bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rich Chemistry in Inorganic Halide Perovskite Nanostructures
Authors: Huang Jianmei , Lai Minliang , Lin Jia , Yang Peidong 
Published: September 2018

AbstractHalide perovskites have emerged as a class of promising semiconductor materials owing to their remarkable optoelectronic properties exhibiting in solar cells, light‐emitting diodes, semiconductor lasers, etc. Inorganic halide perovskites are attracting increasing attention because of the higher stability toward moisture, light, and heat as compared with their organic–inorganic hybrid counterparts. In particular, inorganic halide perovskite nanomaterials provide controllable morphology, tunable optoelectronic properties, and improved quantum efficiency. Here, the development controlled synthesis of desired inorganic halide perovskite nanostructures by various chemical approaches is described. Utilizing these nanostructures as platforms, anion exchange chemistry for wide compositional and optical tunabilities is described, and the rich structural phase transition phenomenon and mechanism investigated systematically. Furthermore, these nanostructures and extracted knowledge are applied to design photonic, photovoltaic, and thermoelectric devices. Finally, future directions and challenges toward improvement of the optical, electrical, and optoelectronic properties, exploration of the anion and cation exchange kinetics, and alleviation of the stability and toxicity issues in inorganic lead based halide perovskites are discussed to provide an outlook on this promising field.
Dynamic Visualization of Stress/Strain Distribution and Fatigue Crack Propagation by an Organic Mechanoresponsive AIE Luminogen
Authors: Qiu Zijie , Zhao Weijun , Cao Mingkui , Wang Yuqi , Lam Jacky W. Y. , Zhang Zhe , Chen Xu , Tang Ben Zhong 
Published: September 2018

AbstractStress exists ubiquitously and is critically important for the manufacturing industry. Due to the ultrasensitive mechanoresponse of the emission of 1,1,2,2,‐tetrakis(4‐nitrophenyl)ethane (TPE‐4N), a luminogen with aggregation‐induced emission characteristics, the visualization of stress/strain distributions on metal specimens with a pure organic fluorescent material is achieved. Such a fluorescence mapping method enjoys the merits of simple setup, real‐time, full‐field, on‐site, and direct visualization. Surface analysis shows that TPE‐4N can form a nonfluorescent, crystalline uniform film on the metal surface, which cracks into fluorescent amorphous fragments upon mechanical force. Therefore, the invisible information of the stress/strain distribution of the metal specimens are transformed to visible fluorescent signals, which generally matches well but provides more details than software simulation. Remarkably, fatigue crack propagation in stainless steel and aluminum alloy can be observed and predicted clearly, further demonstrating the ultrasensitivity and practicability of TPE‐4N.
A Dual‐Crosslinking Design for Resilient Lithium‐Ion Conductors
Authors: Lopez Jeffrey , Sun Yongming , Mackanic David G. , Lee Minah , Foudeh Amir M. , Song Min‐Sang , Cui Yi , Bao Zhenan 
Published: September 2018

AbstractSolid‐state electrolyte materials are attractive options for meeting the safety and performance needs of advanced lithium‐based rechargeable battery technologies because of their improved mechanical and thermal stability compared to liquid electrolytes. However, there is typically a tradeoff between mechanical and electrochemical performance. Here an elastic Li‐ion conductor with dual covalent and dynamic hydrogen bonding crosslinks is described to provide high mechanical resilience without sacrificing the room‐temperature ionic conductivity. A solid‐state lithium‐metal/LiFePO4 cell with this resilient electrolyte can operate at room temperature with a high cathode capacity of 152 mAh g−1 for 300 cycles and can maintain operation even after being subjected to intense mechanical impact testing. This new dual crosslinking design provides robust mechanical properties while maintaining ionic conductivity similar to state‐of‐the‐art polymer‐based electrolytes. This approach opens a route toward stable, high‐performance operation of solid‐state batteries even under extreme abuse.
An Efficient Ga(OTf)3/Isopropanol Catalytic System for Direct Reduction of Benzylic Alcohols
Authors: Sai Masahiro 
Published: September 2018

AbstractThis study aims to report the first gallium‐catalyzed direct reduction of benzylic alcohols using isopropanol as a reductant. The reaction proceeds via gallium catalyst‐assisted hydride transfer of the in situ‐generated benzylic isopropyl ether. The method generates only water and acetone as byproducts and thus provides an atom‐economic and environmentally friendly approach to the synthesis of di‐ and triarylmethanes, which are important substructures in various bioactive compounds and functional materials.magnified image
Low‐Temperature Processable High‐Performance D–A‐Type Random Copolymers for Nonfullerene Polymer Solar Cells and Application to Flexible Devices
Authors: Kim Ji‐yeong , Park Sungmin , Lee Seungjin , Ahn Hyungju , Joe Sung‐yoon , Kim Bumjoon J. , Son Hae Jung 
Published: September 2018

AbstractDonor–acceptor random copolymers incorporating 1,3‐bis(thiophen‐2‐yl)‐5,7‐bis(2‐ethylhexyl)benzo[1,2‐c:4,5‐c′]dithiophene‐4,8‐dione (BDD) and 4,8‐bis(5‐(2‐ethylhexyl)thiophen‐2‐yl)benzo[1,2‐b:4,5‐b′]dithiophene (BDT‐Th) are developed. Nonfullerene solar cells introducing the random copolymer PBDB‐T73 (BDT‐Th:BDD=7:3) and 3,9‐bis(2‐methylene‐(3‐(1,1‐dicyanomethylene)‐indanone))‐5,5,11,11‐tetrakis(4‐hexylphenyl)‐dithieno[2,3‐d:2′,3′‐d′]‐s‐indaceno[1,2‐b:5,6‐b′]dithiophene are found to exhibit efficiency of 11.14%, which is superior to that of the PBDB‐T alternating copolymer (10.02%). The PBDB‐T73 device exhibits high performance due to low bimolecular charge recombination and good charge transport balance even though none of the treatments that are usually necessary for improving crystalline properties of active layers are performed; in contrast, the PBDB‐T device requires thermal annealing in order to enhance the polymer's crystallinity and obtain improved fill factor and Jsc values. It is demonstrated that efficient charge transport occurs in the PBDB‐T73 blend despite relatively low crystallinity of the polymer. The percolating network structure of the large mixed phase in the PBDB‐T73 blend has an important role in its efficient charge transport. Moreover, due to the low‐temperature processability of PBDB‐T73, flexible PBDB‐T73 solar cell devices prepared on polyethylene terephthalate (PET) substrates exhibit high photovoltaic performance, 10.02%, whereas the efficiency of PBDB‐T‐based flexible devices (7.2%) is significantly lower due to damage to the active layer on indium tin oxide (ITO)/PET that results from thermal annealing.
Efficiency Exceeding 20% in Perovskite Solar Cells with Side‐Chain Liquid Crystalline Polymer–Doped Perovskite Absorbers
Authors: Arivunithi Veera Murugan , Reddy Saripally Sudhaker , Sree Vijaya Gopalan , Park Ho‐Yeol , Park Juuyn , Kang Yong‐Cheol , Shin Eun‐Sol , Noh Yong‐Young , Song Myungkwan , Jin Sung‐Ho 
Published: September 2018

AbstractAttaining high quality perovskite films with enhanced morphology, high efficiency, and better stability is a great research challenge. Here, a side‐chain liquid crystalline polymer (SCLCP) is incorporated as a dopant into the perovskite film to achieve perovskite solar cells (PSCs) with high efficiency and long‐term stability. SCLCP doping increases the grain size in the crystalline perovskite film by controlled solvent evaporation and reduced grain boundaries, which slow the material degradation and reduce the charge recombination. Using this approach, the PSC power conversion efficiency (PCE) is significantly boosted from 18.0% (nondoped) to 20.63% for the SCLCP‐doped perovskite film with much improved air stability. Furthermore, the trap state density in the SCLCP‐doped films is decreased because the SCLCP effectively passivates the perovskite grain surface. Notably, the SCLCP appears to act as a bridge between grains for effective charge transfer from perovskite toward the electrode, which would partially explain the enhanced efficiency and stability.
Surgery for Pancreatic Cancer after neoadjuvant treatment
Authors: Hackert Thilo 
Published: September 2018

AbstractPancreatic ductal adenocarcinoma (PDAC) remains to be a therapeutic challenge as only 15%‐20% of all patients present with resectable tumor stages by the time of diagnosis. In the remaining patients, either local tumor extension or systemic spread are obstacles for a surgical therapy as the only chance for long‐term survival. With regard to local tumor extension, PDAC has been classified as resectable, borderline‐resectable (BR) or locally advanced (LA). While there is currently no evidence for neoadjuvant therapy in resectable PDAC, this issue remains controversial in BR‐PDAC. In the case of venous tumor involvement, guidelines mostly recommend upfront resection, when technically possible; whereas arterial involvement is regarded as an indication for chemotherapy or chemoradiotherapy first. Furthermore, in locally advanced PDAC, neoadjuvant treatment approaches have recently resulted in high rates of secondary resection, thus allowing “conversion” surgery in an otherwise palliative treatment situation. The present review gives an overview on the current literature of treatment concepts in these situations and additionally focuses of evaluation of resectability after neoadjuvant therapy as well as technical aspects in this specific situation.
Occupational exposures and parkinsonism among Shanghai women textile workers
Authors: Checkoway Harvey , Ilango Sindana , Li Wenjin , Ray Roberta M. , Tanner Caroline M. , Hu Shu‐Ching , Wang Xin , Nielsen Susan , Gao Dao L. , Thomas David B. 
Published: September 2018

BackgroundEndotoxin, a contaminant of cotton dust, is an experimental model for parkinsonism (PS).MethodsWe investigated associations between exposures to endotoxin, solvents, magnetic fields, and night shift work, and neurologist‐determined PS among Shanghai women textile workers, including 537 retired cotton factory workers ages ≥50 years and an age‐matched reference group of 286 retired textile workers not exposed to cotton dust. Repeat exams were conducted 2.5 years after enrollment among 467 cotton workers and 229 reference workers.ResultsWe identified 39 prevalent PS cases and 784 non‐cases. No consistent or statistically significant associations were observed for endotoxin, solvents, magnetic fields, or shift work with PS risk, severity, or progression.ConclusionsDespite the null findings, additional studies of endotoxin exposure and risk of PS in other well‐characterized occupational cohorts are warranted in view of toxicological evidence that endotoxin is a pathogenic agent and its widespread occurrence in multiple industries worldwide.
2,7‐Dioctylbenzofuro[3,2‐b]benzofuran: An Organic Semiconductor with Two‐dimensional Transport Channels
Authors: Chen Daoliang , Li Jie , Ma Weimin , Li Baolin , Zhen Yonggang , Zhu Xiaozhang , Hu Wenping , Tsuji Hayato , Nakamura Eiichi 
Published: September 2018

AbstractWe report herein a synthesis of benzofuro[3,2‐b]benzofuran (BFBF) by an intramolecular Ullmann C−O coupling reaction. To tune the film forming ability and self‐assembling behaviour, the derivative possessing two alkyl chains, 2,7‐dioctylbenzofuro[3,2‐b]benzofuran (C8‐BFBF), was further prepared. The packing structures of these two compounds were studied by XRD analysis, showing a two‐dimensional (2D) stacking structure in the solid state. DFT calculations indicated that C8‐BFBF exhibited large transfer integrals along the two stacking directions. The OFET devices based on C8‐BFBF showed typical hole transport properties with mobility up to 0.076 cm2 V−1 s−1.
Strukturaufklärung von Spurenkomponenten durch Kombination von GC/MS, GC/IR, DFT‐Simulationen und Synthese – Salinilactone, neuartige bicyclische Lactone aus Salinispora Bakterien
Authors: Schlawis Christian , Kern Simone , Kudo Yuta , Grunenberg Jörg , Moore Bradley S. , Schulz Stefan 
Published: September 2018

AbstractDie Analyse flüchtiger Verbindungen aus marinen Salinispora Bakterien führte zur Entdeckung einer neuen Klasse von Naturstoffen mit ungewöhnlichem Bicyclo[3.1.0]‐Lactongerüst. Die Kombination verschiedener analytischer Methoden, Computational Spectroscopy und Synthese erlaubte die zweifelsfreie Strukturaufklärung der Verbindungen, genannt Salinilactone, ohne aufwendige Isolation mit nur sub‐μg Substanzmengen. Die Verwendung zweier orthogonaler Kupplungsmethoden, GC/MS und Festphasen‐GC/IR, erlaubte die Erstellung einer Reihe von Strukturvorschlägen. Durch den Vergleich des experimentellen IR‐Spektrums mit DFT‐Simulationen wurde einer der Strukturvorschläge für die Synthese priorisiert. So konnten die Struktur und absolute Konfiguration der drei Lactone, Salinilactone A–C, bestätigt werden. Die Salinilactone sind strukturell eng mit den Verbindungen der A‐Faktor‐Klasse verwandt, Autoregulatoren aus Streptomyceten, und zeigen inhibitorische Aktivität gegenüber Salinispora und Streptomyces Bakterien.
Iridium‐Catalyzed Electrooxidative C−H Activation by Chemoselective Redox‐Catalyst Cooperation
Authors: Qiu Youai , Stangier Maximilian , Meyer Tjark H. , Oliveira João C. A. , Ackermann Lutz 
Published: September 2018

AbstractIridium‐catalyzed electrochemical C−H activation was accomplished within a cooperative catalysis manifold, setting the stage for electrooxidative C−H alkenylations through weak O‐coordination. The iridium‐electrocatalyzed C−H activation featured high functional‐group tolerance through assistance of a metal‐free redox mediator through indirect electrolysis. Detailed mechanistic insights provided strong support for an organometallic C−H cleavage and a synergistic iridium(III/I)/redox catalyst regime, enabling the use of sustainable electricity as the terminal oxidant with improved selectivity features.
MXene Aerogel Scaffolds for High‐Rate Lithium Metal Anodes
Authors: Zhang Xinyue , Lv Ruijing , Wang Aoxuan , Guo Wenqing , Liu Xingjiang , Luo Jiayan 
Published: September 2018

AbstractLi metal is considered to be an ultimate anode for metal batteries owing to its extremely high theoretical capacity and lowest potential. However, numerous issues such as short lifespan and infinite volume expansion caused by the dendrite growth during Li plating/stripping hinder its practical usage. These challenges become more grievous under high current densities. Herein, 3D porous MXene aerogels are proposed as scaffolds for high‐rate Li metal anodes using Ti3C2 as an example. With high metallic electron conductivity, fast Li ion transport capability, and abundant Li nucleation sites, such scaffolds could deliver high cycling stability and low overpotential at current density up to 10 mA cm−2. High rate performance is also demonstrated in full cells with LiFePO4 as cathodes. This work provides a new type of scaffolds for Li metal anodes and paves the way for the application of non‐graphene 2D materials toward high energy density Li metal batteries.
Synthesis, characterization, and performance of a novel polycarboxylate superplasticizer with a crosslinked topological structure
Authors: Zhao Hongwei , Liao Bing , Wang Kun , Zhao Yangyang , Nian Fuwei , Meng Yeyun , Pang Hao 
Published: September 2018

ABSTRACTIn this work, a novel crosslinked topological polycarboxylate superplasticizer (TPC) was successfully synthesized. In comparison with conventional comb‐shaped superplasticizer (CPC), the TPC performed better dispersion maintaining stronger water reduction capabilities. The TPC provided a large spherical space due to its crosslinked molecular structure, which was the main reason for enhanced dispersion performance. It was evident that the addition of TPC leads to a delayed and lowered heat flow peak during the early stage of the hydration process. Thermogravimetric analysis showed that the hydrated products exhibited a more stable performance in the presence of the TPC. Changing the molecular structure from a comb‐shape to a crosslinked topological could effectively improve the comprehensive performances of the PCs. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46716.
Dynamic mechanical and shape memory properties of copolymers based on polyetheramine‐type benzoxazines and diglycidylether of bisphenol‐A
Authors: Li Cuiyun , Shen Shanshan , Li Zhiyun , Zhen Hecheng , Huang Jinbai , Liu Yanfang 
Published: September 2018

ABSTRACTTwo series of benzoxazine/epoxy copolymers are prepared from polyetheramine‐type benzoxazines and diglycidyl ether of bisphenol A (DGEBA) in various weight ratios. Each copolymer appears a single glass‐transition temperature (Tg), and theTgshows a systematic increase with increasing DGEBA content for both copolymer systems, but copolymers with low DGEBA content show respectively lowerTgs than the corresponding pristine polybenzoxazines. Compared to the corresponding pristine polybenzoxazines, the effect of DGEBA content on the variation inTgof the copolymers depends on the substituent structure of benzoxazines. The two series of copolymers exhibit one‐way dual shape memory effect based onTg, and the shape memory effect is affected by both the substituent structure of benzoxazines and the content of DGEBA. Under motion constraints in tensile deformation mode, copolymers with low DGEBA content exhibit high shape recovery ratios (91.0–96.1%) over the corresponding polybenzoxazines (84.5%), whereas copolymers with high DGEBA content show relatively low shape recovery ratios (75.0–84.7%). © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2018,135, 46838.
Synthesis of new functional hexamethyltrisiloxanes and telechelic polydimethylsiloxanes based on them
Authors: Drozdov F. V. , Cherkaev G. V. , Demchenko N. V. , Muzafarov A. M. 
Published: September 2018

ABSTRACTOligo‐ and polysiloxanes with terminal functional groups are of great interest in terms of syntheses of siloxane‐containing block copolymers by various synthetic methods. In this study, synthesis of bifunctional di‐ and trisiloxanes with different terminal 4‐(phenylene ethylene) substituents was developed using hydrosilylation under mild reaction conditions. Six new trisiloxanes with different functional substituents can be produced either directly by hydrosilylation of 4‐substituted styrene derivatives or by consistent conversion of the homologues obtained. All the functional trisiloxanes synthesized are suitable as chain stoppers in the ring‐opening polymerization of cyclosiloxanes. We believe that synthesis not only of symmetrical oligosiloxanes but also of asymmetrical hydrodosiloxane‐containing analogues is a promising approach. Compounds of this kind will be in demand as precursors for the production of functional siloxane derivatives by the hydrosilylation reaction. Thus, symmetrical or asymmetrical telechelic oligo‐ or polydimethylsiloxanes with different functional groups are suitable as AA‐type blocks for further synthesis of block copolymers. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2018,135, 46848.
Epoxy terminated polysiloxane blended with diglycidyl ether of bisphenol‐A. 1: Curing behavior and compatibility
Authors: Yang Yang , Li Weizhen , Chen Kaimin , Gan Wenjun , Wang Cheng 
Published: September 2018

ABSTRACTAn epoxypropoxypropyl terminated polydimethylsiloxane (DMS‐E09) is blended with a commercial epoxy resin [diglycidyl ether of bisphenol‐A (DGEBA)], using methyl tetrahydrophthalic anhydride as a curing agent in the presence of the accelerator N, N‐dimethyl benzyl amine. The co‐curing behaviors, glass‐transition temperature (Tg) are studied by differential scanning calorimetry (DSC) and curing kinetic parameters are calculated by Kissinger and Ozawa methods. It is found that the apparent activation energy for DMS‐E09 is slightly lower than that of the DGEBA by 9–10 kJ mol−1. Dynamic mechanical analysis is subsequently employed and reveals that the value of Tg (peak of tan δ at higher temperature) consists with the result of DSC very well. With the increase of DMS‐E09 content, storage modulus and the values of Tg and Tβ (peak of tan δ at lower temperature) all have a tendency of decreasing monotonically. Furthermore, Tg and Tβ follow Fox and Gordon‐Taylor expression well, indicating compatible networks in certain level are obtained. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46891.
Chitosan/polyaniline hybrid for the removal of cationic and anionic dyes from aqueous solutions
Authors: Minisy I. M. , Salahuddin N. A. , Ayad M. M. 
Published: September 2018

ABSTRACTNanostructured chitosan/polyaniline (CH/PANI) hybrid was synthesized via in situ polymerization of aniline in the presence of chitosan. The CH/PANI hybrid was characterized by FTIR spectroscopy, X‐ray diffraction, thermogravimetric analysis, and scanning electron microscopy. The CH/PANI hybrid had a nanofibrous structure with an average diameter of 70 nm. This hybrid was employed as an ecofriendly and efficient adsorbent with high adsorption capacity for the removal of Acid Green 25 (AG) and methylene blue (MB) from aqueous solutions. AG and MB were used as anionic and cationic model dyes, respectively. The CH/PANI adsorbent showed high dependence on the pH of the medium with an excellent adsorption performance and regeneration manner. The kinetics and adsorption isotherms were studied. The CH/PANI hybrid follows the pseudo second‐order adsorption kinetics and Temkin isotherm model for the adsorption of both AG and MB dyes. This assumes that the enthalpy of dyes molecules decreases with the adsorption on heterogeneous surface with various kinds of adsorption sites and as well as the ability to form multilayers of the dye. Also, intraparticle diffusion was found to play an important role in the adsorption mechanism. The maximum adsorption capacity was found to be 240.4 mg g−1 of AG at pH 4 and 81.3 mg g−1 of MB at pH 11. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47056.
VZLUSAT‐1: Health monitoring system, preliminary results
Authors: Nentvich O. , Urban M. , Stehlikova V. , Sieger L. , Inneman A. 
Published: September 2018

The health monitoring (HM) system placed on VZLUSAT‐1 nondestructively measures the mechanical and thermal properties of the newly developed carbon fiber material for space usage. The carbon material is exposed to the vacuum, radiation, and temperature changes in space. It can be used as a substitute for the currently used aluminum alloys because it has lower mass density and better mechanical properties compared to aluminum. The HM payload evaluates the quality changes of a material according to the difference in Young's modulus. Young's modulus of elasticity is a characteristic property of every solid material, and on VZLUSAT‐1 it is measured in terms of the eigenfrequencies of a free‐hanging beam. In this paper we present the first data measured in orbit – the eigenfrequencies, attenuation, and six temperatures from a carbon fiber panel. Based on these data, the quality of the mechanical properties and time stability are determined over the VZLUSAT‐1's life span.