bluuebunny/crossref_metadata_2025_split huggingface dataset:
A 4D‐Printed Electromagnetic Cloaking and Illusion Function Convertible Metasurface
Authors: Liang Qingxuan , Li Zhaohui , Xu Jiahui , Duan Yubing , Yang Zhen , Li Dichen 
Published: March 2023

AbstractThe appearance of metasurfaces provides a new way for the realization of cloaking and illusion devices. However, most proposed metasurface functional devices only display a single cloaking and illusion function. Herein, a dynamic metasurface device with switchable electromagnetic cloaking and illusion functions is fabricated based on a 4D‐printing process. Owing to the shape memory polymer's characteristic of shape change above the glass transition temperature, under the stimulation of temperature, it can control the structural shape change of the metasurface, change the phase distribution law, and realize dynamic cloaking and illusion functions. As proof, the metasurface samples with changeable structure are designed and fabricated by fused deposition modeling of 4D printing combined with liquid metal injection molding. Both the simulation and experimental results confirm that the designed metasurface has excellent cloaking and illusion performance at microwave frequency. This work provides a new idea for the realization of integrated metasurface devices with electromagnetic cloaking and illusion functions.
Revealing Ultrafast Carrier Dynamics of Hybrid Perovskites at Various Stages of Nucleation and Growth Kinetics
Authors: Dhami Bibek S. , Tripathi Ravi P.N. , Hoxie David J. , Appavoo Kannatassen 
Published: March 2023

AbstractWith hybrid organic–inorganic perovskites expanding their technological reach, from photovoltaic solar cells that operate at low carrier densities (1011 − 1013 cm−3) to light‐emitting diodes and lasers that operate at higher carrier densities (1013 − 1019 cm−3), it is critical to know how microstructure dictates carrier dynamics at varying injected carrier densities. For fabrication at scale, it is equally critical to know how quickly during the growth process do hybrid perovskites develop their characteristic optoelectronic properties. This work reports on a facile fabrication method that “freezes” different stages of nucleation and growth kinetics of prototypical hybrid perovskite on the same substrate—providing a unique strategy to assess differences in optoelectronic properties and carrier dynamics from nascent nucleating microcrystals to large‐grain thin films. The solution‐processed fabrication technique, optimized to control the nucleation density of an intermediate phase, successfully decouples the nucleation and growth steps that lead to large‐grain thin films. Ultrafast broadband absorption microscopy finds that the nucleating microcrystals already possess the optoelectronic properties of hybrid perovskites and share similar femtosecond‐to‐nanosecond dynamics as large‐grain thin films. When compared to the large‐grain thin films, the confining microcrystals exhibit enhanced carrier interactions, marked by an increase in bimolecular and Auger recombination rates.
Excitation Wavelength‐Dependent Upconversion Luminescence Enhancement in Tm3+‐Doped LiErF4@LiYF4 System Under High Pressure
Authors: Zhang Ling , Lang Zhongling , Lu Yang , Zhao Xu , Jiang Bin , Yan Xu , Sun Peng , Liu Fengmin , Zhou Guangdong , Zhou Mi , Wang Yanchao , Liu Xiaomin , Lu Geyu 
Published: March 2023

AbstractLocal structural engineering is an endogenous approach to modulate upconversion luminescence (UCL) from upstream to meet the needs of specific application scenarios. Herein, high pressure is utilized as a means to modulate the local structure, and the designed LiErF4:0.5%Tm3+@LiYF4 (Er:Tm@Y) nanoparticles with fast energy transfer rates, abundant cross‐relaxation processes, and multiple near‐infrared wavelengths (808, 980, 1530 nm) excitation properties are tailored as local structure‐sensitive hosts. A unique excitation wavelength‐dependent UCL enhancement of Er:Tm@Y upconversion nanoparticles is observed by pressure‐induced local structure distortions. When the pressure of ≈6 GPa is applied, the UCL is enhanced by a factor of 2.6 at 980 nm excitation only. After pressure release, the luminescence diminishes and recovers. Density functional theory calculations show that the symmetry distortion of the LiErF4 crystal reaches a maximum at pressurization to 6 GPa, while a new Er‐4f state emerges, greatly reducing the bandgap from 8.3 to 5.7 eV. Comparative experiments demonstrate that the local symmetry distortion caused by 0.5%Tm3+ doping and the different energy transfer patterns of Er3+ to Tm3+ at different excitations are responsible for this wavelength‐dependent luminescence enhancement.
π‐Conjugated Carbon‐Based Materials for Infrared Thermal Imaging
Authors: Cho Eunkyung , Pratik Saied Md , Pyun Jeffrey , Coropceanu Veaceslav , Brédas Jean‐Luc 
Published: March 2023

AbstractInfrared (IR) thermal imaging is receiving a great deal of attention due to its wide range of applications. Given multiple issues (like cost and availability) with the inorganic materials currently exploited for IR imaging, there is nowadays a great push of developing organic imaging materials. Carbon‐based materials are known to have significant transparency in the visible and IR regions and some are used as transparent conductors. Here, whether π‐conjugated carbon‐based materials are suitable for long‐wave (LW) and mid‐wave (MW) IR imaging applications is computationally assessed. Using density functional theory calculations, the IR‐vibrational properties of molecules from acenes to coronenes and fullerenes, and of periodic systems like graphene and carbon nanotubes are characterized. Fullerenes, graphenes, and double‐walled carbon nanotubes are found to be very attractive as they are transparent in both the LWIR and MWIR regions, a feature resulting from the absence of hydrogen atoms. Also, it is found that replacing hydrogen atoms in a molecule with deuterium or sulfur atoms can be an efficient way to improve their LWIR or MWIR transparency, respectively. For fused‐ring systems having hydrogen atoms on the periphery, designing molecules with trio CH‐units is another way to enhance the transparency in the LWIR region.
RuHCl(CO)(PPh3)3‐Catalyzed Isomerization of Homoallyl Silyl Ethers and Carbonates to Allyl Silyl Ethers and Carbonates
Authors: Fukuyama Takahide , Kuwahara Takashi , Yamamoto Yuki , Picard Baptiste , Ryu Ilhyong 
Published: March 2023

AbstractThe selective olefin isomerization of homoallyl silyl ethers and carbonates was studied using RuHCl(CO)(PPh3)3 as a catalyst. While an aryl or alkyl substituent at the α‐position to the oxygen atom caused the selective conversion to allyl silyl ethers, no substituent at the α‐position resulted in the isomerization to enol silyl ethers. In contrast, the isomerization of homoallyl carbonates gave the corresponding allyl carbonates selectively regardless of the substituent at α‐position.magnified image
Metal‐free Dehydrogenation of Substituted Cyclohexanones to Phenols
Authors: Leng Li‐Jing , Zhang De‐Long , Zhang Liang , Lin Xiao‐Long , Cai Tian , Tan Jian‐Ping , Luo Qun‐Li 
Published: March 2023

AbstractThe preparation of substituted phenols via a direct carbonyl desaturation is an intrinsic challenging task in modern synthetic chemistry. Herein, we develop a modular catalytic protocol for the synthesis of substituted phenols via the direct dehydrogenative aromatization of simple cyclohexanones in a metal‐free manner. A broad variety of substrates bearing an assortment of functional substituent groups are compatible with this protocol. Preliminary mechanistic investigations revealed that the reaction underwent a hydride leaving mechanism in the presence of a catalytic amount of tetrabutylammonium iodide. The current approach features simple operation, low reagent cost and green conditions. Insight gained from our studies is expected to advance general efforts towards the green synthesis of structurally diverse phenols via readily available raw materials, offering an alternative strategy for the carbonyl desaturation in organic synthesis.magnified image
A Low‐Temperature Synthetic Route Toward a High‐Entropy 2D Hexernary Transition Metal Dichalcogenide for Hydrogen Evolution Electrocatalysis
Authors: Qu Jie , Elgendy Amr , Cai Rongsheng , Buckingham Mark A. , Papaderakis Athanasios A. , de Latour Hugo , Hazeldine Kerry , Whitehead George F. S. , Alam Firoz , Smith Charles T. , Binks David J. , Walton Alex , Skelton Jonathan M. , Dryfe Robert A. W. , Haigh Sarah J. , Lewis David J. 
Published: March 2023

AbstractHigh‐entropy (HE) metal chalcogenides are a class of materials that have great potential in applications such as thermoelectrics and electrocatalysis. Layered 2D transition‐metal dichalcogenides (TMDCs) are a sub‐class of high entropy metal chalcogenides that have received little attention to date as their preparation currently involves complicated, energy‐intensive, or hazardous synthetic steps. To address this, a low‐temperature (500 °C) and rapid (1 h) single source precursor approach is successfully adopted to synthesize the hexernary high‐entropy metal disulfide (MoWReMnCr)S2. (MoWReMnCr)S2 powders are characterized by powder X‐ray diffraction (pXRD) and Raman spectroscopy, which confirmed that the material is comprised predominantly of a hexagonal phase. The surface oxidation states and elemental compositions are studied by X‐ray photoelectron spectroscopy (XPS) whilst the bulk morphology and elemental stoichiometry with spatial distribution is determined by scanning electron microscopy (SEM) with elemental mapping information acquired from energy‐dispersive X‐ray (EDX) spectroscopy. The bulk, layered material is subsequently exfoliated to ultra‐thin, several‐layer 2D nanosheets by liquid‐phase exfoliation (LPE). The resulting few‐layer HE (MoWReMnCr)S2 nanosheets are found to contain a homogeneous elemental distribution of metals at the nanoscale by high angle annular dark field‐scanning transmission electron microscopy (HAADF‐STEM) with EDX mapping. Finally, (MoWReMnCr)S2 is demonstrated as a hydrogen evolution electrocatalyst and compared to 2H‐MoS2 synthesized using the molecular precursor approach. (MoWReMnCr)S2 with 20% w/w of high‐conductivity carbon black displays a low overpotential of 229 mV in 0.5 M H2SO4 to reach a current density of 10 mA cm−2, which is much lower than the overpotential of 362 mV for MoS2. From density functional theory calculations, it is hypothesised that the enhanced catalytic activity is due to activation of the basal plane upon incorporation of other elements into the 2H‐MoS2 structure, in particular, the first row TMs Cr and Mn.
Upgrading Electricity Generation and Electromagnetic Interference Shielding Efficiency via Phase‐Change Feedback and Simple Origami Strategy
Authors: Hu Xinpeng , Quan Bingqing , Zhu Chuanbiao , Wen Haoye , Sheng Mengjie , Liu Shuang , Li Xiaolong , Wu Hao , Lu Xiang , Qu Jinping 
Published: March 2023

AbstractDeveloping ultimate electromagnetic interference (EMI) shielding materials that can simultaneously upgrade the quality of generated electricity and the light‐thermal‐electric conversion efficiency based on traditional thermoelectric devices is crucially desired. Herein, a series of flexible multilayered phase change films (PCFs) is developed by a simple and novel origami strategy. The PCFs are first reported to improve the light‐thermal‐electric conversion efficiency by as high as 11.3%. Simultaneously, the PCFs could significantly upgrade the generated electricity on average voltage (27.3%), average current (23.8%), and lasting power outputs by 2010 times from microwatts to milliwatts. Besides, the EMI shielding efficiency of PCFs could be tuned from 39.2 to 71.9 dB by the origami process, the wide‐range EMI shielding performance could be suitable for varying occasions. Overall, this work provides a promising solution for both the preparation of multifunctional materials, high‐efficiency solar energy harvesting and upgrading electricity generation, which shows broad application prospects in EMI shielding, energy storage, and conversion.
Multilayered Molybdate Microflowers Fabricated by One‐Pot Reaction for Efficient Water Splitting
Authors: Wang Jingyi , Feng Jianrui , Li Yuying , Lai Feili , Wang Gui‐Chang , Liu Tianxi , Huang Jiajia , He Guanjie 
Published: March 2023

AbstractThe development of high‐performance, low‐cost and rapid‐production bifunctional electrocatalysts towards overall water splitting still poses huge challenges. Herein, the authors utilize a facile hydrothermal method to synthesize a novel structure of Co‐doped ammonium lanthanum molybdate on Ni foams (Co‐ALMO@NF) as self‐supported electrocatalysts. Owing to large active surfaces, lattice defect and conductive channel for rapid charge transport, Co‐ALMO@NF exhibits good electrocatalytic performances which requires only 349/341 mV to achieve a high current density of 600 mA cm−2 for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), respectively. Besides, a low cell voltage of 1.52 V is required to reach the current density of 10 mA cm−2 in alkaline medium along with an excellent long‐term stability for two‐electrode configurations. Density functional theory calculations are performed to reveal the reaction mechanism on Co‐ALMO@NF, which shows that the Mo site is the most favorable ones for HER, while the introduction of Co is beneficial to reduce the adsorption intensity on the surface of Co‐ALMO@NF, thus accelerating OER process. This work highlighted the importance of the structural design for self‐supporting electrocatalysts.
High‐Performance X‐Ray Imaging using Lanthanide Metal–Organic Frameworks
Authors: Zhang Xintong , Qiu Haiyi , Luo Wang , Huang Kaofeng , Chen Ying , Zhang Jiacheng , Wang Bohan , Peng Daoling , Wang Yu , Zheng Kezhi 
Published: March 2023

AbstractScintillating materials that convert ionizing radiation into low‐energy photons hold great potential for radiation detection, nondestructive inspection, medical radiography, and space exploration. However, organic scintillators are characterized by low radioluminescence, while bulky inorganic scintillators are not suitable for the development of flexible detectors. Here, high‐resolution X‐ray imaging using solution‐processable lanthanide‐based metal–organic frameworks as microscale scintillators is demonstrated. Mechanistic studies suggest that lanthanide ions absorb X‐rays to generate high‐density molecular triplet excitons, and excited linkers subsequently sensitize lanthanide ions via nonradiative resonance energy transfer. Furthermore, the crystalline nature offers a delocalized electronic feature rather than isolated subunits, which enables direct trapping of charge carriers by lanthanide emitters. By controlling the concentration ratio between Tb3+ and Eu3+ ions, efficient and color‐tunable radioluminescence of lanthanide ions can be achieved. When coupled with elastic, transparent polymer matrices, these metal–organic framework‐based microscintillators allow the fabrication of flexible X‐ray detectors. Such detectors feature a detection limit of 23 nGy s−1, which is 240 times lower than the typical radiation dose for medical diagnosis. X‐ray imaging with resolution higher than 16.6 line pairs per millimeter is further demonstrated. These findings provide insight into the future design of hybrid scintillators for optoelectronics and X‐ray sensing and imaging.
Self‐Reconstructed Spinel Surface Structure Enabling the Long‐Term Stable Hydrogen Evolution Reaction/Oxygen Evolution Reaction Efficiency of FeCoNiRu High‐Entropy Alloyed Electrocatalyst
Authors: Huang Kang , Xia Jiuyang , Lu Yu , Zhang Bowei , Shi Wencong , Cao Xun , Zhang Xinyue , Woods Lilia M. , Han Changcun , Chen Chunjin , Wang Tian , Wu Junsheng , Huang Yizhong 
Published: March 2023

AbstractHigh catalytic efficiency and long‐term stability are two main components for the performance assessment of an electrocatalyst. Previous attention has been paid more to efficiency other than stability. The present work is focused on the study of the stability processed on the FeCoNiRu high‐entropy alloy (HEA) in correlation with its catalytic efficiency. This catalyst has demonstrated not only performing the simultaneous hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) with high efficiency but also sustaining long‐term stability upon HER and OER. The study reveals that the outstanding stability is attributed to the spinel oxide surface layer developed during evolution reactions. The spinel structure preserves the active sites that are inherited from the HEA's intrinsic structure. This work will provide an insightful direction/pathway for the design and manufacturing activities of other metallic electrocatalysts and a benchmark for the assessment of their efficiency–stability relationship.
Selective Ethylene Glycol Oxidation to Formate on Nickel Selenide with Simultaneous Evolution of Hydrogen
Authors: Li Junshan , Li Luming , Ma Xingyu , Han Xu , Xing Congcong , Qi Xueqiang , He Ren , Arbiol Jordi , Pan Huiyan , Zhao Jun , Deng Jie , Zhang Yu , Yang Yaoyue , Cabot Andreu 
Published: March 2023

AbstractThere is an urgent need for cost‐effective strategies to produce hydrogen from renewable net‐zero carbon sources using renewable energies. In this context, the electrochemical hydrogen evolution reaction can be boosted by replacing the oxygen evolution reaction with the oxidation of small organic molecules, such as ethylene glycol (EG). EG is a particularly interesting organic liquid with two hydroxyl groups that can be transformed into a variety of C1 and C2 chemicals, depending on the catalyst and reaction conditions. Here, a catalyst is demonstrated for the selective EG oxidation reaction (EGOR) to formate on nickel selenide. The catalyst nanoparticle (NP) morphology and crystallographic phase are tuned to maximize its performance. The optimized NiS electrocatalyst requires just 1.395 V to drive a current density of 50 mA cm−2 in 1 m potassium hydroxide (KOH) and 1 m EG. A combination of in situ electrochemical infrared absorption spectroscopy (IRAS) to monitor the electrocatalytic process and ex situ analysis of the electrolyte composition shows the main EGOR product is formate, with a Faradaic efficiency above 80%. Additionally, C2 chemicals such as glycolate and oxalate are detected and quantified as minor products. Density functional theory (DFT) calculations of the reaction process show the glycol‐to‐oxalate pathway to be favored via the glycolate formation, where the CC bond is broken and further electro‐oxidized to formate.
Advances in Ultrathin Soft Sensors, Integrated Materials, and Manufacturing Technologies for Enhanced Monitoring of Human Physiological Signals
Authors: Kim Hodam , Lee Yoon Jae , Byun Garan , Choi Chanyoung , Yeo Woon‐Hong 
Published: March 2023

AbstractRecent advances in soft sensors and flexible electronics offer various applications in detecting physical, electrical, and chemical signals. However, there are still technical barriers in current mechanical, electrical, and material properties for enhanced signal sensing. When measuring signals from the human skin, minimizing the skin‐sensor contact impedance is still challenging while maximizing sensitivity through optimized materials and soft electronics. Here, this review summarizes recent advances in materials, manufacturing, and integration technologies to develop ultrathin soft sensors for monitoring various human physiological signals. The enhancements in soft and compliant structures and mechanical properties are critical to making reliable wearable electronic systems. This article shares the details of soft sensors, integration processes, manufacturing methods, and their applications to target physical, electrical, and chemical signals. In addition, the limitations and current trends in developing multifunctional sensors, self‐powered devices, and integration with external stimuli systems are discussed.
Accelerated Perovskite Oxide Development for Thermochemical Energy Storage by a High‐Throughput Combinatorial Approach
Authors: Cai Runxia , Bektas Hilal , Wang Xijun , McClintock Kyle , Teague Lauren , Yang Kunran , Li Fanxing 
Published: March 2023

AbstractThe structural and compositional flexibility of perovskite oxides and their complex yet tunable redox properties offer unique optimization opportunities for thermochemical energy storage (TCES). To improve the relatively inefficient and empirical‐based approaches, a high‐throughput combinatorial approach for accelerated development and optimization of perovskite oxides for TCES is reported here. Specifically, thermodynamic‐based screening criteria are applied to the high‐throughput density functional theory (DFT) simulation results of over 2000 A/B‐site doped SrFeO3−δ. 61 promising TCES candidates are selected based on the DFT prediction. Of these, 45 materials with pure perovskite phases are thoroughly evaluated. The experimental results support the effectiveness of the high‐throughput approach in determining both the oxygen capacity and the oxidation enthalpy of the perovskite oxides. Many of the screened materials exhibit promising performance under practical operating conditions: Sr0.875Ba0.125FeO3−δ exhibits a chemical energy storage density of 85 kJ kgABO3−1 under an isobaric condition (with air) between 400 and 800 °C whereas Sr0.125Ca0.875Fe0.25Mn0.75O3−δ demonstrates an energy density of 157 kJ kgABO3−1 between 400 °C/0.2 atm O2 and 1100 °C/0.01 atm O2. An improved set of optimization criteria is also developed, based on a combination of DFT and experimental results, to improve the effectiveness for accelerated development of redox‐active perovskite oxides.
Enhancing Carrier Mobility and Seebeck Coefficient by Modifying Scattering Factor
Authors: Su Lizhong , Shi Haonan , Wang Sining , Wang Dongyang , Qin Bingchao , Wang Yuping , Chang Cheng , Zhao Li‐Dong 
Published: March 2023

AbstractThermoelectric materials possess the potential for refrigeration and power generation due to their ability to directly convert heat and electricity. Carrier mobility and the Seebeck coefficient are key properties of thermoelectric materials. Improving the effective mass is the most effective and frequent way to optimize the Seebeck coefficient. However, carrier mobility deteriorates dramatically with increasing effective mass and thus limits further improvement of thermoelectric performance. Here, the focus is on the importance of modifying the scattering factor (r) to enhance the electrical properties, and it is found that the anisotropic scattering factor enhances the carrier mobility and Seebeck coefficient of anion‐doped n‐type tin selenide crystals along the out‐of‐plane direction, indicating the potential of modifying r to improve electrical properties. Following this strategy, the average dimensionless figure of merit (ZTave) for iodine‐doped SnSe crystals is significantly improved from 0.84 to 1.57 in 300–773 K. The results emphasize the critical role of scattering factor and propose a new perspective for enhancing carrier mobility, providing a novel strategy to optimize thermoelectric performance.
Do large farms make better choices: Evidence from dairy margin coverage program participation patterns
Authors: Yu Jisang , Gabrielyan Georgi T. 
Published: March 2023

AbstractRisk management has been a centerpiece of U.S. farm policy since the Agricultural Act of 2014. The 2018 Farm Bill authorized the new Dairy Margin Coverage (DMC) program, which replaced the Margin Protection Program for Dairy. We study the DMC program by utilizing administrative data from the operation‐level information on program participation. By investigating the participation and choice decisions of dairy operations in the U.S., we find that larger operations are more likely to participate in DMC and to make margin coverage choices that maximize the net returns from the program. In addition, we show that the budgetary consequences of continued consolidation in the dairy industry depend on whether milk production from exiting dairies is absorbed by larger farms alone or is more evenly distributed among the remaining dairies.