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   1000篇
  免费   26篇
  2021年   8篇
  2020年   20篇
  2019年   19篇
  2018年   32篇
  2017年   20篇
  2016年   34篇
  2015年   7篇
  2014年   15篇
  2013年   131篇
  2012年   42篇
  2011年   33篇
  2010年   25篇
  2009年   32篇
  2008年   39篇
  2007年   51篇
  2006年   36篇
  2005年   31篇
  2004年   23篇
  2003年   37篇
  2002年   22篇
  2001年   15篇
  2000年   29篇
  1999年   11篇
  1998年   15篇
  1997年   7篇
  1996年   12篇
  1995年   6篇
  1994年   10篇
  1993年   7篇
  1992年   13篇
  1990年   14篇
  1989年   9篇
  1988年   9篇
  1987年   10篇
  1986年   11篇
  1985年   12篇
  1984年   13篇
  1983年   7篇
  1982年   7篇
  1981年   6篇
  1978年   6篇
  1976年   7篇
  1975年   6篇
  1973年   13篇
  1970年   7篇
  1959年   7篇
  1957年   6篇
  1953年   5篇
  1951年   8篇
  1950年   6篇
排序方式: 共有1026条查询结果,搜索用时 15 毫秒
911.
Proposed somatic cell gene-therapies (especially those involving in utero therapies) may involve a small risk of germ-line modifications; this risk has engendered serious concern, and arguments have been made that such therapies ought not be pursued if such risks exists. We argue here that while pursuing deliberate germ-line modifications in humans would be inappropriate given the current state of the art, the risk of accidental germ-line modifications from most currently proposed in utero gene therapy is no different in kind or degree from other risks regularly taken in medical procedures. Given the possible benefits of such therapies, we argue that the risk of accidental germ-line modifications is well worth taking in these cases.  相似文献   
912.
Although past research has demonstrated a “health disadvantage” for Puerto Rican adults, very little is known about correlates of health among this group. Given Puerto Ricans’ unique experiences of migration and settlement, an ethnic enclave framework that integrates nativity, ethnic density, and neighborhood SES may offer insight into factors influencing Puerto Ricans’ health. This study uses a sample of 449 adult mainland- and island-born Puerto Ricans living in New York City and Chicago. The data, collected as a part of the MIDUS Survey of Minority Groups, are stratified by neighborhood ethnic density and neighborhood SES, allowing for the examination of the individual and joint influences of neighborhood characteristics on physical health. Results revealed that ethnic density and neighborhood SES were not independently or interactively related to physical health for mainland-born Puerto Ricans. However, the interaction between ethnic density and neighborhood SES was related to self-reported health, functional limitations, and health symptoms for island-born Puerto Ricans. Island-born Puerto Ricans living in ethnically dense, low SES neighborhoods reported worse health than island-born Puerto Ricans living in other types of neighborhoods. This may be a result of isolation from resources both within and outside the neighborhood.  相似文献   
913.
This study examined performance on the Iowa Gambling Task (IGT; Bechara, Damasio, Damasio, & Anderson, 1994) as a measure of low-income school-aged children’s affective decision-making and considered its utility as a direct indicator of impulsivity. One hundred and ninety-three 8–11 year olds performed a computerized version of the Iowa Gambling Task, a validated measure of decision-making. Multi-level modeling was used to examine children’s performance over the course of the task, with age, gender, and teachers’ ratings of child impulsivity (BIS-11; Patton, Stanford, & Barratt, 1995) used to predict children’s Iowa Gambling performance. Higher impulsivity scores predicted a decrease in slope of Iowa Gambling performance, indicating students rated higher on impulsivity chose more disadvantageously across the task blocks. Results support evidence of the validity of the Iowa Gambling Task as a measure of impulsivity in low-income minority children.  相似文献   
914.
Rapid human movements can be assimilated to the output of a neuromuscular system with an impulse response modeled by a Delta-Lognormal equation. In such a model, the main assumption concerns the cumulative time delays of the response as it propagates toward the effector following a command. To verify the validity of this assumption, delays between bursts in electromyographic (EMG) signals of agonist and antagonist muscles activated during a rapid hand movement were investigated. Delays were measured between the surface EMG signals of six muscles of the upper limb during single rapid handwriting strokes. From EMG envelopes, regressions were obtained between the timing of the burst of activity produced by each monitored muscle. High correlation coefficients were obtained supporting the proportionality of the cumulative time delays, the basic hypothesis of the Delta-Lognormal model. A paradigm governing the sequence of muscle activities in a rapid movement could, in the long run, be useful for applications dealing with the analysis and synthesis of human movements.  相似文献   
915.

This study demonstrates the usefulness of the KMSS and RDAS in distinguishing between the maritally distressed and nondistressed. For conceptual and statistical clarity, many marital interaction and marital therapy research measures, use a single cutoff score. It was determined that the cutoff score is 17 for the Kansas Marital Satisfaction Scale (KMSS) and 48 for the Revised Dyadic Adjustment Scale (RDAS) for husbands, wives, and couples. An equivalency table of mathematical formulas is also presented, allowing the conversion of individual and couple scores from one measure of marital quality to another. It is now possible to convert a score from any one of a number of instruments (KMSS, RDAS, Dyadic Adjustment Scale, Marital Adjustment Test, Revised Marital Adjustment Test) to an equivalent score as measured by another instrument.  相似文献   
916.
This study explored how negative communication and spirituality influence relationship quality across four couple groups. Data was gathered from Anglo couples, interethnic Latino and Anglo couples, and Latino couples. Data was analyzed in a mediating Actor–Partner Interaction Model (APIM) with a multiple group analysis. Negative communication was negatively associated with relationship quality uniformly. Generally, male spirituality positively influenced his own relationship quality and was positively associated with female relationship quality in one group. Female spirituality was negatively associated with relationship quality for both genders in that same group and her spirituality partially mediated that process. Clinical implications are discussed.  相似文献   
917.
A significant challenge for researchers and clinicians is in the process of determining culturally sensitive strategies to ensure treatment effectiveness with ethnic populations in the United States. This article highlights key aspects of treating Chinese American families where a child is struggling with adolescent depression. Relevant literatures associated with adolescent depression and effective treatment of Chinese Americans are reviewed and organized according to the dimensions of therapist knowledge, awareness, and skills. Therapist guidelines are provided using key aspects of cognitive behavioral therapy. Additional suggestions are presented for culturally competent therapy with Chinese American youth and their families.  相似文献   
918.
As the practice of marriage and family therapy is spreading across the world, it is important for knowledge regarding marital processes and patterns to expand to countries outside of North America and Europe. This study examined common marital problems faced by Brazilian couples. The sample consisted of 80 married couples living in Porto Alegre, Brazil. Results showed that money, children, jealousy, and sex were common problems faced by Brazilian couples. There were few gender differences found. Sex and alcohol had a significant impact on marital satisfaction of wives, and sex had a significant impact on marital satisfaction of husbands.  相似文献   
919.
This article discusses the concept of mathematical metaphor as a tool for analyzing the formation of mathematical knowledge. It reflects on the work of Lakoff and Núñez as a reference point against which to rearticulate a richer notion of mathematical metaphor that can account for actual mathematical evolution. To reach its goal this article analyzes historical case studies, draws on cognitive research, and applies lessons from the history of metaphors in philosophy as analyzed by Derrida and de Man.  相似文献   
920.
These experiments aimed at studying the influence of emotional context on global/local visual processing in children. Children 5 years old, known to present an immature global visual bias, and 8 years old, known to pay attention predominantly to global information, were placed in either a neutral or pleasant emotional context and subsequently presented with a global/local visual judgement task. As with previous findings for adults, both age groups presented a pronounced perceptual bias toward global information following exposure to emotionally pleasant pictures. Interestingly, younger children, who do not present a global bias during the neutral exposure, presented the same preference for global information as older children when exposed to the pleasant context. These findings indicate that emotion may strongly affect visual perception in children, with important implications for educational practice and models of cognition.  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