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801.
802.
Summary A mathematical programming model for scheduling open pit mining was developed and validated using data from a surface mining operation. A two-phase solution procedure was used involving repeated evaluations of an integer scheduling model and a simple transportation model. 相似文献
803.
Three satellite-tracked drifting buoys released in the south equatorial current in the Indian Ocean followed the path of the
current moving westward approximately zonally in the vicinity of 10 S latitude. On nearing the east coast of Africa two buoys
moved north and the third moved south. Over the open sea regime the buoys moved with a speed of approximately 30 cm/s at an
angle of about 35° to the left of the wind. The overall tendencies seen in the buoy drift are similar to those observed elsewhere
in the world oceans. 相似文献
804.
805.
Wiesław Wiśniewolski Janusz Górczyński Wiesław Madry 《Aquatic Sciences - Research Across Boundaries》1989,51(3):249-259
Width of the first ray of the pectoral fin has been measured in two places for 154 young and 89 adult wels. Statistical relationships between the above characters and fish length as well as its maturity and sex have been proved. Three models of discriminant function for identification of adult fish sex have been derived and verified. The accuracy of sex separation has been 89,5% in a standard sample of wels, and 90,6% in a routine sample, after an adjustment in the procedure. 相似文献
806.
Theoretical background for the inversion of seismic waveforms including elasticity and attenuation 总被引:3,自引:0,他引:3
Albert Tarantola 《Pure and Applied Geophysics》1988,128(1-2):365-399
To account for elastic and attenuating effects in the elastic wave equation, the stress-strain relationship can be defined through a general, anisotropic, causal relaxation function
ijkl
(x, ). Then, the wave equation operator is not necessarily symmetric (self-adjoint), but the reciprocity property is still satisfied. The representation theorem contains a term proportional to the history of strain. The dual problem consists of solving the wave equation withfinal time conditions and an anti-causal relaxation function. The problem of interpretation of seismic waveforms can be set as the nonlinear inverse problem of estimating the matter density (x) and all the functions
ijkl
(x, ). This inverse problem can be solved using iterative gradient methods, each iteration consisting of the propagation of the actual source in the current medium, with causal attenuation, the propagation of the residuals—acting as if they were sources—backwards in time, with anti-causal attenuation, and the correlation of the two wavefields thus obtained. 相似文献
807.
808.
岩体结构面粗糙度系数JRC的定向统计研究 总被引:5,自引:2,他引:5
本文回顾了岩体结构面粗糙度系数JRC的研究成果,分析了各种JRC研究方法的应用范围。在野外实际结构面形态的详细调查和深入研究的基础上,发展了Barton直边法,并提出按岩性定向统计研究结构面粗糙度系数JRC的科学思想。 相似文献
809.
Long-period surface waves and mantle boundary undulations 总被引:2,自引:0,他引:2
810.