UF4水解制备UO2粉末工艺的研究

本文研究了在H2 H2O混合气流下,UF4水解制备UO2粉末过程中的工艺条件,以及影响UO2粉末物性指标和产品含氟量的主要因素,通过试验确定了UF4水解制备UO2粉末的工艺参数.     

关于我国高师院校公共外语教学课程设置模式的若干思考

本文从我国高师院校现行的公共外语教学两年制的课程设置模式中存在的弊端入手,提出构建大学公共外语教学“2 2”课程设置模式的观点,并对此模式的内容构成、核心、指导思想以及在构建和实施中所必备的几个重要因素进行初步的探讨。     

ON THE USE OF X2 AS A TEST OF INDEPENDENCE IN CONTINGENCY TABLES WITH SMALL CELL EXPECTATIONS

When an r×c contingency table has many cells having very small expectations, the usual χ² approximation to the upper tail of the Pearson χ² goodness-of-fit statistic becomes very conservative. The alternatives considered in this paper are to use either a lognormal approximation, or to scale the usual χ² approximation. The study involves thousands of tables with various sample sizes, and with tables whose sizes range from 2×2 through 2×10×10. Subject to certain restrictions the new scaled χ² approximations are recommended for use with tables having an average cell expectation as small as 0·5.     

领属关系主谓谓语句分析

领属关系主谓谓语句是主谓谓语句中的典型句式,大小主语间仅仅是语义上的隶属关系,而不是结构上的偏正关系.大主语常常是说话的起点,小主语则往往是表达的重点.主谓谓语句本身的语法、语义及语用特征是区别它与其他相似句式的最重要因素.     

Ca2+促进丝瓜离体生根（英）

Ca2+信使系统是植物体内重要的信号通路,它将许多细胞外信号转化为细胞内的信号以影响许多蛋白激酶活性,从而引起植物生长发育的多种反应.在正常Ca2+浓度下,仅激素处理不能生根的丝瓜外植体,处以不同Ca2+浓度处理时,随Ca2+浓度升高,外植体生根数明显加快并增多,且有少量植株叶腋处异化生根,在一定程度上改变了腋芽的发育方向,这说明Ca2+改变了卷须芽或花芽的发育方向,使其发育为根.但Ca2+超过一定浓度后会影响外植体的正常营养生长.     

大学英语2＋2＋X教学模式的初步探索与实践

本文在学习了教学模式的定义和内容的基础上,讨论了大学英语教学模式及2+2+X这一新教学模式的由来及其内容,并以一次教学实验探讨并验证了新教学模式实施的可能性,从而为大规模实施这一教学模式提供了一些经验。如:科学利用多媒体;以主题内容安排教学活动;提问式是课堂互动的主要形式;结合效果检查培训学习策略。这一教学实验的不足之处在于没有能够对网络在线的教学活动进行探讨,因此未能对新教学模式中的X部分提出意见和评价。     

Two remarks on order statistics

Let X₍₁₎,…,X_(n) be the order statistics of n iid distributed random variables. We prove that (X_(i)) have a certain Markov property for general distributions and secondly that the order statistics have monotone conditional regression dependence. Both properties are well known in the case of continuous distributions.     

Analyzing cross-sectional and longitudinal lung-function measurements: The effects of age

The problem of interpreting lung-function measurements in industrial workers is examined. The data under discussion pertain to FEV₁ and FVC measurements in smoking and in nonsmoking groups of grain-elevator workers in British Columbia and of workers in Vancouver City Hall. Initial observations have now been enriched by longitudinal follow up data on the same groups after three and after six years. It is shown that interesting selection phenomena, favouring “fit” individuals, take place over time, with regard both to lung symptoms and lung functions. Thus cross-sectional and longitudinal studies refer to somewhat different populations. It also appears that longitudinal studies are considerably more sensitive to identifying cumulative lung damage than are corresponding cross-sectional studies. The nonlinearity of the effect of age on lung functions is noted in the longitudinal data in a number of cases, lending support to the hypothesis of association between quadratic age effect and cumulative exposure to lung insults.     

钒钛湿度传感器的綫性化及溫度补偿

本文根据钒-钛陶瓷湿度传感器的湿度-阻抗特性,运用最小二乘法对其湿-阻特性进行了理论拟合,从而得到了湿-阻特性的解析式。并根据电路理论,提出了钒-钛陶瓷湿度传感器的线性化及其温度补偿方法。     

Possible causes of tax evasion

Only a limited number of empirical investigations, into possible causes of tax evasion, have been carried out. Most of these have been conducted since 1970 and they have been carried out in countries other than Australia. Much of the published research was reviewed lo develop a set of hypotheses which were then tested with Australian data. The results of those tests are reported in this article. It appears that several things might influence taxpayer's behaviour and in Australia, the exchange indicator could be one of the important influences.