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31.
采用第一性原理方法分析了Ag(110)、(211)与Ni(110)、(211)的界面结合情况。通过对界面结合能、电荷布居以及界面处的电子结构等研究分析发现,在Ag与Ni界面的结合形式中,以Ag(110)/Ni(211)的界面结合能最高,界面处的电子杂化最为剧烈,其界面结合也是最稳定的 相似文献
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采用离子束溅射镀膜装置制备了一种新的材料组合Si/C多层膜 ,用于 30 4nm波段的正入射多层膜反射镜。并用软X射线反射率计测得其反射比最大值为 0 14。有效地抑制了 15 0nm处的二级衍射峰。 相似文献
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阐述了如何利用Java消息服务和心跳技术实现对分散模块状态的监控,以及保证模块间通信无阻。通过收发消息的形式,集中监控关键模块,并准确定位故障所在,尽可能保证系统长时间的无故障运作。 相似文献
36.
Xu Peng Ni YiKun Liu JingLong Zhang WeiRong Liu SiJian Wang LiZhen Fan YuBo 《中国科学:技术科学(英文版)》2021,64(5):1101-1106
Woodpeckers can withstand a fierce impact during pecking. Previous studies have focused on the biomechanical analysis of the pecking process, the properties of the beak and hyoid bone of woodpecker; however, the biological characteristics of the woodpecker brain are also important in resisting impact injuries. We employed impact experiments and biological analysis in normal and injured brains to reveal the impact-resistant biological characteristics of woodpecker brains, as well as the impact energy's biological effects on the woodpecker brain. The hoopoe, which has a similar size but only a slight pecking behavior, was selected as the control group to compare brain morphology and neuronal cells differences in normal brains between woodpecker and hoopoe by sectioning and staining. A loading device was designed to conduct a quantifiable impact energy to the woodpeckers' head. Four groups of woodpeckers were impacted with the same energy on the forehead, beak, tempus and occiput,respectively. Biological changes in the injured brains were evaluated by Nissl staining and enzyme-linked immunosorbent assay.The results showed that:(1) woodpeckers had a larger cerebellum and a higher density of Nissl bodies than hoopoe;(2) Nissl apoptosis appeared in the brain samples after the forehead and the occiput impact experiments, but no obvious Nissl body apoptosis was observed after impact on the tempus and the beak;(3) β-amyloid protein accumulated in the normal status woodpecker brain. This study reveals that: woodpecker brain morphology is well-adapted to impact, woodpecker heads display location-dependent protective performance, with beak and tempus regions having a better protective performance than the forehead and occiput, Nissl apoptosis appears in injured woodpecker brains, and that the accumulation of β-amyloid protein does not show a direct relationship with the injury state of woodpecker's brain tissue in our study. 相似文献
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Yuan-zheng Guo Deng-xiong ShenHong-jiang Ni Jin-gang Liu Shi-yong Yang 《Progress in Organic Coatings》2013
Semi-alicyclic polyimides (PI-1–PI-4) have been prepared from a newly-developed alicyclic dianhydride, 3,4-dicarboxy-1,2,3,4-tetrahydro-6-tert-butyl-1-naphthalene succinic dianhydride (TTDA) and various aromatic diamines. The asymmetrical alicyclic tetralin structure in TTDA endowed the derived PI resins good solubility in various organic solvents. They were soluble not only in polar aprotic solvents but also in solvents with low boiling points including dichloromethane and tetrahydrofuran. Flexible and tough PI films were successfully cast from their N-methyl-2-pyrrolidone (NMP) solution except PI-1 derived from TTDA and 4,4′-oxydianiline (ODA). The PI films exhibited good optical transparency in the ultraviolet and visible light region with optical transmittances around 80% at a wavelength of 400 nm. The PI films showed good thermal stability up to 400 °C in nitrogen, after that they thermally decomposed rapidly. The thermal degradation behaviors of the PIs were investigated by means of thermogravimetric analysis-mass spectrometry (TG-MS), thermogravimetric analysis-Fourier transform infrared spectrometry (TG-FTIR) and the real time FTIR spectra (RT-FTIR) analysis techniques. The results revealed that the decomposition of PI-1 (as a representative) took place mainly in the range of 450–550 °C. The major degradative fragments at 500 °C were clearly identified as the tert-butyl-substituted tetralin moiety and its dealkylation products. Therefore, it can be deduced that for the TTDA-PIs, the single bond bridge attached the maleic anhydride and tetralin anhydride units in TTDA moiety might break first during the heating; thus producing the tetralin fragments. 相似文献
39.
The synthesis of hyperbranched polyphosphoramidate (HPPAE) has been successfully achieved via a facial A2 + CB2 approach. First, an AB2 type intermediate is generated by the reaction between the phosphorus chloride group of ethyldichlorophosphate and the secondary amine group of diethanolamine. Second, the above intermediate can further self‐condense to produce the hyperbranched polymer. The molecular weight and the structural characterization of HPPAE were checked by gel permeation chromatography and Fourier transform infrared and NMR (13C and 31P) spectroscopy. The degradation study of HPPAE indicated that phosphate and phosphoramide bonds between the branch points are responsible for its complete hydrolysis in an aqueous phosphate buffer (pH 7.4) after 6 days. In addition, HPPAE presents a strong fluorescence peak at 450 nm, exhibiting the potential to track drug transport and distribution in real time. © 2012 Society of Chemical Industry 相似文献
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介绍了甲醇生产中焦炉煤气精脱硫系统积碳与结焦的危害以及应对方法。通过设备改造及工艺调整等措施,减少各种杂质进入精脱硫系统,使加氢催化剂保持良好效果,实现设备长周期运行。 相似文献