杆塔接地电阻的测量方法

该文简单介绍了杆塔接地电阻测量的重要性,接地系统以及接触电阻的概念,传统的测量方法、简单原理及各自的优缺点。分析了利用各自优点而改进的接地电阻测量新方法,并提出了几种理接地电阻超标值的方法。送电线路杆塔必须可靠接地,以确保雷电流泄入大地,保护线路绝缘。为提高耐雷水平,保护设备绝缘和避免跨步电压产生的人身伤害,就一定要降低杆塔的接地电阻。     

Early conduct problems and later life opportunities

Associations between the extent of conduct problems at age 8 years and later life opportunity outcomes at age 18 years were examined in a birth cohort of New Zealand children studied prospectively to age 18 years. Conduct problems at age 8 were assessed using a combination of parent and teacher reports of conduct disordered and oppositional behaviours. Two measures of life opportunities were assessed at age 18: (a) whether the young person had left school by age 18 without educational qualifications; (b) whether the young person had experienced a period of unemployment of 3 months or longer following school leaving. The analysis suggested the following conclusions: (1) There were clear and significant (p < .0001) tendencies for increasing levels of conduct problems at age 8 to be associated with increasing risks of leaving school without qualifications and of unemployment by age 18. (2) A substantial component of these associations was explained by a series of confounding social, family, and individual factors (notably child intelligence, early attentional problems, and family sociodemographic disadvantage) that were associated with both early conduct problems and later life opportunities. (3) Further analysis suggested that linkages between early conduct problems and later educational underattainment and unemployment (after adjustment for confounders) were mediated by a series of adolescent behavioural processes including patterns of peer affiliations, substance use, truancy, and problems with school authority.     

Intra-host versus inter-host selection: viral strategies of immune function impairment

We investigate the evolution of viral strategies to counteract immunological attack. These strategies can be divided into two classes: those that impair the immune response inside or at the surface of a virus-infected cell and those that impair the immune response outside an infected cell. The former strategies confer a "selfish" individual selective advantage for intra-host competition among viruses. The latter strategies confer an "unselfish" selective advantage to the virus population as a group. A mutant, defective in the gene coding for the extracellular immune function-impairment strategy, may be protected from immune attack because the wild-type virus in the same host successfully impairs the host's immune function. Such "unselfish" defense strategies are neutral with respect to intra-host competition. We present simple models of viral intra-host and combined inter- and intra-host evolution. We show that selfish strategies can evolve by intra-host evolution. Unselfish strategies may evolve if inter-host selection pressures outweigh intra-host selection, suggesting that such strategies can only evolve in viruses with low mutation rates.     

The theoretical status of latent variables.

This article examines the theoretical status of latent variables as used in modern test theory models. First, it is argued that a consistent interpretation of such models requires a realist ontology for latent variables. Second, the relation between latent variables and their indicators is discussed. It is maintained that this relation can be interpreted as a causal one but that in measurement models for interindividual differences the relation does not apply to the level of the individual person. To substantiate intraindividual causal conclusions, one must explicitly represent individual level processes in the measurement model. Several research strategies that may be useful in this respect are discussed, and a typology of constructs is proposed on the basis of this analysis. The need to link individual processes to latent variable models for interindividual differences is emphasized. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Reactance and the unwillingness to help others.

Notes that a demand, explicit or implicit, to help someone, and even a felt obligation to do this, is often resented because the demand or obligation is a bothersome threat to the individual's freedom of action. Evidence is cited in accord with J. Brehm's (see PA, Vol. 41:8061) reactance theory indicating that increased pressure to aid a person in need at times reduces the individual's willingness to help the person who is dependent upon him. Experiments demonstrate that this "reactance effect" is lessened when the individual is in a good mood and increased when he is self-concerned and when the help request seems improper or unwarranted. It is proposed that people might be induced to act helpfully, in spite of the threat to their independence, by procedures that establish helpfulness as socially desirable conduct and provide practice in behaving helpfully. (29 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The right question, wrong answers.

Comments on L. R. O'Leary's (see record 1973-25947-001) article on predicting job success via testing. The problem with using biographical data (e.g., age, sex, race) as a legitimate basis for employment selection is not a question of psychometrics but of social values and public policy. While the use of job samples is more socially defensible, it can create a set of special problems. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of group support on the evaluation of an antagonist.

"The present experiment was concerned with variations in person perception as a function of the perceiver's role in instigating a stimulus person to hostility." Perception of the stimulus person was manipulated by experimentally determining information feedback concerning acceptance of ideas by a group of which S was a part. Interpersonal perception was seen to be a function of inner (individual) as well as outer (socially determined) criteria. The results are discussed in terms of their implication for studies on person perception and in light of cognitive and frustration-aggression theories. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Multicultural approaches in psychotherapy: A rejoinder.

In this rejoinder, the authors address several issues raised by R. L. Worthington and F. R. Dillon (see record 2010-26150-001) and C. R. Ridley and M. Shaw-Ridley (see record 2011-00622-001) regarding (a) the measurement of multicultural competencies (MCCs), (b) sampling considerations in multicultural research, and (c) the conceptual frame of multicultural psychotherapy research. The authors challenge the wisdom of exploring MCCs in psychotherapy research and provide a different framework to understand therapists' multicultural effectiveness with clients based on their cultural race/ethnicity. Additionally, the concept of therapists' multicultural orientation or approach is introduced to illuminate the process of aligning with clients about salient cultural issues in psychotherapy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Race--Social, Biological, or Lemonade?

Comments on an article by R. L. Sternberg, E. L. Grigorenko, and K. K. Kidd (see record 2005-00117-006) and another article by H. Tang, T. Quertermous, B. Rodriguez, S. L. Kardia, X. Zhu, X., A. Brown, et al. (2005). On the day that I read Sternberg, Grigorenko, and Kidd's (January 2005) article on race, an article from the American Journal of Human Genetics (Tang et al., 2005) also crossed my desk. As part of their research, the latter authors compared the results of a cluster analysis of people using many genetic markers with the respondent's self-identified race/ethnicity: "Of 3,636 subjects of varying race/ethnicity, only 5 (0.14%) showed genetic cluster membership different from their self-identified race/ethnicity" (Tang et al., 2005, p. 268). I would very much like to hear a response to this finding from Sternberg et al. (2005), who maintained that "race is a socially constructed concept, not a biological one" (p. 49), that reifies those physical correlates of ancient population dispersions "as deriving from some imagined natural grouping of people that does not in fact exist, except in our heads" (p. 51). My take is that if we psychologists could use genetics (or any other biological variables) to distinguish those with schizophrenia from those with bipolar disorder with an error rate even a hundredfold greater than that of Tang et al. (2005), we would announce--and do it with no small fanfare--that there are valid, biological differences between the two disorders. I suspect that much of the difficulty in discussing this issue stems from a tendency to treat "social" and "biological" (or "genetic" and "environmental") phenomena as mutually exclusive. Placing a complicated construct like race into a discrete "social" or "biological" box makes as much sense as asking whether lemonade is (a) lemon juice, (b) water, or (c) sugar. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

冷轧平整机延伸率控制技术

介绍冷轧平整机组的延伸率控制系统,包括延伸率的定义、测量和控制技术等。对延伸率的直接和间接测量方法进行比较,分析各自的优缺点,提出在恒延伸率控制模式下,针对不同的带钢厚度,采用调节轧制力或者张力的方法来保证延伸率的恒定。     

On the complexities of measuring naming.

The aims of this study were to investigate the adequacy of electronic voice keys for the purpose of measuring naming latency and to test the assumption that voice key error can be controlled by matching conditions on initial phoneme. Three types of naming latency measurements (hand-coding and 2 types of voice keys) were used to investigate effects of onset complexity (e.g., sat vs. spat) on reading aloud (J. R. Frederiksen & J. F. Kroll, 1976, A. H. Kawamoto & C. T. Kello, 1999). The 3 measurement techniques produced the 3 logically possible results: a significant complexity advantage, a significant complexity disadvantage, and a null effect. Analyses of the performance of each voice key are carried out, and implications for studies of naming latency are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Executive function and theory of mind: Predictive relations from ages 2 to 4.

Despite robust associations between children's theory of mind (ToM) and executive function (EF) skills, longitudinal studies examining this association remain scarce. In a socially diverse sample of 122 children (seen at ages 2, 3, and 4), this study examined (a) developmental stability of associations between ToM, EF, verbal ability, and social disadvantage; (b) continuity and change in ToM and EF; and (c) predictive relations between ToM and EF. Verbal ability and social disadvantage independently predicted changes in EF (but not ToM). Task scores improved with age and showed stable individual differences. The authors examined predictive relations between ToM and EF using partial correlations (controlling for age and verbal ability) and hierarchical regressions (that also controlled for social disadvantage and initial ToM and EF). The findings provide only partial support for the view that ToM is a prerequisite for EF but stronger support for the proposal that EF facilitates children's performance on ToM tasks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Stereotype Threat and Group Differences in Test Performance: A Question of Measurement Invariance.

Studies into the effects of stereotype threat (ST) on test performance have shed new light on race and sex differences in achievement and intelligence test scores. In this article, the authors relate ST theory to the psychometric concept of measurement invariance and show that ST effects may be viewed as a source of measurement bias. As such, ST effects are detectable by means of multigroup confirmatory factor analysis. This enables research into the generalizability of ST effects to real-life or high-stakes testing. The modeling approach is described in detail and applied to 3 experiments in which the amount of ST for minorities and women was manipulated. Results indicate that ST results in measurement bias of intelligence and mathematics tests. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Within- and between-culture variation: Individual differences and the cultural logics of honor, face, and dignity cultures.

The CuPS (Culture × Person × Situation) approach attempts to jointly consider culture and individual differences, without treating either as noise and without reducing one to the other. Culture is important because it helps define psychological situations and create meaningful clusters of behavior according to particular logics. Individual differences are important because individuals vary in the extent to which they endorse or reject a culture's ideals. Further, because different cultures are organized by different logics, individual differences mean something different in each. Central to these studies are concepts of honor-related violence and individual worth as being inalienable versus socially conferred. We illustrate our argument with 2 experiments involving participants from honor, face, and dignity cultures. The studies showed that the same “type” of person who was most helpful, honest, and likely to behave with integrity in one culture was the “type” of person least likely to do so in another culture. We discuss how CuPS can provide a rudimentary but integrated approach to understanding both within- and between-culture variation. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Applied behavioral analysis of societal problems: Population change, a case in point.

Suggests that current approaches to societal problems, such as population change, have resulted in inadequate solutions and that various methodological and conceptual biases exist which limit problem solution alternatives. Applied behavior analysis approaches employ strategies which have been successful in effecting behavior change in educational, clinical, and institutional contexts and should be carefully considered in approaching population change problems. Interdisciplinary contributions are suggested that facilitate identification of relevant behaviors and selection of appropriate behavioral intervention strategies. Training programs for family planning trainers and workers are currently feasible and are felt to provide a potentially effective response to the individual family's needs. (54 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Previous personal experience and reactions to depression and physical disability.

Conducted 2 experiments with 121 undergraduates to examine the effects of prior experience with people with disability on interpersonal reactions to depression expressed by a person with a disability. In the 1st study, Ss rejected further involvement with the depressed person and perceived this person to be socially impaired. In the 2nd study, Ss ascribed significantly more negative personal characteristics to the depressed person and evidenced more stereotypic attitudes toward persons with disability than Ss who viewed the nondepressed person. Results provide evidence that prior personal experience with people with disability does not moderate negative reactions to social displays of depressive behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Assessing social approachability: Individual differences, in-group biases, and experimental control.

The willingness of strangers to approach others and engage in social interactions is a fundamental social evaluation. Yet, evidence is lacking on how well these social engagement decisions can be assessed. The authors evaluated the psychometric characteristics of an experimentally based measure of social approachability tendencies. Young adults (N = 130) rated the approachability of 48 emotionally neutral and mildly positive faces. Significant variance in approachability judgements was attributable to differences in the faces and in the participants making the judgements. Face-level approachability ratings were comparable across face gender and face race. Person-level approachability ratings identified reliable individual differences, gender, and race in-group biases, and subtle mere-exposure effect preferences. Thus, this social approachability measure is internally reliable, sensitive to individual differences, and amenable to experimental manipulations. This ability to differentiate individual-, group-, and experimental-level responses is important for furthering the understanding of the primary social decision of when to approach and socially engage others. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Race and jury selection: Psychological perspectives on the peremptory challenge debate.

The legal system is a domain of potential relevance for psychologists, whether in the capacity of expert witness or citizen juror. In this article, the authors apply a psychological framework to legal debate surrounding the impact of race on the process of jury selection. More specifically, the authors consider race and the peremptory challenge, the procedure by which attorneys may remove prospective jurors without explanation. This debate is addressed from a psychological perspective by (a) examining traditional justifications for the practice of the peremptory challenge, (b) reviewing research regarding the influence of race on social judgment, (c) considering empirical investigations that examine directly race and peremptory challenge use, and (d) assessing current jury selection procedures intended to curtail racial discrimination. These analyses converge to suggest that the discretionary nature of the peremptory challenge renders it precisely the type of judgment most likely to be biased by race. The need for additional psychological investigation of race and jury selection is emphasized, and specific avenues for such research are identified. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Artifactual and genuine relationships of lateral difference scores to overall accuracy in studies of laterality.

A persistent problem in the measurement of lateral advantage (greater ability to perform on one side—that is, one visual hemifield or ear—than on the other) has been the artifactual curvilinear relationship of the right-minus-left (R?–?L) difference score to (R?+?L) overall accuracy. This relationship is not primarily attributable to the often-cited restriction imposed by (R?+?L) overall accuracy on the possible size of the (R?–?L) difference score. Rather, the relationship is a consequence of the mere existence of a difference between mean scores on two measures of accuracy. The generality of this psychometric principle is demonstrated using two vocabulary tests. Alternative designs are described that make it possible to measure lateral advantage free from effects of the artifact. One design solution is demonstrated in two studies of how the manipulation of exposure time affects lateral advantage. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

In the Eye of the Storm: Race and Genomics in Research and Practice.

The difficulties of operationalizing race in research and practice for social, behavioral, and genetic researchers and practitioners are neither new nor related to recent genetic knowledge. For geneticists, the bases for understanding groups are clines, observed traits that gradually change in frequency between geographic regions without distinct identifiable population boundaries and population histories that carry information about the distribution of genetic variants. For psychologists, race may not exist or be a social and cultural construct associated with fluid social inferences. Because definitions of populations and race can be socially and biologically incongruent, the authors suggest that geneticists and social and behavioral scientists and clinicians attend to external validity issues by operationalizing population and racial categories and avoiding race proxies for other biological, social, and cultural constructs in research designs, data analyses, and clinical practice. (PsycINFO Database Record (c) 2010 APA, all rights reserved)