bluuebunny/crossref_metadata_2025 huggingface dataset:
IMPROVE THE ZY-3 HEIGHT ACCURACY USING ICESAT/GLAS LASER ALTIMETER DATA
Authors: Li Guoyuan , Tang Xinming , Gao Xiaoming , Zhang Chongyang , Li Tao
Published: June 2016

Abstract. ZY-3 is the first civilian high resolution stereo mapping satellite, which has been launched on 9th, Jan, 2012. The aim of ZY-3 satellite is to obtain high resolution stereo images and support the 1:50000 scale national surveying and mapping. Although ZY-3 has very high accuracy for direct geo-locations without GCPs (Ground Control Points), use of some GCPs is still indispensible for high precise stereo mapping. The GLAS (Geo-science Laser Altimetry System) loaded on the ICESat (Ice Cloud and land Elevation Satellite), which is the first laser altimetry satellite for earth observation. GLAS has played an important role in the monitoring of polar ice sheets, the measuring of land topography and vegetation canopy heights after launched in 2003. Although GLAS has ended in 2009, the derived elevation dataset still can be used after selection by some criteria. In this paper, the ICESat/GLAS laser altimeter data is used as height reference data to improve the ZY-3 height accuracy. A selection method is proposed to obtain high precision GLAS elevation data. Two strategies to improve the ZY-3 height accuracy are introduced. One is the conventional bundle adjustment based on RFM and bias-compensated model, in which the GLAS footprint data is viewed as height control. The second is to correct the DSM (Digital Surface Model) straightly by simple block adjustment, and the DSM is derived from the ZY-3 stereo imaging after freedom adjustment and dense image matching. The experimental result demonstrates that the height accuracy of ZY-3 without other GCPs can be improved to 3.0 meter after adding GLAS elevation data. What’s more, the comparison of the accuracy and efficiency between the two strategies is implemented for application.
OBJECT-BASED ANALYSIS OF LIDAR GEOMETRIC FEATURES FOR VEGETATION DETECTION IN SHADED AREAS
Authors: Lin Yu-Ching , Lin ChinSu , Tsai Ming-Da , Lin Chun-Lin
Published: June 2016

Abstract. The extraction of land cover information from remote sensing data is a complex process. Spectral information has been widely utilized in classifying remote sensing images. However, shadows limit the use of multispectral images because they result in loss of spectral radiometric information. In addition, true reflectance may be underestimated in shaded areas. In land cover classification, shaded areas are often left unclassified or simply assigned as a shadow class. Vegetation indices from remote sensing measurement are radiation-based measurements computed through spectral combination. They indicate vegetation properties and play an important role in remote sensing of forests. Airborne light detection and ranging (LiDAR) technology is an active remote sensing technique that produces a true orthophoto at a single wavelength. This study investigated three types of geometric lidar features where NDVI values fail to represent meaningful forest information. The three features include echo width, normalized eigenvalue, and standard deviation of the unit weight observation of the plane adjustment, and they can be derived from waveform data and discrete point clouds. Various feature combinations were carried out to evaluate the compensation of the three lidar features to vegetation detection in shaded areas. Echo width was found to outperform the other two features. Furthermore, surface characteristics estimated by echo width were similar to that by normalized eigenvalues. Compared to the combination of only NDVI and mean height difference, those including one of the three features had a positive effect on the detection of vegetation class.
Reviewer Acknowledgements for English Language and Literature Studies, Vol. 6, No. 2
Authors: Ding Alice
Published: June 2016

Reviewer Acknowledgements for English Language and Literature Studies, Vol. 6, No. 2, 2016.
Joins, coronas and their vertex-edge Wiener polynomials
Authors: Azari Mahdieh , Iranmanesh Ali
Published: June 2016

The vertex-edge Wiener index of a simple connected graph $G$ is defined as the sum of distances between vertices and edges of $G$. The vertex-edge Wiener polynomial of $G$ is a generating function whose first derivative is a $q-$analog of the vertex-edge Wiener index. Two possible distances $D_1(u, e|G)$ and $D_2(u, e|G)$ between a vertex $u$ and an edge $e$ of $G$ can be considered and corresponding to them, the first and second vertex-edge Wiener indices of $G$, and the first and second vertex-edge Wiener polynomials of $G$ are introduced. In this paper, we study the behavior of these indices and polynomials under the join and corona product of graphs. Results are applied for some classes of graphs such as suspensions, bottlenecks, and thorny graphs.
Second degree generalized Jacobi iteration method for solving system of linear equations
Authors: Enyew Tesfaye Kebede
Published: June 2016

In this paper, a Second degree generalized Jacobi Iteration method for solving system of linear equations, $Ax=b$ and discuss about the optimal values $a_{1}$ and $b_{1}$ in terms of spectral radius about for the convergence of SDGJ method of $x^{(n+1)}=b_{1}[D_{m}^{-1}(L_{m}+U_{m})x^{(n)}+k_{1m}]-a_{1}x^{(n-1)}.$ Few numerical examples are considered to show that the effective of the Second degree Generalized Jacobi Iteration method (SDGJ) in comparison with FDJ, FDGJ, SDJ.
Uniqueness of difference-differential polynomials of entire functions sharing one value
Authors: Dyavanal Renukadevi S. , Hattikal Ashwini M.
Published: June 2016

In this paper, we study the uniqueness of difference-differential polynomials of entire functions $f$ and $g$ sharing one value with counting multiplicity. In this paper we extend and generalize the results of X. Y. Zhang, J. F. Chen and W. C. Lin [17] L. Kai, L. Xin-ling and C. Ting-bin [7] and many others [2, 16].
Inequalities for power series with nonnegative coefficients via a reverse of Jensen inequality
Authors: Dragomir Silvestru Sever
Published: June 2016

Some inequalities for power series with nonnegative coefficients via a reverse of Jensen inequality obtained by Dragomir & Ionescu in 1994 are given. Applications for some fundamental functions defined by power series are also provided.
Growth of solutions of second order linear differential equations with extremal functions for Denjoy's conjecture as coefficients
Authors: Long Jianren
Published: June 2016

The classical problem of finding conditions on the entire coefficients $A(z)$ and $B(z)$ guaranteeing that all nontrivial solutions of $f''+A(z)f'+B(z)f=0$ are of infinite order is discussed. Some such conditions which involve deficient value, Borel exceptional value and extremal functions for Denjoy's conjecture are obtained.
Presentación
Authors: Moreno Feliú Paz
Published: June 2016

El presente número monográfico de la revista Éndoxa coincide con la puesta en marcha del Centro de Estudios Afrohispánicos de la UNED, cuyo objetivo es promover y coordinar la investigación multidisciplinar sobre distintas poblaciones afro-hispánicas, así como difundir –mediante seminarios, la docencia y la publicación- los resultados de las investigaciones que llevemos a cabo.
Introducción
Authors: Moreno Feliú Paz , Aranzadi Juan
Published: June 2016

Este número monográfico de ENDOXA dedicado a Nuevas investigaciones sobre y desde Guinea Ecuatorial es uno de los primeros frutos del desarrollo del proyecto de investigación HAR2012-345999 titulado “Lo que sabemos, ignoramos, inventamos y deformamos acerca del pasado y el presente de Guinea Ecuatorial. Revisión crítica multidisciplinar y nuevas vías de investigación”, llevado a cabo por un amplio equipo internacional y multidisciplinar de investigadores pertenecientes al Centro de Estudios Afro-Hispánicos (CEAH) recientemente creado por la UNED y cuya presentación realiza en este mismo número de ENDOXA su primera y actual directora, la profesora Paz Moreno Feliú.
El legado cultural de Sierra Leona en Bioko. Comparativa de dos espacios de criollización africana
Authors: Aranzadi Isabela
Published: June 2016

El grupo de los criollos fernandinos o crió en Malabo, comparte su historia con la ciudad de Malabo. Esta comunidad criolla se gestó preservando un status basándose en el origen de sus habitantes. Los procedentes de Freetown constituyeron el núcleo más importante. Establecemos comparativas entre los procesos de criolizaciónen Freetown y Bioko, asentamientos de esclavos liberados con diferentes orígenes, una estratificación y el papel de socialización llevado por un grupo de más peso, a través de la acogida en los hogares y de la labor de la escuela y la iglesia. En Freetown serían el grupo de los Black Loyalists y de los cimarrones y en Bioko los denominados “sierraleonas” los que introdujeron esta ideología adscrita a una identidad británica, heredera del impulsoabolicionista. Encontramos un “purismo étnico” entre los krio de Freetown y entre los crió de Malabo. Ello supone especiales atribuciones en algunos ritos que forman parte del ñánkue o bonkó -rito-danza heredado de Calabar y Cuba conservado hasta hoy ysímbolo en la navidad malabeña. El tambor cuadrado con patas cumbé y el rito-danza del ñánkue han experimentado un proceso de adaptación a un nuevo entorno, en el que la música ocupa un espacio social interétnico. El cumbé es un tambor africano utilizadoen Jamaica y posteriormente en Freetown llevado por los cimarrones cuya cultura llega a Bioko con los “sierraleonas”. Esta africanidad se inserta en una identidad criolla en la que la tarea civilizadora y la adscripción a una identidad británica, requisitos en el impulso abolicionista, continuaron prevaleciendo en las complejas trayectorias de poblaciones descendientes de esclavos liberados, desde Sierra Leona hasta Bioko.
La oposición guineana entre dos “diálogos nacionales” (1993-2014)
Authors: Nse Angüe Amancio , Micó Abogo Plácido
Published: June 2016

Guinea Ecuatorial, país de poco más de 28.000 Kilómetros cuadradosde extensión y unos 700.000 habitantes, explota una gran cantidad de petróleo desde el año 1.996 y vive desde 1991 un atípico proceso político. Obiang Nguema, el dictador que ocupa y ejerce el poder de forma absoluta y omnímoda desde que en el año 1.979 derrocara a su tío y valedor Macías (presidente desde la Independencia en 1.968) delque era un estrecho colaborador, prometió democratizar el país al viento del discurso de Mitterrand en La Baule (1990). En noviembre del año pasado (2014) tuvo lugar la llamada V Mesa de Diálogo Nacional, cuyo resultado es la constatación de que 23 años después de la legalización de los partidos políticos, y 22 años desde la firma del Pacto Nacional (I Mesa de Diálogo) dicho proceso no ha avanzado. El reflejo del fracaso fue el abandono de la V Mesa de Diálogo por CPDS, FDR y la facción legítima de UP, tres de los pocos grupos a los que se les puede denominar con propiedad oposición. Pues el resto de los partidos legalizados que participaron, aunque el régimen pretende hacerlos pasar por oposición, son partidos que apoyan y están en el gobierno del PDGE, partido de Obiang. Y los que participaron procedentes del exilio, son una ínfima parte de los más de treinta grupos políticos guineo-ecuatorianos que hay en el exilio. Un exilio, por cierto, atípico: pues muchos exiliados han hecho, en los últimos años, varios viajes de ida y vuelta a Guinea. Una oposición fragmentada, por tanto debilitada, incapaz de organizarse y tener madera de alternativa. Y la dictadura sigue, porque poder y oposición, en elementos claves de la institucionalidad, tienen los mismos comportamientos: apego a los cargos, laxitud ante las leyes, falta de objetivos y programas. Pero mientras Obiang viola las leyes para mantenerse (lubricado por el petróleo), la misma actitud le impide a la oposición organizarse y tener una cierta unidad de acción.
La protesta de los jefes en 1948. Una tradición oral nacionalista en Guinea Ecuatorial
Authors: Álvarez Chillida Gonzalo
Published: June 2016

En 1948 varios jefes de la zona continental de la Guinea española entregaron a una comisión de tres ministros que visitaba la colonia dos escritos de protesta por la situación de los nativos. El de Mikomeseng, localidad fronteriza con el agitado Camerún, mereció el castigo de sus dos principales promotores. A diferencia de similares protestas anteriores, la de 1948 se transmitió oralmente y desde los años sesenta los nacionalistas la convirtieron en el origen de su movimiento.
Subjunctive and subject pronoun realization: a study of "no creo que"
Authors: Harrington Sophie , Pérez-Leroux Ana Teresa
Published: June 2016

Subjunctive mood in complement clauses is licensed under selection from certain predicates or under the scope of a modal or negation. In contexts where mood choice varies, such as the complement of a negated epistemic verb no creer, it introduces a contrast in interpretation. The subjunctive is thought to contribute to a shift in the modal anchoring of the embedded clause, and is consequently interpreted as indicative of a dissociation between the epistemic models of the speaker and the subject. We provide evidence that these uses also interact with pragmatic context. Given independent claims that 1) the overt realization of first person subject pronouns is contrastive and 2) it generally serves to anchor discourse to the speaker’s perspective and 3) overt use is particularly frequent with epistemic verbs, we examined the interaction between negation, first person subject pronoun realization, and mood of the dependent clause for the verb creer.  An analysis of oral speech from the Proyecto de Habla Culta revealed that for negative sentences (no creo que), yo is overtly realized more frequently for cases with exceptional indicative dependents than for those with canonical subjunctive dependents; there was no association with mood for affirmative uses of creer. These results support analyses where negation has specific scope over the contrastive subject, rather than over the epistemic clause. As a consequence, the matrix proposition remains an assertion and use of indicative complements is licensed.
E. Hernández & P. Martín Butragueño (eds.), 'Variación y diversidad lingüística. Hacia una teoría convergente'
Authors: Ivanova Olga
Published: June 2016

Desde que Hugo Schuchardt defendiera que toda lengua es un continuum en variación (Abad 1993: 76), como objeto de estudio la variación lingüística ha sido abordada desde múltiples enfoques científicos que se han centrado en la variación tanto como la diversidad dentro del sistema lingüístico como la diversidad entre sistemas lingüísticos distintos.A esta diversidad, concebida no solo como la dialectalidad interna del sistema (Abad 1993: 74) sino también como la heterogeneidad entre sistemas, está dedicado el volumen editado por Esther Hernández y Pedro Martín Butragueño, volumen cuyo fin último, al reunir trabajos de muy variada perspectiva sobre la variación, es ofrecer una definición inclusiva de este concepto indisociable del uso lingüístico.
Cyclic transfer in the derivation of Complete Parenthetical Clauses
Authors: Cerrudo Aguilar Alba
Published: June 2016

The goal of this paper is to show that some parentheticals are indeed syntactic orphans (cf. Haegeman 1988) and that this intuition can be formalized using tools independently motivated in linguistic theory. We concentrate on new data regarding clitic realization in what are commonly called Reduced Parenthetical Clauses (RPCs). We show that these constructions with clitic differ of their reduced counterpart in many aspects; crucially, they behave as root domains. Thus, we argue that they are derived independently from the host clause (in a parallel workspace) and their linear interpolation occurs during the Spell-Out process, assuming a dynamic version of cyclic Transfer (cf. Chomsky 2001, Uriagereka 1999).
Estimation of seismic wave velocity at seafloor surface and sound source localization based on transmitted wave observation with an ocean bottom seismometer offshore of Kamaishi, Japan
Authors: Iwase Ryoichi
Published: June 2016

An in situ method of estimating the seismic wave velocity at the seafloor surface by observing the particle motion of a wave transmitted into the sediment is presented; this method uses a sound source whose location is known. Conversely, a sound source localization method using the obtained seismic velocities and involving particle motion observation is also presented. Although this method is applicable only when the sound source exists within the critical incidence angle range, it is expected to contribute to the tracing of vocalizing baleen whales, which are unknown around Japanese waters.
ELF/VLF wave propagation at subauroral latitudes: Conjugate observation between the ground and Van Allen Probes A
Authors: Martinez‐Calderon Claudia , Shiokawa Kazuo , Miyoshi Yoshizumi , Keika Kunihiro , Ozaki Mitsunori , Schofield Ian , Connors Martin , Kletzing Craig , Hanzelka Miroslav , Santolik Ondrej , Kurth William S.
Published: June 2016

We report simultaneous observation of ELF/VLF emissions, showing similar spectral and frequency features, between a VLF receiver at Athabasca (ATH), Canada, (L = 4.3) and Van Allen Probes A (Radiation Belt Storm Probes (RBSP) A). Using a statistical database from 1 November 2012 to 31 October 2013, we compared a total of 347 emissions observed on the ground with observations made by RBSP in the magnetosphere. On 25 February 2013, from 12:46 to 13:39 UT in the dawn sector (04–06 magnetic local time (MLT)), we observed a quasiperiodic (QP) emission centered at 4 kHz, and an accompanying short pulse lasting less than a second at 4.8 kHz in the dawn sector (04–06 MLT). RBSP A wave data showed both emissions as right‐hand polarized with their Poynting vector earthward to the Northern Hemisphere. Using cross‐correlation analysis, we did, for the first time, time delay analysis of a conjugate ELF/VLF event between ground and space, finding +2 to +4 s (ATH first) for the QP and −3 s (RBSP A first) for the pulse. Using backward tracing from ATH to the geomagnetic equator and forward tracing from the equator to RBSP A, based on plasmaspheric density observed by the spacecraft, we validate a possible propagation path for the QP emission which is consistent with the observed time delay.
Reconstruction of the East Africa and Antarctica continental margins
Authors: Nguyen Luan C. , Hall Stuart A. , Bird Dale E. , Ball Philip J.
Published: June 2016

The Early Jurassic separation of Antarctica from Africa plays an important role in our understanding of the dispersal of Gondwana and Pangea. Previous reconstruction models contain overlaps and gaps in the restored margins that reflect difficulties in accurately delineating the continent‐ocean‐boundary (COB) and determining the amount and distribution of extended continental crust. This study focuses on the evolution of the African margin adjacent to the Mozambique Basin and the conjugate Antarctic margin near the Riiser‐Larsen Sea. Satellite‐derived gravity data have been used to trace the orientations and landward limits of fracture zones. A 3‐D gravity inversion has produced a crustal thickness model that reliably quantifies the extent and amount of stretched crust. Crustal thicknesses together with fracture zone terminations reveal COBs that are significantly closer to the African and Antarctic coasts than previously recognized. Correlation of fracture zone azimuths and identified COBs suggests Antarctica began drifting away from Africa at approximately 171 Ma in a roughly SSE direction. An areal‐balancing method has been used to restore the crust to a uniform prerift thickness so as to perform a nonrigid reconstruction for both nonvolcanic and volcanic margins. Both margins reveal a trend of increasing extension from east to west. Our results suggest Africa underwent extension of 60–120 km, while Antarctic crust was stretched by 105–180 km. Various models tested to determine the direction of extension during rifting suggest that Antarctica moved away from Africa in a WNW‐ESE direction during the period between 184 and 171 Ma prior to the onset of seafloor spreading.
Atmospheric forcing of the upper ocean transport in the Gulf of Mexico: From seasonal to diurnal scales
Authors: Judt Falko , Chen Shuyi S. , Curcic Milan
Published: June 2016

The 2010 Deepwater Horizon oil spill in the Gulf of Mexico (GoM) was an environmental disaster, which highlighted the urgent need to predict the transport and dispersion of hydrocarbon. Although the variability of the atmospheric forcing plays a major role in the upper ocean circulation and transport of the pollutants, the air‐sea interaction on various time scales is not well understood. This study provides a comprehensive overview of the atmospheric forcing and upper ocean response in the GoM from seasonal to diurnal time scales, using climatologies derived from long‐term observations, in situ observations from two field campaigns, and a coupled model. The atmospheric forcing in the GoM is characterized by striking seasonality. In the summer, the time‐average large‐scale forcing is weak, despite occasional extreme winds associated with hurricanes. In the winter, the atmospheric forcing is much stronger, and dominated by synoptic variability on time scales of 3–7 days associated with winter storms and cold air outbreaks. The diurnal cycle is more pronounced during the summer, when sea breeze circulations affect the coastal regions and nighttime wind maxima occur over the offshore waters. Realtime predictions from a high‐resolution atmosphere‐wave‐ocean coupled model were evaluated for both summer and winter conditions during the Grand LAgrangian Deployment (GLAD) in July–August 2012 and the Surfzone Coastal Oil Pathways Experiment (SCOPE) in November–December 2013. The model generally captured the variability of atmospheric forcing on all scales, but suffered from some systematic errors.
Hygrosopicity measurements of aerosol particles in the San Joaquin Valley, CA, Baltimore, MD, and Golden, CO
Authors: Orozco Daniel , Beyersdorf A. J. , Ziemba L. D. , Berkoff T. , Zhang Q. , Delgado R. , Hennigan C. J. , Thornhill K. L. , Young D. E. , Parworth C. , Kim H. , Hoff R. M.
Published: June 2016

Aerosol hygroscopicity was investigated using a novel dryer‐humidifier system, coupled to a TSI‐3563 nephelometer, to obtain the light scattering coefficient (σscat) as a function of relative humidity (RH) in hydration and dehydration modes. The measurements were performed in Porterville, CA (10 January to 6 February 2013), Baltimore, MD (3–30 July 2013), and Golden, CO (12 July to 10 August 2014). Observations in Porterville and Golden were part of the NASA‐sponsored Deriving Information on Surface Conditions from Column and Vertically Resolved Observations Relevant to Air Quality project. The measured σscat under varying RH in the three sites was combined with ground aerosol extinction, PM2.5 mass concentrations, and particle composition measurements and compared with airborne observations performed during campaigns. The enhancement factor, f(RH), defined as the ratio of σscat(RH) at a certain RH divided by σscat at a dry value, was used to evaluate the aerosol hygroscopicity. Particles in Porterville showed low average f(RH = 80%) (1.42) which was attributed to the high carbonaceous loading in the region where residential biomass burning and traffic emissions contribute heavily to air pollution. In Baltimore, the high average f(RH = 80%) (2.06) was attributed to the large contribution of SO42− in the region. The lowest water uptake was observed in Golden, with an average f(RH = 80%) = 1.24 where organic carbon dominated the particle loading. Different empirical fits were evaluated using the f(RH) data. The widely used Kasten (gamma) model was found least satisfactory, as it overestimates f(RH) for RH < 75%. A better empirical fit with two power law curve fitting parameters c and k was found to replicate f(RH) accurately from the three sites. The relationship between the organic carbon mass and the species that are affected by RH and f(RH) was also studied and categorized.
The ionospheric source of magnetospheric plasma is not a black box input for global models
Authors: Welling D. T. , Liemohn M. W.
Published: June 2016

Including ionospheric outflow in global magnetohydrodynamic models of near‐Earth outer space has become an important step toward understanding the role of this plasma source in the magnetosphere. Of the existing approaches, however, few tie the outflowing particle fluxes to magnetospheric conditions in a self‐consistent manner. Doing so opens the magnetosphere‐ionosphere system to nonlinear mass‐energy feedback loops, profoundly changing the behavior of the magnetosphere‐ionosphere system. Based on these new results, it is time for the community eschew treating ionospheric outflow as a simple black box source of magnetospheric plasma.
New insights into fault activation and stress transfer between en echelon thrusts: The 2012 Emilia, Northern Italy, earthquake sequence
Authors: Cheloni D. , Giuliani R. , D'Agostino N. , Mattone M. , Bonano M. , Fornaro G. , Lanari R. , Reale D. , Atzori S.
Published: June 2016

Here we present the results of the inversion of a new geodetic data set covering the 2012 Emilia seismic sequence and the following 1 year of postseismic deformation. Modeling of the geodetic data together with the use of a catalog of 3‐D relocated aftershocks allows us to constrain the rupture geometries and the coseismic and postseismic slip distributions for the two main events (Mw 6.1 and 6.0) of the sequence and to explore how these thrust events have interacted with each other. Dislocation modeling reveals that the first event ruptured a slip patch located in the center of the Middle Ferrara thrust with up to 1 m of reverse slip. The modeling of the second event, located about 15 km to the southwest, indicates a main patch with up to 60 cm of slip initiated in the deeper and flatter portion of the Mirandola thrust and progressively propagated postseismically toward the top section of the rupture plane, where most of the aftershocks and afterslip occurred. Our results also indicate that between the two main events, a third thrust segment was activated releasing a pulse of aseismic slip equivalent to a Mw 5.8 event. Coulomb stress changes suggest that the aseismic event was likely triggered by the preceding main shock and that the aseismic slip event probably brought the second fault closer to failure. Our findings show significant correlations between static stress changes and seismicity and suggest that stress interaction between earthquakes plays a significant role among continental en echelon thrusts.
Detailed magnetic monitoring of the enhanced magnetism of ferrihydrite along its progressive transformation into hematite
Authors: Gutiérrez L. , Barrón V. , Andrés‐Vergés M. , Serna C. J. , Veintemillas‐Verdaguer S. , Morales M. P. , Lázaro F. J.
Published: June 2016

Under certain aging conditions, ferrihydrite evolves into hematite through intermediate products of enhanced magnetism. Although the magnetic properties of the end product, hematite, are to date satisfactorily known, those of ferrihydrite (and especially the products of its progressive aging) are not sufficiently explored. To this end, magnetic experiments, conducted mostly by using alternating magnetic fields, have been performed. The results reveal that two‐line ferrihydrite exhibits conspicuous low‐temperature spin glass behavior, a new finding that, on the other hand, could be expected given the previous microstructural observations that described this mineral as a very disordered gel. Upon aging, a progressive increase of the effective magnetic moment per iron ion is detected, in agreement with previous observations that ascribed ferrimagnetic character to an intermediate crystalline phase (sometime called ferriferrihydrite) that disappears just before the full transformation into hematite. Transmission electron microscopy observations suggest that this intermediate crystalline phase nucleates at the expense of the primordial gel, remaining physically attached to it until complete transformation into hematite. This microstructural picture appears well supported as, upon aging, the glassy magnetic dynamics found in ferrihydrite persists for the aged products even when dispersed in a nonmagnetic matrix, very likely because part of the so grown ferrimagnetic nanoparticles form aggregates within remains of the nontransformed gel. We propose a coherent model of ferrihydrite aging, based on integrated microstructural and magnetic observations, which is useful for the identification of aging products in geological and biological environments.
On the long‐term stability of the Lofoten Basin Eddy
Authors: Søiland H. , Chafik L. , Rossby T.
Published: June 2016

In recent years, several studies have identified an area of intense anticyclonic activity about 500 km straight west of the Lofoten Islands at 70°N in the northern Norwegian Sea. Now recognized as the coherent Lofoten Basin Eddy (LBE), it is maintained by a supply of anticyclonic eddies that break away from the Norwegian Atlantic Current. Here we show from ship‐based surveys of its velocity field that it is quite stable with a central core in solid body rotation ∼1000 m deep, ∼8 km radius, and a relative vorticity close to its theoretical limit –f. The surveys also show the LBE typically has a >60 km radius with maximum swirl velocities at 17–20 km radius. From the velocity field, we estimate the dynamic height amplitude at the surface to be about ∼0.21 ± 0.03 dyn. m. Second, altimetry from the last 20 years shows the extremum in sea surface height relative to the surrounding waters to be about the same, 0.2 dyn. m. Third, a float trapped in the LBE for many months reveals a clear cyclonic wandering of the eddy over the deepest parts of the basin. Last, three hydrographic sections from the 1960s show the dynamic height signal to be virtually the same then as it is now. From these observations, we conclude that the LBE is a permanent feature of the Nordic Seas and plays a central role in maintaining the pool of warm water in the western Lofoten Basin.
Evaluating Arctic cloud radiative effects simulated by NICAM with A‐train
Authors: Hashino Tempei , Satoh Masaki , Hagihara Yuichiro , Kato Seiji , Kubota Takuji , Matsui Toshihisa , Nasuno Tomoe , Okamoto Hajime , Sekiguchi Miho
Published: June 2016

Evaluation of cloud radiative effects (CREs) in global atmospheric models is of vital importance to reduce uncertainties in weather forecasting and future climate projection. In this paper, we describe an effective way to evaluate CREs from a 3.5 km mesh global nonhydrostatic model by comparing it against A‐train satellite data. The model is the Nonhydrostatic Icosahedral Atmospheric Model (NICAM), and its output is run through a satellite‐sensor simulator (Joint Simulator for satellite sensors) to produce the equivalent CloudSat radar, CALIPSO lidar, and Aqua Clouds and the Earth's Radiant Energy System (CERES) data. These simulated observations are then compared to real observations from the satellites. We focus on the Arctic, which is a region experiencing rapid climate change over various surface types. The NICAM simulation significantly overestimates the shortwave CREs at top of atmosphere and surface as large as 24 W m−2 for the month of June. The CREs were decomposed into cloud fractions and footprint CREs of cloud types that are defined based on the CloudSat‐CALIPSO cloud top temperature and maximum radar reflectivity. It turned out that the simulation underestimates the cloud fraction and optical thickness of mixed‐phase clouds due to predicting too little supercooled liquid and predicting overly large snow particles with too little mass content. This bias was partially offset by predicting too many optically thin high clouds. Offline sensitivity experiments, where cloud microphysical parameters, surface albedo, and single scattering parameters are varied, support the diagnosis. Aerosol radiative effects and nonspherical single scattering of ice particles should be introduced into the NICAM broadband calculation for further improvement.
Asymmetric Aldol Reaction of Dichloroacetaldehyde Catalyzed by Diarylprolinol
Authors: Hayashi Yujiro , Nakamura Daichi , Yasui Yusuke , Iwasaki Kotaro , Chiba Hiroaki
Published: June 2016

The asymmetric cross‐aldol reaction of dichloroacetaldehyde with aldehyde pronucleophiles proceeds in the presence of a trifluoromethyl‐substituted diarylprolinol to afford γ,γ‐dichloro‐β‐hydroxy aldehydes in good yield with excellent enantioselectivity. The obtained products are useful synthetic intermediates; they were successfully converted to form chiral alkynes and dichloroalkenes.

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N,N‐Dimethylacetamide (DMA) as a Methylene Synthon for Regioselective Linkage of Imidazo[1,2‐a]pyridine
Authors: Modi Anju , Ali Wajid , Patel Bhisma K.
Published: June 2016

A copper(II)‐catalyzed oxidative methylene‐bridged dimerization of two analogous imidazo[1,2‐a]pyridines has been achieved using N,N‐dimethylacetamide (DMA) as solvent cum methylene source. This reaction works with a variety of substituted imidazo[1,2‐a]pyridines giving their products in moderate to good yields. Isotopic labelling experiments revealed that the methylene group in the product originates from the N,N‐dimethyl moiety of DMA.

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Bandgap Engineering of Conjugated Nanoporous Poly‐benzobisthiadiazoles via Copolymerization for Enhanced Photocatalytic 1,2,3,4‐Tetrahydroquinoline Synthesis under Visible Light
Authors: Wang Zi Jun , Ghasimi Saman , Landfester Katharina , Zhang Kai A. I.
Published: June 2016

Conveniently combining properties such as high interfacial surface area, excellent visible light absorption and semiconductor‐range bandgap, conjugated nanoporous polymer networks are promising candidates as pure organic, metal‐free, visible light‐responsive and heterogeneous photocatalysts. Here, a facile yet precise bandgap engineering strategy to achieve fine justification of the valence and conduction band positions of a series of nanoporous polymers to optimally bracket the redox potential of the targeted individual photoredox reaction via copolymerization of the electron‐withdrawing benzobisthiadiazole moieties into the polymer network backbone is presented. The enhanced photocatalytic activity of the nanoporous polymer networks was demonstrated in the synthesis of 1,2,3,4‐tetrahydroquinoline, an important motif in pharmaceutical compounds, via photooxidative cyclization of N,N‐dimethylanilines with maleimides.

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Lewis Acid‐Catalyzed [3+2] Cycloaddition of Donor‐Acceptor Cyclopropanes and Enamines: Enantioselective Synthesis of Nitrogen‐Functionalized Cyclopentane Derivatives
Authors: Verma Kamal , Banerjee Prabal
Published: June 2016

A straightforward and efficient method for the synthesis of nitrogen‐functionalized cyclopentane derivatives via [3+2] cycloaddition of enamines with donor‐acceptor cyclopropanes in the presence of catalytic amounts of various Lewis acids at room temperature has been developed; furthermore, the corresponding β‐amino acid was synthesized by monodecarboxylation and hydrogenolysis. An enantioenriched synthesis of nitrogen‐functionalized cyclopentane derivatives through dynamic kinetic asymmetric transformation of racemic donor‐acceptor cyclopropanes has also been achieved employing a copper complex [Cu(OTf)2‐L1] as the catalyst affording an enantiomeric ratio up to 8:1.

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Regioselective Organocatalytic Formation of Carbamates from Substituted Cyclic Carbonates
Authors: Sopeña Sergio , Laserna Victor , Guo Wusheng , Martin Eddy , Escudero‐Adán Eduardo C. , Kleij Arjan W.
Published: June 2016

A highly regioselective catalytic approach has been developed towards carbamates derived from cyclic organic carbonates by reaction of the latter with amine reagents under organocatalytic control. For various combinations of carbonate and amine substrates, an organocatalyst (TBD: 1,5,7‐triazabicyclo[4.4.0]dec‐5‐ene) was used to increase the reaction kinetics while exerting excellent regioselective control. The current method is the first general approach towards the control over the regioselectivity of this reaction using a wide variety of easily accessed substituted organic carbonates.

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Rhodium‐Catalyzed N‐tert‐Butoxycarbonyl (Boc) Amination by Directed CH Bond Activation
Authors: Wippich Julian , Truchan Nadina , Bach Thorsten
Published: June 2016

N‐tert‐Butoxycarbonyl azide (BocN3) was shown to be an efficient and economic source for the directed introduction of N‐Boc protected amino groups into the thiophene and benzene nucleus. Yields for the amination of 2‐pyridin‐2‐ylthiophenes (10 examples) were 52–88%. For the amination of the respective benzenes (10 examples) yields between 54% and 99% were recorded with an improved reactivity observed for substrates that bear an electron‐withdrawing group. The reaction was applied to short total syntheses of the indoloquinoline alkaloids quindoline and cryptolepine. The facile removal of the Boc protecting group was the key to the success of the syntheses. The scope of the reaction was extended to a C(sp3)H bond amination and to the amination of 2‐phenyloxazoline. For the amination of 2‐pyridin‐2‐ylbenzene a kinetic deuterium isotope effect of 2.0 was determined.

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Peptide‐Catalyzed Stereoselective Conjugate Addition Reactions of Aldehydes to Maleimide
Authors: Grünenfelder Claudio E. , Kisunzu Jessica K. , Wennemers Helma
Published: June 2016

The tripeptide H‐dPro‐Pro‐Asn‐NH2 is presented as a catalyst for asymmetric conjugate addition reactions of aldehydes to maleimide. The peptidic catalyst promotes the reaction between various aldehydes and unprotected maleimide with high stereoselectivities and yields. The obtained products were readily derivatized to the corresponding pyrrolidines, lactams, lactones, and peptide‐like compounds. 1H NMR spectroscopic, crystallographic, and computational investigations provided insight into the conformational properties of H‐dPro‐Pro‐Asn‐NH2 and revealed the importance of hydrogen bonding between the peptide and maleimide for catalyzing the stereoselective C−C bond formation.
Enhanced Intrinsic Catalytic Activity of λ‐MnO2 by Electrochemical Tuning and Oxygen Vacancy Generation
Authors: Lee Sanghan , Nam Gyutae , Sun Jie , Lee Jang‐Soo , Lee Hyun‐Wook , Chen Wei , Cho Jaephil , Cui Yi
Published: June 2016

Chemically prepared λ‐MnO2 has not been intensively studied as a material for metal–air batteries, fuel cells, or supercapacitors because of their relatively poor electrochemical properties compared to α‐ and δ‐MnO2. Herein, through the electrochemical removal of lithium from LiMn2O4, highly crystalline λ‐MnO2 was prepared as an efficient electrocatalyst for the oxygen reduction reaction (ORR). The ORR activity of the material was further improved by introducing oxygen vacancies (OVs) that could be achieved by increasing the calcination temperature during LiMn2O4 synthesis; a concentration of oxygen vacancies in LiMn2O4 could be characterized by its voltage profile as the cathode in a lithiun–metal half‐cell. λ‐MnO2−z prepared with the highest OV exhibited the highest diffusion‐limited ORR current (5.5 mA cm−2) among a series of λ‐MnO2−z electrocatalysts. Furthermore, the number of transferred electrons (n) involved in the ORR was >3.8, indicating a dominant quasi‐4‐electron pathway. Interestingly, the catalytic performances of the samples were not a function of their surface areas, and instead depended on the concentration of OVs, indicating enhancement in the intrinsic catalytic activity of λ‐MnO2 by the generation of OVs. This study demonstrates that differences in the electrochemical behavior of λ‐MnO2 depend on the preparation method and provides a mechanism for a unique catalytic behavior of cubic λ‐MnO2.
Structural and antibacterial properties of a γ‐radiation‐assisted,in situprepared silver–polycarbonate matrix
Authors: Deore A. V. , Hareesh K. , Ramya P. , Ianni E. , Guagliardo P. , Samarin S. , Williams J. F. , Sanjeev G. , Dahiwale S. S. , Kanjilal D. , Dhole N. A. , Kodam K. M. , Bhoraskar V. N. , Dhole S. D.
Published: June 2016

A silver–polycarbonate (Ag–PC) matrix was prepared by a γ‐radiation‐assisted diffusion method, and its antibacterial properties were studied. Rutherford backscattering spectroscopy, X‐ray diffraction, and transmission electron microscopy results showed the diffusion of good, crystalline‐structured (face‐centered cubic) silver nanoparticles (AgNPs) inside polycarbonate (PC) after irradiation. Ultraviolet–visible spectroscopic results indicated a blueshift in the surface plasmon resonance of the AgNPs; this revealed a particle size decrease with increasing γ‐radiation dose. This was also supported by the scanning electron microscopy results. The microstructure of the pristine PC and silver‐doped PC was monitored with positron annihilation spectroscopy, and it showed decreases in the free‐volume hole size and fractional free‐volume for Ag–PC and γ‐ray‐irradiated PC. This corroborated the Doppler broadening spectroscopy results. The thermal degradation temperature of PC was increased because of the diffusion of AgNPs in PC. The antibacterial activity of the synthesized Ag–PC matrix was evaluated by the zone of inhibition, and the results demonstrated its bacterial growth inhibition ability. The results indicate the potential to produce an Ag–PC matrix for various applications in medical and food industries. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2016,133, 43729.
Fragrance‐Containing Microcapsules Based on Interfacial Thiol‐Ene Polymerization
Authors: Liao Ziyang , Xue Daquan , Li Hao , Shi Lei
Published: June 2016

In this study, microcapsules containing fragrance oils as active agent were synthesized by interfacial thiol‐ene polymerization in oil‐in‐water emulsion. One water‐soluble dithiol and four oil‐soluble acrylates were used as “click”able monomers. The polymerization kinetics was studied by HPLC and 1H‐NMR. The size and morphology of the microcapsules were characterized by means of light scattering, optical microscope, and scanning electron microscope, and their thermal property was examined by TGA. The encapsulation efficiency and stability of the microcapsules were monitored at room temperature and 45 °C for 1 month. In general, this interfacial thiol‐ene polymerization was demonstrated to be a facile and efficient approach for fragrance microencapsulation with new and stable shell materials. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43905.
Kinetic study of the nonthermal effect of the esterification of octenyl succinic anhydride modified starch treated by microwave radiation
Authors: Shi Haixin , Yin Yanzhen , Wang Airong , Fang Liping , Jiao Shufei
Published: June 2016

With cassava starch as a raw material and octenyl succinic anhydride as an esterifying agent, octenyl succinic anhydride modified starch (OSA–starch) was prepared in an aqueous medium and treated by water‐bath heating and microwave radiation at a certain temperature, respectively. The reaction kinetics of esterification were studied. The structural analysis and synthesis mechanism of OSA–starch were investigated by means of scanning electron microscopy and Fourier transform infrared spectroscopy. The differences in the esterification reaction kinetics between starches treated with water‐bath heating and microwave radiation were observed. Under the condition of water‐bath heating, the apparent activation energy of the esterification reaction was 52.22 ± 1.21 kJ/mol, and the pre‐exponential factor was 9018.20/min−1. Under the condition of microwave radiation, the apparent activation energy of the esterification reaction was 50.13 ± 1.16 kJ/mol, and the pre‐exponential factor was 4510.21/min−1. We found that microwave radiation could reduce both the activation energy of the reaction and the pre‐exponential factor. The lowering effect of the apparent activation energy was greater than that of the pre‐exponential factor under the condition of microwave radiation, and this resulted in increased reaction rates. The change in the esterification reaction kinetics was a nonthermal effect of microwave radiation on the esterification of cassava starch. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43909.
Bio‐based plasticizer and thermoset polyesters: A green polymer chemistry approach
Authors: Rowe Mathew D. , Eyiler Ersan , Walters Keisha B.
Published: June 2016

Renewable resource‐based polyesters, poly(trimethylene malonate) (PTM) and poly(trimethylene itaconate) (PTI), were synthesized from 1,3‐propanediol, malonic acid, and itaconic acid via melt polycondensation using green chemistry principles. Aluminum chloride, a Lewis acid, was used as the catalyst at different reaction temperatures. Chemical structure of PTM and PTI with low dispersities showed the presence of ester and ether bonds. A bimodal molecular weight distribution exists, with the high molecular weight fraction ranging from 22 to 38 kDa while the low molecular weight fraction did not exceed 2.5 kDa. Thermal analysis of PTM showed a Tg ranging between –66 and –41 °C. PTM could be used as a plasticizer for other degradable bioplastics, sensor applications, and drug delivery. PTI, a semi‐crystalline thermoset polymer, may be used for production of packaging material, disposable utensils, tableware, indoor furnishings, and more importantly, as a degradable biomaterial for biomedical applications. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43917.
Naphthalenediimide‐alt‐Fused Thiophene D–A Copolymers for the Application as Acceptor in All‐Polymer Solar Cells
Authors: Xue Lingwei , Yang Yankang , Zhang Zhi‐Guo , Zhang Jing , Gao Liang , Bin Haijun , Yang YunXu , Li Yongfang
Published: June 2016

Three n‐type alternating D–A copolymers based on a naphthalenediimide (NDI) acceptor (A) unit and three different donor (D) units with varied electron‐donating strength including thiophene (P(NDI‐T)), thieno[3,2‐b]thiophene (P(NDI‐TT)), and thieno[3,2‐b;4,5‐b]dithiophene (P(NDI‐TDT)), were synthesized, for the application as acceptor materials in all‐polymer solar cells (all‐PSCs). The effect of the donor units of thiophene, thienothiophene (TT) and thienodithiophene (TDT) on the physicochemical and photovoltaic properties of the n‐type D–A copolymers was systematically investigated. It was found that the absorption spectrum is red‐shifted and the energy band gap (Eg) is reduced for the NDI‐based D–A copolymers with increasing number of thiophene rings in the thiophene or fused thiophene donor units. All‐PSCs were fabricated with the medium band gap conjugated polymer J51 (Eg of ca 1.9 eV) as polymer donor and the n‐type D–A copolymers as acceptor. The power conversion efficiency reached 2.59 %, 3.70 % and 5.10 % for the all‐PSCs with P(NDI‐T), P(NDI‐TT), and P(NDI‐TDT) as acceptor, respectively. The results indicate that a larger conjugated fused molecular plane with more thiophene rings as donor units in the NDI‐based D–A copolymers is beneficial to reduce the band gap, broaden the absorption and enhance the photovoltaic performance of n‐type D–A copolymer acceptors.