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841.
842.
Contextual learning induces an increase in the number of hippocampal CA1 neurons expressing high levels of BDNF 总被引:3,自引:0,他引:3
Chen J Kitanishi T Ikeda T Matsuki N Yamada MK 《Neurobiology of learning and memory》2007,88(4):409-415
We examined behaviorally induced expression of brain-derived neurotrophic factor (BDNF) in area CA1 of the hippocampus. Sprague-Dawley rats were trained in a contextual fear conditioning (CFC) task, sacrificed 4h later, and their brains were processed for immunohistochemistry. We found distinctively high levels of BDNF immunoreactivity in a small number ( approximately 1%) of CA1 neurons in untrained animals. The number of these exceptional neurons, which are identified as BDNF(++) in this study, was increased by up to approximately 3% after CFC. This increase was blocked in the presence of a memory-impairing dose of a NMDA receptor antagonist (MK801 0.3 mg/kg, i.p.) given 30 min prior to training. The BDNF signal intensity in BDNF(++) neurons correlated with that of surrounding glutamic acid decarboxylase (GAD) 65. This correlation between GAD65 and BDNF signal intensities suggests that BDNF upregulation was associated with increased signaling via inhibitory GABAergic synapses that would lessen further intervening neuronal activity. Our observation that neurons which upregulate BDNF expression following a learning experience are rich in GAD65-enriched afferent synapses suggests that these neurons may have distinct roles in memory consolidation. 相似文献
843.
The present study examined the reliability and the construct validity of a questionnaire designed to measure the attitudes toward computers in everyday life. A total of 2,050 participants responded to the questionnaire. Confirmatory factor analysis suggests that attitudes toward computers are composed of three dimensions: sense of benefit, sense of dependence, and sense of harm. 相似文献
844.
Looking-time studies examined whether 11-month-old infants can individuate two pairs of objects using only shape information. In order to test individuation, the object pairs were presented sequentially. Infants were familiarized either with the sequential pairs, disk-triangle/disk-triangle (XY/XY), whose shapes differed within but not across pairs, or with the sequential pairs, disk-disk/triangle-triangle (XX/YY), whose shapes differed across but not within pairs. The XY/XY presentation looked to adults like a single pair of objects presented repeatedly, whereas the XX/YY presentation looked like different pairs of objects. Following familiarization to these displays, infants were given a series of test trials in which the screen was removed, revealing two pairs of objects in one of two outcomes, XYXY or XXYY. On the first test trial, infants familiarized with the identical pairs (XY/XY) apparently expected a single pair to be revealed because they looked longer than infants familiarized with the distinct pairs (XX/YY). Infants who had seen the distinct pairs apparently expected a double pair outcome. A second experiment showed outcomes of a single XY pair. This outcome is unexpected for XX/YY-familiarized infants but expected for XY/XY-familiarized infants, the reverse of Experiment 1. This time looking times were longer for XX/YY infants. Eleven-month-olds appear to be able to represent not just individual objects but also pairs of objects. These results suggest that if they can group the objects into sets, infants may be able to track more objects than their numerosity limit or available working memory slots would normally allow. We suggest possible small exact numerosity representations that would allow tracking of such sets. 相似文献
845.
以东、西部被征地新居民为对象,通过访谈和问卷调查,着重考察了被征地新居民对土地被征用的情绪反应、行为变化和需求状况。结果发现:大多数被征地新居民都为土地被征用而担心生计问题;在土地被征用后,只有个别被征地新居民(不到6.4%)的生活水平和生活满意度有所提高,但比较西部地区,东部地区被征地新居民的情形要好得多;绝大多数被征地新居民虽然迫切希望解决他们所面临的问题,但尚无如何帮助他们的具体建议、也无自身如何努力的具体方向。研究认为,有关部门应加强对被征地新居民的再社会化培训和教育。 相似文献
846.
研究表明应付方式问卷中的幻想与工作压力问卷中的工作兴趣有显著的相关,而与合理化有非常显著的相关。外显性焦虑量表与应付方式量表中的解决问题、自责、求助、幻想和退避因子有非常显著的相关,与合理化有显著的相关;而与上工作压力量表上的三个维度只有弱相关。 相似文献
847.
初中生元认知阅读策略训练效应的实验研究 总被引:8,自引:0,他引:8
采用对比实验的方法,运用自编的元认知阅读策略训练教程对重点中学和普通中学的初二学生进行了训练。结果表明:(1)对初中生进行元认知阅读策略训练能有效地提高其阅读理解成绩;(2)对普通中学初中生进行元认知阅读策略训练的效果优于对重点中学初中生进行训练的效果。 相似文献
848.
时间变量对大学新生人格特质的影响 总被引:1,自引:0,他引:1
以台湾地区某大学新生,从1998至2003共六届3141人为对象,分析人格改变情形,统计结果发现13项人格特质的赖氏人格量表中达显著差异的有6项,包括社会外向、攻击性、变异性、神经质、自卑感及虚伪性。性别分析达显著差异的共7项,包括活动性、客观性、协调性、攻击性、变异性、自卑感及神经质;男学生显著高于女学生的有活动性及攻击性,女学生显著高于男学生的有客观性、协调性、变异性、自卑感及神经质。结果显示在时间变量中,大学新生的人格的确发生了转变。 相似文献
849.
以34名五年级儿童为被试,采用出声思维法考查了阅读材料类型和难度对儿童阅读策略使用情况的影响。结果发现,被试在记叙文阅读过程中使用的阅读策略种类数和总次数均多于说明文。阅读材料难度对于阅读策略种类数和使用次数没有影响。阅读材料类型和难度都对多个阅读策略的使用次数有影响,但是阅读材料类型和难度对于各阅读策略使用次数的影响并不一致。 相似文献
850.