Aimed at the problem,which the helical blade scraped the bottom plate of spiral groove or the delivered material was blocked,generally existing in the spiral conveyor,the method of reinforcing the bend stiffness of spiral shaft by means of setting an additional support seat at the extension end of spiral shaft is presented,and the detail theoretical derivation and calculation are conducted.
This does not, however, give rise to vanishing identities for the standard nonsymmetric Macdonald and Koornwinder polynomials; we discuss the required modification to these polynomials to support such results.
A simple parametrization is given for the set of positive measures with finite support on the circle group T that are solutions of the truncated trigonometric moment problem:
Then it is shown that for many (and perhaps all) pairs E, F, of wavelet sets, the corresponding MSF wavelets can be connected by a continuous path in L2(?) of MSF wavelets for which the Fourier transform has support contained in E ∪ F.
The distribution of supporting force of the hydraulic supports should be adaptable to the characteristics of the on-coming roof pressure. Analysis has been made of the working resistance of all types of hydraulic supports, by means of probability statistical method. The two important indices for roof classification are the inceptive cave-in span of the immediate roof and the sensitivity of the roof cave'-in'. In accordance with a certain number of observed data of roof pressure, this paper...
In this paper a comprehensive investigation on the stability of a large-span cavern is described, including in-situ rock tests, measurement of initial stress field, application of seismic velocity method etc.. A finite element method of non-linear analysis used for numerical modelling is also introduced. Finally, some useful conclusions for selecting the site of a large-span cavern and for the design and construction of support are given.
Various types of failures in shotcreted, roof-bolted roadways in coal mines are illustrated. By demonstrating the crucial factor oa which the success of bolting-shotcreting support depends, analyzing the characteristics of deformation of surrounding rocks of roadways due to convergence and studying theoretically the deformation of strata seqence caused by instability and buckling, the writer has come to a conclusion in respect of such supports in coal-bearing strata: that it is necessary to make...