Two-pion interferometry for a partially coherent evolution source

We give the formulas of two-pion Hanbury-Brown-Twiss （HBT） correlation function for a partially coherent evolution pion-emitting source, using quantum probability amplitudes in a path-integral formalism. The multiple scattering of the particles in the source is taken into consideration based on Glauber scattering theory. Two-pion interferometry with effects of the multiple scattering and source collective expansion is examined for a partially coherent source of hadronic gas with a finite baryon density and evolving hydrodynamically. We do not find observable effect of either the multiple scattering or the source collective expansion on HBT chaotic parameter.

Similarity Solution for the Synchronous Grouting of Shield Tunnel Under the Vertical Non-Axisymmetric Displacement Boundary Condition

Abstract.Similarity solution is investigated for the synchronous grouting of shield tunnel under the vertical non-axisymmetric displacement boundary condition in the paper.The synchronous grouting process of shield tunnel was simplified as the cylindrical expansion problem,which was based on the mechanism between the slurry and stratum of the synchronous grouting.The stress harmonic function on the horizontal and vertical ground surfaces is improved.Based on the virtual image technique,stress function solutions and Boussinesq’s solution,elastic solution under the vertical non-axisymmetric displacement boundary condition on the vertical surface was proposed for synchronous grouting problems of shield tunnel.In addition,the maximum grouting pressure was also obtained to control the vertical displacement of horizontal ground surface.The validity of the proposed approach was proved by the numerical method.It can be known fromthe parameter analysis that larger vertical displacement of the horizontal ground surface was induced by smaller tunnel depth,smaller tunnel excavation radius,shorter limb distance,larger expansion pressure and smaller elastic modulus of soils.

Water-conserving Potential for Agriculture in the Tarim Basin

o satisfy the water demand for Tarim Basin's economic development in the year 2000, about 33 4×10 8 m 3 water needs to be further tapped. According to the analysis of the current status of water utilization, it is pointed out that, to achieve such economic objectives, the policy of emphasizing both water exploitation and water conservation with the preference given to conservation measures must be followed. For this end, the potentials of exploring new additional sources and strengthening water conservation have been well analyzed, along with the calculation and tech economic assessment of some related parameters like the canal transmission efficiency in water delivery systems and the water irrigation efficiency in the field. The results indicate the potentials of water resource expansion and conservation are 34×10 8 m 3 and 57×10 8 m 3, respectively. Based on such research outputs, a water conservation program has been developed for the Tarim Basin, to provide important references and policy recommendations for the decision makers in Xinjiang agricultural department to implement water utilization measures.