bluuebunny/crossref_metadata_2025 huggingface dataset:
Mystic London
Authors: Davies Charles Maurice
Published: October 2011

The Anglican clergyman and founding member of the Society of the Holy Cross, Charles Maurice Davies (1828–1910), published Mystic London in 1875. The work is a collection of Davies' observations and researches into urban spiritualism. It includes descriptions of London mesmerists, mediums and séances, and discussions of Darwinism, secularism and the non-religious. Davies, who discovered spiritualism in Paris in the mid-1850s, and became a committed spiritualist after the death of his son in 1865, argued in this work that the principles and practices of spiritualism did not pose any threat to Christianity and that the two movements had much in common and could peacefully coexist. The work is an indispensable source on the presence of alternative religion in London and for the beliefs and practices of nineteenth-century spiritualists. It offers a fascinating insight into Victorian experiences and attitudes towards the occult and the supernatural.
The Life and Works of Goethe
Authors: Lewes George Henry
Published: October 2011

Johann Wolfgang von Goethe (1749–1832) was one of Germany's greatest intellectuals. He exerted enormous influence in many fields, through works ranging from literature, linguistics and philosophy to the theory of colours and the biological sciences. Goethe's poetry and plays inspired music and opera as well as later writers, and his thought influenced philosophers including Nietzsche and Jung. Darwin himself referred to Goethe's botanical studies. The British philosopher and literary critic G. H. Lewes (1817–1878) carried out research for this hugely successful two-volume biography during a trip to Berlin and Weimar in 1854. First published in 1855, and reissued here in the second, 1858 edition, it draws on personal letters and recollections provided by Goethe's closest friends, family and colleagues to construct a portrait of this polymath, and assess how his personal relationships shaped his legacy to the world. Volume 1 focuses on Goethe's early life until 1779.
London Past and Present
Authors: Wheatley Henry Benjamin , Cunningham Peter
Published: October 2011

The bibliographer and editor Henry Benjamin Wheatley (1838–1917) produced a prodigious number of books and articles on a wide range of topics, literary, historical, bibliographical and artistic. He worked for many years for the Royal Society and the Royal Society of Arts, was a founder member of the Library Association, and produced an edition of Pepys' diary which was not superseded until the 1970s. London Past and Present was published in 1891, expanding and updating Peter Cunningham's Handbook of London of 1849. It is a three-volume topographical and historical dictionary of London places and landmarks, and the people who lived there. Based on historical, literary and architectural sources, it reveals many fascinating details as it traces the development of the metropolis from medieval times to the time of writing. Nineteenth-century London was experiencing rapid change, and this work preserves the memory of many buildings now lost.
A Comparative View of the Huttonian and Neptunian Systems of Geology
Authors: Murray John
Published: October 2011

John Murray (1778–1820) was a public lecturer and writer on chemistry and geology. After attending the University of Edinburgh he became a popular public lecturer on chemistry and pharmacy. He was also a prolific writer of chemistry textbooks which were widely used in British universities. This popular volume, first published anonymously in 1802, contains Murray's critical response to John Playfair's volume Illustrations of the Huttonian Theory of the Earth, also published in 1802 and re-issued in this series. In this volume Murray clearly describes both the competing Huttonian and Neptunian (also known as Wernerian) theories of rock formation. Using much of the same geological evidence as Playfair, Murray also objectively analyses the theories' claims through rock and fossil formations and concludes in support of the Wernerian theory. This valuable volume explores one of the major geological controversies of the period and illustrates the main contemporary criticisms of Hutton's work.
Thermodynamics of the Earth and Planets
Authors: Patiño Douce Alberto
Published: October 2011

This textbook provides an intuitive yet mathematically rigorous introduction to the thermodynamics and thermal physics of planetary processes. It demonstrates how the workings of planetary bodies can be understood in depth by reducing them to fundamental physics and chemistry. The book is based on two courses taught by the author for many years at the University of Georgia. It includes 'Guided Exercise' boxes; end-of-chapter problems (worked solutions provided online); and software boxes (Maple code provided online). As well as being an ideal textbook on planetary thermodynamics for advanced students in the Earth and planetary sciences, it also provides an innovative and quantitative complement to more traditional courses in geological thermodynamics, petrology, chemical oceanography and planetary science. In addition to its use as a textbook, it is also of great interest to researchers looking for a 'one stop' source of concepts and techniques that they can apply to their research problems.
Sketches of Persia
Authors: Malcolm John
Published: October 2011

Sketches of Persia, although published anonymously in 1827, is attributed to Sir John Malcolm (1769–1833). Malcolm was a diplomat and administrator in India: arriving at the age of fourteen in 1783 to work for the East India Company, he was known during his long career as 'Boy' Malcolm. He swiftly moved into more political and diplomatic roles. He became fluent in Persian and was despatched to Persia for part of his career, though he would eventually return to India and become Governor of Bombay (1827–1830). In Volume 1 of Sketches, Malcolm starts the journey from Bombay, sailing into the Persian Gulf, arriving at Abusheher, where he stays many weeks. From there his party moves inland into the mountains, and finally reaches Shiraz and then Persepolis. Throughout his journey, Malcolm fills this work with his observations about the people he meets, and recounts Persian folk stories and fables.
Measurement in Medicine
Authors: de Vet Henrica C. W. , Terwee Caroline B. , Mokkink Lidwine B. , Knol Dirk L.
Published: October 2011

The success of the Apgar score demonstrates the astounding power of an appropriate clinical instrument. This down-to-earth book provides practical advice, underpinned by theoretical principles, on developing and evaluating measurement instruments in all fields of medicine. It equips you to choose the most appropriate instrument for specific purposes. The book covers measurement theories, methods and criteria for evaluating and selecting instruments. It provides methods to assess measurement properties, such as reliability, validity and responsiveness, and interpret the results. Worked examples and end-of-chapter assignments use real data and well-known instruments to build your skills at implementation and interpretation through hands-on analysis of real-life cases. All data and solutions are available online. This is a perfect course book for students and a perfect companion for professionals/researchers in the medical and health sciences who care about the quality and meaning of the measurements they perform.
The Appearance of Print in Eighteenth-Century Fiction
Authors: Flint Christopher
Published: October 2011

Eighteenth-century fiction holds an unusual place in the history of modern print culture. The novel gained prominence largely because of advances in publishing, but, as a popular genre, it also helped shape those very developments. Authors in the period manipulated the appearance of the page and print technology more deliberately than has been supposed, prompting new forms of reception among readers. Christopher Flint's book explores works by both obscure 'scribblers' and canonical figures, such as Swift, Haywood, Defoe, Richardson, Sterne and Austen, that interrogated the complex interactions between the book's material aspects and its producers and consumers. Flint links historical shifts in how authors addressed their profession to how books were manufactured and how readers consumed texts. He argues that writers exploited typographic media to augment other crucial developments in prose fiction, from formal realism and free indirect discourse to accounts of how 'the novel' defined itself as a genre.
Letters and Memorials of Jane Welsh Carlyle
Authors: Carlyle Jane Welsh
Published: October 2011

Widely recognised as one of the greatest female letter writers in English, Jane Welsh Carlyle (1801–1866) possessed a famous sense of wit and irony, which, together with her keen observational skills, made her an important literary figure in her own right. This three-volume set of her letters, published in 1883 and annotated throughout by her husband Thomas Carlyle, represents a fine example of the letter-writing genre. The publication of the letters made a significant contribution to a growing acceptance and critical recognition of this often dismissed literary form. In Volume 2 (from 1847 to 1859) the reader will find humorous observations of eminent figures of the time, such as Emerson and Ruskin, witness Jane's strong devotion to her mother and sympathise with her failing health. Her descriptions of everyday life will entertain and amuse, and will reveal a fascinating insight into the highs and lows of her marriage.
Spatial distribution of antimicrobial peptides and mast cells in the skin of the external auditory canal
Authors: Yoon Y J , Lee E J
Published: October 2011

Objective:

The direct activity of antimicrobial peptides against microbes is thought to be an essential first line of defence in the skin; however, little is known about antimicrobial peptide secretion in the skin of the external auditory canal. Evidence suggests that mast cells contribute to the secretion of antimicrobial peptides. This study aimed to examine the distribution of mast cells and antimicrobial peptides, including human β-defensin-1 and -2 and LL-37, in the external auditory canal skin.

Methods:

External auditory canal skin samples from 12 patients undergoing middle-ear surgery with canaloplasty were immunohistochemically stained to detect expression of mast cell markers (tryptase and chymase) and antimicrobial peptides (human β-defensin-1 and -2 and LL-37).

Results:

Mast cells and human β-defensin-1 were present in the ceruminous glands but not in the sebaceous glands. The increased presence of mast cells, human β-defensin-1 and LL-37 in ceruminous glands suggests that mast cells may participate in the secretion of antimicrobial peptides from ceruminous glands.

Conclusion:

These findings suggest that mast cells contribute to the secretion of antimicrobial peptides in the ceruminous glands of the external auditory canal skin.
Conundrums in species concepts: the discovery of a new cryptic species segregated from Parmelina tiliacea(Ascomycota: Parmeliaceae)
Authors: NÚÑEZ-ZAPATA Jano , DIVAKAR Pradeep K. , DEL-PRADO Ruth , CUBAS Paloma , HAWKSWORTH David L. , CRESPO Ana
Published: October 2011

Parmelina tiliacea is a common, widely distributed species in south-western Europe, easily identifiable by morphology and much used as an air pollution bioindicator in many regions. A molecular phylogenetic survey of samples from many geographical areas, using Maximum Parsimony and Bayesian inference of nuITS and mtLSU rDNA regions, revealed a group of samples geographically restricted to a small region of the Iberian Peninsula and genetically separated from the other P. tiliacea specimens studied. These samples are morphologically indistinguishable from P. tiliacea, apart from subtle anatomical characters in the ascomata (hyphae of the exciple and ascospore width), which are frequently absent. Although geographically different, the two taxa occupy similar habitats and are even sympatric in some areas, indicating that they do not exchange genetic material. This previously overlooked, and apparently endemic lineage, is described as P. cryptotiliacea sp. nov., and the name Lichen tiliaceus is epitypified by a sequenced specimen to fix the application of Parmelina tiliacea to the widespread genotype. A second unexpected result was the discovery that the morphologically distinct P. pastillifera was nested within P. tiliacea. These two cases stress the need to use molecular tools to elucidate species concepts even within widespread morphologically well-characterized macrolichens. Such investigations are necessary to improve our understanding and estimation of biodiversity, and to facilitate the development of sound biodiversity conservation strategies for lichens.
Using genetic distances in addition to ITS molecular phylogeny to identify potential species in theParmotrema reticulatumcomplex: a case study
Authors: DEL-PRADO Ruth , DIVAKAR Pradeep K. , CRESPO Ana
Published: October 2011

We used a genetic distance approach in conjunction with molecular phylogeny to establish species boundaries and detect cryptic lineages in theParmotrema reticulatum–P. pseudoreticulatumcomplex. The phylogeny of specimens from a broad geographic distribution was reconstructed from the internal transcribed spacer region. Pairwise genetic distances were calculated and compared to an intraspecific range defined for the parmelioid lichens to circumscribe species-level groups. Our results showed thatP. reticulatumandP. pseudoreticulatumare polyphyletic, being comprised of at least seven well-supported lineages. In contrast, the genetic distance approach revealed ten cryptic lineages within theP. reticulatum–P. pseudoreticulatumcomplex. Neither morphology nor geography was conclusive in attempting to corroborate these genetic lineages. However FSTindices suggest significant genetic differentiation between these lineages. Our results suggest that the morphology-based circumscriptions underestimated species inParmotremaand that, in some cases, genetic distances may be used as an additional tool to determine species boundaries in morphologically cryptic species complexes. The most significant contribution of the present study is the application of a fast and accurate method to identify problematic groups and candidate species using the ITS locus with a genetic distances approach.
Intertidal meiofauna communities along an estuarine gradient in a protected area (Ria de Foz, north-west Spain)
Authors: Rubal M. , Besteiro C. , Veiga P.
Published: October 2011

The northern Galician rias provide important economic and social services from fisheries, shellfish harvesting and recreational activities. Consequently, these rias have been included in the Nature 2000 Network as a Special Conservation Zone. The aims of this study were to describe the meiofauna spatial structure in terms of diversity and abundance of major taxa, as well as its relationship with the environmental characteristics in the Ria de Foz nature reserve. For this aim, environmental gradients and distribution patterns of intertidal meiobenthic communities at the Ria de Foz nature reserve were studied using multivariate methods. Ria de Foz showed to be a complex transitional habitat with significant changes in its environment along the estuarine gradient. An abundant and rich meiofauna community was reported at Ria de Foz. A total of 21 higher taxa of meiofauna were found. The most common taxa were nematodes, copepods, ostracods and turbellarians. Three clear different meiobenthic communities were defined. These three communities showed a clear spatial distribution pattern along the estuarine gradient. Moreover, a high degree of similarity between distribution patterns of meiobenthic communities and previously studied macrobenthic communities was found. Regarding the role of environmental factors shaping meiobenthic community distribution patterns distance to the river mouth was the environmental variable that best explained meiobenthic community structure and distribution. Therefore, changes on hydrodynamics that affect environmental factors related to the estuarine gradient will change the distribution pattern and diversity of benthic communities. This work provides the first information about meiobenthos diversity and structure in the Ria de Foz nature reserve and should be useful for future management and conservation plans on this and other similar protected areas.
Increased plasticity of the bodily self in eating disorders
Authors: Eshkevari E. , Rieger E. , Longo M. R. , Haggard P. , Treasure J.
Published: October 2011

Background

The rubber hand illusion (RHI) has been widely used to investigate the bodily self in healthy individuals. The aim of the present study was to extend the use of the RHI to examine the bodily self in eating disorders (EDs).

Method

The RHI and self-report measures of ED psychopathology [the Eating Disorder Inventory – 3 (EDI-3) subscales of Drive for Thinness, Bulimia, Body Dissatisfaction, Interoceptive Deficits, and Emotional Dysregulation; the 21-item Depression, Anxiety and Stress Scale (DASS-21); and the Self-Objectification Questionnaire (SOQ)] were administered to 78 individuals with an ED and 61 healthy controls.

Results

Individuals with an ED experienced the RHI significantly more strongly than healthy controls on both perceptual (i.e. proprioceptive drift) and subjective (i.e. self-report questionnaire) measures. Furthermore, both the subjective experience of the RHI and associated proprioceptive biases were correlated with ED psychopathology. Approximately 23% of the variance for embodiment of the fake hand was accounted for by ED psychopathology, with interoceptive deficits and self-objectification significant predictors of embodiment.

Conclusions

These results indicate that the bodily self is more plastic in people with an ED. These findings may shed light on both aetiological and maintenance factors involved in EDs, particularly visual processing of the body, interoceptive deficits, and self-objectification.
Early references to collective punishment in an excavated Chinese text: analysis and discussion of an imprecation from the Wenxian covenant texts
Authors: Williams Crispin
Published: October 2011

Susan Roosevelt Weld has observed that the Houma and Wenxian covenant texts, excavated texts dating to the fifth centurybc, can be considered “examples of collective responsibility”. New materials from the Wenxian covenant texts provide further evidence relevant to this issue. In this article I present my analysis of a previously unseen imprecation, “Cause [you] to have no descendants” 俾毋有胄後. I suggest the excavated covenants provide the earliest references found in a legal context to collective punishment, a practice that, while archaic in origin, is generally better known from Qin and later penal codes. I also discuss the scope of the termshì氏, as it is used in the imprecation, in the context of Mark Lewis's work defining basic social units in the Zhou period.
Action sequencing using dynamic movement primitives
Authors: Nemec Bojan , Ude Aleš
Published: October 2011

General-purpose autonomous robots must have the ability to combine the available sensorimotor knowledge in order to solve more complex tasks. Such knowledge is often given in the form of movement primitives. In this paper, we investigate the problem of sequencing of movement primitives. We selected nonlinear dynamic systems as the underlying sensorimotor representation because they provide a powerful machinery for the specification of primitive movements. We propose two new methodologies which both ensure that consecutive movement primitives are joined together in a continuous way (up to second-order derivatives). The first is based on proper initialization of the third-order dynamic motion primitives and the second uses online Gaussian kernel functions modification of the second-order dynamic motion primitives. Both methodologies were validated by simulation and by experimentally using a Mitsubishi PA-10 articulated robot arm. Experiments comprehend pouring, table wiping, and carrying a glass of liquid.
An elementary proof and an extension of Thas' theorem on k-arcs
Authors: Kaneta Hitoshi , Maruta Tatsuya
Published: October 2011

Let q be the finite field of q elements. Denote by Sr q the projective space of dimension r over q. In Sr,q, where r ≥ 2, a k-arc is defined (see [4]) as a set of k points such that no j + 2 lie in a Sj,q, for j = 1,2,…, r−1. (For a k-arc with k > r, this last condition holds for all j when it holds for j = r−1.) A rational curve Cn of order n in Sr,q, is the set
Object clitics and their omission in child L2 French: The contributions of processing limitations and L1 transfer
Authors: GRÜTER THERES , CRAGO MARTHA
Published: October 2011

This article explores the widely documented difficulty with object clitics in the acquisition of French. The study investigates the effects of L1 transfer and processing limitations on the production and comprehension of object clitics in child L2 learners of French with different L1 backgrounds (Chinese, Spanish). The Spanish-speaking learners performed better than Chinese-speaking learners on clitic-related tasks, indicating a facilitative effect of transfer when the L1 also has object clitics. Yet no evidence was found for (negative) transfer of null objects from Chinese to French, as learners consistently rejected interpretations requiring referential null objects on a receptive task. The frequency of Chinese-speaking learners’ object omissions in production was negatively correlated with an independent measure of working memory (backward digit span), consistent with the hypothesis that object clitic omission is affected by processing limitations. These findings are discussed within a psycholinguistic model of syntactic encoding during language production.
Regulation by mitochondrial superoxide and NADPH oxidase of cellular formation of nitrated cyclic GMP: potential implications for ROS signalling
Authors: Ahmed Khandaker Ahtesham , Sawa Tomohiro , Ihara Hideshi , Kasamatsu Shingo , Yoshitake Jun , Rahaman Md. Mizanur , Okamoto Tatsuya , Fujii Shigemoto , Akaike Takaaki
Published: October 2011

8-Nitro-cGMP (8-nitroguanosine 3′,5′-cyclic monophosphate) is a nitrated derivative of cGMP, which can function as a unique electrophilic second messenger involved in regulation of an antioxidant adaptive response in cells. In the present study, we investigated chemical and biochemical regulatory mechanisms involved in 8-nitro-cGMP formation, with particular focus on the roles of ROS (reactive oxygen species). Chemical analyses demonstrated that peroxynitrite-dependent oxidation and myeloperoxidase-dependent oxidation of nitrite in the presence of H2O2 were two major pathways for guanine nucleotide nitration. Among the guanine nucleotides examined, GTP was the most sensitive to peroxynitrite-mediated nitration. Immunocytochemical and tandem mass spectrometric analyses revealed that formation of 8-nitro-cGMP in rat C6 glioma cells stimulated with lipopolysaccharide plus pro-inflammatory cytokines depended on production of both superoxide and H2O2. Using the mitochondria-targeted chemical probe MitoSOX™ Red, we found that mitochondria-derived superoxide can act as a direct determinant of 8-nitro-cGMP formation. Furthermore, we demonstrated that Nox2 (NADPH oxidase 2)-generated H2O2 regulated mitochondria-derived superoxide production, which suggests the importance of cross-talk between Nox2-dependent H2O2 production and mitochondrial superoxide production. The results of the present study suggest that 8-nitro-cGMP can serve as a unique second messenger that may be implicated in regulating ROS signalling in the presence of NO.
Endothelial dysfunction and increased oxidative stress in mitochondrial diseases
Authors: Minuz Pietro , Fava Cristiano , Vattemi Gaetano , Arcaro Guido , Riccadonna Matteo , Tonin Paola , Meneguzzi Alessandra , Degan Maurizio , Guglielmi Valeria , Lechi Alessandro , Tomelleri Giuliano
Published: October 2011

MDs (mitochondrial diseases) are a clinically heterogeneous group of disorders characterized by impairment of the respiratory chain function with altered oxidative phosphorylation. We tested the hypothesis that the function of vascular endothelium is affected by increased oxidative stress in MDs. A total of 12 patients with MDs and pair-matched controls were studied. Endothelial function was assessed by measuring FMD (flow-mediated vasodilation) of brachial and common femoral arteries. The test was repeated after vitamin C (500 mg, twice a day) and E (400 mg, once a day) supplementation for 30 days and 90 days after vitamin withdrawal. FMD was reduced in patients compared with controls [AUC/τ (time-averaged area under the curve) for the brachial artery, 1.05±0.24 compared with 4.19±0.59% respectively, P<0.001; AUC/τ for the femoral artery, 0.98±0.19 compared with 2.36±0.29% respectively, P=0.001; values are means±S.E.M.] and correlated (brachial artery) with plasma lactate (r=−0.63, P<0.01). Urinary 8-iso-PGF2α (8-iso-prostaglandin F2α) was higher in patients than controls (505.6±85.9 compared with 302.5±38.7 pg/mg of creatinine; P<0.05) and correlated with plasma lactate (r=0.70, P<0.05). Immunohistochemical analysis showed 8-iso-PGF2α staining in MD-affected striated muscle cells and in blood vessels in muscle biopsies of patients. Antioxidant vitamins transiently restored FMD in patients [ΔAUC/τ (change in AUC/τ) for the brachial artery, +1.38±0.49%, P<0.05; ΔAUC/τ for the femoral artery, +0.98±0.24%, P<0.01] but had no effect on FMD in controls (brachial artery, −1.3±0.63%; and common femoral artery, −0.58±0.30%), thus abolishing the differences between patients and controls. The results of the present study indicate that oxidative stress is increased and is, at least partly, responsible for endothelial dysfunction in MDs.
Prenatal programming of renal salt wasting resets postnatal salt appetite, which drives food intake in the rat
Authors: Alwasel Saleh H. , Barker David J. P. , Ashton Nick
Published: October 2011

Sodium retention has been proposed as the cause of hypertension in the LP rat (offspring exposed to a maternal low-protein diet in utero) model of developmental programming because of increased renal NKCC2 (Na+/K+/2Cl− co-transporter 2) expression. However, we have shown that LP rats excrete more rather than less sodium than controls, leading us to hypothesize that LP rats ingest more salt in order to maintain sodium balance. Rats were fed on either a 9% (low) or 18% (control) protein diet during pregnancy; male and female offspring were studied at 4 weeks of age. LP rats of both sexes held in metabolism cages excreted more sodium and urine than controls. When given water to drink, LP rats drank more and ate more food than controls, hence sodium intake matched excretion. However, when given a choice between saline and water to drink, the total volume of fluid ingested by LP rats fell to control levels, but the volume of saline taken was significantly larger [3.8±0.1 compared with 8.8±1.3 ml/24 h per 100 g of body weight in control and LP rats respectively; P<0.001]. Interestingly food intake also fell to control levels. Total body sodium content and ECF (extracellular fluid) volumes were greater in LP rats. These results show that prenatal programming of renal sodium wasting leads to a compensatory increase in salt appetite in LP rats. We speculate that the need to maintain salt homoeostasis following malnutrition in utero stimulates greater food intake, leading to accelerated growth and raised BP (blood pressure).
Hydration patterns and salting effects in sodium chloride solution
Authors: Li Weifeng , Mu Yuguang
Published: October 2011

The salting effects of 2M sodium chloride electrolyte are studied based on a series of model solutes with properties ranging from hydrophobic to hydrophilic. Generally, hydrophobic solutes will be salted out and hydrophilic solutes will be salted in by NaCl solution. The solvation free energy changes are highly correlated with Kirkwood-Buff integrals. The underlying mechanism resorts to the preferential binding of ions and water to solutes. Our results demonstrate that the salting effect not only depends on the salt's position in Hofmeister series, but also on the solutes’ specifics. Taking the hydration free energies of solutes and ions as independent variables, a schematic diagram of salting effects is suggested. The resolved multifaceted salting effects rely on the sensitive balance of the tripartite interaction among solutes, ions, and water.
Plasma wakefield acceleration with a modulated proton bunch
Authors: Caldwell A. , Lotov K. V.
Published: October 2011

The plasma wakefield amplitudes which could be achieved via the modulation of a long proton bunch are investigated. We find that in the limit of long bunches compared to the plasma wavelength, the strength of the accelerating fields is directly proportional to the number of particles in the drive bunch and inversely proportional to the square of the transverse bunch size. The scaling laws were tested and verified in detailed simulations using parameters of existing proton accelerators, and large electric fields were achieved, reaching 1 GV/m for LHC bunches. Energy gains for test electrons beyond 6 TeV were found in this case.
Non-stationary self-focusing of intense laser beam in plasma using ramp density profile
Authors: Habibi M. , Ghamari F.
Published: October 2011

The non-stationary self-focusing of high intense laser beam in under-dense plasma with upward increasing density ramp is investigated. The obtained results show that slowly increasing plasma density ramp is very important in enhancing laser self-focusing. Also, the spot size oscillations of laser beam in front and rear of the pulse for two different density profiles are shown. We have selected density profiles that already were used by Sadighi-Bonabi et al. [Phys. Plasmas 16, 083105 (2009)]. Ramp density profile causes the laser beam to become more focused and penetrations deeps into the plasma by reduction of diffraction effects. Our computations show more reliable results in comparison to the previous works.
Analysis of interface carrier accumulation and relaxation in pentacene/C60 double-layer organic solar cell by impedance spectroscopy and electric-field-induced optical second harmonic generation
Authors: Chen Xiangyu , Taguchi Dai , Shino Tatsunori , Manaka Takaaki , Iwamoto Mitsumasa
Published: October 2011

By using the impedance spectroscopy (IS) and optical electric-field-induced second harmonic generation (EFISHG) measurement, interfacial carrier relaxation in pentacene/C60 double-layer organic solar cell (OSC) has been analyzed. The IS measurements showed that the interfacial carrier relaxation time was diminished 70 times under photo illumination, due to the increase of carrier density caused by the photovoltaic effect. The equivalent circuit analysis using a Maxwell-Wagner effect model well accounted for the IS results. On the other hand, the EFISHG measurements directly probed the interfacial carrier behaviors caused by the photovoltaic effect. The results showed the suppression of the Maxwell-Wagner type carrier relaxation in OSCs by applying a voltage corresponding to the open circuit voltage Voc. EFISHG measurement coupled with IS measurement provides a clear physics picture of interfacial phenomena related to the photovoltaic effect in OSCs.
The putative liquid-liquid transition is a liquid-solid transition in atomistic models of water
Authors: Limmer David T. , Chandler David
Published: October 2011

We use numerical simulation to examine the possibility of a reversible liquid-liquid transition in supercooled water and related systems. In particular, for two atomistic models of water, we have computed free energies as functions of multiple order parameters, where one is density and another distinguishes crystal from liquid. For a range of temperatures and pressures, separate free energy basins for liquid and crystal are found, conditions of phase coexistence between these phases are demonstrated, and time scales for equilibration are determined. We find that at no range of temperatures and pressures is there more than a single liquid basin, even at conditions where amorphous behavior is unstable with respect to the crystal. We find a similar result for a related model of silicon. This result excludes the possibility of the proposed liquid-liquid critical point for the models we have studied. Further, we argue that behaviors others have attributed to a liquid-liquid transition in water and related systems are in fact reflections of transitions between liquid and crystal.
On the role of dynamical barriers in barrierless reactions at low energies: S(1D) + H2
Authors: Lara Manuel , Jambrina P. G. , Varandas A. J. C. , Launay J.-M. , Aoiz F. J.
Published: October 2011

Reaction probabilities as a function of total angular momentum (opacity functions) and the resulting reaction cross sections for the collision of open shell S(1D) atoms with para-hydrogen have been calculated in the kinetic energy range 0.09–10 meV (1–120 K). The quantum mechanical hyperspherical reactive scattering method and quasi-classical trajectory and statistical quasi-classical trajectory approaches were used. Two different ab initio potential energy surfaces (PESs) have been considered. The widely used reproducing kernel Hilbert space (RKHS) PES by Ho et al. [T.-S. Ho, T. Hollebeek, H. Rabitz, S. D. Chao, R. T. Skodje, A. S. Zyubin, and A. M. Mebel, J. Chem. Phys 116, 4124 (2002)]10.1063/1.1431280 and the recently published accurate double many-body expansion (DMBE)/complete basis set (CBS) PES by Song and Varandas [Y. Z. Song and A. J. C. Varandas, J. Chem. Phys. 130, 134317 (2009)]10.1063/1.3103268. The calculations at low collision energies reveal very different dynamical behaviors on the two PESs. The reactivity on the RKHS PES is found to be considerably larger than that on the DMBE/CBS PES as a result of larger reaction probabilities at low total (here also orbital) angular momentum values and to opacity functions which extend to significantly larger total angular momentum values. The observed differences have their origin in two major distinct topographic features. Although both PESs are essentially barrierless for equilibrium H–H distances, when the H–H bond is compressed the DMBE/CBS PES gives rise to a dynamical barrier which limits the reactivity of the system. This barrier is completely absent in the RHKS PES. In addition, the latter PES exhibits a van der Walls well in the entrance channel which reduces the height of the centrifugal barrier and is able to support resonances. As a result, a significant larger cross section is found on this PES, with marked oscillations attributable to shape resonances and/or to the opening of partial wave contributions. The comparison of the results on both PESs is illustrative of the wealth of the dynamics at low collision energy. It is also illuminating about the difficulties encountered in modeling an all-purpose global potential energy surface.
Global existence and blow-up phenomena for a weakly dissipative periodic 2-component Camassa-Holm system
Authors: Hu Qiaoyi
Published: October 2011

We first establish local well posedness for a weakly dissipative periodic 2-component Camassa-Holm system. We then present two global existence results for strong solutions to the equation. We finally obtain several blow-up results and the blow-up rate of strong solutions to the equation.
Nonlinear dispersive Alfven waves in dusty plasma in the transition limit, α~1
Authors: Sah O. P.
Published: October 2011

Localized nonlinear structures associated with dispersive Alfven waves are investigated in dusty plasma in the transition limit, i.e., α≡(β/2Q)~1, where β is the ratio of thermal to magnetic pressure and Q is electron to ion mass ratio. Sagdeev pseudopotential is obtained from the basic governing equations, which is then numerically solved to study the existence and the behaviors of the nonlinear structures. It is found that both compressive and rarefactive solitons can coexist above and below certain critical α- values determined by the wave direction cosine (KZ) and the Mach number (M); and the compressive (rarefactive) solitons are much wider than the rarefactive ones for the case MKZ). In addition, the rarefactive solitons are found to be converted into rarefactive double layers, for the case M>KZ, if the dust grains are negatively charged and their density exceeds certain critical value.
The multi-mode gyrotron
Authors: Savilov A. V. , Glyavin M. Yu. , Philippov V. N.
Published: October 2011

It is possible to provide a situation in the gyrotron when it possesses a dense spectrum of axial eigenmodes having different frequencies but almost similar Q-factors. In this case, the single-frequency operation of the gyrotron is provided due to non-linear competition of the eigenmodes. It is shown that such an approach opens a way to provide in gyrotrons a close-to-continuous frequency tuning.
Graphene formation on step-free 4H-SiC(0001)
Authors: Bolen M. L. , Colby R. , Stach E. A. , Capano M. A.
Published: October 2011

Step-free SiC was thermally decomposed in vacuum to better understand graphene formation in the absence of step fronts. Atomic force microscopy revealed graphene nucleating at surface pits that preferentially form along SiC{11¯00} planes. The density of these pits is 1×108cm-2, which is three orders of magnitude greater than the measured density of SiC threading dislocations. Additionally, Raman spectroscopy demonstrated that graphene on step-free regions have a redshifted 2D peak position and a smaller peak width than does graphene grown on stepped regions. This difference is attributed to film thickness, which is confirmed by cross-sectional transmission electron microscopy. Stepped regions have a graphitic film nearly 2 nm thick as compared to less than 0.7 nm for step-free regions.
Minimum free-energy pathway of nucleation
Authors: Philippe T. , Blavette D.
Published: October 2011

Nucleation in a two-component incompressible system was studied by examining the topology of the free-energy landscape. The properties of a single nucleus during nucleation were derived from the minimum free-energy pathway (MFEP) within the Cahn-Hilliard continuum theory of nucleation. MFEPs were computed using the string method. In particular, we have provided a detailed description of the nucleation process for a regular solution (T/Tc = 0.8656) for increasing supersaturation up to the spinodal line. Two original results were found in terms of the physics of nucleation. A universal two-step behaviour was found whatever the supersaturation: nuclei sharply enrich up to equilibrium and then grow. Embryos show diffuse interfaces along the MFEP. The width of interfaces quickly saturates to its value at the critical nuclei and stays constant afterwards.
High temperature step-flow growth of gallium phosphide by molecular beam epitaxy and metalorganic chemical vapor deposition
Authors: Ratcliff C. , Grassman T. J. , Carlin J. A. , Ringel S. A.
Published: October 2011

Post-growth surface morphologies of high-temperature homoepitaxial GaP films grown by molecular beam epitaxy (MBE) and metalorganic chemical vapor deposition (MOCVD) have been studied. Smooth, stepped surface morphologies of MBE-grown layers, measured by atomic force microscopy, were found for a wide range of substrate temperatures and P2:Ga flux ratios. A MOCVD-based growth study performed under similar conditions to MBE-grown samples shows a nearly identical smooth, step-flow surface morphology, presenting a convergence of growth conditions for the two different methods. The additional understanding of GaP epitaxy gained from this study will impact its use in applications that include GaP-based device technologies, III-V metamorphic buffers, and III-V materials integration with silicon.
Impact-induced initiation and energy release behavior of reactive materials
Authors: Wang Haifu , Zheng Yuanfeng , Yu Qingbo , Liu Zongwei , Yu Weimin
Published: October 2011

Reactive material fragment is an extremely efficient damage enhancement technology that incorporates the defeat mechanisms of kinetic energy and chemical energy. In this paper, the polymer-based reactive material fragment/target interactions are investigated. Related dynamic testing techniques for energy release characteristics of reactive material fragments are presented, and a series of ballistic experiments is conducted. The results show the reactive material fragment, which perforates the closed test chamber, undergoes a violent chemical reaction under highly dynamic loads and releases great amounts of thermo-chemical energy on the interior. The impact-initiated process and energy release behavior are markedly influenced by the impact velocity, indicating the material’s fracture is of importance to the reaction. A relationship between the maximum pressure inside the chamber and the reaction efficiency is derived to analyze the influence quantitatively, and the venting effects are also considered.
Metal induced crystallization mechanism of the metal catalyzed growth of silicon wire-like crystals
Authors: Sarikov Andrey
Published: October 2011

A thermodynamic mechanism explaining the universal role of metal catalyst in the transformation of Si in the crystalline state and the preferential growth of Si wire-like crystals in the vapor-liquid-solid and relative processes is proposed based on the mechanism of the metal induced crystallization of amorphous Si. It includes metal stimulated crystallization of disordered Si formed on the catalyst and substrate surfaces and the wire-like crystal sidewalls, driven by the chemical potential difference of Si in the disordered and crystalline states. Obtained results have general nature and are applicable to the metal catalyzed wire-like crystal growth in different metal/semiconductor systems.
Linking the historical and chemical definitions of diabatic states for charge and excitation energy transfer reactions in condensed phase
Authors: Pavanello Michele , Neugebauer Johannes
Published: October 2011

Marcus theory of electron transfer (ET) and Förster theory of excitation energy transfer (EET) rely on the Condon approximation and the theoretical availability of initial and final states of ET and EET reactions, often called diabatic states. Recently [Subotnik et al., J. Chem. Phys. 130, 234102 (2009)10.1063/1.3148777], diabatic states for practical calculations of ET and EET reactions were defined in terms of their interactions with the surrounding environment. However, from a purely theoretical standpoint, the definition of diabatic states must arise from the minimization of the dynamic couplings between the trial diabatic states. In this work, we show that if the Condon approximation is valid, then a minimization of the derived dynamic couplings leads to corresponding diabatic states for ET reactions taking place in solution by diagonalization of the dipole moment matrix, which is equivalent to a Boys localization algorithm; while for EET reactions in solution, diabatic states are found through the Edmiston–Ruedenberg localization algorithm. In the derivation, we find interesting expressions for the environmental contribution to the dynamic coupling of the adiabatic states in condensed-phase processes. In one of the cases considered, we find that such a contribution is trivially evaluable as a scalar product of the transition dipole moment with a quantity directly derivable from the geometry arrangement of the nuclei in the molecular environment. Possibly, this has applications in the evaluation of dynamic couplings for large scale simulations.
Gauge-origin independent calculations of Jones birefringence
Authors: Shcherbin Dmitry , Thorvaldsen Andreas J. , Jonsson Dan , Ruud Kenneth
Published: October 2011

We present the first gauge-origin independent formulation of Jones birefringence at the Hartree–Fock level of theory. Gauge-origin independence is achieved through the use of London atomic orbitals. The implementation is based on a recently proposed atomic orbital-based response theory formulation that allows for the use of both time- and perturbation-dependent basis sets [Thorvaldsen, Ruud, Kristensen, Jørgensen, and Coriani, J. Chem. Phys. 129, 214108 (2008)]. We present the detailed expressions for the response functions entering the Jones birefringence when London atomic orbitals are used. The implementation is tested on a set of polar and dipolar molecules at the Hartree–Fock level of theory. It is demonstrated that London orbitals lead to much improved basis-set convergence, and that the use of small, conventional basis sets may lead to the wrong sign for the calculated birefringence. For large basis sets, London orbitals and conventional basis sets converge to the same results.
Effect of carbon/hydrogen species incorporation on electronic structure of anatase-TiO2
Authors: Li N. , Yao K. L. , Li L. , Sun Z. Y. , Gao G. Y. , Zhu L.
Published: October 2011

The energy band structure and optical properties of C-doped and C/H-codoped anatase TiO2 are investigated using the first-principles based on density-functional theory. The obtained results indicate that the structure of C/H-codoping is more stable than that of C-doping. For C-doped anatase TiO2, the band gap narrowing is small, and the high visible-light catalytic ability originates from the isolated C 2p states above the valence-band maximum. With the same carbon doping level, the C/H-codoping produces significant bandgap narrowing, which leads to higher visible-light photocatalytic efficiency than the C-doping does.
Electronic structure and polaronic excitation in FeVO4
Authors: Dixit A. , Chen P. , Lawes G. , Musfeldt J. L.
Published: October 2011

We investigated the electronic properties of FeVO4 films using optical, valence band x-ray photoelectron, and infrared spectroscopies. These studies show that FeVO4 is a direct bandgap system with a 2.7 eV gap with the Fermi level in the middle of the valence band maximum and conduction band minimum. A polaronic excitation is also observed in the middle infrared, indicating the importance of charge-lattice coupling in this multiferroic material. Fits to a model for the optical response of large polarons yield a binding energy of approximately 130 meV.
A compact sub-Kelvin ultrahigh vacuum scanning tunneling microscope with high energy resolution and high stability
Authors: Zhang L. , Miyamachi T. , Tomanić T. , Dehm R. , Wulfhekel W.
Published: October 2011

We designed a scanning tunneling microscope working at sub-Kelvin temperatures in ultrahigh vacuum (UHV) in order to study the magnetic properties on the nanoscale. An entirely homebuilt three-stage cryostat is used to cool down the microscope head. The first stage is cooled with liquid nitrogen, the second stage with liquid 4He. The third stage uses a closed-cycle Joule-Thomson refrigerator of a cooling power of 1 mW. A base temperature of 930 mK at the microscope head was achieved using expansion of 4He, which can be reduced to ≈400 mK when using 3He. The cryostat has a low liquid helium consumption of only 38 ml/h and standing times of up to 280 h. The fast cooling down of the samples (3 h) guarantees high sample throughput. Test experiments with a superconducting tip show a high energy resolution of 0.3 meV when performing scanning tunneling spectroscopy. The vertical stability of the tunnel junction is well below 1 pm (peak to peak) and the electric noise floor of tunneling current is about $6 \text{fA}/\sqrt{\text{Hz}}$6fA/Hz. Atomic resolution with a tunneling current of 1 pA and 1 mV was achieved on Au(111). The lateral drift of the microscope at stable temperature is below 20 pm/h. A superconducting spilt-coil magnet allows to apply an out-of-plane magnetic field of up to 3 T at the sample surface. The flux vortices of a Nb(110) sample were clearly resolved in a map of differential conductance at 1.1 K and a magnetic field of 0.21 T. The setup is designed for in situ preparation of tip and samples under UHV condition.