High-speed GeSn resonance cavity enhanced photodetectors for a 50 Gbps Si-based 2 μm band communication system

Expanding the optical communication band is one of the most effective methods of overcoming the nonlinear Shannon capacity limit of single fiber.In this study,GeSn resonance cavity enhanced(RCE)photodetectors(PDs)with an active layer Sn component of 9%–10.8%were designed and fabricated on an SOI substrate.The GeSn RCE PDs present a responsivity of 0.49 A/W at 2μm and a 3-dB bandwidth of approximately 40 GHz at 2μm.Consequently,Si-based 2μm band optical communication with a transmission rate of 50 Gbps was demonstrated by using a GeSn RCE detector.This work demonstrates the considerable potential of the Si-based 2μm band photonics in future high-speed and high-capacity optical communication.

Prediction of energy resolution in the JUNO experiment

This paper presents an energy resolution study of the JUNO experiment,incorporating the latest knowledge acquired during the detector construction phase.The determination of neutrino mass ordering in JUNO requires an exceptional energy resolution better than 3% at 1 MeV.To achieve this ambitious goal,significant efforts have been undertaken in the design and production of the key components of the JUNO detector.Various factors affecting the detection of inverse beta decay signals have an impact on the energy resolution,extending beyond the statistical fluctuations of the detected number of photons,such as the properties of the liquid scintillator,performance of photomultiplier tubes,and the energy reconstruction algorithm.To account for these effects,a full JUNO simulation and reconstruction approach is employed.This enables the modeling of all relevant effects and the evaluation of associated inputs to accurately estimate the energy resolution.The results of this study reveal an energy resolution of 2.95% at 1 Mev.Furthermore,this study assesses the contribution of major effects to the overall energy resolution budget.This analysis serves as a reference for interpreting future measurements of energy resolution during JUNO data collection.Moreover,it provides a guideline for comprehending the energy resolution characteristics of liquid scintillator-based detectors.

Mechanosensitive Ion Channel TMEM63A Gangs Up with Local Macrophages to Modulate Chronic Post-amputation Pain

Post-amputation pain causes great sufering to amputees,but still no efective drugs are available due to its elusive mechanisms.Our previous clinical studies found that surgical removal or radiofrequency treatment of the neuroma at the axotomized nerve stump efectively relieves the phantom pain aficting patients after amputation.This indicated an essential role of the residual nerve stump in the formation of chronic post-amputation pain(CPAP).However,the molecular mechanism by which the residual nerve stump or neuroma is involved and regulates CPAP is still a mystery.In this study,we found that nociceptors expressed the mechanosensitive ion channel TMEM63A and macrophages infltrated into the dorsal root ganglion(DRG)neurons worked synergistically to promote CPAP.Histology and qRT-PCR showed that TMEM63A was mainly expressed in mechanical pain-producing non-peptidergic nociceptors in the DRG,and the expression of TMEM63A increased signifcantly both in the neuroma from amputated patients and the DRG in a mouse model of tibial nerve transfer(TNT).Behavioral tests showed that the mechanical,heat,and cold sensitivity were not afected in the Tmem63a-/-mice in the naïve state,suggesting the basal pain was not afected.In the infammatory and post-amputation state,the mechanical allodynia but not the heat hyperalgesia or cold allodynia was signifcantly decreased in Tmem63a-/-mice.Further study showed that there was severe neuronal injury and macrophage infltration in the DRG,tibial nerve,residual stump,and the neuromalike structure of the TNT mouse model,Consistent with this,expression of the pro-infammatory cytokines TNFα,IL-6,and IL-1βall increased dramatically in the DRG.Interestingly,the deletion of Tmem63a signifcantly reduced the macrophage infltration in the DRG but not in the tibial nerve stump.Furthermore,the ablation of macrophages signifcantly reduced both the expression of Tmem63a and the mechanical allodynia in the TNT mouse model,indicating an interaction between nociceptors and macrophages,and that these two factors gang up together to regulate the formation of CPAP.This provides a new insight into the mechanisms underlying CPAP and potential drug targets its treatment.

Measurement of muon-induced neutron yield at the China Jinping Underground Laboratory

Solar,terrestrial,and supernova neutrino experiments are subject to muon-induced radioactive background.The China Jinping Underground Laboratory(CJPL),with its unique advantage of a 2400 m rock coverage and long distance from nuclear power plants,is ideal for MeV-scale neutrino experiments.Using a 1-ton prototype detector of the Jinping Neutrino Experiment(JNE),we detected 3 43 high-energy cosmic-ray muons and(7.86±3.97)muon-induced neutrons from an 820.28-day dataset at the first phase of CJPL(CJPL-I).Based on the muon-induced neutrons,we measured the corresponding muon-induced neutron yield in a liquid scintillator to be(3.44±1.86_(stat.)±0.76_(syst.))×10^(-4) μ^(-1)g^(-1)cm^(2) at an average muon energy of 340 GeV.We provided the first study for such neutron background at CJPL.A global fit including this measurement shows a power-law coefficient of(0.75±0.02) for the dependence of the neutron yield at the liquid scintillator on muon energy.