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1.
The static permittivity (εm ) and the permittivity at the high-frequency limit (ε∞m ) of a binary mixture of propionic acid with tetrahydrofuran (THF) have been determined for different concentrations at temperatures of 303, 308, 313, and 318 K. The data have been used to compute the Kirkwood correlation factor, the excess permittivity, and the excess free-energy of the mixtures. The Kirkwood correlation factor is found to increase with increasing THF concentration. The mixture exhibited positive values of the excess permittivity and negative values of the excess free-energy of mixing, respectively. UV-Vis and FT-IR spectral measurements have also been carried out. The observed bathochromism and hypochromism in the UV-Vis spectra have been explained in terms of complex formation and ordering of dipoles of the complex. The FT-IR spectrum of the mixture shows considerable shifts in the positions of some of the absorption bands, indicating extensive hydrogen bonding between solute and solvent molecules.  相似文献   

2.
The molecular interactions in binary mixtures of anisole with o-chlorophenol and o-cresol have been studied at three different temperatures using dielectric measurements. The static permittivity and the permittivity at optical frequency have also been determined and used to obtain the Kirkwood correlation factors, the Bruggeman parameter, the excess permittivity and the excess free energy for different concentrations of two binary mixtures, namely (1) anisole + o-chlorophenol and (2) anisole + o-cresol. Using the effective Kirkwood correlation factor, parallel and anti-parallel alignments among the dipoles are identified. The corrective Kirkwood correlation factor, the excess permittivity and the Bruggeman parameter are used to explain the interaction between unlike molecules. The temperature dependences of the above parameters are also reported. The investigation shows systematic changes in the dielectric behaviour with variations in concentration and temperature.  相似文献   

3.
4.
Excessive variability in binary choice (categorical judgment) can take the form of probability matching rather than the normatively correct behavior of deterministically choosing the more likely alternative. Excessive variability in continuous choice (judgment rating) can take the form of underconfidence, understating the probability of highly likely events and overstating the probability of very unlikely events. We investigated the origins of choice variability in terms of noise prior to decision (at the evidence stage) and at the decision stage. A version of the well-known medical diagnosis task was conducted with binary and continuous choice on each trial. Noise at evidence stage was reduced by allowing the subjects to view historical summaries of prior relevant trials, and noise at the decision stage was reduced by giving the subjects a numerical score on the basis of their continuous choice and the actual outcome. Both treatments greatly reduced variability. Cash payments based on the numerical score had a less reliable incremental effect in our experiment. The overall results are more consistent with a Logit model of decision than with a simple criterion (or maximization) rule or a simple probabilitymatching rule.  相似文献   

5.
The static dielectric constants of binary mixtures of N-methylformamide (NMF), used as a solute with the solvents water (W), ethyl alcohol (EA), ethylene glycol (EG), dimethyl sulphoxide (DMSO), acetone (Ac) and 1,4-dioxane (Dx), have been measured over the entire concentration range at 30°C. The negative values of excess dielectric constant and less-than-unity values of the corrective Kirkwood correlation factor of these binary mixtures are used to analyse the formation of H-bond complexes and molar ratio of the stable adduct. In these systems, the unassociated mixture constituents, DMSO, Ac and Dx, act as structure-breakers for self-associated linear structures of NMF, whereas, both the self-associated mixture constituents (W, EA and EG mixtures with NMF) act as structure-breakers to each other during the complexations. It is found that the large variations in the strength of H-bond complexation and the effective number of parallel aligned dipoles in the mixtures are governed by the dielectric constant of the solvents.  相似文献   

6.

It is known that a reduction in the number of independent interdiffusivities and intrinsic diffusivities is possible if thermodynamic ideality of the (ternary) alloy is assumed or if the off-diagonal phenomenological coefficients are ignored. In the present letter we present a new analysis which shows generally, and exactly, that a reduction in the number of independent interdiffusivities and intrinsic diffusivities is always possible for ternary and higher alloys. In the general case, thermodynamic activities are also required.  相似文献   

7.
Abstract

Background: Genderqueer and nonbinary () people have remained largely invisible in health research. Previous research shows worse outcomes on health indicators for trans people when compared with cisgender controls, but the differences between binary trans and GQNB individuals are inconclusive.

Aims: To compare overall health and well-being of GQNB people with controls of trans men and trans women, taking into account the impact of the additive effect of their socio-economic position, as well as their current need for gender affirming medical interventions.

Methods: A community-driven survey was conducted in 2016 in five countries (Georgia, Poland, Serbia, Spain, and Sweden). Self-reported health and general well-being were analysed for differences between binary trans and GQNB respondents. The effects of multiple control variables (age, economic situation, educational level, belonging to an ethnic, religious, sexual or ability minority group, sex assigned at birth) as well as the current need for gender affirming medical interventions were controlled for.

Results: The sample consisted of 853 respondents aged 16 and older, with 254 trans women (29.8%), 369 trans men (43.2%), and 230 GQNB people (26%). GQNB respondents showed significantly worse self-reported health and worse general well-being in comparison to binary trans respondents. Additional negative impacts of having a lower educational level, having more economic stress, and belonging to a disability minority group were found. Being in need of gender affirming medical interventions contributed significantly to worse self-reported health, whereas being younger contributed to worse general well-being.

Discussion: In understanding health disparities between binary trans and GQNB people, it is necessary to take into account the additive effect of multiple socio-economic positions, and the current need for gender affirming medical interventions. The high proportion of GQNB respondents who report worse health outcomes highlights the need for policy makers and health-care providers in creating nonbinary-inclusive environments.  相似文献   

8.
Three studies were conducted to quantify perceptual changes that occur when sapid chemicals are tasted in mixture solutions. The primary effect when mixing sweetness (glucose or fructose) with salt (NaCl), sour (citric acid), or bitter (quinine sulfate) was to reduce the intensity of each taste in the mixture. The reduction was not equal for the two components, although the overall (total) taste intensity of the mixture appeared to be approximately 50% of the sum of the intensities of the unmixed components. Mixtures of sweet and salt developed an “unblended” or “clashing” taste, in which the components alternated in attempting to dominate the taste percept. Sweet mixed with either sour or bitter blended in almost all proportions. The “flavor” of sweetness in mixtures differed from that of simple sugar sweetness, suggesting that the presence of a second taste modified the qualitative aspect of sweetness. The magnitude of change in sweetness quality depended upon the sugar being rated, and upon the quality and intensity of the second, or modifying, taste.  相似文献   

9.
In recent years there has been a growing interest in representing data by trees. Most of the literature has been concerned with inferring trees from pairwise data. In this paper, trees are constructed from ternary relations; the model represents each object of an empirical set by a node of a tree so that a betweenness relation among the nodes (the node b is on the path from the node a to the node c) in the graph reflects a ternary relation among the objects. Various systems of formal properties that lead to three different kinds of tree representation are investigated.  相似文献   

10.
McGrath RE 《心理评价》2008,20(3):195-205
Professional psychologists are often confronted with the task of making binary decisions about individuals, such as predictions about future behavior or employee selection. Test users familiar with linear models and Bayes's theorem are likely to assume that the accuracy of decisions is consistently improved by combination of outcomes across valid predictors. However, neither statistical method accurately estimates the increment in accuracy that results from use of additional predictors in the typical applied setting. It was demonstrated that the best single predictor often can perform better than do multiple predictors when the predictors are combined using methods common in applied settings. This conclusion is consistent with previous findings concerning G. Gigerenzer and D. Goldstein's (1996) "take the best" heuristic. Furthermore, the information needed to ensure an increment in fit over the best single predictor is rarely available.  相似文献   

11.
Attention, Perception, & Psychophysics - Character classification tasks and “same” “different” judgments of letter strings were examined with reference to major...  相似文献   

12.
Yiu-Fai Yung 《Psychometrika》1997,62(3):297-330
In this paper, various types of finite mixtures of confirmatory factor-analysis models are proposed for handling data heterogeneity. Under the proposed mixture approach, observations are assumed to be drawn from mixtures of distinct confirmatory factor-analysis models. But each observation does not need to be identified to a particular model prior to model fitting. Several classes of mixture models are proposed. These models differ by their unique representations of data heterogeneity. Three different sampling schemes for these mixture models are distinguished. A mixed type of the these three sampling schemes is considered throughout this article. The proposed mixture approach reduces to regular multiple-group confirmatory factor-analysis under a restrictive sampling scheme, in which the structural equation model for each observation is assumed to be known. By assuming a mixture of multivariate normals for the data, maximum likelihood estimation using the EM (Expectation-Maximization) algorithm and the AS (Approximate-Scoring) method are developed, respectively. Some mixture models were fitted to a real data set for illustrating the application of the theory. Although the EM algorithm and the AS method gave similar sets of parameter estimates, the AS method was found computationally more efficient than the EM algorithm. Some comments on applying the mixture approach to structural equation modeling are made.Note: This paper is one of the Psychometric Society's 1995 Dissertation Award papers.—EditorThis article is based on the dissertation of the author. The author would like to thank Peter Bentler, who was the dissertation chair, for guidance and encouragement of this work. Eric Holman, Robert Jennrich, Bengt Muthén, and Thomas Wickens, who served as the committee members for the dissertation, had been very supportive and helpful. Michael Browne is appreciated for discussing some important points about the use of the approximate information in the dissertation. Thanks also go to an anonymous associate editor, whose comments were very useful for the revision of an earlier version of this article.  相似文献   

13.
In this article, we propose an efficient atomic packing cluster-based composition protocol to help design Al-based metallic glasses. Its validity is verified by some typical experimental data from the literatures. Furthermore, with this understanding, the Al–Ni–Y alloy system is re-evaluated. As a result, the best glass former Al86Ni9Y5 in this system, with the critical thickness of about 500 µm, is successfully fabricated by wedge casting.  相似文献   

14.
The capacity of humans to identify the components of taste mixtures and odour-taste mixtures was investigated in two experiments. Subjects were trained to identify the components presented alone and to use a 'yes/no' procedure to identify them in mixtures. All stimuli were presented with a retronasal (by mouth) technique. A maximum of three tastants were identified in both types of mixtures, only one tastant was identified in five-component taste mixtures, and no component was identified in four-component odour-taste mixtures. Importantly, in no instance was the olfactory stimulus identified in any mixture with tastes, including binary mixtures. Loss of identity of the odorant in binary and ternary mixtures may have been due to suppression as a consequence of temporal processing, or to the absence of an association between the odorant and tastants that had established an identifiable percept. In contrast, poor identification of the components of the quaternary odour-taste mixture and quinternary taste mixture is attributed to the limited capacity of working memory. Overall, the poorer ability to identify components in odour-taste mixtures than in taste mixtures indicates that interactions occurred between the two senses, challenging the proposal that odours and tastes are processed independently when present in complex chemosensory stimuli.  相似文献   

15.
Some differences in the efficiency of coding were found between 4- and 6-year-olds. However, it appeared that the coding strategies were similar at lower and higher levels of memory capacity and development.  相似文献   

16.
The present study was designed to investigate the ability of humans to detect changes in the underlying probability structure of binary sequences of events. Four Ss were presented with sequences of 30 events (zeros and ones) which had been generated by two underlying probability values. P1 was the probability of a one in the first i events, P2 was the probability of a one in the last 30-i events, and the distribution of i was uniform from 1 to 29. The Ss indicated, without feedback, where the transition point from P1 to P2 took place for four sets of problems in which P1 and P2 took on the following pairs of values: (.40, .60), (.20, .80), (.05, .60), and (.50, 1.00). Estimates by Ss were compared with true transition points, i, and with maximum likelihood estimates of i. The difference between P1 and P2 and the closeness of at least one P value to the boundaries, either zero or unity, interacted in determining the difficulty of the problem for Ss.  相似文献   

17.
A recent study of the override and update operations defined on sets of partial functions placed both operations within the algebraic context of a certain variety of algebras. We show the latter to be term equivalent to the variety of right-handed skew Boolean algebras. Both operations are then studied within the broader context of skew lattices with an eye towards achieving greater insight into their joint algebraic behavior. A decision procedure is given to determine whether an equation in both operations holds for all sets of partial functions.  相似文献   

18.
The permittivity and the dielectric loss of ternary mixtures of equimolar concentrations of m-cresol, o-cresol with acetonitrile, acrylonitrile and benzonitrile in benzene have been measured at 8.33 GHz and 308 K. The distribution parameter α, the most probable relaxation time τ, the relaxation time for overall rotation of the molecule τ(1), the relaxation time for group rotation τ(2), and the excess dipole moment for various systems have been calculated by the Cole-Cole and Higasi methods. Data has been analyzed in terms of two-relaxation processes: overall rotation and group rotation.  相似文献   

19.
Researchers studying argumentation often make the simplifying assumption that rational persuasion can be studied independently from the processes through which social identities are established and maintained. However, developments in the study of message design, particularly the groundbreaking work of Brown and Levinson (1978, 1987) on politeness, suggests that in practice the multiple functions of messages are intertwined in message structure and effects. In contrast to the view that identity issues distort rational processes in communication, both the communication of identity and the use of identity-based appeals in social influence are best seen as prototypical examples of rationality in message design.  相似文献   

20.
A significance test is proposed for determining whether a correlation coefficient is less than unity by an amount greater than that attributable to errors of measurement.  相似文献   

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