Geographical Authentication of Tequila According to its Mineral Content by Means of Support Vector Machines

The elemental profile of tequila samples from the three main production areas of the State of Jalisco, namely Amatitlan, Guadalajara, and Tequila, was used to carry out their geographical characterization. With this aim, the concentration of Al, Ba, Ca, Cu, Fe, K, Mg, Mn, Na, S, Sr, and Zn was determined by inductively coupled plasma atomic emission spectroscopy. Principal component analysis was addressed to visualize data trends. The number of input variables was reduced by means of backward stepwise linear discriminant analysis and support vector machines were used to construct an adequate classification model. The best classification performance was obtained by a linear support vector machine model with 100% of prediction ability.     

Emission characteristics of heavy metals and their behavior during coking processes

Besides organic pollutants, coke production generates emissions of toxic heavy metals. However, intensive studies on heavy metal emissions from the coking industry are still very scarce. The current work focuses on assessing the emission characteristics of heavy metals and their behavior during coking. Simultaneous sampling of coal, coke, residues from air pollution control devices (APCD), effluent from coke quenching, and fly ash from different processes before and after APCD has been performed. The total heavy metal concentration in the flue gas from coke pushing (CP) was significantly higher than that from coal charging (CC) and combustion of coke oven gases (CG). Emission factors of heavy metals for CP and CC were 378.692 and 42.783 μg/kg, respectively. During coking, the heavy metals that were contained in the feedstock coal showed different partitioning patterns. For example, Cu, Zn, As, Pb, and Cr were obviously concentrated in the inlet fly ash compared to the coke; among these metals Cu, As, and Cr were concentrated in the outlet fly ash, whereas Zn and Pb were distributed equally between the outlet fly ash and APCD residue. Ni, Co, Cd, Fe, and V were partitioned equally between the inlet fly ash and the coke. Understanding the behavior of heavy metals during coking processes is helpful for the effective control of these heavy metals and the assessment of the potential impact of their emissions on the environment.     

低糖苦瓜果脯的加工工艺

以苦瓜为原料,对影响苦瓜果脯品质的烫漂、护色、温度、渗糖等关键工艺进行研究。结果表明:苦瓜最佳切分厚度为0.7 cm～0.8 cm;烫漂时间为3 min;烫漂温度为90℃。最佳护色和硬化工艺配方为:氯化钙0.5%、亚硫酸氢钠0.5%、氯化钠0.2%、醋酸锌0.3%。最佳渗糖工艺为:CMC浓度为2.0%、β-环状糊精的添加量3%、浸泡液浓度梯度为30%-40%-50%、每次冷浸时间8 h。制成的低糖苦瓜果脯风味好、色泽自然。     

超高压处理对轻度加工茭白保鲜的影响

探讨了超高压处理对微加工茭白货架期保鲜效果的影响,在25℃、600 MPa下处理10 min,贮藏至第7天,对照组和超高压处理组茭白的失重率分别达到10.9%、7.2%,呼吸强度分别为56.63、64.24 CO2mg/(kg.h),细胞膜透性分别为53.3%、45.5%,VC含量下降了56.3%、48.2%,纤维素含量分别为1.49%、1.37%,L值分别下降至70.35、62.45,a值分别上升至-0.54、-0.38,b值分别上升至16.7、15.5。     

Production of biogenic amines by lactic acid bacteria and enterobacteria isolated from fresh pork sausages packaged in different atmospheres and kept under refrigeration

The occurrence of in vitro amino acid activity in bacterial strains associated with fresh pork sausages packaged in different atmospheres and kept in refrigeration was studied. The presence of biogenic amines in decarboxylase broth was confirmed by ion-exchange chromatography and by the presence of the corresponding decarboxylase genes by PCR. From the 93 lactic acid bacteria and 100 enterobacteria strains analysed, the decarboxylase medium underestimates the number of biogenic amine-producer strains. 28% of the lactic acid bacteria produced tyramine and presented the tdc gene. All the tyramine-producer strains were molecularly identified as Carnobacterium divergens. Differences on the relative abundance of C. divergens were observed among the different packaging atmospheres assayed. After 28 days of storage, the presence of argon seems to inhibit C. divergens growth, while packing under vacuum seems to favour it. Among enterobacteria, putrescine was the amine more frequently produced (87%), followed by cadaverine (85%); agmatine and tyramine were only produced by 13 and 1%, respectively, of the strains analysed. Packing under vacuum or in an atmosphere containing nitrogen seems to inhibit the growth of enterobacteria which produce simultaneously putrescine, cadaverine, and agmatine. Contrarily, over-wrapping or packing in an atmosphere containing argon seems to favour the growth of agmatine producer-enterobacteria. The production of putrescine and cadaverine was associated with the presence of the corresponding amino acid decarboxylase genes. The biogenic amine-producer strains were included in a wide range of enterobacterial species, including Kluyvera intermedia, Enterobacter aerogenes, Yersinia kristensenii, Serratia grimesii, Serratia ficaria, Yersinia rodhei, Providencia vermicola and Obesumbacterium proteus.     

建筑的隐性线秩序形态

建筑线秩序形态与其内在规律,乃自成一体。外在线秩序形态有其内在规律,且内在规律具有明晰的线性机制特征。这些线性机制为形态的内核与机理,控制并转化为建筑线秩序形态;线秩序形态又是线性机制的逻辑物化表达,是其本体的外显与图解。该文是基于建筑线秩序形态与线性机制间的逻辑关系的研究,可以成为建筑本体与表现相契合的一种途径,对如何运用线秩序方法构思出符合内在线性机制的建筑线秩序形态,具有重要的意义。     

TMP合成与分离工艺研究

采用康尼扎罗合成法和萃取分离技术,对三羟甲基丙烷的合成与分离工艺进行了研究,确定了较佳合成和分离工艺条件,在较佳工艺条件下,产品收率≥８５％,产品纯度≥９９％。     

零电压开关准谐振半桥变换器的系统建模和研究

分析了零电压开关准谐振半桥ＤＣ／ＤＣ 变换器的工作原理和主电路谐振元件参数的计算方法, 推出了以ＭＣ３４０６７ 芯片为控制核心的系统闭环模型, 通过原理样机的实验验证, 表明计算方法和系统模型是合理正确的, 为相关变换器的研究打下了良好的基础。     

基于耐久性评定的钢筋混凝土结构的剩余寿命预测

本文着意建立一套钢筋混凝土结构耐久性的评定方法,这一方法提供了一套客观、公正地分析和处理现场检测数据的手段并有助于评定者选择合适的评定指标,从而可以得到结构的性能状况及剩余寿命。这一方法将结构的耐久性分为恶化程度和恶化速度两项评定;利用Ｓａａｔｙ１－９比率标度法将专家根据主观经验所得的判断信息进行客观、科学地量化;采用熵的性质,使多指标评定体系的固有信息与专家经验判断量化的主观信息相结合,解决了各