SOFTWARE REVIEWS     

《The Professional geographer》1988,40(1):106-116

software reviews are in this article BMDP/PC CONCEPTS COMPUTERIZED ATLAS EVALUATION OF ALTERNATE PROPOSALS (EAP) EXTRA: EXPRESS TRANSIT ANALYSIS MATC CAD MOTORS TRANSPORTATION PACKAGE PCMAP: Thematic Mapping Software for the IBM Personal Computer, Version 2.3 PLACE TRANPLAN . US-ATLAS  相似文献   

Comparison of food compositon of clupeid fishes in the Bohai Sea     

Li Jun  Wang Hong 《中国海洋湖沼学报》1992,10(4):376-381

Analysis of stomach contents of samples of clupeid fishes (Japanese anchovy, half-fin anchovy, zunas' scaled sardine, rednosed glassnose and tapertail anchovy) collected from the catches of a 1982–1984 fishery resource survey showed they are zooplanktonivorous. Similar food groups, such as copepoda. Chaetognatha, Amphipoda and Mysidacea were found in the stomach. Dietary similarity coefficients were studied to evaluate the degree of similarity in the dietary species-pairs. Seasonal variation is discussed. Contribution No.2050 from the Institute of Oceanology, Academia Sinica.  相似文献   

杭州L波段和59-701高空探测系统资料对比分析   总被引：1，自引：0，他引：1  

朱兰娟  华行祥 《气象科技》2007,35(5):750-754

为比较L波段高空探测系统和59-701高空探测系统的资料异同,采用平均差、均方差比较的方法分析了杭州站平行观测一个月资料的温压湿资料,比较其异同及产生原因,为更好利用高空探测资料、改进L波段高空探测系统提供参考。通过比较发现:L波段高空探测系统比59-701高空探测系统所测的温度、高度资料更稳定、离散率更小,对提高预报准确率有利。两套系统的温度差值在70 hPa层出现明显拐点,其原因有待进一步研究。  相似文献   

玉龙斑岩铜矿含矿与非含矿斑岩元素和同位素地球化学对比研究   总被引：3，自引：3，他引：3  

姜耀辉蒋少涌  戴宝章凌洪飞 《岩石学报》2006,22(10):2561-2566

地质地球化学对比研究表明,玉龙含矿与非舍矿斑岩是由岩石圈地慢中交代成因的金云母-石榴石单斜辉石岩脉发生不同程度部分熔融而形成的。分矿斑岩是最早阶段熔融体,主要是由交代成因脉中副矿物(如磷灰石和碳酸盐矿物等)和舍水矿物金云母发生部分熔融而形成的,因而富含 F、Cl 和水等挥岌份,加上该阶段岩浆具有高氧化性特征,从而富含 Cu 等成矿元素;非含矿斑岩是交代成固咏相对较高熔融程度的产物,单斜辉石和石榴石介入了熔融作用,岩浆熔体相对贫乏F、Cl 和水等挥发份,加上该阶段岩浆具有较低的 f_(0_2),从而不利于成矿。斑岩体全岩的 F 和 Cl 含量(舍矿斑岩 F>1200 ppm,Cl>150 ppm;非含矿斑岩 F<1200 ppm,Cl<150 ppm)、K_2O/Na_2O(含矿斑岩>1.2,非含矿斑岩<1.2)和 Sm/Yb(含矿斑岩>6.5,非含矿斑岩<6.5)比值以及黑云母中的 Fe~(3 )/Fe~(2 )比值(含矿斑岩>0.7,非舍矿斑岩<0.7)是区分含矿与非含矿斑岩的重要地球化学参数。含矿斑岩与非分矿斑岩具有非常相似的 Sr-Nd-Pb 同位素组成,,表明含矿与非含矿班岩具有相同的源区。  相似文献   

基于EOS/MODIS 数据的NDVI 与 EVI 比较研究   总被引：24，自引：0，他引：24  

李红军  郑力  雷玉平  李春强  周戡 《地理科学进展》2007,26(1):26-32

作为NOAA/AVHRR 归一化植被指数(NDVI) 的延续和发展, EOS/MODIS 归一化植被指 数(NDVI) 和增强植被指数( EVI) 在许多领域得到广泛应用。应用数理统计和地统计学方法对二 者进行的对比研究表明: NDVI 在植被生长旺盛期容易达到饱和, 而EVI 则能克服这一现象, 比 较真实地反映植被的生长变化过程; 相同空间分辨率下, EVI 取值范围、标准差与变异系数均高 于NDVI, NDVI 数据比较均一, 其空间相关性高于EVI, EVI 更能反映研究区域内植被空间差异。 关键词:MODIS; 归一化植被指数(NDVI) ; 增强植被指数( EVI) ; 对比  相似文献   

晚上新世-早更新世北太平洋和黄土高原的风尘沉积记录的初步对比   总被引：1，自引：1，他引：1  

孙有斌  刘青松 《第四纪研究》2007,27(2):263-269

保存在陆地、海洋和冰芯中的风尘沉积物与粉尘源区的干旱化历史、过去大气环流模式及其强度的演化密切相关,因而,直接的海陆风尘记录对比一直是古气候研究中的热点.为了获得对亚洲粉尘源区的干旱化波动和东亚季风演化的全面认识,较高分辨率地提取了北太平洋ODP 885站深海沉积物中的风尘组分,进而估算了晚上新世-早更新世时段北太平洋中部的风尘通量变化.结果表明,亚洲内陆粉尘源区的干燥度具有大时间尺度的变化特征,在2.7Ma左右急剧增加,随后在2.7～1.5Ma时段逐渐减小,自1.5Ma开始又逐渐增加.此外,在2.7～0.9Ma时段,粉尘源区经历了多次显著的轨道时间尺度上的干湿波动.通过对北太平洋和黄土高原的风尘记录的直接对比,发现在距今约2.7Ma,东亚地区的古环境发生了显著的变动,表现为亚洲内陆干旱化的加剧和大幅度冬、夏季风环流的盛行.然而,自2.7Ma开始,尤其是1.5Ma以后,由于北太平洋和黄土高原与亚洲粉尘源区的距离不同,两地的风尘通量所揭示的干旱化趋势和变化幅度存有明显差异.北太平洋远离亚洲内陆,其风尘通量变化基本不受粉尘源区范围变化的影响,因而更能反映源区干燥度的变化.相反,黄土高原由于距离粉尘源区较近,风尘通量的变化可能同时受到粉尘源区干燥度和范围的变化以及携带粉尘的风动力强度变化的影响.显然,海洋和陆地古气候记录的直接对比,可为深入认识过去气候变化提供新的思路.  相似文献   

Comparison of Products from ERA-40, NCEP-2, and CRU with Station Data for Summer Precipitation over China   总被引：4，自引：0，他引：4  

赵天保  符淙斌 《大气科学进展》2006,23(4):593-604

Summer precipitation products from the 45-Year European Centre for Medium-Range Weather Forecast (ECMWF) Reanalysis (ERA-40), and NCEP-Department of Energy (DOE) Atmospheric Model Intercomparison Project (AMIP-II) Reanalysis (NCEP-2), and Climatic Research Unit (CRU) TS 2.1 dataset are compared with the corresponding observations over China in order to understand the quality and utility of the reanalysis datasets for the period 1979–2001. The results reveal that although the magnitude and location of the rainfall belts differ among the reanalysis, CRU, and station data over South and West China, the spatial distributions show good agreement over most areas of China. In comparison with the observations in most areas of China, CRU best matches the observed summer precipitation, while ERA-40 reports less precipitation and NCEP-2 reports more precipitation than the observations. With regard to the amplitude of the interannual variations, CRU is better than either of the reanalyses in representing the corresponding observations. The amplitude in NCEP-2 is stronger but that of ERA-40 is weaker than the observations in most study domains. NCEP-2 has a more obvious interannual variability than ERA-40 or CRU in most areas of East China. Through an Empirical orthogonal function (EOF) analysis, the main features of the rainfall belts produced by CRU agree better with the observations than with those produced by the reanalyses in the Yangtze-Huaihe River valley. In East of China, particularly in the Yangtze-Huaihe River valley, CRU can reveal the quasi-biennial oscillation of summer precipitation represented by the observations, but the signal of ERA-40 is comparatively weak and not very obvious, whereas that of NCEP-2 is also weak before 1990 but very strong after 1990. The results also suggest that the magnitude of the precipitation difference between ERA-40 and the observations is smaller than that between NCEP-2 and the observations, but the variations represented by NCEP-2 are more reasonable than those given by ERA-40 in most areas of East China to some extent.  相似文献   

浅谈有强降水时小型蒸发器加盖的意义     

林梅香 《气象研究与应用》2006,27(2):58-58

通过对有强降水时,小型蒸发器在加盖和不加盖两种不同情况下蒸发量的对比,说明加盖的意义。  相似文献   

Galileo和GPS的几点比较     

田晓振  陈正阳  冯光财  郝卫峰  王潜心 《测绘信息与工程》2007,32(1):41-43

利用GSSF 2.0软件模拟出Galileo系统全球范围的卫星可见性、GDOP、TDOP、PDOP、HDOP、VDOP值,并与GPS进行了比较。  相似文献   

河西走廊春季强冻害成因及防御对策     

罗晓玲  郭良才  兰晓波 《沙漠与绿洲气象(新疆气象)》2006,29(3):20-21

应用酒泉、张掖、武威实况资料,从作物的各个生长发育期进行了对比分析,结果表明强冷空气爆发是造成冻害的直接原因,前期气温异常偏高使农作物生育期提前、气温和地温较低加剧了冻害程度。并提出了防御冻害发生的有效措施。  相似文献