CO2/H2S对油气管材的腐蚀规律

本文综述了CO2、H2S对油气管材的腐蚀机理及影响因素,提出了开发经济型油管的设想.     

基于DSP320F2812的数字化CO2焊机研制

设计了数字化CO2焊机的硬件结构,并根据CO2焊接工艺的特点,编写了相应的控制软件,实现了整个焊接系统的数字化.试验结果表明,基于DSP320F2812芯片控制的焊接电源具有良好的动特性,获得了较好的控制效果,为控制策略的智能化和最优化提供了良好的平台.     

CO2焊短路过程动特性与外特性的关系

CO2短路过渡焊在制造业上的应用非常广泛，对系统动特性有较高要求。该文结合电路理论和焊接短路过程的特点对过程动特性及其与外特性进行了细致的分析，突破了以往在外特性控制和动特性控制之间的关系上互不清楚、互不相关、相互分离的传统观念，认识到在CO2焊短路过渡过程中，动特性和外特性密切相关，既不能用外特性来解释动态过程；也不能认为动特性与外特性无关，动特性会受到外特性的制约，它们之间的关系可以用明确的数学语言进行分析，提出了动特性的最大响应能力及可控性的思想，分析结果有很大的理论意义。     

纳米Fe2O3的制备与气敏性质的研究

报道了纳米氧化铁的制备工艺，采用沉淀法、溶胶凝胶法制备了纳米α-Fe2O3、γ-Fe2O3粉体，用热重－差热分析（TG－DTA）、X射线衍射（XRD）、透射电镜（TEM）和二次粒度分布对粒子进行表征，并制作了气体敏感元件。讨论了纳米氧化铁的制备工艺对气敏性质的影响。     

Catalytic wet air oxidation of olive mill wastewater

Au-based catalysts, known for ambient temperature CO oxidation, have to provide stable performance of up to 5000 h in order to be commercially applicable in automotive fuel cells. In this report, the on-line deactivation characteristics of Au/TiO₂ in unconventional PROX conditions are discussed. As opposed to CO removal from air, results in this report suggests that carbonates have a minor effect on deactivation of Au/TiO₂ in dry H₂-rich conditions. Also, no conclusive correlation between surface hydration and deactivation was observed. Rather, deactivation appeared to have occurred as a result of an intrinsic transformation in the oxidation state of the active species in the reducing operating conditions; a process which was reversible in an oxidizing atmosphere.     

大化肥煤代油CO耐硫变换工艺流程的设计

分析石脑油制氨装置改扩建为水煤浆制氨装置ＣＯ耐硫变换工艺的特点，具体阐述其工艺流程优化设计中需考虑的主要技术问题。     

Characterization and Catalytic Properties of Combustion Synthesized Au/CeO2 Catalyst

Ceria-supported Au catalyst has been synthesized by the solution combustion method for the first time and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). Au is dispersed as Au⁰ as well as Au³⁺ states on CeO₂ surface of 20-30 nm crystallites. On heating the as-prepared 1% Au/CeO₂ in air, the concentration of Au³⁺ ions on CeO₂ increases at the expense of Au⁰. Catalytic activities for CO and hydrocarbon oxidation and NO reduction over the as-prepared and the heat-treated 1% Au/CeO₂ have been carried out using a temperature-programmed reaction technique in a packed bed tubular reactor. The results are compared with nano-sized Au metal particles dispersed on -Al₂O₂ substrate prepared by the same method. All the reactions over heat-treated Au/CeO₂ occur at lower temperature in comparison with the as-prepared Au/CeO₂ and Au/Al₂O₂. The rate of NO + CO reaction over as-prepared and heat-treated 1% Au/CeO₂ are 28.3 and 54.0 mol g^-1 s^-1 at 250 and 300 °C respectively. Activation energy (E _a) values are 106 and 90 kJ mol^-1 for CO + O₂ reaction respectively over as-prepared and heat-treated 1% Au/CeO₂ respectively.     

Kinetics of the methanation of carbon dioxide over a supported Ni-La2O3 catalyst

The kinetics of the methanation of carbon dioxide was investigated using an alumina supported Ni-La₂O₂ catalyst in a differential and integral reactor. In the differential reactor the molar ratio of H₂ to CO₂ was varied from 0.6 to 30. In the integral reactor the rates were measured with up to 90% conversion. Both reactor tests were carried out at temperatures between 513 and 593 K. The experimental results were described by a Langmuir-Hinshelwood type equation. The kinetics can be explained by assuming equilibrium of dissociative carbon dioxide and hydrogen adsorption, and assuming hydrogenation of surface carbon as the rate determining step.     

IR study of the interaction of hydroxyl groups of silica gel with Cr species of Phillips' type catalysts

Spectroscopic evidence for the interaction of hydroxyl groups and chromium ions was obtained using a catalyst prepared from chromyl chloride. A new OH peak, observed at 3705 cm^–1 after pumping away CO gas, is attributed to the direct interaction of OH with the low-valent chromium. This peak shifts to 3590 cm^–1 on contact with O₂ at room temperature and it is assigned to a hydroxyl interacting with the oxidized chromium. New assignments are also proposed for IR bands of CO presorbed on the catalyst. The peak due to CO at 2188 cm^–1 decreases as the OH intensity at 3705 cm^–1 increases, suggesting that the former peak arises from adsorption on Cr(II) species to which two oxygen atoms are attached.     

Reduction of NO2 stored in a commercial lean NO x trap at low temperatures

Isothermal storage of NO₂ and subsequent reduction with different reducing agents (H₂, CO or H₂ + CO) in a lean NO _x trap catalyst was tested by Temperature Programmed Desorption (TPD) and Temperature Programmed Reduction (TPR) experiments at temperatures representative of automotive “cold-start” conditions (<200 °C) using a commercial NO _x trap catalyst. Results from the TPR experiments revealed that no reduction of stored NO₂ to N₂ was observed at 100–180 °C, and at 200 °C 10% reduction only of NO₂ to N₂ was measured. A special affinity of H₂ to form NH₃ was observed during the reduction of stored NO₂. The formation of NH₃ increases with increasing amount of stored NO₂ and decreases with increasing storage temperature. Direct relation exists between the amount of adsorbed and/or stored NO₂ and the formation of H₂O and NH₃.