Tianjin urban/industrial complex is highly polluted by some persistent organic pollutants. In this study, the levels of 16 priority polycyclic aromatic hydrocarbons (PAHs) were tested in sediment, ...water, and suspended particulate matter (SPM) samples in 10 rivers in Tianjin. The total concentration of 16 PAHs varied from 0.787 to 1943
μg/g dry weight in sediment, from 45.81 to 1272
ng/L in water, and from 0.938 to 64.2
μg/g dry weight in SPM. The levels of PAHs in these media are high in comparison with values reported from other river and marine systems. Variability of total concentrations of PAHs in sediment, water, and SPM from nine different rivers is consistent with each other. No obvious trends of total PAHs concentration variations were found between upstream and downstream sediment, water, and SPM samples for most rivers, which indicate local inputs and disturbances along these rivers. The spatial distributions of three-phase PAHs are very similar to each other, and they are also similar to those found in topsoil. However, their chemical profiles are significantly different from that of topsoil. The change of profiles is consistent with the different aqueous transport capability of 16 PAHs. Low molecular weight PAHs predomination suggests a relatively recent local source and coal combustion source of PAHs in the study area.
Coal combustion is suggested as a recent local source of PAHs in this area.
This study investigated the between-limb asymmetry in kinetic and temporal characteristics during bilateral plyometric drop jumps from different heights. Seventeen male basketball players performed ...drop jumps from 3 heights on two platforms in randomized orders. Vertical ground reaction force data were analysed with respect to the lead limb (i.e. the limb stepping off the raised platform first) and trail limb. Peak forces and loading rates of each limb were calculated. The absolute time differential between the two limbs at initial ground contact and takeoff were determined. The frequency of symmetrical landing and taking off with "both limbs together" were counted using 3 time windows. Results showed that the lead limb displayed higher peak forces and loading rates than the trail limb across all heights (p <.05). As drop height increased, the absolute time differentials decreased at initial ground contact (p <.001) but increased at takeoff (p =.035). The greater the preset time window, the more landings and takeoffs were classified as bilaterally symmetrical. In conclusion, higher drop heights allowed subjects to become more bilaterally symmetrical in the timing of landing but this reduction in temporal asymmetry did not accompany with any reduction in kinetic asymmetry.
Dynamic heterogeneity as one of the most important properties in supercooled liquids has been found for several decades. However, its structural origin remains open for many systems. Here, we propose ...a new structural parameter to characterize local atomic packing in metallic liquids. It is found that the new parameter in a simulated metallic glass-forming liquid is closely correlated with potential energy and atomic mobility. It also exhibits significant spatial heterogeneities and these structural fluctuations show close correlation with the spatial distribution of the long-time dynamic propensities. Therefore, our results provide a direct evidence of the correlation between atomic structure and dynamical heterogeneity. The new structural parameter might be used to reflect the structural “defect” in metallic liquids and glasses and further play an important role to uncover the structure-property relationship in these disordered systems.
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•A new parameter is proposed to describe local atomic packing.•The new parameter is closely correlated with potential energy.•Close correlation between atomic structure and dynamic propensities is found.
Corneal epithelial injury induces release of endogenous metabolites that are cannabinoid receptor 1 (CB1) and transient receptor potential vanilloid 1 (TRPV1) agonists. We determined the functional ...contributions by CB1 and TRPV1 activation to eliciting responses underlying wound healing in human corneal epithelial cells (HCEC). Both the selective CB1 and TRPV1 agonists (i.e., WIN55,212-2 WIN and capsaicin CAP, respectively) induced EGFR phosphorylation whereas either inhibition of its tyrosine kinase activity with AG1478 or functional blockage eliminated this response. Furthermore, EGFR transactivation was abolished by inhibitors of proteolytic release of heparin bound EGF (HB-EGF). CB1-induced Ca
2+ transients were reduced during exposure to either the CB1 antagonist, AM251 or AG1478. Both CAP and WIN induced transient increases in Erk1/2, p38, JNK1/2 MAPK and Akt/PI-3K phosphorylation status resulting in cell proliferation and migration increases which mirrored those elicited by EGF. Neither EGF nor WIN induced any increases in IL-6 and IL-8 release. On the other hand, CAP-induced 3- and 6-fold increases, which were fully attenuated during exposure to CPZ, but AG1478 only suppressed them by 21%. The mixed CB1 and TRPV1 antagonist, AM251, enhanced the CAP-induced rise in IL-8 release to a higher level than that elicited by CAP alone. In conclusion, CB1 and TRPV1 activation induces increases in HCEC proliferation and migration through EGFR transactivation leading to global MAPK and Akt/PI-3K pathway stimulation. On the other hand, the TRPV1-mediated increases in IL-6 and IL-8 release are elicited through both EGFR dependent and EGFR-independent signaling pathways.
► CB1 and TRPV1 agonists in human corneal epithelial cells transactivate EGFR. ► Proliferation and migration increases by CB1 and TRPV1 agonists similar to those elicited by EGF. ► Blunting by CB1 activation of TRPV1-induced increases in IL-6 and IL-8. ► Dependence of IL-6 and IL-8 release on EGFR transactivation by CB1 and TRPV1 modulators.
•Mesoporous NiO nanowall arrays are prepared by a hydrothermal method.•Mesoporous structure is favorable for fast ion/electron transfer.•Mesoporous NiO nanowall arrays show fast switching speed and ...high color contrast.
Mesoporous NiO nanowall arrays are prepared by a facile hydrothermal synthesis method in combination with a following annealing process. The as-prepared NiO nanowalls have average diameters of ∼10nm and composed of interconnected nanoparticles ranging from 5 to 30nm. The NiO nanowall arrays show a hierarchical porous structure from mesopores of 5–20nm to macropores of 30–200nm. The electrochromic performances of the NiO nanowall arrays are characterized by means of UV–vis spectroscopy and cyclic voltammetry (CV) measurements. The mesoporous NiO nanowall arrays exhibit much better electrochromic performance with faster switching speed and higher color contrast than the dense NiO film. The mesoporous NiO nanowall arrays show a transmittance variation with 77% at 550nm, and the coloration and bleaching times are 2s and 2.5s, respectively. The improved electrochromic performances are due to the porous morphological characteristics, which provide fast ion and electron transfer resulting in fast reaction kinetics and high color contrast.
The anti-phase boundaries (APBs) in the T (Al20Cu2Mn3) phase and the interfaces of the T phase with an Al matrix were observed. The effects of pre-deformation on the precipitation behavior of T phase ...and hardening behavior of alloy were investigated by hardness measurement, mechanical tensile test, transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM). Results show that two kinds of APBs exist in the T phase, i.e. {101}T and {301}T-type APBs. The first is commonly observed, while the latter is newly found and only coexists with the first to form a zig-zag shaped APB. Whatever its orientation relationships (ORs) with Al matrix and cross-section (CS) shape, the T phase always retains its interfaces constituted by {200}T, {101}T and {301}T planes. Pre-deformation increases the APBs in T phase and intensifies the irregularity of the CS shape of a T phase. Besides, it also promotes the nucleation and refines the size of the T phase during precipitation which enhances the mechanical properties of the alloy.
•A new type of APB with slip displacement of 1/4 T is found in the T-phase.•The {301}T type APB coexists with {101}T type APB to form a zig-zag-shaped APB.•The T-phase interfaces are always constituted by {200}T, {101}T, and {301}T planes.•Pre-deformation increases APBs and causes a more irregular cross-section of T-phase.•Pre-deformation promotes the nucleation rate and refines T-phase.
SrFeO
(SFO
) compounds exhibit ionic conduction and oxygen-related phase transformation, having potential applications in solid oxide fuel cells, smart windows, and memristive devices. The phase ...transformation in SFO
typically requires a thermal annealing process under various pressure conditions, hindering their practical applications. Here, we have achieved a reversible phase transition from brownmillerite (BM) to perovskite (PV) in SrFeO
(SFO
) films through ionic liquid (IL) gating. The real-time phase transformation is imaged using in situ high-resolution transmission electron microscopy. The magnetic transition in SFO
is identified by fabricating an assisted La
Sr
MnO
(LSMO) bottom layer. The IL-gating-converted PV phase of a SrFeO
(SFO
) layer shows a ferromagnetic-like behavior but applies a huge pinning effect on LSMO magnetic moments, which consequently leads to a prominent exchange bias phenomenon, suggesting an uncompensated helical magnetic structure of SFO
. On the other hand, the suppression of both magnetic and exchange coupling signals for a BM-phased SFO
layer elucidates its fully compensated G-type antiferromagnetic nature. We also demonstrated that the phase transition by IL gating is an effective pathway to tune the resistive switching parameters, such as set, reset, and high/low-resistance ratio in SFO
-based resistive random-access memory devices.
ABSTRACT
The follow-up timing observations were carried out for 24 pulsars discovered with the Five-hundred-meter Aperture Spherical radio Telescope (FAST) in Commensal Radio Astronomy FAST Survey. ...We report their phase-connected timing ephemeris, polarization pulse profiles, and Faraday rotation measurements. With their spin periods spanning from 2.995 ms to 4.34 s, their period derivatives were determined to spread between 7.996(8) × 10−21 and 9.83(3) × 10−15 s s−1, which imply that they have characteristic ages from 1.97 × 106 to 5.93 × 109 yr. It is inferred that PSRs J0211+4235 and J0518+2431 are beyond the ‘traditional death line’. PSR J0211+4235 is beyond the ‘death valley’. The death line model of Zhang et al. also cannot explain the radio presence of PSR J0211+4235. This suggests that radiation theory needs to be improved. Besides, ten of the 22 canonical pulsars show nulling phenomena. Moreover, PSR J1617+1123 exhibits variation of emission and J0540+4542 shows subpulse drifting. The DM of five pulsars is larger than the estimated by the YMW16 electron density model, which could suggest that electron density models need updates for higher Galactic latitude regions. PSRs J0447+2447 and J1928−0548 are isolated millisecond pulsars. With their flux densities spanning from 5(1)–553(106) μJy, some of these new pulsars found by FAST are distant, dim, and low-$\dot{E}$ ones and are suitable for testing pulsar emission theories.
The South Pole Telescope Summertime Line Intensity Mapper (SPT-SLIM) is a pathfinder experiment that will demonstrate the use of on-chip filter-bank spectrometers for mm-wave line intensity mapping. ...The SPT-SLIM focal plane consists of 18 dual-polarization filter-bank spectrometers covering 120–180 GHz with resolving power of 300, coupled to aluminum kinetic inductance detectors. A compact cryostat holds the detectors at 100 mK. SPT-SLIM will be deployed to the 10-m South Pole Telescope for observations during the 2023–2024 austral summer without removing the primary receiver. We discuss the overall instrument design, expected detector performance, and sensitivity to the carbon monoxide line signal at
0.5
<
z
<
2
. The technology and observational techniques demonstrated by SPT-SLIM will enable next-generation line intensity mapping experiments that constrain cosmology beyond the redshift reach of galaxy surveys.
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