Dissimilarity scaling and INDSCAL analysis in the study of flavour differences between normal pHu and DFD beef

Overall dissimilarity measurement of paired stimuli followed by Individual Differences Scaling (INDSCAL) analysis was used to study flavour perception in a set of beef extracts. The experiment was designed to determine whether pH contributed to flavour difference between beef of “normal” ultimate pH (pHu5.8) and “dark-cutting” (DFD) beef (pHu6.2). Assessors distinguished the flavour of “normal” pHu and DFD beef both by a combination of pH and titratable acidity, and a second dimension independent of pH. The chemicals added to adjust pH independently of the original muscle composition contributed a third flavour dimension. Substantial assessor variation was observed in the relative weight given to the three flavour dimensions, and this is discussed in relation to the task of judging overall dissimilarity.     

双核二茂铁衍生物(DFD)分子结构对超细AP/DFD二元体系撞击感度的影响

从双核二茂铁衍生物(DFD)分子结构入手,分析了DFD与AP之间的反应特性,研究了DFD分子结构特性与超细AP/DFD二元体系撞击感度间的结构-性能关系。找到了用于分析DFD与AP之间反应特性的DFD分子特征参数。结果表明,双核二茂铁衍生物负电性二茂铁基的静电势、NH_4~+-DFD分子平均结合能与超细AP/DFD二元体系的撞击感度直接相关。由于DFD分子结构的差异,桥联基团为亚甲撑的DFD组和对称性分子结构的DFD组的两个参数与超细AP/DFD二元体系撞击感度的相关性不同。对于桥联基团为亚甲撑的DFD,分子中负电性二茂铁基的静电势越小,NH_4~+-DFD分子平均结合能越大,超细AP/DFD混合物的撞击感度越高;对于对称性DFD,负电性二茂铁基的静电势和NH_4~+-DFD分子的平均结合能越小,DFD分子的前线轨道能级越大,超细AP/DFD混合物的撞击感度越高。     

皮质醇激素和血液生化指标变化对猪肉劣质肉的指示作用

为寻找猪肉劣质肉的指示指标,比较了不同质量猪肉对应皮质醇激素和血液生化指标的变化。结果表明,劣质肉中白肌肉(PSE)对应生猪血糖浓度显著高于正常肉(RFN)(P<0.05),劣质肉中黑干肉(DFD)对应生猪皮质醇浓度显著高于RFN肉(P<0.05)。说明血糖可作为劣质肉中PSE肉的重要指示指标,当宰前血糖浓度达到(17.21±3.12)mol/L时,可能产PSE肉;皮质醇可作为劣质肉中DFD肉的重要指示指标,当宰前皮质醇浓度达到(512.70±49.9)nmol/L时,可能产生DFD肉。     

一种鲁棒的视频分割算法

无论是在图象识别，还是在基于MPEG－4的图象压缩编码等应用领域，视频对象分割取是其中一个很重要的技术环节，为了在静止背景的情况下，能很好地解决多目标分割的问题，同时能进行单目标的分割，提出了一种鲁棒性较好的视频分割算法，该算法通过对图象序列中每连续3 帧图象进行对称差分，首先检测出目标的运动范围，然后通过对差分结构进行聚类分析来确定该帧图象中视频对象的个数，接着再利用在二值差分图象上收缩的活动轮廓，把视频对象的轮廓精确地包围起来，即得到该帧分割结果；最后利用光流法来对视频对象进行投注跟踪，修正，另外还利用多个图象序列对该方法进行了试验，实验结果表明，在静止背景下，该算法无论是对运动的单目标，还是对运动的多目标，均能较好地从静止背景中分离出来，即能得到理想的分割结果，故具有一定的鲁棒性和实用性。     

Risk assessment of DFD meat due to pre-slaughter conditions in pigs

A polychotomous logistic regression model was used to identify and assess the risk factors for pork becoming dark, firm and dry meat (DFD). A total of 116 deliveries, comprising 3075 commercial pigs delivered from different farms to five commercial Spanish pig abattoirs were surveyed. The DFD condition was described as an ordinal response variable (normal, moderate and serious) based on measurements of pH₂₄ in the Semimembranosus muscle. The abattoir, the floor of the lorry, the season, the gender, and the stocking density during transportation influenced the risk of DFD, as well as on-farm fasting time, lairage time and estimated carcass lean content. No effect of the RYR1 gene in the risk of DFD was found. Abattoirs should be especially careful with females slaughtered in winter, where the risk of serious DFD is 4.6% higher than with males slaughtered in summer. The risk of DFD increased with high stocking density and lairage time, and with on-farm fasting times longer than 22 h. Our results revealed that lowering the stocking density from 0.37 to 0.50 m² per 100 kg pig during transport would increase the risk of DFD pork by 11%.     

Failure evaluation and the establishment of an improvement model for product data management introduced to enterprises

The efficient control of correct and consistent production information is becoming increasingly difficult due to keener global competition and shortening product life cycles. Total e-business is a solution to the urgent requirement for management and organization changes. Product data management (PDM) is an excellent strategy to introduce e-process and personnel reorganization. However, the performance of introducing the PDM system is usually unsatisfying, due to the impact upon personnel and the product flow. An approach of assessing personnel organization and process failure is proposed in this research in order to locate the factors and reasons that cause a failure for a critical decision reference of enterprises planning for the PDM structure and the product flow. A traditional enterprise that introduced the PDM system was taken as an example in this article to explain the application of the failure mode and effects analysis (FMEA) and quality function deployment (QFD) for an efficient introduction of the PDM system.     

软件需求定义语言NDRDL的设计

本文概述了软件需求定义语言ＮＤＲＤＬ的设计目标及设计原则，并讨论了一些语言基本成分，如数据流图，控制流图，实体关系图等的设计，文中采用个人帐目管理系统作为示例。     

Effect of ultimate pH and freezing on the biochemical properties of proteins in turkey breast meat

Biochemical and functional properties of proteins from turkey breast meat with different ultimate pH at 24 h post-mortem (pH₂₄) in fresh and frozen conditions have been studied. Meat with different pH₂₄ was referred to as low, normal and high pH meat. Low and normal pH meat showed similar properties indicating their similarity in the extent of protein denaturation. Total (193 mg/g) and sarcoplasmic (99 mg/g) protein solubilities were significantly (p < 0.0001) higher in high pH meat compared to those of low and normal pH meat, and hence expected to have better functional properties. Freezing caused denaturation and oxidation of proteins as revealed by a significant decrease in Ca²⁺-ATPase activity (p < 0.0001), total protein solubility (p < 0.0001), reactive (p < 0.05) and total sulphydryl groups (p < 0.0001) and an increase in the formation of carbonyl groups (p < 0.0001), which may have implications for functionality.     

远程供水监控系统设计

通过对供水系统的深入研究,提出了一种新型供水系统的整体设计方案。这种供水系统通过利用主机与远程测控端通信,实现对远程端的监测与控制,并利用计算机对测量数据与控制信号进行处理,从而实现对供水系统的监控。在进行测控的同时,对采集到的流量数据与已有的用户信息进行处理,为用户提供方便快捷地查询与交费。文章首先对这种供水系统的控制中心进行需求分析,决定采用C／S与B／S结合的方式设计控制中心,分析该系统的数据流,并对系统进行模式划分。     

PSE(白肌)、RFN(正常)、DFD(黑干)3种质量猪肉冷藏期间的肉色稳定性

比较了PSE(白肌)、RFN(正常)、DFD(黑干)3种质量猪肉冷藏期间的肉色稳定性。宰后24h直接切块取样的3种质量猪肉(背最长肌)于(2±1)℃下避光透氧包装[O2透过率=2.06×10-3mL/(m2.h.Pa)]冷藏6d,采用色度计法测定了样品表面L*(亮度)值、a*(红色度)值、b*(黄色度)值、hueangle(色调角)值。从上述指标的变化研究了3种质量猪肉表面的肉色稳定性。3种质量猪肉表面肉色稳定性顺序为:DFD>RFN>PSE;a*值下降、hueangle值上升可反映肉色稳定性变差。