鲜食葡萄电商悬固包装薄膜的力学性能分析与优化设计研究

目的 针对电商物流包装存在操作繁琐、透气透湿不足、寄递中暴力分拣的问题以及葡萄易落粒损伤的特点,设计一种针对鲜食葡萄的透气透湿性适宜的简便化包装。方法 采用激光打孔调整TPU薄膜透气透湿性,通过力学性能测试选出适宜厚度与孔隙排列方式,根据跌落试验确认TPU薄膜包裹葡萄的最佳凹陷程度,并验证悬固包装的有效性。结果 厚度为0.08 mm、孔隙排列方式为Z形的TPU薄膜有优良的力学性能与透气透湿性,打孔后薄膜水蒸气透过率极显著提高(P<0.01),并且0.08 mm的Z形TPU薄膜凹陷3 cm的悬固包装在610 mm的高度跌落不触底,对葡萄的保护效果良好。纸浆模塑盒可承受400 N以上的力,循环压缩20次后仍有很好的支撑性,通过跌落测试可得悬固包装葡萄的表面损伤指数比袋中袋更小。结论 综合来看,该悬固包装操作方便,打孔后透气透湿性显著提高,与包装箱匹配使用能满足堆码与运输要求,是一种符合包装运输要求的鲜食葡萄电商包装方式,本研究为果蔬类产品的电商包装结构设计提供了新思路。     

The range of pro‐ecological activities concerning packaging in Poland against the background of the European Union (EU)

The aim of this work was to present the legal status relating to fundamental issues of packaging ecology. Next, the fundamental requirements established for packaging from the point of view of environmental protection are analysed. For this reason requirements related to the manufacture of packaging and its raw material composition, to returnable packaging, suitability for various forms of processing, marking of packaging and the content of heavy metals in packaging are presented. These requirements may significantly influence the manufacturing technologies of packaging materials and packaging, as well as the packaging systems applied. It should be remembered that manufacturers and users of packaging are responsible for the quantity and types of packaging introduced to the market. The amount and the nature of waste depend on them. These links are of major influence on the final form of packaging as well as on creating and shaping consumer habits, which are not always justified in terms of ecological requirements established for packaging. Copyright © 2001 John Wiley & Sons, Ltd.     

电商包装方式对水蜜桃运输缓冲防震及货架品质的影响

目的 研究常规电商包装中不同缓冲材料和包装量对水蜜桃在跌落、随机振动条件下的损伤防护及货架品质的影响。方法 以“华玉”水蜜桃为试材,分别采用瓦楞纸隔板+单盒包装、聚乙烯发泡棉(EPE)内衬+单盒包装、瓦楞纸隔板+两盒包装及EPE内衬+两盒包装等4种形式包装后,依据ISTA 3A标准开展模拟公路运输实验,分析水蜜桃货架期品质变化。结果 瓦楞纸隔板+两盒包装在面跌落时的加速度仅为90.306 m/s²,缓冲性能比单盒包装更好,但其在随机振动中响应较大,而EPE内衬+单盒包装处理受随机振动影响最小,一阶共振响应和二阶共振响应分别为0.012 2 g²/Hz和0.014 3 g²/Hz。模拟运输后在常温货架条件下,瓦楞纸隔板+两盒包装的水蜜桃在货架期内始终保持较低的呼吸强度和乙烯释放量,维持较好的外观品质。相较于单盒包装,两盒包装对维持水蜜桃质地、可溶性固形物、总酸含量及外观品质具有积极作用。结论 综合来看,以瓦楞纸隔板为缓冲材料,两盒包装更有利于水蜜桃电商物流运输中的震动防护,并能较好地保持货架品质,为适宜水蜜桃的电商物流包装...     

New Observations on a Geological Hotspot Track: Excursions in Madeira and Porto Santo (1825) by Mrs T. Edward Bowdich

This paper works with the modern concept of the geological hotspot track – the building processes and movements of volcanic island chains – applied strategically to one of its illustrative formations, the Madeira Archipelago. By analogy, however, the concept works equally well to describe the important early 19th‐century scientific knowledge‐building activity that produced Charles Lyell's On the Geology of Some Parts of Madeira (1854). A central section of the paper uncovers the contributions to knowledge of this geology before Lyell's, and in particular, Excursions of Madeira and Porto Santo (1825) by Mr [sic] T. Edward Bowdich. A thorough examination of this text then constitutes an important case study for literal and figurative investigation of geological hotspot tracks. The main argument proposed is that current specialist research forgets its submerged and longer histories to its detriment. Insights contained in older information often supply reminders of the key questions and contributions from the past that provide checks and balances for further developments of a field. By promoting multi‐level, multi‐stranded and multi‐lingual investigation of the history of 19th‐century geology in Madeira before Lyell ( 1854 ) as central to hotspot track research, this paper marks nodal conditions that constitute advancement in critical knowledge‐building within and outside the discipline of geology.     

Effects of Packaging and Preservation Treatments on the Shelf Life of Murtilla Fruit (Ugni molinae Turcz) in Cold Storage

Murtilla (Ugni molinae Turcz) fruit has a unique aroma; along with its pleasant sweet flavour, this has stimulated its commercial development in international markets. This development, however, requires the application of suitable conservation methods. Five different packaging treatments for murtilla fruit (Red Pearl‐INIA variety) conservation were evaluated at 0 °C for 60 days. The treatments consisted of two types of packaging [polyethylene terephthalate (PET) punnets and low‐density polyethylene (LDPE) bags] and the application of an edible coating of carboxymethyl cellulose to the fruits. The incorporation of the aqueous extracts of murtilla leaves from the 18‐1 and 27‐1 ecotypes into the carboxymethyl cellulose edible coating was also evaluated for its antimicrobial effects. There was a significant (p < 0.05) reduction in the moisture content, a significant weight loss and an increase in soluble solids when the murtilla fruit was packed only in a PET punnet. However, with the other four treatments, in which an LDPE bag and edible coating were used, the moisture content (76.8–74.4 g/100 g) and soluble solids (15.6–17.8 ºBrix) in the fruit remained stable during storage. Low weight loss (1.64–2.25%) occurred in the fruits that received treatments with the LDPE bag and edible coating. Under experimental conditions and from operational facilities, packaging in PET punnets with an LDPE bag was the best alternative to preserve the murtilla fruit at 0 °C for 60 days. Copyright © 2013 John Wiley & Sons, Ltd.     

Effects of cushioning materials on the firmness of Huanghua pears (Pyrus pyrifolia Nakai cv. Huanghua) during distribution and storage

The type and quality of cushioning materials could significantly affect the vibration intensity and physical quality of fruits during transport. In the current paper, we evaluated the different cushioning materials (paper‐wrap materials, foam‐net packages) for their protective effect on the vibration levels, number of bruises and mechanical damage to Huanghua pears (Pyrus pyrifolia Nakai cv. Huanghua) during transport. Changes in pear firmness, hydrolase activity and cell wall constituents were examined in fruits stored for up to 36 days after transport. Our data suggested that the choice of cushioning material significantly reduced the vibration intensity in transit, affecting the physical quality of fruits and their subsequent commercialization, and that foam‐net packages provided a greater protective effect than paper‐wrap packages. Copyright © 2007 John Wiley & Sons, Ltd.     

Effects of substitution of X (X=rhenium,chromium and zirconium) on the properties of Co7Mo6 μ phase: A first‐principles study

The effects of three typical refractory elements (rhenium, chromium and zirconium) substituting the molybdenum atom in Co₇Mo₆ μ phase were investigated using first‐principles calculations based on the density functional theory (DFT). Energy (including binding energy and defect energy) and electronic structures (including density of states and charge density) of Co₇Mo₅X (X=rhenium, chromium and zirconium) were calculated. The optimized lattice structure of Co₇Mo₆ agrees well with the experimental data. The calculated results show the bonding between doped rhenium atom and its nearest neighbor molybdenum and cobalt atoms gets visibly stronger, contributing to the good stability of the unit cell. Neverthless, the bonding between chromium and its nearest neighbor molybdenum and cobalt is weaker, and the zirconium‐molybdenum and zirconium‐cobalt bonds are much weaker. The results reveal rhenium tends to participate in the formation of μ phase, but zirconium and chromium atoms are not prone to concentrate in μ phase.     

热处理对(Fe_(0.52)Co_(0.30)Ni_(0.18))_(73)Cr_(17)Zr_(10)非晶合金的组织结构及磁性能的影响

采用单辊急冷法制备(Fe_(0.52)Co_(0.30)Ni_(0.18))_(73)Cr_(17)Zr_(10)非晶薄带,并对该合金进行等温退火。采用XRD,AFM,VSM研究退火温度对(Fe_(0.52)Co_(0.30)Ni_(0.18))_(73)Cr_(17)Zr_(10)非晶合金的组织结构和磁性能的影响。结果表明:非晶合金晶化过程为Am→α-Fe(Co)+Am′→α-Fe(Co)+Cr_2Ni_3+Fe_3Ni_2+Cr_2Zr+未知相。当退火温度Ti玻璃转变温度Tg时,由于结构弛豫、内应力的释放,合金的饱和磁化强度Ms有所提高;当晶化起始温度TxTi第一晶化峰值温度Tp1时,由于铁磁性α-Fe(Co)相的析出,Ms显著提升;当TiTp1时,由于晶粒长大和第二相的析出,Ms急剧恶化,565℃退火能够获得最好磁性能(Ms=106.8A·m~2·kg~(-1))。490℃和565℃退火后薄带表面的AFM观察表明,AFM图片所呈现的颗粒尺寸要比用Scherrer法测得的α-Fe(Co)纳米晶尺寸大得多,这是典型的包裹晶粒现象。