bluuebunny/crossref_metadata_2025 huggingface dataset:
Magnetic ordering in Gd2Fe2Si2C
Authors: Susilo R. A. , Cadogan J. M. , Hutchison W. D. , Campbell S. J.
Published: January 2014

The intrinsic magnetism of Gd2Fe2Si2C has been investigated using magnetization and specific heat measurements. Gd2Fe2Si2C orders magnetically below 58 K, consistent with the de Gennes scaling observed for the remaining (heavy‐R) R2Fe2Si2C compounds.A second magnetic event at ∼38 K is also observed in the susceptibility and specific heat data which might signal a spin–reorientation transition. Field dependent magnetometry suggests that the magnetic structure of this compound is quite complex.
Towards a practice‐based view of strategy
Authors: Bromiley Philip , Rau Devaki
Published: January 2014

Many studies in strategic management attempt to explain macro‐level firm behaviors or characteristics and/or the influence of such behaviors or characteristics on firm performance. Current strategy scholarship, however, rarely considers specific, actual techniques that managers might use to develop strategies or generally applicable firm practices. We propose a practice‐based view (PBV) of strategy scholarship to address this gap. In contrast with the resource‐based view emphasis on things that other firms cannot imitate, thePBVexamines publicly known, imitable activities, or practices amenable to transfer across firms. We provide evidence for thePBVand discuss its contribution to strategy. ThePBVhas two important implications, one relating to potential explanations for performance and the other relating to the kinds of prescription strategy that scholars might offer. Copyright © 2014 John Wiley & Sons, Ltd.
The politics of climate change in the UK
Authors: Carter Neil
Published: January 2014

Between 2006 and 2010 climate change rose rapidly up the UK political agenda and the Labour Government, with cross‐party support, introduced major changes in domestic climate and energy policy, including the landmark Climate Change Act 2008, which represented an important step toward the UK becoming a low carbon economy. Cross‐party consensus was initially sustained by the Conservative‐Liberal Democrat Coalition, before growing criticism from the political right began to turn climate change into an increasingly partisan issue, thereby weakening the commitment of David Cameron to climate leadership. The article examines the transition of climate change from low politics to high politics, assessing the role of public opinion, the media, business, environmental groups, and party competition in overcoming the obstacles to progressive climate change and energy policy. The roles of party politics and of individual political leadership are identified as critical factors in raising the profile of climate change and delivering radical policy change. The significance of the growing partisan divisions over climate change is assessed.

This article is categorized under:

The Carbon Economy and Climate Mitigation > Policies, Instruments, Lifestyles, Behavior

Policy and Governance > National Climate Change Policy
Synthesis and Characterization of an Azobenzene‐Functionalized Ethene‐Bridged PMO
Authors: Gräfenstein Lydia , Venkatachalam Sabarinathan , van Wüllen Leo , Bensch Wolfgang
Published: January 2014

The azobenzene‐functionalized ethene‐bridged periodic mesoporous organosilica (PMO) was synthesized in a three step process. After synthesizing the pure PMO the azobenzene switch was post synthetically grafted at the ethene bridge. The successful synthesis was verified by N2 sorption measurements, IR spectroscopy, elemental analysis, and solid state MAS‐NMR spectroscopy. The switching process of the azobenzene was proven by UV/Vis measurements.
Inverse Opal SiO2 Photonic Crystals as Structurally‐Colored Pigments with Additive Primary Colors
Authors: Josephson David P. , Miller Matthew , Stein Andreas
Published: January 2014

Porous silica, structured as three‐dimensionally ordered macroporous (3DOM) photonic crystal particles, is investigated as a pigment material with structural color. Brightly and uniformly colored 3DOM SiO2 powders were obtained by templating of a tetraethoxysilane‐containing precursor in polymeric colloidal crystals, pyrolysis in an inert atmosphere to maintain a small amount (ca. 5–8 wt %) of residual carbon as a background absorber, and particle size reduction. The color depended on placing optical stop bands in the appropriate range of the visible spectrum. This was achieved through selection of the polymer sphere diameter in the colloidal crystal template and fine‐tuning by the pyrolysis temperature, which controls the extent of condensation and shrinkage of the 3DOM SiO2 structure. The stop bands shifted to shorter wavelengths, and the chroma of these pigments increased with increasing pyrolysis temperature in the range from 475 to 900 °C. Using this temperature control, it was possible to obtain materials with a variety of colors and chroma using a single template sphere size. In addition, the assortment of spectral colors could be extended by mixing 3DOM SiO2 pigments with primary colors (red, green, blue) via a unique additive color‐mixing mechanism, which distinguishes these pigments from most conventional pigments that rely on subtractive color mixing. These approaches enable the preparation of pigments with multiple colors using a single material composition, providing opportunities to replace potentially harmful dyes and pigments with nontoxic and relatively inert silica.
Novel Carbons: Habits and Oddities
Authors: Boulfelfel Salah Eddine , Selli Daniele , Leoni Stefano
Published: January 2014

Carbon is a surprising material in all respects. In this Review, we present results of metadynamics calculations for crystal structure prediction of novel carbon polymorphs with even and odd rings. So‐called superhard graphite results from cold‐compressing graphite. We review the results of molecular dynamics simulations on the graphite‐to‐diamond phase transition, that yields Oganov's M‐carbon. The latter, like some of the modifications predicted by metadynamics, features five‐ and seven‐membered odd rings. We identify the role of odd rings at times of phase nucleation, and we speculate on the preference for odd‐membered rings over even motifs in a context of nucleation and phase growth.
Relationship Strength and Network Form: An Agent-Based Simulation of Interaction in a Business Network
Authors: Prenkert Frans , Følgesvold Atle
Published: January 2014

Given an international business network with the same focal resource, the same source and markets, but exhibiting two different inter-related sub-networks with different internal organization, we study how these network forms affects interactions. The purpose is to compare and explain differences between the two network forms and the effects this have on dyadic international relationship development using a qualitative experimental methodology involving computerized simulations. We simulate various changes in quality variation of the focal resource as well as changing demand preferences of buyers to investigate the impact on relationship strength. From this we develop three scenarios.
The Story of King Jannaeus (b. Qiddušin66a): A Pharisaic Reply to Sectarian Polemic
Authors: Noam Vered
Published: January 2014

As is well known, no Pharisaic document has survived. What we know of this Jewish faction has been transmitted through the mediation of other, frequently hostile, factions, or later sources. The sudden discovery of a Pharisaic document hidden in a cave somewhere would certainly arouse profound interest and excitement. In what follows, I would like to propose that the story of the rupture between King Jannaeus and the Pharisees recounted inb. Qiddušin66a is actually such a discovery, except that it was not concealed in a sealed jar but rather embedded in the Babylonian Talmud (BT).
Possible reason of ionospheric anomaly post the April 20, 2013, Mw = 6.6 China' Lushan earthquake: Applying two-dimensional principal component analysis (2DPCA) to two-dimensional total electron content (TEC)
Authors: Lin Jyh-Woei
Published: January 2014

In this study, two-dimensional principal component analysis (2DPCA) was used to determine the reason for the ionospheric two-dimensional total electron content (TEC) anomaly after China's Lushan earthquake at 00:02:47 UT on April 20, 2013 (Mw = 6.6). TEC data from 00:00 to 00:15 (UT) on April 20, 2013 were examined. The TEC anomaly was very intense 00:05 to 00:10 (UT) after the earthquake. One potential cause of the TEC anomaly, which might have been a density variance, is a rising acoustic shock wave, with speed of at least 1127.82, ms−1, resulting from the mainshock. The duration of the TEC anomaly was at least 5 min.
Terahertz wave generation by beating of two spatial-Gaussian lasers in collisional plasma
Authors: Sharifian M. , Sharifinejad H. R. , Golbakhsi H.
Published: January 2014

This paper revisits the resonant excitation of terahertz (THz) radiation by beating of two spatial-Gaussian laser beams shaving different frequencies and wave numbers but the same electric fields, where the ponderomotive force in the transverse direction is resulted due to the beating and spatial variation of the field of lasers. Effect of the electron-neutral collision frequency on the THz wave generation in the collisional plasma has been discussed.
Effects of morphodynamics and across-shore physical gradients on benthic macroinfauna on two sandy beaches in south-eastern Brazil
Authors: Santos Joaquim N.S. , Gomes Rafaela de S. , Vasconcellos Ruan Managna , Silva Débora de Souza , Araújo Francisco Gerson
Published: January 2014

We examined the benthic macroinfauna at three strata during two seasons (winter and summer) on two sandy beaches (dissipative and reflective) in south-eastern Brazil. The hypothesis raised is that effects of morphodynamics and zonation determine the structure of macroinfauna, with dissipative beaches having comparatively higher species richness and density than the reflective beaches. Flamengo beach (dissipative) had higher species richness but lower density compared to Grumari beach (reflective). A high dissimilarity in assemblage structure (91.75%) was detected between the two beaches. Zonation in the occurrence of macroinfauna was detected for the two beaches in the two examined seasons. At Grumari beach, Emerita brasiliensis occurred mainly in stratum 1 (intertidal swept zone) while Saccocirus sp. occurred in stratum 2 (infralittoral at 0.5 m depth), whereas at Flamengo beach E. brasiliensis and Enoploides sp. had the highest density in stratum 1 (intertidal swept zone) whereas Scolelepis goodbodyi and Donax uncinata dominated in stratum 3 (infralittoral at 1.0 m depth). Scolelepis goodbodyi, Dispio uncinata, Enoploides sp., Nematoda and Trileptium sp. were associated with higher a Dean parameter and content of organic matter at Flamengo beach. In contrast, Hastula sp., Donax sp., Pisionidens indica, Hemipodus californiensis, Saccocirus sp. and Phyllodocidae were associated with the higher wave period and grain size of Grumari beach. The hypothesis that macroinfauna structure differs between the beaches and strata was confirmed, with the dissipative beaches having comparatively higher richness but lower density than the reflective beaches.
ENTROPY OF SOME MODELS OF SPARSE RANDOM GRAPHS WITH VERTEX-NAMES
Authors: Aldous David J. , Ross Nathan
Published: January 2014

Consider the setting of sparse graphs on N vertices, where the vertices have distinct “names”, which are strings of length O(log N) from a fixed finite alphabet. For many natural probability models, the entropy grows as c N log N for some model-dependent rate constant c. The mathematical content of this paper is the (often easy) calculation of c for a variety of models, in particular for various standard random graph models adapted to this setting. Our broader purpose is to publicize this particular setting as a natural setting for future theoretical study of data compression for graphs, and (more speculatively) for discussion of unorganized versus organized complexity.
Kant's Only Possible Argument and Chignell's Real Harmony
Authors: Abaci Uygar
Published: January 2014

Andrew Chignell recently proposed an original reconstruction of Kant's ‘Only Possible Argument’ for the existence of God. Chignell claims that what motivates the ‘Grounding Premise’ of Kant's proof, ‘real possibility must be grounded in actuality’, is the requirement that the predicates of a really possible thing must be ‘really harmonious’, i.e. compatible in an extra-logical or metaphysical sense. I take issue with Chignell's reconstruction. First, the pre-Critical Kant does not present ‘real harmony’ as a general condition of real possibility. Second, the real harmony requirement is not what motivates the ‘Grounding Premise’ of the proof. Instead, this premise is sufficiently motivated by what Chignell labels the ‘content’ requirement. Finally, Kant's downgrading of the proof in his Critical period is not based on a concern regarding the real harmony of the predicates of God, but on his Critical restrictions on cognition in general and modal cognition in particular.
Can Positive Duties be Derived from Kant's Formula of Universal Law?
Authors: Kahn Samuel
Published: January 2014

According to the standard reading of Kant's formula of universal law (FUL), positive duties can be derived from FUL. In this article, I argue that the standard reading does not work. In the first section, I articulate FUL and what I mean by a positive duty. In the second section, I set out an intuitive version of the standard reading of FUL and argue that it does not work. In the third section, I set out a more rigorous version of the standard reading of FUL and argue that even this more rigorous version does not work.
Commentary on Chapter 15 of Patricia Kitcher's Kant's Thinker
Authors: Rosefeldt Tobias
Published: January 2014

I argue that Patricia Kitcher's Kant-inspired account of self-consciousness overintellectualizes the requirements for rational cognition. Kitcher claims that a person can only believe something on the ground of another belief if she is able to recognize the grounding belief as grounding the first belief and as one of her own. I criticize this claim by arguing that (i) someone can believe something for a certain reason without recognizing this reason as a reason (the possibility of unreflected reasons), and that (ii) she can recognize something as a reason for something else without being able to self-ascribe either her original belief or the belief that grounds it (the possibility of reflected but not self-conscious reasons).
‘Kant our Contemporary’? Kitcher on the Fruitfulness of Kant's Theory of the Cognitive Subject
Authors: Sturm Thomas
Published: January 2014

In chapter 15 of Kant's Thinker, Patricia Kitcher claims that we can treat Kant as ‘our contemporary’, and that his theory of apperception ‘offers “new” and plausible perspectives on issues of considerable recent interest’. I question this with respect to two of her four chosen topics. First, I address her attempt to show that Kant's theory of apperceptive self-knowledge is immune to sceptical doubts of the sort Barry Stroud presents. Second, I turn to her argument that this theory is superior to current accounts of the special authority of self-knowledge. Over and above specific weaknesses, it seems that Kitcher's considerations generally lack sufficient reflection on how philosophical arguments of the past can be relevant to current agendas.
The Nature of the ‘I Think’: Comments on Chapter 11 ofKant's Thinker
Authors: Wunderlich Falk
Published: January 2014

The article deals with Kant's theory of the self in Patricia Kitcher'sKant's Thinkerin three respects: (1) I argue that it is doubtful whether accompanying representations with the ‘I think’ as such yields a principle for the categories since it does not require any strong kind of connection between them. (2) I discuss textual evidence for and against Kitcher's attempt to make sense of Kant's claim that the ‘I think’ requires the continued existence of cognizersper se. (3) I ask whether Kitcher's understanding of Kant's positive theory of the self leans towards minimal substantialism or towards functionalism.
Poverty Reduction in Urban China: The Impact of Cash Transfers
Authors: Wu Alfred M. , Ramesh M.
Published: January 2014

The extent to which social protection programmes in general, and targeted programmes in particular, actually alleviate poverty has been a central issue in development debates for decades. The objective of this article is to contribute to the debate by empirically examining the poverty-alleviation effects of one of the largest targeted programmes in the world: the Minimum Living Standard Assistance (MLSA) or Dibao in China. Using newly available data on MLSA spending and a unique panel survey dataset covering the 1993 to 2009 period, this research investigates the impact of the MLSA on poverty alleviation. The analyses using fixed-effects and random-effects logit models and hierarchical liner models offer insights that go beyond the existing studies on the subject. Findings from the study confirm that targeted social protection programmes are an effective tool for reducing poverty.
Microsatellite high-resolution melting (SSR-HRM) analysis for genotyping and molecular characterization of an Olea europaea germplasm collection
Authors: Xanthopoulou Aliki , Ganopoulos Ioannis , Koubouris Georgios , Tsaftaris Athanasios , Sergendani Chrysa , Kalivas Apostolos , Madesis Panagiotis
Published: January 2014

Olea europaea L. has been cultivated in the Mediterranean region for thousands of years and is of major economic importance. The origin of olive cultivars remains as complex to trace as their identification. Thus, their molecular characterization and discrimination will enable olive germplasm management. In addition, it would be a useful tool for authentication of olive products. High-resolution melting (HRM) analysis, coupled with five microsatellite markers, was integrated to facilitate molecular identification and characterization of main O. europaea cultivars collected from the National Olive Tree Germplasm Collection established in Chania, Greece. The five microsatellite loci used were highly informative and generated a unique melting curve profile for each of the 47 cultivars and for each microsatellite tested. In particular, three microsatellite markers (DCA03, DCA09 and DCA17), which generated 29 HRM profiles, were sufficient to genotype all the olive cultivars studied, highlighting their potential use for cultivar identification. Furthermore, this assay provided a flexible, cost-effective and closed-tube microsatellite genotyping method well suited for molecular characterization of olive cultivars.
Public law and the value of conceptual analysis
Authors: Mauthe Barbara
Published: January 2014

The goal of this paper is to demonstrate the viability and potential of conceptual analysis as a methodological tool. It is argued that conceptual analysis represents a flexible and open method for connecting public law with analyses that are different, and even incommensurable with its own epistemology. The particular area that this paper seeks to connect public law with is that of feminist critiques. It is a journey that does not occur without some difficulty. Conceptual analysis is unknown within public law and therefore the notion requires defining and explaining. Public law has also been particularly resistant to the inclusion of feminist critiques and therefore the task of identifying suitable concepts is not straightforward. The outcome is, however, not only the identification of a new methodological tool for public lawyers but the capacity to broaden the range of material that can be incorporated within their analyses.
Legislating personhood: realising the right to support in exercising legal capacity
Authors: Flynn Eilionoir , Arstein-Kerslake Anna
Published: January 2014

This paper examines the regulation of ‘personhood’ through the granting or denying of legal capacity. It explores the development of the concept of personhood through the lens of moral and political philosophy. It highlights the problem of upholding cognition as a prerequisite for personhood or the granting of legal capacity because it results in the exclusion of people with cognitive disabilities (intellectual, psycho-social, mental disabilities, and others). The United Nations Convention on the Rights of Persons with Disabilities (CRPD) challenges this notion by guaranteeing respect for the right to legal capacity for people with disabilities on an equal basis with others and in all areas of life (Article 12). The paper uses the CRPD to argue for a conception of personhood that is divorced from cognition and a corresponding recognition of legal capacity as a universal attribute that all persons possess. Finally, a support model for the exercise of legal capacity is proposed as a possible alternative to the existing models of substituted decision-making that deny legal capacity and impose outside decision-makers.
Dye chemistry with time-dependent density functional theory
Authors: Laurent Adèle D. , Adamo Carlo , Jacquemin Denis
Published: January 2014

We present a representative panel of TD-DFT applications in the colour chemistry field.
Superamphiphobic surfaces
Authors: Chu Zonglin , Seeger Stefan
Published: January 2014

Progress in superamphiphobic surfaces, including the characterization, different techniques towards the fabrication of surface roughness and surface modification with low-surface-energy materials as well as their applications, is reviewed.
Vapour phase hydrocyclisation of levulinic acid to γ-valerolactone over supported Ni catalysts
Authors: Mohan Varkolu , Venkateshwarlu Velpula , Pramod Chodimella Venkata , Raju Burri David , Rao Kamaraju Seetha Rama
Published: January 2014

A Ni/SiO2 catalyst is found to be effective for the hydrogenation of levulinic acid to yield γ-valerolactone with a quantitative yield in vapour phase conditions at atmospheric pressure without any additives.
Rapid decomposition and visualisation of protein–ligand binding free energies by residue and by water
Authors: Woods Christopher J. , Malaisree Maturos , Michel Julien , Long Ben , McIntosh-Smith Simon , Mulholland Adrian J.
Published: January 2014

Recent advances in computational hardware, software and algorithms enable simulations of protein–ligand complexes to achieve timescales during which complete ligand binding and unbinding pathways can be observed. While observation of such events can promote understanding of binding and unbinding pathways, it does not alone provide information about the molecular drivers for protein–ligand association, nor guidance on how a ligand could be optimised to better bind to the protein. We have developed the waterswap (C. J. Woodset al.,J. Chem. Phys., 2011,134, 054114) absolute binding free energy method that calculates binding affinities by exchanging the ligand with an equivalent volume of water. A significant advantage of this method is that the binding free energy is calculated using a single reaction coordinate from a single simulation. This has enabled the development of new visualisations of binding affinities based on free energy decompositions to per-residue and per-water molecule components. These provide a clear picture of which protein–ligand interactions are strong, and which active site water molecules are stabilised or destabilised upon binding. Optimisation of the algorithms underlying the decomposition enables near-real-time visualisation, allowing these calculations to be used either to provide interactive feedback to a ligand designer, or to provide run-time analysis of protein–ligand molecular dynamics simulations.
Probing the interaction of spermine and 1-naphthyl acetyl spermine with DNA polynucleotides: a comparative biophysical and thermodynamic investigation
Authors: Kabir Ayesha , Kumar Gopinatha Suresh
Published: January 2014

The interaction of spermine and its analogue, 1-naphthyl acetyl spermine with four double stranded DNA polynucleotides has been studied to understand the structural and thermodynamic basis of the binding.
Self-modification of titanium dioxide materials by Ti3+ and/or oxygen vacancies: new insights into defect chemistry of metal oxides
Authors: Su Juan , Zou Xiaoxin , Chen Jie-Sheng
Published: January 2014

In this review, we highlight the recent research efforts towards understanding the defect chemistry of titanium dioxide. Particular attention is paid to the synthesis of self-modified TiO2 materials with Ti3+/oxygen vacancies and the favorable effects of these defects on the properties and applications of the obtained materials.
Sandwich-structured MnO2/polypyrrole/reduced graphene oxide hybrid composites for high-performance supercapacitors
Authors: Han Guangqiang , Liu Yun , Kan Erjun , Tang Jian , Zhang Lingling , Wang Huanhuan , Tang Weihua
Published: January 2014

Sandwich-structured hierarchical (MnO2, PPy)/rGO nanosheets composites exhibited a maximum specific capacitance of 404 F g−1 and ∼91% of capacitance retention over 5000 cycling.
A water soluble FRET-based ratiometric chemosensor for Hg(ii) and S2−applicable in living cell staining
Authors: Sen Buddhadeb , Mukherjee Manjira , Pal Siddhartha , Dhara Koushik , Mandal Sushil Kumar , Khuda-Bukhsh Anisur Rahman , Chattopadhyay Pabitra
Published: January 2014

A new water soluble rhodamine-based ratiometric dual ‘off–on–off’ probe can selectively detect Hg2+ions in ppb level through time dependent FRET process with reversibility in presence of S2−anions.
A rhodamine based “off-on” probe for selective detection of Hg(ii) and subsequent l-proline and 4-hydroxyproline discrimination
Authors: Pal Ajoy , Bag Bamaprasad
Published: January 2014

The Rhodamine derivatized probe 2 selectively coordinates with Hg(ii) ions to exhibit dual mode “turn-on” signaling, subsequently ‘turned-off’ with addition of l-proline, specific among various amino acids due to its favorable coordination environment.
Stereoselective construction of all-carbon quaternary center by means of chiral phosphoric acid: highly enantioselective Friedel–Crafts reaction of indoles with β,β-disubstituted nitroalkenes
Authors: Mori Keiji , Wakazawa Manari , Akiyama Takahiko
Published: January 2014

Chiral phosphoric acid catalyzed Friedel–Crafts reaction of indoles with β-alkoxycarbonyl-β-disubstituted nitroalkenes was achieved.
Multiple sorption cycles evaluation of cadmium oxide–alkali metal halide mixtures for pre-combustion CO2 capture
Authors: Vogt Christian , Knowles Gregory P. , Chaffee Alan L.
Published: January 2014

Both powdered and pelletised CdO–NaI composite CO2 sorbents were tested in reversible CO2 sorption experiments. Sorption capacity stability improved in moist environments and if pre-treated in inert gas.
Digital colour tone for fluorescence sensing: a direct comparison of intensity, ratiometric and hue based quantification
Authors: Hakonen Aron , Beves Jonathon E. , Strömberg Niklas
Published: January 2014

Standard digital cameras combined with hue-parameter photoscopy demonstrate simple yet superior and high-performance quantitative fluorescence sensing and imaging of pH.
Paper-based standard addition assays
Authors: Chaplan Cory A. , Mitchell Haydn T. , Martinez Andres W.
Published: January 2014

Standard addition assays conducted on paper-based microfluidic devices are introduced as an alternative to external standards for calibrating quantitative tests. To demonstrate this technique, a colorimetric, paper-based, standard addition assay was optimized for the determination of glucose concentrations in the range of 0 to 5 mM. Comparable results were obtained from the assay via digital image colorimetry under three different lighting conditions.
Organelle-selective fluorescent Cu2+ion probes: revealing the endoplasmic reticulum as a reservoir for Cu-overloading
Authors: Lee Yun Hak , Park Nayoung , Park Young Bin , Hwang Yu Jeong , Kang Chulhun , Kim Jong Seung
Published: January 2014

Two novel Cu2+sensors, bearing naphthalimide and a DPA moiety, were synthesized to study copper accumulation in organelles and serve as a valuable tool to elucidate the subcellular location of copper ions.
Lewis acid promoted C–C and copper-catalyzed C–O bond formation: synthesis of neoflavans
Authors: Suchand B. , Krishna J. , Mritunjoy K. , Satyanarayana G.
Published: January 2014

An intramolecular [Cu]-catalyzed C–O bond formation for the synthesis of neoflavans is presented.
2000 hours photostability testing of dye sensitised solar cells using a cobalt bipyridine electrolyte
Authors: Jiang Roger , Anderson Assaf , Barnes Piers R. F. , Xiaoe Li , Law Chunhung , O'Regan Brian C.
Published: January 2014

DSSCs incorporating Co(ii/iii) tris(bipyridine) redox couple in acetonitrile and the Z907 dye were subjected to ≥2000 hours of light soaking at 20 °C and ∼1 sun light intensity from white LEDs (∼no UV component).
Effects of carbonic anhydrase-related protein VIII on human cells harbouring an A8344G mitochondrial DNA mutation
Authors: Wang Tze-Kai , Cheng Che-Kun , Chi Tang-Hao , Ma Yi-Shing , Wu Shi-Bei , Wei Yau-Huei , Hsieh Mingli
Published: January 2014

MERRF (myoclonus epilepsy associated with ragged-red fibres) is a maternally inherited mitochondrial encephalomyopathy with various syndromes involving both muscular and nervous systems. The most common mutation in MERRF syndrome, the A8344G mutation in mtDNA, has been associated with severe defects in the respiratory function of mitochondria. In the present study, we show that there is a significant decrease in CA8 (carbonic anhydrase-related protein VIII) in cybrids harbouring the MERRF A8344G mutation. CA8 deficiency and mutations were found to be associated with a distinctive lifelong gait disorder in wdl (Waddles) mice and novel syndromes characterized by cerebellar ataxia and mental retardation in humans. The results of the present study showed that overexpression of CA8 in MERRF cybrids significantly decreased cell death induced by STS (staurosporine) treatment, suggesting a protective function of CA8 in cells harbouring the A8344G mutation of mtDNA. Interestingly, an increase in the formation of LC3-II (microtubule-associated protein 1 light chain 3-II) was found in the cybrids with down-regulated CA8 expression, suggesting that reduced expression of CA8 leads to autophagy activation. Furthermore, cybrids exhibiting down-regulated CA8 showed increased cytosolic Ca2+ signals and reduced levels of phospho-Akt compared with those in the cybrids with overexpressed CA8, indicating that phospho-Akt is involved in the protection of cells by CA8. Our findings suggest that CA8 is involved in the autophagic pathway and may have a protective role in cultured cells from patients with MERRF. Targeting CA8 and the downstream autophagic pathway might help develop therapeutic agents for treatment of MERRF syndrome in the future.
One‐pot synthesis and characteristics of ZnO/Ag composites
Authors: Zhang Guoqing , Lu Lijiang , Zhang Zhaoxia , Zhou Lan , Shao Jianzhong
Published: January 2014

A simple one‐pot hydrothermal method was used to prepare ZnO/Ag composites by adding zinc acetate and silver nitrate in turn into a high temperature glycol solvent. The ZnO/Ag composites were characterised by powder X‐ray diffraction, scanning electron microscopy, transmission electron microscopy and photoluminescence (PL). The results show that the octahedral ZnO particle was synthesised, before the spherical silver nanoparticles were reduced and uniformly adhered onto the surface of the ZnO. The PL spectra indicated that doping of the silver improves the PL property of the composites.
High field magnetotransport and point contact Andreev reflection measurements on CuCr2Se4 and CuCr2Se3Br—Degenerate magnetic semiconductor single crystals
Authors: Borisov K. , Alaria J. , Coey J. M. D. , Stamenov P.
Published: January 2014

Single crystals of the metallically degenerate fully magnetic semiconductors CuCr2Se4 and CuCr2Se3Br have been prepared by the Chemical Vapour Transport method, using either Se or Br as transport agents. The high-quality, millimetre-sized, octahedrally faceted, needle- and platelet-shaped crystals are characterised by means of high field magnetotransport (μ0H≤ 14 T) and Point Contact Andreev Reflection. The relatively high spin polarisation observed |P|>0.56, together with the relatively low minority carrier effective mass of 0.25 me, and long scattering time  10−13 s, could poise these materials for integration in low- and close-to-room temperature minority injection bipolar heterojunction transistor demonstrations.
Setup for in situ investigation of gases and gas/solid interfaces by soft x-ray emission and absorption spectroscopy
Authors: Benkert A. , Blum M. , Meyer F. , Wilks R. G. , Yang W. , Bär M. , Reinert F. , Heske C. , Weinhardt L.
Published: January 2014

We present a novel gas cell designed to study the electronic structure of gases and gas/solid interfaces using soft x-ray emission and absorption spectroscopies. In this cell, the sample gas is separated from the vacuum of the analysis chamber by a thin window membrane, allowing in situ measurements under atmospheric pressure. The temperature of the gas can be regulated from room temperature up to approximately 600 °C. To avoid beam damage, a constant mass flow can be maintained to continuously refresh the gaseous sample. Furthermore, the gas cell provides space for solid-state samples, allowing to study the gas/solid interface for surface catalytic reactions at elevated temperatures. To demonstrate the capabilities of the cell, we have investigated a TiO2 sample behind a mixture of N2 and He gas at atmospheric pressure.
Ultrasensitive quartz crystal microbalance enabled by micropillar structure
Authors: Wang Pengtao , Su Junwei , Dai Wen , Cernigliaro George , Sun Hongwei
Published: January 2014

We report a method to significantly enhance the mass sensitivity of a quartz crystal microbalance (QCM) device in which Polymethyl Methacrylate (PMMA) micropillars were fabricated on QCM surface to form a two-degrees-of-freedom vibration system. PMMA micropillars were fabricated using nanoimprinting lithography technology. The QCM-micropillar coupled system exhibits a unique resonant frequency, near which the mass sensitivity of QCM can be enhanced by several orders of magnitude. Both numerical simulation and theoretical analysis were conducted to understand this improvement. Thereafter, ultrahigh sensitivity of the QCM-micropillar system was demonstrated by detecting a 1H, 1H, 2H, 2H-perfluorooctyl-trichlorosilane single monolayer film.
Analytic energy gradients for constrained DFT-configuration interaction
Authors: Kaduk Benjamin , Tsuchimochi Takashi , Van Voorhis Troy
Published: January 2014

The constrained density functional theory-configuration interaction (CDFT-CI) method has previously been used to calculate ground-state energies and barrier heights, and to describe electronic excited states, in particular conical intersections. However, the method has been limited to evaluating the electronic energy at just a single nuclear configuration, with the gradient of the energy being available only via finite difference. In this paper, we present analytic gradients of the CDFT-CI energy with respect to nuclear coordinates, which gives the potential for accurate geometry optimization and molecular dynamics on both the ground and excited electronic states, a realm which is currently quite challenging for electronic structure theory. We report the performance of CDFT-CI geometry optimization for representative reaction transition states as well as molecules in an excited state. The overall accuracy of CDFT-CI for computing barrier heights is essentially unchanged whether the energies are evaluated at geometries obtained from quadratic configuration-interaction singles and doubles (QCISD) or CDFT-CI, indicating that CDFT-CI produces very good reaction transition states. These results open up tantalizing possibilities for future work on excited states.
The role of space charge compensation for ion beam extraction and ion beam transport (invited)
Authors: Spädtke Peter
Published: January 2014

Depending on the specific type of ion source, the ion beam is extracted either from an electrode surface or from a plasma. There is always an interface between the (almost) space charge compensated ion source plasma, and the extraction region in which the full space charge is influencing the ion beam itself. After extraction, the ion beam is to be transported towards an accelerating structure in most cases. For lower intensities, this transport can be done without space charge compensation. However, if space charge is not negligible, the positive charge of the ion beam will attract electrons, which will compensate the space charge, at least partially. The final degree of Space Charge Compensation (SCC) will depend on different properties, like the ratio of generation rate of secondary particles and their loss rate, or the fact whether the ion beam is pulsed or continuous. In sections of the beam line, where the ion beam is drifting, a pure electrostatic plasma will develop, whereas in magnetic elements, these space charge compensating electrons become magnetized. The transport section will provide a series of different plasma conditions with different properties. Different measurement tools to investigate the degree of space charge compensation will be described, as well as computational methods for the simulation of ion beams with partial space charge compensation.
A hybrid analog-digital phase-locked loop for frequency mode non-contact scanning probe microscopy
Authors: Mehta M. M. , Chandrasekhar V.
Published: January 2014

Non-contact scanning probe microscopy (SPM) has developed into a powerful technique to image many different properties of samples. The conventional method involves monitoring the amplitude, phase, or frequency of a cantilever oscillating at or near its resonant frequency as it is scanned across the surface of a sample. For high Q factor cantilevers, monitoring the resonant frequency is the preferred method in order to obtain reasonable scan times. This can be done by using a phase-locked-loop (PLL). PLLs can be obtained as commercial integrated circuits, but these do not have the frequency resolution required for SPM. To increase the resolution, all-digital PLLs requiring sophisticated digital signal processors or field programmable gate arrays have also been implemented. We describe here a hybrid analog/digital PLL where most of the components are implemented using discrete analog integrated circuits, but the frequency resolution is provided by a direct digital synthesis chip controlled by a simple peripheral interface controller (PIC) microcontroller. The PLL has excellent frequency resolution and noise, and can be controlled and read by a computer via a universal serial bus connection.
Configuration-dependent electronic and magnetic properties of graphene monolayers and nanoribbons functionalized with aryl groups
Authors: Tian Xiaoqing , Gu Juan , Xu Jian-bin
Published: January 2014

Graphene monolayers functionalized with aryl groups exhibit configuration-dependent electronic and magnetic properties. The aryl groups were adsorbed in pairs of neighboring atoms in the same sublattice A (different sublattices) of graphene monolayers, denoted as the M2AA (M2AB) configuration. The M2AA configuration behaved as a ferromagnetic semiconductor. The band gaps for the majority and minority bands were 1.1 eV and 1.2 eV, respectively. The M2AB configuration behaved as a nonmagnetic semiconductor with a band gap of 0.8 eV. Each aryl group could induce 1 Bohr magneton (μB) into the molecule-graphene system. Armchair graphene nanoribbons (GNRs) exhibited the same configuration-dependent magnetic properties as the graphene monolayers. The net spin of the functionalized zigzag GNRs was mainly localized on the edges demonstrating an adsorption site-dependent magnetism. For the zigzag GNRs, both the M2AA and M2AB configurations possibly had a magnetic moment. Each aryl group could induce 1.5–3.5 μB into the molecule-graphene system. There was a metal-to-insulator transition after adsorption of the aryl groups for the zigzag GNRs.
Microscopic dynamics perspective on the relationship between Poisson's ratio and ductility of metallic glasses
Authors: Ngai K. L. , Wang Li-Min , Liu Riping , Wang W. H.
Published: January 2014

In metallic glasses a clear correlation had been established between plasticity or ductility with the Poisson's ratio νPoisson and alternatively the ratio of the elastic bulk modulus to the shear modulus, K/G. Such a correlation between these two macroscopic mechanical properties is intriguing and is challenging to explain from the dynamics on a microscopic level. A recent experimental study has found a connection of ductility to the secondary β-relaxation in metallic glasses. The strain rate and temperature dependencies of the ductile-brittle transition are similar to the reciprocal of the secondary β-relaxation time, τβ. Moreover, metallic glass is more ductile if the relaxation strength of the β-relaxation is larger and τβ is shorter. The findings indicate the β-relaxation is related to and instrumental for ductility. On the other hand, K/G or νPoisson is related to the effective Debye-Waller factor (i.e., the non-ergodicity parameter), f0, characterizing the dynamics of a structural unit inside a cage formed by other units, and manifested as the nearly constant loss shown in the frequency dependent susceptibility. We make the connection of f0 to the non-exponentiality parameter n in the Kohlrausch stretched exponential correlation function of the structural α-relaxation function, $\phi (t) = \exp [ { - ( {\frac{t}{{\tau _\alpha }}})^{1 - n} }]$ϕ(t)=exp[−(tτα)1−n]. This connection follows from the fact that both f0 and n are determined by the inter-particle potential, and 1/f0 or (1 − f0) and n both increase with anharmonicity of the potential. A well tested result from the Coupling Model is used to show that τβ is completely determined by τα and n. From the string of relations, (i) K/G or νPoisson with 1/f0 or (1 − f0), (ii) 1/f0 or (1 − f0) with n, and (iii) τα and n with τβ, we arrive at the desired relation between K/G or νPoisson and τβ. On combining this relation with that between ductility and τβ, we have finally an explanation of the empirical correlation between ductility and the Poisson's ratio νPoisson or K/G based on microscopic dynamical properties.
Metallophilic interactions from dispersion-corrected density-functional theory
Authors: Otero-de-la-Roza Alberto , Mallory Joel D. , Johnson Erin R.
Published: January 2014

In this article, we present the first comprehensive study of metallophilic (aurophilic) interactions using dispersion-corrected density-functional theory. Dispersion interactions (an essential component of metallophilicity) are treated using the exchange-hole dipole moment (XDM) model. By comparing against coupled-cluster benchmark calculations on simple dimers, we show that LC-ωPBE-XDM is a viable functional to study interactions between closed-shell transition metals and that it performs uniformly better than second-order Møller-Plesset theory, the basic computational technique used in previous works. We apply LC-ωPBE-XDM to address several open questions regarding metallophilicity, such as the interplay between dispersion and relativistic effects, the interaction strength along group 11, the additivity of homo- and hetero-metallophilic effects, the stability of [E(AuPH3)4]+ cations (E = N, P, As, Sb), and the role of metallophilic effects in crystal packing. We find that relativistic effects explain the prevalence of aurophilicity not by stabilizing metal-metal contacts, but by preventing gold from forming ionic structures involving bridge anions (which are otherwise common for Ag and Cu) as a result of the increased electron affinity of the metal. Dispersion effects are less important than previously assumed and their stabilization contribution is relatively independent of the metal.
Three-dimensional patchy lattice model: Ring formation and phase separation
Authors: Tavares J. M. , Almarza N. G. , Telo da Gama M. M.
Published: January 2014

We investigate the structural and thermodynamic properties of a model of particles with 2 patches of type A and 10 patches of type B. Particles are placed on the sites of a face centered cubic lattice with the patches oriented along the nearest neighbor directions. The competition between the self-assembly of chains, rings, and networks on the phase diagram is investigated by carrying out a systematic investigation of this class of models, using an extension of Wertheim's theory for associating fluids and Monte Carlo numerical simulations. We varied the ratio r ≡ εAB/εAA of the interaction between patches A and B, εAB, and between A patches, εAA (εBB is set to 0) as well as the relative position of the A patches, i.e., the angle θ between the (lattice) directions of the A patches. We found that both r and θ (60°, 90°, or 120°) have a profound effect on the phase diagram. In the empty fluid regime (r < 1/2) the phase diagram is reentrant with a closed miscibility loop. The region around the lower critical point exhibits unusual structural and thermodynamic behavior determined by the presence of relatively short rings. The agreement between the results of theory and simulation is excellent for θ = 120° but deteriorates as θ decreases, revealing the need for new theoretical approaches to describe the structure and thermodynamics of systems dominated by small rings.
Optimization of high frequency characteristics in Co-Ta thin films
Authors: Chang H. W. , Chuang L. C. , Shih C. W. , Chang W. C. , Xue D. S.
Published: January 2014

Magnetic properties and high frequency characteristics of binary Co100−xTax (x = 0–24) thin films, prepared by using the oblique sputtering method under an external magnetic field of 1200 Oe have been studied. All the Co100−xTax films are easy to form amorphous phase, and thus exhibit strong in-plane uniaxial magnetic anisotropy, high resistivity, and low coercivity. With increasing x, the saturation magnetization (4πMs) and coercivity along the easy and hard axes (Hce and Hch) are decreased, while the magnetic anisotropy field (Hk) reaches the maximum value of 578 Oe for the films with the composition to become fully amorphous phase. Due to large Hk, high ferromagnetic-resonance frequency (fFMR) of 4.7–6.6 GHz is obtained for Co100−xTax (x = 11–24) films. The optimal magnetic properties of 4πMs = 10.9 kG, Hce = 6.2 Oe, Hch = 6.0 Oe, Hk = 507 Oe, and high resonance characteristics of fFMR = 6.4 GHz, respectively, are reached for Co84Ta16 films. Finally, high fFMR of 5.4–7.2 GHz and Hk of 434–617 Oe can be tuned by the modification of the sputtering parameters. This result reflects the benefit of Co100−xTax (x = 11–22) films for above 5 GHz applications.
Spin-orbit torque magnetization switching of a three-terminal perpendicular magnetic tunnel junction
Authors: Cubukcu Murat , Boulle Olivier , Drouard Marc , Garello Kevin , Onur Avci Can , Mihai Miron Ioan , Langer Juergen , Ocker Berthold , Gambardella Pietro , Gaudin Gilles
Published: January 2014

We report on the current-induced magnetization switching of a three-terminal perpendicular magnetic tunnel junction by spin-orbit torque and its read-out using the tunnelling magnetoresistance (TMR) effect. The device is composed of a perpendicular Ta/FeCoB/MgO/FeCoB stack on top of a Ta current line. The magnetization of the bottom FeCoB layer can be switched reproducibly by the injection of current pulses with density 5 × 1011 A/m2 in the Ta layer in the presence of an in-plane bias magnetic field, leading to the full-scale change of the TMR signal. Our work demonstrates the proof of concept of a perpendicular spin-orbit torque magnetic memory cell.