稀土对铜及铜合金性能的影响

本文综述了稀土元素对铜及铜合金的净化、去杂、细化晶粒作用，以及对其物理、化学和机械加工性能等方面的影响。     

糜米粉对面团特性及面包品质的影响

为研究糜米粉对面团特性及面包品质的影响,探究了糜米粉添加量(0、10%、20%、30%、40%和50%)对面团的微观结构、拉伸特性、动态流变学特性以及面包品质的影响。结果表明:随着糜米粉添加量的增加,面团的面筋网络出现了断层结构。添加糜米粉使得面团的拉伸强度和拉伸距离均呈下降趋势,面团的弹性模量和黏性模量均呈上升趋势。糜米粉的添加明显增加了面包的硬度和咀嚼度,降低了面包的弹性、粘聚性、回复性、比容和感官评分。因此,糜米粉的添加改变了小麦面团的特性和面包的品质,其添加量不宜超过30%。     

Expression of milk-derived angiotensin I-converting enzyme-inhibitory peptides in Lactococcus lactis

Angiotensin I-converting enzyme (ACE) plays a key role in the regulation of blood pressure. Currently, most single or tandem repeats of ACE-inhibitory (ACE-I) peptides have been expressed in Escherichia coli. However, in this study, a food-grade system was constructed using Lactococcus lactis (L. lactis) to simultaneously express four different milk-derived ACE-I peptides with antihypertensive activity. Mixed peptides (MPs) fused with green fluorescent protein (GFP) and eight histidines were synthesized. To ensure potent ACE inhibition by the MPs in human digestive juice, pepsin and trypsin cleavage sites were introduced among the four ACE-I peptides. The MP fusion gene was inserted into expression vector pSEC-E7 with nisin induction and expressed in L. lactis NZ9000, then purified by affinity chromatography. The transformants containing pSEC-MP:GFP were identified based on green fluorescence using Leica laser scanning confocal microscopy. The target proteins were detected by SDS-PAGE analysis and displayed obvious immunogenicity by western blot. After hydrolysis with digestive enzymes, the IC₅₀ of the MPs was 118.63 μM. These results suggested that multiple milk-derived ACE-I peptides with antihypertensive properties could be produced using a food-grade lactococcal expression system.     

张家界市酸鱼细菌类群解析及其功能预测

该研究采用Illumina MiSeq高通量测序技术对采集自张家界市的7个酸鱼样品进行了细菌类群分析,结果发现厚壁菌门（Firmicutes）为优势菌门,其平均相对含量为95.49%。优势细菌属为乳酸杆菌属（Lactobacillus）、四联球菌属（Tetragenococcus）和葡萄球菌属（Staphylococcus）,其平均相对含量分别为66.53%、11.77%和8.10%。发现8个核心分类操作单元中有6个注释为Lactobacillus,各有1个注释为Tetragenococcus和Staphylococcus,其中乳酸菌的累计平均相对含量达60.27%。PICRUSt技术预测酸鱼菌群功能结果表明,酸鱼中的细菌菌群在“氨基酸转运与代谢”和“碳水化合物运输和代谢”功能上表达较高,说明菌群在代谢方面的功能比较突出。由此可见,张家界地区酸鱼中蕴含了丰富的乳酸菌资源,且以Lactobacillus、Tetragenococcus和Lactococcus为主。     

当阳地区鲊广椒中乳酸菌的分离鉴定及其应用

采用传统培养分离方法和分子生物学技术对湖北省当阳地区鲊广椒中的乳酸菌进行分离鉴定,通过电子舌和电子鼻技术评价植物乳杆菌（Lactobacillus plantarum）强化发酵对鲊广椒品质的影响,并通过主成分分析（PCA）获得具有优良鲊广椒发酵特性的菌株。结果表明,从5份鲊广椒样品中分离获得18株产生溶钙圈的菌株,经16S rDNA序列分析鉴定发现,其中11株为L. plantarum。通过电子鼻分析发现,L. plantarum强化发酵时,多数鲊广椒样品挥发性风味物质中的芳香类物质含量明显提升;通过电子舌分析发现,L. plantarum强化发酵时,多数鲊广椒样品酸味明显提升,而鲜味和丰度（鲜味的回味）明显下降;PCA结果表明,L. plantarum HBUAS52019和L. plantarum HBUAS52006可作为鲊广椒发酵优良的菌株。     

高压辅助提取海蜇胶原蛋白的工艺

研究了高压辅助提取海蜇胶原蛋白的工艺条件。以胶原蛋白得率为指标,优化的工艺条件为:料液比(g∶mL)1∶4,高压功率250MPa,高压处理时间10min,热水处理温度70℃,热水提取时间1.5h。此条件下,海蜇胶原蛋白的得率为68.2%。此生产工艺操作简单,生产周期短,产品质量好和生产环保等优点。     

Hydrogen production from organic fatty acids using carbon-doped TiO2 nanoparticles under visible light irradiation

The photocatalytic production of H₂ using carbon-doped TiO₂ (CTiO₂) nanoparticles has been investigated in single or mixed systems of organic fatty acids (OFAs) under visible light irradiation, including acetic acid, propionate acid, butyric acid and lactic acid. When OFAs were applied at the same electron density (10 e-eq L^?1), the H₂ evolution rates followed the order of propionic acid > butyric acid ≈ acetic acid > lactic acid, whereas at the same molar concentration (0.5 mol L^?1), that order changed to lactic acid > acetic acid > butyric acid ≈ propionic acid. This result implied that the electron transfer efficiency differed from four OFAs, probably due to their different affinity with CTiO₂. O₂^?? and CH₃? partially contributed to OFAs degradation and H₂ production. The quantum dynamics simulations of electron transfer revealed that the dominant mechanism of H₂ production was direct electron transfer from adsorbed OFAs to CTiO₂. This work aims to pursue the synergy of solar energy utilization and conversion of OFAs into H₂.     

低品位难选铁矿还原焙烧－磁选生产金属化团块的研究

本文结合我国铁矿资源多为低品位难选铁矿的特点，通过试验研究，提出采用直接还原－细磨磁选生产铁品位高、质量稳定的金属化团块，作为电炉炼钢的生产原料。     

IGBT等离子喷涂逆变器的研究

介绍了ＩＧＢＴ等离子弧喷涂逆变器的工作原理和主电路结构。分析了这种特大功率（６０ｋＶＡ级）逆变器在高压大电流下，如何对工作条件恶劣的功率开关器件ＩＧＢＴ进行控制和保护。对工作电压电流波形进行优化，以确保安全工作和减少开关功率损耗，提高效率。为实现主电路的大功率合理运行，比较了主电路的两种运行方式，并作了优选。     

高硫铁矿中金氰化过程中磨矿细度研究

为了获得高硫铁矿在氰化生产中较好的生产指标,对高硫铁矿进行了磨矿细度的氰化浸出试验.通过对试验数据进行分析,得到了该矿的最佳磨矿细度,从而为氰化生产提供了依据.为了了解金损失在氰渣中的粒级情况,对氰化浸出后的氰渣进行了筛析试验.