全文获取类型
收费全文 | 2833篇 |
免费 | 231篇 |
国内免费 | 216篇 |
出版年
2024年 | 8篇 |
2023年 | 84篇 |
2022年 | 67篇 |
2021年 | 94篇 |
2020年 | 180篇 |
2019年 | 185篇 |
2018年 | 141篇 |
2017年 | 148篇 |
2016年 | 152篇 |
2015年 | 106篇 |
2014年 | 112篇 |
2013年 | 431篇 |
2012年 | 87篇 |
2011年 | 91篇 |
2010年 | 81篇 |
2009年 | 109篇 |
2008年 | 92篇 |
2007年 | 107篇 |
2006年 | 90篇 |
2005年 | 105篇 |
2004年 | 85篇 |
2003年 | 74篇 |
2002年 | 78篇 |
2001年 | 65篇 |
2000年 | 48篇 |
1999年 | 56篇 |
1998年 | 48篇 |
1997年 | 38篇 |
1996年 | 32篇 |
1995年 | 33篇 |
1994年 | 34篇 |
1993年 | 19篇 |
1992年 | 18篇 |
1991年 | 26篇 |
1990年 | 16篇 |
1989年 | 13篇 |
1988年 | 6篇 |
1987年 | 9篇 |
1986年 | 14篇 |
1985年 | 17篇 |
1984年 | 15篇 |
1983年 | 2篇 |
1982年 | 7篇 |
1981年 | 12篇 |
1980年 | 11篇 |
1979年 | 19篇 |
1978年 | 5篇 |
1977年 | 3篇 |
1976年 | 5篇 |
1975年 | 2篇 |
排序方式: 共有3280条查询结果,搜索用时 31 毫秒
131.
Xenotransplantation, or the use of animal cells, tissues and organs for humans, has been promoted as an important solution
to the worldwide shortage of organs. While scientific studies continue to be done to address problems of rejection and the
possibility of animal-to-human virus transfer, socio-ethical and legal questions have also been raised around informed consent,
life-long monitoring, animal welfare and animal rights, and appropriate regulatory practices. Many calls have also been made
to consult publics before policy decisions are made. This paper describes the Canadian public consultation process on xenotransplantation
carried out by the Canadian Public Health Association in an arm’s length process from Health Canada, the ministry overseeing
government health policy and regulation. Focusing on six citizen fora conducted around the country patterned after the citizen
jury deliberative approach, the paper describes the citizen panelists’ recommendations to hold off on proceeding with clinical
trials and the rationales behind this recommendation. The consultation process is discussed in the context of constructive
technology assessment, a framework which argues for broader input into earlier stages of technology innovation, particularly
at the technology design stage.
This study was supported by a grant to the first author from the Social Sciences and Humanities Research Council in Canada. 相似文献
132.
The aim of the present study was to test the properties of an instrument that assesses concerns about weight and eating without reference to dieting behavior. A short instrument, the Weight and Eating Concerns Inventory (WECI) was examined in a sample of 569 boys and 548 girls aged 11 to 15 years. Confirmatory factor analyses with LISREL showed a better fit with a version of the instrument that did not include a reference to dieting behavior, compared to a version that included such a reference. This was true for both boys and girls, irrespective of their age group. However, the results indicated that both versions should be used with caution for young boys. The internal consistency of the WECI (that is, the version without reference to dieting) was satisfactory, ranging from 0.78 to 0.86 for girls and from 0.68 to 0.73 for boys. The WECI correlated quite substantially with negative self-evaluations and depression for boys and girls in all the age groups assessed, suggesting that high scores on the WECI may indicate a problem that goes beyond worries or concerns, and should be taken seriously. In general, girls reported more of these concerns than boys, and the correlation between the WECI and dieting was stronger among girls compared to boys. 相似文献
133.
Tangible preference assessments were compared with verbal preference assessments for 6 individuals with mental retardation, behavior disorders, or both. In the tangible assessment, items were placed in front of the participant. In the verbal assessment, participants were asked, “Do you want X or Y?” and the items were not present. The two assessments yielded similar high‐preference items for 4 of the 6 participants. The verbal assessment was typically completed in less time than the tangible assessment. 相似文献
134.
Taravella CC Lerman DC Contrucci SA Roane HS 《Journal of applied behavior analysis》2000,33(1):105-108
The generality of the findings reported by DeLeon, Iwata, and Roscoe (1997) was examined by conducting two stimulus-choice preference assessments, the second of which evaluated low-ranked items from the initial assessment. Results for the 2 participants suggested that supplementary assessments of low-ranked items may be useful for identifying a wider variety of reinforcing stimuli. 相似文献
135.
Although Yalom's (1995) framework of the therapeutic factors facilitating outcome in group has been accepted by group specialists, no empirically based instrument assesses all of these factors. The Therapeutic Factors Inventory (TFI), with 11 scales based on the therapeutic factors, has been designed to fill this gap. This article summarizes the development and preliminary reliability testing of the TFI. Each scale of the instrument demonstrated high internal consistency; however, one scale obtained unacceptably low test-retest reliability. Further validity testing is needed. Implications of these findings are discussed. 相似文献
136.
Brief multiple-stimulus-without-replacement (MSWO) preference assessments were conducted with 3 adolescent boys with emotional-behavioral disorders in the context of their public school educational program. The reinforcing effects of stimuli identified as high, medium, and low preference were then evaluated using an alternating treatments design in which, following an initial baseline, stimuli were delivered contingent on on-task behavior. High-preference stimuli produced the highest percentages of on-task behavior for all 3 participants. 相似文献
137.
An 11-year-old boy presented in an outpatient clinic with a vocal habit that occurred during reading and conversation. A brief reading assessment was conducted to determine an effective intervention to decrease the habit. A modified version of the word error-correction procedure resulted in positive changes and was implemented by his mother during home reading practices. Significant decreases in the rate of vocal habit were observed during home reading probes, generalization probes, and follow-up. 相似文献
138.
The present study evaluated the effects of a lag differential reinforcement contingency on 2 students' activity selections using reversal designs. Results showed that the lag contingency was responsible for promoting increased novel selections, engagement in diverse activities, and greater progress with respect to programmed academic activities. 相似文献
139.
People often claim that they perform better in memory performance tasks when they are more motivated. However, past research has shown minimal effects of motivation on memory performance when factors contributing to item-specific biases during encoding and retrieval are taken into account. The purpose of the present study was to examine the generality of this apparent dissociation by using more sensitive measures of experienced motivation and memory performance. Extrinsic motivation was manipulated through competition instructions, and subjective ratings of intrinsic and extrinsic motivation were obtained before and after study instructions. Participants studied a series of words, and memory performance was assessed by content recall (Experiment 1) and source recall (Experiment 2). Both experiments showed dissociation between subjective ratings of extrinsic motivation and actual memory performance, so that competition increased self-rated extrinsic motivation but had no effects on memory performance, including source recall. Inconsistent with most people's expectations, the findings suggest that extrinsic motivation has minimal effects on memory performance. 相似文献
140.
The Impact of the Big Five Personality Traits on Reports of Child Behavior Problems by Different Informants 总被引:1,自引:0,他引:1
The present study compared ratings of a standardized sample of child behavior problems across informants and examined the effects of informant personality traits on child behavior ratings by mothers, teachers, and group-care workers. Participants were 55 clinic-referred children, aged 6–12 years. All informants watched and rated the same 17-min videotaped behavior sample of a familiar target child. Independent trained observers rated the same videotapes to provide criterion ratings. Informants personality traits were assessed using the NEO Five Factor Personality Inventory. Results showed that mothers reported fewer behavior problems than did the professionals, that the informants who were familiar with the child reported more behavior problems than did the independent observers, and that higher levels of informant neuroticism were related to higher ratings of child behavior problems in the case of the professionals, but not in the case of the mothers. In addition, group-care workers who were less extraverted and open were likely to report more child behavior problems than group-care workers with normal levels of extraversion and openness. Finally, no relations were found between agreeableness or conscientiousness and ratings of child behavior. Findings suggest that professionals who work with children are not immune to distortions based on their own personality. 相似文献