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排序方式: 共有195条查询结果,搜索用时 78 毫秒
1.
Purdy W.E. Gaiser P.W. Poe G.A. Uliana E.A. Meissner T. Wentz F.J. 《Geoscience and Remote Sensing, IEEE Transactions on》2006,44(3):496-505
Geolocation and pointing accuracy analyses of the WindSat flight data are presented. The two topics were intertwined in the flight data analysis and will be addressed together. WindSat has no unusual geolocation requirements relative to other sensors, but its beam pointing knowledge accuracy is especially critical to support accurate polarimetric radiometry. Pointing accuracy was improved and verified using geolocation analysis in conjunction with scan bias analysis. Two methods were needed to properly identify and differentiate between data time tagging and pointing knowledge errors. Matchups comparing coastlines indicated in imagery data with their known geographic locations were used to identify geolocation errors. These coastline matchups showed possible pointing errors with ambiguities as to the true source of the errors. Scan bias analysis of U, the third Stokes parameter, and of vertical and horizontal polarizations provided measurement of pointing offsets resolving ambiguities in the coastline matchup analysis. Several geolocation and pointing bias sources were incrementally eliminated resulting in pointing knowledge and geolocation accuracy that met all design requirements. 相似文献
2.
The objectives of this study were to determine the concentration of endotoxin, determine 20 water quality variables, and identify and enumerate fungal and bacterial pathogens from United States southern High Plains dairy lagoons and control lakes during summer and winter. Water samples were collected in triplicate from the north, south, east, and west quadrants of each body of water. The mean (± SEM) winter dairy lagoon endotoxin concentration was significantly higher (9,678 ± 1,834 ng/mL) than the summer concentration (3,220 ± 810 ng/mL). The mean endotoxin concentration of the 2 control lakes (summer: 58.1 ± 8.8 ng/mL; winter: 38.6 ± 4.2 ng/mL) was significantly less than that of the dairy lagoons. Two hundred-one Salmonella enterica spp. isolates were identified, 7 serovars were recovered from the dairy lagoons, and 259 Salmonella ssp. were identified from 5 other dairy locations (milk barn, ditch effluent, settling basin, feed alley pad flush, and center pivots). Twenty-eight Salmonella spp. were identified from center pivot water. Escherichia coli O157:H7 pathogens were isolated from other dairy locations but not from lagoons. Neither Salmonella spp. nor E. coli O157:H7 were identified from control lakes. Enterobacteriaceae opportunistic pathogens were isolated from both dairies and control lakes. Important mesophilic and thermophilic catabolic (to manure biosolids) fungal isolates were identified from dairy effluent locations, but no thermophilic fungal isolates were cultured from the control lakes. Adequate curing of green forage following center pivot irrigation is important to kill lagoon water enteric pathogens, even though the lagoon water is mixed with fresh water. Recirculating lagoon water to flush the feed alley pad, where cows stand while eating, to remove manure and using lagoon water to abate dairy dust in loafing pens and unimproved dairy roads is inconsistent with good environmental practice management. 相似文献
3.
H. S. Zurob D. Panahi C. R. Hutchinson Y. Brechet G. R. Purdy 《Metallurgical and Materials Transactions A》2013,44(8):3456-3471
A self-consistent model for non-partitioning planar ferrite growth from alloyed austenite is presented. The model captures the evolution with time of interfacial contact conditions for substitutional and interstitial solutes. Substitutional element solute drag is evaluated in terms of the dissipation of free energy within the interface, and an estimate is provided for the rate of buildup of the alloying element “spike” in austenite. The transport of the alloying elements within the interface region is modeled using a discrete-jump model, while the bulk diffusion of C is treated using a standard continuum treatment. The model is validated against ferrite precipitation and decarburization kinetics in the Fe-Ni-C, Fe-Mn-C, and Fe-Mo-C systems. 相似文献
4.
Photographs produced by still and ciné techniques are presented to illustrate various aspects of needle action during needle-punching with a loom operating at 240 cycles/min. Complete loom cycles were studied in addition to isolated events. It appears that some fibre extension occurs during reorientation along with the slippage, which allows fibre movement. This study also illustrates how a stitched structure can be produced on the base of needled fabric under certain production conditions and that needle points assist in fibre reorientation. 相似文献
5.
Reports an error in the original article by M. Domjan and J. E. Purdy (American Psychologist, 1996 [Jul], Vol 51[7], 736–737). Portions of the text were inadvertently omitted in the production process; the comment is presented in its entirety. (The following abstract of this article originally appeared in PA, Vol 83:32272.). Responds to P. F. Cunningham's (see record 83:32271) and S. D. Gosling's (see record 1995-45383-001) study of the acknowledgment of contributions of animal experimentation in leading introductory psychology textbooks. The authors agree with Gosling that the primary goal of the general psychology course is to facilitate the students' understanding of psychology and that animal research is not presented in an educationally effective fashion in general psychology textbooks. However, it is argued that students need to know not only the conclusions of research but also something about how the research was conducted. In response to Cunningham's contention that psychology instructors will have to address why research animals are kept under stressful laboratory conditions, the authors note that psychology experiments typically do not involve deadly diseases or experimental pathologies. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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The work described here deals with the problems of modeling and simulation for MEMS devices. The eventual goal is to produce a top-down MEMS design system similar to today’s powerful VLSI design systems. In this work a fixed fabrication process (MUMPS) and a fixed layout tool (L-Edit) are chosen. Thus our efforts are concentrated on reliable simulation of designs and eventual comparison with actual fabricated parts. The cantilever beam is chosen as an example of how extraction from a physical layout may be modeled and interfaced with various simulators. 相似文献
8.
Frank R. Safayeni R. Lyn Purdy Christopher A. Higgins 《Behaviour & Information Technology》1989,8(2):99-107
The social meaning of personal computers for 34 managers and professionals was measured using a situational approach. The results, in general, indicated a positive perception towards computers within the context of their work situations. The methodology was developed in an attempt to overcome some of the difficulties of traditional measures of attitudes. The advantages and the limitations of the method, as well as the process by which impressions are formed, are discussed. 相似文献
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