全文获取类型
收费全文 | 1832篇 |
免费 | 106篇 |
专业分类
1938篇 |
出版年
2023年 | 24篇 |
2022年 | 17篇 |
2021年 | 25篇 |
2020年 | 41篇 |
2019年 | 36篇 |
2018年 | 67篇 |
2017年 | 64篇 |
2016年 | 74篇 |
2015年 | 75篇 |
2014年 | 55篇 |
2013年 | 226篇 |
2012年 | 98篇 |
2011年 | 113篇 |
2010年 | 66篇 |
2009年 | 73篇 |
2008年 | 83篇 |
2007年 | 78篇 |
2006年 | 61篇 |
2005年 | 70篇 |
2004年 | 66篇 |
2003年 | 64篇 |
2002年 | 67篇 |
2001年 | 32篇 |
2000年 | 23篇 |
1999年 | 25篇 |
1998年 | 20篇 |
1997年 | 16篇 |
1996年 | 24篇 |
1995年 | 19篇 |
1994年 | 18篇 |
1993年 | 17篇 |
1992年 | 16篇 |
1991年 | 8篇 |
1990年 | 10篇 |
1989年 | 14篇 |
1988年 | 10篇 |
1987年 | 10篇 |
1986年 | 9篇 |
1985年 | 12篇 |
1984年 | 10篇 |
1983年 | 15篇 |
1982年 | 10篇 |
1981年 | 12篇 |
1980年 | 6篇 |
1979年 | 7篇 |
1978年 | 11篇 |
1977年 | 6篇 |
1975年 | 4篇 |
1974年 | 4篇 |
1972年 | 4篇 |
排序方式: 共有1938条查询结果,搜索用时 8 毫秒
71.
The authors divided 34 participants who had a history of depression into 2 groups, those having previous suicidal ideation or behavior (n=19) and those having no such symptoms (n=15), then compared the 2 groups with a group of participants who had no history of depression (n=22). Assessment of interpersonal problem-solving performance using the Means-Ends Problem-Solving (MEPS) task before and after a mood-induction procedure showed that only those formerly depressed people with a history of suicidal ideation shifted in MEPS performance, producing significantly less effective problem solutions following mood challenge, consistent with a differential activation account of vulnerability for recurrence of suicidal ideation and behavior. The deterioration in effectiveness following mood challenge was moderated by lack of specificity in autobiographical memory. 相似文献
72.
Sealey DM Sumpter CE Temple W Foster TM 《Journal of the experimental analysis of behavior》2005,84(1):19-35
To examine the effects on concurrent performance of independent manipulations of response-unit duration and number, 6 hens were exposed to concurrent second-order schedules of reinforcement. Each first-order operant unit required completion of a fixed-ratio schedule within the time specified by a fixed-interval schedule, with one further response completing the fixed-interval schedule. The fixed-ratio and fixed-interval requirements comprising the first-order operant units were systematically and independently varied under three pairs of concurrent variable-interval schedules to produce differences in the first-order response and duration requirements (response and duration differentials). These manipulations produced consistent changes in response, time, and operant-unit biases. A 1:4 response differential biased the time and operant-unit measures towards the smaller fixed ratio, but to a degree less than the imposed response differential. The response-based biases favored the larger fixed ratio. Duration differentials of 4:1 and 8:1 biased the response and operant-unit measures towards the shorter fixed interval, again less than the imposed duration differential, but the time biases remained close to zero. Both sorts of differentials acted to bias operant-unit completions more systematically than the other measures, but undermatching to the differentials occurred. The undermatching appears to have arisen from a pattern of fix and sample (in which visits to the less preferred alternative involved only a single completed operant unit) under combinations of unequal operant-unit requirements and reinforcer rates. The response and time bias measures appeared to arise as by-products of the changes in operant-unit completions. 相似文献
73.
The hypothesis to be tested in this study was that the cognitive deficits that have been documented in patients with Borderline Personality Disorder (BPD) are largely the consequence of organic insult, either developmental or acquired. Using a cross-sectional design, 80 subjects (males and females) who met the criteria for BPD participated in the study. They completed a battery of neuropsychological tests and a comprehensive interview assessing organic status as well as measures of the potentially confounding factors of current levels of depression and anxiety. It was expected that BPD-patients with a probable history of organic insult would perform significantly worse than would BPD patients without such a history. Analyses of the results provided partial support for the hypothesis. Subjects with both BPD and a history of organic insult were significantly more impaired on several measures including measures of attention than were BPD only subjects. The results suggested that the impaired cognitive performance of persons diagnosed with BPD may, in part, be attributed to organic factors. 相似文献
74.
Perspective-taking judgments among young adults, middle-aged, and elderly people were examined. In 1 condition, participants were instructed to judge the likelihood of acceptance of a painkiller as a function of 3 cues: severity of the condition, potential side effects, and level of trust in the health care provider. In the other condition, participants were instructed to judge the likelihood of purchasing pieces of clothing. Judgments were given from 2 viewpoints: the viewpoint of another person known to place no importance on one of the 3 cues, and the viewpoint of another person known to place very great importance on this cue. The hypotheses were that elderly people would not, to the same extent as young adults, be likely to discount the impact of the "no-importance" cue, and to magnify the impact of the "very important" cue. In both judgment situations, the results support these hypotheses. 相似文献
75.
A number of measures have been used in epidemiological studies of children's exposure to community violence, yet the quality
of these instruments is not uniformly good. This paper undertakes a systematic review of the most commonly used (or most promising)
self-report or interview-administered instruments, with regard to their conceptual bases and psychometric properties. Based
on the review, recommendations are made for working with the current state of the science in order to move the field forward.
A key recommendation is for sounder conceptualization of work in the field and greater transparency in the reporting of research,
in order to facilitate the comparability of studies. 相似文献
76.
The effects of early-onset blindness on the development of the visual system have been explained traditionally by the stabilization of transient connections through Hebbian competition. Although many of the findings from congenital cataract and congenital blindness are consistent with that view, there is inconsistent evidence from studies of visual cognition in children treated for visual deprivation from cataract, case reports of recovery of vision in adults, and studies of visual reorganization after late-onset blindness. Collectively, the data from congenital cataract and congenital blindness indicate that early visual experience sets up the infrastructure for later learning involving both the dorsal ("where") and ventral ("what") streams. Nevertheless, there is surprising residual plasticity in adulthood that can be revealed if vision is lost either temporarily or permanently. This has important implications for understanding the role of early visual experience in shaping visual cognitive development. 相似文献
77.
Most studies of animal tool use require subjects to use one object to gain access to a food reward. In many real world situations, however, animals perform more than one action in sequence to achieve their goals. Of theoretical interest is whether animals have the cognitive capacity to recognize the relationship between consecutive action sequences in which there may be one overall goal and several subgoals. Here we ask if cotton-top tamarins, a species that in captivity uses tools to solve means-end problems, can go one step further and use a sequence of tools (means) to obtain food (end). We first trained subjects to use a pulling tool to obtain a food reward. After this initial training, subjects were presented with problems in which one tool had to be used in combination with a second in order to obtain food. Subjects showed great difficulty when two tools were required to obtain the food reward. Although subjects attended to the connection between the tool and food reward, they ignored the physical connection between the two tools. After training on a two-tool problem, we presented subjects with a series of transfer tests to explore if they would generalize to new types of connections between the tools. Subjects readily transferred to new connections. Our results therefore provide the first evidence to date that tamarins can learn to solve problems involving two tools, but that they do so only with sufficient training. 相似文献
78.
79.
Genetic Cancer Risk Assessment and Counseling: Recommendations of the National Society of Genetic Counselors 总被引:4,自引:0,他引:4
Trepanier A Ahrens M McKinnon W Peters J Stopfer J Grumet SC Manley S Culver JO Acton R Larsen-Haidle J Correia LA Bennett R Pettersen B Ferlita TD Costalas JW Hunt K Donlon S Skrzynia C Farrell C Callif-Daley F Vockley CW;National Society of Genetic Counselors 《Journal of genetic counseling》2004,13(2):83-114
These cancer genetic counseling recommendations describe the medical, psychosocial, and ethical ramifications of identifying at-risk individuals through cancer risk assessment with or without genetic testing. They were developed by members of the Practice Issues Subcommittee of the National Society of Genetic Counselors Cancer Genetic Counseling Special Interest Group. The information contained in this document is derived from extensive review of the current literature on cancer genetic risk assessment and counseling as well as the personal expertise of genetic counselors specializing in cancer genetics. The recommendations are intended to provide information about the process of genetic counseling and risk assessment for hereditary cancer disorders rather than specific information about individual syndromes. Key components include the intake (medical and family histories), psychosocial assessment (assessment of risk perception), cancer risk assessment (determination and communication of risk), molecular testing for hereditary cancer syndromes (regulations, informed consent, and counseling process), and follow-up considerations. These recommendations should not be construed as dictating an exclusive course of management, nor does use of such recommendations guarantee a particular outcome. These recommendations do not displace a health care provider's professional judgment based on the clinical circumstances of a client. 相似文献
80.
Adults with auditory-visual synesthesia agree that higher pitched sounds induce smaller, brighter visual percepts. We have
hypothesized that these correspondences are remnants of cross-modal neural connections that are present at birth and that
influence the development of perception and language even in adults and children without synesthesia. In this study, we explored
these correspondences in preschoolers (30-36 months; n=12 per experiment). The children were asked to indicate which of two
bouncing balls was making a centrally located sound. The balls varied in size and/or surface darkness; the sound varied in
pitch. The children reliably matched the higher pitched sound to a smaller and lighter (white) ball (Experiment 1), to a lighter
(white) ball (Experiment 2), and in one of two groups, to a smaller ball (Experiment 3). Children’s matching of pitch and
size cannot be attributed to intensity matching or to learning. These data support the hypothesis that some cross-modal correspondences
may be remnants of the neural mechanisms underlying neonatal perception. 相似文献