bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spin‐Dependent Electronic Structure and Magnetic Properties of 2D JANUS Mn2CFCl/CuBiP2Se6 Van Der Waals Multiferroic Heterostructures
Authors: Fu Luqian , Wang Xiaocha , Mi Wenbo 
Published: October 2021

Abstract2D van der Waals (vdW) multiferroic heterostructures have potential applications in novel 2D spintronic devices. Here, the electronic structure and magnetic anisotropy of 2D vdW multiferroic Mn2CFCl/CuBiP2Se6 heterostructures are investigated systematically by first‐principles calculations. Ferroelectric material CuBiP2Se6 has a built‐in electric field. Mn2CFCl is a half‐metallicity with ferromagnetic. The plane average potential difference of Mn2CFCl/CuBiP2Se6 heterostructures is 0.02 eV in P↓ state and 0.39 eV in P↑ state. The magnetic anisotropy of P↑ and P↓ states is shown perpendicular magnetic anisotropy (PMA). The P↑ state exhibits metallic character with the biaxial strain of 4%, −6%, while the P↓ state demonstrates half‐metallicity at a strain of 2%, 4%, 6%. The P↑ state shows PMA at the different biaxial strain. However, the P↓ state shows PMA at biaxial strain of −2%, −4%, and 6%, which shifts PMA to in‐plane magnetic anisotropy at −6%, 2%, and 4%. These tunable electronic structure and magnetic anisotropy suggest that the 2D multiferroic Mn2CFCl/CuBiP2Se6 vdW heterostructures have potential applications in spintronic devices.
Sulfurization Engineering of One‐Step Low‐Temperature MoS2 and WS2 Thin Films for Memristor Device Applications
Authors: Gu Yuqian , Serna Martha I. , Mohan Sivasakthya , Londoño‐Calderon Alejandra , Ahmed Taimur , Huang Yifu , Lee Jack , Walia Sumeet , Pettes Michael T. , Liechti Kenneth M. , Akinwande Deji 
Published: October 2021

Abstract2D materials have been of considerable interest as new materials for device applications. Non‐volatile resistive switching applications of MoS2 and WS2 have been previously demonstrated; however, these applications are dramatically limited by high temperatures and extended times needed for the large‐area synthesis of 2D materials on crystalline substrates. The experimental results demonstrate a one‐step sulfurization method to synthesize MoS2 and WS2 at 550 °C in 15 min on sapphire wafers. Furthermore, a large area transfer of the synthesized thin films to SiO2/Si substrates is achieved. Following this, MoS2 and WS2 memristors are fabricated that exhibit stable non‐volatile switching and a satisfactory large on/off current ratio (103–105) with good uniformity. Tuning the sulfurization parameters (temperature and metal precursor thickness) is found to be a straightforward and effective strategy to improve the performance of the memristors. The demonstration of large‐scale MoS2 and WS2 memristors with a one‐step low‐temperature sulfurization method with simple strategy to tuning can lead to potential applications such as flexible memory and neuromorphic computing.
Cubic Spinel XIn2S4 (X = Fe, Co, Mn): A New Type of Anode Material for Superfast and Ultrastable Na‐Ion Storage
Authors: Yan Dong , Li Ke , Yan Yaping , Huang Shaozhuan , Von Lim Yew , Shang Yang , Fang Daliang , Ang Lay Kee , Yang Hui Ying 
Published: October 2021

AbstractBimetallic sulfides are prospective candidates as Na‐ion battery (NIB) anodes owing to their abundant redox active sites and high specific capacities, while the rate and cycling performances are limited due to their severe mechanical strain and sluggish reaction kinetics. Herein, for the first time, a series of cubic spinel XIn2S4 (X = Fe, Co, Mn) anodes is proposed for superfast and ultrastable Na‐ion storage. The FeIn2S4 delivers the best electrochemical performance among them with the amazing results especially for its superfast charging (9–13 s per charge with ≈300 mAh g−1 input) and ultrastable cycling capabilities (25 K cycles with ultralow 0.000801% capacity loss per cycle). Further density functional theory calculations and experimental results indicate that Fe substitution at tetrahedral sites of cubic spinel In2.77S4 can significantly enhance its electrical conductivity, Na‐ion binding kinetics, and pseudocapacitive contributions, reduce its Na‐ion diffusion barrier, and relieve its mechanical strain. Moreover, the inherent In skeleton at octahedral sites can induce a complementary reaction to stabilize the conversion‐type Fe‐based components. Furthermore, the FeIn2S4‐based full cells with excellent electrochemical performance are assembled. This work demonstrates the feasibility of enhancing the synergies within bimetallic sulfides to realize remarkable electrochemical performance.
Rapid‐cycle deliberate practice improves time to defibrillation and reduces workload: A randomized controlled trial of simulation‐based education
Authors: Lemke Daniel S. , Young Ann L , Won Sharon K. , Rus Marideth C. , Villareal Nadia N. , Camp Elizabeth A. , Doughty Cara 
Published: October 2021

AbstractBackgroundThe optimal structure of simulation to train teams to perform pediatric advanced life support (PALS) requires further research. Most simulation is structured with an uninterrupted scenario with postsimulation debriefing (PSD). Rapid‐cycle deliberate practice (RCDP) is structured with a series of simulations with microdebriefing quickly switching within action targeting specific performance goals.ObjectiveThe objective was to compare team performance immediately after training, as well as learner workload, for teams trained using either PSD or RCDP.MethodsIn 2018–2019, a total of 41 interprofessional teams of 210 residents and nurses were recruited from 250 eligible participants (84%) and randomized into either arm (RCDP or PSD) teaching the same objectives of resuscitation of a patient in PEA arrest, in the same time frame. The structure of the simulation varied. Demographic surveys were collected before training, the National Aeronautics and Space Administration‐Task Load Index (NASA‐TLX) was administered immediately after training to assess workload during training and performance was assessed immediately after training using a pulseless ventricular tachycardia arrest with the primary outcome being time to defibrillation.ResultsThirty‐nine teams participated over a 16‐month time span. Performance of teams randomized to RCDP showed significantly better time to defibrillation, 100 s (95% confidence interval [CI] = 90–111), compared to PSD groups, 163 s (95% CI = 120–201). The workload of the groups also showed a lower total NASA‐TLX score for the RCDP groups.ConclusionsFor team‐based time‐sensitive training of PALS, RCDP outperformed PSD. This may be due to a reduction in the workload faced by teams during training.
Selective forces on the maintenance of outcrossing in an almost exclusively cleistogamous violet species
Authors: Seguí Jaume , Hervías‐Parejo Sandra , Traveset Anna 
Published: October 2021

AbstractPremiseCleistogamous species constitute interesting study systems to resolve the longstanding question of how outcrossing is maintained given that seed production is ensured through selfing. In this work, we investigate the selective forces that allow the persistence of producing self‐pollinated cleistogamous (CL) and chasmogamous (CH) flowers inViola jaubertianaMarès & Vigin.MethodsWe monitored three populations at different elevation for two years, and studied the flowering phenology and the relative contribution of each flower morph to parental fitness. We tested whether allocation to CH and CL flowers differed across populations and if it covaried with herbivory and water stress conditions. We also performed hand‐pollination and bagging experiments in CH flowers to estimate inbreeding depression and heterosis.ResultsThe CH flowers open in winter under unfavorable conditions for pollination, show high pollen limitation and no‐delayed selfing, and thus produce a low amount of seeds. Conversely, CL flowers appear in early spring, are physiologically cheaper to produce (i.e., dry weight is 3.4 times lower than that of CH flowers), and yield approximately 100 times more seeds than CH flowers. The CH flowers were favored under water stress and low herbivory. Crosses between populations showed up to 25% greater fitness than those within populations.ConclusionsDespite the great pollen limitation in CH flowers, we suggest that the interaction among different environmental determinants and heterosis are probably sufficient forces to maintain chasmogamy in this long‐lived species, reducing deleterious fixed mutations in the selfed lines.
Strain‐Induced Magnetism in MSi2N4 (M = V, Cr): A First‐Principles Study
Authors: Li Yingmei , Wang Jing , Yang Guochun , Liu Yong 
Published: October 2021

AbstractThe discovery of ferromagnetic 2D van der Waals (vdW) materials has opened up opportunities for exploring and harnessing magnetism in low‐dimensional limit, and developing innovative paper‐like spintronic devices. Stress engineering demonstrates unique advantages in regulating material properties, especially for 2D materials. With the aid of first‐principles calculations, the effectiveness of strain engineering for modulating the electronic and magnetic properties of MSi2N4 (M = V, Cr) monolayers from a new family of layer‐structured 2D vdW materials is explored. Their magnetic configurations are effectively tuned via the uniaxial and biaxial tensile strain of in‐plane lattice vectors. VSi2N4 exhibits half‐metallic ferromagnetic character, whereas CrSi2N4 is prone to be antiferromagnetic (AFM), which is rationalized from the competition between the direct metal–metal AFM interaction and the 900 ferromagnetic superexchange. More intriguingly, VSi2N4 demonstrates a high magnetic ordering temperature of 285 K, which is close to room temperature. The predicted appealing properties of VSi2N4 under strain await experimental confirmation.
Molybdän‐vermittelte N2‐Spaltung und Funktionalisierung in Gegenwart eines koordinierten Alkins
Authors: Wagner Hannah K. , Wadepohl Hubert , Ballmann Joachim 
Published: October 2021

AbstractEs wird von einem neuen [PCCP]Mo‐Pincerkomplex mit einem koordinierten Alkin berichtet, der zur Spaltung von molekularem Stickstoff eingesetzt wurde. Das, im Liganden fixierte η2‐Alkin blieb während dieser Reduktion verschont. DFT‐Rechnungen deuten darauf hin, dass die Reaktion über einen zunächst generierten terminalen N2‐Komplex verläuft, der dann in ein di‐nukleares μ‐(η1:η1)‐N2‐verbrücktes Intermediat überführt wird, bevor es zum N−N‐Bindungsbruch kommt. Die Protonierung, Alkylierung und Acylierung des hierbei gebildeten Molybdännitrido‐Komplexes führte zu den entsprechenden N‐funktionalisierten Imido‐Komplexen. Im Zuge einer nachgelagerten Oxidation des N‐acylierten Imido‐Derivats in MeCN kam es zur C−C‐Kupplung von MeCN und zum Aufbau eines Fumaronitril‐Fragments, welches zwei Molybdänzentren verbrückt. Die wichtige Erkenntnis, dass die starke N≡N‐Bindung in Gegenwart einer schwächeren, aber entsprechend fixierten C≡C‐Bindung gespalten werden kann, widerspricht der weit verbreiteten Denkweise, dass koordinierte Alkine stets reaktiver sind als gasförmiger Stickstoff.
La3Ga3Ge2S3O10: An Ultraviolet Nonlinear Optical Oxysulfide Designed by Anion‐Directed Band Gap Engineering
Authors: Yan Hong , Matsushita Yoshitaka , Yamaura Kazunari , Tsujimoto Yoshihiro 
Published: October 2021

AbstractChalcogenide‐containing compounds have been widely studied as infrared nonlinear optical (NLO) materials. However, they have never been applied in the ultraviolet (UV) region owing to the high energy levels of chalcogen anions, leading to band gap narrowing. We report the synthesis of a new UV NLO oxysulfide La3Ga3Ge2S3O10 with an exceptionally wide band gap of 4.70 eV due to from the unique anion‐ordered frameworks comprising 1D 1∞[(Ga3/5Ge2/5)3S3O3] triangular tubes and 0D (Ga3/5Ge2/5)2O7 dimers of corner‐sharing (Ga/Ge)S2O2 and (Ga/Ge)O4 tetrahedra, respectively. Second harmonic generation (SHG) measurements revealed that La3Ga3Ge2S3O10 was phase matchable with twice the SHG response of KH2PO4. The results of theoretical calculations suggest that the strong SHG response is mainly attributable to the S‐3p and O‐2p orbitals in the occupied states. The anion‐directed band‐gap engineering may give insights into the application of NLO oxychalcogenides in the UV regions.
Molybdenum‐Mediated N2‐Splitting and Functionalization in the Presence of a Coordinated Alkyne
Authors: Wagner Hannah K. , Wadepohl Hubert , Ballmann Joachim 
Published: October 2021

AbstractA new [PCCP]‐coordinated molybdenum platform comprising a coordinated alkyne was employed for the cleavage of molecular dinitrogen. The coordinated η2‐alkyne was left unaffected during this reduction. DFT calculations suggest that the reaction proceeds via an initially generated terminal N2‐complex, which is converted to a dinuclear μ‐(η1:η1)‐N2‐bridged intermediate prior to N−N bond cleavage. Protonation, alkylation and acylation of the resulting molybdenum nitrido complex led to the corresponding N‐functionalized imido complexes. Upon oxidation of the N‐acylated imido derivative in MeCN, a fumaronitrile fragment was built up via C−C coupling of MeCN to afford a dinuclear molybdenum complex. The key finding that the strong N≡N bond may be cleaved in the presence of a weaker, but spatially constrained C≡C bond contradicts the widespread paradigm that coordinated alkynes are in general more reactive than gaseous N2.
Taming the Lewis Superacidity of Non‐Planar Boranes: C−H Bond Activation and Non‐Classical Binding Modes at Boron
Authors: Osi Arnaud , Mahaut Damien , Tumanov Nikolay , Fusaro Luca , Wouters Johan , Champagne Benoît , Chardon Aurélien , Berionni Guillaume 
Published: October 2021

AbstractThe rational design of a geometrically constrained boron Lewis superacid featuring exceptional structure and reactivity is disclosed. It enabled the formation of non‐classical electron deficient B−H−B type of bonding, which was supported by spectroscopic and structural parameters as well as computational studies. Taming the pyramidal Lewis acid electrophilicity through weak coordinating anion dissociation enabled a series of highly challenging chemical transformations, such as Csp2−H and Csp3−H activation under a frustrated Lewis pair regime and the cleavage of Csp3−Si bonds. The demonstration of such rich chemical behaviour and flexibility on a single molecular compound makes it a unique mediator of chemical transformations generally restricted to transition metals.
Copper‐Catalyzed 1,2‐Trifluoromethylation Carbonylation of Unactivated Alkenes: Efficient Access to β‐Trifluoromethylated Aliphatic Carboxylic Acid Derivatives
Authors: Wu Fu‐Peng , Yuan Yang , Wu Xiao‐Feng 
Published: October 2021

AbstractA novel copper‐catalyzed carbonylative trifluoromethylation of unactivated alkenes has been developed. A broad range of β‐trifluoromethylated carboxylic acid derivatives were prepared in moderate to excellent yields from simple alkenes with excellent regioselectivity. It is noteworthy that ethylene gas, as the simplest olefin, can also be applied directly to obtain β‐trifluoromethylated amides and ester. This transformation presents the first example on carbonylative trifluoromethylation of alkenes.
Polysulfone membranes with the improved antibacterial property via surface co‐deposition of dopamine and sodium polystyrene sulfonate
Authors: Zhang Yan , Chen Bin , Zhao Haichao , Zhu Lijing 
Published: October 2021

AbstractMussel‐inspired dopamine (DA) surface modification has been widely recognized as a promoting strategy to design and exploit valuable multifunctional materials. Herein, polysulfone porous membrane was modified by the co‐deposition of DA and sodium polystyrene sulfonate. In the case of extended duration of the reaction time, the water contact angle of the membrane decreased by 30 ° and the color of the modified membrane presented dark. The rejection rates of bovine serum albumin and lysozyme can close to 100% of the modified membrane and the bacteriostatic rate reached 100% at 18 h. In addition, the co‐deposited membrane performed well bactericidal and excellent antiadhesion to Escherichia coli. This work provides a simple way for the fabrication of an antibacterial surface.
Study on electroactive shape memory behaviors of polyvinyl alcohol/waterborne polyurethane/short carbon fiber composites
Authors: Lin Liulan , Xu Yi , Sun Zhanli 
Published: October 2021

AbstractThe properties of electroactive shape memory composites fabricated from polyvinyl alcohol (PVA) and waterborne polyurethane (WPU) filled with short carbon fibers (SCFs) were studied. The addition of WPU effectively enhanced the elongation property and reduced the glass transition temperature. The elongation at break of the composites doubled, with a maximum content of WPU at nearly 50%. The tensile strength of the samples increased first and then decreased, reaching the maximum when the content of WPU was 10%. At the same time, the sample with WPU content of 10% showed the best electrical properties and the speed of response to external stimuli was faster. However, with the increase of WPU, the shape fixity ratio and the shape recovery ratio of the composites slightly dropped. Further, a reciprocating deformable robot was designed without adding any other materials, which could move forward under the action of alternating electric field. The above results indicated that the composites blended with an appropriate content of WPU could offer the possibility for the potential application in the field of soft robot.
Effect of varying polydimethylsiloxane chain length and content on the adhesion and thermal properties of polydimethylsiloxane‐grafted acrylic pressure‐sensitive adhesives
Authors: Park Hee‐Woong , Seo Hyun‐Su , Kwon Kiok , Shin Seunghan 
Published: October 2021

AbstractAcrylic pressure‐sensitive adhesive (acrylic PSA) has advantages such as high adhesion, low cost, and high light transmittance, but it has a low adhesion to low‐surface‐energy substrates and low thermal stability. To solve these problems, PSA was modified with low surface energy moieties and crosslinked by UV curing. In this study, a polydimethylsiloxane (PDMS) structure with a low surface energy and good thermal properties was introduced into PSA through grafting polymerization to compensate for the disadvantages of acrylic PSA. PDMS‐grafted acrylic PSAs (PGPs) were synthesized by grafting through method using macromonomers with PDMS of three different lengths. They showed improved loop tack and 180° peel strength values on polypropylene, a low‐surface‐energy substrate. However, when a long PDMS‐based macromonomer (Mw ~ 5000) was used, phase separation was observed even at a low concentration, and the degree of improvement was decreased. The peel strength of PGPs significantly changed with dwelling time. As the surface energy difference between the substrate and PSA increased, the peel strength increased dramatically with dwelling time. 90° peel strengths measured with varying temperature (25–100°C) showed that a long PDMS chain was most effective in improving the thermal stability of the acrylic PSA by its own domains.
SMC/TPE bi‐layer configurations for structural vibration damping applications
Authors: Burgoa Aizeti , Lekube Blanca , Zulueta Kepa 
Published: October 2021

AbstractSheet molding compounds (SMCs) have considerable potential as lightweight alternative to traditional materials used in automotive components. However, despite their outstanding mechanical properties, their vibration damping characteristics are often relatively poor for several applications. Therefore, enhancing the vibration damping capability of SMCs represents a field with increasing interest. Application of viscoelastic layers to high stiffness materials, such as SMCs, represents an effective approach to add vibration damping functionalities to lightweight structural components. In this work, the incorporation of thermoplastic elastomers (TPEs) is studied as a novel strategy to enhance the structural vibration damping capability of SMCs. Several types of SMC and TPEs have been considered and the effect of TPE‐SMC thickness ratio on the damping and stiffness properties is investigated. The viscoelastic properties and vibration damping performance were evaluated by dynamic mechanical analysis. The effect of TPE addition on stiffness was studied by three‐point bending. Results reveal the potential of the incorporation of thin TPE layers as cost‐effective strategy to enlarge the vibration damping efficiency of SMCs while maintaining their overall high stiffness. It is expected that the bi‐material configurations presented in the current study will contribute to advance the development of new lightweight multi‐functional solutions for modern transport applications.
Modelling and predicting freshwater mussel distributions in the Midwestern USA
Authors: Schartel Tyler E. , Cao Yong , Henning Bridget , Feng Mei‐Ling , Hinz Leon C. 
Published: October 2021

AbstractHistorically diverse and abundant freshwater mussel communities in the Midwestern USA, as elsewhere in the world, are in substantial decline. An understanding of mussel distributions, habitat requirements and biodiversity is required to develop and optimize mussel conservation efforts.Maxent was used to generate species distribution models (SDMs) based on a wide range of environmental variables. Binary predictions were generated using two approaches. Species richness (SR) was estimated through model stacking and evaluated with an independent dataset derived from intensive sampling. Two measures of species endemism were estimated. Factors important for mussel occurrence were identified and geospatial analyses characterized spatial patterns of predicted SR and endemism at multiple spatial scales.SDMs generally performed at ‘fair’ or better levels (0.7 < AUC < 1). Stream size, climate and land use were important to mussel occurrence. SR estimates were positively and significantly correlated with observed SR in a separate dataset. SR and endemism hot and cold spots varied across spatial scales.This study introduces a novel background selection process for aquatic SDMs that considers sampling biases, species records relative to stream size and species' geographical ranges. The results provide valuable insight into species status and distributions, important and actionable factors influencing mussel occurrence, and spatial patterns of highly diverse or endemic regions. This study demonstrates how synthesizing SDMs can inform regional, multi‐species efforts for conserving freshwater mussel diversity.
A creeping threat? Introduced Macquarie turtles and the future of endangered helmeted turtles in southern Australia
Authors: Chessman Bruce C. 
Published: October 2021

Abstract

The introduction of freshwater turtle species outside their natural ranges may threaten native turtles through competition for resources such as food or basking sites, hybridization, and transmission of diseases or parasites.
The three southern species of Australian helmeted turtles (Myuchelys bellii, Myuchelys georgesi, and Myuchelys purvisi) had no or minimal distributional overlap with the widespread Australian Macquarie turtle, Emydura macquarii, until about 30 years ago. Since that time, E. macquarii has been introduced within the ranges of all three Myuchelys spp., possibly through the release or escape of pet turtles.
The occurrence, catch per unit effort, and population structure of E. macquarii were compared among four introduced populations within the ranges of southern Myuchelys spp. and four native populations. The aim was to provide insight into the status of the introduced populations, their likely current impact on Myuchelys spp., and their potential for future increase.
Data analysis suggested that the introduced populations of E. macquarii are at varying stages of the invasion process and not yet severe threats to Myuchelys spp. However, continuing proliferation of introduced E. macquarii is likely, potentially placing intensifying pressure on Myuchelys populations in the long term.
Research is needed on interactions of E. macquarii and Myuchelys spp. and their comparative competitive abilities in order to inform the difficult policy decision of whether invasive E. macquarii should be removed or controlled.