bluuebunny/crossref_metadata_2025 huggingface dataset:
El plástico en el arte popular y en el arte moderno contemporáneo en Guatemala
Authors: García Escobar Carlos René
Published: February 2016

Desde el pasado siglo XX, específicamente después de la II Guerra Mundial, Centro América, como muchos territorios nacionales del llamado III Mundo o también como parte de los denominados países subdesarrollados, ha sufrido con más intensidad que nunca la penetración desmedida y abusiva de los intereses económicos y políticos de las potencias autodenominadas “superdesarrolladas” en términos de penetración de sus mercados de productos industrializados, en el contexto de sus modernas tecnologías auxiliándose del usufructo de aranceles de exportación/importación favorables a las megaindustrias mono y polipólicas, en desmedro de las pobres y débiles economías de estos pueblos tercermundistas.
Los bienes temporales de la iglesia: tesoros sagrados para la comunidad cristiana y tesoros culturales para los pueblos
Authors: Marcelino Regalado Roque
Published: February 2016

“La visión antropomórfica en las religiones como fundamento de la expresión artística de la fe”En la mayoría de religiones el hombre siempre ha expresado las realidades trascendentes con una visión antropomórfica.En especial en el judaísmo como en el cristianismo, esta visión ha llevado a atribuir características a Dios que han inspirado la representación plástica del mismo. Así, cuando se describe en los textos sagrados que Dios oye, ve, camina con su pueblo, abraza, golpea, tiene una espada en su mano, etc.Son expresiones de la cercanía de la trascendencia de Dios. Esta expresión plástica con el paso del tiempo en el cristianismo tomó forma en las artes occidentales de tal manera que la cultura plástica de los pueblos se vio revestida de sacralidad.Sin embargo, con la llegada de la cultura moderna, con su producción en masa y la visión de lo desechable, nos ha hecho perder el valor de lo sagrado y de lo cultural. Es necesario recobrar el espíritu de la humanidad y los valores que de la cultura y la fe emanan.
José Martí en la hora de la integración latinoamericana y caribeña
Authors: Prada Pedro P.
Published: February 2016

Pido ante todo transmitir un afectuoso saludo a nuestro amigo, el Dr. José Mauricio Loucel, Presidente de la Junta General Universitaria, a quien debemos este feliz encuentro. Igualmente, ruego saludar al Sr. Rector, Ing. Nelson Zárate.Agradezco profundamente a la Universidad Tecnológica de El Salvador la decisión de acoger hoy, 28 de enero de 2013, este evento dedicado a rendir tributo a un ser humano excepcional y a sus ideas; que nació en Cuba, vivió, padeció y murió por ella, pero cuyo legado pertenece por derecho propio a todos los pueblos de Nuestra América y a la humanidad entera, a la que declaró como su Patria.
La política rural de mejoramiento social del general Maximiliano Hernández Martínez y sus contradicciones, 1932-1944
Authors: Sevillano Payés Dennis Francisco
Published: February 2016

La vida de los jornaleros-colonos y estacionarios en las fincas y haciendas, entre 1920 y 1932, era paupérrima. Un ejemplo de lo mencionado es que para 1930 los jornaleroscolonos y estacionarios sin tierras eran alrededor de 50.000, solamente en la zona occidental, que representaban, de acuerdo con Jeffrey Gould y Aldo Lauria, el 18 % de la población rural del occidente del país, y quienes vivían en su mayoría en las fincas productoras de café.El aumento de este sector rural se debió a la expansión de la superficie cultivada de café, que ocasionó la reconcentración de las pequeñas propiedades de campesinos que se dedicaban a cultivos de granos básicos en pequeña escala, en fincas cafetaleras latifundistas y a las malas condiciones económicas de estos campesinos, que habían sido favorecidos con tierras durante las reformas liberales de finales del siglo XIX; que no pudieron pagar sus tierras por falta de acompañamiento técnico y económico gubernamental, y que se vieron obligados a venderlas o hipotecarlas, con cafetaleros con mayor poder adquisitivo.Entre las diferentes formas de pérdida de las pequeñas propiedades estaban las deudas contraídas con los cafetaleros y hacendados o por presiones, que obligaban a los campesinos colindantes con sus propiedades a vender sus tierras, con la promesa de que estos se quedaran en sus fincas o haciendas como colonos.
El sitio arqueológico Cinacantan. Primer levantamiento indígena en Cuscatlán
Authors: Gallardo Mejía Francisco Roberto
Published: February 2016

Cinacantan es uno de los sitios arqueológicos históricos más importantes y representativos en El Salvador.Su relevancia no solamente radica en que aquí ocurrió una de las batallas mejor documentadas entre españoles y nativos en nuestro territorio, sino también en que este acontecimiento puede considerarse como el primer levantamiento indígena en Cuscatlán.El lugar exacto donde ocurrió esta batalla fue olvidado y se mantuvo desconocido para los investigadores hasta que fue identificado en el año 1999 en un peñón sobre la cordillera del Bálsamo, municipio de Tamanique.Tal y como lo afirma Lardé y Larín (2000), conocer la ubicación exacta del antiguo pueblo y fortaleza de Cinacantan es de vital interés en la reconstrucción histórica y los orígenes de la nacionalidad salvadoreña.
Huertos en flor
Authors: Molina Tamacas Carmen
Published: February 2016

Nueva York está entre los cuatro destinos más importantes para los inmigrantes centroamericanos desde los años 60. Cientos de miles de hombres y mujeres que dejaron la tierra que los vio nacer, ahora ven sus huertos florecer: hijos profesionales, nietos y hasta bisnietos que aportan al desarrollo de la comunidad hispana en Nueva York.De acuerdo con los censos de población estadounidense de 2000 y 2009, el estado se ubica en el tercer lugar de la migración salvadoreña, después de California y Texas; para los hondureños y guatemaltecos, es el cuarto destino predilecto. En el caso de los hondureños, después de Texas, Florida y California. Para los guatemaltecos, después de California, Florida y Texas.El flujo migratorio, especialmente del Triángulo Norte de Centroamérica (Guatemala, El Salvador y Honduras), es reciente, comparado con el de otros países pioneros como Puerto Rico, de acuerdo con el estudio “US Immigration Policy and Mexican /Central American Migration Flows: Then and Now, del Migration Policy Institute y el Woodrow Wilson International Center for Scholars”.
Claribel Alegría: mujer que se compromete. Cenizas de Izalco: obra que delata
Authors: Vilá de Lara Ana Cecilia
Published: February 2016

En este artículo se exploran los acontecimientos sociales y los momentos de violencia en El Salvador, particularmente en el año clave de 1932, en la novela de Cenizas de Izalco de Claribel Alegría.A través de un acercamiento de género, se explora cómo Alegría usa la representación tradicional de la mujer, como la mejor manera de poner en evidencia las injusticias sociales ante el lector.
Ríos San Francisco y San Agustín: ejes de memoria e historia de la ciudad de Bogotá, Colombia
Authors: Santos Moreno Juanita
Published: February 2016

El presente artículo pretende dar una mirada patrimonial hacia los ríos San Francisco y San Agustín, trascendiendo de su significado como “recursos naturales” propios de un territorio —en este caso la ciudad de Bogotá (Colombia), la cual es atravesada por sus cauces de oriente a occidente—, para ser interpretados como elementos de comprensión histórica de la evolución de una región y como ejes de evocación de la memoria capitalina.Por lo anterior, la investigación se aborda, en primer lugar, con el desarrollo de un marco teórico-conceptual a partir de las nociones de patrimonio cultural y patrimonio natural y sus indivisibles relaciones conforme a la trayectoria histórica de los ríos.En segundo lugar, pretende contextualizar al lector sobre el territorio de estudio mediante una caracterización de los ríos y su entorno inmediato, y, así mismo, mostrar las transformaciones de los ríos San Francisco y San Agustín en los diferentes periodos para finalizar con una caracterización y especialización aproximada de las zonas en las que hoy en día se inscriben los cuerpos de agua.
La investigación histórica en los proyectos de gestión del patrimonio construido. Propuesta metodológica
Authors: García Perdigón Jorge Rolando
Published: February 2016

El presente estudio, realizado en el bienio 2007-2008 como tesis de maestría, define una propuesta metodológica para la realización de una investigación histórica en los proyectos de gestión y manejo del patrimonio edificado. Constituyendo un importante aporte, dado que las fuentes estudiadas hasta el momento solo se quedaban en brindar una guía metodológica solamente a la hora de intervenir en una edificación.Se ejemplifica su necesidad tomando como caso específico el antiguo Convento de Santa Clara de Asís, a la luz de su restauración para sede del Centro Nacional de Conservación, Restauración y Museología (Cencrem), y como edificación patrimonial donde no se aplicó correctamente el examen histórico en su proyecto de gestión. Además, la elaboración de esta investigación sobre los procedimientos metodológicos, resolvería problemas comunes a otras realidades presentes en Cuba y Latinoamérica.La propuesta parte de la definición del objeto de estudio, según la clasificación del patrimonio cultural dado por la legislación vigente, analiza la situación del estado informativo que se tiene sobre el mismo, para después realizar la investigación propiamente dicha siguiendo un orden cronológico.Finalizando con la elaboración del informe de los resultados obtenidos, para completar la base de datos históricos sobre el objeto tratado. Queda así definido, del modo más acabado posible, el acercamiento investigativo propuesto.
Carbon Price instead of Support Schemes: Wind Power Investments by the Electricity Market
Authors: Petitet Marie , Finon Dominique , Janssen Tanguy
Published: February 2016

This paper studies wind power development within electricity markets with a significant carbon price as the sole incentive. Simulation of electricity market and investment decisions by System Dynamics modelling is used to trace the evolution of the electricity generation mix over a 20-year period from an initially thermal system. A range of carbon prices is tested to determine the value above which market-driven development of wind power becomes economically possible.This requires not only economic competitiveness in terms of cost-price, but also profitability versus traditional fossil-fuel technologies. Results stress that wind power is profitable for investors only if the carbon price is significantly higher than the price required for making wind power MWh’s cost-price competitive on the basis of levelized costs. In this context, the market-driven development of wind power seems only possible if there is a strong commitment to climate policy, reflected in a stable and high carbon price. Moreover, marketdriven development of wind power becomes more challenging if nuclear is part of investment options.
Determination of Vitamin E and Vitamin A in Infant Formula and Adult Nutritionals by Normal-Phase High-Performance Liquid Chromatography: Collaborative Study, Final Action 2012.10
Authors: McMahon Adrienne ,   Collaborators:, Christiansen S , Chee F-F , Chua A , Braddock H , Gill B , De Guzman R , Kohler K , Labitan D P , Larkin G , Le Grandois J , Marceau E , Martin F , Meng Jensen S , Meyer L , Piot D , Rael L , Schimpf K , Thompson M , Torres M
Published: February 2016

The main objective of the AOAC Stakeholder Panel on Infant Formula and Adult Nutritionals (SPIFAN) project is to establish international consensus methods for infant formula and adult nutritionals, which will benefit intermarket supply and dispute resolution. A collaborative study was conducted on AOAC First Action Method 2012.10 Simultaneous Determination of 13-cis and All-trans Vitamin A Palmitate (Retinyl Palmitate), Vitamin A Acetate (Retinyl Acetate), and Total Vitamin E (α-Tocopherol and D-α-tocopherol acetate) in Infant Formula and Adult Nutritionals by Normal-Phase HPLC. Fifteen laboratories from 11 countries participated in an interlaboratory study to determine 13-cis and all-trans vitamin A palmitate (retinyl palmitate), vitamin A acetate (retinyl acetate), and total vitamin E (α-tocopherol and D-α-tocopherol acetate) in infant formula and adult nutritionals by normal-phase HPLC and all laboratories returned valid data. Eighteen test portions of nine blind duplicates of a variety of infant formula and adult nutritional products were used in the study. The matrixes included milk-based and soy-based hydrolyzed protein as well as a low fat product. Each of the samples was prepared fresh and analyzed in singlicate. As the number of samples exceeded the recommended number to be prepared in a single day, analysis took place over 2 days running 12 samples on day one and 10 samples on day two. The reference standard stock was prepared once and the six-point curve diluted freshly on each day. Results obtained from all 15 laboratories are reported. The RSDR for total vitamin A (palmitate or acetate) ranged from 6.51 to 22.61% and HorRat values ranged from 0.33 to 1.25. The RSDR for total vitamin E (as tocopherol equivalents) ranged from 3.84 to 10.78% and HorRat values ranged from 0.27 to 1.04. Except for an adult low fat matrix which generated reproducibility RSD >40% for some isomers, most SPIFAN matrixes gave results within the acceptance criteria of <16% RSD as stated in the respective Standard Method Performance Requirements.
Determination of Sodium Fluoroacetate in Dairy Powders by Liquid Chromatography–Tandem Mass Spectrometry: Single-Laboratory Validation, First Action 2015.02
Authors: Fleury Lauren M , Scahill Bryan G , Taskova Rilka
Published: February 2016

A single-laboratory validation (SLV) study was conducted for the determination of sodium fluoroacetate in dairy powders by LC-tandem MS (LC-MS/MS). Linearity of response was confirmed by analysis of samples fortified over the concentration range 0.10–100 μg/kg. The LOD was estimated to be 0.028 μg/kg (0.028 ppb) from the SD of the measured concentrations of infant formula samples fortified at 0.10 μg/kg. The corresponding LOQ calculates at 0.085 μg/kg (0.085 ppb), which ensures excellent reliability of quantification at the limit of reporting of 1.0 μg/kg (1 ppb). Repeatability and intermediate precision were estimated from the SD of the recovery of samples fortified at 0.075, 0.10, 0.20, 0.50, 1.0, and 10.0 μg/kg. The previously mentioned method performance values were established using a representative stage 2 (6–12 months) bovine infant formula, and the robustness of the method was tested by the analysis of 107 unique dairy powders and formulations fortified at 1.0 μg/kg. The data collected in this study satisfy the requirements of SLV studies established by the AOAC Stakeholder Panel on Infant Formula and Adult Nutritionals (SPIFAN), and the method was awarded First Action Official MethodSM status by the AOAC Expert Review Panel on SPIFAN Nutrient Methods (Contaminants) on March 17, 2015.
Formyl-Peptide Receptor Agonists and Amorphous SiO2-NPs Synergistically and Selectively Increase the Inflammatory Responses of Human Monocytes and PMNs
Authors: Tavano Regina , Segat Daniela , Fedeli Chiara , Malachin Giulia , Lubian Elisa , Mancin Fabrizio , Papini Emanuele
Published: February 2016

We tested whether amorphous SiO2-NPs and formylpeptide receptor (FPRs) agonists synergistically activate human monocytes and neutrophil polymorphonuclear granulocytes (PMNs). Peptide ligands specifically binding to FPR1 (f-MLP) and to FPR2 (MMK-1, WKYMVM and WKYMVm) human isoforms did not modify the association of SiO2-NPs to both cell types or their cytotoxic effects. Similarly, the extent of CD80, CD86, CD83, ICAM-1 and MHCII expression in monocytes treated with SiO2-NPs was not significantly altered by any FPRs agonist. However, FPR1 stimulation with f-MLP strongly increased the secretion of IL-1β, IL-6 and IL-8 by human monocytes, and of IL-8 by PMNs in the presence of SiO2-NPs, due to the synergic stimulation of gene transcription. FPR2 agonists also up-modulated the production of IL-1β induced by monocytes treated with SiO2-NPs. In turn, SiO2-NPs increased the chemotaxis of PMNs toward FPR1-specific ligands, but not toward FPR2-specific ones. Conversely, the chemotaxis of monocytes toward FPR2-specific peptides was inhibited by SiO2-NPs. NADPH-oxidase activation triggered by FPR1- and FPR2-specific ligands in both cell types was not altered by SiO2-NPs. Microbial and tissue danger signals sensed by FPRs selectively amplified the functional responses of monocytes and PMNS to SiO2-NPs, and should be carefully considered in the assessment of the risk associated with nanoparticle exposure.
Picturing Proportionality in Fuel Economy//Home Runs Harder to Make
Authors: Cibes Margaret
Published: February 2016

Students analyze data related to fuel efficiency and baseball to answer questions about functional relationships.
Speaking Up and Speaking Out about Gender in Mathematics
Authors: Rubel Laurie H.
Published: February 2016

Expand the focus on diversity and equity to discuss the importance of gender and sexual identity for mathematics education.
Don't Just Do the Math—Type It!
Authors: Stephens Greg
Published: February 2016

Equation editors and editing technology have a visual impact that helps students correctly design expressions.
Gauss's Method for Summation
Authors: Terry Elaine A.
Published: February 2016

Gauss's method of computing finite sums involves a pattern that can be generalized into a formula—a great introduction to inductive reasoning.
Stretching Probability Explorations with Geoboards
Authors: Wheeler Ann , Champion Joe
Published: February 2016

Peg students' knowledge about probability by using a common manipulative to connect number sense, geometry, and algebraic thinking.
A Trip to the Circus
Authors: Ferguson Christine
Published: February 2016

A trip to the circus is so much fun. You will see elephants, tightrope walkers, lions, tigers, and more! But did you know that you could also learn math while you are there? Let's see how much we can learn at the circus.
Mapping a Way to Decimal Understanding
Authors: Denton Paula
Published: February 2016

Using Cuisenaire Rods, metric measurement, and mapping, students worked collaboratively to calculate, keep records, build, and problem solve with use of decimal fractions as a key element.
Mirrors & Windows into Student Noticing
Authors: Dominguez Higinio
Published: February 2016

Learn how to help culturally diverse and socioeconomically disempowered students use problem posing to reflect their knowledge and gain insight into new knowledge.
Goldilocks an Engineer?
Authors: Hefty Lukas J.
Published: February 2016

How do you teach engineering to kindergartners? This is a fair question, given the stereotype of STEM workers as lab scientists and number crunchers; however, when approached from a wider perspective, even the youngest of children can be engineers. A framework for K–grade 12 science education defines engineering “in a very broad sense to mean any engagement in a systematic practice of design to achieve solutions to particular human problems” (NRC 2012, pp. 11–12). This aligns closely with the first of the Common Core's Standards for Mathematical Practice (SMP 1): Make sense of problems and persevere in solving them (CCSSI 2010, p. 6). Children as young as kindergarten are capable of identifying problems and designing solutions in science and mathematics, and it turns out that many fairy tales provide a rich problemsolution context.
Unique manifestations of mixed‐phase cloud microphysics over Ross Island and the Ross Ice Shelf, Antarctica
Authors: Scott Ryan C. , Lubin Dan
Published: February 2016

Spaceborne radar and lidar observations from the CloudSat and CALIPSO satellites are used to compare seasonal variations in the microphysical and radiative properties of clouds over Ross Island, Antarctica, with two contrasting Arctic atmospheric observatories located in Barrow, Alaska, and Summit, Greenland. At Ross Island, downstream from recurrent intrusions of marine air over the West Antarctic Ice Sheet and eastern Ross Ice Shelf, clouds exhibit a tendency toward the greatest geometrical thickness and coldest temperatures in summer, the largest average ice water content, IWC, at low altitude during summer and autumn, the most abundant IWC at cold mixed‐phase temperatures (−40°C <T< −20°C), and the strongest impact from ice water on the surface energy budget year round, all with likely origins in orographic lifting of marine air over complex ice sheet and mountainous terrain. Clouds over Barrow form and evolve in a contrastingly warm and moist atmosphere and on average contain the largest liquid water content and ice and liquid water effective particle radii, re, year round. In contrast, clouds observed atop the central Greenland Ice Sheet are relatively tenuous, containing the smallest IWC and ice re of all sites.
El Niño–Southern Oscillation influence on tropospheric mercury concentrations
Authors: Slemr Franz , Brenninkmeijer Carl A. , Rauthe‐Schöch Armin , Weigelt Andreas , Ebinghaus Ralf , Brunke Ernst‐Günther , Martin Lynwill , Spain T. Gerard , O'Doherty Simon
Published: February 2016

The El Niño–Southern Oscillation (ENSO) affects the tropospheric concentrations of many trace gases. Here we investigate the ENSO influence on mercury concentrations measured in the upper troposphere during Civil Aircraft for the Regular Investigation of the atmosphere Based on an Instrumented Container flights and at ground at Cape Point, South Africa, and Mace Head, Ireland. Mercury concentrations cross‐correlate with Southern Oscillation Index (SOI) with a lag of 8 ± 2 months. Highest mercury concentrations are always found at the most negative SOI values, i.e., 8 months after El Niño, and the amplitude of the interannual variations fluctuates between ~5 and 18%. The time lag is similar to that of CO whose interannual variations are driven largely by emissions from biomass burning (BB). The amplitude of the interannual variability of tropospheric mercury concentrations is consistent with the estimated variations in mercury emissions from BB. We thus conclude that BB is a major factor driving the interannual variation of tropospheric mercury concentrations.
Perceptions of low agency and high sexual openness mediate the relationship between sexualization and sexual aggression
Authors: Blake Khandis R. , Bastian Brock , Denson Thomas F.
Published: February 2016

Researchers have become increasingly interested in the saturation of popular Western culture by female hypersexualization. We provide data showing that men have more sexually aggressive intentions toward women who self‐sexualize, and that self‐sexualized women are vulnerable to sexual aggression if two qualifying conditions are met. Specifically, if perceivers view self‐sexualized women as sexually open and lacking agency (i.e., the ability to influence one's environment), they harbor more sexually aggressive intentions and view women as easier to sexually victimize. In Experiment 1, male participants viewed a photograph of a woman whose self‐sexualization was manipulated through revealing versus non‐revealing clothing. In subsequent experiments, men and women (Experiment 2) and men only (Experiment 3) viewed a photograph of a woman dressed in non‐revealing clothing but depicted as open or closed to sexual activity. Participants rated their perceptions of the woman's agency, then judged how vulnerable she was to sexual aggression (Experiments 1 and 2) or completed a sexually aggressive intentions measure (Experiment 3). Results indicated that both men and women perceived self‐sexualized women as more vulnerable to sexual aggression because they assumed those women were highly sexually open and lacked agency. Perceptions of low agency also mediated the relationship between women's perceived sexual openness and men's intentions to sexually aggress. These effects persisted even when we described the self‐sexualized woman as possessing highly agentic personality traits and controlled for individual differences related to sexual offending. The current work suggests that perceived agency and sexual openness may inform perpetrator decision‐making and that cultural hypersexualization may facilitate sexual aggression. Aggr. Behav. 42:483–497, 2016. © 2016 Wiley Periodicals, Inc.
Upconversion Luminescent Chemodosimeter Based on NIR Organic Dye for Monitoring Methylmercury In Vivo
Authors: Yang Huiran , Han Chunmiao , Zhu Xingjun , Liu Yi , Zhang Kenneth Yin , Liu Shujuan , Zhao Qiang , Li Fuyou , Huang Wei
Published: February 2016

While most luminescent organic dyes display intense Stokes fluorescence, some of them exhibit unique single‐photon frequency upconversion luminescence (FUCL). Compared to conventional anti‐Stokes luminescence of lanthanides and two‐photon excitation, FUCL materials display adjustable spectrum area and require a much lower excitation power. Although this is very beneficial for biological applications in the perspective of reducing photodamage to biological samples and photobleaching of the dyes, the utilization of FUCL for biosensing and bioimaging in vivo has not been reported. In this study, we developed a near‐infrared (NIR) rhodamine derivative (FUC‐1) as a chemodosimeter, which displays weak luminescence but undergoes thiolactone ring‐open process leading to luminescence turn‐on in response to mercury(II) cation or methylmercury with good selectivity and high sensitivity in aqueous solution. Interestingly, FUC‐1 displays particular FUCL, excitation at 808 nm leads to luminescence at 745 nm. Compared to Stokes luminescence resulted from excitation at 630 nm, the use of FUCL lowers the detection limit of Hg2+ to be 0.207 nM. FUC‐1 has been used for FUCL bioimaging of methylmercury in live cells and mice. To the best of our knowledge, this is the first example of FUCL biosensing and bioimaging in vivo using visible and NIR fluorescence of small‐molecular dyes.
A Dendrimer‐Based Electropolymerized Microporous Film: Multifunctional, Reversible, and Highly Sensitive Fluorescent Probe
Authors: Ma Hongwei , Li Feng , Li Peng , Wang Hailong , Zhang Ming , Zhang Guang , Baumgarten Martin , Müllen Klaus
Published: February 2016

A dendrimer PYTPAG2 composed of a central pyrene “core” and four exterior “arms” capped with electroactive triphenylamine is developed as an electroactive precursor to prepare fluorescent films through electropolymerization (EP). The fluorescence emission comes from the central pyrene “core” and the steric hindrance of the exterior “arms” is beneficial for the formation of microporous morphology. The stable and highly cross‐linked fluorescent EP films can be obtained even as free‐standing films. Further, these dendrimer EP films are first studied as the multifunctional fluorescent probe: the emission of EP films exposed to trinitrotoluene vapor is quenched by 82% in 120 s; while the fluorescence is increased to nearly 400% in 120 s upon exposure to benzene vapor, EP films also act as the fluorescent sensor to Fe3+ in solution and the limit of detection is obtained to be 8.5 × 10−8 m. All the above detection processes exhibit remarkable reversibility. These excellent performances are attributed to both the specific molecular features of PYTPAG2 and the intrinsic properties of EP films.
Graphene Reinforced Carbon Nanotube Networks for Wearable Strain Sensors
Authors: Shi Jidong , Li Xinming , Cheng Huanyu , Liu Zhuangjian , Zhao Lingyu , Yang Tingting , Dai Zhaohe , Cheng Zengguang , Shi Enzheng , Yang Long , Zhang Zhong , Cao Anyuan , Zhu Hongwei , Fang Ying
Published: February 2016

Transparent, stretchable films of carbon nanotubes (CNTs) have attracted significant attention for applications in flexible electronics, while the lack of structural strength in CNT networks leads to deformation and failure under high mechanical load. In this work, enhancement of the strength and load transfer capabilities of CNT networks by chemical vapor deposition of graphene in the nanotube voids is proposed. The graphene hybridization significantly strengthens the CNT networks, especially at nanotube joints, and enhances their resistance to buckling and bundling under large cyclic strain up to 20%. The hybridized films show linear and reproducible responses to tensile strains, which have been applied in strain sensors to detect human motions with fast response, high sensitivity, and durability.
Understanding the Stability for Li‐Rich Layered Oxide Li2RuO3 Cathode
Authors: Li Biao , Shao Ruiwen , Yan Huijun , An Li , Zhang Bin , Wei Hang , Ma Jin , Xia Dingguo , Han Xiaodong
Published: February 2016

Lithium‐rich layered oxides are considered as promising cathode materials for Li‐ion batteries with high energy density due to their higher capacity as compared with the conventional LiMO2 (e.g., LiCoO2, LiNiO2, and LiNi1/3Co1/3Mn1/3O2) layered oxides. However, why lithium‐rich layered oxides exhibit high capacities without undergoing a structural collapse for a certain number of cycles has attracted limited attention. Here, based on the model of Li2RuO3, it is uncovered that the mechanism responsible for the structural integrity shown by lithium‐rich layered oxides is realized by the flexible local structure due to the presence of lithium atoms in the transition metal layer, which favors the formation of O22−‐like species, with the aid of in situ extended X‐ray absorption fine structure (EXAFS), in situ energy loss spectroscopy (EELS), and density functional theory (DFT) calculation. This finding will open new scope for the development of high‐capacity layered electrodes.
Lithium–Iron Fluoride Battery with In Situ Surface Protection
Authors: Gu Wentian , Borodin Oleg , Zdyrko Bogdan , Lin Huan‐Ting , Kim Hyea , Nitta Naoki , Huang Jiaxin , Magasinski Alexandre , Milicev Zoran , Berdichevsky Gene , Yushin Gleb
Published: February 2016

Lithium–metal fluoride (MF) batteries offer the highest theoretical energy density, exceeding that of the sulfur–lithium cells. However, conversion‐type MF cathodes suffer from high resistance, small capacity utilization at room temperature, irreversible structural changes, and rapid capacity fading with cycling. In this study, the successful application of the approach to overcome such limitations and dramatically enhance electrochemical performance of Li–MF cells is reported. By using iron fluoride (FeF2) as an example, Li–MF cells capable of achieving near‐theoretical capacity utilization are shown when MF is infiltrated into the carbon mesopores. Most importantly, the ability of electrolytes based on the lithium bis(fluorosulfonyl)imide (LiFSI) salt is presented to successfully prevent the cathode dissolution and leaching via in situ formation of a Li ion permeable protective surface layer. This layer forms as a result of electrolyte reduction/oxidation reactions during the first cycle of the conversion reaction, thus minimizing the capacity losses during cycling. Postmortem analysis shows the absence of Li dendrites, which is important for safer use of Li metal anodes. As a result, Li–FeF2 cells demonstrate over 1000 stable cycles. Quantum chemistry calculations and postmortem analysis provide insights into the mechanisms of the passivation layer formation and the performance boost.
Controlling Phase Assemblage in a Complex Multi‐Cation System: Phase‐Pure Room Temperature Multiferroic (1−x)BiTi(1−y)/2FeyMg(1−y)/2O3–xCaTiO3
Authors: Mandal Pranab , Pitcher Michael J. , Alaria Jonathan , Niu Hongjun , Zanella Marco , Claridge John B. , Rosseinsky Matthew J.
Published: February 2016

A room temperature magnetoelectric multiferroic is of interest as, e.g., magnetoelectric random access memory. Bulk samples of the perovskite (1−x)BiTi(1−y)/2FeyMg(1−y)/2O3–xCaTiO3 (BTFM–CTO) are simultaneously ferroelectric, weakly ferromagnetic, and magnetoelectric at room temperature. In BTFM–CTO, the volatility of bismuth oxide, and the complex subsolidus reaction kinetics, cause the formation of a microscopic amount of ferrimagnetic spinel impurity, which complicates the quantitative characterization of their intrinsic magnetic and magnetoelectric properties. Here, a controlled synthesis route to single‐phase bulk samples of BTFM–CTO is devised and their intrinsic properties are determined. For example, the composition x = 0.15, y = 0.75 shows a saturated magnetization of 0.0097μB per Fe, a linear magnetoelectric susceptibility of 0.19(1) ps m−1, and a polarization of 66 μC cm−2 at room temperature. The onset of weak ferromagnetism and linear magnetoelectric coupling are shown to coincide with the onset of bulk long‐range magnetic order by neutron diffraction. The synthesis strategy developed here will be invaluable as the phase diagram of BTFM–CTO is explored further, and as an example for the synthesis of other compositionally complex BiFeO3‐related materials.
Tribotronic Phototransistor for Enhanced Photodetection and Hybrid Energy Harvesting
Authors: Zhang Chi , Zhang Zhao Hua , Yang Xiang , Zhou Tao , Han Chang Bao , Wang Zhong Lin
Published: February 2016

Tribotronics is a new field developed by coupling triboelectricity and semiconductor, which can drive triboelectric‐charge‐controlled optoelectronic devices by further introducing optoelectronics. In this paper, a tribotronic phototransistor (TPT) is proposed by coupling a field‐effect phototransistor and a triboelectric nanogenerator (TENG), in which the contact‐induced inner gate voltage by the mobile frictional layer is used for modulating the photodetection characteristics of the TPT. Based on the TPT, alternatively, a coupled energy‐harvester (CEH) is fabricated for simultaneously scavenging solar and wind energies, in which the output voltage on the external resistance from the wind driven TENG is used as the gate voltage of the TPT for enhancing the solar energy conversion. As the wind speed increases, the photovoltaic characteristics of the CEH including the short‐circuit current, open‐circuit voltage, and maximal output power have been greatly enhanced. This work has greatly expanded the functionality of tribotronics in photodetection and energy harvesting, and provided a potential solution for highly efficient harvesting and utilizing multitype energy.
Emerging Parallel Dual 2D Composites: Natural Clay Mineral Hybridizing MoS2 and Interfacial Structure
Authors: Peng Kang , Fu Liangjie , Ouyang Jing , Yang Huaming
Published: February 2016

MoS2/montmorillonite (MoS2/MMT) composite nanosheets have been successfully synthesized by a facile hydrothermal method, and the catalytic activities of composites are evaluated by reduction reaction of methyl orange in aqueous phase. A preparation strategy demonstrates that MoS2 can be in situ formed on the surface of MMT from Na2MoO4· and H2NCSNH2. The microstructures and morphologies characterization indicates that few‐layered MoS2 nanosheets are uniformly grown on the surface of montmorillonite, and the hydrogen bonds are formed at the interfaces. The catalytic activity of MoS2/MMT is enhanced by support of montmorillonite, which can be attribu­ted to the large surface area, more reactive sites, dispersibility of MoS2/MMT, and the synergistic adsorption property of montmorillonite. Based on density functional theory calculations, the preferred adsorption configurations of MoS2 cluster on MMT are studied. The supporting effect of MMT on MoS2 nanoparticles will lead to the anchoring of these reactive MoS2 nanoparticles on clay surface and enhance the absorption ability of MoS2 to the organics and meanwhile improving the catalytic properties of the MoS2/MMT composite. The MoS2/MMT composite nanosheets show prospective application to treat effectively wastewater of dyes.
Microwave‐Assisted Preparation of White Fluorescent Graphene Quantum Dots as a Novel Phosphor for Enhanced White‐Light‐Emitting Diodes
Authors: Luo Zhimin , Qi Guangqin , Chen Keyu , Zou Min , Yuwen Lihui , Zhang Xinwen , Huang Wei , Wang Lianhui
Published: February 2016

Graphene quantum dots (GQDs) with white fluorescence are synthesized by a microwave‐assisted hydrothermal method using graphite as the precursor. A solution‐processed white‐light‐emitting diode (WLED) is fabricated using the as‐prepared white fluorescent GQDs (white‐light‐emitting graphene quantum dots, WGQDs) doped 4,4‐bis(carbazol‐9‐yl)biphenyl as the emissive layer. White‐light emission is obtained from the WLED with 10 wt% doping concentration of WGQDs, which shows a luminance of 200 cd m−2 at the applied voltage of 11–14 V. Importantly, an external quantum efficiency of 0.2% is achieved, which is the highest among all the reported WLED based on GQDs or carbon dots. The results demonstrate that WGQDs as a novel phosphor may open up a new avenue to develop the environmentally friendly WLEDs for practical application in solid‐state lighting.
Advances in the Application of Silicon and Germanium Nanowires for High‐Performance Lithium‐Ion Batteries
Authors: Kennedy Tadhg , Brandon Michael , Ryan Kevin M.
Published: February 2016

Li‐alloying materials such as Si and Ge nanowires have emerged as the forerunners to replace the current, relatively low‐capacity carbonaceous based Li‐ion anodes. Since the initial report of binder‐free nanowire electrodes, a vast body of research has been carried out in which the performance and cycle life has significantly progressed. The study of such electrodes has provided invaluable insights into the cycling behavior of Si and Ge, as the effects of repeated lithiation/delithiation on the material can be observed without interference from conductive additives or binders. Here, some of the key developments in this area are looked at, focusing on the problems encountered by Li‐alloying electrodes in general (e.g., pulverization, loss of contact with current collector etc.) and how the study of nanowire electrodes has overcome these issues. Some key nanowire studies that have elucidated the consequences of the alloying/dealloying process on the morphology of Si and Ge are also considered, in particular looking at the impact that effects such as pore formation and lithium‐assisted welding have on performance. Finally, the challenges for the practical implementation of nanowire anodes within the context of the current understanding of such systems are discussed.
Exfoliated 2D Transition Metal Disulfides for Enhanced Electrocatalysis of Oxygen Evolution Reaction in Acidic Medium
Authors: Wu Jingjie , Liu Mingjie , Chatterjee Kuntal , Hackenberg Ken P. , Shen Jianfeng , Zou Xiaolong , Yan Yong , Gu Jing , Yang Yingchao , Lou Jun , Ajayan Pulickel M.
Published: February 2016

The scarcity of inexpensive and efficient electrocatalyst for acid water oxidation to molecular oxygen presents the development of nonprecious catalysts for water oxidation a scientific priority. For water splitting, transition‐metal dichalcogenides have attracted great interest as advanced catalysts for hydrogen evolution reaction, but there has been no sincere attention to generate significant anodic current density of oxygen evolution reaction (OER) with these materials. Addressing this unmet need, here, the outstanding catalytic performance of MoS2 and TaS2 in OER is demonstrated. Chemically exfoliated 2D thin sheets of MoS2 and TaS2, in both of their 1T and 2H polymorph, have been employed for OER catalysis in acid medium. The best performance for oxygen evolution, which is also comparable to benchmark IrO2, comes out from 1T‐MoS2 followed by 1T‐TaS2, 2H‐MoS2, and 2H‐TaS2. Theoretical study reveals that the dominant catalytic activity is on edge sites instead of surface and corroborates the experimental results of polymorphic dependence of electrocatalytic activity. The materials have also shown moderate durability in the harsh acidic medium. The study brings up new set of electrocatalyst for oxygen evolution in acid regime that hitherto has remained largely unrevealed.
An Aqueous Process for Durable Superamphiphobic Diblock Copolymer Coatings on Fabrics
Authors: Zou Hailiang , Lin Shudong , Tu Yuanyuan , Li Fei , Hu Jiwen , Liu Guojun , Hu Shengyu , Yang Gonghua , Yu Zhiwei
Published: February 2016

Many strategies have been developed to prepare superamphiphobic fabrics that strongly repel water‐ and oil‐borne contaminants and etchants. However, the common drawback in these reported strategies is the use of organic solvents, which should be eliminated or reduced for practical applications. In this paper, the diblock copolymer of poly(2‐perfluorooctylethyl acrylate)‐block‐poly(glycidyl methacrylate‐ radom‐methoxy oligoethyleneglycolyl methacrylate) [PFOEA‐b‐P(GMA‐r‐mOEGMA)]is synthesized via atom transfer radical polymerization and used to coat cotton and poly(ethylene terphthalate) fabrics from an aqueous process. It is found that fabrics with tunable and robust wettablity can be prepared from copolymer solution at different concentrations. For example, fabrics coated at a copolymer solution concentration of 22.8 mg mL‐1 are superamphiphobic. This process of current stratey is environment‐friendly, simple, and reproducible, and may find commercial applications.
Potassium Phosphate‐Catalyzed Chemoselective Reduction of α‐Keto Amides: Route to Synthesize Passerini Adducts and 3‐Phenyloxindoles
Authors: Muthukumar Alagesan , Mamillapalli N. Chary , Sekar Govindasamy
Published: February 2016

A chemoselective reduction of α‐keto amides to biologically important α‐hydroxy amides (mandelamides) by polymethylhydrosiloxane (PMHS) using 5 mol% potassium phosphate (K3PO4) as catalyst has been developed. This transition metal‐free protocol discloses excellent chemoselectivity for the ketone reduction of α‐keto amides in the presence of other reducible functionalities like ketone, nitro, halides, nitrile and amide. Also, the chemoselectively reduced α‐hydroxy amide has been derivatized to isocyanide‐free Passerini adducts. The N‐alkyl‐α‐hydroxy amides have been successfully converted to 3‐phenyloxindole derivatives by treatment with methanesulfonyl cholride and triethylamine.

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Influence of Carboxylic Acids on Poly(lactic acid)/Thermoplastic Starch Biodegradable Sheets Produced by Calendering–Extrusion
Authors: Shirai Marianne Ayumi , Zanela Juliano , Kunita Marcos Hiroiuqui , Pereira Guilherme Miranda , Rubira Adley Forti , Müller Carmen Maria Olivera , Grossmann Maria Victória Eiras , Yamashita Fabio
Published: February 2016

Sheets of poly(lactic acid) (PLA) and thermoplastic starch (TPS) with citric and adipic acid additives were produced through a calendering–extrusion process at pilot scale, and its mechanical, barrier, thermal, and morphological characteristics were determined. According to the micrographs, citric acid improved the fragmentation and dispersion of starch granules by facilitating interactions with PLA chains and increasing interfacial adhesion. Citric acid also induced a significant increase in the tensile strength and elongation at break, reducing water vapor permeability, increasing crystallinity, but decreased slightly the thermal stability. Adipic acid did not demonstrate the same efficiency, even when mixed with citric acid.
Transition Metal Carbides and Nitrides in Energy Storage and Conversion
Authors: Zhong Yu , Xia Xinhui , Shi Fan , Zhan Jiye , Tu Jiangping , Fan Hong Jin
Published: February 2016

High‐performance electrode materials are the key to advances in the areas of energy conversion and storage (e.g., fuel cells and batteries). In this Review, recent progress in the synthesis and electrochemical application of transition metal carbides (TMCs) and nitrides (TMNs) for energy storage and conversion is summarized. Their electrochemical properties in Li‐ion and Na‐ion batteries as well as in supercapacitors, and electrocatalytic reactions (oxygen evolution and reduction reactions, and hydrogen evolution reaction) are discussed in association with their crystal structure/morphology/composition. Advantages and benefits of nanostructuring (e.g., 2D MXenes) are highlighted. Prospects of future research trends in rational design of high‐performance TMCs and TMNs electrodes are provided at the end.
Demonstration of Single Hole Transistor and Hybrid Circuits for Multivalued Logic and Memory Applications up to 350 K Using CMOS Silicon Nanowires
Authors: Lavieville Romain , Barraud Sylvain , Arvet Christian , Vizioz Christian , Corna Andrea , Jehl Xavier , Sanquer Marc , Vinet Maud
Published: February 2016

The operation of hybrid circuits consisting of a single hole transistor coupled to a metal oxide semiconductor field effect transistor (MOSFET) is demonstrated at 350 K. The devices are designed at ultimate scaling with complementary metal oxide semiconductor technology on 300 mm diameter silicon on insulator wafers using deep ultra‐violet lithography. Coulomb blockade oscillations up to 350 K are measured from silicon nanowire transistors with 20 nm Ω‐gate length and diameter under 5 nm. These oscillations are exploited to produce inverter/amplifier, literal gate, negative differential resistance and memory loop circuits for multivalued (MV) logic and MV memory applications, via hybridization with MOSFET in SETMOS configuration. The fabrication and the operation of these SHT‐MOSFET hybrid circuits at high temperature should spur single charge transistor integration into circuits for innovative applications in nanoelectronics.
Gate‐Free Controlled Multibit Memories Based on Individual ZnO:In Micro/Nanowire Back‐to‐Back Diodes
Authors: Zhao Jie , Cheng Baochang , Xiao Yanhe , Guo Rui , Lei Shuijin
Published: February 2016

Most actively tunable Schottky diodes have a tendency to set up gate voltages or complex configurations. In this work, gate‐free two‐terminal devices based on individual ZnO:In micro/nanowire back‐to‐back diodes are fabricated for nonvolatile bias sensors and multibit memories, which can be controllably set by drain‐source bias voltage (VDS) after annealing at 150 °C. The nonvolatile sensor and multibit memory effect dominantly originates from the controllable modulation of trap‐related Schottky barrier height by the synergistic action of thermal excitation and electric field injection of electrons. The tubable electrical properties of individual ZnO:In micro/nanowire‐based two‐terminal devices, regulated by temperature and VDS, point a way to develop a new type of nonvolatile bias sensors and multibit resistance random access memories with superior repeatability and stability.
Annual decline in forced expiratory volume is steeper in aluminum potroom workers than in workers without exposure to potroom fumes
Authors: Søyseth Vidar , Henneberger Paul K. , Einvik Gunnar , Virji Mohammed Abbas , Bakke Berit , Kongerud Johny
Published: February 2016

Background

Aluminum potroom exposure is associated with increased mortality of COPD but the association between potroom exposure and annual decline in lung function is unknown. We have measured lung volumes annually using spirometry from 1986 to 1996. The objective was to compare annual decline in forced expiratory volume in 1 s (dFEV1) and forced vital capacity (dFVC).

Methods

The number of aluminum potroom workers was 4,546 (81% males) and the number of workers in the reference group was 651 (76% males). The number of spirometries in the index group and the references were 24,060 and 2,243, respectively.

Results

After adjustment for confounders, the difference in dFEV1 and dFVC between the index and reference groups were 13.5 (P < 0.001) and −8.0 (P = 0.060) ml/year.

Conclusion

Aluminum potroom operators have increased annual decline in FEV1 relative to a comparable group with non‐exposure to potroom fumes and gases. Am. J. Ind. Med. 59:322–329, 2016. © 2016 The Authors. American Journal of Industrial Medicine Published by Wiley Periodicals, Inc.