Gauss-Markov模型参数的岭型广义逆估计及其优良性

本文继续文献 [10 ]的工作 ,进一步讨论了测量平差 Gauss- Markov模型参数岭型广义逆估计的若干性质 ,如允许性、优效性、相对效率、抗干扰性等等 ,得到了许多重要结论。计算结果表明 ,在设计阵呈病态时 ,岭型广义逆估计确能明显改善 L S估计     

A Report on a Biotite-Calcic Hornblende Geothermometer

This paper presents a biotite-calcic hornblende geothermometer which was empirically calibrated based on the gamet-biotite geothermometer and the gamet-plagioclase-hornblende-quartz geobarometer, in the ranges of 560-800℃ (T) and 0.26-1.4 GPa (P) using the data of metadolerite, amphibolite, metagabbro, and metapelite collected from the literature. Biotite was treated as symmetric Fe-Mg-AlVI-Ti quaternary solid solution, and calcic hornblende was simplified as symmetric Fe-Mg binary solid solution. The resulting thermometer may rebuild the input garnet-biotite temperatures well within an uncertainty of ±50℃. Errors of ±0.2 GPa for input pressure, along with analytical errors of ?% for the relevant mineral compositions, may lead to a random error of ±16℃ for this thermometer, so that the thermometer is almost independent of pressure estimates. The thermometer may clearly discriminate different rocks of lower amphibolite, upper amphibolite and granulite facies on a high confidence level. It is assume     

Discovery of Radiolarian Fossils from the Aiketik Group at the Western End of the South Tianshan Mountains of Chinaand Its Implications

The Aiketik Group, distributed at the western end of the South Tianshan Mountains, China, is an important lithostratigraphic unit involved in the South Tianshan orogen. It is separated from the adjacent rocks by faults. Generally, the geologists ascribed it to the Upper Carboniferous according to Pseudostaffella sp., Profusulinella sp. and Fusulinella sp. found from the limestone and sandy limestone of Aiketik. Our radiolarian fossils were obtained from the chert samples collected from the Haladaok section located at the upper Tuoshihan River. The fossils mainly include Albaillella undulata Deflandre, Albaillella paradoxa Deflandre, Albaillella sp. aff. A. paradoxa Deflandre, Albaillella sp. cf. A. deflandrei Gourmelon, Albaillella sp., Albaillella excelsa Ishiga, Kito and Imoto (?), Belowea variabilis (Ormiston et Lane), Callella cf. C. parvispinosa Won, Entactinia cf. E. tortispina Ormiston et Lane, Entactinia aff. E. tortispina Ormiston et Lane, Entactinia variospina Won, Entactinia sp., Eostylodicty     

CHARACTERISTICS OF VEGETATION COVER,ROUGHNESS AND ALBEDO DISTRIBUTION OVER CHINA

To build land surface dataset for climate model,with application of remote sensing techniqueas well as the Geographic Information System(GIS),the data of surface type,roughness andalbedo over China in 1997 were retrieved,resolutions being 10 km×10 km.Based on these data,an analysis is conducted on the geographic distributions and seasonal variations of surfacevegetation cover and roughness as well as albedo over China.Results show that surface vegetationcover is mainly located to the south of Yangtze River,in Southwest and Northeast China andsparse vegetation cover is in the Northwest.The variation of land surface cover affects thevariations of land surface roughness and albedo.High albedo occurred in the north of XinjiangAutonomous Region,the north of Northeast China and the Qinghai-Xizang Plateau in winter,incorrespondence with the location of snow cover.For most part of China,surface roughness decreases and albedo increases in winter,while theroughness increases and the albedo decreases in summer,which could mainly result from landsurface cover(snow cover and vegetation cover)and soil moisture changes.This shows that thegeographic distribution and seasonal variation of the albedo are almost opposite to those of theroughness,in agreement with theoretical results.Temporally,the amplitude of surface roughnesschange is quite small in comparison with the roughness itself.     

通海地磁台(L=1.03)Pc3地磁脉动的出现率

利用通海地磁台(L=1．03)1999年SMALL磁通门磁力仪记录资料，对Pc3脉动出现率的统计结果表明，日出现频次有两个峰值，即清晨06：00-07：00LT(地方时)出现频次最高，午后14：00～15：00LT为次峰值。Pc3脉动月出现频率最高的是4月和12月，其次是8月和9月；最少的是6月和7月。按季节统计结果为春秋季出现频次最高，冬季次之，夏季最低。     

Petrogenesis of Cenozoic Potassic Volcanic Rocks in the Nangqen Basin

The Nangqen basin is one of the Tertiary pull-apart basins situated in the east of the Qiangtang block.Similar to the adjacent Dengqen basin and Baxoi basin, there occurred a series of potassic volcanic and sub-volcanic rocks, ranging from basic, intermediate to intermediate-acid in lithology.Based on the study of petrology, mineralogy and geochemistry, including REEs, trace elements, isotopic elements and chronology, the authors concluded that the Cenozoic potassic volcanic rocks in the Nangqen basin were formed in the post-collisional intraplate tectonic settings. The relations between the basic, intermediate and intermediate-acid rocks are neither differentiation nor evolution, but instead the geochemical variability is mainly attributable to the different partial melting degrees of the mantle sources formed at depths of 50-80 km.The sources of the potassic rocks are enriched metasomatic mantle that has experienced multiple mixing of components mainly derived from the crust. The recycling model can b     

Early-Middle Permian Reef Frameworks and Reef-building Models in the Eastern Kunlun Mountains

Reef frameworks and building models of the Early-Middle Permian in the eastern Kunlun Mountains have been verified through studies of reef-building communities, palaeoecology and carbonate facies. The eastern Kunlun reefs are built mainly by 6 reef-building communities, which include 11 major categories of frame-building organisms and 6 categories of reef-associated organisms. Eight types of reef-frames have been distinguished and eleven kinds of rocks identified to belong to 6 reef facies. Three sorts of reefs classified by previous researchers, namely mudmounds, knoll reefs and walled reefs, are well developed in the study area. Such reef-facies association and reef distribution show that there are 4 models of reef growth and development, i.e. the tidal-bank knoll-reef model, the plateau-margin wall-reef model, the composite wall-reef model and the deep-water mudmound model. The reefs are mainly constructed by calcareous sponge and calcareous algae, which are similar to all Permian reefs in other area     

青海省阿尼玛卿带布青山蛇绿混杂岩的地球化学性质及形态环境

布青山蛇绿混杂岩位于阿尼玛卿带西段，它是由早古生代和早石炭世一早二叠世两期蛇绿岩组成的复合蛇绿混杂岩带。蛇绿岩中的变质橄榄岩以方辉橄榄为主，高镁，∑PEE是球粒陨石的0．2－0．65倍，HREE是球粒陨石的0．28－0．32倍，属亏损的大洋岩石圈地幔。早古生代蛇绿岩中辉长岩、辉绿岩和玄武岩等镁铁质岩主要具N－MORB性质，少量具T－MORB性质。早石炭世一早二叠世蛇绿岩中玄武岩也主要具N－MORB性质、少量具T－MORB性质。它们均形成于洋中脊环境。本区曾存在成熟的早古生代洋盆和古特提斯洋盆，有更复杂的构造演化史。     

Amplitude Ratio of Regional Seismic Phases: An Efficient Indicator of Thermal State of the Lithosphere

By analyzing seismograms of short period records at the Beijing SeismoJogicaJ Observatory, the present paper investigates the amplitude ratio of seismic phases. The results indicate that the amplitude ratio of Sn/Lg is correlated with the lithosphere structure, the thermal state, and strong earthquake occurrence in the region the seismic rays pass through. The significance of such a correlation in the study on the genesis and prediction of strong earthquakes is discussed.     

Confidence Evaluation of Medium-and Long-Term Earthquake Prediction by Use of the Analytical Hierarchy Process

This paper offers an approach to the relative confidence level of medium- and long-term earthquake prediction methods by use of the analytical hierarchy process (AHP). We construct the criterion judgment matrices according to the results of an expert questionnaire known as the Delphi scheme. From the matrices we can obtain a scale for the relative preference or priority weight of each factor. The quantitative weights might be applied to make synthetic prediction of earthquake risk areas in the northern part of the North China seismic region.