Fehler der Eisen-Konstantan-Thermoelemente bei Feuchtemessungen mit dem thermoelektrischen Psychrometer     

T. Gilbert 《Theoretical and Applied Climatology》1955,6(3):280-291

Zusammenfassung Drei verschiedene Eisen-Konstantan Thermoelemente wurden in Petroleum und in Wasser geeicht, wobei die passive Lötstelle einmal auf 0° und einmal auf 50° C lag. Die beiden Eichkurven in Wasser zeigen bei dem extremsten Thermoelement eine maximale Temperaturdifferenz von 1,1°C. Die Eichung in Petroleum ergibt gegenüber Wasser eine etwas geringere Temperaturdifferenz, die aber mit ausreichender Genauigkeit vernachlässigt werden kann. Auffallend ist das Auseinanderlaufen der Eichkurven der einzelnen Thermoelemente. Der Unterschied hierbei ist direkt proportional zur Temperaturdifferenz (t _akt.–t _pass.) und ist wohl auf die Vorgeschichte der Materialien zurückzuführen.

---

Summary Three different iron-constantan thermocouples were gauged in both petroleum and water, the passive soldered joint lying at 0°C and subsequently at 50°C. The two gauging curves in water show, for the extremest thermocouple, a highest temperature difference of 1,1°C. Gauging in petroleum yields, with regard to water, a somewhat smaller temperature difference which can be neglected with sufficient accuracy. There is an obvious divergence of the gauging curves of the three thermocouples. The difference is directly proportional to the temperature difference (t _active–t _passive) and may be accounted for by the previous state and treatment of the material in question.

---

Résumé On a étalonné trois thermoéléments différents de ferro-constantan dans du pétrole et dans de l'eau, les soudures passives étant une fois à 0° et une autre fois à 50° C. Les deux courbes d'étalonnage dans l'eau accusent pour le thermoélément le plus extrême une différence de température n'excédant pas 1,1°, tandis que dans le pétrole cette différence est un peu plus faible, mais peut être pratiquement négligée. La divergence des courbes d'étalonnage de chaque thermoélément est remarquable; l'écart est proportionnel à la différence de température des soudures et s'explique probablement par l'état antérieur des matériaux.

---

---

Mit 5 Textabbildungen.  相似文献   

Quartz diorites derived by partial melting of eclogite or amphibolite at mantle depths   总被引：4，自引：0，他引：4  

Joseph G. Arth  Gilbert N. Hanson 《Contributions to Mineralogy and Petrology》1972,37(2):161-174

Rare earth elements, Rb, Sr, Ba and K have been determined in tonalite, trondhjemite, dacite, tholeiite and graywacke from the 2700 m.y. old Early Precambrian greenstone-granite terrane of northeastern Minnesota-northwestern Ontario, and also in trondhjemite from the 3550 m.y. old Morton Gneiss, southwestern Minnesota; and the Mesozoic Craggy Peak Pluton, Klamath Mountains, California.The Early Precambrian tholeiites have trace element compositions similar to modern oceanic tholeiites, while the quartz dioritic rocks, regardless of age, have total rare earth contents lower than that of tholeiitic basalts, with near chondritic heavy rare earth contents. Rb, Sr, Ba and K contents of the quartz diorites are about five times that of oceanic tholeiites, with similar alkali and alkaline earth ratios. The Early Precambrian graywacke has a rare earth content intermediate between greenstone and quartz diorite, reflecting its provenance.It is proposed that the analyzed quartz dioritic rocks, whether plutonic tonalite, dacite porphyry, gneissic or plutonic trondhjemite, or trondhjemite dikes had similar modes of origin, and were derived by partial melting of amphibolite or eclogite of basaltic or gabbroic composition at depths greater than thirty kilometers, leaving a residue consisting predominantly of garnet and clinopyroxene.  相似文献   

Sea-Level Changes and δO Record for the Past 34,000 yr from Mayotte Reef, Indian Ocean     

Michel Colonna  Joel Casanova  Wolf-Christian Dullo  Gilbert Camoin 《Quaternary Research》1996,46(3):335-339

New sea-level and δ¹⁸O curves for the past 34,000 yr, based on uranium–thorium chronology, are proposed for the southwestern part of the Indian Ocean. The archives include cores drilled from onshore coral reefs and submersed samples from foreslope corals of Mayotte in the Comoro Islands. The Mayotte sea-level curve shows a lowstand of 145 ± 5 m below the present level during the last glacial maximum dated at 18,400 yr. This lowstand is supported by the maximum¹⁸O enrichment in the coral colonies. The residual signal (Δδ¹⁸O), controlled by sea-surface temperature changes, indicates that surface waters 18,400 yr ago were approximately 5°C cooler than present. The deglacial sea-level rise is clearly recorded, with a mean rate of about 1.7 cm yr⁻¹between 18,400 and 10,000 yr ago. The deglaciation phase is characterized by a strong¹⁸O depletion marked by two pulses related to meltwater discharges into the North Atlantic Ocean but also characterized by responses specific to the tropical Indian Ocean.  相似文献   

Paleoenvironmental assessment from the physical properties of lacustrine and marine sediments: a Canadian contribution to IGCP 374     

Robert Gilbert  Joseph R. Desloges  Donald S. Lemmen 《Journal of Paleolimnology》1997,17(3):295-296

  相似文献   

Ice-melt collapse pits and associated features in the 1991 lahar deposits of Volcán Hudson,Chile: criteria to distinguish eruption-induced glacier melt     

M. J. Branney  J. S. Gilbert 《Bulletin of Volcanology》1995,57(5):293-302

In subaerial volcaniclastic sequences structures formed by ice blocks can provide information about a volcano's history of lahar generation by glacier melt. At Volcán Hudson in Chile, catastrophic lahars were initiated by eruption-induced melting of glacier ice in August and October 1991. They transported large ice blocks 50 km down the Rio de los Huemules valley to the sea. Large current crescents with lee-side lenses were formed where ice blocks were deposited during waning stages of the flood. When stranded blocks of ice melted, they left cone-shaped and ring-shaped heaps of ice-rafted debris on the sediment surface. Several hundred ice blocks were completely buried within the aggrading lahar sediment, and when these melted circular collapse pits formed in the sediment. Collapse types included subsided coherent blocks of sediment bounded by an outward-dipping ring-fracture, trapdoor structures with horseshoe-shaped fractures, downsag pits with centroclinal dips locally up to 60°, pits with peripheral graben and crevasses, piecemeal (highly fragmented) collapse structures and funnel-shaped pits containing disaggregated sediment. A sequence of progressive collapse is inferred in which initial downsag and subsidence on an outward-dipping ring fracture produces a small diameter pit. This is followed by widening of the pit by progressive development of concentric ring fractures and downsag outside the early formed pit, and by collapse of overhanging pit walls to produce vertical to inward-dipping walls and aprons of collapse debris on the pit floor. The various structures have potential for preservation even in regions prone to high rainfall and flooding, and they can be used to indicate that former lahars contained abundant blocks of ice.  相似文献   

A revised stratigraphic framework for later Cenozoic sequences in the northeastern Mediterranean region     

Cengiz Yetiş  Gilbert Kelling  Prof. Dr. Sungu L. Gökçen  Francois Baroz 《International Journal of Earth Sciences》1995,84(4):794-812

This study describes the lithostratigraphic character of mid-Cenozoic (Oligocene-Pliocene) sequences in different parts of the northeastern Mediterranean area and offers a detailed stratigraphic correlation for this region. The sequences concerned are drawn from the Camardi area (south-central Anatolia), the Adana Basin, the Misis Mountains and the Kyrenia Range (northern Cyprus) and the submerged Florence Rise (west of Cyprus). The stratigraphic relationships identified here indicate the following: (a) Following the middle Eocene (Lutetian) regression there was uplift throughout the entire region; (b) Episodes of fluvial and lacustrine deposition in intramontane settings ensued in most of this region during the late Eocene/early Miocene interval; (c) Following a regionally extensive phase of tectonic compression, major marine transgression commenced in the late Oligocene in northern Cyprus and in the early Miocene in adjacent southern Turkey, with the exception of the Ecemi§ Fault Zone where continental deposition continued; (d) These Oligo-Miocene transgressive sequences comprise a broadly diachronous complex of both shallow and deeper marine facies, including reefal carbonates, littoral clastics, basinal shales and fan-turbidites; (e) Deeper marine Miocene facies persisted longer in the Misis area and in northern Cyprus; (f) A regional regression occurred throughout most of the area during the late Serravallian to Tortonian interval and is marked by the abrupt, locally discordant appearance of extensive shallow marine, deltaic and fluvial deposits; (g) Continued regression in the Messinian led to the formation of significant evaporite deposits in the western and southern parts of the region, but localized uplift of the Misis area is attested by the initial deformation of the Neogene rocks there and the absence of Messinian sediments from this area; (h) In the Pliocene there was extensive emergence of the northern parts of the region interrupted by brief marine incursions. The present-day drainage pattern was established at this time; (i) Marine conditions persisted longer in northern Cyprus, where emergence occurred only in the latest Pliocene.  相似文献   

Late Quaternary barrier and fringing reef development of Bora Bora (Society Islands,south Pacific): First subsurface data from the Darwin‐type barrier‐reef system          下载免费PDF全文

Eberhard Gischler  J. Harold Hudson  Marc Humblet  Juan C. Braga  Anton Eisenhauer  Anja Isaack  Flavio S. Anselmetti  Gilbert F. Camoin 《Sedimentology》2016,63(6):1522-1549

The universally known subsidence theory of Darwin, based on Bora Bora as a model, was developed without information from the subsurface. To evaluate the influence of environmental factors on reef development, two traverses with three cores, each on the barrier and the fringing reefs of Bora Bora, were drilled and 34 uranium‐series dates obtained and subsequently analysed. Sea‐level rise and, to a lesser degree, subsidence were crucial for Holocene reef development in that they have created accommodation space and controlled reef architecture. Antecedent topography played a role as well, because the Holocene barrier reef is located on a Pleistocene barrier reef forming a topographic high. The pedestal of the fringing reef was Pleistocene soil and basalt. Barrier and fringing reefs developed contemporaneously during the Holocene. The occurrence of five coralgal assemblages indicates an upcore increase in wave energy. Age–depth plots suggest that barrier and fringing reefs have prograded during the Holocene. The Holocene fringing reef is up to 20 m thick and comprises coralgal and microbial reef sections and abundant unconsolidated sediment. Fringing reef growth started 8780 ± 50 yr bp ; accretion rates average 5·65 m kyr^?1. The barrier reef consists of >30 m thick Holocene coralgal and microbial successions. Holocene barrier‐reef growth began 10 030 ± 50 yr bp and accretion rates average 6·15 m kyr^?1. The underlying Pleistocene reef formed 116 900 ± 1100 yr bp , i.e. during marine isotope stage 5e. Based on Pleistocene age, depth and coralgal palaeobathymetry, the subsidence rate of Bora Bora was estimated to be 0·05 to 0·14 m kyr^?1. In addition to subsidence, reef development on shorter timescales like in the late Pleistocene and Holocene has been driven by glacioeustatic sea‐level changes causing alternations of periods of flooding and subaerial exposure. Comparisons with other oceanic barrier‐reef systems in Tahiti and Mayotte exhibit more differences than similarities.  相似文献   

Globular clusters as microlensing targets     

Geza Gyuk  & Gilbert P. Holder 《Monthly notices of the Royal Astronomical Society》1998,297(2):L44-L48

We investigate the possibility of using globular clusters as targets for microlensing searches. Such searches will be challenging and require more powerful telescopes than now employed, but are feasible in the near future. Although expected event rates are low, we show that the wide variety of lines of sight to globular clusters greatly enhances the ability to distinguish between halo models using microlensing observations as compared with LMC/SMC observations alone. In particular, the halo core radius and power-law exponent can be determined with good accuracy.  相似文献   

Vegetation associations in the Ougarta Mountains and dayas of the Guir hamada, Algerian Sahara     

S. S. Benhouhou  T. C. D. Dargie  O. L. Gilbert 《Journal of Arid Environments》2003,54(4):739-753

  相似文献   

Origin of Archean lamprophyre dykes,Superior Province,Canada: rare earth element and Nd−Sr isotopic evidence   总被引：1，自引：0，他引：1  

Richard A. Stern  Gilbert N. Hanson 《Contributions to Mineralogy and Petrology》1992,111(4):515-526

Hornblende- and clinopyroxene-phyric lamprophyre dykes exposed in the Roaring River Complex, Superior Province are alkaline, nepheline-normative, basaltic compositions (>50 wt% SiO₂), that range from primitive to fractionated [Mg/(Mg + total Fe)=0.66–0.40; Ni=200–35 ppm], and which have high abundances of light rare earth elements (REE) [(Ce/Yb)_n=16–26, Ce_n=60–300; n = chondrite normalized], Sr (870–1,800 ppm), P₂O₅ (0.4–1.3 wt%), and Ba (150–900 ppm). Crystal fractionation of the lamprophyres produced coeval gabbro and clinopyroxenite cumulate bodies. A whole-rock Sm–Nd isochron for lamprophyres and gabbro-pyroxenite yields a crystallization age of 2,667±51 Ma Ma (I=0.50929±0.0004; _Nd = + 2.3 0.7). Whole-rock Sr isotope data are scattered, but suggest an initial ⁸⁷Sr/⁸⁶Sr ratio of 0.7012, similar to bulk Earth. The elevated levels of light REEs and Sr in the lamprophyres were not due to crustal contamination or mixing with contemporaneous monzodioritic magmas, but a result of partial melting of a mantle source which was enriched in these and other large-ion-lithophile elements (LILEs) shortly before melting. The lamprophyres were contemporaneous with mantle-derived, high-Mg, LILE-enriched monzodiorite to granodiorite of the Archean sanukitoid suite. Both suites have concave-downward light REE profiles, suggesting that depleted mantle was common to their source regions, but the higher light REE abundances, higher Ba/La ratios, and lower _Nd values (+1.3±0.3) of the parental monzodiorites suggest a more enriched source. The lamprophyres and high-Mg monzodiorites were derived from a mineralogically and compositionally heterogeneous, LILE-enriched mantle lithosphere that may have been part of a mantle wedge above a subducting plate in an arc environment.  相似文献