显性语法知识传授中的发现原则     

PatMoore 《成都信息工程学院学报》2002,17(4):289-299

尽管语法在交际教学法鼎盛时期一度遭到冷遇，但现在又重新被英语语言教学所接纳，作为一种新的语法教学方式，发现原则综合了传统归纳发和演绎法的长处，概述了发现原则的理论依据，指出发现原则旨在鼓励学习者积极参与而非被动接受，符合当前认知主义对二语学习的认识。  相似文献   

Development of a passive transform margin: Côte d’Ivoire–Ghana transform margin – ODP Leg 159 preliminary results     

Jean Mascle  Pat Lohmann  Peter Clift 《Geo-Marine Letters》1997,17(1):4-11

The Côte d’Ivoire–Ghana transform margin is bounded to the south by a prominent marginal ridge. ODP Leg 159 shipboard analyses on sediments from four sites document three distinct transform margin sedimentary and tectonic stages of evolution: (1)?an intracontinental stage of transform faulting recorded in deformed lacustrine to marine siliciclastic sequences; (2)?a marginal ridge uplift stage, recorded by shallow water limestones, appears coeval with the passing of a hot, oceanic spreading center just south of the sediment wedge; and (3)?cool ing subsidence of the transform margin recorded in bathyal to abyssal sediments emphasizes a passive margin stage. These results are consistent with previously published models of evolution.  相似文献   

An analysis of morphological characters of Owenia useful to distinguish species: description of three new species of Owenia (Oweniidae: Polychaeta) from Australian waters     

Evan Ford  & Pat Hutchings 《Marine Ecology》2005,26(3-4):181-196

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Habitat Provision for Meiofauna by Fucus serratus Epifauna with Particular Data on the Flatworm Monocelis lineata     

Pat J. S.  Boaden 《Marine Ecology》1996,17(1-3):67-75

Abstract. Fucus serratus provides a habitable site For much epifauna if conditions are right. Epifaunal colonies in their turn as well Provide habitats in which meiofauna can dwell. Thus micro-environment is provided which is Dependent on colony-species, -size and silt for its riches. Analysis of population data shows the facts are Turbellarian abundance rarely relates to other taxa, However the flatworms' population count Closely relates to total meiofaunal amount. Experiments on bryozoan-choice by Monocelis lineata show This worm prefers Flustrellidra as a place to go. This may in part be due to thigmotactic deference But mainly seems related to a feeding preference. In addition to behaviour towards food and concavity, Responses are shown to light, temperature, current and gravity. In the discussion thus it is partly explained How meiofauna finds epifauna and there is maintained.  相似文献   

Reply to 'Can magnetic-force microscopy determine micromagnetic structures?' by Grütter and Allenspach     

W. Williams  V. Hoffmann  F. Heider  T. Göddenhenrich  C. Heiden 《Geophysical Journal International》1994,116(2):506-507

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Rock Magnetic Investigation of Historical Lavas Used in Palaeointensity Studies     

Muxworthy  Adrian R.  Heider  Franz 《Studia Geophysica et Geodaetica》2001,45(3):283-296

Five samples from historical lava flows on Mt. Etna, which had previously been used in a palaeointensity study, were examined using a combination of rock magnetic and microscopic techniques to elucidate the causes of failure of palaeointensity determination. The samples were characterised using a combination of low-temperature susceptibility (LT-), Bitter pattern imaging and scanning electron microscope (SEM). High-temperature susceptibility curves and hysteresis loops had been previously measured by Calvo et al. (2001). Of the five samples only one gave an accurate palaeointensity. This sample was deuterically oxidised and consisted of large exsolved ore grains. It was only possible to distinguish this sample either optically or magnetically from a similar sample by the LT- warming curves; the unsuccessful sample displayed alteration in the LT- warming curves, which was not readily observed in the high temperature susceptibility curves. It is proposed that the measurement of LT- curves before and after heating could be a more sensitive method of determining suitability for palaeointensity determination than previous rock magnetic pre-selection techniques.  相似文献   

Occurrence of a regular C₂₅ isoprenoid hydrocarbon in tertiary sediments representing a lagoonal-type,saline environment     

Douglas W Waples  Pat Haug  Dietrich H Welte 《Geochimica et cosmochimica acta》1974,38(3):381-387

A regular C₂₅ isoprenoid alkane (2,6,10,14,18-pentamethyleicosane) has been isolated from highly saline Tertiary sediments. The isolation utilized elution chromatography, urea adduction and gas chromatography; identification was based on the mass spectrum. This C₂₅ isoprenoid may represent a biological marker, possibly typical for a lagoonal-type, saline environment.  相似文献   

Satellite-based assessment of large-scale land cover change in Asian arid regions in the period of 2001–2009     

Jaeil Cho  Yang-Won Lee  Pat J.-F. Yeh  Kyung-Soo Han  Shinjiro Kanae 《Environmental Earth Sciences》2014,71(9):3935-3944

Arid regions in Asia are commonly characterized by rapidly growing populations with limited land resources and varying rainfall frequencies under climatic change. Despite being one of the most important environmental challenges in Asia, the changing aridity in this region, particularly due to large-scale land cover change, has not been well documented. In this study, we used rainfall data and a new land heterogeneity index to identify recent trend in land cover changes in the Asian arid regions. The result indicates a significant decreasing trend of barren lands and an increasing trend of vegetated lands. Although the potential land cover change is commonly believed to be strongly sensitive to rainfall change, such sensitivity has not been observed during the nine-year period (2001–2009) analyzed. Through the analyses of two separate periods (2001–2005 and 2005–2009), the sensitivity of rainfall to land cover change in arid regions is found to be dependent on the initial spatial heterogeneity of vegetated land cover. The approach used and the findings in this study represent an important step toward better understanding of large-scale land cover change in the Asian arid regions, and have the potential to predict future land cover change under various climate change scenarios.  相似文献   

Public involvement in extra-solar planet detection     

Pat Dasch 《Astrophysics and Space Science》1996,241(1):147-153

A survey of recent popular literature on planet detection was undertaken to develop a broad view of public reactions to a program to search for planets around other stars. In this article, I discuss the interest in extra-solar planet searches, compared to other space ventures in the current political and economic climate. I also describe the role of the press and the need for public support to develop a nationally-funded space science program.  相似文献   

Using analytic element models to delineate drinking water source protection areas     

Raymond HA  Bondoc M  McGinnis J  Metropulos K  Heider P  Reed A  Saines S 《Ground water》2006,44(1):16-23

Since 1999, Ohio EPA hydrogeologists have used two analytic element models (AEMs), the proprietary software GFLOW and U.S. EPA's WhAEM, to delineate protection areas for 535 public water systems. Both models now use the GFLOW2001 solution engine, integrate well with Geographic Information System (GIS) technology, have a user-friendly graphical interface, are capable of simulating a variety of complex hydrogeologic settings, and do not rely upon a model grid. These features simplify the modeling process and enable AEMs to bridge the gap between existing simplistic delineation methods and more complex numerical models. Ohio EPA hydrogeologists demonstrated that WhAEM2000 and GFLOW2000 were capable of producing capture zones similar to more widely accepted models by applying the AEMs to eight sites that had been previously delineated using other methods. After the Ohio EPA delineated protection areas using AEMs, more simplistic delineation methods used by other states (volumetric equation and arbitrary fixed radii) were applied to the same water systems to compare the differences between various methods. GIS software and two-tailed paired t-tests were used to quantify the differences in protection areas and analyze the data. The results of this analysis demonstrate that AEMs typically produce significantly different protection areas than the most simplistic delineation methods, in terms of total area and shape. If the volumetric equation had been used instead of AEMs, Ohio would not have protected 265 km2 of critical upgradient area and would have overprotected 269 km2 of primarily downgradient land. Since an increasing number of land-use restrictions are being tied to drinking water protection areas, this analysis has broad policy implications.  相似文献