139 research outputs found
Medium-Assisted Enhancement of Production from Small to Large Colliding Systems
Studies of exotic hadrons such as the state provide
crucial insights into the fundamental force governing the strong interaction
dynamics, with an emerging new frontier to investigate their production in high
energy collisions where a partonic medium is present. Latest experimental
measurements from the Large Hadron Collider show an intriguing evolution
pattern of the -to- yield ratio from proton-proton
collisions with increasing multiplicities toward proton-lead and lead-lead
collisions. Here we propose a novel mechanism of medium-assisted enhancement
for the production, which competes with the more
conventional absorption-induced suppression and results in a non-monotonic
trend from small to large colliding systems. Realistic simulations from this
model offer the first quantitative description of all available data.
Predictions are made for the centrality dependence of this observable in PbPb
collisions as well as for its system size dependence from OO and ArAr to XeXe
and PbPb collisions. In both cases, a non-monotonic behavior emerges as the
imprint of the competition between enhancement and suppression and can be
readily tested by future data.Comment: 7 pages, 4 figure
Linearized integrated microwave photonic circuit for filtering and phase shifting
Photonic integration, advanced functionality, reconfigurability, and high radio frequency (RF) performance are key features in integrated microwave photonic systems that are still difficult to achieve simultaneously. In this work, we demonstrate an integrated microwave photonic circuit that can be reconfigured for two distinct RF functions, namely, a tunable notch filter and a phase shifter. We achieved > 50 dB high-extinction notch filtering over 6-16 GHz and 2π continuously tunable phase shifting over 12-20 GHz frequencies. At the same time, we implemented an on-chip linearization technique to achieve a spurious-free dynamic range of more than 120 dB · Hz 4/5 for both functions. Our work combines multi-functionality and linearization in one photonic integrated circuit and paves the way to reconfigurable RF photonic front-ends with very high performance.</p
High-detectivity ultraviolet photodetectors based on laterally mesoporous GaN
Photodetectors for the ultraviolet (UV) range of the electromagnetic spectrum are in great demand for several technologies, but require the development of novel device structures and materials. Here we report on the high detectivity of UV photodetectors based on well-ordered laterally mesoporous GaN. The specific detectivity of our devices under UV-illumination reaches values of up to 5.3×1014 Jones. We attribute this high specific detectivity to the properties of the mesoporous GaN/metal contact interface: the trapping of photo-generated holes at the interface lowers the Schottky barrier height thus causing a large internal gain. The high detectivity along with the simple fabrication process make these laterally mesoporous GaN photodetectors of great potential for applications that require selective detection of weak optical signals in the UV range
Gymnothelignans A–O: Conformation and Absolute Configuration Analyses of Lignans Bearing Tetrahydrofuran from Gymnotheca chinensis
An Improved Current-Doubler Rectifier for the Marine Controlled Source Electromagnetic Transmitter
High power marine controlled source electromagnetic transmitters have gained interest with applications in marine geological survey and mineral resources exploration. The direct current to direct current (DC-DC) converter that is typically used in marine transmitters has some issues, as the insulated-gate bipolar transistor (IGBT) tube cannot achieve zero-voltage switching (ZVS). In particular, lagging-leg switching cannot easily achieve ZVS. The conversion efficiency of the heat converter requires improvement. This paper proposes an improved current-doubler rectifier for the marine controlled source electromagnetic transmitter (ICDR-MCSET). Resonant inductance is increased and a blocking capacitor is added to the converter (DC-DC) circuit, where the converter can achieve ZVS in a wide load range. This results in the effective decrease of the heating temperature and the improvement of transformation efficiency. Saber software simulation and a 20 KW electromagnetic transmitter are used to verify the results, which show that the method is feasible and effective
Tackling Inflammatory Bowel Diseases: Targeting Proinflammatory Cytokines and Lymphocyte Homing
Inflammatory bowel diseases (IBDs) are characterized by chronic inflammatory disorders that are a result of an abnormal immune response mediated by a cytokine storm and immune cell infiltration. Proinflammatory cytokine therapeutic agents, represented by TNF inhibitors, have developed rapidly over recent years and are promising options for treating IBD. Antagonizing interleukins, interferons, and Janus kinases have demonstrated their respective advantages in clinical trials and are candidates for anti-TNF therapeutic failure. Furthermore, the blockade of lymphocyte homing contributes to the excessive immune response in colitis and ameliorates inflammation and tissue damage. Factors such as integrins, selectins, and chemokines jointly coordinate the accumulation of immune cells in inflammatory regions. This review assembles the major targets and agents currently targeting proinflammatory cytokines and lymphatic trafficking to facilitate subsequent drug development
Linearized phase modulated microwave photonic link based on integrated ring resonators
An on-chip linearization method for phase modulated microwave photonic link based on integrated ring resonators is proposed. By properly tailoring the phase and amplitude of optical carrier band and second-order sidebands, the third-order intermodulation distortion (IMD3) components can be suppressed. Theoretical analysis are taken and a proof-of-concept experiment is carried out. Experimental results demonstrate that IMD3 is suppressed by 21.7 dB. When the noise of the link is properly optimized, an SFDR of 112.7 dB·Hz2/3 can be achieved. This opens the possibility of integrating linearization into a functional photonic integrated circuit
- …