One Pot Synthesis of Large Gold Nanoparticles with Triple Functional Ferrocene Ligands

In biomedical, toxicological, and optoelectronic applications, the size of nanoparticles is one of the decisive factors. Therefore, synthesis of nanoparticles with controlled sizes is required. The current methods for synthesis of larger gold nanoparticles (GNPs, ~200 nm) are complex and tedious, producing nanoparticles with a lower yield and more irregular shapes. Using ferrocene as a primary reducing agent and stabilizer, sodium citrate as a dispersant, and sodium borohydride as an accessory reducing agent, GNPs of 200 nm were synthesized in a one pot reaction. Besides the roles of reducing agent and GNP stabilizer, ferrocene also served a role of quantitative marker for ligand loading, allowing an accurate determinate of surface ligands.     

Pyrolysis kinetics of phenol-formaldehyde resin by non-isothermal thermogravimetry

The potential damage during the pyrolysis of phenol-formaldehyde (PF) resin in the manufacturing of carbon/carbon components is serious. Accurately modeling the kinetics of the pyrolysis reaction can lead to improvements in processing. To study the pyrolysis kinetics of PF resin, non-isothermal pyrolysis kinetics is investigated using thermogravimetric analysis (ТGA) at controlled heating rates. The research indicates that the pyrolysis process consists of three consecutive and overlapping stages. PEAKFIT was employed to separate overlapping regions, and then pyrolysis kinetic triplet of PF resin is calculated. With the determined apparent activation energies, the most probable mechanism functions and the corresponding pre-exponential factor, the model agrees well with the experimental data.     

基于背压式气动测量的喷油嘴偶件自动分选/选配机

研制了基于背压式气动测量和 80 31单片机控制的喷油嘴偶件 (针阀、针阀体 )自动分选 /选配机 ,介绍了系统测量原理以及气路特性、气电转换、误差补偿、信号处理与控制电路、测量程序设计等关键技术     

高能超声稀释原位反应烧结块的研究

通过高能超声稀释原位反应烧结块，制备锌铝合金基复合材料。试验表明，复合材料组织分布均匀，强度较基体有大幅度提高，增强机制为Orowan强化理论。高能超声均匀稀释增强相是声空化与声流效应协同作用的结果。     

挤压铸造Mullite短纤维/M124F铝基复合材料

用挤压铸造工艺制备了莫来石(mullite)短纤维增强马勒124合金(M124F)铝合金基复合材料.研究了其从常规室温到400℃高温的拉伸性能,以及热膨胀性能和硬度;体积分数为17%的莫来石(mullite)短纤维增的复合材料,在300℃高温强度比其他增强相复合材料提高15%以上.通过对拉伸断口的SEM观察,分析了复合材料的失效机制,裂纹源主要生成于增强纤维与基体的复合界面上.     

不同开采时期井田瓦斯赋存特征研究

根据对下霍井田3#煤层瓦斯含量分布规律和瓦斯赋存的分析研究,绘制了井田内瓦斯含量等值线图,并对矿井不同开采时期的瓦斯涌出量进行了预测,确定了矿井不同开采时期的瓦斯涌出等级,指出矿井开采二、三、四采区时需要进行瓦斯抽放,对矿井安全工作具有指导意义。     

Al-TiO_2-B_2O_3系XD合成铝基复合材料研究

主要讨论Al-TiO_2-B_2O_3系XD法制备铝基复合材料的合成工艺及其反应机理。结果表明:在B2 O3 与TiO2 摩尔比小于1时,真空炉温预热至10 0 0K左右时压坯爆燃,反应产物由TiB2 、Al3 Ti和Al2 O3 组成,其中Al3 Ti为棒状物,TiB2 、Al2 O3 为细小颗粒,粒径为数μm左右。同时分析了球磨时间、预紧实度对反应产物的影响规律。     

High-Temperature Oxidation Behavior of 5Cr21Mn9Ni4N Steel Micro-Alloyed by Rare Earth

The oxidation resistance of 5Cr21Mn9Ni4N steel micro-alloying by RE at 700 - 900 ℃ was investigated. The results indicate that oxidation exponent n and oxidation activation energy are increased, and oxidation velocity constant kp is decreased when 0.2% RE is added in 5Cr21Mn9Ni4N steel. The addition of RE elements does not alter phase constitution of oxidation scale, however it improves the configuration of oxidation scale, and increases thermal stability and adhesivity of oxidation scale, which results in the raise of oxidation resistance of 5Cr21Mn9Ni4N steel at high temperature. The oxidation scale constitutes of refractory steel transfer from manganic oxide mostly to ferric oxide mostly with the increase of temperature, which leads to descend of compactness and desquamation resistance of oxidation scale. The mass increase of ferric oxide in the oxidation scale and the looseness of oxidation scale are the main reason to descend the oxidation resistance of refractory steel.     

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涩北气田为一成岩程度较低的砂泥岩浅层大型气田，岩心实验表明各种粒级的砂质和泥质岩类孔隙度相差不大，尤其对泥质含量高的储层气层电性特征不明显，不能有效地划分储层。根据涩北气田的储层和盖层的特征，章提出采用排驱压力法来区分储层和盖层，通过岩心分析和试油结果建立的泥质含量、产能、渗透率与排驱压力的关系表明，排驱压力与泥质含量为很好的正相关的关系，储层与盖层排驱压力差越大产能越高，而排驱压力与岩心渗透率有良好的负相关关系，说明采用排驱压力可以较理想地识别储层。考察各测井资料与排驱压力关系，确定自然伽马的相对值和电阻率与排驱压力关系密切，因而建立起测井资料与排驱压力关系，进而比较全面地建立起了一套适用于该浅层生物气田的测井储层评价方法。使用该方法，对涩北气田的储层进行了重新解释，新层经试油得到验证，为本气田的增储上产发挥了重要作用。     

EFFECTS OF ATMOSPHERE AND TRACE ELEMENT ON THE WETTABILITY OF SOLID W BY LIQUID Ag

The contact angle of liquid Ag with solid W and its temperature dependance wereexamined by sessile drop method under various atmospheres,e.g.vacuum,Ar,H_2 andcarcked NH_3.The O_2 partial pressure in the atmosphere is found to be the major factor.An obvious improvement on the wettability may be made by a trace amount of Ni,Cu orCe added to liquid Ag,The contact angle near M.P.is then narrowed from 69 to about10—20 deg.