Aiming at the limitation of the traditional method for determination of protection region, combined with the actual situation of a mine, a new method for determination of protection region was put forward (including ...Aiming at the limitation of the traditional method for determination of protection region, combined with the actual situation of a mine, a new method for determination of protection region was put forward (including the protection of working face layout and development direction), that is, gas flow observation analysis on the spot and gas content contrast method. The protection region was determined by gas flow observation analysis, gas content contrast, and computer numerical simulation combined with engineering practice. In the process of gas content test, the fixed sampling method "big hole drill reaming, small orifice drill rod connected with core tube" was employed. The results show that the determined protection region is in accordance with the actual site situation. The fixed sampling method ensures the accuracy of gas measurement of gas content.展开更多
For more than two decades rudimentary versions of the fixed sample and sequential search strategies have provided the primary theoretical foundation for the study of mate choice decisions by searchers. The theory that...For more than two decades rudimentary versions of the fixed sample and sequential search strategies have provided the primary theoretical foundation for the study of mate choice decisions by searchers. The theory that surrounds these models has expanded markedly over this time period. In this paper, we review and extend results derived from these models, with a focus on the empirical analysis of searcher behavior. The basic models are impractical for empirical purposes because they rely on the as- sumption that searchers--and, for applied purposes, researchers--assess prospective mates based on their quality, the fitness consequences of mate choice decisions. Here we expound versions of the models that are more empirically useful, reformulated to reflect decisions based on male phenotypic characters. For some organisms, it may be possible to use preference functions to de- rive predictions from the reformulated models and thereby avoid difficulties associated with the measurement of male quality per se. But predictions derived from the two models are difficult to differentiate empirically, regardless of how the models are formu- lated. Here we develop ideas that illustrate how this goal might be accomplished. In addition, we clarify how the variability of male quality should be evaluated and we extend what is known about how this variability influences searcher behavior under each model. More general difficulties associated with the empirical study of mate choice decisions by searchers are also discussed [Current Zoology 59 (2): 184-199, 2013].展开更多
文摘Aiming at the limitation of the traditional method for determination of protection region, combined with the actual situation of a mine, a new method for determination of protection region was put forward (including the protection of working face layout and development direction), that is, gas flow observation analysis on the spot and gas content contrast method. The protection region was determined by gas flow observation analysis, gas content contrast, and computer numerical simulation combined with engineering practice. In the process of gas content test, the fixed sampling method "big hole drill reaming, small orifice drill rod connected with core tube" was employed. The results show that the determined protection region is in accordance with the actual site situation. The fixed sampling method ensures the accuracy of gas measurement of gas content.
文摘For more than two decades rudimentary versions of the fixed sample and sequential search strategies have provided the primary theoretical foundation for the study of mate choice decisions by searchers. The theory that surrounds these models has expanded markedly over this time period. In this paper, we review and extend results derived from these models, with a focus on the empirical analysis of searcher behavior. The basic models are impractical for empirical purposes because they rely on the as- sumption that searchers--and, for applied purposes, researchers--assess prospective mates based on their quality, the fitness consequences of mate choice decisions. Here we expound versions of the models that are more empirically useful, reformulated to reflect decisions based on male phenotypic characters. For some organisms, it may be possible to use preference functions to de- rive predictions from the reformulated models and thereby avoid difficulties associated with the measurement of male quality per se. But predictions derived from the two models are difficult to differentiate empirically, regardless of how the models are formu- lated. Here we develop ideas that illustrate how this goal might be accomplished. In addition, we clarify how the variability of male quality should be evaluated and we extend what is known about how this variability influences searcher behavior under each model. More general difficulties associated with the empirical study of mate choice decisions by searchers are also discussed [Current Zoology 59 (2): 184-199, 2013].