EVA was widely used as the pour point depressant for waxy oil.In order to improve its effect,some graft copolymerization methods should be used to modify EVA's property.EVA has long side chains and nitrogen polar ...EVA was widely used as the pour point depressant for waxy oil.In order to improve its effect,some graft copolymerization methods should be used to modify EVA's property.EVA has long side chains and nitrogen polar groups to enforce its adaptability and effect of waxy oil.The pure amine,maleicanhydride and their reaction product were tested using infrared spectra and the NMR spectral.The results show that when the modified EVA is added into oil,the wax deposits not only on the main chain but also on the side chains.And the polar groups have the function to avoid and resist the wax crystals connection each other to form the net.Using the reaction product of maleicanhydride and high carbonic amine(C12,C16,C18 amine) as the graft component,the toluene as the solvent and BPO as the initiator,the series of new EVA graft copolymer with special side chains are prepared under controlled condition.A series of cylmaleimide exist indeed in modified EVA and the highest grafted percentage is 18.8%.EVA-16,the new graft copolymer,is better than EVA about 3 ℃ more in depressant the pour-point of Daqing waxy crude oil.展开更多
The influences of solid particles in leach solution on the formation of the third phase crud during solvent extraction of copper were studied. Analyzed from the point of view of pH value and surface tension, the study...The influences of solid particles in leach solution on the formation of the third phase crud during solvent extraction of copper were studied. Analyzed from the point of view of pH value and surface tension, the study results showed that the solid particle is one of the most important contributors for the formation of the third phase crud. During solvent extraction, if the pH value was greater than 2.30, the number of solid particles in the mother solution increased, in which case the possibility of forming the third phase crud could also increase, and the interface tension value might grow in pace with the quantity of the third phase crud.展开更多
The authors investigated the mechanism of crud formation in copper solvent extraction. It is indicated that pH value of solution and the phase ratio (O/A) are the main factors affecting crud formation in solvent extra...The authors investigated the mechanism of crud formation in copper solvent extraction. It is indicated that pH value of solution and the phase ratio (O/A) are the main factors affecting crud formation in solvent extraction. The amount of crud extraction increases with aqueous pH value increase, and reduces with the increase of the phase ratio. Fe 3+ , Mg 2+ , fine air bubble and suspended particulates in leaching solution contribute to crud formation. One case is that a series of reactions of hydrolization and polymerization occurs for Fe 3+ , while pH>2.5, polyhydric complex or Fe SO 4 complex are formed. Then the complex ions of FeOH 2+ , Fe 2(OH) 4+ 2 cause poly reaction, which is likely to lead emulsion. The study on Zeta potential indicates the repulsion between electriferous droplets in solvent extraction prevents phase coalescence, which is one of the major reasons for emulsion.展开更多
Under normal water chemistry conditions, the oxygen and hydrogen peroxide produced by water radiolysis in the coolant of boiling water reactors(BWRs) can lead to intergranular stress corrosion cracking in the constitu...Under normal water chemistry conditions, the oxygen and hydrogen peroxide produced by water radiolysis in the coolant of boiling water reactors(BWRs) can lead to intergranular stress corrosion cracking in the constituent materials of plant components. This fact has led to the wide-scale adoption of hydrogen water chemistry(HWC) in the nuclear industry to counteract these effects.This study seeks to characterize the metallic composition and the surface properties of the constituent materials of plant components in order to determine their effects on the accumulation of chalk river unidentified deposits(crud) on fuel rods in the BWR Unit-1 of the Kuosheng Nuclear Power Plant in Taiwan. Inductively coupled plasma-atomic emission spectroscopy was used to calculate the concentrations of surface crud and gamma spectrometry was used to determine the radioactivity of the corrosion products, as well as their axial distribution across the surface of the fuel rods. X-ray diffraction analysis and scanning electron microscopy/energy-dispersive X-ray spectroscopy were used to identify the crystalline phase and morphology of the crud as irregular shapes and flakes. The amount of crud deposited during the fourth fuel cycle exceeded that of the third fuel cycle due to extended burn-up time. Our analytical results indicate that the implementation of HWC had no significant effect on the characteristics of subsequent crud.展开更多
为研究压水堆一回路堆芯污垢中放射性物质的产量和分布情况,以典型压水堆(Pressurized Water Reactor,PWR)一回路为研究对象,针对一回路中的放射性物质,建立了污垢沉积及放射性物质的产量分布预测模型。模型对污垢沉积和放射性物质的预...为研究压水堆一回路堆芯污垢中放射性物质的产量和分布情况,以典型压水堆(Pressurized Water Reactor,PWR)一回路为研究对象,针对一回路中的放射性物质,建立了污垢沉积及放射性物质的产量分布预测模型。模型对污垢沉积和放射性物质的预测结果与污垢仿真程序CRUDSIM(Chalk River Unidentified Deposits SIMulation)的计算结果差异小于5%。在此基础上,分析了冷却剂流速、氢气含量和冷却剂入口温度的影响。结果表明:放射性物质的含量随堆芯冷却剂流速和氢气含量而增大,且对蒸汽发生器(Steam Generator,SG)中放射性物质含量的影响比堆芯分别高93.9%和10%。冷却剂入口温度增加8%时,放射性物质的含量减小9%,且对堆芯中放射性物质含量的影响比SG大19%。降低冷却剂流速和降低氢气含量有利于降低SG的放射性物质含量;提高冷却剂入口温度可以有效降低堆芯的放射性物质含量。展开更多
典型海洋摇摆对压水堆堆芯的热工水力特性有显著影响,从而导致一回路腐蚀产物的沉积生长规律发生变化。本文基于数据交换方法,通过多尺度耦合建立反应堆一回路系统模型,将摇摆条件下的冷却剂流动数学模型和腐蚀产物沉积生长模型加入模拟...典型海洋摇摆对压水堆堆芯的热工水力特性有显著影响,从而导致一回路腐蚀产物的沉积生长规律发生变化。本文基于数据交换方法,通过多尺度耦合建立反应堆一回路系统模型,将摇摆条件下的冷却剂流动数学模型和腐蚀产物沉积生长模型加入模拟中,对摇摆条件下3×3棒束上腐蚀产物的生长过程进行了研究。结果表明,摇摆会导致冷却剂流速和棒外壁温发生周期性变化,流量脉动和温度波动会加剧摇摆切线方向上的剥蚀作用,削弱沉积过程。在轴向高度较低的通道截面上,靠近外围绝热壁面的棒表面上生长的多孔介质沉积层(Chalk River Unidentified Deposit,CRUD)最厚;在轴向高度较高的通道截面上,所有位置的棒上的CRUD分布规律趋于一致,并且在燃料棒周向的分布体现在极坐标系中呈现出趋近于椭圆形的规律。展开更多
文摘EVA was widely used as the pour point depressant for waxy oil.In order to improve its effect,some graft copolymerization methods should be used to modify EVA's property.EVA has long side chains and nitrogen polar groups to enforce its adaptability and effect of waxy oil.The pure amine,maleicanhydride and their reaction product were tested using infrared spectra and the NMR spectral.The results show that when the modified EVA is added into oil,the wax deposits not only on the main chain but also on the side chains.And the polar groups have the function to avoid and resist the wax crystals connection each other to form the net.Using the reaction product of maleicanhydride and high carbonic amine(C12,C16,C18 amine) as the graft component,the toluene as the solvent and BPO as the initiator,the series of new EVA graft copolymer with special side chains are prepared under controlled condition.A series of cylmaleimide exist indeed in modified EVA and the highest grafted percentage is 18.8%.EVA-16,the new graft copolymer,is better than EVA about 3 ℃ more in depressant the pour-point of Daqing waxy crude oil.
基金This study is financially supported by the "973" National Basic Research of China (No. 2004CB619206).
文摘The influences of solid particles in leach solution on the formation of the third phase crud during solvent extraction of copper were studied. Analyzed from the point of view of pH value and surface tension, the study results showed that the solid particle is one of the most important contributors for the formation of the third phase crud. During solvent extraction, if the pH value was greater than 2.30, the number of solid particles in the mother solution increased, in which case the possibility of forming the third phase crud could also increase, and the interface tension value might grow in pace with the quantity of the third phase crud.
文摘The authors investigated the mechanism of crud formation in copper solvent extraction. It is indicated that pH value of solution and the phase ratio (O/A) are the main factors affecting crud formation in solvent extraction. The amount of crud extraction increases with aqueous pH value increase, and reduces with the increase of the phase ratio. Fe 3+ , Mg 2+ , fine air bubble and suspended particulates in leaching solution contribute to crud formation. One case is that a series of reactions of hydrolization and polymerization occurs for Fe 3+ , while pH>2.5, polyhydric complex or Fe SO 4 complex are formed. Then the complex ions of FeOH 2+ , Fe 2(OH) 4+ 2 cause poly reaction, which is likely to lead emulsion. The study on Zeta potential indicates the repulsion between electriferous droplets in solvent extraction prevents phase coalescence, which is one of the major reasons for emulsion.
文摘Under normal water chemistry conditions, the oxygen and hydrogen peroxide produced by water radiolysis in the coolant of boiling water reactors(BWRs) can lead to intergranular stress corrosion cracking in the constituent materials of plant components. This fact has led to the wide-scale adoption of hydrogen water chemistry(HWC) in the nuclear industry to counteract these effects.This study seeks to characterize the metallic composition and the surface properties of the constituent materials of plant components in order to determine their effects on the accumulation of chalk river unidentified deposits(crud) on fuel rods in the BWR Unit-1 of the Kuosheng Nuclear Power Plant in Taiwan. Inductively coupled plasma-atomic emission spectroscopy was used to calculate the concentrations of surface crud and gamma spectrometry was used to determine the radioactivity of the corrosion products, as well as their axial distribution across the surface of the fuel rods. X-ray diffraction analysis and scanning electron microscopy/energy-dispersive X-ray spectroscopy were used to identify the crystalline phase and morphology of the crud as irregular shapes and flakes. The amount of crud deposited during the fourth fuel cycle exceeded that of the third fuel cycle due to extended burn-up time. Our analytical results indicate that the implementation of HWC had no significant effect on the characteristics of subsequent crud.
文摘为研究压水堆一回路堆芯污垢中放射性物质的产量和分布情况,以典型压水堆(Pressurized Water Reactor,PWR)一回路为研究对象,针对一回路中的放射性物质,建立了污垢沉积及放射性物质的产量分布预测模型。模型对污垢沉积和放射性物质的预测结果与污垢仿真程序CRUDSIM(Chalk River Unidentified Deposits SIMulation)的计算结果差异小于5%。在此基础上,分析了冷却剂流速、氢气含量和冷却剂入口温度的影响。结果表明:放射性物质的含量随堆芯冷却剂流速和氢气含量而增大,且对蒸汽发生器(Steam Generator,SG)中放射性物质含量的影响比堆芯分别高93.9%和10%。冷却剂入口温度增加8%时,放射性物质的含量减小9%,且对堆芯中放射性物质含量的影响比SG大19%。降低冷却剂流速和降低氢气含量有利于降低SG的放射性物质含量;提高冷却剂入口温度可以有效降低堆芯的放射性物质含量。
文摘典型海洋摇摆对压水堆堆芯的热工水力特性有显著影响,从而导致一回路腐蚀产物的沉积生长规律发生变化。本文基于数据交换方法,通过多尺度耦合建立反应堆一回路系统模型,将摇摆条件下的冷却剂流动数学模型和腐蚀产物沉积生长模型加入模拟中,对摇摆条件下3×3棒束上腐蚀产物的生长过程进行了研究。结果表明,摇摆会导致冷却剂流速和棒外壁温发生周期性变化,流量脉动和温度波动会加剧摇摆切线方向上的剥蚀作用,削弱沉积过程。在轴向高度较低的通道截面上,靠近外围绝热壁面的棒表面上生长的多孔介质沉积层(Chalk River Unidentified Deposit,CRUD)最厚;在轴向高度较高的通道截面上,所有位置的棒上的CRUD分布规律趋于一致,并且在燃料棒周向的分布体现在极坐标系中呈现出趋近于椭圆形的规律。
