bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mindfulness, impulsivity, and moral disengagement as parameters of bullying and victimization at school
Authors: Georgiou Stelios N. , Charalambous Kyriakos , Stavrinides Panayotis 
Published: November 2019

AbstractThe aim of the present study was to examine the existing association between mindfulness, impulsivity, moral disengagement, and bullying experiences at school. Longitudinal data were collected in three points in time (T1, T2, T3) with 6 months interval between them. Participants were 558 adolescents attending secondary schools in Cyprus, with their ages ranging from 14 to 17 years (M = 15.3; standard deviation = 0.69). Through structural equation modeling, it was found that mindfulness at T1 had a significant negative effect on both impulsivity and moral disengagement at T2 and these, in turn, had a positive effect on bullying and victimization at T3. Thus, mindfulness had an indirect effect on both bullying and victimization, fully mediated by impulsivity and moral disengagement.
Multifunctional High‐Power Sources for Smart Contact Lenses
Authors: Takamatsu Taiki , Sijie Yin , Shujie Fang , Xiaohan Liu , Miyake Takeo 
Published: November 2019

AbstractPowering an electrical contact lens is a significant challenge for wearable applications such as augmented reality displays and iontophoretic drug delivery to the eye. Here a hybrid power generation device is developed comprising a wireless power transfer system and a bioabsorbable metal–air primary battery, which provides a multifunctional direct current (DC) and/or alternating current (AC) output. The DC power is generated by Zn loop anode and a bilirubin oxidase (BOD) biocathode in an artificial tear. The Zn‐based loop anode is also used as the antenna of a wireless power transfer system that results in high power transfer efficiency of 17.6% at 13.56 MHz. The wireless‐powered AC voltage is boosted from 1.5 to 1.5 V + 0.5 Vpp by a DC offset, enabling red light‐emitting diode (LED) emission. Furthermore, the hybrid AC and DC offset voltages are boosted to 2.3 V + 0.5 Vpp by a capacitive booster circuit that provides blue LED emission. No hydrogen evolution or pH change is observed in the tear electrolyte. The present hybrid power source can potentially power wearable electronics in body fluids.
Boosting Efficiency of Near‐Infrared Organic Light‐Emitting Diodes with Os(II)‐Based Pyrazinyl Azolate Emitters
Authors: Yuan Yi , Liao Jia‐Ling , Ni Shao‐Fei , Jen Alex K.‐Y. , Lee Chun‐Sing , Chi Yun 
Published: November 2019

AbstractTremendous effort has been devoted to developing novel near‐infrared (NIR) emitters and to improving the performance of NIR organic light‐emitting diodes (OLEDs). Os(II) complexes are known to be an important class of NIR electroluminescent materials. However, the highest external quantum efficiency achieved so far for Os(II)‐based NIR OLEDs with an emission peak wavelength exceeding 700 nm is still lower than 3%. A new series of Os(II) complexes (1–4) based on functional pyrazinyl azolate chelates and dimethyl(phenyl)phosphane ancillaries is presented. The reduced metal‐to‐ligand charge transfer (MLCT) transition energy gap of pyrazinyl units in the excited states results in efficient NIR emission for this class of metal complexes. Consequently, NIR OLEDs based on 1–4 show excellent device performance, among which complex 4 with a triazolate fragment gives superior performance with maximum external quantum efficiency of 11.5% at peak wavelength of 710 nm, which represent the best Os(II)‐based NIR‐emitting OLEDs with peak maxima exceeding 700 nm.
Role of Excess FAI in Formation of High‐Efficiency FAPbI3‐Based Light‐Emitting Diodes
Authors: Jia Yong‐Heng , Neutzner Stefanie , Zhou Yang , Yang Ming , Tapia Jetsabel Maria Figueroa , Li Nan , Yu Hui , Cao Jie , Wang Jian‐Pu , Petrozza Annamaria , Wong Ching‐Ping , Zhao Ni 
Published: November 2019

AbstractIntroducing extensively excess ammonium halides when forming perovskites has recently been demonstrated as an effective approach to improve the performance of perovskite light‐emitting diodes (PeLEDs). Here, Cs0.17FA0.83PbI2.5Br0.5 is used as a model system to elucidate the impact of introducing excess formamidinium iodide (FAI) on the crystallization process of the perovskite film and operation of the corresponding PeLED. The excess FAI ratio is varied from 0 to 120 mol% and the crystallization process of the perovskite through in situ absorbance, in situ photoluminescence, and ex situ X‐ray diffraction measurements is systematically monitored. The results suggest that excess FAI triggers formation of a compact wide‐bandgap intermediate phase in the as‐deposited film, which then transforms to isolated and highly crystalline perovskite grains upon annealing. Using excitation correlation photoluminescence spectroscopy it is found that excess FAI results in a lower density of deep trap states and therefore a reduction of nonradiative losses in the material. This leads to a greatly enhanced maximum external quantum efficiency (EQE) from 0.25% (stoichiometric) to 12.7% (90 mol% excess). Furthermore, the FAI‐excess perovskite film is optimized with Pb(SCN)2 and 5‐ammonium valeric acid iodide additives and achieve a record radiance of 965 W Sr−1 m−2 for near‐infrared PeLEDs and a high EQE of 17.4%.
Tailored Redox Kinetics, Electronic Structures and Electrode/Electrolyte Interfaces for Fast and High Energy‐Density Potassium‐Organic Battery
Authors: Tong Zhongqiu , Tian Shuang , Wang Hui , Shen Dong , Yang Rui , Lee Chun‐Sing 
Published: November 2019

AbstractPotassium‐organic batteries have a great potential for applications in large‐scale electricity grids and electric vehicles because of their low cost and sustainability. However, their inferior cycle stability and more importantly low energy density under fast discharge/charge process of organic cathodes limit their applications. This work introduces a simple polymerization processing which enables comprehensive tuning of redox kinetics, electronic structures, and electrode/electrolyte interfaces of the polymer cathodes. With this approach, a potassium‐organic battery with an impressive energy density of 113 Wh kg−1 at a high power of 35.2 kW kg−1 is shown which corresponds to a high current density of 147 C and a fully discharge within 10 s. The battery also has impressive cycling stability that a 100% Columbic efficiency is maintained and shows negligible capacity degradation after 1000 cycle at a high current density of 7.35 C. Using the polymer cathode and a dipotassium terephthalate anode, a full battery with superior energy density and cycling stability is demonstrated among all reported all‐organic full potassium ion batteries.
Fast‐Response, Highly Air‐Stable, and Water‐Resistant Organic Photodetectors Based on a Single‐Crystal Pt Complex
Authors: Periyanagounder Dharmaraj , Wei Tzu‐Chiao , Li Ting‐You , Lin Chun‐Ho , Gonçalves Théo Piechota , Fu Hui‐Chun , Tsai Dung‐Sheng , Ke Jr‐Jian , Kuo Hung‐Wei , Huang Kuo‐Wei , Lu Norman , Fang Xiaosheng , He Jr‐Hau 
Published: November 2019

AbstractOrganic semiconductors demonstrate several advantages over conventional inorganic materials for novel electronic and optoelectronic applications, including molecularly tunable properties, flexibility, low‐cost, and facile device integration. However, before organic semiconductors can be used for the next‐generation devices, such as ultrafast photodetectors (PDs), it is necessary to develop new materials that feature both high mobility and ambient stability. Toward this goal, a highly stable PD based on the organic single crystal [PtBr2(5,5′‐bis(CF3CH2OCH2)‐2,2′‐bpy)] (or “Pt complex (1o)”) is demonstrated as the active semiconductor channel—a material that features a lamellar molecular structure and high‐quality, intraligand charge transfer. Benefitting from its unique crystal structure, the Pt‐complex (1o) device exhibits a field‐effect mobility of ≈0.45 cm2 V−1 s−1 without loss of significant performance under ambient conditions even after 40 days without encapsulation, as well as immersion in distilled water for a period of 24 h. Furthermore, the device features a maximum photoresponsivity of 1 × 103 A W−1, a detectivity of 1.1 × 1012 cm Hz1/2 W−1, and a record fast response/recovery time of 80/90 µs, which has never been previously achieved in other organic PDs. These findings strongly support and promote the use of the single‐crystal Pt complex (1o) in next‐generation organic optoelectronic devices.
Decoding the Polymer p–n Junction: Controlled Dedoping and Reverse Bias Electroluminescence
Authors: Wang Dongze , Desroche Emmett , Gao Jun 
Published: November 2019

AbstractThe polymer light‐emitting electrochemical cell (PLEC) is a unique solid‐state device possessing attractive attributes for low‐cost applications, but also a junction structure that is still poorly understood. In a PLEC, the applied voltage causes in situ electrochemical p‐ and n‐doping of the semiconducting polymer and the formation of a dynamic light‐emitting p–n junction. Once the junction is fixed by cooling or chemical manipulation, the “frozen‐junction” PLEC exhibits a unipolar electroluminescence (EL) and photovoltaic response. Repeated thermal cycling, however, can cause the frozen‐junction PLEC to experience drastically enhanced EL under forward bias and the emergence of reverse bias EL. In this study, a combination of transport measurements and direct imaging is used to elucidate the origin of the mysterious reverse bias EL. A model is developed that explains the reverse bias EL as caused by the tunnel injection of electrons and holes from bandgap states into a dedoped “intrinsic” region between the p‐ and n‐doped regions. The model explains the location, relative intensity, and evolution of EL under both forward and reverse bias. The results hint at a junction that is much narrower than previously resolved.
Tuning Areal Density and Surface Passivation of ZnO Nanowire Array Enable Efficient PbS QDs Solar Cells with Enhanced Current Density
Authors: Tavakoli Dastjerdi Hadi , Prochowicz Daniel , Yadav Pankaj , Tavakoli Mohammad Mahdi 
Published: November 2019

AbstractColloidal PbS quantum dots (QDs) have provoked a revolution in the field of optoelectronic devices owing to their low‐cost fabrication processing and excellent physical properties. Recently, the fabrication of nanostructured PbS QD photovoltaic (PV) devices based on zinc oxide (ZnO) nanowire array appears as an effective strategy for improving the overall device performance. Despite its potentially strong impact on the device performance, the role of nanowire areal density on photon absorption and exciton dynamics has not yet been studied and still remains unexplored. Here, for the first time, the areal density of ZnO nanowires is tuned through controlling the precursor concentration and its impact on PbS QD PV performance is studied. It is found that the device with optimized ZnO nanowire areal density yields significantly increased power conversion efficiency (PCE) (10.1% vs 8.5% of control nanowire‐based device) due to improved antireflection effect and reduced surface recombination states. To further improve the photovoltaic performance, the ZnO nanowire surface is treated with hydrogen plasma. Transient photovoltage (TPV) measurement reveals that this passivation process noticeably reduces the nonradiative charge recombination yielding a champion device with a remarkable PCE of 10.8%.
Conducting Polymer‐Based Biocomposites Using Deoxyribonucleic Acid (DNA) as Counterion
Authors: Tekoglu Serpil , Wielend Dominik , Scharber Markus Clark , Sariciftci Niyazi Serdar , Yumusak Cigdem 
Published: November 2019

AbstractIn this work, the preparation of conducting polymer‐based composites using a biological anionic polymer based on salmon deoxyribonucleic acid (DNA) is presented. The most commonly used polymers poly(3,4‐ethylenedioxythiophene) (PEDOT), as well as polypyrrole, are polymerized in the presence of DNA. Since conjugated polymers are in the polycationic state in their electrically conducting form, the role of the counterion is now fulfilled by the low cost biomolecule DNA as an alternative material, which is also a polyanion thanks to its phosphate chain. The resulting synthesized material is a conducting polymer–DNA biocomposite. Such materials are highly attractive for the rising field of bioelectronics and biosensors, especially in organic electrochemical transistors (OECTs) and ion pumps. OECTs made of these conducting polymer biocomposites are fabricated and their electrochemical device operation is compared to the most widely used PEDOT:polystyrenesulfonate.
A Machine Learning Tool for Materials Informatics
Authors: Wang Zhi‐Lei , Ogawa Toshio , Adachi Yoshitaka 
Published: November 2019

AbstractIn response to the increasing demand for the highly efficient design of materials, materials informatics has been proposed for using data and computational sciences to extract data features that provide insight into how properties track with microstructure variables. However, the general metrics of microstructural features often ignore the complexities of the microstructure geometry for many properties of interest. An independently developed machine learning tool called shiny materials genome integration system for phase and property analysis (ShinyMIPHA), which is designed with either standalone software or cloud system based on an R programing package of “Shiny”, is introduced. ShinyMIPHA provides topological microstructure analysis methods based on image processing technology by employing a two‐point correlation function, persistent homology, and mean (H)–Gauss (K) curvature approaches, as well as sparse study and regression analysis methods that enable a data‐driven properties‐to‐microstructure‐to‐processing inverse materials‐design approach. The demo version is available athttps://adachi-lab.shinyapps.io/demo/.
Electromagnetic Vorticity in a Square‐Well Crystal System Described by a Supersymmetric Wave‐Equation
Authors: Manzetti Sergio , Trounev Alexander 
Published: November 2019

AbstractVortices occur under all electromagnetic phenomena in quantized systems, as well as macroscopic systems. In particular, vorticity in square‐wells is of great appeal to the scientific community, as it models electromagnetic fields and formation of condensates in crystal lattices. A supersymmetric wave‐equation (SWE) is devised to model vorticity in a square‐well system, and the numerical results of several states of vorticity are shown by increased energy of the system. It is shown that square‐well vorticity obeys specific symmetries when modeled with the SWE and generates non‐overlapping vortices of the same spin. Nucleation of vortices when subjected to increased angular velocity and formation of giant vortices is also shown. This is of importance to the modeling of magnetism in quantum systems, and the generation of new results to describe quantum vorticity.
Lightweight and Flexible Cotton Aerogel Composites for Electromagnetic Absorption and Shielding Applications
Authors: Cheng Yan , Zhao Huanqin , Lv Hualiang , Shi Tengfei , Ji Guangbin , Hou Yanglong 
Published: November 2019

AbstractCurrently, a versatile route is urgently required to achieve excellent electromagnetic wave (EMW) absorption and shielding functions simultaneously. A lightweight, flexible and sustainable 3D framework aerogel is designed to reach this goal, which is assembled by unique “1D‐1D” combination, nanoscale carbon nanotubes (CNTs) grown on microscale carbon fiber. EM absorption requires appropriate conductivity of filler to acquire moderate permittivity. On the contrary, EM shielding requires great conductivity to reflect most of the incident EMW. Based on this design concept, the change of electric conductivity of as‐obtained samples through in situ regulation of the growth state of CNTs is successfully controlled. When the CNTs are short and curly, the optimized conductivity favors excellent microwave absorption with wide absorption bandwidth of 5.08 GHz at only 1.6 mm. When the CNTs are long and straight, the increased conductivity is clearly boosted with 29.8 dB EM shielding effectiveness. This elaborate architecture and controlled CNT growth allow the designed 3D framework aerogel to be applied in both EM wave absorption and shielding. This conductivity tunable route gives inspiration for fabricating other efficient EM absorption and shielding devices.
Large Piezoelectricity in Ternary Lead‐Free Single Crystals
Authors: Wang Yaojin , Luo Chengtao , Wang Shuhao , Chen Chao , Yuan Guoliang , Luo Haosu , Viehland Dwight 
Published: November 2019

AbstractSince industry‐standard piezoelectric materials, such as lead zirconium titanate ceramics, contain toxic lead, a rapid surge in research on lead‐free piezoelectric materials is occurring due to concerns over environmental safety and human health. A ternary lead‐free (Na0.5Bi0.5)TiO3‐BaTiO3‐(K0.5Na0.5)NbO3 single crystal with a large field induced strain of ≈0.9% and a giant piezoelectric coefficient d33 of 840 pC N−1 at room temperature is reported. It is revealed that the electric‐field‐induced phase transition and phase boundary between energetically comparable polar states (i.e., R3c and P4mm) play an important role in achieving the ultrahigh piezoelectricity. Transmission electron microscopy and scan probe microscopy are employed to verify the weak‐polar ferroelectric R3c and P4bm structure in the ground state. These unprecedentedly high piezoelectric properties make lead‐free ternary single crystals a leading candidate for piezoelectric‐based device applications, especially toward the era of smart homes and implantable medical devices.
Re‐assessing the applicability of the Jarman/Bell model and Kay's threshold to the insectivorous aye‐aye (Daubentonia madagascariensis)
Authors: Sefczek Timothy M. , Randimbiharinirina Doménico R. , Raharivololona Brigitte M. , Razafimahaleo Harison , Randrianarison Olivier , Louis Edward E. 
Published: November 2019

AbstractObjectivesJarman/Bell principle and Kay's threshold suggest that large animals should not be able to sustain themselves on insects. However, animals with specialized morphological and/or behavioral adaptations violate these assumptions. Male aye‐ayes were recently identified as having an insectivorous diet despite weighing 2.5 kg. We further explored this diet/body size disparity by studying behaviors of an adult female and juvenile male aye‐aye.Materials and MethodsWe collected behavioral data on an adult female and juvenile male aye‐aye in Torotorofotsy, Madagascar from January 2016 to December 2017. We used instantaneous sampling to determine the frequency of feeding events and continuous sampling during feeding behaviors to assess duration of feeding bouts.ResultsInvertebrates comprised over 88% of the diet for both animals. A Wilcoxon signed‐rank test found no significant difference in the female's feeding frequencies between the hot/rainy seasons and the cold/dry seasons.DiscussionOur results support earlier findings that invertebrates are the aye‐aye's main resource and corroborate that aye‐ayes violate assumptions of the Jarman/Bell model and Kay's threshold. We suggest that the Jarman/Bell principle and Kay's threshold be used as supporting evidence and not to repudiate findings that do not conform to these guidelines.
Modeling the Ultrafast Response of Two‐Magnon Raman Excitations in Antiferromagnets on the Femtosecond Timescale
Authors: Batignani Giovanni , Pontecorvo Emanuele , Bossini Davide , Ferrante Carino , Fumero Giuseppe , Cerullo Giulio , Mukamel Shaul , Scopigno Tullio 
Published: November 2019

AbstractIlluminating a magnetic material with femtosecond laser pulses induces complex ultrafast dynamical processes. The resulting optically detectable response usually contains contributions from both the optical properties and the magnetic degrees of freedom. Disentangling all the different components concurring to the generation of the total signal is a major challenge of contemporary experimental solid‐state physics. Here, this problem is tackled, addressing the purely optical, nonmagnetic artifacts on the time resolved two‐magnon stimulated Raman spectrum of an antiferromagnet, rationalizing the recent observation on the exchange energy modification upon photo‐excitation. It is demonstrated how the genuine dynamics of the magnetic eigenmode can be disentangled from the nonlinear optical effects, generated by cross phase modulation, on the femtosecond timescale. The introduced approach can be extended for the investigation of <100 fs dynamic processes by means of coherent Raman scattering.
Towards a better understanding of the release mechanisms of caffeine from PLGA microparticles
Authors: Tamani Fahima , Hamoudi Mounira Chérifa , Danede Florence , Willart Jean‐François , Siepmann Florence , Siepmann Juergen 
Published: November 2019

ABSTRACTPoly(lactic‐co‐glycolic acid) (PLGA)‐based microparticles can be successfully used to control the release rate of a drug and optimize the therapeutic efficacy of a medical treatment. However, the underlying drug release mechanisms can be complex and are often not fully understood. This renders system optimization cumbersome. In this study, differently sized caffeine‐loaded PLGA microparticles were prepared and the swelling and drug release behaviors of single microparticles were monitored upon exposure to phosphate buffer pH 7.4. Ensembles of microparticles were characterized by X‐ray diffraction, differential scanning calorimetry, scanning electron microscopy, gel permeation chromatography, and optical microscopy. The observed triphasic drug release patterns could be explained as follows. The initial burst release can be attributed to the dissolution of tiny drug crystals with direct surface access. The subsequent second drug release phase (with an about constant release rate) could be attributed to the release of drug crystals in regions, which undergo local swelling. The third release phase (again rapid, leading to complete drug exhaust) could be explained by substantial polymer swelling throughout the systems. Once a critical polymer molecular weight is reached, the PLGA chains are sufficiently hydrophilic, insufficiently entangled and the osmotic pressure created by water soluble degradation products attracts high amounts of water into the system. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48710.
Attempting to prepare a plastic scintillator from a biobased polymer
Authors: Hamel Matthieu , Lebouteiller Guillaume 
Published: November 2019

ABSTRACTA new plastic scintillator was prepared from a renewable polymer source. It is composed of the mighty 2,5‐diphenyloxazole and 1, 4‐bis(2‐methylstyryl)benzene molecules (PPO and bis‐MSB), acting as primary and secondary fluorophores, respectively, together dissolved in a polylactic acid matrix—PLA. This polymer is indeed considered as the biomass‐based equivalent of petroleum‐derived plastics in terms of mechanical and optical properties. Subsequent to the bis‐MSB emission, the emission wavelength is centered around 424 nm and the fluorescence decay time is in the nanosecond range. The material was fully characterized, and its scintillation performances were compared to a commercial PVT‐based plastic scintillator: EJ‐200. Like polystyrene‐ or polyvinyltoluene‐based scintillators, the material displayed a good response linearity with the energy of the incident gamma‐ray. However, the observed scintillation yield was rather modest, with a reported 500 ph/MeV value when excited with a gamma‐ray‐emitting 60Co source. This preliminary test could pave the way to new and renewable polymers for unexpected applications such as nuclear physics. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48724.