118 research outputs found
The comparison of optical variability of broad-line Seyfert 1 and narrow-line Seyfert 1 galaxies from the view of Pan-STARRS
By means of the data sets of the Panoramic Survey Telescope and Rapid
Response System (Pan-STARRS), we investigate the relationship between the
variability amplitude and luminosity at 5100 \AA, black hole mass, Eddington
ratio, ( the ratio of the flux of Fe II line within
4435-4685 \AA ~to the broad proportion of line) as well as (the ratio of the flux [O III] line to the total line)
of the broad line Seyfert 1 (BLS1) and narrow line Seyfert 1 (NLS1) galaxies
sample in g,r,i,z and y bands, respectively. We also analyze the similarities
and differences of the variability characteristics between the BLS1 galaxies
and NLS1 galaxies. The results are listed as follows. (1). The cumulative
probability distribution of the variability amplitude shows that NLS1 galaxies
are lower than that in BLS1 galaxies. (2). We analyze the dependence of the
variability amplitude with the luminosity at 5100 \AA, black hole mass,
Eddington ratio, and , respectively. We find
significantly negative correlations between the variability amplitude and
Eddington ratio, insignificant correlations with the luminosity at 5100 \AA.
The results also show significantly positive correlations with the black hole
mass and , significantly negative correlations with which are consistent with Rakshit and Stalin(2017) in low redshift bins
(z<0.4) and Ai et al.(2010). (3). The relationship between the variability
amplitude and the radio loudness is investigated for 155 BLS1 galaxies and 188
NLS1 galaxies. No significant correlations are found in our results.Comment: 10 pages, 5 figures, accepted by Astrophysics and Space Science, in
Pres
Design of a Multimodal Fingertip Sensor for Dynamic Manipulation
We introduce a spherical fingertip sensor for dynamic manipulation. It is
based on barometric pressure and time-of-flight proximity sensors and is
low-latency, compact, and physically robust. The sensor uses a trained neural
network to estimate the contact location and three-axis contact forces based on
data from the pressure sensors, which are embedded within the sensor's sphere
of polyurethane rubber. The time-of-flight sensors face in three different
outward directions, and an integrated microcontroller samples each of the
individual sensors at up to 200 Hz. To quantify the effect of system latency on
dynamic manipulation performance, we develop and analyze a metric called the
collision impulse ratio and characterize the end-to-end latency of our new
sensor. We also present experimental demonstrations with the sensor, including
measuring contact transitions, performing coarse mapping, maintaining a contact
force with a moving object, and reacting to avoid collisions.Comment: 6 pages, 2 pages of references, supplementary video at
https://youtu.be/HGSdcW_aans. Submitted to ICRA 202
Towards Robust Autonomous Grasping with Reflexes Using High-Bandwidth Sensing and Actuation
Modern robotic manipulation systems fall short of human manipulation skills
partly because they rely on closing feedback loops exclusively around vision
data, which reduces system bandwidth and speed. By developing autonomous
grasping reflexes that rely on high-bandwidth force, contact, and proximity
data, the overall system speed and robustness can be increased while reducing
reliance on vision data. We are developing a new system built around a
low-inertia, high-speed arm with nimble fingers that combines a high-level
trajectory planner operating at less than 1 Hz with low-level autonomous reflex
controllers running upwards of 300 Hz. We characterize the reflex system by
comparing the volume of the set of successful grasps for a naive baseline
controller and variations of our reflexive grasping controller, finding that
our controller expands the set of successful grasps by 55% relative to the
baseline. We also deploy our reflexive grasping controller with a simple
vision-based planner in an autonomous clutter clearing task, achieving a grasp
success rate above 90% while clearing over 100 items.Comment: 6 pages, 1 page of references, supplementary video at
https://youtu.be/f8Coo02Jvdg. Submitted to ICRA 202
An upcycled wood sponge adsorbent for drinking water purification by solar steam generation
The shortage of freshwater resources caused by heavy metal pollution is an acute global issue. Herein, a novel nanoplatform was fabricated by hydrothermal deposition of 3D-MoS2 nanospheres onto biocompatible wood sponge (WS) for Hg(ii) removal. Moreover, a secondary water purification strategy was investigated to produce drinkable water using the exhausted wood sponge. The exhausted MoS2-wood sponge (MWS) was used to construct a solar steam generator by wrapping with a hydrophilic polyvinyl alcohol (PVA) layer to prevent heavy metal ion leakage and to enhance the hydrophilicity. The energy conversion efficiency of the evaporator was calculated to be 95.48% under one sun illumination. Remarkably, the treatment of model desulphurization wastewater from power plants with this functional wood sponge could efficiently reduce the mercury concentration below the limit proposed by the World Health Organization for drinking water. These results provide a basis for the application of upcycled hazardous adsorbents for the purification of drinkable water.</p
Anti-oxidant effects of cannabidiol relevant to intracerebral hemorrhage
Intracerebral hemorrhage (ICH) is a subtype of stroke with a high mortality rate. Oxidative stress cascades play an important role in brain injury after ICH. Cannabidiol, a major non-psychotropic phytocannabinoids, has drawn increasing interest in recent years as a potential therapeutic intervention for various neuropsychiatric disorders. Here we provide a comprehensive review of the potential therapeutic effects of cannabidiol in countering oxidative stress resulting from ICH. The review elaborates on the various sources of oxidative stress post-ICH, including mitochondrial dysfunction, excitotoxicity, iron toxicity, inflammation, and also highlights cannabidiol’s ability to inhibit ROS/RNS generation from these sources. The article also delves into cannabidiol’s role in promoting ROS/RNS scavenging through the Nrf2/ARE pathway, detailing both extranuclear and intranuclear regulatory mechanisms. Overall, the review underscores cannabidiol’s promising antioxidant effects in the context of ICH and suggests its potential as a therapeutic option
Self-assembling fluorescent hydrogel for highly efficient water purification and photothermal conversion
Employing fluorescent hydrogels for hazardous Hg(II) detection and removal is an efficient method for water purification. However, it remains challenging to establish a fluorescent system with low detection limit and high adsorption capacity that can readily be upcycled into a valuable material resource. Herein, we report on a fluorescent hydrogel with 0D sulfydryl-based carbon dots that are self-assembled with a 3D hydrogel network. The cellulose-based hydrogel exhibited good sensitivity for the detection of Hg(II) over a range from 0 to 40 µM with a limit detection of 3.0 × 10-6 M. The adsorption experiments confirmed that the cellulose-based hydrogel exhibits good Hg(II) extraction capacity of over 662.25 mg g−1 at room temperature, and can effectively reduce the Hg concentration to attain acceptable levels that comply with industrial water standards (0.05 mg L-1). Subsequently, we used a facile strategy to convert the exhausted waste adsorbent by in-situ sulfurization into a suitable material for solar steam generation. The as-prepared upcycled aerogel evaporators exhibited excellent evaporation rates of ∼ 1.30 kg m−2 h−1 under one sun irradiation. These results not only provide a strategy for heavy metal ion recognition and adsorption, but also provide a route to recycle hazardous waste for seawater desalination.</p
Characterization and genome analysis of Vibrio phage vB_VhaP_PG11, representing a new viral genus
Vibrio is a kind of common gram-negative bacteria, which is widely distributed in marine and estuarine environments. In the study, a novel marine phage vB_VhaP_PG11, infecting Vibrio hangzhouensis, was isolated from the offshore waters of Qingdao, China. vB_VhaP_PG11 is a double-stranded DNA phage. The whole genome proteomic tree shows that vB_VhaP_PG11 phage is related to two Vibrio phages, Vibrio phage 1.238.A._10N.261.52.F10 and Vibrio phage 1.245.O._10N.261.54.C7, but with low homology. Their amino acids identity with vB_VhaP_PG11 is 42.77 and 41.49% respectively. The prediction results of genome-blast distance phylogeny (GBDP) and the analysis gene-sharing network indicate that vB_VhaP_PG11 belongs to a new genus in Schitoviridae, named Qingschitovirus. The study of Vibrio phage vB_VhaP_PG11 provides basic information contributing to a better understanding of interactions between Vibrio phages and their hosts and helps analyze unknown viral sequences in the metagenomic database
Diagnostic assessment by dynamic contrast-enhanced and diffusion-weighted magnetic resonance in differentiation of breast lesions under different imaging protocols
Programmed Death 1 Deficiency Induces the Polarization of Macrophages/Microglia to the M1 Phenotype After Spinal Cord Injury in Mice
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