CVC轧机冷轧宽带材板形控制特性的数值模拟

以六次偶函数拟合宽带材出口横向厚度分布，计算了ＣＶＣ轧机冷轧宽带材前张应力横向分布，首次以张应力横向分布的形式，模拟了ＣＶＣ轧机冷轧宽带材板形控制特性，模拟结果证明：ＣＶＣ轧机冷轧宽带材时具有很强的板形控制能力。     

燃烧合成Mg2Ni的固相扩散-溶解-析出机理

采用自蔓延燃烧模式及热爆燃烧模式合成较纯的Mg2Ni金属间化合物。通过对不同预热温度下热爆反应过程的研究,证实在较低温度下,Mg-Ni体系存在固固反应,且反应的程度随预热速度的降低而增大。由于Mg-Ni体系为弱放热体系,因此燃烧过程为不完全燃烧。采用试样顶部添加引燃剂(Al-Ti-C)的方法,成功淬熄了Mg-Ni反应。对不同区域进行的SEM、EDS和XRD分析表明反应直接生成了Mg2Ni而没有中间相。     

推广冰缸贮奶 提高乳品质量

本文回顾了二十年来中国乳业的风雨历程和奶源质量对乳业发展的重大影响。指出速冷奶罐是适合收奶站的理想设备,冰缸是乳品专业的最佳冷藏设备,它能给乳品厂和奶牛专业户带来可观的经济效益。推广冰缸是适合我国国情,提高乳品质量的有效途径。     

右前门外拉手盖注射模具设计

分析右前门外拉手盖的结构工艺性,介绍该注射模具关键机构的技术要点及设计思路。根据产品结构设计出模具的浇注系统、成形零件、顶出机构、侧抽芯机构以及冷却系统,特别是采用二级滑块抽芯机构合理地解决斜孔成型与抽芯的工艺难题。结果表明,该模具结构紧凑,动作可靠,可为类似结构的注射模具提供借鉴。     

Analysis of the scale up of a transpiring wall reactor with a hydrothermal flame as a heat source for the supercritical water oxidation

Experimental data from a tubular reactor and from a transpiring wall reactor (TWR) are used to analyze the scaling up of SCWO reactors operating with a hydrothermal flame as a heat source. Results obtained with the tubular reactor show that fluid velocity inside the reactor determines the minimum injection temperature at which a stable hydrothermal flame is formed. When the fluid velocity inside of the reactor is lower, the extinction temperature of the hydrothermal flame in that reactor is also lower. Using this reactor, extinction temperatures are always near or above the critical temperature of water. Total TOC removals are possible working with isopropyl-alcohol at temperatures between 650 and 700 °C and residence times of 0.5 s. Results of the TWR show that steady operation with a hydrothermal flame inside is possible even when reagents are injected at subcritical conditions as low as 170 °C. Temperature measurements show that reaction is not initiated in the injector but in the reaction chamber, where fluid velocity is lower than 0.1 s. This was explained by estimating that the flame front velocity of a hydrothermal flame is of the order of 0.1 m/s. Thus, it is expected that the flame is stabilized in the reaction chamber and not in the injector, where fluid velocities are higher than 2 m/s. A previously developed model of the TWR was modified in order to describe the ignition in the reaction chamber and not in the injector. The model reproduces satisfactorily experimental data and it was used to propose the design of scaled up reactors for SCWO with a hydrothermal flame inside.     

Dynamic behavior of particles across flame propagation through micro-iron dust cloud with thermal radiation effect

In this investigation, a theoretical study is performed to analyze the dynamic behavior of particles across flame propagation through a two-phase mixture consisting of micro-iron particles and air. In the first step for calculation of the particle velocity profile, the Lagrangian approach of particle motion is employed, and then thermophoretic, gravitational and buoyancy forces are taken into consideration. In order to simulate the temperature profile for the thermophoretic force, it is assumed that the flame structure consists of three zones: preheat, reaction, and post flame (burned). It should be noted that the radiative heat-transfer equation is employed to describe the thermal radiation exchanged between the burned zone and the preheat zone. In the resumption, a control volume above the leading edge of the combustion zone is considered and the change in the particle number density in this volume is obtained via the balance of particle mass fluxes passing through it. The results show that the induced thermal radiation plays a significant role in increasing the mixture temperature all over the preheat zone, and that the particle velocity profile and the concentration distribution of particles as a function of distance from the leading edge of the combustion zone also have considerable consistency with published experimental data.     

精英克隆局部搜索的多目标动态环境经济调度差分进化算法

为有效解决复杂多目标动态环境经济调度问题,提出一种基于精英克隆局部搜索的多目标动态环境经济调度差分进化算法.以传统的差分进化(differential evolution,DE)算法为框架,为了提高DE算法的开采和探索能力,增设精英群的克隆和突变机制,采用动态选择方式确定精英群,有效增强算法的全局搜索能力.数值试验以I...     

精铰挤光复合铰刀在气缸盖加工中的应用

介绍了一种精铰挤光复合铰刀，它可以一次完成三个工序的工作，从而达到提高加工精度，节省劳动时间和操作工人的目的。     

《前厅客房管理及实务》课程考试改革方案设计

酒店管理专业的培养目标是要求学生重点掌握从事酒店领域实际工作需要的基本能力和服务技能,《前厅客房管理及实务》课程承载着培养学生从事酒店前厅部和客房部主要岗位的服务技能。为使学生更好地掌握各岗位的服务程序,进行合理的考试改革是强化学生重视学习、掌握服务技能的必要手段。通过课程分析,找到《前厅客房管理及实务》课程考试改革的设计方案。     

汽车前大灯LED光源散热技术

散热问题一直是制约LED在车灯上广泛运用的技术瓶颈。通过分析高温环境对LED的危害、LED的发热机理,基于神龙公司某款车型大灯的LED散热模型,对当前通用的翅片散热法进行探讨。研究结果表明,翅片散热面积、厚度、材料等对翅片散热这种被动散热方式的散热效果影响显著,设计时需综合考虑。而翅片散热作为一种优秀的散热方案,可作为后期开发LED大灯的优先选择方案。