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991.
992.
选用医用级热塑性聚氨酯(TPU)为原材料,在旋转流变仪和毛细管流变仪上对TPU进行稳态、动态流变测试。采用Power Law方程进行流变数据拟合,得到200℃时TPU零切黏度为855 Pa·s,非牛顿指数为0.65,松弛时间为0.06 s。利用时温等效原理对动态流变数据进行主曲线滑移拟合,通过阿伦尼乌斯方程求得黏流活化能(ΔE)为137 k J/mol。流变测试结果表明,TPU是一种温敏性较强的材料,准确选择并控制TPU的加工条件十分重要。 相似文献
993.
针对某款变频新国标机器匹配过程中出现制冷能力不稳定、蒸发器没有进行充分换热的情况,主要从以下两方面进行优化,解决了以上问题:1通过Wei sman流型图定量分析确定了分流器要达到雾状流所需要的孔径;2通过布热电偶数据判断每一路的蒸发情况来最终确定U管数量及分流毛细管长度,保证蒸发器充分换热。最终确定该款变频新国标机器采用D5蒸发器、¢4孔径分流器的方案,实现能力达到稳定且APF能够满足新国标3.35的要求。 相似文献
994.
Effect of hydraulic retention time,temperature, and organic load on a horizontal subsurface flow constructed wetland treating cheese whey wastewater 下载免费PDF全文
995.
2,4,5‐Trifluorobromobenzene is a valuable intermediate with important application in the synthesis of biologically active peptides and fluorescent reagents. A continuous‐flow system has been successfully developed for the synthesis of 2,4,5‐trifluorobromobenzene in a microreactor using FeBr3 as a catalyst, which is steadily generated in situ from the reaction of Br2 and Fe. The procedure is efficient and easy‐to‐handle, and 2,4,5‐trifluorobromobenzene can be obtained within minutes in high yields. 相似文献
996.
Energy Savings through Microwave Selective Heating of Pd/AC Catalyst Particulates in a Fixed‐Bed Reactor 下载免费PDF全文
Microwave radiation is a novel energy source to drive chemical reactions. In conventional reactors, however, the heat created either escapes through uninsulated reactor walls, or the microwave radiation is attenuated by insulated walls. Here, microwave selective heating of Pd catalyst particles supported on activated carbon particulates was examined in a fixed‐bed reactor using a novel vacuum‐filled Dewar‐like double‐walled continuous‐flow reactor. This reactor was developed toward energy savings in performing such organic reactions as the transformation of the hydride methyl cyclohexane to toluene. 相似文献
997.
998.
999.
Variation in sequential task processing times is common in manufacturing systems. This type of disturbance challenges most scheduling methods since they cannot fundamentally change job sequences to adaptively control production performance as jobs enter the system because actual processing times, are not known in advance. Some research literature indicates that simple rules are more suitable than algorithmic scheduling methods for adaptive control. In this work, a ‘state space – average processing time’ (SS-APT) heuristic is proposed and compared to four most commonly used scheduling rules and two well-established heuristics based on Taillard’s benchmarks. It is shown that the adaptive control is made possible under variation in processing times given the flexibility and strong performance of the SS-APT heuristic, especially for work-in-process inventory control. 相似文献
1000.
A new version of a system to monitor the average void fraction, φ, the quality, x, and the mass flow rate, G, of two-phase liquefied natural gas (LNG) flows is offered. It is based on a combination of a gamma-densitometer with a Cs-137 radioactive source and a narrowing device. The metrological characteristics of this system are estimated and its practical realization is substantiated. A model of ID =100 mm has been manufactured and tested at the State Primary Special Standard of the Unit of Mass Flow Rate of Gas-Liquid Mixtures GET 195-2011 (Kazan, Russia) with simulated two-phase flows “Exxsol – compressed air”. The offered system can be used for pipelines up to ID =500 mm by applying a gamma source with the necessary activity. The experiments on GET 195–2011 have shown that the void fraction error and the relative mass flow rate error for Exxsol do not exceed 5% and 2%, respectively, at φ<50%. It appears to be suitable for practical application. If one adds a second gamma-source (for example, Am-241) to the proposed system, it can serve as a separationless three-phase flow-meter for mixtures “oil-gas-formation water”. 相似文献