∼$6\%$ of all known pulsars have been observed to exhibit sudden spin-up events, known as glitches. For more than fifty years, these phenomena have played an important role in helping to understand pulsar (astro)physics. Based on the review of pulsar glitches search method, the progress made in observations in recent years is summarized, including the achievements obtained by Chinese telescopes. Glitching pulsars demonstrate great diversity of behaviours, which can be broadly classified into four categories: normal glitches, slow glitches, glitches with delayed spin-ups, and anti-glitches. The main models of glitches that have been proposed are reviewed and their implications for neutron star structure are critically examined regarding our current understanding. Furthermore, the correlations between glitches and emission changes, which suggest that magnetospheric state-change is linked to the pulsar-intrinsic processes, are also described and discussed in some detail.

We report on the pulse-to-pulse energy distribution and longitude-resolved modulation properties of PSR J1631+1252 discovered by the Five-hundred-meter Aperture Spherical radio Telescope. Our analysis made use of the data acquired at 1250 MHz from the follow-up timing observations that lasted over a year. PSR J1631+1252 has a rotational period of ∼0.310 s, and a dispersion measure of ∼32.73 pc cm⁻³. The energy distribution is well described by a lognormal distribution, the parameters of which do not vary with time. We show that large modulation occurs across the bridge emission of the pulse profile, with sporadic bright bursts at the leading emission region. The fluctuation spectral analysis reveals the existence of subpulse drifting in the leading component with vertical spacing between the drift bands of 3.28 ± 0.08 pulse periods between consecutive drift bands. Possible physical mechanisms for subpulse drifting are discussed.

We presented timing results of PSR B2035+36 using ∼9-yr observations with the Nanshan 25-m radio telescope. PSR B2035+36 was reported to exhibit significant changes in pulse profile correlated with spin-down state variations. We found that the pulsar underwent a glitch with a jump in frequency of $\Delta {\nu }\sim 12.4(5)\, \rm nHz$ around MJD 52950. Unusually, the spin-down rate increased persistently over 800 d after the glitch, and the average spin-down rate post-glitch was about $9.6 \, {per\,cent}$ larger than that pre-glitch. After the glitch activity, the pulse profile became narrower and the pulsar began to switch between two emission modes, with pulse widths ($W_{\ 50 \rm mean}$) of 8.5(7)° and 3.7(3)°, respectively. In addition to that, the relatively narrow pulse profile gradually became dominant. All of the observations indicate that there should be a connection between magnetospheric behaviour and glitch activity. We discuss one possibility of magnetosphere fluctuation triggered by the glitch event.

We report detailed investigation of nulling and drifting behavior of two pulsars PSRs J1741−0840 and J1840−0840 observed from the Giant Meterwave Radio Telescope at 625 MHz. PSR J1741−0840 was found to show a nulling fraction (NF) of around 30% ± 5% while PSR J1840−0840 was shown to have an NF of around 50% ± 6%. We measured drifting behavior from different profile components in PSR J1840−0840 for the first time with the leading component showing drifting with 13.5 ± 0.7 periods while the weak trailing component showed drifting of around 18 ± 1 periods. Large nulling hampers accuracy of these quantities derived using standard Fourier techniques. A more accurate comparison was drawn from driftband slopes, measured after sub-pulse modeling. These measurements revealed interesting sporadic and irregular drifting behavior in both pulsars. We conclude that the previously reported different drifting periodicities in the trailing component of PSR J1741−0840 is likely due to the spread in these driftband slopes. We also find that both components of PSR J1840−0840 show similar driftband slopes within the uncertainties. Unique nulling–drifting interaction is identified in PSR J1840−0840 where, on most occasions, the pulsar tends to start nulling after what appears to be the end of a driftband. Similarly, when the pulsar switches back to an emission phase, on most occasions it starts at the beginning of a new driftband in both components. Such behaviors have not been detected in any other pulsars to our knowledge. We also found that PSR J1741−0840 seems to have no memory of its previous burst phase while PSR J1840−0840 clearly exhibits memory of its previous state even after longer nulls for both components. We discuss possible explanations for these intriguing nulling–drifting interactions seen in both pulsars based on various pulsar nulling models.

Pulse arrival time measurements over 14 yr with the Nanshan 25-m and Parkes 64-m radio telescopes have been used to determine the average profile and timing properties for PSR J1757−2421 (B1754−24). Analysis of the radio profile data shows a large variation of spectral index across the profile and an unusual increase in component separation with increasing frequency. The timing observations show that PSR B1754−24 underwent a large glitch with a fractional increase in spin frequency of Δν_g/ν ∼ 7.8 × 10⁻⁶ in 2011 May. At the time of the glitch, there was a large permanent jump in the rotational frequency accompanied by two exponential recovery terms with time-scales of 15(6) and 97(15) d, respectively.