基于统计分析方法的地理要素显示重要性确定研究

运用统计分析的理论与方法,研究地理要素显示重要性的确定,制作基础地理要素显示重要性问卷调查表,对不同区域、不同用户进行调查统计,运用统计分析中的调查统计法对数据的权重值进行计算分析,总结地理要素显示重要性的分级体系,并在多尺度电子地图制作中得到应用。     

基于大倾角的角锥体空间后方交会研究

在摄影测量中,当倾角变大时,由于三角函数的多值性和奇异性导致传统的共线条件方程线性化的空间后方交会方法已经不能稳定地求解出摄影瞬间影像的外方位元素。文中通过对传统空间后方交会、基于单位四元素的空间后方交会和文中所用到的基于简化的DLT线性方程求解线元素初值的角锥体法比较发现,在像片倾角逐渐变大,传统方法和四元素法不能正确求解出外方位元素的情况下,基于角锥体法的空间后方交会仍能稳定、准确地求解出像片的外方位元素。     

新疆荒漠地区C4植物的生态分布与区系分析

以前人工作为基础,对照已发表的C3/C4植物一览表,及近年国内外陆续发表的资料,综合整理出新疆荒漠地区已知的C4植物名录,共有14科63属的279种植物,同时归纳分析了279种C4。植物的分类地位、生活型、地理成分以及区系特点等方面。研究结果表明：藜科最多,其次是禾本科、莎草科、百合科和蓼科等等。所以该区的C4类型中被...     

ICP-OES法同时测定进口铜精矿中有害元素

本文优化了进口铜精矿的样品处理技术,通过对影响铜精矿消解的因素和仪器参数进行分析建立了同时测定铜精矿中有害元素的精确方法,回收率在91.7%-96%,并与FAS测试结果进行了比较。     

Geochemical evidences of dry climate in the Mid-Holocene in Gonghe Basin, northeastern Qinghai-Tibetan Plateau

Previous research on climatic change in the Mid-Holocene in China indicates that it was a warm and humid period, accompanied by stronger summer monsoons, and it is defined as the Megathermal in the Holocene, or the Holocene Optimum period. However, this conclusion is mainly directed at the monsoonal region in eastern China. In this research, we chose the Gonghe Basin in the northeastern Qinghai-Tibetan Plateau as the study area. Geochemical analysis of the profiles of paleosols and aeolian sand in the Santala area in the middle of the Gonghe Basin, along with OSL (optically stimulated luminescence) dating, indicates that the regional climate has experienced several warm-humid and cold-dry cycles since 11.8 ka. In particular, the Mid-Holocene (8.1–4.6 ka) was relatively cold and dry as evidenced by drastic fluctuations in chemical weathering degree and humidity, a higher aridity index, and sparse vegetation, accompanying increased winter monsoonal strength. In order to clarify whether this is an individual or local signal, we compared our geochemical analysis results with lake and peat records and aeolian deposits of the monsoonal boundary region. The results indicate that the climate deteriorated widely, with declines in temperature and moisture, in the Mid-Holocene in the modern monsoonal boundary zone. Furthermore, the duration of climate deterioration (relatively dry period) generally decreased from west to east in the aforementioned regions. Therefore, this dry phase in Gonghe Basin may be representative of dry events in Mid-Holocene in northern China. In addition, we discuss the reasons for this dry climate from several perspectives: (1) it probably can be attributed to a decline in summer monsoonal strength; (2) the regional evaporation loss (forced by high temperature) was not compensated by regional precipitation; (3) the thermal dynamic effect of the Qinghai-Tibetan Plateau.     

Prediction of satellite orbits contraction due to diurnally varying oblate atmosphere and altitude-dependent scale height using KS canonical elements

A new non-singular analytical theory for the motion of near-Earth satellite orbits with the air drag effect is developed in terms of uniformly regular KS canonical elements. Diurnally varying oblate atmosphere is considered with variation in density scale height dependent on altitude. The series expansion method is utilized to generate the analytical solutions and terms up to fourth-order terms in eccentricity and c (a small parameter dependent on the flattening of the atmosphere) are retained. Only two of the nine equations are solved analytically to compute the state vector and change in energy at the end of each revolution, due to symmetry in the equations of motion. The important drag perturbed orbital parameters: semi-major axis and eccentricity are obtained up to 500 revolutions, with the present analytical theory and by numerical integration over a wide range of perigee height, eccentricity and inclination. The differences between the two are found to be very less. A comparison between the theories generated with terms up to third- and fourth-order terms in c and e shows an improvement in the computation of the orbital parameters semi-major axis and eccentricity, up to 9%. The theory can be effectively used for the re-entry of the near-Earth objects, which mainly decay due to atmospheric drag.     

Contraction of near-Earth satellite orbits using uniformly regular KS canonical elements in an oblate atmosphere with density scale height variation with altitude

A new non-singular analytical theory for the contraction of near-Earth satellite orbits under the influence of air drag is developed in terms of uniformly regular Kustaanheimo and Stiefel (KS) canonical elements using an oblate atmosphere with variation of density scale height with altitude. The series expansions include up to fourth power in terms of eccentricity and c (a small parameter dependent on the flattening of the atmosphere). Only two of the nine equations are solved analytically to compute the state vector and change in energy at the end of each revolution, due to symmetry in the equations of motion. It is observed that the analytically computed values of the semi-major axis and eccentricity are consistent with the numerically integrated values up to 500 revolutions over a wide range of the drag-perturbed orbital parameters. The theory can be effectively used for re-entry of near-Earth objects.     

云南鸡街碱性超基性岩铂族元素地球化学特征

本文首次报道了攀西裂谷南段云南省鸡街碱性超基性岩中铂族元素(PGE)的地球化学特征。采用改进的Carius管法测定了霞霓钠辉岩、霓霞岩和磷霞岩中的低含量PGE。PPGE与IPGE呈现强烈分馏,推断幔源岩在低程度部分熔融过程中Pt、Pd表现为相似的不相容性,而Ir、Ru表现为相容性,这种分馏效应随着结晶分异作用的进行而逐渐增强。3种岩石均出现Ru的负异常及Pt、Pd的解耦,说明母岩浆经历了早期的橄榄石晶出,在结晶分异过程中Pd较Pt更不相容。由于岩浆上升过程中的压力减小和结晶分异作用导致的成份变化使岩浆可以达到硫的局部饱和而熔离,表现为部分样品中Cu/Pd远高于原始地幔值。本文通过碱性超基性岩与金伯利岩、煌斑岩和邻区碱性、过碱性玄武岩PGE特征的对比,探讨了其岩浆源区及演化特征。     

四川攀西地区几个小型镁铁-超镁铁岩体含矿性的铂族元素示踪

峨眉山大火成岩省内带,四川攀西地区的杨合伍、黄草坪和清水河等镁铁-超镁铁岩体分布在南北向的安宁河断裂和磨盘山-元谋断裂之间。分析表明,这些岩体无矿岩石与金宝山、杨柳坪、力马河等含矿岩体无矿岩石具有相似的铂族元素组成,普遍较高的Cu/Pd比值暗示这些岩体的母岩浆在侵入到目前层位前经历过硫化物熔离作用。定量模拟计算表明,原始岩浆经过大约0.01%的硫化物熔离作用形成了杨合伍岩体母岩浆,经过0.035%硫化物熔离形成了黄草坪和清水河岩体的母岩浆。根据硫化物熔离情况,认为杨合伍等岩体底部可能形成Ni-Cu-(PGE)硫化物矿床,而黄草坪和清水河岩体之下及附近可能存在Ni-Cu硫化物矿化的岩体。     

辽宁红透山块状硫化物矿床蚀变带元素迁移特征及定量计算

辽宁红透山块状硫化物矿床（MSD）位于华北地台东北部的浑北花岗岩-绿岩地体内,矿区岩石在30～28 亿年期间受到了600～650℃的高级角闪岩相变质。研究结果表明,广泛分布于红透山层状矿体下盘数百米处的和直接产于矿体下盘的堇青-直闪片麻岩,分别代表了变质后的MSD成矿系统以绿泥石化为特征的半整合和筒状不整合海底热液蚀变带。微量元素特征显示,层状堇青-直闪片麻岩的原岩并非同一种岩石,而是由5种不同岩性的岩石组成,筒状堇青-直闪片麻岩的原岩主要由流纹质岩石组成,而在堇青-直闪片麻岩走向上与之过渡的角闪片麻岩和黑云片麻岩则代表了不同岩性蚀变岩的未蚀变原岩。质量变化计算表明,相对于未蚀变原岩而言,两种蚀变岩的成分发生了显著变化,其中层状堇青-直闪片麻岩的Fe、Mg发生了富集,Na、K、Ca、Cu、Pb和Zn等元素被迁出,而筒状堇青-直闪片麻岩的Fe、Mg、Si、Na、Pb、Cu和Zn等元素则发生了富集,K被迁出。重稀土元素（HREE）和高场强元素(Zr、Ti、Nb、Hf和Ta)在海底热液蚀变过程中保持惰性,而Rb、Sr、Ba和轻稀土元素（LREE,尤其是Eu）则被强烈的迁出。这些元素变化特征表明海底热液蚀变以绿泥石化和硅化为特征,同时海底水-岩反应体系具有高水/岩比值。层状堇青-直闪片麻岩可作为红透山矿区成矿潜力评价的重要依据,而含硫化物石英脉的筒状堇青-直闪片麻岩不但本身可成为工业矿体,还可作为上覆层状矿体的近矿找矿标志。