106 research outputs found
Classification Identification of Acoustic Emission Signals from Underground Metal Mine Rock by ICIMF Classifier
To overcome the drawback that fuzzy classifier was sensitive to noises and outliers, Mamdani fuzzy classifier based on improved chaos immune algorithm was developed, in which bilateral Gaussian membership function parameters were set as constraint conditions and the indexes of fuzzy classification effectiveness and number of correct samples of fuzzy classification as the subgoal of fitness function. Moreover, Iris database was used for simulation experiment, classification, and recognition of acoustic emission signals and interference signals from stope wall rock of underground metal mines. The results showed that Mamdani fuzzy classifier based on improved chaos immune algorithm could effectively improve the prediction accuracy of classification of data sets with noises and outliers and the classification accuracy of acoustic emission signal and interference signal from stope wall rock of underground metal mines was 90.00%. It was obvious that the improved chaos immune Mamdani fuzzy (ICIMF) classifier was useful for accurate diagnosis of acoustic emission signal and interference signal from stope wall rock of underground metal mines
An assumption of in situ resource utilization for âbio-bricksâ in space exploration
Microbially induced carbonate precipitation (MICP) mimics the natural cementation process that occurs in various geological settings by using the bicarbonate minerals resulting from various bacterial metabolic pathways as cementing agents. This bio-technique can be used to manufacture so-called âbio-bricks,â which rival regular bricks in strength and durability. In the last two decades, MICP has been increasingly utilized for the maintenance and repair of infrastructure. More recently, this process has also been shown to have great potential as an energy-saving and cost-effective means of in situ resource utilization (ISUR) to produce construction materials; these can be utilized for extraterrestrial human settlements for space programs such as lunar exploration. We thus review the description of natural cementation, the anaerobic and aerobic bacterial metabolic activities leading to calcium carbonate precipitation, the properties of the lunar regolith, the production of bio-bricks, and potential research needs
Unshifted Metastable He I* Mini-Broad Absorption Line System in the Narrow Line Type 1 Quasar SDSS J080248.18551328.9
We report the identification of an unusual absorption line system in the
quasar SDSS J080248.18551328.9 and present a detailed study of the system,
incorporating follow-up optical and NIR spectroscopy. A few tens of absorption
lines are detected, including He I*, Fe II* and Ni II* that arise from
metastable or excited levels, as well as resonant lines in Mg I, Mg II, Fe II,
Mn II, and Ca II. All of the isolated absorption lines show the same profile of
width km s centered at a common redshift as that of
the quasar emission lines, such as [O II], [S II], and hydrogen Paschen and
Balmer series. With narrow Balmer lines, strong optical Fe II multiplets, and
weak [O III] doublets, its emission line spectrum is typical for that of a
narrow-line Seyfert 1 galaxy (NLS1). We have derived reliable measurements of
the gas-phase column densities of the absorbing ions/levels. Photoionization
modeling indicates that the absorber has a density of and a column density of , and is located at
pc from the central super-massive black hole. The location of the absorber, the
symmetric profile of the absorption lines, and the coincidence of the
absorption and emission line centroid jointly suggest that the absorption gas
is originated from the host galaxy and is plausibly accelerated by stellar
processes, such as stellar winds \zhy{and/or} supernova explosions. The
implications for the detection of such a peculiar absorption line system in an
NLS1 are discussed in the context of co-evolution between super-massive black
hole growth and host galaxy build-up.Comment: 28 pages, 16 figures; accepted for publication in Astrophysical
Journa
The physical constraints on a new LoBAL QSO at z=4.82
Very few low-ionization broad absorption line (LoBAL) QSOs have been found at
high redshifts to date. One high-redshift LoBAL QSO, J0122+1216, was recently
discovered at the Lijiang 2.4-m Telescope with an initial redshift
determination of 4.76. Aiming to investigate its physical properties, we
carried out follow-up observations in the optical and near-IR spectroscopy.
Near-IR spectra from UKIRT and P200 confirms that it is a LoBAL, with a new
redshift determination of based on the \mgii~ emission-line. The
new \mgii~ redshift determination reveals strong blueshifts and asymmetry of
the high-ionization emission lines. We estimated a black hole mass of and Eddington ratio of according to the
empirical \mgii-based single-epoch relation and bolometric correction factor.
It is possible that strong outflows are the result of an extreme quasar
environment driven by the high Eddington ratio. A lower limit on the outflowing
kinetic power () was derived from both emission and absorption
lines, indicating these outflows play a significant role in the feedback
process to regulate the growth of its black hole as well as host galaxy
evolution.Comment: 12 pages, 10 figures. Accepted for publication in The Astrophysical
Journa
High-Power Electromagnetic Pulse Exposure of Healthy Mice: Assessment of Effects on Mice Cognitions, Neuronal Activities, and Hippocampal Structures
Electromagnetic pulse (EMP) is a high-energy pulse with an extremely rapid rise time and a broad bandwidth. The brain is a target organ sensitive to electromagnetic radiation (EMR), the biological effects and related mechanisms of EMPs on the brain remain unclear. The objectives of the study were to assess the effects of EMP exposure on mouse cognitions, and the neuronal calcium activities in vivo under different cases of real-time exposure and post exposure. EMP-treated animal model was established by exposing male adult C57BL/6N mice to 300 kV/m EMPs. First, the effects of EMPs on the cognitions, including the spatial learning and memory, avoidance learning and memory, novelty-seeking behavior, and anxiety, were assessed by multiple behavioral experiments. Then, the changes in the neuronal activities of the hippocampal CA1 area in vivo were detected by fiber photometry in both cases of during real-time EMP radiation and post-exposure. Finally, the structures of neurons in hippocampi were observed by optical microscope and transmission electron microscope. We found that EMPs under this condition caused a decline in the spatial learning and memory ability in mice, but no effects on the avoidance learning and memory, novelty-seeking behavior, and anxiety. The neuron activities of hippocampal CA1 were disturbed by EMP exposure, which were inhibited during EMP exposure, but activated immediately after exposure end. Additionally, the CA1 neuron activities, when mice entered the central area in an Open field (OF) test or explored the novelty in a Novel object exploration (NOE) test, were inhibited on day 1 and day 7 after radiation. Besides, damaged structures in hippocampal neurons were observed after EMP radiation. In conclusion, EMP radiation impaired the spatial learning and memory ability and disturbed the neuronal activities in hippocampal CA1 in mice
Common susceptibility variants are shared between schizophrenia and psoriasis in the Han Chinese population
Previous studies have shown that individuals with schizophrenia have a greater risk for psoriasis than a typical person. This suggests that there might be a shared genetic etiology between the 2 conditions. We aimed to characterize the potential shared genetic susceptibility between schizophrenia and psoriasis using genome-wide marker genotype data
Is There a Valence-Specific Pattern in Emotional Conflict in Major Depressive Disorder? An Exploratory Psychological Study
Objective: Patients with major depressive disorder (MDD) clinically exhibit a deficit in positive emotional processing and are often distracted by especially negative emotional stimuli. Such emotional-cognitive interference in turn hampers the cognitive abilities of patients in their ongoing task. While the psychological correlates of such emotional conflict have been well identified in healthy subjects, possible alterations of emotional conflict in depressed patients remain to be investigated. We conducted an exploratory psychological study to investigate emotional conflict in MDD. We also distinguished depression-related stimuli from negative stimuli in order to check whether the depression-related distractors will induce enhanced conflict in MDD. Methods: A typical word-face Stroop paradigm was adopted. In order to account for valence-specificities in MDD, we included positive and general negative as well as depression-related words in the study. Results: MDD patients demonstrated a specific pattern of emotional conflict clearly distinguishable from the healthy control group. In MDD, the positive distractor words did not significantly interrupt the processing of the negative target faces, while they did in healthy subjects. On the other hand, the depression-related distractor words induced significant emotional conflict to the positive target faces in MDD patients but not in the healthy control group. Conclusion: Our findings demonstrated for the first time an altered valence-specific pattern in emotional conflict in MD
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