Landsat-8长条带影像正射校正

目的 Landsat-8传感器采用线阵推扫式成像,通过分景处理获得标准景产品。面对大范围遥感数据需求,长条带数据具有更高的应用价值。长条带数据的一般获取方法是通过拼接标准景正射产品的方式,该方法处理效率不高,并且当条带中某景由于云覆盖量较多无法生产正射产品时,将无法通过多景拼接的方式生成相应的长条带正射产品。针对此方法存在的问题,本文提出一种Landsat-8长条带影像的正射校正方法。方法 以长条带影像为整体,通过控制点匹配、长条带几何精校正和正射校正3个部分,直接生成长条带级别的正射校正产品。在长条带几何精校正过程中,提出了Landsat-8的基于轨道约束的长条带平差模型及控制点优化选取方法。结果 在15景的条带长度范围内,本文方法生成的长条带正射产品的几何精度在12 m以内,满足Landsat-8正射产品的精度要求,且处理效率相较于标准景拼接方式提升1倍左右;对于云覆盖较多的景,利用连续3景进行长条带正射校正,可以得到与标准景正射产品几何精度相当的长条带正射产品。结论 本文提出的长条带处理方法,在一定长度范围内,能够得到满足Landsat-8正射产品的精度要求的长条带正射产品,处理效率得到较大提高,且能够有效克服传统方法中云覆盖情形对长条带产品获取的限制。     

A Monge-Ampère enhancement for semi-Lagrangian methods

Demanding the compatibility of semi-Lagrangian trajectory schemes with the fundamental Euler expansion formula leads to the Monge-Ampère (MA) nonlinear second-order partial differential equation. Given standard estimates of the departure points of flow trajectories, solving the associated MA problem provides a corrected solution satisfying a discrete Lagrangian form of the mass continuity equation to round-off error. The impact of the MA enhancement is discussed in two diverse limits of fluid dynamics applications: passive tracer advection in a steady cellular flow and in fully developed turbulence. Improvements of the overall accuracy of simulations depend on the problem and can be substantial.     

VM中Fedora8系统下NFS的安装与配置研究

Linux操作系统下,文件的共享可以用NFS实现,NFS可以设置允许指定的客户端或指定的网段访问服务器。虚拟机VM中,安装Fedora8操作系统,其中一台配置成NFS服务器,另一台配置成客户端,实现在客户端访问NFS服务器中共享的文件。     

Waterbody mapping: a comparison of remotely sensed and GIS open data sources

Surface water maps are essential for many environmental applications. Waterbody delineation from satellite images remains a challenging task due to sensor limitations, the presence of clouds, the low albedo surfaces in urban areas, topographic, and atmospheric conditions. In this paper, a model based on the Supported Vector Machine (SVM) classifier was adopted for waterbody extraction from Sentinel-2, Landsat 8 Operational Land Imager (OLI) and RapidEye satellite images. As well, the accuracy of two other sources (OpenStreetMapping (OSM) and Military Geographic Institute (MGI)) was tested. The free images from Sentinel-2 and Landsat 8 OLI were more accurate (Kappa (KHAT):0.89, 0.88) data sources than commercial RapidEye images (KHAT: 0.79). Regarding the performance between Sentinel-2 and Landsat 8 OLI, Sentinel-2 obtained the most accurate results (overall accuracy 94.49 vs. 94.17, commission error 1.34 vs. 1.87). Due to the variable spatial resolution of OSM and MGI data, it was not possible to detect small waterbodies with these sources, and therefore high values of omission error and a strong underestimation of the area of surface water were obtained. This study demonstrates the suitability of free images for mapping and monitoring of surface waterbodies, including small water bodies.     

茶树菇凝集素AAL、AAL-2检测小鼠CD8~+T淋巴细胞表面糖基化研究

本研究使用两种大型真菌茶树菇新型凝集素AAL(Agrocybe aegerita lectin)和AAL2(Agrocybe aegerita lectin 2),以检测小鼠CD8~+T淋巴细胞表面糖基化。用生物素标记的AAL和AAL2结合流式细胞仪,分别分析从C57BL/6小鼠脾脏和腹股沟淋巴结分离出来的CD8~+T淋巴细胞表面的糖基化水平,及其细胞因子表达水平。结果发现脾脏中AAL~+CD8~+,AAL2~+CD8~+T淋巴细胞所占的比例(%)分别为6.72±3.00和12.18±5.28,而腹股沟淋巴结的AAL~+CD8~+,AAL2~+CD8~+T淋巴细胞所占的比例(%)分别为12.18±5.28和10.15±3.46。细胞因子表达水平结果发现小鼠脾脏AAL2~+CD8~+T细胞表达perforin的细胞比例低于AAL2-CD8~+T细胞(p0.05,有统计学意义),腹股沟淋巴结中AAL~+CD8~+T细胞表达perforin的细胞比例则高于AAL-CD8~+T细胞(p0.05,有统计学意义)。该数据为研究小鼠脾脏和腹股沟淋巴结CD8~+T细胞表面糖基化提供了新的数据,也为两种新型凝集素AAL和AAL2的应用提供理论依据。     

Synergistic Sex Pheromone Components of White-Spotted Tussock Moth, Orgyia thyellina

In 1996, the exotic white-spotted tussock moth (WSTM), Orgyia thyellina (Lepidoptera: Lymantriidae), was discovered in Auckland, New Zealand. Because establishment of WSTM would threaten New Zealand's orchard industry and international trade, eradication of WSTM with microbial insecticide was initiated. To monitor and complement eradication of WSTM by capture of male moths in pheromone-baited traps, pheromone components of female WSTM needed to be identified. Coupled gas chromatographic–electroantennographic detection analysis of pheromone gland extract revealed several compounds that elicited responses from male moth antennae. Mass spectra of the two most EAD-active compounds suggested, and comparative GC-MS of authentic standards confirmed, that they were (Z)-6-heneicosen-11-one (Z6–11-one) and (Z)-6-heneicosen-9-one, the latter termed here thyellinone. In field experiments in Japan, Z6–11-one plus thyellinone at a 100:5 ratio attracted WSTM males, whereas either ketone alone failed to attract a single male moth. Addition of further candidate pheromone components did not enhance attractiveness of the binary blend. Through the 1997–1998 summer, 45,000 commercial trap lures baited with 2000 g of Z6–11-one and 100 g of thyellinone were deployed in Auckland towards eradication of the residual WSTM population.Dedicated to my dear mother in honor of her 75th birthday     

8-R-9苄基-9H-嘌呤衍生物的合成研究

采用 (Ph3 P) 2 PdCl2 为催化剂 ,DMF为溶剂 ,对 8 碘 9 苄基 9H 嘌呤与有机锡试剂RSnBu3 (R=乙烯基、2 噻吩基、2 呋喃基、苯乙炔基和苯基等 )之间的Stille偶合反应进行了研究 ,合成出了5种 8位取代的嘌呤衍生物。在反应温度为 80℃ ,n(8 碘 9 苄基 9H 嘌呤 )∶n (RSnBu3 )∶n〔(Ph3 P) 2 PdCl2 〕 =1 0∶1 2∶0 0 5的较佳工艺条件下 ,产品收率 4 1%～ 91%。用1H NMR、13 C NMR和MS对产物进行了表征     

硝基-3-氧-3，4-二氢-2H-[1，4]苯并噁嗪-6-羧酸的合成

以4-羟基-3-硝基苯甲酸为原料,经酯化、醚化、还原合环、硝化、水解等5步反应,合成了两个未见文献报导的化合物7-硝基-3-氧-3,4-二氢-2H-[1,4]苯并噁嗪-6-羧酸和8-硝基-3-氧-3,4-二氢-2H-[1,4]苯并嗪-6-羧酸,其结构经IR、LC/MS、1HNMR和元素分析确证。     

K2S2O8-Na2S2O3引发淀粉与丙烯酸接枝产物吸水性能的主要影响因素

以玉米淀粉和丙烯酸为主要原料,采用溶液聚合的方法,制备了淀粉与丙烯酸接枝共聚物,用FTIR等方法对共聚产物结构进行了表征。研究了在过硫酸钾-硫代硫酸钠组成的氧化-还原引发体系中,引发剂、交联剂不同浓度及丙烯酸不同中和度等因素对共聚产物吸水性能的影响。实验结果表明采用K2S2O8-Na2S2O3引发体系,通过控制引发剂、交联剂浓度,接枝产物吸去离子水可达920 g/g;采用玉米粉代替玉米淀粉与丙烯酸接枝共聚,产物吸去离子水可达870 g/g;这些实验结果进一步提高了吸水树脂的吸水能力。     

平面8杆机构的动力学分析

基于运动学反解写出了平面三自由度8杆机构的位移、速度、加速度输入输出方程,再根据达郎怕原理和等效力原理导出了其动力学方程,分析了其正反两个方向的动力学方程的解法并分别给出了数值例.