foundation for collaborative action towards shared goals. It is also vital that they understand the need to be influential, to look continually outside their own fields to see who to influence to support their aims.
Developing videocasts for integration into a library information literacy program at a medical college
Authors: Birch Sally , Burnett Alice , Sayed Ellen N.
Published: February 2011

Established in 2001 as a partnership between Cornell University and Qatar Foundation, Weill Cornell Medical College in Qatar (WCMC-Q) is part of Weill Cornell Medical College in New York and shares its mission of dedication to excellence in education, patient care and research.

The Distributed eLibrary (D eLib) at the WCMC-Q is a library without walls, existing in a distributed electronic environment, transcending space and place. One of its key defining features is its disseminated yet interconnected services, resources, and presence that are accessible, flexible, and dynamic.

D eLib’s strategic plan, Futura, charts the future for information resources and services and the library’s role in supporting WCMC-Q’s tripartite mission. It is a challenging and innovative plan, with eight pathways focusing on different aspects of an interconnected world of information, including end-user instruction, application of technology and promotion of library programs and services.

The ACRL Information Literacy Competency Standards for Higher Education was selected as the conceptual framework for the D eLib Information Literacy Program. It was this planning effort that prompted the librarians to consider multi-media tools, such as videos, to compliment the librarians’ classroom instruction, and to enhance the students’ information related learning experiences and knowledge base.

Within this distributed environment infused with technology D eLib introduced DeLibCasts on select, pre-defined topics from the D eLib Information Literacy Plan to facilitate utilization of our resources and services: keyword search, search limits, my account, among others.

This paper discusses the planning and implementation process of producing videocasts, from identifying a need, acquiring the right software, development of a consistent layout for each video cast, creation of a framework, involving library staff, promotion and delivery. DeLib currently has nine videocasts available and more under production.

An assessment of the D eLibCasts will be part of the comprehensive assessment of D eLib’s Information Literacy Program.
"La frontera norte tiene tres problemas: tráfico de armas, de drogas y de migrantes". Migración irregular y discursos 'securitarios' en Centroamérica: el caso de Costa Rica
Authors: Kron Stefanie
Published: February 2011

Tomando Costa Rica como caso ejemplar, en el ensayo se explora la tematización y el tratamiento institucional de la migración irregular en Centroamérica. Partiendo del paradigma mundial de una "securitización" de la migración irregular (Waever et al., 1993; Weiner, 1995), y aplicando un marco de análisis transnacional y de multiniveles, se preguntará por los repertorios discursivos, los actores y medidas específicos que confluyen en la creación de un nexo migración/(in)seguridad en Centroamérica en general y en Costa Rica en particular. La hipótesis principal es que se está fomentando un nuevo régimen regional de migración y de fronteras que (ya) no proyecta principalmente reforzar los mecanismos de control del territorio nacional, proteger las fronteras y detener las migraciones irregulares. Más bien se trata de establecer, a través de ciertos ‘discursos securitarios’, una nueva gobernabilidad (Foucault, 1991) de la alta permeabilidad de las fronteras centroamericanas y de los movimientos de los individuos que las cruzan. Usando métodos etnográficos y análisis del discurso (Jäger, 2001), el artículo analiza cómo los 'discursos securitarios' que circulan a nivel mundial y regional se manifiestan, por un lado, en la nueva legislación de migración en Costa Rica, y por otro, en las prácticas de "movilidad transfronteriza" y de control de la misma en la llamada "frontera norte" que separa Costa Rica y Nicaragua.
Situación actual de las revistas académicas nicaragüenses y sus posibilidades de incorporación al movimiento de Acceso Abierto
Authors: García Mauricio , Bellanger Wendy , Huete-Pérez Jorge A
Published: February 2011

Con la iniciativa de Acceso Abierto (Open Access), la comunidad científica -a través de las revistas académicas- promueve el acceso gratuito a la literatura científica de manera que se pueda leer, imprimir o distribuir, teniendo garantizada la calidad mediante la revisión de pares. La iniciativa, surgida en los países industrializados, ha ido tomando auge en los países pequeños. Sin embargo, se desconoce su alcance. Aquí se expone el estado de las publicaciones académicas Nicaragüenses en relación a sus procesos de gestión editorial, el cumplimiento de normas y estándares de calidad propios de las revistas científicas, la gestión de los derechos derivados de la propiedad intelectual, y su posición y requerimientos técnicos, tecnológicos, económicos, y de capacitación, respecto al acceso abierto y a su disposición de convertirse en una publicación electrónica de acceso abierto.
No sea así entre ustedes: ensayo sobre política y esperanza de Juan Hernández Pico
Authors: Rocha José Luis
Published: February 2011

Siempre he pensado que todo libro vale por lo que tiene de prolongación de la experiencia vital. Los libros no sustituyen a la vida. La prolongan y la profundizan. Y sin duda en No sea así entre ustedes hay mucha experiencia vital concentrada y profundizada.
Social Isolation and Loneliness in Older Adults
Authors: Gerlach Lauren B. , Solway Erica S. , Malani Preeti N.
Published: May 2024

This JAMA Patient Page discusses social isolation and loneliness as important public health concerns, especially among older adults.
The Other Side of the Curtain
Authors: Stevens Paige
Published: May 2024

In this narrative medicine essay, a newly minted pediatric critical care physician learns firsthand what holistic medical care is from the love and attention she received during a hospitalization for mediastinal lymphoma.
Shingles Vaccination in Medicare Part D After Inflation Reduction Act Elimination of Cost Sharing
Authors: Qato Dima M. , Romley John A. , Myerson Rebecca , Goldman Dana , Fendrick A. Mark
Published: May 2024

This cross-sectional study uses data from retail pharmacies to examine shingles vaccine uptake among Medicare Part D beneficiaries following an IRA policy to eliminate cost sharing.
A Patient With Slow Communication and Difficulty Walking
Authors: Matsushima Hirokazu , Kikuchi Masayuki , Shintani Tsunehiro
Published: May 2024

A 70-year-old woman with hypertension and dyslipidemia presented with slow communication and difficulty walking 90 days after 6 courses of postoperative chemotherapy following right breast cancer surgery. What is your diagnosis?
Mandibular Advancement vs Combined Airway and Positional Therapy for Snoring
Authors: Ioerger Patrick , Afshari Azadeh , Hentati Firas , Strober William , Kallogjeri Dorina , Ju Yo-El , Piccirillo Jay F.
Published: May 2024

Importance

Approximately 150 million individuals in the US snore in the absence of obstructive sleep apnea (primary snoring), but few studies have examined the efficacy of treatments for snoring or evaluated the effect of snoring in sleeping partners.

Objective

To evaluate the efficacy of 2 treatments for primary snoring.

Design, Setting, and Participants

This pilot randomized clinical trial that included a convenience sample of people who snore without sleep apnea and their sleeping partner who underwent 4 weeks of snoring treatment was conducted at an academic medical center between October 3, 2022, and July 3, 2023.

Interventions

Fifty couples were randomized to either use a mandibular advancement device (MAD) or receive combined airway and positional therapy (CAPT; external nasal dilator, nasal saline lavage with mometasone, mouth taping, and lateral positional therapy).

Main Outcome and Measure

Percentage of sleeping partners who reported that their partner’s snoring was either very much improved or much improved (responder) on the Clinical Global Impression of Improvement scale.

Results

A total of 42 dyads completed the study; 23 (55%) were randomized to MAD and 19 (45%) to CAPT. Among people who snore, 26 (62%) were female, and the mean (SD) age was 48 (14) years. Of 23 dyads randomized to MAD, 21 people who snore (91%) were rated by the sleeping partner as a responder, while 11 of the 19 dyads (58%) randomized to CAPT were rated by the sleeping partner as responder, resulting in a difference of 33 percentage points (95% CI, 8-58) and a number needed to treat of 3. Of the 10 participants who were withdrawn, 4 were withdrawn due to adverse effects of the treatment that were evenly distributed between the MAD (n = 2) and CAPT (n = 2) groups.

Conclusion and Relevance

The results of this randomized clinical trial showed that the MAD may be more effective than CAPT for treating primary snoring, while both treatment options were found to reduce primary snoring. Physicians should have a patient-centered discussion to determine which treatment is best for individual patients with primary snoring, weighing convenience, adverse effects, and cost as factors.

Trial Registration

ClinicalTrials.gov Identifier: NCT05756647
A Review on Laser Beam Shaping Application in Laser‐Powder Bed Fusion
Authors: Bakhtari Ahmad Reshad , Sezer Huseyin Kursad , Canyurt Olcay Ersel , Eren Oğulcan , Shah Mussadiq , Marimuthu Sundar
Published: May 2024

Laser‐powder bed fusion (L‐PBF) is extensively adopted in the aerospace and automobile industries for producing metallic components. The L‐PBF process involves rapid melting and solidification of metallic powders using a laser source to produce dense parts. Most industrial L‐PBF systems use a fiber‐based laser source that emits a Gaussian beam distribution. However, the conventional Gaussian beam used in L‐PBF processes presents inherent limitations that can impact the quality and properties of the final products. This review aims to provide a theoretical background of laser beam shaping techniques and explores the application of alternative beam shapes in L‐PBF. It investigates how different beam profiles affect the melt pool geometry, process stability, productivity, mechanical properties, microstructure, and surface roughness of fabricated parts. Additionally, it discusses different types of beam shaping techniques and elements utilized to generate distinct beam shapes. Furthermore, different constraints and limitations that hinder the full exploitation of beam shaping are critically discussed. By analyzing the impact of beam shaping in L‐PBF, this review provides insight into optimizing the additive manufacturing process, enhancing part quality, and improving processing performance. It will also help readers to overview the research gaps, challenges, and promising future directions in laser beam shaping applications in L‐PBF.
Spontaneous Structuration of Biohydrogels by Membrane‐Free Osmosis
Authors: Guilbert Emilie , de Loubens Clément , Vilotte Alice , Schmitt Christophe , Gunes Deniz , Bodiguel Hugues
Published: May 2024

Many bio‐hydrogels are prepared thanks to the addition of divalent ions. These gels usually exhibit partial ionic selectivity, a feature is leveraged to instigate an osmotic flow during the gelation process across a range of bio‐hydrogels. A simple experimental setup consisting a glass capillary filled by the reactant solution is taken as an advantage, brought into contact with a reservoir of calcium chloride. Direct observation allows to characterize the gelation kinetics, the permeability and the selectivity of several gels, including some made of protein aggregates, pectin, and alginate. It is shown that these intrinsic properties, coupled with appropriate gelation kinetics, intricately govern the osmotic flow induced by the chemical potential difference of the calcium chloride ions imposed during gel formation, consistent with the Kedem–Kashalsky equation. The forming gel acts as a semi‐permeable membrane for calcium chloride ions. The consequences of this osmotic flow are of potentially great interest since it triggers an increase of the gel concentration close to its boundary, opening the road to their spontaneous structuration. The formation of this dense shell is well accounted for the combination of a mass balance and a kinetic model.
Polarization‐Induced Mechanically Socketed Ultra‐Stretchable and Breathable Textile‐Based Nanogenerator and Pressure Sensor
Authors: Garg Romy , Majhi Abhisek , P Nagasreenivasarao , Patra Nikhil Ram , Barve Ritesh , Parida Kaushik
Published: May 2024

Textile‐based wearable triboelectric nanogenerators (TENGs) have emerged as viable power sources for wearable electronics. However, it is still a daunting challenge to realize a high‐performing textile‐based nanogenerator without compromising its intrinsic textile‐like properties, such as stretchability, breathability, and conformability. The above challenge is addressed by fabricating a record high‐performing wearable, breathable and stretchable nanogenerator based on polarization‐induced ultra‐stretchable EVA/Nylon‐11 micro/nano‐fibers (1250%) as the triboelectric positive layer and polarization‐induced ultra‐stretchable EVA/PVDF/BA2CsAgBiBr7 micro/nano‐fibers (1480%) as the triboelectric negative layer. The excellent stretchability, breathability (1.15 Kgm−2d−1) and high energy‐harvesting performance (650 V, 19.5 µAcm−2) are attributed to the mechanically‐socketed structure of the aligned stretchable EVA microfibers with the polarized nanofibers, thus providing a universal framework to fabricate stretchable piezoelectric fibers. Compositional engineering and polarization‐induced surface charges coupled with triboelectric‐induced surface charges enabled enhanced performance compared to other wearable stretchable textile‐based nanogenerators. Additionally, it is utilized as a stretchable self‐powered pressure sensor with an ultra‐wide pressure sensing range (0.05–500 kPa) and high sensitivity (2.5 VkPa−1) even under deformations. To the best of the knowledge, PI‐STENG stands out amongst various stretchable self‐powered pressure sensors in terms of pressure sensing range and stretchability. The PI‐STENG is demonstrated as a machine learning‐enabled intellisensor for workforce safety monitoring.
Designed 3D Dumpling‐Shaped Femtosecond Laser Structured Light Field for Nanoscale Sensing
Authors: Pan Deng , Fuyang Zhijuan , Wang Hui , Wang Zhiqiang , Kuai Yan , Zhang Chenchu , Lao Zhaoxin , Zhang Jingjing , Ni Jincheng , Xu Bing , Zhen Shenglai , Yu Benli , Wu Dong
Published: May 2024

Nanoscale optical sensing plays a crucial role in achieving high‐precision non‐contact distance and displacement measurements. As one of the promising alternatives, structured light can greatly simplify optical sensing systems. In this study, a novel optical phenomenon of a structured beam called the “Dumpling‐shaped Structured Light Field” (DSLF) is revealed, which forms during the focusing of cylindrical lens beams. The 3D DSLF comprises two mutually perpendicular primary and secondary foci, offering unique possibilities in micro/nano processing and sensing applications. A thorough investigation of the DSLF is conducted, revealing a correlation between the secondary foci and the phase status at the objective lens's entrance pupil. The propagation of DSLF under tight focus conditions has been verified and discussed through methods of femtosecond laser two‐photon polymerization and light field analysis. Finally, thanks to the unique 3D intensity distribution of 3D DSLF, the applicability of DSLF in high‐precision position and vibration sensing has been demonstrated. By detecting the horizontal and vertical dimensions of the reflected DSLF, position and vibration sensing is achieved with a Z‐direction accuracy of 10 nm (λ/80). This research contributes to understanding structured light, and offers practical applications in various fields, including micro/nano laser processing, optical imaging, sensing, etc.
Photoluminescence Probes Ion Insertion into Amorphous and Crystalline Regions of Organic Mixed Conductors
Authors: Collins Garrett W. , Lone Mohd Sajid , Jackson Seth R. , Keller Jolene N. , Kingsford Rand L. , Noriega Rodrigo , Bischak Connor G.
Published: May 2024

Organic mixed ionic‐electronic conductors (OMIECs) have emerged as promising materials for a wide range of next‐generation technologies, including bioelectronics and neuromorphic computing. The performance of these materials depends on the transport of ions through the polycrystalline polymer matrix as well as how the distribution of ions and polarons in crystalline and amorphous regions impacts electronic transport. However, it is often challenging to distinguish whether ions enter crystalline or amorphous regions. In this work, steady‐state and time‐resolved photoluminescence (PL) spectroelectrochemistry is used to probe initial ion insertion in crystalline and amorphous regions of the OMIEC material poly(3‐[2‐[2‐(2‐methoxyethoxy)ethoxy]ethyl]thiophene ‐2,5‐diyl) (P3MEEET) as a function of applied voltage. It is found that PL spectroelectrochemistry reports on the initial stages of electrochemical doping through the quenching of PL emission. By distinguishing between amorphous and crystalline contributions to the PL spectrum, ion insertion in crystalline and amorphous regions as a function of voltage is tracked. It is found that PL spectroelectrochemistry is much more sensitive to the initial injection of ions than complementary methods, highlighting its potential as a sensitive tool for interrogating ion injection in OMIECs.
Suppressing Shuttle Effect via Cobalt Phthalocyanine Mediated Dissociation of Lithium Polysulfides for Enhanced Li‐S Battery Performance
Authors: Zhang Wei , Zhu Jiawen , Ye Yadong , She Jiaxuan , Kong Xianghua , Jin Song , Peng Zhangquan , Ji Hengxing
Published: May 2024

Cationic lithium polysulfides (LiPSs) within ether‐based electrolytes are essential intermediates pivotal in instigating the shuttle effect. Suppressing the generation of cationic LiPSs is crucial for enhancing the performance of high‐energy‐density Li‐S batteries in practical applications. Herein, for the first time, it is demonstrated that cobalt phthalocyanine (CoPc) can significantly enhance the dissociation of LiPSs, leading to a decrease in cationic LiPSs species within the electrolyte. Employing NMR and in‐situ Raman spectroscopy, it is observed that CoPc interacts with sulfur anions within LiPSs, modifying the dissociation equilibrium of LiPSs in 1,2‐dimethoxyethane (DME)/1,3‐dioxolane (DOL) electrolyte. This CoPc‐mediated shift toward dissociation equilibrium reduces the concentration of cationic LiPSs, effectively suppressing the electromigration of LiPSs intermediates toward the Li anode during the charging process of Li‐S battery. As a result, the Li‐S battery enabled a high reversible areal capacity of 4.2 mAh cm−2 at a high sulfur loading of 5.0 mg cm−2 and a low electrolyte/sulfur (E/S) ratio of 3 µL mgs−1. This work affords a promising strategy for tackling the fundamental challenges regarding Li‐S batteries.
Bi2S3 Confined by Covalent Organic Frameworks Enables High‐Rate High‐Capacity Potassium Storage
Authors: Li Wentao , Zhang Qingfeng , Pei Quan , Yang Ying , Zhao Jingxin , Xie Shuhong , Huang Jianyu
Published: May 2024

Potassium‐ion hybrid capacitors (PIHCs) are highly promising as an energy‐storage system. However, the rate performance and cycling performance of most materials with high capacity cannot simultaneously meet the requirements of PIHCs. In this work, a composite material of Bi2S3 nanoparticles in situ confined within a sulfur‐doped covalent organic framework (COF) and combined with graphene (Bi2S3@SCOF/G) is synthesized. Due to the synergistic effect of the stability of COF to buffer large mechanical stresses and the high electronic conductivity of graphene, the Bi2S3@SCOF/G anode reveals a high reversible capacity (503.8 mAh g−1 at 100 mA g−1 after 100 cycles) and favorable rate performance (223.9 mAh g−1 even at 5000 mA g−1). Furthermore, the PIHCs assembled with activated carbon show excellent energy density and cycling performance, indicating their potential for practical applications.
Self‐Adjustment of Intrinsic Reaction Intermediate on Atomically Dispersed Co2–N6 Binuclear Sites Achieving Boosted Electrocatalytic Oxygen Reduction Performance
Authors: Lu Tingyu , Zhou Qixing , Li Jing , Li Tongfei , Gong Jiayue , Zhang Songtao , Pang Huan , Xi Shibo , Xu Lin , Luo Gan , Sun Dongmei , Sun Kang , Tang Yawen
Published: May 2024

Isolated dual‐atom catalysts (DACs) have sparked enormous research enthusiasm in new energy community due to their great potentials to substitute the state‐of‐the‐art Pt‐based catalysts. Nevertheless, explicitly unraveling the underlying catalytic mechanisms is of critical significance for performance enhancement, yet remains a huge challenge. Herein, the study reports a reliable hard template‐mediated strategy to accomplish the construction of atomically isolated binuclear Co2‐N6 sites stabilized by ultrathin hollow carbon nanospheres (abbreviated as Co2‐DAs@CHNSs). Systematic spectroscopy characterization and theoretic calculations uncover that the Co2‐N6 sites follow a self‐adjusting mechanism caused by the intrinsic OH intermediate. The involvement of the ‐OH energy‐level modifier is found to induce the electron redistribution and alternation of antibonding orbital fillings for the generated Co2‐N6‐OH site, leading to reduced potential‐determining step (PDS) energy barrier, and thus boosted intrinsic activity. Consequently, the well‐managed Co2‐DAs@CHNSs afford outstanding oxygen reduction reaction (ORR) activity with a half‐wave potential of 0.87 V in alkaline electrolyte, overmatching the Pt benchmark. Furthermore, the Co2‐DAs@CHNSs‐assembled aqueous and all‐solid‐state rechargeable zinc–air batteries (ZABs) demonstrate high power density, large specific capacity, and robust stability. The findings offer an innovative avenue to rationally manipulate the electronic structures of active sites for DACs via a powerful self‐ligand modification strategy.
Defect‐Expedited Photocarrier Separation in Zn2In2S5 for High‐Efficiency Photocatalytic C─C Coupling Synchronized with H2 Liberation from Benzyl Alcohol
Authors: Ma Minmin , Wang Ran , Shi Li , Li Ronghua , Huang Jie , Li Zhuo , Li Peng , Konysheva Elena Yu. , Li Yanbo , Liu Gang , Xu Xiaoxiang
Published: May 2024

Photocatalytic carbon‐carbon (C─C) coupling of benzyl alcohol is a promising means to coproduce the value‐added chemicals with H2 but is generally subject to low efficiency in terms of photon utilization. Here, efficient benzyl alcohol C─C coupling is achieved over Zn2In2S5 containing a tunable content of Zn vacancies (VZn). The VZn tends to form shallow defect states below the conduction band that can expedite photocarrier separation by collecting the photo‐generated electrons. The VZn‐collected electrons are essential for a high selectivity of the C─C coupling reactions because they enable a fast elimination of the byproduct benzaldehyde by catalyzing its reduction back to the ketyl radicals. Under simulated sunlight, the VZn‐containing Zn2In2S5 accomplishes ≈100% conversion of benzyl alcohol for merely 1 h and attains ≈100% selectivity for the C─C coupling compounds for 2 h, delivering an apparent quantum yield as high as 7.7% at 420 ± 20 nm. The benefits of VZn have also been verified by the theoretical calculations that indicate reduced energy barriers for various surface reactions in the presence of VZn. This work brings fresh mechanistic insights into the role of VZn and can serve as a useful guideline in the design of efficient photocatalysts.
A Cyanine with 83.2% Photothermal Conversion Efficiency and Absorption Wavelengths over 1200 nm for Photothermal Therapy
Authors: Zhao Liang , Zhu Han , Duo You‐Yang , Wang Zhi‐Gang , Pang Dai‐Wen , Liu Shu‐Lin
Published: May 2024

Developing small‐molecule photothermal agents (PTAs) with good near‐infrared‐II (NIR‐II) response for deeper tissue penetration and minimizing damage to healthy tissues has attracted much attention in photothermal therapy (PTT). However, concentrating ultra‐long excitation wavelengths and high photothermal conversion efficiencies (PCEs) into a single organic small molecule is still challenging due to the lack of suitable molecular structures. Here, six polymethine cyanine molecules based on the structure of indocyanine green are synthesized by increasing the conjugated structure of the two‐terminal indole salts and the number of rigid methine units, and incorporating longer alkyl side chains into the indole salts. Ultimately, IC‐1224 is obtained with an absorption wavelength of more than 1200 nm, which has a high PCE up to 83.2% in the NIR‐II window and exhibits excellent PTT tumor ablation performance. This provides a high‐performance NIR‐II‐responsive PTA, and offers further possibilities for the application of PTT in biomedical fields.
Reprograming Clots for In Vivo Chemical Targeting in Traumatic Brain Injury
Authors: Kandell Rebecca M. , Wu Jason R. , Kwon Ester J.
Published: May 2024

Traumatic brain injury (TBI) is a critical public health concern, yet there are no therapeutics available to improve long‐term outcomes. Drug delivery to TBI remains a challenge due to the blood‐brain barrier and increased intracranial pressure. In this work, a chemical targeting approach to improve delivery of materials to the injured brain, is developed. It is hypothesized that the provisional fibrin matrix can be harnessed as an injury‐specific scaffold that can be targeted by materials via click chemistry. To accomplish this, the brain clot is engineered in situ by delivering fibrinogen modified with strained cyclooctyne (SCO) moieties, which incorporated into the injury lesion and is retained there for days. Improved intra‐injury capture and retention of diverse, clickable azide‐materials including a small molecule azide‐dye, 40 kDa azide‐PEG nanomaterial, and a therapeutic azide‐protein in multiple dosing regimens is subsequently observed. To demonstrate therapeutic translation of this approach, a reduction in reactive oxygen species levels in the injured brain after delivery of the antioxidant catalase, is achieved. Further, colocalization between azide and SCO‐fibrinogen is specific to the brain over off‐target organs. Taken together, a chemical targeting strategy leveraging endogenous clot formation is established which can be applied to improve therapeutic delivery after TBI.
Passivation Layers in Mg‐Metal Batteries: Robust Interphases for Li‐Metal Batteries
Authors: Zhao Zhiming , Nian Binbin , Lei Yongjiu , Zhao Lingyun , Hedhili Mohamed N. , Guo Dong , Shi Zixiong , Zhao Wenli , El‐Demellawi Jehad K. , Wang Yizhou , Zhu Yunpei , Xu Kang , Alshareef Husam N.
Published: May 2024

In advanced batteries, interphases serve as the key component in stabilizing the electrolyte with reactive electrode materials far beyond thermodynamic equilibria. While an active interphase facilitates the transport of working ions, an inactive interphase obstructs ion flow, constituting the primary barrier to the realization of battery chemistries. Here, a successful transformation of a traditionally inactive passivating layer on Mg‐metal anode, characteristic of Mg‐metal batteries with typical carbonate electrolytes, into an active and robust interphase in the Li‐metal scenario is presented. By further strategically designing magnesiated Li+ electrolytes, the in situ development of this resilient interphase on Li‐metal anodes, imparting enduring stability to Li‐metal batteries with nickel‐rich cathodes is induced. It is identified that the strong affinity between Mg2+ and anions in magnesiated Li+ electrolytes assembles ionic clusters with a bias for reducibility, thereby catalyzing the creation of anion‐derived interphases rich in inorganic constituents. The prevalence of ionic clusters induced by magnesiation of electrolytes has brought properties only available in high‐concentration electrolytes, suggesting a fresh paradigm of tailing electrolytes for highly reversible LMBs.
Multi‐Interface Engineering of MXenes for Self‐Powered Wearable Devices
Authors: Liu Chao , Feng Ziheng , Yin Tao , Wan Tao , Guan Peiyuan , Li Mengyao , Hu Long , Lin Chun‐Ho , Han Zhaojun , Xu Haolan , Cheng Wenlong , Wu Tom , Liu Guozhen , Zhou Yang , Peng Shuhua , Wang Chun , Chu Dewei
Published: May 2024

Self‐powered wearable devices with integrated energy supply module and sensitive sensors have significantly blossomed for continuous monitoring of human activity and the surrounding environment in healthcare sectors. The emerging of MXene‐based materials has brought research upsurge in the fields of energy and electronics, owing to their excellent electrochemical performance, large surface area, superior mechanical performance, and tunable interfacial properties, where their performance can be further boosted via multi‐interface engineering. Herein, a comprehensive review of recent progress in MXenes for self‐powered wearable devices is discussed from the aspects of multi‐interface engineering. The fundamental properties of MXenes including electronic, mechanical, optical, and thermal characteristics are discussed in detail. Different from previous review works on MXenes, multi‐interface engineering of MXenes from termination regulation to surface modification and their impact on the performance of materials and energy storage/conversion devices are summarized. Based on the interfacial manipulation strategies, potential applications of MXene‐based self‐powered wearable devices are outlined. Finally, proposals and perspectives are provided on the current challenges and future directions in MXene‐based self‐powered wearable devices.
A Cable‐Stayed Honeycomb Superstructure to Improve the Stability of Li‐Rich Materials via Inhibiting Interlaminar Lattice Strain
Authors: Jiang Yun‐shan , Liao Zhong‐miao , Yu Fu‐da , Ke Wang , Li Xin‐yu , Xia Yang , Xu Gui‐jing , Sun Gang , Xia Yuan‐guang , Yin Wen , Deng Liang , Zhao Lei , Wang Zhen‐bo
Published: May 2024

In layered Li‐rich materials, over stoichiometric Li forms an ordered occupation of LiTM6 in transition metal (TM) layer, showing a honeycomb superstructure along [001] direction. At the atomic scale, the instability of the superstructure at high voltage is the root cause of problems such as capacity/voltage decay of Li‐rich materials. Here a Li‐rich material with a high Li/Ni disorder is reported, these interlayer Ni atoms locate above the honeycomb superstructure and share adjacent O coordination with honeycomb TM. These Ni─O bonds act as cable‐stayed bridge to the honeycomb plane, and improve the high‐voltage stability. The cable‐stayed honeycomb superstructure is confirmed by in situ X‐ray diffraction to have a unique cell evolution mechanism that it can alleviate interlaminar lattice strain by promoting in‐plane expansion along a‐axis and inhibiting c‐axis stretching. Electrochemical tests also demonstrate significantly improved long cycle performance after 500 cycles (86% for Li‐rich/Li half cell and 82% for Li‐rich/Si‐C full cell) and reduced irreversible oxygen release. This work proves the feasibility of achieving outstanding stability of lithium‐rich materials through superstructure regulation and provides new insights for the development of the next‐generation high‐energy‐density cathodes.
Gradient Doping Enables an Extraordinary Efficiency in Thermoelectric PbTe1−xIx
Authors: Zhou Jiayu , Chen Zhiwei , Luo Jun , Li Wen , Pei Yanzhong
Published: May 2024

The conversion efficiency of thermoelectric generators that have to be operated under a temperature difference (ΔT) is mainly determined by material's dimensionless figure of merit (zT). However, maximization of zT at each temperature requires an optimization of carrier concentration (nopt) which strongly depends on the temperature and band parameters. Commonly utilized strategy of chemical doping usually enables a homogeneous carrier concentration throughout the material, leading the maximal zT to be achievable only within a narrow temperature range. In this work, a gradiently doping is successfully realized in PbTe1−xIx using a vertical gradient solidification technique, enabling a spatial gradient in carrier concentration that correspondingly optimizes zT at each portion of the material under its operating temperature. Such a gradient doping results in an extraordinary device efficiency of ≈14% at a ΔT of ≈500 K, corresponding to a ≈40% improvement as compared to that of homogeneous doping. Since directional solidification technique commonly enables gradient dopant concentrations in semiconductors, the resultant gradient carrier concentration is illustrated here as an effective approach for advancing thermoelectrics.
Bulged CH3NH3PbBr3 Microwires for Single‐Mode Lasing
Authors: Wu Wanling , Luo Zhiqiang , Xu Tao , Lun Yipeng , Deng Jiale , Huang Xingzhao , Ye Huanqing , Yu Huakang , Yang Zhongmin
Published: May 2024

Herein, the lasing action of fabricated bulged CH3NH3PbBr3 microwires is demonstrated with features of a low threshold, narrow linewidth, single‐mode operation, and high intensity. Benefiting from the bulged end facets, the CH3NH3PbBr3 microwires are feasible for constructing a high‐brightness, whispering‐gallery‐mode(WGM)‐type, and single‐mode laser while suppressing Fabry–Pérot‐type multi‐mode lasing. Numerical simulation unveils that the bulged end facets result in the significantly reduced reflectivity of fundamental waveguided modes. The obtained microlasers require neither complex structures (such as distributed Bragg reflector) nor careful pumping adjustment, suggesting the practical feasibility of a higher single‐mode lasing intensity than conventional WGM perovskite microlasers. The results provide new routes to realize high‐performance perovskite microlasers and their potential application in sensing refractive index.
Silicon‐Rich Nitride Refractive Index as a Degree of Freedom to Maximize Nonlinear Wave Mixing in Nanowaveguides
Authors: Belogolovskii Dmitrii , Alic Nikola , Grieco Andrew , Fainman Yeshaiahu
Published: May 2024

Silicon nitride is widely used in integrated photonics for optical nonlinear wave mixing due to its low optical losses combined with relatively high nonlinear optical properties and a wide‐range transparency window. It is known that a higher concentration of Si in silicon‐rich nitride (SRN) magnifies both the nonlinear response and optical losses, including nonlinear losses. To address the trade‐off, four‐wave mixing (FWM) is implemented in over a hundred SRN waveguides prepared by plasma‐enhanced chemical vapor deposition in a wide range of SRN refractive indices varying between 2.5 and 3.2 (measured in the C‐band). It is determined that SRN with a refractive index of about 3 maximizes the FWM efficiency for continuous‐wave operation, indicating that the refractive index of SRN is indeed a crucial optimization parameter for nonlinear optics applications. The FWM efficiency is limited by large nonlinear optical losses observed in SRN waveguides with indices larger than 2.7, which are not related to two‐photon absorption. Finally, the third‐order susceptibility and the nonlinear refractive index are estimated for multiple SRN refractive indices, and, specifically, the nonlinearities as large as and are estimated in a waveguide with an SRN refractive index of 3.2.
Miura Origami‐Inspired Reconfigurable Phase Gradient Metasurface for Linearly and Circularly Polarized Differential Modulation
Authors: Zhu Zhibiao , Li Yongfeng , Wang Jiafu , Jiang Lixin , Qin Zhe , Zheng Lin , Chen Hongya , Wang Wenjie , Qu Shaobo
Published: May 2024

Miura origami's reconfigurable characteristic and structural asymmetry, combined with electromagnetic (EM) wave manipulation, crashed a unique spark. However, the complexity of the three‐dimensional (3D) origami structure after folding makes it challenging to study the phase regulation mechanism. Here, we propose a reconfigurable phase gradient metasurface based on Miura origami and derive the underlying mechanism of phase modulation in detail under linearly and circularly polarized (LP and CP) incidence. We adopt the one‐dimensional (1D) gradient design along the x direction to verify the idea. The phase calculation formulas are given under LP and CP incidence through the Jones matrix's derivation. The beam deflector angles corresponding to LP and CP waves are identical in the planar state. As the folding angle increases, the phase evolution rules corresponding to the LP and CP waves are discrepant, leading to differential beam steering. Finally, the origami sample is processed for verification, and the experimental data are consistent with the simulation and theoretically calculated values. We believe this work can help analyze the EM behavior of complex 3D origami structures and lay a foundation for designing a multifunctional EM origami metasurface.
Can Pressure be a Good Strategy for Optimizing Thermoelectric Performance of SnPS3${\rm SnPS}_3$?
Authors: Sharma Gautam , Singh Nirpendra
Published: May 2024

External pressure can significantly alter the transport coefficients, power factor, and figure of merit because of its direct influence on the electronic structure, electron–phonon, and phonon–phonon couplings. This study delves into the electronic and thermal transport properties of at external pressures up to 30 GPa using first‐principles calculations and Boltzmann transport theory. The electron–phonon relaxation time is computed within the electron–phonon‐averaged (EPA) approximation, enabling exploration beyond the constant relaxation time approximation. The first‐principles calculations reveal an indirect bandgap of 1.76 (without pressure) and 0.12 eV (30 GPa). The density functional perturbation theory calculations confirm the dynamic stability of at external pressure up to 30 GPa. The electronic transport properties are improved by more than one order of magnitude at 30 GPa, consistent with experimental observations. The Peierls–Boltzmann transport calculations demonstrate the room temperature lattice thermal conductivity of 0.22 (without pressure) and 7.4 (at 30 GPa). The results emanate that exhibits of 0.71 at 900 K at a hole doping of 2 at zero pressure, which decreases with increasing pressure. The findings explore the effect of external pressure on both electronic and thermal transport properties of , warranting further experimental exploration of thermal transport properties at higher pressures.
Control of Ferroelectricity in Solution‐Processed Hafnia Films Through Annealing Atmosphere
Authors: Mandal Barnik , Valle Nathalie , Adib Brahime El , Girod Stéphanie , Menguelti Kevin , Fleming Yves , Grysan Patrick , Defay Emmanuel , Glinsek Sebastjan
Published: May 2024

Chemical Solution Deposition enables low‐cost fabrication of ferroelectric HfO2 films suitable for piezoelectric applications. Control of processing parameters is of utmost importance to obtain high‐quality functional films. However, the impact of the annealing atmosphere on ferroelectric properties of solution‐processed HfO2 films is not clear. In this work, the influence of annealing atmosphere and growth methods on orientation, density and electrical properties of La:HfO2 films is studied. The 45 nm‐thick films are grown by two routes, conventional (crystallization of the final 45 nm‐thick film) and layer‐by‐layer (intermediate crystallizations of 5 nm‐thick films). Annealing is performed in N2:O2 and Ar atmosphere. Films grown by layer‐by‐layer method in an oxygen‐rich atmosphere tend to have higher density (87% of theoretical density) and remanent polarization (15 µC cm–2) than the conventional films (density and remanent polarization of 80% and 7.5 µC cm‐2). Secondary ion mass spectrometry reveals higher amounts of carbon presence in the conventional films annealed in Ar. For layer‐by‐layer films, the ability to control the preferential out‐of‐plane orientation from (111) to (002) simply by changing the annealing atmosphere, is demonstrated. The results can guide the path toward high‐quality thicker films for piezoelectric applications.