冷喷涂技术的应用现状及展望

简要介绍了冷喷涂技术的原理与特点,冷喷涂工艺参数、粒子沉积行为与喷涂后涂层的性能等研究现状,并对冷喷涂技术的应用前景进行了展望。     

基于超音速火焰喷涂技术的冷喷涂技术实现与流场分析

在KY-HVO(A)F多功能超音速火焰喷涂的基础上通过改进喷枪的设计,在喷枪的扩张段加入水实现了冷喷涂技术.进行了冷喷涂过程中焰流流场分析,得到了不同水流量条件下喷枪中气流的速度与温度分布规律.为了定量分析,得到了喷枪出口中心处气流速度与温度随加水量的变化规律.结果表明:随着加水量的增加,粒子的速度与温度都在下降.在加水量较小时,焰流的速度与温度急剧下降.当加水量大于20L/h时,随着加水量的增加,焰流的温度和速度下降较慢.依据此流场分析结果在钢基体上成功制备了功能性涂层.     

液化流程中氧液化器的流程组织和相关参数确定

简介了中压循环液化和低压循环液化两种主要的液化流程,对两种流程进行了比较;分析了在中压循环液化流程中单独设置氧液化器的必要性;探讨了在低压氧液化和中压氧液化时不同的氧液化器流程组织形式;提出了低压氧液化时合理的流程组织方案和相关参数。     

空分设备冷箱鼓胀变形的发生和预防

空分设备冷箱漏液,必须扒砂。介绍了扒砂过程中发生的冷箱鼓胀变形事故,分析了事故的原因和今后的防范措施,提出了安全扒砂的建议。     

五机架UCMW冷连轧机板形平坦度自动控制系统

板形平坦度自动控制系统是板带材冷连轧机过程控制系统的重要组成部分。从国外成套引进的某1550UCMW冷连轧机组装备了具有国际先进水平的板形平坦度自动控制系统。本文通过对此系统的深入消化研究,从预设定控制、弯辊力-轧制力前馈控制和闭环反馈控制三个方面,分别总结介绍了系统的扳形控制策略和控制模型设计思想。     

Quantum Phase Transition in the BCS-to-BEC Evolution of p-wave Fermi Gases

We discuss the possibility of a quantum phase transition in ultra-cold spin-polarized Fermi gases which exhibit a p-wave Feshbach resonance. We show that when fermionic atoms form a condensate that can be externally tuned between the BCS and BEC limits, the zero temperature compressibility and the spin susceptibility of the fermionic gas are non-analytic functions of the two-body bound state energy. This non-analyticity is due to a massive rearrangement of the momentum distribution in the ground state of the system. Furthermore, we show that the low temperature superfluid density is also non-analytic and exhibits a dramatic change in behavior when the critical value of the bound state energy is crossed.     

Fatigue damage accumulation of cold expanded hole in aluminum alloys subjected to block loading

Fatigue damage accumulation of cold expanded hole in aluminum alloys used in land transportation components was investigated. Tests were carried out using pre-cracked SENT specimens and inserting an expanded hole at the crack tip. The degree of the cold expansion was chosen equal to 4.3%. Tests were performed in two and four block loading under constant amplitude. Two sequences were compared.The increasing and the decreasing magnitude were compared. The experimental results were compared to the damage calculated by the Miner's rule and a new simple fatigue damage indicator. This comparison shows that the ‘model of the damage stress’, which take into account of the loading history, yields a good estimation of the experimental results. Moreover, the error is minimized in comparison to the Miner's model.     

Field test investigation of a double-stage coupled heat pumps heating system for cold regions

This paper reports a double-stage coupled heat pumps (DSCHP) heating system, which couples air source heat pump (ASHP) and water source heat pump (WSHP) together. The system is presented for the first time in open literature with the objective to improve the working condition and heating performance of the ASHP under cold environment. A practical project in Beijing firstly installed this system and field test has been performed for one month. The test results indicate that the DSCHP system can be smoothly and efficiently used for heating in cold regions. Compared with the traditional ASHP heating system, the operating characteristics of the DSCHP heating system are greatly improved, demonstrating that the system can offer considerable application potential in cold regions.     

基于ECA 规则的仿真系统研究设计

分析冷连轧仿真系统的主动性需求，结合数据库在仿真系统中的作用，提出基于主动数据库的仿真系统设计。对主动规则的原理和执行进行分析，给出了基于主动规则——ECA规则的仿真系统的设计和运行机制，用ECA规则描述应用系统执行操作和事件处理，完成系统的主动性行为。并以冷连轧仿真系统中物料跟踪在一机架前的事件动作为例，运用ECA规则进行设计。