998 resultados para 19-184


Relevância:

70.00% 70.00%

Publicador:

Resumo:

Late Cenozoic ash deposits cored in Deep Sea Drilling Project Leg 19 in the far northwest Pacific and in the Bering Sea have altered to bentonite beds. Some bentonite layers were subsequently replaced by carbonate beds. A significant part of the Neogene volcanic history of land areas adjacent to the far north Pacific is represented by these diagenetic deposits. Bentonite beds are composed of authigenic smectite and minor amounts of clinoptilolite. Authigenic smectite has fewer illite layers than detrital smectite. Opal-A and opal-CT, abundant in Bering Sea sediment, are not found in ash or bentonite layers. The percentage of smectite in the total clay-mineral assemblage of ash beds is greater than that for adjacent terrigenous sediment, but the total amount of clay minerals in ash sequences is less than in surrounding deposits. Morphology of the 17-Å peak of smectite found in ash may represent newly formed, poorly crystalline smectite. Smectite becomes better crystallized as bentonite layers form. The percentage of smectite of the total clay-mineral assemblage in bentonite beds is greater than that in surrounding sediment, and, in contrast to ash beds, the total amount of clay minerals (mostly smectite) in bentonite layers is greater than in adjacent terrigenous sediment. Apparently, silica is not mobilized when volcanic ash layers transform to bentonite beds. Saponite-nontronite varieties of smectite and high Fe/Al and Ti/Al ratios distinguish bentonite beds derived from basaltic parent material from those beds formed from more silicic volcanic ash. These silicic ash beds produce bentonite composed mostly of montmorillonite. The basal sediment section at site 192 is rich with bentonite beds. Smectite in the upper part of this section (Eocene) was formed by low-temperature diagenesis of volcanic debris of intermediate or more silicic composition derived from arc or Pacific volcanoes. In contrast, smectite from the lowest 10 to 20 m of the sedimentary section (Cretaceous) is formed from either low-temperature or hydrothermal alteration of the underlying basaltic basement and associated pyroclastic debris. This near-basement smectite contains Mg and K acquired from sea water and Si, Al, Fe, Ti, and Mn released from the volcanic material.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

对来自云南昭通、景洪、元阳、潞西和镇康等5个地区的25只雌按蚊,及4只雄按蚊进行随机扩增多态DNA分析。从使用的20个随机引物中,选择其中扩增谱带清晰的12个引物进行分析。结果发现,只有2个引物获得的RAPD谱带呈单型,其余均表现为不同程度的多态型。UPGMA法构建的分子系统树表明该29只微小按蚊实际上可以归并为显著不同的5个组,分别对应于它们的地理来源,说明云南微小按蚊群体间的基因流程度不高,不同地理群体间存在显著的遗传分化。

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Compressional (Vp) and shear (Vs) wave velocities have been measured to 1.0 kbar for 14 cores of well-consolidated sedimentary rock from Atlantic and Pacific sites of the Deep Sea Drilling Project. The range of VP (2.05-5.38 km/sec at 0.5 kbar) shows significant overlap with the range of oceanic layer-2 seismic velocities determined by marine refraction surveys, suggesting that sedimentary rocks may, in some regions, constitute the upper portion of layer 2. Differing linear relationships between VP and Vs for basalts and sedimentary rocks, however, may provide a method of resolving layer-2 composition. This is illustra ted for a refraction survey site on the flank of the Mid-Atlantic Ridge where layer-2 velocities agree with basalt, and two sites on the Saya de Malha Bank in the Indian Ocean where layer-2 velocities appear to represent sedimentary rock.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Detrital modes for 524 deep-marine sand and sandstone samples recovered on circum-Pacific, Caribbean, and Mediterranean legs of the Deep Sea Drilling Project and the Ocean Drilling Program form the basis for an actualistic model for arc-related provenance. This model refines the Dickinson and Suczek (1979) and Dickinson and others (1983) models and can be used to interpret the provenance/tectonic history of ancient arc-related sedimentary sequences. Four provenance groups are defined using QFL, QmKP, LmLvLs, and LvfLvmiLvl ternary plots of site means: (1) intraoceanic arc and remnant arc, (2) continental arc, (3) triple junction, and (4) strike-slip-continental arc. Intraoceanic- and remnant-arc sands are poor in quartz (mean QFL%Q < 5) and rich in lithics (QFL%L > 75); they are predominantly composed of plagioclase feldspar and volcanic lithic fragments. Continental-arc sand can be more quartzofeldspathic than the intraoceanic- and remnant-arc sand (mean QFL%Q values as much as 10, mean QFL%F values as much as 65, and mean QmKP%Qm as much as 20) and has more variable lithic populations, with minor metamorphic and sedimentary components. The triple-junction and strike-slip-continental groups compositionally overlap; both are more quartzofeldspathic than the other groups and show highly variable lithic proportions, but the strike-slip-continental group is more quartzose. Modal compositions of the triple junction group roughly correlate with the QFL transitional-arc field of Dickinson and others (1983), whereas the strike-slip-continental group approximately correlates with their dissected-arc field.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Sand and sandstone compositions from different types of basins reflect provenance terranes governed by plate tectonics. One hundred and one thin sections of Upper Miocene to Holocene sand-sized material were examined from DSDP/IPOD Sites in the North Pacific Ocean and the Bering Sea. The Gazzi-Dickinson point-counting method was used to establish compositional characteristics of sands from different tectonic settings. Continental margin forearc sands from the western North America continental margin arc system are clearly different from backarc/marginal-sea sands from the Aleutian intraoceanic arc system. The forearc sands have average QFL percentages of 29-42-29, LmLvLst percentages of 32-34-34, 3 Fmwk%M and 0.82 P/F. Aleutian backarc sands have average QFL percentages of 8-22-69. LmLvLst percentages of 9-85-6, 0.5 Fmwk%M and 0.96 P/F. A trend of increasing QFL%Q and decreasing LmLvLst%Lv westward in the backarc region of the Aleutian Ridge reflects the influence of the Asiatic continental margin. Aleutian backarc sands without continental influence have average QFL percentages of 1-20-79, LmLvLst percentages of 1-98-1, 0 Fmwk%M and 0.99 P/F. Of the continental margin forearc samples, sands on the Astoria Fan (west of the Oregon-Washington trench) contain the highest LmLvLst%Lv and lowest P/F; sands from mixed transform-fault and trench settings (Delgada Fan and Gulf of Alaska samples) have slightly higher Qp/Q (0.03); and sands from the Pacific-Juan de Fuca-North America triple junction have the highest Fmwk%M. Delgada Fan and Gulf of Alaska sands have average QFL percentages of 27-38-35, LmLvLst percentages of 37-26-37, 2 Fmwk%M and 0.86 P/F. Astoria Fan sands have average QFL percentages of 35-41-24, LmLvLst percentages of 30-47-23, 3 Fmwk%M and 0.74 P/F. The triple-junction sands have average QFL percentages of 28-59-13, LmLvLst percentages of 25-26-49, 9 Fmwk%M and 0.87 P/F. The petrologic data from the modern ocean basins examined in this study can provide useful analogs for interpretation of ancient oceanic sequences. Our data suggest some refinements of, but generally substantiate, existing petrologic models relating sandstone composition to tectonic setting.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Search for low-spin signature inversion in the pi i(13/2) circle times nu i(13/2) bands in odd-odd Au-182,Au-184,Au-186 has been conducted through the standard in-beam gamma-spectroscopy techniques. The experiments for Au-182 and 186Au have been performed in the Japan Atomic Energy Agency (JAEA) via the Sm-152(Cl-35,5n)Au-182 and Yb-172(F-19,5n)Au-186 reactions, respectively. A study of Au-184 has been made using a multi-detector array GASP in LNL, Italy, via the Tb-159(Si-29,4n)Au-184 reaction. The pi i(13/2) circle times nu i(13/2) bands in these three nuclei have been identified and extended up to high-spin states. In particular, the inter-band connection between the pi i(13/2) nu i(13/2) band and the ground-state band in 184 Au has been established, leading to a firm spin-and-parity assignment for the pi i(13/2) circle times nu i(13/2) band. The low-spin signature inversion is found in the pi i(13/2) circle times nu i(13/2) bands in Au-182,Au-184,Au-186 according to our spin-assignment and the signature crossing observed at high-spin states.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Search for low-spin signature inversion in the pi i(13/2) circle times nu i(13/2) bands in odd-odd Au-182,Au-184,Au-186 has been conducted through the standard in-beam gamma-spectroscopy techniques via the Sm-152(Cl-35,5n) Au-182, Yb-172(F-19,5n) (186)An, and Tb-159(Si-29,4n) (184)An reactions, respectively. The pi i(13/2) circle times nu i(13/2) bands in these three nuclei have been identified and extended up to high-spin states. In particular, the inter-band connection between the pi i(13/2) circle times nu i(13/2) band and the ground-state band in Au-184 has been established, leading to a firm spin-and-parity assignment for the pi i(13/2) circle times nu i(13/2) band. The low-spin signature inversion is found in the pi i(13/2) circle times nu i(13/2) bands according to our spin-assignment and-the signature crossing observed at high-spin states.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Purpose: It is a commonly held perception that most young children are naturally active and meet physical activity recommendations. However, there is no scientific evidence available on which to confirm or refute such perceptions. The purpose of this study was to describe the physical activity levels and patterns of Australian toddlers.


Methods: Physical activity and demographic data of two hundred ninety-five 19-month-old children from the Melbourne InFANT Program were measured using accelerometers and parent surveys. Validated cut points of 192–1672 and >1672 counts per minute were used to determine time spent in light- (LPA) and moderate-to-vigorous- (MVPA) intensity physical activity, respectively. To be included in the analysis, children were required to have four valid days of accelerometer data to provide an acceptable (>0.70) reliability estimate of LPA and MVPA. Physical activity data for different periods of the day were examined.


Results: On average, toddlers engaged in 184 min of LPA and 47 min of MVPA daily, and 90.5% met the current Australian physical activity recommendations for 0- to 5-yr-olds (180 min of LPA/MVPA per day). Physical activity levels during mid morning and mid afternoon were higher than those during other periods. Physical activity patterns for boys and girls were similar, although boys engaged in more physical activity during the morning hours than girls did.


Conclusions: Most children meet the physical activity recommendations, although the majority of activity undertaken in the study was of light intensity. Boys were more active than girls were in the morning hours, but there were no differences between sexes over the entire day. Certain periods of the day may hold more promise for intervention implementation than others do.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

"German Refugees from the Eastern Zone" 1952; 1. "Outline of a Pilot Study of German Refugees from the Eastern Zone Who are presently in Berlin" a) Typoskript, 4 Blatt; b) Typoskript, 3 Blatt; 2. "Budget for a Pilot Study of German Refugees from the Eastern Zone in Berlin" a) 2 Blatt; b) 1 Blatt; c) 1 Blatt; d) 1 Blatt; "Universität und Gesellschaft" 1952-1956; 1. "Universität und Gesellschaft" Teil III: Expertenbefragung. Forschungsbericht, 1953; als Typoskript vervielfältigt und gebunden, 77 Blatt; 2.-7. Allgemeine Darstellung der Untersuchungen; 2. "Einige wichtige Ergebnisse der Universitätsstudie", 1956. Als Typoskript vervielfältigt, 5 Blatt; 3. "Vorläufige Gliederung für den Bericht der Hochschul-Untersuchung" 2 Blatt; 4. "The German University of Today. Progress Report on a Research Project" 02.11.1955 a) Typoskirpt, 12 Blatt; b) Typoskript mit handschriftlichen Korrekturen, 12 Blatt; 5. "The German University of Today. A Progress Report on a Research Project" a) Typoskript, 7 Blatt; b) Typoskript mit handschriftlichen Korrekturen, 8 Blatt; c) Typoskirpt mit handschriftlichen Korrekturen, 12 Blatt; 6. "Funktion und Wirklichkeit der Universität heute. Zwischenbericht über drei Studien des Instituts für Sozialforschung an der Johann Wolfgang Goethe- Universität". Typoskript, 25 Blatt; 7. "Pläne einer Untersuchung über die Vorstellung von der Finktion der heutigen deutschen Universität bei bestimmten Personenkreisen" a) Typoskirpt, 11 Blatt; b) Typoskript, 11 Blatt; 8.-10. Studentenbefragung; 8. Fagebogen zur Umfrage "Warum studieren Studenten?", als Typoskript vervielfältigt, 19 Blatt; 9. "The Economic Situation of Students at the Johann Wolfgang Goethe- University in Frankfurt am Main" Resultate der Umfrage vom Winter 1952/43; Januar 1956; a) Typoskript, 43 Blatt; b) 43 Blatt; 10. "Students and Parentl Influence. Results of a Survey" a) Typoskript, 25 Blatt; b) Typoskript mit handschriftlichen Korrekturen von Frederick Pollock, 25 Blatt; 11.-14. Aktennotizen; 11. "Bericht über die Verhandlungen zwischen Herrn Professor Baumgarten, Tenbruck und Habermas am 12.12.1956 im Institut für vergleichende Sozialwissenschaften in Stuttgart. Betreff: Professorenstudie" 13.13.1956 vermutlich 13.03.1956. Typoskript, 2 Blatt; 12. Gembardt, Ulrich: Aktennotiz zur Hochschuluntersuchung. 23.05.1955, Typoskript, 3 Blatt; 13. Gembardt, Ulrich: Bemerkungen zur Aktennotiz vom 23.05.1955, Typoskript, 2 Blatt; 14. "Aktennotiz über die Hochschul-Forschungsprojekte des Göttinger Soziologischen Seminars und des Frankfurter Institut für Sozialforschung, die deim Hauptausschuß der Deutschen Forschungsgemeinschaft am 1. August 1953 zur Finanzierung vorgelegt werden" 20.07.1953. Typoskript, 2 Blatt; 15.-18. Briefe; 15. Löwenthal, Leo: 1 Brief mit Unterschrift an MAx Horkheimer, New York, 20.01.1955, 3 Blatt; 16. Horkheimer, Max [?]: 1 Brief an Chauncy D. Harris, ohne Ort, Januar 1955; a) Typoskirpt, 1 Blatt; b) Typoskirpt mit handschriftlichen Korrekturen, 1 Blatt; c) Typoskirpt mit handschriftlichen Korrekturen, 1 Blatt; d) Typoskirpt, 1 Blatt; 17. Horkheimer, Max: Drei gleichlautende Briefe an die Rektoren der Universität Bonn, Heidelberg und Koel, ohne Ort, 15.11.1953; a) Typoskript, 6 Blatt; b) Typoskript mit eigenhändigen KOrrekturen, 3 Blatt; 18. Plessner, Helmuth: 1 Brief mit Unterschrift mit Beilage an Max Horkheimer, Göttingen 02.07.1953, 4 Blatt;

Relevância:

30.00% 30.00%

Publicador: