宜兴地区紫砂泥料收缩率的影响因素探究

文章利用泥片法对宜兴地区紫砂泥料收缩率的影响因素进行探究,以期为紫砂工艺品的制作和利用提供科学依据。通过对紫砂不同泥料种类、同种泥料不同温度、同种泥料不同目数、同种泥料不同烧成方式以及同种泥料的不同泥片形状的烧制,计算烧制前后泥片的收缩率。在探究中,主要采用紫泥和朱泥进行实验,发现在不同泥料中朱泥的收缩率最大;相同泥料不同温度下1150℃对泥料收缩率影响最大;相同泥料80目的泥料收缩率最大;相同泥料直接升温至1150℃泥料收缩率最大;同种泥料不同泥片形状与收缩率没有显著的相关性。     

双级真空挤出机控制系统的PLC设计与应用

双级真空挤出机已经普遍用于砖瓦行业,实现挤出生产自动化、节约资源和提高挤出质量是今后挤出机研究的主要方向。经过对挤出机的结构与实际工作过程的分析研究,确定挤出机整个工作过程的自动化控制方案,应用PLC和传感器,实现了对含水率、料位、真空度、温度和压力的监控,提高了挤出机的自动化程度。同时,也达到了增加产量,延长设备寿命,节约资源,提高生产效率和产品质量的目的。      

双级真空挤出机控制系统的PLC设计与应用

双级真空挤出机已经普遍用于砖瓦行业,实现挤出生产自动化、节约资源和提高挤出质量是今后挤出机研究的主要方向。经过对挤出机的结构与实际工作过程的分析研究,确定挤出机整个工作过程的自动化控制方案,应用PLC和传感器,实现了对含水率、料位、真空度、温度和压力的监控,提高了挤出机的自动化程度。同时,也达到了增加产量,延长设备寿命,节约资源,提高生产效率和产品质量的目的。     

淀粉单螺杆挤出过程的可视化实验研究

利用全程可视单螺杆挤出机实验研究了木薯淀粉在挤出过程中主要操作参数对挤出设备和产品性能的影响,通过挤出机的玻璃视窗直观观测了木薯淀粉在螺杆挤出过程中的真实动态过程,获得木薯淀粉在单螺杆挤出机内输送和糊化等理化特性变化过程照片图像资料,研究了木薯淀粉的含水率、螺杆转速对产品膨化比,挤出机产量、主机动耗,滞留时间的影响。综合各指标,该设备挤出膨化木薯淀粉时的最佳螺杆转速在９０ｒ／ｍｉｎ￣１２０ｒ／ｍｉ     

沙棘果泥中黄酮提取工艺优化研究

本试验主要研究沙棘果榨汁后的沉淀物中黄酮的最佳提取工艺。采用乙醇回流浸提的方法提取沙棘果泥中的黄酮,使用分光光度计对沙棘果泥中的黄酮含量进行测定。利用正交试验考察提取温度、提取时间以及料液比对黄酮提取率的影响,最终确定提取黄酮的最佳工艺。结果表明:最佳提取条件为提取温度75℃、提取时间2h、料液比1∶45。     

橡胶挤出机内胶料的三维流动模拟与分析

挤出机模拟过程中常常出现问题,这些问题主要源自于模拟挤出机并没有落到实处地具体模拟出挤出机的性能,它的模拟并不切合实际,而在现实生活中,三维流动更能贴合实际。挤出机的内部流动完全可以做成三维流动,把挤出机中的胶料的粘性设置为一个变化的固定值,用不同的固定值进行变量研究,将螺杆的扭矩进行变化,记录下随着扭矩的变化其他参数的变化,从而研究出功耗变化的规律,重点突出各个参数对于整个挤出机内胶料性能的影响。     

基于CFX的内嵌双螺杆挤出机流场特性分析

在传统双螺杆挤出机的基础上,设计了一种具有内外流道的双螺杆挤出机。文章基于有限元法,利用Pro/E三维绘图软件建模、ANSYS/CFX流体模块,对新型双螺杆挤出机进行数值模拟,通过分析宏观压力、宏观速度以及挤出量来与传统双螺杆挤出机进行对比。分析结果显示,新型双螺杆挤出机内流道流速小于新型双螺杆挤出机外流道流速小于传统双螺杆挤出机外流道流速,从而延长了物料的停留时间,提高了混合性能;由于内流道的出现,使挤出效率提高了约55.5%。研究结果表明,新型双螺杆挤出机在保证豆粕挤出质量的同时,其豆粕挤出产量是传统双螺杆挤出机的1.4～1.7倍。本研究结果为双螺杆挤出机的设计提供了新思路。     

紫玉米色素的提取工艺及产品稳定性研究

以紫玉米为原料提取紫玉米色素,并对产品稳定性进行研究。通过单因素试验,确定各工艺参数对紫玉米色素提取率的影响;选择提取温度、提取时间和料液比3个因素进行正交试验设计,对紫玉米色素的提取工艺进行优化。试验结果表明:影响紫玉米色素提取率的因素主次顺序为提取温度>提取时间>料液比;以80%乙醇与0.2mol/L柠檬酸混合溶液为提取剂,最佳工艺条件为提取温度60℃、提取时间2h、料液比1:10。     

秸秆揉搓机物料抛送过程的理论分析与试验

针对揉搓机在抛料过程中存在的排料难、负荷大的问题,结合理论进行了抛料器主要工作参数的试验研究,对切碎物料进行了运动分析,并对抛料筒结构对抛送过程的影响进行了试验研究,建立了抛送叶板速度的数学模型。通过多次试验研究,确立了合理的抛料器结构参数。     

紫薯馅料广式月饼的工艺优化

研究了转化糖浆、花生油、紫薯泥及白砂糖用量对紫薯馅料广式月饼品质的影响。结果表明:各因素对紫薯馅料广式月饼品质影响的主次顺序为转化糖浆＞花生油＞白砂糖＞紫薯泥。通过正交试验确定了紫薯馅料广式月饼加工的较优配方为枧水1 mL,花生油5.5 mL,糕点用低筋粉21 g,奶粉1 g,紫薯泥57 g,白砂糖4.7 g,小麦淀粉1.3 g,转化糖浆14 g。      

Reducing water losses from channels using linings: Costs and benefits in Pakistan

To evaluate the effectiveness of various types of linings in reducing the seepage losses from field channels, 10 conventional and 12 low cost test sections were constructed. The conventional test sections included six rectangular brick masonry sections and four trapezoidal concrete sections with varying thickness of walls and bed lining materials. The low cost sections consisted of six rectangular brick masonry sections and six trapezoidal sections with brick masonry, pre-cast concrete slab and tile lining having different thickness of wall and bed linings. In some low cost sections lining was not provided in the bed. Water loss rates were measured before construction, immediately after construction and 24 years after construction. Higher seepage loss rates were measured in the cement–concrete conventional test sections than in the conventional brick masonry sections with plaster on the inside walls. Water loss rate measurements in concrete sections showed that quality control was more critical than the thickness and richness of the concrete mix. Economic analyses showed that low cost linings were a better investment than the conventional linings. Low cost lining with 11 cm thick brick masonry in vertical walls, or 2:1 sloped walls, plastered on the inside, without lining in the bed, is recommended. Lining walls, with 2:1 slope, using fired tile or pre cast concrete slabs were also good investments when the joints were plastered.     

血粉膨化机温度控制系统的研究

由于血粉蛋白属于硬质蛋白,只有膨化加工方法才能使其血细胞膜全部破坏及血粉中硬质蛋白未充分变性,从而被动物消化吸收。为了提高血粉膨化机挤出血粉的质量(在对挤压过程进行了分析和研究的基础上),采用Smith预估PID控制,实现了对血粉膨化机各区温度控制。实验结果表明:该控制系统具有较优的动态控制性能,使用效果良好。     

船式拖拉机气层减阻影响因素分析与参数优化研究

针对船式拖拉机船壳在水田泥浆环境中作业行进阻力大的问题,对船式拖拉机船壳气层减阻进行研究.通过构建仿真模型,对影响气层减阻性能的泥浆来流速度和气流量两个因素进行分析,并对船壳底板凹槽结构进行参数优化,研究不同深度凹槽结构的气层减阻性能.研究结果表明:泥浆来流速度增大在一定程度上会使气层产生破裂,导致总阻力增大,而气流量...     

影响单螺杆挤压膨化机性能因素的试验研究

对被挤压物料的熔融过程进行了分析，应用正交多项式回归设计法，找出转速，物料湿度，压力等因素对机器生产率，耗电量，膨化率等的影响，并用模糊数学综合评判法，通过多因素试验对机器的诸性能进行评价，得出优选组合排序，为提高单螺杆式挤压膨化机的性能和制品质量，提供了一定的理论依据。     

Analysis of a two-component hydrograph separation model to predict herbicide runoff in drained soils

This paper evaluates the use of a two-component hydrograph separation model to predict the leaching of two relatively soluble herbicides, isoproturon and simazine, from an agricultural drained clay soil. The model successfully predicted the pattern and extent of herbicide leaching in drainflow at a 15-min time interval using electrical conductivity of rainfall and drainflow as the single chemical parameter. Analysis of the hydrological characteristics of individual rainfall events allowed current sources of uncertainty in the model to be identified and highlighted areas for further research. For example, future use of the model should incorporate the measurement of intra-event variations in electrical conductivity of rainfall as an input in order to improve model accuracy and precision. Repeated under-estimation of herbicide concentration in drainflow when suspended sediment concentrations were elevated indicated that desorption hysteresis may have occurred at the soil surface and during transport through the tile drain system. This resulted in the transport of a greater proportion of herbicide through preferential pathways in sediment-associated form than predicted by assuming an instantaneous desorption at the soil surface. The results of the research suggest that the nature and importance of sediment-associated herbicide transport through tile drains warrants further investigation.     

Effect of tile effluent on nutrient concentration and retention efficiency in agricultural drainage ditches

Tile drainage is a common water management practice in many agricultural landscapes in the Midwestern United States. Drainage ditches regularly receive water from agricultural fields through these tile drains. This field-scale study was conducted to determine the impact of tile discharge on ambient nutrient concentration, nutrient retention and transport in drainage ditches. Grab water samples were collected during three flow regimes for the determination of soluble phosphorus (SP), ammonium nitrogen (NH₄⁺-N), nitrate nitrogen (NO₃-N) concentrations and their retention in three drainage ditches. Measured nutrient concentration indicated lower SP and NH₄⁺-N, and greater NO₃-N concentrations in tile effluents compared to the ditch water. Net uptake lengths were relatively long, especially for NO₃-N, indicating that nutrients were generally not assimilated efficiently in these drainage systems. Results also indicated that the study reaches were very dynamic showing alternating increases or decreases in nutrient concentration across the flow regimes. The drainage ditches appeared to be nutrient-rich streams that could potentially influence the quality of downstream waters.     

蔬菜移栽机顶夹式取苗装置末端执行器设计与试验

为解决顶夹式取苗出现的顶苗失败、钵体被夹持时受压变形、破损等问题,以顶夹式取苗末端执行部件为研究对象,建立顶苗和夹苗过程力学分析模型,得出影响取苗效果的主要因素包括顶针直径、顶针长度、顶苗速度和夹苗加载距离。通过试验测定钵体相关物理性能参数,在EDEM软件中选用EEPA接触模型建立钵体颗粒模型。利用EDEM仿真模拟顶苗与夹苗过程,采用Box-Behnken设计法和单变量控制法分别进行顶苗和夹苗仿真试验设计,利用Design-Expert软件分析得到优化参数组合为：顶针直径1.9mm、顶针长度18mm、顶苗速度0.3m/s和夹苗加载距离4mm。在频率100株/min下进行取投苗性能验证试验,经过优化的取苗末端执行部件取投苗成功率93.25%,钵体完整度良好,满足叶菜类蔬菜穴盘苗自动旱地移栽取苗要求。     

马铃薯螺杆挤压制泥设备优化与试验研究

针对传统工艺加工的马铃薯泥风味差、质构破坏严重、营养损失大等问题，对马铃薯制泥工艺及设备进行优化。基于螺旋挤压成型原理，设计沟槽腔体和变螺距螺杆，进行挤压制泥机试验，检测不同制泥工艺对马铃薯泥营养成分、风味和质构等特性的影响。结果表明，马铃薯片厚1.0cm、汽蒸11min、压力为0.01~0.2MPa时，马铃薯泥质量最好。同时结合马铃薯泥的物化特性，完善薯泥品质评价指标体系。仿真结果表明，沟槽腔体变螺距螺杆的组合下挤压破碎效果最好，设计的多孔板出口结构使出料稳定、均匀，随着螺杆转速或进料速度增加，挤压段腔体和多孔板外筒中压力递增。试验结果表明，螺杆挤压制出的马铃薯泥软糯细腻、香味浓郁、营养损失小，产品质量显著提升。     

冬水田机插秧影响因素的试验研究

通过L8(23)正交试验,对筛选的两种泥脚深度的冬水田—田A(21.9cm泥脚深度)和田B(31.6cm泥脚深度)进行水稻品种内香8518的机插秧栽插试验。结合冬水田性状特点,设置插秧机、秧苗和田块这三大试验主体的插秧机浮板类型、秧苗栽插密度和田块泥脚深度为三因素,每个因素设两个水平,在此条件下进行三因素对插秧机行走速度、秧苗栽插质量及水稻实收产量的影响及程度研究。结果显示,在冬水田机插秧作业时:1对插秧机行走速度影响最大的是泥脚深度,影响显著;其次是浮板类型,影响显著;栽插密度看不出影响。2对秧苗漏插率影响最大的是浮板类型,影响特别显著;其次是栽插密度,影响显著;影响最小的是泥脚深度。3三因素对水稻实收产量的影响均特别显著,影响最大的是浮板类型,其次是栽插密度,再是泥脚深度。4最优整体方案是泥脚深度21.9cm、采用改进浮板类型、栽插密度13.95万/hm2。