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排序方式: 共有1093条查询结果,搜索用时 15 毫秒
1.
Diane M. Hopkins Alan D. Jackson Kenneth Oates 《Microscopy research and technique》1991,18(2):176-182
The standardisation of frozen hydrated bulk biological specimens using gelatin standards is described. The relationship between corrected elemental X-ray counts and ionic concentration was found to be linear, and minimum detectable limits for each element are stated. Variations in uncorrected standard curves were found to be due to changes in aluminium coating thickness. There was an inverse relationship between coating thickness and elemental X-ray counts. The factors causing this are discussed. To avoid errors arising from inconsistent aluminium thickness, experimental material should only be compared with standards of similar aluminium net counts. This can be achieved most easily by mounting and analysing specimen and standard together. 相似文献
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The purpose of this study was to assess the use, in computer-mediated communication, of the strategic message structuring tactic known as framing. Interlocutors in computer-mediated environments have software supported systemic resources facilitative of constructing messages using framing tactics in their argumentative discourse. It is hypothesized that framing strategies are related to the emotional tenor of a disputant's message and that a speaker's emotional involvement with an issue should be curvilinearly related to the appropriation of framing as an argumentative discourse strategy. Results from the analysis of 3000 messages, obtained from a diverse sampling of computer-mediated discussion groups and forums, provided support for the primary hypothesized relationship. A speaker's emotional involvement was significantly and curvilinearly related to two message framing devices (message dependency and coalition building) and a measure of conciliatory face-saving moves. 相似文献
4.
Diane M. Moran F. S. Richardson
M. Koralewski
B. M. Wanklyn
《Journal of Alloys and Compounds》1992,180(1-2):171-175Chiroptical luminescence and circular dichroism measurements are reported for single crystals of Ho2Ge2O7. These crystals belong to the tetragonal space group P4,2,2 (or P43212) with Z=4. Each Ho3+ ion in the crystal structure is coordinated to seven oxygens to form a distorted pentagonal bipyramid. The Ho3+ ions exhibit luminescence from several excited multiplet levels; chiroptical luminescence spectra are reported for 6I8 → 6F6, 6S2, and 6F3 at a sample temperature of 10 K. Room-temperature absorption and circular dichroism measurements are reported for the 6I8 → 6F6, 5S2, 6F4, and 6F3 transition regions. 相似文献
5.
Fleming Alison S.; Ruble Diane N.; Flett Gordon L.; Shaul David L. 《Canadian Metallurgical Quarterly》1988,24(1):71
Self-report data were obtained from a middle-income sample of first-time mothers during pregnancy and at 1 and 3 months postpartum, and behavioral interactions between the mother and her infant were observed at 3 days and 1, 3, and 16 months postpartum. The main analyses revealed that pregnancy and postpartum mood states together explain a high proportion of the variance in mothers' maternal attitudes during the postpartum, although postpartum mood has the greater predictive power. Additionally, prior experience with children is significantly associated with maternal attitudes at all time points. Moreover, at both 1 and 3 months postpartum, depressed mothers, relative to nondepressed mothers, exhibit fewer affectionate contact behaviors toward their infants and are less likely to respond to infant vocalizations by vocalizing themselves, and, at 3 months, a higher proportion of the depressed mothers had started bottle-feeding their infants. Finally, differences in maternal behavior between depressed and nondepressed mothers during the early postpartum period were no longer apparent at 16 months postpartum. The implications of these findings are discussed with particular reference to the interrelations between prior child-care experience, mood, and maternal responsiveness. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
6.
Diane J. Cook 《Applied Intelligence》1991,1(2):133-144
Analogical planning provides a means of solving engineering problems where other machine learning methods fail. Unlike many machine learning paradigms, analogy does not require numerous previous examples or a rich domain theory. Instead, analogical planners adapt knowledge of solved problems in similar domains to the current problem. Unfortunately, the analogical planning task is an expensive one. While the process of forming correspondences between a known problem and a new problem is complex, the problem of selecting a base case for the analogy is virtually intractable.This paper addresses the issue of efficiently forming analogical plans. The Anagram planning system is described, which takes advantage of the massively parallel architecture of the Connection Machine to perform base selection and map formation. Anagram provides a tractable solution to analogical planning, with a complexity that is sublinear in the size of the plans.This paper describes the Anagram system and its parallel algorithms. The paper also presents theoretical analyses and empirical results of testing the system on a large database of plans from the domain of automatic programming. 相似文献
7.
M Nishikawa P Chowdhury K Takaori GT Blevins PL Rayford 《Canadian Metallurgical Quarterly》1998,9(2):26-30
Excitability of functionally different alpha-motoneurons was studied in 62 patients with gunshot injuries of nervous trunks of lower extremities both before and during process of rehabilitation by means of physical factors. The correlation of reactions of spinal cord motoneurons and the degree of injuries of nervous trunks was observed. Neuroapraxia of nervous trunks was accompanied by multidirectional alterations in reflex activity of large and small alpha-motoneurons. It was depressed in axonothermesis and lost in simultaneous full anatomic interruption of ischiatic nerve and trunks of both fibular and tibial nerves. Under influence of physical factors the function of motoneurons was normalized in neuroapraxia and was improved in axonothermesis of nervous trunks. 相似文献
8.
Advances in technology and changes in necessary workplace skills have made the ability to think critically more important than ever before, yet there is ample evidence that many adults consistently engage in flawed thinking. Numerous studies have shown that critical thinking, defined as the deliberate use of skills and strategies that increase the probability of a desirable outcome, can be learned in ways that promote transfer to novel contexts. A 4-part empirically based model is proposed to guide teaching and learning for critical thinking: (a) a dispositional component to prepare learners for effortful cognitive work, (b) instruction in the skills of critical thinking, (c) training in the structural aspects of problems and arguments to promote transcontextual transfer of critical-thinking skills, and (d) a metacognitive component that includes checking for accuracy and monitoring progress toward the goal. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
9.
Topic models are a useful and ubiquitous tool for understanding large corpora. However, topic models are not perfect, and for many users in computational social science, digital humanities, and information studies—who are not machine learning experts—existing models and frameworks are often a “take it or leave it” proposition. This paper presents a mechanism for giving users a voice by encoding users’ feedback to topic models as correlations between words into a topic model. This framework, interactive topic modeling (itm), allows untrained users to encode their feedback easily and iteratively into the topic models. Because latency in interactive systems is crucial, we develop more efficient inference algorithms for tree-based topic models. We validate the framework both with simulated and real users. 相似文献
10.
During courtship, premolt female lobsters,Homarus americanus, choose a male and initiate a pair bond by repeated approaches to his shelter. The male allows such a female to share his shelter for about one week. This knowledge formed the basis to search for quantitative evidence for lobster sex pheromone(s) used in courtship: male cues to allow premolt females to identify a preferred male, and female cues to allow males to identify a premolt mature female. In each of four 1500-liter naturalistic aquaria, the behavioral responses of one female and two male lobsters to male and female lobster urine (0.5 ml) and body odor (20 ml) stimuli were observed. These stimuli were injected once or twice per day into a continuously flowing delivery tube attached to lobster shelters. Habituation to stimulus introduction—a serious problem in earlier experiments—was apparently avoided in the more natural social and physical environment we employed in these experiments. We demonstrated that male and female molt body odors contain different chemical substances: females responded to male molt body odor and males responded to female molt body odor but not vice versa. In general, male and female intermolt urine caused strong responses; however, females responded only weakly to male urine. This suggests that male and female urine are chemically different. Female urine and molt body odor caused a typically male high-on-legs response. These results show that molt body odors and intermolt urine contain sex-specific substances, which may be used in lobster courtship as well as other social interactions. 相似文献