线性规划法在钢筋下料中的应用

应用线性规划法描述钢筋下料中的约束条件,目标函数,设计相应的优化下料方法,提高原材料的利用率。     

大体积混凝土施工体会

通过两个工程大体积混凝土施工情况,从大体积混凝土的原材料选择、配合比设计及施工检测等方面对大体积混凝土的防裂提出预控措施,并取得了良好的效果.     

林林总总的深加工玻璃(连载三)

对林林总总的深加工玻璃进行了分类,并对其加工技术、产品性能特点进行了比较全面的介绍.     

论化工行业易制毒化学品

在分析我省易制毒化学品生产及管理工作的特点与难点后,提出若干改进工作的建议,可为我省禁毒工作者提供参考。     

Browning susceptibility of minimally processed Baby and Romaine lettuces

 This study was conducted to determine the effects of cultivar, tissue susceptibility and storage temperature on the keeping quality of minimally processed Baby and Romaine lettuces. Midrib and photosynthetic tissues were lightly processed and stored for up to 7 days at 5  °C and 13  °C. Changes in L ^* and a ^* values and absorbance at 430 nm were compared. The relationship between polyphenols, phenylalanine ammonia lyase (PAL) and polyphenol oxidase (PPO) activities and browning was examined. Measurements of L ^* and a ^* values on midribs showed that browning discoloration was the same for Baby as for Romaine lettuces and there was no relationship for temperature. In addition, L ^* and a ^* values in photosynthetic tissue indicated a decrease in green pigmentation during storage, especially at 13  °C. For both kinds of tissue at the end of cold storage an increase in soluble brown polymers was detected. In midribs, total phenolics increased significantly throughout the storage period because of the tissue-wounding response. The photosynthetic tissue had a higher phenolic content than the midrib one. For both kinds of tissue an increase in PPO activity occurred throughout cold storage. On the other hand, PAL activity in midrib tissue only increased initially, followed by a slow decline to reach normal levels. Browning potential estimated by L ^* values correlated significantly (P>95%) with PPO activity and with absorbance at 430 nm for Romaine lettuce. Based on colour and browning potential no differences between Romaine and Baby lettuce cultivars were observed. However, photosynthetic tissue was the most suitable tissue for the preparation of minimally processed salad mixes because of its high phenolic content. Received: 28 September 1998     

SN/T 2980-2011在动物源性成分检测中的适用性分析

目的 探讨行业标准SN/T 2980-2011《动物产品中牛、山羊和绵羊源性成分三重实时荧光PCR检测方法》在动物源性成分检测中的适用性。方法 基于中华人民共和国出入境检验检疫行业标准SN/T 2980-2011和国家标准GB/T 25165-2010《明胶中牛、羊、猪源性成分的定性检测方法实时荧光PCR法》对鲜肉组织及加工肉制品进行动物源性成分检测实验, 建立依托上述标准的动物源性成分检测能力。结果 SN/T 2980-2011中牛源性成分检测特异性不佳, 山羊源性成分检测特异性良好, 绵羊探针仅适用于单通道实时荧光PCR检测; GB/T 25165-2010中的牛、羊源性成分检测均展示出良好的特异性。结论 建议SN/T 2980-2011行业标准的起草单位及起草人重新设计适用于三重实时荧光PCR的牛、绵羊引物及探针,既要保证引物和探针的特异性也要保证适用性。     

高效液相色谱法测定高温加工食品中丙烯酰胺

目的 建立一种快速、简便、可靠的液相色谱法测定高温加工食品中丙烯酰胺含量的分析方法。方法 样品粉碎后经超纯水提取、正己烷脱脂、C18固相萃取柱萃取、流动相洗脱后得到样品净化液,经液相色谱仪,以乙腈-水(体积比2:98)作为流动相,流速为0.8mL/min,测定波长205nm,柱温20℃的色谱条件测定,外标法定量。结果 在该条件下,丙烯酰胺在0.1μg/mL-2.0μg/mL内具有良好的线性关系(R²=0.9987),检出限14μg/kg,定量限40μg/kg,加标回收率在91.5%~95.0%之间,1.0μg/mL丙烯酰胺标准溶液重复6次进样的相对标准偏差为(RSD)为0.16%。结论 液相色谱法可以准确、快速测定高温加工食品中的丙烯酰胺含量。     

Comminuted meat products—consumption,composition, and approaches to healthier formulations

Comminuted meat products are significant contributors to consumer fat and salt intakes, which are currently above World Health Organization recommended levels. Reducing fat and salt in comminuted meat products may therefore have a significant positive effect on public health in countries with a high consumption of these meats. As an example, the processed meat intake and the fat and salt levels of various comminuted meat products in Ireland and the UK are presented. The review focuses on substitution of fat and salt (including nitrite) with ingredients that yield products with acceptable organoleptic properties and have proven human health benefits.