Proportioning earthquake‐resistant RC frames in central/eastern U.S.     

JoAnn Browning 《地震工程与结构动力学》2002,31(6):1267-1280

A maximum allowable period criterion is used to determine reasonable stiffness requirements for reinforced concrete frames with the seismicity associated with central and eastern U.S. A general relationship is developed to describe the displacement demand expected for central and eastern U.S. based on a survey of available ground motions, opinions of seismologists, and code‐based provisions. A series of hypothetical reinforced concrete frames is proportioned using a maximum allowable period criterion and evaluated for expected maximum displacement response using non‐linear dynamic analyses and a suite of ground motions. Results indicate that for the reinforced concrete structural systems considered in the study, proportioning for gravity loads will provide sufficient stiffness in central and eastern U.S. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   

Fine-scale structure and mixing within an inversion     

C. J. Readings  E. Golton  K. A. Browning 《Boundary-Layer Meteorology》1973,4(1-4):275-287

This paper describes some of the results that were obtained in an experimental study of an inversion capping a convective boundary layer, during which a balloon-borne probe was flown through the actual interface at the same time as it was scanned by a high power 10-cm Doppler radar. The initial analysis has revealed several interesting features including the possible presence of small-scale Kelvin-Helmholtz billows at the crest of the hummocks of the inversion and the absence of an inertial subrange. A model is proposed for the transfer of sensible heatdownwards across the inversion. This is hypothesised as a two-stage process — sporadic thickening by the entrainment of air from above and below due to the action of the breaking billows, and a continual erosion of the lower surface by convective activity.  相似文献   

USENET NEWS     

Paul Browning 《地学学报》1993,5(4):405-408

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Effect of Vegetation on Landfill Stabilization     

Fred J. Molz  V. Douglas Browning 《Ground water》1977,15(6):409-415

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Structure of a Large low-Latitude Coronal Hole     

Bromage  B.J.J.  Alexander  D.  Breen  A.  Clegg  J.R.  Del Zanna  G.  DeForest  C.  Dobrzycka  D.  Gopalswamy  N.  Thompson  B.  Browning  P.K. 《Solar physics》2000,193(1-2):181-193

Coronal holes on the Sun are the source of high-speed solar wind streams that produce magnetic disturbances at the Earth. A series of multi-wavelength, multi-instrument observations obtained during the 1996 Whole Sun Month campaign examined a large coronal hole in greater detail than ever before. It appeared on the Sun in August, and extended from the north pole to a large active region in the southern hemisphere. Its physical and magnetic structure and subsequent evolution are described.  相似文献   

SOME GRAPHIC FILE UTILITIES     

Paul Browning 《地学学报》1990,2(6):665-668

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GEO LOGIC     

Paul Browning 《地学学报》1989,1(1):95-97

Let me begin by outlining the role of this column. It is aimed at European geoscientists who use personal computers. Rather than duplicating what is already discussed in the hundreds of computer magazines that can be found at any newsagent, I will concentrate on those products and services that have a particular application in the Earth Sciences. This is not to say that only those products with a specific Earth Science application will be discussed. Instead, anything that a practising geoscientist might find useful will be a candidate for review; a software package for compiling reference lists in the many styles demanded by different journals would be an example. The column will devote itself to products for IBM-PC and Mac users. I apologise in advance for the UK perspective offered in the first few articles; this reflects my ignorance of the European scene and the difficulties I have faced in overcoming it. I look forward to feedback from continental geoscientists who, I hope, will bring me up to date regarding the truly European picture.  相似文献   

PETROLOGICAL PROGRAMS FOR THE MAC 2     

Paul Browning 《地学学报》1992,4(4):514-518

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The origin of refractory minerals in comet 81P/Wild 2     

Miaofang Chi  Hope A. Ishii  Steven B. Simon  John P. Bradley  Zurong Dai  David Joswiak  Nigel D. Browning  Graciela Matrajt 《Geochimica et cosmochimica acta》2009,73(23):7150-7161

Refractory Ti-bearing minerals in the calcium-, aluminum-rich inclusion (CAI) Inti, recovered from the comet 81P/Wild 2 sample, were examined using analytical (scanning) transmission electron microscopy (STEM) methods including imaging, nanodiffraction, energy-dispersive spectroscopy (EDX) and electron energy loss spectroscopy (EELS). Inti fassaite (Ca(Mg,Ti,Al)(Si,Al)₂O₆) was found to have a Ti³⁺/Ti⁴⁺ ratio of 2.0 ± 0.2, consistent with fassaite in other solar system CAIs. The oxygen fugacity (logf_O2) of formation estimated from this ratio, assuming equilibration among phases at 1509 K, is −19.4 ± 1.3. This value is near the canonical solar nebula value (−18.1 ± 0.3) and in close agreement with that reported for fassaite-bearing Allende CAIs (−19.8 ± 0.9) by other researchers using the same assumptions. Nanocrystals of osbornite (Ti(V)N), 2–40 nm in diameter, are embedded as inclusions within gehlenite, spinel and diopside in Inti. Vanadium is heterogeneously distributed within some osbornite crystals. Compositions range from pure TiN to Ti_0.36V_0.64N. The possible presence of oxide and carbide in solid solution with the osbornite was evaluated. The osbornite may contain O, but C is not present at detectable levels. The presence of osbornite, likely a refractory early condensate, together with the other refractory minerals in Inti, indicates that the parent comet contains solids that condensed closer to the proto-sun than the distance at which the parent comet itself accreted. The estimated oxygen fugacity and the reported isotopic and chemical compositions are consistent with Inti originating in the inner solar system like other meteoritic CAIs. These results provide insight for evaluating the validity of models of radial mass transport dynamics in the early solar system. The oxidation environments inferred for the Inti mineral assemblage are inconsistent with an X-wind formation scenario. In contrast, radial mixing models that allow accretion of components from different heliocentric distances can satisfy the observations from the cometary CAI Inti.  相似文献   

Generation of a stochastic precipitation model for the tropical climate     

Ng  Jing Lin  Abd Aziz  Samsuzana  Huang  Yuk Feng  Wayayok  Aimrun  Rowshon  MK 《Theoretical and Applied Climatology》2018,133(1-2):489-509

Theoretical and Applied Climatology - A tropical country like Malaysia is characterized by intense localized precipitation with temperatures remaining relatively constant throughout the year. A...  相似文献