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51.
Xianlong Wang Jinchuan Jie Shichao Liu Zhuangzhuang Dong Guomao Yin Tingju Li 《材料科学技术学报》2021,61(2):138-146
In the present work, in-situ Ti5Si3 reinforced special brasses were prepared by melt reaction method. The synthesized Ti5Si3 phase shows various morphologies in brasses with different Ti5Si3 content, and the3 D morphological evolution of primary Ti5Si3and its growth mechanism were investigated. The Ti5Si3 crystal, which bears D88 hexagonal crystal structure, grows along <0001> direction and is revealed by{1010} faces during growth. With the increase of Ti5Si3 content in the brasses, the morphology of primary Ti5Si3significantly changes from fibers to hexagonal prisms to short-rods with hollow. In addition,the influence of Ti5Si3 volume fraction and morphology on the wear behavior of special brass was also revealed. It was substantiated that the wear resistance increases with the increasing volume fraction of Ti5Si3, and the corresponding wear mechanism changes from delamination to slight adhesive wear and abrasive wear. However, the friction coefficient shows an abnormal increase when most of the Ti5Si3 containing hollows appears in the brass. That is mainly due to the fact that the Ti5Si3 is easier to break and fall off resulted by the hollow as a crack source, which makes it unable to resist the plastic deformation of the contact surface during the sliding. 相似文献
52.
纵观当今的发展格局,是科学技术高速发展的时代。随着5G时代的来临,网络技术在各个领域中扮演着越来越重要的角色。特别是在医疗方面,为医院的日常工作奠定了坚实的基础。今天就5G网络技术在医院只能服务中的应用展开谈论。 相似文献
53.
Paulina Koodziej-Wojnar Joanna Borkowska Zofia Wicik Anna Domaszewska-Szostek Jacek Poosak Marta Ckaa-Jakimowicz Olga Bujanowska Monika Puzianowska-Kuznicka 《International journal of molecular sciences》2021,22(1)
5-Hydroxymethylcytosine (5hmC) is a functionally active epigenetic modification. We analyzed whether changes in DNA 5-hydroxymethylation are an element of age-related epigenetic drift. We tested primary fibroblast cultures originating from individuals aged 22–35 years and 74–94 years. Global quantities of methylation-related DNA modifications were estimated by the dot blot and colorimetric methods. Regions of the genome differentially hydroxymethylated with age (DHMRs) were identified by hMeDIP-seq and the MEDIPS and DiffBind algorithms. Global levels of DNA modifications were not associated with age. We identified numerous DHMRs that were enriched within introns and intergenic regions and most commonly associated with the H3K4me1 histone mark, promoter-flanking regions, and CCCTC-binding factor (CTCF) binding sites. However, only seven DHMRs were identified by both algorithms and all of their settings. Among them, hypo-hydroxymethylated DHMR in the intron of Rab Escort Protein 1 (CHM) coexisted with increased expression in old cells, while increased 5-hydroxymethylation in the bodies of Arginine and Serine Rich Protein 1 (RSRP1) and Mitochondrial Poly(A) Polymerase (MTPAP) did not change their expression. These age-related differences were not associated with changes in the expression of any of the ten-eleven translocation (TET) enzymes or their activity. In conclusion, the distribution of 5hmC in DNA of in vivo aged human fibroblasts underwent age-associated modifications. The identified DHMRs are, likely, marker changes. 相似文献
54.
2020作为脱贫关键期,随着全国人民生活水平日益提升,动车、地铁成为人们日常出行的交通工具。高铁、地铁隧道覆盖的好坏,对用户体验感受有极大的影响,目前隧道主要通过泄漏电缆进行覆盖,本文将结合济南地铁R2线,针对移动5G对不同型号的泄露电缆的覆盖能力进行对比研究。 相似文献
55.
Senliang Xi Xiaojun Wang Kudzaishe Caren Tome Tonghuan Zhang Zongying Han Meng Gao Shixue Zhou Hao Yu 《International Journal of Hydrogen Energy》2021,46(46):23748-23756
The hydrogen storage performances of MgH2 improved by the addition of Ni and SAPO-34 were studied in detail. The mixture of MgH2 with Ni and SAPO-34 was a physical reaction as shown by the X-ray diffraction (XRD) results. The SAPO-34 and Ni were uniformly distributed on the surface of MgH2. The thermodynamic and kinetic properties of 90MgH2/5Ni/5SAPO-34 were investigated by differential scanning calorimetry (DSC) and pressure-composition-isothermal (PCI) methods. The results showed that the dehydrogenation activation energy of 90MgH2/5Ni/5SAPO-34 decreased by 64.3 kJ/mol compared with that of MgH2. In addition, the relationship between the value of dehydrogenation heat and hydrogen content was also investigated by in-situ calorimetry. The enthalpy value of each sample in the dehydrogenation processes were calculated by in-situ calorimetry measurement. The dehydrogenation enthalpies of as-milled MgH2 and 90MgH2/5Ni/5SAPO-34 were 63.2 kJ/mol H2 and 53.6 kJ/mol H2, respectively. Thus, the co-doping of Ni and SAPO-34 contributed significantly to decrease the thermodynamic stability and improve the hydrogen sorption kinetic properties of MgH2. 相似文献
56.
57.
Cornelia Wiegand Tanja Hansen Johanna Köhnlein Ines Exner Marlen Damisch-Pohl Peter Schott 《纺织学会志》2018,109(7):891-902
Biocompatibility of six different compression stockings and cytotoxic effects were determined using HaCaT keratinocytes, L929 mouse fibroblasts, primary adult and juvenile keratinocytes Cells were quantified using a luminometric ATP assay and the photometric BCA test. Cytotoxic effects were determined by LDH release. An area-based extraction ratio of 1.25 cm2:mL could be shown to be superior to the weight-based extraction of test material. Extraction medium should be an acidic sweat solution as this helps to recreate in vivo conditions. Monolayer cultures of HaCaT keratinocytes or L929 mouse fibroblasts should be used for testing. Primary adult keratinocytes or primary juvenile keratinocytes can also be used. For the latter, testing under DMEM with FCS is recommended to achieve comparable results. It was found that the compression stockings tested exhibited no negative influence on cell viability in vitro and no direct cytotoxic effects measured as release of LDH. Hence, good biocompatibility could be asserted. 相似文献
58.
论述了5G光模块的技术和产业化发展现状,分析了4种波分复用技术应用于5G前传网络的优缺点,给出了后续5G光模块发展的策略建议. 相似文献
59.
为更有针对性地进行故障排除工作,文章设计研发了一款多媒体软件平台,嵌入细化后的DZZ5型自动气象站各观测要素的故障排查流程,并在相应故障检测节点中添加文字、图片和操作视频。用户可按照流程逐一进行排查操作,或者搜索关键字查看节点内容。同时提供带有关键字查询功能的故障实例库,供基层装备保障业务人员参考。 相似文献
60.
在通信用户数密集用户业务总量较多的UMi场景下,无线网络节点较多小区覆盖半径较小,用户在小区间移动导致小区间用户分布不均匀,原有用户数及业务量标准部署的5G异构网络相对稀疏,无法满足用户流动产生热点热时容量需求时,双小区协作流动热点补偿采用异构网络多点协作传输技术对小区进行补热,将处于相同移动状态的多个用户虚拟成一个以中心用户为中心的用户簇,建立3D MIMO流动热点模型,提出在两小区以用户最小传输速率为约束条件,最小化小区基站总功率的优化算法,得出高容量、高速率用户体验的"潮汐效应"解决方案。 相似文献