12,378 research outputs found

    Early production of the passive in two Eastern Bantu languages

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    The passive construction is acquired relatively late by children learning to speak many languages, with verbal passives not fully acquired till age 6 in English. In other languages it appears earlier, around age 3 or before. Use of passive construction in young children was examined in two Eastern Bantu languages spoken in Kenya (Kiswahili and Kigiriama), both with frequent use of passive. The passive was used productively very early (2;1) in these languages, regardless of the method used to measure productivity. In addition non-actional passives, particularly rare in English and some other European languages, were seen at these early ages. The proportion of verbs that were passive varied between individuals, both in children's speech and in the input to children. Pragmatic and grammatical features of the passive in some languages have previously been suggested to drive early passive acquisition, but these features are not found consistently in the two languages studied here. Findings suggest that the relatively high frequency of input found in these languages is the most plausible reason for early productive use of the passive

    Data on Apollo 11 and 12 samples. Speculations on petrologic differentiation Final report

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    Petrologic and mineralogic studies of Apollo 11 and 12 lunar rock

    Effect of surface roughness on the microwave emission from soils

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    The effect of surface roughness on the brightness temperature of a moist terrain was studied through the modification of Fresnel reflection coefficient and using the radiative transfer equation. The modification involves introduction of a single parameter to characterize the roughness. It is shown that this parameter depends on both the surface height variance and the horizontal scale of the roughness. Model calculations are in good quantitative agreement with the observed dependence of the brightness temperature on the moisture content in the surface layer. Data from truck mounted and airborne radiometers are presented for comparison. The results indicate that the roughness effects are greatest for wet soils where the difference between smooth and rough surfaces can be as great as 50K

    Levinson's Theorem for Non-local Interactions in Two Dimensions

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    In the light of the Sturm-Liouville theorem, the Levinson theorem for the Schr\"{o}dinger equation with both local and non-local cylindrically symmetric potentials is studied. It is proved that the two-dimensional Levinson theorem holds for the case with both local and non-local cylindrically symmetric cutoff potentials, which is not necessarily separable. In addition, the problems related to the positive-energy bound states and the physically redundant state are also discussed in this paper.Comment: Latex 11 pages, no figure, submitted to J. Phys. A Email: [email protected], [email protected]

    Investigation of remote sensing techniques of measuring soil moisture

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    Major activities described include development and evaluation of theoretical models that describe both active and passive microwave sensing of soil moisture, the evaluation of these models for their applicability, the execution of a controlled field experiment during which passive microwave measurements were acquired to validate these models, and evaluation of previously acquired aircraft microwave measurements. The development of a root zone soil water and soil temperature profile model and the calibration and evaluation of gamma ray attenuation probes for measuring soil moisture profiles are considered. The analysis of spatial variability of soil information as related to remote sensing is discussed as well as the implementation of an instrumented field site for acquisition of soil moisture and meteorologic information for use in validating the soil water profile and soil temperature profile models

    Formalism for obtaining nuclear momentum distributions by the Deep Inelastic Neutron Scattering technique

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    We present a new formalism to obtain momentum distributions in condensed matter from Neutron Compton Profiles measured by the Deep Inelastic Neutron Scattering technique. The formalism describes exactly the Neutron Compton Profiles as an integral in the momentum variable yy. As a result we obtain a Volterra equation of the first kind that relates the experimentally measured magnitude with the momentum distributions of the nuclei in the sample. The integration kernel is related with the incident neutron spectrum, the total cross section of the filter analyzer and the detectors efficiency function. A comparison of the present formalism with the customarily employed approximation based on a convolution of the momentum distribution with a resolution function is presented. We describe the inaccuracies that the use of this approximation produces, and propose a new data treatment procedure based on the present formalism.Comment: 11 pages, 8 figure

    Number development and children with Specific Language Impairment.

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    The aims of this chapter is to investigate whether the number skills of children with specific language impairment (SLI) differ from those of their typically developing peers, matched in nonverbal reasoning, and a group of younger typically developing children matched on language comprehension. It assesses whether small number quantification accuracy accounts for additional variation in number tasks beyond the other influences. How children develop competence with numbers and why they differ so much in their progress are important questions whether one is concerned with numeracy, the skills and knowledge for dealing with numerical information in everyday life, or mathematics, the sciences dealing with the logic of quantity, shape, and arrangement. The study of number development in children with SLI has the potential to contribute both to the understanding of the factors that influence children's progress generally and to the knowledge base for professionals working with these children. Previous work on number in children with SLI had indicated selective impairments: children with SLI showed impaired procedural skills, particularly in counting, from an early age but less impaired understanding of number, for example counting principles. An investigation of children with SLI provided ample evidence of the continuing deficit in counting and calculation

    Microwave soil moisture measurements and analysis

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    An effort to develop a model that simulates the distribution of water content and of temperature in bare soil is documented. The field experimental set up designed to acquire the data to test this model is described. The microwave signature acquisition system (MSAS) field measurements acquired in Colby, Kansas during the summer of 1978 are pesented

    Terminal velocity and drag reduction measurements on superhydrophobic spheres

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    Super water-repellent surfaces occur naturally on plants and aquatic insects and are created in the laboratory by combining micro- or nanoscale surface topographic features with hydrophobic surface chemistry. When such types of water-repellent surfaces are submerged they can retain a film of air (a plastron). In this work, we report measurements of the terminal velocity of solid acrylic spheres with various surface treatments settling under the action of gravity in water. We observed increases in terminal velocity corresponding to drag reduction of between 5% and 15% for superhydrophobic surfaces that carry plastrons

    Evidence of Double Phonon Excitations in ^{16}O + ^{208}Pb Reaction

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    The fusion cross-sections for ^{16}O + ^{208}Pb, measured to high precision, enable the extraction of the distribution of fusion barriers. This shows a structure markedly different from the single-barrier which might be expected for fusion of two doubly-closed shell nuclei. The results of exact coupled channel calculations performed to understand the observations are presented. These calculations indicate that coupling to a double octupole phonon excited state in ^{208}Pb is necessary to explain the experimental barrier distributions.Comment: 6 pages, 2 figures, To be published in the Proceedings of the FUSION 97 Conference, South Durras, Australia, March 1997 (J. Phys. G
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