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991.
992.
993.
研究了复平面上 ,广义 Hermite-Fejer插值多项式的收敛性。得到了其在空间 lp(| z| =1 ) (0
相似文献
994.
西秦岭北带泥盆纪Nereites遗迹相及其环境分析 总被引:4,自引:1,他引:3
西秦岭北带泥盆系舒家坝组下一中上部的巨厚陆源碎屑岩系中含有极丰富的遗迹化石,它们可为解释该组沉积环境提供重要信息:(1)由大量典型深水遗迹化石组成的Nereites遗迹相,可与世界各地浊积岩系和复理石相中的Nereites遗迹相进行对比,该遗迹相主要发育在浊流沉积区直至深海平原,其沉积水深最大可超过2000m;(2)舒家坝组的遗迹群落中,除大量属深水型分子外,还见有典型的浅水分子,两种水深性质不同的遗迹组合共生在一个沉积剖面,正是浊积岩系和复理石相才具有的独特分布特征;(3)根据沉积层序和遗迹组合的对比确认舒家坝组不存在风暴岩。 相似文献
995.
996.
Sapphirine-bearing granulites and related high-temperature metamorphic rocks from the Higo metamorphic terrane, west-central Kyushu, Japan 总被引:7,自引:0,他引:7
The Higo metamorphic unit in west-central Kyushu island, southwest Japan is an imbricated crustal section in which a sequence of units with increasing metamorphic grade from high (northern part) to low (southern part) structural levels is exposed. The basal part of the metamorphic sequence representing an original depth of 23–24 km consists mainly of garnet–cordierite–biotite gneiss, garnet–orthopyroxene gneiss, orthopyroxene-bearing amphibolite and orthopyroxene-bearing S-type tonalite. These metamorphic rocks underwent high amphibolite-facies up to granulite facies metamorphism with peak P – T conditions of 720 MPa, 870 °C. In addition sapphirine-bearing granulites and related high-temperature metamorphic rocks also occur as tectonic blocks in a metamorphosed peridotite intrusion. The sapphirine-bearing granulites and their related high-temperature metamorphic rocks can be subdivided into five types of mineral assemblages reflecting their bulk chemical compositions as follows: (1) sapphirine–corundum–spinel–cordierite (2) corundum–spinel–cordierite (3) garnet–corundum–spinel–cordierite (4) garnet–spinel–gedrite–corundum, and (5) orthopyroxene–spinel–gedrite. These metamorphic rocks are characterized by unusually high Al2 O3 and low SiO2 contents, which could represent a restitic nature remaining after partial melting of pelitic granulite under the ultra high-temperature contact metamorphism at the peak metamorphic event of the Higo metamorphic unit. The metamorphic conditions are estimated to be about 800 MPa and above 950 °C which took place at about 250 Ma as a result of the thermal effect of the regional gabbroic rock intrusions. 相似文献
997.
滇东南芦柴冲大型银多金属矿床的海底喷流成矿作用沉积旋回划分 总被引:4,自引:1,他引:3
芦柴冲矿床位于滇东南砚山县境内,属南岭地区西南端--滇东南早泥盆世的层控矿带。经野外调研和室内系统研究,发现矿床为典型非火山成因的、严格受沉积相(台盆相区)控制的海底喷流沉积成因矿床。矿床中发育的南北向同生扩张断裂是重要的控盆和控矿构造,是海底喷流成矿的含矿流体运移的通道,它具周期性的振荡运动的特点,导致海底喷流成矿具周期性的沉积旋回。 相似文献
998.
云南金厂金矿床蚀变超基性岩体与金的成矿作用 总被引:10,自引:0,他引:10
金矿化与蚀变超基性岩体的空间关系、矿化特征、蚀变超基性岩体、成矿流体、微量元素、硫同位素组成、表明金主要来源于金厂蛇纹石化、滑石化、碳酸盐化超基性岩体。在岩体蚀变过程中,在碱性相对还原的介质条件下,金主要以硫络合物的形式进入成矿溶液,在T、P、PH、Eh等物理化学参数发生变化的条件下沉淀。 相似文献
999.
A survey was made of the number of the heterotrophic bacteria in surface seawater of Great Wall Bay and its adjacent waters, Antarctica during the period of austral summers from Dec.1993 to Feb. 1994. The result shows that the number of the heterotrophic bacteria in the surface waterof the surveyed area is about 798 CFU. cm-3, ranging from 53 to 4 250 CFU. cm-3. Comparison of thenumbers for three months shows a declining tendency month by month. Comparing with the previous results, this one shows that the heterotrophic bacteria number changes somewhat, but slightly. It is lower than that in nearshore waters but higher than that in the open area. This shows that there is a positive correlative relationship between CFU and NH4- N, which means that heterotrophic bacteria should be an important agent in NH4-N reproduction in the environment surveyed. There is an significant negative correlation both between CFU and NOZ-N, and between CFU and PO4-P. This means that the NOZ-N, PO.-P, which were decomposed and transformed by bacteria, were used rapidly by phytoplankton. 相似文献
1000.
CHEN Hao-Wen 《冰川冻土》1998,(4)
The outdoor air borne microbial content over Great Wall Station, Antarctica has been monitored, including its diurnal variations and states in fair or foul weather conditions.The results obtained show: the concentration averaged 161. 9 CFU. m-3. When the weather condition was fair, its range of variation is 0~1 336. 2 CFU. m-3, the average value was 1488. 3 CFU. m-3,when the weather was foul, the range of variation was 471. 4-4 296. 8 CFU. m-3. The average value of air borne microbial number in either fair or foul weather was 383. 0 CFU. m-3. This value is over than 21 times that obtained during 1986/1987.The results seem to show that the influence of human activities have been increasing on Antarctic ecosystem. The diurnal variation of the outdoor air borne microbes shows that the peak of content appeared at about 01: 00, and the trough at about 13: 00 in a whole day. Analyses were made of the relationships between the microbial concentration with its related indexes, i. e. relevant air temperature relative humidity or wind force.The results showed some particularities as compared with those from the areas outside Antarctica. 相似文献