Orbital and millennial Antarctic climate variability over the past 800,000 years   总被引：3，自引：0，他引：3  

Jouzel J  Masson-Delmotte V  Cattani O  Dreyfus G  Falourd S  Hoffmann G  Minster B  Nouet J  Barnola JM  Chappellaz J  Fischer H  Gallet JC  Johnsen S  Leuenberger M  Loulergue L  Luethi D  Oerter H  Parrenin F  Raisbeck G  Raynaud D  Schilt A  Schwander J  Selmo E  Souchez R  Spahni R  Stauffer B  Steffensen JP  Stenni B  Stocker TF  Tison JL  Werner M  Wolff EW 《Science (New York, N.Y.)》2007,317(5839):793-796

A high-resolution deuterium profile is now available along the entire European Project for Ice Coring in Antarctica Dome C ice core, extending this climate record back to marine isotope stage 20.2, approximately 800,000 years ago. Experiments performed with an atmospheric general circulation model including water isotopes support its temperature interpretation. We assessed the general correspondence between Dansgaard-Oeschger events and their smoothed Antarctic counterparts for this Dome C record, which reveals the presence of such features with similar amplitudes during previous glacial periods. We suggest that the interplay between obliquity and precession accounts for the variable intensity of interglacial periods in ice core records.  相似文献   

Response of subsoil organic matter contents and physical properties to long-term,high-rate farmyard manure application     

Frederic Leuther  Maximilian Wolff  Klaus Kaiser  Lena Schumann  Ines Merbach  Robert Mikutta  Steffen Schlüter 《European Journal of Soil Science》2022,73(2):e13233

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Plasma observations near uranus: initial results from voyager 2     

Bridge HS  Belcher JW  Coppi B  Lazarus AJ  McNutt RL  Olbert S  Richardson JD  Sands MR  Selesnick RS  Sullivan JD  Hartle RE  Ogilvie KW  Sittler EC  Bagenal F  Wolff RS  Vasyliunas VM  Siscoe GL  Goertz CK  Eviatar A 《Science (New York, N.Y.)》1986,233(4759):89-93

Extensive measurements of low-energy positive ions and electrons in the vicinity of Uranus have revealed a fully developed magnetosphere. The magnetospheric plasma has a warm component with a temperature of 4 to 50 electron volts and a peak density of roughly 2 protons per cubic centimeter, and a hot component, with a temperature of a few kiloelectron volts and a peak density of roughly 0.1 proton per cubic centimeter. The warm component is observed both inside and outside of L = 5, whereas the hot component is excluded from the region inside of that L shell. Possible sources of the plasma in the magnetosphere are the extended hydrogen corona, the solar wind, and the ionosphere. The Uranian moons do not appear to be a significant plasma source. The boundary of the hot plasma component at L = 5 may be associated either with Miranda or with the inner limit of a deeply penetrating, solar wind-driven magnetospheric convection system. The Voyager 2 spacecraft repeatedly encountered the plasma sheet in the magnetotail at locations that are consistent with a geometric model for the plasma sheet similar to that at Earth.  相似文献   

Spectral reflectance and morphologic correlations in eastern Terra Meridiani, Mars   总被引：1，自引：0，他引：1  

Arvidson RE  Poulet F  Bibring JP  Wolff M  Gendrin A  Morris RV  Freeman JJ  Langevin Y  Mangold N  Bellucci G 《Science (New York, N.Y.)》2005,307(5715):1591-1594

The Mars Express Observatoire pour la Minéralogie, l'Eau, les Glaces, et l'Activité (OMEGA) hyperspectral image data covering eastern Terra Meridiani indicate the ubiquitous presence of molecular water in etched terrain materials that disconformably overlie heavily cratered terrains and underlie the hematite-bearing plains explored by the Opportunity rover. Identification of crystalline water in kieserite (MgSO4.H2O) is linked to materials exposed in a valley and plateau to the north of hematite-bearing plains. The mineralogical similarities between the etched terrain deposits examined with OMEGA data and the layered rocks examined by Opportunity imply that the ancient aqueous environments inferred from analyses of the rover data extend over regional scales.  相似文献   

Seed lipids     

Wolff IA 《Science (New York, N.Y.)》1966,154(3753):1140-1149

Many of the newly discovered seedoil acids have reactive or unusual functional groups or other facets of molecular structure that permit their ready differentiation from oleic, linoleic, linolenic, and the other most prevalent saturated and unsaturated long-chain fatty acids. The recognition and availability of the new acids, coupled with methods that make detection and determination easy, will help studies of lipid biosynthesis in the plant and of lipid metabolism and utilization in animals, and will stimulate more studies in depth on the fine points of seedlipid structure. Correlations of structural patterns in seed lipids of particular groups of plants with classical taxonomic categories will permit clarifications, raise needed questions concerning classifications, and accelerate research in chemotaxonomy and phylogenetics. Seed lipids are particularly well suited for establishing relationships among plants because of their great variety in structure compared to the more limited structural types of amino acids, sugars, purines, and many other plant substances. The newly characterized seed oils are potentially important industrial raw materials whenever they come from agronomically promising plant species. The molecular structures of seed triglycerides have major influence on their physical properties and therefore advances in knowledge in that sphere have practical implications. For example, the unusual characteristics of cocoa butter that make it so valuable for food and confectionery use are attributed to the specific arrangement of fatty acids it its triglycerides. The glycerides are almost all 2-oleic-1,3-disaturated acid triglycerides. The physical characteristics of lard are advantageously changed by catalytically rearranging fatty acyl groups among the glycerides initially in the fat to achieve a more nearly random distribution, followed sometimes by further fractionation to remove more saturated glycerides. Through this change of glyceride structures a preferred, less grainy texture is achieved. Future studies to understand, unravel, and control seed-oil triglyceride structures will be significant in developing margarines of improved texture and "feel," cocoa-butter substitutes, and many other products. I expect rapid, fruitful progress in seedlipid research and utilization to continue. Such progress will be aided by investigation of seed lipids from a large number and variety of different plants to find new types of fatty acids, to find new sources of familiar oils, and to obtain more data regarding their glyceride structures.  相似文献   

Solar Irradiance Change and Special Longitudes Due to r-Modes     

Wolff CL  Hickey JR 《Science (New York, N.Y.)》1987,235(4796):1631-1633

Sluggish global oscillations, having a periodicity of months and trapped in the sun's convection zone, modulate the amount of energy reaching Earth and seem to impose some large-scale order on the distribution of solar surface features. These recently recognized oscillations (r-modes) increase the predictability of solar changes and may improve understanding of rotation and variability in other stars. Most of the 13 periodicities ranging from 13 to 85 days that are caused by r-modes can be detected in Nimbus 7 observations of solar irradiance during 3 years at solar maximum. These modes may also bear on the classical question of persistent longitudes of high solar activity.  相似文献   

The Spirit Rover's Athena science investigation at Gusev Crater, Mars     

Squyres SW  Arvidson RE  Bell JF  Brückner J  Cabrol NA  Calvin W  Carr MH  Christensen PR  Clark BC  Crumpler L  Des Marais DJ  D'Uston C  Economou T  Farmer J  Farrand W  Folkner W  Golombek M  Gorevan S  Grant JA  Greeley R  Grotzinger J  Haskin L  Herkenhoff KE  Hviid S  Johnson J  Klingelhöfer G  Knoll A  Landis G  Lemmon M  Li R  Madsen MB  Malin MC  McLennan SM  McSween HY  Ming DW  Moersch J  Morris RV  Parker T  Rice JW  Richter L  Rieder R  Sims M  Smith M  Smith P  Soderblom LA  Sullivan R  Wänke H  Wdowiak T  Wolff M  Yen A 《Science (New York, N.Y.)》2004,305(5685):794-799

The Mars Exploration Rover Spirit and its Athena science payload have been used to investigate a landing site in Gusev crater. Gusev is hypothesized to be the site of a former lake, but no clear evidence for lacustrine sedimentation has been found to date. Instead, the dominant lithology is basalt, and the dominant geologic processes are impact events and eolian transport. Many rocks exhibit coatings and other characteristics that may be evidence for minor aqueous alteration. Any lacustrine sediments that may exist at this location within Gusev apparently have been buried by lavas that have undergone subsequent impact disruption.  相似文献   

Comparative growth and mortality of cultured Lion's Paw scallops (Nodipecten subnodosus) from Gulf of California and Pacific populations and their reciprocal transplants          下载免费PDF全文

Volker Koch  Anna Rengstorf  Marc Taylor  José M. Mazón‐Suástegui  Francisco Sinsel  Matthias Wolff 《Aquaculture Research》2015,46(1):185-201

This study focused on the comparison of growth and mortality of Lion's Paw scallops Nodipecten subnodosus from Gulf of California and Pacific populations and their reciprocal transplants, cultured in suspended module and bottom culture in Baja California Sur, Mexico. Environmental parameters were monitored to determine site‐specific differences and were correlated with scallops' population‐specific responses. Significant differences in growth were found between sites, populations and grow‐out methods. Growth performance of scallops originating from the Pacific population was lower and uniform between Pacific and Gulf culture sites, whereas Gulf scallops cultured at the Pacific site grew better. Growth and survival was higher in suspended than bottom culture, mainly due to depth‐associated differences in food and oxygen supply. Increasing temperatures and decreasing food and oxygen during summer months resulted in depressed growth and elevated mortality. At the Pacific site, this was partially compensated by considerably higher food availability. Gulf scallops resisted high diurnal temperature changes at San Buto significantly better than Pacific scallops. They also survived generally better than the Pacific population, independent of site and grow‐out method, indicating physiological adaptations to high temperatures and low food availability in their habitat. Consequently, the Gulf population appears to be more feasible for aquaculture operations in coastal lagoons with stressful conditions.  相似文献   

The association between farmers’ participation in herd health programmes and their behaviour concerning treatment of mild clinical mastitis     

Ann-Kristina Lind  Peter T Thomsen  Simo Rintakoski  Mari N Espetvedt  Cecilia Wolff  Hans Houe 《Acta veterinaria Scandinavica》2012,54(1):62

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Optical Environment about the OGO-III Satellite     

Wolff C 《Science (New York, N.Y.)》1967,158(3804):1045-1046

An upper limit to the brightness of the daytime sky near a large unmanned satellite has been obtained; it is some 30 times less than the darkest daytime sky yet reported by an astronaut. However, there still remains the danger that this background light (less than 5 x 10(-13) as bright as the sun) will interfere with observations of the solar corona and zodiacal light.  相似文献