Accurate water level measurement in nuclear reactors,particularly in PWRs(pressurized water reactors)and BWRs(boiling water reactors),is essential for ensuring the safety and efficiency of reactor operations.K-type HJ...Accurate water level measurement in nuclear reactors,particularly in PWRs(pressurized water reactors)and BWRs(boiling water reactors),is essential for ensuring the safety and efficiency of reactor operations.K-type HJTCs(heated junction thermocouples)are widely used for this purpose due to their ability to withstand extreme temperatures and radiation conditions.This article explores the role of HJTCs in reactor water level measurement and compares the performance of 2-wire and 3-wire connections.While the 2-wire connection is simple and cost-effective,it can introduce measurement inaccuracies due to wire resistance.In contrast,the 3-wire connection compensates for lead resistance,offering more precise and reliable measurements,particularly in long-distance applications.This paper discusses the operational considerations of these wiring configurations in the context of nuclear reactors and highlights the importance of choosing the appropriate connection type to optimize safety and measurement accuracy in PWR and BWR reactors.展开更多
采用熔盐法制备α-Al_(2)O_(3),采用硅烷偶联剂γ-氨丙基三乙氧基硅烷(KH550)对α-Al_(2)O_(3)进行表面改性,得到KH-α-Al_(2)O_(3)。以低密度聚乙烯(LDPE)为基体、不同的α-Al_(2)O_(3)为添加剂,制备α-Al_(2)O_(3)/XLPE和KH-α-Al_(2)...采用熔盐法制备α-Al_(2)O_(3),采用硅烷偶联剂γ-氨丙基三乙氧基硅烷(KH550)对α-Al_(2)O_(3)进行表面改性,得到KH-α-Al_(2)O_(3)。以低密度聚乙烯(LDPE)为基体、不同的α-Al_(2)O_(3)为添加剂,制备α-Al_(2)O_(3)/XLPE和KH-α-Al_(2)O_(3)/XLPE接地线绝缘材料。对α-Al_(2)O_(3)和KH-α-Al_(2)O_(3)的晶体结构、微观结构以及基团进行分析,考察不同α-Al_(2)O_(3)含量对α-Al_(2)O_(3)/XLPE接地线绝缘材料电学性能和热学性能的影响。结果表明:熔盐法制备的α-Al_(2)O_(3)是具有六方结构、结晶度高、直径5~10μm的不规则圆片,KH550的改性不会造成α-Al_(2)O_(3)结晶度的变化。KH-α-Al_(2)O_(3)在KH-α-Al_(2)O_(3)/XLPE接地线绝缘材料中沿材料厚度方向排列,且分散更为均匀,有利于抑制电荷在基体中的传输。KH-α-Al_(2)O_(3)有利于提高XLPE的直流击穿场强和直流电导率。当KH-α-Al_(2)O_(3)的添加质量分数为1.5%时,KH-α-Al_(2)O_(3)/XLPE的直流击穿场强达到320 k V/mm,电导率为1.043×10^(-13)S/m。KH-α-Al_(2)O_(3)的引入使XLPE基体和KH-α-Al_(2)O_(3)之间的界面产生一定数量的陷阱,有效实现了对注入电荷的抑制。KH-α-Al_(2)O_(3)可以明显降低XLPE的热失重速率,提高KH-α-Al_(2)O_(3)/XLPE接地线绝缘材料热稳定性。当KH-α-Al_(2)O_(3)的质量分数达到1.5%时,分解温度升高至475.44℃,90℃条件下的导热系数从0.390 W/(m·K)增加到0.545 W/(m·K)。展开更多
目的:观察涂有重组人骨形态发生蛋白-2(recombinant human bone morphogenetic protein 2,rhBMP-2)克氏针对骨折愈合影响。方法:36只新西南大白兔,随机分成两组,在其双侧胫骨制作骨折模型,扩髓,实验组胫骨骨折髓腔内插入rhBMP-2/左消旋...目的:观察涂有重组人骨形态发生蛋白-2(recombinant human bone morphogenetic protein 2,rhBMP-2)克氏针对骨折愈合影响。方法:36只新西南大白兔,随机分成两组,在其双侧胫骨制作骨折模型,扩髓,实验组胫骨骨折髓腔内插入rhBMP-2/左消旋聚乳酸(poly-D,L-lactide,PDLLA)涂层的克氏针固定骨折,对照组髓腔内插入单纯PDLLA涂层的克氏针固定骨折,术后分别于4、8、12周处死大白兔,取胫骨骨折标本进行骨形态学分析和生物力学测定,比较两组骨折处新骨形成、生物力学情况。结果:实验组新骨形成优于对照组;实验组断裂应力、最大应力高于对照组(P<0.05)。结论:rhBMP-2、PDLLA混合后涂抹在克氏针表面来固定骨折,随着PDLLA降解,缓慢释放rhBMP-2,促进骨折愈合,缩短骨折愈合时间。展开更多
文摘Accurate water level measurement in nuclear reactors,particularly in PWRs(pressurized water reactors)and BWRs(boiling water reactors),is essential for ensuring the safety and efficiency of reactor operations.K-type HJTCs(heated junction thermocouples)are widely used for this purpose due to their ability to withstand extreme temperatures and radiation conditions.This article explores the role of HJTCs in reactor water level measurement and compares the performance of 2-wire and 3-wire connections.While the 2-wire connection is simple and cost-effective,it can introduce measurement inaccuracies due to wire resistance.In contrast,the 3-wire connection compensates for lead resistance,offering more precise and reliable measurements,particularly in long-distance applications.This paper discusses the operational considerations of these wiring configurations in the context of nuclear reactors and highlights the importance of choosing the appropriate connection type to optimize safety and measurement accuracy in PWR and BWR reactors.
文摘采用熔盐法制备α-Al_(2)O_(3),采用硅烷偶联剂γ-氨丙基三乙氧基硅烷(KH550)对α-Al_(2)O_(3)进行表面改性,得到KH-α-Al_(2)O_(3)。以低密度聚乙烯(LDPE)为基体、不同的α-Al_(2)O_(3)为添加剂,制备α-Al_(2)O_(3)/XLPE和KH-α-Al_(2)O_(3)/XLPE接地线绝缘材料。对α-Al_(2)O_(3)和KH-α-Al_(2)O_(3)的晶体结构、微观结构以及基团进行分析,考察不同α-Al_(2)O_(3)含量对α-Al_(2)O_(3)/XLPE接地线绝缘材料电学性能和热学性能的影响。结果表明:熔盐法制备的α-Al_(2)O_(3)是具有六方结构、结晶度高、直径5~10μm的不规则圆片,KH550的改性不会造成α-Al_(2)O_(3)结晶度的变化。KH-α-Al_(2)O_(3)在KH-α-Al_(2)O_(3)/XLPE接地线绝缘材料中沿材料厚度方向排列,且分散更为均匀,有利于抑制电荷在基体中的传输。KH-α-Al_(2)O_(3)有利于提高XLPE的直流击穿场强和直流电导率。当KH-α-Al_(2)O_(3)的添加质量分数为1.5%时,KH-α-Al_(2)O_(3)/XLPE的直流击穿场强达到320 k V/mm,电导率为1.043×10^(-13)S/m。KH-α-Al_(2)O_(3)的引入使XLPE基体和KH-α-Al_(2)O_(3)之间的界面产生一定数量的陷阱,有效实现了对注入电荷的抑制。KH-α-Al_(2)O_(3)可以明显降低XLPE的热失重速率,提高KH-α-Al_(2)O_(3)/XLPE接地线绝缘材料热稳定性。当KH-α-Al_(2)O_(3)的质量分数达到1.5%时,分解温度升高至475.44℃,90℃条件下的导热系数从0.390 W/(m·K)增加到0.545 W/(m·K)。
文摘目的:观察涂有重组人骨形态发生蛋白-2(recombinant human bone morphogenetic protein 2,rhBMP-2)克氏针对骨折愈合影响。方法:36只新西南大白兔,随机分成两组,在其双侧胫骨制作骨折模型,扩髓,实验组胫骨骨折髓腔内插入rhBMP-2/左消旋聚乳酸(poly-D,L-lactide,PDLLA)涂层的克氏针固定骨折,对照组髓腔内插入单纯PDLLA涂层的克氏针固定骨折,术后分别于4、8、12周处死大白兔,取胫骨骨折标本进行骨形态学分析和生物力学测定,比较两组骨折处新骨形成、生物力学情况。结果:实验组新骨形成优于对照组;实验组断裂应力、最大应力高于对照组(P<0.05)。结论:rhBMP-2、PDLLA混合后涂抹在克氏针表面来固定骨折,随着PDLLA降解,缓慢释放rhBMP-2,促进骨折愈合,缩短骨折愈合时间。
