bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preparation of Ti3C2Tx MXene‐Derived Quantum Dots with White/Blue‐Emitting Photoluminescence and Electrochemiluminescence
Authors: Xu Gengfang , Niu Yusheng , Yang Xuecheng , Jin Zhaoyong , Wang Yao , Xu Yuanhong , Niu Haitao 
Published: October 2018

AbstractMXene‐derived quantum dots (MQDs) have begun to attract much attention recently, but their most attractive features (i.e., optical properties) are still explored less than expected. In the present work, Ti3C2Tx MQDs with solvent‐determined optical characteristics and size distributions are prepared through solvothermal treatment of Ti3C2Tx nanosheets in various solvents. White‐emitting photoluminescence (PL) under 365 nm UV irradiation is obtained in dimethyl sulfoxide (DMSO), while blue in dimethylformamide (DMF) and ethanol, respectively. Moreover, the average diameters and quantum yields of the MQDs are 3.3 ± 0.2 nm and 10.7%; 2.5 ± 0.2 nm and 6.9%; as well as 1.8 ± 0.1 nm and 4.1% in DMF, ethanol, and DMSO, respectively. Interestingly, among a variety of metal ions, Fe3+ shows specific quenching effect toward the PL of the MQDs in DMF rather than in the other two. Moreover, electrochemiluminescence of the MQDs is observed using persulfate as coreactant for the first time. The possible mechanisms are discussed based on the combined influences of polarity, oxidation effect, and boiling point of the different solvents and the various characterizations.
Palladium‐Catalyzed Regioselective Synthesis of 3‐(Hetero)Arylpropynamides from gem‐Dibromoalkenes and Isocyanides
Authors: Salehi Parvin , Shiri Morteza 
Published: October 2018

AbstractAn alternative method related to the formation of 3‐(hetero)arylpropynamides using palladium/Cs2CO3, regiochemically‐controlled coupling of isocyanides with 1,1‐dibromo‐1‐alkenes is described. It was found that the presence of palladium is crucial in the media so activated the C−Br bond in the 1,1‐dibromo‐1‐alkenes. Subsequent isocyanide insertion followed by reductive elimination yielded an intermediate that could be easily converted to the desired product in satisfactory yields.magnified image
A Moss‐Inspired Electroless Gold‐Coating Strategy Toward Stretchable Fiber Conductors by Dry Spinning
Authors: Zhao Yunmeng , Dong Dashen , Gong Shu , Brassart Laurence , Wang Yan , An Tiance , Cheng Wenlong 
Published: October 2018

AbstractStretchable fiber conductors are appealing in the field of soft electronics due to their potential to be woven into fabrics leading to smart textile electronics. Coating highly conductive metal films onto elastic polymer fibers can be a potential strategy, however, it is nontrivial to achieve strong metal/polymer adhesion to avoid interfacial failure under large mechanical strains. Here, a novel moss‐inspired gold‐coating strategy by using an ultrathin gold nanowires (AuNWs)‐seeded electroless deposition strategy to fabricate stretchable fiber conductors in a dry spinning process is reported. By optimizing Hildebrand's and Hansen's solubility parameter, the AuNWs are dispersed well in an elastomer matrix leading to the efficient scalable production of AuNWs‐impregnated elastomeric fibers. Remarkably, these AuNWs can serve as “seeds” to promote conformal electroless deposition of gold films to substantially enhance the fiber conductivity. Such gold films resemble moss exhibiting strong adhesion to elastomeric polymer fibers because they have AuNWs roots embedded in the polymer matrix. With prestrained fibers, directional cracks along the axis are found, but they can be repaired reversibly when strains are reapplied. This leads to substantial conductivity enhancement. The fiber conductors can be woven into an everyday glove to exhibit superior strain‐insensitivity without changing the intensity of the light‐emitting diode under severe deformations.
Deciphering the Cathode–Electrolyte Interfacial Chemistry in Sodium Layered Cathode Materials
Authors: Mu Linqin , Feng Xu , Kou Ronghui , Zhang Yan , Guo Hao , Tian Chixia , Sun Cheng‐Jun , Du Xi‐Wen , Nordlund Dennis , Xin Huolin L. , Lin Feng 
Published: October 2018

AbstractThe ever‐increasing demand for stationary energy storage has driven the prosperous investigation of low‐cost sodium ion batteries. The inferior long‐term cycling stability of cathode materials is a significant roadblock toward the wide commercialization of sodium ion batteries. This study enlightens a path toward empowering stable sodium ion batteries through incisive diagnostics of the multiscale surface chemical processes in layered oxide materials (e.g., O3‐NaNi1/3Fe1/3Mn1/3O2). The major challenges are unraveled in a promising sodium layered cathode material using a range of complementary advanced spectroscopic and imaging diagnostic techniques. It is discovered that the cathode–electrolyte interfacial reaction triggers transition metal reduction, heterogeneous surface reconstruction, metal dissolution, and formation of intragranular nanocracks. These surface chemistry driven processes are partly responsible for significant performance decay. This diagnostic study also rationalizes the elemental substitution and surface passivation methods that are widely applied in the field. The prepassivated and Ti‐substituted cathode materials allow for significantly improved cycling stability by inhibiting the metal dissolution. Therefore, incisively diagnosing the interfacial chemistry not only creates scientific insights into understanding sodium cathode chemistry, but also represents an advance toward establishing universal interfacial design principles for all alkali metal ion cathode materials.
Ion‐Sieving Carbon Nanoshells for Deeply Rechargeable Zn‐Based Aqueous Batteries
Authors: Wu Yutong , Zhang Yamin , Ma Yao , Howe Joshua D. , Yang Haochen , Chen Peng , Aluri Sireesha , Liu Nian 
Published: October 2018

AbstractAs an alternative to lithium‐ion batteries, Zn‐based aqueous batteries feature nonflammable electrolytes, high theoretical energy density, and abundant materials. However, a deeply rechargeable Zn anode in lean electrolyte configuration is still lacking. Different from the solid‐to‐solid reaction mechanism in lithium‐ion batteries, Zn anodes in alkaline electrolytes go through a solid‐solute‐solid mechanism (Zn‐Zn(OH)4
2−‐ZnO), which introduces two problems. First, discharge product ZnO on the surface prevents further reaction of Zn underneath, which leads to low utilization of active material and poor rechargeability. Second, soluble intermediates change Zn anode morphology over cycling. In this work, an ion‐sieving carbon nanoshell coated ZnO nanoparticle anode is reported, synthesized in a scalable way with controllable shell thickness, to solve the problems of passivation and dissolution simultaneously. The nanosized ZnO prevents passivation, while microporous carbon shell slows down Zn species dissolution. Under extremely harsh testing conditions (closed cell, lean electrolyte, no ZnO saturation), this Zn anode shows significantly improved performance compared to Zn foil and bare ZnO nanoparticles. The deeply rechargeable Zn anode reported is an important step toward practical high‐energy rechargeable aqueous batteries (e.g., Zn‐air batteries). And the ion‐sieving nanoshell concept demonstrated is potentially beneficial to other electrodes such as sulfur cathode for Li‐S batteries.
The Digital EMS California Academy of Learning: One State's Innovative Approach to EMS Fellow Education
Authors: Staats Katherine , Mercer Mary P. , Bosson Nichole , Joelle Donofrio J. , Schlesinger Shira , Sanko Stephen , Kazan Clayton , Brown John , Loza‐Gomez Angelica , Eckstein Marc , Gausche‐Hill Marianne 
Published: October 2018

AbstractIntroductionEmergency medical services (EMS) fellowships are growing in significance within the United States prehospital health care system. While fellowships represent a cornerstone of EMS subspecialty education, an individual learner's experiences are limited by local resources and practices. California EMS fellowships have developed an innovative method for expanding fellows’ educational experiences outside their immediate programs.The Innovative Education MethodEach month, fellows, fellowship directors, and local EMS medical directors from throughout the state participate in a video conference. This meeting is divided into four distinct components: book chapter presentation, board‐style question review, call review, and an EMS literature review.Chapter ReviewThe two‐volume text Emergency Medical Services: Clinical Practice and Systems Oversight has been categorized into 12 modules, one for each month of the fellowship. Every meeting, one fellow prepares a didactic presentation summarizing the highlights from that month's chapters.Question ReviewFellows each create five multiple‐choice questions and answers, based on the section reading. Questions are assessed by the group, both for informational content and for appropriate formatting. After completion, these questions are submitted for future review for the EMS fellowship in‐service examination.Call ReviewBased on that month's module topics, a call is chosen and reviewed. Regional protocol and practice differences from different systems are discussed. The online medical oversight provided and the prehospital provider performance are evaluated by the group.Literature ReviewFellows not assigned to present a call or didactic segment each choose one paper focusing on a subject relevant to the module or call. Strengths of the study design, analysis, outcomes, and relevance to EMS practice are discussed.OutcomesFellows and experienced EMS attendings are exposed to different protocol and system approaches in an interactive and accessible format. This partnership expands educational opportunities for fellows and promotes collaboration across EMS systems.
Improving the interfacial properties of carbon fiber–epoxy resin composites with a graphene‐modified sizing agent
Authors: Li Lingtong , Yan Chun , Xu Haibing , Liu Dong , Shi Pengcheng , Zhu Yingdan , Chen Gang , Wu Xiaofei , Liu Wenqing 
Published: October 2018

ABSTRACTWe successfully prepared a graphene‐modified carbon fiber (CF) sizing agent with good dispersity and stability by dispersing reduced graphene oxide (RGO) into an emulsion‐type sizing agent. RGO was obtained by the reduction of graphene oxide (GO) with the help of gallic acid. The influence of the graphene‐modified sizing agent on the interfacial properties of the CF–epoxy resin composites was investigated with microbond testing and the three‐point bending method. The results show that optimized interfacial properties were achieved when the size of the modified graphene was less than 1 μm, the content of RGO was 20 ppm, and the pH value of the sizing agent was 10.5. The interfacial shear strength of the composites reached 92.3 MPa, which was 29.6% higher than that of the composites with unmodified CFs. Compared with commercial‐CF‐fabric‐reinforced composites, the interlaminar shear strength of the composites treated with the RGO‐modified sizing agent increased by 21.5%. Both the interfacial and interlaminar failure morphologies of the composites were examined with scanning electron microscopy (SEM). The results show that a large amount of residual resin adhered to the surfaces of the CFs treated with the RGO‐modified sizing agent; this indicated good interfacial properties between the CFs and the resin matrix. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47122.
Elastic modulus of thermoplastic elastomers investigated with the instantaneous volumetric strain method
Authors: Cheng Shuai , Qian Shanhua , Huang Chuanhui , Ni Zifeng , Liu Liguo 
Published: October 2018

AbstractThe factors influencing the elastic modulus [K(t)] of thermoplastic elastomers (TPEs) were investigated under spherical indentation mode with the instantaneous volumetric strain method. The TPE samples were prepared by the hot‐pressing method, and the variation inK(t) was investigated at different thicknesses, loading forces, and spherical indenter radii (Rs). The results demonstrate that theK(t) values of the TPEs decreased nonlinearly with the depth–radius ratio. The sample thickness [H(t)] andRshowed positive and negative relationships withK(t), respectively. However, the loading force did not exhibit any significant effect onK(t). In a certain depth–radius ratio range,K(t) had strong functional relationships withH(t),R, and indentation depth. These results provide a reference for the mechanical property investigation of elastoplastic materials. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2019,136, 47181.
Influence of cenosphere on tribological properties of short carbon fiber reinforced PEEK composites
Authors: Liu Houbao , Su Xinqing , Tao Jie , Fu Renli , Yang Wenguang , You Chaoqun , Qiu Liangsheng 
Published: October 2018

ABSTRACTThis investigation focuses on the effects of cenosphere fillers on tribological properties of carbon fiber reinforced PEEK composites. Dry sliding wear behavior of 15 wt % short carbon fiber (SCF) reinforced PEEK composites filled with 5, 10, 15, and 20 wt % cenosphere was reported in this study, pure PEEK and 15 wt % SCF reinforced PEEK composites were also prepared for comparative analysis. Friction and wear experiments were conducted on a ring‐on‐block apparatus under different loads (100–400 N). The experimental results showed that all the composites exhibited lower coefficient of friction and better wear resistance than the matrix resin under different load conditions. It is noted that 10 wt % of the cenosphere particles filled SCF reinforced PEEK composites show superior tribological properties when compared to the other composites in this study. The morphologies of the worn surface and the fracture surface were analyzed by scanning electron microscopy and the transfer film was observed by optical microscope to understand the dominant wear mechanisms. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47245.
Aero‐Engine DCS Fault‐Tolerant Control with Markov Time Delay Based On Augmented Adaptive Sliding Mode Observer
Authors: Zhang Ledi , Xie Shousheng , Zhang Yu , Ren Litong , Zhou Bin , Wang Hao , Peng Jingbo , Wang Lei , Li Yingjie 
Published: October 2018

AbstractWith a focus on aero‐engine distributed control systems (DCSs) with Markov time delay, unknown input disturbance, and sensor and actuator simultaneous faults, a combined fault tolerant algorithm based on the adaptive sliding mode observer is studied. First, an uncertain augmented model of distributed control system is established under the condition of simultaneous sensor and actuator faults, which also considers the influence of the output disturbances. Second, an augmented adaptive sliding mode observer is designed and the linear matrix inequality (LMI) form stability condition of the combined closed‐loop system is deduced. Third, a robust sliding mode fault tolerant controller is designed based on fault estimation of the sliding mode observer, where the theory of predictive control is adopted to suppress the influence of random time delay on system stability. Simulation results indicate that the proposed sliding mode fault tolerant controller can be very effective despite the existence of faults and output disturbances, and is suitable for the simultaneous sensor and actuator faults condition.
A New SSUKF Observer for Sliding Mode Force Tracking H∞ Control of Electrohydraulic Active Suspension
Authors: Zhang Jie , Ding Fei , Zhang Nong , Chen Shengzhao , Zhang Bangji 
Published: October 2018

AbstractCompared to passive and semi‐active suspensions, active suspensions have the capacity to overcome the tradeoff design of vehicle ride comfort and handling performance. In this paper, a new control system with modified spherical simplex UKF (SSUKF) observer and sliding mode force tracker is proposed for electrohydraulic active suspensions. The estimated states obtained from the SSUKF observer are used to derive the mode energy of body motion and design the target demanded forces for suspension actuators. A sliding mode controller is presented to drive electrohydraulic actuators to track the demanded forces. Based on a robust H∞ control method, a new control strategy depending on body mode energy is proposed to restrict body motion. The performance comparisons between passive and active suspensions under three typical excitations are presented, and the obtained results indicate that the proposed control system can significantly depress body motion and decrease the mode energy to improve ride comfort and also effectively enhance the road hold abilities.
Atypical longitudinal development of functional connectivity in adolescents with autism spectrum disorder
Authors: Lawrence Katherine E. , Hernandez Leanna M. , Bookheimer Susan Y. , Dapretto Mirella 
Published: October 2018

Autism spectrum disorder (ASD) is consistently associated with alterations in brain connectivity, but there are conflicting results as to where and when individuals with ASD display increased or reduced functional connectivity. Such inconsistent findings may be driven by atypical neurodevelopmental trajectories in ASD during adolescence, but no longitudinal studies to date have investigated this hypothesis. We thus examined the functional connectivity of three neurocognitive resting‐state networks—the default mode network (DMN), salience network, and central executive network (CEN)—in a longitudinal sample of youth with ASD (n = 16) and without ASD (n = 22) studied during early/mid‐ and late adolescence. Functional connectivity between the CEN and the DMN displayed significantly altered developmental trajectories in ASD: typically developing (TD) controls—but not youth with ASD—exhibited an increase in negative functional connectivity between these two networks with age. This significant interaction was due to the ASD group displaying less negative functional connectivity than the TD group during late adolescence only, with no significant group differences in early/mid‐adolescence. These preliminary findings suggest a localized age‐dependency of functional connectivity alterations in ASD and underscore the importance of considering age when examining brain connectivity. Autism Research 2019, 12: 53–65. © 2018 International Society for Autism Research, Wiley Periodicals, Inc.Lay SummaryBrain connectivity may develop differently during adolescence in youth with autism spectrum disorder (ASD). We looked at changes in brain connectivity over time within individuals and found that, for some brain regions, adolescents with ASD did not show the same changes in brain connectivity that typically developing adolescents did. This suggests it is important to consider age when studying brain connectivity in ASD.
Pre‐screening of sleep‐disordered breathing after stroke: A systematic review
Authors: Takala Mari , Puustinen Juha , Rauhala Esa , Holm Anu 
Published: October 2018

AbstractObjectivesSleep‐Disordered Breathing (SDB) is frequent in stroke patients. Polysomnography (PSG) and cardiorespiratory polygraphy are used to confirm SDB, but the need for PSG exceeds the available resources for systematic testing. Therefore, a simple and robust pre‐screening instrument is necessary to identify the patients with an urgent need for a targeted PSG. The aim of this systematic review was to identify and evaluate the available methods to pre‐screen stroke patients possibly suffering from SDB.Materials and MethodsEleven studies out of 3,561 studies met the inclusion criteria. The selected studies assessed the efficiency of seven instruments based on the data acquired clinically or by inquiries (Berlin Questionnaire, Epworth Sleepiness Scale, SOS, Modified Sleep Apnea Scale of the Sleep Disorders Questionnaire, STOP‐BANG, Four‐variable Screening Tool and Multivariate Apnea Index) and three physiological measures (capnography, nocturia, nocturnal oximetry). The instruments were used to predict SDB in patients after acute or subacute stroke. Either PSG or cardiorespiratory polygraphy was used as a standard to measure SDB.ResultsNo independent studies using the same questionnaires, methods or criteria were published reducing generalizability. Overall, the questionnaires were quite sensitive in finding SDB but not highly specific in identifying the non‐affected. The physiological measures (capnography) indicated promising results in predicting SDB, but capnography is not an ideal pre‐screening instrument as it requires a specialist to interpret the results.ConclusionsThe results of pre‐screening of SDB in acute and subacute stroke patients are promising but inconsistent. The current pre‐screening methods cannot readily be referred to clinicians in neurologic departments. Thus, it is necessary to conduct more research on developing novel pre‐screening methods for detecting SDB after stroke.
Implementing gamification in a university‐level UML modeling course: A case study
Authors: Jurgelaitis Mantas , Čeponienė Lina , Čeponis Jonas , Drungilas Vaidotas 
Published: October 2018

AbstractThe paper analyses the effect of applying gamification in a course for undergraduate computer science students in the Faculty of Informatics at Kaunas University of Technology. The course teaches Unified Modelling Language (UML) and its application in the Unified Process for software development. In this paper, the gamified course metamodel is presented, and it specifies a level‐based course structure as well as other gamification elements used in the course, such as points and other types of rewards (coins, items, and badges), the leaderboard, content locking and trading. The gamified course was implemented on Moodle platform, and the experiment was carried out during spring semester 2018. The analysis of students’ grades confirms the hypothesis which states that students’ grades can increase as a result of applying gamification to their learning process. The results of students’ questionnaire (based on the Intrinsic Motivation Inventory scale) also confirm the hypothesis which states that gamification can improve students’ motivation.
Nanostructured Pd−Cu Catalysts Supported on Zr−Al and Zr−Ti for Synthesis of Vinyl Acetate
Authors: Gonzalez Caranton Alberth Renne , Dille Jean , Barreto Jade , Stavale Fernando , Pinto José Carlos , Schmal Martin 
Published: October 2018

AbstractRenewable ethylene can be obtained by dehydration of bio‐ethanol and used for production of vinyl acetate (VAM) through reaction with acetic acid (AcOH), using Pd−Cu catalysts. In the present manuscript, structural characterizations of Pd−Cu/ZrO2 catalysts show that these systems present cubic structure with different spatial distributions. Particularly, it is shown that combustion of ethylene and acetic acid can be inhibited below 180 °C, maximizing the rates of VAM formation, when the catalysts are modified with Ti+4. The effects of AcOH concentration on rates of VAM formation show that higher AcOH concentrations favor the formation of undesired byproducts, while lower AcOH concentrations favor effects related to O2 mobility, which can lead to surface decomposition. VAM formation is favored, with selectivities ranging from 0.8 to 1.0. XPS results indicate the existence of metallic Pd, CuO species and Zr species, in agreement with IR results. DRIFTS results also show that different Pd‐acetate intermediates can be present, depending on the electronic effects associated to Pd−Cu and Zr species.
NIS/TBHP Induced Regioselective Selenation of (Hetero)Arenes via Direct C−H Functionalization
Authors: Ding Chaochao , Yu Yuanzu , Yu Qiongli , Xie Zixin , Zhou Yan , Zhou Jianmin , Liang Guang , Song Zengqiang 
Published: October 2018

AbstractA simple and efficient method for the regioselective selenation of (hetero)arenes via direct C−H functionalization has been established using NIS and TBHP. The present protocol is compatible with different functional groups, and suitable for various (hetero)arenes and diselenides, efficiently affording the desired products in moderate to excellent yields.