Results About Ocean Satellite Observation

They have played more and more important roles in marine pollution monitoring, marine environment and marine disaster monitor and forecasting, marine resource investigation and marine scientific research. In this paper, the author will give a brief review of China's operational and scientific activities in satellites ocean observation during 2008 to 2010. These activities include the application of the HY-1B for red tide and green tide detecting and monitoring, sea ice monitoring, fishery resources assessment at coastal zone and ocean, marine water quality assessment, sea surface temperature monitoring and forecasting, ocean primary productivity and carbon cycle research, and the development in the ocean dynamic environment parameter application technology before launch of HY-2. The achievements we have made in the ocean observation and monitoring during the past 3 years indicate that, the development of the ocean satellite series and the application of the ocean satellite can greatly promote the development of China's three-dimensional marine observation system and earth-observation system from space, accordingly we can improve the ability of acquiring the marine environmental parameter to sustain the marine economy development and the sea defense construction.      

航天“血淤症”及其防护措施

根据实验结果及国外有关资料证明,失重或模拟失重时人和动物血循环系统的紊乱和中医“血淤症”时的变化十分相似,提出我国“活血化淤”中药有可能成为防止失重血循环紊乱的一种有效药物的看法。     

回流口位置对液体火箭液氧贮箱热分层的影响

低温液体火箭射前需要采用自然循环方式对火箭发动机进行充分预冷,循环预冷管路的回流口位置是影响液氧贮箱内部场分布的重要因素.采用计算流体力学(CFD)技术,通过对不同回流位置的液氧贮箱物理场的数值模拟,揭示了贮箱内部温度场及速度场的分布特性,分析了回流口位置对贮箱内部热分层的影响规律.研究表明,当回流口位于下封头以上2 m位置时,贮箱内部液氧过冷度最大,过冷液体含量最多,回流位置最佳.此研究结果为运载火箭推进系统的设计提供了重要的理论支持.      

Merged series of normalized water leaving radiances obtained from multiple satellite missions for the Mediterranean Sea

Merging time series of ocean color-derived products provided by independent satellite missions supports related biogeochemical and environmental applications by combining temporally overlapping data sets and by increasing data coverage. The creation of a merged series of normalized water leaving radiances _LWN$L_{\text{WN}}$, the primary ocean color product, is presented for the Mediterranean Sea using the SeaWiFS and MODIS data records. The merging relies on an optically-based technique that combines the available _LWN$L_{\text{WN}}$ signal in a spectrally consistent way. Validation statistics indicate uncertainties associated with the merged _LWN$L_{\text{WN}}$ decreasing from 23% at 412 nm to 12% in the 500- to 555-nm spectral range. The inter-comparison of the sensor-specific products, conducted at the scale of the basin for daily-to-monthly time scales, indicates an overall consistency. The level of differences varies with the wavelength considered and shows a marked seasonal cycle, with differences that tend to be higher in winter. The merged series is remarkably consistent with the sensor-specific data, with average absolute percent differences lower than 10% for all wavelengths below 555 nm. The benefit of merging in terms of sampling frequency over the basin is also illustrated. A merged series of _LWN$L_{\text{WN}}$ data based on the two considered missions provides valid data over 36% of the basin area on a daily basis.     

环量控制技术研究

未来军/民运输机的高性能要求促使近年来环量控制技术正成为研究的新热点。本文简单介绍了环量控制研究的进展;深入讨论了包括二维环量控制翼型标模和CCA/OTW(Circulation Control Airfoil/Over the Wing)实验、半模型子系统实验和三维翼身融合体全机实验等可供CFD验证用的NASA实验研究。在2个尺寸相近的风洞中对同一二维标模的实验结果表明,源于切向吹气的最大升力系数C_Lmax在中等缝道出口高度时可达8~9。数据对比表明此实验结果可供计算流体力学(CFD)验证用。二维CCA/OTW实验表明,发动机位置前移可大幅增大失速迎角和C_Lmax;CCA后缘吹气噪声的低频部分强度与速度的8次方成正比,高频部分与速度的6次方成正比。半模型子系统的FACT-MAC跨声速实验不仅可研究高雷诺数效应,且可提供2种飞行状态的数据。初步结果表明,与无射流的低速数据相比,在α=25°时C_L增大约33%,跨声速时在非设计状态下射流可有效地使激波诱导的分离再附,在保持原有强度下激波位置可后推5%的弦长。三维全机CCW/OTW的实验数据尚在整理分析中,但初步结果已表明,应用前缘吹气可将失速迎角增大至25°,C_Lmax增大至6,正确安排OTW位置可增大升力线斜率等。     

Study of seasonal variation of winds in upper stratosphere over Hyderabad

A predictability of the stratospheric zonal winds above 38 km during the turnaround is an essential parameter for planning of the high-altitude scientific balloon flights. This information is more relevant in the case of Hyderabad balloon facility which is closer to equator and has much more unstable wind reversal patterns which appears to have changed enormously during the last decade probably in correlation with the global warming. With a majority of our flights reaching the altitudes of 38–42 km and the requirement of long float durations, a prior knowledge of wind pattern during the summer and winter turnaround seasons is highly desirable. Furthermore, the flight operation corridor for balloon flights from Hyderabad is limited to 400 km and though in the west direction there are flat lands, in all other three directions, the landscape is dotted by water bodies, reserve forests and hilly terrain, and therefore need of such a data is essential. In order to establish the climatology of the stratospheric winds and study their inter-annual variability over Hyderabad for the turnaround periods, we have made a detailed analysis of the United Kingdom Meteorological office data between 2000 and 2007, to derive average wind parameters (magnitude, direction) at different ceiling altitudes above 38 km. These results can be used only as general trend of stratospheric wind and should not be the limitation of the UKMO Data.     

空间站水循环处理系统中微生物的检测技术

如何控制空间站水循环处理系统的微生物数量对于保证航天员的饮用水和生活用水十分重要。微生物数量超标会对航天员身体健康产生影响,某些硫酸盐还原菌也会附着在管道设备上并发生化学反应,产生的H₂S气体会腐蚀设备。控制水循环处理系统的微生物有地面控制、选用特殊材料和在轨杀菌共3个方面。2003年NASA给出了空间站中微生物控制的一系列要求。文章中提出了两种微生物检测方法:ATP生物发光法和比色固相萃取法测碘和银离子数量的方法,通过比较两者的优劣以及多方面的探究,最后,确定通过监测碘和银离子的数量来控制微生物数量更加方便有效。     

面向海洋探测的多源信息融合技术研究及展望

多源信息融合技术包括数据级、特征级和决策级3个层级。在海洋探测应用中,现有方法存在信息获取、融合质量及目标识别等难点问题,提出了体系化探测、分布式融合和利用先验知识的解决思路。体系化探测能够全面获取原始信息,分布式融合可以在降低计算复杂度的同时减少信息损失,先验知识能够在决策级融合中提高目标识别的准确性。此外,还提出了构建探测系统和先验知识库、优化智能算法和模型等未来信息融合技术发展方向。     

旋翼诱导速度空间分布的一种计算方法

采用无限片桨叶的固定尾迹分析法,建立了前飞状态下固定涡系对空间一点诱导速度的数学模型,用Fourier级数表示诱导速度和环量沿方位角的变化,积分得到了含有三类完全椭圆积分的诱导速度各谐波系数解析表达式.该表达式可在给定环量分布的情况下求解桨盘内和桨盘外空间一点的诱导速度分布.基于固定尾迹理论,提出一种在前飞状态下计算旋翼环量分布的数值方法,该方法根据叶素理论、儒可夫斯基公式和挥舞运动方程推导了环量方程,将理想的无限个斜向涡柱离散成有限个斜向涡柱.通过求解有限个斜向涡柱的谐波系数得到旋翼在前飞下环量、诱导速度、挥舞系数的相容解.通过理论和对算例的计算分析,本文方法对计算旋翼平面外的诱导速度以及多旋翼系统具有工程应用价值.     

基于最佳环量分布的螺旋桨滑流影响预测

为了更加快速且准确地预测螺旋桨滑流对机翼气动系数的影响,提出了基于最佳环量分布并结合激励盘数值模拟技术实现螺旋桨滑流影响预测的方法,选择Prandtl最佳环量分布解析法并在此基础上提出了一种桨毂修正办法,从而得到桨盘的最佳环量分布解析式。将采用不同方法计算螺旋桨压力阶跃分布作为激励盘模型的边界条件,采用CFD数值模拟得到了一种典型的桨-翼组合体的气动参数。结果表明,本文提出的修正方法预测结果更接近于试验数据,升力系数的相对误差不超过3%,阻力系数的相对误差不超过20%。这种方法具有不依赖试验数据、低计算资源消耗的优势,对飞机概念设计初期快速确定螺旋桨滑流对机翼气动系数的影响方面具有优势。