MnOx/Mg-Al2O3催化甲烷燃烧反应的研究

在Al2O3上浸渍Mg（NO3）2溶液,焙烧后制得Mg改性Al2O3（Mg-Al2O3）。以Mg-Al2O3为载体,制备了MnOx/Mg-Al2O3系列催化剂,测试了这些催化剂对甲烷燃烧反应的催化活性。结果表明：Mg的加入有效抑制了Al2O3在高温焙烧时发生γ相变,提高了Al2O3的热稳定性,MnOx/10%Mg-Al2O3对甲烷燃烧的催化活性较高,Mg的适宜加入量为10%。     

Zn(H2PO4)2-N[CH2CH2OPO(OH)2]3对碳钢的协同效应与缓蚀机理研究

采用失重法、表面观察法、极化曲线法、氩离子刻蚀法和ＸＰＳ分析法研究Ｚｎ（Ｈ２ＰＯ４）２－Ｎ「ＣＨ２ＣＨ２ＯＰＯ（ＯＨ）２」３在海水中对碳钢的协同效应与缓蚀机理。结果发现：５０％Ｚｎ（Ｈ２ＰＯ４）２＋５０＾Ｎ「（ＣＨ２ＣＨ２ＯＰＯ（ＯＨ）２」３（ＸＭ－３０３在海水中对碳钢具有明显的协同缓蚀效应。５０％Ｚｎ（Ｈ２ＰＯ４）２＋５０％Ｎ「ＣＨ２ＣＨ２ＯＰＯ（ＯＨ）２」３（ＸＭ－３０３）主要为阴极抑制型缓蚀     

AVR单片机在粒谱分析仪中的应用

介绍了以AVR单片机系列的ATmegal28芯片为控制核心的粒谱分析仪的设计思路,针对电子学部分给出了系统的软硬件设计方法,单片机与上位机通讯对仪器进行控制和气溶胶粒子的分析,并驱动液晶模块实现二维图形以及仪器状态等的显示,实现了人机交互.目前该系统正在试运行中并准备投入到环境气体监测中.     

基于CH375的USB移动存储接口设计

CH375作为USB移动存储设备的接口芯片,可大大减少外围电路,降低成本,提高研发速度。文中详细介绍了CH375的功能、特性,同时结合在蓄电池活化设备中的实际应用,给出了CH375与AVR单片机的接口电路和软件设计方法。     

一种使用CH341A编程器修改Hawk仪器FSU站号的方法

在Hawk仪器FSU维修过程中有对FSU站号修改的需求,使用CH341A编程器对U20芯片重新编程可以实现对FSU站号修改的目的。本文详细介绍了使用CH341A编程器修改Hawk仪器FSU站号的方法。     

甲醇转化制丙烯反应机理研究

以杂化轨道理论和关于含Si、Al元素催化剂酸中心的认识为理论依据和研究方法,从反应物与催化剂B酸中心相互作用为切入点,分析相互作用过程中甲醇与B酸中心分子结构变化,揭示甲醇制烯烃反应机理本质。研究结果表明甲醇转化制丙烯反应过程可分为3步：(1)B酸中心释放H+攻击甲醇分子中C-O键,C-O键断裂生成甲基碳正离子(CH+3)和H2O,CH+3中C原子外层有个空轨道,释放了H+后的B酸中心失去活性。(2)失活B酸中心从CH+3中获得H+,反应生成了一种新中间体H-form,H-form中C原子外层有1对孤对电子(e-)和1个空轨道,结构式为C↑↓〇H2;失活的B酸中心获得H+后恢复活性。第3步,有3个H-form结构的C原子,第1个C原子上的孤对e－占据第2个C原子上空轨道,第2个C原子上的孤对e－占据第1个C原子上空轨道,彼此共用2对e-,形成C=C键;第3个C原子上的空轨道与第1个C原子上C、H原子重叠轨道再次重叠,形成C、H和C三原子共用1对e－结构,结果是第1个C原子与第2个C原子形成C=C键,第1个C原子与第3个C原子形成C-C键,3个C原子形成C=C-C结构,即生成丙烯。     

Stabilization of natural gas foams using different surfactants at high pressure and high temperature conditions

Natural gas foam can be used for mobility control and channel blocking during natural gas injection for enhanced oil recovery, in which stable foams need to be used at high reservoir temperature, high pressure and high water salinity conditions in field applications. In this study, the performance of methane (CH₄) foams stabilized by different types of surfactants was tested using a high pressure and high temperature foam meter for surfactant screening and selection, including anionic surfactant (sodium dodecyl sulfate), non-anionic surfactant (alkyl polyglycoside), zwitterionic surfactant (dodecyl dimethyl betaine) and cationic surfactant (dodecyl trimethyl ammonium chloride), and the results show that CH₄-SDS foam has much better performance than that of the other three surfactants. The influences of gas types (CH₄, N₂, and CO₂), surfactant concentration, temperature (up to 110°C), pressure (up to 12.0 MPa), and the presence of polymers as foam stabilizer on foam performance was also evaluated using SDS surfactant. The experimental results show that the stability of CH₄ foam is better than that of CO₂ foam, while N₂ foam is the most stable, and CO₂ foam has the largest foam volume, which can be attributed to the strong interactions between CO₂ molecules with H₂O. The foaming ability and foam stability increase with the increase of the SDS concentration up to 1.0 wt% (0.035 mol/L), but a further increase of the surfactant concentration has a negative effect. The high temperature can greatly reduce the stability of CH₄-SDS foam, while the foaming ability and foam stability can be significantly enhanced at high pressure. The addition of a small amount of polyacrylamide as a foam stabilizer can significantly increase the viscosity of the bulk solution and improve the foam stability, and the higher the molecular weight of the polymer, the higher viscosity of the foam liquid film, the better foam performance.     

Separation of Methane and Carbon Dioxide Gas Mixtures Using Activated Carbon Modified with 2‐Methylimidazole

Activated carbon was modified by loading 2‐methylimidazole (mIm), ethanol, and glycol onto its surface and adopted to capture CO₂ using the absorption‐adsorption method. The modified activated carbon showed high selectivity for separating CH₄+CO₂ gas mixtures, compared with other methods to modify activated carbon given in the literature. The separation factor was 4.75 times higher than that for the fresh activated‐carbon system, and the separation performance of the activated carbon increased with increasing amount of mIm. The addition of glycol showed greater potential to enhance the selectivity of the activated carbon than ethanol. A recycling test verified the stability of the modified activated carbon for CH₄+CO₂ gas mixture separation.     

Synthesis of Ti(C,O, N) from ilmenite at low temperature by a novel reducing and carbonitriding approach

The clean and effective utilization of titanium-bearing minerals has challenged the titanium industry all over the world. In order to realize the high-efficiency, clean, and high value-added comprehensive utilization of ilmenite concentrate, a novel process has been proposed in this study by reducing and carbonitriding ilmenite with the CH₄-N₂-H₂ gas mixture at low temperature. Carbonitride performance and mechanism have been investigated experimentally and theoretically. The obtained results showed that the reaction process could be divided into three stages: formation of metallic iron, reduction of titanium oxide to titanium suboxides, and formation of Ti(C, O, N). The metallic iron congregated at the first two stages, but dispersed once the Ti(C, O, N) formed. The effects of both reaction temperature and preoxidation treatment on the reaction have been studied as well. It was found that the increase of temperature was conducive to the formation of Ti(C,O), and the ilmenite could be reduced completely to Ti(C,O) at 1170°C for 8 hours. The preoxidation treatment could improve the kinetics of reduction. At 1170°C, the introduction of N₂ could apparently increase the reduction rate, with the complete reduction time decreasing from 8 hours in CH₄-H₂ gas mixture to 3 hours in CH₄-N₂-H₂ gas mixture. The proposed novel process has been assessed and it showed many potential advantages and feasibility.     

Utilization of coordinating green solvents for high quality methylammonium bismuth iodide thin films for photovoltaic applications

Photovoltaic performances of the bismuth-based solar cells are profoundly affected by the thin film quality of the photoactive layer. Herein, we report on various green solvent system to obtain the highly crystalline, pinhole free and homogeneously methylammonium bismuth iodide (MBI) active layer. The MBI structure prepared with tetrahydrofuran:2-ethoxy-ethanol (THF-2ETO) solvent system was found to have the best film quality. Adding 0.05 M 2ETO as the co-solvent is sufficient to produce high quality BiI₃ and MBI thin films. According to the X-ray photoelectron spectroscopy (XPS) analyzes, we have demonstrated that there is an interaction between BiI₃ and 2ETO according to the concentration of 2ETO added to the main THF. Our study clarifies the importance of THF-2ETO solvent system that can accelerate the evolution of the Bi-based solar cells by creating high-quality BiI₃ or MBI thin films.