Analyzed the support instable mode of sliding,tripping,and so on,and believed the key point of the support stability control of fully mechanized coal caving face with steep coal seams was to maintain that the seam tru...Analyzed the support instable mode of sliding,tripping,and so on,and believed the key point of the support stability control of fully mechanized coal caving face with steep coal seams was to maintain that the seam true angle was less than the hydraulic support instability critical angle.Through the layout of oblique face,the improvement of support setting load,the control of mining height and nonskid platform,the group support system of end face,the advance optimization of conveyor and support,and the other control tech- nical measures,the true angle of the seam is reduced and the instable critical angle of the support is increased,the hydraulic support stability of fully mechanized coal caving face with steep coal seams is effectively controlled.展开更多
Previous studies on modulation instabilities（MIs） in birefringent optical fibers focus on the ordinary linearly and circularly ones. This paper reports an analysis of MIs in the general elliptically birefringent fib...Previous studies on modulation instabilities（MIs） in birefringent optical fibers focus on the ordinary linearly and circularly ones. This paper reports an analysis of MIs in the general elliptically birefringent fibers with the emphasis on investigating the effects of ellipticity angle（0？ ≤θ≤ 90？）. Both symmetric and antisymmetric CW states are considered. In the anomalous dispersion regime, for the symmetric（antisymmetric） CW states, we show that MI gain increases dramatically（reduces first and then enhances greatly） as the increment of θ. In the normal dispersion regime, for the both CW states, the distinctive feature is that the gain of the MI bands reduces first, vanishes at θ = 45？,reappears across this ellipticity angle, and quickly increases after then.展开更多
基金the National Natrual Science Foundation of China(50504014)
文摘Analyzed the support instable mode of sliding,tripping,and so on,and believed the key point of the support stability control of fully mechanized coal caving face with steep coal seams was to maintain that the seam true angle was less than the hydraulic support instability critical angle.Through the layout of oblique face,the improvement of support setting load,the control of mining height and nonskid platform,the group support system of end face,the advance optimization of conveyor and support,and the other control tech- nical measures,the true angle of the seam is reduced and the instable critical angle of the support is increased,the hydraulic support stability of fully mechanized coal caving face with steep coal seams is effectively controlled.
基金Supported by the National Natural Science Foundation of China under Grant Nos.11447113 and 11305031 Natural Science Foundation of Jiangsu Provincial Universities under Grant No.14KJB140009 the Startup Foundation for Introducing Talent of Nanjing University of Information Science and Technology under Grant No.2241131301064
文摘Previous studies on modulation instabilities（MIs） in birefringent optical fibers focus on the ordinary linearly and circularly ones. This paper reports an analysis of MIs in the general elliptically birefringent fibers with the emphasis on investigating the effects of ellipticity angle（0？ ≤θ≤ 90？）. Both symmetric and antisymmetric CW states are considered. In the anomalous dispersion regime, for the symmetric（antisymmetric） CW states, we show that MI gain increases dramatically（reduces first and then enhances greatly） as the increment of θ. In the normal dispersion regime, for the both CW states, the distinctive feature is that the gain of the MI bands reduces first, vanishes at θ = 45？,reappears across this ellipticity angle, and quickly increases after then.
