PLC在农产品称量包装控制中的应用

设计用可编程序控制器(PLC)来控制农产品称量包装的自动化生产.同时,介绍了系统的构成及工作过程,给出了系统流程图及PLC控制梯形图以及提高精度的各项措施.该系统不仅线路简洁、可靠性高,而且较好地兼顾了动态称量的精度和速度,满足了在线快速动态称量包装的要求.     

木/竹基复合材料在机电产品包装的应用

我国机电产品的包装大量使用实木材料,面临着资源紧张和成本高昂等问题。通过分析机电产品包装材料的结构形式和承载要求,讨论重组木/竹复合材料在包装行业应用的可行性,从政策、成本和性能等方面,总结新型重组木/竹复合材料替代实木材料用于机电产品包装的优势及发展前景。     

构建主义学习理论与基于网络的包装材料学教学应用

构建主义学习理论强调学习的主动性,认为学习是学习者主动构建意义的过程。这一全新的学习理论对如何利用网络技术进行包装材料学的教学,对提高包装工程专业学生包装材料学课程的学习兴趣与其综合能力的提高有着重要的启示。     

家具包装设计及实例

家具包装作为现代家具生产不可分割的一部分,对保障货物储存、运输和销售各个阶段起着重要的作用。论文从包装定位、装潢设计、包装尺寸的确定、包装容器的结构设计、包装零部件位置摆放及封箱处理等进行阐述,以婴儿床为案例进行包装设计。     

商品包装装潢设计构思——定位设计

构思是设计的灵魂。包装装潢设计中最重要的一环是“创意构思”。包装装潢设计构思的创意应紧紧围绕内容对形式的要求来进行，即不仅要在艺术上表现出产品的个性特色、设计者或消费群体的个性特色，使包装新颖别致，感染力强，能吸引消费者，而且应尽可能地反映商品的内在品质及其在功能上的优越性。     

Frozen Storage Studies of Formulated Skipjack Tuna Patties

Plain and flavored formulated skipjack tuna patties with textural characteristics similar to that of ground beef were developed for use in school lunch programs. Shelf life studies of these patties indicated that the nutrient composition of raw and cooked fish patties held under frozen storage for nine months essentially remained the same. In a 100 gm edible serving, raw and cooked tuna patties contained 71%-75% moisture, 18%-21% protein, 0.15%-0.22% fat, 1.8%-2.1% ash, and 3.3%-4.0% carbohydrate. Mean caloric content ranged from 88 to 91 kilocalories/patty. Furthermore, a 100 gm patty serving provided about 29% of the U.S. Recommended Dietary Allowance (RDA) for protein, 18%-20% for niacin, about 14% for phosphorous, 10%-11% for iron, 6% for magnesium, less than 5% for zinc, copper, and manganese, about 2% for thiamin, and less than 2% for vitamins A, E and calcium. Sensory testing on fish patties indicated that cooked patties could be stored up to nine months in frozen storage (minus 24°C) with only slight changes in odor, taste and texture. The storage life for frozen, raw patties appeared to be about three months. If uncooked patties were frozen, they should be cooked and eaten within a three month period. Based on the data gathered in this study it was recommended that the tuna patties be fully cooked, frozen quickly, vacuum-sealed, and stored at -24°C or below in order to maintain a frozen shelf-life of up to nine months.     

Preharvest and postharvest factors related to off-odours of fresh-cut iceberg lettuce

The influence of different preharvest and postharvest factors affecting off-odour development of fresh-cut iceberg lettuce in low-O₂ modified atmospheres (MA) was investigated. Fresh-cut iceberg lettuce developed undesirable off-odours under low O₂ and elevated CO₂ atmospheres. A strong relationship between CO₂ concentration and off-odour development was observed. Significant differences in off-odour development existed among different cultivars in two harvests in consecutive years. The influence of maturity stage was evaluated, comparing fresh-cut product from immature and over-mature heads with commercial ones. Higher CO₂ concentrations and higher accumulation of ethanol and acetaldehyde were detected in the headspace of MA-packed lettuce from immature heads. Differences in respiration rate of the fresh-cut product from heads cultivated during the winter–spring seasons were around 30%. Respiration rate of fresh-cut iceberg lettuce increased when medium temperature during cultivation increased. Changes in the product weight generated different CO₂ levels which correlated with the production of ethanol and acetaldehyde and other off-odour metabolites related with the lipoxygenase (LOX) pathway such as hexanal, 1-hexanol, and cis-3-hexen-1-ol. Volatile compounds such as cis-3-hexen-1-ol, β-elemene, ethyl acetate and dimethyl sulphide increased their content more than 10 times compared with other volatiles. Moreover, differences in the initial flushed gas-mixture with or without CO₂ showed higher CO₂ concentrations and the development of stronger off-odours when samples were flushed with an enriched CO₂ gas-mixture. In summary, visual quality of fresh-cut iceberg lettuce is important but so are odour and flavour. MAP currently used for fresh-cut lettuce may need some modification to inhibit off-odours and achieve better aroma and flavour qualities for preserving “freshness” of the cut product. Screening for cultivars with low browning potential and fermentation, harvested at optimum maturity stage and with an adequate package design are recommended.     

数字化人体模型在车身逆向布置中的应用

以人体参数为依据建立的数字化人体模型能有效的描述人体的形态特性.本文在CATIA人机工程模块中,建立了人群文件,生成自定义的三维数字化人体模型。在此基础上建立了满足不同百分位需求的参数化人体模型。以某汽车为对象,根据SAE标准,综合考虑了踏板行程、汽车视野和上下肢舒适性等因素对驾驶员的影响,最终得到满足各种约束的驾驶员最佳舒适性H点区域。论文研究为针对不同地区人群特性对车型进行逆向开发和逆向布置提供了很好的参考。     

食品抗菌包装系统的研究与展

由于人们对食品安全、货架期延长、成本效益、环境问题和消费便利性要求的提高,食品包装技术也得到了充分的发展,为了提高包装的性能,满足人们的需求,活性包装技术便应运而生.食品抗菌包装技术是活性包装技术的一种, 它可以有效地抑制食品表面的微生物,延长食品的货架期,保证食品品质.本文主要论述了抗菌包装技术类型以及它们在食品中的应用,并对抗菌包装系统中无机抗菌剂、有机抗菌剂和天然抗菌剂作了概括.最后,本文对抗菌包装技术未来发展趋势作了描述.     

我国基于木质材料包装存在的问题及对策

根据木材包装的优良特性、应用前景和我国的发展现状，并与国外作了对比，找出了我国木质品包装的严重浪费和回收体系不足的根本原因。建议政府宏观调控，制定和完善包装企事业单位的生产、管理和消费等各项规章制度，建立科学合理的回收体系，并在全民树立环保意识和正确的消费观念，以保障经济、社会和生态三方面的可持续发展。