首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   3247篇
  免费   49篇
  国内免费   17篇
教育   2445篇
科学研究   264篇
各国文化   5篇
体育   340篇
综合类   177篇
信息传播   82篇
  2024年   1篇
  2023年   4篇
  2022年   26篇
  2021年   75篇
  2020年   71篇
  2019年   191篇
  2018年   215篇
  2017年   180篇
  2016年   111篇
  2015年   117篇
  2014年   261篇
  2013年   286篇
  2012年   155篇
  2011年   269篇
  2010年   127篇
  2009年   141篇
  2008年   153篇
  2007年   171篇
  2006年   115篇
  2005年   128篇
  2004年   109篇
  2003年   101篇
  2002年   55篇
  2001年   51篇
  2000年   31篇
  1999年   26篇
  1998年   13篇
  1997年   9篇
  1996年   12篇
  1995年   9篇
  1994年   6篇
  1993年   8篇
  1992年   8篇
  1991年   4篇
  1990年   3篇
  1989年   1篇
  1987年   1篇
  1985年   21篇
  1984年   4篇
  1983年   9篇
  1982年   11篇
  1981年   13篇
  1980年   4篇
  1979年   3篇
  1978年   2篇
  1977年   1篇
  1957年   1篇
排序方式: 共有3313条查询结果,搜索用时 390 毫秒
1.
In addition to money or other compensation, other motives for selling sex may be important in a welfare country such as Sweden. The aim of this study was to carry out an exploratory investigation of adolescents’ motives for selling sex in a population-based survey in Sweden. A total of 5839 adolescents from the third year of Swedish high school, mean age 18.0 years, participated in the study. The response rate was 59.7% and 51 students (0.9%) reported having sold sex. Exploratory factor analysis and hierarchical cluster analysis were used to identify groups of adolescents according to underlying motives for selling sex. Further analyses were carried out for characteristics of selling sex and risk factors. Three groups of adolescents were categorized according to their motives for selling sex: Adolescents reporting; 1) Emotional reasons, being at a greater risk of sexual abuse, using sex as a means of self-injury and having a non-heterosexual orientation. 2) Material but no Emotional reasons, who more often receive money as compensation and selling sex to a person over 25 years of age, and 3) Pleasure or no underlying motive for selling sex reported, who were mostly heterosexual males selling sex to a person under 25 years of age, the buyer was not known from the Internet, the reward was seldom money and this group was less exposed to penetrative sexual abuse or using sex as a means of self-injury. In conclusion, adolescents selling sex are a heterogeneous group in regard to underlying motives.  相似文献   
2.
Child discipline is a central component of parent-child interactions. Evidence suggests corporal discipline impairs children’s physical, cognitive, and socioemotional development and compromises their future chances, especially since it is more frequently used against at-risk children. Using geocoded data for 1209 children under the age of five and their mothers, this study analyses the relation between the occurrence of crimes in close proximity to households in four major urban municipalities of Colombia and a particularly violent corporal discipline practice: hitting children with objects. Results indicate that exposure to violent crimes, such as homicides and personal injuries, predicts a higher probability of hitting children with objects, even after controlling for a set of individual, family, and neighborhood characteristics. Sensitivity analyses suggest violent crimes are not related to other discipline methods, and less threatening crimes, such as robbery and drug trafficking, are not associated with hitting children with objects. These findings suggest households’ walls are permeable, and outside threats may interfere with families’ dynamics and well-being. Future directions and implications are discussed.  相似文献   
3.
BackgroundMaltreated youth are at an elevated risk for the development of problem behaviors. Coping with the death of a family member or close friend during adolescence, referred to as bereavement, is a stressful event that could potentiate risk linked to maltreatment. However, developmental research suggests that youth adjustment is a product of multiple risk and protective factors. Although maltreated youth who experience loss may be particularly vulnerable to behavior problems, personal and contextual factors may attenuate or exacerbate youths’ risk for internalizing and externalizing psychopathology.ObjectiveThe overarching goal of this study is to examine individual, family, and community-level protective factors for maltreated youth who experience bereavement. Specifically, we aim to examine the effect of age 12 bereavement on age 16 internalizing and externalizing psychopathology, and to investigate the moderating role of multi-level protective factors at ages 14 and 16.MethodsThe study consisted of a sample of 800 youth (52.4% female, 45.1% African-American) drawn from the Longitudinal Studies of Child Abuse and Neglect (LONGSCAN), collected from 1998 to 2011.ResultsMaltreated youth who experienced significant loss were at increased risk for externalizing symptoms, compared to non-bereaved maltreated youth (β = 0.085, p < .05). Individual future orientation (β = 0.103, p < .05) family future orientation (β = −0.120, p < .05), parental monitoring (β = −0.123, p< .01), and neighborhood collective efficacy (β = −0.126, p < .01) each significantly moderated the association between bereavement and externalizing symptoms.ConclusionsThese results have implications for future interventions aimed towards reducing problem behaviors in adolescents with a history of child maltreatment and who experience bereavement.  相似文献   
4.
The aim of the study was to determine if sex differences exist in the key elbow and wrist joint injury risk factors during different cartwheel (CW) and round-off (RO) techniques performed by young male and female artistic gymnasts. Sixteen active young gymnasts (8 males and 8 females) performed 30 successful trials of CW and RO with three different hand positions (parallel (10), T-shape (10) and reverse (10)). Synchronised kinematic and kinetic data were collected for each trial. Two-way repeated measures ANOVA (3 × 2, technique × sex) and effect-sizes (ES) were used for statistical analysis. In conclusion, female gymnasts exhibited greater normalised peak vertical ground reaction forces (VGRF), elbow and wrist compression forces and elbow internal adduction moments during CW and RO skills compared with male gymnasts. In both sexes, the parallel and reverse techniques increased peak VGRF, elbow and wrist compression forces and the elbow internal adduction moment. Increased elbow flexion resulted in decreased peak VGRF, elbow compression forces and elbow internal adduction moment. Injury risk factors including elbow extension and internal adduction moment with axial compression force suggest that a CW and RO in reverse and parallel techniques can be hazardous especially for young female gymnasts.  相似文献   
5.
随着科学技术的不断进步,人们的生活水平得到了显提高。业余时间的增加,使得人们对体育运动、活动的热情不断高涨,与此同时,体育运动事故也不断增加。有鉴于此,章以日本的学校体育运动事故实际状况为线索,从防止事故发生和安全管理的观点出发,把握、分析事故发生的主要原因,并提出建议。  相似文献   
6.
运动性贫血的发生机制与监测   总被引:29,自引:1,他引:28  
运动性贫血在体育运动 ,尤其是耐力运动中 ,不仅严重影响运动技能的发挥和成绩的提高 ,而且对身体也十分有害。高血容量反应是运动训练适应性表现 ,不会造成真正意义的贫血 ,而运动训练中红细胞溶血和铁储备状况的监测则是预防运动性贫血的重点。本文以近年来的研究进展 ,就运动性贫血的发生机制做一简述 ,并筛选取血量微、测试简易、灵敏的指标 ,加强运动训练中铁代谢和红细胞溶血等状况的监控 ,将对预防运动性贫血的发生有着十分重要的意义  相似文献   
7.
健身运动预防和治疗老年性疾病的作用   总被引:4,自引:0,他引:4  
文章就健身运动对预防和治疗老年性疾病的作用进行了理论综述研究,结合目前最新的研究成果指出健身活动对老年常见多发疾病的预防和治疗具有积极的作用。  相似文献   
8.
运用文献资料法从生物力学和解剖学的角度结合肌电图对足球运动员短距离冲刺跑时腘绳肌活动的特点进行了研究,分析了腘绳肌损伤的主要原因,并对足球运动员比赛中预防腘绳肌损伤提出合理化建议。  相似文献   
9.
山西师大新生军训伤病分析及医务监督   总被引:3,自引:0,他引:3  
通过对山西师范大学2003年夏季军训学生伤病情况进行统计分析,结果显示,军训伤病种类主要有中暑、晕厥、皮肤软组织损伤、过度紧张、运动中腹痛等。军训伤病原因及病机主要由气候炎热、心理素质、体质、生理状态不良及运动负荷过大引起,学生卫生保健知识欠缺,不注意饮食营养,休息不足,训练中没有掌握正确的动作要领而容易导致运动伤病的发生。  相似文献   
10.
警体运动损伤预防机制的研究   总被引:1,自引:0,他引:1  
警察体育运动包含大量的技战术训练内容,运动损伤的类型特点与其他运动损伤差异较大。对其深入探讨有助于提高教学和训练的成效。从警察体育运动的项目特点分析出发,探索性讨论在警察体育教学和训练中运动损伤的一般性规律,提出运动损伤的具体预防机制,供广大警体教官参考。  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号