A review of research on seismic behaviour of irregular building structures since 2002   总被引：1，自引：1，他引：0  

Mario De Stefano  Barbara Pintucchi 《Bulletin of Earthquake Engineering》2008,6(2):285-308

The paper presents an overview of the progress in research regarding seismic response of plan and vertically irregular building structures. Three areas of research are surveyed. The first is the study of the effects of plan-irregularity by means of single-storey and multi-storey building models. The second area encompasses passive control as a strategy to mitigate torsional effects, by means of base isolation and other types of devices. Lastly, the third area concerns vertically irregular structures and setback buildings. Although fewer papers have been published in this last area with respect to the former ones, this state-of-the-art reports extensively on research efforts and progress into the seismic behaviour of irregular buildings in elevation to show the growing interest among specialists in the field.  相似文献   

A 2000 year varve-based climate record from the central Brooks Range,Alaska     

Broxton W. Bird  Mark B. Abbott  Bruce P. Finney  Barbara Kutchko 《Journal of Paleolimnology》2009,41(1):25-41

Varved minerogenic sediments from glacial-fed Blue Lake, northern Alaska, are used to investigate late Holocene climate variability. Varve-thickness measurements track summer temperature recorded at Atigun Pass, located 41 km east at a similar elevation (r ² = 0.31, P = 0.08). Results indicate that climate in the Brooks Range from 10 to 730 AD (varve year) was warm with precipitation inferred to be higher than during the twentieth century. The varve-temperature relationship for this period was likely compromised and not used in our temperature reconstruction because the glacier was greatly reduced, or absent, exposing sub-glacial sediments to erosion from enhanced precipitation. Varve-inferred summer temperatures and precipitation decreased after 730 AD, averaging 0.4°C above the last millennial average (LMA = 4.2°C) from 730 to 850 AD, and 0.1°C above the LMA from 850 to 980 AD. Cooling culminated between 980 and 1030 AD with temperatures 0.7°C below the LMA. Varve-inferred summer temperatures increased between 1030 and 1620 AD to the LMA, though the period between 1260 and 1350 AD was 0.2°C below the LMA. Although there is no equivalent to the European Medieval Warm Period in the Blue Lake record, two warm intervals occurred from 1350 to 1450 AD and 1500 to 1620 AD (0.4 and 0.3°C above the LMA, respectively). During the Little Ice Age (LIA; 1620 to 1880 AD), inferred summer temperature averaged 0.2°C below the LMA. After 1880 AD, inferred summer temperature increased to 0.8°C above the LMA, glaciers retreated, but aridity persisted based on a number of regional paleoclimate records. Despite warming and glacial retreat, varve thicknesses have not achieved pre-730 AD levels. This reflects limited sediment availability and transport due to a less extensive retreat compared to the first millennium, and continued relative aridity. Overall, the Blue Lake record is similar to varve records from the eastern Canadian Arctic that document a cool LIA and twentieth century warming. However, the occurrence and timing of events, such as the LIA and Medieval Warm Period, varies considerably among records, suggesting heterogeneous climatic patterns across the North American Arctic.

Broxton W. BirdEmail:

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Integrating a calibrated groundwater flow model with error-correcting data-driven models to improve predictions     

Yonas K. Demissie  Albert J. Valocchi  Barbara S. Minsker  Barbara A. Bailey 《Journal of Hydrology》2009,364(3-4):257-271

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Microbial populations in contaminant plumes   总被引：4，自引：1，他引：3  

Sheridan K. Haack  Barbara A. Bekins 《Hydrogeology Journal》2000,8(1):63-76

Received, May 1999/Revised, October 1999/Accepted, October 1999  相似文献   

Evolution of White-Light Flares Observed by YOHKOH     

Sylwester  Barbara  Sylwester  Janusz 《Solar physics》2000,194(2):305-325

We consider in detail the evolutionary patterns of few white-light flares observed by Yohkoh. The following data have been used in the analysis: sequences of de-convolved SXT images in X-ray and optical filters, MEM reconstructed HXT images and the other supporting data. The resolution in the de-convolved images is below 1 arc sec. Working with sequences of de-convolved images makes it also possible to investigate the dynamics of these structures with high spatial accuracy. Comparison of the morphology of flare brightenings as observed in hard, soft and optical ranges reveals that these emissions are not co-spatial and are most probably related to different plasma volumes at any instant. These observations cannot be easily accommodated within standard flare scenarios. Traditionally, the hard and optical flare emissions are expected to be co-spatial and the soft X-ray emission is presumed to fill the coronal portion of flaring loop(s) during rise phase. Present observations do not easily fit to such scenario.  相似文献   

The Leannan Fault in the Malin Head Peninsula,Co. Donegal,Eire     

Barbara Dickinson 《Geological Journal》1973,8(2):399-405

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A reassessment appraised: Comment on “Hornblende KAr ages and the climax of Tertiary metamorphism in the Lepontine Alps (south-central Switzerland): an old problem reassessed”—reply to Peter K. Zeitler and Jan R. Wijbrans     

Alexander Deutsch  Rudolf H. Steiger 《Earth and Planetary Science Letters》1986,76(3-4)

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Magnetism of igneous rocks from the Tourmakeady and Glensaul inliers, W. Ireland: mode of emplacement and aspects of the Ordovician field pattern     

E. R. Deutsch  K. M. Storetvedt 《Geophysical Journal International》1988,92(2):223-234

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Biogeographical drivers of ragweed pollen concentrations in Europe     

Matyasovszky  István  Makra  László  Tusnády  Gábor  Csépe  Zoltán  Nyúl  László G.  Chapman  Daniel S.  Sümeghy  Zoltán  Szűcs  Gábor  Páldy  Anna  Magyar  Donát  Mányoki  Gergely  Erostyák  János  Bodnár  Károly  Bergmann  Karl-Christian  Deák  Áron József  Thibaudon  Michel  Albertini  Roberto  Bonini  Maira  Šikoparija  Branko  Radišić  Predrag  Gehrig  Regula  Rybníček  Ondřej  Severova  Elena  Rodinkova  Victoria  Prikhodko  Alexander  Maleeva  Anna  Stjepanović  Barbara  Ianovici  Nicoleta  Berger  Uwe  Seliger  Andreja Kofol  Weryszko-Chmielewska  Elżbieta  Šaulienė  Ingrida  Shalaboda  Valentina  Yankova  Raina  Peternel  Renata  Ščevková  Jana  Bullock  James M. 《Theoretical and Applied Climatology》2018,133(1-2):277-295

Theoretical and Applied Climatology - The drivers of spatial variation in ragweed pollen concentrations, contributing to severe allergic rhinitis and asthma, are poorly quantified. We analysed the...  相似文献   

The ecological implications of a Yakutian mammoth's last meal   总被引：1，自引：0，他引：1  

Bas van Geel  Andr Aptroot  Claudia Baittinger  Hilary H. Birks  Ian D. Bull  Hugh B. Cross  Richard P. Evershed  Barbara Gravendeel  Erwin J.O. Kompanje  Peter Kuperus  Dick Mol  Klaas G.J. Nierop  Jan Peter Pals  Alexei N. Tikhonov  Guido van Reenen  Peter H. van Tienderen 《Quaternary Research》2008,69(3):361-376

Part of a large male woolly mammoth (Mammuthus primigenius) was preserved in permafrost in northern Yakutia. It was radiocarbon dated to ca. 18,500 ¹⁴C yr BP (ca. 22,500 cal yr BP). Dung from the lower intestine was subjected to a multiproxy array of microscopic, chemical, and molecular techniques to reconstruct the diet, the season of death, and the paleoenvironment. Pollen and plant macro-remains showed that grasses and sedges were the main food, with considerable amounts of dwarf willow twigs and a variety of herbs and mosses. Analyses of 110-bp fragments of the plastid rbcL gene amplified from DNA and of organic compounds supplemented the microscopic identifications. Fruit-bodies of dung-inhabiting Ascomycete fungi which develop after at least one week of exposure to air were found inside the intestine. Therefore the mammoth had eaten dung. It was probably mammoth dung as no bile acids were detected among the fecal biomarkers analysed. The plant assemblage and the presence of the first spring vessels of terminal tree-rings of dwarf willows indicated that the animal died in early spring. The mammoth lived in extensive cold treeless grassland vegetation interspersed with wetter, more productive meadows. The study demonstrated the paleoecological potential of several biochemical analytical techniques.  相似文献