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211.
促进剂对高碳数碳氢燃料点火特性的影响 总被引:3,自引:0,他引:3
在JP-10和煤油点火特性激波管实验基础上,进行了促进剂CH3NO2、CH2Cl2对JP-10和煤油点火特性影响的实验.在预加热激波管上采用缝合运行技术,获得了近7ms的实验时间.采用单色仪和光电倍增管记录点火过程中OH自由基在306.5nm发射谱强度变化作为点火发生的判据.当促进剂加入量约为JP-10的10%~20%(摩尔比),质量比为5%~12%时,实验观测到明显的点火促进作用.在1100K时,添加10%(摩尔比)CH3NO2使JP-10的点火延时时间缩短了70%.当CH3NO2的加入量占煤油的10%~15%(摩尔比),质量比约为5%~6%时,对煤油点火有明显的促进作用,在1000K时使煤油点火延时时间缩短了50%. 相似文献
212.
R.P. Aswathy G. Manju 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2021,67(4):1254-1260
The seasonal and solar activity variation of the post sunset F- region zonal plasma drift, at the magnetic equatorial region over Indian longitudes is analyzed using the Republic of China Satellite-1 data from January 2000 to April 2004. The post sunset F- region zonal drifts are observed to be higher in the years of high solar activity in comparison with low solar activity, while seasonally the drifts are minimum in summer with much higher values in other seasons. The seasonal and solar activity variations of zonal plasma drift are attributed to the corresponding variations in the neutral winds. The dependences of the F region peak vertical drift on the zonal plasma drift at 18.5 IST (Indian Standard Time) and the time difference of the conjugate points sunset times, are quantitatively analyzed. Further an integrated parameter (incorporating the above mentioned two independent factors), which is able to predict the peak vertical drift and growth rate of Rayleigh Taylor instability is proposed. The other major outcome of the study is the successful prediction of the Equatorial Spread F (ESF) onset time and duration using the new integrated parameter at 18.5 IST. ESF irregularities and associated scintillations adversely affect communication and navigation systems. Hence, the present methodology for the prediction of the characteristics of these nocturnal irregularities becomes relevant. 相似文献
213.
Chunhua Jiang Hui Hu Guobin Yang Jing Liu Zhengyu Zhao 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2019,63(10):3167-3176
Ionograms recorded at Puer station (PUR, 22.7°N, 101.05°E, Dip Latitude 12.9°N) in the Southwest of China from January 2015 to December 2016 were used to study characteristics of the F2 layer stratification at the northern equatorial ionization anomaly. Ionosonde observations show that the development of the F2 layer stratification is different under different conditions. Both the upward and downward movement of the F2 layer stratification could be observed. The F2 layer stratification could occur both at daytime and nighttime. The new cusp could originate from different positions on ionograms. Moreover, statistical results indicate that the F2 layer stratification occurred later in the winter than in other seasons at daytime, it occurred frequently in the local spring, and most of ionograms with the F2 layer stratification at post-midnight occurred in March and April. Our results also show that the F2 layer stratification has a correlation with solar activity. 相似文献
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217.
Thai Lan Hoang M.A. Abdu John MacDougall Inez S. Batista 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2010
We present the results of a comparative study of the equatorial spread F (ESF) and the F layer critical parameter, the base height of the F layer bottomside (h′F) over the two equatorial sites, Ho Chi Minh City – HCM (dip latitude: 2.9°N) in Vietnam and Sao Luis – SL (dip latitude: ∼2°S) in Brazil. The study utilizes simultaneous data collected by a CADI at HCM and a digisonde at SL during the year 2002 with the monthly mean solar 10.7 cm flux (F10.7) varying from ∼120 to ∼185. This study focuses on the quiet time seasonal behavior of the F layer parameters in the two widely separated longitude sectors, and addresses the question as to what can we learn from such comparative studies with respect to the ambient ionospheric and thermospheric parameters that are believed to control the ESF generation and hence its longitudinal occurrence pattern. The observed differences/similarities in the diurnal and seasonal patterns of the F Layer height vis-à-vis the ESF occurrences are evaluated in terms of the known longitudinal differences in the F layer heights, thermospheric meridional winds and the geomagnetic peculiarities of the two sites. 相似文献
218.
提出了一种基于F偏差代表点的高斯过程矩匹配滤波方法。该方法通过高斯过程学习系统的过程函数和观测函数,在高斯矩匹配滤波的框架下利用F偏差代表点进行数值计算。在单变量非线性模型及静基座初始对准中进行的仿真实验表明,该方法的精度不低于解析计算的高斯过程假设密度滤波(GP-ADF),远高于高斯过程无迹卡尔曼滤波(GP-UKF)。 相似文献
219.
智能远程温湿度监测系统的设计 总被引:1,自引:0,他引:1
王晓银 《西安航空技术高等专科学校学报》2009,27(1)
介绍了一种通用的温湿度测量系统的设计,提出了以高集成度的温度湿度传感器SHT71作为数据采集模块,以MSP430F449为控制核心的多点测量系统的设计方案,该系统具有低成本、低功耗、高可靠性、抗干扰能力强等特点,根据不同需要可应用于多种温湿度检测系统中. 相似文献
220.
基于深度学习的太阳10.7 cm射电流量日值的中期预报 总被引:2,自引:0,他引:2
针对太阳10.7cm射电流量中期日值预报问题,采用深度学习方法,建立了一个典型的基于多层感知器模型的神经网络。该网络采用1个包含90个神经元的隐含层,实现了一种非参数的时间序列自回归模型。预报中不仅考虑历史日值,还考虑了历史预报误差。模型根据前27d的历史数据实现了未来27d的日值预报。通过对50多年数据的训练和试验分析,该方法在短期和中期预报上较传统方法的相对误差明显降低。特别是模型经一次训练后,参数可以完全固定,不同于以往研究参数需要每天滚动更新,大大简化了日常预报,同时极为有利于模型在其他相关应用中的推广。 相似文献