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191.
We investigated the adaptation of balancing behavior during a continuous, predictable perturbation of stance consisting of 3-min backward and forward horizontal sinusoidal oscillations of the support base. Two visual conditions (eyes-open, EO; eyes-closed, EC) and two oscillation frequencies (LF, 0.2 Hz; HF, 0.6 Hz) were used. Center of Mass (CoM) and Center of Pressure (CoP) oscillations and EMG of Soleus (Sol) and Tibialis Anterior (TA) were recorded. The time course of each variable was estimated through an exponential model. An adaptation index allowed comparison of the degree of adaptation of different variables. Muscle activity pattern was initially prominent under the more challenging conditions (HF, EC and EO; LF, EC) and diminished progressively to reach a steady state. At HF, the behavior of CoM and CoP was almost invariant. The time-constant of EMG adaptation was shorter for TA than for Sol. With EC, the adaptation index showed a larger decay in the TA than Sol activity at the end of the balancing trial, pointing to a different role of the two muscles in the adaptation process. At LF, CoM and CoP oscillations increased during the balancing trial to match the platform translations. This occurred regardless of the different EMG patterns under EO and EC. Contrary to CoM and CoP, the adaptation of the muscle activities had a similar time-course at both HF and LF, in spite of the two frequencies implying a different number of oscillation cycles. During adaptation, under critical balancing conditions (HF), postural muscle activity is tuned to that sufficient for keeping CoM within narrow limits. On the contrary, at LF, when vision permits, a similar decreasing pattern of muscle activity parallels a progressive increase in CoM oscillation amplitude, and the adaptive balancing behavior shifts from the initially reactive behavior to one of passive riding the platform. Adaptive balance control would rely on on-line computation of risk of falling and sensory inflow, while minimizing balance challenge and muscle effort. The results from this study contribute to the understanding of plasticity of the balance control mechanisms under posture-challenging conditions.  相似文献   
192.
Prefrontal cortex (PFC) is dysregulated in women with restricting anorexia nervosa (RAN). It is not known whether appetitive non-conscious stimuli bias cognitive responses in those with RAN. Thirteen women with RAN and 20 healthy controls (HC) completed a dorsolateral PFC (DLPFC) working memory task and an anterior cingulate cortex (ACC) conflict task, while masked subliminal food, aversive and neutral images were presented. During the DLPFC task, accuracy was higher in the RAN compared to the HC group, but superior performance was compromised when subliminal food stimuli were presented: errors positively correlated with self-reported trait anxiety in the RAN group. These effects were not observed in the ACC task. Appetitive activation is intact and anxiogenic in women with RAN, and non-consciously interacts with working memory processes associated with the DLPFC. This interaction mechanism may underlie cognitive inhibition of appetitive processes that are anxiety inducing, in people with AN.  相似文献   
193.
For honeybees, Apis mellifera, the hive has been well known to function as a primary decision-making hub, a place from which foragers decide among various directions, distances, and times of day to forage efficiently. Whether foraging honeybees can make similarly complex navigational decisions from locations away from the hive is unknown. To examine whether or not such secondary decision-making hubs exist, we trained bees to forage at four different locations. Specifically, we trained honeybees to first forage to a distal site “CT” 100?m away from the hive; if food was present, they fed and then chose to go home. If food was not present, the honeybees were trained to forage to three auxiliary sites, each at a different time of the day: A in the morning, B at noon, and C in the afternoon. The foragers learned to check site CT for food first and then efficiently depart to the correct location based upon the time of day if there was no food at site CT. Thus, the honeybees were able to cognitively map motivation, time, and five different locations (Hive, CT, A, B, and C) in two spatial dimensions; these are the contents of the cognitive map used by the honeybees here. While at site CT, we verified that the honeybees could choose between 4 different directions (to A, B, C, and the Hive) and thus label it as a secondary decision-making hub. The observed decision making uncovered here is inferred to constitute genuine logical operations, involving a branched structure, based upon the premises of motivational state, and spatiotemporal knowledge.  相似文献   
194.
Abstract

Improved methods for assessing the interrelationships of the family environment and individuals' patterns of adaptation are needed for clinical and research purposes. To address this need, a typology of family environments based on multidimensional assessments of a representative sample of community families is presented. Seven family types were identified: 1) independence oriented, 2) achievement oriented, 3) moral/religious oriented (structured and unstructured), 4) intellectual/cultural oriented, 5) support oriented, 6) conflict oriented, and 7) disorganized. Differences in environmental stressors and coping resources were examined as mediators of the associations between the family types and family members' levels of functioning. Clinical and research applications of the typology are discussed.  相似文献   
195.
Health-related quality of life (QoL) is an important and widely used outcome measure in cardiac populations. We examined the relationship between positive affect and health-related quality of life, controlling for traditional cardiovascular risk factors, clinical variables and negative affect. We further investigated the role of gender in this relationship given the well-known gender differences in cardiovascular health. We enrolled 746 patients with coronary heart disease (CHD) before they entered outpatient cardiac rehabilitation. All patients completed the Global Mood Scale and the SF-36 Health Survey. Positive affect was independently associated with mental (p < .001) and physical QoL (p < .001) after controlling for control variables. Gender moderated the relationship between positive affect and physical QoL (p = .009) but not mental QoL (p = .60). Positive affect was positively associated with physical QoL in men (p < .001) but not in women (p = .44). The health-related QoL of patients with CHD is associated with a person’s level of positive affect.  相似文献   
196.
At least since Descartes the epistemological turn derived its impetus from the sceptical challenge to provide a justification for all knowledge claims. According to a foundational view, a claim to know something is justified only when the justification refers to ultimate grounds in the form of self‐supporting propositions. This paper's title suggests that justification may be seen from a different perspective, namely that of acting. Wittgenstein's examples show that the sceptic's maxim ‐ doubt everything ‐ breaks down because some beliefs and judgments have to be accepted unconditionally if one is to believe or judge something else. Wittgenstein concludes that the certainty we are looking for is to be found in the very nature of the language‐game.  相似文献   
197.
Four experiments examined the effect of category cueing on recall-to-reject, one of the central memory-editing mechanisms thought to prevent the occurrence of false memories. When category names were used as retrieval cues, the typically observed false recognition effect was eliminated for semantically associated distractors (Experiment 1a) and, moreover, a reduction in the absolute level of the false alarm rate was found for phonologically associated distractors (Experiment 2a). In addition to the old/new-recognition data, analyses using multinomial models support the interpretation that category cueing was successful in increasing the probability of recall-to-reject (Experiments 1b and 2b). The results are in line with dual-process theories of recognition memory and provide further evidence for recall-to-reject in single item recognition. They demonstrate its potential to reduce false recognition even when explicit instructions are not given. In addition, the results demonstrate that the paradigm can give rise to side effects that oppose recall-to-reject. A simultaneous familiarity increase can explain why many studies failed to find evidence for recall-to-reject in terms of false alarm rates.  相似文献   
198.
A year-long psychotherapy group consisting of two co-therapists and eight grandmothers who were parenting their daughters' children is presented. Three models that correspond to the co-therapists' psychoanalytic developmental orientation were used to describe the group phases of development. A number of themes that emerged at different points in the group's life are delineated. They include: authority, control, sibling rivalry, the generation gap, dealing with schools, illness and mortality, isolation, defensiveness, anger, fear of going crazy, guilt, shame, separation, and abandonment. Transference and countertransference issues are also discussed.  相似文献   
199.
Women recall the appearance of others better than men. The goal of the present research was to shed light on the explanations and boundary conditions of this gender difference. In three studies (592 participants), the authors tested potential mediators and moderators of the gender difference. Results corroborated the robustness of the gender difference. General task motivation, general memory ability, importance of appearance, appearance knowledge, attention paid to target, gazing at target, and communal or agentic orientation could not explain why women were better at recalling others' appearance than men were. Except for importance of appearance and appearance knowledge, which both decreased the magnitude of the gender difference, general task motivation, attention paid to target, length of exposure to target, delay in responding, cognitive load, and response format (verbal vs. nonverbal) had no effect on the gender difference. Results are discussed in relation to gender differences found in the nonverbal sensitivity literature.  相似文献   
200.
Correlations of naming ability and performance in the Token Test are known from aphasia; however, the mechanisms underlying these correlations are unclear. Naming tasks are commonly used in intraoperative mapping for identification of cortical areas involved in language processing. In the present study, we measured performance in an elementary Token Test task, i.e., single word comprehension, during electrical stimulation of cortical sites at which this stimulation previously had disturbed the naming process. It was found that at about half of the sites at which naming could be disturbed electrical stimulation also led to disturbances in Token Test performance, indicating that there are common neural structures critical for performance in both tasks. These findings are discussed in terms of a multilayered semantic network in which the level of the simultaneous binding of features into concepts and the level of units that are organized with respect to semantic relations may be disturbed separately.  相似文献   
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