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排序方式: 共有683条查询结果,搜索用时 15 毫秒
51.
Stanton Annette L.; Lobel Marci; Sears Sharon; DeLuca Robyn Stein 《Canadian Metallurgical Quarterly》2002,70(3):751
Emphasizing research published in the past decade, this article presents a summary and evaluation of psychosocial investigations of women's reproductive health, with a focus on selected aspects of menstruation, pregnancy and birth, infertility, and menopause. In some areas, studies have focused on negative physical and psychological concomitants of these health issues. However, research reveals substantial individual variability, with most women adapting well to reproductive health changes. Although methodological and conceptual shortcomings have limited firm conclusions, research has advanced our understanding of the multivariate biological, psychological, and social influences on women's reproductive health and associated outcomes. Understanding and promoting women's reproductive health across the lifespan requires biopsychosocial approaches to research. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
52.
A variety of different experimental results show substantial evidence that the order parameter in high-temperature superconducting copper oxides is not of pure d-wave symmetry, but that an s-wave component exists, which especially shows up in experiments that test the c-axis properties. These findings are modeled theoretically within a two-band model with interband interactions, where the superconducting order parameters in the two bands are allowed to differ in symmetry. It is found that the coupling of order parameters with different symmetries (s+d) leads to substantial enhancements of the superconducting transition temperature T
c as compared to order parameters with only s-wave symmetry. An additional enhancement factor of T
c is obtained from the coupling of the bands to the lattice where moderate couplings favor superconductivity while too strong couplings lead to electron (hole) localization and consequently suppress superconductivity. 相似文献
53.
Windschitl Paul D.; Martin René; Flugstad Annette R. 《Canadian Metallurgical Quarterly》2002,82(5):742
Four experiments investigated how people's perceptions about a group's (e.g., women's) vulnerability to a disease are influenced by information about the prevalence of the disease in a comparable group (e.g., men). Participants read symptom and prevalence information about fictitious diseases before answering questions regarding target group vulnerability. Participants used the prevalence rate for a nontarget group as an immediate comparison standard for intuitively interpreting the degree of vulnerability of a target group, resulting in robust contrast effects. Experiments 3 and 4 illustrated that these contrast effects can cause a person's intuitive perceptions about a group's vulnerability to selected diseases to conflict with his or her knowledge of the prevalence rates for the diseases. The results support a distinction between 2 components of psychological uncertainty--beliefs in objective probability and more intuitive perceptions of certainty. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
54.
Branko Deljanin Dusan Simic Alexander Zaitsev John Chapman Inga Dobrinets Annette Widemann Nicholas Del Re Tara Middleton Elena Deljanin Andrea De Stefano 《Diamond and Related Materials》2008,17(7-10):1169-1178
One of the commercial challenges today in the gem industry is to quickly identify the origin of color in pink diamonds — natural, treated and synthetic by use of standard and advanced gemological instruments.An analytical technique that is used by many gem labs involves UV fluorescence. The principle factors in the technique are the excitation wavelengths and the emission spectra. No systematic study of fluorescence of pink natural diamonds, pink treated and pink synthetic diamonds has been undertaken. This study is mainly focused on using fluorescence techniques to characterize pink diamonds and to compile a reference library of emission spectra. Longwave (LW) and shortwave (SW) fluorescence of 365, 254 and 220 nm illumination were used in a custom built microscope with a fluorescence camera to record images and a spectrometer to record spectral data with which to establish a correlation with the cause of color.Other advanced instruments (CL imaging, UV–VIS–NIR, FTIR, PL spectroscopy and electrical conductance) were used to establish additional criteria for distinguishing natural, treated and synthetic pink diamonds and to find a correlation with the “EGL USA CIS (Cross-reference Identification System) fluorescence method”. 相似文献
55.
Meckelein Barbara; Nikiforov Theo; Clemen Annette; Appelhans Heribert 《Protein engineering, design & selection : PEDS》1990,3(3):215-220
Human mucus proteinase inhibitor (MPI) consists of 107 aminoacids arranged in two domains showing high homology to eachother. This protein is an inhibitor of different serine proteinasesincluding trypsin, chymotrypsin, leukocyte elastase and cathepsinG. On the basis of sequence comparisons it has been suggestedthat the first domain inhibits trypsin, whereas the second onewas thought to be active against chymotrypsin and elastase.To prove the location of the different inhibitory activitiesgene fragments for both domains have been cloned separatelyand expressed in Escherichia coli. Inhibition assays with theisolated recombinant domains showed that the second domain isactive against chymotrypsin, neutrophil elastase and trypsin,whereas for the first domain only a weak activity against trypsincould be detected. These results suggest that the inhibitoryactivities of the native molecule towards these three proteinasesare all located in the second domain. 相似文献
56.
Berninghaus Siegfried K.; Güth Werner; Kirstein Annette 《Canadian Metallurgical Quarterly》2008,1(1):33
Systematic experiments with distribution games have shown that participants are strongly motivated by considerations of fairness and efficiency. This evidence, however, results mainly from experimental designs in which money is shared directly. Furthermore, fairness does not necessarily require equal payoffs, but may instead require equal allocations. We investigate experimentally the frame dependency of reaching equal (commodity or payoff) splits by systematically comparing net-trade proposals and payoff proposals for the same exchange economy with two traders, two commodities and multi-period negotiations. We can confirm the hypothesis that asking participants to allocate money directly, rather than more naturally via the allocation of commodities, is far from being harmless and likely overstates fairness and efficiency concerns. What is more, we try to apply the insights gained from our experiment to management problems. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
57.
Ulrich Reffle Annette Gotscharek Christoph Ringlstetter Klaus U. Schulz 《International Journal on Document Analysis and Recognition》2009,12(3):165-174
The detection and correction of false friends—also called real-word errors—is a notoriously difficult problem. On realistic
data, the break-even point for automatic correction so far could not be reached: the number of additional infelicitous corrections
outnumbered the useful corrections. We present a new approach where we first compute a profile of the error channel for the
given text. During the correction process, the profile (1) helps to restrict attention to a small set of “suspicious” lexical
tokens of the input text where it is “plausible” to assume that the token represents a false friend. In this way, recognition
of false friends is improved. Furthermore, the profile (2) helps to isolate the “most promising” correction suggestion for
“suspicious” tokens. Using a conventional word trigram statistics for disambiguation we obtain a correction method that can
be successfully applied to unrestricted text. In experiments for OCR documents, we show significant accuracy gains by fully
automatic correction of false friends. 相似文献
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60.
Hansson J Båth M Håkansson M Grundin H Bjurklint E Orvestad P Kjellström A Boström H Jönsson M Jonsson K Månsson LG 《Radiation protection dosimetry》2005,114(1-3):278-285
The aim of this study was to find the optimum tube voltage for neonatal chest imaging in computed radiography. The study was designed to take full advantage of the benefits of digital imaging, for example, by comparing the tube voltages at constant effective dose. A phantom study using a living rabbit was first conducted. Images were collected at tube voltages ranging from 40 to 90 kV(p). The reproduction of four structures (central vessels, peripheral vessels, carina and thoracic vertebrae) was rated by 10 radiologists. The reproduction of both central and peripheral vessels was relatively independent of tube voltage. The carina was better reproduced at higher tube voltages whereas the opposite was true for the thoracic vertebrae. Based on the higher importance of the reproduction of the carina it was decided that 90 kV(p) was the optimal tube voltage. To validate the result from the phantom study, a follow-up study was conducted in which images of neonates collected at the tube voltage regularly used at Sahlgrenska University Hospital (70 kV(p)) were compared with images collected at the tube voltage proposed by the phantom study. The follow-up study confirmed the results from the phantom study that the reproduction of the carina was better at 90 than at 70 kV(p). In conclusion, for neonatal chest imaging-given the same effective dose-90 kVp gives better reproduction of important structures than the regularly used 70 kV(p). 相似文献