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441.
A man with multiple disabilities was taught to perform a head‐turning response to activate optic sensors embedded in a small spongy structure at his shoulder and produce preferred stimuli. By touching the spongy structure with chin and mouth (i.e., to activate the sensors), the man would clean these areas thus curbing the effects of his drooling. Data showed that the man increased the frequency of his head‐turning responses and reduced drooling effects (chin wetness) through the intervention and a 3‐month follow‐up. Forty university students, who were involved in a social validation assessment, indicated that the intervention was suitable and enjoyable to the man, had a social/educational function, and represented an approach that they supported. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   
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443.
This study assessed the rising star hypothesis, which proposes that individuals who are on the fast track to career success are more likely to gain mentors than others. The study used a sample of employees who had never been mentored and examined the relationship between rising star attributes measured at Time 1 and the attainment of a mentor a year later. In support of the hypothesis, individuals who were on the fast-track for promotion, had higher advancement expectations, and engaged in more proactive career behaviors were more likely to gain a mentor than individuals lacking these attributes. Implications of these results for the theory, research and practice of mentoring are discussed.  相似文献   
444.
Segmentation of target odorants from background odorants is a fundamental computational requirement for the olfactory system and is thought to be behaviorally mediated by olfactory habituation memory. Data from our laboratory have shown that odor-specific adaptation in piriform neurons, mediated at least partially by synaptic adaptation between the olfactory bulb outputs and piriform cortex pyramidal cells, is highly odor specific, while that observed at the synaptic level is specific only to certain odor features. Behavioral data show that odor habituation memory at short time constants corresponding to synaptic adaptation is also highly odor specific and is blocked by the same pharmacological agents as synaptic adaptation. Using previously developed computational models of the olfactory system we show here how synaptic adaptation and potentiation interact to create the observed specificity of response adaptation. The model analyzes the mechanisms underlying the odor specificity of habituation, the dependence on functioning cholinergic modulation, and makes predictions about connectivity to and within the piriform neural network. Predictions made by the model for the role of cholinergic modulation are supported by behavioral results.Filtering sensory input is critical for information processing tasks such as background segmentation, and shifting processing power away from redundant, stable, or repetitive stimuli toward dynamic, novel stimuli. A critical aspect of this filtering however, is stimulus specificity. Under most circumstances it may be most beneficial to selectively filter the redundant stimulus, while maintaining responsiveness to different, though perhaps highly similar stimuli.In the olfactory system, short-term habituation to stable or repeated odorants involves a metabotropic glutamate receptor (mGluR)-dependent depression of afferent synapses to the piriform cortex (Best and Wilson 2004). Blockade of group III mGluR receptors prevents cortical adaptation odors (Best and Wilson 2004), and reduces short-term habituation of odor-evoked reflexes (Best et al. 2005) and odor investigation (Yadon and Wilson 2005; Bell et al. 2008; McNamara et al. 2008). This short-term habituation is highly odor specific, with minimal cross-adaptation of piriform cortical single-unit responses or cross-habituation of behavioral responses to similar odors, including between mixtures and their components (Wilson 2000; Cleland et al. 2002). Interestingly, there is an experience-dependent component to short-term habituation odor specificity. The odor specificity is most pronounced for familiar odors, with very brief (<20 sec) exposure to odors producing more generalization, and longer exposures (>50 sec) sufficient to permit strong odor specificity in cortex adaptation (Wilson 2003).The homosynaptic nature of afferent synaptic depression underlying cortical adaptation (Wilson 1998; Best and Wilson 2004) may contribute to this odor specificity. However, the experience dependence suggests that there may be an additional process involved. In fact, theoretical views of piriform cortical function suggest that the cortex learns previous patterns of input via potentiation of intracortical association fiber synapses (Hasselmo et al. 1990; Barkai et al. 1994; Haberly 2001; Linster et al. 2003). This autoassociative process essentially creates a template of previous network activity, against which new input patterns can be compared, allowing enhanced discrimination between similar patterns, as well as completion of degraded patterns (Barkai et al. 1994; Barnes et al. 2008). In support of this hypothesis, previous work has demonstrated that disruption of normal synaptic potentiation in association fiber synapses through blockade of cholinergic muscarinic receptors (Patil et al. 1998; Linster et al. 2003), reduces odor specificity of cortical adaptation (Wilson 2001b), prevents the effects of odor experience on subsequent behavioral cross-habituation (Fletcher and Wilson 2002), and disrupts odor discrimination (Linster et al. 2001).The present series of studies further explored the role of combined afferent synaptic depression and intracortical association fiber synaptic potentiation on the specificity of cortical adaptation and odor habituation. Using a computational model of the olfactory system (Linster et al. 2007), the results suggest that activity-dependent association fiber plasticity is necessary to account for the specificity of odor habituation. Furthermore, in behavioral experiments blockade of cholinergic muscarinic receptors during habituation enhances generalization of odor habituation, consistent with the modeling and with previous electrophysiological results.  相似文献   
445.
Jones RM  Taylor DE  Dick AJ  Singh A  Cook JL 《Adolescence》2007,42(167):539-553
This investigation examined gender differences in niche-building preference and activity among 238 8th and 9th grade boys and girls. A questionnaire was developed to measure both the actual and preferred bedroom content, bedroom design activity, and the level of perceived influence by the immediate and extended family, friends, and social institutions. Gender differences were identified for preference, activity, and influence in bedroom design and decoration. Girls and boys differed in the type of items contained in their bedrooms. Girls' rooms contained stuffed animals and pictures of people, including themselves, more frequently than the boys' rooms. In contrast, boys' rooms contained sports-related items, and things for building or that they had built themselves. Although bedroom design activity for both boys and girls was influenced by older teens, friends, media, and popular culture, boys (but not girls) were also influenced by their mothers, fathers, girlfriends, and activities such as sports, Boy or Girl Scouts, and music lessons.  相似文献   
446.
Legal abortion worldwide: incidence and recent trends   总被引:1,自引:0,他引:1  
CONTEXT: Information on abortion levels and trends can inform research and policies affecting maternal and reproductive health, but the incidence of legal abortion has not been assessed in nearly a decade. METHODS: Statistics on legal abortions in 2003 were compiled for 60 countries in which the procedure is broadly legal, and trends were assessed where possible. Data sources included published and unpublished reports from official national reporting systems, questionnaires sent to government agencies and nationally representative population surveys. The completeness of country estimates was assessed by officials involved in data collection and by in-country and regional experts. RESULTS: In recent years, more countries experienced a decline in legal abortion rates than an increase, among those for which statistics are complete and trend data are available. The most dramatic declines were in Eastern Europe and Central Asia, where rates remained among the highest in the world. The highest estimated levels were in Armenia, Azerbaijan and Georgia, where surveys indicate that women will have close to three abortions each on average in their lifetimes. The U.S. abortion rate dropped by 8% between 1996 and 2003, but remained higher than rates in many Northern and Western European countries. Rates increased in the Netherlands and New Zealand. The official abortion rate declined by 21% over seven years in China, which accounted for a third of the world's legal abortions in 1996. Trends in the abortion rate differed across age-groups in some countries. CONCLUSIONS: The abortion rate varies widely across the countries in which legal abortion is generally available and has declined in many countries since the mid-1990s.  相似文献   
447.
448.
The present study assessed the possibility of promoting pre-ambulatory foot–leg movements in children with multiple disabilities by motivating their action through contingent stimulation combined with a support device. Two children aged 10 and 8 years participated. Microswitch technology (i.e., pressure sensors under the shoes or optic sensors at the front–inner side of the shoes) served for detecting the foot–leg movements and providing contingent stimulation on their occurrence. Sensor activation produced 5 s of stimulation during intervention. Data showed that both children had significant increases in foot–leg movements during the intervention phases. Implications of the data in terms of skill acquisition and further intervention prospects are discussed.  相似文献   
449.
This study assessed the viability of a microswitch cluster (i.e. a combination of microswitches) plus contingent stimulation for promoting adaptive responding and reducing aberrant behavior in a boy with profound multiple disabilities. The boy was initially taught an adaptive foot-movement response that activated a motion microswitch and produced preferred stimuli. Subsequently, his foot response led to preferred stimuli only if it occurred in the absence of aberrant behavior (i.e. hand mouthing and eye poking which were detected through optic microswitches). Moreover, full access to the stimuli required that the boy refrain from aberrant behavior during their presentation as well. The study also included a 3-month post-intervention check and a social validation assessment. Data showed that the boy (i) increased his adaptive responding, (ii) learned to perform this responding largely free from aberrant behavior and refrained from that behavior for most of the session time, and (iii) maintained this performance at the post-intervention check. The social validation ratings of 40 teachers and teacher assistants significantly favored the last intervention period (in which aberrant behavior was reduced) over the initial period.  相似文献   
450.
Post-9/11 era is marked by the resurgence of white American nationalisms across the country. Members of Arab, Muslim, Sikh, and South Asian communities experienced hate crimes, anti-immigrant sentiments, and government surveillance due to suspicions of being ‘terrorist-monsters’. Since 2001, Sikh advocacy groups participated in the nationalist discourse to express their desire for legitimacy as national subjects while distancing themselves from the ‘terrorist-other’. This article explores the politics embedded within the thrusts of these desires. I examine the disciplining nature of these groups and the possible ways they homogenize and foreclose Sikh subjectivities through a rather violent love for the nation.  相似文献   
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