Spatially resolved self-consistent spectral modelling of jellyfish galaxies from MUSE with FADO: trends with mass and stripping intensity

We present a spatially resolved stellar population analysis of 61 jellyfish galaxies and 47 control galaxies observed with ESO/MUSE attempting to understand the general trends of the stellar populations as a function of the stripping intensity and mass. This is the public sample from the GASP programme, with $0.01 < z < 0.15$ and $8.9 <\log(M_{\star}/M_{\odot}) < 12.0$. We apply the spectral population synthesis code FADO to fit self-consistently both the stellar and nebular contributions to the spectra of the sources. We present 2D morphological maps for mean stellar ages, metallicities, gas-phase oxygen abundances, and star formation rates for the galaxies with Integrated Nested Laplace Approximation ({\sc inla}), which is efficient in reconstructing spatial data of extended sources. We find that ``extreme stripping'' and ``stripping'' galaxies are typically younger than the other types. Regarding stellar and nebular metallicities, the ``stripping'' and ``control passive'' galaxies are the most metal-poor. Based on the phase space for jellyfish cluster members we find trends in ages, metallicities, and abundances with different regions of the diagram. We also compute radial profiles for the same quantities. We find that both the stripping and the stellar masses seem to influence the profiles, and we see differences between various groups and distinct mass bins. The radial profiles for different mass bins present relations already shown in the literature for undisturbed galaxies, i.e., profiles of ages and metallicities tend to increase with mass. However, beyond $\sim0.75$ effective radius, the ages of the most massive galaxies become similar to or lower than the ages of the lower mass ones.Comment: Accepted by MNRAS. 71 pages (13 of main text and 58 of supplementay material). 123 figure

Study on SnO2/graphene composites with superior electrochemical performance for lithium-ion batteries

NSFC [U1305246, 21321062]; Xiamen city [3502Z20121002]; Quanzhou "Tong-Jiang Scholar" program; Fujian "Min-Jiang Scholar" program; program for New Century Excellent Talents in University [NCET-13-0879]; Education and Scientific Research Foundation (Class A) for Young Teachers of Education Bureau of Fujian Province, China [JA13263]; National Natural Science Foundation of China [21353001]In this study, the in situ growth of tin dioxide (SnO2) nanoparticles on reduced graphene oxide (rGO) has been realized using a hydrothermal method. The size of the SnO2 nanoparticles in the SnO2/rGO composites prepared by three different procedures is about 5 nm, and they are well dispersed on rGO. When applied as anode materials for lithium-ion batteries, we found that the composites synthesized from the stannous oxalate precursor showed the best rate performance and highest cyclic stability. The surface status of the composites, including interactions between SnO2 and rGO and surface chemical components, was investigated in detail in order to understand why the composites prepared using different procedures displayed vastly different electrochemical performances. The results presented here describe a new approach for the synthesis of uniform and nanosized metal-oxide/rGO composites with excellent electrochemical performance

An electrochemical impedance spectroscopic study of the electronic and ionic transport properties of LiCoO2 cathode

The storage behavior and process of the first delithiation-lithiation of LiCoO2 cathode were investigated by electrochemical impedance spectroscopy (EIS). The electronic and ionic transport properties of LiCoO2 cathode along with variation of electrode potential were obtained in 1 mol.L-1 LiPF6-EC: DMC: DEC electrolyte solution. It was found that after 9 h storage of the LiCoO2 cathode in electrolyte solutions, a new arc appears in the medium frequency range in Nyquist plots of EIS, which increases with increasing the storage time. In the charge/discharge processes, the diameter of the new arc is reversibly changed with electrode potential. Such variation coincides well with the electrode potential dependence of electronic conductivity of the LiCoO2.. Thus this new EIS feature is attributed to the change of electronic conductivity of LixCoO2 during storage of the LiCoO2 cathode in electrolyte solutions, as well as in processes of intercalation-deintercalationtion of lithium ions. It has been revealed that the reversible increase and decrease of the resistance of SEI film in charge-discharge processes can be also ascribed to the variation of electronic conductance of active materials of the LiCoO2 cathode

Inhibition of COX2/PGD2-Related Autophagy Is Involved in the Mechanism of Brain Injury in T2DM Rat

The present study was designed to observe the effect of COX2/PGD2-related autophagy on brain injury in type 2 diabetes rats. The histopathology was detected by haematoxylin–eosin staining. The learning and memory functions were evaluated by Morris water maze. The levels of insulin and PGD2 were measured by enzyme-linked immunosorbent assay. The expressions of COX2, p-AKT(S473), p-AMPK(T172), Aβ, Beclin1, LC3BII, and p62 were measured by immunohistochemistry and Western blotting. In model rats, we found that the body weight was significantly decreased, the blood glucose levels were significantly increased, the plasma insulin content was significantly decreased, the learning and memory functions were impaired and the cortex and hippocampus neurons showed significant nuclear pyknosis. The levels of COX2, p-AKT(S473), PGD2, Aβ, Beclin1 and p62 were significantly increased, whereas the expression of p-AMPK(T172) and LC3BII was significantly decreased in the cortex and hippocampus of model rats. In meloxicam-treated rats, the body weight, blood glucose and the content of plasma insulin did not significantly change, the learning and memory functions were improved and nuclear pyknosis was improved in the cortex and hippocampus neurons. The expression of p-AMPK(T172), Beclin1 and LC3BII was significantly increased, and the levels of COX2, p-AKT(S473), PGD2, Aβ, and p62 were significantly decreased in the cortex and hippocampus of meloxicam-treated rats. Our results suggested that the inhibition of COX2/PGD2-related autophagy was involved in the mechanism of brain injury caused by type 2 diabetes in rats

Electrochemical impedance spectroscopic study of the first delithiation of spinel lithium manganese oxide

The first delithiation of the spinel LiMn2O4 electrode was studied using electrochemical impedance spectroscopy (EIS). Appropriate equivalent circuits were proposed to fit the experimental EIS data. Based on the fitting results, the variation of the capacitance and the resistance of SEI (solid electrolyte interphase) film, the resistance of charge transfer, and the capacitance of double layer along with the increase of polarization potential were quantitatively analyzed. The results demonstrated that the resistance and the thickness of the SEI film formed on the spinel LiMn2O4 electrode were both increased with the increase of polarization potential in the first delithiation of the spinel LiMn2O4 electrode; The charge transfer resistance decreases below 4.15 V and increases above 4.15 V, corresponding to the two-step reversible (de)intercalation of lithium between LiMn2O4 and lambda-MnO2; The double layer capacitance was influenced by both the state of the spinel LiMn2O4 electrode (different polarization potential) and the two-step reversible (de)intercalation of lithium

High-cycle fatigue behaviour and crack growth mechanism of Ni-base single crystal superalloy under intermediate temperature

This study investigates the high cycle fatigue behaviour of a Ni-base single crystal superalloy under 760 °C and 850 °C. At 760 °C, the crack initially grows in the crystallographic shearing mode and the crack tip propagation mechanism is non-crystallographic mode. Furthermore, near the crack tip propagated at 760 °C, the oxide film distributes along the γ/γʹ interface and the Ni-rich γʹ phase dissolution channels pass through the matrix in different ways, resulting in the wavy-like and dendritic cracks. When the temperature rises to 850 °C, recrystallization grains are observed in the fatigue initiation region. Moreover, the stress reduction leads to the increment of accumulative strain and the aggravation of the recrystallization. This will enhance the crack growth driving factor, promoting the crack to grow in crystallographic shearing mode. Finally, the mechanisms of high cycle fatigue crack growth influenced by temperatures and stresses are obtained and enhancement conditions of crack growth driving factor are revealed

Numerical Simulation of the Shear Capacity of a GFRP-Strengthened Natural Bamboo-Bolt Composite Joint

As an ecological green building material, natural bamboo has many advantages such as a light weight, high strength, and short growth cycle. Natural bamboo is widely used in landscape architecture and fabricated structures. However, in bamboo building structures, the most common bolted joints often appear cleaved along the grain. In this paper, glass fiber-reinforced polymer (GFRP) is designed to wrap and improve the shear capacity of natural bamboo-bolt composite joints. According to the corresponding material parameters, the finite element model of composite joints is established, and the key influencing variables of the bearing capacity, namely the bolt diameter, bamboo tube outer diameter, and screw end distance, are analyzed. In addition, according to the European analytical yield model of bolted connections, the analytical calculation method of the bearing capacity is proposed and compared with the experimental and simulated values. The results showed that the numerical model and the modified analytical model can suitably describe the bearing capacity of composite joints, and a higher bolt diameter, along with the bamboo outer diameter, will lead to a higher ultimate load of the composite joints. Moreover, the bearing capacity of composite joints has no obvious relationship with the end spacing

Unsupervised Capsule Networks of High-Dimension Point Clouds classification

Three-dimensional point clouds learning is widely applied, but the point clouds are still unable to deal with classification and recognition tasks satisfactorily in the cases of irregular geometric structures and high-dimensional space. In 3D space, point clouds tend to have regular Euclidean structure because of their density. On the contrary, due to the high dimensionality, the spatial structure of high-dimensional space is more complex, and point clouds are mostly presented in non-European structure. Furthermore, among current 3D point clouds classification algorithms, Canonical Capsules algorithm based on Euclidean distance is difficult to decompose and identify non-Euclidean structures effectively. Thus, aiming at the point clouds classification task of non-Euclidean structure in 3D and high-dimensional space, this paper refers to the LLE algorithm based on geodesic distance for optimizing and proposes the unsupervised algorithm of high-dimensional point clouds capsule. In this paper, the geometric features of point clouds are considered in the extraction process, so as to transform the high-dimensional non-Euclidean structure into a lower-dimensional Euclidean structure with retaining spatial geometric features. To verify the feasibility of the unsupervised algorithm of high-dimensional point clouds capsule, experiments are conducted in Swiss Roll dataset, point clouds MNIST dataset and point clouds LFW dataset. The results show that (1) non-Euclidean structures can be can effectively identified by this model in Swiss Roll dataset; (2) a significant unsupervised learning effect is realized in point clouds MNIST dataset. In conclusion, the high-dimensional point clouds capsule unsupervised algorithm proposed in this paper is conducive to expand the application scenarios of current point clouds classification and recognition tasks.Comment: 24 page

Comparative Physiology and Transcriptome Analysis Provides Insights into the Regulatory Mechanism of Albinotic <i>Bambusa oldhamii</i>

Albinism is a unique problem encountered in tissue culture experiments, but the underlying mechanism remains unclear in most bamboo species. In this study, we identified the putative regulatory genes in an albino mutant of Bambusa oldhamii using comparative physiology and transcriptome analysis. The degeneration of chloroplasts, low chlorophyll (Chl) content and reduced photosynthetic capacity were observed in albinotic B. oldhamii compared to normal lines. A total of 6191 unigenes were identified that were clearly differentially expressed between albino and normal lines by transcriptome sequencing. Most genes related to chloroplast development (such as Psa, Psb) and pigment biosynthesis (such as LHC, GUN4, ZEP) were downregulated significantly in albinotic lines, which might be responsible for the albino phenotype. Moreover, some transcription factors (TFs) such as PIF and GLK1 were identified to be involved in chloroplast development and Chl synthesis, indicating the involvement of putative regulatory pathways PIF-LHC and GLK1-LHC/Psa/Psb in albinotic B. oldhamii. Finally, the downregulation of some stress responsive TFs (like ICE1 and EREB1) suggested a reduction in stress resistance of albinotic B. oldhamii. The above findings provided new insights into the molecular mechanism of albinism in bamboo