Abstract: In order to find the dynamic characteristics of shale gas reservoirs and improve shale gas well production, it is very important to research on shale gas seepage mechanism and production evaluation. Based on the shale gas seepage mechanism, adsorption and desorption characteristics, the diffusion mechanism and mass conservation theory in shale gas development, the dual pore medium sha...

Ulrich (1981) supposes in the hypothesis of humusdisintegration that the balance between polymerisation and breakdown of organic material may be disturbed in chemically well buffered European forest soils. This new aspect of aluminium toxicity may cause nitrogen exceedance in forest ecosystems and subsequent seasonal nitrate output (Eichhorn and Hutterman, 1999). In a research program the subst...

We present in this paper a new inverse method for the study of the seepage from symmetrical earthen open channels. We map the half-strip from the complex potential domain onto the unit half-disk from an auxiliary ζ plane. We introduce Levi-Civitá’s function whose imaginary part vanishes on the diameter [−1, 1] of the half-disk by virtue of the boundary conditions imposed on the free lines. Then...

In order to investigate the influence of 3D morphology parameters of marble joint surface on its mechanical and seepage characteristics, artificial joints of coarse-grained marbles were scanned by Tianyuan OKIO-typed 3D laser scanner; and then, the professional software was used to obtain the 3D morphology parameters of marble joint surface. Tests of water flowing through a single joint were co...

We study the problem of Upward Point-Set Embeddability, that is the problem of deciding whether a given upward planar digraph D has an upward planar embedding into a point set S. We show that any switch tree admits an upward planar straight-line embedding into any convex point set. For the class of k-switch trees, that is a generalization of switch trees (according to this definition a switch t...

By a celebrated theorem of Morley, a theory T is א1-categorical if and only if it is κ-categorical for all uncountable κ. In this paper we are taking the first steps towards extending Morley’s categoricity theorem “to the finite”. In more detail, we are presenting conditions, implying that certain finite subsets of certain א1-categorical T have at most one n-element model for each natural numbe...

Abstract. Recently, we have presented a new practical method for upward crossing minimization [4], which clearly outperformed existing approaches for drawing hierarchical graphs in that respect. The outcome of this method is an upward planar representation (UPR), a planarly embedded graph in which crossings are represented by dummy vertices. However, straight-forward approaches for drawing such...