Lubricating behavior of iron rhenate and its relation to matching pairs

The iron rhenate was compounded by chemical method, which may be generated during wear process of Fe-Re alloys at elevated temperature. The friction coefficient of iron rhenate has been determined by a pin-on-disc device. The results show that iron rhenate plays role of lubricating at RT-600 °C. The lubricating behavior is related to the matching pairs. The hardness of the materials of matching pairs, compatibility of iron rhenate with materials of matching pairs and surface roughness of disc affect the lubricating behavior of iron rhenate mostly. The principle of matching pairs is proposed. Project supported by the National Natural Science Foundation of China Synopsis of the first author Xiong Dangsheng. associated professor, born in 1960. Current research fields include high-temperature self-lubricating alloys and tribological properties of material.     

稳定态二氧化氯杀菌剂的制备及应用

稳定态二氧化氯(C1O2)是一新型杀菌消毒剂，具有高效、广谱、安全的特性，适用范围广，不产生对人体有害物质。介绍了稳定态ClO2的性质、检测、制备条件及其在有关领域的应用。     

喷雾型地板上光蜡的研制

喷雾型地板上光蜡也称乳剂型地板上光蜡，是蜡和乳化剂在加热搅拌条件下进行乳化反应而生成的水乳状液蜡上光剂，生产工艺简单，稳定性和上光效果较好，本文对新型光蜡的典型配方和影响乳液稳定性，上光效果的诸因素进行研究，找出配制稳定剂乳液及提高上光效果的最佳工艺条件。     

Single-phase gold/palladium catalyst: The nature of synergistic effect

The liquid phase oxidation of glycerol with oxygen has been studied using mono and bimetallic catalysts based on Au and Pd metals supported on activated carbon, in order to study the effect of the metal on the distribution of the products and on activity of catalysts. It was found that by using bimetallic catalysts (Au–Pd) a strong synergistic effect was shown. By using a preformed nucleating centre we were able to obtain a single alloyed phase, which allowed us to address the synergistic effect to the presence of alloyed Au/Pd. The advantage of using this latter catalyst lies not only in the high activity but also in a prolonged catalyst life. Although a partial leaching of palladium and assembling of the particles have been revealed by ICP and HRTEM respectively, activity after 10 re-cycles decreased less than expected (about 10%).     

Mechanism of ZrTiO4 Synthesis by Mechanochemical Processing of TiO2 and ZrO2

High-energy ball milling initiates a solid-state reaction in an equimolar mixture of TiO₂ and ZrO₂. The first stage of ball milling induced the transformation of anatase TiO₂ to high-pressure phase TiO₂ (II), isostructural with ZrTiO₄. The formation of solid solutions monoclinic ZrO₂/TiO₂ and TiO₂ (II)/ZrO₂ was observed in the intermediate stage. Afterward, a nanosized ZrTiO₄ phase was formed in the milled product from the TiO₂ (II)/ZrO₂ solid solution. The sintering of the milled product at a temperature <1100°C was examined in situ by Raman spectroscopy. The full solid-state reaction toward ZrTiO₄ ceramic is completed at a temperature considerably lower than reported in the literature.     

Determination of the acidic properties of carboxylated carbocatalysts in an acid-catalyzed ring-opening reaction using kinetic profiling

The acid-catalyzed ring-opening reaction of styrene oxide was used as a probe reaction for evaluating the acidic properties of carboxylated carbocatalysts. Significant discrepancies in the initial reaction rates were normalized using the total number of carboxyl groups, and demonstrated that the average catalytic activities of the carboxyl moieties on the carbocatalysts differed. Comparisons between the apparent activation energy E _a and the pre-exponential factor A, derived from Arrhenius analysis, demonstrated that A varied more significantly, and therefore had a more significant effect on the reaction rates than E _a. The variation in the calculated pKa values of the carboxyl groups was attributed to the electronic effects of the nitro groups. This hypothesis was supported by the temperature programmed desorption profiles of nitrogen monoxide ions.

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水力喷射泵及其应用优势与效果

介绍了水力喷射泵的工作原理及三种地面动力与喷射泵的配套系统,其中电动潜油离心泵－喷射泵系统在同等条件下开采高粘、高凝油藏,一次性投资比电热杆低１５％ 以上,无故障工作时间一年以上;注水管网－喷射泵系统地面结构简单,投资少,见效快,对于解决注水管网地区油井的管柱偏磨、油稠、腐蚀问题具有明显的优势;磁传动多级离心泵－喷射泵系统采用了静密封,实现了无摩擦、无泄漏的动力传递,可在无人管理的条件下正常运行。井下泵的检泵周期达二年以上。喷射泵技术除了在普通采油井的生产中应用以外,在稠油井、高凝油井、低液面深井、高气油比井、斜井以及工况复杂的特殊油井中应用也获得了较好的效果。在油田地面集输泵站、注水泵站的污油、污水回收等方面,也具有独特的技术优势。实践证明,因地制宜、合理匹配是喷射泵现场应用取得良好经济效益的前提。     

激光表面微造型对摩擦学性能的影响

为了研究表激光织构化对机械零件接触面的摩擦性能影响,采用Nd:YAG脉冲激光在钢盘表面形成了具有一定直径、间距和密度的微坑型织构阵列,在环/盘式摩擦试验机上进行了摩擦学性能测试。结果表明,微坑的深度和直径随脉冲次数增加而增大,调整微坑参量（直径和间距）可以获得不同密度的织构阵列,密度为8%~10%范围内的试样具有最低的摩擦因素（0.055~0.06）和磨损率（5.2×10-16m3/（N·m））;通过曲线拟合,得到摩擦磨损性能随织构密度变化的趋势。该研究获得了具有最佳摩擦学性能的参量,能提高机械的使用效率和使用寿命。     

A Novel Ion-exchange Method for the Synthesis of Nano-SnO/micro-C Hybrid Structure as High Capacity Anode Material in Lithium Ion Batteries

A novel and simple ion-exchange method was developed for the synthesis of nano-SnO/micro-C hybrid structure. The structure of the as prepared nano-SnO/micro-C was directly revealed by scanning electron microscopy（SEM） and transmission electron microscopy（TEM）.SnO particles with the size about 25 nm were well confined in amorphous carbon microparticles.Carbon matrix in micrometer scale not only acts as a protective buffer for the SnO nanoparticles during the battery cycling processes,but also avoids the shortcomings of nanostructures, such as low tap density and potential safety threats.Electrochemical behaviors of the nano-SnO/micro-C were tested as anode material in lithium ion batteries.The initial reversible capacity is 508 mA h g^-1,and the reversible capacity after 60 cycles is 511 mA h g^-1,indicating good capacity retention ability.     

Tribological behavior of graphite-containing nickel-based composite as function of temperature,load and counterface

Nickel-based graphite-containing composites were prepared by powder metallurgy method. Their mechanical properties at room temperature and friction and wear properties from room temperature to 600 °C were investigated by a pin-on-disk tribometer with alumina, silicon nitride and nickel-based alloy as counterfaces. The effects of graphite addition amount, temperature, load, sliding speed and counterface materials on the tribological properties were discussed. The micro-structure and worn surface morphologies were analyzed by scanning electron microscope (SEM) attached with energy dispersive spectroscopy (EDS). The results show that the composites are mainly consisted of nickel-based solid solution, free graphite and carbide formed during hot pressing. The friction and wear properties of composites are all improved by adding 6–12 wt.% graphite while the anti-bending and tensile strength as well as hardness decrease after adding graphite. The friction coefficients from room temperature to 600 °C decrease with the increase of load, sliding speed while the wear rates increase with the increasing temperature, sliding speed. The lower friction coefficients and wear rates are obtained when the composite rubs against nickel-based alloy containing molybdenum disulfide. Friction coefficients of graphite-containing composites from room temperature to 600 °C are about 0.4 while wear rates are in the magnitude of 10^?5 mm³/(N m). At high temperature, the graphite is not effective in lubrication due to the oxidation and the shield of ‘glaze’ layer formed by compacting back-transferred wear particles. EDS analysis of worn surface shows that the oxides of nickel and molybdenum play the main role of lubrication instead of graphite at the temperature above 400 °C.