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81.
Developing human-nonhuman chimeras in human stem cell research: ethical issues and boundaries 总被引:1,自引:0,他引:1
The transplantation of adult human neural stem cells into prenatal non-humans offers an avenue for studying human neural cell development without direct use of human embryos. However, such experiments raise significant ethical concerns about mixing human and nonhuman materials in ways that could result in the development of human-nonhuman chimeras. This paper examines four arguments against such research, the moral taboo, species integrity, "unnaturalness," and human dignity arguments, and finds the last plausible. It argues that the transfer of human brain or retinal stem cells to nonhuman embryos would not result in the development of human-nonhuman chimeras that denigrate human dignity, provided such stem cells are dissociated. The article provides guidelines that set ethical boundaries for conducting such research that are consonant with the requirements of human dignity. 相似文献
82.
This study presents a database of 500 words from five semantic categories: animals, body parts, furniture, clothing, and intelligence.
Each category contains 100 words, and data on lexical availability, age of acquisition, imageability, typicality, concept
familiarity, written word frequency, and word length in number of syllables are provided with each word. The full set of norms
may be downloaded from www.psychonomic.org/archive. 相似文献
83.
Ellis BJ 《Psychological bulletin》2004,130(6):920-958
Life history theory provides a metatheoretical framework for the study of pubertal timing from an evolutionary-developmental perspective. The current article reviews 5 middle-level theories--energetics theory, stress-suppression theory, psychosocial acceleration theory, paternal investment theory, and child development theory--each of which applies the basic assumptions of life history theory to the question of environmental influences on timing of puberty in girls. These theories converge in their conceptualization of pubertal timing as responsive to ecological conditions but diverge in their conceptualization of (a) the nature, extent, and direction of environmental influences and (b) the effects of pubertal timing on other reproductive variables. Competing hypotheses derived from the 5 perspectives are evaluated. An extension of W. T. Boyce and B. J. Ellis's (in press) theory of stress reactivity is proposed to account for both inhibiting and accelerating effects of psychosocial stress on timing of pubertal development. This review highlights the multiplicity of (often unrecognized) perspectives guiding research, raises challenges to virtually all of these, and presents an alternative framework in an effort to move research forward in this arena of multidisciplinary inquiry. 相似文献
84.
Although marital and relationship support programs are available for couples, few churches offer comprehensive marital and relationship ministry (MRM). This research examined MRM topics and formats desired by congregants and advocated adoption by clergy of MRM as a tenant of pastoral care. Eight faith communities in a Midwestern city were non-randomly selected for ethnic and denominational diversity. Overall analyses indicated congregants desired specific areas of marital and relationship ministry that included communication, family, and enrichment topics. 相似文献
85.
Predicting stability and change in toddler behavior problems: contributions of maternal behavior and child gender 总被引:1,自引:0,他引:1
This study examined the stability and continuity of early-identified behavior problems and the factors associated with this stability. Children and their mothers (N=125) were seen when the children were 2 and 4 years of age. Maternal reports of child externalizing behavior and laboratory observations of child noncompliance were stable from age 2 to age 4. Early externalizing behaviors decreased over time; however, child noncompliance in the laboratory did not. Although few associations were found between maternal positive behavior and child behavior problems, maternal controlling behavior was related to increases in child behavior problems, particularly at high levels of both prior noncompliance and prior maternal control. Child noncompliance was predictive of increases in maternal controlling behavior over time. 相似文献
86.
Maternal regulation of infant reactivity from 2 to 6 months 总被引:1,自引:0,他引:1
Previous research has investigated the effect of maternal soothing behaviors on reducing infant reactivity but not the differential effects of specific maternal behaviors on infant stress responses. The present study investigated maternal regulation of 2- and 6-month-olds' responses to an inoculation and found a significant decline with age in both the intensity and duration of infants' crying. Maternal affection and touching decreased from 2 to 6 months, whereas maternal vocalizing and distraction behaviors increased. At both ages, the combination of maternal holding/rocking and vocalizing was associated with decreases in all levels of infant reactivity. Neither strategy alone, however, was found to be effective. Feeding/ pacifying behaviors were effective only when initial distress was at a low or moderate level, which suggests that the effectiveness of maternal regulatory behaviors may depend on the intensity of infants' crying. 相似文献
87.
Drew MR Yang C Ohyama T Balsam PD 《Journal of experimental psychology. Animal behavior processes》2004,30(3):163-176
Three experiments investigated the effects of varying the conditioned stimulus (CS) duration between training and extinction. Ring doves (Streptopelia risoria) were autoshaped on a fixed CS-unconditioned stimulus (US) interval and extinguished with CS presentations that were longer, shorter, or the same as the training duration. During a subsequent test session, the training CS duration was reintroduced. Results suggest that the cessation of responding during an extinction session is controlled by generalization of excitation between the training and extinction CSs and by the number of nonreinforced CS presentations. Transfer of extinction to the training CS is controlled by the similarity between the extinction and training CSs. Extinction learning is temporally specific. 相似文献
88.
This study examined the nature of verb deficits in 14 individuals with probable Alzheimer's Disease (PrAD) and nine with agrammatic aphasia. Production was tested, controlling both semantic and syntactic features of verbs, using noun and verb naming, sentence completion, and narrative tasks. Noun and verb comprehension and a grammaticality judgment task also were administered. Results showed that while both PrAD and agrammatic subjects showed impaired verb naming, the syntactic features of verbs (i.e., argument structure) influenced agrammatic, but not Alzheimer's disease patients' verb production ability. That is, agrammatic patients showed progressively greater difficulty with verbs associated with more arguments, as has been shown in previous studies (e.g., Kim & Thompson, 2000; Thompson, 2003; Thompson, Lange, Schneider, & Shapiro, 1997), and suggest a syntactic basis for verb production deficits in agrammatism. Conversely, the semantic complexity of verbs affected PrAD, but not agrammatic, patients' performance, suggesting "bottom-up" breakdown in their verb lexicon, paralleling that of nouns, resulting from the degradation or loss of semantic features of verbs. 相似文献
89.
The present study evaluated the effectiveness of the Positive Parenting Program (Triple P) with a sample of Chinese parents of children with early onset conduct-related problems in Hong Kong. The participants consisted of 91 parents whose children attended maternal and child health centers and child assessment centers for service, and were between three to seven years old. Participants were randomly assigned to the intervention (TP) and a waitlist control group (WL). There was no significant difference in pre-intervention measures between the two groups. However, at post intervention, participants in the TP group reported significantly lower levels of child behavior problems, lower dysfunctional parenting styles, and higher parent sense of competence, compared to the WL group. Implications of these findings for the use of Triple P with families of Chinese descent are discussed. 相似文献
90.
We examine whether children's performance on a false-belief task is impaired by task content that activates an early-developing, prepotent motivational system: predator-avoidance. In two studies (N = 46 and N = 37), children aged 3-4 years completed variants of a false-belief task that involved predator-avoidance, playmate-avoidance, prey-seeking, and playmate-seeking, respectively. The proportion of correct answers on the playmate-avoidance task (Study 1: 52%; Study 2: 51%) was significantly greater than the proportion of correct answers on the analogous predator-avoidance task (Study 1: 28%; Study 2: 22%). This difference was not an artifact of children generally performing better on playmate stories than on predator-prey stories. The findings are consistent with the hypothesis that activation of the predator-avoidance system generates prepotent response patterns that pre-empt full consideration of the mental states of the prey characters in false-belief stories. 相似文献