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Using observational data obtained with the Five-hundred-meter Aperture Spherical radio Telescope, we succeeded in identifying subcomponents of different pulse profile components of PSR B1822−09 by the phase-to-phase cross correlations between intensity sequences of single pulses. The determined number of the subcomponents and edges of the subcomponents are consistent with the results of Gaussian fitting on the mean pulse profiles of PSR B1822−09. According to the results, the main pulse (MP) in both the radio burst mode (B mode) and the radio-quiet mode (Q mode), the precursor (PC), and the interpulse (IP) of PSR B1822−09 are all composed of three subcomponents. The correlation coefficients between intensity sequences at different pulse phases reveal a positive correlation between the subcomponent C8 of the MP and C3 of the IP in the Q mode, and a positive correlation between C5 of the PC and C2 of the IP during the switching process from the B mode to the Q mode. These complex correlations present a challenge for the existing scenarios that describe relations between different pulse profile components. We proposed a hypothesis that different subcomponents correspond to different subpatches on the pulsar surface, and emissions from a subpatch reveal responses of the subpatch to some variations like the voltage in the magnetosphere. Therefore, correlations between different subcomponents depend on the responses of the subpatches to the variations. [ABSTRACT FROM AUTHOR]

In this paper, the urban signal propagation characteristics based on the location of blind sources are investigated. To address the issue of blind electromagnetic radiation sources in complex urban environments, intelligent methods for propagation channel path classification, and model determination are brought forth based on field test data. The intelligent classification method distinguishes between the Line-of-Sight (LoS) path channel and a direct path, the LoS multipath channel with a direct path and other multiple paths, and the Non-Line-of-Sight (NLoS) multipath channel without a direct path from the source to the test point. The modeling aspect determines the model type to which the received signal belongs based on the statistical model derived from the tested data of a specific source. A validation measurement system was constructed for the FM broadcasting band, and validation campaigns were conducted in the city of Wuhan. The process and analysis of the data using this method demonstrate the accurate distinction of the different propagation path channels and models and involve the construction of a statistical model for the FM band in Wuhan's urban area. [ABSTRACT FROM AUTHOR]

Parabolic equations (PE) are commonly employed for calculating the spatial propagation loss of wireless signals. The initial field is a crucial factor. To investigate the impact of construction accuracy on the calculation of radio wave propagation loss, we selected the half-wave dipole antenna and its Gaussian approximation to examine the influence of wide-angle PE modeling. We analyzed the disparities between the actual antenna pattern and the Gaussian beam approximation, as well as the discrepancies in the corresponding initial field and the calculation of radio wave propagation loss in PE modeling. The simulation results indicate that the error of the Gaussian approximation increases as the angle of departure from the antenna main beam increases, with a relative error of approximately 30% in the initial field. A comparison between the experimental test of the broadcast signal and the simulation calculation reveals that the model based on the actual antenna aligns more closely with the measured value on a flat underlying surface. However, in mountainous areas with significant fluctuations, the simulation results are consistent with each other and higher than the measured value. The inversion results obtained through the particle swarm optimization algorithm demonstrate that the model based on the actual antenna exhibits superior inversion accuracy for the tropospheric atmospheric duct structure. [ABSTRACT FROM AUTHOR]

Gallstones were examined for 58 patients in Jilin, Jilin. It was found that gallstones from only one who suffered from cholecystectomy were composed of 20 spheroidal stones and they rarely exhibited three different types of surface appearances. Six representative powder samples were analyzed for gallstones compositions and Mn2+ using X-ray diffraction (XRD)/Infrared (IR) and electron spin resonance (ESR), respectively. The results suggested that all gallstones from this patient were identified by XRD to be gallstones consisting mainly of cholesterol and CaCO3 (GCCC). They rarely exhibited three different kinds of surface appearances corresponding to different concentration of trace Mn2+ in calcite (CMn2+/CCal): 18 dark/light brown spheres with smooth surfaces and CMn2+/CCal = 0–6 μg/g/%, a yellowish-brown huge sphere with a rougher surface and CMn2+/CCal = 30 μg/g/%, and an ashy sphere composed of tens of microspheres with the roughest surface and CMn2+/CCal = 60 μg/g/%. The difference in surface appearance showed significant association with CMn2+/CCal, and its increase made the gallstone's surface change from smooth to rough and to fade in color. The unbalanced and competitive Mn2+ accumulation could occur occasionally in individual stones owing to different affinities to Mn2+, resulting in the formation of a huge stone and an ashy sphere. These two aberrations caused by higher CMn2+/CCal played an important role in suppressing the crystalline growth of the majority of dark/light brown spheres. GCCC from a patient might have a prominent Mn2+ partitioning feature corresponding to different surface appearances. [ABSTRACT FROM AUTHOR]

Cerebral venous sinus thrombosis (CVST) is a special type of stroke with an increasing rate of diagnosis and a higher rate of disability and mortality. Currently, anticoagulant therapy, systemic venous thrombolysis, arterial thrombolysis, contact venous catheterization thrombolysis, mechanical thrombolysis, stent implantation and other treatment methods coexist, with different therapeutic effects. This paper reviews the progress in the treatment of CVS. [ABSTRACT FROM AUTHOR]