Studies on Three Dimensional Finite Element Modeling of Pulsed Eddy Current Testing

脉冲涡流检测技术是一种新型的涡流检测技术。由于它的激励信号频谱宽广，并且不同频率分量对应不同的趋肤深度，使检测信号包含丰富的材料内部深度方向的信息，在航空航天、石油化工、核能电力等领域有着广阔的应用前景。因此对脉冲涡流检测技术的研究有着重要的意义。 对脉冲涡流检测的仿真可以指导脉冲涡流检测技术的研究。相对于实验研究，仿真所需的设备简单，研究成本低，研究过程更灵活，同时可以避免实验研究中不确定因素带来的干扰。基于这一点，本文以电磁场理论为基础，建立了脉冲涡流检测的仿真模型，应用有限元分析方法，使用FORTRAN语言编写程序，实现了含有磁芯探头扫描的脉冲涡流检测的三维仿真。通过与实验、理论解及二...Pulsed eddy current testing (PECT) is one of the new techniques of eddy current testing (ECT). Thanks to the large amount of frequency components, the response signal of PECT contains much richer information about defect and material properties along the depth direction than conventional ECT. Therefore, PECT will play an important role in the maintenance of aircrafts, nuclear power plants, oil and...学位：工学硕士院系专业：物理与机电工程学院_航空宇航制造工程学号：3202010115268

Comparison of Two Axisymmetrical Finite Element Models for Pulsed Eddy Current Simulation

脉冲涡流检测技术是近年来发展迅速的一种新型涡流检测技术。由于其激励信号频谱宽广,不同频率分量的涡流能够渗透到不同深度,使其检测信号包含更丰富的深度方向的缺陷信息,在航空维修等工业领域有着重要的意义。对脉冲涡流检测的仿真可以指导脉冲涡流检测技术的研究。本文利用二维轴对称模型,介绍了脉冲涡流有限元仿真的两种方法—傅里叶变换法和时间步进法,并详细比较了这两种方法的优缺点。Pulsed eddy current testing(PECT) is one of the new techniques of eddy current testing.Thanks to the large amount of frequency components,the response signal contains rich information about defect and material properties along the depth direction.Therefore the PECT plays a significant role in the maintenance of aircrafts,nuclear power plants and so on.This paper introduces the two main methods used in the finite element modeling of PECT.Comparison of the methods is given.航空科学基金项目资助(批准号:2009ZD68004

RGD-FasL羟乙基壳聚糖缓释纳米粒制备及生物学研究

目的使用羟乙基壳聚糖制备纳米颗粒(NPs),用来包载RGD-FasL融合蛋白(RF),鉴定其功能并评估其在肝癌治疗中的作用。方法采用离子凝胶法制备RF羟乙基壳聚糖缓释纳米粒(RF-NPs);通过透射电镜、动态光散射法考察其理化性质;用紫外分光光度仪检测蛋白浓度来计算其载药率、包封率和体外释放度;通过MTT比色法检测对H22细胞增殖活性的影响,应用H22细胞建立小鼠肝癌模型进行体内抑瘤研究。结果制备的RF-NPs呈球形或类球形,平均粒径198.3 nm,Zeta电位+25 mV,包封率较高,且具有缓释效果,150 mg/L浓度时对H22细胞抑制率大于70%,并能在小鼠体内产生比较明显的抑瘤效果。结论离子凝胶法制备RF-NPs的条件缓和、方法简单,是癌症治疗中具有很好的前景的蛋白药物载体

羟乙基壳聚糖抗人死亡受体5单链抗体纳米粒的制备、鉴定及体内抑瘤研究

目的为提高抗人死亡受体5单链抗体治疗肝癌的效果,探讨羟乙基壳聚糖抗人死亡受体5单链抗体纳米粒(GCS-aDR5ScFv)的制备、鉴定并研究其对小鼠肝癌H22模型的治疗效果及机制。方法用亲和镍柱层析法纯化抗人死亡受体5单链抗体(aDR5ScFv),采用离子凝胶法制备GCS-aDR5ScFv,应用扫描电镜来检测GCS-aDR5ScFv的外观形态,激光粒度分析仪分析纳米粒的粒径及粒径分布,并检测其表面Zeta电势。建立小鼠肝癌H22模型,用0.272 mg/ml GCS-aDR5ScFv隔天治疗并测量小鼠体质量及肿瘤大小,治疗2周。通过Western blot检测active-caspase8、active-caspase3及BAX表达。结果纯化的aDR5ScFv符合理论条带(Mr30 000),GCS-aDR5ScFv纳米粒形态均一,纳米粒径大小、Zeta电势和多分散指数表明GCS-aDR5ScFv稳定。与正常组相比,治疗组小鼠体质量显著差异,治疗组肿瘤体积和大小差异显著。Western blot检测active-caspase8、active-caspase3、BAX的表达水平上调。结论本研究制备的GCS-aDR5ScFv稳定,对小鼠肝癌H22模型具有抑瘤作用,其机制可能与active-caspase8、active-caspase3及BAX蛋白表达上调相关

Determination of Trace Mercury Isotopes in Liquid and Solid Samples by Inductively Coupled Plasma Mass Spectrometry with Oxidation,Purge-trap,Dual-stage Thermal Desorption

建立了液体和固态环境样品中痕量Hg同位素的氧化-吹扫-金柱捕集-热脱附-电感耦合等离子体质谱(ICP-MS)测定法。样品采用美国环保局(uSEPA)1631方法预处理,气液分离降低基底干扰,金柱富集提高灵敏度;将Hg蒸气直接引入ICP-MS,利用ICP-MS的分辨能力,测定Hg同位素。198 Hg和201 Hg的检测限分别为0.07、0.11ng/l;土壤、沉积物和生物等固体样品中198 Hg和201 Hg的检测限分别为0.15、0.20ng/g。在最佳条件下,连续7次测定198 Hg和201 Hg基底加标水样,测定结果的相对标准偏差(rSd)均为7.0%,同位素比值(201 Hg/198 Hg)的内精度为0.26%(I rSd)。痕量198 Hg和201 Hg海水样基底加标回收率分别为98.3%~116.0%、92.4%~109.4%,生物样198 Hg和201 Hg的基底加标回收率分别为88.4%~106.7%、79.7%~88.0%。与标准参考溶液198 Hg和201 Hg的相对偏差分别为-0.15%、-0.09%。对于褶牡蛎的同位素组成分析,2次测定同位素比值(201 Hg/198 Hg)与自然界Hg同位素比理论值的相对偏差分别为0.4‰、-6.0‰。该方法成功用于标准参考样品和实际生物样品的同位素组成分析,并可成为Hg迁移和转化示踪实验的分析技术手段。A method based on inductively coupled plasma mass spectrometry(ICP-MS) coupling with oxidation,purge-trap and dual-trap thermal desorption has been established for the determination of trace mercury(Hg) isotopes in liquid and solid environmental samples.U.S.Environmental Protection Agency(USEPA) Method 1631 was employed for sample pretreatment.Matrix interference was reduced with gas-liquid separation,and sensitivity was improved with gold amalgamation.Hg vapor was directly introduced to ICP-MS after thermal desorption from the gold trap,and Hg isotopes were simultaneously determined.The detection limits of 198Hg and 201Hg were 0.07 ng/L and 0.11 ng/L,respectively.For solid samples such as soil,sediment,and biota,the detection limits were 0.15 ng/g and 0.20 ng/g,respectively.Under the optimized conditions,the RSDs(n=7) of 198Hg and 201Hg were both 7.0% for a matrix spiked water sample,and the internal precision(I RSD) of Hg isotope ratios(201Hg/198Hg) was 0.26‰.The recoveries of matrix spiked seawater samples containing trace 198Hg and 201Hg were 98.3%-116.0%,92.4%-109.4%.The recoveries of 198Hg and 201Hg from matrix spiked biota samples were 88.4%-106.7%,79.7%-88.0%.The determination result of a standard reference solution showed-0.15% relative deviation for 198Hg,and-0.09% for 201Hg.For duplicate measurement of mercuy isotopes in Ostrea Plicatula Gmelin samples collected from ambient environment,the relative deviations for isotopic ratios(201Hg/198Hg) between measured and its theoretical value in nature were 0.4‰ and-6.0‰.The proposed method was successfully applied to determine Hg isotopic composition in stardard reference samples and practical biota samples,and was expected to be applied in tracing experiments for studying Hg transportation and transformation.国家自然科学基金(No.NSF20777063

25 MeV/u~(40)Ar+~(197)Au反应中高激发热核的时空演化

报道了２５ＭｅＶ／ｕ４０Ａｒ＋１９７Ａｕ反应中从两粒子相对动量关联函数提取的发射时间随空间大小演化的规律．结果表明，即使发射源质量数减小５０％，对计算的关联函数及提取的发射时间影响仍然很小．在短发射时间（τ≤１００ｆｍ／ｃ）情况下，较小的核物质密度，导致提取的发射时间变小．因此，在正常核物质密度参数下提取的τ值可作为发射时间的上限值．在长发射时间（τ≥３００ｆｍ／ｃ）情况下发射时间不随空间大小变化，提取的τ即为实际的发射时间．The emission time extracted from two particle relative momentum correlation functions has been studied as a function of the spatial extent of the source for 40 Ar+ 197 Au reaction at 25MeV/u.Reduction of ～50% in the mass number of the source has a very small effect on the calculated correlation functions and the extracted emission time.For the cases of short emission time τ(τ ≤100fm/ c ), use of a smaller nuclear density would lead to somewhat smaller assignment for τ...国家自然科学基金,中国科学院重点项

高激发热核衰变中哪些粒子先发射

通过测量两裂片符合下两关联粒子的速度差分布 ,研究了 2 5MeV/u40 Ar +197Au反应中高激发核出射轻粒子和Li碎片的发射次序 .通过比较实验结果和三体弹道计算结果 ,观察到高速轻粒子 (氚和氦粒子 )优先于高速Li碎片发射 ,但低速轻粒子却在低速Li碎片之后发射 .此外 ,观测到轻粒子之间 (如氘和氚 )无优先发射中国科学院“九五”重点课题;; 国家自然科学基金资助项目!(批准号 :195 75 0 5 5和 196 75 0 5 3

“心理科学与文化建设”研讨会发言纪要

各位领导,各位专家,早上好!非常高兴在元旦刚过、春年即将来临之际,我们举办一次心理科学与文化建设的论坛(或者称研讨会),请来各位专家,就这样一个非常重要的议题各抒己见。同时,我们也希望通过这样一个研讨会,将来逐渐形成一个机制或者一个平台,以便使我国心