排序方式： 共有14条查询结果，搜索用时 15 毫秒
1.
2.
云南禄丰煤岩与围岩中富勒烯（C60）物质的初步探索 总被引：3，自引：0，他引：3
中国云南煤中是否存在富勒烯还没有科学定论。本工作运用高效液相色谱方法，对中国云南禄丰晚三叠世煤岩及其围岩中是否存在天然富勒烯物质的问题进行了探索性研究；同时发展了适于从复杂地质样品中分离纯化富勒烯和定性与定量检测富勒烯的一套技术方法。结果显示，从定性角度有两个样品确实存在富勒烯。本文据此提出，富勒烯的赋存与煤岩／围岩交互相上的含煤碳质泥岩有着密切的关系。下一步研究应着重调查比煤岩与顶板和底板界面层并大力研究其中天然富勒烯的地学成因。本工作的意义还在于为今后我国加入和独立开展以富勒烯类物质（如C60／C70）及其衍生物质（如He C60 C70)作为地球化学示踪物的古地球突变大事件的研究，奠定了实验方法学基础。 相似文献
3.
Vít Kárník Dana Procházková Zdeňka Schenková Julius Drimmel Dieter Mayer-Rosa Dragutin Cvijanovic Vladimir Kuk Andelka Miloševič Francesco Giorgetti Reviewer J. Janský 《Studia Geophysica et Geodaetica》1978,22(4):411-414
Summary Isoseismal maps of the three strongest Friuli aftershocks of September 1976 were compiled using the contributions from European countries within the shaken area. The characteristic features of the macroseismic fields are discussed. 相似文献
4.
V. Kárník D. Procházková Z. Schenková L. Ruprechtová A. Dudek J. Drimmel E. Schmedes G. Leydecker J. P. Rothé B. Guterch H. Lewandowska D. Mayer-Rosa D. Cvijanović V. Kuk F. Giorgetti G. Grünthal E. Hurtig 《Pure and Applied Geophysics》1978,116(6):1307-1313
Summary The isoseismal map of the North-Italian earthquake of 6 May 1976 was compiled using the contributions of the European countries lying within the shaken area. The characteristic feature of the macroseismic field is discussed. 相似文献
5.
6.
Carlo Baroni Francesco Fasano Giovanna Giorgetti Maria Cristina Salvatore Cristiana Ribecai 《Global and Planetary Change》2008,60(3-4):457-470
The relationship between the Ricker Hills Tillite (RHT), which represents the northernmost outcrop of lithified continental glacial deposits in Victoria Land, is discussed with respect to the glacial landscape assemblage of the Ricker Hills, a nunatak at the internal border of the Transantarctic Mountains. A warm-based ice sheet deposited the tillite and induced syn- to post-depositional glacial deformation under wet conditions both of the tillite and of the bedrock. The thickness of the ice sheet on the nunatak is estimated to have been 600 m, at most. The area had been deeply eroded before deposition of the RHT as documented by the low elevation of tillite outcrops located in overdeepened depressions of the nunatak. Micropaleontological analysis evidences only the presence of Permian to Jurassic palynomorphs. X-ray diffraction and SEM–EDS analyses of clay minerals in the RHT indicate continental chemical weathering under wet conditions after the RHT deposition. As documented by clay mineral assemblage variation in CRP drillholes, the progressive cooling of the Antarctic continent allowed chemical weathering in “warm” conditions until the Late Oligocene period in southern Victoria Land, leading to a chronological constrain for RHT deposition. Conservatively estimating the sea level to have been between the tillite outcrops and the erosional trimline limiting horns in the Ricker Hills, at the time of RHT deposition, we suggest that the maximum uplift of the area would not have exceeded 900–1500 m since at least Late Oligocene. 相似文献
7.
This study compares the composition, species richness and biomass of macrofaunal and algal assemblages on intertidal boulder shores as compared with those on adjacent rock-platforms, at six sites along the southwest coast of South Africa. Of 214 species identified, 175 were recorded on boulder shores and 124 on rock-platform shores; of these, 99 species were common to both habitat types, 92 were exclusive to boulders, and 23 were exclusive to rock-platforms. Significant differences in community structure (F(1,95) = 13.02, p < 0.01) (PERMANOVA test), species richness (F(1,95) = 14.28, p < 0.01), biomass (F(1,95) = 9.45, p < 0.01) and diversity (F(1,95) = 578.83, p < 0.01) (two-way ANOVA) were detected between the two habitat types. Average dissimilarity of community structure between rock-platform and boulder shores was 87.96% (SIMPER analysis). The increased species richness and biomass on boulder shores extended across all tidal levels, but was most marked in the highshore. These results confirm that boulder shores along the southwestern Cape support a distinct biota, richer and very different from that on adjacent rock-platforms, and rich in boulder-dependent species. We propose that boulder shores merit separate management and conservation targets as compared to rock-platforms, though the ecology of boulder shores in the region remains very poorly known and requires further study. 相似文献
8.
A new multi‐proxy investigation of Late Quaternary palaeoenvironments along the north‐western Barents Sea (Storfjorden Trough Mouth Fan) 
下载免费PDF全文
下载免费PDF全文 9.
Interleaved phyllosilicate grains (IPG) of various compositions are widespread in low-grade Verrucano metasediments of the
northern Apennines (Italy). They are ellipsoidal or barrel shaped, up to 300–400 μm long and they are often kinked and folded;
phyllosilicate packets occur as continuous lamellae or as wedge-shaped layers terminating inside the grain. Using electron
microscopy techniques (SEM, TEM) six types of IPG have been distinguished on the basis of their mineralogical composition:
(1) Chl+Ms ± Kln; (2) Chl+ Ms+Pg ± Kln; (3) Ms+Prl ± Pg; (4) Ms+Prl+Su; (5) Ms+Prl+Chl+Su; (6) Su+Ms. Types (1) and (2) are
mainly composed of chlorite, with Ms and Pg as minor phases; Kln grows on Ms in highly weathered samples. Types (3), (4),
(5), and (6) are composed of muscovite, with intergrown Prl, Chl, Su and new-formed muscovite. The IPG show all kinds of contacts:
from coherent grain boundaries with parallel basal planes and along-layer transitions to low- and high-angle grain boundaries.
The IPG formed on pristine minerals such as chlorite and muscovite. The transformations took place during the prograde and
retrograde metamorphic path of the rocks: they were facilitated by deformation and they occurred in equilibrium with a fluid
phase, which allowed cation diffusion. Prograde reactions [Chl = Ms (or Pg); Ms = Prl; Ms = Chl] involve dehydration and sometimes
a decrease in volume, whereas retrograde reactions (Ms = Kln; Ms = Su) involve hydration and an increase in volume. These
transformations do not simply occur through an interchange of cations, but often involve deep structural changes: transitions
from one phyllosilicate to another generally proceed through dissolution-recrystallization reactions. In conclusion, Verrucano
IPG represent microstructural sites which have not completely equilibrated with the whole rock and whose mineral assemblage
depends on the original composition of the microstructural sites.
Received: 20 June 1996 / Accepted: 3 February 1997 相似文献
10.