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   18047篇
  免费   800篇
  国内免费   5篇
  2020年   252篇
  2019年   275篇
  2018年   409篇
  2017年   411篇
  2016年   403篇
  2015年   327篇
  2014年   375篇
  2013年   1669篇
  2012年   617篇
  2011年   649篇
  2010年   398篇
  2009年   391篇
  2008年   585篇
  2007年   552篇
  2006年   518篇
  2005年   475篇
  2004年   444篇
  2003年   409篇
  2002年   422篇
  2001年   524篇
  2000年   488篇
  1999年   384篇
  1998年   231篇
  1997年   162篇
  1996年   173篇
  1995年   186篇
  1994年   158篇
  1993年   159篇
  1992年   279篇
  1991年   285篇
  1990年   260篇
  1989年   267篇
  1988年   264篇
  1987年   237篇
  1986年   224篇
  1985年   249篇
  1984年   237篇
  1983年   183篇
  1982年   177篇
  1979年   193篇
  1978年   164篇
  1976年   157篇
  1975年   199篇
  1974年   213篇
  1973年   223篇
  1972年   191篇
  1971年   174篇
  1968年   204篇
  1967年   165篇
  1966年   178篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
121.
122.
The Companeros model of HIV infection prevention in Ciudad Juarez, Mexico, is presented as conceived by the National Institute of Drug Abuse (NIDA). 518 women who were IV drug users, sexual partners of drug addicts, or prostitutes were requested to participate, and 232 consented. Initial and follow-up AIDS assessments were utilized along with an assessment of sociodemographic variables, including knowledge, sexual behavior, use and abuse of drugs, and previous health history. Educative sessions about AIDs and sexually transmitted diseases (STDs) included group discussions and interaction, video watching, personal experiences, and sociodramas. 61% of prostitutes were 29, 12.6% were 13-19 years old, 31.1% were aged 30-39, and 8.9% were 40. 11% had no formal education, 58% had 6 years of primary and part of 3 years of secondary education, only 18.6% completed secondary education; and 13% had higher education. 19% lived in a hotel or shelter. Family disintegration reached 44%; these women did not live with their children. Only 5.2% thought they had excellent health, 51% said they had good health, 31% stated they had average health, and 12% admitted having had health problems. 14.6% had genital ulcers, 1.3% had herpes, 15% had gonorrhea, and 10% had syphilis. Since IV drug use among these women was almost nonexistent sexual relations constituted the principal risk factor. Responses to a questionnaire showed that the most frequent sexual behavior was vaginal penetration followed by fellatio; anal penetration was less common. 34.9% of the women practiced fellatio without protection, 16.3% had anal intercourse without protection. The proportion of AIDS cases in Mexico in women of reproductive age was growing at an exponential rate, possible because of misinformation about AIDS, a history of STDs, and a low rate of condom use.  相似文献   
123.
Although visuoconstructive impairment has been reported in both Alzheimer's (DAT) and Huntington's (HD) disease, there is little knowledge concerning how this cognitive deficit differs quantitatively and qualitatively in these two progressive dementias. To address this issue, the present study compared performances on the Clock Drawing Test (CDT: command and copy) of 25 DAT patients, 25 equally demented HD patients, and 25 elderly normal controls (NC). In the command condition, both patients groups were significantly impaired compared to the NC group. Although there was no significant difference between DAT and HD patients' total quantitative scores, a qualitative error analysis revealed a number of dissociations between the two patient groups. Graphic difficulties, very common in HD patients, were virtually absent in DAT patients; in contrast, conceptual errors were almost exclusively seen in DAT patients and were related to the severity of their dementia. Perseveration and "stimulus-bound" responses were also more frequent in DAT patients, and both groups made visuospatial errors. In the copy condition, the DAT, but not the HD, patients evidenced a marked improvement in performance. These results indicate that while both DAT and HD patients have significant visuoconstructive difficulties even in the early stages of their disorders, the specific cognitive processes underlying their quantitative impairments are quite different. It is possible that the DAT patients' conceptual errors are yet another indicator of the deterioration of their semantic knowledge.  相似文献   
124.
Studies of time estimation have provided evidence that human time perception is determined by an internal clock containing a temporal oscillator and have also provided estimates of the frequency of this oscillator (Treisman, Faulkner, Naish, & Brogan, 1992; Treisman & Brogan, 1992). These estimates were based on the observation that when the intervals to be estimated are accompanied by auditory clicks that recur at certain critical rates, perturbations in time estimation occur. To test the hypothesis that the mechanisms that underlie the perception of time and those that control the timing of motor performance are similar, analogous experiments were performed on motor timing, with the object of seeing whether evidence for a clock would be obtained and if so whether its properties resemble those of the time perception clock. The prediction was made that perturbations in motor timing would be seen at the same or similar critical auditory click rates. The experiments examined choice reaction time and typing. The results support the hypothesis that a temporal oscillator paces motor performance and that this oscillator is similar to the oscillator underlying time perception. They also provide an estimate of the characteristic frequency of the oscillator.  相似文献   
125.
One major purpose of this study was to identify environmental factors related to suicide in long-term care facilities. Questionnaires were mailed to a random sample of administrators at 1,080 facilities. Information was collected on facility characteristics, overt suicide, and intentional life-threatening behavior. Chi-square analyses revealed 4 environmental characteristics related to suicidal behavior and deaths from suicide: staff turnover, size, auspices, and per diem cost. More suicides occurred in larger facilities and facilities with higher staff turnover. Religious or "other" facilities experienced more suicidal deaths than public or private facilities; facilities charging less experienced more deaths.  相似文献   
126.
The relationship between memories of childhood experiences (e.g., adverse parenting) and adult depression often found raises questions of interpretation. On the one hand, both laboratory studies and clinicians' experiences suggest that subjects in a depressed mood frequently show a negative bias in perceptions and memories. Negative childhood memories in depressed persons might, therefore, be interpreted as epiphenomena of depressed mood instead of etiological factors. On the other hand, memories of childhood experiences seem remarkably stable across changes in depressed mood, especially when memories are elicited by means of standardized questionnaires. In the mood and memory literature several explanations for this stability are offered. For one thing, highly structured cues to elicit memories (such as in questionnaires) are hypothesized to be less susceptible to mood bias than unstructured memory cues (such as in free recall procedures). On the other hand, resource allocation theorists suggest that childhood memories, being well established and rehearsed, are relatively impervious to mood bias no matter how they are elicited. In this study we examined whether different methods of eliciting childhood memories (i.e., free recall and questionnaire-cued) are differentially susceptible to mood bias. To this aim, we used a mood induction procedure to induce depressed, neutral, and elated mood and assessed childhood memories both before and after the mood induction using both questionnaires and free recall to elicit memories. Results suggested that memories elicited by means of free recall as well as by means of questionnaire-cued recall were susceptible to depressed and elated mood bias. The implications for research addressing the link between childhood experiences and depression are discussed.  相似文献   
127.
Elderly women in subjectively good health--free of acute illness and major sleep pathologies--who were self-identified as good (n = 22) and poor (n = 16) sleepers were compared on measures of physical health, psychological symptoms, psychosocial status, and life-style. Poor sleepers reported longer sleep latencies, less total sleep time, more nonrestorative sleep, and more daytime fatigue than did good sleepers. Sleep recordings confirmed subjective reports, with shorter total sleep times and trends for lower sleep efficiency, longer sleep latencies, and more wake-after-sleep onset among women with subjective poor sleep. Poor sleepers also were more frequent users of sedative-hypnotic medications in the past. Current medication use, alcohol and caffeine use, daytime napping, and exercise were equivalent in both groups. Psychosocial status failed to discriminate groups. Poor sleepers reported significantly more psychological symptoms than did good sleepers. The levels of both psychological symptoms and sleep disturbance were mild.  相似文献   
128.
Researchers examined the importance of similar ethnicity and the preference for a counselor of the same sex among American Indian secondary school students.  相似文献   
129.
Kelley and Stahelski's (1970) triangle hypothesis states that competitors hold homogeneous views of others by assuming that most others are competitive, whereas cooperators or pro-social people hold more heterogeneous views by assuming that others are either cooperative or competitive. To evaluate the triangle hypothesis, this study examines differences between pro-socials, individualists, and competitors not only in their expectations about others' choice behaviour, but also in the confidence with which such expectations are held. It was found that pro-social subjects expected more cooperation than individualists and competitors. More importantly, as predicted on the basis of the triangle hypothesis, pro-socials were less confident about their expectations than competitors, with individualists holding intermediate levels of confidence.  相似文献   
130.
Evidence supporting the fundamental position of Rational-Emotive Therapy (RET) that dysfunctional emotions and behaviors are heavily influenced by irrational beliefs has been questioned due to the fact that many measures of beliefs contain items that actually refer to emotions and behaviors. In this study individual items on the Jones Irrational Beliefs Test (IBT) (Jones, 1968/69) were rated by a panel of experts in RET as to whether they referred to beliefs, behaviors, emotions, or were ambiguous. Then Belief items and Non-belief items from the responses of 368 participants were extracted and scored separately. The Non-belief scores, based on items mostly referring to emotions and behaviors, were strongly related to measures of distress, as would be expected. But scores based on items unequivocally referring to beliefs were also significantly related to measures of emotional distress, psychosomatic symptoms, and suicidal contemplation. These findings are interpreted as clear support for RET's position on the relationship between irrational beliefs (B's) and dysfunctional emotions and behaviors (C's).Co-Editor of thisJournal, is a Fellow of the Institute for Rational-Emotive Therapy in New York City, a Professor of Psychology at Hollins College, and a Licensed Psychologist in independent practice in Roanoke, Virginia.  相似文献   
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