制图综合知识及其应用   总被引：9，自引：0，他引：9  

王家耀  钱海忠 《武汉大学学报(信息科学版)》2006,31(5):382-387

阐述了制图综合知识的概念、结构和组织方法，提出了基于制图综合知识的综合任务提取、综合算法与结果的评估、综合操作监控以及基于知识的制图综合任务存储等原理和方法。实验表明，制图综合知识的使用，对制图综合各个环节的评价提供了依据。对综合自动化程度的提高有着重要的推动作用。  相似文献   

北非和青藏高原感热振荡特征及与我国东部夏季降水的关系   总被引：5，自引：2，他引：5  

宁亮  钱永甫 《高原气象》2006,25(3):357-365

利用EOF方法,分析了NCEP/NCAR 1948—2002年再分析资料中月平均全球地面感热资料,揭示了北非和青藏高原感热的振荡特征。分析了振荡关键区的感热距平与我国东部51个测站1951—2000年汛期降水距平的相关关系,用SVD方法分析了关键区感热距平场与我国东部51个测站全年各月降水距平场的空间耦合和时滞关系及关键区感热异常对我国东部降水异常的影响。结果表明,北非和青藏高原两个区域的感热变化呈负相关,它们对我国华北、江淮和华南三个区域的汛期降水滞后影响明显。感热对我国降水的影响以年代际为主。  相似文献   

Interannual Thermocline Signals and El Nio-La Nia Turnabout in the Tropical Pacific Ocean     

钱维宏  胡豪然 《大气科学进展》2006,(6)

One of the fundamental questions concerning the nature and prediction of the oceanic states in the equatorial eastern Pacific is how the turnabout from a cold water state (La Nina) to a warm water state (El Nino) takes place, and vice versa. Recent studies show that this turnabout is directly linked to the interannual thermocline variations in the tropical Pacific Ocean basin. An index, as an indicator and precursor to describe interannual thermocline variations and the turnabout of oceanic states in our previous paper (Qian and Hu, 2005), is also used in this study. The index, which shows the maximum subsurface temperature anomaly (MSTA), is derived from the monthly 21-year (1980-2000) expendable XBT dataset in the present study. Results show that the MSTA can be used as a precursor for the occurrences of El Nino (or La Nina) events. The subsequent analyses of the MSTA propagations in the tropical Pacific suggest a one-year potential predictability for El Nino and La Nina events by identifying ocean temperature anomalies in the thermocline of the western Pacific Ocean. It also suggests that a closed route cycle with the strongest signal propagation is identified only in the tropical North Pacific Ocean. A positive (or negative) MSTA signal may travel from the western equatorial Pacific to the eastern equatorial Pacific with the strongest signal along the equator. This signal turns northward along the tropical eastern boundary of the basin and then moves westward along the north side of off-equator around 16°N. Finally, the signal returns toward the equator along the western boundary of the basin. The turnabout time from an El Nino event to a La Nina event in the eastern equatorial Pacific depends critically on the speed of the signal traveling along the closed route, and it usually needs about 4 years. This finding may help to predict the occurrence of the El Nino or La Nina event at least one year in advance.  相似文献   

CLIMATE CHANGE: LONG-TERM TRENDS AND SHORT-TERM OSCILLATIONS   总被引：2，自引：0，他引：2  

高新全  张欣  钱维宏 《热带气象学报(英文版)》2006,12(2):139-149

Identifying the Northern Hemisphere (NH) temperature reconstruction and instrumental data for the past 1000 years shows that climate change in the last millennium includes long-term trends and various oscillations. Two long-term trends and the quasi-70-year oscillation were detected in the global temperature series for the last 140 years and the NH millennium series. One important feature was emphasized that temperature decreases slowly but it increases rapidly based on the analysis of different series. Benefits can be obtained of climate change from understanding various long-term trends and oscillations. Millennial temperature proxies from the natural climate system and time series of nonlinear model system are used in understanding the natural climate change and recognizing potential benefits by using the method of wavelet transform analysis. The results from numerical modeling show that major oscillations contained in numerical solutions on the interdecadal timescale are consistent with that of natural proxies. It seems that these oscillations in the climate change are not directly linked with the solar radiation as an external forcing. This investigation may conclude that the climate variability at the interdecadal timescale strongly depends on the internal nonlinear effects in the climate system.  相似文献   

运用归一化光谱混合模型分析城市地表组成   总被引：7，自引：1，他引：7  

钱乐祥  崔海山 《国土资源遥感》2006,(2):64-68

运用归一化光谱混合分析(NSMA)方法,用ETM 数据调查广州市海珠区城市地表组成,采用亮度标准化方法减小亮度变化。通过标准化,使亮度差异在每个植被-非渗透性表面-土壤-水体(V-I-S-W)组成中减小或者消除,这样使得一个单一的端元能够代表一种地表组分。在此基础上,通过归一化影像,选择了植被、非渗透性表面、土壤和水体4种端元,运用一种约束光谱混合分析(SMA)模型,分解了不同种类的城市地表组成。通过与已有模型计算结果比较,认为本文所构建的模型较优,其对研究区非渗透性表面估计的均方根误差为12.6%。  相似文献   

内蒙古东乌旗阿尔哈达铅锌矿区矿床成因探讨     

钱明  高群学 《地质找矿论丛》2006,21(10):70-73

阿尔哈达铅锌矿主要产于泥盆系的NW向断裂破碎带中，矿体具雁行排列、局部交叉产出的特征，以盲矿体为主；成矿早期可能以岩浆热液（399-407℃）为主，而中、晚期的热液以大气降水或混合水（194-287℃）为主；硫分别来源于岩浆热液、沉积地层和大气降水；铅同位素测试结果则显示了成矿（岩）物质的混源特点。矿床为与岩浆热液有关的受断裂控制的中温热液铅锌（银）矿。  相似文献   

青藏高原地形对东亚夏季风北缘影响的数值试验     

汤绪  赵兵科  孙国武  梁萍  钱维宏 《高原气象》2007,26(5):921-927

使用中国科学院大气物理研究所大气科学和地球流体力学数值模拟国家重点实验室(LASG/IAP)发展的大气环流谱模式SAMIL(R42L9),进行了有、无青藏高原对亚洲夏季风北边缘影响的数值模拟。结果表明,青藏高原大地形对夏季风北边缘活动有重要影响。有(无)高原时,其东侧的偏南风较强(弱)、较深(浅),向北扩展偏北(南),有(不)利于引导和加强夏季风北上,使北边缘偏北(南);同时,西太平洋副热带高压偏北偏西(偏南偏东),也有(不)利于夏季风向北深入我国大陆,从而使夏季风北边缘偏北(南)。与之相对应的夏季风降水区也偏北(南)。  相似文献   

可变分辨率展宽网格在区域物理参数化大气模式中的应用     

钱建华 《地球科学进展》2007,22(11):1185-1190

将有限区域展宽网格方法应用于区域物理参数化大气模式中，来检验其模拟湿物理过程的能力。展宽网格模型旨在在一个大的有限空间区域中得到我们所关注的小区域的高分辨率。运用展宽网格模型对南美地区进行模拟的结果表明：当拥有充足的物理参数集时，模型模拟效果良好；并且，如果改进计算机功率，便可得到与始终保持高分辨率模拟具有可比性的输出结果。  相似文献   

滇东北地区峨眉山玄武岩铜矿成矿物质来源   总被引：1，自引：0，他引：1  

钱壮志  徐翠玲  章正军  姜常义  侯蜀光  唐冬梅 《矿物岩石》2007,27(1):78-82

针对滇东北峨眉山玄武岩分布区铜矿中矿石矿物及玄武岩的微量元素Co,Cr,Ni,Pb,Th,U以及铅同位素组成进行研究,结果显示:在玄武岩和矿石中,Pb平均丰度分别为7.87×10-6和7.13×10-6,Th平均丰度分别为5.27×10-6和6.27×10-6,U平均丰度分别为1.16×10-6和0.97×10-6;从Th,U,Pb的质量分数揭示了玄武岩和矿石物源的相似性;Co,Cr,Ni的质量分数除矿石Cr略低外,玄武岩和矿石的Co和Ni均大于上部地壳平均值,提供了成矿物质非上部地壳来源的信息;铜矿石中主要矿物铅同位素组成(206Pb/204Pb平均18.3442、07Pb/204Pb平均15.620 22、08Pb/204Pb平均38.653 9)与玄武岩铅同位素组成(206Pb/204Pb平均18.805 32、07Pb/204Pb平均15.602 72、08Pb/204Pb平均39.250 8)相似,在206Pb/204Pb-207Pb/204Pb和206Pb/204Pb-208Pb/204Pb图中,二者铅同位素组成呈线性排列,从而在铅同位素示踪上显示了二者具有相同的铅源。由此判定滇东北峨眉山玄武岩区3类铜矿的成矿物质是源自于该区的玄武岩。  相似文献   

2007年宁洱6.4级地震余震序列尾波QC值研究     

李琼  秦嘉政  钱晓东 《地震研究》2007,30(4):337-343

基于Aki和Chouet的地方震尾波单次散射模型,利用思茅台记录到的2007年云南宁洱6.4地震余震的数字化波形观测资料,测量了震源区尾波Qc(f)值。当中心频率为1.5Hz时,宁洱地区的尾波Qc值在51～147之间,平均值为79,尾波的振幅衰减率βc(f)在0.014～0.039之间,平均值为0.028;测量得到该地区尾波Qc值与频率f的关系为Qc(f)=53f0.88;尾波波源因子与震级成正比关系,满足关系lgA0=1.51ML-0.94;测量结果显示宁洱地震余震序列的尾波值Qc较低,表明宁洱震源区属于构造运动较为活跃区。  相似文献