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   45980篇
  免费   854篇
  国内免费   5篇
  46839篇
  2019年   428篇
  2018年   624篇
  2017年   691篇
  2016年   707篇
  2015年   476篇
  2014年   630篇
  2013年   3268篇
  2012年   1144篇
  2011年   1254篇
  2010年   825篇
  2009年   753篇
  2008年   1143篇
  2007年   1067篇
  2006年   994篇
  2005年   874篇
  2004年   873篇
  2003年   827篇
  2002年   892篇
  2001年   1294篇
  2000年   1277篇
  1999年   980篇
  1998年   489篇
  1997年   477篇
  1996年   449篇
  1992年   878篇
  1991年   814篇
  1990年   833篇
  1989年   793篇
  1988年   780篇
  1987年   761篇
  1986年   795篇
  1985年   808篇
  1984年   677篇
  1983年   614篇
  1982年   476篇
  1981年   475篇
  1979年   744篇
  1978年   587篇
  1977年   519篇
  1976年   495篇
  1975年   660篇
  1974年   755篇
  1973年   772篇
  1972年   633篇
  1971年   619篇
  1970年   559篇
  1969年   646篇
  1968年   755篇
  1967年   689篇
  1966年   703篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
911.
Fibrositis (fibromyalgia) patients were compared with normal controls in terms of electrophysiology (EEG), self-report indicants of awakening, quality of sleep, behaviourally signalled awakenings, and Symptom Check List 90R (SCL-90R) scores. The results differentiated fibrositis patients from normal controls in terms of SCL-90R scores, with fibrositis patients showing significantly more psychopathology. Fibrositis patients had more alpha EEG sleep and less REM and Stage 1 sleep. They were better able to recall their behaviourally signalled awakenings the following morning and reported qualitatively less satisfying sleep than the normal controls. The alpha EEG sleep anomaly may reflect a vigilant arousal state during nocturnal sleep and result in the daytime experience of unrefreshing sleep, psychologic distress, that re-enforces the perpetuation of the sleep-related symptoms.  相似文献   
912.
One-hundred and ninety-two probands were selected on the basis of personality questionnaires as being cancer-prone (100) or CHD-prone (92). They were then randomly divided into a control and a treatment group, the latter receiving a special kind of behaviour therapy attempting to change the personality patterns in the direction of a healthier, more autonomous personality. Follow-up after 10 and 13 years disclosed significantly lower death rates in probands receiving prophylactic treatment than in controls. Of special interest was the degree of sclerosis in the fundus of the eye, rateds on a 3-point scale. This was significantly higher prior to therapy in the CHD-prone group than in the cancer-prone group. Treatment reduced the degree of sclerosis, particularly in the CHD group; lack of treatment was followed by an increase in sclerosis. Similar but less marked changes were found in the cancer-prone group. Clearly psychological treatment affects significantly bodily functions associated with CHD. Other risk factors considered were systolic and diastolic blood pressure, blood cholesterol and blood sugar, all of which, together with personality, influenced the degree of sclerosis observed.  相似文献   
913.
We examined the effectiveness of using dolls to teach young children with tracheostomies to self-administer a suctioning procedure. Four children between the ages of 5 and 8 years, who had had tracheostomies for 6 months or longer, participated. After skills were taught via doll-centered simulations, in vivo skills were evaluated. All of the training and probe sessions were conducted in the participants' classrooms or homes. Results of a multiple baseline design across subjects and skill components indicated that the performance of all children improved as a function of training. Skill maintenance was demonstrated by all participants during follow-up assessments conducted 2 to 6 weeks posttraining. Results of a questionnaire completed by caregivers and interviews with the children revealed high levels of satisfaction with the training procedures and outcomes.  相似文献   
914.
915.
Illegal use of reserved parking spaces represents a major obstacle to the independence and mobility of people with physical disabilities. Using an ABACACA reversal design, the daily rates of illegal parking in four reserved spaces were examined across three types of sign displays: (a) a vertical sign alone or in combination with (b) a message sign that announced the possibility of public surveillance or (c) a message dispenser device that announced community involvement and dispensed politely worded reminder notes. The average rate of illegal parking dropped from 51.3% during the initial vertical sign phase to 37.3% under the message sign condition, followed by an increase to 50.4% when the message was removed. Illegal parking decreased to 24.5% when the message dispensers were first used (followed by an increase to 57.0% when they were removed) and to 23.7% when the message dispenser condition was repeated. Illegal parking in the final vertical sign condition failed to return to previous levels (M = 37.3%).  相似文献   
916.
The effects of multiple role juggling (i.e., simultaneously attending to demands of different roles) on daily mood states of employed mothers were examined. Ss completed activity and mood questionnaires 8 times a day for 8 days. Multiple role juggling had immediate negative effects on task enjoyment and mood. However, contrast effects and habituation to role juggling occurred when mood and satisfaction were examined over time. Furthermore, mood states tended to spill over from one episode to the next within a day, but contrast effects were found across days. These results reflect the complex nature of psychological adjustment to multiple role occupancy.  相似文献   
917.
Three experiments investigated the influence of an after-contraction phenomenon on the performance and learning of a dynamic force-production task. The after-contraction effect refers to an involuntary potentiation (induced by a sustained precontraction) that is thought to summate with voluntary motor commands to bias subsequent responding. The precontraction involved a brief (20 s) static contraction. The subsequent influence of the precontraction on a dynamic force-production task was assessed. Experiments 1 and 2 were aimed at demonstrating the direct impact of the precontraction intensity on the magnitude and decay of the after-contraction effect. The results indicated that as the intensity of the precontraction increased, the magnitude of the induced bias increased. In Experiment 3, the indirect influence on subsequent retention of varying the precontraction intensity during acquisition was investigated. The results indicated that the performance of subjects experiencing varying precontraction intensities during acquisition was inferior to that of subjects experiencing a constant precontraction intensity, but the performance of the varied precontraction intensities group was superior on the test of retention. It is noted that the paradoxical reversal from acquisition to retention is similar to that found in contextual interference experiments and may arise from similar mechanisms.  相似文献   
918.
Speed of word identification is important in the theories of reading proposed by La Berge and Samuels (1974) and Perfetti (1985), and is substantially correlated with reading skill. However, there is controversy about whether disabled readers have a speed deficit that is restricted to the identification of printed words, or if instead, they have a more general speed deficit in retrieving names of even single digits. To investigate this issue, poor and average readers (N = 43) in grade 2 were assessed on several indices of speed of digit and letter naming, using both continuous-list and discrete-trial methodologies. MANCOVA indicated clear effects of reader group on discrete-trial latencies, as well as an interaction between reader group and the speed with which to-be-named items were presented. A series of hierarchical regression analyses explored the amount of shared variance between various measures of digit naming speed and five indices of reading skill. Latency for word identification shares considerable variance with latency for digit naming, and, in general, accounts for the shared variance of naming speed and several other measures of reading skill. Naming speed contributed variance in reading skill. Naming speed contributed variance in reading skill independently of measures of phonological awareness.  相似文献   
919.
The present experiment determined whether object texture influenced the transport and grasp components of human prehension. Infrared markers placed on the index finger, thumb, and wrist were recorded using a WATSMART system. The test objects were cylindrical dowels (103 mm high, 25 mm diameter, and 150 g in weight) of various surface materials (plain metal, coated with Vaseline, and covered with coarse sandpaper). Only temporal kinematic measures were affected by texture: Movement time (ms), time after peak deceleration (ms), percentages of movement time following maximum aperture, velocity, and deceleration were all significantly greater for the slippery dowel than the normal and rough dowels. Results indicated that the increased time associated with the slippery dowel could be explained entirely by increased time between contact with the dowel and dowel lift. Thus, these results are like those of Weir, MacKenzie, Marteniuk, Cargoe, and Frazer (1991), in which object weight was shown not to affect the free-motion phase, which includes the transport and grasp components of prehension. It appears that intrinsic object properties like weight and texture affect only the finger-object interaction phase of prehension; subsequent research is needed to dissociate inertial and surface friction effects while in contact with objects  相似文献   
920.
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