超细负离子粉末在PP中分散性的研究

采用不同偶联剂表面处理环己烷-负离子粉末溶胶,通过离心沉降的方法研究了表面处理对负离子粉末表面性质的影响,并考察了聚丙烯／负离子粉末共混物的纺丝性能。结果表明,选择单烷氧型钛酸酯类偶联剂质量分数8％时,经过处理后负离子粉末与聚合物基体界面结合状况得到改善,微粒的分散性较好,表面处理效果最好。纺丝时组件压力上升情况得到明显改善,且纺丝状况比较稳定。     

某V型发电柴油机机油耗高问题分析及改进

针对某V型发电柴油机机油耗过高的情况,采用仿真及试验的手段,确定了机油消耗量大的主要原因,明确了降低活塞温度、优化活塞环组运动、增强控油能力的优化方向。通过优化改进气缸套网纹、活塞内冷油道结构和活塞环组尺寸,优化活塞、活塞环和缸套的配合间隙,增加刮碳环,实现了对活塞环组降温、顺气、控油和及时清除积碳的效果,达到降低柴油机机油耗的目的,改进方案经市场验证效果良好。     

动力锂电池组非稳态射流强化换热数值模拟

为动力锂电池组设计了通风冷却系统,在控制总通风量的前提下,研究了非稳态射流对动力锂电池组的冷却效果,针对26650型锂电池组射流冲击方案进行数值模拟分析,揭示非稳态射流送风周期、送风变化量对电池组温升和温度均匀性的影响。研究结果表明:冲击射流的非稳态特性改善了电池组温度场的均匀性,对电池组总温升影响不明显。     

冷冻食品的复合式泡沫包装箱设计研究

目的 设计一种能提高结构强度的复合式泡沫包装箱。 方法 将由护边套和护板构成的护架套装在泡沫包装箱的外部,组合成复合式泡沫包装箱,通过静态压缩实验和跌落实验,对比测试普通泡沫包装箱和复合式泡沫包装箱的抗压强度、抗破损性能。结果 复合式泡沫包装箱单体抗压强度1959.29N,普通泡沫包装箱单体抗压强度1557.22N;对于交错堆码条件下的抗压强度,由普通泡沫包装箱的1039.18N提升到复合式泡沫包装箱的1978.56N。采用护架后,箱体载物面跌落破损高度由800mm提高到1400mm,棱跌落破损高度由600mm提高到1200mm,角跌落破损高度由400mm提高到1000mm。结论 采用护架的复合式泡沫包装箱,箱体结构强度、耐破损性能都得到提升,解决多层堆码箱体压损问题,降低箱体的破损率,提高包装箱重复使用率。     

基于热管阵列锂电池组喷雾冷却实验研究

为了解决传统空气冷却系统散热效率不足的问题,通过实验方法将喷雾蒸发过程与强制空气冷却相结合,强化电池热管理系统的散热效率。建立了基于热管阵列/喷雾冷却复合结构的电池组散热系统,对比了不同冷却措施的散热性能,研究了入口风速、喷雾频率及喷雾占空比对系统散热性能的影响规律。结果表明：复合温控结构在1 C倍率下可完全抑制电池组升温,在3 C倍率下可将电池组平均温度维持在41℃左右;采用10 s喷雾周期进行冷却可将电池组平均温度降低2℃,喷雾频率的增加可显著降低电池温度波动。     

Microbial Safety in Radio-frequency Processing of Packaged Foods

ABSTRACT: Thermal resistance of Clostridium sporogenes (PA 3679) was determined at 115.6 °C, 118.3 °C, and 121.1 °C (240 °F, 245 °F, and 250 °F, respectively) in phosphate buffer (pH 7.0) and mashed potatoes (pH 6.3) using aluminum thermal-death-time (TDT) tubes developed at Washington State Univ. D-values were 1.8, 1.1, and 0.62 min in phosphate buffer and 2.2, 1.1, and 0.61 min in mashed potatoes at 115.6 °C, 118.3 °C, and 121.1 °C, respectively. Z-values were 12 °C and 10 °C in phosphate buffer and mashed potatoes, respectively. The thermal inactivation kinetic results were then used to validate a novel thermal process based on 27.12 MHz radio frequency (RF) energy. Trays of mashed potatoes inoculated with PA 3679 were subjected to 3 processing levels: target process (F₀∼4.3), under-target process (F₀∼2.4), and over-target process (F₀∼7.3). The microbial challenge test data showed that microbial destruction from the RF process agreed with the calculated sterilization values. This study suggests that thermal processes based on RF energy can produce safe and shelf-stable packaged foods.     

Microwave sterilization of sliced beef in gravy in 7-oz trays

This research was to investigate the feasibility for developing a short-time sterilization protocol for a highly inhomogeneous food prepackaged in polymeric trays using 915 MHz microwave (MW) energy. A 915-MHz, single-mode, 10-kW pilot-scale MW system developed at Washing State University was used for this study. The inhomogeneous food consisted of sliced beef and gravy packaged in 7-oz polymeric trays. Specially formulated whey protein gel, matching the beef product in their dielectric properties, was chosen as a model food to emulate the real food for determination of heating patterns and cold spots inside food trays. The heating patterns and cold spots were detected using a chemical-marker-assisted computer vision method. Processing schedules to achieve desired levels of F₀ for 7-oz trays of beef in gravy were established based on temperature histories measured at the identified cold spot location. The developed processing schedules were validated by inoculated pack studies using Clostridium sporogenes PA 3679 spores. The results of this study indicate that the 915-MHz single-mode MW sterilization technology is effective for processing of the inhomogeneous food. The procedure established could be used for developing MW sterilization processes for other packaged inhomogeneous foods, such as chicken meat in gravy in trays and salmon in sauce in pouches. The processing data collected could be helpful for industrial scale-up of the MW system.     

Corn silage management: effects of maturity, inoculation, and mechanical processing on pack density and aerobic stability

Three experiments were conducted to evaluate the effects of inoculation, maturity, and mechanical processing of corn silage on aerobic stability and pack density. Corn silage was stored in 20-L mini silos for the three aerobic stability experiments. Corn silage was stored in 80-L mini silos for the three pack-density experiments. The wet pack density of corn silage tended to decrease as maturity advanced in all of the pack-density experiments, and processed corn silage had a greater wet pack density compared with unprocessed corn silage in two of the three 20-L mini silo experiments. Aerobic stability, measured as the number of hours to reach 1.7 degrees C above ambient, was greater for processed corn silage in two of the three 20-L mini silo experiments, and was greater for inoculated corn silage across the three 20-L mini silo experiments. Inoculation of corn silage with lactic acid producing bacteria tended to improve aerobic stability of corn silage more than maturity and mechanical processing.     

一种针对串联电池组带电不均衡的均衡技术

针对串联电池组的带电不均衡进行了研究,提出了一种新型的均衡技术,以电池ＳＯＣ作为判别 依据确定不均衡状态并制定相应的均衡方案,利用所设计的均衡电路来实施具体的均衡方案。为了验证该 技术的可行性,采用了６节磷酸铁锂电池组成的串联电池组作为实验对象,实验结果充分表明了所提出技术 高效性。     

三组分复合防伪纤维组件设计研究

以常规涤纶的生产工艺参数为依据,根据组件设计原则及分配板的压力损失公式,计算出孔径及长度、压力降等相关数据,设计了生产防伪纤维的三组分复合纺丝组件,并纺丝制得了三组分复合防伪纤维。结果表明:在聚酯切片中,按聚酯切片/色母粒质量比为100/3的比例添加红色和蓝色母粒,在设计的三组分复合组件中纺丝,制得的三组分复合防伪纤维截面和颜色效果较好,可起到防伪作用。