Formation of Sn filled CNTs nanocomposite: Study of their magnetic,dielectric properties and enhanced microwave absorption performance at gigahertz frequencies

The Simplistic formation, advantageous configuration, non-colossal magnetoresistance and broadband absorption are important parameters for microwave absorbent materials. In this study, a core-shell nanocomposite comprising of Sn-filled carbon nanotubes (Sn/CNTs) was prepared by arc discharge method. The microstructure, morphology and surface composition of Sn/CNTs-based core-shell nanocomposites were characterized in detail. Sn/CNTs nanocomposite showed a magnetic signal due to the broken bonds and defects at interfaces in Sn/CNTs. The weak ferromagnetism was found to be helpful in improving magnetic permeability in the Sn/CNTs which confirms its role as a magnetic loss material under incident electromagnetic wave. Sn-filled CNTs revealed an appropriate value of dielectric constant, which plays an important role in impedance matching upon incident electromagnetic wave. The composite of Sn-CNTs and paraffin with a 50 wt % loading showed the lowest reflection loss (RL) of ?43.87 dB at 10 GHz, with a wide effective absorption band (RL ≤ ?10 dB) of 3 GHz in thickness of 2.3 mm. This enhanced performance is attributed to the combined effect of the conduction loss in one-dimensional core-shell architecture, the interfacial loss Sn-CNT interface, the magnetic loss due to defects-induced ferromagnetism in Sn shell, and in the carbon-containing atomic layers of CNTs.     

Growth,mechanical properties,and tribological performance of TiAlN/NbN and NbN/TiAlN bilayer coatings

Three different coatings, namely TiAlN, TiAlN (external)/NbN (internal) and NbN (external)/TiAlN (internal), were deposited on cemented carbides by arc ion plating. The comparative investigation conducted in this study elucidates the effect of the NbN layer and coating systems on the growth, mechanical properties, and tribological performance of the coatings. The results showed that the surface of the TiAlN and TiAlN/NbN coatings was smoother when TiAlN served as the external layer. The NbN/TiAlN coating, wherein NbN formed the external layer, had a much rougher but more symmetrical surface. With the introduction of the NbN layer, the increased micro stress induced a lower adhesion strength in the TiAlN/NbN and NbN/TiAlN coatings. The TiAlN/NbN and NbN/TiAlN coatings exhibited higher hardness and hardness/effective elastic modulus (H/E*). During the friction test, when the temperature was elevated to 700 °C, the tribological performance of the monolayer TiAlN coating was the lowest because of the TiO₂-induced breakage of the dense tribo-oxide film. The NbN layer participated in the formation of a NbO_x film at elevated temperatures, which was responsible for the high tribological performance of the two bilayer coatings. When the NbN layer was on the outermost layer and in direct contact with the elevated temperature atmosphere, the NbN/TiAlN coating generated a tribo-oxide film with high integrity, and its coefficient of friction decreased by 27% of that at room temperature. Therefore, the NbN/TiAlN coating exhibited the highest wear resistance at 700 °C.     

一株芝麻香型白酒高温大曲细菌Q2B1的鉴定及其产酶活性研究

大曲细菌关系到白酒酿造的品质，其中酶的含量与活性与白酒的风味紧密关联。以芝麻香型白酒高温大曲优势细菌代表菌株Q2B1为研究对象，利用分子生物学技术对其分类学地位进行研究，并通过全基因组研究技术对产酶相关功能基因与代谢通路进行研究。结果表明，菌株Q2B1被鉴定为贝莱斯芽孢杆菌（Bacillus velezensis）。利用传统的培养技术定性定量地检测其酶活力，发现菌株Q2B1可产淀粉酶和蛋白酶，活力分别为5.852 U/mL和26.770 U/mL；其产酶相关功能基因组长度为3 475 602 bp，包括蛋白酶编码基因以及淀粉酶编码基因，在基因水平上初步揭示了Q2B1菌株合成蛋白酶和淀粉酶的分子机理，为进一步合理开发白酒大曲微生物奠定理论基础，为提高白酒品质提供科学依据。     

基于大数据的酒业舆情信息监测平台

酒业发展至今,网络舆情已经成为企业不得不认真对待的一部分,面对舆论汹涌,研究大数据在线网络舆情的挖掘、方法和预警具有重要的社会价值和理论意义。将网络主流媒体的新闻数据爬取存入数据库后,利用数据统计、情感词分析和深度学习方法BERT,平台可以实时收集并整理酒企与主要竞争对手在主流舆论对社会媒体的信息,识别相关的话题和事件,判断新闻的情感倾向,跟踪事件的发展和实时预警,从而帮助酒企全面了解自己和竞争对手的网络媒体舆论动力学,为品牌形象优化策略提供指导。     

浓香型大曲白酒窖泥微生物研究进展

基于传统微生物技术和现代生物学技术对白酒窖泥微生物的研究，阐述了研究白酒酿造微生物所运用生物学技术的各种方法、原理及对窖泥微生物的研究现状。主要对宏基因组、聚合酶链式反应-变性梯度凝胶电泳（PCR-DGGE）技术、高通量测序技术等现代分子生物技术在窖泥微生物代谢活动和群落代谢机制研究中的应用进行了综述，为解决白酒生产中遇到的实际问题提供了理论指导。     

浓香型白酒窖泥放线菌的原位分离及代谢特性研究

以川南某浓香型白酒生产企业50年窖龄且发酵正常的窖泥为研究对象。通过高通量测序技术分析细菌群落结构以及放线菌群落结构,利用原位分离法从中分离得到2株放线菌,结合形态鉴定、生理生化和16S rRNA基因序列比对分析确定菌种属,并对其进行耐酸、耐乙醇特性研究,基于风味导向思路,分别对2株菌进行液态培养和固态培养,采用顶空固相微萃取法和气相色谱质谱联用对发酵挥发性产物进行分析,为放线菌的相关研究和应用提供理论参考。结果显示,放线菌在该窖泥样品含有较高操作分类单元(operational taxonomic unit,OTU),相对丰度达(10.7±3.4)%,且主要分布于链霉菌亚目(Streptomycineae)和科里氏杆菌亚目(Coriobacterineae)。采用原位分离法分离放线菌,将分离得到的2株菌编号为A1、A2,菌株A1鉴定为桑氏链霉菌(Streptomyces sampsonii),菌株A2鉴定为鲁地链霉菌(Streptomyces rutgersensis)。菌株A1、A2均可在pH>4.3或乙醇体积分数<6%的环境中生长。菌株A1在液态和固态发酵条件下都会产生大量土臭素以及萜烯类物质,菌株A2在液态条件下能产生多种酯类,其中己酸乙酯相对含量(5.384%)较高,而固态条件下能够检测出大量的3-羟基-2丁酮、2,3-丁二醇和吡嗪类物质。     

酿造米酒发酵条件的优化

为优化酿造米酒的发酵条件以提高其品质，以米曲霉（Aspergillus oryzae）及酿酒酵母（Saccharomyces cerevisiae）为发酵菌株，采用两步发酵法制备酿造米酒，研究了酵母接种量、发酵温度、发酵时间对酿造米酒品质的影响。通过测定酿造米酒的酒精度、总糖、总酸、风味物质和感官评价等指标，以确定酿造米酒最佳发酵工艺条件。结果表明，酿造米酒最优发酵工艺条件为：酵母接种量1.0%（以原料大米计），发酵温度25 ℃，发酵周期13 d。在此最佳条件下，酿造米酒酒精度为13.21%vol，感官评分为87.14分，颜色呈米黄色，酒体丰满醇和，香气自然纯正，具有幽雅的水果香和花香。     

Hydrogen production potential from agricultural biomass in Punjab province of Pakistan

Depleting resources and popping environmental concerns instigate the development of sustainable and clean energy solutions. Amongst others, Hydrogen (H₂) is an imperious alternative due to the lowest emissions, higher calorific value, and usability. It has great relevance in Pakistan due to sequester Agricultural biomass potential that can be used as feedstock for H₂ production. So, this study estimates the H₂ production potential from agricultural biomass (rice, sugarcane, cotton, wheat, and maize) of Punjab, Pakistan. In doing so, simulations are performed using Aspen Plus under various conditions to derive an optimal value of H₂ output. The results indicate significant heterogeneity across districts and crop residues types. Therefore, the Geographic Information System (GIS) is used to draw the spatial distribution of optimal H₂ production across crops and districts. The simulated results reveal that Punjab province has the potential to produce 2619.90 × 10³ Metric tons (MT)/year H_2, and the highest potential derives from sugarcane trash (1012.77 × 10³ MT/year), followed by maize straw (433.67 × 10³ MT/year). The estimated H₂ potential (2.62 million MT/year) can be used in industries, transportation, and urea production as a sustainable alternative in Pakistan.     

茶树品种对筠连红茶品质的影响

本文主要探讨不同茶树品种对筠连红茶品质的影响。选择当地主栽的福选9号、乌牛早、早白尖5号和四川群体品种四个茶树品种的原叶,按四川工夫红茶工艺制成红茶成品,检测主要生化成分、挥发性物质、感官指标。结果显示:4个品种所制红茶的茶多酚含量在16.12%~17.22%之间,可溶性糖含量在4.50%~9.11%之间,总黄酮含量在2.29%~2.70%之间,其中四川群体品种的茶多酚和可溶性糖含量显著(P<0.05)高于早白尖5号,乌牛早可溶性糖含量显著(P<0.05)高于其它3种红茶,早白尖5号的总黄酮显著(P<0.05)低于乌牛早和福选9号;4种红茶氨基酸总量在27.42~39.04 mg/g之间,其中呈味氨基酸占64.08%~69.38%,具有较好的滋味物质基础,四川群体品种、乌牛早及早白尖5号鲜味氨基酸分别占53.15%、52.05%和55.13%,具有开发高鲜红茶潜质;福选9号、乌牛早、早白尖5号和四川群体品种共检测出醇、醛、酯、酮、碳氢化合物和其它化合物等6类61种挥发性成分,共有成分22种,其中醇类物质是4个品种红茶的主要挥发性香气成分,且芳樟醇及其氧化产物含量丰富;感官审评结果显示,四川群体品种、乌牛早和早白尖5号所制红茶鲜爽醇厚,优于福选9号。因此,四川群体品种、乌牛早及早白尖5号更适宜生产优质筠连红茶。