Electronic structure of the muonium center as a shallow donor in ZnO

The electronic structure and the location of muonium centers (Mu) in single-crystalline ZnO were determined for the first time. Two species of Mu centers with extremely small hyperfine parameters have been observed below 40 K. Both Mu centers have an axial-symmetric hyperfine structure along with a [0001] axis, indicating that they are located at the AB_{O,//} and BC_{//} sites. It is inferred from their small ionization energy (~6 meV and 50 meV) and hyperfine parameters (~10^{-4} times the vacuum value) that these centers behave as shallow donors, strongly suggesting that hydrogen is one of the primary origins of n type conductivity in as-grown ZnO.Comment: 4 pages, 4 figures, submitted to PR

Complejos de halógeno acetatos de uranio (iv) y torio (iv) con sulfoxidos y fosfinoxidos

En este trabajo se ha Investigado el efecto sterico sobre los modos de coordinación del grupo carboxilato (unidentado, bidentado y puente), en complejos de halógeno acetato con fosfinóxidos y sulfóxidos y la correlación de los resultadoscon el modelo "Cone Angle" e\ cual ha sido descrito en otra publicación previa' Los complejos preparados son: M(RCO )^ .nL donde n = 4, M = Th ó U, L = Me^SO (dmso), R = CF,3 y L = Me3P0 (tmpo); n = 3, M = Th, L = tmpo, R = CF3 y L = ppo o dmso, R OCCI3; M = U, L = t p p o , R =CF3 y L =dmso, dpso, R = C C l 3 ; n = 2 , M = T h , L = tppo, R = CF3, CHCI^On^ 1, M = Th ó U, L =dmso

Comparison of Characteristics and Complications in Men Versus Women Undergoing Chronic Total Occlusion Percutaneous Intervention

Gender differences exist in clinical outcomes after routine percutaneous coronary intervention (PCI), but studies reporting such outcomes after chronic total occlusion (CTO) PCI are limited. We assessed the characteristics and outcomes of female patients undergoing CTO PCI. We retrospectively analyzed a dedicated national (United Kingdom) prospective CTO database from 2011 to 2015 for outcomes and characteristics of female patients undergoing CTO PCI (unmatched and propensity matched). Female patients constituted 20.5% (n = 260 of 1,271) of the unmatched cohort and 33.3% (n = 233 of 699) of the matched cohort and were more likely to be older (women aged >70 years, 48% in the unmatched and 45% in the matched cohort). An increased inhospital complication rate was observed in female patients (unmatched: 10% women vs 4.45% men, p = 0.0012, and matched 9.87% women vs 3.86% men, p = 0.0032). Coronary perforation, bleeding, and contrast-induced nephropathy were more frequently observed in female patients. Femoral access site with >6 French sheath was associated with an increased risk of bleeding. Presence of calcification in the CTO artery was associated with coronary perforation (grade III) in female patients in the matched cohort (p = 0.007). Female patients undergoing CTO PCI were older and experienced increased of inhospital complications. Increased awareness of these complications could influence the selection of access site and sheath size, the need for prehydration, judicious choice of balloon size, collateral selection, and wire placement in female patients undergoing CTO PCI

A Preliminary List of Some Families of Iowa Insects

For some ten years the Iowa Insect Survey has been collecting specimens and data from all parts of this state in a study of the geographic and seasonal distribution of the insects of Iowa. Comparatively little has been done heretofore with most of the families of the Hymenoptera and the Diptera of Iowa. With the hope of stimulating a more general interest in these groups, preliminary lists of the species now known to occur within the state are being submitted. Students in systematic Entomology in the college have taken a family and given it special attention in their collecting for one or more years. These students have collaborated with the senior author in the preparation of this paper. The name of the student thus taking the responsibility of getting a list for a family in shape is printed at the head of the list. Determinations throughout the list have been made or checked by specialists as indicated for each group. Assistance given by the Iowa Academy of Science and the State University of Iowa has helped materially in keeping the Survey going

Physical properties of metal-doped zinc oxide films for surface acoustic wave application

Metal-doped ZnO [MZO] thin films show changes of the following properties by a dopant. First, group III element (Al, In, Ga)-doped ZnO thin films have a high conductivity having an n-type semiconductor characteristic. Second, group I element (Li, Na, K)-doped ZnO thin films have high resistivity due to a dopant that accepts a carrier. The metal-doped ZnO (M = Li, Ag) films were prepared by radio frequency magnetron sputtering on glass substrates with the MZO targets. We investigated on the optical and electrical properties of the as-sputtered MZO films as dependences on the doping contents in the targets. All the MZO films had shown a preferred orientation in the [002] direction. As the quantity and the variety of metal dopants were changed, the crystallinity and the transmittance, as well as optical band gap were changed. The electrical resistivity was also changed with changing metal doping amounts and kinds of dopants. An epitaxial Li-doped ZnO film has a high resistivity and very smooth surface; it will have the most optimum conditions which can be used for the piezoelectric devices

Anomalous Lattice Vibrations of Single and Few-Layer MoS2

Molybdenum disulfide (MoS2) of single and few-layer thickness was exfoliated on SiO2/Si substrate and characterized by Raman spectroscopy. The number of S-Mo-S layers of the samples was independently determined by contact-mode atomic-force microscopy. Two Raman modes, E12g and A1g, exhibited sensitive thickness dependence, with the frequency of the former decreasing and that of the latter increasing with thickness. The results provide a convenient and reliable means for determining layer thickness with atomic-level precision. The opposite direction of the frequency shifts, which cannot be explained solely by van der Waals interlayer coupling, is attributed to Coulombic interactions and possible stacking-induced changes of the intralayer bonding. This work exemplifies the evolution of structural parameters in layered materials in changing from the 3-dimensional to the 2-dimensional regime.Comment: 14 pages, 4 figure

Decision level ensemble method for classifying multi-media data

In the digital era, the data, for a given analytical task, can be collected in different formats, such as text, images and audio etc. The data with multiple formats are called multimedia data. Integrating and fusing multimedia datasets has become a challenging task in machine learning and data mining. In this paper, we present heterogeneous ensemble method that combines multi-media datasets at the decision level. Our method consists of several components, including extracting the features from multimedia datasets that are not represented by features, modelling independently on each of multimedia datasets, selecting models based on their accuracy and diversity and building the ensemble at the decision level. Hence our method is called decision level ensemble method (DLEM). The method is tested on multimedia data and compared with other heterogeneous ensemble based methods. The results show that the DLEM outperformed these methods significantly

Recombination dynamics of a human Y-chromosomal palindrome:rapid GC-biased gene conversion, multi-kilobase conversion tracts, and rare inversions

The male-specific region of the human Y chromosome (MSY) includes eight large inverted repeats (palindromes) in which arm-to-arm similarity exceeds 99.9%, due to gene conversion activity. Here, we studied one of these palindromes, P6, in order to illuminate the dynamics of the gene conversion process. We genotyped ten paralogous sequence variants (PSVs) within the arms of P6 in 378 Y chromosomes whose evolutionary relationships within the SNP-defined Y phylogeny are known. This allowed the identification of 146 historical gene conversion events involving individual PSVs, occurring at a rate of 2.9-8.4×10(-4) events per generation. A consideration of the nature of nucleotide change and the ancestral state of each PSV showed that the conversion process was significantly biased towards the fixation of G or C nucleotides (GC-biased), and also towards the ancestral state. Determination of haplotypes by long-PCR allowed likely co-conversion of PSVs to be identified, and suggested that conversion tract lengths are large, with a mean of 2068 bp, and a maximum in excess of 9 kb. Despite the frequent formation of recombination intermediates implied by the rapid observed gene conversion activity, resolution via crossover is rare: only three inversions within P6 were detected in the sample. An analysis of chimpanzee and gorilla P6 orthologs showed that the ancestral state bias has existed in all three species, and comparison of human and chimpanzee sequences with the gorilla outgroup confirmed that GC bias of the conversion process has apparently been active in both the human and chimpanzee lineages

Geochemistry of Vein Calcites Hosted in the Troodos Pillow Lavas and Their Implications for the Timing and Physicochemical Environment of Fracturing, Fluid Circulation, and Vein Mineral Growth

Calcite veins hosted in pillow lavas of the Late Cretaceous Troodos suprasubduction zone ophiolite provide insights into the timing and physicochemical environment of postmagmatic fracturing and fluid circulation through oceanic crust. This study presents rare earth element and yttrium (REE+Y) concentrations, δ13C, δ18O, 87Sr/86Sr, and clumped isotopic (Δ47) compositions of vein calcites in order to investigate their fluid sources, formation temperatures, and precipitation ages. These geochemical data are combined with microtextural analyses. Intersections of 87Sr/86Sr ratios of vein calcites with the Sr isotope seawater curve suggest two distinct calcite veining phases. Major calcite veining within an interval of ~10 Myr after crust formation is characterized by microtextures that point to extensional fracturing related to crack and sealing, host rock brecciation, and advective fluid flow. These vein calcites show REE+Y characteristics, 87Sr/86Sr ratios, and clumped isotopic compositions indicative of precipitation from seawater at <50 °C. Extended fluid residence times intensified fluid‐rock interactions and lowered Y/Ho ratios of some blocky vein calcites, whereas crack and sealing resulted in pristine seawater signatures. Low 87Sr/86Sr ratios of localized high‐temperature blocky vein calcites point to the involvement of hydrothermal fluids. These calcites show Mn‐controlled oscillatory growth zonations that probably developed in a closed system out of equilibrium. Later calcite veining (<75 Ma) may have coincided with rotation and/or uplift of the Troodos ophiolite. Microtextures of these vein calcites indicate fluid diffusion and fracture‐independent crystallization pressure‐driven veining. Their variably modified seawater signatures resulted from diffusion‐related fluid interaction with hydrothermal sediments