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您的检索式：作者名="David C.Harris"
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| 1 | 分析和选择教学策略及方法显示文摘一般的教学设计模式都少不了“依据教学内容和学生的需要制定教学策略”这一环节(Andrew& Goodson,1980,p.5),然而在各种教学设计模式中,教学策略的含义和目的却大相径庭。传统的教学设计模式常把教学策略等同于选择教学传递方式(如讲授、演示、计算机辅助教学等)和教学支持活动(如练习、辅导)(Tracey,Flynn,& Legere,1970)。如果把这些教学策略的概念与精细加工理论(Reigeluth& Stein,1983)所提出的“包容性排序,自我调整、综合、总结和激活认知策略”等教学策略作一比较,我们不难看出不同的教学设计人员对教学策略的定义并不一致,许多所谓的教学策略其实只是呈现方式而已。本文首先对交互式教学设计模式中的教学策略及其教学方法加以界定和区分,然后列举出一系列教学策略和教学方法,最后提出帮助设计人员优选教学方法的决策思路。 | David H.Jonassen R.Scott Grabinger N.Duncan C.Harris 褚献华 | 2004 | 远程教育杂志2004，22，3： | 12 |
| 2 | Geomechanical properties will constrain CO_(2)injection into the lower Ordovician Rose Run sandstone deep saline reservoir,Appalachian Basin,Kentucky,USA显示文摘The Kentucky Geological Survey(KGS)1 Hanson Aggregates stratigraphic research well,Carter County,Kentucky,USA,was drilled to a total depth of 1474 m as a field-scale test of potential CO2 storage reservoir properties in the Central Appalachian Basin.Geomechanical properties of the Rose Run sandstone(upper Ordovician Knox group)were tested for its suitability as a storage reservoir.A 9.8-m thick section of the Rose Run was penetrated at 1000 m drilled depth and a whole-diameter core and rotary sidewall cores were taken.Average porosity and permeability measured in core plugs were 9.1%and 44.6 mD,respectively.Maximum vertical stress gradient calculated in the wellbore was 26 MPa/km.Wellbore fractures in dolomites underlying and overlying the Rose Run follow the contemporary N53E Appalachian Basin stress field.The Rose Run elastic geomechanical properties were calibrated to values measured in core plugs to evaluate its fracturing risk as a CO2 storage reservoir.Mean Young’s modulus and Poisson’s ratio values of the Rose Run were 45 GPa and 0.23,respectively,whereas Young’s modulus and Poisson’s ratio values were 77.1 GPa and 0.28,respectively,in the overlying Beekmantown dolomite,suggesting the Rose Run may fracture if overpressured during CO2 injection but be confined by the Beekmantown.Triaxial compressive strength measured in core plugs found the Rose Run and Beekmantown fractured at mean axial stresses of 156.5 MPa and 282.2 MPa,respectively,confirming the Beekmantown as suitable for confining CO2 injected into the Rose Run.A step-rate test was conducted in a mechanically-isolated 18.6-m interval bracketing the Rose Run.Static Rose Run reservoir pressure was 9.3 MPa,and fracture gradient under injection was 13.6 MPa/km,suggesting step-rate testing before CO2 injection,and subsequent pressure monitoring to ensure confinement.As the region around the KGS 1 Hanson Aggregates well is underpressured and adjacent to faulted Precambrian basement,further research is needed to evaluate its induced seismicity risk during CO2 injection. | John Richard Bowersox Stephen F.Greb Junfeng Zhu David C.Harris | 2021 | Journal of Rock Mechanics and Geotechnical Engineering2021，13，5： | 0 |
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