层次分析法在喷粉桩与沉管灌注桩方案优选中的应用

运用层次分析法建立了喷粉桩与沉管灌注桩的比较优选模型，结合工程实例介绍了模型的具体运用。     

肝纤维化动物模型的研究进展

肝纤维化及其发生发展的研究已从细胞水平进入分子生物学水平。但肝纤维化动物模型的建立 ,仍是临床研究和实验研究的重点和难点。至今已建立的常见肝纤维化动物模型有 :1四氯化碳诱导肝纤维化动物模型 ;2异种动物血清诱导肝纤维化动物模型 ;3乙醇诱导肝纤维化动物模型 ;4二甲基亚硝胺诱导肝纤维化动物模型 ;5复合因素诱导肝纤维化模型。文章综述了每一种动物模型复制的方法与该模型的肝脏病理变化 ,并对几种常见的动物实验模型进行比较。因不同的动物模型具有不同的特点 ,建议根据实验的要求选择适当的模型。     

邻水县农村产业系统基础线性规划模型

利用系统分析和诊断的结果,在众多的系统模型方案中,选择了线性规划为该系统的总模型。经多次反馈和反复模拟运算,从而确定了系统基础线性规划总模型,为邻水县近期和1990、1995和2000三个年段的系统总模型方案的设定奠定了基础。     

Bayesian methods in plant conservation biology

We provide an introduction to Bayesian methods in conservation biology, illustrating inferences, prediction and decision making issues. After presenting the basic framework with a recovery plan evaluation problem, we illustrate more complex issues related to forecasting trends of structured populations using matrix population models and, finally, describe relevant topics in spatial and logistic regression problems. Computational and other implementation difficulties are also discussed.     

高校系资料室情报资料服务系统结构与功能评估模型

从系统工程的观点出发,分析研究了系资料室情报资料服务系统的诸多要素及其结构与功能.运用模糊线性加权变换原理制订出该系统的结构与功能评估模型.模型分4级定性定量,24个评价指标.     

川东丘陵区两系杂交稻高产栽培技术模型研究

 为了大幅度提高水稻产量,我们引进了两系杂交稻“两优培九”,并采用五元二次回归正交旋转组合设计方法,研究了它的高产栽培技术,建立了相应的数学模型,筛选出了“两优培九”产量为9 000 kg/hm²以上的优化组合方案821个,得到了其对应的农艺措施为3月11～12日播种育秧,采用密度:25.72～26.52万窝/hm²,施纯N:235.43～243.62 kg/hm²,P₂O₅:79. 20～84.0 kg/hm²,K2O:133.32～144.24 kg/hm²,该结果与示范情况基本一致,可在丘陵地区大面积推广,对促进水稻再上新台阶,具有十分重要作用。     

旱地谷子高产栽培措施模型研究

1987～1988年在山西省屯留试点进行试验,采用二次回归正交旋转组合设计,对影响谷子产量形成的密度、播期、氮、磷和农家肥五项关键农艺措施进行了定量化的综合研究,初步确定了最佳农艺措施组合方案,并利用产量反应模型研究了各项措施对产量形成的单独反应以及各项农艺措施间的互作效应.优化方案经1988和1989年的示范对比和小面积推广,证明是切实可行的.     

Predicting wheat head blight incidence using models based on meteorological factors in Pergamino,Argentina

A computer program using the language and statistical procedures available from SAS (Statistical Analysis System) was written in order to identify the most highly correlated meteorological factors with the incidence of wheat head blight (caused byFusarium graminearum Schwabe) at Pergamino, in the humid pampeana region. Applying linear regression techniques, different models from simple up to a maximum of three independent variables were fitted to the data (1978–1990). The meteorological variables were processed in a time segment beginning eight days prior to the heading date (50% of emerged ears) and finishing when 530 degree days were accumulated (26–32 days). The number of two day periods with rainfall and relative humidity >81% in the first day and relative humidity 78% in the second (NPPRH) was the variable that showed the strongest association with disease incidence (FI) (R²=0.81). After examining the models in several ways (R², Adjusted R², PRESS statistic), two equations were selected: FI%=20.37 + 8.63 NPPRH – 0.49 DDXNT (R²=0.86) and FI%=16.39 + 5.43 NPPRH – 0.45 DDXNT + 2.95 DPRH (R²=0.886), in which DDXNT represents the daily accumulation of the residuals resulting from subtracting 9 to the minimum temperature values (<9 °C) and the exceeding amounts of maximum temperatures from 26 ° C and DPRH is the number of days with precipitation and relative humidity greater than 83%. Successful local predictions of incidence of scab for the years 1991–1993 (reserved for validation purposes) were achieved using both equations.     

Factorial models to estimate isoleucine requirements for broilers

The objective of this work was to determine the efficiency of utilization (EU) and produce factorial models for optimal isoleucine (Ile) intake. Six dose–response trials were carried out, three for males and three for females, with 640 Ross 308 in each studied phase. The initial (1–14 days), grower (15–28 days) and finisher (29–42 days) phases were evaluated to cover the growing phase of the broiler chicken. In total, eight treatments were randomly distributed to four replicates of 20 birds each. The treatments consisted of seven crescent levels of Ile and one counter proof to ensure that Ile was the first limiting amino acid in the diet. Dilution technique was applied to produce the levels of Ile and keep the amino acid ratio with lysine. The EU was determined to account for whole body or partitioned for feather‐free body (Bff) and feather. Two distinct factorial models were adjusted, M1 and M2. The M2 model was evaluated for one or two EU, being denominated as M2 and M3. When the efficiency was partitioned, the values of 53% and 69% for feather and Bff were determined. The optimal Ile intake estimated for each model were of 275, 908, 1,412 mg of Ile/bird/day (M1); 258, 829, 1,321 mg of Ile/bird/day (M2); and 284, 835, 1,288 mg of Ile/bird/day (M3) for initial, grower and finisher phases respectively. The EU partitioned for feather‐free body and feather reduced the biased of the model M3. Overall, higher values of Ile intake are estimated when model M1 is used, which may be the difference in account for body weight gain (M1) or only protein gain (M2 and M3) to estimate the amount of amino acid required for broiler.