bluuebunny/crossref_metadata_2025_split huggingface dataset:
In Situ Atomic‐Scale Observation of Reversible Potassium Storage in Sb2S3@Carbon Nanowire Anodes
Authors: Cheng Yong , Yao Zhenpeng , Zhang Qiaobao , Chen Jiamin , Ye Weibin , Zhou Shiyuan , Liu Haodong , Wang Ming‐Sheng 
Published: September 2020

AbstractAntimony trisulfide‐based materials have drawn growing attention as promising anode candidates for potassium‐ion batteries (PIBs) because of their high capacity and good working potential. Despite the extensive investigations on their electrochemical properties, the fundamental reaction mechanisms of Sb2S3 anodes, especially the reaction kinetics, structural changes, and phase evolutions, remain controversial or even largely unknown. Here, using in situ transmission electron microscopy, the entire potassiation–depotassiation cycles of carbon‐coated Sb2S3 single‐crystal nanowires are tracked in real time at the atomic scale. The potassiation of Sb2S3 involves multistep reactions including intercalation, conversion, and two‐step alloying, and the final products are identified as cubic K2S and hexagonal K3Sb. These findings are confirmed by density functional theory calculations. Interestingly, a rocket‐launching‐like nanoparticle growth behavior is observed during alloying reactions, which is driven by the K+ concentration gradient and release of stress. More impressively, the potassiated products (i.e., K3Sb and K2S) can transform into the original Sb2S3 phase during depotassiation, indicating a reversible phase transformation process, as distinct from other metal chalcogenide based electrodes. This work reveals the detailed potassiation/depotassiation mechanisms of Sb2S3‐based anodes and can facilitate the analysis of the mechanisms of other metal chalcogenide anodes in PIBs.
Highly Crystalline Graphene Fibers with Superior Strength and Conductivities by Plasticization Spinning
Authors: Li Peng , Liu Yingjun , Shi Shaoyi , Xu Zhen , Ma Weigang , Wang Ziqiu , Liu Senping , Gao Chao 
Published: September 2020

AbstractGraphene fiber (GF), a macroscopic one‐dimensional assembly of individual graphene sheets, promises both extraordinary mechanical performance and superior multifunctionality. However, the properties of graphene fiber are still limited due to the unfavorable crystalline structures, especially induced by wrinkled conformations of graphene. A plasticization spinning strategy is presented to achieve GF with both high mechanical strength and electrical/thermal conductivity. Adjusting the interlayer space from 1.2 to 1.8 nm by intercalating proper plasticizers to adjacent graphene oxide sheets enables graphene oxide fibers to achieve a 580% enhanced deformable plasticity. Such a plasticization spinning flattens random graphene wrinkles, and regulates sheets with high order and stacking density, thereby forming large crystallite domains. The GF exhibits all around record performance including mechanical strength (3.4 GPa), electrical conductivity (1.19 × 106 S m−1), and thermal conductivity (1480 W m−1 K−1). The optimally crystalline GF with the integration of benchmark overall properties and scalable fabrication is likely to be attractive and competitive in future industrial applications.
A MXene‐Based Hierarchical Design Enabling Highly Efficient and Stable Solar‐Water Desalination with Good Salt Resistance
Authors: Fan Xiangqian , Yang Yang , Shi Xinlei , Liu Yang , Li Hongpeng , Liang Jiajie , Chen Yongsheng 
Published: September 2020

AbstractA solar‐thermal water evaporation structure that can continuously generate clean water with high efficiency and good salt rejection ability under sunlight is highly desirable for water desalination, but its realization remains challenging. Here, a hierarchical solar‐absorbing architecture is designed and fabricated, which comprises a 3D MXene microporous skeleton with vertically aligned MXene nanosheets, decorated with vertical arrays of metal–organic framework‐derived 2D carbon nanoplates embedded with cobalt nanoparticles. The rational integration of three categories of photothermal materials enables broadband light absorption, efficient light to heat conversion, low heat loss, rapid water transportation behavior, and much‐improved corrosion and oxidation resistance. Moreover, when assembling with a hydrophobic insulating layer with hydrophilic channel, the MXene‐based solar absorber can exhibit effective inhibition of salt crystallization due to the ability to advect and diffuse concentrated salt back into the water. As a result, when irradiating under one sun, the solar‐vapor conversion efficiency of the MXene‐based hierarchical design can achieve up to ≈93.4%, and can remain over 91% over 100 h to generate clean vapor for stable and continuous water desalination. This strategy opens an avenue for the development of MXene‐based solar absorbers for sustainable solar‐driven desalination.
Prevascularized Scaffolds Bearing Human Dental Pulp Stem Cells for Treating Complete Spinal Cord Injury
Authors: Guo Shaowei , Redenski Idan , Landau Shira , Szklanny Ariel , Merdler Uri , Levenberg Shulamit 
Published: September 2020

AbstractThe regeneration of injured spinal cord is hampered by the lack of vascular supply and neurotrophic support. Transplanting tissue‐engineered constructs with developed vascular networks and neurotrophic factors, and further understanding the pattern of vessel growth in the remodeled spinal cord tissue are greatly desired. To this end, highly vascularized scaffolds embedded with human dental pulp stem cells (DPSCs) are fabricated, which possess paracrine‐mediated angiogenic and neuroregenerative potentials. The potent pro‐angiogenic effect of the prevascularized scaffolds is first demonstrated in a rat femoral bundle model, showing robust vessel growth and blood perfusion induced within these scaffolds postimplantation, as evidenced by laser speckle contrast imaging and 3D microCT dual imaging modalities. More importantly, in a rat complete spinal cord transection model, the implantation of these scaffolds to the injured spinal cords can also promote revascularization, as well as axon regeneration, myelin deposition, and sensory recovery. Furthermore, 3D microCT imaging and novel morphometric analysis on the remodeled spinal cord tissue demonstrate substantial regenerated vessels, more significantly in the sensory tract regions, which correlates with behavioral recovery following prevascularization treatment. Taken together, prevascularized DPSC‐embedded constructs bear angiogenic and neurotrophic potentials, capable of augmenting and modulating SCI repair.
Scalable Fabrication of Molybdenum Disulfide Nanostructures and their Assembly
Authors: Huang Yun , Yu Kang , Li Huaizhi , Xu Kai , Liang Zexi , Walker Debora , Ferreira Paulo , Fischer Peer , Fan Donglei (Emma) 
Published: September 2020

AbstractMolybdenum disulfide (MoS2) is a multifunctional material that can be used for various applications. In the single‐crystalline form, MoS2 shows superior electronic properties. It is also an exceptionally useful nanomaterial in its polycrystalline form with applications in catalysis, energy storage, water treatment, and gas sensing. Here, the scalable fabrication of longitudinal MoS2 nanostructures, i.e., nanoribbons, and their oxide hybrids with tunable dimensions in a rational and well‐reproducible fashion, is reported. The nanoribbons, obtained at different reaction stages, that is, MoO3, MoS2/MoO2 hybrid, and MoS2, are fully characterized. The growth method presented herein has a high yield and is particularly robust. The MoS2 nanoribbons can readily be removed from its substrate and dispersed in solution. It is shown that functionalized MoS2 nanoribbons can be manipulated in solution and assembled in controlled patterns and directly on microelectrodes with UV‐click‐chemistry. Owing to the high chemical purity and polycrystalline nature, the MoS2 nanostructures demonstrate rapid optoelectronic response to wavelengths from 450 to 750 nm, and successfully remove mercury contaminants from water. The scalable fabrication and manipulation followed by light‐directed assembly of MoS2 nanoribbons, and their unique properties, will be inspiring for device fabrication and applications of the transition metal dichalcogenides.
Highly Sensitive and Selective Sensors for CF4 Gas Molecules Based on Two‐Node Hollow Fullerene
Authors: Zhang Lishu , Li Tao , Feng Yuan Ping , Li Hui , Shen Lei 
Published: September 2020

AbstractHollow nanostructures are widely used in chemistry, materials, and bioscience due to their excellent electrochemical and photoelectric properties. Recently, hollow fullerene nanostructures with tailored opening and shapes have been synthesized. Here, the transport properties of two‐node hollow‐fullerene‐based nanoelectronic devices, and their performance are studied for sensing the greenhouse gas molecule, CF4, by density functional theory combined with nonequilibrium Green's function formalism. It is found that such a device has a high sensitivity to CF4 molecules in both dry and humid environments owing to its good selectivity to H2O molecules. The microscopic physics responsible for these fascinating properties are investigated by the transmission spectra, density of states, and voltage drop. This work paves a way to build new functional electronic devices based on the newly discovered hollow nanostructures.
Near‐Field Electrospinning Enabled Highly Sensitive and Anisotropic Strain Sensors
Authors: Huang Yan , You Xiangyu , Fan Xiangyu , Wong Ching Ping , Guo Ping , Zhao Ni 
Published: September 2020

AbstractThe rapid advances in manufacturing technologies have provided great opportunities for scalable fabrication of novel sensing structures and devices. Here, the application of near‐field electrospinning to the fabrication of flexible strain sensors is explored. Through theoretical modeling, it is first verified that a strong anisotropic response of a strain sensor can be obtained through introducing a grid‐shaped design to its sensing layer. Following this guideline, near‐field electrospinning is applied to fabricate polyurethane grids with well‐controlled period and thickness and the grid is further decorated with conductive silver nanowires. Through tuning the structure of the polyurethane grid and the density of the silver nanowires, a high gauge factor (GF = 338.47) under high strain (200%) is achieved, representing the best sensing and stretching property combination reported for flexible strain sensors. In good agreement with the theoretical model, the strain sensors are only sensitive to the strain along the electrode direction and are insensitive to perpendicular direction strains. Based on this characteristic response, the excellent capability of the strain sensors in distinguishing hand movement and monitoring physiological signals is demonstrated, suggesting the great application potential of the sensors in robotic vision and prosthesis.
Metal Island Structure as a Power Booster for High‐Performance Triboelectric Nanogenerators
Authors: Ravichandran Aravind Narain , Ramuz Marc , Blayac Sylvain 
Published: September 2020

AbstractThe development of the Internet of Things requires the availability of compact and efficient power sources for the supply of autonomous systems. In recent times, electromechanical transduction devices like triboelectric nanogenerators (TENGs) have gained strong attention as they permit simple, robust, and cost‐effective techniques. However, TENGs generally do not achieve the electrical power density required for the targeted applications, and the challenges of optimization are therefore to increase their generated power density. In this work, a multilayer flexible composite structure is developed by employing an insulator–metal–insulator island architecture in place of a single insulator material to accumulate and store the charges created by triboelectrification. This increase in stored charges has a strong effect in inducing free charges on the electrodes resulting in a maximum output power density of 4.8 W m−2, which is ≈150‐fold increase compared to the structure without metal inclusions. The results demonstrate a maximum charge density of 1076.56 µC m−2, which is to the knowledge, the best charge density value ever reported for TENGs in ambient working conditions. Therefore, this work proposes a new direction to significantly increase the electrical power density in obtaining high‐performance triboelectric nanogenerators attractive to future applications for active sensors and portable electronics.
Active Membranes on Rigidity Tunable Foundations for Programmable, Rapidly Switchable Adhesion
Authors: Swift Matthew D. , Haverkamp Cole B. , Stabile Christopher J. , Hwang Dohgyu , Plaut Raymond H. , Turner Kevin T. , Dillard David A. , Bartlett Michael D. 
Published: September 2020

AbstractRapidly controlling and switching adhesion is necessary for applications in robotic gripping and locomotion, pick and place operations, and transfer printing. However, switchable adhesives often display a binary response (on or off) with a narrow adhesion range, lack post‐fabrication adhesion tunability, or switch slowly due to diffusion‐controlled processes. Here, pneumatically controlled shape and rigidity tuning is coupled to rapidly switch adhesion (≈0.1 s) across a wide range of programmable adhesion forces with measured switching ratios as high as 1300x. The switchable adhesion system introduces an active polydimethylsiloxane membrane supported on a compliant, foam foundation with pressure‐tunable rigidity where positive and negative pneumatic pressure synergistically control contact stiffness and geometry to activate and release adhesion. Energy‐based modeling and finite element computation demonstrate that high adhesion is achieved through a pressure‐dependent, nonlinear stiffness of the foundation, while an inflated shape at positive pressures enables easy release. This approach enables adhesion‐based gripping and material assembly, which is utilized to pick‐and‐release common objects, rough and porous materials, and arrays of elements with a greater than 14 000x range in mass. The robust assembly of diverse components (rigid, soft, flexible) is then demonstrated to create a soft and stretchable electronic device.
Ultrastretchable, Wearable Triboelectric Nanogenerator Based on Sedimented Liquid Metal Elastomer Composite
Authors: Pan Chengfeng , Liu Dongye , Ford Michael J. , Majidi Carmel 
Published: September 2020

AbstractProgress in soft and stretchable electronics depends on energy sources that are mechanically compliant, elastically deformable, and renewable. Energy harvesting using triboelectric nanogenerators (TENGs) made from soft materials provides a promising approach to address this critical need. Here, an elastomeric composite is introduced with sedimented liquid metal (LM) droplets for TENG‐based energy harvesting that relies on assembly of the LM to form phase‐separated conductive and insulating regions. The sedimented LM elastomer TENG (SLM‐TENG) exhibits ultrahigh stretchability (strain limit > 500% strain), skin‐like compliance (modulus < 60 kPa), reliable device stability (>10 000 cycles), and appreciable electrical output performance (max peak power density = 1 mW cm−2). SLM‐TENGs can be integrated with highly elastic stretchable fabrics, thereby enabling broad integration with wearable electronics. A stretchable and wearable SLM‐TENG is demonstrated that harvests energy from human motion through a patch attached to the knee or integrated into exercise clothing. This body‐mounted TENG device can generate enough electricity to fully power a wearable computing device (hygro‐thermometer with digital display) after 2.2 min of running on a treadmill.
Ynamides in Free Radical Reactions
Authors: Mahe Capucine , Cariou Kevin 
Published: September 2020

AbstractIn this review we present the transformations that have been developed with ynamides and free radicals. These reactions involve carbon‐, heteroatom‐ or even metalloid‐centered radicals and include inter‐ and intra‐molecular reactions. The scope and mechanism of these transformations are discussed in details, including the most recent examples relying on photoredox catalysis.magnified image
Air‐Source Heat Pump for Distributed Steam Generation: A New and Sustainable Solution to Replace Coal‐Fired Boilers in China
Authors: Yan Hongzhi , Hu Bin , Wang Ruzhu 
Published: September 2020

AbstractWith the ratification of the Paris Climate Change Agreement, the use of coal‐fired boilers in China are being gradually restricted and removed from use to control air pollution and reduce CO2 emissions. However, current alternatives to coal‐fired boilers such as gas‐fired boilers, electric boilers, biomass boilers, and solar boilers have obvious limitations and drawbacks that can limit the spread of their use. An air‐source heat pump boiler that can extract thermal energy from air and generate high‐temperature steam is proposed, developed, and verified. The air‐source heat pump boiler shows a stable system output with ambient temperature variations from 5 to 35 °C, with an energy efficiency as high as 150–210% to generate steam at more than 120 °C. Furthermore, by taking technical and economic analysis and carbon trading into consideration, air‐source heat pump boiler has shown significant application advantages than other boilers. This research shows that air‐source heat pump steam generation is feasible for replacing coal‐fired boilers in China and could be a sustainable steam generation method.
Addressable Acoustic Actuation of 3D Printed Soft Robotic Microsystems
Authors: Kaynak Murat , Dirix Pietro , Sakar Mahmut Selman 
Published: September 2020

AbstractA design, manufacturing, and control methodology is presented for the transduction of ultrasound into frequency‐selective actuation of multibody hydrogel mechanical systems. The modular design of compliant mechanisms is compatible with direct laser writing and the multiple degrees of freedom actuation scheme does not require incorporation of any specific material such as air bubbles. These features pave the way for the development of active scaffolds and soft robotic microsystems from biomaterials with tailored performance and functionality. Finite element analysis and computational fluid dynamics are used to quantitatively predict the performance of acoustically powered hydrogels immersed in fluid and guide the design process. The outcome is the remotely controlled operation of a repertoire of untethered biomanipulation tools including monolithic compound micromachinery with multiple pumps connected to various functional devices. The potential of the presented technology for minimally invasive diagnosis and targeted therapy is demonstrated by a soft microrobot that can on‐demand collect, encapsulate, and process microscopic samples.
Modeling Endothelialized Hepatic Tumor Microtissues for Drug Screening
Authors: Wang Ying , Kankala Ranjith Kumar , Zhang Jianting , Hao Liuzhi , Zhu Kai , Wang Shibin , Zhang Yu Shrike , Chen Aizheng 
Published: September 2020

AbstractCompared to various traditional 2D approaches, the scaffold‐based 3D tumor models have emerged as an effective strategy to investigate the complex mechanisms behind cancer progression and responses to drug treatments, by providing biomimetic extracellular matrix and stromal‐like microenvironments including the vascular elements. Herein, the development of a 3D endothelialized hepatic tumor microtissue model based on the fusion of multicellular aggregates of human hepatocellular carcinoma cells and human umbilical vein endothelial cells cocultured in poly(lactic‐co‐glycolic acid)‐based porous microspheres (PLGA PMs) is reported. In contrast to the conventional 2D culture, the cells within the PLGA PMs exhibit significantly higher half‐maximal inhibitory concentration values against anticancer drugs, including doxorubicin and cisplatin. Furthermore, the feasibility of coculturing other cell types, such as fibroblasts (L929) and HepG2 cells, is investigated. Together, the findings emphasize the significance of engineered 3D hepatic tumor microtissue models using PLGA PM‐based multicellular aggregates for drug screening applications.
17% Non‐Fullerene Organic Solar Cells with Annealing‐Free Aqueous MoOx
Authors: Tran Hong Nhan , Park Sujung , Wibowo Febrian Tri Adhi , Krishna Narra Vamsi , Kang Ju Hwan , Seo Jung Hwa , Nguyen‐Phu Huy , Jang Sung‐Yeon , Cho Shinuk 
Published: September 2020

AbstractA charge transport layer based on transition metal‐oxides prepared by an anhydrous sol–gel method normally requires high‐temperature annealing to achieve the desired quality. Although annealing is not a difficult process in the laboratory, it is definitely not a simple process in mass production, such as roll‐to‐roll, because of the inevitable long cooling step that follows. Therefore, the development of an annealing‐free solution‐processable metal‐oxide is essential for the large‐scale commercialization. In this work, a room‐temperature processable annealing‐free “aqueous” MoOx solution is developed and applied in non‐fullerene PBDB‐T‐2F:Y6 solar cells. By adjusting the concentration of water in the sol–gel route, an annealing‐free MoOx with excellent electrical properties is successfully developed. The PBDB‐T‐2F:Y6 solar cell with the general MoOx prepared by the anhydrous sol–gel method shows a low efficiency of 7.7% without annealing. If this anhydrous MoOx is annealed at 200 °C, the efficiency is recovered to 17.1%, which is a normal value typically observed in conventional structure PBDB‐T‐2F:Y6 solar cells. However, without any annealing process, the solar cell with aqueous MoOx exhibits comparable performance of 17.0%. In addition, the solar cell with annealing‐free aqueous MoOx exhibits better performance and stability without high‐temperature annealing compared to the solar cells with PEDOT:PSS.
Climate warming alters photosynthetic responses to elevated CO2 in prairie plants
Authors: Sage Emma , Heisler‐White Jana , Morgan Jack , Pendall Elise , Williams David G. 
Published: September 2020

PremiseThe impact of elevated CO2 concentration ([CO2]) and climate warming on plant productivity in dryland ecosystems is influenced strongly by soil moisture availability. We predicted that the influence of warming on the stimulation of photosynthesis by elevated [CO2] in prairie plants would operate primarily through direct and indirect effects on soil water.MethodsWe measured light‐saturated photosynthesis (Anet), stomatal conductance (gs), maximum Rubisco carboxylation rate (Vcmax), maximum electron transport capacity (Jmax) and related variables in four C3 plant species in the Prairie Heating and CO2 Enrichment (PHACE) experiment in southeastern Wyoming. Measurements were conducted over two growing seasons that differed in the amount of precipitation and soil moisture content.ResultsAnet in the C3 subshrub Artemisia frigida and the C3 forb Sphaeralcea coccinea was stimulated by elevated [CO2] under ambient and warmed temperature treatments. Warming by itself reduced Anet in all species during the dry year, but stimulated photosynthesis in S. coccinea in the wet year. In contrast, Anet in the C3 grass Pascopyrum smithii was not stimulated by elevated [CO2] or warming under wet or dry conditions. Photosynthetic downregulation under elevated [CO2] in this species countered the potential stimulatory effect under improved water relations. Warming also reduced the magnitude of CO2‐induced down‐regulation in this grass, possibly by sustaining high levels of carbon utilization.ConclusionsDirect and indirect effects of elevated [CO2] and warming on soil water was an overriding factor influencing patterns of Anet in this semi‐arid temperate grassland, emphasizing the important role of water relations in driving grassland responses to global change.