Changes in physicochemical properties and DNA quality of milk as affected by different heat treatments

The effects of three common heat treatments (pasteurisation, boiling and autoclaving) on milk physicochemical properties and DNA quality were investigated. Milk composition, colour and pH value varied significantly during the heating process. The heat treatment also affected the DNA quality of the milk and, in particular, reduced the content of both mitochondrial DNA (mtDNA) and nuclear DNA (nDNA). These reached their lowest values when autoclaving was conducted, but the content of nDNA was never greater than that of mtDNA. The physicochemical and DNA quality changes in milk are crucial factors in any authentication process using polymerase chain reaction (PCR)‐based methods.     

Cuticle and cortical cell morphology of alpaca and other rare animal fibres

The null hypothesis of the experiments reported is that the cuticle and cortical morphology of rare animal fibres are similar. The investigation also examined if the productivity and age of alpacas were associated with cuticle morphology and if seasonal nutritional conditions were related to cuticle scale frequency. Cuticle and cortical cell dimensions and ellipticity of the fibre cross section were investigated in 32 samples of cashmere, alpaca, mohair, bison, qiviut and vicuña from various origins. In addition, 24 Peruvian alpaca samples from animals ages 2–6 years and of varying fleece productivity were examined. Cuticle scale frequency, cuticle thickness and cortical cell dimensions (length, diameter, volume and ratio of length to diameter) and ellipticity differed between fibres and cuticle scale frequency also varied with mean fibre diameter. For Peruvian alpaca fleece samples, cuticle scale frequency varied with the age of alpaca and fleece productivity. Fibre ellipticity increased with increasing fibre diameter. Cortical cell length was strongly related to cortical cell diameter. The cuticle scale morphology of these rare animal fibres did not have fixed dimensions. Using cuticle scale morphology as a diagnostic tool to positively identify rare natural animal fibres needs to standardize measurements for fibre diameter but will still be affected by differences in animal productivity.     

石油套管质量评价方法研究

石油套管是油气田开采中重要的物资装备,其质量直接影响油气田的生产安全与开采效率。对石油套管质量评价方法进行研究,优选反映石油套管质量的性能参数,通过归一化处理,结合专家知识,建立评价模型,进而得到石油套管质量的评价结果。将所研究的评价方法应用于P110石油套管质量评价中,评价结果准确、直观,方法有效实用。     

ISO9001质量管理体系在质检工作中的应用

ISO9001质量管理体系是指国际标准组织颁布的国际通用标准,是各国质量管理体系制定的参考规范。就当前我国质量管理发展现状来看,ISO9001质量管理体系在质检工作中的应用至关重要。根据自身相关工作经验,并结合广泛的社会实践调查研究,就ISO9001质量管理体系在质检工作的应用展开了相关研究,望能提供借鉴。     

The digital twin of the quality monitoring and control in the series solar cell production line

With the development of intelligent manufacturing (IM), the Digital twin (DT) has become an important means to the evolution mechanism of the process. Many researchers pay attention on the realization of DT in different industries. Based on the DT and Digital Twin Shop Floor (DTS) model, a novel, high throughput metrology method is proposed in the process quality monitoring and control of the Series Solar Cell Production Line (SSCPL) for detailed performance analysis. The variance of individual loss parameters and their impact on quality performance are quantified and mapped into the virtual space. The nature of their distributions and correlations provide great insights about quality loss mechanisms in process monitoring, helping to prioritize efforts for optimizing the control of the SSCPL in the physical space. Additionally, the parameters can be tied back to the physical space, allowing the data to be used directly for the control in the manufacturing. The data-loop of “Autonomous perception of process parameters - Dynamic behaver mapping - Online monitoring - Online data analysis - Parameters configuration & control” can be obtained in the model. This paper provides an application paradigm for DT and IM.     

含有植物纤维或玉米淀粉的食品接触产品质量安全风险研究

研究市售的含有植物纤维或玉米淀粉的食品接触产品质量状况并对其安全性进行初步评价。参考标准要求并结合可能存在的质量安全隐患,从傅里叶变换红外(FTIR)材质分析、总迁移量、重金属(以Pb计)、脱色试验、五氯苯酚特定迁移量及砷、镉、铬、铅含量等维度对含有植物纤维或玉米淀粉的食品接触产品进行研究。35批次样品中有2批次塑料主体材质为密胺,2批次塑料主体材质为聚乳酸,31批次塑料主体材质均为聚丙烯;35批次样品的重金属(以Pb计)、脱色试验、五氯苯酚特定迁移量等项目均符合所参照标准的要求;35批次样品均检出至少含2种重金属,有4批次一次性淀粉餐具总迁移量超标。从检验结果可知,市面上销售的含有植物纤维或玉米淀粉的食品接触产品存在总迁移量超标及样品含重金属的情况,说明市场上该类产品确实存在一定的潜在风险。     

Profiling of knowledge organisation systems for the annotation of Linked Data cultural resources

The importance of cultural heritage for supporting the knowledge economy has promoted its digitisation and online publication. Many cultural heritage repositories have published millions of digitised items using semantic web technologies and Linked Data approaches. These repositories frequently use knowledge organisation systems to classify the resources, but the domain heterogeneity makes it difficult to know if they are the most suitable ones. This paper describes the process used to discover and profile the knowledge organisation systems used in the cultural heritage domain. Additionally, for those knowledge organisation systems with a thesaurus-like structure, a detailed quality analysis is performed. The results of this analysis can be used as a key factor for the selection of knowledge organisation systems in classification tasks.     

简析变压器油的生产工艺及质量

本文简要介绍了变压器油的运用价值,同时分析如何实现对变压器油生产工艺的优化,并从物理性能以及化学性能两个方面分析生产工艺改良后变压器油整体质量,以期为变压器油生产工作提供一定的参考与帮助。     

Review of the structural characterization,quality evaluation,and industrial application of Lycium barbarum polysaccharides

BackgroundLycium barbarum polysaccharides (LBPs) are considered to be the major bioactive components in L. barbarum. Due to the considerable health benefits of LBPs, and the significant research interest in LBPs, quality evaluation of LBPs and their related products is imperative for ensuring their efficacy and safety. The bioactivities of polysaccharides are closely associated with their physicochemical properties, which can be easily monitored via chemical techniques. Therefore, analysis of physicochemical properties is a more straightforward and viable approach for the quality control of polysaccharides.Scope and approachIn this review, special techniques for the structural characterization of LBPs are summarized and discussed. In addition, quality evaluation approaches of LBPs that have never been emphasized are highlighted herein. Furthermore, industrial applications of LBPs are reviewed and discussed.Key findings and conclusionsHigh-performance anion-exchange chromatography coupled with pulsed amperometric detection is one of the most effective techniques for analysis of both acidic and neutral LBPs. Size-exclusion chromatography coupled with multi-angle laser light scattering and refractive index detection is able to determine absolute molecular weights, chain conformations, and contents of LBPs. Fingerprinting analysis and saccharide mapping analysis are effective approaches for quality evaluation of LBPs. However, the lack of appropriate quality evaluation approaches indicates an unreliable regulation of LBPs and their related products. This reveals the deficiency in the quality control of commercial products. Thus, the development of reliable approaches for pharmacological activity-based quality control of LBPs and their related products must be extensively investigated.     

Study of golden pompano (Trachinotus ovatus) freshness forecasting method by utilising Vis/NIR spectroscopy combined with electronic nose

Golden pompano (Trachinotus ovatus) quality forecasting method utilising Vis/NIR spectroscopy combined with electronic nose (EN) was investigated in this article. Responses of Vis/NIR spectroscopy and EN to pompanos stored at 4°C were measured for 6 days. Physical/chemical indexes including texture, total volatile basic nitrogen, pH, total viable counts, and human sensory evaluation were synchronously examined as quality references. Chemometric methods including principal component analysis (PCA) and stochastic resonance (SR) were employed for spectroscopic and EN data analysis. Physicochemical examination demonstrated that fish quality decreased rapidly during storage. PCA qualitatively classified freshness degree of pompano samples, while SR signal-to-noise ratio (SNR) spectrum using SNR maximum quantitatively characterised quality for all samples. Golden pompano quality predictive models were developed based on spectroscopy, EN, and spectroscopy combined with EN, respectively. Results demonstrated that the model developed based on spectroscopy combined with EN presented a forecasting accuracy of 93.3%.