神经网络法在食品安全预警中的应用

神经网络法是一种反应快、成本低并且能解决非线性复杂问题的处理方法,在食品安全预警中有着重要的作用。综述了国内外神经网络法在食品安全预警风险评估、信息源系统和预警分析系统构建中的应用情况,具体介绍了神经网络法在环境危害评估、生物化学危害评估、粮食安全风险评估,以及微生物污染、食品添加剂、食品有毒有害物质、假冒伪劣产品信息源检测中的应用进展状况。     

Has China's coal consumption actually reached its peak? National and regional analysis considering cross-sectional dependence and heterogeneity

To investigate whether China's coal consumption has actually peaked, this study tests the national and regional coal Kuznets curve (CKC) hypothesis by using a panel dataset of 30 provinces covering 2000 to 2016. To fully capture the trends of coal consumption at the national, regional, and provincial levels, this study proposes a novel regional division method based on coal dependence and economic level. Considering the potential cross-sectional dependence and slope homogeneity, the newly developed methods allowing for heterogeneous slope coefficients are employed. The whole panel and subpanel results validate the CKC hypothesis for China, and province-specific results are mixed. The subpanel results reveal that only in the coal-dependent developing region has the peak of coal consumption not been reached, and for other regions, coal consumption displays a downward trend along with gross domestic product (GDP) increases. Furthermore, the province-specific results suggest that coal consumption will continue to increase slightly in certain provinces. This study implies that to reduce coal consumption, the coal-dependent developing region and provinces with a future turning point should act with great urgency to achieve a balance of economic growth and environmental responsibility. In addition, policymakers formulating coal consumption reduction policy in China must consider the remarkable differences across regions and provinces.     

抗菌肽应用于食品中的研究现状及面临的挑战

食品安全问题一直为人们所关注,其中微生物污染是导致食品腐败变质的主要原因。抗菌肽来源广泛,抑菌谱广,杀菌速度快,可以较好地控制食品中腐败微生物的滋生;对pH值、蛋白酶和热处理有较好的稳定性,在成分复杂的食品体系中有一定的适用性;由于其抑菌机理特殊,不易产生耐药性;部分具有抗氧化和提高免疫力等多种功能,对人体具有一定的保健作用。抗菌肽的以上特点满足了人们对新型防腐保鲜剂的多种需求,有望在食品工业上发挥重大作用。因此,在抗菌肽的生物学功能以及抗菌肽保鲜机理简单介绍的基础上,对抗菌肽应用于不同食品中的研究现况进行详细综述,最后对抗菌肽在食品中应用目前存在的问题和发展方向提供了思考。     

基于本体论的食品安全数据融合框架研究

庞杂的食品安全抽检数据由于分类编码问题不统一而使得数据融合难以实现,并进一步阻碍了与其他监测系统的融合与数据分析。解决各种食品安全数据融合的问题将对国家的食品安全监管具有重要意义,文章归纳总结了食品安全大数据在分类编码方面的主要存在问题,引入本体论的思想,并结合计算机工程,提出了构建基于本体论的计算机工程与大数据分析相结合的总体框架,以实现数据融合,服务政府和企业的有效监管。     

茶树花黄酮类化合物研究进展

在我国悠久的种茶历史中,茶树花由于具有会与茶叶争夺营养的特点,常常作为废弃物处理,导致该资源得不到很好地开发和利用.研究发现,茶树花成分与茶叶基本相似,含有丰富的营养活性物质.随着越来越多的学者意识到茶树花的高价值,有关茶树花营养成分及生理功能的研究逐渐深入开展.茶树花中黄酮类化合物含量高于其他花卉.黄酮类物质具有抗氧...     

叶面喷施秸秆源提取物对草莓果实产量和品质的影响

为了提高设施温室种植草莓的生产效率和产品附加值,以草莓品种‘红颜’为试材,在冬季设施温室内,通过叶面喷施的方式以秸秆源提取物对草莓植株进行处理,探讨不同喷施量的处理对草莓的产量、单果质量、感病率和采后果实的可溶性糖、尤其是抗坏血酸、花青素、总酚物质等抗氧化性营养指标的影响。结果表明：叶面喷施秸秆源提取物的最适喷施方法为：用量1 200 mL/（hm2·次）,每隔10 d喷施1 次,共喷施3 次,能够显著提高草莓果实的产量、单果质量和营养品质,尤其对果实抗坏血酸含量的提高作用最明显,草莓果实的商品价值得到了显著提升。     

Hierarchical representation of complex systems for supporting human decision making

The work presented in this paper is devoted to intelligent on-line supervision tools. In the proposed approach, the human operator remains in the decision loop, at the highest level, and acts on the process. To help operators make decisions, process knowledge is represented with a model whose complexity can be adapted on line to the operation needs at the request of the operator. The model thus helps to focus only on the phenomena that are relevant at a given time. To give the model explanatory capacity, it is represented as a causal directed graph, and allows the representation of temporal phenomena, which is fundamental for dynamic monitoring. A hierarchical representation of the functional properties of the process is proposed. The conception of a hierarchy of causal models with a top-down analysis is discussed. Path algebra is used to construct a higher-level graph on-line at the request of the operator from the most detailed graph, while conserving the semantics of the latter. No intermediate level is defined a priori; only the highest and lowest level graphs are fixed: the others are constructed dynamically. Finally, a study of how graphs can convey information on the dynamics of the process for approximate temporal reasoning that is largely sufficient for supervision purposes is analyzed. An example of a causal graph hierarchy for a nuclear process illustrates the method. As a final point, the use of such causal graphs in advanced industrial supervision tools is considered.     

加拿大肉与肉制品法规和标准体系分析

加拿大肉与肉制品法规和标准体系较为完善,能够有效地规范肉与肉制品的生产加工,保证质量与安全.本文介绍了加拿大肉与肉制品的法规和标准体系现状,并分析和总结其体系的特点,为我国建设完整的肉与肉制品法规与标准体系提供经验借鉴和启示.     

旱生植物内生细菌的分离及耐旱菌株的筛选鉴定

为筛选耐旱内生细菌,并对其进行鉴定,以典型耐旱植物为材料,分离纯化出142株内生细菌。采用液体培养基中添加聚乙二醇6000降低渗透势的方法分析内生细菌的耐旱情况。从中筛选出1株能够耐受质量浓度为60g/100mL聚乙二醇6000的内生细菌PB14。对该菌株进行形态学观察,生理生化和16S rDNA序列鉴定,判定菌株PB14为蜡样芽孢杆菌(Bacillus cereus)。