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11.
甲骨文中的否定词比较丰富,它们的用法也不完全相同。研究这些否定词的用法,不仅丰富汉语史的内容,而且也看到,秦汉时期汉语中某些否定词的用法,早在3000年前的殷商时代就已形成,说明汉语的历史的确是悠久而又丰富的。  相似文献   
12.
从唐末至今 ,论者对晚唐诗大多持否定态度。反思这种带有明显历史惯性的批评现象 ,不难发现 ,不是晚唐诗缺乏思想价值和艺术魅力 ,而是其出现的异于此前诗坛的人生哲学、生活情趣、审美情趣、艺术思维和艺术风格 ,不仅使那些视文学为伦理、政治奴婢的封建文学观念批评者难以认同 ,也使那些对思想文化史发展缺乏认识和分析的批评者 ,难以理解出现在晚唐诗中的种种变化 ,因而导致千余年来的批评失误  相似文献   
13.
Summary. This study investigates whether there was evidence of increasing risk of still-birth with increasing paternal exposure to ionizing radiation received during employment at the Sellafield nuclear installation before the child was conceived. A significant positive association is found between the total paternal preconceptional exposure to external ionizing radiation and the risk of still-birth (after adjustment for year of birth, social class, birth order and paternal age, odds ratio at 100 mSv 1.24 (95% confidence interval 1.04–1.45)). A summary of the principal scientific findings of this study has been published in the Lancet . This paper describes in detail the statistical methods that were used in the investigation and presents the results in full.  相似文献   
14.
通过2个月的运动元记忆训练,检验其对非体育专业学生元记忆水平和动作记忆成绩的影响.结果显示运动元记忆训练能显著提高大学生运动记忆策略和记忆监控水平;结果还表明训练能明显提高大学生的艺术体操和健美操动作记忆成绩(表现在动作数量上),而且艺术体操动作记忆的训练效应大于健美操.  相似文献   
15.
The last observation carried forward (LOCF) approach is commonly utilized to handle missing values in the primary analysis of clinical trials. However, recent evidence suggests that likelihood‐based analyses developed under the missing at random (MAR) framework are sensible alternatives. The objective of this study was to assess the Type I error rates from a likelihood‐based MAR approach – mixed‐model repeated measures (MMRM) – compared with LOCF when estimating treatment contrasts for mean change from baseline to endpoint (Δ). Data emulating neuropsychiatric clinical trials were simulated in a 4 × 4 factorial arrangement of scenarios, using four patterns of mean changes over time and four strategies for deleting data to generate subject dropout via an MAR mechanism. In data with no dropout, estimates of Δ and SEΔ from MMRM and LOCF were identical. In data with dropout, the Type I error rates (averaged across all scenarios) for MMRM and LOCF were 5.49% and 16.76%, respectively. In 11 of the 16 scenarios, the Type I error rate from MMRM was at least 1.00% closer to the expected rate of 5.00% than the corresponding rate from LOCF. In no scenario did LOCF yield a Type I error rate that was at least 1.00% closer to the expected rate than the corresponding rate from MMRM. The average estimate of SEΔ from MMRM was greater in data with dropout than in complete data, whereas the average estimate of SEΔ from LOCF was smaller in data with dropout than in complete data, suggesting that standard errors from MMRM better reflected the uncertainty in the data. The results from this investigation support those from previous studies, which found that MMRM provided reasonable control of Type I error even in the presence of MNAR missingness. No universally best approach to analysis of longitudinal data exists. However, likelihood‐based MAR approaches have been shown to perform well in a variety of situations and are a sensible alternative to the LOCF approach. MNAR methods can be used within a sensitivity analysis framework to test the potential presence and impact of MNAR data, thereby assessing robustness of results from an MAR method. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   
16.
“请”字用法汉英对比的语用分析   总被引:1,自引:0,他引:1  
迁移是语际语用学和二语习得研究领域的重要范畴。现回顾迁移的相关理论,并考察请字在汉英两种语言里的用法及其异同点。并指出母语与知识对目的语表达的牵制作用、对母语句式或用法的泛化以及语言表达背后的社会价值观是造成语用负迁移的重要原因。  相似文献   
17.
For a wide variety of applications, experiments are based on units ordered over time or space. Models for these experiments generally may include one or more of: correlations, systematic trends, carryover effects and interference effects. Since the standard optimal block designs may not be efficient in these situations, orthogonal arrays of type I and type II, which were introduced in 1961 by C.R. Rao [Combinatorial arrangements analogous to orthogonal arrays, Sankhya A 23 (1961) 283–286], have been recently used to construct optimal and efficient designs for many of these experiments. Results in this area are unified and the salient features are outlined.  相似文献   
18.
由于历史和现实的缘故,国民政府十分关注海外华侨尤其南洋华侨的教育,形成了比较完善的华侨教育体系,学校和学生数量呈上升趋势,学生素质也不断提高。然而由于国民政府侨教政策自身固有的弊病,给南洋侨教带来了相当的消极作用,限制了南洋侨教事业的进一步发展。  相似文献   
19.
以英语学习中出现的正向迁移和负向迁移为例证,分析汉语对学习英语所产生的影响,而重点论述以汉语为母语的思维定势对英语学习产生的负向迁移影响,并提出了如何排除母语干扰的若干意见。  相似文献   
20.
Missing data, and the bias they can cause, are an almost ever‐present concern in clinical trials. The last observation carried forward (LOCF) approach has been frequently utilized to handle missing data in clinical trials, and is often specified in conjunction with analysis of variance (LOCF ANOVA) for the primary analysis. Considerable advances in statistical methodology, and in our ability to implement these methods, have been made in recent years. Likelihood‐based, mixed‐effects model approaches implemented under the missing at random (MAR) framework are now easy to implement, and are commonly used to analyse clinical trial data. Furthermore, such approaches are more robust to the biases from missing data, and provide better control of Type I and Type II errors than LOCF ANOVA. Empirical research and analytic proof have demonstrated that the behaviour of LOCF is uncertain, and in many situations it has not been conservative. Using LOCF as a composite measure of safety, tolerability and efficacy can lead to erroneous conclusions regarding the effectiveness of a drug. This approach also violates the fundamental basis of statistics as it involves testing an outcome that is not a physical parameter of the population, but rather a quantity that can be influenced by investigator behaviour, trial design, etc. Practice should shift away from using LOCF ANOVA as the primary analysis and focus on likelihood‐based, mixed‐effects model approaches developed under the MAR framework, with missing not at random methods used to assess robustness of the primary analysis. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   
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