Spatial distribution, source identification, and transportation paths of plutonium in the Beibu Gulf, South China Sea.

To investigate the spatial distribution and source of plutonium isotopes in the Beibu Gulf, surface sediments were collected and analyzed using sector field inductively coupled plasma mass spectrometry (SF-ICP-MS). The activities of Pu in surface sediments ranged from 0.012 to 0.

Assessment of the depositional characteristics of the Yellow River estuary from 1960s by Pu and Cs.

The spatial and vertical distribution of Pu and Cs in the sediments of the Yellow River Delta was studied to evaluate the deposition dynamics in the Yellow River estuary from 1960s. The activity of Pu and Cs in sediment core ranged from 0.001 to 0.

Radioactivity research in mosses from typical Karst Regions in Leye Tiankeng, Southern China.

Radionuclides in environmental ecosystems have ecotoxicity and health impact on human and environment, so radioactive contamination has always been one of the global concerns. This study mainly focused on the radioactivity of mosses collected from the Leye Tiankeng Group in Guangxi. The activities of Pu measured by SF-ICP-MS and Cs measured by HPGe in moss and soil samples are as follows: 0-2.

Beam alignment based on two-dimensional power spectral density of a near-field image.

Beam alignment is crucial to high-power laser facilities and is used to adjust the laser beams quickly and accurately to meet stringent requirements of pointing and centering. In this paper, a novel alignment method is presented, which employs data processing of the two-dimensional power spectral density (2D-PSD) for a near-field image and resolves the beam pointing error relative to the spatial filter pinhole directly. Combining this with a near-field fiducial mark, the operation of beam alignment is achieved.