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   156篇
  免费   10篇
  2023年   2篇
  2022年   1篇
  2021年   2篇
  2019年   2篇
  2018年   2篇
  2017年   8篇
  2016年   3篇
  2015年   1篇
  2014年   5篇
  2013年   24篇
  2012年   8篇
  2011年   5篇
  2010年   7篇
  2009年   5篇
  2008年   5篇
  2007年   4篇
  2006年   7篇
  2005年   5篇
  2004年   7篇
  2003年   6篇
  2002年   6篇
  2001年   9篇
  2000年   5篇
  1999年   2篇
  1998年   5篇
  1997年   5篇
  1996年   1篇
  1995年   1篇
  1994年   1篇
  1993年   2篇
  1992年   2篇
  1991年   4篇
  1990年   1篇
  1989年   1篇
  1988年   2篇
  1982年   1篇
  1980年   1篇
  1978年   1篇
  1973年   1篇
  1971年   1篇
  1969年   1篇
  1968年   1篇
  1967年   2篇
  1965年   1篇
排序方式: 共有166条查询结果,搜索用时 31 毫秒
81.

Al-Ni-Ru alloys with a wide composition range have been synthesized and examined by X-ray and electron diffraction experiments. In this system, two types of decagonal (d) phases are formed, namely basic-type and superlattice-type d phases. Annealing experiments have shown that the basic-type d phase is stable at high temperatures and that its single-phase region is located in a small composition range around Al 75 Ni 15 Ru 10 . On the other hand, the superlattice-type d phase is metastable and has been found to form only in the samples before annealing. Besides the d phases, a high-order crystal approximant phase with lattice parameters a = 99.5 Å and b = 84.6 Å has been found. The structural relation between the approximant phase and the d phase is discussed in terms of a phason tensor.  相似文献   
82.
A variety of perceptual correspondences between auditory and visual features have been reported, but few studies have investigated how rhythm, an auditory feature defined purely by dynamics relevant to speech and music, interacts with visual features. Here, we demonstrate a novel crossmodal association between auditory rhythm and visual clutter. Participants were shown a variety of visual scenes from diverse categories and asked to report the auditory rhythm that perceptually matched each scene by adjusting the rate of amplitude modulation (AM) of a sound. Participants matched each scene to a specific AM rate with surprising consistency. A spatial-frequency analysis showed that scenes with greater contrast energy in midrange spatial frequencies were matched to faster AM rates. Bandpass-filtering the scenes indicated that greater contrast energy in this spatial-frequency range was associated with an abundance of object boundaries and contours, suggesting that participants matched more cluttered scenes to faster AM rates. Consistent with this hypothesis, AM-rate matches were strongly correlated with perceived clutter. Additional results indicated that both AM-rate matches and perceived clutter depend on object-based (cycles per object) rather than retinal (cycles per degree of visual angle) spatial frequency. Taken together, these results suggest a systematic crossmodal association between auditory rhythm, representing density in the temporal domain, and visual clutter, representing object-based density in the spatial domain. This association may allow for the use of auditory rhythm to influence how visual clutter is perceived and attended.  相似文献   
83.
84.
The physical, emotional, and psychological changes that occur in adolescence prompt youths to have serious questions about their bodies, relationships, and health that are often personal, sensitive, or embarrassing. Past research has shown that adolescents are often reluctant to consult physicians, peers, and others for personal health questions due to concerns about confidentiality. One new venue for health information is the Internet, which is a promising resource due to its accessibility, interactivity, and anonymity. This study is a snapshot investigation of a popular health support website, which utilized a peer-generated bulletin board format to facilitate the discussion of adolescent health and social issues. Analyses of two health bulletin boards—one on teen issues and one on sexual health—were conducted on the questions and replies found on 273 topics of mainly anonymous adolescents collected over a 2-month period. Results revealed that the questions most frequently posted and viewed reflected interests and concerns about their changing physical, emotional, and social selves: Romantic relationships were the most frequent topic on the teen issues bulletin board; sexual health was the most frequent topic on the sexuality bulletin board. The bulletin boards proved to be a valuable forum of personal opinions, actionable suggestions, concrete information, and emotional support and allowed teens to candidly discuss sensitive topics, such as sexuality and interpersonal relations.  相似文献   
85.
How do the characteristics of sounds influence the allocation of visual–spatial attention? Natural sounds typically change in frequency. Here we demonstrate that the direction of frequency change guides visual–spatial attention more strongly than the average or ending frequency, and provide evidence suggesting that this cross-modal effect may be mediated by perceptual experience. We used a Go/No-Go color-matching task to avoid response compatibility confounds. Participants performed the task either with their heads upright or tilted by 90°, misaligning the head-centered and environmental axes. The first of two colored circles was presented at fixation and the second was presented in one of four surrounding positions in a cardinal or diagonal direction. Either an ascending or descending auditory-frequency sweep was presented coincident with the first circle. Participants were instructed to respond to the color match between the two circles and to ignore the uninformative sounds. Ascending frequency sweeps facilitated performance (response time and/or sensitivity) when the second circle was presented at the cardinal top position and descending sweeps facilitated performance when the second circle was presented at the cardinal bottom position; there were no effects of the average or ending frequency. The sweeps had no effects when circles were presented at diagonal locations, and head tilt entirely eliminated the effect. Thus, visual–spatial cueing by pitch change is narrowly tuned to vertical directions and dominates any effect of average or ending frequency. Because this cross-modal cueing is dependent on the alignment of head-centered and environmental axes, it may develop through associative learning during waking upright experience.  相似文献   
86.
Japanese women are often described as heavily invested in the role of mother, yet young women in contemporary Japan are increasingly likely to postpone or opt out of marriage and child rearing. To understand the psychological dynamics of parenting among Japanese women who have chosen to become mothers, we examined the relation of maternal role salience beliefs, personal maternal role commitment, and parenting self-efficacy to life satisfaction, number of children, and employment status. Survey data were obtained from 116 urban Japanese women with children in the 2nd grade. Mothers with more children expressed greater personal role commitment. Those who had sought employment were less likely to hold strong maternal role salience beliefs. Life satisfaction was predicted by having more children, feeling efficacious as a parent, and being employed. These findings suggest that even in a society characterized by strong normative expectations for women, women's life satisfaction and choices about family life and employment are related to individual beliefs, attitudes, and judgments about their role.  相似文献   
87.
The adult cerebral cortex can adapt to environmental change. Using monocular deprivation as a paradigm, we find that rapid experience-dependent plasticity exists even in the mature primary visual cortex. However, adult cortical plasticity differs from developmental plasticity in two important ways. First, the effect of adult, but not juvenile monocular deprivation is strongly suppressed by administration of barbiturate just prior to recording visual evoked potentials, suggesting that the effect of adult experience can be inactivated acutely. Second, the effect of deprivation is less persistent over time in adults than in juveniles. This correlates with the known decline in CREB function during maturation of the visual cortex. To compensate for this decline in CREB function, we expressed persistently active VP16-CREB and find that it causes adult plasticity to become persistent. These results suggest that in development and adulthood, the regulation of a trans-synaptic signaling pathway controls the adaptive potential of cortical circuits.  相似文献   
88.
This study demonstrates that children's difficulties in the interpretation of passives are attributed to their perspective-taking ability. Thirty-six Japanese preschool children participated in act-out sentence comprehension tasks. They were asked to manipulate two toy animals to demonstrate the meaning of two types of stimulus sentences: Type I had the child's toy, whose reference involved the child's actual name (e.g., Jun-kun no neko Jun's cat) encoded as grammatical subject, while Type II had the child's toy encoded as non-subject. Since passive structures take the perspective of the patient-denoting subject NP, it is assumed that only Type I passives have the perspective that matches that of the child.The results show that children's performance on passives was significantly better in Type I than in Type II sentences. But this difference was not observed for active sentences. For those who showed (nearly) perfect performance on active sentences, only Type I passives were equally well understood. These results strongly suggest that perspective-taking difficulties mask children's true competence on passives and that even 6-year-olds may not yet have attained the full perspective-taking ability required for comprehension of passive sentences.  相似文献   
89.
We investigated the association between alexithymic tendencies as measured by the 20-item Toronto Alexithymia Scale and the characteristics of aesthetic impressions for words and drawings. Impressions were measured using the semantic differential technique in three groups of Japanese students (High scores n = 31, Moderate scores n = 40, and a Control group n = 182) who were presented only words (Word condition), only drawings (Drawing condition), or pairs comprising one word plus one drawing that represented the same emotional categories (Drawing/Word condition). In a factor analysis on the data from participants, three factors (Evaluation, Activity, and Potency) were extracted. Based on the factor scores, the distances among the three conditions were calculated for each of the groups. For Potency, significant group differences were found between the Drawing/Word and other conditions. In the High-scoring alexithymia group, in particular, the Potency impressions based on tactile sensation, e.g., soft-hard, blunt-sharp, were amplified regardless of stimulus condition. These results are discussed in the context of somatosensory amplification associated with alexithymia and the difficulty of distinguishing between emotion and somatic sensations.  相似文献   
90.
Many studies have indicated that recognition of facial expression is geometrically represented in terms of two underlying bipolar dimensions, pleasure-displeasure and the intensity of arousal. A psychological space defined by these two dimensions has been found under particular conditions using prototype faces: however, the question arises whether this two-dimensional psychological space is also an accurate representation for faces with lower emotional intensity. To test this we prepared four different conditions of emotional intensity (100%, 75%, 50%, and 25% of emotionality) for six basic facial expressions using morphing. Participants (29 for the 100%, 30 for 75%, 35 for 50%, and 34 for the 25% condition) in each condition rated the facial stimuli on a 6-point scale of "not at all" and "very much so". Multidimensional scaling for each condition clearly indicated a two-dimensional representation and multiple correlations showed significant similarity across conditions (p < .001). This shows that the two-dimensional representation of recognition of facial expression is robust.  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