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基于gamma和时变Markov模型的天然气管道剩余寿命预测

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设备管理与维修 2024年第7期 38-40页

作者：李岩鹏陈博儒朱思言中国石油吉林油田分公司松原采气厂吉林松原原138000

基于gamma和时变Markov模型,对天然气管道的剩余寿命进行深入研究。采用gamma随机过程建立管道的退化模型,以腐蚀深度为指标,并应用SY/T6151一2009标准划分了不同腐蚀状态。为更准确地模拟管道退化过程中的实际情况,引入时变转移概率矩... 详细信息

基于gamma和时变Markov模型,对天然气管道的剩余寿命进行深入研究。采用gamma随机过程建立管道的退化模型,以腐蚀深度为指标,并应用SY/T6151一2009标准划分了不同腐蚀状态。为更准确地模拟管道退化过程中的实际情况,引入时变转移概率矩阵,考虑随时间变化的状态迁移。以APILX52级别钢制管路为对象,通过监测数据预测剩余寿命,并验证模型的准确性。结果表明,与传统的Markov模型相比,该方法能够更精准地预测管道寿命的减少或延长。

关键词： gamma Markov 天然气管道剩余寿命预测

基于Jeffreys先验的参数相关退化可靠性评估

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机械强度 2024年第1期46卷 249-254页

作者：殷泽凯郭宇江苏徐工国重实验室科技有限公司可靠性技术研究所徐州221004 国防科技大学空天科学学院长沙410073

通过Jeffreys无信息先验分布描述了gamma退化过程中参数的相关性,由贝叶斯模型得到各参数满条件分布,使用马尔科夫链蒙特卡洛(Markov Chain Monte Carlo,MCMC)方法得到参数后验期望估计,最后给出可靠度评价模型。工程实例表明,所得可靠... 详细信息

通过Jeffreys无信息先验分布描述了gamma退化过程中参数的相关性,由贝叶斯模型得到各参数满条件分布,使用马尔科夫链蒙特卡洛(Markov Chain Monte Carlo,MCMC)方法得到参数后验期望估计,最后给出可靠度评价模型。工程实例表明,所得可靠性评估较独立情形更为保守,能够更早地给出产品修理建议。同时,仿真表明,可靠度要求越高,相关与独立情形寿命估计结果偏差越大,0.9999可靠度下偏差率最大可达9.26%。

关键词： gamma 过程参数相关 Jeffreys 无信息先验马尔科夫链蒙特卡洛方法

Bayesian Group Chain Sampling Plan for Poisson Distribution with gamma Prior

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Computers, Materials & Continua 2022年第2期70卷 3891-3902页

作者： Waqar Hafeez Nazrina Aziz Zakiyah Zain Nur Azulia Kamarudin School of Quantitative Sciences Universiti Utara MalaysiaUUM Sintok06010KedahMalaysia Institute of Strategic Industrial Decision Modelling(ISIDM) Universiti Utara MalaysiaUUM Sintok06010KedahMalaysia

Acceptance sampling is a statistical quality control technique that consists of procedures for sentencing one or more incoming lots of finished products.Acceptance or rejection is based on the inspection of sampled products drawn randomly from the lot.The theory of previous acceptance sampling was built upon the assumption that the process from which the lots are produced is stable and the process fraction nonconforming is a constant.Process variability is inevitable due to random fluctuations,which may inadvertently lead to quality variation.As an alternative to traditional sampling plans,Bayesian approach can be used by considering prior information of the process.Using different combinations of design parameters,this study introduces a Bayesian group chain sampling plan(BGChSP).For the first time in group chain sampling plan,the probability of lot acceptance is derived by using Poisson distribution to estimate an average number of defectives.gamma distribution is used as a prior distribution with Poisson distribution.Taking into account both consumer’s and producer’s risks,this research considers two quality regions namely,probabilistic quality region(PQR)and indifference quality region(IQR).By minimizing consumer’s and producer’s risks,BGChSP can be used to minimize the average number of defective products in industry.

关键词： Bayesian acceptance sampling gamma produce risk consumer risk

gamma induced changes in Makrofol/CdSe nanocomposite films

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Chinese Physics B 2022年第9期31卷 547-553页

作者： Ali A.Alhazime M.ME.Barakat Radiyah A.Bahareth E.M.Mahrous Saad Aldawood S.Abd El Aal S.A.Nouh Physics Department Faculty of ScienceTaibah UniversityMedinaSaudi Arabia Department of Physics Faculty of ScienceTaibah UniversityYanbuSaudi Arabia Department of Physics Faculty of ScienceAlexandria UniversityAlexandriaEgypt Physics Department College of ScienceJeddah UniversityJeddahSaudi Arabia Department of Physics and Astronomy College of ScienceP.O.BOX 2455King Saud UniversitySaudi Arabia Center of Radiation Research and Technology Egyptian Atomic AuthorityNasr CityCairoEgypt Qassim University P.B.6644Buraidah 51452QassimSaudi Arabia Physics Department Faculty of ScienceAin Shams UniversityCairoEgypt

We applied an ex-situ casting procedure to prepare a nanocomposite(NCP)from Makrofol polycarbonate(PC)and CdSe nanoparticles.The CdSe nanoparticles were prepared by a thermolysis procedure in the presence of N_(2) gas flow.Rietveld refinement of x-ray data illustrated that the CdSe adopts a cubic zinc blend structure of 6.057 A lattice parameter and 2 nm typical grain size.Samples from the prepared NCP were exposed to γ dosages(20 kGy-250 kGy).The modifications induced in the NCP films owing to γ dosages have been studied.Theγirradiation(50 kGy-250 kGy)causes crosslinks that reduce the optical bandgap from 4.15 eV to 3.81 eV,associated with an increase in dielectric parameters and refractive index.This is attributed to an increase in the mass fraction of the disordered regions as specified by x-ray diffraction.The PC-CdSe NCP was found to have a reaction to color modification which makes it suitable for saleable reproduction on a printing press.

关键词： gamma nanocomposite x-ray dfraction UV spectra color changes

多内部调制参数相关的CCD高温计测量能力评估理论及实验验证

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传感器技术与应用 2024年第3期12卷 268-285页

作者：顾晟羽于千淞董渊长春理工大学物理学院吉林长春

基于像元输出信号强度与目标温度的积分关系,定义并构建了温度分辨率在不同内部调制参数下的评估模型。结合标定实验进行数值模拟,讨论了增益和gamma调制参数对CCD系统温度分辨率的影响。并开展调制参数对温度分辨率影响的理论验证性实... 详细信息

基于像元输出信号强度与目标温度的积分关系,定义并构建了温度分辨率在不同内部调制参数下的评估模型。结合标定实验进行数值模拟,讨论了增益和gamma调制参数对CCD系统温度分辨率的影响。并开展调制参数对温度分辨率影响的理论验证性实验,得到了在不同增益和gamma调制参数影响下的304不锈钢和黄铜的温度分辨率情况。通过实验与模拟结果的对比分析,总结了两种内部调制参数对温度分辨率的影响效果。完善了CCD温度测量理论体系,同时也为CCD测温系统在不同条件下的参数选择提供了理论指导。

关键词： CCD探测器调制参数增益 gamma 温度分辨率

gamma and X-ray radiation compatibility of Ti–Ta–Hf–Zr alloys used for coronary stent applications

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Nuclear Science and Techniques 2018年第1期29卷 16-22页

作者： L. Seenappa H. C. Manjunatha K. N. Sridhar Chikka Hanumantharayappa Department of Physics Government College for WomenKolar Karnataka 563101 India Department of Physics Government First Grade CollegeKolar Karnataka 563101 India Vivekananda Degree College Bangalore Karnataka 560055India Research and Development Centre Bharathiar UniversityCoimbatore 641046 India

We have studied the gamma and X-ray radiation compatibility of Ti-based alloys such as Ti–37 Ta–26 Hf–13 Zr-24(wt%) [Alloy 1], Ti–40 Ta–22 Hf–11.7 Zr-26.3(wt%) [Alloy 2], Ti–45 Ta–18.4 Hf–10 Zr-26.6(wt%) [Alloy3], Ti–50 Ta–15 Hf–8 Zr-27(wt%) [Alloy 4], Ti–55 Ta–12 Hf–7 Zr-26(wt%) [Alloy 5], and Ti–60 Ta–10 Hf–5 Zr-25(wt%) [Alloy 6]. gamma and X-ray radiation compatibility is studied by evaluating the mass attenuation coefficient,mean free path, HVL, TVL effective atomic number,effective electron density, exposure buildup factor, and relative dose. We have compared these parameters for studied alloys with that of arteries. The alloys Ti–55 Ta–12 Hf–7 Zr-26 and Ti–60 Ta–10 Hf–5 Zr-25 have added properties such as gamma/X-ray radiation compatibility,high elastic admissible strain, high mechanical strength,and excellent biocompatibility. Hence, we may suggest that, among Ti–Ta–Hf–Zr alloys, these alloys are best materials for coronary stent applications.

关键词： Stentalloys X-ray gamma Mass attenuation coefficient

A new method for detecting pulse gamma ray with scattered electrons

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Chinese Physics B 2008年第12期17卷 4466-4471页

作者：夏良斌欧阳晓平王群书康克军谭新建 Department of Engineering Physics Tsinghua University Northwest Institute of Nuclear Technology

This paper describes a newly designed gamma pulse detector of current mode that uses the scattered electron method. Tungsten is used as the scattering target, an organic thin film scintillator ST401 is used to collect the scattered electrons. The spatial distribution of the electronic energy-flux density is studied by using the MCNP code. The optimization of the target and the thickness of the scintillator are also discussed. The results indicate that the energy response is relatively flat in the range of 0.4 to 5 MeV.

关键词： scattering electron gamma response

Estimating the resistance of aging service-proven bridges with a gamma process-based deterioration model

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Journal of Traffic and Transportation Engineering(English Edition) 2019年第1期6卷 76-84页

作者： Cao Wang Kairui Feng Long Zhang Aming Zou School of Civil Engineering The University of Sydney Department of Civil Engineering Tsinghua University CCCC Highway Consultants CO. Ltd.

The environmental or anthropogenic factors, to which the in-service bridges are subjected,are responsible for the reduction of bridge performance, and finally lead to great service risk for bridges and increase the probability of substantial economic losses. Probabilitybased estimate of bridge resistance is an essential indicator for the bridge condition evaluation and for optimization of bridge maintenance/repair decisions. It places an emphasis on the proper probabilistic models of structural properties and assessment methods. Making full use of historical service load information may improve the accuracy of bridge performance assessment with reduced epistemic uncertainty for existing aging bridges. In to-date analyses to update the bridge resistance with past service information,the models of resistance deterioration have been assumed as either deterministic or fully correlated, which may differ significantly from the realistic case. With this regard, this paper proposes a novel method for updating the resistance of service-proven bridges with a realistic deterioration model. The gamma stochastic process has been suggested in the literature to describe the probabilistic behavior of structural time-dependent resistance and thus is adopted in this paper. An illustrative bridge is presented to demonstrate the applicability of the proposed method. Parametric examples are conducted to investigate the role of resistance deterioration model in the updated estimate of bridge resistance with historical service information.

关键词： Existing aging bridges Historical load information Resistance updating gamma deterioration process Bridge safety

Using organotypic hippocampal slice cultures to gain insight into mechanisms responsible for the neuroprotective effects of meloxicam: a role for gamma aminobutyric and endoplasmic reticulum stress

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Neural Regeneration Research 2019年第1期14卷 65-66页

作者： Elisa Landucci Irene L.Llorente Berta Anuncibay-Soto Domenico E.Pellegrini-Giampietro Arsenio Fernández-López Sezione di Farmacologia Clinica e Oncologia Dipartimento di Scienze della SaluteUniversità di Firenze Department of Neurology David Geffen School of Medicine University of California área de Biología Celular Instituto de BiomedicinaUniversidad de León Neural Therapies SL Edificio Institutos de Investigación

This perspective aims to put into context the recent article by Landucci et al.(2018)on mechanisms involved in the neuroprotective effects of meloxicam on an organotypic hippocampal slice cultures(OHSCs)model.In vitro cell cultures are the main method for studying large quantities of homogeneous cells in an isolated environment.Thus,the use of primary dissociated neuron,astrocyte,oligodendrocyte,microglia,or endothelial cell cultures has become a standard

关键词： gamma 文化海马机制应力蜂窝环境学习胃