排序方式: 共有15条查询结果,搜索用时 31 毫秒
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EFFECTS OF MELT TEMPERATURES ON MICROSTRUCTURE AND MECHANICAL PROPERTIES OF RAPIDLY SOLIDIFIED Al-(14%-18%)Si RIBBONS 总被引:5,自引:0,他引:5
研究了提高熔体喷射温度和附加高温处理对快凝Al-Si合金条带微观组织结构,硬度及韧性的影响,分析了因不同处理温度而引起的熔体结构变化对快凝微观组织的影响规律的冶金物理本质。 相似文献
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本文以水溶液脱酸后的整本图书为对象,选取真空冷冻干燥法对脱酸后的整本图书进行干燥实验,研究了预冻方式对图书冷冻干燥过程和干燥品质的影响,分别采用液氮预冻和慢速预冻两种预冻方式对图书进行真空冷冻干燥,并比较分析了图书干燥过程和干燥后纸张白度、色差、抗张强度、撕裂度、耐折度及外观等指标。结果表明:慢速预冻可以减短图书冷冻干燥所需要的干燥时间,提高干燥效率;在图书纸张机械性能保持方面,慢速预冻效果更佳;在图书光学性能和外观保持方面,液氮预冻效果更优;从经济性及图书的长久保存方面考虑,推荐采用慢速预冻。 相似文献
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计算流体力学技术在食品冷藏链中的应用 总被引:1,自引:1,他引:0
目的综述国内外计算力体力学(CFD)在食品冷藏链中的应用现状。方法分类讨论CFD在食品冷藏链中预冷、冷冻、冷藏、冷藏运输4个环节中的应用。结果归纳总结了CFD在食品冷链设备中的应用研究与进展,并指出了今后的发展方向。结论 CFD数值模拟技术在食品冷藏链中得到了广泛的应用,通过CFD数值模拟技术对冷链设备中的流场进行模拟分析,对冷链设备的优化与降低设备能耗具有重要意义。 相似文献
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Jui-Yang Lai 《International journal of molecular sciences》2015,16(8):18796-18811
The development of porous hyaluronic acid (HA) hydrogels for corneal endothelial tissue engineering is attractive because they can be used as functional cell delivery carriers to help in the reconstruction of damaged areas. The purpose of this study was to investigate the corneal endothelial cytocompatibility and cell delivery performance of porous HA hydrogel biomaterials fabricated at different pre-freezing temperatures. As compared to their counterparts prepared at −80 °C, the HA samples fabricated at higher pre-freezing temperature (i.e., 0 °C) exhibited a larger pore size and higher porosity, thereby leading to lower resistance to glucose permeation. Live/dead assays and gene expression analyses showed that the restricted porous structure of HA carriers decreases the viability and ionic pump function of cultured corneal endothelial cells (CECs). The results also indicated that the porous hydrogel biomaterials fabricated at high pre-freezing temperature seem to be more compatible with rabbit CECs. In an animal model of corneal endothelial dysfunction, the wounded rabbit corneas receiving bioengineered CEC sheets and restricted porous-structured HA carriers demonstrated poor tissue reconstruction. The therapeutic efficacy of cell sheet transplants can be improved by using carrier materials prepared at high pre-freezing temperature. Our findings suggest that the cryogenic operation temperature-mediated pore microstructure of HA carriers plays an important role in corneal endothelial cytocompatibility and cell delivery performance. 相似文献
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The effects of on-board handling and freezing on the quality of meats from the sea scallop, Placopecten magellanicus , in the Atlantic Canadian fishery were investigated. The results show that meats frozen within 6 h of catching, pre-rigor, were markedly superior to meats frozen after storage in ice for up to 10 days, with lower drip loss, more tender texture, less flavour loss and higher overall acceptability.
Inferior results were obtained without pre-chilling of the meats before storage in cotton bags in melting ice and with live holding for 3 days followed by freezing and storage at minus 30°C for up to 6 months. Days in ice before freezing, however, exerted by far the greatest influence on quality.
According to these results, freezing on board warrants consideration on grounds of superior quality including increased yield of cooked product. 相似文献
Inferior results were obtained without pre-chilling of the meats before storage in cotton bags in melting ice and with live holding for 3 days followed by freezing and storage at minus 30°C for up to 6 months. Days in ice before freezing, however, exerted by far the greatest influence on quality.
According to these results, freezing on board warrants consideration on grounds of superior quality including increased yield of cooked product. 相似文献
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熔体温度对快凝Al-Si过共晶合金条带微观组织及性能的影响 总被引:3,自引:0,他引:3
研究了提高熔体喷射温度和附加高温(1200℃)处理对快凝Al-(14%-18%)Si合金条带微观组织结构、硬度及韧性的影响,分析了因不同处理温度而引起的熔体结构变化对快凝微观组织的影响规律的冶金物理本质,实验发现,快凝熔体喷射温度的提高或在熔体喷射前附加高温(如1200℃)或恒温均匀化处理,有利于合金微观组织均匀化和细化,有利于快凝条带综合机械性能的优化. 相似文献
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