Proportionality Assumption in Latent Basis Curve Models: A Cautionary Note

Latent basis curve models (LBCMs) have been popular in modeling change when the change trajectories are unknown or nonlinear. The estimated change trajectories from LBCMs are often viewed as optimal and used as reference points against which other change trajectories are tested. However, there is a proportionality assumption underlying LBCMs that has received little attention from researchers. This study uses a Monte Carlo simulation to show that violation of this assumption can potentially result in substantially biased estimates of the means and variances of changes and covariate effects on these changes, leading to incorrect statistical inference. The implications of the simulation study are discussed and alternatives to LBCMs are suggested for use when the proportionality assumption is likely to be violated.     

植物人工种子技术及应用前景

植物人工种子是指将植物离体培养中产生的体细胞胚或能发育成完整植株的分生组织,包埋在含有营养物质和具有保护功能的外壳内,形成的在适宜条件下能够发芽出苗的颗粒体。完整的人工种子包括3部分:胚状体、人工胚乳、人工种皮。植物人工种子技术主要包括体细胞胚的诱导与同步化、包埋方法、人工种皮制备、干化、贮藏及防腐等。人工种子具有可工厂化大规模制备、贮藏和迅速推广优良种质资源等优点,应用前景十分广阔。     

论生命视角下的教师教育

教育的起点是“人”的教育,教师的责任是教人做人。教育不仅要关注学生的生命成长,也需要关注教师的生命成长。在以往的教师教育中,我们过分注重教师的技能化培训,而忽视了教师生命的完善与发展。因此,要实现人的完整性,使之走向完美境界,就必须完善教师的生命价值,使其在帮助学生完整实现自己的同时也创造着属于教师自己的生命意义与自身价值。     

FDI对中国区域经济增长的影响及差异分析

目前外商直接投资(FDI)虽有向中西部推进的趋势,但仍集中于东部沿海地区。各地区投资效率的差异是外商直接投资的重要因素。我国中西部地区应从改善投资软环境入手,强化其促进经济增长的传导机制,努力消除与东部地区在投资效率上的差距,实现区域经济协调发展。     

教育叙事与教师成长

教师成长乃是教师在立足于个人教育生活合理性的基础上，对个人教育生活的不断发现和个体教育意识的全面觉知。教育叙事正是通过对教师个体成长过程之中的各种偶然性事件的发现，而提升教师对自我教育生活观照的能力，全面提升自我教育意识，在不断提高教育专业水平的同时，提高教师教育生涯的生命质量，促进教师的成长。     

增长曲线模型中回归系数的线性估计的可容许性

对增长曲线模型,当协差阵是降秩的,在矩阵损失函数下,本文分别给出了回归系数的线性估计在非齐次线性估计类和全体估计类中是可容许估计的条件.     

常绿植物SOD活性与植物耐寒力相关性的研究

本实验研究了6种常绿植物越冬期间,在植株正常生长情况下,各因子共同作用对常绿植物SOD活性的影响。结果表明：六种常绿植物越冬期间SOD活性变化曲线均呈“M”状,并不随环境温度降低而持续下降;常绿植物抗寒力与植物内源SOD活性水平密切相关,呈种间特异性。     

Boundary control of a linear distributed parameter bioprocess

This paper is concerned with boundary control of a linear distributed parameter bioprocess. Huang's result (Ann. Differential Equations 1(1) (1985) 43) on the spectrum determined growth assumption is applied to prove that the closed-loop system becomes exponentially stable under a certain condition with respect to the feedback gain. Moreover, it is shown that the decay rate of the open-loop system is given by letting the feedback gain tend to zero.     

Undesirable economic growth via agents’ self-protection against environmental degradation

Our model analyzes the effects of the interplay between environmental degradation and consumption choices on economic growth dynamics and on economic agents’ welfare. We show that if private goods can be consumed as substitutes for environmental goods, then economic growth may be fueled by environmental deterioration. In this context, undesirable economic growth may occur, characterized by an inverse correlation between aggregate capital accumulation and economic agents’ welfare.     

唐山城乡居民消费对经济增长影响差异化的实证分析

作为多年来经济总量位居河北省第一位的唐山市,这几年国民经济得到了飞速发展,消费需求总量的逐步扩大在一定程度上对经济增长的拉动起到了举足轻重的作用。本文建立了城乡居民消费水平与唐山经济增长关系的误差修正模型,研究表明唐山城乡居民消费对其经济增长有正向拉动作用,城镇居民消费的拉动作用比农村居民的要大。因而,采取措施缩小城乡居民消费的差距,统筹二者的发展,是唐山完成两个"率先"的目标、建成全面小康社会不得不面对的问题。