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221.
Photo-induced phenomena in glasses excited by two-photon absorption have been studied and compared with those produced by bandgap illumination. The two-photon excitation of As2S3 gives a refractive-index increase, unaccompanied by photodarkening. Raman-scattering spectra show that the excitation increases the density of ‘wrong’ bonds. These observations are discussed and compared with photo-induced changes in SiO2.  相似文献   
222.
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   
223.
ABSTRACT

The Autobiographical Memory Test (AMT) has been central in psychopathological studies of memory dysfunctions, as reduced memory specificity or overgeneralised autobiographical memory has been recognised as a hallmark vulnerability for depression. In the AMT, participants are asked to generate specific memories in response to emotional cue words, and their responses are scored by human experts. Because the manual coding takes some time, particularly when analysing a large dataset, recent studies have proposed computerised scoring algorithms. These algorithms have been shown to reliably discriminate between specific and non-specific memories of English-speaking children and Dutch- and Japanese-speaking adults. The key limitation is that the algorithm is not developed for English-speaking adult memories, which may cover a wider range of vocabulary that the existing algorithm for English-speaking child memories cannot process correctly. In the present study, we trained a new support vector machine to score memories of English-speaking adults. In a performance test (predicting memory specificity against human expert coding), the adult-memory algorithm outperformed the child-memory variant. In another independent performance test, the adult-memory algorithm showed robust performances to score memories that were generated in response to a different set of cues. These results suggest that the adult-memory algorithm reliably scores memory specificity.  相似文献   
224.
胃转流术治疗重度肥胖由来已久.近年来,国内研究通过接受胃转流术的肥胖患者的长期随访后发现,胃转流术可长期、稳定的缓解2型糖尿病,并能减少糖尿病并发症,为2型糖尿病的外科治疗开辟了新途径.本文总结我院32例接受腹腔镜胃转流术的2型糖尿病患者术后随访情况,分析后认为腹腔镜下胃转流术治疗2型糖尿病疗效显著,具有微创、安全、有效的特点,是2型糖尿病治疗方法的一种补充和完善,值得临床推广.  相似文献   
225.
The paper starts with a critics of the potential information which is related to the statistical entropy. In order to include the syntactic and semantic aspects of information, we propose a distinction between structural and functional information, instead. Structural information represents the structural determination of a system state, it measures the content of information, as given by the material structure. Functional information, on the other hand, represents the operational closure of the system, it could be e.g. an algorithm which activates and interprets the existing structural information.

From an evolutionary point of view, pragmatic information is generated by an interplay of structural and functional information. This leads to a new insight into the concept of pragmatic information, which is not an invariant of evolution, but must be steadily re‐generated.

The active role of information in a self‐organization process is demonstrated in a model of artificial agents. It is shown by means of computer simulations that the feedback of already existing information on the generation of new information performs analogies to the creation of a collective memory.  相似文献   
226.
We assessed choices on a computerized test of self-control (CTSC) for a group of children with features of attention deficit hyperactivity disorder (ADHD) and a group of controls. Thirty boys participated in the study. Fifteen of the children had been rated by their parents as hyperactive and inattentive, and 15 were age- and gender-matched controls in the same classroom. The children were observed in the classroom for three consecutive mornings, and data were collected on their activity levels and attention. The CTSC consisted of two tasks. In the delay condition, children chose to receive three rewards after a delay of 60 s or one reward immediately. In the task-difficulty condition, the children chose to complete a difficult math problem and receive three rewards or complete an easier problem for one reward. The children with ADHD features made more impulsive choices than their peers during both conditions, and these choices correlated with measures of their activity and attention in the classroom.  相似文献   
227.
The author has surveyed a quarter of the accredited undergraduate computer science programs in the United States. More than half of these programs offer a “social and ethical implications of computing” course taught by a computer science faculty member, and there appears to be a trend toward teaching ethics classes within computer science departments. Although the decision to create an “in house” computer ethics course may sometimes be a pragmatic response to pressure from the accreditation agency, this paper argues that teaching ethics within a computer science department can provide students and faculty members with numerous benefits. The paper lists topics that can be covered in a computer ethics course and offers some practical suggestions for making the course successful. An earlier version of this paper was presented at the 2005 conference, Ethics and Social Responsibility in Engineering and Technology, Linking Workplace Ethics and Education, co-hosted by Gonzaga University and Loyola Marymount University, Los Angeles, California, 9–10 June 2005.  相似文献   
228.
Courses on ethics and technology have become compulsory for many students at the three Dutch technical universities during the past few years. During this time, teachers have faced a number of didactic problems, which are partly due to a growing number of students. In order to deal with these challenges, teachers in ethics at the three technical universities in the Netherlands — in Delft, Eindhoven and Twente — have developed a web-based computer program called Agora (see www.ethicsandtechnology.com). This program enables students to exercise their ethical understanding and skills extensively. The program makes it possible for students to participate actively in moral reflection and reasoning, and to develop the moral competencies that are needed in their later professional practice. The developers of the program have tried to avoid two traps. Firstly, they rejected, from the outset, a cookbook style of dealing with ethical problems that applied ethics is often taken to be and, secondly, they wanted to design a flexible program that respects the student’s as well as the teacher’s creativity, and that tries to engage students in moral reflection. Agora meets these requirements. The program offers possibilities that extend beyond the requirements that are usually accepted for case-exercises in applied ethics, and that have been realised in several other computer models for teaching ethics. In this article, we describe the main considerations in the development of Agora and the features of the resulting program.  相似文献   
229.
This paper describes a one-day workshop format for introducing ethics into the engineering curriculum prepared at the University of Puerto Rico at Mayagüez (UPRM). It responds to the ethics criteria newly integrated into the accreditation process by the Accreditation Board of Engineering and Technology (ABET). It also employs an ethics across the curriculum (EAC) approach; engineers identify the ethical issues, write cases that dramatize these issues, and then develop exercises making use of these cases that are specially tailored to mainstream engineering classes.The different activities and strategies employed in this workshop are set forth. Specific references are made to the cases and exercises developed as a result of these workshops. The paper ends by summarizing the different assessments made of the workshop by addressing the following questions: how did it contribute to the overall ABET effort at UPRM; could other universities benefit from a similar activity; and how did the participants evaluate the workshop?  相似文献   
230.
Brain-computer interface (BCI) technology relies on the ability of individuals to voluntarily and reliably produce changes in their electroencephalographic (EEG) activity. The present paper reviews research on cognitive tasks and other methods of generating and controlling specific changes in EEG activity that can be used to drive BCI systems. To date, motor imagery has been the most commonly used task. This paper explores the possibility that other cognitive tasks, including those used in imaging studies, may prove to be more effective. Other factors which influence performance are also considered in relation to selection of tasks, as well as training of subjects.  相似文献   
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