bluuebunny/crossref_metadata_2025_split huggingface dataset:
Optical Outcoupling Efficiency in Polymer Light‐Emitting Diodes
Authors: Li Yungui , Van der Zee Bas , Wetzelaer Gert‐Jan A. H. , Blom Paul W. M. 
Published: May 2021

AbstractThe electrical properties of polymer‐based light‐emitting diodes (PLEDs) have been extensively studied, resulting in quantitative device models. However, for a complete description of the optoelectronic properties of a PLED, the obtained recombination profiles need to be integrated with an optical model describing the local outcoupling efficiency of the generated light. In this work, combined electrical and optical model calculations are presented, demonstrating that the light‐outcoupling efficiency in PLEDs is governed by the presence of electron traps and the anisotropy factor of optical dipoles. Electron trapping confines the recombination in a region close to cathode, resulting in strong optical trapping in surface plasmon polariton modes. Trap‐filling leads to a voltage‐dependent recombination profile and optical outcoupling efficiency. For a typical electron trap density of ≈1023 m−3, the calculated outcoupling efficiency raises from 5.5% at 2 V to 10.4% at 5 V in case of isotropic emitters. For conjugated polymers such as super yellow poly(p‐phenylene vinylene) with the chains preferentially aligned in the plane of the film, the outcoupling efficiency can reach ≈18% at 5 V. Elimination of electron trapping would allow for a further enhancement up to 24%.
Numerical simulation of atomic layer deposition for thin deposit formation in a mesoporous substrate
Authors: Zhuang Liwei , Corkery Peter , Lee Dennis T. , Lee Seungjoon , Kooshkbaghi Mahdi , Xu Zhen‐liang , Dai Gance , Kevrekidis Ioannis G. , Tsapatsis Michael 
Published: May 2021

AbstractZnO deposition in porous γ‐Al2O3 via atomic layer deposition (ALD) is the critical first step for the fabrication of zeolitic imidazolate framework membranes using the ligand‐induced perm‐selectivation process (Science, 361 (2018), 1008–1011). A detailed computational fluid dynamics (CFD) model of the ALD reactor is developed using a finite‐volume‐based code and validated. It accounts for the transport processes within the feeding system and reaction chamber. The simulated precursor spatiotemporal profiles assuming no ALD reaction were used as boundary conditions in modeling diethylzinc reaction/diffusion in porous γ‐Al2O3, the predictions of which agreed with experimental electron microscopy measurements. Further simulations confirmed that the present deposition flux is much less than the upper limit of flux, below which the decoupling of reactor/substrate is an accurate assumption. The modeling approach demonstrated here allows for the design of ALD processes for thin‐film membrane formation including the synthesis of metal–organic framework membranes.
A spatially resolved model for pressure filtration of edible fat slurries
Authors: Van den Akker Harry E. A. , Hazelhoff Heeres Doedo P. , Kloek William 
Published: May 2021

AbstractA spatially resolved one dimensional pressure filtration model was developed for a slurry of edible fat crystals. The model focuses on the expression step in which a cake is compressed to force the liquid through a filter cloth. The model describes the local oil flow in the shrinking cake modeled as a porous nonlinear elastic medium existing of two phases, viz. porous aggregates and interaggregate liquid. Conservation equations lead to a set of two differential equations (vs. time and vs. a material coordinate ω) for two void ratios, which are solved numerically by exploiting a finite‐difference scheme. A simulation with this model results in a spatially resolved cake composition and in the outflow velocity, both as a function of time, as well as the final solid fat contents of the cake. Simulation results for various filtration conditions are compared with experimental data collected in a pilot‐plant scale filter press.
Copper‐Catalyzed Decarboxylative Synthesis of α‐Ketothioamides Using α,β‐Unsaturated Arylcarboxylic Acids, Alicyclic Secondary Amines and Elemental Sulfur
Authors: Jaiswal Anjali , Sharma Anup Kumar , Preeti  , Singh Krishna Nand 
Published: May 2021

AbstractAn efficient and straightforward synthesis of α‐ketothioamides has been accomplished via in situ decarboxylative oxidative thioamidation using α,β‐unsaturated arylcarboxylic acids, alicyclic secondary amines and elemental sulfur under solvent‐free aerobic conditions.
DBU‐Catalyzed Regioselective α‐Alkylation of Enones Using the Vinylogous Strategy
Authors: Tian Yawei , Shang Yaping , Su Weiping 
Published: May 2021

AbstractA convenient and atom‐economic transformation of enones with electron‐deficient alkenes under mild conditions has been developed using DBU as a catalyst. This method utilizes vinylogous strategy to form dienolate intermediates, which provides a new approach for the regioselective α‐alkylation of enones. This protocol exhibits a broad range of substrate scope and good functional group compatibility. Moreover, it enabled the formation of unexpected cyclic 1,5‐diketone by employing phenyl acrylate as Michael acceptor to construct all‐carbon quaternary centers at γ‐position of enones. Overall, this synthetic method establishes a new route from readily available enones to valuable 1,5‐dicarbonyl compounds.
Synthese und mehrfache Folgereaktivität von anionischen cyclo‐E3‐Ligandkomplexen (E=P, As)
Authors: Piesch Martin , Reichl Stephan , Seidl Michael , Balázs Gábor , Scheer Manfred 
Published: May 2021

AbstractEin synthetischer Zugang zur Synthese neuartiger anionischer Sandwichkomplexe mit einem cyclo‐E3‐Liganden (E=P, As) als Enddeck wurde entwickelt, der [Cp′′′Co(η3‐E3)]− (Cp′′′=1,2,4‐Tri‐tert‐butylcyclopentadienyl; E=P ([5]), As ([6])) in guten Ausbeuten ergibt und damit diese für weitere Reaktivitätsstudien geeignet macht. In der Reaktion mit den Chlorophosphanen R2PCl (R=Ph, Cy, tBu) wurden neutrale Komplexe mit einem zweifach substituierten cyclo‐E3P‐Liganden (E=P, As) in [Cp′′′Co(η3‐E3PR2)] (E=P (7 a–c), As (9 a–c)) erhalten. Diese Verbindungen können teilweise oder vollständig in Komplexe mit einem cyclo‐E3‐Liganden mit einer exocyclischen {PR2}‐Einheit in [Cp′′′Co(η2:η1‐E3PR2)] (E=P (8 a–c), As (10 a–c)) transferiert werden. Darüber hinaus gelang es, das Chlorosilylen [LSiCl] (L=(tBuN)2CPh) in den cyclo‐E3‐Liganden von [5] und [6] zu insertieren und die neuartigen heteroatomaren Komplexe [Cp′′′Co(η3‐E3SiL)] (E=P (11), As (12)) zu isolieren. Der Reaktionsweg konnte durch DFT‐Rechnungen aufgeklärt werden.
Unprecedented Noncanonical Features of the Nonlinear Nonribosomal Peptide Synthetase Assembly Line for WS9326A Biosynthesis
Authors: Kim Myoun‐Su , Bae Munhyung , Jung Ye‐Eun , Kim Jung Min , Hwang Sunghoon , Song Myoung Chong , Ban Yeon Hee , Bae Eun Seo , Hong Suckchang , Lee Sang Kook , Cha Sun‐Shin , Oh Dong‐Chan , Yoon Yeo Joon 
Published: May 2021

AbstractSystematic inactivation of nonribosomal peptide synthetase (NRPS) domains and translocation of the thioesterase (TE) domain revealed several unprecedented nonlinear NRPS assembly processes during the biosynthesis of the cyclodepsipeptide WS9326A in Streptomyces sp. SNM55. First, two sets of type ΙΙ TE (TEΙΙ)‐like enzymes mediate the shuttling of activated amino acids between two sets of stand‐alone adenylation (A)‐thiolation (T) didomain modules and an “A‐less” condensation (C)‐T module with distinctive specificities and flexibilities. This was confirmed by the elucidation of the affinities of the A‐T didomains for the TEΙΙs and its structure. Second, the C‐T didomain module operates iteratively and independently from other modules in the same protein to catalyze two chain elongation cycles. Third, this biosynthetic pathway includes the first example of module skipping, where the interpolated C and T domains are required for chain transfer.
Response to “What Shall We Do with Computed Detonation Performance? Comment on ‘1,3,4‐Oxadiazole Bridges: A Strategy to Improve Energetics at the Molecular Level’”
Authors: Ma Jinchao , Chinnam Ajay Kumar , Cheng Guangbin , Yang Hongwei , Zhang Jiaheng , Shreeve Jean'ne M. 
Published: May 2021

AbstractThe values obtained for detonation performance are a function of the computational methods utilized. Since there are many such methods, the literature may contain a range of values for a single compound.
Enhancing Thermocatalytic Activities by Upshifting the d‐Band Center of Exsolved Co‐Ni‐Fe Ternary Alloy Nanoparticles for the Dry Reforming of Methane
Authors: Joo Sangwook , Kim Kyeounghak , Kwon Ohhun , Oh Jinkyung , Kim Hyung Jun , Zhang Linjuan , Zhou Jing , Wang Jian‐Qiang , Jeong Hu Young , Han Jeong Woo , Kim Guntae 
Published: May 2021

AbstractDry reforming of methane (DRM) is a feasible solution to address the reduction of greenhouse gases stipulated by the Paris Climate Agreement, given that it adds value by converting trivial gases, CO2 and CH4, simultaneously into useful syngas. However, the conventional Ni catalyst undergoes deactivation due to carbon coking and particle agglomeration. Here we demonstrate a highly efficient and durable DRM catalyst: exsolved Co‐Ni‐Fe ternary alloy nanoparticles on the layered perovskite PrBaMn1.7Co0.1Ni0.2O5+δ produced by topotactic exsolution. This method readily allows the generation of a larger number of exsolved nanoparticles with enhanced catalytic activity above that of Ni monometallic and Co‐Ni bimetallic particles. The enhancement is achieved by the upshift of the d‐band center of Co‐Ni‐Fe relative to those of Co‐Ni and Ni, meaning easier charge donation to the adsorbate. Furthermore, the exsolved catalyst shows exceptional stability, with continuous DRM operation for about 350 hours.
ZIF‐Based Nanoparticles Combine X‐Ray‐Induced Nitrosative Stress with Autophagy Management for Hypoxic Prostate Cancer Therapy
Authors: Li Yanli , Gong Teng , Gao Hongbao , Chen Yang , Li Huiyan , Zhao Peiran , Jiang Yaqin , Wang Kun , Wu Yelin , Zheng Xiangpeng , Bu Wenbo 
Published: May 2021

AbstractAlthough reactive oxygen species (ROS)‐mediated tumor treatments are predominant in clinical applications, ROS‐induced protective autophagy promotes cell survival, especially in hypoxic tumors. Herein, X‐ray triggered nitrite (NO2−) is used for hypoxic prostate cancer therapy by inhibiting autophagy and inducing nitrosative stress based on an electrophilic zeolitic imidazole framework (ZIF‐82‐PVP). After internalization of pH‐responsive ZIF‐82‐PVP nanoparticles, electrophilic ligands and Zn2+ are delivered into cancer cells. Electrophilic ligands can not only consume GSH under hypoxia but also capture low‐energy electrons derived from X‐rays to generate NO2−, which inhibits autophagy and further elevates lethal nitrosative stress levels. In addition, dissociated Zn2+ specifically limits the migration and invasion of prostate cancer cells through ion interference. In vitro and in vivo results indicate that ZIF‐82‐PVP nanoparticles under X‐ray irradiation can effectively promote the apoptosis of hypoxic prostate cancer cells. Overall, this nitrosative stress‐mediated tumor therapy strategy provides a novel approach targeting hypoxic tumors.
Altering Hydrogenation Pathways in Photocatalytic Nitrogen Fixation by Tuning Local Electronic Structure of Oxygen Vacancy with Dopant
Authors: Bo Yanan , Wang Haiyun , Lin Yunxiang , Yang Tian , Ye Run , Li Yu , Hu Canyu , Du Pengye , Hu Yangguang , Liu Zhi , Long Ran , Gao Chao , Ye Bangjiao , Song Li , Wu Xiaojun , Xiong Yujie 
Published: May 2021

AbstractTo avoid the energy‐consuming step of direct N≡N bond cleavage, photocatalytic N2 fixation undergoing the associative pathways has been developed for mild‐condition operation. However, it is a fundamental yet challenging task to gain comprehensive understanding on how the associative pathways (i.e., alternating vs. distal) are influenced and altered by the fine structure of catalysts, which eventually holds the key to significantly promote the practical implementation. Herein, we introduce Fe dopants into TiO2 nanofibers to stabilize oxygen vacancies and simultaneously tune their local electronic structure. The combination of in situ characterizations with first‐principles simulations reveals that the modulation of local electronic structure by Fe dopants turns the hydrogenation of N2 from associative alternating pathway to associative distal pathway. This work provides fresh hints for rationally controlling the reaction pathways toward efficient photocatalytic nitrogen fixation.
A Synthetic Galectin Mimic
Authors: Timmer Brian J. J. , Kooijman Arjaan , Schaapkens Xander , Mooibroek Tiddo J. 
Published: May 2021

AbstractGalectins are a galactoside specific subclass of carbohydrate binding proteins (lectins) involved in various cellular activities, certain cancers, infections, inflammations, and many other biological processes. The molecular basis for the selectivity of galectins is well‐documented and revolves around appropriate interaction complementarity: an aromatic residue for C−H⋅⋅⋅π interactions and polar residues for (charge assisted) hydrogen bonds with the axial hydroxyl group of a galactoside. However, no synthetic mimics are currently available. We now report on the design and synthesis of the first galectin mimic (6), and show that it has a higher than 65‐fold preference for n‐octyl‐β‐galactoside (8) over n‐octyl‐β‐glucoside (7) in CD2Cl2 containing 5 % [D6]DMSO (with Ka≥4500 M−1 for 6:8). Molecular modeling informed by nOe studies reveal a high degree of interaction complementarity between 6 and galactoside 8, which is very similar to the interaction complementarity found in natural galectins.
1,3‐Bis(tricyanoborane)imidazoline‐2‐ylidenate Anion—A Ditopic Dianionic N‐Heterocyclic Carbene Ligand
Authors: Zapf Ludwig , Radius Udo , Finze Maik 
Published: May 2021

AbstractThe 1,3‐bis(tricyanoborane)imidazolate anion 1 was obtained in high yield from lithium imidazolate and B(CN)3−pyridine adduct. Anion 1 is chemically very robust and thus allowed the isolation of the corresponding H5O2+ salt. Furthermore, monoanion 1 served as starting species for the novel dianionic N‐heterocyclic carbene (NHC), 1,3‐bis(tricyanoborane)imidazoline‐2‐ylidenate anion 3 that acts as ditopic ligand via the carbene center and the cyano groups at boron. First reactions of this new NHC 3 with methyl iodide, elemental selenium, and [Ni(CO)4] led to the methylated imidazolate ion 4, the dianionic selenium adduct 5, and the dianionic nickel tricarbonyl complex 6. These NHC derivatives provide a first insight into the electronic and steric properties of the dianionic NHC 3. Especially the combination of properties, such as double negative charge, different coordination sites, large buried volume and good σ‐donor and π‐acceptor ability, make NHC 3 a unique and promising ligand and building block.
Evaluation of micropillar array columns for chromatographic separation of phosphorothioated oligonucleotides and their diastereomers
Authors: Dillen Lieve , Deschrijver Tiny , Van Mol Kurt , Op de Beeck Jeff , Jacobs Paul , Cuyckens Filip 
Published: May 2021

AbstractChromatographic analysis of therapeutic oligonucleotides is challenging due to the presence of closely related impurities, degradants or metabolites and due to the presence of phosphorothioate bonds, which introduce chiral centers. In the present study, ion pair reversed phase chromatography of oligonucleotides on micropillar array columns was investigated. Two commonly used mobile phase conditions were included. With 16.3 mM triethylamine and 400 mM hexafluoroisopropanol, the separation of 16‐mer oligonucleotides differing in the number and positions of phosphorothioate linkages as well as some n‐1 and n‐2 truncations demonstrated complete suppression of diastereoselectivity. Although the positional phosphorothioate isomers evaluated could not be resolved, an increase in phosphorothioate bonds resulted in more retention. A therapeutic 19‐mer RNA sequence with 2′‐fluor and 2′‐O‐methyl modifications showed partial separation of some very close impurities. When using 15 mM triethyl ammonium acetate in the mobile phase, diastereomer selectivity was clearly observed for all analytes. The best result was obtained for the 19‐mer RNA therapeutic mimic with four phosphorothioate bonds, since all 16 theoretical diastereomers were clearly observed under the conditions tested. A limited benchmark exercise demonstrated the improved capability of the new micropillar array columns. Therefore, these columns can be positioned as a valuable alternative when challenging oligonucleotide separations are expected.
Polymer melting temperatures and crystallinity at different pressure applied
Authors: Chen Kailin , Zhang Wenshuo , Yarin Alexander L. , Pourdeyhimi Behnam 
Published: May 2021

AbstractThe present work aims at the experimental investigation of the effect of an increased thermal bonding pressure on the melting point (the so‐called Clapeyron effect) of three polymers employed in nonwovens. Namely, this work quantifies the dependence of melting temperature on pressure in these polymers. The following three polymers were used in the present experiments: polybutylene terephthalate (PBT), polyethylene terephthalate (PET), and polypropylene (PP) (all three already received in the form of nonwovens). A simple novel method of measurements of melting points of such polymers under different pressures was proposed and developed. The results revealed: (i) the melting point of PBT nonwovens increased by about 12°C when the applied pressure was increased up to 277.79 atm; (ii) the melting point of the PET nonwovens increased by about 7°C when the applied pressure increased up to 104.86 atm; (iii) the melting point of PP nonwovens increased by about 6°C when the applied pressure was increased up to 104.86 atm. The melting temperature measurements by the present method were also validated through differential scanning calorimetry measurements with the above‐mentioned three polymers without applied pressure.
Synthesis and characterization of biobased polyester PVC plasticizers to industrial manufacturing of tubes
Authors: Fernandes Mónica C. S. , Pereira Vanessa A. , Fonseca Ana C. , Ramalho Amílcar , Coelho Jorge F. J. , Barros Rodrigo , Pereira Paula , Pereira João , Serra Arménio C. 
Published: May 2021

AbstractThe search for the substitution of phthalate derivatives in the process of polyvinyl chloride (PVC) plasticization is a matter of intensive research, due to the increasing proofs about phthalate toxicity. With this objective, a series of novel saturated polyesters (SPs) were synthesized by polycondensation from different biobased acids and diols, and end‐capped with 2‐tetradecyloctadecan‐1‐ol (TDOD). After characterization, the SPs were incorporated in an industrial formulation for flexible PVC and the mechanical properties of the films analyzed by tensile tests, DMTA, and DSC. The tensile tests revealed a similar ultimate tensile strength and a higher elongation at break for the PVC with SP as plasticizers compared with DEHTP (di[2‐ethylhexyl] terephthalate). The SP showing the most promising results was chosen to carry on an industrial manufacturing of a transparent tube. The migration tests of the tube show a much less leaching properties compared with tube prepared using the plasticizer DEHTP. All the results indicate that SPs can be an industrially viable and excellent alternative to DEHTP.
Core‐shell structured BaTiO3@SiO2@PDA for high dielectric property nanocomposites with ultrahigh energy density
Authors: Wang Rui , Xie Congzhen , Gou Bin , Xu Huasong , Luo Shoukang , Du Yan , Zhou Jiangang , Yang Hao 
Published: May 2021

AbstractFlexible nanocomposite dielectrics with high dielectric constant and discharge energy density have broad application prospects in the field of energy storage. However, dielectrics with high dielectric constant tend to have a high dielectric loss. Herein, we prepared a dielectric composite material with ultra‐high discharge energy density by modifying the interface between nanoparticles and poly(vinylidene fluoride‐co‐hexafluoropropylene) (P[VDF‐HFP]). After coating a shell of insulating amorphous SiO2 (~7 nm) outside the barium titanate (BT), the electric field concentration and current density inside BT particles can be significantly reduced. In addition, coating the SiO2 shell with a polydopamine (PDA) shell (~7 nm) not only enhances the interface interaction between the nanoparticles and the polymer matrix, but also can form lots of microcapacitors in the composite. As a result, an ultra‐high discharge energy density of 13.78 J/cm3 at the expense of relatively inconspicuous efficiency (~59.8%) in the BT@SiO2@PDA/P (VDF‐HFP) with 2.5 wt% loading has been achieved under 460 kV/mm. This is mainly attributed to the increases of dielectric constant from 12.1 to 14.2 and the relatively low dielectric loss (0.086) at 100 Hz. Moreover, compared with the pure P (VDF‐HFP) (400 kV/mm), the breakdown voltage of the composite with 2.5 wt% loading is surged to 460 kV/mm, which benefited from the hindrance of nanoparticles on carrier migration at low content. This work has realized a thin‐film dielectric with ultra‐high discharge energy density through a novel design of the nanoparticle structure, providing a theoretical direction for the development of polymer dielectric capacitors.
Effect of silane coupling on the properties of polylactic acid/barium ferrite magnetic composite filament for the 3D printing process
Authors: Sukthavorn Kankavee , Phengphon Natkritta , Nootsuwan Nollapan , Jantaratana Pongsakorn , Veranitisagul Chatchai , Laobuthee Apirat 
Published: May 2021

AbstractPoly(lactic acid) (PLA)/barium ferrite (BaFe12O19) with different composition ratios was fabricated by magnetic composite filaments using an extrusion process for a 3D printer. The silane modified surface of BaFe12O19 was studied to observe the effect on the mechanical, morphology, thermal, and magnetic properties of magnetic composite filaments. The results showed that the silane treated surface BaFe12O19 not only enhanced the mechanical properties of magnetic composite filaments, but also improved adhesion and homogeneity between the BaFe12O19 filler and PLA matrix. Moreover, the thermal and magnetic properties of magnetic composite filaments were not obviously changed after adding silane treated surface BaFe12O19. The achievement of the magnetic composite filaments preparation with silane treated surface BaFe12O19 for the 3D printing process could become a guideline to develop and design other magnetic composites products in the near future.
Characterization of wood‐filled thermoplastic polyurethanes for the injection molding process
Authors: Moritzer Elmar , Richters Maximilian 
Published: May 2021

AbstractFiber fillings of wood plastic composites (WPC) are almost exclusively limited to standard plastics such as polyethylene and polypropylene. At the Kunststofftechnik Paderborn of the University of Paderborn the wood fiber filling of engineering plastics is being promoted. WPC with different fiber types and fiber contents based on two thermoplastic polyurethanes (TPU) were compounded and subsequently characterized. We found that the physicochemical properties of the materials differ from standard plastic‐based WPC. Wood filling with increasing fiber content did not immediately correlate with an increase in density. A decrease in density and swelling of the compound was detected with reaching a critical fiber content. Our compounds showed an increased water absorption at high‐fiber contents over time, which can be described logarithmically. The observed viscosity curves obey the Ostwald and de Waele power law, but an increased viscosity at increased fiber content was not apparent for both TPU matrices.