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131.
Elliott Stephen N.; Kratochwill Thomas R.; McKevitt Brian C.; Malecki Christine Kerres 《Canadian Metallurgical Quarterly》2009,24(4):224
The present study examined the effect accommodations have on test results of students with and without disabilities and documented experts’ judgments about the appropriateness of testing accommodations. Test score data were collected from 218 fourth-grade students with and without disabilities on mathematics and science performance tasks and from eight testing experts who evaluated the fairness and validity of a sample of testing accommodations used with these students. Results indicated that, for most students with disabilities and some students without disabilities, packages of testing accommodations had a moderate to large effect on performance task scores. Expert reviewers rated most accommodations for a student with disabilities as being both valid and fair, and they gave accommodations listed on a student’s individualized education program (IEP) significantly higher validity and fairness ratings than accommodations that were not listed on the student’s IEP. Interpretations of these data are provided and implications for practice and future research are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
132.
Rainer Dudek Ralf Doering Christine Bombach Bernd Michel 《Microelectronics Reliability》2009,49(8):839-845
Secondary effects on thermal fatigue of solder joints, which frequently have been neglected, were studied by means of the finite element method (FEM). Based on a semi-empirical approach to predict fatigue life by evaluating the cyclic accumulated equivalent creep strain or energy density, effects of organic boards intrinsic properties on solder joint fatigue were investigated. Aspects of more realistic FR-4 board modelling were studied, in particular concerning its in-plane anisotropy and intrinsic warpage behaviour. Intrinsic board warpage was measured on test board level as well as for boards from series production. High intrinsic warpage was in particular found for several test boards. The effects for the worst case scenario observed so far were analysed for both first level and second level interconnects. The change in predicted fatigue life varied between 30% and 500%, the latter most critical effects were found at large QFN components. Another secondary effect studied was to include the frequently neglected interfacial intermetallics into FEM. It turned out that for components with relatively large standoff like LFBGAs the effects were actually negligible, but for the highly miniaturized components like chip resistors CR0201 they are the decisive factor. 相似文献
133.
We analyze the determinants of the real price of crude oil by means of an equilibrium correction model over the last two decades where we focus on the aspects of the physical market that impact on the clearing price. We find that two cointegrating relations affect the changes in prices: one refers to OPEC's behavior, attempting to control prices using its market power and quotas; the other to the coverage rate of OECD expected future demand using inventory behaviors. We derive a forecasting equation for the change in oil prices which we use to assess the speculative elements of the price increases of the period 2000–05. We show that worries alien to the physical markets were the causes of the increase in oil prices and we quantify their overall impact. 相似文献
134.
Two phenolic acids were identified in the collembolan Ceratophysella denticulata: 3-hydroxy-4,5 dimethoxy benzoic acid and 4-hydroxy-3,5-dimethoxybenzoic acid (syringic acid). These are localized on or in the integument of the springtail, in field-collected animals, in a ratio of 47:100 (v/v). Springtails kept under different temperature regimes showed differences in production and ratio of the benzoic acid derivatives. At 20 degrees C, C. denticulata produced only syringic acid, whereas at 10 degrees C both isomers in a ratio of 100:61 (v/v) were detected. Bioassays with C. denticulata as well as with the specialized collembolan predator Stenus comma (Staphylinidae) were carried out. Staphylinid beetles topically treated with the acids try to clean their mouthparts by rubbing them on the ground significantly more often than do control beetles. Both compounds individually and as a natural mixture have deterrent effects towards the predator S. comma. 相似文献
135.
Colleges and universities conduct student satisfaction studies for many important policy making reasons. However the differences in instrumentation and the use of students' self-reported ratings of satisfaction makes such decisions sample-, instrument-, and institution-dependent. A common metric of student satisfaction would assist decision makers by providing a richness of information not typically obtained. The present study investigated the extent to which two nationally known instruments of student satisfaction could be scaled on the same quantitative metric. Pseudo-common item equating (Fisher, 1997) based on five link items of low and high endorsability enabled comparisons of "similar, but not identical items, from different instruments, calibrated on different samples" (p. 87). Results suggest that both instruments measured similar constructs and could be reasonably used to create a single, common metric. While samples used in the experiment were less than ideal, results clearly demonstrated the usefulness and reasonability of the pseudo-common item equating process. 相似文献
136.
137.
Scarpulla John Mozulay Robert Ausnit Christine Hogan Edward W. Casey Richard H. 《IEEE transactions on nuclear science》1980,27(6):1442-1448
Rapid annealing test results show that the hardened RCA/Sandia 1802 Bulk CMOS Microprocessor will function immediately after application of intense ionizing radiation pulses. This result was established in LINAC tests using a comprehensive test procedure which exercised the ?P in logarithmic time intervals from 10 ?s to 1000 s. It was found that no loss of functionality occurs for doses up to about 280 KRads. At 790 KRads, the device initially loses functionality but anneals in 600 ms. At 1.6 MRads, the device loses functionality for 4 s, and at 2.4 MRads, the device loses functionality for at least 1000 s. A sample size of five devices was used. The 1802 ?P was tested using hardware and software especially designed for this purpose. The microprocessor was exercised using software routines of exponentially increasing length starting at 10 ?s after the pulse. A measure of ?P functionality was therefore provided at logarithmically increasing sample times, After 2 seconds was reached, the routines repeated every two seconds up to 1000 seconds when the test ended. The hardware and software are described in detail. 相似文献
138.
139.
Michael F. Wilson Christine A. Blunden 《Journal of the science of food and agriculture》1983,34(9):973-978
The polyphenol content of three orchard pear varieties, Conference, Doyenne du Comice and Williams bon Chretien as determined between November 1981 and March 1982 as a preliminary part of a study to ascertain the basis of dietary self-selection by bullfinches. The varieties most susceptible to bird damage, Conference and Williams, were shown to contain higher levels of extractable phenolic material than the partly bird-resistant variety, Comice. There were no major intravarietal differences between buds of the same variety collected at different areas of the same site. The significance of these results is discussed. 相似文献
140.
Production and physicochemical characterization of resistant starch type III derived from pea starch 总被引:1,自引:0,他引:1
Smooth pea starch was used for the production of physiological important resistant starch type III. For reduction of the molecular weight of the starch, different strategies including enzymatic debranching and acid hydrolysis (lintnerization), were tested to obtain an optimal starting material for retrogradation. The resulting polymer chain lengths were analyzed by high-performance anion-exchange chromatography. Temperature regimes and starch concentrations in gel were optimized during the retrogradation with the aim to obtain a high yield of resistant starch. Optimal conditions led to resistant starch contents up to 74%. The products were thermostable and showed no loss of resistant structures after autoclaving. The peak temperatures of the thermal transition were at approximately 147 degrees C. The resulting resistant starch products are suitable for the generation of functional foods. 相似文献