Model for water pollution remote sensing based on double scattering and its application in the Zhujiang River outfall

It is a valid route for quantitatively remote sensing on water pollution to build a model according to the physical mechanisms of scattering and absorbing of suspended substance, pollutant, and molecules of water. Remote sensing model for water pollution based on single scattering is simple and easy to be used, but the precision is affected by turbidity of water. The characteristics of the energy composition of multiple scattering, are analyzed and it is proposed that, based on the model of single scattering, if the flux of the second scattering is considered additionally, the precision of the model will be remarkably improved and the calculation is still very simple. The factor of the second scattering is deduced to build a double scattering model, and the practical arithmetic for the calculation of the model is put forward. The result of applying this model in the water area around the Zhujiang(Pearl) River outfall shows that the precision is obviously improved. The result also shows that the seriously polluted water area is distributed in the northeast of Lingding Sea, the Victoria Bay of Hong Kong, and the Shengzhen Bay.

Determination of Matrine and Oxymatrine in Radix Sophorae Flavescentis by Resonance Rayleigh Scattering, Second-order Scattering and Frequency Doubling Scattering Technique

In 0.1 mol/L HCl medium, 12-tungstophosphoric（TP） acid reacted with matrine（Mat） and oxymatrine（Oxy） to form an ion-association complex. As a result, the new spectra of resonance Rayleigh scattering（RRS）, second-order scattering（SOS） and frequency doubling scattering（FDS） appeared and their intensities were enhanced greatly. The maximum scattering wavelengths of RRS, SOS and FDS were located at 370, 670 and 390 nm, respectively. The in-crements of scattering intensity were directly proportional to the concentration of Mat and Oxy in a certain range. Based on this, the method for the determination of matrine and oxymatrine has been established. It has been applied to the determination of matrine and oxymatrine in samples of Radix sophorae flavescentis with satisfactory result. The reaction mechanism and reasons of RRS enhancement were discussed.

Resonance Rayleigh Scattering and Resonance Nonlinear Scattering Methods for Determination of Methylene Blue with 12-Tungstophosphoric Acid

In a pH=0.65―1.5 NaAc-HCl medium, methylene blue（MB） reacts with 12-tungstophosphoric acid （TPA） by virtue of electrostatic attraction and hydrophobic force to form a 3：2 ion-association complex. As a result, the intensities of resonance Rayleigh scattering（RRS）, second-order scattering（SOS） and frequency doubling scatte- ring（FDS） are enhanced greatly. The maximum scattering wavelengths of RRS, SOS and FDS are located at 316, 647 and 311 nm. The increments of scattering intensity（△I） are directly proportional to the concentration of MB in a certain range. The methods exhibited high sensitivity, and the detection limits（3s） for MB are 2.3 ng/mL（RRS method）, 5.6 ng/mL（SOS method） and 6.4 ng/mL（FDS method）, respectively. The effects of coexisting substances have been examined, and the results indicate that the methods have good selectivity. Based on the above researches, a new spectral method for the determination of trace amounts of MB has been developed. It can be applied to the determination of MB in human serum, and the recoveries are 97.5%―105.0%. The results are in good agreement with those obtained by the pharmacopoeia method. In this work, the optimum conditions of the reaction and the influencing factors were investigated. In addition, the reaction mechanism and the reasons of the enhancement of resonance light scattering were discussed.

Production of γγ+2 jets from double parton scattering in proton-proton collisions at the LHC

Cross sections for the production of pairs of photons plus two additional jets produced from double parton scattering in high-energy proton-proton collisions at the LHC are calculated for the first time. The estimates are based on the theoretical perturbative QCD predictions for the productions of γγ at next-to-next-to-leading-order, jet＋jet and γ＋jet at next-to-leading-order, for their corresponding single-scattering cross sections. The cross sections and expected event rates for γγ＋2 jets from double parton scattering, after typical acceptance and selections, are given for proton-proton collisions with the collision energy s=13 TeV and integrated luminosity of 100 fb-1 planned for the following years, and also s=14 TeV with 3000 fb 1 of integrated luminosity as the LHC design.

Study on Frequency Doubling Scattering and Second-Order Scattering Spectra of Heparin-Methylene Blue System

Binding of heparin with methylene blue (MB) in pH 5.7 Britton Robinson buffer can result in a significant enhancement of frequency doubling scattering (FDS) and second order scattering (SOS). Their maximum scattering wavelengths ( λ max ) appear at 350 nm for FDS and 700 nm for SOS, respectively. The optimum conditions of the reaction, the influencing factors and the relationship between the two scattering intensities and the concentration of heparin have been investigated. The new methods for the determination of trace amounts of heparin based on the FDS and SOS methods have been developed, which exhibit high sensitivities. The detection limits of heparin are 4.36 ng/mL for the FDS method and 3.55 ng/mL for the SOS method, respectively. Both of the methods have fairly good selectivity and were applied to the determination of heparin in sodium heparinate injection samples with satisfactory results. Moreover, the relative mechanisms have also been discussed.

Study of ~3He inelastic scattering on ^(13)C and ^(14)C at 37.9 MeV

The differential cross sections of elastic and inelastic scattering of ~3He ions on ^（13）C and ^（14）C have been studied at an energy of 37.9 MeV with a double folding model based on M3Y-Reid effective nucleon-nucleon interaction.The resulted parameters have been used for the standard Distorted Wave Born Approximation calculations of angular distributions corresponding to different excitations levels of ^（13）C and ^（14）C and deformation parameters have been deduced.

Luminosity determination for the pd reaction at 2.14 GeV with WASA-at-COSY

The luminosity for a WASA-at-COSY experiment involving the pd reaction at 2.14 GeV proton- beam energy is determined by the forward pd elastic scattering, which yields an average beam-on-target value of [5.2±0.3（stat）±0.3（syst）] × 10^30 s^-1 cm^-2. In addition, the forward pd elastic-scattering angular distribution is obtained with four-momentum transfer squared -t between 0.16 （GeV/c）2 and 0.78 （GeV/c）2 at this beam energy, which is compared with other experimental data and the pd double scattering model.