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   517篇
  免费   59篇
  国内免费   13篇
  589篇
  2025年   1篇
  2024年   8篇
  2023年   2篇
  2022年   10篇
  2021年   23篇
  2020年   27篇
  2019年   19篇
  2018年   24篇
  2017年   22篇
  2016年   29篇
  2015年   22篇
  2014年   21篇
  2013年   95篇
  2012年   10篇
  2011年   17篇
  2010年   5篇
  2009年   8篇
  2008年   17篇
  2007年   16篇
  2006年   14篇
  2005年   25篇
  2004年   17篇
  2003年   16篇
  2002年   11篇
  2001年   22篇
  2000年   12篇
  1999年   18篇
  1998年   7篇
  1997年   10篇
  1996年   5篇
  1995年   5篇
  1994年   5篇
  1993年   9篇
  1992年   9篇
  1989年   3篇
  1988年   1篇
  1987年   2篇
  1986年   1篇
  1985年   2篇
  1982年   2篇
  1981年   1篇
  1980年   3篇
  1979年   1篇
  1978年   3篇
  1977年   4篇
  1976年   4篇
  1975年   1篇
排序方式: 共有589条查询结果,搜索用时 0 毫秒
81.
    
Abstract:  In test operations using IRT (item response theory), items are included in a test before being used to rate subjects and the response data is used to estimate their item parameters. However, this method of test operation may lead to item content leakage and an adequate test operation can become difficult. To address this problem, Ozaki and Toyoda (2005, 2006 ) developed item difficulty parameter estimation methods that use paired comparison data from the perspective of the difficulty of items as judged by raters familiar with the field. In the present paper, an improved method of item difficulty parameter estimation is developed. In this new method, an item for which the difficulty parameter is to be estimated is compared with multiple items simultaneously, from the perspective of their difficulty. This is not a one-to-one comparison but a one-to-many comparison. In the comparisons, raters are informed that items selected from an item pool are ordered according to difficulty. The order will provide insight to improve the accuracy of judgment.  相似文献   
82.
    
This research is concerned with two topics in assessing model fit for categorical data analysis. The first topic involves the application of a limited-information overall test, introduced in the item response theory literature, to structural equation modeling (SEM) of categorical outcome variables. Most popular SEM test statistics assess how well the model reproduces estimated polychoric correlations. In contrast, limited-information test statistics assess how well the underlying categorical data are reproduced. Here, the recently introduced C2 statistic of Cai and Monroe (2014) is applied. The second topic concerns how the root mean square error of approximation (RMSEA) fit index can be affected by the number of categories in the outcome variable. This relationship creates challenges for interpreting RMSEA. While the two topics initially appear unrelated, they may conveniently be studied in tandem since RMSEA is based on an overall test statistic, such as C2. The results are illustrated with an empirical application to data from a large-scale educational survey.  相似文献   
83.
    
Health professionals do not inform their patients’ kin about BRCA1/2 test results or genetic testing without their written consent. Thus, the onus is on women attending genetic counselling to talk to relatives about the family history and their potential increased risk. This communication process within the family is largely unexplored and provides the focus of the present study. Fifteen healthy women attending a genetics clinic for predictive testing were interviewed prior to receiving their test result and again 6 months later. A grounded theory approach was used. Findings illustrate the dilemmas women faced in juggling social roles and expectations, which had an impact on communication within the family in the context of predictive genetic testing. Tensions between responsibilities towards themselves and others and their fulfilment of social roles had an impact on who women informed and on how they did so. These factors should be considered when assigning patients the role of information provider.  相似文献   
84.
    
This study assessed the unique associations of risk perceptions and worry with attitudes about genetic testing for breast cancer susceptibility. Women (general practitioner clinic attenders, university students, and first-degree relatives of breast cancer survivors; N?=?303) read information about genetic testing and completed measures assessing perceived cancer risk, cancer worry, and genetic testing attitudes and beliefs. Worry was associated with greater interest in genetic testing, stronger beliefs that testing has detrimental emotional consequences, and positive beliefs about benefits of testing and risk-reducing surgeries. Perceived risk was unrelated to interest and associated with more skeptical beliefs about emotional consequences and benefits of testing and risk-reducing surgeries. At low worry levels, testing interest increased with more positive beliefs about testing benefits; at high worry levels, interest was high regardless of benefits beliefs. The findings support Leventhal's Common-Sense Model of self-regulation delineating interactive influences of risk-related cognitions and emotions on information processing and behavior.  相似文献   
85.
    
Direct-to-consumer (DTC) genetic testing is an increasingly available option among individuals searching for information about their health risk factors and ancestry. This study is one of the first to examine predictors of interest in DTC genetic testing. Participants read one of the three types of information about DTC genetic testing (positive only, negative only or both) and reported perceptions of and intentions to pursue testing. The information which people read, their perceptions of the benefits of testing, their perceptions of the barriers to testing and anticipated regret predicted intentions to undergo testing. Interestingly, people who read both positive and negative information did not differ from people who read only negative information in their intentions to pursue testing. We discuss the implications of these findings for predicting interest in this relatively new type of genetic testing and for designing interventions to encourage (or discourage) testing.  相似文献   
86.
    
This article discusses 3 modern forced-choice personality tests developed for the U.S Armed Services to provide resistance to faking and other forms of response distortion: the Assessment of Individual Motivation, the Navy Computerized Adaptive Personality Scales, and the Tailored Adaptive Personality Assessment System. These tests represent the transition from Likert to forced-choice formats and from static to computerized adaptive item selection to meet the challenges of large-scale, high-stakes testing environments. For each test, we briefly describe the personality constructs that are assessed, the response format and scoring methods, and selected ongoing research and development efforts. We also highlight the potential of these tests for personnel selection, classification, and diagnostic screening purposes.  相似文献   
87.
    
The work-hardening behaviour of virgin martensitic steel has been investigated in a strictly un-aged state and after various ageing conditions. At room temperature (RT), the un-aged alloy shows astonishing tensile performances (ultimate tensile stress?=?1600?MPa/uniform elongation?=?15%) but unexpected serrations. These serrations can be suppressed by static ageing (at RT or higher) while maintaining the initial work-hardening rate (ageing at RT). Parallel investigations using atom probe tomography reveal that the distribution of carbon at the atomic scale evolves from purely homogeneous for virgin martensite to partly segregated at a very fine scale (5–10?nm) after static ageing. This particular mechanical behaviour can therefore be associated with a very local decrease in available carbon in solid solution due to redistribution and segregations on defects (nanotwins) that occurs rapidly, even after few days at RT.  相似文献   
88.
The present study reports a two-year follow-up of psychological effects of predictive testing for Huntington's disease. Questionnaires assessing depression, general health, well-being, self injurious behavior, life satisfaction, and lifestyle were completed by 35 carriers and 58 non-carriers before the predictive test, and 2, 6, 12, and 24 months afterwards. Both carriers and non-carriers showed high suicidal ideation before the predictive testing. Depression scores and frequency of suicidal thoughts increased for carriers, compared to non-carriers, over time. There were no differences regarding life satisfaction or life style between carriers and non-carriers. Predictive testing was beneficial in reducing overall ill-health symptoms and increasing well-being for those initially expressing concern about Huntington's disease. The importance of assessing suicidal ideation and of continuing to provide adequate support is emphasized.  相似文献   
89.
The decision to undergo BRCA testing is very complex and emotionally laden. This decision can be further complicated by the loss of a mother at an early age. The following personal account by a genetic counselor discusses the testing process and the struggle to accept the results and reframe one’s self-identity. The sensitive nature of this testing and the implications for other family members is explored.  相似文献   
90.

As compared with conventional vaccine production systems, plant-made vaccines (PMVs) are said to enjoy a range of advantages including cost of production and ease of storage for distribution in developing countries. In this article, we introduce the science of PMV production, and address ethical issues associated with development and clinical testing of PMVs within three interrelated domains: PMVs as transgenic plants; PMVs as clinical research materials; and PMVs as agents of global health. We present three conclusions: first, while many of the ethical issues raised by PMVs are familiar, PMVs add a new dimension to old issues, and raise some novel issues for ethicists and policy-makers; secondly, it is premature to promise broad applicability of PMVs across the developing world without having demonstrated their feasibility; thirdly, in particular, proponents of PMVs as a solution to global health problems must, as a condition of the ethical conduct of their research, define the commercial feasibility of PMVs for distribution in the developing world.  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