264 research outputs found
Mining Parallel Text from the Web based on Sentence Alignment
PACLIC 21 / Seoul National University, Seoul, Korea / November 1-3, 200
Ore Extension of Group-cograded Hopf Coquasigroups
The aim of this paper is the Ore extension of group-cograded Hopf
coquasigroups. This paper first shows a categorical interpretation and some
examples of group-cograded Hopf coquasigroups, and then gives a necessary and
sufficient conditions for the Ore extensions of group-cograded Hopf
coquasigroups to be group-cograded Hopf coquasigroups. Finally, a certain
isomorphism between Ore extensions are considered.Comment: 15page
Characterization, dissolution and solubility of the hydroxypyromorphiteâhydroxyapatite solid solution [(PbxCa1âx)5(PO4)3OH] at 25 °C and pH 2â9
Additional file 1: Appendix A. Supplementary dataâX-ray diffractograms (XRD) of the hydroxypyromorphiteâhydroxyapatite solid solution [(PbxCa1âx)5(PO4)3(OH)] after dissolution at 25âËC and an initial pH of 5.60 and 9.00 for 300d
Statistic inversion of multi-zone transition probability models for aquifer characterization in alluvial fans
Understanding the heterogeneity arising from the complex architecture of
sedimentary sequences in alluvial fans is challenging. This paper develops a
statistical inverse framework in a multi-zone transition probability approach
for characterizing the heterogeneity in alluvial fans. An analytical solution
of the transition probability matrix is used to define the statistical
relationships among different hydrofacies and their mean lengths, integral
scales, and volumetric proportions. A statistical inversion is conducted to
identify the multi-zone transition probability models and estimate the optimal
statistical parameters using the modified Gauss-Newton-Levenberg-Marquardt
method. The Jacobian matrix is computed by the sensitivity equation method,
which results in an accurate inverse solution with quantification of parameter
uncertainty. We use the Chaobai River alluvial fan in the Beijing Plain, China,
as an example for elucidating the methodology of alluvial fan characterization.
The alluvial fan is divided into three sediment zones. In each zone, the
explicit mathematical formulations of the transition probability models are
constructed with optimized different integral scales and volumetric
proportions. The hydrofacies distributions in the three zones are simulated
sequentially by the multi-zone transition probability-based indicator
simulations. The result of this study provides the heterogeneous structure of
the alluvial fan for further study of flow and transport simulations.Comment: 29 pages, 7 figures, and 3 table
Modeling 3-D permeability distribution in alluvial fans using facies architecture and geophysical acquisitions
Alluvial fans are highly heterogeneous in hydraulic properties due to complex depositional processes, which make it difficult to characterize the spatial distribution
of the hydraulic conductivity (K). An original methodology is developed to identify the spatial statistical parameters (mean, variance, correlation range) of the hydraulic conductivity in a three-dimensional (3-D) setting by using geological and geophysical data. More specifically, a large number of inexpensive vertical electric soundings are integrated with a facies model developed from borehole lithologic data to simulate the log10(K) continuous distributions in multiplezone
heterogeneous alluvial megafans. The Chaobai River alluvial fan in the Beijing Plain, China, is used as an example to test the proposed approach. Due to the non-stationary property of the K distribution in the alluvial fan, a multiplezone parameterization approach is applied to analyze the conductivity statistical properties of different hydrofacies in the various zones. The composite variance in each zone is computed to describe the evolution of the conductivity along the flow direction. Consistently with the scales of the sedimentary transport energy, the results show that conductivity variances of fine sand, medium-coarse sand, and gravel decrease from the upper (zone 1) to the lower (zone 3) portion along the flow direction. In zone 1, sediments were moved by higher-energy flooding, which induces poor sorting and larger conductivity variances. The composite variance confirms this feature with statistically different facies from zone 1 to zone 3. The results of this study provide insights to improve our understanding on conductivity heterogeneity and a method for characterizing the spatial distribution
of K in alluvial fans
Legume Green Manuring Improves Soil Fertility and Plant Growth of Eucalyptus Plantation in South Subtropical China
Legume green manure is extensively planted to improve soil fertility in crop field. However, the application of legume in Eucalyptus plantation is still limited and depends on site specific and species. Therefore, the objective of this study was to determine the effects of green manure interplantation on soil fertility and plant growth of Eucalyptus plantation in a short term. A field experiment of one year was established to investigate the green manure growth, forest soil nutrients and Eucalyptus plant growth inter-planted with two legume species (Tephrosia candida, TC and Sesbania cannabina, SC) at south subtropical China. Legumes were inter-planted in linear among the tree space of Eucalyptus stand. Result showed that the green manure inter-plantation increased soil organic matter by 9.66% of TC and 18.44% of SC. Soil available nitrogen, phosphorus and potassium were improved significantly by the legume treatments as well. The increment of height and diameter at breast height of Eucalyptus during the experiment was significant in legume treatments. Thus, the timber volume increment was improved significantly by 46.81% of TC and 35.47% of SC compared with the control treatment. Therefore, the inter-plantation of legume green manure under the Eucalyptus plantation is effective to improve soil fertility and tree growth. Such a measure is potential and referenced for the sustainable forest management
Unique opportunity to harness polarization in GaN to override the conventional power electronics figure-of-merits
Owing to the large breakdown electric field, wide bandgap semiconductors such
as SiC, GaN, Ga2O3 and diamond based power devices are the focus for next
generation power switching applications. The unipolar trade-off relationship
between the area specific-on resistance and breakdown voltage is often employed
to compare the performance limitation among various materials. The GaN material
system has a unique advantage due to its prominent spontaneous and
piezoelectric polarization effects in GaN, AlN, InN, AlxInyGaN alloys and
flexibility in inserting appropriate heterojunctions thus dramatically broaden
the device design space.Comment: Invited paper, to appear in IEEE Device Research Conference (DRC),
June 201
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