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   5618篇
  免费   1466篇
  2021年   86篇
  2020年   115篇
  2019年   419篇
  2018年   313篇
  2017年   429篇
  2016年   427篇
  2015年   392篇
  2014年   329篇
  2013年   747篇
  2012年   347篇
  2011年   292篇
  2010年   277篇
  2009年   263篇
  2008年   257篇
  2007年   188篇
  2006年   171篇
  2005年   183篇
  2004年   160篇
  2003年   172篇
  2002年   176篇
  2001年   117篇
  2000年   115篇
  1999年   81篇
  1998年   39篇
  1997年   42篇
  1996年   48篇
  1995年   42篇
  1994年   34篇
  1993年   39篇
  1992年   38篇
  1991年   39篇
  1990年   38篇
  1989年   33篇
  1988年   41篇
  1987年   41篇
  1986年   31篇
  1985年   35篇
  1984年   33篇
  1983年   33篇
  1982年   35篇
  1981年   42篇
  1980年   36篇
  1979年   20篇
  1978年   40篇
  1977年   36篇
  1976年   27篇
  1975年   26篇
  1974年   24篇
  1973年   23篇
  1972年   16篇
排序方式: 共有7084条查询结果,搜索用时 31 毫秒
131.
OBJECTIVE: The premise that pessimistic health appraisals compromise well-being whereas optimistic appraisals are compensatory was examined in a longitudinal study of 232 community-dwelling older adults (ages 79-98 years). DESIGN: Subjective health (SH) appraisals were contrasted with objective health (OH) to identify realists, whose ratings were congruent (SH = OH), distinguishing them from health pessimists (SH < OH) and health optimists (SH > OH), whose ratings were incongruent. Analyses of covariance were used to examine group differences 2 years later on well-being and health care. MAIN OUTCOME MEASURES: Outcome measures were psychological well-being (life satisfaction, positive and negative emotions), functional well-being (objective and perceived physical activity, activity restriction), and health care (health care management, hospital admissions, length of hospital stays). RESULTS: Compared with realists, pessimists had significantly poorer outcomes and optimists had better outcomes. Because perceived control (PC) was weaker among pessimists and stronger among optimists, supplemental analysis determined whether PC differences explained these findings. When accounting for PC, many pessimism and optimism effects became nonsignificant, yet effects on functional well-being remained unchanged. CONCLUSION: Findings have implications for older adults at risk of functional decline.  相似文献   
132.
Recent experience with attempts to test relatively simple patterns such as three-tone sequences in a traditional dichotic-listening paradigm indicates that when such sequences are used for both target and contralateral interference, performance tends to be low in both ears and not useful for measuring or comparing ear advantages in various target conditions. It is reported that tests with a variety of sounds presented contralaterally to three-element patterns show that several such sounds can (1) allow performance in at least one ear to remain above floor values, (2) result in performance in at least one ear that is below ceiling, and (3) reveal ear advantages that are similar in direction and magnitude to those seen with the traditional dichotic paradigm.  相似文献   
133.
134.
135.
This paper proposes an approach for strategic revenue management under uncertainty for real estate projects. It integrates three modelling techniques: first, artificial neural network integrated support vector machines for forecasting the profit and loss‐making real estate residential projects; second, analytical network process approach using decision making trials and evaluation laboratory methodology for establishing interrelationships among factors; and third, multiobjective genetic algorithm approach for obtaining optimal numbers and types of apartments in a real estate project. We compare the respective revenues generated with the new number of apartments and price from the suggested revenue maximization model and that of the old practiced one through a case study of India. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   
136.
The sociological literature has produced a remarkably consistent picture of the quantitative patterns of religious disaffiliations in Western countries. This article argues, and demonstrates, that strong changes in a social context may lead individuals to disaffiliate rapidly, leading to very different aggregate effects from those in the “western model.” We use the unique situation of the separation of Germany from 1949 to 1989 and its subsequent reunification as a “natural experiment” to show just how much the relationships routinely found can be disrupted under changed conditions. The state socialist “treatment” affected religious disaffiliations in East Germany profoundly as it (a) made disaffiliations 10 times more probable in the East than in the West in the 1950s and 1960s, (b) shielded East German church members from factors that led to mass disaffiliations in the West in the late 1960s and early 1970s, (c) reversed the education‐disaffiliation link in the East, thus making disaffiliation more likely among the less educated, and (d) led to an especially strong increase in disaffiliations in the East right after the reunification  相似文献   
137.
In jurisdictions throughout the United States, thousands of sexual assault kits (SAKs; also known as a “rape kits”) have not been submitted by the police for forensic DNA testing. DNA evidence may be helpful to sexual assault investigations and prosecutions by identifying perpetrators, revealing serial offenders through DNA matches across cases, and exonerating those who have been wrongly accused. This paper describes a longitudinal action research project conducted in Detroit, Michigan after that city discovered approximately 11,000 untested sexual assault kits in a police department storage facility. We conducted a root cause analysis to examine individual, organizational, community, and societal factors that contributed to the development of the rape kit backlog in Detroit. Based on those findings, we implemented and evaluated structural changes to increase staffing, promote kit testing, and retrain police and prosecutors so that cases could be reopened for investigation and prosecution. As we conducted this work, we also studied how this action research project impacted the Detroit criminal justice system. Participating in this project changed stakeholders’ attitudes about the utility of research to address community problems, the usefulness of DNA evidence in sexual assault cases, and the impact of trauma on survivors. The results led to new protocols for SAK testing and police investigations, and new state legislation mandating SAK forensic DNA testing.  相似文献   
138.
Women of Haitian descent living in the Dominican Republic experience oppression due to their gender, ethnicity, and economic status. They also exhibit high rates of participation in evangelical Christian communities, a paradoxical finding given the restricted roles women have traditionally played in these settings. The goals of this study were to explore the perceived benefits of participation in evangelical communities and the setting characteristics that lead to these benefits. The research team interviewed 19 current and former church participants aged 18–59. Thematic analysis revealed three perceived benefits of congregational life. Participants viewed their participation as: (a) an opportunity for personal growth and development; (b) protective against negative social influences; and (c) providing social support in the face of life challenges. In addition, dependable, expected, and reciprocal relational support was a key characteristic of evangelical communities. Findings extend the current understanding of how religious communities enhance well‐being for marginalized women through social support networks. Findings also explore the dialectical nature of settings as both empowering and disempowering. Implications for future interventions are discussed.  相似文献   
139.
We investigated ADHD symptoms and CU traits as predictors of violent media use in adolescence, controlling for delinquency and ODD symptoms. The effects on of disinhibition and arousal to negative stimuli, core characteristics of ADHD symptoms and CU traits, and of gender were investigated. At age 15, 88 adolescents, 50 % boys reported on CU traits, ADHD symptoms and delinquency. Parents rated the adolescents’ CU traits, ADHD‐ and ODD symptoms. At age 16, adolescents reported on their media habits and performed tests of disinhibition and arousal to negative stimuli. Boys had higher levels of CU traits and violent media use and girls had higher levels of arousal to negative pictures. CU traits and inattention symptoms predicted violent media use, the latter association applying only to boys, with CU traits being the strongest predictor. Low arousal to threat pictures explained variance in violent media use, above CU traits. Attraction to violent media seems affected by problem behaviors, with CU traits coming forth as especially important.  相似文献   
140.
Identifying the specificity of students’ individual interest in physical education is necessary to capture the different facets of this construct. In contrast to existing questionnaires in education which assess the multidimensionality of individual interest, the current scale used in physical education consists of a single‐item measurement which rates students’ individual interest for multiple physical activities taught during lessons. Even if this single‐item rating provides a basis for classifying interest relative to others, it does not provide information about the nature and internal components of individual interest. Therefore, the purpose of this study was to develop a valid and reliable questionnaire measuring the multidimensionality of students’ individual interest in physical education. Four stages were followed: (1) the development of a preliminary version based on the findings of a literature review on individual interest and a committee process validation; (2) a first study conducted on 481 secondary school students to establish the factor structure, and internal reliability of this questionnaire; (3) a second study based on 243 secondary school students to confirm its factor structure and to test its temporal stability; and finally, (4) a third study with 253 students to test its concurrent validity. The final form of the questionnaire consists of a three‐factor structure based on 14 items that measure students’ individual interest in physical education: positive affect and willingness to reengage (five items), stored utility value (four items), and stored attainment value and knowledge‐seeking intentions (five items).  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