Seasonal hydrological and hydrochemical surveys in the Voevoda Bay (Amur Bay, Japan Sea)

Hydrological and hydrochemical surveys were conducted in the Voevoda Bay in May, August, and October, 2011 and February, 2012, in total 140 stations. Free water exchange of the bay with the Amur Bay is observed, with exception of its inner bights Kruglaya and Melkovodnaya. The water exchange is maintained by anticyclonic circulation with the inflow along the southern coast and outflow along the northern coast of the Voyevoda Bay. However, the opposite cyclonic circulation is observed in the Melkovodanaya Bight because of its coastal line patterns and fresh water discharge by the river. Dissolved oxygen content and partial pressure of CO2 in the bay waters are determined mostly by intensive processes of production and destruction of organic matter. There are three main groups of primary producers there, as diatom algae, sea grass Zostera marina , and periphyton. Specific chemical regime is formed in the Melkovodnaya Bight, in particular in winter when primary production depends on the ice cover and is driven by variations of photosynthetically active radiation passed through the ice. Seasonal variability of production-destruction processes intensity is discussed on the data of chemical parameters changes

Synthetic single crystal diamonds for X-ray optics

In the manuscript we report on characterization of single-crystalline (111) plates prepared from type Ib diamonds with nitrogen content of 100-150 ppm and (100) plates prepared from IIa diamond by means of high-resolution rocking curve imaging (RCI). Contrary to a common opinion about intrinsic poor diffraction quality of type Ib diamonds, RCI showed the presence of nearly defect-free areas of several mm2 in the central part of the (111)-oriented diamond plates. In comparison with the (100)-oriented IIa diamond plates prepared by the same HPHT setup the Ib diamonds possess better diffraction quality. The observed broadening of the rocking curves associates with the cutting and polishing processes, causing strains around the edges of the plates and rare defects. An improvement of preparation technique will thus allow to make single-crystalline diamond plates for Laue and Bragg monochromators and beam splitters from type Ib diamond with areas large enough to be used as wavefront-preserving optical elements at 4th generation synchrotron facilities. Contrary to a common opinion about intrinsically poor diffraction quality of type I diamonds, RCI showed the presence of nearly defect-free areas of several mm2 in the central part of the diamond plates. The observed broadening of the rocking curves results from the cutting and polishing processes, causing strains around the edges of the plates and rare defects. An improvement of preparation technique will thus allow to make single-crystalline diamond plates for Laue and Bragg monochromators and beam splitters from type Ib material with areas large enough to be used as optical elements at 4th generation synchrotron facilities