The Synergistic Effect Between Phosphonocarboxylic Acid Salts and Fatty Amines for the Corrosion Protection of a Carbon Steel

This work was carried out to have a better understanding of the synergistic effect between phosphonocarboxylic acid salts (PCAS) and fatty amines (FA) for the corrosion protection of a carbon steel in a 200 mg l^–1 NaCl solution. These compounds, combined with a biocide at low dosage, are used for water treatment in cooling circuits. First, electrochemical impedance measurements were performed to verify the inhibitive properties of the mixtures. Among the different concentrations tested, maximum efficiency was reached for the mixture containing 200 mg l^–1 PCAS + 50 mg l^–1 FA. Then, electrochemical measurements (current—voltage curves and impedance diagrams) were combined with surface analysis (X-ray photoelectron spectroscopy) for each compound at the optimized concentrations and for the mixture. In the presence of amines, the iron oxide/hydroxide layer remained porous and the inhibition efficiency was relatively low. The FA acted by repelling the water molecules from the interface. PCAS sealed the pores of the oxide layer by forming a chelate. Thus, the growth of the inhibitive layer was limited but the efficiency was higher than for the FA alone. For the optimized mixture, the formation of the chelate was enhanced and the protective properties of the layer improved. A competitive adsorption mechanism was proposed to account for the synergistic effect observed in the presence of both compounds.     

Mischer mit mikrostrukturierten Folien für chemische Produktionsaufgaben

Mixers with Microstructured Foils for Chemical Production Purposes Since about 10 years the Institut für Mikrotechnik Mainz GmbH (IMM) is engaged with the application of microstructures for chemical micro process engineering. Their advantages – more efficient heat exchange and mass transport – lead to, among other things, an increase in yield and selectivity even while saving resources. The development of microstructured mixers thereby played a key role for carrying out advanced syntheses of fine chemicals as well as for the generation of dispersions, creams, foams, and emulsions. So far, microstructured mixers were mainly limited for laboratory‐scale or at best pilot plant‐scale – typical maximum flow rates were from 2 – 100 L/h for watery fluid systems. With the introduction of the StarLaminators StarLam300 and StarLam3000 this barrier could be lifted far beyond 300 L/h up to the m³/h domain. Both apparatus yield at high flow rates a mixing efficiency which reaches the high performance of today's low‐capacity (L/h) micro mixers. Therefore, continuity from the ”?real”? micro mixers over the herein described high‐throughput tools to conventionally manufactured static mixers with even higher flow rates is given.     

基于ATmega16单片机的数显电压表设计

针对测试仪器内部直流电平检测的需要,设计了一款以ATmega16为核心,结合电阻分压网络以及反相求和电路的数显电压表。用单片机自带的十位内部ADC进行模拟数据的采集和转换,设计软件精度校准的方法实现对-19.9~+19.9 V正负量程范围内直流电平的精确测量,并用三位数码管显示,超过设定阈值产生报警。实际测试结果表明,该系统误差不超过0.1 V,具有测量精度高、成本低、性能可靠、显示清晰等优点,有着很好的实用价值。     

阿瓦提凹陷沙井子断裂带特征及控油气作用

沙井子断裂为塔里木盆地阿瓦提凹陷北部的控凹边界断裂,呈北东—南西向展布,倾向北西,长约180 km.通过对该断裂带的平面分布和剖面特征、断裂发育演化及其对油气聚集成藏控制作用等的分析,指出沙井子断裂带具有明显的分段特征,可分为西、中、东3段。沙井子断裂带自海西运动早期开始发育,主断裂持续活动至今,控制了阿瓦提凹陷北部地区的构造格架和沉积作用、圈闭形成和油气运移,对油气的聚集成藏起到重要的控制作用。     

脉冲电沉积法制备Al基Pb—WC—Ce02复合惰性阳极

为了制备性能优良的Al基Pb—WC—CeO：惰性阳极材料,考察了WC、CeO：颗粒浓度对阴极极化的影响,正向脉冲参数、温度和搅拌对沉积速率以及复合镀层表面形貌的影响,并研究了其在锌电解液中的耐蚀性能,确定了脉冲电沉积制备Al基Pb-WC-C02复合镀层的最佳工艺条件：基础镀铅液中添加40g／LWC（粒径1斗m）,30g...     

45钢外加直流电场粉末法铝硅共渗工艺及渗层性能

为了节能、快速共渗铝硅,以45钢为基材,在介质与试样间施加一定强度直流电场,进行固体粉末铝硅共渗,并对处理试样的高温抗氧化性和耐蚀性进行研究。采用金相显微镜和XRD分析了铝硅共渗层的组织特点在800℃下,研究了渗层的抗氧化性能;于10％H2SO4中研究了渗层的耐蚀性。结果表明：直流电场可降低铝硅共渗加热温度,提高渗速;...     

基于弯曲板波的延迟线振荡器的ANSYS仿真

针对复合板结构中弯曲板波谐振频率计算相对复杂的问题,建立并分析了基于弯曲板波延迟线振荡器的理论模型,计算得到A0(0阶反对称)模式板波的谐振频率为41 MHz;为了验证理论分析的结果,利用有限元软件ANSYS建立了基于弯曲板波的延迟线振荡器的3D有限元模型,并对其进行了谐响应分析以及瞬态动力学分析。谐响应分析得到A0模式的谐振频率为37.2 MHz,与理论计算结果的相对误差为9.3%;瞬态动力学分析得到A0模式的谐振频率为39.1 MHz,与理论计算结果的相对误差为4.6%。计算和仿真为基于弯曲板波的延迟线振荡器的结构设计提供了重要的依据。     

热灌装饮料瓶用丙丁共聚聚丙烯的结构与性能

采用高温凝胶渗透色谱（GPC）仪、差式扫描量热（DSC）仪、偏光显微镜等分析了热灌装饮料瓶用丙丁共聚聚丙烯（牌号PB 13 HF,简称试样1）的结构与性能,并与相应的市售产品（牌号为E 980 BHF,简称试样2）性能进行了对比分析。结果表明:试样1与试样2的相对分子质量及其分布相近;与试样2相比,试样1的熔融结晶性能略有提高,热变形温度、拉伸屈服应力、弯曲应力等刚性较好,冲击强度略低,雾度相近。     

Future developments for Terahertz Schottky barrier mixer diodes

Contents With the steady improvement of whisker contacted GaAs Schottky barrier mixer diodes during the recent years, the frequency range for heterodyne detection has been extended towards frequencies as high as 2.5 THz. However, whisker contacted devices show reliability and handling problems, and space qualification is extremely difficult. Furthermore, whiskered diodes cannot be integrated. This paper shows future planar concepts suitable for THz heterodyne detection in order to overcome the above problems with whisker contacted diodes.

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<blockquote>Zukünftige Entwicklungen für Terahertz-Schottky-Barrier-Diodenblockquote><blockquote>Übersicht Durch eine fortlaufende Verbesserung von whiskerkontaktierten GaAs-Schottky-Barrier-Mischerdioden konnte der Frequenzbereich für die heterodyne Detektion bis auf 2.5 THz erweitert werden. Neben schwieriger Handhabung zeigen whiskerkontaktierte Bauelemente jedoch Zuverlässigkeits- und Stabilitätsprobleme und sind nicht integrierbar. Als Lösung werden Konzepte für planare Dioden vorgestellt und ihre Eignung für Terahertz-Mischeranwendungen diskutiert.blockquote>