全文获取类型
收费全文 | 420篇 |
免费 | 149篇 |
国内免费 | 37篇 |
出版年
2024年 | 2篇 |
2023年 | 8篇 |
2022年 | 2篇 |
2021年 | 12篇 |
2020年 | 23篇 |
2019年 | 26篇 |
2018年 | 17篇 |
2017年 | 21篇 |
2016年 | 23篇 |
2015年 | 9篇 |
2014年 | 24篇 |
2013年 | 76篇 |
2012年 | 13篇 |
2011年 | 18篇 |
2010年 | 15篇 |
2009年 | 28篇 |
2008年 | 11篇 |
2007年 | 28篇 |
2006年 | 17篇 |
2005年 | 12篇 |
2004年 | 12篇 |
2003年 | 10篇 |
2002年 | 15篇 |
2001年 | 9篇 |
2000年 | 7篇 |
1999年 | 9篇 |
1998年 | 7篇 |
1997年 | 6篇 |
1996年 | 10篇 |
1995年 | 5篇 |
1994年 | 9篇 |
1993年 | 3篇 |
1992年 | 9篇 |
1991年 | 4篇 |
1990年 | 4篇 |
1989年 | 3篇 |
1988年 | 6篇 |
1987年 | 7篇 |
1986年 | 3篇 |
1985年 | 6篇 |
1984年 | 5篇 |
1983年 | 5篇 |
1982年 | 5篇 |
1981年 | 8篇 |
1980年 | 7篇 |
1979年 | 11篇 |
1978年 | 10篇 |
1977年 | 8篇 |
1976年 | 16篇 |
1975年 | 2篇 |
排序方式: 共有606条查询结果,搜索用时 15 毫秒
41.
42.
人体系统非优性的进化论诠释 总被引:3,自引:2,他引:1
吴廷瑞 《医学与哲学(人文社会医学版)》1999,20(1):20-23
从进化论的角度论述了人体系统非优性的成因,说明了生物竿化在人体系统中保留下大量的时空沉迹,其形式与特征表现为层次套叠,多元集合,转化退化。从而成为新与旧,高级与低级,复杂与简单,一句话就是优 与非优相互缠绕,相互作用,互补关联的协同统一性,而疾病的发生则是这种辩证统一的失调或破坏。 相似文献
43.
The effects of type of feedback and base rate on threshold learning in a multiple‐cue decision task were examined. In most such decision experiments, participants receive feedback after every trial (full feedback), and a single base rate (usually 0.5) is used. Our experiment explored conditional feedback (feedback only after positive decisions) representing common selection and detection tasks (such as hiring), where the decision maker receives no feedback unless the decision is positive (e.g., hire the applicant). We used three base rates (0.2, 0.5, and 0.8). As expected, performance was best in full feedback, but after 300 learning trials, the difference was small. Conditional feedback generally resulted in fewer positive decisions than full feedback, but this difference was not found in the low (0.2) base rate condition. There were interactions between base rates and types of feedback. Results provide partial support for the constructivist encoding hypothesis of Elwin and colleagues. Simulation results suggest that our results may reflect overconfidence when feedback is not given. With respect to rate of learning, when the base rate was 0.2, conditional feedback participants reached approximately the same selection rate but did so more slowly than the full feedback participants. Partial feedback participants learned slower and appeared to be still learning after 500 trials. When the base rate was 0.5 or 0.8, partial feedback was nearly as good as full feedback, but conditional feedback resulted in a systematically lower rate of positive decisions. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
44.
Natalie U. Rolider Brian A. Iwata Christopher E. Bullock 《Journal of applied behavior analysis》2012,45(4):753-762
We examined the effects of several variations in response rate on the calculation of total, interval, exact‐agreement, and proportional reliability indices. Trained observers recorded computer‐generated data that appeared on a computer screen. In Study 1, target responses occurred at low, moderate, and high rates during separate sessions so that reliability results based on the four calculations could be compared across a range of values. Total reliability was uniformly high, interval reliability was spuriously high for high‐rate responding, proportional reliability was somewhat lower for high‐rate responding, and exact‐agreement reliability was the lowest of the measures, especially for high‐rate responding. In Study 2, we examined the separate effects of response rate per se, bursting, and end‐of‐interval responding. Response rate and bursting had little effect on reliability scores; however, the distribution of some responses at the end of intervals decreased interval reliability somewhat, proportional reliability noticeably, and exact‐agreement reliability markedly. 相似文献
45.
Recent years have seen a surge in accounts motivated by information theory that consider language production to be partially driven by a preference for communicative efficiency. Evidence from discourse production (i.e., production beyond the sentence level) has been argued to suggest that speakers distribute information across discourse so as to hold the conditional per-word entropy associated with each word constant, which would facilitate efficient information transfer (Genzel & Charniak, 2002). This hypothesis implies that the conditional (contextualized) probabilities of linguistic units affect speakers' preferences during production. Here, we extend this work in two ways. First, we explore how preceding cues are integrated into contextualized probabilities, a question which so far has received little to no attention. Specifically, we investigate how a cue's maximal informativity about upcoming words (the cue's effectiveness) decays as a function of the cue's recency. Based on properties of linguistic discourses as well as properties of human memory, we analytically derive a model of cue effectiveness decay and evaluate it against cross-linguistic data from 12 languages. Second, we relate the information theoretic accounts of discourse production to well-established mechanistic (activation-based) accounts: We relate contextualized probability distributions over words to their relative activation in a lexical network given preceding discourse. 相似文献
46.
心理资本近年已成为研究大学生就业状况相关问题的热点之一.研究采用问卷调查法探讨了性别、生源地、专业、实习经验等因素对大学生心理资本的影响,以及两者对大学生就业成功率的影响.具体采用列联表分析、£检验、方差分析以及二元logistic回归分析分析了心理资本各维度与各因素对大学生就业成功率的影响,发现专业和实习经历对心理资本有显著影响,心理资本中的乐观维度对大学生就业成功率有显著影响;建议为了提高大学生就业成功率,学校应努力为大学生提供更多的实践机会,重视大学生的人文教育,营造乐观的文化氛围. 相似文献
47.
48.
利用眼动分析技术,通过设置不同难度和分值的计算项目,探讨了在有时间压力下学习者的学习时间分配。结果发现:(1)在首次项目选择上,学习者优先选择学习率最高的项目;(2)在学习过程中,学习者的项目选择次序也是根据学习率由高到低。总之,在学习时间分配上,如果需要权衡难度与分值,学习者会考虑单位时间的获益,也就是以学习率为议程的主要依据。研究不仅利用眼动分析技术证实了基于议程的学习时间分配模型,而且进一步揭示了学习率是设置学习时间分配议程的重要依据。 相似文献
49.
Motor vehicle collisions are the leading cause of death in people ages 5–34 in the US, and secondary task engagement, such as talking on a cell phone, is a leading contributor to motor vehicle collisions. The negative effects of secondary task engagement on driving performance has become a prominent recent topic of study given the increasing amount of time drivers engage in distracted driving. However, few studies have examined the effects of secondary task engagement while driving on health related outcomes such as cardiovascular reactivity. Cardiovascular reactivity, as measured by heart rate and blood pressure, has been used in previous studies as a means of measuring effort in task engagement as well as a means to predict cardiovascular disease and stroke. This study investigates the effect of secondary task (talking on a cell phone, texting, and driving with no task) while driving in a simulator on cardiovascular reactivity. Using difference scores between baseline (a period of inactivity) and stimulus (driving with no task and driving with secondary tasks), a repeated measures analysis of variance using a mixed model approach was used to determine the effect of secondary task on cardiovascular reactivity. Findings indicated that talking on a cell phone while driving significantly increased cardiovascular reactivity via heart rate and blood pressure compared to driving with no task. Texting while driving did not differ significantly from driving with no task. This study demonstrates the need for more research on the long term effects of secondary tasks while driving on cardiovascular reactivity and for assessing the risks associated with secondary task use while driving on developing cardiovascular disease or stroke. 相似文献
50.
Aina Fiol-Veny Alejandro De la Torre-Luque Maria Balle Xavier Bornas 《Anxiety, stress, and coping》2018,31(4):375-386
Background and Objectives: Diminished heart rate variability has been found to be associated with high anxiety symptomatology. Since adolescence is the period of onset for many anxiety disorders, this study aimed to determine sex- and anxiety-related differences in heart rate variability and complexity in adolescents.Methods: We created four groups according to sex and anxiety symptomatology: high-anxiety girls (n?=?24) and boys (n?=?25), and low-anxiety girls (n?=?22) and boys (n?=?24) and recorded their cardiac function while they performed regular school activities. A series of two-way (sex and anxiety) MANOVAs were performed on time domain variability, frequency domain variability, and non-linear complexity.Results: We obtained no multivariate interaction effects between sex and anxiety, but highly anxious participants had lower heart rate variability than the low-anxiety group. Regarding sex, girls showed lower heart rate variability and complexity than boys.Conclusions: The results suggest that adolescent girls have a less flexible cardiac system that could be a marker of the girls’ vulnerability to developing anxiety disorders. 相似文献