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101.
102.
为满足上海先进质子治疗装置治疗头中剂量电离室电子学A/D转换后的数据率和降噪要求,提出一种多级级联的数字滤波器结构。本文中设计LMS自适应滤波器来滤除50 Hz的工频噪音,相比于传统数字陷波器,不会对有用信号造成损失。通过MATLAB软件仿真对信号处理结果表明,电子学延时减少到170μs,数据率50 kHz,基本符合量化后的剂量数据处理要求。 相似文献
103.
《能源学会志》2014,87(4):372-382
Recent technologies have been introduced for gas turbine engine to meet with stringent emission regulations. One of the technologies is to introduce recirculation in the combustion zone to control the residence time and mixing by help of swirling flow. Effect of variation in geometric parameters and inlet mass flow of swirler have been examined in this study by help of CFD. Detailed design methodologies have been proposed in this study to design a series of axial swirler with different vane angles and vane numbers. Substantial variation in swirler performance has been observed by changing vane angle, vane number and mass flow. Four different types of axial and radial velocity profiles have been observed. Turbulence distribution pattern shows double peaks at all positions and reduces with increasing axial distance. 相似文献
104.
105.
Hyoungchul Kim Jongsup Hong Kyung Joong Yoon Ji‐Won Son Jong‐Ho Lee Byung‐Kook Kim Hae‐Weon Lee 《国际能源研究杂志》2016,40(6):726-732
We demonstrate the high‐performance and robust operation of anode‐supported solid oxide fuel cells under a mixed‐gas atmosphere applying a novel cell structure and characterization method, useful for minimizing the conventional problems of mixed‐gas operation with anode‐supported solid oxide fuel cells. To achieve the exothermic methane (CH4) partial oxidation and sufficient difference in oxygen partial pressure even in mixed‐gas mode, a composite of metallic rhodium and cerium dioxide (CeO2) was chosen as the optimized reforming and oxygen barrier layer after the comprehensive catalytic experiment. We also obtained increased cell operation reliability through the combination of anode pre‐reduction, an optimized material system, and a customized characterization jig (including cathode‐ahead layout and impinging jet flow). According to the cell test at 600°C under a feeding gas of CH4 and O2, an open‐circuit voltage and maximum power density of 0.916 V and 0.422 W/cm2, respectively, were successfully achieved. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
106.
Jaeyoung LeeJong-Chul Lee 《Vacuum》2012,86(10):1522-1527
In this study, we calculated the whole arcing history of SF6 thermal plasmas happened inside a puffer-assisted self-blast chamber during the alternative current interruption process with two different turbulence models. It is very difficult to correctly realize all phenomena happened inside the interrupter using the computational schemes; therefore, we have been trying to simplify the physics related in the problem. Because most flows encountered in the process are turbulent, the ability to predict turbulence for this application is invaluable for the engineer to design the chamber reliably. The objective of this paper is to model turbulence by averaging the unsteadiness of the turbulence, which are called Reynolds averaged Navier-Stokes models, and to compare the results with pressure and temperature field distributions during the whole arcing history. It was found that the two-equation turbulent model predicts bigger mixing of momentum, heat and species on the arc discharge of this interrupter than the zero-equation model does. 相似文献
107.
U. Muschelknautz 《化学工程与技术》2012,35(12):2099-2106
An approach for calculating the separation efficiency of uniflow cyclones for the separation of solid particles from gases is proposed. The analytical model is based on an equilibrium orbit concept, similar to that used in the Barth‐Muschelknautz model for conventional reverse‐flow cyclones, which has been proven to be successful for designing and calculating cyclones in a wide range of industrial applications. The proposed model takes into account the special flow pattern of uniflow cyclones, which differs substantially from that in reverse‐flow cyclones. The model provides correct dependencies of the separation efficiency on the main geometry and operation data of low‐loaded uniflow cyclones. Applying the calculation method to uniflow cyclones operated in test facilities indicates good agreement with experimental data. 相似文献
108.
温控非饱和土三轴试验装置的研制及其应用 总被引:2,自引:0,他引:2
高放核废物地质处置、地热资源开采与贮存以及城市地下供热管道设计等现代岩土工程的建设都需要考虑温度的影响,使得温度对天然非饱和土体基本性质影响的研究成为土力学的重要课题之一。为了研究非饱和土水力和力学性质受温度影响的规律,需要研制新的温控试验装置,以便为这种研究提供工具和手段。基于对既有非饱和土静三轴仪的改造,研制了一种温控非饱和土三轴试验装置,通过将所研制的温控压力室与非饱和土三轴试验系统的有机结合,实现了试验过程中对温度控制及量测的目的。利用该试验装置,对不同温度下非饱和土土水特征曲线进行了测定,所得结果与现有理论结果相吻合。 相似文献
109.
土工格室是由高分子聚合片材经高强度焊接而形成的一种网格结构,进行渠道边坡衬砌时,采用土工格室的框架,浇筑混凝土在其内,使之成为混凝土“板”结构的土工格室,因格室边框具有连锁作用,保证土板的完整性和整体性,使基础能够适应冻胀变形,防止坡面由于局部破坏产生大面积的脱坡。 相似文献
110.
对有限负压下熔体硅中磷的挥发去除进行研究。采用电子级硅配制Si-P合金,并采用GD-MS来检测实验前后硅中的磷含量。理论计算结果表明:在有限负压下,硅中的磷以P和P2的气体形式从熔体硅中挥发。实验结果显示:在温度1873K、真空度0.6-0.8Pa、熔炼3600s的条件下,熔体硅中的磷从0.046%(460ppmw)下降到0.001%(10ppmw)。实验结果与理论结果一致表明:当熔体硅中磷的含量大且炉腔内气压相对较高时,磷的去除与气压高度相关;而当炉腔气压很低时,磷的去除基本与气压无关。原因是在相对高磷含量的熔体硅中,磷主要以P2气体的形式挥发;在磷含量较低时,磷主要以单原子气体P的形式挥发。 相似文献