基于B／S高职院校实验教学系统的分析与设计

针对传统实验教学模式存在的弊端,提出将计算机信息技术应用于高职实验教学之中,建立一种自主性、个性化的开放式实验教学模式,在此基础上分析和设计基于B／S的开放式实验教学系统,并对其进行评价和效果分析。     

肇庆地区男子1500m运动员专项素质结构特征分析

运用文献资料法、调查法、训练实验和数理统计法,对肇庆学院及肇庆市体校12名男子1 500 m运动员的15项专项素质指标进行了测试,应用＂旋转后的因子载荷矩阵＂统计方法进行分析,揭示了影响肇庆地区男子1 500 m运动员专项成绩提高的专项素质结构性要素,其主导因素为速度耐力、速度、下肢爆发力和一般耐力,典型指标为2 000 m、5 000 m、400 m、600 m跨步跳.     

基于WEB的院系二级教务管理系统的设计模式

高校院系二级教务管理是高校教务管理中的关键环节,管理的质量直接关系到高校在社会竞争中的地位甚至生存与发展。本文分析了该系统的优点,研究了它的体系结构和基本功能。结合高校院系教务管理的实际需求,采用JAVA技术,设计开发了B／S模式的院系二级教务管理系统。     

小麦-簇毛麦端体附加系中6V端体的细胞遗传学行为及其在Moisson 6MV/6B中的传递

簇毛麦6V染色体上携有抗白粉病基因Pm21.本研究利用抗白粉病小麦-簇毛麦单端体和双端体附加系(2n=42+1t和2n=42+2t)为材料,通过自交,观察后代植株6V端体出现频率,以评价外源染色体在小麦背景中的遗传平衡程度及稳定性,为利用培育小麦-簇毛麦导入系提供理论依据.通过对自交群体植株根尖细胞染色体数观察,发现在双端体附加系(2n=42+2t)自交群体(F2)中,2n=42+2t,2n=42+1t,2n=42的出现频率分别为51.92%,40.38%和7.7%;在单端体附加系(2n=42+1t)的F2群体中,2n=42+2t,2n=42+1t,2n=42的出现频率分别为1.85%,17.59%和80.56%.χ2检验表明(χ20.01=0.000),两自交群体问6V端体传递能力存在显著差异,6V端体的传递能力与亲本携带的端体数密切相关,双端体附加系在减数分裂时主要形成n+t配子,而单端体附加系则形成n和n+t两种配子,n+t配子参与受精的竞争能力主要取决于6V端体的遗传平衡程度,单端体附加系自交群体中的6V端体出现频率较低.这表明6V端体可能携有较多的不利基因导致n+t配子竞争能力较差.小麦-簇毛麦6V双端体附加系Pana(2n=42+2t)6VS在Moisaon 6MV/6B中通过雌雄配子传递频率研究发现,6VS通过雌配子的传递频率(33.33%)远高于通过雄配子的传递频率(4.87%).这也与其抗病性鉴定结果一致.此外,还发现以Pana(2n=42+21)为母本获得了小麦-偏凸山羊草-簇毛麦三属杂种,而以Pana(2n=42+2t)为父本却未能获得小麦-偏凸山羊草-簇毛麦三属杂种,暗示Pana(2n=42+2t)附加端体可能对花粉育性有一定不利影响.     

根际通气和盐分胁迫对玉米生长特性的影响

通过盆栽实验研究了根际通气和盐分胁迫对玉米植株生长状况及生物量的影响.结果表明,不同浓度的盐水(3,6和9 g/L NaCl水溶液)灌溉处理,均使玉米的株高、茎粗、叶面积及各器官的生物量减小,且随着盐分浓度的增大,胁迫效应加强;在所有灌水处理中,根际通气均使玉米的株高、茎粗、叶面积及各器官的生物量增大,在一定程度上可以缓解盐水灌溉对植物生长发育的胁迫效应;盐分胁迫和根际通气均使玉米的根冠比在一定程度上有所增大,但其影响机制可能不同.     

A STEPWISE CONFIDENCE INTERVAL PROCEDURE BASED ON AN ASYMMETRIC LOSS FUNCTION WITH APPLICATIONS TO TOXICOLOGICAL EVALUATION

The purpose of toxicological studies is a safety assessment of compounds (e.g. pesticides, pharmaceuticals, industrial chemicals and food additives) at various dose levels. Because a mistaken declaration that a really non-equivalent dose is equivalent could have dangerous consequences, it is important to adopt reliable statistical methods that can properly control the family-wise error rate. We propose a new stepwise confidence interval procedure for toxicological evaluation based on an asymmetric loss function. The new procedure is shown to be reliable in the sense that the corresponding family-wise error rate is well controlled at or below the pre-specified nominal level. Our simulation results show that the new procedure is to be preferred over the classical confidence interval procedure and the stepwise procedure based on Welch's approximation in terms of practical equivalence/safety. The implementation and significance of the new procedure are illustrated with two real data sets: one from a reproductive toxicological study on Nitrofurazone in Swiss CD-1 mice, and the other from a toxicological study on Aconiazide.     

Wealth: Determinants of Savings Net Worth and Housing Net Worth of Pre-Retired Households

The objectives of this study are to determine effects of household members' characteristics, financial resources, and attitude toward intergenerational support on change in savings net worth and change in housing net worth. Subsamples of White respondents, Black respondents, and Hispanic respondents were analyzed to identify the effects of race or ethnicity on the dependent variables. Attitude toward intergenerational support was the intervening variable. Change in labor income had a positive impact on change in savings net worth for all three racial or ethnic groups. An additional child in a household and an older age of the household head were likely to decrease the change in savings net worth. Effects of the remaining variables differed by subsample. The effects of labor and nonlabor income were different for the change in savings net worth but not for the change in housing net worth. Some different effects for variables across the three racial or ethnic groups were noted.     

KF／Al2O3催化下导眠能的合成

采用ＫＦ／Ａｌ２Ｏ３催化合成镇静药导眠能,具有反应条件温和,操作简便,产率高的特点。     

溴化锂溶液降膜吸收传热传质的研究

在分析国内外相关文献的基础上,介绍了溴化锂水溶液降膜吸收水蒸气过程传热传质的理论与实验研究进展,提出了研究中存在的不足及进一步研究的方向．     

竖直矩形通道降膜吸收器热质性能的试验研究

试验研究了溴化锂水溶液沿竖直矩形通道降膜吸收过程的传热传质情况。结果表明,溴化锂水溶液降膜流量、吸收压力、溶液进口浓度及进口温度对总传热系数、平均降膜吸收率的影响比较大。