基于TRIZ解决航空航天用吸波贴片成本高的问题

目的 解决隐身飞机在飞行过程中因吸波贴片自身过重产生巨大的飞行成本,吸波贴片在飞行条件下易产生划痕、损伤、材料损耗快,以及因修复工序复杂、耗时长产生大量维护费用等问题。方法 应用TRIZ理论进行分析求解,通过采用功能模型分析、因果分析等找到航空航天用吸波贴片成本高的关键缺陷,利用技术矛盾分析、物理矛盾分析、物场模型及标准解、小人法等工具得到多个解决方案。经过综合评估最终找到经济、易于实现的解决方案。结果 通过运用TRIZ理论,并且通过综合评价找到了减少吸波贴片成本的最优方案：吸波贴片中的吸波体由掺杂杂原子的石墨烯构成了多孔结构,增加了其吸波性能;再将材料与自愈合材料相结合,增加其自愈能力,从而得到吸波性能好、质量小、自愈合能力强的吸波贴片。结论 文中得出的结果对减少隐身战机吸波贴片成本的研究具有一定的理论指导意义,有助于减少高集成设备过多对人类及环境产生的危害。     

Synthesis and electrochemical properties of nickel oxide/carbon nanofiber composites

The electrospinning of polyacrylonitrile (PAN) with a polyaniline and graphene sol–gel mixture produced uniform, smooth fibers with an average diameter of 0.3 μm. These electrospun fibers were stabilized for 2 h at 200 °C and then carbonized at 800 °C for 5 h. Composites were prepared by depositing Ni(OH)₂ on the carbon nanofibers (CNFs) and calcining them at different temperatures. The composites were characterized with X-ray diffraction (XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The effect of the calcination temperatures on the electrochemical properties was studied using cyclic voltammetry and electrochemical impedance spectroscopy. The specific capacitance (SC) was found to be highest (738 F g⁻¹) at a calcination temperature of 400 °C. The charge transfer resistance (R_p) decreased as the calcination temperature was increased. However, the electrical double layer capacitance (EDLC) increased with an increase in the calcination temperature. The EDLC increased from 0.144 F g⁻¹ at a calcination temperature of 100 °C to 485 F g⁻¹ at a calcination temperature of 500 °C.     

Synthesis and characterization of microporous polymer microspheres with strong cation-exchange character

In this paper the synthesis and characterization of microporous polymer microspheres with ultra-high specific surface areas (>1000 m²/g) and strong cation-exchange character is described. The microspheres were synthesized by the hypercrosslinking of swellable precursor particles which had been produced by precipitation polymerization. The strong cation-exchange character, arising from the presence of sulfonic acid groups, was introduced through post-hypercrosslinking chemical modification reactions. Two alkyl sulfate reagents of differing polarity were compared as reagents for the sulfonation reactions, and a synthetic methodology was devised that allowed the sulfonic acid content of the microspheres to be controlled. Following a series of small-scale optimization experiments, optimized conditions were applied on a larger scale to the synthesis of three distinct polymers (HXLPP-SCX) tailored for use as strong cation-exchange (SCX) sorbents in solid-phase extraction (SPE) studies. All three polymers were in the form of polymer microspheres (mean particle diameters 3–5 μm) with relatively narrow particle size distributions and specific surface areas up to 1370 m²/g, and had tuneable ion-exchange capacities (IECs) ranging from 1.7–2.8 mmol/g.     

Optical properties of impact diamonds from the Popigai astrobleme

Impact diamonds from Popigai astrobleme were found to consist of different carbon phases: cubic and hexagonal diamond with sp³ bonding according to X-ray structural analysis as well as amorphous, crystalline and disordered graphite with sp²-bonding (Raman scattering). The sizes of graphite domains vary from 10 to 100 nm. Fundamental absorption edge for Popigai impact diamonds is shifted ~ 0.5 eV to lower energies in comparison with kimberlite diamonds (5.47 eV) as a result of the lonsdaleite input, in good agreement with ab initio calculations (E_g = 5.34 and 4.55 eV for 3C cubic and 2H hexagonal diamonds, respectively). Yellowish color of impact diamonds is due to Rayleigh light scattering on structural defects whereas graphite is responsible for gray to black coloring. In the mid-IR region there is a multi-phonon absorption of 3C diamond in the 1800 to 2800 cm^− 1 range and some new bands at 969, 1102, 1225, and 1330 cm^− 1 in the one-phonon region. Micro-Raman study shows inclusions of side noncarbon minerals (quartz, magnetite, and hematite) some of which contain Cr^3 + impurity. The vibration modes of cubic diamond and lonsdaleite exhibited in the Raman spectra were elucidated by the first-principles studies. Popigai impact diamonds demonstrate a broad-band luminescence in 2.1, 2.38, and 2.84 eV components similar to that for nanocrystal polycrystalline 3C diamond. All emissions are excited at band-to-band transitions whereas the last two are observed also at excitation into 2.4 and 3.0 bands supposedly as a result of intracenter processes within the H3(NVN) and NV⁰ centers.     

平凉钙基膨润土干法钠化工艺研究

采用干法工艺,对甘肃平凉膨润土进行钠化改性,分别从不同钠化剂(碳酸钠、氯化钠、氢氧化钠)的选择和配比、钠化高混时间、自然放置时间等因素对钠化土性能的影响进行了研究.用FT IR和XRD对钠化土进行分析,结果表明,钠化土在不改变原土结构的同时发生了阳离子交换,层间距明显增大.     

烯烃复分解法制备端基官能化液体橡胶研究进展

用烯烃复分解法制备端基官能化液体橡胶具有分子量可控、易于引入多种官能团、反应条件较温和等优势。本文即综述了利用烯烃复分解法制备端羟基、端羧基、端酯基等官能化液体橡胶的研究新进展,并提示了其今后的发展方向。     

Oxygen transfer and catalytic properties of nickel iron oxides for steam reforming of methane

Nickel iron oxide (NiFe₂O₄) has been tested as a combined catalyst precursor and oxygen transfer material for improved conversion of methane into syngas. Thermogravimetric measurements with simultaneous gas analysis have demonstrated the superior behavior of nickel iron oxide compared to iron oxide. The enhanced catalytic activity is attributed to the generation of fresh nickel surfaces in the course of the reduction of the metal oxide. This allows for a periodic in situ generation of fresh, catalytically active nickel.     

Friction of molybdenum disulfide–titanium films under cryogenic vacuum conditions

The tribological behavior of steel and sapphire sliding on a sputtered MoS₂+Ti coating was studied in ultra-high vacuum as a function of temperature over the range of 4–300 K. The coefficient of kinetic friction for the steel/moly interface was determined to be approximately 0.05 from room temperature to 240 K, and increased monotonically to 0.125 at 4 K. The sapphire/moly friction coefficient was measured to be 0.15±0.05 at room temperature and increased monotonically to 0.25 at 4 K. We also analyze in detail the flash temperature due to frictional heating at the sliding contacts. Flash heating is a particularly strong effect at cryogenic temperatures.     

基于荧光素的荧光聚硫酸酯的制备及表征

采用双酚A（BA）、双酚A硫酰氟和荧光素进行高温溶液缩聚反应,制备了荧光聚硫酸酯（PSE-FL）,并对其进行了结构表征及荧光特性研究。结果表明,制备的PSE-FL的数均分子量为33 413 g/mol,重均分子量为55 043 g/mol,分子量分布指数为1.64,为典型的无定形聚合物,分解温度约为319 ℃,玻璃化转变温度约为128 ℃。固体紫外吸收测试结果表明,PSE-FL在502 nm处有最大吸收波长,荧光发射光谱表明PSE-FL在554 nm处显示出荧光发射波长。     

Effect of hydroxyl and Mo doping on activity and carbon deposition resistance of hydroxyapatite supported NixMoy catalyst for syngas production via DRM reaction

The doping of the second metal Mo is expected to further enhance the carbon deposition resistance of Ni-based catalysts for syngas production via dry reforming of methane (DRM). In this study, the hydroxyapatite (HAP) was used as the support and a small Mo dosage was doped in the Ni-based catalysts to investigate the effect of intrinsic hydroxyl and Mo doping on the catalytic activity and carbon deposition resistance in DRM reaction. The catalyst characterization results show that both Ni and Mo are doped into the HAP structure with relatively uniform dispersion. The basic site strength of Ni4Mo0.2-HAP catalyst containing Mo is significantly higher than that of without Mo. The Mo dopant significantly improves the initial catalytic activity, but has minimal effect on the stability enhancement. Whether the catalyst is pre-reduced or not is crucial to the initial activity of the DRM reaction, the non-pre-reduced catalysts will go through a “self-activation” stage at the beginning of the reaction, where the “hydroxyl group” are proved to play as an “oxygen supply” for the partial oxidation of CH₄ or the oxidation of the carbon deposition in the initial stage. Only trace amount of carbon deposition is found after 100 h of DRM reaction on Ni3Mo0.2-HAP catalyst. The NiMo-HAP catalysts exhibit excellent initial activity and resistance to carbon deposition due to the synergistic effect of Ni–Mo alloy and hydroxyl groups in the hydroxyapatite support.