基于SOFM神经网络的核心种质取样算法

介绍了核心种质和自组织特征映射网络的基本概念，使用自组织特征映射网络的自组织特性对种质性状数据进行了聚类，利用聚类的分组结果，提取核心种质，通过对核心种质的各种参数的检验并与完全随机取样和一般的系统聚类的对比。结果表明，SOFM的取样算法，是一种比较有效快捷的算法，可以在实际中加以应用。     

滇重楼不同居群的表型多样性研究

为揭示滇重楼不同居群的表型多样性,为滇重楼种质资源的保护利用提供科学的理论依据。观测20个居群滇重楼15个性状的表型性状, 采用变异系数、方差分析、主成分分析和聚类分析进行分析。滇重楼各表型性状变异丰富,变异系数在14.3%~46.2%之间,表型分化系数为52.13%,居群间和居群内变异相当。滇重楼显示出较高的多样(2.4415),20个不同居群的平均多样性指数为2.2255~2.5363。主成分分析显示茎高、叶柄长、叶片长、宽、花瓣长,花萼长,花茎高是引起滇重楼不同居群间表型差异较大的因素。聚类分析表明,滇重楼20个居群可以分为3大类。滇重楼表型多样性较高,对其资源的保护和利用具有重要意义。     

Water Quality Forecasting Method Based on Compensative Fuzzy Neural Network

The forecasting of water quality variation is very important in the process of sewage treatment, which helps the control system work reliably and steadily. In this paper, the compensative fuzzy neural network (CFNN) based on compensative fuzzy logic and neural network and its study arithmetic are introduced. Considering its features as fast speed, steady studying course, global dynamic optimization, CFNN is applied to establish water quality forecasting model. The practical example indicates that the model is not sensitive to initial parameters and has better forecasting precision and faster convergence.     

THE STUDY ON THE MAXIMUM POWER TRANSFER PROBLEM FOR MULTIPORTS

This paper discusses about maximum power tranrfer from the active resistive network to the passive reactive network, and derives the condition that the load network must satisfy when the power transfer is maximum, and gives some examples about its application.     

AN ACCURATE FAULT LOCATION METHOD FOR PARALLEL TRANSMISSION LINES

So far, the accuracy of the existing methods of fault location based on calculating the impedance at only one terminal of lines is certainly affected by the variation of the system impedance at the remote end. In accordance with parallel lines' special characteristics, this paper presents a method that can calculate the system impedance of the remote end when one of the two lines has fault, so that the effect of its variation can be eliminated completely. This method has been tested by the computer digital simulation, and the results are very satisfactory.     

深山草莓花瓣离体培养诱导变异植株及性状稳定变异株系的品种特性

应用均匀设计法研究了影响深山草莓花瓣愈伤组织诱导及愈伤组织再分化变异植株的主要因子和水平。深山草莓花瓣愈伤组织诱导率超过65.0%以上的适宜培养基共有11个,经过组合优化后可知,培养基LS+TDZ2.06 mg?L-1+2,4-D0.60 mg?L-1对深山草莓花瓣愈伤组织诱导效果最好,诱导率为98.0%;其中,以培养基LS+TDZ2.20 mg?L-1 +2,4-D0.40 mg?L-1诱导形成的愈伤组织在10个适宜的分化培养基中培养均分化出再生芽苗,优化后的最佳再分化培养基为1/2LS+TDZ 2.30 mg?L-1+KT 1.38 mg?L-1,分化率为96.3%,田间试验发现变异率高达2.77%。对10个含有不同激素和浓度配比及1个优化后的培养基诱导形成的再生芽苗生根后经5年的田间栽培观察可知,有6个性状稳定的优良变异株系。这说明深山草莓花瓣在适当激素和浓度配比的条件下可产生变异植株,并能趋向稳定性状变异。     

AUTOMATIC CONTINGENCY SELECTION AND RANKING BY NETWORK PROGRAMMING APPROACH

This paper presents a new approach ,to the automatic contingency selection and ranking by the network flow programming (NFP). A complex cost optimisation model based on economy and security, and several simplified models are proposed in the paper. The performance index is the total load curtailment or its weighted value. All the solution algorithms are OKA. The model and its algorithm is tested on IEEE 30-Bus System and the encouraging results are obtained.     

甘薯实生系与其无性系性状相关关系及早期选择利用研究

甘暮实生系是分离世代,其性状的变异与资源品种表现同一趋势,与其无性系在诸多性状上呈强弱不同的正相关关系,这是对实生系进行早期选择利用的基础.根据结薯性可将实生系分为成薯、膨大和直根3个类型,成薯系%因组合而异,受环境影响不明显.5年的研究结果证明:无性系类型间的产量性状有明显差异,从成薯类型选育高产新品系的入选率高.在此问题上和美国Granberry.M.等的认识不同.建议把我国甘薯育种的初选期提早到实生系时期,以缩短育种周期,提高育种效率.笔者认为把甘薯杂交种子培育的株系,定名为实生系,比较确切.     

基于主成分分析的BP神经网络估算藏北高寒草地覆盖度变化

藏北高寒牧区草地是中国高寒草地分布面积最大的地区。为了及时准确地获得该区域草地覆盖度的变化趋势,本研究利用多年气象数据、社会统计数据、GIMMS、MODIS两种归一化植被指数（NDVI）数据作为参数,构建 BP神经网络模型,估算2010—2014年藏北高寒草地年际变化趋势,并用主成分分析方法优化参数来改进模型。结果表明,① BP神经网络模型及其改进模型对藏北高寒草地覆盖度年际变化趋势与遥感值的相关系数为0.16、0.47,表明通过主成分分析优化参数后的BP神经网络模型具有较好的模拟效果。 ②两种BP神经网络估算的植被指数值与NDVI值平均误差率分别为2.36%、2.20%。均有较高的模拟精度。③从神经网络训练步数上看,BP神经网络结果训练收敛步长为5000,基于主成分分析的BP神经网络模型训练收敛步长为454,表明后者提高了计算效率,体现出良好的收敛性。因此,无论从年际变化趋势拟合程度、植被指数估算值精度、还是从计算效率来看,改进的BP神经网络模型对于估算藏北高寒草地覆盖度变化更加行之有效。     

草地螟滞育性的研究

草地螟在我国部分地区有滞育现象.是影响越冬虫源分布和种群数量变动的重要原因之一.1982—1984年观察研究结果,光周期是影响滞育性的决定性条件.其临界光周期为14—15小时,最低临界点13小时,最高临界点16小时,温度是影响年度间滞育量的重要因素.以光周期划分草地螟的滞育区和非滞育区,是掌握虫源基地的重要依据.以滞育区的气温变化,分析幼虫滞育量,对展望种群数量的自然积累或衰落,即种群数量变动规律,具有重要意义.     

A Study Transient on Predictive Calculation Method of on Underground Ventilation Network

The authors developed a computer program of transient predictive calculation method on underground ventilation network. The program approximated a field data set of seasonal cyclic changes of air Temperature and humidity at the inlet to the sine curves, and included sensible heat conduction from rock to air current. The temperature of rock around and airway was calculated by finite difference method. The prediction method can be used to calculate the variation of flow rates, temperatures and humidities of air flow in the airways along underground network.     

Analysis of Wheat Cultivar Differences in Grain Yield, Grain Nitrogen Yield and Nitrogen Utilization Efficiency.

More detailed information on the causes of yield variability among wheat cultivars is needed to further increase wheat yield. Field studies were conducted in Northern Greece over the two cropping seasons of 1985—1986 and 1986—1987 to assess the effects of nitrogen fertilizer and application timing of the various component traits that determine grain yield, grain nitrogen yield and nitrogen utilization efficiency of two bread ( Triticum aestivum L.) and two durum ( Triticum durum Desf.) wheat cultivars, using yield and yield component analysis. Nitrogen at a rate of 150 kg ha^-1 was applied before planting or 100 N kg ha^-1 before planting and then 50 N kg ha^-1 top dressed at early boot stage. Nitrogen and cultivars affected all traits examined, while split nitrogen application affected only some of the traits. Grain yields in the most cases were correlated with number of grains per unit area and grain weight and grain nitrogen yields in all cases with grain number per unit area. The contribution of the number of grains per spike to total variation in grain yield among cultivars was almost consistent (37 to 55 %), while the contribution of grain weight was more significant (up to 55 %) in high yields (>6.500kg ha^-1) and number of spikes per unit area (>500). The number of grains per spike contributed from 60 to 83 % to the total variation in grain nitrogen per spike. Increased grain nitrogen concentration resulted in a reduction of its contribution in grain nitrogen yield variation. Nitrogen utilization efficiency was higher during grain filling than during vegetative biomass accumulation. The contribution of nitrogen harvest index to the variation of utilization efficiency for grain yield was higher in plants receiving nitrogen application.     

遮荫对欧洲荚蒾光合特性日变化的影响

为了解欧洲荚蒾的耐荫特性,采用LI－6400便携式光合测定系统对不同遮荫处理欧洲荚蒾的光合生理特性日变化及其与生理生态因子的关系进行了研究。结果表明：(1) 欧洲荚蒾在100％和60％光照的净光合速率(Pn)日变化都呈“双峰型”曲线,有明显的“午休”现象,20％光照的Pn日变化呈“单峰型”曲线。(2)欧洲荚蒾光合速率控制因子为非气孔限制。(3)在100%和60%光照条件下,Gs是Pn的第1影响因子,而在20%光照条件下,Tr是Pn的第1影响因子。(4)适当遮荫对欧洲荚蒾的光合作用没有太大影响,深度遮荫,其光合速率明显下降。3个处理的光合能力为100％光照＞60％光照＞20％光照,欧洲荚蒾可以种植在较荫暗处。     

山核桃子代甲基化分析及其与薄壳山核桃甲基化的比较

为了研究山核桃的遗传,本研究采用MSAP (Methylation sensitive amplification polymorphism)标记分析了山核桃30个半同胞子代群体及薄壳山核桃29个无性系,并在山核桃亲子代间及山核桃与薄壳山核桃间比较了遗传及甲基化水平。研究发现,山核桃半同胞子代群体非甲基化遗传位点(Non-methylation loci,NML)的比例较高,占33.69%,随后依次是内部胞嘧啶甲基化位点(15.18%)、半甲基化位点(9.25%);其遗传多样性(0.110 3±0.028 4)极显著地小于表观遗传多样性(0.568 5±0.112 3)(p<0.000 1);半同胞子代群体间存在显著的遗传与表观遗传分化,且大部分遗传变异和表观遗传变异存在于群体内,说明亲本间存在遗传差异。甲基化水平在山核桃亲子代间无显著差异(p>0.05),说明甲基化存在代际遗传。山核桃中NML的比例远大于薄壳山核桃,两物种表观遗传多样性相当,但薄壳山核桃的遗传多样性要高于山核桃;两物种遗传和表观遗传差异极显著(p<0.000 1),供试个体基于物种的遗传位点可以分别聚类,说明两物种各自个体间有遗传差异。甲基化敏感位点(Methylation-sensitive loci, MSL)及NML在两物种间存在极显著差异,且变异主要存在于物种内,两物种有明显的分化,但从各遗传参数值来讲,两物种又十分相像,正反交基于亲缘关系可行。不同于山核桃,薄壳山核桃遗传位点对甲基化位点影响极显著。     

Speed Estimation Methods Based on Neural Network

In order to solve the speed estimation problems of speed sensorless vector-controlled induction motor drives, the paper presents two speed estimation schemes based on neural network mode identification theory. The advantages of each scheme are discussed and the simulation results show that the estimated speed can trace the actual speed better (even under the circumstances of load variation or speed step variation). Also, these schemes are not sensitive to the variations of motor parameters and the effect of iron loss. Therefore, the proposed neural network based on speed sensorless vector-controlled induction motor drives have good performance in stady-state and transient-state operation.     

农户社会网络关系评价体系设计及测算研究——基于1440份调查数据的分析

从网络规模、网络紧密度、信任与承诺、社会风气与归属感及社会参与5个方面构建评价农户社会网络关系的指标体系,按照区域分布,将所调查区域分为河套地区、中原地区和关中地区,采用实地调查的1440份农户数据,运用变异系数法确定各指标权重,进而对农户社会网络关系水平进行测算。研究得出：按照权重大小依次为社会参与、网络规模、网络紧密度、信任与承诺、社会风气与归属感;农户社会网络关系评价值整体较低,呈正偏态分布,且存在地区差异;关中地区最高,但个体差异明显,其次依次为河套地区和中原地区;从一级指标的测算结果看,社会参与得分最高,其次为社会风气与归属感、信任与承诺,最后为网络规模和网络紧密度,可见农户更愿意参与集体行动,人文环境得到进一步改善;地缘与亲缘限制了网络规模的扩大,而农村人口的流失也使得网络紧密度减弱。在此研究基础上提出相关建议,以期为相关政府机构实施乡村治理提供依据。     

Limiting the Arc Over-voltage of 10 kV Grids in Application of Nonlinear Resistance

The aufhors calculate and analyze the arcing grounding overvoltage of 10 kV power network in case of neutral ungrounded and grounding through nonlinear resistance using EMTP, with a actual 10 kV power network of a substation in Guizhou province as an example. The emulational calculation results show that the grounding method which grounds through nonlinear resisitance has the advantages of the other two methods, can better limit the arcing grounding overvoltage and can not stop the power supply .even one phase is grounded by fault, so it can ensure the security of the power networkg supply . the network neutral grounding through nonlinear resistance needs more deep study and analysis as a new network neutral grounding mehtod.     

系统调控下棉花比叶重的变化机制

[目的]比叶重是叶片经济谱功能性状关系网络中的核心指标,受到各种环境因素的影响.但是,植物不同部位叶片间存在的系统调控如何影响比叶重的变化尚不清楚.[方法]本研究通过田间密度试验和室内遮荫试验,测定棉花不同部位叶片的比叶重及其组织结构性状,分析比叶重和组织结构性状之间的关系以及影响比叶重的因素.[结果]改变棉花下部叶片...     

乐东拟单性木兰光合、蒸腾及水分利用效率研究

运用Li-6400光合测定仪对乐东拟单性木兰的光合蒸腾特性进行了初步研究。结果表明：（1）乐东拟单性木兰的光补偿点为65.5μmol&#8226;m-2&#8226;s-1,光饱和点为1467μmol&#8226;m-2&#8226;s-1,表观量子效率为0.024;（2）乐东拟单性木兰在晴天条件下光合日变化为双峰曲线,分别在10和16时达到峰值,而在14时到达谷底,表现出午休现象。相关分析表明其影响因子主要是蒸腾速率、气孔导度和光合有效辐射;（3）乐东拟单性木兰蒸腾速率日变化近似单峰型,其主要影响因子为大气温度、叶面温度和光合有效辐射;（4）乐东拟单性木兰水分利用效率日变化为倒单峰型曲线变化。     

棉花海陆杂交纤维品质性状遗传参数分析

为了研究棉花海陆杂交纤维品质性状的遗传规律,本试验采用5个陆地棉品种（系）作母本与5个海岛棉品种（系）杂交,配制25个杂交组合,随机区组试验设计,重复2次。主要检测杂交种F1代纤维品质性状,以小区平均数进行相应的方差分析及遗传参数估计。结果表明：陆地棉亲本间变异除马克隆值外,其他纤维品质性状均差异显著或极显著,而海岛棉亲本间除伸长率外,其他性状均存在显著或极显著差异;各纤维品质性状双亲互作效应均不显著。另外,遗传参数结果表明：绒长、比强度和马克隆值的遗传变异系数与表型变异系数变化趋势基本吻合,且均大于环境变异系数。整齐度和伸长率的遗传变异系数均小于环境变异系数,说明整齐度和伸长率的变异中环境因素的作用不容忽视。绒长、比强度和马克隆值的广义遗传率较高,在采用海陆杂交改良棉花纤维品质性状时,适宜在早代选择优异株系。