Enhanced Photocatalytic Activity of BiVO4/Bi2S3/SnS2 Heterojunction under Visible Light

Heterojunction photocatalysts have attracted a significant amount of attention due to their advantages over a single photocatalyst and, particularly, their superior spatial charge separation. Herein, the BiVO4/Bi2S3/SnS2 heterojunction was synthesized via solvothermal synthesis with different ratios of BiVO4 to SnS2. The photodegradation rate of the 0.03 BiVO4/SnS2 sample for rhodamine B removal is 2.3 times or 2.9 times greater than that of a single SnS2 or BiVO4, respectively. The chemical bond between photocatalysts is confirmed by X-ray photoelectron spectroscopy (XPS), and the synchronized shift observed in binding energies strongly indicates the electron screening effect at the heterojunction. A Z-scheme model is proposed to explain charge transfer pathway in the system, in which the formation of Bi2S3 plays a crucial role in the enhanced photocatalytic performance of the heterojunction

Assessing the geospatial nature of location-dependent costs in installation of solar photovoltaic plants

A major hurdle in increasing the economic feasibility of solar photovoltaic (SPV) plants is the ever-increasing share of location-dependent costs (land, transmission, labor, etc.) in total installation costs. Such costs are geospatial in nature, due to spatial socio-economics affecting them. Present geolocation methods, for locating SPV installation sites, do not consider the effect of location-dependent costs in installation. We use a spatial parameterization model for examining the factors causing spatial variation of the installation costs of land, labor, transmission and supply chains for suburban SPV plants, within a geographic boundary. The model is applied to Kolkata city, India, and the spatial variation of the costs are checked in a 2500 km²2 suburban boundary. The spatial variation of the location-dependent costs is mainly caused by the distance from an economic focal point of the city. The variations significantly optimize at minima points in the 2500 km² boundary, where the location-dependent costs increase by 10% with an average 2.6 km deviation and an average 6.7 km deviation from the global minima, for small and large plants, respectively. The spatial minima is mainly caused by variance of land and transmission costs. This minima location lies on the extrapolation of a line that connects the city focal point with the substation. The capacity of the SPV plants at the optima increases with increasing transmission voltage (11 kV to 66 kV), ranging from 4 MW to 257 MW in the case-study (small to large scale), while the minima shift away from the city focal point (ranging 29 km to 48 km) with increasing capacity. This study provides a perspective on how the spatial variation of installation costs can play a role in the geolocation of SPV plants. Furthermore, the empirical and spatial variation of location-dependent costs can enable energy planners to evaluate the economic feasibility of solar power and promote better land-use near cities

The zona incerta in control of novelty seeking and investigation across species

Many organisms rely on a capacity to rapidly replicate, disperse, and evolve when faced with uncertainty and novelty. But mammals do not evolve and replicate quickly. They rely on a sophisticated nervous system to generate predictions and select responses when confronted with these challenges. An important component of their behavioral repertoire is the adaptive context-dependent seeking or avoiding of perceptually novel objects, even when their values have not yet been learned. Here, we outline recent cross-species breakthroughs that shed light on how the zona incerta (ZI), a relatively evolutionarily conserved brain area, supports novelty-seeking and novelty-related investigations. We then conjecture how the architecture of the ZI\u27s anatomical connectivity - the wide-ranging top-down cortical inputs to the ZI, and its specifically strong outputs to both the brainstem action controllers and to brain areas involved in action value learning - place the ZI in a unique role at the intersection of cognitive control and learning

Asymmetric projections of the arcuate fasciculus to the temporal cortex underlie lateralized language function in the human brain

The arcuate fasciculus (AF) in the human brain has asymmetric structural properties. However, the topographic organization of the asymmetric AF projections to the cortex and its relevance to cortical function remain unclear. Here we mapped the posterior projections of the human AF in the inferior parietal and lateral temporal cortices using surface-based structural connectivity analysis based on diffusion MRI and investigated their hemispheric differences. We then performed the cross-modal comparison with functional connectivity based on resting-state functional MRI (fMRI) and task-related cortical activation based on fMRI using a semantic classification task of single words. Structural connectivity analysis showed that the left AF connecting to Broca's area predominantly projected in the lateral temporal cortex extending from the posterior superior temporal gyrus to the mid part of the superior temporal sulcus and the middle temporal gyrus, whereas the right AF connecting to the right homolog of Broca's area predominantly projected to the inferior parietal cortex extending from the mid part of the supramarginal gyrus to the anterior part of the angular gyrus. The left-lateralized projection regions of the AF in the left temporal cortex had asymmetric functional connectivity with Broca's area, indicating structure-function concordance through the AF. During the language task, left-lateralized cortical activation was observed. Among them, the brain responses in the temporal cortex and Broca's area that were connected through the left-lateralized AF pathway were specifically correlated across subjects. These results suggest that the human left AF, which structurally and functionally connects the mid temporal cortex and Broca's area in asymmetrical fashion, coordinates the cortical activity in these remote cortices during a semantic decision task. The unique feature of the left AF is discussed in the context of the human capacity for language.National Institutes of Health (U.S.) (Grant R01NS069696)National Institutes of Health (U.S.) (Grant P41EB015896)National Institutes of Health (U.S.) (Grant S10ODRR031599)National Institutes of Health (U.S.) (Grant S10RR021110)National Science Foundation (U.S.) (Grant NFS-DMS-1042134)Uehara Memorial Foundation (Fellowship)Society of Nuclear Medicine and Molecular Imaging (Wagner-Torizuka Fellowship)United States. Dept. of Energy (Grant DE-SC0008430

MRI plaque imaging and its role in population-based studies

Noninvasive direct vessel wall (plaque) imaging may provide a good opportunity to study unique aspects of atherosclerotic lesions in different populations. The article published by Esposito et al. provides new insights into our understanding of diabetic atherosclerotic vascular disease by using direct plaque imaging techniques. The findings from this article call for attention to more in vivo imaging to understand the nature of high-risk atherosclerosis, especially in prospective studies in diabetic patients

On the lack of strong O-line excess in the Coma cluster outskirts from Suzaku

About half of the baryons in the local Universe are thought to reside in the so-called warm-hot intergalactic medium (WHIM) at temperatures of 0.1-10 million K. Thermal soft excess emission in the spectrum of some cluster outskirts that contains OVII and/or OVIII emission lines is regarded as evidence of the WHIM, although the origin of the lines is controversial due to strong Galactic and solar system foreground emission. We observed the Coma-11 field, where the most prominent thermal soft excess has ever been reported, with Suzaku XIS in order to make clear the origin of the excess. We did not confirm OVII or OVIII excess emission. The OVII and OVIII intensity in Coma-11 is more than 5 sigma below that reported before and we obtained 2 sigma upper limits of 2.8 and 2.9 photons cm^-2 s^-1 sr^-1 for OVII and OVIII, respectively. The intensities are consistent with those in another field (Coma-7) that we measured, and with other measurements in the Coma outskirts (Coma-7 and X Com fields with XMM-Newton). We did not confirm the spatial variation within Coma outskirts. The strong oxygen emission lines previously reported are likely due to solar wind charge exchange.Comment: 5 pages, 3 figures. Accepted for publication in Ap

Histopathology

The aim of this study was to establish a model, which can be used to investigate the response of periodontal tissues to excessive occlusal loading in mice by observing histopathological changes. The experiment was performed on ten 7-week-old ddY male mice. Under general anesthesia by intraperitoneal injectionpentobarbital sodium, a micro-plus-screwpin (head part, 1.7mm in diameter, thickness 0.5mm thickness) was screwed into the pulp cavity of the upper-left-first molar. R_mCT images of the experimental site indicated the occlusal contact position between the upper- and lower-left-first molars during the experimental periods. A micro-plus-screwpin was maintained at a constant position on the occlusal surface throughout the experimental period. Histopathological changes of the periodontal ligament at the furcation lesion of the lower-left-first molar and its surrounding periodontal tissues were observed under a light microscope. The densities of deeply dyeing cells in hematoxylin staining with a round-shaped nucleus were increased in the periodontal ligament, with a peak effect of day 4. Multinucleated giant cells appeared in the central lesion of the periodontal ligament on day 7. The distribution of resorption on the surface of both of the cementum and the alveolar bone was accompanied by multinucleated giant cells, which expanded rapidly from day 7 to day 14. These results showed that histopathological changes of periodontal tissues to excessive occlusal load were observed at the furcation area of molar teeth. The present method confirmed the effectiveness of the experimental model to examine the occlusal trauma on periodontal tissues produced by excessive occlusal load

Dust Destruction in the High-Velocity Shocks Driven by Supernovae in the Early Universe

We investigate the destruction of dust grains by sputtering in the high-velocity interstellar shocks driven by supernovae (SNe) in the early universe to reveal the dependence of the time-scale of dust destruction on the gas density $n_{{\rm H}, 0}$ in the interstellar medium (ISM) as well as on the progenitor mass $M_{\rm pr}$ and explosion energy $E_{\rm 51}$ of SN. The sputtering yields for the combinations of dust and ion species of interest to us are evaluated by applying the so-called universal relation with a slight modification. The dynamics of dust grains and their destruction by sputtering in shock are calculated by taking into account the size distribution of each dust species, together with the time evolution of temperature and density of gas in spherically symmetric shocks. The results of calculations show that the efficiency of dust destruction depends not only on the sputtering yield but also on the initial size distribution of each grain species. The efficiency of dust destruction increases with increasing $E_{\rm 51}$ and/or increasing $n_{{\rm H}, 0}$, but is almost independent of $M_{\rm pr}$ as long as $E_{\rm 51}$ is the same. The mass of gas swept up by shock is the increasing function of $E_{\rm 51}$ and the decreasing function of $n_{{\rm H}, 0}$. Combining these results, we present the approximation formula for the time-scale of destruction for each grain species in the early universe as a function of $E_{\rm 51}$ and $n_{{\rm H}, 0}$. This formula is applicable for investigating the evolution of dust grains at the early epoch of the universe with the metallicity of Z \la 10^{-3} $Z_\odot$. The effects of the cooling processes of gas on the destruction of dust are briefly discussed.Comment: 49 pages including 7 tables and 25 figures, accepted for publication in Ap

Blueprint for a Scalable Photonic Fault-Tolerant Quantum Computer

Photonics is the platform of choice to build a modular, easy-to-network quantum computer operating at room temperature. However, no concrete architecture has been presented so far that exploits both the advantages of qubits encoded into states of light and the modern tools for their generation. Here we propose such a design for a scalable and fault-tolerant photonic quantum computer informed by the latest developments in theory and technology. Central to our architecture is the generation and manipulation of three-dimensional hybrid resource states comprising both bosonic qubits and squeezed vacuum states. The proposal enables exploiting state-of-the-art procedures for the non-deterministic generation of bosonic qubits combined with the strengths of continuous-variable quantum computation, namely the implementation of Clifford gates using easy-to-generate squeezed states. Moreover, the architecture is based on two-dimensional integrated photonic chips used to produce a qubit cluster state in one temporal and two spatial dimensions. By reducing the experimental challenges as compared to existing architectures and by enabling room-temperature quantum computation, our design opens the door to scalable fabrication and operation, which may allow photonics to leap-frog other platforms on the path to a quantum computer with millions of qubits.Comment: 38 pages, many figures. Comments welcom