12,446 research outputs found
Geochemistry and petrogenesis of volcanic rocks from Daimao Seamount (South China Sea) and their tectonic implications
The South China Sea (SCS) experienced three episodes of seafloor spreading and left three fossil spreading centers presently located at 18Ā°N, 17Ā°N and 15.5Ā°N. Spreading ceased at these three locations during magnetic anomaly 10, 8, and 5c, respectively. Daimao Seamount (16.6. Ma) was formed 10. my after the cessation of the 17Ā°N spreading center. Volcaniclastic rocks and shallow-water carbonate facies near the summit of Daimao Seamount provide key information on the seamount's geologic history. New major and trace element and Sr-Nd-Pb isotopic compositions of basaltic breccia clasts in the volcaniclastics suggest that Daimao and other SCS seamounts have typical ocean island basalt-like composition and possess a 'Dupal' isotopic signature. Our new analyses, combined with available data, indicate that the basaltic foundation of Daimao Seamount was formed through subaqueous explosive volcanic eruptions at 16.6. Ma. The seamount subsided rapidly (>. 0.12. mm/y) at first, allowing the deposition of shallow-water, coral-bearing carbonates around its summit and, then, at a slower rate (<. 0.12. mm/y). We propose that the parental magmas of SCS seamount lavas originated from the Hainan mantle plume. In contrast, lavas from contemporaneous seamounts in other marginal basins in the western Pacific are subduction-related
Increase in soil organic carbon by agricultural intensification in northern China
Acknowledgements. This research was supported by National Natural Science Foundation of China (no. 31370527 and 31261140367) and the National Science and Technology Support Program of China (no. 2012BAD14B01-2). The authors gratefully thank the Huantai Agricultural Station for providing of the Soil Fertility Survey data. We also thank Zheng Liang from China Agricultural University for the soil sampling and analysis in 2011. Thanks are extended to Jessica Bellarby for helpful discussion and suggestions.Peer reviewedPublisher PD
Reduced c-Fos expression in orexin neurons of the lateral hypothalamic area and the locus coeruleus following injection of spinosin into mice
Background: Spinosin, a major component of Samen Ziziphi spinosae, has been shown to modulate sedation and hypnosis; however, the underlying neuronal mechanisms of its stimulatory effects remain unclear.
Materials and methods: In the present study, we injected spinosin (15 mg/kg) or saline into mice, which were killed after 90 min. We isolated the brains, which were immunohistochemically stained for c-Fos as a biomarker for neuronal activation and assessed the expression profile of c-Fos in various sleepāarousal brain areas.
Results: Our findings revealed that there were no statistically significant differences in the expression of c-Fos in the nucleus accumbens and ventrolateral preoptic area, the vertical limb of the diagonal band nucleus, horizontal limb of the diagonal band nucleus, ventral tuberomammillary nucleus, ventral tegmental area, and dorsal raphe nucleus relative to saline between saline and spinosin-treated mice. Unlike saline, spinosin markedly decreased c-Fos expression in the lateral hypothalamic area (LHA) as well as the locus coeruleus (LC). Compared to the saline injection, the application of spinosin also resulted in a marked decrease in c-Fos expression in the LHA orexin neurons.
Conclusions: These findings suggest that spinosin administration results in a restricted pattern of c-Fos expression within the LHA orexin neurons and the LC, suggesting that this particular neuronal inactivation contributes to sedation and hypnosis
Bromelain and Cardiovascular Risk Factors in Diabetes: An Exploratory Randomized, Placebo Controlled, Double Blind Clinical Trial
Objective: The objective of this trial was to assess whether the dietary supplement (bromelain) had the potential to reduce plasma fibrinogen and other Cardiovascular Disease (CVD) risk factors in patients with diabetes. Methods: This randomized placebo controlled, double blind, parallel design, efficacy study was carried out in China and investigated the effect of 12 weeks of bromelain (1.05g/day) on plasma fibrinogen . This randomized controlled trial (RCT) recruited 68 Chinese diabetic patients (32 males and 36 females; Han origin, mean age of 61.26 years (Standard Deviation, 12.62 years)) with at least one CVD risk factor. Patients were randomized into either bromelain or placebo group. While bromelain group received bromelain capsule, the placebo group received placebo capsule which consisted inert ingredient and has no treatment effect. Patients and researcher were blinded and did not know whether they received bromelain or placebo capsules. Plasma fibrinogen, CVD risk factors and anthropometric indicators were determined at baseline and at 12 weeks. Results: The change in the fibrinogen level in the placebo group at the end of the study showed a mean reduction of 0.36g/L (Standard Deviation (SD) 0.96g/L) compared with the mean reduction of 0.13g/L (SD 0.86g/L) for the bromelain group. However, there was no significant difference in the mean change in fibrinogen between the placebo and bromelain groups (mean difference=0.23g/L (SD 0.22g/L), p=0.291). Similarly, the difference in mean change in other CVD risk factors (blood lipids, blood pressure), blood glucose, C - reactive protein (CRP) and anthropometric measures between the bromelain and placebo groups was also not statistically significant. Conclusions: This RCT failed to show a beneficial effect in reducing fibrinogen or influencing other selected CVD risk factors but suggests other avenues for subsEquent research on bromelain
Better Stereo Matching From Simple Yet Effective Wrangling of Deep Features
Cost volume plays a pivotal role in stereo matching. Most recent works focused on deep feature extraction and cost refinement for a more accurate cost volume. Unlike them, we probe from a different perspective: feature wrangling. We find that simple wrangling of deep features can effectively improve the construction of cost volume and thus the performance of stereo matching. Specifically, we develop two simple yet effective wrangling techniques of deep features, spatially a differentiable feature transformation and channel-wise a memory-economical feature expansion, for better cost construction. Exploiting the local ordering information provided by a differentiable rank transform, we achieve an enhancement of the search for correspondence; with the help of disparity division, our feature expansion allows for more features into the cost volume with no extra memory required. Equipped with these two feature wrangling techniques, our simple network can perform outstandingly on the widely used KITTI and Sceneflow datasets
A molecular dynamics simulation on the oxidation of core-shell aluminum nanoparticles in oxygen and water environments
The oxidation mechanisms of core-shell aluminum nanoparticles (ANPs) in high-temperature steam and oxygen are investigated by ReaxFF molecular dynamics (MD) simulation. The details concerning reaction heat release, heat transfer, atomic diffusion process, and ANP structure evolution are studied by examining the temporal variations of temperature, energy, atoms concentration distributions and particle structure, respectively. The atomic-level heat and mass transfer processes reveal that for both ANP/H2O and ANP/O2 systems, at the initial stage of oxidation, the heat transfer between ANP and environmental oxidizer is dominant. Thereafter, the reaction plays an increasingly significant role. The heat transfer efficiency of ANP/H2O is higher than that of ANP/O2, while the reaction exotherm of ANP/H2O is lower than ANP/O2. The final particle temperature for ANP/O2 system is much higher than that of ANP/H2O. The diameter of the former is also larger. During the oxidation of ANP, the core Al atoms diffuse outward into the oxide shell, which pushes the shell Al atoms outward and results in the expansion of ANP. The shell O atoms diffuse inward and left a vacant lattice site, through which the ambient H and O atoms diffuse into the oxide shell
Disparity Estimation with Scene Depth Cues
The cost volume plays a pivotal role in stereo matching, usually working as an optimization object. However, we find it also can provide effective scene prior to guide the disparity learning, as it reflects well the depth relationship between scenario objects. Inspired by this new perspective, we propose the CSA module, which consists of a new correlation and selection (CS) layer and a new aggregation layer. The CS layer can regulate the matching costs and re-encode the feature information into the correlation volume. The aggregation layer can preserve better the depth cues of the refined cost volume, through a convolution network and a unimodalization operation. The proposed module can be trained in a supervised manner, making the extraction of scene depth cues more accurate. Extensive experiments on the Sceneflow and KITTI datasets have demonstrated that with our module embedded, SOTA networks can achieve substantially better performance
Size-derived reaction mechanism of core-shell aluminum nanoparticle
To prompt the application of aluminum nanoparticles (ANPs) in combustion as the fuel additive and in chemical synthesis as the catalyst, this study examines the reaction dynamics of core-shell ANPs under an oxygen atmosphere via Transient Non-Equilibrium Reactive Molecular Dynamics simulations. Two distinct oxidation modes determined by the competition between the oxide shell melting and core reaction have been identified. One is the fast oxidation mode with a high reaction heat release rate, where core Al and ambient O atoms diffuse into each other to form a homogeneous alumina particle. The other is the moderate oxidation with lower heat release, where only core Al atoms diffuse into the oxide shell to form a hollow spherical structure. By modeling the shell melting and Al core reaction, a size-derived oxidation model has been proposed to conveniently but accurately predict the ANP reaction dynamics. This work also provides fundamental insight into the synthesis of ANPs that serve as a high energy density fuel and high-performance catalyst
First-Order Reorientation of the Flux-Line Lattice in CaAlSi
The flux line lattice in CaAlSi has been studied by small angle neutron
scattering. A well defined hexagonal flux line lattice is seen just above Hc1
in an applied field of only 54 Oe. A 30 degree reorientation of this vortex
lattice has been observed in a very low field of 200 Oe. This reorientation
transition appears to be of first-order and could be explained by non-local
effects. The magnetic field dependence of the form factor is well described by
a single penetration depth of 1496(1) angstroms and a single coherence length
of 307(1) angstroms at 2 K. At 1.5 K the penetration depth anisotropy is 2.7(1)
with the field applied perpendicular to the c axis and agrees with the
coherence length anisotropy determined from critical field measurements.Comment: 5 pages including 6 figures, to appear in Physical Review Letter
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