bluuebunny/crossref_metadata_2025_split huggingface dataset:
Smart Learning Environments and Ergonomics: An Approach to the State of the Question
Authors: García-Tudela Pedro Antonio , Prendes-Espinosa María Paz , Solano-Fernández Isabel María 
Published: July 2020

Abstract
Educational technology evolves constantly, in line with the innovative technologies we implement, but always catering for the improvement of teaching and learning. For this, Smart Learning Environments (SLE) emerge as an optimal alternative to traditional teaching as, through ergonomics, an inclusive outlook which is bound to enhance the educational experience of every student is provided. The method utilized is based on a systematic review of the existing literature which has allowed us to analyze in depth a final sample of 19 documents after an initial review of 633, being these all the works published between 2013 and 2019.Therefore, the principal objective of the present work is carrying out an analysis of the state of the art in relation to ergonomics, inclusiveness and the SLE. The analysis of results is performed utilizing a semantic network, generated through atlas.ti. v.8, by means of which 3 categories, 10 codes and 33 quotes are extracted. Namely, the results reveal the emerging nature of the thematic line researched and how ergonomics is linked to inclusiveness and stands out as one of the most defining components when designing an educational proposal based on SLE.
Self‐Healable and Recyclable Tactile Force Sensors with Post‐Tunable Sensitivity
Authors: Zhou Xiaozhuang , Zhang Xuan , Zhao Huaixia , Krishnan Baiju P. , Cui Jiaxi 
Published: July 2020

AbstractIt is challenging to post‐tune the sensitivity of a tactile force sensor. Herein, a facile method is reported to tailor the sensing properties of conductive polymer composites by utilizing the liquid‐like property of dynamic polymer matrix at low strain rates. The idea is demonstrated using dynamic polymer composites (CB/dPDMS) made via evaporation‐induced gelation of the suspending toluene solution of carbon black (CB) and acid‐catalyzed dynamic polydimethylsiloxane (dPDMS). The dPDMS matrices allow CB to redistribute to change the sensitivity of materials at the liquid‐like state, but exhibit typical solid‐like behavior and thus can be used as strain sensors at normal strain rates. It is shown that the gauge factor of the polymer composites can be easily post‐tuned from 1.4 to 51.5. In addition, the dynamic polymer matrices also endow the composites with interesting self‐healing ability and recyclability. Therefore, it is envisioned that this method can be useful in the design of various novel tactile sensing materials for many applications.
Realization of Epitaxial Thin Films of the Topological Crystalline Insulator Sr3SnO
Authors: Ma Yanjun , Edgeton Anthony , Paik Hanjong , Faeth Brendan D. , Parzyck Christopher T. , Pamuk Betül , Shang Shun‐Li , Liu Zi‐Kui , Shen Kyle M. , Schlom Darrell G. , Eom Chang‐Beom 
Published: July 2020

AbstractTopological materials are derived from the interplay between symmetry and topology. Advances in topological band theories have led to the prediction that the antiperovskite oxide Sr3SnO is a topological crystalline insulator, a new electronic phase of matter where the conductivity in its (001) crystallographic planes is protected by crystallographic point group symmetries. Realization of this material, however, is challenging. Guided by thermodynamic calculations, a deposition approach is designed and implemented to achieve the adsorption‐controlled growth of epitaxial Sr3SnO single‐crystal films by molecular‐beam epitaxy (MBE). In situ transport and angle‐resolved photoemission spectroscopy measurements reveal the metallic and electronic structure of the as‐grown samples. Compared with conventional MBE, the used synthesis route results in superior sample quality and is readily adapted to other topological systems with antiperovskite structures. The successful realization of thin films of Sr3SnO opens opportunities to manipulate topological states by tuning symmetries via strain engineering and heterostructuring.
Crystallized Monolayer Semiconductor for Ohmic Contact Resistance, High Intrinsic Gain, and High Current Density
Authors: Peng Boyu , Cao Ke , Lau Albert Ho Yuen , Chen Ming , Lu Yang , Chan Paddy K. L. 
Published: July 2020

AbstractThe contact resistance limits the downscaling and operating range of organic field‐effect transistors (OFETs). Access resistance through multilayers of molecules and the nonideal metal/semiconductor interface are two major bottlenecks preventing the lowering of the contact resistance. In this work, monolayer (1L) organic crystals and nondestructive electrodes are utilized to overcome the abovementioned challenges. High intrinsic mobility of 12.5 cm2 V−1 s−1 and Ohmic contact resistance of 40 Ω cm are achieved. Unlike the thermionic emission in common Schottky contacts, the carriers are predominantly injected by field emission. The 1L‐OFETs can operate linearly from VDS = −1 V to VDS as small as −0.1 mV. Thanks to the good pinch‐off behavior brought by the monolayer semiconductor, the 1L‐OFETs show high intrinsic gain at the saturation regime. At a high bias load, a maximum current density of 4.2 µA µm−1 is achieved by the only molecular layer as the active channel, with a current saturation effect being observed. In addition to the low contact resistance and high‐resolution lithography, it is suggested that the thermal management of high‐mobility OFETs will be the next major challenge in achieving high‐speed densely integrated flexible electronics.
Photoactivatable Protherapeutic Nanomedicine for Cancer
Authors: Zhang Yan , Xu Cheng , Yang Xiangliang , Pu Kanyi 
Published: July 2020

AbstractTherapeutic systems with site‐specific pharmaceutical activation hold great promise to enhance therapeutic efficacy while reducing systemic toxicity in cancer therapy. With operational flexibility, noninvasiveness, and high spatiotemporal resolution, photoactivatable nanomedicines have drawn growing attention. Distinct from traditional controlled release systems relying on the difference of biomarker concentrations between disease and healthy tissues, photoactivatable nanomedicines capitalize on the interaction between nanotransducers and light to either trigger photochemical reactions or generate reactive oxygen species (ROS) or heat effect to remotely induce pharmaceutical actions in living subjects. Herein, the recent advances in the development of photoactivatable protherapeutic nanoagents for oncology are summarized. The design strategies and therapeutic applications of these nanoagents are described. Representative examples of each type are discussed in terms of structure, photoactivation mechanism, and preclinical models. Last, potential challenges and perspectives to further develop photoactivatable protherapeutic nanoagents in cancer nanomedicine are discussed.
Energy Levels of Molecular Dopants in Organic Semiconductors
Authors: Li Peicheng , Lu Zheng‐Hong 
Published: July 2020

AbstractThe energy level alignments between hosts and dopants dictate many key physical processes such as charge transport and exciton formation, and thus the functionality and performance of organic semiconductor devices. Therefore, design and fabrication of high‐performance organic devices require knowledge of the energy offsets between hosts and dopants. Due to a typically low dopant concentration used in devices such as organic light‐emitting diodes and sometimes overlapping density of states, it is generally not possible to measure directly the energy offset in a doped system by photoemission technique. Here it is demonstrated that the energy offset between a host and a dopant in a doped system equals to that of its reciprocal heterojunction system. This opens the door for facile data collection. These directly measured offsets are also shown to be the same as the detrapping activation energies extracted from variable temperature charge transport modeling analysis. The energy level alignments between hosts and noncharge transfer dopants, charge transfer p‐type donors, and charge transfer n‐type acceptors are shown to exhibit the universal energy alignment rule for organic–organic heterojunction interfaces.
Heater‐Free and Substrate‐Independent Growth of Vertically Standing Graphene Using A High‐Flux Plasma‐Enhanced Chemical Vapor Deposition
Authors: Wu Zhiheng , Zhang Yongshang , Shen Yonglong , Zhang Wei , Shao Guosheng 
Published: July 2020

AbstractVertically standing graphene (VSG) films have demonstrated various appealing functionalities on the basis of excellent electrical/thermal conductivity and electrochemical/catalytic properties, owing to their unique morphology, preferable orientation of the basal planes, and adequate defects as effective catalytic sites. Most fabrication processes for VSG suffer from the disadvantage of high processing temperature, difficulty in structural control, or poor scalability, which limits their many potential applications. Herein, a scalable high‐flux plasma‐enhanced chemical vapor deposition system is designed, with streamlined magnetic field to enable high and uniform ion density over a spatially extended plasma flux, which facilitates large‐area deposition of structurally tuned VSG independent of substrate materials without additional heating, for the first time. The orientation, density, and the degree of order for the as‐fabricated VSG can be tailored through adjusting the plasma environment, which in turn affects crystallization mechanisms. Such low‐temperature synthesized VSG films are demonstrated as high‐performance anode in sodium ion batteries, achieving a high capacity retention of 86% after 2000 cycles at a current density of 1 A g−1. It is expected that the current VSG films would have great potential for electrochemical applications that request catalytic sites together with favorable conductivity for ions and electrons.
Efficient Modulation of Photonic Bandgap and Defect Modes in All‐Dielectric Photonic Crystals by Energetic Ion Beams
Authors: Du Guiqiang , Zhou Xiachen , Pang Chi , Zhang Kaiyuan , Zhao Yunpeng , Lu Guang , Liu Fen , Wu Ailing , Akhmadaliev Shavkat , Zhou Shengqiang , Chen Feng 
Published: July 2020

AbstractThe photonic bandgap and localization in photonic crystals can be effectively modulated by energetic ion beams owing to the induced modification of the thickness and refractive indices of the materials. In this work, the modulation of photonic bandgap and defect modes in 1D all‐dielectric photonic crystals is investigated theoretically and experimentally by using carbon (C5+) ion irradiation. It is found that the photonic bandgap and defect mode have a remarkable hypsochromic shift under the C5+ ion irradiation. The degree of the blueshift mainly depends on the reduction of the material thickness that is nearly proportional to the fluences of C5+ ions. The blueshift of the band edges and defect modes shows a step‐like behavior from transparency to opacification (near‐zero transmittance or high reflectance) or a converse trend. The work paves a new way to tailor the photonic crystals toward the development of novel devices with tunable specific wavelengths and wavebands.
Bromine Doping of MAPbI3 Films Deposited via Chemical Vapor Deposition Enables Efficient and Photo‐Stable Self‐Powered Photodetectors
Authors: Pammi Sri Venkata Narayana , Tran Van‐Dang , Maddaka Reddeppa , Eom Ji‐Ho , Jung Jang Su , Jeong Hyeon‐Myeon , Kim Moon‐Deock , Pecunia Vincenzo , Yoon Soon Gil 
Published: July 2020

AbstractHybrid lead‐halide perovskite photodetectors represent a highly promising technology, but long‐term operational stability under ambient conditions must be improved before these devices can be deployed in real‐world applications. In consideration of the relationship between film quality and device stability, this work explored photodetectors based on bromine‐doped CH3NH3PbI3 (i.e., CH3NH3PbI3−xBrx, MAPbI3−xBrx in short form) perovskite layers deposited via chemical vapor deposition (CVD). These layers have good compactness and no pinholes, hence they enable sandwich‐type photodetectors with high performance in self‐powered mode. Under 632 nm illumination, these photodetectors achieve a level of responsivity as high as 45 A/W, along with a specific detectivity of 1.15 × 1014 Jones and an external quantum efficiency of 8.84 × 103%. It is important to note that these photodetectors exhibit outstanding operational stability that is superior to that of their pure‐iodide (i.e., CH3NH3PbI3, MAPbI3 in short form) counterparts. When the MAPbI3−xBrx devices are stressed under simulated solar illumination in ambient air, their photoresponse is maintained to within 29% loss of the original value for more than 500 h, while the photoresponse of the MAPbI3 devices is reduced by 62%. The key figures of merit of the fabricated devices and their operational level of photostability are expected to create new avenues for future outdoor photodetector applications.
Color‐Tunable Circularly Polarized Luminescence with Helical Polyacetylenes as Fluorescence Converters
Authors: Zhao Biao , Gao Xiaobin , Lu Na , Deng Jianping 
Published: July 2020

AbstractCircularly polarized luminescence (CPL) materials are currently drawing rapidly increasing interest. However, constructing color‐tunable CPL materials is still a big challenge, primarily due to the lack of simple, powerful, and universal preparation strategies. In this contribution, color‐tunable CPL emissions are easily realized by taking helical polyacetylenes as fluorescence converters. The investigated helical polyacetylenes are prepared by solution polymerization of a substituted acetylenic monomer with cholesteryl pendant. The prepared polymer exhibits dynamically reversible solvatochromism performance in different solvents, owing to the change of conjugated length of polymer main‐chains. More excitingly, when circularly polarized light with blue emission passes through the as‐prepared helical polyacetylene with different conjugated lengths, multicolor CPL emissions of cyan, green, and orange are obtained, with high dissymmetry factors (glum) in the range of 10−2–10−1. Also notably, neither any covalent nor noncovalent interaction is required during this CPL color‐tuning process. The present study provides a new insight for developing multicolor CPL materials.
Synthesis of Cyclopenta[b]indoles via a Formal [3+2] Cyclization of N‐Sulfonyl‐1,2,3‐triazoles and Indoles
Authors: Duan Shengguo , Zhang Wan , Hu Yuntong , Xu Ze‐Feng , Li Chuan‐Ying 
Published: July 2020

AbstractAnnulation of benzoxy‐tethered N‐sulfonyl‐1,2,3‐triazoles and indoles has been developed in this paper, providing an efficient and convenient access to valuable cyclopenta[b]indoles in moderate to good yields. α,β‐Unsaturated imine, which generated in situ from denitrogenation and 1,2‐OBz migration of triazole, provided three carbons for the formal [3+2] cyclization reaction for the first time.magnified image
Heterojunction Photocatalysts Based on 2D Materials: The Role of Configuration
Authors: Su Qian , Li Yao , Hu Ran , Song Fang , Liu Siyuan , Guo Cuiping , Zhu Shenmin , Liu Wenbin , Pan Jian 
Published: July 2020

AbstractSemiconductor photocatalysis is currently attracting tremendous attention as it holds great potential to address the issues of energy shortage and environmental pollution. 2D materials are excellent candidates for photocatalysis owing to their attractive structural and electronic properties. However, practical applications of 2D materials are still hindered due to limitations, such as fast electron–hole recombination and poor redox ability, both of which lead to low efficiency of photocatalytic reactions. Constructing a heterojunction is the most widely used strategy to solve these problems. In particular, heterojunctions composed of 2D materials interfaced with other semiconductors of different dimensionalities can integrate the respective advantages and mitigate the drawbacks of each component. Hence, this review focuses on the recent developments in the rational design of 2D material‐based heterojunction photocatalysts with different configurations. The synthetic strategies, physicochemical properties, component functions, photocatalytic mechanisms, and applications of these heterojunctions are systematically summarized. Emphasis is placed on correlations between photocatalytic performance and heterojunction configuration. Finally, the ongoing challenges and potential directions for future development of 2D material‐based heterojunction photocatalysts are also proposed.
Generation of Axially Polar Ferroelectricity in a Columnar Liquid Crystal Phase by Introducing Chirality
Authors: Akiyama Azumi , Jido Keita , Kohri Michinari , Taniguchi Tatsuo , Kishikawa Keiki 
Published: July 2020

AbstractAxially polar ferroelectric columnar liquid crystals (AP‐FCLCs) are materials in which the molecules are self‐organized into axially polar columns and exhibit switching and holding of their polar directions. If the polar directions along the columnar axis can be controlled by using a nanosized electrode, AP‐FCLCs have the potential to realize ultrahigh‐density memory devices. Though switching polarities in columnar liquid crystal phases have been studied by many scientists, it remains difficult to realize bistable switching. In this study, it is found that replacement of the normal alkyl groups (decyl groups) with chiral groups ((S)‐citronellyl groups) in an N,N’‐bis(3,4,5‐trialkoxyphenyl)urea realizes perfect ferroelectricity in the rectangular columnar liquid crystal phase, and it is confirmed that the phase is an AP‐FCLC phase. The differences in the properties and molecular packing structures between the achiral and chiral urea compounds are investigated. Furthermore, the mechanism for achieving ferroelectricity by introduction of the chiral alkyl chains is postulated.
Achieving High Thermoelectric Performance by Introducing 3D Atomically Thin Conductive Framework in Porous Bi2Te2.7Se0.3‐Carbon Nanotube Hybrids
Authors: Li Shuankui , Wang Rui , Zhu Weiming , Chu Mihai , Huang Zhongyuan , Zhang Yanjun , Zhao Wenguang , Liu Fusheng , Luo Jun , Xiao Yinguo , Pan Feng 
Published: July 2020

AbstractFabricating thermoelectric (TE) materials with porous structure is an effective approach to reduce lattice thermal conductivity; however, the electrical conductivity is usually severely sacrificed. In this work, a high performance porous Bi2Te2.7Se0.3‐carbon nanotube (BTS‐CNTs) thermoelectric hybrid is prepared by introducing atomically thin BTS conductive networks on the BTS‐CNT interface, which simultaneously possess ultralow lattice thermal conductivity and high electrical conductivity. The 3D conductive framework built by atomically thin BTS layers on CNTs enables the creation of an intimate contact with bulk BTS and serves as a fast pathway of the electric conductivity, resulting in high electrical conductivity. Meanwhile, the phonon scattering around nanopore wall is greatly enhanced, and the lattice thermal conductivity is found to be as low as 0.19 W m−1 K−1, which is close to the minimal lattice thermal conductivity according to Debye–Cahill model. Consequently, the porous BTS/CNTs hybrid displays a high ZT value of about 1.2, which is 65% higher than that of fully dense pristine BTS. The present work demonstrates a novel and practical approach to design and fabricate high performance porous TE materials through an unconventional sacrificial template method.
Microgravity method in archaeological prospection: methodical comments on selected case studies from crypt and tomb detection
Authors: Pašteka Roman , Pánisová Jaroslava , Zahorec Pavol , Papčo Juraj , Mrlina Jan , Fraštia Marek , Vargemezis George , Kušnirák David , Zvara Ivan 
Published: July 2020

AbstractDetailed and precise measurement of the Earth's gravity field (microgravity method) can be effectively used for the detection and quantification of subsurface voids and/or cavities. There exist a variety of successful applications of the microgravity method in near surface geophysics, namely in geotechnical, environmental and archaeological prospection. Using state‐of‐the‐art ‘microgal’ relative gravity meters, cavities of several metres in each dimension (positioned at a similar depth) can be detected and interpreted. Such objects produce negative anomalies with amplitudes of several tens of microGals (1 microGal = 10−8 m s−2). This contribution is focused on a methodological overview of the most important acquisition and processing steps in archaeological microgravimetry. In the processing of acquired gravimetrical data into a Bouguer anomaly, the so‐called building correction plays an important role, because the gravitational effect of building masses can produce false, usually negative anomalies. Several selected methods for quantitative interpretation are presented, these are based on depth estimation and density modelling. These interpretation methods give satisfactory results in the case of these type of negative anomalies that are caused by subsurface cavities. Microgravimetry can obtain good support from electromagnetic and electrical methods, mainly from ground penetrating radar and electrical resistivity tomography, respectively. Finally, we present successful case‐studies of microgravimetrical detection of crypts in various churches from the Middle Ages and period of Modern History, surveyed during recent decades in Slovakia and Czechia.
C−N, C−S and S−S Bond Cleavage by Rhodium PCcarbeneP Pincer Complexes
Authors: Tinnermann Hendrik , Young Rowan D. 
Published: July 2020

AbstractRhodium PCcarbeneP complexes 1‐L {L=PPh3, PPh2(C6F5)} react with isothiocyanate, carbodiimide and disulphide to enable C−S, C−N and S−S bond cleavage. The cleaved molecules are sequestered by the metal center and the pincer alkylidene linkage, forming η2‐coordinated sulfide or imide centered pincer complexes. When a C−S or S−S bond is cleaved, the resulting complexes can bridge two rhodium centers through sulphur forming dimeric complexes and eliminating a monodentate phosphine ligand.
Palladium‐Catalyzed Intramolecular Alder‐Ene Type Cycloisomerization Reactions
Authors: Yadav Sonu , Ramasastry S. S. V. 
Published: July 2020

AbstractAn overview of the recent literature on palladium‐catalyzed intramolecular Alder‐ene (IMAE) reaction of a variety of 1,n‐unsaturated systems is presented. The reaction which was first reported by Trost and Lautens provided an efficient alternative to the thermal or Lewis acid catalyzed cycloisomerizations involving ene‐type reaction. The IMAE cyclization of enynes and dienes has emerged as an important area and found significant applications in building up of complex molecular architectures and in the synthesis of several bioactive natural products. Since highly impactful reviews on this subject have covered the literature till 2015, this article focuses on summarizing the works subsequent to 2015.