目的：建立快速、灵敏的血清5′-核苷酸酶（5′-NT）单一试剂匀相速率法检测新技术。方法：通过酶催化反应动力学体系选择、表面活性剂选择、液体酶稳定条件等关键技术研究,建立了嘌呤核苷磷酸化酶-黄嘌呤氧化酶-过氧化物酶（PNP-XTO-PO...目的：建立快速、灵敏的血清5′-核苷酸酶（5′-NT）单一试剂匀相速率法检测新技术。方法：通过酶催化反应动力学体系选择、表面活性剂选择、液体酶稳定条件等关键技术研究,建立了嘌呤核苷磷酸化酶-黄嘌呤氧化酶-过氧化物酶（PNP-XTO-POD）偶联单一试剂匀相速率法测定血清5′-核苷酸酶（5′-NT）体系。结果：该方法的线性范围可达0.1-202.7 U/L,平均回收率为100.8%,批内变异系数和批间变异系数（CV）分别为0.013-0.032和0.020-0.045,与美国D iazym e Laboratores提供的5′-NT检测试剂比较具有良好的相关性,线性回归方程和相关系数分别为Y=1.0046X-0.051,r=0.9982。结论：用PNP-XTO-POD偶联单一试剂匀相速率法测定血清5′-核苷酸酶（5′-NT）,方法简便、快速、灵敏、可靠,适合临床推广应用。展开更多
采用动电位扫描、慢应变拉伸(SSRT)和扫描电镜观察研究了温度和外加电位对X70管线钢在成都土壤模拟溶液中的应力腐蚀行为的影响。结果表明,在不同温度和不同电位下,X70管线钢在土壤模拟溶液中表现出不同的应力腐蚀敏感性。在温度和外加...采用动电位扫描、慢应变拉伸(SSRT)和扫描电镜观察研究了温度和外加电位对X70管线钢在成都土壤模拟溶液中的应力腐蚀行为的影响。结果表明,在不同温度和不同电位下,X70管线钢在土壤模拟溶液中表现出不同的应力腐蚀敏感性。在温度和外加电位的交互试验中,电位的变化对X70管线钢在成都土壤模拟溶液中的应力腐蚀敏感性的影响占主导地位,应力腐蚀敏感性在不同温度下的变化趋势保持一致。在-450 m V(vs SCE,下同)的阳极电位下,SCC的机理为阳极溶解;在-850 m V电位下,阴极保护作用抑制了阳极溶解;当电位负移至-1200 m V时,表现出较强的应力腐蚀敏感性,SCC机理以氢脆为主。温度对应力腐蚀敏感性的影响主要体现在对阴极极化电位的影响,但是各种因素综合在一起导致应力腐蚀敏感性随温度变化的复杂性。展开更多
The crevice corrosion behavior of XTO steel was investigated with a wedge-shaped crevice assembly under -1000 m V （SCE） cathodic polarization in the solutions with various HCO3 concentrations. The potential, current...The crevice corrosion behavior of XTO steel was investigated with a wedge-shaped crevice assembly under -1000 m V （SCE） cathodic polarization in the solutions with various HCO3 concentrations. The potential, current, pH and the oxygen content within the crevice were measured with or without outside coupled specimen. The results indicated that the polarization potential of XTO steel in the crevice dropped with the increase of time under the cathodic polarization. There was a remarkable influence of HCO3 concentration on the potential of XTO steel in the crevice. When HCO3 concentration was up to 0.125%, the surface of the metal was covered with the corrosion products that resulted in the polarization extent of XTO steel decreased. The pH value in the crevice rose and it dropped gradually from the crevice mouth to the bottom under the cathodic polarization. With the increasing of HCO3 concentration, the hydrolyzation reaction of metal in the crevice bottom aggravated. Most of the dissolved oxygen in the crevice was consumed by the cathodic current. The maximum cathodic current on the metal surface was at the crevice mouth and it was much more than that at the crevice bottom.展开更多
Corrosion monitoring techniques were performed on X7O steel in saline solution saturated with CO2 with and without thiourea additives within the concentration range 5-25 mg/L. It was found that when the concentration ...Corrosion monitoring techniques were performed on X7O steel in saline solution saturated with CO2 with and without thiourea additives within the concentration range 5-25 mg/L. It was found that when the concentration of the inhibitors were increased, the inhibitor efficiencies（IE） of thiourea varied with solution temperature and immersion time. The results indicated that thiourea had the highest inhibition efficiency. The potentiondynamic polarization studies revealed that thiourea are mixed-type inhibitor that mainly restrains the anodic process.展开更多
文摘目的：建立快速、灵敏的血清5′-核苷酸酶（5′-NT）单一试剂匀相速率法检测新技术。方法：通过酶催化反应动力学体系选择、表面活性剂选择、液体酶稳定条件等关键技术研究,建立了嘌呤核苷磷酸化酶-黄嘌呤氧化酶-过氧化物酶（PNP-XTO-POD）偶联单一试剂匀相速率法测定血清5′-核苷酸酶（5′-NT）体系。结果：该方法的线性范围可达0.1-202.7 U/L,平均回收率为100.8%,批内变异系数和批间变异系数（CV）分别为0.013-0.032和0.020-0.045,与美国D iazym e Laboratores提供的5′-NT检测试剂比较具有良好的相关性,线性回归方程和相关系数分别为Y=1.0046X-0.051,r=0.9982。结论：用PNP-XTO-POD偶联单一试剂匀相速率法测定血清5′-核苷酸酶（5′-NT）,方法简便、快速、灵敏、可靠,适合临床推广应用。
文摘采用动电位扫描、慢应变拉伸(SSRT)和扫描电镜观察研究了温度和外加电位对X70管线钢在成都土壤模拟溶液中的应力腐蚀行为的影响。结果表明,在不同温度和不同电位下,X70管线钢在土壤模拟溶液中表现出不同的应力腐蚀敏感性。在温度和外加电位的交互试验中,电位的变化对X70管线钢在成都土壤模拟溶液中的应力腐蚀敏感性的影响占主导地位,应力腐蚀敏感性在不同温度下的变化趋势保持一致。在-450 m V(vs SCE,下同)的阳极电位下,SCC的机理为阳极溶解;在-850 m V电位下,阴极保护作用抑制了阳极溶解;当电位负移至-1200 m V时,表现出较强的应力腐蚀敏感性,SCC机理以氢脆为主。温度对应力腐蚀敏感性的影响主要体现在对阴极极化电位的影响,但是各种因素综合在一起导致应力腐蚀敏感性随温度变化的复杂性。
基金the National R&D Infrastructure and Facility Development Program of China(No.2005DKA10400)Financial support from the National Key Technology R&D Program of China (No.2006BAKO2B01-06)is also acknowledged.
文摘The crevice corrosion behavior of XTO steel was investigated with a wedge-shaped crevice assembly under -1000 m V （SCE） cathodic polarization in the solutions with various HCO3 concentrations. The potential, current, pH and the oxygen content within the crevice were measured with or without outside coupled specimen. The results indicated that the polarization potential of XTO steel in the crevice dropped with the increase of time under the cathodic polarization. There was a remarkable influence of HCO3 concentration on the potential of XTO steel in the crevice. When HCO3 concentration was up to 0.125%, the surface of the metal was covered with the corrosion products that resulted in the polarization extent of XTO steel decreased. The pH value in the crevice rose and it dropped gradually from the crevice mouth to the bottom under the cathodic polarization. With the increasing of HCO3 concentration, the hydrolyzation reaction of metal in the crevice bottom aggravated. Most of the dissolved oxygen in the crevice was consumed by the cathodic current. The maximum cathodic current on the metal surface was at the crevice mouth and it was much more than that at the crevice bottom.
文摘Corrosion monitoring techniques were performed on X7O steel in saline solution saturated with CO2 with and without thiourea additives within the concentration range 5-25 mg/L. It was found that when the concentration of the inhibitors were increased, the inhibitor efficiencies（IE） of thiourea varied with solution temperature and immersion time. The results indicated that thiourea had the highest inhibition efficiency. The potentiondynamic polarization studies revealed that thiourea are mixed-type inhibitor that mainly restrains the anodic process.
