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   1355篇
  免费   55篇
  国内免费   4篇
管理学   50篇
民族学   12篇
人口学   36篇
丛书文集   137篇
理论方法论   65篇
综合类   960篇
社会学   138篇
统计学   16篇
  2023年   11篇
  2022年   6篇
  2021年   11篇
  2020年   24篇
  2019年   18篇
  2018年   20篇
  2017年   27篇
  2016年   29篇
  2015年   55篇
  2014年   62篇
  2013年   91篇
  2012年   84篇
  2011年   87篇
  2010年   63篇
  2009年   86篇
  2008年   76篇
  2007年   90篇
  2006年   107篇
  2005年   74篇
  2004年   92篇
  2003年   83篇
  2002年   59篇
  2001年   56篇
  2000年   26篇
  1999年   20篇
  1998年   8篇
  1997年   7篇
  1996年   6篇
  1995年   10篇
  1994年   1篇
  1993年   5篇
  1992年   6篇
  1991年   3篇
  1990年   7篇
  1989年   3篇
  1988年   1篇
排序方式: 共有1414条查询结果,搜索用时 31 毫秒
1.
The idea that language skills support school readiness, predicting later self‐regulation and academic success, is widely accepted. Although vocabulary is often emphasized in the developmental literature, the ability to use language appropriately in the classroom, or social communication skills, may also be critical. This article examined longitudinal contributions of children's vocabulary and social communication skills, from preschool to kindergarten, to kindergarten academic achievement (reading and math) and self‐regulation (executive functions and learning behaviors). Participants were 164 children (14% Latinx, 30% Black, 56% White; 57% girls) enrolled in Head Start programs. Results revealed that initial levels and growth in vocabulary and communication skills predicted better academic achievement. Social communication skills uniquely predicted self‐regulation, after accounting for vocabulary. We discuss potential mechanisms for these links and recommend that strategies to build social communication skills be incorporated in preschool interventions promoting school readiness.  相似文献   
2.
新疆陆梁油田呼图壁河组油藏发育一类特殊的薄层底水型油藏,其特点是油层厚度薄,构造幅度低,底水能量大,利用水平井开采,表现出无水采油期短、含水率上升速度快、产量递减大的特点。针对这些问题,采用水平井数值模拟方法,建立了考虑摩擦压力损失的水平井井筒模型,明确了摩擦压力损失对水平井的压力分布以及水平段产量的影响,在此基础上,分析研究了水平井底水锥进的水脊特征,判断了水平井出水位置,提出了封堵出水井段并结合油藏工程方法确定了水平井合理产液量,从而达到抑制底水快速锥进,减小压力损失,降低含水率上升速度的目的。  相似文献   
3.
Prominent authors in the behavioral genetics tradition have long argued that shared environments do not meaningfully shape intelligence and academic achievement. However, we argue that these conclusions are erroneous due to large violations of the additivity assumption underlying behavioral genetics methods – that sources of genetic and shared and nonshared environmental variance are independent and non-interactive. This is compounded in some cases by the theoretical equation of the effective and objective environments, where the former is defined by whether siblings are made more or less similar, and the latter by whether siblings are equally subject to the environmental characteristic in question. Using monozygotic twin fixed effects models, which compare outcomes among genetically identical pairs, we show that many characteristics of objectively shared environments significantly moderate the effects of nonshared environments on adolescent academic achievement and verbal intelligence, violating the additivity assumption of behavioral genetic methods. Importantly, these effects would be categorized as nonshared environmental influences in standard twin models despite their roots in shared environments. These findings should encourage caution among those who claim that the frequently trivial variance attributed to shared environments in behavioral genetic models means that families, schools, and neighborhoods do not meaningfully influence these outcomes.  相似文献   
4.
人工智能技术的发展对传统著作权制度带来了显著的冲击。以人工智能生成物著作权第一案为例,通过审视作品构成要件判断标准发现,独创性始终贯彻以人类作者为中心的评价标准,同时,智力成果要件则是认定人工智能生成物构成著作权法意义上作品与否的重要标准。从人类是否实际参与作品的创作过程来看,多数人工智能生成物不构成作品,而保护人工智能生成物的价值追求与邻接权制度的基本理念相适应,且邻接权制度的扩张趋势也为把人工智能生成物纳入其保护范畴创造了机会。建议立法通过扩张邻接权制度的权利内容与客体类型以对人工智能生成物提供必要保护。而在当前阶段,反不正当竞争法可以为人工智能生成物相关利益主体提供一定限度的过渡保护。  相似文献   
5.
In the current paper, we employ the most recent Programme for International Student Assessment (PISA) data to calculate a less-biased estimate of poverty on US achievement. The PISA was specifically chosen as it is an assessment removed from a specific curriculum and instead focuses on concepts that students should know in order to participate in a global economy. Using a propensity score matching approach, our findings suggest that US students in poverty have notable educational attainment deficiencies compared to a matched group of students who are not in poverty. In other words, when we select two students who have a great deal in common but for the fact that one comes from a poverty background, the student in poverty is expected to perform nearly 28 points, or about a quarter of a standard deviation lower, on the PISA assessment. In real terms, this puts math achievement for children not in poverty on-par with the Organisation for Economic Co-operation and Development (OECD) average, while children in poverty are well below the OECD average.  相似文献   
6.
从世界石油经济和供求前景分析出发,得到了石油工业上游领域必须重视难拿储量、重视改造挖潜、重视增产增效、重视提高探井水平的结论。从这些必须要重视的技术领域出发,分析了地质特点、储层特点和经济技术特点,指出了完成这些艰巨任务必须要采用低压欠平衡钻井技术。最后介绍了国外低压欠平衡钻井技术发展的现状及存在问题,结合西南石油学院近7年的储备研究成果,介绍了我国低压欠平衡钻井技术发展的重点和方向。  相似文献   
7.
We examined the moderating roles of individualistic and collectivistic cultural orientations and academic achievement on the relation between Chinese adolescents’ shyness and depressive symptoms. A sample of Chinese adolescents (N = 492) from an urban school participated in the study during seventh (T1) and eighth (T2) grades. Adolescents self‐reported their shyness, cultural orientations, and depressive symptoms. The school provided records of their academic achievement. Concurrently, shyness and individualism were positively whereas collectivism and academic achievement were negatively, associated with adolescents’ depressive symptoms. Longitudinally, T1 shyness (but not individualism, collectivism, or academic achievement) predicted T2 depressive symptoms after controlling for stability in depressive symptoms. Concurrent relations between shyness and depressive symptoms were moderated by adolescents’ cultural orientations. Specifically, collectivism was protective whereas individualism was harmful, for shy adolescents’ adjustment. Furthermore, collectivism and academic achievement jointly moderated the relations between shyness and depressive symptoms concurrently and longitudinally. The results suggest that cultural orientations may influence shy adolescents’ depression symptoms through individual‐level self‐evaluation, and indicate that cultural factors and academic achievement need to be considered comprehensively for understanding and improving shy Chinese adolescents’ psychological adjustment.  相似文献   
8.
放松卖空管制后,投资者可通过挖掘公司“坏消息”在资本市场投资获利,在允许被卖空情境中,公司内部股东和管理层面临股价下行压力增大,会积极采取行动以规避被卖空的风险。借助中国证券市场2010年开始逐步放松卖空管制的准自然实验,以2007—2015年上市公司为样本,考察卖空压力对企业债券契约的影响。研究发现:放松卖空管制与企业债券期限显著负相关,特别是在大股东持股比例较高和管理层市场压力更大时。进一步分析发现,放松卖空管制与企业债务期限结构显著负相关,表明放松卖空管制会促使企业缩短发行债券的期限。研究结果显示,面对放松卖空管制引起的股价下行压力,公司大股东和管理层为了规避被卖空风险,会积极选择缩短发行债券期限以传递信号,证实了卖空机制对改善市场信息环境的积极作用。政府可以通过加强卖空机制制度建设和监管,推动企业调整行为决策,降低信息不对称。  相似文献   
9.
经济承压背景下中国能源经济预测与展望   总被引:1,自引:0,他引:1  
2019年中央经济工作会议强调,中国正处在转变发展方式、优化经济结构、转换增长动力的攻关期,经济下行压力不断加大。以此为背景阐述能源经济发展现状,分析重点行业发展前景,通过不同情景下的预测分析,探讨经济承压背景下中国能源经济发展的路径与趋势。根据预测结果,经济承压对各行业的能源消费量存在普遍影响,尤其是煤炭、黑色金属冶炼和汽车行业的能源消费量在未来一段时间将呈下降趋势;在基准情形下,预计到2030年,中国GDP将达到171.97万亿元(2018年不变价水平),能源消费总量约57.09亿吨标准煤,煤炭消费占比将不断下降,清洁能源占比预计达到41.7%。根据预测结果,有针对性地在能源消费结构、能源效率和能源合作方面提出政策建议。  相似文献   
10.
摘 要:目的:为明确父母教养方式对小学高年级学生学业拖延的作用机制,本研究构建了一个有调节的中介模型,考察了自我概念在二者关系中的中介作用以及成就动机的调节作用。方法:以1181名小学生为被试,采用问卷法对其学业拖延程度、父母教养方式以及自我概念和成就动机进行调查。结果:1)在控制了性别、年级和独生与否后,父亲教养方式对学业拖延具有显著的负向预测作用,而母亲教养方式对学业拖延的预测不显著。2)自我概念能够在父母教养方式与拖延的关系中起中介作用;3)成就动机对中介路径后半段具有显著的调节作用。结论:自我概念很有可能是父母教养方式影响小学高年级学生学业拖延的重要中间环节,而上述中介效应会受到成就动机的调节。  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