Effects of high hydrostatic pressure on secondary structure and emulsifying behavior of sweet potato protein

In this study, secondary structures of sweet potato protein (SPP) after high hydrostatic pressure (HHP) treatment (200–600?MPa) were evaluated and emulsifying properties of emulsions with HHP-treated SPP solutions in different pH values (3, 6, and 9) were investigated. Circular dichroism analysis confirmed the modification of the SPP secondary structure. Surface hydrophobicity increased at pH 3 and decreased at 6 and 9. Emulsifying activity index at pH 6 increased with an increase in pressure, whereas emulsifying stability index increased at pH 6 and 9. Oil droplet sizes decreased, while volume frequency distribution of the smaller droplets increased at pH 3 and 6 with the HHP treatment. Emulsion viscosity increased at pH 6 and 9 and pseudo-plastic flow behaviors were not altered for all emulsions produced with HHP-treated SPP. These results suggested that HHP could modify the SPP structure for better emulsifying properties, which could increase the use of SPP emulsion in the food industry.     

A novel imaging tool for hepatic portal system using phase contrast technique with hydrogen peroxide‐generated O2 gas

The objective of this study was to investigate the potential of hydrogen peroxide‐generated oxygen gas‐based phase contrast imaging (PCI) for visualizing mouse hepatic portal veins. The O₂ gas was made from the reaction between H₂O₂ and catalase. The gas production was imaged by PCI in real time. The H₂O₂ was injected into the enteric cavity of the lower sigmoid colon to produce O₂ in the submucosal venous plexus. The generated O₂ gas could be finally drained into hepatic portal veins. Absorption contrast imaging (ACI) and PCI of O₂‐filled portal veins were performed and compared. PCI offers high resolution and real‐time visualization of the O₂ gas production. Compared with O₂‐based ACI, O₂‐based PCI significantly enhanced the revealing of the portal vein in vivo. It is concluded that O₂‐based PCI is a novel and promising imaging modality for future studies of portal venous disorders in mice models.     

基于RST-QFD-Bayes的新型装甲装备通用质量特性评价指标体系构建研究

针对新型装甲装备通用质量特性评价指标体系难以确定的问题,在明确评价指标体系构建原则的基础上,结合新型装甲装备特点,确定了通用质量特性初始评价指标及指标筛选要求,运用QFD将新型装甲装备通用质量特性需求映射为评价指标筛选要求,采用粗糙集理论(Rough Set Theory,RST)确定了指标筛选重要度,考虑到关联度的不确定性及多个专家估计值的平均值和估计值的波动程度,将贝叶斯理论引入关系矩阵的确定中,用区间数确定了关联度,进行了评价指标筛选,构建了新型装甲装备通用质量特性评价指标体系,为新型装甲装备通用质量特性评价奠定了基础。     

一种牧场配料系统的设计与实现

提出了一种应用于移动Ad Hoc网络的分布式资源接纳控制机制,在目的节点和中间节点部署不同的资源接纳控制模块,能以接近通话或者分组传输的时间间隔适应网络的动态变化,为业务提供较好的QoS保障,并且能够支持多播及接收者异质性。仿真结果表明,添加资源接纳控制机制后,时延、抖动及丢包率分别降低了25.75%,51.76%和24.15%。     

LNG尾气中提取氦气的流程分析

LNG产业的蓬勃发展为资源利用开发了新的途径。基于液化天然气尾气的特点,文中提出了一种与液化天然气产业联产氦气的新方法,设计了相应的工艺流程。通过对尾气进行增压脱酸、冷凝分离、加氧脱氢、内纯化除杂等多种处理,可对天然气尾气中的氦进行有效提取分离,最终达到纯氦的技术指标。该方法有望使国内不具备工业提取价值的氦资源重新得到利用,在国内建立一种新型的氦供应途径。     

奥氏体不锈钢深冷低温冲击试验方法研究

以液氦作为冷源,结合G-M低温制冷机,实现-196~-269℃深冷温度环境,探索深冷低温冲击试验方法。结果表明,试样从低温环境中取出后置于大气环境中,温度出现快速回升。对于不同试验低温,可采用不同方法进行试验。试验温度T=4.2K时,可采用制冷机预冷+液氦持续喷淋的方法进行降温。试验温度10≤T77K时,可采用玻璃容器填充气凝胶粉体对试样进行绝热保温处理;或根据试验温度以及回温测试结果,以一定的过冷温度补偿值保证试验温度。过冷温度补偿方法可满足常规冲击试验的要求,但需要相对较大的过冷温度补偿值;玻璃容器填充粉体包裹试样,可减缓试样温度回升,但对材料冲击吸收能量有一定影响,可用多试样冲击试验并进行修正以反映材料冲击韧性水平。     

基于微机电系统技术的高性能集成型微富集器（英文）

由于大部分环境样品的浓度非常低,为了实现其直接检测,提出将一种集成化的微型富集器应用到色谱系统中。富集器可实现色谱系统的进样与样品富集,能将色谱仪的检测限提高1~2个数量级。设计的富集器采用了高容量4平行通道结构,沟道内填充了高吸附率的Tenax-TA吸附材料,来实现对环境样品中挥发性有机化合物组分的富集。此外,为了密闭热解吸过程中所释放的组分,在微型富集器后集成了微型阀。试验结果表明,研制的微型富集器取得了15倍以上的富集因子。而且,通过微阀的控制,色谱峰的拖尾和峰展宽得到了有效的控制。因此,该微型富集器可广泛应用到环境样品的快速检测中,提高各检测器对复杂环境的适应能力。     

微通道换热器复合翅片的传热特性研究

研究了管径对微通道换热器传热性能的影响,并在百叶窗翅片的基础上开发了两种复合翅片。计算结果表明:在同一迎面风速下,1mm管径的百叶窗翅片Nu数分别比1.5mm和1.8mm管径的大4.8%~10.5%和24.6%~25.8%。JF值增加11%~15%和26%~28%,说明管径为1mm时微通道换热器的综合性能更好。与百叶窗翅片相比,百叶窗-三角翼复合翅片的换热系数减小1.9%~5.4%,但压降降低7.8%~12.7%,表明复合翅片是一种高效低阻翅片。     

电容式液氢密度计冷冲击性能试验研究

建立了一套电容式液氢密度计冷冲击试验系统,对新研制的密度计传感器和变送器进行液氢工况下的联合调试,研究其在液氢冲击下的数据采集传输转换性能。从理论分析、系统设计、试验验证、数据分析四方面详细阐述了该试验过程。试验结果表明:密度计在液氢下的信号采集传输特性与理论分析特性基本吻合,输出信号正常,实现了该试验预期效果。     

Global continuum of positive solutions for discrete <Emphasis Type="Italic">p</Emphasis>-Laplacian eigenvalue problems

We discuss the discrete p-Laplacian eigenvalue problem,

$$\left\{ \begin{gathered} \Delta (\phi _p (\Delta u(k - 1))) + \lambda a(k)g(u(k)) = 0,k \in \{ 1,2,...,T\} , \hfill \\ u(0) = u(T + 1) = 0, \hfill \\ \end{gathered} \right.$$

where T > 1 is a given positive integer and φ _p (x):= |x| ^p?2 x, p > 1. First, the existence of an unbounded continuum C of positive solutions emanating from (λ, u) = (0, 0) is shown under suitable conditions on the nonlinearity. Then, under an additional condition, it is shown that the positive solution is unique for any λ > 0 and all solutions are ordered. Thus the continuum C is a monotone continuous curve globally defined for all λ > 0.