Continental-scale spatial distribution of chromium (Cr) in China and its relationship with ultramafic-mafic rocks and ophiolitic chromite deposit

2021 ◽  
Vol 126 ◽  
pp. 104896
Author(s):  
Taotao Yan ◽  
Xueqiu Wang ◽  
Dongsheng Liu ◽  
Qinghua Chi ◽  
Jian Zhou ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Mafic Rocks ◽  
Continental Scale ◽  
Chromite Deposit

Continental-scale geochemical survey of lead (Pb) in mainland China's pedosphere: Concentration, spatial distribution and influences

2019 ◽  
Vol 100 ◽  
pp. 55-63 ◽  
Author(s):  
Xueqiu Wang ◽  
Zhixuan Han ◽  
Wei Wang ◽  
Bimin Zhang ◽  
Hui Wu ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Continental Scale ◽  
Geochemical Survey

scholarly journals The spatial distribution characteristics of Nb–Ta of mafic rocks in subduction zones

2021 ◽  
Vol 13 (1) ◽  
pp. 390-400
Author(s):  
Weiwei Li ◽  
Can Ge ◽  
Fangyue Wang ◽  
He Sun ◽  
Haiou Gu
Keyword(s):  
Spatial Distribution ◽  
Subduction Zone ◽  
Subduction Zones ◽  
Crustal Contamination ◽  
Quantitative Relationship ◽  
Threshold Value ◽  
Cumulative Distribution ◽  
Function Estimation ◽  
Mafic Rocks ◽  
Geophysical Model

Abstract High field-strength elements have been regarded as one of the most important discriminations in subduction zone magma. However, the spatial distribution of Nb and Ta in subduction zone-related rocks has been rarely studied; it is still unclear whether there is a quantitative relationship between the Nb–Ta concentrations and their subduction distance. In this paper, the Nb–Ta concentrations of mafic rocks in arc tectonic systems were calculated from a statistical perspective based on the combined geophysical model and geochemical database. The results showed a typical spatial distribution pattern. The threshold value of Nb (12.20 ppm) and Ta (0.796 ppm) in arc settings was estimated by a cumulative distribution function, which can be used to determine whether the rock is generated in arc tectonic environment. A probability density function of Nb–Ta contents and related subduction distance has been obtained using kernel function estimation. The Nb–Ta concentrations are exponentially correlated with the subduction distance (<700 km), while the Nb/Ta ratios keep in the range of 12–19. We proposed that the subduction depth, along with the degree of partial melting, and possible crustal contamination might be responsible for the Nb–Ta variation correlation with subduction distances.

scholarly journals Atmospheric inversion of surface carbon flux with consideration of the spatial distribution of US crop production and consumption

2015 ◽  
Vol 12 (2) ◽  
pp. 323-343 ◽  
Author(s):  
J. M. Chen ◽  
J. W. Fung ◽  
G. Mo ◽  
F. Deng ◽  
T. O. West
Keyword(s):  
Spatial Distribution ◽  
Crop Production ◽  
Spatial Information ◽  
General Pattern ◽  
Surface Carbon ◽  
Continental Scale ◽  
Production And Consumption ◽  
Carbon Transfer ◽  
The Us ◽  
Atmospheric Inversion

Abstract. In order to improve quantification of the spatial distribution of carbon sinks and sources in the conterminous US, we conduct a nested global atmospheric inversion with detailed spatial information on crop production and consumption. County-level cropland net primary productivity, harvested biomass, soil carbon change, and human and livestock consumption data over the conterminous US are used for this purpose. Time-dependent Bayesian synthesis inversions are conducted based on CO2 observations at 210 stations to infer CO2 fluxes globally at monthly time steps with a nested focus on 30 regions in North America. Prior land surface carbon fluxes are first generated using a biospheric model, and the inversions are constrained using prior fluxes with and without adjustments for crop production and consumption over the 2002–2007 period. After these adjustments, the inverted regional carbon sink in the US Midwest increases from 0.25 ± 0.03 to 0.42 ± 0.13 Pg C yr−1, whereas the large sink in the US southeast forest region is weakened from 0.41 ± 0.12 to 0.29 ± 0.12 Pg C yr−1. These adjustments also reduce the inverted sink in the west region from 0.066 ± 0.04 to 0.040 ± 0.02 Pg C yr−1 because of high crop consumption and respiration by humans and livestock. The general pattern of sink increases in crop production areas and sink decreases (or source increases) in crop consumption areas highlights the importance of considering the lateral carbon transfer in crop products in atmospheric inverse modeling, which provides a reliable atmospheric perspective of the overall carbon balance at the continental scale but is unreliable for separating fluxes from different ecosystems.

scholarly journals Inverse modelling of the spatial distribution of NO<sub>x</sub> emissions on a continental scale using satellite data

2006 ◽  
Vol 6 (7) ◽  
pp. 1747-1770 ◽  
Author(s):  
I. B. Konovalov ◽  
M. Beekmann ◽  
A. Richter ◽  
J. P. Burrows
Keyword(s):  
Spatial Distribution ◽  
Satellite Data ◽  
A Priori ◽  
Inverse Modelling ◽  
Geometric Standard Deviation ◽  
Nox Emissions ◽  
A Posteriori ◽  
Near Surface ◽  
Continental Scale ◽  
Tropospheric No2

Abstract. The recent important developments in satellite measurements of the composition of the lower atmosphere open the challenging perspective to use such measurements as independent information on sources and sinks of atmospheric pollutants. This study explores the possibility to improve estimates of gridded NOx emissions used in a continental scale chemistry transport model (CTM), CHIMERE, by employing measurements performed by the GOME and SCIAMACHY instruments. We set-up an original inverse modelling scheme that not only enables a computationally efficient optimisation of the spatial distribution of seasonally averaged NOx emissions (during summertime), but also allows estimating uncertainties in input data and a priori emissions. The key features of our method are (i) replacement of the CTM by a set of empirical models describing the relationships between tropospheric NO2 columns and NOx emissions with sufficient accuracy, (ii) combination of satellite data for tropospheric NO2 columns with ground based measurements of near surface NO2 concentrations, and (iii) evaluation of uncertainties in a posteriori emissions by means of a special Bayesian Monte-Carlo experiment which is based on random sampling of errors of both NO2 columns and emission rates. We have estimated the uncertainty in a priori emissions based on the EMEP emission inventory to be about 1.9 (in terms of geometric standard deviation) and found the uncertainty in a posteriori emissions obtained from our inverse modelling scheme to be significantly lower (about 1.4). It is found also that a priori NOx emission estimates are probable to be persistently biased in many regions of Western Europe, and that the use of a posteriori emissions in the CTM improves the agreement between the modelled and measured data.

Ecosystem services of organic wine production – Linking different views

2020 ◽  
Author(s):  
Ana Iglesias ◽  
Luis Garrote ◽  
Vicente Sotes ◽  
Isabel Bardaji
Keyword(s):  
Spatial Distribution ◽  
Ecosystem Services ◽  
Value Chain ◽  
Management Practices ◽  
Local Policy ◽  
Wine Production ◽  
Public And Private ◽  
Continental Scale ◽  
Organic Wine

&lt;p&gt;Aiming to explore and exchange ideas about the ecosystem services of organic wine production, this presentation will address two questions. First, what is the potential for improving ecosystem services? This is explored at the continental scale, looking at the spatial distribution of the effect of organic management practices in permanent crops. Second, how can the targets be reached based on public and private solution? This is explored based on local policy targets and contract based solutions including the private sector and the value chain. A case study of organic wine production in the Spanish Denomination of Origin Rueda is presented as a practical example. The content of the study is based on the results of the iSQAPER (http://www.isqaper-project.eu/) and CONSOLE (https://console-project.eu/) H2020 projects.&lt;/p&gt;

scholarly journals Inverse modelling of the spatial distribution of NO<sub>x</sub> emissions on a continental scale using satellite data

2005 ◽  
Vol 5 (6) ◽  
pp. 12641-12695 ◽  
Author(s):  
I. B. Konovalov ◽  
M. Beekmann ◽  
A. Richter ◽  
J. P. Burrows
Keyword(s):  
Spatial Distribution ◽  
Satellite Data ◽  
A Priori ◽  
Inverse Modelling ◽  
Geometric Standard Deviation ◽  
Nox Emissions ◽  
A Posteriori ◽  
Near Surface ◽  
Continental Scale ◽  
Tropospheric No2

Abstract. The recent important developments in satellite measurements of the composition of the lower atmosphere open the challenging perspective to use such measurements as independent information on sources and sinks of atmospheric pollutants. This study explores the possibility to improve estimates of gridded NOx emissions used in a continental scale chemistry transport model (CTM), CHIMERE, by employing measurements performed by the GOME and SCIAMACHY instruments. We set-up an original inverse modelling scheme that not only enables a computationally efficient optimisation of the spatial distribution of seasonally averaged NOx emissions (during summertime), but also allows estimating uncertainties of input data and a priori emissions. The key features of our method are (i) replacement of the CTM by a set of empirical models describing the relationships between tropospheric NO2 columns and NOx emissions with sufficient accuracy, (ii) combination of satellite data for tropospheric NO2 columns with ground based measurements of near surface NO2 concentrations, and (iii) evaluation of uncertainties of the a posteriori emissions by means of a special Bayesian Monte-Carlo experiment which is based on random sampling of errors of both NO2 columns and emission rates. We have estimated the uncertainty in a priori emissions based on the EMEP emission inventory to be about 1.9 (in terms of the geometric standard deviation) and found the uncertainty in a posteriori emissions obtained from our inverse modelling scheme to be significantly lower (about 1.4). It is found also that a priori NOx emission estimates are probable to be persistently biased in many regions of Western Europe, and that the use of a posteriori emissions in the CTM improves the agreement between the modelled and measured data.

scholarly journals Spatial distribution of net surface accumulation on the Antarctic ice sheet

2000 ◽  
Vol 31 ◽  
pp. 171-178 ◽  
Author(s):  
M. B. Glovinetto ◽  
H. J. Zwally
Keyword(s):  
Spatial Distribution ◽  
Field Data ◽  
Ice Sheet ◽  
Regional Assessment ◽  
Ice Shelf ◽  
Antarctic Ice Sheet ◽  
Drainage Systems ◽  
Continental Scale ◽  
The Antarctic ◽  
Larsen Ice Shelf

AbstractAn isopleth map showing the spatial distribution of net mass accumulation at the surface on the Antarctic ice sheet, excluding Graham Land, the Larsen Ice Shelf and eastern Palmer Land, is produced based on field data from approximately 2000 sites. A database of accumulation values for 5365 gridpoint locations with 50 km spacing is interpolated from the isopleth map, giving a bulk accumulation of 2151 Gt a–1 and a mean of 159 kg m–2 a–1 for an area of 13.53 × 106 km2. Following the implementation of deflation and ablation adjustments applicable to sectors of the coastal zone, the accumulation values are reduced to 2020 Gt a–1 and 149 kg m–2 a–1. The new accumulation distribution is compared with another recent distribution, which was based on essentially the same field data using different analysis and interpolation criteria. Differences between the distributions are assessed using residuals for the 50 km gridpoint locations and by comparing average accumulation values for 24 drainage systems. The assessment based on residuals indicates that the two distributions show patterns of accumulation that are coherent at the continental scale, a shared attribute underscored by a small mean residual value of 6 kg m–2 a–1 (a difference of <4%). However, the regional assessment based on average accumulation values for the drainage systems shows differences that are larger than the assessment error (>22%) for six systems that collectively comprise approximately 4/10 of the ice-sheet area and 3/10 of the accumulation.

Lithography below 100 nm

1983 ◽  
Vol 41 ◽  
pp. 96-99
Author(s):  
L. D. Jackel
Keyword(s):  
Spatial Distribution ◽  
Electron Beam ◽  
Electron Scattering ◽  
Electron Beam Lithography ◽  
Substrate Material ◽  
Local Electron ◽  
Electron Dose ◽  
Positive Resist ◽  
Exposure Process

Most production electron beam lithography systems can pattern minimum features a few tenths of a micron across. Linewidth in these systems is usually limited by the quality of the exposing beam and by electron scattering in the resist and substrate. By using a smaller spot along with exposure techniques that minimize scattering and its effects, laboratory e-beam lithography systems can now make features hundredths of a micron wide on standard substrate material. This talk will outline sane of these high- resolution e-beam lithography techniques.We first consider parameters of the exposure process that limit resolution in organic resists. For concreteness suppose that we have a “positive” resist in which exposing electrons break bonds in the resist molecules thus increasing the exposed resist's solubility in a developer. Ihe attainable resolution is obviously limited by the overall width of the exposing beam, but the spatial distribution of the beam intensity, the beam “profile” , also contributes to the resolution. Depending on the local electron dose, more or less resist bonds are broken resulting in slower or faster dissolution in the developer.

SEM evaluation of the TEM cold-stage double-film specimen

1984 ◽  
Vol 42 ◽  
pp. 272-273
Author(s):  
Jayesh Bellare
Keyword(s):  
Spatial Distribution ◽  
Sample Preparation ◽  
Sample Thickness ◽  
Specimen Preparation ◽  
Preparation Technique ◽  
Liquid Sample ◽  
Thin Specimen ◽  
Sample Preparation Technique ◽  
Cold Stage ◽  
Film Specimen

Seeing is believing, but only after the sample preparation technique has received a systematic study and a full record is made of the treatment the sample gets.For microstructured liquids and suspensions, fast-freeze thermal fixation and cold-stage microscopy is perhaps the least artifact-laden technique. In the double-film specimen preparation technique, a layer of liquid sample is trapped between 100- and 400-mesh polymer (polyimide, PI) coated grids. Blotting against filter paper drains excess liquid and provides a thin specimen, which is fast-frozen by plunging into liquid nitrogen. This frozen sandwich (Fig. 1) is mounted in a cooling holder and viewed in TEM.Though extremely promising for visualization of liquid microstructures, this double-film technique suffers from a) ireproducibility and nonuniformity of sample thickness, b) low yield of imageable grid squares and c) nonuniform spatial distribution of particulates, which results in fewer being imaged.

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