刀切法在森林双重回归抽样调查中的应用初探

为进一步 改进抽样 效果, 将 刀切法 结 合顺 序统 计 量应 用于 双 重回 归抽 样 中, 以 材 积为目的因 子, 胸径 为辅助因 子。结果 表明, 在 减少 二重 样本 ５０ ％ 的情 况下 , 与 普通 双重 回 归抽样相比 , 精度仍 达９８２ ％ 。因 此认为, 在林 相整 齐, 生长 正常 的 林分 中进 行 双重 回归 抽 样调查时, 利 用刀切法 , 可 在减 少 二重 样 本, 减少 外 业工 作 量 的情 况 下, 仍能 保 持 较 高 的精 度。另外, 对二重样 本单元和 单元数 的确定以 及刀切 法的局限 性进行了 讨论。     

Early generation testing for yield and physiological components in groundnut (Arachis hypogaea L.)

Selection of superior crosses of groundnut (Arachis hypogaea L.) in early generations would increase the probability of identifying superior lines. The objective of this study was to determine the potential of selecting for physiological traits identified in a yield model [crop growth rate (C), reproductive duration (DR) and partitioning (p)] in segregating populations. Forty populations and nine parental lines were evaluated in replicated trials in 1992 (F2, 1993 (F3) and 1994 (F4) at three locations in Niger. Physiological traits were estimated from final yield and biomass as well as data on flowering and maturity. Regressions from two different parent-offspring generations (F2: F3 and F3: F4) were calculated. The results were compared to determine if early generation performance accurately predicts the performance of cross bulks in later generations. Differences were observed among populations and parents for all traits. Effects of locations were significant for C, p and DR in F2 and F3 but nonsignificant for yield and C in F4. Regression coefficients from F3: F2 were 0.10 ± 0.08 for C, 0.45 ± 0.17 for p, 0.10 ± 0.03 for DR and 0.16 ± 0.03 for pod yield. Based on F3: F4 regression, the coefficients were 0.12 ± 0.23 for C, 0.46 ± 0.17 for p and 0.57 ± 0.17 for yield. Parent-offspring correlations were in most cases similar to the regression values. It was concluded that selection for yield and model components in early generation bulks may inneffective. This revised version was published online in July 2006 with corrections to the Cover Date.     

高粱在盐胁迫下特定蛋白的表达及与耐盐性关系的研究

报道了通过统计学上逐步回归的方法,筛选出对植物耐盐性有显著贡献的蛋白质,并应用方差分析探讨上述蛋白质的最佳诱导条件,以便探明盐胁迫一特定蛋白一耐盐性之间的关系。结果表明: 由NaCl诱导的高粱耐盐性是众多蛋白质综合作用的结果,其中不受盐诱导的15. 5 kD根蛋白、受盐诱导的71. 4 kD叶蛋白对高粱耐盐性具有显著正贡     

An Analysis of Thick Plates underIn-plane and Transversal Loadings by the BEM

In accordance with the behaviours of thick plates under the in-plane and transversal loadings,and introducing the concept of equivalent load, the coupled equations for the problem have been deduced with the theory of BEM in this paper.Thus a new method is presented for solving the problems of interaction of superstructure and foundation and subsoil,as well as for the problems of the thick plates under the complicated loadings.     

The Fuzzy Shadow Price

This paper discusses some properties of a kind of the fuzzy linear programming,gives the definition of the fuzzy shadow price,and presentes a simple solution of it as well.     

渭北旱原大官杨水分生理综合分析

由P—V技术推广得到的P—SD、P—ND曲线法在林木组织水分状况动态监测中有较大价值。主成分分析表明:渭北旱原大官杨水分关系的主要环节是组织水分状况、蒸腾耗水、土壤供水三方面,三者呈良好的线性关系。回归分析表明:影响大官杨蒸腾强度作用大小的次序是照度、气温、湿度、风速、土壤含水量。渭北旱原大官杨在7～8月耗水最大、6～7月土壤供水最差,但其在渭北旱原上仍可以良好生长。     

Predicting survival of planted Douglas-fir and ponderosa pine seedlings on dry,low-elevation sites in southwestern Oregon

Four equations were developed for predicting the probability of Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco] and ponderosa pine (Pinus ponderosa Dougl. ex Laws.) survival for the first (0–1) and first to third (1–3) growing seasons after applying mulching, scalping, or artificial shading (shade cards) treatments in plantations in southwestern Oregon, U.S.A. Variables describing conifer size, levels of competing vegetation, presence of silvicultural treatments, site factors, and climate factors were collected from 13 sites ranging from 0 to 6 years after planting and examined as potential predictors of survival. Age, stem diameter, a competition index for shrubs, severity of growing season at time of treatment, average annual precipitation, aspect, and slope angle were predictors of Douglas-fir survival during 0–1 and 1–3 growing seasons after treatment; the presence of silvicultural treatments was also a predictor only during the first growing season after treatment. Age, aspect, and slope angle were predictors of ponderosa pine survival over both 0–1 and 1–3 growing seasons after treatment; height-diameter ratio, competition indices for herbs, shrubs, and hardwoods, silvicultural treatment, severity of growing season at time of treatment, and average annual precipitation were also predictors only during the first growing season after treatment; crown width was a predictor of survival only during 1–3 growing seasons after treatment. When significant in the models, predicted probability of survival increases with treatments, less severe weather conditions, diameter, crown width, age, and precipitation; probability decreases with increasing height-diameter ratio and competition indices for herbs, shrubs, and hardwoods.     

榆林地区农田开发与粮食增产回归分析及潜力研究

陕西榆林地区１２个县,均为黄河流域水域流失重点是和贫困县,建国以来修水地,坝地,梯田３７．８万ｈｍ＾２,占粮田总面积６０％,该文采用回归分析方法,求出大田面积与大田作物单产的回归系数为４３．９,即每修１万ｈｍ＾２“三田”的增产效益要当于粮田总面积每１ｈｍ＾２,增产４３．９ｋｇ,３５ａ来“三田”总增产为７２６．６万,其相关系数为０．９９５５,为极显著正相关,１９９６年农民人均占有粮４４４ｋｇ,比１９     

油用向日葵籽仁蛋白质含量与气候因素的关系

以３个不同类型油葵品种为试材,对４个地区、９个气候因素与油葵蛋白质含量进行了相关和逐步回归分析。结果表明：开花—成熟期日平均最高气温和相对湿度是影响蛋白质含量的主要气候因素。在一定范围内,日平均最高气温和相对湿度偏高,有利于蛋白质含量的积累。     

多元线性回归中控制问题求解方法的探讨

从标准线性回归方程出发,首先确定标准化因变量回归值的控制区间,然后找出一个ｍ元一次不完全方程的解集合,根据回归方程的特定意义,在该解集合中求得满足标准回归方程控制问题的子集合,最后应用标准回归方程与一般回归方程的关系,求出一般线性回归控制问题解的子集合及计算公式,经实例验证符合要求。