基于Cortex-M4内核的μCOS-Ⅱ移植

针对TI公司新推出的基于Cortex-M4内核的TM4C123G高性能低功耗芯片,详细介绍了嵌入式开源实时操作系统μCOS-Ⅱ在芯片上的移植方法。根据移植的需求,首先介绍了芯片的一些基本功能以及相关的软件开发环境,然后结合芯片的固有特性以及μCOS-Ⅱ移植的需求,使用C语言和汇编语言修改了相关的源文件,并详细阐述了修改的原因。     

基于ARM9内核的智能灌溉控制系统的设计

介绍了基于ARM920T内核的嵌入式控制系统的设计与实施,并将控制系统引入设施栽培自动灌溉控制中。实践证明,该系统的设计达到了预期的效果。     

Effects of particle size on the quality attributes of reconstituted whole-wheat flour and tortillas made from it

The objective of this study was to examine the effects of whole-wheat flour (WWF) particle size on the quality attributes of WWF tortillas. WWF samples of different particle size distributions from commercial U.S. hard white (median diameters: 175.7, 128.6, 120.0, 108.5 and 102.4 μm), hard red winter (median diameters: 173.7, 133.6, 124.3, 110.8 and 104.2 μm) and hard red spring (median diameters: 173.7, 132.1, 124.7, 112.9, 106.3 μm) wheat classes were obtained by fine grinding of bran and shorts and re-combining with the rest of fractions. For all three wheat classes, as WWF median particle size decreased, the L* (lightness) value decreased but the adjusted damaged starch, polyphenol oxidase activity, and a* and b* values increased. Mixolab data showed that development time decreased as WWF particle size was reduced, while stability time and starch retrogradation increased. As for WWF tortilla quality, the breaking force and extensibility increased with decreasing particle size from ∼175 to 129–134 μm, but diameter and thickness were not significantly affected. The results indicated that reducing the median particle sizes of WWFs from ∼175 μm to ∼130 μm would significantly improve the WWF tortilla quality.     

砷胁迫下磷对三七砷的微区及亚细胞组织分布特征的影响

通过同步辐射X射线荧光分析(μ-SRXRF)和亚细胞组分分离技术相结合,从植株各部位微区及亚细胞组分层面揭示了药用植物三七在外源磷素作用下砷吸收累积的分布特征。结果表明:三七的根部和茎部是砷的主要富集部位,添加外源磷素可以有效降低三七根部、茎部和叶片的砷含量,降低幅度分别为47%、80%和33%;三七各部位的亚细胞组分砷的累积量不同,其中细胞液是砷的主要富集组分,具有一定的区隔化作用,但不能有效地减少砷对植物细胞新陈代谢的影响和毒害;外源磷素的加入可以显著降低三七不同部位亚细胞各组分中砷的累积量,其降低幅度由高到低依次为细胞液细胞壁细胞器,但分析表明,外源磷素的添加对三七各部位的亚细胞组分砷累积量占植株总砷累积量比例的影响不大。     

基于μC/OS-Ⅱ系统的无线手持数据监控系统的设计

针对传统温室数据监控系统费用高、传感器布线复杂、部署不灵活、功耗大等特点,设计了一套基于μC/OS-Ⅱ系统的手持嵌入式监控系统。系统以STM3 2 F1 0 3 ZET6为核心控制器件,移植了具有多任务、实时性特点的嵌入式操作系统μC/OS-Ⅱ,并添加了与Windows操作界面类似的图形界面软件μC/GUI,方便用户操作。系统使用了遵从Zig Bee协议的Z-Stack协议栈,实现数据无线传输。实验表明:该系统完全适用于农业温室大棚等高湿环境,且无线通信功能安全可靠。     

野猪、家猪及野家杂种猪CAPN1基因3′UTR区的SNPs检测及PCR-RFLP分析

μ-钙蛋白酶(μ-calpain,CAPN1)是动物体内肌原纤维蛋白降解的主要酶,为了揭示其基因变异与瘦肉率和嫩度的关系,文章以野猪、家猪及野家杂种猪为研究对象,通过测序和PCR-RFLP方法对CAPN1基因3′UTR进行了SNPs检测和多态性分析。结果表明,共发现7个SNPs,分别是C114T,G220C,C344T,T380C,G501A,T543C,T610C;对G220C/T380C两处突变建立了基于限制性内切酶HinfⅠ/AlwNⅠ的PCR-RFLP检测技术;群体遗传学分析表明,在这两个位点不同基因型在不同品种(品系)猪中的分布都存在着极显著的差异(P<0.01),野猪和民猪之间的差异都不显著(P>0.05),并且HinfⅠ位点的B等位基因频率具有随着品种瘦肉率的增加而增多的趋势。该结果为寻找高瘦肉率的分子标记提供了基础。     

宰前短期添加天冬氨酸镁和维生素D_3对育肥猪肉品质及μ-Calpain与Calpastatin基因表达的影响

试验考察宰前添加天冬氨酸镁(MgAsp)与维生素D3(VD3)对试猪血液理化指标、猪肉品质以及μ-Calpain和Calpastatin基因mRNA含量的影响。选体重约90 kg DLY杂交猪48头,随机分到4个处理:对照、加MgAsp、加VD3和加MgAsp与VD3。试验期为9 d,试验结束后选取24头进行屠宰。结果表明:宰前短期添加MgAsp和VD3对育肥猪胴体品质无影响;与对照相比,添加MgAsp提高血清镁含量(P<0.05),添加VD3提高血清磷(P<0.05)和钙的含量,MgAsp和VD3联合添加可进一步提高血清镁含量(P<0.01);添加MgAsp降低臀肌L值(P<0.01),并有提高肌肉pH值和降低滴水损失的趋势,提高了μ-Calpain与Calpastatin mRNA的比值,改善了嫩度;添加VD3降低了臀肌的L24h值(P<0.05),有提高pH和嫩度的趋势;MgAsp和VD3联合添加除对剪切力略有改善而外,对其他肉质指标并没有进一步改善。     

基于μC/OS-II税控收款机的VFD模块编程设计

为了实现VFD的全部点亮及实时时钟的显示,设计了一个基于微控制器LPC2294和嵌入式操作系统μC/OS-II的VFD模块显示工程,对其文件构架和主要的工程函数进行了详细分析,利用ADS开发软件,在CodeWarrior IDE集成开发环境下编写编译链接,然后使用TechorICE ARM仿真器调试并下载程序,同时提供了VFD模块的接口函数.     

刺槐素对禽源性大肠杆菌的抑菌作用及耐药性消除的研究

该试验研究刺槐素对鸡源性大肠杆菌的抑菌作用和耐药性消除效果。采用药敏纸片判断刺槐素的抑菌效果,对比前后2次MIC的浓度大小判断刺槐素对大肠杆菌的耐药性消除效果。结果:刺槐素抑菌效果:大肠杆菌①的MIC为32μg/mL,大肠杆菌②的MIC为128μg/mL,大肠杆菌③的MIC为64μg/mL,大肠杆菌④的MIC为16μg/mL,大肠杆菌⑤的MIC为32μg/mL。耐药性消除试验结果:大肠杆菌①的MIC由1024μg/mL下降为128μg/mL,大肠杆菌②的MIC由512μg/mL下降为64μg/mL,大肠杆菌③的MIC由2048μg/mL下降为128μg/mL,大肠杆菌④的MIC由256μg/mL下降为32μg/mL,大肠杆菌⑤的MIC由512μg/mL下降为64μg/mL。结论:刺槐素对鸡源性大肠杆菌具有抑制作用,对头孢耐药性有消除作用。     

Phosphorylation of sarcoplasmic and myofibrillar proteins in three ovine muscles during postmortem ageing

This study aimed to examine changes in phosphorylation of sarcoplasmic and myofibrillar proteins from longissimus lumborum, semitendinosus, and psoas major muscles during postmortem ageing for 5 d. These sarcoplasmic and myofibrillar proteins were separated using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and stained with phosphorous and protein specific stains. Myofibril fragmentation index, pH, the content of lactic acid and the relative activity of μ-calpain in three ovine muscles were measured. These results showed that the relative phosphorylation level of sarcoplasmic and myofibrillar proteins of psoas major muscle were lower compared with longissimus lumborum and semitendinosus muscles (P<0.05). The pH of psoas major muscle was the lowest at 0.5 h postmortem, and the highest after 12 h postmortem (P<0.05). In addition, the relative activity of μ-calpain was higher within 5 d postmortem and myofibril fragmentation index was higher after 1 d postmortem in psoas major muscle than those of longissimus lumborum and semitendinosus muscles (P<0.05). The sarcoplasmic protein phosphorylation may regulate the rate of pH decline to influence the μ-calpain activity and then proteolysis of proteins consequently. This study gives a new perspective of the mechanism of postmortem meat tenderization.