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   2285篇
  免费   96篇
  国内免费   57篇
教育   1436篇
科学研究   451篇
各国文化   12篇
体育   239篇
综合类   169篇
文化理论   8篇
信息传播   123篇
  2024年   2篇
  2023年   17篇
  2022年   38篇
  2021年   53篇
  2020年   74篇
  2019年   57篇
  2018年   65篇
  2017年   56篇
  2016年   62篇
  2015年   58篇
  2014年   124篇
  2013年   155篇
  2012年   189篇
  2011年   158篇
  2010年   136篇
  2009年   121篇
  2008年   151篇
  2007年   176篇
  2006年   181篇
  2005年   137篇
  2004年   121篇
  2003年   82篇
  2002年   63篇
  2001年   62篇
  2000年   42篇
  1999年   12篇
  1998年   9篇
  1997年   13篇
  1996年   7篇
  1995年   3篇
  1994年   5篇
  1993年   1篇
  1991年   1篇
  1990年   1篇
  1985年   1篇
  1983年   1篇
  1982年   2篇
  1979年   1篇
  1978年   1篇
排序方式: 共有2438条查询结果,搜索用时 15 毫秒
51.
文中基于美国西部联合电网(Western Systems Coordinating Council,WSCC)3机9节点系统,建立了1个带有逆变并网接口的输电网模型,并利用逆变并网接口模型模拟了微电网与上级输电网的连接,对微电网对上级电网电压与频率的支持情况进行了数字仿真。仿真结果表明在上级输电网的有功与无功负荷发生突变时,微电网的接入使上级输电系统的有功与无功功率能够实现就地平衡,并保持系统频率与电压幅值的稳定。整个微电网系统仿真环境设定均按照实验室所能达到的低电压低容量条件下完成。文中所有仿真算法及结果均在PSCAD/EMTDC软件环境及动态模拟实验室中得到验证。  相似文献   
52.
This study explores the role of the motivational self-regulation in academic procrastination under the personality framework. Therefore, the aims of the study were to investigate: (a) the role of personality dimensions in the self-regulation of motivation; (b) the role of self-regulation of motivation in procrastination; and (c) the mediating role of the self-regulation of motivation. The participants were 274 university students (M?=?21 years). The Big Five traits explained from 6% to 17% variance of the individual motivational regulation strategies (MRSs). Both personality (conscientiousness) and the MRS (environmental control) were significant predictors of academic procrastination. Conscientiousness, agreeableness, and intellect showed an indirect effect on reducing academic procrastination, mediated through the strategy of environmental control, thus additionally suggesting the important role of this motivational strategy. Since this strategy can be taught, these findings have a strong practical value.  相似文献   
53.
唐山市依据治理理论,探索了以六项综合措施和一个评价体系为主要内容的社会矛盾综合调控"六加一"模式。实践证明具有实践和理论上的双重意义。  相似文献   
54.
利用达坂城气象站1981-2010年逐年气温、降水和大风资料,分析了近30年来气温、降水及大风的年、季变化特征,结果表明:年均气温总体呈上升趋势,线性倾向率为0.33℃/10a,年1内气温的季节变化存在差异,秋季增温明显,春夏季次之;降水量线性倾向率为9.44mm/10a,气候变湿显著,降水年际变率较大且季节分配不均;Mann-Kendall突变检验表明,气温在1991年发生一次突变,变暖趋势显著,降水在1986年发生由少向多的突变过程;大风日数、平均风速呈现波动下降过程,大风日数线性趋向率为-30.5d/10a,平均风速递减率为-0.76(m/s)/10a,春季大风发生频率最高,为33%,静风频率为10.32%;主导风向以偏西风(WNW)和东南风(SE)为主。  相似文献   
55.
目前,普通话水平测试工作存在测试员队伍管理松散、态度懒散、理论知识欠缺、新知探求动力不足、主观可操作性强等问题。本文旨在为相关领导监管工作提供帮助,保证普通话测试的顺利开展。  相似文献   
56.
我国校企合作办学制度的回顾与思考   总被引:2,自引:0,他引:2  
自新中国成立以来,我国出台了一系列支持职业教育校企合作的政策规章,以浙江宁波、四川泸州及深圳宝安等为代表的地方政府也在校企合作制度建设方面积累了一定经验。为进一步完善校企合作办学制度,我国政府应进一步加强校企合作法规及相关激励与监督机制建设;同时,促进职业院校完善校企合作办学规章制度,引导企业构建校企合作的配套机制。  相似文献   
57.
ObjectivesMaltreatment is linked with poor health outcomes. Attachment and affect regulation may mitigate the long-term impact of these adverse experiences on health outcomes. Little is known about the relative impact of maternal versus paternal maltreatment and interparental violence (IPV) on general health status of female and male youth.MethodThe present study examined the impact of exposure to maternal and paternal emotional and physical maltreatment, neglect, IPV, and cumulative maltreatment exposure in adolescence on general physical health problems reported five years later. High-risk youth (N = 179; Mage = 15.34, SD = 1.53; 46.4% female) self-reported maltreatment experiences, attachment insecurity, and affect dysregulation at Time 1; and affect dysregulation and physical health five years later at Time 2.ResultsAttachment insecurity accounted for the effect of maternal and paternal emotional maltreatment, and maternal and paternal cumulative maltreatment exposure, on physical health. Additionally, attachment insecurity accounted for the effect of paternal neglect on physical health. Further sex differences were found with regard to maltreatment type and are discussed.ConclusionBoth maternal and paternal maltreatment in adolescence predicted poor general health five years later via attachment insecurity. Youth who lack a secure attachment with their parents are most vulnerable to these impacts.  相似文献   
58.
BackgroundMaternal childhood experiences of maltreatment affect parenting and have consequences for a child’s social-emotional development. Adolescent mothers have a higher frequency of a history of maltreatment than adult mothers. However few studies have analyzed the interactions between adolescent mothers with a history of childhood maltreatment and their infants.ObjectiveThe aim of the study was to examine the effect of maternal childhood experiences of maltreatment on mother-infant emotion regulation at infant 3 months, considering both infant and mother individual emotion regulation and their mutual regulation.ParticipantsParticipants were 63 adolescent and young adult mother-infant dyads recruited at a hospital.MethodsThe mothers were administered the Adult Attachment Interview to evaluate reflective functioning and attachment and the Childhood Experiences of Care and Abuse was used to evaluate maternal childhood experiences of maltreatment. Mother-infant interactions were coded with a modified version of the Infant Caregiver Engagement Phases.ResultsDyads with mothers with childhood maltreatment (vs dyads with mothers with no maltreatment) spent more time in negative emotional mutual regulation (p = .009) and less time in positive and neutral mutual emotion regulation (p = .019). Cumulative maternal childhood experiences of maltreatment were associated positively with mother and infant negative states at individual and dyadic level and with the AAI scales of Passivity and Unresolved Trauma (p < .05). The effect of cumulative maternal childhood experiences of maltreatment on mother-infant emotion regulation was direct and not mediated by maternal attachment and reflective function.ConclusionsMaternal childhood experiences of maltreatment increase the risk connected to early motherhood, affecting mother-infant emotion regulation.  相似文献   
59.
BackgroundEarly adversity and negative experiences in the adoptive family can put adopted children at risk for emotional and behavior problems.ObjectiveThis study analyzes the influence of children’s preadoptive history and adoptive parents’ characteristics on the psychosocial adjustment of nationally and internationally adopted children in Germany.Participants and settingThe survey included 172 adopted children aged between 24 and 145 months and their adoptive parents.MethodsParents provided information about preadoptive history. Information about emotional and behavior problems was obtained from the parental version of the Strengths and Difficulties Questionnaire (SDQ). Parental well-being was obtained through a composite score of three standardized measures (self-efficacy questionnaire, Perceived Stress Scale PSS-4, Brief Symptom Inventory BSI); parenting behavior was assessed with the Alabama Parenting Questionnaire (DEAPQ).Results12.5% of the adopted children scored in the clinical range of the SDQ. In a multiple regression analysis, the experience of maltreatment and neglect was the most important predictor of emotional and behavior problems at time of assessment, followed by pre- and perinatal risk and parental stress regulation difficulties, = .423, F(4, 128) = 28.539. Increases in the number of risk factors present were associated with a greater odd of children scoring in the clinical range of the SDQ.ConclusionsMost of the nationally and internationally adopted children in this sample were well-adjusted. Prenatal and preadoptive risk as well as stress regulation capacities of the main caregiver contributed to the child’s development. An accumulation of risks increased the likelihood of adjustment problems in adopted children.  相似文献   
60.
ObjectivesChildhood maltreatment (CM) and cognitive emotion regulation strategies (CERSs) may be important in alcohol craving and dependence in alcohol-dependent individuals. The aim of this study was to evaluate direct effects of CM on the subscales of alcohol craving and alcohol dependence and its indirect effects via CERSs in individuals with a diagnosis of alcohol dependence.MethodsIn a cross-sectional design, 329 alcohol-dependent males completed the Childhood Trauma Questionnaire-Short Form (CTQ-SF), the Cognitive Emotion Regulation Questionnaire-Short version (CERQ-Short), the Alcohol Dependence Scale (ADS), the Obsessive Compulsive Drinking Scale (OCDS), and the Beck Depression Inventory-II (BDI-II).ResultsParticipants with alcohol dependence had early age of onset of alcohol use (mean = 20.78 years), relatively long duration of alcohol use (mean = 11.14 years), and low education (mean = 9.55 years). Indirect effects were observed from CM to the subscales of alcohol craving and dependence only through maladaptive CERSs after adjusting for demographic and clinical factors. No direct effect was observed through CM on the subscales of alcohol craving and dependence.ConclusionsAlthough drawing causal conclusions from the current research is impossible, the findings suggest that maladaptive CERSs may be a possible mechanism relating CM to alcohol craving and dependence in treatment-seeking alcohol-dependent individuals, while adaptive CERSs may be less important regarding this relation. However, the findings of the current study need longitudinal research.  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