孔隙塌缩对工业炸药爆轰的多重作用

通过对工业炸药爆轰反应过程中微孔隙压溃的细观与宏观过程进行研究,提出炸药孔隙压溃不仅产生绝热压缩、射流冲击、摩擦剪切生热的“热点”因素;冲击射流产生的旋涡运动,还会起到搅拌混合作用,促进爆轰燃烧反应;同时旋涡运动的湍流能量还会通过粘性耗散转变为热能,供给爆轰波,与化学反应放热一起维持爆轰传播;即工业炸药爆轰中的微孔隙塌缩同时起到了“热点”、搅拌混合促燃和湍流释能的多重作用。炸药孔隙的搅拌混合作用决定了“化学反应区”和“湍流耗散区”的厚度大小,其中“化学反应区”的厚度与孔隙度成反比,“湍流耗散区”则与孔隙度成正比,两者的共同作用构成支持爆轰波的“释能区”,这使得工业炸药存在能量利用率最高的最佳装药密度。基于爆轰波“释能区”的新观点,建立了工业炸药的最佳装药密度、极限直径、临界直径、高密度“压死”、炸药能量利用率等爆轰性能经典问题之间的内在联系。通过“孔隙混合效应”和乳化炸药粒径分析,基于敏化气泡与炸药粒径相匹配原则,提出对于粒径5~6μm的乳化炸药,敏化气泡以直径10~100μm为最佳。

A Philosophical Appraisal of John Rawls＇ Difference Principle in the Context of the Quota System of Nigeria

The concept of justice is a complex phenomenon which has been subjected to various legal, social, and philosophical interpretations. In other words, for the concept to make meaning to analysts and various intellectual communities, it has to undergo a process of concept conceptualization and operationalisation. It is therefore this lack of univocal definition of justice that one can philosophically assert that there is no theory of justice but theories of justice. The purpose of this article is not to delve into the various analyses of theories, meanings, definitions, and/or explanations of justice but to examine John Rawls＇ Difference Principle of justice in the context of the Nigerian Quota System. In order to make this writing less nebulous and less ambiguous and more explicit and clear, I shall examine the definitions of the concepts of both justice and Quota System. In addition, evaluation of the philosophical and theoretical assumptions of the Rawls＇ theory and the Quota System will be made with a view to revealing their applicability and relevance in our real economic socio-political system （in Nigeria）.