Effective preparation and collisional decay of atomic condensate in excited bands of an optical lattice

We present a method for the effective preparation of a Bose-Einstein condensate (BEC) into the excited bands of an optical lattice via a standing-wave pulse sequence. With our method, the BEC can be prepared in either a single Bloch state in a excited-band, or a coherent superposition of states in different bands. Our scheme is experimentally demonstrated by preparing a $^{87}$Rb BEC into the $d$-band and the superposition of $s$- and $d$-band states of a one-dimensional optical lattice, within a few tens of microseconds. We further measure the decay of the BEC in the $d$-band state, and carry an analytical calculation for the collisional decay of atoms in the excited-band states. Our theoretical and experimental results consist well.Comment: 9 pages, 5 figures, Accepted by Phys. Rev.

Functionally Graded Concrete Structure

By inverse analysis, the concept, functionally gradient, is introduced into thick-walled lining to improve the supporting performance. Theoretical results show that for two linings with the same sizes, an ideal functionally graded lining (IFGL) has higher elastic ultimate bearing capacity than a traditional single-layered lining (TSL). But the IFGL model requires that the Young’s modulus should be a continuously monotonically increasing function in the radial direction, which, obviously, cannot be achieved currently for the concrete materials. In order to apply this idea to real lining, we use a simplest multilayered lining, a double-layered functionally graded lining (DFGL), as an approximate simulation of the IFGL. Then, we carried out elastoplastic analysis on IDFL and DFGL and model test on DFGL to assess the support performance. Results of elastoplastic analysis show that the elastic ultimate bearing capacities of both the IDFL and DFGL are higher than the traditional single-layered lining. Model tests also verify the conclusion

Exploring multi-band excitations of interacting Bose gases in a 1D optical lattice by coherent scattering

We use a coherent Bragg diffraction method to impart an external momentum to ultracold bosonic atoms trapped in a one-dimensional optical lattice. This method is based on the application of a single light pulse, with conditions where scattering of photons can be resonantly amplified by the atomic density grating. An oscillatory behavior of the momentum distribution resulting from the time evolution in the lattice potential is then observed. By measuring the oscillating frequencies, we extract multi-band energy structures of single-particle excitations with zero pseudo-momentum transfer for a wide range of lattice depths. The excitation energy structures reveal the interaction effect through the whole range of lattice depth.Comment: 6 pages, 5 figure

Gastroprotective effect of the root extract of Alpinia officinarum Hance (Zingiberoside) against acute indomethacin-induced gastric injuries in rats: Involvement of H+/K+-ATPase and prostaglandin E receptors

Purpose: To investigate the protective effects of Alpinia officinarum root ethanol extract (AOE) and galangin against acute indomethacin-induced injury on rat gastric mucosaMethods: Sprague-Dawley rats were daily treated with bismuth potassium citrate (0.08 g/kg), AOE at doses of 0.09, 0.18 and 0.36 g/kg; and galangin (0.2 g/kg) for 15 days. Then, gastric injury on rats was induced by intragastric administration of indomethacin (30 mg/kg). Blood flow and thickness of gastric mucosa were determined using neutral red clearance test and Alcian blue staining. The activity of H+/K+-ATPase was assayed using a biochemical kit. Prostaglandin E receptor expressions were assayed by western blotting.Results: High doses of ethanol extract of Alpinia officinarum root significantly inhibited H+/K+-ATPase activity by 8.12 % (p < 0.01), increased gastric mucosal blood flow (p < 0.001), enhanced mucus thickness (p < 0.05), and elevated the activities of prostaglandin E receptors 1 and 4 (p < 0.05).Galangin significantly inhibited H+/K+-ATPase activity by 4.82 % (p < 0.05) and increased gastric mucosal blood flow (p < 0.01).Conclusion: The ethanol extract of Alpinia officinarum root attenuates indomethacin-induced gastric injury by reinforcing gastric mucosal barrier and inhibiting excessive gastric acid secretion. Thus, the extract can be potentially developed for management of gastric injuries. Keywords: Galangin, Gastric mucosal barrier, Gastric acid, Prostaglandin, Indomethaci