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41.
通过试验分析了用土量对密度计法颗粒分析结果和土质分类的影响,结果表明:颗粒级配曲线随着试验用土量的增加向上抬升,但增幅随着用土量的增加而逐渐降低,沙土级配曲线比黏土级配曲线受用土量影响大;当试验用土量为20~50 g时,级配曲线没有显著变化,也不会影响土质的分类结果,而当用土量少于20 g时会显著影响级配曲线测量结果。 相似文献
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43.
本文考虑当理赔次数N的分布为Poisson-逆高斯分布时,相应的总理陪量分布(即复合Poisson-逆高斯分布)的两种近似:正态分布和平移Gamma分布。同时还考虑了当理赔量的分布为下指数分布时复合Poisson-逆高斯分布的尾概率的一种近似计算。 相似文献
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针对我国铀矿γ测井实际情况,指出FD-3019γ,测井仪与数字测井系统连接时,应考虑电缆匹配和死时间修正问题。对改装后的γ测井仪的校准,应按照测井时使用的系统配置进行。提出了将计数电路和数据传输电路加装到FD-3019γ探管中的连接方案,并探讨了γ测井仪换算系数的含义、影响因素及其在γ测井中的作用。 相似文献
46.
M. AHMAD W. AHMAD M. U. RAJPUT A. QAYYUM 《核技术(英文版)》2005,16(6):325-329
The thermal neutron capture gamma ray facility at Pakistan Research Reactor (PARR-1) is being used for the re-estimation of various properties like capture cross-sections, resonance integral, absolute gamma intensities, etc. of different isotopes. The data for gamma ray transitions from the capture of thermal neutrons by ^55Mn are not in good agreement specifically below 2 MeV. So there is a need to re-estimate its intensities with better accuracy. Analytical grade MnCl2 powder and high purity Mn metal pieces were used in this study. Standard ^152Eu and ^60Co radioactive sources as well as thermal neutron capture γ-rays in chlorine were chosen for efficiency calibration. The k0 standardization technique was applied for these measurements to eliminate systematic errors in efficiencies. Chlorine also acted as a comparator in k0-factor calculations. The results have been tabulated for the main gamma rays from ^56Mn in the low as well as in the medium energy regions. The absolute intensities are in good agreement with most of the reported values. 相似文献
47.
Abstract— A novel method to characterize CRT displays through visual assessment and a pair of visual experiments that were conducted to validate this method will be discussed. The temporal integration method discussed in this paper has many advantages over previously described methods, which have employed spatially modulated patterns to characterize displays. Included among the advantages are improvements in usability and enhanced robustness to single errors in human judgment. The observer study demonstrates that the method provides a robust estimate of CRT display gamma for both novice and experienced observers. This method may be applied to provide improved electronic‐display matching in e‐commerce applications, including online catalogs and online photofinishing. 相似文献
48.
You Na Lee 《Journal of Nuclear Science and Technology》2016,53(8):1178-1182
Emergency power systems in nuclear power plants are necessary for supplying power for safe operation during emergencies. Lithium-ion batteries can be used in power systems, but they have issues with material degradation under irradiation. To solve these problems, the development of an electrode with high stability under irradiation is needed. The electrochemical stability of Fe2O3-coated LiCoO2 (LCO) under irradiation was investigated. Fe2O3 is known to have a radiation shielding effect. The X-ray diffraction results for irradiated Fe2O3/LCO materials exhibited peaks of pristine LCO. In addition, Fe2O3 particles were observed to be well dispersed on LCO by scanning electron microscopy/energy dispersive X-ray spectroscopy. Electrochemical measurements revealed that the retention ratio of the discharge capacity for Fe2O3-coated/LCO was more stable than the capacity retention of non-coated LCO under irradiation. 相似文献
49.
R. Ahmadi 《国际生产研究杂志》2016,54(17):5303-5316
Given a reward structure, this paper addresses an optimal replacement problem for complex multi-component systems. To maintain revenue stream resulting from system, the system is inspected according to a homogeneous Poisson process and certain actions are carried out in response to the system state. Decisions are based on a performance measure described by a Squared Bessel process. Given some assumption, we explore the inherent relation between the Squared Bessel process and an extended Gamma (EG) process. Since there are some flow of income and increasing costs due to inspections, the problem is to optimally stop processing the system and carrying out a renewal to maximize the reward functional. To this end, using the local characteristics of the EG process as a stopping criterion and the expected total discounted reward as a measure of policy, this paper aims at determining an optimal operating (stopping) time which truly balances both income and cost and so maximizes the expected discounted reward over a cycle. In support of the model a numerical example is provided to show feasibility of this programme in real application. Attention is restricted to perfect repair and inspection, but the paper provides the structure so that different scenarios can be explored. 相似文献
50.
《Journal of Nuclear Science and Technology》2013,50(11):1228-1232
The photon mass attenuation coefficients of the important materials for γ-ray detection, Ge and BGO (Bi4Ge3O12) crystals, have been measured for 10.0 MeV γ-rays. The measurement system using the laser-Compton backscattering γ-rays and the high-resolution high-energy photon spectrometer has been developed and utilized. The effectiveness of the system achieving the total systematic uncertainties of 0.5% for the measurements of the photon mass attenuation coefficients was demonstrated. It was shown that the measured photon mass attenuation coefficients, 318.1 ± 1.7 [cm2/g] for the Ge crystal and 425.2 ± 2.4 [cm2/g] for the BGO crystal, agree within the achieved experimental uncertainties with the evaluated values including atomic and nuclear processes at 10.0 MeV. 相似文献