交叉引物等温扩增检测猪肉源性成分

肉制品掺假现象已成为我国食品行业重点关注的问题。本研究使用交叉引物恒温扩增技术(Cross priming amplification,CPA)和核酸试纸条检测相结合的方法快速检测肉制品中猪肉成分。对猪线粒体的D-loop基因序列设计特异性的引物和探针,通过优化引物浓度及反应条件,确立最佳反应体系。实验结果表明,CPA扩增系统对猪源性成分的检测特异性良好,对单猪源性成分的检出限为1 ng/μL,对混合肉制品中猪源性成分的检出比例为10%(相当于10 ng/μL)。同时核酸试纸条可以快速检测CPA扩增产物,结果与凝胶电泳系统检测保持一致。本研究建立的CPA-核酸试纸条检测方法是一种特异、高效的肉制品中猪肉成分检测方法,可以为肉制品质量控制提供有效的新手段。     

碳酸钙热分解进展

CaCO₃热分解产生CaO与CO₂的反应,是钙循环过程中CaCO₃再生的重要反应。钙循环过程在烟气脱碳、反应吸附强化甲烷蒸气重整制氢以及太阳热能储存等过程中都有重要应用。评价CaCO₃热分解的重要性能是分解温度和分解速率。本文从CaCO₃分解机理、热力学和反应动力学方面,分析了颗粒粒径、结构和组成以及加热速率、分解气氛和分解压力等变量对CaCO₃分解温度和分解速率的影响,为工业应用时降低CaCO₃分解温度、提高分解速率、减少分解能耗的研究提供了参考。     

单增李斯特菌与志贺氏菌多重PCR检测技术的建立

目的:为食品、卫生行业提供一种简便、灵敏、快速,并且特异性强的单增李斯特菌(Listeria Monocyto-genes)与志贺氏菌(Shigella)多重PCR检测方法.方法:根据单增李斯特茵转录调节子基因prfA、志贺氏茵侵袭性质粒抗原H基因ipaH筛选出引物;优化多重PCR的引物浓度、退火温度及Mg2+等条件,分析单-PCR及多重PCR的特异性、灵敏度;结合24 h增茵培养.确定多重PCR检测人工污染脱脂灭茵乳的检出限.结果:多重PCR扩增出了预计的PCR产物,即单增李斯特茵(274bp)和志贺氏茵(421bp).该方法的灵敏度:78 pg单增李斯特茵基因组DNA、7.5pg志贺氏茼基因组DNA.多重PCR检测人工污染脱脂灭菌乳,单增李斯特茵与志贺氏茵的灵敏度分别为2cfu/25mL和1.6cfu/25mL.结论:该方法在食品、卫生行业具有很好的应用和开发前景.     

254/185 nm photolysis of p-nitrophenol

<正>Degradation of low-concentration p-nitrophenol(p-NP)aqueous solution was carried out in 254/185 nm photolysis.The effects of Mn~(2+),pH value,O_2 and O_3 on the degradation efficiency have been investigated.It was observed that the singlet oxygen scavenger Mn~(2+)did not affect the degradation of p-NP.In acidic and alkaline solutions,the degradation efficiency was enhanced in comparison to that in neutral solution.The presence of O_2 dramatically promoted the degradation of p-NP,while that of O_3 impeded it.     

台内薄层礁滩型碳酸盐岩储层定量描述及控制因素——以珠江口盆地A地区为例

礁滩型碳酸盐岩储层是南海周缘含油气盆地重要的油气聚集的储层之一。珠江口盆地A地区受地震资料品质低和有效储层刻画手段弱的限制,准确表征该区礁、滩相储层的分布特征研究一直较为薄弱。本次研究基于拓频处理后的高分辨率三维地震资料,采用稀疏脉冲反演、物性反演和三维可视化组合等技术,有效预测并刻画了该区礁滩型储层的空间分布,并结合钻井资料揭示了油水界面关系,对礁、滩体油藏的储量进行了准确计算。目前基于本次研究获得的有效储层定量描述结果部署的评价井获得了工业油流,并且储层预测结果与钻井吻合较好,证实了本次研究采用的技术方法对薄层礁滩型储层预测的实用性和有效性。同时,论文还分析了沉积相带、四级海平面下降引起的淡水淋滤溶蚀作用与礁滩型储层发育具有密切的相关,而风向是影响生物礁相储层平面非均质性的另一主要控制因素。     

数据流聚类算法在入侵检测中的应用

处理数据流的能力成为入侵检测系统面临的挑战,针对这一现状提出DC-stream算法,该算法采用在线离线两阶段聚类,设计了一套缓冲式异常点处理机制,在保证数据流聚类效率和精度的同时,能够过滤噪音数据。实验结果证明,该算法能在海量的网络数据流中及时有效地发现入侵行为,并具有较强的抗干扰能力。     

Countermeasures against Crisis by Generation Enterprises

Since October 2008,China‘s social consumption of electricity had,for the first time,grown negatively compared to the same period of the previous year,and in November the negative growth range further expanded. The major pressure faced by the electricity industry has now turned from the contradiction between coal and electricity to electricity quantity. This is undoubtedly a true and new test to electricity enterprises which get used to high growth but are now suffering great losses. The reform of electricit...     

Microwave absorption response of nickel/graphene nanocomposites prepared by electrodeposition

In this study, nanostructures of nickel have been successfully deposited on graphene nanosheet by direct electrochemical deposition. The morphology, nickel content, and magnetic properties of the graphene as well as composites were examined by scanning electron microscopy, transmission electron microscopic, elemental analysis, and vibrating sample magnetometer, respectively. Their relative complex permeability and permittivity were also measured, and reflection loss values were calculated at given thickness layer according to transmit line theory in the range 2–18 GHz. The results reveal that with the increasing of the thickness of the samples, the matching frequency tends to shift to the lower frequency region, and theoretical reflection loss becomes less at the matching frequency. When the absorbing thickness is 1 mm, the maximum absorption value of graphene is ?6.5 dB at about 7 GHz. After decorating graphene sheet with magnetic nickel nanoparticles, the composites were shown to efficiently promote microwave absorbability. When the thickness is 1.5 mm, the absorption value of the composites exceeds ?10 dB in the 5 GHz absorbing bandwidth and the maximum absorption value is ?16.0 dB at 9.15 GHz.     

气相色谱法测定3，3-二甲基丁醛的含量

建立了用毛细管色谱柱气相色谱内标法分析测定3,3-二甲基丁醛的方法,选用Hp-225毛细管柱,目标组分的分离效果良好。在选定的实验条件下利用内标法分析测定了3,3．二甲基丁醛的含量。结果表明,内标法测定3,3-二甲基丁醛的相对标准偏差不大于2％,回收率在96．96％-100．87％之间。该方法为3,3．二甲基丁醛生产企业分析检测提供了一种快速、可靠的方法。