大型钢制焊接双层低温储罐设计建造

介绍了大型钢制焊接双层低温储罐的结构形式、选材、建造、检验及保冷要求 ,结合所设计的低温液氨储罐 ,对设计建造这类储罐必须考虑的一些问题作了分析     

From IP to Start-up： Building a Robust Life Science Incubator

An incubator is an organization that supports new ventures to grow and survive during the early stages. Mainly dedicated to information technology, life science may appear to be the next hot spot for incubators. Are there stabilized good practices？ Are the business models in information technology and in life science comparable when it goes to start-ups＇ incubation？ Leveraging our experience as practitioner in this field and using an inductive methodology, this paper tends to propose simple principles to help build robust incubators in life science, and to contribute to disseminate an entrepreneurial approach through an industry still dominated by blue chips.     

冷冻凝聚工艺生产CR322的研制

对原电解质凝聚工艺生产CR322(混合调节型氯丁橡胶)进行了改进，实现了冷冻凝聚新工艺法生产切块CR322，即主乳化剂由松香皂／脂肪酸皂复合型代替了单一松香皂。新工艺解决了冷冻转鼓装置生产CR322过程中“黏杆”及干胶门尼黏度控制等问题。产品无焦烧粒子。且焦烧时间明显延长。     

考虑电池损耗的电动冷藏车路径及充电策略

电池充电造成的电池损耗对企业运营成本影响较大,以不同SOC区间内一次充电造成的电池容量衰退成本模型估计电池损耗成本,研究了车辆途中可多次进入充电站充电的路径优化问题,在考虑运输成本、制冷成本、货损成本、充电时间成本、惩罚成本的基础上,将电动冷藏车的电池损耗成本纳入总成本最小的目标函数,并建立了线性规划数学模型。采用增加粒子间共享信息类型的改进粒子群算法对该模型进行求解。将改进粒子群算法应用于构造的算例中,得到包括充电策略在内的车辆最优路径方案和最小运营成本,结果表明充电上限为80%的车辆路径方案可得到最低的运营成本,同时与标准粒子群算法求得的计算结果进行了比较分析,证明该改进粒子群算法在求解该问题上的可行性。     

食品减压冷冻保藏的理论与实验研究

在减压冷冻的环境中、通常用有限微分方程来模拟计算球体、无限大平板、无限长圆柱状食品中的非稳态的冷冻与传质过程。模拟计算涉及环境中水蒸气分压力、食品初始温度、水分子活性、食品表面及内部扩散力。食品中的含水量和温度变化可用这种方法预测、并又用实验验证了模型的准确性。     

基于人工神经网络的敞开立式冷藏陈列柜负荷预测研究

以陈列柜为研究对象,利用陈列柜进出口风幕参数计算确定出陈列柜的负荷.通过人工神经网络对敞开立式冷藏陈列柜负荷进行预测,结果显示预测值与计算值比较吻合.在运用中发现预测精度较高,具有实际的可行性和应用价值.     

Comparative studies of quality changes in white and dark muscles from common carp (Cyprinus carpio) during refrigerated (4 °C) storage

Differences between white and dark muscles from common carp (Cyprinus carpio) in sensory assessment, total viable counts (TVC), total volatile basic nitrogen (TVB‐N), pH, electrical conductivity (EC), biogenic amines (BAs), nucleotide degradation products and colours were investigated under air and vacuum conditions during refrigerated (4 °C) storage. Compared with white muscle, dark muscle had a higher lipid content, but lower crude protein and moisture content. TVC, TVB‐N, pH, and L* value were higher in white muscle, while K value and a* value were higher in dark muscle. Under both conditions, white and dark muscles had significant (P < 0.05) differences in tyramine and cadaverine content. Although dark muscle was significantly (P < 0.05) lower in ATP content, it had higher rate of IMP degradation and K value increase. Taking sensory and microbial indexes into consideration, dark muscle appeared to have a longer shelf life than white muscle under both conditions.     

The applied pretreatment (blanching,ascorbic acid) at the manufacture process affects the quality of nectarine purée processed by hydrostatic high pressure

A nectarine purée was manufactured with different pretreatments (thermal blanching or ascorbic acid – AA – addition), and then, the purée was processed by high‐pressure treatment to evaluate the effect of the initial manufacture conditions in the stability of the processed purées. A thermal treatment was also carried out to compare the effect with the high‐pressure processing (HPP). All applied processes were effective to ensure the microbiological safety of the purées. However, the pretreatment (thermal blanching or AA addition) applied during the manufacture affected the final quality of the processed purées. Initially, the AA addition had a protective effect on colour degradation during the manufacture of the purées; however, when these purées were treated by HPP showed less colour stability during storage, lower bioactive compounds content, and antioxidant activity. In contrast, purées with an initial thermal blanching maintained better the quality after HPP and during storage.     

Combined effect of antimicrobial edible coatings with reduction of initial microbial load on the shelf-life of fresh hake (Merluccius merluccius) medallions

Two distinct strategies were combined to preserve fresh fish (Merluccius merluccius) under refrigeration at 4 °C for 12 days: (i) the application of an antimicrobial edible coating enriched with oregano essential oil (OEO) or carvacrol (CV) and (ii) the reduction of initial microbial load by good handling practise and the use of sodium hypochlorite (NaOCl). The action of antimicrobial coatings alone retarded the growth of Enterobacteriaceae, lactic acid bacteria (LAB) and H₂S producing bacteria on fish samples. The reduction of initial microbial load by itself only affected the evolution of LAB, but not the rest of the bacterial groups. When using both techniques combined, edible antimicrobial coatings were significantly more effective with additional and significant delays in the growth of mesophilic, psychrotrophic and Pseudomonas bacteria. Thus, the use of both strategies combined resulted in a reduction of the counts of all bacterial groups after 12 days of storage which ranged from 1.5 log and 8 log, in Pseudomonas and H₂S producing bacteria, respectively. Moreover, no significant differences were observed when comparing the microbiological evolution of samples treated with OEO compared to those only treated with CV.