全文获取类型
收费全文 | 494篇 |
免费 | 49篇 |
国内免费 | 129篇 |
专业分类
672篇 |
出版年
2024年 | 3篇 |
2023年 | 8篇 |
2022年 | 25篇 |
2021年 | 17篇 |
2020年 | 16篇 |
2019年 | 10篇 |
2018年 | 16篇 |
2017年 | 24篇 |
2016年 | 16篇 |
2015年 | 13篇 |
2014年 | 15篇 |
2013年 | 38篇 |
2012年 | 23篇 |
2011年 | 35篇 |
2010年 | 39篇 |
2009年 | 35篇 |
2008年 | 30篇 |
2007年 | 46篇 |
2006年 | 54篇 |
2005年 | 35篇 |
2004年 | 36篇 |
2003年 | 28篇 |
2002年 | 25篇 |
2001年 | 13篇 |
2000年 | 15篇 |
1999年 | 6篇 |
1998年 | 5篇 |
1997年 | 6篇 |
1996年 | 2篇 |
1995年 | 6篇 |
1994年 | 6篇 |
1993年 | 5篇 |
1992年 | 2篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1983年 | 3篇 |
1982年 | 3篇 |
1981年 | 3篇 |
1980年 | 1篇 |
排序方式: 共有672条查询结果,搜索用时 0 毫秒
81.
Sarah L. Anderson Yao Zheng Robert J. McMahon 《Journal of abnormal child psychology》2017,45(6):1147-1156
Conduct disorder (CD) symptoms and callous-unemotional (CU) traits have been shown to be uniquely associated with risky sexual behavior (RSB) in adolescence and early adulthood, yet their interactive role in predicting RSB remains largely unknown. This study aimed to investigate the predictive value of CD symptoms and CU traits, as well as their interaction, on several RSB outcomes in adolescence and early adulthood. A total of 683 participants (41.7 % female, 47.4 % African American) were followed annually and self-reported age of first sexual intercourse, frequency of condom use, pregnancy, contraction of sexually transmitted infections, and engagement in sexual solicitation from grade 7 to 2-years post-high school. CD symptoms predicted age of first sexual intercourse, condom use, and sexual solicitation. CU traits predicted age of first sexual intercourse and pregnancy. Their interaction predicted a composite score of these RSBs such that CD symptoms positively predicted the composite score among those with high levels of CU traits but not among those with low levels of CU traits. The current findings provide information regarding the importance of both CD symptoms and CU traits in understanding adolescent and early adulthood RSB, as well as the benefits of examining multiple RSB outcomes during this developmental period. These findings have implications for the development and implementation of preventive efforts to target these risky behaviors among adolescents and young adults. 相似文献
82.
Guohua Fan Lin Geng Zhenzhu Zheng Xiping Cui Dong Hu 《Philosophical Magazine Letters》2017,97(6):241-248
The aim of the present study is to reveal the most critical underlying factor influencing the mechanical properties of metal matrix composites (MMCs). It is shown that the mechanical properties of MMCs are essentially governed by the degree of strain localisation during plastic deformation. In other words, the MMCs exhibit superior mechanical performance only if the strain localisation is obviously inhibited and the accumulated stresses can be effectively transferred out. The work provides a new perspective in guiding the design of next-generation high-performance MMCs by suppressing the strain localisation as far as possible. 相似文献
83.
84.
中国文化中自尊结构的内隐社会认知研究 总被引:21,自引:4,他引:17
本研究同时运用外显的自陈式量表和自行设计的内隐联想测验(IAT)及Go/No-go联想任务(GNAT)来研究中国大学生的自尊结构,结果表明:(1)运用内隐联想测验和Go/No-go联想任务来测量内隐自尊是敏感的;(2)中国文化中自尊是一个双重的结构:包括一个内隐的成分和一个外显的成分。(3)自尊在内隐和外显两个层面上都不存在性别差异。 相似文献
85.
人格特质对选择性加工偏向的影响 总被引:6,自引:0,他引:6
采用词性辨别和注意探测任务,考察了神经质和外倾性对选择性加工偏向的影响。结果表明:(1)放试在选择信息时存在特质一致性倾向;(2)在单一刺激条件下,当刺激词呈现时间为0.5s时,高神经质对所有效价词的RT均快于低神经质;而当呈现时间为1.0s时,外倾者比内倾者的反应潜伏期更短4(3)双重刺激条件下的选择性加工偏向比单一刺激条件更明显;(4)在词性辨别任务中.刺激词呈现时间只影响了神经质被试对情绪词的RT;在注意探测任务中,呈现时间对内外倾被试的加工偏向影响不显著。 相似文献
86.
87.
食管癌内镜技术最优化原则的思考 总被引:1,自引:0,他引:1
随着消化内镜及其配件的不断更新和内镜医师操作技术的进步,消化内镜在食管癌的应用从诊断为主发展到诊断与治疗并重.回顾历史,医疗需求是医学科学进步的强大动力,科学技术进步推动医学的发展,内镜技术的发展促进了食管癌诊断与治疗水平的最优化. 相似文献
88.
89.
120名在校孤儿影响学习的心理因素调查研究 总被引:5,自引:0,他引:5
本文研究120名在校孤儿影响其学习的儿项心理因素情况.录川问卷测验法和个案调查法,结果表明:孤儿的智力水平、心理健康水平低于同龄正常儿童,提高学习能力较差,问题行为较多,但在校学习方法、与教师关系较好。 相似文献
90.
Age-related degeneration of intracortical inhibition could underlie declines in cognitive function during senescence. Based
on a hypothesis that a decrease in basal concentration of ambient (extrasynaptic) GABA with aging leads to depressing intracortical
inhibition, we investigated how the basal concentration affects stimulus-evoked activity (as signal), ongoing-spontaneous
activity (as noise) of neurons and their (signal-to-noise) ratio S/N. We simulated a neural network model equipped with a
GABA transport system that regulates ambient GABA concentration in a neuronal activity-dependent manner. An increase in basal
concentration augmented ambient GABA, increased GABA-mediated inhibitory current, and depressed ongoing-spontaneous activity
while still keeping stimulus-evoked activity. This led to S/N improvement, for which it was necessary for the reversal potential
of GABA transporter to be close to the resting potential of neurons. Above the resting potential, ongoing-spontaneous activity
was predominantly enhanced due to excessive GABA-uptake from the extracellular space by transporters. Below the resting potential,
stimulus-evoked activity was predominantly depressed, caused by excessive GABA-release. We suggest that the insufficient augmentation
of ambient GABA due to a decrease in its basal concentration may be one of the possible causes of cognitive deficit with aging,
increasing ongoing-spontaneous neuronal activity as noise. GABA transporter may contribute to improving S/N, provided that
its reversal potential is close to the resting potential. 相似文献