深过冷Cu50Ni50熔体凝固的定向枝晶组织

在高真空度下,采用熔融玻璃净化与循环过热相结合的方法,在宽的过冷度范围内,研究了Ｃｕ５０Ｎｉ５０合金凝固组织开头演化过程。结果表明,随着过冷度增大,凝固组织发生了３次转变。其中,当１２０Ｋ（ΔＴ＾＊２）〈ΔＴ〈１９２Ｋ（ΔＴ＾＊３）时,凝固组织发生第２次转变,由粒状晶演变为定向生长的深过冷枝晶。通过组织观察和过冷熔体枝晶生长过程的计算发现,快速凝固形成的枝晶在再辉和再辉结束后枝晶熟化过程被高度抑制     

κ-阿片受体与β1-肾上腺素受体交互作用抑制异丙肾上腺素诱导的心肌肥大

目的: 观察选择性 kappa 阿片受体(kappa opi-oid receptor,κ-OR)与 β 肾上腺素受体(β adrenergicreceptor, β-AR)在心肌细胞肥大方面的交互作用。方法: 以 体 外 培 养 的 乳 鼠 心 肌 细 胞 为 模 型, 10 μmol°L^-1 的异丙肾上腺素(β肾上腺素受体激动剂,β-AR)诱导心肌肥大, 观察 1μmol°L^-1的 U50,488H(κ-OR激动剂,U50)对其作用。进一步探索在100 nmol°L^-1ICI118, 551(β₂ -AR 阻断剂)存在情况下,κ-OR的激活对心肌肥大的作用。用 Lowry's 法测心肌细胞的蛋白质含量;用消化分离法,并利用计算机图象分析系统测心肌 细胞的体积;用[³H]leucine 掺入法测定心肌细胞蛋白的合成。结果: 异丙肾上腺素使心肌细胞总蛋白含量、体积、蛋白合成明显增加;1 μmol°L^-1 的 U50, 488H 使 ISO 诱导的心肌细胞总蛋白含量、体积、蛋白合成减少, 这种作用可被选择性 κ-OR阻断剂-nor-BNI(norbinaltorphimine)抑制。在 ICI118, 551 存在的情况下, U50 也能起到减弱 ISO 诱导心肌细胞肥大的作用。结论: U50,488H 通过激活 κ-OR 与β₁ -AR 交互作用抑制 ISO 所诱导的心肌细胞肥大。     

Sb对AM50-Y镁合金组织和力学性能的影响

研究合金元素Sb对AM50-Y合金显微组织和力学性能的影响。结果表明,加入Sb后,合金晶粒明显细化,同时形成弥散分布的YSb相。YSb相作为异质形核核心,促进了细小弥散分布的Al2Y颗粒相的形成。随着Sb含量的增加,合金室温和150℃高温抗拉强度、延伸率及室温冲击韧性先上升后下降。当Sb含量为0.6%时,合金综合力学性能最好:合金室温抗拉强度、延伸率和冲击韧性分别为257MPa、9.9%和26J·cm-2,与未添加Sb合金相比分别提高了13.7%、15.9%和14.9%;合金的高温抗拉强度和延伸率达到203MPa和11.9%,分别提高了12.8%和15.5%。     

Performance of cold sprayed Ni‐20Cr and Ni‐50Cr coatings on SA 516 steel in actual industrial environment of a coal fired boiler

Power plants are one of the major industries suffering from severe erosion–corrosion (E‐C) problems resulting in substantial losses. One way of tackling this problem is by the use of thermal spray coatings. In the current investigation a new emerging technique i.e. cold spray coating process was used to deposit Ni‐20Cr and Ni‐50Cr powder on SA 516 (grade 70) boiler steel. The bare as well as the coated steels were subjected to cyclic experimental studies, in the superheater zone of a coal fired boiler. Weight change, thickness loss, XRD, FE‐SEM/EDS and X‐ray mapping techniques were used to analyse the eroded‐corroded specimens. The uncoated steel showed weight gain after exposure in the actual boiler environment, whereas, for the coated steels there was initial weight loss followed by negligible weight change. Based upon thickness loss data the cold‐sprayed Ni‐50Cr coating was found to provide better E‐C resistance than the Ni‐20Cr coating.     

Pro-Inflammatory Effect of Gliadins and Glutenins Extracted from Different Wheat Cultivars on an In Vitro 3D Intestinal Epithelium Model

There is a need to assess the relationship between improved rheological properties and the immunogenic potential of wheat proteins. The present study aimed to investigate the in vitro effects of total protein extracts from three modern and two landrace Triticum aestivum commercial flour mixes, with significant differences in gluten strength (GS), on cell lines. Cytotoxicity and innate immune responses induced by wheat proteins were investigated using Caco-2 monocultures, two dimensional (2D) Caco-2/U937 co-cultures, and three dimensional (3D) co-cultures simulating the intestinal mucosa with Caco-2 epithelial cells situated above an extra-cellular matrix containing U937 monocytes and L929 fibroblasts. Modern wheat proteins, with increased GS, significantly reduced Caco-2 cell proliferation and vitality in monoculture and 2D co-cultures than landrace proteins. Modern wheat proteins also augmented Caco-2 monolayer disruption and tight junction protein, occludin, redistribution in 3D co-cultures. Release of interleukin-8 into the cell medium and increased U937 monocyte migration in both 2D and 3D co-cultures were similarly apparent. Immuno-activation of migrating U937 cells was evidenced from cluster of differentiation 14 (CD14) staining and CD11b-related differentiation into macrophages. The modern wheat proteins, with gluten polymorphism relatedness and increased GS, were shown to be more cytotoxic and immunogenic than the landrace wheat proteins.     

液体分布器检测专用工具在汽提塔中的应用

介绍一种液体分布器检测专用工具的原理,该工具应用在尿素汽提塔后,保证了汽提塔液体分布效果,对汽提塔设备保护和节省汽耗起到关键作用.     

Minor Intron Splicing from Basic Science to Disease

Pre-mRNA splicing is an essential step in gene expression and is catalyzed by two machineries in eukaryotes: the major (U2 type) and minor (U12 type) spliceosomes. While the majority of introns in humans are U2 type, less than 0.4% are U12 type, also known as minor introns (mi-INTs), and require a specialized spliceosome composed of U11, U12, U4atac, U5, and U6atac snRNPs. The high evolutionary conservation and apparent splicing inefficiency of U12 introns have set them apart from their major counterparts and led to speculations on the purpose for their existence. However, recent studies challenged the simple concept of mi-INTs splicing inefficiency due to low abundance of their spliceosome and confirmed their regulatory role in alternative splicing, significantly impacting the expression of their host genes. Additionally, a growing list of minor spliceosome-associated diseases with tissue-specific pathologies affirmed the importance of minor splicing as a key regulatory pathway, which when deregulated could lead to tissue-specific pathologies due to specific alterations in the expression of some minor-intron-containing genes. Consequently, uncovering how mi-INTs splicing is regulated in a tissue-specific manner would allow for better understanding of disease pathogenesis and pave the way for novel therapies, which we highlight in this review.     

Fabrication of three-dimensional TKX-50 network-like nanostructures by liquid nitrogen-assisted spray freeze-drying method

ABSTRACT

Design and fabrication of micro- and nanostructures for energetic materials have attracted more attention recently to improve safety properties and enhance detonation performance. Exploring and developing dihydroxylammonium 5,5′-bistetrazole-1,1′-diolate (TKX-50) with unique microstructures, an emerging high-energy-density material with superior comprehensive properties, is of great significance for the potential applications. In this work, we reported that three-dimensional (3D) TKX-50 network-like nanostructures were designed and fabricated successfully via the liquid nitrogen-assisted spray freeze-drying method. Characterization results suggested 3D TKX-50 network-like nanostructures were constructed by self-assembly of small nanoparticles. Furthermore, a nucleation-and-growth self-assembly formation mechanism of the network-like nanostructures depended on the different concentrations of the aqueous solution of TKX-50 was proposed in detail based on the experimental results. More interestingly, thermal analysis results demonstrated these novel 3D TKX-50 network-like nanostructures are much easier to be activated and have a lower decomposition temperature than the raw material, due to decrease in particle sizes, and the impact sensitivity of 3D TKX-50 network-like nanostructures become more sensitive than that of raw TKX-50. Their friction sensitivity of as-prepared samples is similar to the raw materials. Therefore, this work could provide a new prospect for fabrication and application of TKX-50 nanostructures.     

在检波点域分离50Hz工业干扰

地面高压线路和设备的增加为油区工业化带来了方便,但其产生的50Hz工业干扰却严重影响了这些地区的野外地震数据采集质量。本文以官7地区三维地震资料为例,研究开发出了一种有效压制50Hz工业干扰的方法——检波点域分离法。实际资料处理证明了该方法的有效性。     

小波包变换及正弦函数模拟消除50 Hz工业干扰

陷波技术是用于消除50 Hz工业干扰的一种有效工具，由于其采用频率切除技术，故在消除50 Hz工业干扰的同时，使50 Hz及其附近的有效信号受到损失，给后续处理带来不利影响。为此，提出采用正弦函数来模拟50 Hz工业干扰，并采用减法运算从数据中减去它，达到消除50 Hz工业干扰又使有效波损失减小到最小的目的。为了使去噪处理仅在有限频带上进行，采用小波包变换分解来得到50 Hz工业干扰所在频带；为使在有限频带内模拟50 Hz工业干扰实现方便，采用了卷积型小波包变换来得到含有50 Hz工业干扰且其小波系数保持了与原始记录相同的样点数。最后给出了理论模型测试结果，并应用实际单炮记录进行了对比处理。