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31.
针对电站锅炉回转式空气预热器运行时上下表面不可见的问题,本文提出了一种视频监控与故障分析系统,可直接监测转子表面情况。该系统通过视频监控获取图像,结合改进的Retinex算法对其进行处理,实现了以下2个功能:1)能分析积灰程度以判断转子堵塞 情况;2)与温度场融合实时显示转子表面热点分布以预防二次燃烧。该系统已应用于某600 MW机组,实现了在热态环境下对空气预热器转子积灰程度、热点分布、堵塞程度的估算与可视化,大大提高了空气预热器运行的可靠性。 相似文献
32.
不确定性因素存在于火电机组负荷分配中,影响机组负荷分配、节能环保目标。本文综合考虑负荷预测不确定性、机组煤耗率不确定性与其CO2排放系数不确定性,分别构建火电机组一次能源消耗成本与CO2排放量最小目标下的火电机组负荷优化分配模型;以此为基础,引入析因分析方差分解方法,量化多源不确定性因素单独与交互作用下对节能、环保目标的影响程度。结果表明:负荷预测不确定性对火电机组节能、环保目标影响最为显著,相对影响程度分别为51.13%、62.70%;机组煤耗特性及其CO2排放系数影响次之,相对影响程度分别为47.58%、34.95%。此研究结果对不确定性条件下电力系统负荷分配具有借鉴价值。 相似文献
33.
Mohammad Reza Gaeeni Morteza Sasani Ghamsari Abbas Majd Abadi Mohammad Hossein Majles Ara Wooje Han Hyung‐Ho Park 《Journal of the American Ceramic Society》2015,98(6):1818-1822
A facile sol–gel procedure has been developed for the synthesis of colloidal alumina nanocrystals. For the first time, optical characterization procedures were employed to study the quantum confinement effects in optical properties of the prepared Al2O3 sol. Accordingly, the hyperbolic band model was used to determine the optical band gap of colloidal alumina nanocrystals. X‐Ray diffraction pattern was used to study the crystallographic phase of the dried gel. Morphological characterization was performed using scanning electron microscopy (SEM). Inductively Coupled Plasma (ICP) emission spectroscopy was used to determination purity of the Al2O3 powder. High‐resolution TEM showed that the diameter of colloidal nanocrystals is about 10 nm. Photoluminescence spectroscopy demonstrated that quantum yields for colloidal nanocrystals are 68% with 300 nm excitation wavelength. The experimental observations confirm that highly stable alumina sol with strong UV emission was synthesized. The mentioned optical properties have not been reported before. 相似文献
34.
35.
目前,基于因素空间理论的背景基提取算法计算过程复杂,初始化必须依赖各因素极值,基点数量提取冗余等原因,未能在应用中取得很好效果。为此,结合内点判别法和知识可继承、可扩展的思想,提出一种计算简单、初始化独立、基点数量小的改进的背景基提取算法。然后,利用改进的背景基提取算法构造出一种全新的数据分类算法-基点分类算法,基点分类算法以提取每一类样本的背景基为预测模型,再通过新定义的λ-背景基,优化预测模型。数值实验表明:基点分类算法原理简单、构造难度小、分类模型泛化能力强,预测能力准确率高,同时严格的模型限定区域又能为识别新类别提供新方法。 相似文献
36.
对5种活性焦水洗再生前后的脱硫性能进行实验研究,通过比表面积(BET)、X射线光电子能谱(XPS)方法表征水洗再生工艺对活性焦孔隙结构和表面化学性质的影响,揭示影响活性焦水洗再生性能的关键因素。结果表明:活性焦脱硫硫容的大小和水洗再生率的高低没有直接关系;微孔比表面积较大的活性焦脱硫性能较好,中大孔孔容较大的活性焦水洗再生率较高,同时具备较大的微孔比表面积和中大孔孔容结构的活性焦适宜水洗再生工艺;活性焦表面极性含氧官能团含量越高水洗再生效果越好;活性焦AC5经过6次水洗再生循环,微孔中的硫酸经过多次累积后可以被水洗出,稳定再生率保持在45%~50%,最适用于活性焦水洗再生工艺。 相似文献
37.
Zohal Safaei Mahmoudabadi Alimorad Rashidi Mohammad Panahi 《International Journal of Hydrogen Energy》2021,46(7):5270-5285
Highly active ReS2 nanocatalysts were prepared by CVD method and characterized by XRD, BET -BJH, Raman spectroscopy, XPS, TPR, NH3-TPD, SEM, and HRTEM techniques. Catalytic activities were used in upgrading heavy crude oil using methane as hydrogen source. The results showed a significant increase in API and decrease in sulfur and nitrogen content of crude oil. RSM technique was used to investigate the interactive effects of temperature (200–400 °C), pressure (20–40 bar) and dosage of nanocatalyst (0.5–2 wt. %) on the performance of HDS reaction. The results represent that the maximum predicted HDS activity (74.375%) was estimated under the optimal conditions (400 °C, 20 bars, and 2 wt % of nanocatalyst). Also, the effect of reaction temperature, pressure and dosage of ReS2 nanorods catalyst on HDN of heavy crude oil was investigated and highest efficiency in the HDN process (93%) occurred at 400 °C and 40 bar using 2 wt % ReS2. 相似文献
38.
Zahra Kiarsi Mohammad Hojjati Behrooz Alizadeh Behbahani Mohammad Noshad 《Journal of Food Safety》2020,40(3):e12782
Nutmeg (Myristica fragrans) seed was subjected to the hydro-distillation method to extract its essential oil (NEO). Its main constituents were α-pinene (20.16%), sabinene (14.45%), and β-pinene (13.26%) with great antimicrobial and antioxidant actions. A novel edible coating was then fabricated based on the sage seed mucilage (SSM) and NEO, to ameliorate the quality and shelf-life of beef slices. The NEO-loaded SSM coating was able to significantly decrease the population of total viable count, Escherichia coli, Staphylococcus aureus, psychrotrophic bacteria, and fungi. Moreover, lipid oxidation of beef slices was remarkably suppressed upon the application of bioactive NEO-loaded SSM edible coating, as compared with the control by Day 6. The coated beef sample, especially NEO-rich SSM coated ones perceived a higher consumer acceptance and firmness than the SSM coated and noncoated samples. The SSM edible coating containing NEO could therefore have the potential to control the growth of pathogenic microorganisms and lipid oxidation, and to improve the color stability and sensory properties of meat and meat products. 相似文献
39.
A stochastic model for local disturbances, particularly for a temporal harmonic with random modulations in amplitude and/or phase, is proposed in this paper. Results for the second moment responses of a linear single-degree-of-freedom system to this type of stochastic loading demonstrate a significant change in response characteristics due to a small uncertainty. A local phenomenon may last much longer and resonance may be smeared to a broad range. Integrated with wavelet transform, the proposed approach may be used to model a random process with non-stationary frequency content. Especially, it can be effectively used for Monte Carlo simulation to generate large size of samples that have similar characteristics in time and frequency domains as a pre-selected mother sample has. The technique has a great potential for the case where uncertainty study is warranted but the available samples are limited. 相似文献
40.
MMS作为移动通信运营商最近推出的一类业务新品.受到了众多国外手机厂商的热情追捧。MMS在国内市场的成长空间有多大?手机厂商的对策是什么?本文试图运用SWOT战略分析矩阵及三点效用模型对MMS手机的市场进入机会及厂商的营销策略进行研究,旨在探讨MMS在中国市场的成功运营之道。 相似文献