时刻莫忘珍惜土地

土地,被卡尔·马克思称之为"一切生产和一切存在的源泉".也就是人们通常所说,土地是人类赖以生存的物质基础,是不可再生的宝贵资源和重要资产,是人类一切活动和社会经济发展的载体.     

李觏与佛教

李觏佛教思想具有双重性，既有排佛的一面，也有容佛的一面。排佛主要表现在两个领域，一是以经济建设、财富积累和社会秩序为内容的物质领域，一是儒家礼治伦理领域；容佛主要表现在对佛教某些教义、佛教教化功能的肯定。李觏佛教思想的基本内容及其特点，是颇有启示的。     

《汉语大字典》书证疏误举例

《汉语大字典》在义项的书证方面存在一些疏误,内容涉及书证欠妥、书证有误、引文失误、一例两用等问题。     

教师人格研究及其对新课程教师培训的启示

教师人格作为教师影响力的重要构成因素之一,受到我国教育学和心理学研究者的广泛关注.根据近二十年来我国教师人格研究的文献,从优秀教师的典型人格特征、影响教师人格形成和发展的因素、教师人格与学生发展的关系以及教师人格与自身心理健康四个方面进行了归纳和总结.在此基础上提出,聘任和选拔教师应考虑其人格特征;教师培训既要注重专业能力的提高、专业技能的发展,更要重视教师优良人格特征的塑造和培育;注重教师培训的生态效应,强调行动研究,增强培训活动的人格影响力.     

普芬道夫法哲学思想论析

赛缪尔·普芬道夫是17世纪德国法哲学的开创者,是近代世界范围内最杰出的自然法学思想家.普芬道夫对法学的贡献主要表现在他对自然法的捍卫上,作为古典自然法学派在德国的主要代表,其著作中处处充满着自然法思想,尤其是契约论思想更是影响深远.在自然法学说方面,普芬道夫的思想联结着格老秀斯和霍布斯.与其他古典自然法思想家不同,他特别重视对义务的研究.     

数学教学中渗透创造性思维训练的尝试

通过对联想思维、求异思维、逆向思维、求通求变思维训练的分析,阐述了培养创造性思维的具体方法.     

Partner Choice and the Differential Retreat From Marriage

The contemporary retreat from marriage in the United States has had a differential impact across socioeconomic and racial groups. Here, 1990 marriage rates and propensities for Virginia, North Carolina, and Wisconsin are analyzed regarding (a) the likelihood that persons in different groups ever marry and (b) patterns of partner choice with respect to race and educational level. Marriage remains strong in most race‐education groups but is substantially lower among Blacks and among those with less than 12 years of education. Patterns of partner choice have shifted to show greater symmetry between the educational levels of brides and grooms. Changes have been modest with regard to the level and pattern of interracial (Black‐White) marriage. Marriage is increasingly a union of equals, but a union chosen more by Whites than by Blacks and more by the well educated than by the poorly educated.     

Exposure Reconstruction for the TCDD-Exposed NIOSH Cohort Using a Concentration- and Age-Dependent Model of Elimination

Recent studies demonstrating a concentration dependence of elimination of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) suggest that previous estimates of exposure for occupationally exposed cohorts may have underestimated actual exposure, resulting in a potential overestimate of the carcinogenic potency of TCDD in humans based on the mortality data for these cohorts. Using a database on U.S. chemical manufacturing workers potentially exposed to TCDD compiled by the National Institute for Occupational Safety and Health (NIOSH), we evaluated the impact of using a concentration- and age-dependent elimination model (CADM) (Aylward et al., 2005) on estimates of serum lipid area under the curve (AUC) for the NIOSH cohort. These data were used previously by Steenland et al. (2001) in combination with a first-order elimination model with an 8.7-year half-life to estimate cumulative serum lipid concentration (equivalent to AUC) for these workers for use in cancer dose-response assessment. Serum lipid TCDD measurements taken in 1988 for a subset of the cohort were combined with the NIOSH job exposure matrix and work histories to estimate dose rates per unit of exposure score. We evaluated the effect of choices in regression model (regression on untransformed vs. ln-transformed data and inclusion of a nonzero regression intercept) as well as the impact of choices of elimination models and parameters on estimated AUCs for the cohort. Central estimates for dose rate parameters derived from the serum-sampled subcohort were applied with the elimination models to time-specific exposure scores for the entire cohort to generate AUC estimates for all cohort members. Use of the CADM resulted in improved model fits to the serum sampling data compared to the first-order models. Dose rates varied by a factor of 50 among different combinations of elimination model, parameter sets, and regression models. Use of a CADM results in increases of up to five-fold in AUC estimates for the more highly exposed members of the cohort compared to estimates obtained using the first-order model with 8.7-year half-life. This degree of variation in the AUC estimates for this cohort would affect substantially the cancer potency estimates derived from the mortality data from this cohort. Such variability and uncertainty in the reconstructed serum lipid AUC estimates for this cohort, depending on elimination model, parameter set, and regression model, have not been described previously and are critical components in evaluating the dose-response data from the occupationally exposed populations.     

系统科学在大型技术装备项目中的应用

本文论述了系统科学的理论和方法在大型技术装备项目管理中的应用和发展,着重介绍了项目规划的方案优选和项目管理组织体系、计划控制系统,质量控制系统、项目管理信息系统。从这个项目管理系统的总体看,随着加工的进展,系统内信息不断扩大和加深,形成生产管理信息回路,而且采用人-机结合的信息网络,为配合项目管理发挥了重要作用。     

On the shrinkage of local linear curve estimators

Local linear curve estimators are typically constructed using a compactly supported kernel, which minimizes edge effects and (in the case of the Epanechnikov kernel) optimizes asymptotic performance in a mean square sense. The use of compactly supported kernels can produce numerical problems, however. A common remedy is ridging, which may be viewed as shrinkage of the local linear estimator towards the origin. In this paper we propose a general form of shrinkage, and suggest that, in practice, shrinkage be towards a proper curve estimator. For the latter we propose a local linear estimator based on an infinitely supported kernel. This approach is resistant against selection of too large a shrinkage parameter, which can impair performance when shrinkage is towards the origin. It also removes problems of numerical instability resulting from using a compactly supported kernel, and enjoys very good mean squared error properties.