假捻器轴承优化设计分析

为了进一步提高HT825型假捻器轴承的综合机械性能,对其轴承的沟曲率半径、外圈沟心距、圆度、钢球等级、径向游隙参数进行优化设计,并从球轴承沟曲率半径系数、轴承游隙、接触角、原始偏转角、实际接触长度、径向基本额定动载荷、径向额定静载荷、当量动载荷和寿命等方面对HT825型轴承的设计参数进行计算,并对计算结果参照常用参数值进行分析验证。结果表明,优化后的假捻器轴承对提高转速有利,可提高轴承支承轴刚性,满足寿命及使用要求。     

Effects of storage in slurry ice on the microbial,chemical and sensory quality and on the shelf life of farmed turbot (Psetta maxima)

The application of slurry ice, a binary mixture of small spherical ice crystals surrounded by seawater at subzero temperature, is a potentially new preservation method for farmed turbot (Psetta maxima), a flat fish species of increasing commercial interest. Comparative biochemical, microbiological and sensory analyses were carried on turbot specimens stored in either slurry ice or flake ice for up to 40 days. The results obtained in the sensory analysis correlated well with the observed chemical and microbial changes. Storage of turbot in slurry ice resulted in a slowing-down of the nucleotide degradation pathway and lipid oxidation mechanisms. A good stabilisation of the high molecular weight protein fraction of turbot muscle was also achieved as a consequence of storage in slurry ice. A slower production of both trimethylamine and total volatile bases was also observed. Likewise, low levels of total aerobes, anaerobes, coliforms, and proteolytic bacteria were attained. The application of slurry ice to farmed turbot is advisable to achieve better quality maintenance during storage and distribution.     

钩毛搭扣带的物性指标、产品标准和应用

在对钩毛搭扣带的物性指标和产品标准进行探讨和分析的基础上,指出试图制定一套适合所有行业和用途的钩毛搭扣带的统一或所谓权威的产品标准是不合逻辑的,也不具实际意义。随着科技的发展,钩毛搭扣带的产品系列和应用也在不断发展。在选择钩毛搭扣带产品时,用户应根据实际应用的需要选择合适的钩毛搭扣带产品组合,并确定合理的物性指标和相应的产品标准,这样能够取得事半功倍的效果。     

制绳钢丝力学性能与钢丝绳疲劳寿命的关系

在实验的基础上,分析制绳钢丝力学性能与钢丝绳疲劳寿命之间的关系,指出在炉温920℃,铅温540℃的热处理工艺条件下,通过总压缩率为96/%的拉拔工艺,可使制绳钢丝获得良好的力学性能,从而使钢丝绳疲劳寿命进一步提高。     

一种新型水刺喷水板

从水刺喷水板的工作原理入手分析了影响水刺喷水板使用寿命的原因,介绍了一种新型结构的水刺用喷水板,试验表明新型水刺喷水板具有明显的寿命优势。     

古籍装具用纸板的安全性分析

纸板是制作古籍装具的重要材料,其质量决定了装具的安全性。满足文物保护要求的纸板能够对古籍起到保护作用,延长藏品保存寿命。考察了14个纸板样品的安全性,结果表明:大部分纸板的p H值和碱储量可以达到国家标准的要求,而卡伯值是目前制约纸板质量的主要因素。     

港口装卸用钢丝绳的设计与使用

非金属夹杂物的大小、形态和分布状况对钢丝和钢丝绳的疲劳寿命影响很大,提出提高钢丝绳使用寿命的有效措施。港口装卸用钢丝绳具有特殊工作状况:冲击载荷大;承受的应力幅很大;钢丝绳的上下层之间受到非常大的侧向和正向挤压力作用。针对这些情况,港口装卸用钢丝绳结构一般应选择:外层股为6股或8股的钢丝绳;压实股钢丝绳;金属绳芯钢丝绳。在结构设计中应充分考虑钢丝绳股中钢丝之间的间隙、股与股之间的间隙,以及股中心钢丝、钢丝绳芯直径的加大量。在选择和使用港口装卸用钢丝绳时,应按卷筒的大小选择钢丝绳直径,按钢丝绳在卷筒上缠绕方向决定钢丝绳的捻向,并注意钢丝绳所能承受的载荷。     

一种新型软包装米饭罐头工艺研究

传统的软包装米饭罐头通常采用真空封口、高温灭菌技术,产品往往容易板结成块,接受性不好。我们通过应用含气调理杀菌技术,力图能解决这一问题。在对大米浸泡、蒸煮、充氮封口、杀菌强度等工序研究的基础上,提出一条生产软包装米罐头的新工艺,并设计加速贮存试验,分析按新工艺生产的软包装米饭罐头的保存期,试验结果表明,其贮存期可以达到两年以上。     

Determination of shelf life of concentrated yogurt (labneh) produced by in-bag straining of set yogurt using hazard analysis

Strained yogurt, labneh, produced by straining cow's milk set yogurt in cloth bags, was stored at 5, 15, and 25 degrees C, and changes in microbial counts, pH, titratable acidity, percentage of free whey, and sensory attributes were monitored during storage. Counts of total aerobes, psychrotrophic yeasts, yeasts and molds, and lactic acid bacteria, except in samples stored at 25 degrees C, increased irrespective of storage temperature. The pH of samples decreased, titratable acidity and percentage of free whey increased, and texture defects were detected at a later stage than flavor changes during storage. Shelf-life data of labneh was adequately described by the Weibull distribution. The nominal shelf life determined using sensory changes and yeast counts as failure criteria ranged from 8.5 to 10.5, 4.7 to 5.8 and 2.3 to 2.7 d at 5, 15 and 25 degrees C, respectively. Q10 (shelf life at T degrees C/shelf life at T+10 degrees C) for flavor quality loss was 1.98 at 5 degrees C, and the corresponding activation energy was 11.3 kcal/mol.     

高速纸机上靴套的安装与使用

靴套是靴式压榨的易损件。正确安装和使用对提高纸机效率、降低生产成本十分重要。齐齐哈尔造纸有限公司引进的芬兰Metso集团OptiConcept纸机上配有靴式压榨。本文介绍了靴套的安装和使用经验，提出了常见问题的产生原因和解决办法。