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211.
Post-training down-regulation of memory consolidation by a GABA-A mechanism in the amygdala modulated by endogenous benzodiazepines 总被引:3,自引:0,他引:3
I Izquierdo C Da Cunha C H Huang R Walz C Wolfman J H Medina 《Behavioral and neural biology》1990,54(2):105-109
In rats, amygdala benzodiazepine-like immunoreactivity decreases by 29% immediately after the animals step down from the platform of an inhibitory avoidance apparatus and decreases by a further 45% immediately after they receive a training footshock. The decrease is attributable to a release of diazepam or diazepam-like molecules. The immediate post-training intraamygdala injection of the central benzodiazepine antagonist flumazenil (10 nmole/amygdala) causes memory facilitation, and that of the GABA-A agonist muscimol (0.005 to 0.5 nmole) causes retrograde amnesia. Pretraining ip flumazenil administration (2.0 and 5.0 mg/kg) attenuates the effect of post-training muscimol by a factor of at least 100. The higher dose of pretraining flumazenil also causes memory facilitation. The data suggest that post-training consolidation is down-regulated by a GABA-A mechanism in the amygdala modulated by endogenous benzodiazepines released during training and at the time of consolidation. 相似文献
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213.
Three experiments are reported on the tau and kappa effects, the dependence of judgments of distance upon duration (tau) and of judgments of duration upon distance (kappa). In Experiment 1, three lights in a horizontal sequence were used to define two temporal and two spatial intervals over a total duration of 160 msec. The subject was required to choose the shorter of either the two durations or the two distances. The results confirmed Collyer’s (1977) findings that the two effects are inconsistently observed across subjects when the display duration is brief. In Experiment 2, display duration was systematically manipulated from 160 to 1,500 msec. It is argued that relative temporal judgments should become easier as the total display duration is increased and that, hence, the kappa effect should become less marked. On the other hand, relative spatial judgments should become more difficult as the total duration of the display is increased, and the tau effect should become more marked. The data were in conformity with the hypothesis. In Experiment 3, data are presented for a tau experiment which fit the assumption that the effect depends upon a weighted average of distance and the expected distance which would be traversed in the given time at constant velocity. 相似文献
214.
Experiments 1 and 2 investigated sentence context effects on picture encoding in a sentence-picture verification and a picture naming task, respectively. The results showed that a picture following a sentence was encoded faster when the two were congruent than when they were incongruent. Experiment 3 compared two conditions: Under one condition, true affirmatives, false affirmatives, true negatives, and false negatives were mixed in each block of presentation. Under the other condition, different sentence types were presented in different blocks. The results showed (l) that errors committed in verification were largely negation errors, but seldom falsification errors, and (2) that there was a decrease of falsification time, but a resistance to change in negation time from the mixed to the blocked presentation. These results were interpreted to mean that falsification time results from a longer time to encode the picture and to confirm or disconfirm the truth index value by the polarity of the sentence in false affirmatives and true negatives than in true affirmatives and false negatives, whereas negation time and negation errors result from a response-suppression operation. 相似文献
215.
This study investigated students’ perceptions of their own and their peers’ academic dishonesty (AD), their reasons for this dishonesty, their achievement goals, and their willingness to report AD (WRAD) within a Chinese cultural context. The results identified students’ belief that their peers had a greater likelihood of engaging in AD and had more motivation to do so than did the students themselves. Gender and academic major did not affect students’ WRAD. However, students were significantly more willing to report classmates than friends. In terms of the participants’ self-perceptions and peer perceptions concerning motivations for AD, more female students cited the lack of penalties as the reason for their own and their peers’ AD, whereas male students more frequently cited their lack of attention to schoolwork as the reason for their own AD. In contrast to students in the social sciences, business students more frequently cited inadequate capabilities as the reason for their AD, and engineering students more frequently attributed their AD to self-interest. Multiple regression analysis demonstrated that three motivations for AD (opportunism, inadequacy, and self-promotion) could positively predict AD, whereas mastery-approach goals could negatively predict AD. 相似文献
216.
Long-term enrichment enhances the cognitive behavior of the aging neurogranin null mice without affecting their hippocampal LTP 下载免费PDF全文
Neurogranin (Ng), a PKC substrate, is abundantly expressed in brain regions important for cognitive functions. Deletion of Ng caused severe deficits in spatial learning and LTP in the hippocampal CA1 region of mice. These Ng-/- mice also exhibit deficits in the amplification of their hippocampal signaling pathways critical for learning and memory. A short-term exposure to an enriched environment failed to improve their behavioral performances. Here, we showed that a long-term enrichment protocol for the aging mice was beneficial to the Ng-/- as well as Ng+/+ and Ng+/- mice in preventing age-related cognitive decline. Enrichment also caused an increase in the hippocampal CREB level of all three genotypes and Ng level of Ng+/+ and Ng+/- mice, but not that of alphaCaMKII or ERK. Interestingly, hippocampal slices of these enriched aging Ng-/- mice, unlike those of Ng+/+ and Ng+/- mice, did not show enhancement in the high frequency stimulation (HFS)-induced LTP in the CA1 region. It appears that the learning and memory processes in these enriched aging Ng-/- mice do not correlate with the HFS-induced LTP, which is facilitated by Ng. These results demonstrated that long-term enrichment for the aging Ng-/- mice may improve their cognitive function through an Ng-independent plasticity pathway. 相似文献
217.
成人依恋表征与婚恋依恋 总被引:10,自引:1,他引:10
近年来依恋研究已拓展到成人的依恋表征和婚恋依恋,依恋表征是成人对其早期依恋经验的回忆和重构,婚恋依恋是成人与情侣间构成的依恋情感联结。该文介绍了依恋表征和婚恋依恋研究的理论背景、测量方法及主要成果——依恋的代际传递性、依恋的临床应用、婚恋依恋对成人婚恋关系质量和工作的影响。最后探讨了成人依恋领域有待深入研究的问题,如依恋表征与婚恋依恋的关系问题、依恋的稳定性与变化问题以及依恋是个体差异还是关系变量等,并分析了今后的研究方向。 相似文献
218.
219.
情绪形容词词义的模糊赋值 总被引:5,自引:0,他引:5
353名大学生被试用模糊赋值方法对表示喜、怒、哀、惧四种基本情绪的48个形容词的强度和复杂度作语义经验赋值。结果表明:①强度和复杂度是两个不同的情绪评定维度,两者间的情绪形容词模糊语义赋值结果没有必然联系。②在强度和复杂度赋值上,各词的取值基本符合人们日常对这些词所表达情绪体验的理解,性别的量表值存在较大一致性。③男、女生在赋值上的差异主要表现在各词位次和把握度的不同,这种差异可能与性别差异的情绪经验及个体差异有关。④大学生情绪形容词模糊语义赋值的把握度总体上都较高,各词的语义在两个维度上都存在一定的模糊性。⑤根据各词强度赋值隶属度数据计算的模糊距离测度和Phi方关联测度得到了四类形容词相似的聚类分析结果。 相似文献
220.
初中生亲子关系特性的研究 总被引:9,自引:0,他引:9
以自编初中生亲子关系量表对580名初一、初二和初三学生进行了测查。结果表明: (1)初中生亲子关系总体特征是,依恋性高,控制性较高,亲密性、自主性和冲突性较低,平等性处于中等水平。 (2)初中生亲子关系在多方面表现出显著的发展特征,初二、初三年级是一个特殊的时期。亲密性在初二年级开始显著下降;自主性从初二年级起开始直线上升;在初三年级,对平等性的知觉开始显著下降,而冲突性则开始显著增加。 (3)初中生亲子关系特性在多方面受到子代性别、亲代性别及其交互作用的影响。 相似文献