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Probing the local environment of low-Z elements, such as oxygen, is of great interest for understanding the atomic-scale behavior in materials, but it requires experimental techniques allowing it to work with versatile sample envi...
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Probing the local environment of low-Z elements, such as oxygen, is of great interest for understanding the atomic-scale behavior in materials, but it requires experimental techniques allowing it to work with versatile sample environments. In this paper, the local environment of lithium borate crystals is investigated using nonresonant inelastic X-ray scattering (NRIXS) at energy losses corresponding to the oxygen K-edge. Large variations of the spectral features are observed close to the edge onset in the 535-540 eV energy range when varying the Li_2O content. Calculations allow identification of contributions associated with bridging oxygen (BO) and nonbridging oxygen (NBO) atoms. The main result resides in the observed core-level shift of about 1.7 eV in the spectral signatures of the BO and NBO. The clear signature at 535 eV in the O K-edge NRXIS spectrum is thus an original way to probe the presence of NBOs in borates, with the great advantage of making possible the use of complex environments such as a high-pressure cell or high-temperature device for in situ measurements.
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Relationships between local and global scales deserve more attention than they have received in the global change research enterprise to date. This paper examines how and why scale matters, drawing on six basic arguments; examines...
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Relationships between local and global scales deserve more attention than they have received in the global change research enterprise to date. This paper examines how and why scale matters, drawing on six basic arguments; examines the current state of the top-down global change research paradigm to evaluate the fit across relevant scale domains between global structure and local agency; and reviews current research efforts to better link the local and global scales of attention and action.
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Purpose The purpose of this paper is to investigate the importance of localizing online communities (OCs) and examines how OC members form impressions of organizations that use OCs in their communication activities. A conceptual f...
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Purpose The purpose of this paper is to investigate the importance of localizing online communities (OCs) and examines how OC members form impressions of organizations that use OCs in their communication activities. A conceptual framework and measurement scale are developed that consist of complex latent constructs. Design/methodology/approach A sequential multi-method approach is adopted with both qualitative and quantitative investigations. Using Structural equation modeling, the research refines and validates the measurement scales of impression formation in OCs. Findings Findings reveal that comprehensive messages have a direct effect on the impressions that an OC member forms. In particular, social context cues are an important predictor of online community corporate impression (OCCIP). Source credibility, affiliation, characteristics and interpersonal communication are all critical to OCCIP, which in turn, influence members' attitudes toward the company and the intention to use it again. Surprisingly, relevance, timeliness, accuracy and perceived similarity did not have any significant effect on the corporate impression. Originality/value Three contributions are offered: First, the study provides reliable scales for measuring OCCIP. Second, support is given to the conceptual model that links OCCIP to a set of consequences, namely, attitudes toward the company, intention to use the company, and word-of-mouth. Finally, the study is conducted across two different and unique types of OC contexts, stipulating further insights into the localization of OCs.
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Accepting validity of self-consistent theory of localization by Vollhardt and W?lfle, we derive the relations of finite-size scaling for different parameters characterizing the level statistics. The obtained results are compared w...
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Accepting validity of self-consistent theory of localization by Vollhardt and W?lfle, we derive the relations of finite-size scaling for different parameters characterizing the level statistics. The obtained results are compared with the extensive numerical material for space dimensions d = 2, 3, 4. On the level of raw data, the results of numerical experiments are compatible with the self-consistent theory, while the opposite state- ments of the original papers are related with ambiguity of interpretation and existence of small parameters of the Ginzburg number type.
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We investigate the possible locality of potential energy surface (PES) coupling in curvilinear internal valence coordinates using pure electronic energy as well as vibrational energy guided definitions of PES coupling range on the...
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We investigate the possible locality of potential energy surface (PES) coupling in curvilinear internal valence coordinates using pure electronic energy as well as vibrational energy guided definitions of PES coupling range on the example of the floppy but-enal and the semirigid but-dienol molecule C4OH6. We propose ways to exploit found coupling range limits for efficient PES generation leading to significant computational savings. The generation of the 27 dimensional PESs using vibrationally guided convergence criteria within an adaptive PES generation method (AGAPES) at B3LYP quality is reported as well with a detailed error-gain analysis.
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Wetlands can be significant sinks for N-r, via denitrification. There is a lack of understanding about factors controlling denitrification. Research suggests that hydrology, geomorphology, and nitrogen loading are dominant control...
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Wetlands can be significant sinks for N-r, via denitrification. There is a lack of understanding about factors controlling denitrification. Research suggests that hydrology, geomorphology, and nitrogen loading are dominant controls. We compared site-scale characteristics with denitrification enzyme activity (DEA) in wetlands along gradients of drainage basin land use to explore the relative importance of landscape and site-scale factors for determining denitrification potential. DEA rates ranged between 0.01-1.69 (gN gdw(-1)h(-1)), with most sites falling at the lower end. Sites with higher DEA rates had higher percentages of soil carbon and nitrogen, concentrations of soil extractable NO3 and percent loss on ignition. Sites with upstream agricultural activity had higher DEA rates than more natural sites, but there existed a wide range of DEA rates along both agricultural and urban land gradients. When multiple site and landscape-scale explanatory factors were compared to DEA rates, two site and one landscape scale characteristic (Soil NO3, Soil Percent N, and Percent Agriculture) had significant (p<0.001, cum. r(2)=0.77) correlations with DEA rates. Our results suggest that DEA is controlled mainly by local-scale site characteristics with more work needed to determine the interdependencies and relative importance among these and potentially related landscape-scale factors.
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This paper investigates the scale selection problem for nonlinear diffusion scale-spaces. This topic comprises the notions of localization scale selection and scale space discretization. For the former, we present a new approach. ...
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This paper investigates the scale selection problem for nonlinear diffusion scale-spaces. This topic comprises the notions of localization scale selection and scale space discretization. For the former, we present a new approach. It aims at maximizing the image content's presence by finding the scale that has a maximum correlation with the noise-free image. For the latter, we propose to adapt the optimal diffusion stopping time criterion of Mrazek and Navara in such a way that it may identify multiple scales of importance.
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Statistical and scaling properties of the Lyapunov exponent of a tight-binding model with the diagonal disorder described by a dichotomic process are considered near the band edge. The effect of correlations on scaling properties ...
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Statistical and scaling properties of the Lyapunov exponent of a tight-binding model with the diagonal disorder described by a dichotomic process are considered near the band edge. The effect of correlations on scaling properties is discussed. It is shown that correlations lead to the arising of an additional parameter governing the validity of single parameter scaling. (C) 2003 Elsevier B.V. All rights reserved. [References: 7]
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On April 2013, a local scale seismic network, named OTRIONS, composed of twelve short period (1 Hz) three component seismometers, has been located in the northern part of the Apulia (southern Italy). In the first two months of dat...
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On April 2013, a local scale seismic network, named OTRIONS, composed of twelve short period (1 Hz) three component seismometers, has been located in the northern part of the Apulia (southern Italy). In the first two months of data acquisition, the network recorded about one hundred very small (M L <2) magnitude earthquakes. A three-layer 1D V P velocity model was preliminarily computed, using the recordings of earthquakes occurred in the area in the period 2006-2012 and recorded by the national seismic network of INGV (Istituto Nazionale di Geofisica e Vulcanologia). This model was calibrated by means of a multi-scale approach, based on a global search of the minimum misfit between observed and theoretical travel times. At each step of the inversion, a grid-search technique was implemented to infer the elastic properties of the layers, by using HYPO71 to compute the forward models. In a further step, we used P and S travel times of both INGV and OTRIONS events to infer a minimum 1D V P velocity model, using a classical linearized inversion approach. Owing to the relatively small number of data and poor coverage of the area, in the inversion procedure, the V P /V S ratio was fixed to 1.82, as inferred from a modified Wadati diagram. The final 1D velocity model was obtained by averaging the inversion results arising from nine different initial velocity models. The inferred V P velocity model shows a gradual increase of P wave velocity with increasing the depth. The model is well constrained by data until to a depth of about 25-30 km.
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Meiofauna are an important component of deep-sea benthic communities because they are highly abundant and play an important role in the sediment. This review describes trends in the ecology of deep-sea meiofauna based on results f...
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Meiofauna are an important component of deep-sea benthic communities because they are highly abundant and play an important role in the sediment. This review describes trends in the ecology of deep-sea meiofauna based on results from studies published since the review by Soltwedel (2000), with a focus on spatial distribution patterns of deep-sea meiofauna communities at regional (similar to 100-10,000 km), habitat (similar to 0.1-100 km), local (similar to 0.1-100 m), and small scales (similar to 0.1-10 cm), and with reference to the effects of environmental variables and disturbance (biological and human) that influence these patterns. The focus of deep-sea meiofauna studies has shifted from investigations of patterns related to water depth, regions, and vertical gradients in the sediment to the effect of deep-sea habitats on meiofauna communities, the relative importance of different spatial scales, and the relative impacts of disturbance on meiofauna communities. Although deep-sea meiofauna community attributes (abundance, diversity, and community structure) are shown to vary across all spatial scales, the greatest variability is generally observed at regional and sediment depth scales. However, generalisations are difficult to make due to the limited number of studies that allow direct comparisons across multiple scales. At the regional scale, variation in meiofaunal communities appears mostly related to differences in surface productivity, other food proxies, and physical disturbance; however, geological history, oceanographic boundaries and ocean current flows may also contribute to regional patterns. At the small sediment depth scale, meiofauna communities are typically influenced by food proxies, oxygen availability, sediment characteristics, seafloor topography proxies, microhabitat heterogeneity, and bioturbation by larger fauna. Overall, there have been a limited number of studies of small horizontal scale patterns, at seamounts, and in certain geographic regions such as the Indian Ocean and Antarctica. Fewer studies have been conducted in deep ocean basins compared to continental margin. Most studies have focused on nematodes, while other meiofauna taxa such as harpacticoid copepods have not been investigated as often in deep-sea ecological studies. The findings of this review provide a new perspective on the state of knowledge of the factors influencing meiofauna in the deep-sea ecosystem, and highlights the need for future meiofauna studies to provide information that can assist the management of human activities in vulnerable deep-sea areas.
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