bluuebunny/crossref_metadata_2025_split huggingface dataset:
Magnetic Properties from the Perspectives of Electronic Hamiltonian
Authors: Whangbo Myung‐Hwan , Xiang Hongjun 
Published: August 2017

AbstractIn this chapter, we review the quantitative and qualitative aspects of describing the properties of magnetic solids on the basis of electronic Hamiltonian that describes the energy states of a magnetic system using both orbital and spin degrees of freedom. To quantitatively discuss a magnetic property of a given magnetic system, one needs to generate the spectrum of its energy states and subsequently average the properties of these states with each state weighted by its Boltzmann distribution factor. Currently, this is an impossible task to achieve on the basis of an electronic Hamiltonian, so it is necessary to resort to a simple model Hamiltonian, that is, a spin Hamiltonian that describes the energy states of a magnetic system using only the spin degree of freedom. We show that a spin Hamiltonian approach becomes consistent with an electronic Hamiltonian approach if the spin lattice and its associated spin exchange parameters, to be used for the spin Hamiltonian, are determined by the energy‐mapping analysis based onDFTcalculations. The preferred spin orientation (i.e., the magnetic anisotropy) of a magnetic ion is not predicted by a spin Hamiltonian because it does not include the orbital degree of freedom explicitly. In contrast, the magnetic anisotropy is readily predicted by electronic structure theories employing both orbital and spin degrees of freedom, if one takes into consideration the spin–orbit coupling (SOC), , of a magnetic ion where and are, respectively, the spin and orbital operators and λ theSOCconstant. It was shown that the preferred spin orientation of a magnetic ion can be predicted and understood in terms of theHOMO–LUMOinteractions of the magnetic ion by takingSOC, , as perturbation. A spin Hamiltonian gives rise to the spin‐half misconception, namely, the blind belief that spin‐half magnetic ions do not possess magnetic anisotropy that arise fromSOC. This misconception contradicts not only experimental observations on spin‐half ions but also theoretical results based onDFTcalculations and perturbation theory analyses based on an electronic Hamiltonian. This misconception is a direct consequence from the limitedness of a spin Hamiltonian that it lacks the orbital degree of freedom. We show that the magnetic properties of 5dion oxides are better explained by theLS‐coupling than by thejj‐coupling scheme ofSOC, and the spin‐orbital entanglement of 5dions is not as strong as has been assumed.
DFT
Calculations for Real Solids
Authors: Schwarz Karlheinz , Blaha Peter 
Published: August 2017

Abstract

Nowadays, quantum mechanical calculations play an important role when studying the electronic structure of solids at the length scale of nanometers. In this context, different aspects need to be discussed, such as the details of the atomic structure, the quantum mechanical treatment of the electronic structure, which is mainly based on density functional theory (
DFT
), the computer codes for solving
DFT
, the parameters that determine the accuracy of the results, and various properties that can be derived from
DFT
calculations. This chapter introduces these simulation techniques and illustrates, for selected examples, which insights can be gained in structure–property relations.
Basic Properties of Well‐Known Intermetallics and Some New Complex Magnetic Intermetallics
Authors: Entel Peter 
Published: August 2017

AbstractThe structural, electronic, and magnetic properties of novel functional magnetic intermetallics, in particular some of the most prominent magnetic Heusler alloys, have been reviewed with emphasis on their complex magnetic behavior and nonergodic glassy features, in contrast to the well‐known properties ofTi‐NiandNi‐Alshape memory alloys. Calculational procedures have been listed throughout the text and the theoretical results have been compared with experimental findings where possible. The thermodynamic properties of a few systems (Ni–Co–Mn–In), which undergo a structural phase transformation of displacive nature in conjunction with a metamagnetic first‐order phase transition, have been discussed in detail. The importance of such magnetostructural phase transition together with the so‐called thermodynamic (kinetic) arrest phenomenon for the appearance of a giant magnetocaloric effect has been underlined. The list of references should allow bridging the gap between shape memory alloys such asTi–Ni(including recentab initiocalculations that explain the rapid decrease of the martensitic transformation temperature with disorder) and the “exotic properties” of the magnetic intermetallics.
Self‐healing Materials
Authors: Hager Martin D. 
Published: August 2017

AbstractIn contrast to classical man‐made materials, self‐healing materials are capable of restoring their original functionality after being damaged. Scratches in the surface can be closed; the mechanical properties can be restored. This behavior is familiar for natural materials; consequently, several design strategies for self‐healing materials have been inspired by natural processes. For instance bleeding off a small cut was mimicked by the encapsulation of healing agents. In the past few years many different general healing mechanisms, which can provide a self‐healing ability, have been investigated. All these mechanisms have one general theme in common: mobility is generated within the material in order to achieve the healing process. Depending on the different material classes, different strategies have been utilized. The main approaches to obtain self‐healing metals, self‐healing ceramics, self‐healing concrete, self‐healing asphalt, and self‐healing polymers will be presented. Due to the intrinsic properties and limitations of each material class, not all approaches can be applied for each material. Both metals and ceramics require often high temperatures for the healing processes. Concrete can be healed at room temperature due to its intrinsic properties and a kind of a natural ability for self‐healing. Moreover, asphalt as well as polymers can also be healed at room temperature or at slightly elevated temperatures. At present, different self‐healing materials have already reached the status of commercialization. This fact demonstrates the capability of this novel approach for material design.
Hydrogenation by Metals
Authors: Jin Xin , Chaudhari Raghunath V. 
Published: August 2017

AbstractHydrogenation of organic compounds with metal catalysts has been reviewed. Classification of hydrogenation reactions with different functional groups, their general characteristics, and applications are discussed. The conventional as well as novel‐structured catalysts with advances in preparation methods are reviewed. This is a brief review for a quick guidance on hydrogenation by metals with relevant references for more details.
Catalysis by Metal Carbides and Nitrides
Authors: Nash Connor , Yung Matt , Chen Yuan , Carl Sarah , Thompson Levi , Schaidle Josh 
Published: August 2017

AbstractEarly transition metal carbides and nitrides (ETMCNs), materials in which carbon or nitrogen occupies interstitial sites within a parent metal lattice, possess unique physical and chemical properties that motivate their use as catalysts. Specifically, these materials possess multiple types of catalytic sites, including metallic, acidic, and basic sites, and as such, exhibit reactivities that differ from their parent metals. Moreover, their surfaces are dynamic under reaction conditions. This chapter reviews recent (since 2010) experimental and computational investigations into the catalytic properties ofETMCNmaterials for applications including biomass conversion, syngas andCO2upgrading, petroleum and natural gas refining, and electrocatalytic energy conversion, energy storage, and chemicals production, and attempts to link catalyst performance to active site identity/surface structure in order to elucidate the present level of understanding of structure–function relationships for these materials. The chapter concludes with a perspective on leveraging the unique properties of these materials to design and develop improved catalysts through a dedicated, multidisciplinary effort.
High Energy and High Power Lithium‐Ion Capacitors Based on Boron and Nitrogen Dual‐Doped 3D Carbon Nanofibers as Both Cathode and Anode
Authors: Xia Qiuying , Yang Hai , Wang Min , Yang Mei , Guo Qiubo , Wan Liming , Xia Hui , Yu Yan 
Published: August 2017

AbstractHigh energy density at high power density is still a challenge for the current Li‐ion capacitors (LICs) due to the mismatch of charge‐storage capacity and electrode kinetics between capacitor‐type cathode and battery‐type anode. In this work, B and N dual‐doped 3D porous carbon nanofibers are prepared through a facile method as both capacitor‐type cathode and battery‐type anode for LICs. The B and N dual doping has profound effect in tuning the porosity, functional groups, and electrical conductivity for the porous carbon nanofibers. With rational design, the developed B and N dual‐doped carbon nanofibers (BNC) exhibit greatly improved electrochemical performance as both cathode and anode for LICs, which greatly alleviates the mismatch between the two electrodes. For the first time, a 4.5 V “dual carbon” BNC//BNC LIC device is constructed and demonstrated, exhibiting outstanding energy density and power capability compared to previously reported LICs with other configurations. In specific, the present BNC//BNC LIC device can deliver a large energy density of 220 W h kg−1 and a high power density of 22.5 kW kg−1 (at 104 W h kg−1) with reasonably good cycling stability (≈81% retention after 5000 cycles).
Geotechnische Aspekte beim Bau der Großforschungsanlage FAIR
Authors: Kissel Wolfgang , Toker Engin , Reul Oliver 
Published: August 2017

AbstractIn Darmstadt entsteht derzeit mit dem neuen Teilchenbeschleuniger FAIR eine der weltweit größten Forschungsanlagen. Herzstück von FAIR ist ein großer, unterirdischer Ringbeschleuniger von 1,1 km Länge, an den sich 24 Gebäude und Tunnelabschnitte anschließen, die Raum bieten für 3,5 km Strahlführung, für Experimentier‐ und Speicherringe sowie für riesige Teilchendetektoren. Wegen der Anforderungen des Strahlenschutzes sind die Wände und Decken der Bauwerke, deren Gründungssohle sich z. T. bis 21 m unter der Geländeoberfläche befindet, bis zu 8 m dick.Um die In‐situ‐Verformungseigenschaften des Baugrunds, i. W. kompressible Ablagerungen des Pliozän und Miozän, besser einschätzen zu können, wurde eine Probeschüttung aufgebracht sowie Pfahlprobebelastungen und Ankerzugversuche durchgeführt. Auf Grundlage dieser Untersuchungen sowie von 3D‐Finite‐Elemente‐Berechnungen wurden als Gründungen für die setzungsempfindlichen Bauwerke Kombinierte Pfahl‐Plattengründungen gewählt, mit denen die Setzungen und die Winkelverdrehungen auf ein verträgliches Maß reduziert werden. In der ersten Bauphase wurden bereits ca. 1 350 Gründungspfähle mit einer Gesamtbohrlänge (inkl. Leerbohrungen) von rd. 60 000 m und max. Bohrlängen von bis zu 62 m hergestellt.Im Rahmen dieses Beitrags werden die Ergebnisse der Probebelastungen präsentiert sowie geotechnische Aspekte bei der Planung der tiefen Baugruben und der Gründung im Hinblick auf die außergewöhnlichen Projektrandbedingungen diskutiert.
Getting down and dirty: An exploration of participation in the field of obstacle challenges
Authors: Maguire Louise 
Published: August 2017

AbstractThis paper examines the contemporary phenomenon of obstacle challenges and why people participate in events that result in them getting soaking wet, freezing cold, and dirtier than they have ever been while also getting shot with pellets and receiving “electric shocks.” Many participants in these challenges have taken part numerous times and keep coming back for more. Using multiple research methods including questionnaires, participant observation where the author completed one of Ireland's more well‐known and “toughest physical and mental endurance challenges,” and also depth interviews with challenge participants has resulted in a rich and detailed account of the obstacle challenge experience. These events are so much more than a few hours of strenuous and muddy physical exercise. The sense of community and camaraderie that people experience during these challenges could be described as “transformative” with participants in many cases more rewarded and moved by this collaborative aspect than the gruelling physical endeavour that they undertake. The escapism provided by the experience is also one its main rewards, relief from the quotidian and the chance to just “be.” The servicescape proves to be critically important to the experience but in ways that are largely incompatible with research in this area to date in that the comfort and cleanliness expected of more traditional servicescapes are spurned and physical hardship is welcomed. As this is an exploratory and novel research topic, suggestions for further research are plentiful.
Expression analysis of cellulose synthase and main cytoskeletal protein genes in flax (Linum usitatissimum L.)
Authors: Galinousky Dmitry , Padvitski Tsimafei , Bayer Galina , Pirko Yaroslav , Pydiura Nikolay , Anisimova Natallia , Nikitinskaya Tatyana , Khotyleva Liubov , Yemets Alla , Kilchevsky Aleksandr , Blume Yaroslav 
Published: August 2017

AbstractFiber flax is an important source of natural fiber and a comprehensive model for the plant fiber biogenesis studies. Cellulose‐synthase (CesA) and cytoskeletal genes are known to be important for the cell wall biogenesis in general and for the biogenesis of flax fibers in particular. Currently, knowledge about activity of these genes during the plant growth is limited. In this study, we have investigated flax fiber biogenesis by measuring expression of CesA and cytoskeletal genes at two stages of the flax development (seedlings and stems at the rapid growth stage) in several flax subspecies (elongatum, mediterraneum, crepitans). RT‐qPCR has been used to quantify the expression of LusСesA1, LusСesA4, LusСesA7, LusСesA6, Actin, and α‐Tubulin genes in plant samples. We report that CesA genes responsible for the secondary cell wall synthesis (LusCesA4, LusCesA7) have different expression pattern compared with CesA genes responsible for the primary cell wall synthesis (LusCesA1, LusCesA6): an average expression of LusCesA4 and LusCesA7 genes is relatively high in seedlings and further increases in stems at the rapid growth stage, whereas an average expression of LusCesA1 and LusCesA6 genes decreases. Interestingly, LusCesA1 is the only studied gene with different expression dynamics between the flax subspecies: its expression decreases by 5.2–10.7 folds in elongatum and mediterraneum but does not change in crepitans subspecies when the rapid growth stage and seedlings are compared. The expression of cytoskeleton genes (coding actin and α‐tubulin) is relatively stable and significantly higher than the expression of cellulose‐synthase genes in all the studied samples.
Electrode‐Resolved Monitoring of the Ageing of Large‐Scale Lithium‐Ion Cells by using Electrochemical Impedance Spectroscopy
Authors: Heins Tom Patrick , Schlüter Nicolas , Schröder Uwe 
Published: August 2017

AbstractThe ageing of large‐scale lithium‐ion batteries due to prolonged cycling was investigated by means of electrochemical impedance spectroscopy. The resulting spectra were analyzed by using the method of the distribution of relaxation times. Thereby, the number of distinguishable polarization processes that contribute to the overall cell electrochemistry was determined. The physical meaning of these polarization processes was clarified by the assessment of their temperature dependences as well as by comparative measurements in three‐electrode setup cells. In this way, electrode‐resolved interpretation of impedance spectra of large‐scale lithium‐ion cells without any kind of reference electrode was achieved. Based on this electrode resolution, the origin of the cell degradation due to cycling could be elucidated.
Bayes factor biases for non‐nested models and corrections
Authors: Susko Edward 
Published: August 2017

AbstractWith the advent of simulation‐based methods to obtain samples from posteriors and due to increases in computational power, Bayesian methods are increasingly applied to complex problems, sometimes providing the only available methods where likelihood implementations are difficult. As a consequence a large body of research in science and social science increasingly utilizes Bayesian tools, often applying them with default settings. A fundamental problem of interest is model selection, and Bayes factors provide a natural approach to Bayesian model selection. Using Laplace approximations and illustrative examples we demonstrate that Bayes factors can have strong biases toward particular models even in non‐nested settings with the same number of parameters. Several easily implemented corrections are shown to provide effective cross‐checks to default Bayes Factors.The Canadian Journal of Statistics45: 290–309; 2017 © 2017 Statistical Society of Canada
Interface Engineering of Perovskite Solar Cells with Air Plasma Treatment for Improved Performance
Authors: Ma Xiao , Tang Peng , Liu Dong , Zhang Jingquan , Feng Lianghuan , Wu Lili 
Published: August 2017

AbstractFor high‐efficiency perovskite solar cells (PSCs), interface engineering becomes critical for carrier collection from the active perovskite material to the transport layer. To enhance the power conversion efficiency (PCE), herein we demonstrate a novel method named surface plasma treatment on a mesoporous TiO2 electron‐transport layer (ETL) to improve electron extraction and transport properties at the perovskite/TiO2 interface. According to the XPS results, the plasma treatment induced a partial reduction of Ti4+ to Ti3+ within the TiO2 lattice and increased the concentration of oxygen vacancies on the TiO2 surface. Ultraviolet photoelectron spectra (UPS) show that the Fermi level of TiO2 upshifts about 0.2 eV which may effectively promote carrier separation and transfer at the perovskite/TiO2 interface. In addition, these created donor levels of Ti3+ and oxygen vacancies donate extra electrons, increasing the conductivities of TiO2 films and which could further promote transport. The time‐resolved photoluminescence spectra (TRPL) confirm that the decay time decreases dramatically from 656 ns to 235 ns after 90 s plasma treatment, which indicates a more efficient electron‐transfer process. Based on all the above‐mentioned results, a remarkable enhancement in cell efficiency was obtained, such that the average efficiency was improved from 11.5 % to 14.3 % under AM 1.5G irradiation (100 mW cm−2).
Does Confinement Always Lead to Thermodynamically and/or Kinetically Favorable Reactions? A Case Study using Diels–Alder Reactions within ExBox+4 and CB[7]
Authors: Chakraborty Debdutta , Das Ranjita , Chattaraj Pratim Kumar 
Published: August 2017

AbstractThe front cover artwork is provided by the group of Prof. Pratim K. Chattaraj (IIT Kharagpur). The image shows a Diels–Alder reaction occurring between 1,3‐butadiene and ethylene within ExBox+4 and Cucurbit[7]uril. Read the full text of the article at 10.1002/cphc.201700308.
Miocene depositional environments, processes, and depositional elements in the southern Gulf of Mexico
Authors: Gutiérrez Paredes Hilda Clarisa , Catuneanu Octavian , Hernández Romano Ulises 
Published: August 2017

Detailed stratigraphic and facies analyses were conducted and combined with seismic facies and 3D seismic‐derived plan view images to interpret the depositional environments, processes and depositional elements during the Miocene for an area located in the southern Gulf of Mexico.The results showed that deposition during the Miocene mainly occurred in a slope setting, with bathymetric changes associated with highs and mini‐basins related to salt features. From the sedimentological interpretation, 13 sedimentary facies were identified. The abundant lithofacies were structureless (massive) sandstone and massive mudstone. Ripple‐ , parallel and cross‐laminated sandstone and siltstone were found in minor proportions. The main depositional processes were related to turbidity currents, including high‐density and low‐density currents; debris flows (mud flows and grain flows) were of secondary importance, as was deposition from fallout of suspended hemipelagic mud particles.The vertical and lateral distributions of facies revealed seven facies associations linked to depositional environments. These facies associations were the building blocks that were used to characterize the depositional elements recognized on seismic data. The main depositional elements identified were mass‐transport complexes, submarine channels, and frontal splays.Finally, interpretations from different data sets enabled the conclusion that, during the Miocene in this area were submarine fans deposited on an irregular paleotopography, with topographic lows and highs controlled by salt tectonics.
Structural analysis of ductile shear zones in the North Qinling Orogen and its implications for the evolution of the Proto‐Tethys Ocean
Authors: Zhao Shujuan , Li Sanzhong , Li Xiyao , Somerville Ian , Cao Huahua , Liu Xin , Wang Pengcheng 
Published: August 2017

The ductile shear zones in the North Qinling Orogen, such as the Luonan‐Luanchuan, Guanpo‐Qiaoduan, Zhuyangguan‐Xiaguan, and Shangdan shear zones, play an important role in the preclosure and postclosure evolution of the Proto‐Tethys Ocean. On the basis of detailed macrostructural/microstructural analysis and quartz C‐axis electron backscattered diffraction fabric analysis, the sense and formation environment of the 4 shear zones have been obtained. The Luonan‐Luanchuan and Guanpo‐Qiaoduan shear zones mainly present as dextral and sinistral shearing under low temperature, respectively. The Zhuyangguan‐Xiaguan shear zone mainly presents as dextral shearing under medium temperature. The Shangdan shear zone underwent an early dextral shearing under medium temperature and a late sinistral shearing under low temperature. The Qinling Group and the Taibai region were intensively affected by the late sinistral shearing of the Shangdan shear zone. According to published metamorphic ages, the 4 shear zones should have been formed during the collision between the North China Block and the South China Block. Due to the opening of the Mianlue and the Paleo‐Tethys oceans since ~380 Ma, the North China Block and the South China Block departed from northern Gondwanaland and drifted northward along transform faults, which led to the arrangement between the North China Block and the South China Block that transited from an east–west direction to a north–south direction. Since ~320 Ma, the scissors‐type closure between the North China Block and the South Qinling Terrane led to the westward extrusion of the North Qinling Orogen, and the dextral shearing of the Luonan‐Luanchuan and the Zhuyangguan‐Xiaguan shear zones and the sinistral shearing of the Guanpo‐Qiaoduan and the Shangdan shear zones.
Optimal cyclic quaternary constant‐weight codes of weight three
Authors: Lan Liantao , Chang Yanxun 
Published: August 2017

AbstractA cyclic code is a cyclic q‐ary code of length n, constant weight w and minimum distance d. Let denote the largest possible size of a cyclic code. The pure and mixed difference method plays an important role in the determination of upper bound on . By analyzing the distribution of odd mixed and pure differences, an improved upper bound on is obtained for . A new construction based on special sequences is provided and the exact value of is almost completely determined for all d and n except when and . Our constructions reveal intimate connections between cyclic constant weight codes and special sequences, particularly Skolem‐type sequences.