Do Lions Have Manes? For Children,Generics Are About Kinds Rather Than Quantities

Generic statements (e.g., “Lions have manes”) make claims about kinds (e.g., lions as a category) and, for adults, are distinct from quantificational statements (e.g., “Most lions have manes”), which make claims about how many individuals have a given property. This article examined whether young children also understand that generics do not depend purely on quantitative information. Five‐year‐olds (n = 36) evaluated pairs of questions expressing properties that were matched in prevalence but varied in whether adults accept them as generically true (e.g., “Do lions have manes?” [true] vs. “Are lions boys?” [false]). Results demonstrated that children evaluate generics based on more than just quantitative information. Data suggest that even young children recognize that generics make claims about kinds.     

Collisionless tool orientation smoothing above blade stream surface using NURBS envelope

In five-axis machining,tool orientation above a blade stream surface may lead to tool collision and a decrease in workpiece rigidity.Hence,collisionless tool orientation smoothing(TOS)becomes an important issue.On the basis of a constant scallop height tool path,the triangular facets in the faces,vertices format are constructed from cutter contact(CC)using the Voronoi incremental algorithm.The cutter location(CL)points candidate set is represented by an oblique elliptic cone whose vertex lies at CC using NURBS envelope.Whether the CL point is above its CC is judged by the dot product between the normal vector and the point on triangulation nearest to the CL point.The curvatures at CC are obtained by fitting a moving least square(MLS) quadratic patch to the local neighborhood of a vertex and calculating eigenvectors and eigenvalues of the Hessian matrix.Triangular surface elastic energy is employed as the weight in selection from the NURBS envelope.The collision is judged by NURBS surface intersection.TOS can then be expressed by selecting a CL point for each CC point and converted into a numerical control(NC)code automatically according to the postprocessor type of the machine center.The proposed method is verified by finishing of a cryogenic turboexpander impeller of air separation equipment.     

Individual Differences in Children's and Parents' Generic Language

Generics (“Dogs bark”) convey important information about categories and facilitate children's learning. Two studies with parents and their 2‐ or 4‐year‐old children (N = 104 dyads) examined whether individual differences in generic language use are as follows: (a) stable over time, contexts, and domains, and (b) linked to conceptual factors. For both children and parents, individual differences in rate of generic production were stable across time, contexts, and domains, and parents' generic usage significantly correlated with that of their own children. Furthermore, parents' essentialist beliefs correlated with their own and their children's rates of generic frequency. These results indicate that generic language use exhibits substantial stability and may reflect individual differences in speakers' conceptual attitudes toward categories.     

Science in the Classroom: Finding a Balance Between Autonomous Exploration and Teacher-Led Instruction in Preschool Settings

Research Findings: This paper reports on children's use of science materials in preschool classrooms during their free choice time. Baseline observations showed that children and teachers rarely spend time in the designated science area. An intervention was designed to “market” the science center by introducing children to 1 science tool, the balance scale. Baseline measures showed that children did not know the scale's name or function. The intervention was expected to increase children's use of the science area and their knowledge about the scale. Children's voluntary presence and exploration in the science area increased after the balance scale intervention compared to in comparison classrooms. Furthermore, children who participated in this intervention demonstrated improved knowledge about the scale's function, whereas students in the comparison group did not. Practice or Policy: Adults can increase children's autonomous exploration of science tools and materials, and their knowledge about them, by offering particular kinds of large-group learning experiences.     

儿童民族认同的形成与发展

民族认同是儿童自我概念发展的重要内容,尤其对少数民族更为重要。国外研究发现,儿童在5岁后就能产生民族分类意识,并产生内群偏爱,在10岁会出现民族内隐态度和外显态度的分离现象;民族认同与民族刻板印象、偏见和歧视有重要联系;影响民族认同发展的因素有儿童认知发展水平、父母与同伴的种族（族群）态度、家庭社会化、群际接触等。国内研究者应该开展本土化的研究,发现我国儿童民族认同形成与发展的规律,对于促进族际互动、构建和谐的民族关系具有重要的理论和现实意义。     

Boys Will Be Boys; Cows Will Be Cows: Children's Essentialist Reasoning About Gender Categories and Animal Species

Two studies ( N =  456) compared the development of concepts of animal species and human gender, using a switched-at-birth reasoning task. Younger children (5- and 6-year-olds) treated animal species and human gender as equivalent; they made similar levels of category-based inferences and endorsed similar explanations for development in these 2 domains. In contrast, 10-year-olds and adults treated gender and species concepts as distinct from one another. They viewed gender-linked behavioral properties as open to environmental influence and endorsed environment-based mechanisms to explain gender development. At all ages, children demonstrated differentiated reasoning about physical and behavioral properties, although this differentiation became more stable with age. The role of psychological essentialism in guiding conceptual development is discussed.     

Robots and rodents: children's inferences about living and nonliving kinds

This study tests the firm distinction children are said to make between living and nonliving kinds. Three, 4-, and 5-year-old children and adults reasoned about whether items that varied on 3 dimensions (alive, face, behavior) had a range of properties (biological, psychological, perceptual, artifact, novel, proper names). Findings demonstrate that by 4 years of age, children make clear distinctions between prototypical living and nonliving kinds regardless of the property under consideration. Even 3-year-olds distinguish prototypical living and nonliving kinds when asked about biological properties. When reasoning about nonbiological properties for the full range of items, however, even 5-year-olds and adults occasionally rely on facial features. Thus, the living/nonliving distinction may have more narrow consequences than previously acknowledged.     

Do Varieties of Spanish Influence U.S. Spanish–English Bilingual Children's Friendship Judgments?

Latinos are the largest minority group in the United States (U.S. Census, 2014), yet this term comprises individuals from multiple ethnicities who speak distinct varieties of Spanish. We investigated whether Spanish–English bilingual children (N = 140, ages 4–17) use Spanish varieties in their social judgments. The findings revealed that children distinguished varieties of Spanish but did not use Spanish dialects to make third-person friendship judgments until 10–12 years; this effect became stronger in adolescence. In contrast, young children (4–6 years) made friendship judgments based on a speaker's language (English, Spanish). Thus, using language varieties as a social category and as a basis for making social inferences is a complex result of multiple influences for Spanish-speaking children growing up bilingual in the United States.     

试论提升大学生就业能力的方法与途径

大学生就业能力直接影响一个国家社会经济发展的水平与大学生自我价值的实现。本文通过分析当前大学生就业形势的特点,并针对我国高等教育发展的现状和高校教学实践,从政府、高校、大学生自身三个方面探讨并提出提升大学生就业能力的方法和途径。     

浅谈输变电工程质量管理

文章结合牙克石——扎兰屯220KV输变电工程、海拉尔——扎赉诺尔220KV输变电工程、海拉尔——伊敏220KV输变电工程、扎兰屯——尼尔基220KV输变电工程等十多项榆变电工程施工管理经验,围绕工程质量管理这一课题,进行了探讨。