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141.
期刊评价:影响因子及其相关指标   总被引:2,自引:2,他引:2  
在西部大开发环境下,联系陕西省科技期刊的现状,研究了陕西省科技期刊的发展策略,首次提出“寓发展于服务中、中陕西省科技期刊与西部大开发的结合点。指出陕西省科技期刊发展的基本原则是坚持两个效益辩证统一,发展的出发点是服务西部大开发。  相似文献   
142.
This article critically engages the theme of the game as a model for identity, community, and the meaning and function of objects in a recent work by Pierre Levy. Two of Levy's books have recently appeared in English translation, making this a timely moment to return to this theme that resonates throughout cultural modernity, especially in the areas of business, the military, sports, and, of course today, in digital software and network design.  相似文献   
143.
144.
The Holistic Paradigm in Educational Theory   总被引:1,自引:0,他引:1  
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145.
146.
Identifying the Causes of DIF in Translated Verbal Items   总被引:1,自引:0,他引:1  
Translated tests are being used increasingly for assessing the knowledge and skills of individuals who speak different languages. There is little research exploring why translated items sometimes function differently across languages. If the sources of differential item functioning (DIF) across languages could be predicted, it could have important implications on test development, scoring and equating. This study focuses on two questions: “Is DIF related to item type?”, “What are the causes of DIF?” The data were taken from the Israeli Psychometric Entrance Test in Hebrew (source) and Russian (translated). The results indicated that 34% of the items functioned differentially across languages. The analogy items were the most problematic with 65% showing DIF, mostly in favor of the Russian-speaking examinees. The sentence completion items were also a problem (45% D1F). The main reasons for DIF were changes in word difficulty, changes in item format, differences in cultural relevance, and changes in content.  相似文献   
147.
This study investigated the validity of the Autism Behavior Checklist (ABC; Krug, Arick, & Almond, 1993) and the Pervasive Developmental Disorders Rating Scale (PDDRS; Eaves, 1993a). Both instruments are screening devices designed to measure characteristics of individuals with autistic disorder or, more broadly, pervasive developmental disorders. Results showed that the total scores of the ABC and PDDRS measure significantly overlapping constructs (r= .80). Further, both instruments significantly discriminated between participants with autistic disorder and children with diagnoses frequently confused with autistic disorder. Both instruments provided respectable indices for classification accuracy (PDDRS overall accuracy = 88%, ABC overall accuracy = 80%). Finally, the ABC and PDDRS agreed in their classifications of 85% of the 136 participants; a phi coefficient based on the instruments' nominal classifications of the participants equaled .68 (p< .001). © 2000 John Wiley & Sons, Inc.  相似文献   
148.
Progress in microelectrode-based technologies has facilitated the development of sophisticated methods for manipulating and separating cells, bacteria, and other bioparticles. For many of these various applications, the theoretical modeling of the electrical response of compartmentalized particles to an external field is important. In this paper we address the analysis of the interaction between cells immersed in rf fields. We use an integral formulation of the problem derived from a consideration of the charge densities induced at the interfaces of the particle compartments. The numerical solution by a boundary element technique allows characterization of their dielectric properties. Experimental validation of this theoretical model is obtained by investigating two effects: (1) The influence that dipolar “pearl chaining” has on the dielectrophoretic behavior of human T lymphocytes and (2) the frequency variation of the spin and orbital torques of approaching insulinoma β-cells in a rotating field.  相似文献   
149.
This Special Topic section is on dielectrophoresis, a growing area of widespread interest and relevance to the microfluidics and nanofluidics community.There was a time when the arrival of a telegram from the local post office would foreshadow a step-function change in one’s equilibrium. An internet service provider can now deliver the same effect, as illustrated by an unexpected e-mail from Leslie Yeo inquiring if I would “be interested in guest editing a special issue of Biomicrofluidics on recent advances in dielectrophoresis (DEP).” Flattery directed towards vanity can produce interesting results—which I hope this special issue of Biomicrofluidics demonstrates. The rationale for this special issue is the belief of the journal’s Editors (Dr. Chia Chang and Dr. Leslie Yeo) that dielectrophoresis is a growing area of widespread interest and relevance to the microfluidics and nanofluidics community. Papers, both fundamental and applied, were solicited from the leaders working across this broad interdisciplinary area of research. I was delighted by the positive responses of those whose invited contributions appear in this special issue—efforts certainly not motivated by vanity but through enthusiasm for the subject. Some of those invited to contribute were unable to do so because of other demands on their time. Ongoing advances being made in DEP, especially in its various applications, will surely merit another special issue in the future and hopefully include contributions from those unable to do so now.Two of the papers in this special issue address fundamental aspects of dielectrophoresis (DEP), namely the influences on DEP from electrical double-layers and from particle-particle interactions. Consideration of electrical double layers associated with charged particle surfaces is particularly important for nanoparticles because their effective polarizabilities, associated with field-induced dynamics of the counterions and co-ions in the double layer, can dominate over the intrinsic polarizability of the particle itself. This can influence, for example, to what extent the observation of changes in the DEP crossover frequency (marking the transition between positive and negative DEP) can be relied upon in new immunoassays based on the DEP behavior of functionalized nanoparticles. By considering the electrodynamics of double layers, Basuray et al.1 propose a theory to predict how the DEP crossover frequency will vary as a function of particle size and the ionic strength of the suspending electrolyte. In their paper, Sancho et al.2 derive a theoretical model to describe how particle-particle interactions (e.g., “pearl-chaining”) influence the DEP crossover frequency value. This model also describes well the changes in electrorotation and a newly observed precession effect as particles approach each other under the influence of a rotating field.DEP at the nanoscale is also addressed in contributions from the groups of Ralph Hölzel, Junya Suehiro, and Karan Kaler. Thus, Henning et al.3 describe a new method, based on the measurement of capacitance changes between planar microelectrodes, for the automatic acquisition of the DEP properties of nanoparticles without the need for labeling protocols or visual observations. Suehiro4 describes how DEP can be employed as a bottom-up approach for fabricating nanomaterial-based devices such as a carbon nanotube gas sensor and a ZnO nanowire photosensor. Kaler et al.5 describe how the DEP manipulation of miniscule amounts of polar aqueous samples, a method known as liquid-DEP, can be used for on-chip bioassays, such as nucleic acid analysis, and through parallel sample processing offer the potential for conducting automated multiplexed assays. The use of DEP to selectively trap and separate cells has been investigated over many years, and contributions from the groups of Hywel Morgan, Ana Valero, Masau Washizu, and Gerard Markx describe the latest advances and applications. Thomas et al.6 describe a new automated DEP cell trap design for the isolation, concentration, separation, and recovery of human osteoblast-like cells from a heterogeneous population. Recovery of small populations of human osteoblast-like cells with a purity of 100% is demonstrated. A cell-sorting device, based on the opposition of DEP forces that discriminates between cell types according to such properties as their membrane permittivity and cytoplasm conductivity, is described by Valeroet al.7 The versatility of the device is demonstrated by synchronizing a yeast cell culture at a particular phase of the cell cycle. Gel et al.8 describe a DEP-assisted cell trapping method for fusing pairs of cells in an array of micro-orifices. This method produces not only a high yield of viable cell fusants, but also allows for subsequent study of postfusion cell development. Zhu et al.9 describe a DEP-based microfluidic separation system in which dead and active cells can be collected from a given cell suspension, whilst at the same time eluting dormant cells. In the second paper from Gerard Markx’s group, Zhu et al.10 demonstrate that the rate-limiting resuscitation of a colony of dormant bacteria is determined by the diffusion of a resuscitation-promoting factor into the colony interior. This study involved the artificial engineering of different sizes and shapes of bacterial aggregates using DEP forces. Finally, in my own contribution,11 I have attempted to summarize the growing output of DEP publications in terms of their contributions to the theory, technology, and applications of DEP.  相似文献   
150.
College students (308 undergraduates) completed the Five Factor Inventory and the Academic Motivations Scale, and reported their college grade point average (GPA). A correlation analysis revealed an interesting pattern of significant relationships. Further, regression analyses indicated that conscientiousness and openness explained 17% of the variance in intrinsic motivation; conscientiousness and extraversion explained 13% of the variance in extrinsic motivation; and conscientiousness and agreeableness explained 11% of the variance in amotivation. Further, four personality traits (conscientiousness, openness, neuroticism, and agreeableness) explained 14% of the variance in GPA; and intrinsic motivation to accomplish things explained 5% of the variance in GPA. Finally, conscientiousness emerged as a partial mediator of the relationship between intrinsic motivation to accomplish and GPA. These results are interpreted within the context of what educators could do to encourage and nurture student motivation and achievement.  相似文献   
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