bluuebunny/crossref_metadata_2025_split huggingface dataset:
Broadband Cr3+, Sn4+‐Doped Oxide Nanophosphors for Infrared Mini Light‐Emitting Diodes
Authors: Huang Wen‐Tse , Cheng Chiao‐Ling , Bao Zhen , Yang Chia‐Wei , Lu Kuang‐Mao , Kang Chieh‐Yu , Lin Chih‐Min , Liu Ru‐Shi 
Published: December 2018

AbstractLight‐emitting diodes break barriers of size and performance for displays. With devices becoming smaller, the materials also need to get smaller. Chromium(III)‐doped oxide phosphors, which emit near‐infrared (NIR) light, have recently been used in small electronic devices. In this work, mesoporous silica nanoparticles were used as nanocarriers. The nanophosphor ZnGa2O4:Cr3+,Sn4+ formed in the mesopore after sintering. Good dispersity and morphology were performed with average diameters of 71±7 nm. It emitted light at 600–850 nm; the intensity was optimized by tuning the doping ratio of Cr3+ and Sn4+. Meanwhile, the light conversion efficiency increased from 7.8 % to 37 % and the molar concentration increased from 0.125 m to 0.5 m. The higher radiant flux of 3.3 mW was obtained by operating an input current of 45 mA. However, the NIR nanophosphor showed good performance on mini light‐emitting diode chips.
The Nature of Hydrogen Adsorption on Platinum in the Aqueous Phase
Authors: Yang Guoju , Akhade Sneha A. , Chen Xi , Liu Yue , Lee Mal‐Soon , Glezakou Vassiliki‐Alexandra , Rousseau Roger , Lercher Johannes A. 
Published: December 2018

AbstractThe thermodynamic state of H2 adsorbed on Pt in the aqueous phase was determined by kinetic analysis of H2 reacting with D2O to HDO, HD, and D2, and by DFT‐based ab initio molecular dynamics simulations of H2 adsorption on Pt(111), Pt(110), and Pt nanoparticles. Dissociative adsorption of H2 on Pt is significantly weakened in the aqueous phase compared to adsorption at gas–solid interfaces. Water destabilizes the adsorbed H atoms, decreasing the heat of adsorption by 19–22 kJ
while inducing an additional entropy loss of 50–70 J
K−1. Upon dissociative adsorption of H2, the average distance of water from the Pt surface increases and the liquid adopts a structure that is more ordered than before close to the Pt surface, which limits the translation mobility of the adsorbed H atoms. The presence of hydrated hydronium ions next to the Pt surface further lowers the H−Pt bond strength.
Enabling PIEZOpotential in PIEZOelectric Semiconductors for Enhanced Catalytic Activities
Authors: Wang Mengye , Wang Biao , Huang Feng , Lin Zhiqun 
Published: December 2018

AbstractThe past several decades have witnessed significant advances in the synthesis and applications of PIEZOelectric semiconductors, an important class of materials, including piezoelectric, pyroelectric, and ferroelectric semiconductors. The intriguing combination of physical and chemical phenomena in PIEZOelectric semiconductors has triggered much interest in PIEZOcatalysis, that is, catalysis enabled by PIEZOpotential (i.e., piezopotential, pyropotential, and ferropotential)‐induced built‐in electric fields, which is the focus of this Minireview. First, the PIEZOelectric materials are briefly introduced. Second, recent developments in PIEZOcatalysis are highlighted, including the introduction of representative PIEZOelectric semiconductors, their possible catalytic mechanisms, novel techniques to produce their PIEZOelectric effects during the catalytic process, and several examples of PIEZOcatalysis. Finally, the challenges in the field and exciting opportunities to further improve the PIEZOcatalytic efficiency are discussed.
Catalytic Biomimetic Asymmetric Reduction of Alkenes and Imines Enabled by Chiral and Regenerable NAD(P)H Models
Authors: Wang Jie , Zhu Zhou‐Hao , Chen Mu‐Wang , Chen Qing‐An , Zhou Yong‐Gui 
Published: December 2018

AbstractThe development of biomimetic chemistry based on the NAD(P)H with hydrogen gas as terminal reductant is a long‐standing challenge. Through rational design of the chiral and regenerable NAD(P)H analogues based on planar‐chiral ferrocene, a biomimetic asymmetric reduction has been realized using bench‐stable Lewis acids as transfer catalysts. A broad set of alkenes and imines could be reduced with up to 98 % yield and 98 % ee, likely enabled by enzyme‐like cooperative bifunctional activation. This reaction represents the first general biomimetic asymmetric reduction (BMAR) process enabled by chiral and regenerable NAD(P)H analogues. This concept demonstrates catalytic utility of a chiral coenzyme NAD(P)H in asymmetric catalysis.
Azo‐MICs: Redox‐Active Mesoionic Carbene Ligands Derived from Azoimidazolium Dyes
Authors: Chadwick F. Mark , Curchod Basile F. E. , Scopelliti Rosario , Fadaei Tirani Farzaneh , Solari Euro , Severin Kay 
Published: December 2018

AbstractAzoimidazolium dyes were used as precursors for mesoionic carbene ligands (Azo‐MICs). The properties of these ligands were examined by synthesizing RhI, AuI, and PdII complexes. Experimental (NMR, IR) and theoretical investigations show that Azo‐MICs are potent σ‐donor ligands. Yet, they feature a small singlet–triplet gap and very low‐lying LUMO levels. The unique electronic properties of Azo‐MICs allow for reversible one‐electron reductions of the metal complexes, as evidenced by cyclic voltammetry.
Transformation of Imine Cages into Hydrocarbon Cages
Authors: Schick Tobias H. G. , Lauer Jochen C. , Rominger Frank , Mastalerz Michael 
Published: December 2018

AbstractIn contrast to organic cages which are formed by exploiting dynamic covalent chemistry, such as boronic ester cages, imine cages, or disulfide cages, those with a fully carbonaceous backbone are rarer. With the exception of alkyne metathesis based approaches, the vast majority of hydrocarbon cages need to be synthesized by kinetically controlled bond formation. This strategy implies a multiple step synthesis and no correction mechanism in the final macrocyclization step, both of which are responsible for low overall yields. Whereas for smaller cages the intrinsic drawbacks are not always obvious, larger cages are seldom synthesized in yields beyond a few tenths of a percent. Presented herein is a three‐step method to convert imine cages into hydrocarbon cages. The method has been successfully applied to even larger structures such as derivatives of C72H72 , an unknown cage suggested by Fritz Vögtle more than 20 years ago.
Polystyrene bioactive nanofibers using orange oil as an ecofriendly solvent
Authors: Miranda Kelvi W. E. , Mattoso Luiz H. C. , Bresolin Joana D. , Hubinger Silviane Z. , Medeiros Eliton S. , de Oliveira Juliano E. 
Published: December 2018

ABSTRACTSolution blow spun polystyrene (PS) nanofibers were produced from 20 to 30 wt % PS solutions using toluene (industrial solvent) and orange oil (green solvent). The latter being composed of d‐limonene (97.06%) as determined by gas chromatography–mass spectroscopy. The rheological behavior and volatility of the solvents and polymer solutions were correlated with fiber morphology, accessed by scanning electron microscopy. Thermal analysis was used to determine the thermal behavior of fibers. The antimicrobial activity of orange oil was tested for potential applications of the spun mats in active food packaging. Results showed that the nanofibers spun from orange oil solutions had average diameters of 306 ± 74 nm as opposed to 441 ± 110 nm for toluene. Moreover, when compared with fiber spun from toluene solutions, orange oil yielded more flexible fibers with slightly lower contact angles and better antimicrobial properties due to the presence of residual oil confirmed by Fourier‐transform infrared spectroscopy. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47337.
Effect of solvent quality on Poiseuille flow of polymer solutions in microchannels: A dissipative particle dynamics study
Authors: Xu Shaofeng , Lou Yinghou , He Ping , Wang Xiangyang , Wang Jiugen 
Published: December 2018

ABSTRACTThe Poiseuille flows of polymer solutions for varying quality solvents in microchannels have been simulated using dissipative particle dynamics. In particular, the velocity distributions and the polymer migration across the channel have been investigated for good, athermal, and poor solvents. The velocity profiles for all three kinds of solvent deviate from the parabolic profile, and the velocity profile of the athermal solvent falls in between the good solvent and the poor solvent. For the athermal solvent, a migration away from the wall due to the hydrodynamic interactions between the chains and the wall is observed, and a migration away from the channel center due to the different chain Brownian diffusivities is also observed. For the good solvent, because of the more stretched polymer chains, the migration away from the wall is stronger than that for the athermal solvent. However, the migration away from the channel center is not observed for good solvents. For the poor solvent, the hydrodynamic interaction within the chains is screened, and the polymer chains migrate toward the wall and appear to be absorbed by the wall. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2019,136, 47345.
Assessing conservation priorities of endemic freshwater fishes in the Tropical Andes region
Authors: Tognelli Marcelo F. , Anderson Elizabeth P. , Jiménez‐Segura Luz F. , Chuctaya Junior , Chocano Luisa , Maldonado‐Ocampo Javier A. , Mesa‐Salazar Lina , Mojica José I. , Carvajal‐Vallejos Fernando M. , Correa Vanessa , Ortega Hernán , Rivadeneira Romero Juan F. , Sánchez‐Duarte Paula , Cox Neil A. , Hidalgo Max , Jiménez Prado Pedro , Lasso Carlos A. , Sarmiento Jaime , Velásquez Miguel A. , Villa‐Navarro Francisco A. 
Published: December 2018

AbstractAssessing the effectiveness of protected areas for sustaining species and identifying priority sites for their conservation is vital for decision making, particularly for freshwater fishes in South America, the global centre of freshwater fish diversity. Several conservation planning studies have used threatened freshwater fishes or species that are vulnerable to climate change as conservation targets, but none has included both in priority‐setting analysis.The objectives of this study were to identify gaps in the coverage of the existing protected areas in representing the endemic freshwater fishes of the Tropical Andes region, and to identify conservation priority areas that adequately cover threatened species and species vulnerable to climate change.Data on 648 freshwater fishes from the Tropical Andes were used to identify gaps in the protected area coverage, and to identify conservation priority sites under three scenarios: (i) prioritize threatened species; (ii) prioritize species that are vulnerable to climate change; and (iii) prioritize both threatened species and species vulnerable to climate change.A total of 571 species (88% of all species) were not covered by any protected areas; most of them are restricted to ≤10 catchments. To represent both threatened species and species vulnerable to climate change in the third scenario, 635 catchments were identified as priority areas, representing 26.5% of the study area. The number of irreplaceable catchments for this scenario is 475, corresponding to 22.5% of the total area.The results of this study could be crucial for designing strategies for the effective protection of native fish populations in the Tropical Andes, and for planning proactive climate adaptation. It is hoped that the identification of priority areas, particularly irreplaceable catchments, will help to guide conservation and management decisions in the Andean region.
Restricted movement of prairie fishes in fragmented riverscapes risks ecosystem structure being ratcheted downstream
Authors: Schumann David A. , Haag Jenna M. , Ellensohn Paige C. , Redmond Jordon D. , Graeb Katie N.B. 
Published: December 2018

Abstract

Prairie streams are dynamic systems in which habitat patches are sporadically created and lost during extreme hydrological events. The persistence of fish species depends on life‐history traits that facilitate their widespread dispersal to recolonize habitats after stochastic extirpation. Artificial barriers are thought to reduce recolonization opportunities and to ultimately displace populations downstream, but the ecological consequences of lost diversity above the barriers are largely unknown.
The susceptibility of four prairie fishes to fragmentation and the consequent risk to stream ecosystem processes are described. The selected species exhibit wide tolerances to environmental stressors, represent unique functional feeding guilds, and have different habitat affinities.
The ability of each species to access (jumping ability) and successfully traverse (swimming endurance) simulated instream barriers was quantified in the laboratory. Experimental stream complexes were used to isolate the effects of these species on ecosystem structure and function. These replicated single‐species experiments were compared with ‘no fish’ controls to identify the ecological role of each.
Small vertical barriers blocked most passage, and with open access all species were unable to traverse relatively short distances against modest water velocities. Stream fragmentation will alter headwater fish assemblage structure and promote the most mobile species. Each species had slightly different effects on the stream ecosystem structure resulting from their different habitat preferences and diets.
Without colonization opportunities from neighbouring populations, disturbance events will alter headwater fish assemblages and may degrade the ecosystem structure above barriers.
Fragmented riverscapes interact with harsh disturbance regimes to form an ecological ratchet. Systematic species loss above barriers outweighs the opportunity for improvement, suggesting that ecosystem structure may be moving downstream.
Selective Fluorescence Turn‐On Sensing of Phosphate Anion in Water by Tetraphenylethylene Dimethylformamidine
Authors: Yuan Ying‐Xue , Wang Jin‐Hua , Zheng Yan‐Song 
Published: December 2018

AbstractA tetraphenylethylene (TPE) derivative bearing two dimethylformamidine units was synthesized. The dihydrogen chloride salt of this TPE derivative was soluble in water and showed almost no emission. By addition of phosphate anions, the dihydrogen chloride salt could be transformed into the monohydrogen chloride salt, which was barely soluble and emitted strong fluorescence through aggregation‐induced emission (AIE), while many other anions could not bring about a fluorescence enhancement. Meanwhile, the dihydrogen chloride salt and monohydrogen chloride salt could be reversible transformed by addition of acid and base alternately in the presence of phosphate anion, which led to fluorescence turn‐on and turn‐off. Therefore, the TPE dimethylformamidine holds potential for selectively sensing phosphate anions in water and use as fluorescence pH switch. This study provided a new approach to AIEgen sensors by using formamidine groups.
Molecular Links and Knots from Naphthalenediimide: A Balance of Weak Interactions
Authors: Ng Antony Wing Hung , Au‐Yeung Ho Yu 
Published: December 2018

AbstractOwing to its unique structural, electronic, spectroscopic, and redox properties, naphthalenediimide (NDI) is a versatile building block for the construction of a wide variety of supramolecular assemblies with diverse structures, properties, and functions. In this Minireview, the synthesis of topologically nontrivial molecular links and knots based on naphthalenediimide‐derived building blocks will be discussed. In particular, the supramolecular forces that contribute to the formation of these molecular links and knots and their interactions will be discussed.
Multiple‐model sliding mode observer for an artificial gas lift system
Authors: Hammadih Mohammad Luai , Al Hosani Khalifa , Boiko Igor 
Published: December 2018

AbstractArtificial gas lift is widely used in the oil industry to enhance oil recovery. Active feedback control of this process would lead to its stabilization, that in some operating modes may otherwise be unstable, and to the increase of oil production. However, the control strategies are normally constrained to the use of the surface‐measured process variables. The use of down‐hole measurements would improve the performance of the control system but is technically hardly feasible due to the necessity of placing instruments in harsh conditions. The use of state observation might be a feasible alternative to the down‐hole measurements. Recent development of a new accurate model of the artificial gas lift process enables us to increase accuracy of observation due to the account of pressure and density distribution along the well depth. Besides, a new approach to a nonlinear model treatment proposed in the present paper leads to a high computational efficiency of the observer for the gas lift. The paper presents an approach to the design of a novel sliding mode observer for the gas lift process. The observer uses multiple linearized models representing deviations from a set of equilibrium points. These models are then incorporated to produce estimates for the gas lift process variables. The approach is supported by simulations.
Backstepping control of flexible joint manipulator based on hyperbolic tangent function with control input and rate constraints
Authors: Wang Lijun , Shi Qiuyue , Liu Jinkun , Zhang Dan 
Published: December 2018

AbstractIn this paper, we investigate the trajectory tracking problems of the link angle and angle speed of the flexible joint manipulator model based on external disturbance, the control input and rate constraints. The controller of the flexible joint manipulator model is designed using the backstepping control scheme. To achieve this objective, the smooth hyperbolic tangent function is used to solve the problems of control input and rate constraints, and the stability is proved using Lyapunov function in the design procedure of the backstepping control scheme. Finally, the effectiveness of the proposed backstepping controller is verified by numerical simulation.
Females who maltreat animals
Authors: Felthous Alan R. , Calhoun Amanda J. 
Published: December 2018

AbstractStudies of animal maltreatment and of untoward or abnormal aggression predominantly involve male subjects, raising the question as to whether females who engage in such behaviors are like, or fundamentally different than, their male counterparts. Inquiry to address this issue could pertain to gender similarities and differences; moreover, it could provide greater understanding of the behavior itself, in this case, animal maltreatment. Of the various patterns of animal maltreatment in the literature, there are enough studies with gender addressed to allow some observations on two patterns: animal cruelty in childhood and animal hoarding. Animal cruelty among girls may be more common than is widely assumed, but substantial recurrent cruelty appears, as expected, to be more common among males and is consistent with conduct disorder occurring more frequently among boys. Females, especially older females who live alone, predominate among animal hoarders, whose psychology is altogether different from those who engage in antisocial cruelty. The potential significance of these observations is discussed within the contexts of developmental and gender psychology.
Direct C−H Carbamoylation of Nitrogen‐Containing Heterocycles
Authors: Jouffroy Matthieu , Kong Jongrock 
Published: December 2018

AbstractNucleophilic radical additions at innately electrophilic C(sp2) centers are perfectly suited for the direct functionalization of heterocycles. Using bench stable and commercially available alkyl oxamate and oxamic acid derivatives in combination with photoredox catalysis, a direct carbamoylation of heterocycles yielding amide functionalized pharmacophores in a single step is reported. The reaction conditions reported are compatible with structurally complex heterocyclic substrates of pharmaceutical interest. Notably, derivatives containing functional groups incompatible with standard amidation reactions, such as carboxylic acids and unprotected amines, were found to be amenable to this reaction paradigm.
Risk of solid subsequent malignant neoplasms after childhood Hodgkin lymphoma—Identification of high‐risk populations to guide surveillance: A report from the Late Effects Study Group
Authors: Holmqvist Anna S. , Chen Yanjun , Berano Teh Jennifer , Sun Canlan , Birch Jillian M. , van den Bos Cor , Diller Lisa R. , Dilley Kimberley , Ginsberg Jill , Martin Laura T. , Nagarajan Rajaram , Nathan Paul C. , Neglia Joseph P. , Terenziani Monica , Tishler David , Meadows Anna T. , Robison Leslie L. , Oberlin Odile , Bhatia Smita 
Published: December 2018

AbstractBackgroundSurvivors of Hodgkin lymphoma (HL) in childhood have an increased risk of subsequent malignant neoplasms (SMNs). Herein, the authors extended the follow‐up of a previously reported Late Effects Study Group cohort and identified patients at highest risk for SMNs to create evidence for risk‐based screening recommendations.MethodsThe standardized incidence ratio was calculated using rates from the Surveillance, Epidemiology, and End Results program as a reference. The risk of SMN was estimated using proportional subdistribution hazards regression. The cohort included 1136 patients who were diagnosed with HL before age 17 years between 1955 and 1986. The median length of follow‐up was 26.6 years.ResultsIn 162 patients, a total of 196 solid SMNs (sSMNs) were identified. Compared with the general population, the cohort was found to be at a 14‐fold increased risk of developing an sSMN (95% confidence interval, 12.0‐fold to 16.3‐fold). The cumulative incidence of any sSMN was 26.4% at 40 years after a diagnosis of HL. Risk factors for breast cancer among females were an HL diagnosis between ages 10 years and 16 years and receipt of chest radiotherapy. Males treated with chest radiotherapy at age <10 years were found to be at highest risk of developing lung cancer. Survivors of HL who were treated with abdominal/pelvic radiotherapy and high‐dose alkylating agents were found to be at highest risk of developing colorectal cancer and females exposed to neck radiotherapy at age <10 years were at highest risk of thyroid cancer. By age 50 years, the cumulative incidence of breast, lung, colorectal, and thyroid cancer was 45.3%, 4.2%, 9.5%, and 17.3%, respectively, among those at highest risk.ConclusionsSurvivors of childhood HL remain at an increased risk of developing sSMNs. In the current study, subgroups of survivors of HL at highest risk of specific sSMNs were identified, and evidence for screening provided.
Beer's Law – Why Absorbance Depends (Almost) Linearly on Concentration
Authors: Mayerhöfer Thomas G. , Popp Jürgen 
Published: December 2018

AbstractBeer's law assumes a strictly linear dependence of the absorbance from concentration. Usually, chemical interactions and instrumental imperfection are made responsible for experimental deviations from this linearity. In this contribution we show that even in the absence of such interactions and instrumental errors, absorbance should be only approximately proportional to concentration. This can be derived from the quadratic dependence of the complex refractive index, and, by that, of the molar attenuation coefficient, from the dielectric constant and its frequency dispersion. Following dispersion theory, it is the variation of the real and the imaginary part of the dielectric function that depends linearly on concentration in the absence of interactions between the oscillators. We show that this linear correlation translates into a linear dependence of the absorbance for low concentrations or molar oscillator strengths based on an approximation provided by Lorentz in 1906. Accordingly, Beer's law can be derived from dispersion theory.