Song Jian-Ping

Detecting shallow caverns in China using TEM

To detect shallow anomalies under certain conditions, electromagnetic methods can be more effective in reconnaissance surveying than high-resolution surface seismic. This case study describes the results of the transient electromagnetic method (TEM) in an environment where initial field trials showed that surface seismic was difficult to employ effectively and expensive to implement.

Waveguides Induced by Screening-Photovoltaic Solitons in Biased Photorefractive?Photovoltaic Crystals

We investigate theoretically waveguides induced by screening-photovoltaic solitons in biased photorefractive–photovoltaic crystals. We show that the number of guided modes in a waveguide induced by a bright screening-photovoltaic soliton increases monotonically with the increasing intensity ratio of the soliton, which is the ratio between the peak intensity of the soliton and the dark irradiance. On the other hand, waveguides induced by dark screening-photovoltaic solitons are always single mode for all intensity ratios and the confined energy near the centre of a dark screening-photovoltaic soliton increases monotonically with the increasing intensity ratio. When the bulk photovoltaic effect is neglectable, these waveguides are those induced by screening solitons. When the external field is absent, these waveguides predict those induced by photovoltaic solitons.

Four-wave mixing and six-wave mixing in a four-level confined atomic system

We have investigated coexisting four-wave mixing and six-wave mixing (SWM) in ultra-thin, micrometre and long vapour cells. There exists competition between Dicke-narrowing features and polarization interference in the micrometre cell. The oscillation behaviour of SWM signal intensities and linewidths results from destructive interference. With a larger destructive interference, the SWM signal in ultra-thin cells shows a narrow spectrum, in contrast to the long cell case. Due to the Dicke-narrowing features, a narrow spectrum can be obtained, and such spectra can be used for high precision measurements and metrological standards.

Interactions of Three Dual-Dressing Effects of Four-Wave Mixing in a Five-Level Atomic System

We study the four-wave mixing (FWM) in an opening five-level system with two dressing fields. There are three kinds of doubly dressing mechanisms (parallel cascade, sequential cascade, and nested cascade) in the system for doubly dressed four-wave mixing. These mechanisms reflect different correlations between two dressing fields and different effects of two dressing fields to the FWM. Investigation of these mechanisms is helpful to understand the generated high-order nonlinear optical signal dressed by multi-fields.

An Original RBF Network Based on Attribute Similarity

According to the thought of biological receptive field, a model of original radial basis function neural network with attribute similarity (ASRBF) is presented, it not only has evident physical and biologic meanings, but also can simplify topology structure, decrease operation and save cost. Eventually, forecast oil reservoir production with the trained network, the simulation shows that, the application effect of this improved RBF network algorithm is very good; and the algorithm is not only superior to that of tradition RBF network, but also with high fitting precision and quick rate of convergence

Continuum Structures at the Second Dissociation Limit of Hydrogen Molecules

We describe near-threshold high-resolution spectra and continuum resonance dynamical behaviour of all three stable hydrogen isotopic variants, and finally obtain improved values for the dissociation energies of hydrogen molecule and its ion. The second dissociation limit is determined by analysing the onset of the vibrational continuum.