bluuebunny/crossref_metadata_2025_split huggingface dataset:
Photophysical Properties of Copper Halides with Strongly Confined Excitons and Their High‐Performance X‐Ray Imaging
Authors: Zhu Weiguo , Li Ruizi , Liu Xiaowang , Xu Xuhui , Chao Hongxiao , Wang Haoyang , Jiao Yitong , Liu Haodong , Xu Feng , Nie Zhentao , Gao Yuan , Wang Riheng , Zhu Jixin , Huang Wei 
Published: February 2024

AbstractCopper halides, a new class of attractive and potential scintillators, have attracted tremendous attention in X‐ray imaging. However, the ambiguity surrounding their exciton properties and the unclear effect of crystal structure on their photophysical performance hinder an in‐depth understanding of their luminescence mechanism and their further application in the X‐ray imaging field. Herein, copper halide scintillators Cs3Cu2X5 (X = I, Br, and Cl) with a 0D crystal structure is prepared, and their photophysical properties and luminescence mechanism are revealed using both theoretical calculation and experimental verification. The small exciton Bohr diameter together with the high exciton binding energy can cause Cs3Cu2X5 to hold strongly confined excitons and lack quantum‐size effects. The 0D Cs3Cu2X5 materials exhibit a structural framework with a soft crystal lattice and Frenkel excitons with strong confinement effects, further resulting in a luminescence mechanism with self‐trapped excitons. In particular, Cs3Cu2I5 is demonstrated as an efficient scintillator with high radioluminescence efficiency and high spatial resolution of ≈106 µm in radiography, which is primarily attributed to strongly confined excitons to improve the radiative recombination probability of electron‐hole pairs. Overall, this work provides a pathway for developing 0D scintillators with strongly confined excitons to improve X‐ray imaging performance.
A General Synthesis of Soft Magnetic 2:17‐Type Rare‐Earth Cobalt Nanoalloys Decorated with Graphite as High‐Frequency Electromagnetic Materials
Authors: Ma Jie , Li Zhenyang , Tian Hao , Yang Bai , Yuan Yingbo , Li Ran , Yu Ronghai 
Published: February 2024

AbstractA general approach is reported to fabricate a series of single‐phase 2:17‐type rare‐earth cobalt (RE2Co17, RE = Y, Ce, Pr, Nd, and Gd) nanoalloys by precisely controlled calcium thermic reduction of amorphous RE‐Co precursors. High‐purity hexagonal RE2Co17 phases are formed without the precipitation of Co and the other RE‐Co phases through the accurately manipulated co‐reduction of the two ions, which avoids the disadvantages of the impurity or second phases for RE metal alloys. RE2Co17/graphite nanostructures constructed with flower‐like RE2Co17 nanoalloys superficially decorated with nanosized graphite are further fabricated by introducing graphene oxides into the co‐reduction process. Compared with traditional magnetic planar‐anisotropy RE2Co17 alloys, the preserved high saturation magnetization (51.2–102.9 A m2 kg−1) and unusually increased coercivity (152–310.5 Oe) are achieved in these graphite‐decorated RE2Co17 nanoalloys. Moreover, these RE2Co17/graphite nanostructures exhibit good microwave absorption with an applied frequency range of 11.76–18 GHz, which shows their potential applications as new‐type Ku‐band electromagnetic materials. This work provides a facial way for the large‐scale production for varieties of single‐phase 2:17‐type RE‐Co nanoalloys and expands their application fields by constructing novel composite structures.
Highly Stretchable Semiconducting Aerogel Films for High‐Performance Flexible Electronics
Authors: Gu Puzhong , Lu Linlin , Yang Xiao , Hu Zhenyu , Zhang Xiaoyu , Sun Zejun , Liang Xing , Liu Muxiang , Sun Qi , Huang Jia , Zu Guoqing 
Published: February 2024

AbstractHighly stretchable aerogel films are attractive for advanced next‐generation stretchable electronics. However, it is a great challenge to achieve high stretchability for aerogel films. Here, several types of unprecedented ultra‐stretchable semiconducting polymer‐based aerogel films with crimpled porous structures are developed via crosslinking and template methods combined with uniaxial and biaxial pre‐stretching strategies. The semiconducting aerogel films obtained by uniaxial pre‐stretching exhibit ultrahigh stretchability up to 100–200%, while those obtained by biaxial pre‐stretching show high biaxial stretchability up to 50%. The resulting aerogel films show strain‐insensitive electrical and joule heating properties. A prototype of the aerogel film‐based stretchable organic electrochemical transistor (OECT) is developed for the first time. Benefiting from their unique porous structures, the aerogel film‐based OECTs exhibit enhanced on/off ratio and transconductance compared with corresponding dense film‐based OECTs, high stretchability up to 100%, and high stretching stability with 10 000 stretching cycles under 30% strain. It is demonstrated that the aerogel film‐based OECTs can be applied as high‐performance stretchable artificial synapses and biosensors. This work gives a versatile strategy toward highly stretchable aerogel films promising for flexible electronics.
Silk‐Fabric Reinforced Silk for Artificial Bones
Authors: Lu Linlin , Liu Xuqing , Sun Yan , Wang Shujuan , Liu Jiantao , Ge Shengbo , Wei Tongxue , Zhang Haiyang , Su Jinhui , Zhang Yingying , Fan Wei 
Published: February 2024

AbstractBone implants for different body parts require varying mechanical properties, dimensions, and biodegradability rates. Currently, it is still challenging to produce artificial bones with perfect compatibility with human bones. In this study, a silk‐fabric reinforced silk material (SFS) composed of pure silk with exceptional biocompatibility, osteogenesis, and biodegradability is reported, and demonstrates its outstanding performance as a bone implant material. The SFS is fabricated using a simple hot‐pressing technique, with degummed silk fabric as the reinforcement and silk fibroin as the matrix. The SFS as a self‐reinforced composite, has exceptional mechanical properties due to the almost perfect interface between the matrix and reinforcement. More importantly, its mechanical properties, biodegradability rates, and density can be tailored by adjusting the reinforcement structure and the ratio of the reinforcement to the matrix to align with the requirements for bone implantation in different parts of the human body. Besides, the SFS can improve osteoblastic proliferation and increase osteogenic activity, which is not the case with clinically used titanium alloy artificial bone. Therefore, the SFS holds significant potential to replace conventional metal or ceramic implants in the field of medical fracture repair.
Imaging the Breakdown and Restoration of Topological Protection in Magnetic Topological Insulator MnBi2Te4
Authors: Li Qile , Di Bernardo Iolanda , Maniatis Johnathon , McEwen Daniel , Dominguez‐Celorrio Amelia , Bhuiyan Mohammad T. H. , Zhao Mengting , Tadich Anton , Watson Liam , Lowe Benjamin , Vu Thi‐Hai‐Yen , Trang Chi Xuan , Hwang Jinwoong , Mo Sung‐Kwan , Fuhrer Michael S. , Edmonds Mark T. 
Published: February 2024

AbstractQuantum anomalous Hall (QAH) insulators transport charge without resistance along topologically protected chiral 1D edge states. Yet, in magnetic topological insulators to date, topological protection is far from robust, with zero‐magnetic field QAH effect only realized at temperatures an order of magnitude below the Néel temperature TN, though small magnetic fields can stabilize QAH effect. Understanding why topological protection breaks down is therefore essential to realizing QAH effect at higher temperatures. Here a scanning tunneling microscope is used to directly map the size of exchange gap (Eg,ex) and its spatial fluctuation in the QAH insulator 5‐layer MnBi2Te4. Long‐range fluctuations of Eg,ex are observed, with values ranging between 0 (gapless) and 70 meV, appearing to be uncorrelated to individual surface point defects. The breakdown of topological protection is directly imaged, showing that the gapless edge state, the hallmark signature of a QAH insulator, hybridizes with extended gapless regions in the bulk. Finally, it is unambiguously demonstrated that the gapless regions originate from magnetic disorder, by demonstrating that a small magnetic field restores Eg,ex in these regions, explaining the recovery of topological protection in magnetic fields. The results indicate that overcoming magnetic disorder is the key to exploiting the unique properties of QAH insulators.
Suppressing Element Inhomogeneity Enables 14.9% Efficiency CZTSSe Solar Cells
Authors: Li Yimeng , Cui Changcheng , Wei Hao , Shao Zhipeng , Wu Zucheng , Zhang Shu , Wang Xiao , Pang Shuping , Cui Guanglei 
Published: February 2024

AbstractKesterites, Cu2ZnSn(SxSe1−x)4 (CZTSSe), solar cells suffer from severe open‐circuit voltage (VOC) loss due to the numerous secondary phases and defects. The prevailing notion attributes this issue to Sn‐loss during the selenization. However, this work unveils that, instead of Sn‐loss, elemental inhomogeneity caused by Cu‐directional diffusion toward Mo(S,Se)2 layer is the critical factor in the formation of secondary phases and defects. This diffusion decreases the Cu/(Zn+Sn) ratio to 53% at the bottom fine‐grain layer, increasing the Sn‐/Zn‐related bulk defects. By suppressing the Cu‐directional diffusion with a blocking layer, the crystal quality is effectively improved and the defect density is reduced, leading to a remarkable photovoltaic coversion efficiency (PCE) of 14.9% with a VOC of 576 mV and a certified efficiency of 14.6%. The findings provide insights into element inhomogeneity, holding significant potential to advance the development of CZTSSe solar cells.
In Situ Plasma Studies Using a Direct Current Microplasma in a Scanning Electron Microscope
Authors: Grünewald Lukas , Chezganov Dmitry , De Meyer Robin , Orekhov Andrey , Van Aert Sandra , Bogaerts Annemie , Bals Sara , Verbeeck Jo 
Published: February 2024

AbstractMicroplasmas can be used for a wide range of technological applications and to improve the understanding of fundamental physics. Scanning electron microscopy, on the other hand, provides insights into the sample morphology and chemistry of materials from the mm‐ down to the nm‐scale. Combining both would provide direct insight into plasma‐sample interactions in real‐time and at high spatial resolution. Up till now, very few attempts in this direction have been made, and significant challenges remain. This work presents a stable direct current glow discharge microplasma setup built inside a scanning electron microscope. The experimental setup is capable of real‐time in situ imaging of the sample evolution during plasma operation and it demonstrates localized sputtering and sample oxidation. Further, the experimental parameters such as varying gas mixtures, electrode polarity, and field strength are explored and experimental V–I curves under various conditions are provided. These results demonstrate the capabilities of this setup in potential investigations of plasma physics, plasma‐surface interactions, and materials science and its practical applications. The presented setup shows the potential to have several technological applications, for example, to locally modify the sample surface (e.g., local oxidation and ion implantation for nanotechnology applications) on the µm‐scale.
The Asymmetric Synthesis of Polycyclic Tetrahydroxanthone via the Cascade Reaction of Alkene‐Substituted 1,3‐diketones and Alkenyloxindoles
Authors: Zhang Rong , Wang Wenhui , Zhang Yonghui , Chen Yushuang , Yao Weijun , Wang Zhen 
Published: February 2024

AbstractEnantioselective access to polycyclic tetrahydroxanthone compounds was achieved through an organocatalyzed cascade reaction of alkene‐substituted 1,3‐diketones and alkenyloxindoles, using quinine‐derived squaramide as an efficient catalyst. It afforded a variety of optically active spirooxindole‐based tetrahydroxanthones with 18–94% yields, >19:1 dr, and 86–99% ee.
Enabling C2H2/CO2 Separation Under Humid Conditions with a Methylated Copper MOF
Authors: Zhao Yan‐Long , Chen Qiancheng , Zhang Xin , Li Jian‐Rong 
Published: February 2024

AbstractAs a unique subclass of metal‐organic frameworks (MOFs), MOFs with open metal site (OMS) are demonstrated efficient gas separation performance through pi complexation with unsaturated hydrocarbons. However, their practical application faces the challenge of humidity that causes structure degradation and completive binding at the OMS. In this work, the effect of linker methylation of a copper MOF (BUT‐155) on the C2H2/CO2 separation performance under humid condition is evaluated. The water adsorption isotherm, adsorption kinetics, and breakthrough under dry and humid conditions are performed. The BUT‐155 with methylated linker exhibits lower water uptake and adsorption kinetics under humid condition (RH = 20%), in comparison with HKUST‐1. Therefore, the C2H2/CO2 separation performance of BUT‐155 is much less affected by water, especially under higher gas flow rate. Moreover, the dynamic C2H2/CO2 separation performance of BUT‐155 can maintain five breakthrough cycles under humid conditions (RH = 20% and RH = 80%) without obvious performance degradation.
Atomic‐Scale Study of Dead Layers in Epitaxial Perovskite Dielectric Thin Films with Oxide and Metal Top Electrodes
Authors: Bang Jeongil , Do Eun Cheol , Kim Haeryong , Kim Hyungjun , Park Bo‐Eun , Na Byunghoon , Lee Jooho , Park Sehyuck , Jang Ho Won , Lee Jaeho 
Published: February 2024

AbstractPerovskite‐oxide‐based capacitors, which exhibit high charge storage capacity, have attracted considerable attention as a potential candidate for overcoming the limitations of nanoscale integration. Unfortunately, a dead layer forms in these capacitors at the interface between the electrode and the dielectric, which degrades the charge storage capacity; thus, this layer has been extensively investigated. The dead layer in perovskite‐oxide‐based capacitors exhibits different characteristics depending on the electrode materials; however, a method for minimizing this layer is lacking. In this study, the charge storage capacity of a perovskite‐oxide‐based capacitor is evaluated considering the effect of the Ru and SrRuO3 top electrodes on the SrRuO3/Ba0.5Sr0.5TiO3 stack. Dead layers at the interface between each top electrode material and the dielectric are studied on the atomic scale. The results indicate that the Ru metal electrode causes oxygen to diffuse from the dielectric to the electrode, forming elongated perovskite oxide at the interface, which acts as a dead layer. However, minimizing the dead layer at the top interface increases the dielectric permittivity from 667 to 953. Consequently, the phenomenon and mechanism of the dead layer are intuitively identified. This study proposes a method to overcome the limitations of next‐generation dynamic random access memory (DRAM).
Associations of 24‐Hour Rest‐Activity Rhythm Fragmentation, Cognitive Decline, and Postmortem Locus Coeruleus Hypopigmentation in Alzheimer's Disease
Authors: Van Egroo Maxime , van Someren Eus J.W. , Grinberg Lea T. , Bennett David A. , Jacobs Heidi I.L. 
Published: February 2024

ObjectiveWhile studies suggested that locus coeruleus (LC) neurodegeneration contributes to sleep–wake dysregulation in Alzheimer's disease (AD), the association between LC integrity and circadian rest‐activity patterns remains unknown. Here, we investigated the relationships between 24‐hour rest‐activity rhythms, cognitive trajectories, and autopsy‐derived LC integrity in older adults with and without cortical AD neuropathology.MethodsThis retrospective study leveraged multi‐modal data from participants of the longitudinal clinical‐pathological Rush Memory and Aging Project. Indices of 24‐hour rest‐activity rhythm fragmentation (intradaily variability) and stability (interdaily stability) were extracted from annual actigraphic recordings, and cognitive trajectories were computed from annual cognitive evaluations. At autopsy, LC neurodegeneration was determined by the presence of hypopigmentation, and cortical AD neuropathology was assessed. Contributions of comorbid pathologies (Lewy bodies, cerebrovascular pathology) were evaluated.ResultsAmong the 388 cases included in the study sample (age at death = 92.1 ± 5.9 years; 273 women), 98 (25.3%) displayed LC hypopigmentation, and 251 (64.7%) exhibited cortical AD neuropathology. Logistic regression models showed that higher rest‐activity rhythm fragmentation, measured up to ~7.1 years before death, was associated with increased risk to display LC neurodegeneration at autopsy (odds ratio [OR] = 1.46, 95% confidence interval [CI95%]: 1.16–1.84, pBONF = 0.004), particularly in individuals with cortical AD neuropathology (OR = 1.56, CI95%: 1.15–2.15, pBONF = 0.03) and independently of comorbid pathologies. In addition, longitudinal increases in rest‐activity rhythm fragmentation partially mediated the association between LC neurodegeneration and cognitive decline (estimate = ‐0.011, CI95%: ‐0.023–‐0.002, pBONF = 0.03).InterpretationThese findings highlight the LC as a neurobiological correlate of sleep–wake dysregulation in AD, and further underscore the clinical relevance of monitoring rest‐activity patterns for improved detection of at‐risk individuals. ANN NEUROL 2024;95:653–664
Cavity‐Directed Synthesis of Labile Polyoxometalates for Catalysis in Confined Spaces
Authors: Liu Cui‐Lian , Moussawi Mhamad Aly , Kalandia Givi , Salazar Marcano David E. , Shepard William E. , Parac‐Vogt Tatjana N. 
Published: February 2024

AbstractThe artificial microenvironments inside coordination cages have gained significant attention for performing enzyme‐like catalytic reactions by facilitating the formation of labile and complex molecules through a “ship‐in‐a‐bottle” approach. Despite many fascinating examples, this approach remains scarcely explored in the context of synthesizing metallic clusters such as polyoxometalates (POMs). The development of innovative approaches to control and influence the speciation of POMs in aqueous solutions would greatly advance their applicability and could ultimately lead to the formation of elusive clusters that cannot be synthesized by using traditional methods. In this study, we employ host–guest stabilization within a coordination cage to enable a novel cavity‐directed synthesis of labile POMs in aqueous solutions under mild conditions. The elusive Lindqvist [M6O19]2− (M=Mo or W) POMs were successfully synthesized at room temperature via the condensation of molybdate or tungstate building blocks within the confined cavity of a robust and water‐soluble Pt6L4(NO3)12 coordination cage. Importantly, the encapsulation of these POMs enhances their stability in water, rendering them efficient catalysts for environmentally friendly and selective sulfoxidation reactions using H2O2 as a green oxidant in a pure aqueous medium. The approach developed in this paper offers a means to synthesize and stabilize the otherwise unstable metal‐oxo clusters in water, which can broaden the scope of their applications.
A Dual Fluorescence Turn‐On Sensor Array Formed by Poly(para‐aryleneethynylene) and Aggregation‐Induced Emission Fluorophores for Sensitive Multiplexed Bacterial Recognition
Authors: Yu Yang , Ni Weiwei , Hu Qin , Li Huihai , Zhang Yi , Gao Xu , Zhou Lingjia , Zhang Shuming , Ma Shuoyang , Zhang Yanliang , Huang Hui , Li Fei , Han Jinsong 
Published: February 2024

AbstractBacterial infections have emerged as the leading causes of mortality and morbidity worldwide. Herein, we developed a dual‐channel fluorescence “turn‐on” sensor array, comprising six electrostatic complexes formed from one negatively charged poly(para‐aryleneethynylene) (PPE) and six positively charged aggregation‐induced emission (AIE) fluorophores. The 6‐element array enabled the simultaneous identification of 20 bacteria (OD600=0.005) within 30s (99.0 % accuracy), demonstrating significant advantages over the array constituted by the 7 separate elements that constitute the complexes. Meanwhile, the array realized different mixing ratios and quantitative detection of prevalent bacteria associated with urinary tract infection (UTI). It also excelled in distinguishing six simulated bacteria samples in artificial urine. Remarkably, the limit of detection for E. coli and E. faecalis was notably low, at 0.000295 and 0.000329 (OD600), respectively. Finally, optimized by diverse machine learning algorithms, the designed array achieved 96.7 % accuracy in differentiating UTI clinical samples from healthy individuals using a random forest model, demonstrating the great potential for medical diagnostic applications.
Self‐Polymerized Spiro‐Type Interfacial Molecule toward Efficient and Stable Perovskite Solar Cells
Authors: Tian Qiushuang , Chang Jingxi , Wang Junbo , He Qingyun , Chen Shaoyu , Yang Pinghui , Wang Hongze , Lai Jingya , Wu Mengyang , Zhao Xiangru , Zhong Chongyu , Li Renzhi , Huang Wei , Wang Fangfang , Yang Yingguo , Qin Tianshi 
Published: February 2024

AbstractIn the pursuit of highly efficient perovskite solar cells, spiro‐OMeTAD has demonstrated recorded power conversion efficiencies (PCEs), however, the stability issue remains one of the bottlenecks constraining its commercial development. In this study, we successfully synthesize a novel self‐polymerized spiro‐type interfacial molecule, termed v‐spiro. The linearly arranged molecule exhibits stronger intermolecular interactions and higher intrinsic hole mobility compared to spiro‐OMeTAD. Importantly, the vinyl groups in v‐spiro enable in situ polymerization, forming a polymeric protective layer on the perovskite film surface, which proves highly effective in suppressing moisture degradation and ion migration. Utilizing these advantages, poly‐v‐spiro‐based device achieves an outstanding efficiency of 24.54 %, with an enhanced open‐circuit voltage of 1.173 V and a fill factor of 81.11 %, owing to the reduced defect density, energy level alignment and efficient interfacial hole extraction. Furthermore, the operational stability of unencapsulated devices is significantly enhanced, maintaining initial efficiencies above 90 % even after 2000 hours under approximately 60 % humidity or 1250 hours under continuous AM 1.5G sunlight exposure. This work presents a comprehensive approach to achieving both high efficiency and long‐term stability in PSCs through innovative interfacial design.
Elaborate Modulating Binding Strength of Intermediates via Three‐component Covalent Organic Frameworks for CO2Reduction Reaction
Authors: Liu Minghao , Cui Cheng‐Xing , Yang Shuai , Yang Xiubei , Li Xuewen , He Jun , Xu Qing , Zeng Gaofeng 
Published: February 2024

AbstractThe catalytic performance for electrocatalytic CO2reduction reaction (CO2RR) depends on the binding strength of the reactants and intermediates. Covalent organic frameworks (COFs) have been adopted to catalyze CO2RR, and their binding abilities are tuned via constructing donor‐acceptor (DA) systems. However, most DA COFs have single donor and acceptor units, which caused wide‐range but lacking accuracy in modulating the binding strength of intermediates. More elaborate regulation of the interactions with intermediates are necessary and challenge to construct high‐efficiency catalysts. Herein, the three‐component COF with D‐A‐A units was first constructed by introducing electron‐rich diarylamine unit, electron‐deficient benzothiazole and Co‐porphyrin units. Compared with two‐component COFs, the designed COF exhibit elevated electronic conductivity, enhanced reducibility, high efficiency charge transfer, further improving the electrocatalytic CO2RR performance with the faradic efficiency of 97.2 % at −0.8 V and high activity with the partial current density of 27.85 mA cm−2at −1.0 V which exceed other two‐component COFs. Theoretical calculations demonstrate that catalytic sites in three‐component COF have suitable binding ability of the intermediates, which are benefit for formation of *COOH and desorption of *CO. This work offers valuable insights for the advancement of multi‐component COFs, enabling modulated charge transfer to improve the CO2RR activity.