共查询到20条相似文献,搜索用时 140 毫秒
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基于某核电厂堆外核测量系统设备信号线缆电快速瞬变脉冲群抗扰度(EFT)试验不通过的情况,对电快速瞬变脉冲群抗扰度试验以及干扰机理进行研究.结果 表明,对信号线缆增加一定屏蔽效能的屏蔽网并对屏蔽网接地能有效抑制干扰信号.为堆外核测量系统以及同类产品EFT试验提供指导,同时为后续项目电缆选型提供参考. 相似文献
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研究了应用虚拟仪器技术实现核脉冲计数功能的方案,利用NI公司的USB-6009-DAQ板卡设计核脉冲计数测量的软硬件系统;开发了核领域常用核子仪器计数器,扩大虚拟仪器技术的应用领域;实验验证了测量系统具有较好的计数测量功能. 相似文献
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为满足核辐射探测器输出脉冲信号数据采集的需求,基于西门子PLC(S7-200)高速计数器HC4、HC5,研发了核脉冲计数数据采集系统。根据S7-200内嵌高速计数器原理,设计了周期脉冲计数数据采集实验,实验发现符合TTL标准的脉冲信号并不一定能被PLC高速计数器正确进行计数率测量。为此特别设计的甄别电路,满足了核辐射探测器输出信号经过放大器与甄别电路后转换为适合S7-200高速计数器HC4和HC5的输入信号。此外利用S7-200丰富的指令系统,执行核脉冲计数率连续测量和数据处理,并通过文本显示单元完成系统数据实时显示,实现了对核脉冲计数数据采集。 相似文献
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阐述了基于虚拟仪器的采用LabVIEW和通用数据采集卡开发核能谱数据采集系统的全过程.它采取了连续采样和幅度提取的方法,直接对核探头输出的电压脉冲信号进行定性和定量分析.经测试,系统能满足实际测量的要求,并且可以根据需要进行扩展. 相似文献
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《核电子学与探测技术》2018,(6)
针对涉核多样化军事任务NaI(Tl)探测器输出脉冲拖尾较长,不利于高计数条件下的能谱测量的特点,论文通过建立输出脉冲单指数衰减模型和双指数衰减模型的方法进行脉冲反演,并分别对这两种方法进行了仿真和实际信号测试。结果表明,应用双指数反演得到的冲击响应信号比单指数反演信号窄了一倍,更加接近探测器实际输出信号,可应用于多道测量系统,有助于提高系统脉冲通过能力。 相似文献
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The fracture toughness of the zirconium alloy (Zr-2.5Nb) is an important parameter in determining the flaw tolerance for operation of pressure tubes in a nuclear reactor. Fracture toughness data have been generated by performing rising pressure burst tests on sections of pressure tubes removed from operating reactors. The test data were used to generate a lower-bound fracture toughness curve, which is used in defining the operational limits of pressure tubes. The paper presents a comprehensive statistical analysis of burst test data and develops a multivariate statistical model to relate toughness with material chemistry, mechanical properties, and operational history. The proposed model can be useful in predicting fracture toughness of specific in-service pressure tubes, thereby minimizing conservatism associated with a generic lower-bound approach. 相似文献
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The ability of the NDRC equations to estimate the penetration depth in concrete structures has been reevaluated using the presently available test results. This study confirms the industry notion that the NDRC equations overpredict the penetration depth. The NDRC equations, when used with a safety factor, can give a penetration depth about two standard deviations away from the mean value. In a probabilistic formulation the use of this penetration depth is over-conservative and unrealistic. The NDRC equation is updated here statistically using the presently available test results. This statistical NDRC equation significantly improves the predicted penetration depth. However, the form of the NDRC equation may not be ideal. A new relationship is proposed here to estimate the penetration depth by introducing a dimensionless impact factor. It has been shown here that the proposed relationship is better than the NDRC or even the statistical NDRC equations. 相似文献
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航空航天电子系统对电子器件选型评估时需考虑器件的多单元翻转(MCU)情况,而MCU信息提取面临的最主要困难是缺少器件的版图信息。本文提出一种基于概率统计的单粒子MCU信息提取方法,其可在无版图信息条件下以较高精度提取单粒子翻转(SEU)实验数据中的MCU信息。该方法通过统计分析SEU实验数据中不同翻转地址间的按位异或和汉明距离以提取MCU模板,然后利用该模板提取MCU信息。采用一款位交错SRAM器件的重离子实验数据对上述方法进行了验证,结果表明,该方法能以较高的精度提取实验数据中的MCU信息。该方法可省去对器件进行逆向工程的时间和成本,提高科学研究和航空航天器件选型效率。 相似文献
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A model of the dependence of displacement damage in bipolar transistors on material parameters can be used to predict worst-case displacement damage constants for transistors. Many real-device complexities, such as parasitic capacitances, some emitter-crowding effects, unknown base grading, can be eliminated by a worst-case approach. The resulting worst-case damage constant for a 2N914 transistor is near the value extrapolated from statistical test data. 相似文献
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安全壳泄漏率计算过程中,最重要的环节是以不同时刻测量数据对时间进行线性回归分析。对回归的显著性检验以及方差分析是评价试验结果有效性的重要手段。本文基于统计软件R对某电厂调试阶段安全壳泄漏率试验的数据进行分析,通过对线性回归模型的独立性、正态性和异方差性检验以及极端样本点的剔除等方式,探讨泄漏率计算前的回归诊断对计算结果可靠性的影响。通过回归诊断的实例分析发现,在安全壳泄漏率计算的数据样本中,可能存在自相关、非正态和异方差性等问题影响回归结果,进而影响泄漏率的最终结果。因此,在计算泄漏率结果时,须通过回归诊断方法评价数据的有效性,对不能通过检验的样本应通过适当方法对最终结果进行修正。 相似文献
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The most important part in the calculation of the containment leakage is to perform the linear regression on time for a series of data measured at different times. The significance test of the regression and residual analysis are the substantial means to evaluate the test results. This paper analyzes the data of the containment test during the commissioning and startup phase of a power plant based on the statistical software R, and explores the regression diagnosis before the leakage calculation by examining the independence, normality and heteroscedasticity of the regression model and the elimination of extreme sample points impact on the reliability of the result. Through the regression diagnosis on the examples, it was found that in the samples which leakage rate is calculated, there may be problems that affect the regression results and then the affect the final results, such as autocorrelation, non-normality and heteroscedasticity. Therefore, the validity of the data shall be evaluated by the regression diagnostic methods, while calculating the leakage rate, and the final results shall be corrected by appropriate methods for samples that fail the test. 相似文献
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NONLINEAR RESPONSES OF GAMMA —RAY DOSIMETERS 总被引:1,自引:0,他引:1
Either sublinear or supralinear responses of dosimeters to γ-ray can be described by a response function derived from statistical Poisson distribution.The characteristic parameters of the function determine linearity,sublinearity and supralinearlty in their responses.The experimental data of gamma dose-responses of alanine ESR dosimeters film dosimeters.LiF(Mg,Cu,P) and LiF(Mg,Ti) thermoluminescence dosimeters are used to test the response function. 相似文献
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Sang-Ryeol Park Won-Pil Baek Soon-Heung Chang Byung-Ho Lee 《Nuclear Engineering and Design》1992,135(3)
A statistical uncertainty quantification methodology for evaluation of the emergency core cooling system (ECCS) performance is proposed and applied in assessing the best-estimate peak cladding temperature (PCT). In the proposed methodology, the Latin hypercube sampling method is adopted, and separate model uncertainties are used as input variables. The independency of the input variables is verified through a correlation coefficient test for statistical treatment of their uncertainties. Next, the PCT response distribution is determined through a goodness-of-fit test. Finally, the PCT with a one-sided 95% probability and a confidence level of 0.95 is estimated.This methodology is applied to the large-break loss-of-coolant accident (LBLOCA) of Kori Nuclear Units 3 and 4. This study shows that the proposed methodology is a useful one. 相似文献
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F. de Crcy 《Nuclear Engineering and Design》1994,149(1-3)
This paper recalls the statistical origins of the minimum departure from nucleate boiling ratio (MDNBR) concept and Owen's coefficients, as used in CHF studies. The way in which they are currently used may be incorrect, and we shall present a new approach in which the lower tolerance interval limit depends on a number of parameters. The use of least-square regressions and smoothing splines is explained. We also include an example, based on a CHF EPRI test, from the Columbia University data bank. 相似文献