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131.
132.
The generation and transport of impact-ionized electrons in diamond are investigated using secondary electron emission spectroscopy. By studying secondary electron emission from diamond surfaces having a negative electron affinity (NEA), the total transmitted intensity and the full energy spectrum of the internal electrons are revealed in the measurements. Electron yield and energy distribution measurements from C(100) and CVD diamond samples are analyzed as a function of incident beam energy and information is obtained on both the internal gain and electron energy distribution following impact ionization as well as the effects of the transport process on the internal electron distribution. High internal gain and efficient electron transport are inferred from an analysis of the very high yields measured from both samples. In fact, by fitting calculated yield curves to the measured yield data, we deduce a lower limit on the electron escape depth of 5 μm and 1.3 μm in the C(100) and CVD diamond samples, respectively. Energy spectra measured from the diamond samples contain an intense, low-energy peak whose energy position and width are independent of incident beam energy. Based on an analysis of the energy distribution data, a model of the impact-ionization process in diamond is presented. 相似文献
133.
Among hematologic malignancies, there are three disorders whose behavior is governed principally by the abnormal proliferation of a malignant megakaryocytic clone or a product thereof. These disorders are essential thrombocythemia, agnogenic myeloid metaplasia, and acute megakaryoblastic leukemia. Although there are other myeloproliferative diseases that can have high platelet counts, the major pathobiology of those diseases most commonly results from the proliferation of other hematopoietic lineages. Despite the rarity of the three disorders of malignant megakaryopoiesis mentioned above, advances have been made in the diagnosis, prognosis, and treatment of these disorders in recent years. However, understanding of the cellular and especially molecular pathobiology lags far behind. 相似文献
134.
Administered Rotter's Internal-External Control Scale and M. Horner's incomplete story lead designed to evoke achievement anxieties to 108 female undergraduates. The motive to avoid success was significantly positively associated with external control scores. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
135.
Responds to D. T. Lykken (see record 1975-07223-001), noting inaccurate statements concerning the guilty knowledge test, definition of the control question of the lie detector approach, and the admissibility of polygraph results in the courtroom. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
136.
137.
Sound workload generation methodologies have been developed for only a few evaluation environments. For the remainder, only ad hoc methods of limited applicability are available. 相似文献
138.
Ultraviolet light is now recognised to be very effective for inactivation of Cryptosporidium parvum oocysts; however, its application for disinfection of finished water necessitates validation of UV reactors prior to their installation. Although reactor performance will likely be assessed using non-pathogenic microorganisms as biodosimetry surrogates, it would be prudent for the water industry to simultaneously measure Cryptosporidium oocysts inactivation in controlled bench-scale studies using the water matrix intended for disinfection. The likelihood of that occurring is dependent upon the availability of infectivity measurement procedures that are more user-friendly than the mouse infectivity assays currently used. This study describes a modified cell culture procedure that would enable reliable measurement of changes in oocysts' infectivity following their UV treatment. Also, a number of different biodosimetry surrogates were examined and one selected for comparing the UV doses delivered between bench-scale and full-scale biodosimetry studies. Impacts of UV disinfection on production of disinfection byproducts, effects of lamp ageing on effectiveness of disinfection and the costs associated with employing this technology were also examined. 相似文献
139.
James Aronson Edouard Le Floc'h Jean-Franois David Shivcharn Dhillion Mary Abrams Jean-Louis Guillerm Anna Grossmann 《Landscape and urban planning》1998,41(3-4)
Restoration ecology (RE) offers a conceptual meeting ground and methodological approaches for all those concerned with the past, present and future of ecosystems and landscapes. It combines ecological theory, nature conservation concerns and recognition of the need to develop new management tools for ecosystems and landscapes. In our approach, ‘vital ecosystem attributes' (VEAs) of ecosystems and landscapes are monitored along transects permitting detailed assessment of the impact of economic and RE interventions at the scale of whole landscapes. This also enables quantitative and qualitative comparisons among ecosystems and/or among landscapes. At a new long-term ecological research site (LTER) at Cazarils, southern France, we are studying ecosystem and landscape responses to past and present human uses and perturbations, and to contemporaneous interventions aimed at restoration, rehabilitation and landscape reintegration. In this paper, we present selected baseline data of landscape-wide ranges concerning several different VEAs of both above- and below-ground components of biodiversity as well as soils. The purpose is to describe an approach to landscape research planning and ecosystem management in areas with complex geomorphological, ecological and cultural–historical features such as the Mediterranean region, and surrounding arid or semiarid lands. 相似文献
140.
Frings Daniel; Hopthrow Tim; Abrams Dominic; Hulbert Lorne; Gutierrez Roberto 《Canadian Metallurgical Quarterly》2008,12(3):179
This research examined how group processes alter the impact of alcohol on a judgment task requiring vigilance. The authors compared two competing explanations, deindividuation and group monitoring, for the possible effects of alcohol. Two hundred and eighty-six undergraduates with normal drinking habits undertook a vigilance task alone or in four-person groups having consumed either alcohol (calculated to achieve up to .08 blood alcohol content) or a placebo. The vigilance task required them to count occurrences of the word "the" in a spoken passage. Alcohol significantly impaired the performance of individuals but not groups. Group members performed at a similar level in both conditions, making fewer errors than individuals in the alcohol condition. The fit of different decision-making models were tested. In both the alcohol and placebo conditions, group consensus was predicted by processes consistent with the group monitoring hypothesis. The evidence highlights that under certain conditions, group process can compensate for the cognitively impairing effects of alcohol on individuals. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献