排序方式: 共有29条查询结果,搜索用时 15 毫秒
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KEVIN ROBERT GURNEY RACHEL M. LAW A. SCOTT DENNING PETER J. RAYNER DAVID BAKER PHILIPPE BOUSQUET LORI BRUHWILER YU-HAN CHEN PHILIPPE CIAIS SONGMIAO FAN INEZ Y. FUNG MANUEL GLOOR MARTIN HEIMANN KAZ HIGUCHI JASMIN JOHN EVA KOWALCZYK TAKASHI MAKI SHAMIL MAKSYUTOV PHILIPPE PEYLIN MICHAEL PRATHER BERNARD C. PAK JORGE SARMIENTO SHOICHI TAGUCHI TARO TAKAHASHI CHIU-WAI YUEN 《Tellus. Series B, Chemical and physical meteorology》2003,55(2):555-579
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Deinstitutionalisation of psychiatric patients since the 1980s has introduced a new population and a new land use to New Zealand's urban areas. This paper reviews the geography of deinstitutionalisation, and investigates whether the North American phenomenon of a service-dependent ghetto can be identified in Dunedin. 相似文献
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M. J. JESSUP J. M. COTTLE M. P. SEARLE R. D. LAW D. L. NEWELL R. J. TRACY D. J. WATERS 《Journal of Metamorphic Geology》2008,26(7):717-739
U(–Th)–Pb geochronology, geothermobarometric estimates and macro‐ and micro‐structural analysis, quantify the pressure–temperature–time–deformation (P–T–t–D) history of Everest Series schist and calcsilicate preserved in the highest structural levels of the Everest region. Pristine staurolite schist from the Everest Series contains garnet with prograde compositional zoning and yields a P–T estimate of 649 ± 21 ° C, 6.2 ± 0.7 kbar. Other samples of the Everest Series contain garnet with prograde zoning and staurolite with cordierite overgrowths that yield a P–T estimate of 607 ± 25 ° C, 2.9 ± 0.6 kbar. The Lhotse detachment (LD) marks the base of the Everest Series. Structurally beneath the LD, within the Greater Himalayan Sequence (GHS), garnet zoning is homogenized, contains resorption rinds and yields peak temperature estimates of ~650 ± 50 ° C. P–T estimates record a decrease in pressure from ~6 to 3 kbar and equivalent temperatures from structurally higher positions in the overlying Everest Series, through the LD and into GHS. This transition is interpreted to result from the juxtaposition of the Everest Series in the hangingwall with the GHS footwall rocks during southward extrusion and decompression along the LD system. An age constraint for movement on the LD is provided by the crystallization age of the Nuptse granite (23.6 ± 0.7 Ma), a body that was emplaced syn‐ to post‐solid‐state fabric development. Microstructural evidence suggests that deformation in the LD progressed from a distributed ductile shear zone into the structurally higher Qomolangma detachment during the final stages of exhumation. When combined with existing geochronological, thermobarometric and structural data from the GHS and Main Central thrust zone, these results form the basis for a more complete model for the P–T–t–D evolution of rocks exposed in the Mount Everest region. 相似文献
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L. A. BARRIE Y. YI W. R. LEAITCH U. LOHMANN P. KASIBHATLA G.J. ROELOFS J. WILSON F. McGOVERN C. BENKOVITZ M. A. MÉLIÈRES K. LAW J. PROSPERO M. KRITZ D. BERGMANN C. BRIDGEMAN M. CHIN J. CHRISTENSEN R. EASTER J. FEICHTER C. LAND A. JEUKEN E. KJELLSTRÖM D. KOCH P. RASCH 《Tellus. Series B, Chemical and physical meteorology》2001,53(5):615-645
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A comparison of scavenging and deposition processes in global models: results from the WCRP Cambridge Workshop of 1995 总被引:2,自引:1,他引:1
P. J. RASCH J. FEICHTER K LAW N. MAHOWALD J. PENNER C. BENKOVITZ C. GENTHON C. GIANNAKOPOULOS P. KASIBHATLA D. KOCH H. LEVY T. MAKI M. PRATHER D. L. ROBERTS G.J. ROELOFS D. STEVENSON Z. STOCKWELL S. TAGUCHI M. KRITZ M. CHIPPERFIELD D. BALDOCCHI P. McMURRY L. BARRIE Y. BALKANSKI R. CHATFIELD E. KJELLSTROM M. LAWRENCE H. N. LEE J. LELIEVELD K. J. NOONE J. SEINFELD G. STENCHIKOV S. SCHWARTZ C. WALCEK D. WILLIAMSON 《Tellus. Series B, Chemical and physical meteorology》2000,52(4):1025-1056
We report on results from a World Climate Research Program workshop on representations of scavenging and deposition processes in global transport models of the atmosphere. 15 models were evaluated by comparing simulations of radon, lead, sulfur dioxide, and sulfate against each other, and against observations of these constituents. This paper provides a survey on the simulation differences between models. It identifies circumstances where models are consistent with observations or with each other, and where they differ from observations or with each other. The comparison shows that most models are able to simulate seasonal species concentrations near the surface over continental sites to within a factor of 2 over many regions of the globe. Models tend to agree more closely over source (continental) regions than for remote (polar and oceanic) regions. Model simulations differ most strongly in the upper troposphere for species undergoing wet scavenging processes. There are not a sufficient number of observations to characterize the climatology (long‐term average) of species undergoing wet scavenging in the upper troposphere. This highlights the need for either a different strategy for model evaluation (e.g., comparisons on an event by event basis) or many more observations of a few carefully chosen constituents. 相似文献
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湖北铜绿山矿床石英闪长岩的矿物学及Sr-Nd-Pb同位素特征 总被引:3,自引:8,他引:3
铜绿山是长江中下游鄂东南矿集区最重要的、大型夕卡岩型Cu-Fe(Au)矿床。本文对该矿区中与成矿密切的石英闪长岩进行了详细的矿物成分、地球化学及Sr-Nd-Pb同位素研究。结果表明:岩石中斜长石主要为更长石(An=21~31);角闪石贫Ti(0.2),高Mg/(Mg+Fe)(0.5),属于富镁角闪石;而黑云母为镁质黑云母。岩石的地球化学具有高硅(58.86%~67.71%),富碱(Na2O+K2O=5.67%~9.63%),富集轻稀土元素(LREE)和大离子亲石元素(LILE),并强亏损元素Nb、Ta、Ti等特征。岩石的(87Sr/86Sr)i为0.7055~0.7069,εNd(t)为-7.65~-3.44;(206Pb/204Pb)i=17.66~18.00,(207Pb/204Pb)i=15.49~15.56,(208Pb/204Pb)i=37.73~38.19。矿物成分、地球化学和同位素特征说明,铜绿山岩体与阳新岩体为同源岩浆的产物,源区为深度大于40km的富集地幔,经下地壳的混染及分离结晶作用形成。岩浆熔体形成的温度应大于889℃。角闪石和黑云母的温度计估算岩浆结晶温度分别为650~800℃和500~630℃,黑云母开始结晶温度略低于角闪石结晶结束温度,压力为1.49kbar,对应侵位深度约4.9km。岩浆具有利于Cu、Fe、Au等成矿元素进入熔体的条件,可能与板块俯冲作用相关。 相似文献
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漂浮于自由水面的污染物的的迁移、扩散会受到天然随机海浪的影响。之前的研究(以Herterich和Hasselmann(1982)为代表)普遍认为,随机波浪作用下的斯托克司漂移速度会引起水面污染物的离散,这个离散甚至有可能跟风和海流引起的离散同一量级。本研究就随机波浪作用下的斯托克司漂移速度是否会引起水面漂移物的离散进行理论和试验探讨。从理论推导可知,随机波浪下的质量输移速度是个定常分量,因此它不会随时间变化而引起水面漂移物的离散。随后我们在实验室水槽中进行了漂移物在随机波浪(P-M谱)作用下的漂移过程的测量。试验结果也印证了随机波浪作用下的斯托克司漂移速度不会引起水面漂移物离散的结论。 相似文献