bluuebunny/crossref_metadata_2025_split huggingface dataset:
Suppressing Vacancy Defects and Grain Boundaries via Ostwald Ripening for High‐Performance and Stable Perovskite Solar Cells
Authors: Yang Yuqian , Wu Jihuai , Wang Xiaobing , Guo Qiyao , Liu Xuping , Sun Weihai , Wei Yuelin , Huang Yunfang , Lan Zhang , Huang Miaoliang , Lin Jianming , Chen Hongwei , Wei Zhanhua 
Published: December 2019

AbstractAs one kind of promising next‐generation photovoltaic devices, perovskite solar cells (PVSCs) have experienced unprecedented rapid growth in device performance over the past few years. However, the practical applications of PVSCs require much improved device long‐term stability and performance, and internal defects and external humidity sensitivity are two key limitation need to be overcome. Here, gadolinium fluoride (GdF3) is added into perovskite precursor as a redox shuttle and growth‐assist; meanwhile, aminobutanol vapor is used for Ostwald ripening in the formation of the perovskite layer. Consequently, a high‐quality perovskite film with large grain size and few grain boundaries is obtained, resulting in the reduction of trap state density and carrier recombination. As a result, a power conversion efficiency of 21.21% is achieved with superior stability and negligible hysteresis.
Tailoring and Modifying an Organic Electron Acceptor toward the Cathode Interlayer for Highly Efficient Organic Solar Cells
Authors: Liao Qing , Kang Qian , Yang Yi , An Cunbin , Xu Bowei , Hou Jianhui 
Published: December 2019

AbstractWith the rapid advance of organic photovoltaic materials, the energy level structure, active layer morphology, and fabrication procedure of organic solar cells (OSCs) are changed significantly. Thus, the photoelectronic properties of many traditional electrode interlayers have become unsuitable for modifying new active layers; this limits the further enhancement in OSC efficiencies. Herein, a new design strategy of tailoring the end‐capping unit, ITIC, to develop a cathode interlayer (CIL) material for achieving high power conversion efficiency (PCE) in OSCs is demonstrated. The excellent electron accepting capacity, suitable energy level, and good film‐forming ability endow the S‐3 molecule with an outstanding electron extraction property. A device with S‐3 shows a PCE of 16.6%, which is among the top values in the field of OSCs. More importantly, it is demonstrated that the electrostatic potential difference between the CIL molecule and the polymer donor plays a crucial role in promoting exciton dissociation at the CIL/active layer interface, contributing to additional charge generation; this is crucial for enhancement of the current density. The results of this work not only develop a new design strategy for high‐performance CIL, but also demonstrate a reliable approach of density functional theory (DFT) calculation to predict the effect of the CIL chemical structure on exciton dissociation in OSCs.
Highly Porous, Biocompatible Tough Hydrogels, Processable via Gel Fiber Spinning and 3D Gel Printing
Authors: Naficy Sina , Le Thi Yen Loan , Oveissi Farshad , Lee Aeryne , Hung Jui Chien , Wise Steven G. , Winlaw David S. , Dehghani Fariba 
Published: December 2019

AbstractConventional tough hydrogels offer enhanced mechanical properties and high toughness. Their application scope however is limited by their lack of processability. Here, a new porous tough hydrogel system is introduced which is processable via gel fiber spinning and 3D printing. The tough hydrogels are produced by rehydrating processable organogels developed by induced phase separation between two linear polymer chains capable of intermolecular hydrogen bonding. Through a slow sol–gel phase separation, highly porous gel networks made of hydrogen bonded polymer chains is formed. These organogels can be easily transformed to 3D printed multimaterial constructs or gel fibers, and after rehydration produce highly robust hydrogel structures. Although such hydrogels are highly porous and contain large amount of water, their strength can reach as high as 2000 kPa, with high elongation at break (≈900%), and tunable moduli ranging from 250 to 2000 kPa. The hydrogels have fracture energies larger than cartilage and demonstrate excellent load recovery because of their renewable hydrogen bond crosslinks. Furthermore, the hydrogels exhibit excellent hemocompatibility and in vitro biocompatibility. Such hydrogels can further expand the application of tough hydrogels and may serve as a model to explore the toughening mechanism of hydrogen bonded hybrid, tough hydrogel systems.
Continuous fluidized bed drying: Residence time distribution characterization and effluent moisture content prediction
Authors: Chen Hao , Diep Emily , Langrish Timothy A. G. , Glasser Benjamin J. 
Published: December 2019

AbstractThe mixing and drying behavior in a continuous fluidized bed dryer were investigated experimentally by characterizing the residence time distribution (RTD) and incorporating a micromixing model together with the drying kinetics obtained from batch drying. The RTD of the dryer was modeled using a tank‐in‐series model. It was found that a high initial material loading and a low material flow rate resulted in a reduced peak height and broaded peak width of the RTD curve. To predict the continuous dryer effluent moisture content, we combined: (a) the drying kinetics as determined in a batch fluidized bed dryer, (b) the RTD model, and (c) micromixing models—segregation and maximum mixedness models. It was found that the segregation model overpredicted the effluent moisture content by up to 5% for the cases we have studied while the maximum mixedness model gave a good prediction of the effluent moisture content.
Carbene‐Catalyzed Dynamic Kinetic Resolution and Asymmetric Acylation of Hydroxyphthalides and Related Natural Products
Authors: Liu Yingguo , Majhi Pankaj Kumar , Song Runjiang , Mou Chengli , Hao Lin , Chai Huifang , Jin Zhichao , Chi Yonggui Robin 
Published: December 2019

AbstractA catalytic dynamic kinetic resolution and asymmetric acylation reaction of hydroxyphthalides is developed. The reaction involves formation of a carbene catalyst derived chiral acyl azolium intermediate that effectively differentiates the two enantiomers of racemic hydroxyphthalides. The method allows quick access to enantiomerically enriched phthalidyl esters with proven applications in medicine. It also enables asymmetric modification of natural products and other functional molecules that contain acetal/ketal groups, such as corollosporine and fimbricalyxlactone C.
Branching Regulation in Olefin Polymerization via Lewis Acid Triggered Isomerization of Monomers
Authors: Basbug Alhan Hatice E. , Jones Glen R. , Harth Eva 
Published: December 2019

AbstractWe present a new strategy to regulate branching in chain‐walking olefin polymerization by triggering a rapid isomerization of 1‐alkene monomers into internal olefins by adding a Lewis acid. Polymerization of internal alkenes proceeds via chain‐walking to give polymers with much higher branching than 1‐alkene analogues. The utility of this approach is exemplified by synthesis of well‐defined block copolymers with distinct branching characteristics per block by addition of Lewis acid midway through a reaction. We propose a novel mechanism whereby Lewis acid undergoes a counterion swap with the complex which favors isomerization as well as forming adducts with ancillary ligands, freeing coordination sites for internal alkene coordination polymerization.
Photocontrolled Iodine‐Mediated Reversible‐Deactivation Radical Polymerization: Solution Polymerization of Methacrylates by Irradiation with NIR LED Light
Authors: Tian Chun , Wang Peng , Ni Yuanyuan , Zhang Lifen , Cheng Zhenping , Zhu Xiulin 
Published: December 2019

AbstractHerein, near‐infrared (NIR) photocontrolled iodide‐mediated reversible‐deactivation radical polymerization (RDRP) of methacrylates, without an external photocatalyst, was developed using an alkyl iodide (e.g., 2‐iodo‐2‐methylpropionitrile) as the initiator at room temperature. This example is the first use of a series of special solvents containing carbonyl groups (e.g., 1,3‐dimethyl‐2‐imidazolidinone) as both solvent and catalyst for photocontrolled RDRP using long‐wavelength (λmax=730 nm) irradiation. The polymerization system comprises monomer, alkyl iodide initiator, and solvent. Well‐defined polymers were synthesized with excellent control over the molecular weights and molecular weight distributions (Mw/Mn<1.21). The living features of this system were confirmed by polymerization kinetics, multiple controlled “on‐off” light switching cycles, and chain extension experiments. Importantly, the polymerizations proceeded successfully with various barriers (pork skin and A4 paper), demonstrating the advantage of high‐penetration NIR light.
Chiral Overpass Induction in Dynamic Helical Polymers Bearing Pendant Groups with Two Chiral Centers
Authors: Suárez‐Picado Esteban , Quiñoá Emilio , Riguera Ricardo , Freire Félix 
Published: December 2019

AbstractThe dynamic behavior of helical polymers bearing pendant groups with two chiral centers was studied. Controlled conformational changes at the chiral units placed either closer to or further away from the main chain promote different helical structures. Although the first residue is usually responsible for determining a specific helicity (P or M), we now found that the second chiral center is also able to induce a preferred helical sense when it is located closer in space to the main chain, thereby cancelling the order from the first chiral moiety. This result was achieved through proper coordination with a metal cation. As proof of concept, poly(phenylacetylene)s (PPAs) that bear one and two chiral amino acid units of different sizes and configuration combinations (l/d‐alanine and l/d‐phenylalanine) as pendants were evaluated. In total, ten polymers were studied. This constitutes the first report of axial control from a remote stereocenter in polymers bearing complex chiral pendants.
Highly Mesoporous Metal‐Organic Frameworks as Synergistic Multimodal Catalytic Platforms for Divergent Cascade Reactions
Authors: Dutta Soumen , Kumari Nitee , Dubbu Sateesh , Jang Sun Woo , Kumar Amit , Ohtsu Hiroyoshi , Kim Junghoon , Cho Seung Hwan , Kawano Masaki , Lee In Su 
Published: December 2019

AbstractRational engineering and assimilation of diverse chemo‐ and biocatalytic functionalities in a single nanostructure is highly desired for efficient multistep chemical reactions but has so far remained elusive. Here, we design and synthesize multimodal catalytic nanoreactors (MCNRs) based on a mesoporous metal‐organic framework (MOF). The MCNRs consist of customizable metal nanocrystals and stably anchored enzymes in the mesopores, as well as coordinatively unsaturated cationic metal MOF nodes, all within a single nanoreactor space. The highly intimate and diverse catalytic mesoporous microenvironments and facile accessibility to the active site in the MCNR enables the cooperative and synergistic participation from different chemo‐ and biocatalytic components. This was shown by one‐pot multistep cascade reactions involving a heterogeneous catalytic nitroaldol reaction followed by a [Pd/lipase]‐catalyzed chemoenzymatic dynamic kinetic resolution to yield optically pure (>99 % ee) nitroalcohol derivatives in quantitative yields.
Redox‐Active Ligand Assisted Catalytic Water Oxidation by a RuIV=O Intermediate
Authors: Shi Jing , Guo Yu‐Hua , Xie Fei , Chen Qi‐Fa , Zhang Ming‐Tian 
Published: December 2019

AbstractWater splitting is one of the most promising solutions for storing solar energy in a chemical bond. Water oxidation is still the bottleneck step because of its inherent difficulty and the limited understanding of the O−O bond formation mechanism. Molecular catalysts provide a platform for understanding this process in depth and have received wide attention since the first Ru‐based catalyst was reported in 1982. RuV=O is considered a key intermediate to initiate the O−O bond formation through either a water nucleophilic attack (WNA) pathway or a bimolecular coupling (I2M) pathway. Herein, we report a Ru‐based catalyst that displays water oxidation reactivity with RuIV=(O) with the help of a redox‐active ligand at pH 7.0. The results of electrochemical studies and DFT calculations disclose that ligand oxidation could significantly improve the reactivity of RuIV=O toward water oxidation. Under these conditions, sustained water oxidation catalysis occurs at reasonable rates with low overpotential (ca. 183 mV).
Enabling High‐Voltage Lithium Metal Batteries by Manipulating Solvation Structure in Ester Electrolyte
Authors: Jie Yulin , Liu Xiaojing , Lei Zhanwu , Wang Shiyang , Chen Yawei , Huang Fanyang , Cao Ruiguo , Zhang Genqiang , Jiao Shuhong 
Published: December 2019

AbstractLithium metal is an ideal electrode material for future rechargeable lithium metal batteries. However, the widespread deployment of metallic lithium anode is significantly hindered by its dendritic growth and low Coulombic efficiency, especially in ester solvents. Herein, by rationally manipulating the electrolyte solvation structure with a high donor number solvent, enhancement of the solubility of lithium nitrate in an ester‐based electrolyte is successfully demonstrated, which enables high‐voltage lithium metal batteries. Remarkably, the electrolyte with a high concentration of LiNO3 additive presents an excellent Coulombic efficiency up to 98.8 % during stable galvanostatic lithium plating/stripping cycles. A full‐cell lithium metal battery with a lithium nickel manganese cobalt oxide cathode exhibits a stable cycling performance showing limited capacity decay. This approach provides an effective electrolyte manipulation strategy to develop high‐voltage lithium metal batteries.
Photoinduced Proton‐Transfer Reactions for Mild O‐H Functionalization of Unreactive Alcohols
Authors: Jana Sripati , Yang Zhen , Li Fang , Empel Claire , Ho Junming , Koenigs Rene M. 
Published: December 2019

AbstractHexafluoroisopropanol is typically considered as an unreactive solvent and not as a reagent in organic synthesis. Herein, we report on a mild and efficient photochemical reaction of aryl diazoacetates with hexafluoroisopropanol that enables, under stoichiometric reaction conditions, the synthesis of fluorinated ethers in excellent yield. Mechanistic studies indicate there is a preorganization of hexafluoroisopropanol and the diazoalkane acts as an unreactive hydrogen‐bonding complex. Only after photoexcitation does this complex undergo a protonation‐substitution reaction to the reaction product. Investigations on the applicability of this photochemical transformation show that a broad variety of acidic alcohols can be subjected to this transformation and thus demonstrate the feasibility of this concept for O‐H functionalization reactions (54 examples, up to 98 % yield).
Esterified PVA‐lignin resin by maleic acid applicable for natural fiber reinforced composites
Authors: Ko Hyun‐U , Kim Jung W. , Kim Hyun C. , Zhai Lindong , Kim Jaehwan 
Published: December 2019

ABSTRACTThis article reports an esterified polyvinyl alcohol (PVA)‐lignin resin that is applicable for natural fiber reinforced polymer composites. To meet the requirement for the composites, a biopolymer‐based resin is necessary, which should well interact with the natural fiber with good waterproof behavior. By mimicking the relationship between cellulose, lignin and hemicellulose in wood, the esterified PVA‐lignin resin with maleic acid is provided. The preparation and characterization of the environment‐friendly resin are illustrated in this article. 180 °C of esterification reaction temperature and 40% of maleic acid contents are shown to be an optimum condition for the preparation of the resin. The esterified PVA‐lignin resin exhibits 13, 31, and 55% increase of its tensile strength, toughness, and failure strength, respectively. The water contact angle of the esterified PVA‐lignin resin is improved from 0 to 57°. The prepared resin is originally thermoplastic composite and it turned to be a thermoset resin by the esterification reaction at 180 °C, which is beneficial for composite processing. The developed resin is applicable for environment‐friendly and high strength‐natural fiber reinforced polymer composites. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48836.
Flexible and transparent polymer/cellulose nanocrystal nanocomposites with high thermal conductivity for thermal management application
Authors: Wu Xinfeng , Gao Yuan , Yao Hang , Sun Kai , Fan Runhua , Li Xiaofeng , An Yan , Lei Yanhua , Zhang Yuliang 
Published: December 2019

ABSTRACTPolymeric materials play important roles in semiconductor technology and modern electronic devices. However, the weak thermal management capability of polymer seriously restricts the service life, reliability, and efficiency of devices. Consequently, inorganic or metallic thermally conductive fillers are added into polymers to make up the low thermal conductivity, but the optical transparency and flexibility always decrease or even disappear. Herein, we report transparent polymer nanocomposites comprising poly(vinyl alcohol) (PVA) and cellulose nanocrystal (CNC) with highly lateral thermal conductivity [about 5.7 W/(m·K)]. Such a high thermal conductivity is attributed to the aligned structure of CNC in PVA matrix and hydrogen‐bond interaction between CNC and PVA. All the organic nanocomposites also present excellent electrical insulating performance and tensile properties. The transparent and flexible nanocomposites are promising in the thermal management applications of displays, next‐generation wearable devices, sensors, and LEDs. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48864.
Metagenomic insights into bioaugmentation and biovalorization of oily industrial wastes by lipolytic oleaginous yeast Yarrowia lipolytica during successive batch fermentation
Authors: Louhasakul Yasmi , Cheirsilp Benjamas , Treu Laura , Kougias Panagiotis G. , Angelidaki Irini 
Published: December 2019

AbstractThe lipolytic oleaginous yeast Yarrowia lipolytica was used in the bioaugmentation and biovalorization of oily industrial wastes during successive‐batch fermentation. Five cycles of nonsterile successive batch fermentation with 70% medium replacement achieved the highest oil removal of 68.1 ± 5.60% and produced biomass and lipid yields of 0.213 ± 0.07 g/g‐COD and 146.2 ± 46.5 mg/g‐COD, respectively. The cell‐bound lipase activity observed in the system was 170.74 ± 32 U/L. The auto‐flocculation efficiency of the biomass was >90% within 60 Min. The microbial community changes between Y. lipolytica and indigenous microorganisms were monitored by metagenomic next‐generation sequencing of internal transcribed spacer rDNA regions for yeasts and 16S rRNA gene for bacteria. Ylipolytica lipolytica was retained in the consortium together with other indigenous strains until the fifth cycle. Other minor oleaginous yeasts such as Kodamaea ohmeri and Candida tropicalis as well as polyhydroxyalkanoate‐accumulating bacteria were found and are likely to have participated in lipid production. This study has shown the robustness of Y. lipolytica in nonsterile successive batch fermentation and its use could contribute greatly to the practical valorization of industrial wastes for lipids and lipases.
Electrodeposited Manganese Oxide on Carbon Paper for Zinc‐Ion Battery Cathodes
Authors: Dhiman Arjun , Ivey Douglas G. 
Published: December 2019

AbstractNano‐crystalline, flake‐like Mn oxide was electrodeposited onto carbon paper (CP) using a pulsed electrodeposition technique. The electrodeposited Mn oxide was identified as Mn3O4 through a combination of X‐ray photoelectron spectroscopy (XPS), X‐ray diffraction (XRD), and Raman spectroscopy. The Mn3O4 on CP was used as a cathode for Zn‐ion batteries (ZIBs) and showed excellent cyclability at a current density of 1 A g−1 with a capacity retention of 139 % after 200 cycles. Electron microscopy was used to characterize the microstructural changes of the cathode at various stages during discharge/charge cycling. This work in combination with the electrochemical results suggests a two‐step reaction mechanism involving both intercalation and conversion reactions. The results demonstrate that electrodeposition of the cathode material is a simple, quick, and potentially scalable electrode synthesis method for producing high performing Zn‐ion electrodes without the use of binders or other additives.
Adaptation and validation of a scale of self‐efficacy and social support for physical activity in Spanish patients with severe mental disorders
Authors: Perez‐Cruzado David , Vera‐Garcia Elisa , Mayoral‐Cleries Fermin , Luciano Juan Vicente , Cuesta‐Vargas Antonio 
Published: December 2019

AbstractBackgroundPeople with severe mental disorders (SMDs) suffer problems of obesity, a sedentary life, and poor physical condition, mainly due to low levels of physical activity. Self‐efficacy (SE) and social support (SS) are important components that influence participation in physical activity.MethodsThis study adapted a scale to assess SE and SS in promoting physical activity in Spanish people with SMDs, as well as provide preliminary evidence of its validity. One hundred Spanish patients (23% female) with SMDs, between 26 and 61 years old, completed the SE/SS assessment for SMD (SE/SS‐ASMD).ResultsThe instrument seemed to capture a four‐factor structure in people with SMDs. Due to the lack of a gold standard, the scale was related to other instruments with which it might be expected to show a correlation, such as those for physical activity and its quality; however, the levels of correlation found were low (≈0.3). The Internal consistency (Cronbach's α) for the SE‐ASMD, SS‐ASMD staff, SS‐ASMD peers, and SS‐ASMD family scales were 0.76, 0.76, 0.80, and 0.80, respectively.ConclusionsThe psychometric analysis of the SE/SS‐ASMD supported its suitability as a new tool for researchers in the area of physical activity among people with SMDs.
Influence of multimedia and seating location in academic engagement and grade performance of students
Authors: Joshi Gyanendra Prasad , Jha Sudan , Cho Seongsoo , Seo Changho , Son Le Hoang , Thong Pham Huy 
Published: December 2019

AbstractMany universities around the world use multimedia resources in large classrooms. The purpose of this study is to determine if there is any significant influence on student academic performance due to the use of multimedia (environment and tools) and seating location. This study analyses student data on grade performance and seating location for an undergraduate course at a multimedia classroom over eight semesters. This study also analyses whether short multimedia materials attract student attention in class using a computer vision experimental setup. It has been found that there is similar performance and distraction rate of students who sit at a similar proximity to the multimedia screen. The findings of this study are valuable for academic institutions and educators to design multimedia lectures and classrooms to enhance student performance.