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1.
Glasses containing lead, bismuth, or antimony oxides or combinations of these become conducting after several hours’ reduction in hydrogen. The electronic surface conductivity is both stable and reproducible. The magnitude of the conductivity depends on the nature and amounts of the reducible oxides, the temperatures at which reduction is carried out, and the electrical influence of the nonreduced portions of the glasses. 相似文献
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College students (n = 140) were examined to test whether sensation seeking and perceived stress would predict abuse of the Internet. Previous studies have found that disinhibition, boredom susceptibility, and total sensation seeking scores were related to Internet abuse ( 9 and 30). Because stress has been documented to have a negative effect on students ( Pierceall & Keim, 2007), and may be linked to Internet use ( Lavoie & Pychyl, 2001), it was tested as a possible predictor of Internet abuse. This study also analyzed abuse of the Internet for sexual purposes, because sexuality is prevalent online, and college students are in an age of sexual exploration. Results of stepwise regression analyses revealed that disinhibition and total perceived stress were predictive of Internet abuse for sexual purposes, and perceived hopelessness and boredom susceptibility were predictive of Internet abuse for non-sexual purposes. Implications for students and Internet abuse are discussed. 相似文献
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Katharine M. Marko Edward S. Rutherford Brian J. Eadie Thomas H. Johengen Margaret B. Lansing 《Journal of Great Lakes research》2013
Drowned river mouth lakes are major features of coastal Great Lakes habitats and may influence nutrient and organic matter contributions from watersheds to near shore coastal zones. In May through October 2003, we measured loads of nutrients, surficial sediment, and seston to track the delivery of riverine-derived materials from the lower Muskegon River Watershed (MRW) into the near shore area of southeast Lake Michigan. Nutrient flux data indicated that seasonal loads of 1800 metric tons (MT) of particulate organic carbon, 3400 MT of dissolved organic carbon, and 24 MT of total phosphorus were discharged from the lower Muskegon River, with approximately 33% of TP load and 53% of the POC load intercepted within the drowned river mouth terminus, Muskegon Lake. Carbon: phosphorus molar ratios of seston in Muskegon River (C:P = 187) and Muskegon Lake (C:P = 176) were lower than in Lake Michigan (C:P = 334), indicating phosphorus limitation of phytoplankton in near shore Lake Michigan. Isotopic signatures of seston collected in Muskegon Lake were depleted in δ13C (− 30.8 ± 1.6‰) relative to the isotope signatures of seston from Lake Michigan (− 26.2 ± 1.3‰) or the mouth of the Muskegon River (− 28.1 ± 0.5‰), likely due to the presence of biogenic methane in Muskegon Lake. Seston δ15N increased on a strong east-to-west gradient within Muskegon Lake, indicating significant microbial processing of nutrients. The extent of nutrient uptake in Muskegon Lake altered the chemical and isotopic characterization of seston flowing into Lake Michigan from Muskegon River. 相似文献
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Sarah J. Wakes Tanja Maegli Katharine J. Dickinson Mike J. Hilton 《Environmental Modelling & Software》2010,25(2):237-247
Numerical modelling of wind flow over complex dune topography is an ambitious prospect. There is an increasing need to understand wind flow over complex topography for land planning purposes to enable prediction of sediment transport at a particular site. New surveying techniques permit the rapid development of digital terrain models, however a stumbling block is the ability of Computational Fluid Dynamics (CFD) to emulate the wind flow over such a landscape. To overcome these difficulties, it is important to establish the parameters within which such simulations can operate. This paper details an initial two-dimensional numerical model developed in order to test various modelling assumptions against experimental field wind data. Mason Bay, Stewart Island, New Zealand was chosen as an undisturbed but accessible experimental site with a prevalent on-shore wind perpendicular to a simple foredune and a complex down-wind parabolic dune system. A complex topographical two-dimensional model with vegetation represented as a roughness was compared against field data along a transect dissecting a dune system.This paper establishes that:
- * Replicating the roughness patterns at the surface is important
- * The inlet profile should be duplicated with care
- * Modelling only a portion of the domain can have an effect on the flow patterns due to outflow effects
- * There is a modelling decision to be made between the complexity of the topography and the sophistication of the turbulence model and degree to which vegetation and sand transportation are modelled.
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Katharine A. Martindale 《Planning Theory & Practice》2013,14(4):642-644
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Bradley Katharine A.; Bush Kristen R.; Davis Tania M.; Dobie Dorcas J.; Burman Marcia L.; Rutter Carolyn M.; Kivlahan Daniel R. 《Canadian Metallurgical Quarterly》2001,15(4):297
This study evaluated the prevalence and associated risks of binge drinking, defined as having ≥4 drinks on an occasion in the past year, in a female patient population. Of 1,259 female Veterans Affairs patients surveyed, 780 reported drinking alcohol in the past year, and 305 (24% of respondents, 39% of drinkers) reported binge drinking in the past year; 84 (11% of drinkers) had done so monthly or more often. Age-adjusted logistic regression analyses indicated that women who reported past-year binge drinking monthly or more often reported significantly increased odds of morning drinking (odds ratio [OR]?=?40.3), others worrying about their drinking (OR?=?38.6), arguments after drinking (OR?=?13.5), hepatitis or cirrhosis (OR?=?3. 1), frequent injuries (OR?=?2.6), smoking (OR?=?3.7), drug use (OR?=?22.2), and multiple sexual partners (OR?=?4.6). (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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This article examines individual differences (extraversion and neuroticism), environmental factors (social support and work demand), and situational characteristics (type of stressful episode and its perceived importance) as predictors of three self-report measures of coping (general coping, direct coping, and suppression) derived from the Ways of Coping Questionnaire. The data analyzed were collected from 135 first-year female student nurses. Individual differences were assessed prior to exposure to the ward environment, and information about stressful episodes was obtained during the initial period of nursing practice. Multiple regression analyses showed that individual differences and environmental and situational factors were significant predictors of the coping scores and that patterns of main and interactive effects were different for each type of coping. For direct coping and suppression, predicted interactions across person, environmental, and situational variables contributed significantly to the explained variance. Curvilinear interactions between work demand and neuroticism were significant for both direct coping and suppression; interactions of social support and extraversion with perceived importance predicted direct coping; and interactions between neuroticism and extraversion and between work demand and importance predicted suppression. (70 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献