Estimating the spin axis orientation of the Echostar-2 box-wing geosynchronous satellite

For the first time, the spin axis orientation of an inactive box-wing geosynchronous satellite has been estimated from ground-based optical photometric observations of Echostar-2’s specular reflections. Recent photometric light curves obtained of Echostar-2 over four years suggest that unusually bright and brief specular reflections were occurring twice within an observed spin period. These bright and brief specular reflections suggested two satellite surfaces with surface normals separated by approximately 180°. The geometry between the satellite, the Sun, and the observing location at the time of each of the brightest observed reflections, was used to estimate Echostar-2’s equatorial spin axis orientation coordinates. When considering prograde and retrograde rotation, Echostar-2’s spin axis orientation was estimated to have been located within 30° of either equatorial coordinate pole. Echostar-2’s spin axis was observed to have moved approximately 180° in right ascension, within a time span of six months, suggesting a roughly one year spin axis precession period about the satellite’s angular momentum vector.     

过氧化氢/紫外线/臭氧氧化技术处理肼类污水的应用

采用放大试验规模（处理量1 m³/h）的H₂O₂（过氧化氢）/UV（紫外线）/O₃（臭氧）氧化技术处理肼类推进剂污水，在30.0±1.6 ℃，pH=9.0±0.2的条件下，研究肼类的过氧化氢增强光解臭氧化降解。对比不同氧化技术的协同效应以及对污水降解的影响，重点考察过氧化氢、紫外线、臭氧和初始浓度等工艺参数对降解效果的影响，对氧化技术的应用进行了优化。研究结果表明：该技术可使COD去除率提高27.66%，肼类的降解速率随着过氧化氢投加量、紫外线辐射强度、O₃投加速率和水质地提高而升高，随着初始质量浓度的提高而下降。在最佳工艺下，处理5 000 mg/L质量浓度的废水，处理60 min时，COD去除率分别为98.62%（偏二甲肼）、99.17%（甲基肼）、99.94%（肼）和93.25%（单推-3）。     

弹道交班自适应算法研究

为实现复合制导不同制导弹道的平滑过渡,用二阶吻合法设计了一不同制导律间的指令交接导引段。建立了自适应弹道交接导引算法的模型。理论分析和仿真结果表明,该算法具较好的弹道过载平滑能力,有一定的应用价值。     

在二元柔壁自适应风洞中利用面元法进行三元模型实验

简要叙述了在西北工业大学二元柔壁自适应风洞中利用面元法进行二元半机翼模型试验的研究情况，分析了面元法的基本思想和部分试验结果。     

Ту-154М变稳飞机空中飞行模拟试验评述

依据Ту－１５４М变稳飞机的特点，主要进行了不同操纵器、不同控制律和不同显示画面的飞行试验研究。特别是通过中央杆和侧杆、电传系统不同控制律飞行品质特性之间、两种先进控制方案及不同显示方式的比较，不仅掌握了这方面的试飞技术和评定技术，还亲身体验到变稳飞机在发展仿真技术，新机预研及提高试飞员试飞技术和评定技术等方面的巨大作用。     

电子商务及其基本法律问题

本文简单阐述了电子商务的概念、模式、基本流程及其基本法律问题和目前的立法现状，弄清这些问题，无论是对于从事电子商务还是IT产业的经营、管理以及进行相关的科研开发，都具有十分重要的意义。     

Ionospheric behavior of the F2 peak parameters foF2 and hmF2 at Hainan and comparisons with IRI model predictions

Monthly median values of foF2, hmF2 and M(3000)F2 parameters, with hourly time interval resolution for the diurnal variation, obtained with DPS-4 digisonde observations at Hainan (19.4°N, 109.0°E) are used to study the low latitude ionospheric variation behavior. The observational results are compared with the International Reference Ionospheric Model (IRI) predictions. The time period coverage of the data used for the present study is from March 2002 to February 2005. Our present study showed that: (1) In general, IRI predictions using CCIR and URSI coefficients follow well the diurnal and seasonal variation patterns of the experimental values of foF2. However, CCIR foF2 and URSI foF2 IRI predictions systematically underestimate the observed results during most time period of the day, with the percentage difference ΔfoF2 (%) values changing between about −5% and −25%, whereas for a few hours around pre-sunrise, the IRI predictions generally overestimate the observational ones with ΔfoF2 (%) sometimes reaching as large as ∼30%. The agreement between the IRI results and the observational ones is better for the year 2002 than for the other years. The best agreement between the IRI results and the observational ones is obtained in summer when using URSI coefficients, with the seasonal average values of ΔfoF2 (%) being within the limits of ±10%. (2) In general, the IRI predicted hmF2 values using CCIR M(3000)F2 option shows a poor agreement with the observational results. However, when using the measured M(3000)F2 as input, the diurnal variation pattern of hmF2 given by IRI2001 has a much better agreement with the observational one with the detailed fine structures including the pre-sunrise and post-sunset peaks reproduced reasonably well. The agreement between the IRI predicted hmF2 values using CCIR M(30,000)F2 option and the observational ones is worst for the afternoon to post-midnight hours for the high solar activity year 2002. During daytime hours the agreement between the hmF2 values obtained with CCIR M(30,000)F2 option and the observational ones is best for summer season. The discrepancy between the observational hmF2 and that obtained with CCIR M(30,000)F2 option stem from the CCIR M(3000)F2 model, which does not produce the small scale structures observed in the measured M(3000)F2.     

某型工程车多功能检测仪的硬件设计

设计的检测仪用于检测某型工程车的电控系统,以51单片机作为中央处理单元,以MAX392多路选择器实现多路选通,以CPLD扩展外围接口,可较好地实现信号的采集、存储和信息显示等功能。检测仪还具有代用功能,在紧急情况下可代替原车电控系统进行工作。     

对B2C领域两种营销渠道形式的比较探析

在B2C领域,传统营销渠道与网络营销渠道是一对相互竞争的矛盾。网络营销渠道是新生事物,凭借低成本优势得以迅速成长。传统营销渠道根基雄厚,且更贴近消费者的需求,因此仍吸引着大多数的消费者。网络营销渠道如何进一步发展,传统营销渠道如何吸收新的元素,不对两种营销渠道进行比较,是不能获得满意的答案的,而比较这两者之间的相对劣势比比较它们的优势更能引发思考。     

离心泵叶轮内含颗粒的幂律流体的密相两相湍流研究

阐述了幂律流体控制方程的特点，首先对单相的幂律流体与密相液固两相流进行了计算，计算结果与实验数据吻合较好。其次对泵离心叶轮内的含颗粒的幂律流体的两相流动进行了计算，从进口到出口，幂律流体的速度是减小的，压力随半径增大逐渐升高，而且压力面上的压力大于吸力面上的压力。吸力面上的颗粒拟温度小于压力面上的颗粒拟温度，而且靠近壁面处的大于叶道中的。最后比较了液固两相流与含颗粒的幂律流体的两相流的流动。流体相的紊动能有一定的差别，而且颗粒拟温度也有较大差别。