用分级淬火油来控制工件变形

用分级淬火油来控制工件变形好富顿国际公司Ｒ．Ｊ．ＢＲＥＮＮＡＮ分级淬火油这个名词是１９４２年首先提出来的。它是指将钢件由奥氏体状态放到温度比Ｍｓ略高一点的介质中进行淬火。钢件放在其中的时间恰好使各部分温度平衡，随后放在空气中冷却，从而减少表面和芯部转...     

Atmosphere behavior in gas-closed mouse-algal systems: An experimental and modelling study

Concepts of biologically-based regenerative life support systems anticipate the use of photosynthetic organisms for air revitalization. However, mismatches in the rates of production and uptake of oxygen or carbon dioxide between the crew and the plants will lead to an accumulation or depletion of these gases beyond tolerable limits. One method for correcting these atmospheric changes is to use physicochemical devices. This would conflict with the constraint of minimal size and weight imposed upon the successful development of a competitive bioregenerative system. An alternate control strategy is based upon reducing the gas exchange mismatch by manipulation of those environmental parameters known to affect plant or algae gas exchange ratios. We have initiated a research program using a dual approach of mathematical modelling and laboratory experimentation aimed at examining the gas exchange characteristics of artificial animal/plant systems closed to the ambient atmosphere. Our goal is to develop control techniques and management strategies for maintaining the atmospheric levels of carbon dioxide and oxygen at physiological levels. A mathematical model simulating the atmospheric behavior in these systems has been developed and an experimental gas-closed system has been constructed. These will be described and preliminary results will be presented.