Changes in thermohaline system on the west Spitsbergen shelf since 1950 to present time

The west Spitsbergen shelf is the principal region for the Atlantic water pass and it is very dynamic area, which has been changing a lot in the last two centuries. Herein, the analysis results of long-term variability of thermohaline characteristics of West-Spitsbergen current (WSC) and Coastal current (CC) are presented for the period from 1950 to present time based on the in-situ oceanographic data from the “Nordic Seas” database created in the Arctic and Antarctic Research Institute (AARI). Water temperature and salinity of WSC and CC were measured at 10 points and analyzed. It was concluded that the temperature and salinity in the study region were exposed to quasicyclic changes with common periods of about 5-6 and 10 years. Positive trends of water temperature for all points in the both currents were estimated (1.2°C per 60 years for WSC, and 2°C for CC, respectively). Correlation coefficients were calculated to describe the linear relationship between air temperature, atmospheric circulation indexes, the Atlantic multidecadal oscillation index, and water temperature in the region of the western shelf of the Spitsbergen

Nanostructuring and Physical Properties of Metal-Ceramic Composites With a Different Content the Ceramic Components

A comparative analysis of the microstructure and durability of hard-alloy plates treated with high-energy pulsed electron beam generated from the plasma of argon or xenon in steel cutting was conducted. It is shown that the choice of the plasma gas to generate electron from the cathode plasma-filled setting for pulsed electron-beam irradiation has a significant influence on the formation of structural-phase state in the surface layer and the durability of hard-alloy plates in steel cutting

Molecular Cloning of a Bovine Immunoglobulin Lambda Chain cDNA

A cDNA library of the bovine mammary gland constructed in pBR322 was screened by mRNA hybrid-selected translation and by differential hybridization. Several immunoglobulin (Ig) λ light-chain clones were identified and sequenced. Nucleotide sequence comparison of bovine and human Ig λ chains showed a high degree of homology for constant regions and for J regions. The amino acid (aa) sequence encoded by the constant region of the bovine Ig λ chain cDNA contains 107 aa with differences at 24 aa positions from the human Ig A chain. Three complementarity-determining regions (CDR1,2,3) characteristic of the variable region of bovine Ig λ chain cDNA can be distinguished. The bovine and human sequences display good homology in the framework region 3 (FR3) but only patches of homology throughout the FR2 region. The 5′ end of the bovine Ig λ chain cDNA fragment of clone 1-14E contains five stop codons: two in CDR1, one in FR1 and two in the hydrophobic prepeptide region. These data suggest that the Igλ mRNA of clone 1-14E is transcribed from the Vλ pseudogene

Efficient Two-dimensional Subrecoil Raman Cooling of Atoms in a Tripod Configuration

We present an efficient method for subrecoil cooling of neutral atoms by applying Raman cooling in 2D to a four-level tripod-system. The atoms can be cooled simultaneously in two directions using only three laser beams. We describe the cooling process with a simple model showing that the momentum distribution can be rapidly narrowed to velocity spread down to $0.1v_\text{rec}$, corresponding to effective temperature equal to $0.01T_\text{rec}$. This method opens new possibilities for cooling of neutral atoms.Comment: 6 pages, 3 figure

Theoretical description of the decays Λb→Λ(∗)(12±,32±)+J/ψ\Lambda_b \to \Lambda^{(\ast)}(\frac12^\pm,\frac32^\pm) + J/\psi

We calculate the invariant and helicity amplitudes for the transitions $\Lambda_b~\to~\Lambda^{(\ast)}(J^P)~+~J/\psi$ where the $\Lambda^{(\ast)}(J^P)$ are $\Lambda(sud)$-type ground and excited states with $J^P$ quantum numbers $J^P=\frac12^{\pm},\frac32^{\pm}$. The calculations are performed in the framework of a covariant confined quark model previously developed by us. We find that the values of the helicity amplitudes for the $\Lambda^\ast(1520,\,\frac32^-)$ and the $\Lambda^\ast(1890,\,\frac32^+)$ are suppressed compared with those for the ground state $\Lambda(1116,\,\frac12^+)$ and the excited state $\Lambda^\ast(1405,\,\frac12^-)$. This analysis is important for the identification of the hidden charm pentaquark states $P_c^+(4380)$ and $P_c^+(4450)$ which were discovered in the decay chain $\Lambda_b^0~\to~P_c^+(~\to~p~J/\psi)~+~K^-$ because the cascade decay chain $\Lambda_b~\to~\Lambda^\ast(\frac32^\pm)(~\to~pK^-)~+~J/\psi$ involves the same final state.Comment: 15 pages, 4 figures. Minor corrections don

Vortex solitons in moire optical lattices

We show that optical moire lattices enable the existence of vortex solitons of different types in self-focusing Kerr media. We address the properties of such states both in lattices having commensurate and incommensurate geometries (i.e., constructed with Pythagorean and non-Pythagorean twist angles, respectively), in the different regimes that occur below and above the localization-delocalization transition. We find that the threshold power required for the formation of vortex solitons strongly depends on the twist angle and, also, that the families of solitons exhibit intervals where their power is a nearly linear function of the propagation constant and they exhibit strong stability. Also, in the incommensurate phase above the localization-delocalization transition, we found stable embedded vortex solitons whose propagation constants belong to the linear spectral domain of the system

Three-dimensional atom localization by laser fields in a four-level tripod system

We present a scheme for high-precision three-dimensional (3D) localization by the measurement of the atomic-level population. The scheme is applied to a four-level tripod-type atom coupled by three strong standing waves and a probe running wave. As a result, the atom can be localized in volumes that are substantially smaller than a cubic optical wavelength, which is achieved by the increase of standing-wave intensities. The upper-level distribution depends crucially on the atom-field coupling and it forms 3D periodic structures composed of spheres, hourglasses, bowls, donuts, or deformed barrels.</p