Assessing ecohydrological factors variations and their relationships at different spatio-temporal scales in semiarid area,northwestern China

As a typical semiarid farming-pastoral ecotone sensitive to the environmennt, the Plain of West Liaohe Basin (WLBP) is currently experiencing drastic environmental changes. To identify how environmental change affect vegetation in the WLBP, we analysed spatiotemporal variation characteristics of Ecological environment factors based on monthly and annual air temperature (T), precipitation (P) and Normalized Difference Vegetation Index (NDVI) from 1982 to 2015. And the correlations between them were investigated by correlation analysis (Simple correlation, partial correlation and complex correlation) at temporal and spatial scale. The results showed that: (1) the vegetation growth of the WLBP showed ameliorated trend, with a change rate of 0.004/yr.; (2) P was more sensitive to NDVI than T; (3) and the influence of hydrothermal changes on vegetation growth was more significant than that of the change of single climate factors at time scales; (4) the effects of anthropogenic factors on vegetation change were 75.07% (1982–1993) and 98.08% (1994–2015), respectively. At the temp-special scales, P&T and land use type change (LUCC) were the main climatic and anthropogenic factors that affect vegetation changes, respectively.     

凸缘外周带压力的充液拉延工艺的研究

本文论述了一种凸缘外周带压力的充液拉延方法，试验表明，在合适的工艺参数下，采用这种成形方法，可以获得比常规钢模拉延小得多的拉延系数。     

再接再厉，为进一步提高学报的质量和效益而奋斗──庆祝《南京航空航天大学学报》总第100期出版

回顾了学报的发展历程和所取得的基本成绩，阐述了学报坚持正确的编辑思想和贯彻正确的办刊方针与宗旨的若于做法与体会，指出学报今后的发展重点应由发展规模和数量转移到进一步全面提高质量和效益上来，并提出了几点具体措施．     

机翼－机身－吊架－短舱的跨声速流计算

本文通过使用多块网格的嵌合体技术，计算了机翼－机身－吊架－短舱的跨声速流场。将机翼－机身－吊架－短舱流场分为机翼－机身和吊架－短舱两个子区域，根据嵌套网格结构建立机翼－机身－吊架－短舱的组合网格，分别对这两个子区域根据相应的边界条件独立求解，然后采用嵌合体技术传递两个子区域的干扰信息，通过两个流场的耦合迭代得到机翼－机身－吊架－短舱流场的计算结果，数值模拟结果与实验结果进行了比较，两者吻合较好。     

Adaptive imaging for forward-looking ground penetrating radar

Most of the current forward-looking ground-penetrating radar (FLGPR) systems use conventional delay-and-sum (DAS) based methods to form radar images for detection of the target (such as a landmine). However, DAS is a data-independent approach which is known to suffer from low resolution and poor interference and clutter rejection capability. We present a data-adaptive imaging approach for FLGPR image formation based on APES (amplitude and phase estimation) and rank-deficient RCB (robust Capon beamforming). Due to the data-adaptive nature of both APES and RCB, our approach has better resolution and much better interference and clutter rejection capability than the standard DAS-based imaging methods. The excellent performance of the proposed method is demonstrated using experimental data collected via two FLGPR systems recently developed by PSI (Planning Systems, Inc.) and SRI (Stanford Research Institute).     

A global view of the isochronous trajectory families by Hamilton's hodographic transformation

An overall view of the characteristic features of the isochronous trajectory families is presented. The trajectories are assumed Keplerian, isoenergetic, and satisfying Lambert's conditions, that is the sum of radial distances of the two termini, and their linear separation are both constant. A geometric approach is adopted by using Hamilton's hodographic transformation. The connection between Hamilton's hodographic isochronism and the Lambert's theorem is briefly reviewed, and the interrelations among the Hamiltonian set of parameters and the Lambertian sets are developed. The totality of the isochronous trajectory families is then viewed in the velocity space. Various Lambertian invariants as well as some essential noninvariants are examined, and relevant formulas derived. The salient features of some particular isochronous families are then summarized; and Hamilton's time integral is briefly treated. The analysis is essentially two-dimensional, with its extension to the three-dimensional case finally discussed.     

复合材料结构分析系统YIDOYU-Ix

1.程序系统 YIDOYU-I_2是在YIDOYU-I~[1]基础上开发的,除具备YIDOYU-I的全部分析功能外,增加了对复合材料的分析能力。它能对金属结构、复合材料结构或金属一复材结构     

用遗传算法求解柔性作业车间调度问题(英文)

古典作业车间调度问题已经被研究了几十年并证明为 NP-hard问题。柔性作业车间调度是古典作业车间调度问题的扩展 ,它允许工序由一个机床集合中的任意一台加工 ,调度的目的是将工序分配给各机床 ,并对各机床上的工序进行排序以使完成所有工序的时间最小化。本文采用遗传算法进行柔性作业车间调度研究 ,针对柔性作业车间问题提出了一种新颖直观的基因编码方法 ,从而取消了运用遗传算法求解作业车间问题时为使基因合法化而进行的基因修复过程 ,仿真结果表明用该遗传算法解决柔性作业车间调度问题是有效的。     

复调制ZFFT的TMS320C25实现

介绍了用ＴＭＳ３２０Ｃ２５数字信号处理器实现复调制ＺｏｏｍＦＦＴ（ＺＦＦＴ）频率细化技术，在所举的例子中，用１０２４复数点选带ＦＦＴ获得通常８１９２复数点基带ＦＦＴ的频率分辨力。实验结果表明，此种频率细化方法特别适用于不能同时处理Ｎ点，而又要求Ｎ点ＦＦＴ频率分辨力的频谱分析场合，文中给出了几种提高Ｃ２５ＦＦＴ运算速度的方法，使１０２４复数点ＦＦＴ的运算时间减少到１２．６ｍｓ，可供工程应用参考。