历史本原的政治考量——李勣贬任叠州都督原因蠡测

李勣为唐前期著名军事家和地位特殊的重要政治人物。唐太宗在其晚年贬时任宰相李勣为叠州都督,这不仅仅关涉到李世民与李勣的君臣关系,在史料基础上的逻辑推断分析还可能有其他考虑。其一,是李世民设计的一次特殊安排,利用李勣的军事才能起到一定的安边效应,以稳定可能潜在的外部威胁;其二,以贬任的形式合理的把李勣排除在辅政大臣之外,这一方面是对其地位的无奈,同时也因为从某种角度而言更信任长孙无忌和褚遂良二人,亦有可能是对山东豪族的一次变相打压。综合来看,李世民对李勣的贬任,效果上并无不妥,只是其所采取的具体理由究竟为何无从查起。

唐代河西九曲羁縻府州及相关问题研究

河西九曲一名,始出《旧唐书·吐蕃传》:(睿宗景云元年)时杨矩为鄯州都督,吐蕃遣使厚遗之,因请河西九曲之地以为金城公主汤沐之所,矩遂奏与之。吐蕃既得九曲,其地肥良,堪顿兵畜牧,又与唐境接近,自是复叛,始率兵入寇。河西,自是指黄河以西,但此处与河西道无关,而是指今青海共和县以南的黄河以西地区。九曲,依《通鉴》胡注的解释:"九曲者,去积石军三百里,水甘草良,宜畜牧,盖即汉大、小榆谷之地。"

一年级单元02

本单元探索各种不同表现形式的意义、这些形式与设计及建造有着直接的联系。 我们将制作一个对象,从中产生一系列画面。在这些画面中我们创造出一些新的对象,再从这些新的对象中找出新的概念,对所用的材料给出精细的造型。 我们愿意从各种不同的经验和现象中去学习这个城市所能提供的有关土地的建筑学知识。我们探索在各种不同材料和构思下建构建筑,直到它们真实地改变了我们认识各种不同的空间形式和概念的途径。

Re-Os isotopic data for molybdenum from Hejiangkou tungsten and tin polymetallic deposit in Chenzhou and its geological significance

Hejiangkou W-Sn-polymetallic deposit is a newly found deposit in Xitian ore field,one of the important and large scale W-Sn-polymetallic ore fields in the middle segment of Nanling metallogenic zone.Re-Os isotope dating was used on three molybdenite samples from Hejiangkou deposit to determine the ore forming period.The result is(224.9±2.6)Ma-(225±3.1)Ma and isochron age is(225.5±3.6)Ma.The field geological observations,geochronological data and optical petrography indicated that Hejiangkou deposit underwent multi-period of superimposed mineralization.It can be differentiated into three periods composed of six mineralization stages.The first period is the initial period for hydrothermal metasomatism and metal element enrichment during Indosinian Epoch.Further enrichment,strong brittle fracturing and hydrothermal metasomatism,remobilization and superimposition happened in the second period,during early Yanshanian.It is the major mineralization period of Hejiangkou deposit and can be subdivided into four mineralization stages,namely the skarn stage,oxide stage,high-temperature sulfide stage and low-temperature sulfide stage.And the third period is the mineralization period of a porphyry-skarn system related to the emplacement of the granite porphyry dyke.As minerogenic epoch of Hejiangkou deposit is similar with Hehuaping deposit,they show the possibility of Indosinian mineralization event in Nanling metallogenic zone.It can be an important perspective in any future mineral exploration in the same metallogenic zone.

Distribution characteristic and geological signiflcance of rare earth elements in Lopingian mudstone of Permian,Panxian county,Guizhou province

In order to discuss the geochemical characteristic of REEs （rare earth elements） and their geological application, we measured the contents of rare earth elements, trace elements and minerals of 29 Lopingian （Late Permian） mudstone samples in Panxian county, carrying out ICP-MS and XRD analysis. The results show that the amount of REEs （185.56-729.46 ×10-6） is high. The ratios of w（LREE）/w（HREE） （6.84- 13.86） and W（La）N/w（Yb）N （1.01-3.02） show clear differentiation of LREEs and HREEs. ZREE has a significantly or critically positive correlation with lithophile elements Th, Nb, Ta, Ti, Ca, Sc, Cs, Zr, Hf, Sr, Be and chaicophile element Zn, a critically negative correlation with siderophile element Fe and a slightly positive correlation with illite, illite smectite mixed layers and siderite. REEs originate mainly from terrigenous minerals, in an inorganic phase, Source rocks of our samples consist of Emeishan basalt and a small part of sedimentary rocks, as suggested by the distribution patterns of REEs and w（∑REE）- w（La）/w（Yb） diagram. Moreover, abnormal surfaces near the sequence boundaries （SB2, SB3, SB4） are related wiLth the boundaries, identified by geochemical characteristics of the REEs, such as ∑REE. w（LREE）/w（HREE）, Eu/Eu＊ and Ceanom.

Geochemical characteristics of Guizhou Permian coal measure strata and analysis of the control factors

Based on element geochemical studies of the main Permian exploitable coal measure strata in Western Guizhou, the element geochemical distribution characteristics of the main exploitable coal measures were revealed in the regions of Dafang, Qianxi, Weining, Hezhang, Zhijin, etc., of Guizhou Province, and the results show that their element contents are mainly affected by terrestrial material supply. Coal measures formed in the delta plain environment where sufficient terrestrial materials are supplied contain relatively abundant trace elements and rare-earth elements, whereas those formed in the tidal-fiat environment influenced greatly by seawater have relatively low contents of trace elements and rare-earth elements, mainly con- trolled by the geological fact that basalts the parent rocks from source regions contain high trace elements and rare-earth elements. In addition, coal measures affected by later hydrothermal activities and fault tectonics contain a large amount of harmful elements. According to the rules of distribution of elements in coal measures, a new idea was put forward to classify coal-forming environments by using the geochemical composition characteristics, which is of great significance in dissolving the problem of whether coal measures were fbrmed either in delta environments or in tidal-flat environments in Western Gui- zhou. At the same time, the rules of distribution of elements in the main exploitable coal measures in Western Guizhou were fully understood, which is of direct significance in utilizing coal resources on the basis of classification of coals, as well as in developing the coal chemical industry.

Oil-source correlation of Lower-Triassic oil seepages in Ni＇erguan village, Southern Guizhou Depression, China

There are abundant bitumens and oil seepages stored in vugs in a Lower-Triassic Daye formation(T_1d)marlite in Ni'erguan village in the Southern Guizhou Depression. However, the source of those oil seepages has not been determined to date. Multiple suites of source rocks of different ages exist in the depression. Both the oil seepages and potential source rocks have undergone complicated secondary alterations, which have added to the difficulty of an oil-source correlation. For example, the main source rock, a Lower-Cambrian Niutitang Formation"(∈_1n) mudstone, is over mature, and other potential source rocks, both from the Permian and the Triassic, are still in the oil window. In addition, the T_1d oil seepages underwent a large amount of biodegradation. To minimize the influence of biodegradation and thermal maturation, special methods were employed in this oil-source correlation study. These methods included catalytic hydropyrolysis, to release covalently bound biomarkers from the over mature"kerogen of ∈_1n mudstone, sequential extraction, to obtain chloroform bitumen A and chloroform bitumen C from the T_1d marlite, and anhydrous pyrolysis, to release pyrolysates from the kerogen of T_1d marlite. Using the methods above, the biomarkers and n-alkanes releasedfrom the oil samples and source rocks were analysed by GC–MS and GC-C-IRMS. The oil-source correlation indicated that the T_1d oil seepage primarily originated from"the ∈_1n mudstone and was partially mixed with oil generated from the T_1d marlite. Furthermore, the seepage also demonstrated that the above methods were effective for the complicated oil-source correlation in the Southern Guizhou Depression.

Yuzhou Flora——A hidden gem of the Middle and Late Cathaysian Flora

The Yuzhou Flora of the southern North China Platform possesses the typical regional features of the Middle and Late Cathaysian Flora.For a long time during the Permian,this area was located on shoreline marine tidal flats and deltas at low latitudes with a warm and humid climate.Consequently,many successive layers with abundant well-preserved plant fossils and a complete evolutionary sequence were developed.This is a unique and ideal place to study the Middle and Late Cathaysian Flora.We have recognized 111 genera and 307 species from this flora.The rapid morphological evolution and uninterrupted stratigraphic succession of Lobatannularia(Sphenophytes) make this group one of the bases for biostratigraphic divisions of the Permian System of the North China Platform.Ninety percent of Pteridophytes belong to the order Marattiales,which are well developed during the early and middle stages of the Yuzhou Flora but experience a sudden decline during the late stage.Ancient Pteridospermatophytes only flourished during the Middle Permian whereas advanced Peltaspermales are extremely well developed at the end of the early Late Permian.Among them Shenzhouphyllum is one of characteristic elements in the late stage of the Yuzhou Flora.The Cycadophytes evolved relatively early in this area and they differentiated and proliferated during the late Middle to early Late Permian.The number of species of Ginkgophytes is small but this group is extremely abundant,especially in the early Late Permian.The Gigantopteridales(preangiosperms) is a very important and unique group in the Yuzhou Flora.Based upon their venation and leaf architecture,this group can be divided into three evolutionary stages,i.e.,appearance and differentiation,first flourishing,and second flourishing and sudden disappearance,which form the basis for biostratigraphic division and correlation of the Permian System of the North China Platform.Based upon the evolutionary trend of venation pattern and leaf architecture,we propose some taxonomic changes at the generic level.The Yuzhou Flora emerged at the middle Early Permian(Zisongian) and suddenly disappeared at the early Late Permian(Wujiapingian).It is later replaced by the Euro-American Zechstein flora in the late Late Permian.The Yuzhou Flora is divided into three(early,middle and late) stages based upon the cyclic development of its plant groups.Five fossil plant assemblage zones are recognized from the Yuzhou Flora based upon the succession of each group and their combined characters in different layers.