Effect of irradiation on the spin of millisecond pulsars

A millisecond pulsar (MSP) is an old neutron star (NS) that has accreted material from its companion star, causing it to spin up, which is known as the recycling scenario. During the mass transfer phase, the system manifests itself as an X-ray binary. PSR J1402+13 is an MSP with a spin period of $5.89~{\rm ms}$ and a spin period derivative of $\log\dot{P}_{\rm spin}=-16.32$. These properties make it a notable object within the pulsar population, as MSPs typically exhibit low spin period derivatives. In this paper, we aim to explain how an MSP can posses high spin period derivative by binary evolution. By utilizing the stellar evolution code \textsc{MESA}, we examine the effects of irradiation on the companion star and the propeller effect on the NS during binary evolution. We demonstrate that irradiation can modify the spin period and mass of an MSP, resulting in a higher spin period derivative. These results suggest that the irradiation effect may serve as a key factor in explaining MSPs with high spin period derivatives.Comment: Accepted for publication in ApJL. Compiled in AASTEX6

Single-layer behavior and slow carrier density dynamic of twisted graphene bilayer

We report scanning tunneling microscopy (STM) and spectroscopy (STS) of twisted graphene bilayer on SiC substrate. For twist angle ~ 4.5o the Dirac point ED is located about 0.40 eV below the Fermi level EF due to the electron doping at the graphene/SiC interface. We observed an unexpected result that the local Dirac point around a nanoscaled defect shifts towards the Fermi energy during the STS measurements (with a time scale about 100 seconds). This behavior was attributed to the decoupling between the twisted graphene and the substrate during the measurements, which lowers the carrier density of graphene simultaneously

Observation of clinical efficacy of pattern scan laser photocoagulation on diabetic retinopathy

AIM: To evaluate the clinical efficacy of pattern scan laser photocoagulation(Pascal)on proliferative diabetic retinopathy(PDR).<p>METHODS: A total of 93 patients with retinopathy(186 eyes)were randomly divided into treatment group(96 eyes of 48 patients)who treated with panretinal photocoagulation(PRP)using Pascal at one time and control group(90 eyes of 45 patients)who treated with PRP using multi-wavelength krypton laser in 4-5 times. The visual acuity, FFA, OCT, visual field will be evaluated of each patient before and after the treatment.<p>RESULTS: The visual acuity findings were stated as below: the overall effective rate of visual acuity in treatment group is 85.4% while it is 82.2% in control group. The overall effective rate in two groups has no significant difference. The retinal sensitivity has no significant decrease in the treatment group while which decreased significantly in the control group.<p>CONCLUSION: The clinical efficacy of Pascal on treating the PDR is better than which of the regular argon laser. The field of vision has no significant narrowed after the Pascal treatment which can efficiently shorten the length of treatment and reduce the pain sensation