双向自增强PE-HD管材的制备及其增强效果的研究

利用自行设计制造的剪切拉伸双向复合应力场挤管装置制备了轴、周向同时获得自增强的高密度聚乙烯管材。采用万能电子拉力试验机和差示扫描量热仪（DSC）对增强效果及其原因进行了研究。结果表明,剪切拉伸双向复合应力场不仅能明显改善管材轴、周向的力学性能,而且能提升管材的结晶度,其轴向拉伸强度最高提高到30.56 MPa,提高了36.6 %,周向拉伸强度最高提高到33.5 MPa,提高了54.6 %,轴向拉伸模量最高提高到180.3 MPa,提高了47.4 %,周向拉伸模量最高提高到529.8 MPa,提高了140.7 %,结晶度提高了13.51 %,熔点提升了1.5 ℃。DSC测试结果表明,管材性能改善的原因是其结晶度的提高所致。     

“2＋3”提高采收率技术的研究与应用

本文对中、高含水开发后期油田提出了一种改善调剖效果 ,提高采收率的新方法。通过对“2 3”提高采收率技术的研究 ,既提高了洗油效率 ,也提高了波及系数。该技术对濮 4断块应用改善了油藏开发效果 ,提高了采收率 ,取得了较好的效果。     

对提高选煤厂自动化水平的几点看法

:论述了选煤厂提高经济效益的途径 :提高设备及控制系统运行的可靠性 ,提高单机和环节的自动化水平 ,降低成本消耗等 ;指出了提高选煤厂自动化水平对选煤厂经济效益的提高至关重要     

产量预警系统的应用

通过产量预警系统的应用,缩短了发现生产状况异常状态的时滞性,减少了人为不确定因素的影响,使管理数字化、科学化、现代化同时提高了信息反馈速率、提高了生产监控水平、提高了生产效率,最终提高了产量,实现了更大经济效益。     

提高分层注水井注水量精度

本文针对油田分层注入水量测试误差较大的现状,通过注水及测试工艺技术的改进,提高了测试精度,提高了测试效率,进一步提高了注水质量,总结了围绕提高注水量精度而开展的工作和真实评价对提高注水量精度所取得的效果。     

密炼生产线提高产能后节电效果测试与分析

为了提高生产效率、节能降耗,提高了密炼机转速,提速后产能提高.为得知节电效果,进行了专项测试,对同型号腔料在新旧工艺条件下分别测耗电量,得出采用新工艺节电明显,产量提高53％.     

玻璃纤维约束混凝土抗侵彻机理研究

本文探讨了用玻璃纤维约束混凝土构件的力学性质以及在抗侵彻方面的作用,研究表明玻璃纤维约束混凝土既提高了混凝土的抗压强度,又提高了混凝土的延性,从而提高了混凝土构件抗侵彻能力.     

皮带运输机PLC自动控制的设计探析

现阶段,随着我国科技水平的不断提高,我国自动化技术也在快速提升。皮带运输机PLC自动控制技术不仅提高了工作效率,同时还提高了工作质量,降低了劳动强度。     

次氯酸钠反应塔产生泡沫的原因分析及解决办法

随着产量的提高,在次氯酸钠生产过程中反应塔产生大量泡沫,使经济效益下降。针对此进行原因分析并找到解决办法,最大程度地提高了产量,降低了消耗,提高了经济效益。     

酸洗处理对生物质炭孔结构表征的影响

采用氮吸附法对酸洗处理前后3种生物质炭(竹炭、果壳炭和秸秆炭)孔结构进行表征及分析,结果表明:酸洗处理可提高比表面积和总孔容,以秸秆炭效果最为显著,比表面积提高了近5倍,总孔容提高了2.7倍,竹炭和果壳炭不显著.酸洗处理可使微孔率和微孔孔容提高,以竹炭表现最为显著,微孔率提高了近8.8倍,微孔孔容提高了5.5倍,其次是...     

INSTRUCTIONS FOR PREPARATION OF MANUSCRIPTS FOR DIRECT REPRODUCTION

ABSTRACT

The bulk density of garlic slices at different moisture levels (ranging from approximately 3 to 65% MC wet basis) was determined by weighing the contents of a container of known volume. The porosity was calculated using its relationship with bulk and apparent densities. An analysis of variance (ANOVA) revealed that bulk density and porosity were affected significantly by moisture and slice thickness as well as the interaction of these variables. Bulk density varied in a positive linear fashion with moisture and thickness while a negative linear correlation was found for the calculated bulk porosity. The linear model met me adequacy criterion for characterising the behaviour of garlic. Using a laboratory unit, the vertical resistance to airflow through the product and die effect of moisture and slice thickness were investigated for an airflow rates of 0.09 to 1.2 m³/s-m². A higher resistance to airflow was noted for the wet product with the experimental data fitting to Shedd's model when the airflow range was divided into two sub-flow rates and to a modified Ergun's equation for the full range.     

雷达罩复合材料铺层计算的数学方法

雷达罩复合材料的铺层设计直接关系到雷达罩复合材料的强度,现行的商用软件需要依赖结构铺层设计才能实现仿真分析,要针对结构铺层分别划网格、建模型,铺层设计的灵活性、通用性差。采用几何学原理和数据编程处理方法,将雷达罩纤维织物复合材料的平面经纬向依据不同的起始铺层角度并结合三维空间几何转换确定其在三维雷达罩模型上的实际方向,进行雷达罩复合材料铺层设计,将复合材料铺层方向投影到空间雷达罩复合材料的有限元模型中,确定复合材料的铺层角,将铺层设计显性化、通用化,并且增加复合材料铺层计算的灵活性,突破各种软件的约束。     

INSRUCTIONS FOR PREPARATION OF MANUSCRIPTS FOR DIRECT REPRODUCTION

ABSTRACT

We investigate experimentally the behaviour of the receding evaporation front during the drying of food products by measuring the temperature distribution profile within the potato slab. The effect of key process parameters on the receding speed of this evaporation front is investigated. We show that the square root of the drying time varies linearly with the transient position of the front. Also, the receding velocity of the front is seen to be related to the drying rate of the product as the front decelerates inward to the center of the material.