Horizontal divergence of typhoon-generated gravity waves in the upper troposphere and lower stratosphere (UTLS) and its influence on typhoon evolution

The characteristics of horizontal divergence induced by typhoon-generated gravity waves (HDTGWs) and the influence of HDTGW on typhoon evolution are investigated based on the simulation results of Typhoon Saomai (2006) using the Weather Research and Forecasting (WRF) model. The power spectral density of HDTGW shows dominant powers at horizontal wavelengths of 20–30 km and at periods of less than 1 h. This is associated with gravity waves generated by vigorous convective clouds in an inner core region of the typhoon. However, the domain-averaged HDTGW in the upper troposphere and lower stratosphere had a spectral peak at 24 h, which is well correlated with the minimum sea-level pressure of the typhoon, especially during a rapidly developing period. The 24 h period of the averaged HDTGW stems from the inertia–gravity waves generated by the convective clouds in the spiral rainbands, and showed no clear association with the thermal tides or the diurnal variation of precipitation

Research on Self-Calibration of HF Ground Wave Radar Antenna Arrays

Since the performance of high-resolution direction finding algorithm for HF Ground Wave Radar (GWR) is severely degraded by sensor phase and amplitude errors, the radar system's phase calibration is the prerequisite of keeping the radar working in order. According to the characteristic of HF GWR's sea echo, this paper, based on an arbitrary triangular array, presents that Space -Time DOA(direction of arrival) Matrix Method, which is used to estimate 2D DOA under ideal conditions, can be used to estimate planar wave's DOA and sensor phase and amplitude errors simultaneously so as to achieve self-calibration. Its validity is verified not only by computer simulation, but also by comparing treatment results of measured data before and after calibration with the GPS-measured result

Preparation and characterization of antigenic properties of gramicidin A- keyhole limpet hemocyanin and gramicidin A- ovalbumin conjugates

A rapid, simple and low cost procedure for preparing hapten-protein conjugates was developed using gramicidin A (GA) and two other water-soluble proteins, keyhole limpet hemocyanin (KLH) and ovalbumin (OVA). GA was a kind of antimicrobial peptides. Two lysines and a cysteine were linked to amino- terminus and carboxyl-terminus of the peptide chain, respectively, in order to form sulfhydryl groups and improve its water solubility. And the molecule weight and purity of the modified peptidechain were checked by electron spray ionization mass spectrometry (ESI-MS) and high performance liquid chromatography (HPLC). Then the activated KLH and OVA were conjugated to GA by using  4-(Nmaleimidomethyl) cyclohexane-1-carboxylic acid 3-sulfo-N-hydroxysuccinimide ester sodium salt (sulfo-SMCC) to form disulfide linkage. In order to obtain artificial antigen of GA, GA was linked to KLHand OVA by sulfo-SMCC coupling at room temperature. The conjugates of KLH-Peptide and OVAPeptide were identified by infrared and ultraviolet spectrophotometry SDS-PAGE and DTNB method, which could prove the activity of the sulfhydryl-groups. In this way, we have obtained a novel artificial immunogen and coating antigen that could be used to raise polyclonal antibody through immunized rabbits

Tensor coupling effects on spin symmetry in anti-Lambda spectrum of hypernuclei

The effects of $\bar\Lambda\bar\Lambda\omega$-tensor coupling on the spin symmetry of $\bar{\Lambda}$ spectra in $\bar{\Lambda}$-nucleus systems have been studied with the relativistic mean-field theory. Taking $^{12}$C+$\bar{\Lambda}$ as an example, it is found that the tensor coupling enlarges the spin-orbit splittings of $\bar\Lambda$ by an order of magnitude although its effects on the wave functions of $\bar{\Lambda}$ are negligible. Similar conclusions has been observed in $\bar{\Lambda}$-nucleus of different mass regions, including $^{16}$O+$\bar{\Lambda}$, $^{40}$Ca+$\bar{\Lambda}$ and $^{208}$Pb+$\bar{\Lambda}$. It indicates that the spin symmetry in anti-lambda-nucleus systems is still good irrespective of the tensor coupling.Comment: 12 pages, 3 figures

Recovery of Heavy Minerals from Korean Beach Sand

In order to establish the optimized recovery process for heavy minerals from beach sand, we investigated the physical separation methods such as gravity and magnetic separation followed by mineralogical characterization. There was clear relationship between the particle size and the heavy mineral content that the heavy minerals were mostly concentrated in the particles below 100mesh. Grav-ity separation using the spiral and shaking table sepa-rators made it possible to concentrate heavy minerals by rejecting the light and coarse particles consist mainly of quartz. The high-intensity magnetic separator and subsequent induced magnetic separator were applied to fractionate magnetic particles into three fractions accor-ding to their magnetic susceptibility. The content of TiO, of high magnetic susceptible ilmenite-rich fraction was 43.98wt.% while those of ZrO2 of non-magnetic and magnetic residue were 6.78wt.% and 3.11 wt. %. respectively

Molecular dynamics study of the fragmentation of silicon doped fullerenes

Tight binding molecular dynamics simulations, with a non orthogonal basis set, are performed to study the fragmentation of carbon fullerenes doped with up to six silicon atoms. Both substitutional and adsorbed cases are considered. The fragmentation process is simulated starting from the equilibrium configuration in each case and imposing a high initial temperature to the atoms. Kinetic energy quickly converts into potential energy, so that the system oscillates for some picoseconds and eventually breaks up. The most probable first event for substituted fullerenes is the ejection of a C2 molecule, another very frequent event being that one Si atom goes to an adsorbed position. Adsorbed Si clusters tend to desorb as a whole when they have four or more atoms, while the smaller ones tend to dissociate and sometimes interchange positions with the C atoms. These results are compared with experimental information from mass abundance spectroscopy and the products of photofragmentation.Comment: Seven two-column pages, six postscript figures. To be published in Physical Review

Unified theory for Goos-H\"{a}nchen and Imbert-Fedorov effects

A unified theory is advanced to describe both the lateral Goos-H\"{a}nchen (GH) effect and the transverse Imbert-Fedorov (IF) effect, through representing the vector angular spectrum of a 3-dimensional light beam in terms of a 2-form angular spectrum consisting of its 2 orthogonal polarized components. From this theory, the quantization characteristics of the GH and IF displacements are obtained, and the Artmann formula for the GH displacement is derived. It is found that the eigenstates of the GH displacement are the 2 orthogonal linear polarizations in this 2-form representation, and the eigenstates of the IF displacement are the 2 orthogonal circular polarizations. The theoretical predictions are found to be in agreement with recent experimental results.Comment: 15 pages, 3 figure

Fabrication and Characterization of Modulation-Doped ZnSe/(Zn,Cd)Se (110) Quantum Wells: A New System for Spin Coherence Studies

We describe the growth of modulation-doped ZnSe/(Zn,Cd)Se quantum wells on (110) GaAs substrates. Unlike the well-known protocol for the epitaxy of ZnSe-based quantum structures on (001) GaAs, we find that the fabrication of quantum well structures on (110) GaAs requires significantly different growth conditions and sample architecture. We use magnetotransport measurements to confirm the formation of a two-dimensional electron gas in these samples, and then measure transverse electron spin relaxation times using time-resolved Faraday rotation. In contrast to expectations based upon known spin relaxation mechanisms, we find surprisingly little difference between the spin lifetimes in these (110)-oriented samples in comparison with (100)-oriented control samples.Comment: To appear in Journal of Superconductivity (Proceedings of 3rd Conference on Physics and Applications of Spin-dependent Phenomena in Semiconductors