大型机械轴承相对标高测试系统

介绍了一种使用连通管、电涡流传感器测量轴承相对标高的测试系统,它能准确测量大型机械相邻轴承的相对标高变化.文中叙述了其测量原理、特点以及系统的硬件电路和软件设计,最后给出一个测试实例,并对测量结果进行了简要分析.     

Synthesis and characterization of novel polyesterimides

A series of soluble novel polyesterimides was synthesized from diamines [a mixture of 2,2‐bis(4‐(4‐aminophenoxy)phenyl)propane (BAPP) with amine‐terminated polysiloxane (ATPS) in various mole ratios] and the ester‐group‐containing dianhydrides. The ester group containing dianhydrides in turn was synthesized by the transesterification reaction of trimellitic anhydride (TMA) with diacetate ester of hydroquinone (HQ), 4,4′‐dihydrophenyl (BP), 1,6‐hexanediol, or ethylene glycol. The resulted polyesterimides were characterized by using Fourier‐transform infrared spectroscopy, inherent viscosity, solubility, differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). The polyesterimides of BP and HQ had relatively high glass transition temperatures in the range of 214.7–227.2 and 195.7–210.5°C, respectively. The glass transitions decreased rather slowly with the increase in polysiloxane content. Thermal stability and the weight‐loss behavior of polyesterimides were studied by TGA. All polyesterimides of BP and HQ (BPI and HQI) showed no significant weight loss below 500°C in a N₂ environment, and the decomposition temperatures (T_d5%) of BPI and HQI were >520°C. Most polyesterimides were soluble in polar aprotic solvents and m‐cresol. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 730–738, 2004     

熔块中的气泡缺陷及其解决办法

分析了熔块生产中气泡缺陷产生的各种原因．提出了实际生产中的注意事项和具体的解决办法。     

新型甲醇汽油的制备及性能测试

本文研究了甲醇汽油体系相稳定剂,并利用90~#基础汽油和工业精甲醇为主要原料,添加相稳定剂、防腐剂、消烟剂、蒸汽压调节剂和燃烧催化剂等,经科学配方和工艺,成功制备出高性能符合97~#无铅车用汽油国标的甲醇汽油产品。     

新型碳质催化剂用于NH3选择性催化还原NOx的研究

以城市污水处理厂剩余污泥为原料制备了一种新型碳质催化剂。通过试验考察了催化剂在NH₃选择催化还原NO中的应用效果。结果表明,催化性能较好，最佳的制备和催化反应条件为：锌铁物质的量比1∶0.5，热解温度750 ℃，反应温度400 ℃，O₂浓度15%。在此条件下，NOx的最大转化率达98.3%。通过考察证明催化剂自身具有一定的还原性能。对催化剂进行了FTIR、TG、SEM和BET分析，结果表明，催化剂具有很丰富的孔结构、活性粒子和表面官能团，比表面积较大，最大可达307 m²·g^-1，分析结果显示具有良好的催化条件。     

生物质与煤共燃研究(Ⅱ)燃烧性质分析

对低温热解生物质和煤共燃的燃烧性质进行了研究。在热解温度300℃，热解时间30min下对三种生物质（锯屑、谷壳和花生壳）的热解产品、长焰煤、无烟煤、热解锯屑和长焰煤混样（1：10）、热解锯屑和无烟煤混样（1：10）七个样品的燃烧热重分析发现：热解生物质的燃烧性能相近，组成结构相似，主要分为挥发分释放燃烧阶段和焦炭燃烧阶段，分别位于30℃－400℃和400℃－500℃之间，其出现分别较煤的温度低；长焰煤与热解锯屑混燃可以有效地降低着火温度，而热解锯屑与无烟煤混燃时，由于燃烧性质差异较大，是分别燃烧，不产生协同效果；热解锯屑与长焰煤、无烟煤共燃能够有效地提高煤的着火性能，在总体燃烧性能上，虽然热解锯屑明显好于长焰煤和无烟煤，但混合后对其改变不大。     

联苯型双醚二酐的合成及其表征

以4,4′二羟基联苯(联苯二酚)和N甲基4硝基邻苯二甲酰亚胺为主要原料,在非质子性溶剂中,经缩合得到联苯双醚二酞酰亚胺,再经水解、酸化、脱水等工艺制得联苯型双醚二酐(BPEDA)。通过红外光谱对产品进行了表征,结果符合要求。该单体与4,4′二氨基二苯醚(ODA)在N,N二甲基乙酰胺(DMAc)中缩聚所得聚酰胺酸特性粘度为0.72dL/g。将PI制成薄膜,室温下拉伸强度为98.5MPa,成膜性能良好。     

Effect of Pretreatment Atmosphere on CuO/TiO2 Activities in NO + CO Reaction

Using TiO₂ as carrier, CuO/TiO₂ catalysts with different CuO loading were prepared by the impregnation method. The catalytic activities in NO+CO reaction were examined with a micro-reactor gas chromatography reaction system and the methods of TPR, XPS and NO-TPD. It was found that the catalytic activities were affected by pretreatment atmosphere, i.e. H₂ atmosphere > reduction–reoxidation > 10%CO/He > reaction gas (fresh sample). NO decomposition was better by low-valence Cu species than by high-valence Cu species, i.e. Cu⁰>Cu⁺>Cu²⁺. The XPS results indicated that Cu species on CuO/TiO₂ were Cu⁰, Cu⁺, normal Cu²⁺(Cu²⁺(I)) and chain-structured Cu²⁺(Cu²⁺(II)) as –Cu–O–Ti–O–. The activities of Cu²⁺(II) were much higher than that of Cu²⁺(I), but both species were very unstable in the reaction atmosphere and easily reduced by CO, which accounted for the variable activities of fresh catalysts with increasing reaction temperature. In NO+CO reaction, the redox process was a cycle of Cu⁺–Cu²⁺(I) at low reaction temperature but was a cycle of Cu⁰–Cu⁺ at high reaction temperature. As shown by NO-TPD, high catalytic activities could be attributed to the following factors, e.g. oxygen caves on the catalyst’s surface after pretreatment with H₂ and reduction–reoxidation, formation of Cu⁰ after pretreatment with H₂, and increment of Cu species dispersion and formation of Cu²⁺(II) after pretreatment with reduction–reoxidation.     

基于仿真卡的通用1553B总线测试软件设计

1553B总线通信是航天器终端设备的重要功能,在研制各阶段,对设备的总线通信功能进行测试是必不可少的。基于总线仿真卡进行二次开发,提出一种通用1553B总线测试软件设计方法,采用总线消息描述文件和设备参数描述文件分别描述总线消息和设备参数,设计通用程序模块,使软件代码不依赖总线消息或设备参数的具体定义。所述方法已在某航天器多个分系统测试中得以应用。     

细胞固定化催化生产精细化学品的研究进展Q

摘要：细胞固定化技术具有流程简单、生物相容、操作稳定等优点，可有效保证细胞活性，实现高效的细胞催化生产精细化学品。本文介绍了表面附着、凝胶包埋、聚电解质层层自组装膜等多细胞固定化方法，及其在二元醇、生物乙醇、乳酸、酯、多糖等精细化学品生产中的研究现状和进展，并分析讨论了各种方法存在的问题。同时，总结了近年来新发展的单细胞纳米涂层固定化方法的机理、趋势及应用于精细化学品生产的可能性。最后对细胞固定化催化生产精细化学品面临的技术挑战及研究方向做出展望，以期为精细化学品生产提供一定的技术支持。