bluuebunny/crossref_metadata_2025_split huggingface dataset:
Manipulating Aggregation‐Induced Emission with Supramolecular Macrocycles
Authors: Lou Xin‐Yue , Yang Ying‐Wei 
Published: August 2018

AbstractTwo essential elements of smart materials are their capabilities of responding to external stimuli and the specific recognition toward different targets, which renders supramolecular macrocycles an ideal type of building blocks for materials construction. Aggregation‐induced emission (AIE) has been intensively investigated for two decades not only for the realization of solid‐state fluorescent materials, but also for the fabrication of numerous functional luminescent materials for diverse applications. The discrepancy among aggregation states of AIE‐active molecules would bear a big influence on the emission pattern; hence, manipulation of the assembly and control of the morphologies of materials with reversibility are of great importance and should be achievable via the incorporation of macrocyclic elements into AIE systems. In this review, the marriage of AIE and supramolecular macrocyclic chemistry is introduced, leading to smart functional materials with unique fluorescent properties, such as supramolecular polymers, supramolecular nanoparticles, and host–guest complexes on surfaces. Their diverse applications are discussed and perspective on this emerging research direction is also provided.
C6‐Selective Direct Arylation of 2‐Phenylpyridine via an Activated N‐methylpyridinium Salt: A Combined Experimental and Theoretical Study
Authors: Yin Changzhen , Zhong Kangbao , Li Wenjing , Yang Xiao , Sun Rui , Zhang Chunchun , Zheng Xueli , Yuan Maolin , Li Ruixiang , Lan Yu , Fu Haiyan , Chen Hua 
Published: August 2018

AbstractAn elegant pre‐activation strategy, based on the formation of N‐methylpyridinium iodide salts for C6‐selective direct arylation of 2‐phenylpyridines using Pd/Cu cooperative catalysis, has been developed. By this methodology, a wide range of unsymmetrical 2, 6‐diarylpyridines were synthesized with high reactivity and regioselectivity as well as good functional group tolerance. In particular, challenging substrates bearing electron donating groups (EDGs), such as OMe, NMe2, were also successfully employed in this reaction. Deuterium incorporation studies revealed that the C−H bond acidity is improved significantly in N‐methylpyridinium salts compared with their N‐Oxide and N‐iminopyridinium ylide counterparts, thus solving the long‐standing problem associated with previous strategies for the synthesis of diaryl pyridines. Finally, the control experiments and DFT calculations supported a Pd‐catalyzed and Cu‐mediated mechanism in which a carbenoid copper species that is formed in‐situ from N‐methylpyridinium salts, participates in a Pd‐catalyzed arylation followed by an iodide‐promoted N‐demethylation process.magnified image
Decarboxylative Tribromination for the Selective Synthesis of Tribromomethyl Ketone and Tribromovinyl Derivatives
Authors: Jayaraman Aravindan , Cho Eunjeong , Kim Jimin , Lee Sunwoo 
Published: August 2018

AbstractTribromomethyl ketone and tribromovinyl derivatives were selectively prepared from the decarboxylative tribromination. The reaction between propiolic acid derivatives and dibromoisocyanuric acid (DBCA)/H2O afforded predominantly a tribromomethyl ketone derivative in the presence of AgOAc (10 mol%). When the same reaction was conducted with 2,2,6,6‐tetramethyl‐1‐piperidinyloxy (TEMPO) instead of AgOAc, tribromovinyl derivatives were exclusively formed in good yields. It was found that ethynyl bromide is an intermediate.magnified image
Zinc‐Modified Sulfonated Polyetheretherketone Surface with Immunomodulatory Function for Guiding Cell Fate and Bone Regeneration
Authors: Liu Wei , Li Jinhua , Cheng Mengqi , Wang Qiaojie , Yeung Kelvin W. K. , Chu Paul K. , Zhang Xianlong 
Published: August 2018

AbstractThe cytokines released by immune cells are considered important factors to induce bone tissue regeneration. However, the pathway of those bone‐targeting macrophage cytokines induced by biomaterial surface under tissue microenvironment is rarely reported. In this study, the immunomodulatory capability of zinc ions on macrophage polarization and its effects on osteogenic differentiation are investigated. Hence, a layer of zinc ions are incorporated on sulfonated polyetheretherketone (SPEEK) biomaterials by using a customized magnetron sputtering technique. The results reveal that the microenvironment on Zn‐coated SPEEK can modulate nonactivated macrophage polarization to an anti‐inflammatory phenotype and induce the secretion of anti‐inflammatory and osteogenic cytokines. The osteogenic differentiation capability of bone marrow stromal cells (BMSCs) is therefore enhanced, leading to improved osteointegration between the zinc‐coated SPEEK and bone tissue. This study verifies that zinc ion is a promising additive in the osteoimmunomodulation process and provides knowledge that may pave the way to develop the next generation of immunomodulatory biomaterials.
Metallic Octahedral CoSe2 Threaded by N‐Doped Carbon Nanotubes: A Flexible Framework for High‐Performance Potassium‐Ion Batteries
Authors: Yu Qiyao , Jiang Bo , Hu Jun , Lao Cheng‐Yen , Gao Yunzhi , Li Peihao , Liu Zhiwei , Suo Guoquan , He Donglin , Wang Wei (Alex) , Yin Geping 
Published: August 2018

AbstractDue to the abundant and low‐cost K resources, the exploration of suitable materials for potassium‐ion batteries (KIBs) is advancing as a promising alternative to lithium‐ion batteries. However, the large‐sized and sluggish‐kinetic K ions cause poor battery behavior. This work reports a metallic octahedral CoSe2 threaded by N‐doped carbon nanotubes as a flexible framework for a high‐performance KIBs anode. The metallic property of CoSe2 together with the highly conductive N‐doped carbon nanotubes greatly accelerates the electron transfer and improves the rate performance. The carbon nanotube framework serves as a backbone to inhibit the agglomeration, anchor the active materials, and stabilize the integral structure. Every octahedral CoSe2 particle arranges along the carbon nanotubes in sequence, and the zigzag void space can accommodate the volume expansion during cycling, therefore boosting the cycling stability. Density functional theory is also employed to study the K‐ion intercalation/deintercalation process. This unique structure delivers a high capacity (253 mAh g−1 at 0.2 A g−1 over 100 cycles) and enhanced rate performance (173 mAh g−1 at 2.0 A g−1 over 600 cycles) as an advanced anode material for KIBs.
In Situ Surface Oxidized Copper Mesh Electrodes for High‐Performance Transparent Electrical Heating and Electromagnetic Interference Shielding
Authors: Han Yu , Zhong Hui , Liu Nan , Liu Yuxuan , Lin Jie , Jin Peng 
Published: August 2018

AbstractMetallic mesh is a significant candidate of transparent conductive electrodes (TCEs) to substitute the current state‐of‐the‐art material indium tin oxide for optoelectronic devices. However, there remains a challenge to fabricate stable and good‐visibility metallic mesh with the low‐cost copper (Cu) material. A metallic Cu mesh electrode (on glass) with a high absolute transmittance of ≈82% combined with an adjustable low electrical resistance of ≈0.2 Ω sq−1 and a low total light reflectance of 8.7% is demonstrated here. The Cu mesh TCE shows excellent visibility and good thermal, moisture, and environmental stability that can be used in practical applications. This was achieved by in situ forming an oxidation‐resistive and light‐absorptive capping layer of oxide on the surface of Cu meshes. The electrode was fabricated by UV‐lithography and electroplating, and then directly annealing in the air. To assess the application potentials, transparent electrical heating up to 100 °C under 3 V supply and transparent shielding of radiofrequency with ≈24 dB attenuation in Ku band are achieved. Good photoelectric properties, low‐cost material, and excellent stability imply that this Cu mesh electrode is a striking candidate for low‐cost TCE for efficient optoelectronic devices.
Ultraconformable Freestanding Capacitors Based on Ultrathin Polyvinyl Formal Films
Authors: Barsotti Jonathan , Hirata Ikue , Pignatelli Francesca , Caironi Mario , Greco Francesco , Mattoli Virgilio 
Published: August 2018

AbstractConformable electronics refers to a class of electronic devices that have the ability to conformally adhere onto nonplanar surfaces and materials, resulting particularly appealing for skin‐contact applications, such as the case of skin‐worn unobtrusive (bio)sensors for healthcare monitoring. Conformability can be addressed by integrating basic electronic components on ultrathin polymeric film substrates. Among other basic electronic components, capacitors are fundamental ones for energy storage, sensing, frequency tuning, impedance adaptation, and signal processing. In this work, a novel approach for conformable capacitors based on a freestanding, ultrathin, and ultraconformable nanosheet of poly(vinyl formal), which serves as both structural and dielectric component of the capacitor, is presented. A novel fabrication approach is proposed and applied to produce fully freestanding ultrathin capacitors, having an overall thickness as low as 200 nm, which represents the thinnest freestanding capacitors ever reported. Thanks to the ultralow thickness, the proposed capacitors are able to sustain flexure to extremely small curvature radii (as low as 1.5 µm) and to conform to complex surfaces without compromising their operation.
Sulfide Solid Electrolytes for Lithium Battery Applications
Authors: Lau Jonathan , DeBlock Ryan H. , Butts Danielle M. , Ashby David S. , Choi Christopher S. , Dunn Bruce S. 
Published: August 2018

AbstractThe use of solid electrolytes is a promising direction to improve the energy density of lithium‐ion batteries. However, the low ionic conductivity of many solid electrolytes currently hinders the performance of solid‐state batteries. Sulfide solid electrolytes can be processed in a number of forms (glass, glass‐ceramic, and crystalline) and have a wide range of available chemistries. Crystalline sulfide materials demonstrate ionic conductivity on par with those of liquid electrolytes through the utilization of near ideal conduction pathways. Low‐temperature processing is also possible for these materials due to their favorable mechanical properties. The main drawback of sulfide solid electrolytes remains their electrochemical stability, but this can be addressed through compositional tuning or the use of artificial solid electrolyte interphase (SEI). Implementation of sulfide solid electrolytes, with proper treatment for stability, can lead to substantial improvements in solid‐state battery performance leading to significant advancement in electric vehicle technology.
New Binder‐Free Metal Phosphide–Carbon Felt Composite Anodes for Sodium‐Ion Battery
Authors: Sun Dan , Zhu Xiaobo , Luo Bin , Zhang Yu , Tang Yougen , Wang Haiyan , Wang Lianzhou 
Published: August 2018

AbstractMetal phosphides are promising anode candidates for sodium‐ion batteries (SIBs) due to their high specific capacity and low operating potential but suffer from poor cycling stability caused by huge volume expansion and poor solid‐state ion transfer rate. Herein, a new strategy to grow a new class of mesoporous metal phosphide nanoarrays on carbon felt (CF) as binder‐free anodes for SIBs is reported. The resultant integrated electrodes demonstrate excellent cycling life up to 1000 times (>90% retention rate) and high rate capability of 535 mAh g−1 at a current density of 4 A g−1. Detailed characterization reveals that the synergistic effect of unique mesoporous structure for accommodating huge volume expansion during sodiation/desodiation process, ultrasmall primary particle size (≈10 nm) for providing larger electrode/electrolyte contact area and shorter ion diffusion distance, and 3D conductive networks for facilitating the electrochemical reaction, leads to the extraordinary battery performance. Remarkably, a full SIB using the new CoP4/CF anode and a Na3V2(PO4)2F3 cathode delivers an average operating voltage of ≈3.0 V, a reversible capacity of 553 mAh g−1, and very high energy density of ≈280 Wh kg−1 for SIBs. A flexible SIB with outstanding mechanical strength based on this binder‐free new anode is also demonstrated.
Modulation of End Groups for Low‐Bandgap Nonfullerene Acceptors Enabling High‐Performance Organic Solar Cells
Authors: Chen Yuzhong , Liu Tao , Hu Huawei , Ma Tingxuan , Lai Joshua Yuk Lin , Zhang Jianquan , Ade Harald , Yan He 
Published: August 2018

AbstractThe field of nonfullerene organic solar cells (OSCs) has seen an impressive progress, largely due to advances in high‐performance small molecule acceptors (SMAs). As a large portion of the solar energy is located in the near‐infrared region, it is important to develop ultralow‐bandgap SMAs that have extended absorption in the spectral range of 800–1000 nm to maximize light absorption and efficiencies. In this work, three low‐bandgap SMAs, namely, IXIC, IXIC‐2Cl, and IXIC‐4Cl, are designed and synthesized with same fused terthieno[3,2‐b]thiophene donor unit and different end groups (EGs). The three SMAs all have low optical bandgap (Eg) of 1.35, 1.30, and 1.25 eV, respectively. The chlorination on EGs can lower the energy level and broaden absorption range of the SMAs. As a result, the Voc of the devices is reduced but the Jsc is significantly increased. In addition, the addition of chlorine atoms can enhance π–π stacking and crystallinity of the SMAs, which result in high fill factors. Overall, the optimum EGs are monochlorine‐substituted IC and OSCs based on PBDB‐T:IXIC‐2Cl that can achieve remarkable power conversion efficiencies (PCEs) of 12.2%, which is one of the highest PCEs for nonfullerene organic solar cells based on low‐bandgap SMAs.
Solution‐Processed Low‐Bandgap CuIn(S,Se)2 Absorbers for High‐Efficiency Single‐Junction and Monolithic Chalcopyrite‐Perovskite Tandem Solar Cells
Authors: Uhl Alexander R. , Rajagopal Adharsh , Clark James A. , Murray Anna , Feurer Thomas , Buecheler Stephan , Jen Alex K.‐Y. , Hillhouse Hugh W. 
Published: August 2018

AbstractA novel molecular‐ink deposition route based on thiourea and N,N‐dimethylformamide (DMF) that results in a certified solar cell efficiency world record for non‐vacuum deposited CuIn(S,Se)2 (CIS) absorbers and non‐vacuum deposited absorbers with a bandgap of 1.0 eV, is presented. It is found that by substituting the widely employed solvent dimethyl sulfoxide with DMF, the coordination chemistry of InCl3 could be altered, dramatically improving ink stability, enabling up to tenfold increased concentrations, omitting the necessity for elevated ink temperatures, and radically accelerating the deposition process. Furthermore, it is shown that by introducing compositionally graded precursor films, film porosity, compositional gradients, and the surface roughness of the absorbers are effectively reduced and device conversion efficiencies are increased up to 13.8% (13.1% certified, active area). The reduced roughness is also seen as crucial to realize monolithically interconnected CIS‐perovskite tandem devices, where semitransparent MAPbI3 devices are directly deposited on the CIS bottom cell. Confirming the feasibility of this approach, monolithic devices with near perfect voltage addition between subcells of up to 1.40 V are presented.
Metal–Air Batteries: From Static to Flow System
Authors: Han Xiaopeng , Li Xiaopeng , White Jai , Zhong Cheng , Deng Yida , Hu Wenbin , Ma Tianyi 
Published: August 2018

AbstractAs an emerging battery technology, metal–air flow batteries inherit the advantageous features of the unique structural design of conventional redox flow batteries and the high energy density of metal–air batteries, thus showing great potential as efficient electrochemical systems for large‐scale electrical energy storage. This review summarizes the operating principles and recent progress of metal–air flow batteries from a materials and chemistry perspective, with particular emphasis on the latest advanced materials design and cell configuration engineering, which the authors divide into three categories based on the anode species: vanadium–air, zinc–air, and lithium–air flow batteries. Since some of the capabilities developed for metal–air static batteries can be leveraged for next‐generation flow systems, classical works on conventional metal–air batteries are selected and compared with the metal–air flow systems, highlighting the prominent advantages of the latter in achieving high energy capacity and long cycle performance. At the end, a general perspective on current challenges/opportunities and future research directions to promote the commercial application of the metal–air flow battery technology is provided. The aim is to provide a comprehensive overview and to set up a road map for guiding development from conventional static to advanced flow technologies of metal–air batteries.
A First‐Principles and Experimental Investigation of Nickel Solubility into the P2 NaxCoO2 Sodium‐Ion Cathode
Authors: Bianchini Matteo , Wang Jingyang , Clément Raphaële , Ceder Gerbrand 
Published: August 2018

AbstractThe difficulty in finding positive electrode materials for sodium‐ion (Na‐ion) batteries with a large specific energy has slowed down their commercialization. Layered transition metal (M) oxides NaxMO2 with a two‐layer oxygen stacking (P2, 0.6 ≤ x ≤ 0.75), are promising candidates. However, the high average metal oxidation state needed during synthesis means that P2 NaxMO2 cathodes often require the introduction of high‐valent cations (Mn4+, Ti4+, Sn5+, or Te6+), limiting the cathode's performance. Using a combination of first‐principles calculations and experiments, the feasibility of P2 cathodes containing only electrochemically active nickel and cobalt cations is investigated. It is found that P2 NaxNiyCo1–yO2 materials with x = 0.66, 0.75, and 0 ≤ y ≤ 0.33 are either thermodynamically stable or metastable yet close to the convex hull at typical P2 synthesis temperatures (≈1000 K). It is demonstrated that a novel P2 compound with y = 0.22 and both Ni3+/4+ and Co3+/4+ can be successfully synthesized. It is studied electrochemically and structurally, using in situ and ex situ X‐ray diffraction. It is demonstrated that the chemical space of P2 layered compounds is not fully explored yet and that ab initio phase diagrams allow the determination of new high‐specific energy positive electrodes to be targeted experimentally.
Engineering of Mesoscale Pores in Balancing Mass Loading and Rate Capability of Hematite Films for Electrochemical Capacitors
Authors: Song Yu , Liu Tianyu , Li Mingyang , Yao Bin , Kou Tianyi , Feng Dongyang , Wang Fuxin , Tong Yexiang , Liu Xiao‐Xia , Li Yat 
Published: August 2018

AbstractDesign and synthesis of metal oxide‐based pseudocapacitive materials to simultaneously achieve high mass loading (e.g., up to 10 mg cm−2) and excellent rate capability for electrochemical capacitors is a long‐lasting challenge. These two characteristics are usually mutually exclusive due to the poor ion diffusion kinetics of most metal oxides. Here, a glucose‐assisted hydrothermal method to prepare thick hematite film (>1 µm) with engineerable mesopore size through controlled variation of glucose concentration is demonstrated. The capability of controlling the size of mesopores offers a unique opportunity to investigate for the first time the interplay between mesopore size and electrochemical performance of hematite films. The hematite film with an average mesopore size of 3 nm at an ultrahigh loading of 10 mg cm−2 exhibits an areal capacitance of 1502 mF cm−2 at 1 mA cm−2, and retains 871.2 mF cm−2 at 50 mA cm−2. Such performance, to the best of the authors' knowledge, is at the top of the reported hematite electrodes with comparable or even lower mass loadings. The strategy demonstrated herein may be extended to fabricate diverse types of mesoporous metal oxide architectures with improved ion diffusion kinetics, which is critical for a broad range of devices for energy storage and conversion.
FeN4 Sites Embedded into Carbon Nanofiber Integrated with Electrochemically Exfoliated Graphene for Oxygen Evolution in Acidic Medium
Authors: Lei Chaojun , Chen Hengquan , Cao Junhui , Yang Jian , Qiu Ming , Xia Ying , Yuan Chris , Yang Bin , Li Zhongjian , Zhang Xingwang , Lei Lecheng , Abbott Janel , Zhong Yu , Xia Xinhui , Wu Gang , He Qinggang , Hou Yang 
Published: August 2018

AbstractDevelopment of inexpensive and efficient oxygen evolution reaction (OER) catalysts in acidic environment is very challenging, but it is important for practical proton exchange membrane water electrolyzers. A molecular iron–nitrogen coordinated carbon nanofiber is developed, which is supported on an electrochemically exfoliated graphene (FeN4/NF/EG) electrocatalyst through carbonizing the precursor composed of iron ions absorbed on polyaniline‐electrodeposited EG. Benefitting from the unique 3D structure, the FeN4/NF/EG hybrid exhibits a low overpotential of ≈294 mV at 10 mA cm−2 for the OER in acidic electrolyte, which is much lower than that of commercial Ir/C catalysts (320 mV) as well as all previously reported acid transitional metal‐derived OER electrocatalysts. X‐ray absorption spectroscopy coupled with a designed poisoning experiment reveals that the molecular FeN4 species are identified as active centers for the OER in acid. The first‐principles‐based calculations verify that the FeN4–doped carbon structure is capable of reducing the potential barriers and boosting the electrocatalytic OER activity in acid.
Are Emergency Medicine Residents Prepared to Meet the Ethical Challenges of Clinical Practice? Findings from an Exploratory National Survey
Authors: Padela Aasim I. , Davis Joshua , Hall Stephen , Dorey Alyrene , Asher Shellie 
Published: August 2018

AbstractBackgroundAlthough the Accreditation Council for Graduate Medical Education and the American Board of Emergency Medicine require clinical ethics education in residency training, instruction varies widely. We assessed the educational preparedness of trainees in emergency medicine to address ethics challenges common to their field.MethodsThe survey assessed two outcomes: 1) knowledge of specific ethical challenges and 2) perceived educational preparedness, across five ethics areas: 1) informed consent and decisional‐capacity assessment, 2) surrogate decision making, 3) interpretation of advanced directives, 4) withdrawing and/or withholding life support, and 5) presumed consent for emergency treatment. Clinical vignettes, revised through expert panel review and pilot testing, were utilized to evaluate these areas. The final instrument was administered via Web link to emergency medicine residents and recent graduates through adverts within Emergency Medicine Residency Association and Society for Academic Emergency Medicine (SAEM) newsletters and social media platforms. Additionally, targeted e‐mails through the Council of Residency Directors in Emergency Medicine, the Clerkship Directors of Emergency Medicine, and the SAEM Ethics Committee listservs encouraged survey distribution. Analyses involved one‐way analysis of variance for overall knowledge scores and chi‐square tests for categorical outcomes. Multivariable regression models tested associations between respondent characteristics and outcomes.ResultsThere were 302 participants of which 34% reported having a dedicated ethics module within their residency curriculum. The mean (±SD) knowledge score was 59.7% (±12.8%); assessing decisional capacity was the most difficult topic for respondents as only 1% both correctly addressed the general issue and identified the correct plan of action. Participants having a dedicated ethics module perceived themselves better prepared, although there was no association between having a dedicated ethics module and knowledge scores.ConclusionsGaps in clinical ethics knowledge appear prevalent among emergency medicine trainees, and few programs have dedicated ethics modules. Greater study is needed to understand and remedy clinical ethics knowledge shortfalls.