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   96788篇
  免费   3981篇
  国内免费   46篇
  100815篇
  2020年   1122篇
  2019年   1373篇
  2018年   1950篇
  2017年   1972篇
  2016年   2058篇
  2015年   1434篇
  2014年   1744篇
  2013年   8351篇
  2012年   3186篇
  2011年   3300篇
  2010年   1997篇
  2009年   2037篇
  2008年   2956篇
  2007年   2926篇
  2006年   2600篇
  2005年   2288篇
  2004年   2316篇
  2003年   2137篇
  2002年   2118篇
  2001年   3108篇
  2000年   2965篇
  1999年   2277篇
  1998年   1165篇
  1997年   998篇
  1996年   1008篇
  1995年   963篇
  1994年   929篇
  1993年   952篇
  1992年   1827篇
  1991年   1712篇
  1990年   1704篇
  1989年   1572篇
  1988年   1542篇
  1987年   1450篇
  1986年   1472篇
  1985年   1571篇
  1984年   1272篇
  1983年   1095篇
  1982年   864篇
  1979年   1299篇
  1978年   967篇
  1976年   848篇
  1975年   1093篇
  1974年   1215篇
  1973年   1211篇
  1972年   1056篇
  1971年   945篇
  1968年   1054篇
  1967年   983篇
  1966年   899篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
891.
Previous studies have demonstrated that effortful attempts to secure positive outcomes or avoid negative outcomes produce significant increases in systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate (HR). Although these effects of active coping on cardiovascular reactivity are central in current psychosomatic theories, virtually all of the research to date has used impersonal, asocial tasks. Our two studies examined the cardiovascular effects of effortful attempts to influence other people. In Study 1, male subjects attempting to influence the opinions of their discussion partner to improve their own chances of winning money displayed significantly greater SBP, DBP, and HR reactivity. In Study 2, we obtained similar effects on SBP and DBP reactivity in men and women, while both preparing an influence attempt and making that attempt. Furthermore, reactivity levels were larger as the magnitude of incentive for successful persuasion increased. Implications of this interpersonal equivalent of active coping for the development of cardiovascular disease are discussed.  相似文献   
892.
Dimensions of appraisal and physiological response in emotion   总被引:3,自引:0,他引:3  
Appraisal theorists propose physiological activity in emotion to be systematically organized around appraisal of the adaptational significance of the environment in ways that promote two functions commonly ascribed to emotion: communication and preparation for coping. However, relations between appraisal and physiological activity remain largely untested. This article reviews existing evidence to generate specific hypotheses linking appraisal to physiological activity and presents an imagery-based experimental test of a subset of these hypotheses. No evidence was found for a relation between other-agency and the eyebrow frown, but brow activity and heart rate were affected by effort-related appraisals: Anticipated effort influenced heart rate, and perceived goal-obstacles influenced the eyebrow frown. Implications of the findings and theoretical approach are discussed.  相似文献   
893.
Analyzed data from 154 school-age children and their mothers to examine the relations between stress, perceived competence and contingency, and behavior symptoms. Analyses focused on the relative merits of unidimensional vs multidimensional measures of control in predicting symptoms. The stress of undesirable life events and behavior symptoms were related in the expected direction. Multiple regression models with R2 ranging from .11 to .14 (all ps less than .0002) included significant main effects for stress, competence, and control. Analyses supported the relative superiority of the multidimensional measure of control. Models containing main effects and interaction terms were of equivalent magnitudes in accounting for variance in symptom scores. Findings support the idea of perceived control as a moderator of the stress-illness relation and are consistent with earlier suggestions that simple main effects models may be the most useful in examining these relations.  相似文献   
894.
Previous psychophysiological research has demonstrated that both anger expression and anger suppression are related to cardiovascular responses, but in an inconsistent fashion. The present study tested the following hypotheses: (a) that the influence of anger expression style on psychophysiological responses would be limited to Ss exposed to an anger instigation, and (b) that the specific pattern of psychophysiological responses would vary as a function of whether Ss were induced to use their preferred vs. nonpreferred mode of anger expression style in response to the instigation. Seventy-eight male college undergraduates were randomly assigned to work on a task with either an annoying or a pleasant confederate and subsequently to write either a negative or a positive evaluation of the confederate. Blood pressure was measured intermittently and heart rate continuously throughout task performance and a subsequent 15-min rest period. Ss' preferred method of anger expression had been previously assessed by a self-report questionnaire. Systolic blood pressure results generally were consistent with the hypotheses. Implications of the findings for the etiology of cardiovascular diseases are discussed.  相似文献   
895.
A test consistency and confirmatory factor analyses were performed on the Survey of Personal Beliefs, a new measure of irrational thinking based on rational-emotive personality theory. The survey, which was logically derived, includes a general rationality factor and subscales measuring five hypothesized core categories of irrational beliefs. Subjects included a nonclinical sample of 130 men and 150 women, with a mean age of 46. Results indicated that the Survey of Personal Beliefs had satisfactory total and scale reliability. The confirmatory analyses supported a higher order factor model including 5 first-order factors ( awfulizing, self-directed shoulds, other-directed shoulds, low frustration tolerance, and self-worth) and 1 second-order or general factor.  相似文献   
896.
Delusions and hallucinations reported in the social histories of 150 patients admitted to an East Texas state hospital during the 1930s and of 150 patients admitted during the 1980s were examined for content that would characterize and contrast the patient subcultural milieu of the two time periods. Patients admitted during the 1930s tended to reflect the material deprivation and personal powerlessness of the great depression in delusions of great wealth and positive "special powers." The hallucinatory visions and voices of the 1980s patients reflected a more threatening and negative subcultural milieu, with more visions of blood, snakes, and dead people or animals. Command hallucinations to hurt, to kill, or to do "perverse things" would also suggest that the subculture milieu of the 1980s had become more dangerous.  相似文献   
897.
Recent empirical work aimed at identifying test signs of borderline personality disorder is reviewed. The review focuses on commonly employed clinical tests, including the Wechsler Adult Intelligence Scale (WAIS), the Rorschach, and the Minnesota Multiphasic Personality Inventory (MMPI). Possible test signs are considered in relation to their sensitivity to and specificity for the diagnosis and in relation to the criteria of DSM-III, which define the disorder. Although consistent patterns of potentially useful test signs have begun to appear, methodological difficulties have hampered any subsequent development of clinically useful indices. Greater attention to sample size and its composition and definition as well as demonstrations of adequate reliability and predictive utility are required for further development of these signs.  相似文献   
898.
Six pigeons were trained with a chain variable-interval variable-interval schedule on the left key and with reinforcers available on the right key on a single variable-interval schedule arranged concurrently with both links of the chain. All three schedules were separately and systematically varied over a wide range of mean intervals. During these manipulations, the obtained reinforcer rates on constant arranged schedules also frequently changed systematically. Increasing reinforcer rates in Link 2 of the chain increased response rates in both links and decreased response rates in the variable-interval schedule concurrently available with Link 2. Increasing Link-1 reinforcer rates increased Link-1 response rates and decreased Link-2 response rates. Increasing reinforcer rates on the right-key schedule decreased response rates in Link 1 of the chain but did not affect the rate in Link 2. The results extend and amplify previous analyses of chain-schedule performance and help define the effects that a quantitative model must describe. However, the complexity of the results, and the fact that constant arranged reinforcer schedules did not necessarily lead to constant obtained reinforcer rates, precluded a quantitative analysis.  相似文献   
899.
Effects of relative reinforcer frequency on complex color detection   总被引:1,自引:1,他引:0  
Pigeons were trained under a discrete-trials detection procedure in which one of a set of color stimuli was presented on the center key and a single response turned off the stimulus and illuminated two side keys. Single responses to one or the other side key produced occasional reinforcers depending on the value of the color stimulus. In Experiment 1, one color-stimulus set comprised 559, 564, 569, and 574 nm, and right-key pecks were occasionally reinforced following presentations of members of this set. The other stimulus set comprised 579, 584, 589, and 594 nm, and left-key pecks were occasionally reinforced following presentations of members of this set. Across seven experimental conditions, the left/(left + right) relative reinforcer frequency was varied from .1 to .9. In Experiment 2, one stimulus set contained only one member, 574 nm, and right-key responses were occasionally reinforced following its presentation. Over 12 experimental conditions, two manipulations were carried out. First, the number of stimuli comprising the other stimulus set was increased from one (579 nm) to two (579 and 584 nm) to three (579, 584, and 589 nm) and to four (579, 584, 589, and 594 nm), and left-key responses were reinforced occasionally following center-key presentations of members of this set. Second, for each stimulus combination, the left/(left + right) relative reinforcer frequency was varied from .1 to .5 to .9 across three experimental conditions. The principal finding of Experiments 1 and 2 was that reinforcers and stimuli interacted in their effects on behavior. In Experiment 3, pairs of adjacent stimuli (5 nm apart) in the range 559 to 594 nm were presented in each experimental condition, and the left/(left + right) relative reinforcer frequency was held constant at .5. The data from all three experiments were analyzed according to a detection model describing performance in multiple-stimulus two-response procedures. This model provided independent measures of stimulus discriminability, contingency discriminability, and bias. The analysis showed that (a) consistent with the color-naming function, pigeons were better able to discriminate between higher nanometer values than lower nanometer values; (b) their ability to discriminate between the stimuli was independent of the number of wavelengths comprising each stimulus set; (c) they allocated delivered reinforcers very accurately to the previously emitted response; and (d) no consistent biases emerged.  相似文献   
900.
In two experiments, rats were trained to deposit ball bearings down a hole in the floor, using an algorithmic version of shaping. The experimenter coded responses expected to be precursors of the target response, ball bearing deposit; a computer program reinforced these responses, or not, according to an algorithm that mimicked the processes thought to occur in conventional shaping. In the first experiment, 8 of 10 rats were successfully shaped; in the second, 5 of 5 were successfully shaped, and the median number of sessions required was the same as for a control group trained using conventional shaping. In both experiments, “misbehavior,” that is, excessive handling and chewing of the ball bearings, was observed, and when the algorithmic shaping procedure was used, misbehavior could be shown to occur in spite of reduced reinforcement for the responses involved.  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