补偿模糊神经网络水果形状分级器分级误差

针对神经网络对水果进行分级时精度有待提高的问题,分析了补偿模糊神经网络椪柑形状分级器的分级误差。将椪柑图像前4个傅里叶描述子按期望输出模糊变量值大小排列成单调递增、单调递减、钟形分布和锯齿形分布4种训练样本,分别训练同一补偿模糊神经网络水果形状分级器,用递减排序后的同一测试样本检验分级器性能,试验表明,单调递减顺序训练样本所训练的分级器分级误差最小为1.875%,钟形分布、单调递增顺序和锯齿形分布训练样本所训练的分级器分级误差依次增大,分别为15%、63.125%、75%。分析分级误差与样本间顺序的对应关系,建立分级误差模型,结果表明,同顺序的测试样本与训练样本间相关系数大,分级误差小;不同顺序的测试样本与训练样本间相关系数小,分级误差大。因此,测试样本与训练样本按水果同一品质特征同序排列,提高样本间的相关程度,将大幅度降低神经网络类分级器分级误差,提高正确识别率。     

半干旱退化山区不同土地利用方式土壤理化性质的特征研究

通过对半干旱退化山区不同土地利用方式的土壤理化性质的调查研究.得出不同土地利用措施土壤机械成分表现出一定的差异性,在0-40 cm土层,88542整地和人工草地的粗砂粒平均含量高于天然草地;在0-100 cm土层,最大田间持水量:人工林地＞人工草地＞天然草地;毛管持水量:人工草地＞人工林地＞天然草地;土壤总孔隙度:人工林地＞人工草地＞天然草地;毛管孔隙度:人工草地＞人工林地＞天然草地;土壤的透气性:人工林地＞人工草地＞天然草地.在0-100 cm土层:有机质的含量为:人工林地＞天然草地＞人工草地;土壤碱解氮的含量变化为:人工林地＞人工草地＞天然草地;土壤速效磷的含量变化为:人工林地＞人工草地＞天然草地.结果表明,合理的土地利用方式,改善了土壤结构和肥力,增加土壤的通透性,改变土壤水肥气热状况,其中人工造林整地对土壤容重、持水量、土壤养分的促进作用均优于其它利用方式,有利于植被的快速恢复.     

冲积平原区土壤颗粒组成的趋势效应与异向性特征

运用基于ArcGIS的地统计学组件分析了河北省曲周县124个耕层土壤颗粒组成的空间特征.结果表明,区域土壤砂粒含量和粘粒含量在东西方向和南北方向的趋势分别为二阶趋势和一阶趋势;粉粒含量在东西方向呈二阶趋势,南北方向呈零阶趋势.在趋势参数为零阶、一阶和二阶条件下,砂粒含量的异向性分析结果为长轴方向变程接近,短轴方向分别为 17.83 km、16.12 km和21.16 km,但它们都比各向同性且趋势参数为一阶时的变程长.从误差分析和反映区域与局部趋势的结果两方面看,土壤砂粒含量在不同趋势参数或不同异向性参数条件下内插的等值线图以一阶趋势的内插结果最好.     

硫酸根离子添加顺序对可变电荷土壤吸附铜离子的影响

研究了SO2-4添加顺序对三种可变电荷土壤(昆明铁质砖红壤、徐闻砖红壤和江西红壤)吸附Cu2+的影响,作为对照,也研究了其对恒电荷土壤(黄棕壤、棕壤)以及两种不同矿物(高岭石与针铁矿)吸附铜离子的影响。实验结果表明,在同等条件下,SO2-4添加顺序对两类表面性质不同的土壤吸附Cu2+有着不同的影响。对于恒电荷土壤,SO2-4添加顺序对土壤吸附Cu2+几乎没有影响。同等pH条件下,对可变电荷表面而言,加入CuSO4者具有最高的Cu2+吸附率;对昆明砖红壤、徐闻砖红壤以及针铁矿和高岭石而言,先加入Cu2+者相对先加入SO2-4者Cu2+吸附率更高;对江西红壤而言,上述这个次序则刚好相反。SO2-4浓度和有机质去除对同等pH条件下铜离子吸附率高低的排序并无实质性影响。     

土壤养分限制谱序的知识表达和判别体系探讨

本文通过对土壤养分限制谱序的知识表达体系在可行性方面的讨论 ,认为以土壤养分自身的行为特点 (土壤养分 )作为谱序的评价指标和表达方式目前没有较好的理论和方法可遵循 ,难度较大。用与土壤养分密切相关的“支撑产量”揭示和判别土壤养分限制谱序是目前较好的方法。通过对其进行实证研究 ,用“支撑产量”判别出试验区小麦的土壤养分限制谱序为N >P >K >Zn、Mn >B >Cu、Fe ;玉米的谱序为N >P、K >Fe、Zn >B、Cu、Mn。说明用支撑产量判别谱序是科学合理的 ,为土壤养分限制的系统研究铺垫了新的思路和途径     

Root Growth and 14C-Translocation into the Roots of Maize (Zea mays L.) as influenced by local Nitrate Supply

A local nitrate supply to roots of maize causes increasing growth of the first order and the formation of higher order laterals. Number of first order laterals, however, remains unchanged. Labelling plants with ¹⁴CO₂ demonstrates a specific phloem unloading in the supply zone. It is suggested that phloem mobile phytohormones, especially auxins, lead to an endogenous shift in the phytohormone balance responsible for the morphogenetic effect of a local NO₃ · supply.     

不同针叶林对祁连山森林灰褐土理化性质和水源涵养功能的影响

以祁连山针叶林树种青海云杉、油松、侧柏3种树种为研究材料,探讨了不同树种对祁连山森林灰褐土理化性质和水源涵养功能之间的关系。研究结果表明,土壤孔隙度、团粒结构、物理性黏粒含量均为青海云杉油松侧柏;土壤容重、物理性砂粒含量均为侧柏油松青海云杉;土壤有机质、CEC均为青海云杉油松侧柏;CaCO3含量、pH值、全盐含量均为侧柏油松青海云杉;土壤蓄水量和树种枯落物持水量均为青海云杉油松侧柏。     

Density Dependent Grazing In Estuarine Water Quality Models

The objective of this study is to examine the influence different zooplankon grazing rate relationships have on water quality eutrophication model results in a tidal estuary. The water quality model being used includes phytoplankton and both dissolved and particulate constituents as state variables. It includes zooplankton grazing of the phytoplankton, where excretions from the latter increase the particulate constituents. The phytoplankton and particulate constituents also undergo settling. When applied to an existing estuary, the model results are different for a first order zooplankton grazing rate formulation than for a second order zooplankton grazing rate formulation.Constituents enter the estuary as wastewater discharges, freshwater river inflows, exchanges between the sediment and water interface, and exchange across the tidal boundary. The water quality model is coupled with a three-dimensional time varying hydrodynamic and transport model that allows accurate computation of the tidal velocity field transporting the constituents from their sources throughout the estuary. Comparisons of model results between the first order and the second order density dependent zooplankton grazing relationships allow determining which of the two processes best describe water quality behavior for the estuary being examined. The second order density dependent zooplankton grazing relationship performs best in application.     

电网谐波下双馈发电机改进控制策略

电网低次谐波电压会造成双馈发电机(doubly fed induction generator,DFIG)定子电流畸变和电磁转矩脉动。通过电网5次、7次谐波电压下双馈发电机的数学模型建立与分析,揭示了电网谐波电压对双馈发电机定子电流畸变和电磁转矩脉动的影响机理,比较研究了基于比例积分(proportional integral,PI)控制与基于比例积分谐振(proportional integral resonant,PIR)控制的转子电流控制环的谐波抑制能力。并采用了基于R调节器的定子电流闭环和基于PIR调节器的转子电流内环的双馈发电机双闭环控制策略,有效的消除了双馈风力发电机定子输出电流中的5次,7次谐波和电磁转矩脉动,提高了其在电网电压低次谐波下的运行性能,仿真和试验验证了该控制策略的正确性。     

Seasonal patterns of mineral and organic acidification in two streams in Southwestern Nova Scotia

DOC concentrations in two streams of different hydrologic order are highly variable with the higher order stream exhibiting approximately a 3 mo response lag. Seasonal variation of SO⁴ concentration and flux are similar in both streams and do not reflect the seasonal patterns in precipitation. The basins store SO₄ from May to November and lose SO₄ from December to April. Consequently, SO⁴ concentrations and flux are maximum during January to March and reach a minimum during July to September. The highly organic lower order stream exhibits relatively stable pH controlled by two competing mechanisms. The pH is dominated by organic acids during the summer and autumn and by mineral acids during the late winter and early spring. In the higher order system, the pH tends to be inversely related to changes in SO₄ concentration. These observations suggest that organic systems do respond to acidic deposition but that in some systems mineral acid influence may be restricted to the winter and spring.     

公路边坡不同护坡措施表层土壤水分动态变化规律

为了确定公路边坡不同护坡措施保水效果,以沈抚高速沿线的草皮防护（CP）、挂网喷播（GW）、六角空心砖防护（LJ）和菱形防护（LX）四种典型边坡防护措施为研究对象,利用土壤水分测量仪观测不同护坡措施的表层土壤含水量,分析不同护坡措施下土壤含水量的时空演变特征。结果表明:不同护坡措施土壤含水量均表现为坡下 > 坡中 > 坡上;土壤含水量均值在13日,14日均表现为CP > GW > LJ > LX,而在15日,16日均表现为CP > LJ > GW > LX;在同种护坡措施下,土壤含水量变异程度在各坡位均表现为随时间变化呈逐渐增大的规律;在同一坡面情况下,六角空心砖防护坡面表层土壤水分变异系数（CV）表现为坡上 > 坡下 > 坡中,其余三种护坡措施CV均表现为坡上 > 坡中 > 坡下;护坡措施土壤含水量变异程度随时间变化表现为LX（12.5%） > GW（10.6%） > CP（9.2%） > LJ（8.5%）,菱形植草与其余三种措施间差异显著（p < 0.05）,挂网植草与六角空心砖防护差异显著（p < 0.05）,草皮防护与这两种措施均未达到显著水平;六角空心砖配合紫穗槐灌木和小火炬草本植被的护坡形式保水效果较好。     

A Novel Pretreatment Method of Lignocellulosic Material as Adsorbent and Kinetic Study of Dye Waste Adsorption

Sulphuric acid-modified bagasse has been used as low-cost adsorbent for the removal of methylene blue (MB) dye from aqueous solution. In order to remove organic compounds that contribute to chemical oxygen demand (COD), pretreatment with thorough washing of adsorbent using boiling distilled water was performed instead of conventional washing using distilled water at room temperature only. This has resulted in the highest efficiency of color removal of 99.45% and COD reduction of 99.36% for MB dye solution at pH 9. Effects of initial pH, dye concentration, adsorbent dosage, temperature, and contact time have been studied. The adsorption of MB dye was pH dependent. Langmuir and Freundlich isotherm models were tested on the adsorption data. The kinetic experimental data were analyzed using pseudo-first order, pseudo-second order, and the intraparticle diffusion model in order to examine the adsorption mechanisms. The adsorption process followed the Langmuir isotherm as well as the Freundlich isotherm and pseudo-second-order kinetic model. The process was found to be endothermic in nature.     

基于阶次分析的永磁同步电机噪声源识别

为了识别出永磁同步电机的噪声来源,该文对常见的机械噪声和不同影响因素下的电磁噪声特点进行研究。首先分析了滚动轴承产生的噪声阶次特征,识别出了滚珠内外圈通过频率对应的分数阶噪声。其次通过麦克斯韦应力张量法推导了理想条件下作用于定子内表面的径向力波的频率阶次,结合实测电流谐波分析了不同电流谐波类型下的径向力波特征,通过引入偏心修正系数分析了转子动态偏心对径向力波的影响,从而识别出了不同影响因素下的电磁噪声源。并且建立了永磁同步电机的有限元模型,通过模态试验对定子铁芯和绕组的等效进行验证,由电机约束模态分析获取了电机在实际安装条件下的模态参数,对实测的共振噪声来源进行解释。最后分析了各影响因素产生的噪声对总体噪声的贡献量,指出电机的主要噪声源。该研究可以识别出永磁同步电机的每一阶次噪声和共振噪声的来源,为进一步的减振降噪奠定基础。     

发动机进气系统阶次噪声及其消减方法

针对发动机进气噪声的消减与消声元件的位置具有很强的关联性特点,该文利用GT-Power软件分析了进气系统噪声,设计了谐振腔和1/4波长管来降低进气口处噪声。通过SYSNOISE软件进行了声模态分析,研究了声模态与阶次噪声之间的关系,来确定赫尔姆兹谐振腔和1/4波长管在进气系统上最好的消声位置。分析结果表明,消声元件布置在某阶模态的反节点位置与布置在节点位置相比,可以对该模态频率下的阶次噪声降低5 dB。     

Molecular Analysis of Olive Cultivars in the Molise Region of Italy

The Italian region of Molise is characterised by a remarkable variety of microenvironments, where some olive cultivars have settled in the course of many centuries. The study of the varieties cultivated in Molise, and of their relationships with varieties of close regions, is very important in order to clarify the entity of the native olive germplasm, well adapted to the local conditions, and to characterise the oil with regional origin. Eighteen cultivars from Molise have been examined using AFLP markers. They were compared with other cultivars, widely cultivated in Italy and France, in order to evaluate their similarities and to test some hypotheses on their origin and spreading among different areas of cultivation. Numerous varieties showed a high similarity and one case of synonymy (Frantoio-Paesana Bianca) was observed. The results provide useful information in order to distinguish the native germplasm and evaluate the consistency of the olive heritage of the region.     

神东矿区不同治理分区相同治理年限典型灌木群落特征分析

为评估神东矿区典型灌木群落对矿区不同治理分区的适生性,探索其最佳配置模式,选取治理年限为10 a的沙棘群落、15 a的北沙柳群落和柠条锦鸡儿群落,对其群落基本特征进行了分析。从分析结果来看,沙棘群落在风积沙区长势最好,在硬梁地长势最差,不同治理分区适生性排序为风积沙区>黄土丘陵区>黄土丘陵和风沙交错区>硬梁地;北沙柳群落在黄土丘陵和风沙交错区长势最好,在硬梁地长势最差,不同治理分区适生性排序为黄土丘陵和风沙交错区>风积沙区>硬梁地;柠条锦鸡儿群落在黄土丘陵和风沙交错区长势最好,在硬梁地长势最差,不同治理分区适生性排序为黄土丘陵和风沙交错区>风积沙区>黄土丘陵区>硬梁地。在植物配置模式上,沙棘、北沙柳和柠条锦鸡儿在不同治理分区的配置选择顺序和其适生性保持一致。     

元阳梯田全福庄流域水源涵养林的植物多样性分析

元阳梯田已有1 200多年的历史,水源涵养林的存在对于梯田的延续具有重要的价值。为得到元阳梯田水源涵养林的植物多样性分布特征,对元阳梯田全福庄流域4种主要植被类型水源涵养林下的植物物种数量特征、物种丰富度、多样性、均匀度等多样性规律进行了标准样地调查。结果表明,研究区共有植物155种,隶属66科,其中,山茶科、禾本科、蓼科植物占有绝对优势,不同植被类型森林群落的优势种不同;物种丰富度大小为:次生常绿阔叶林>杂木林>次生落叶阔叶林>人工水冬瓜林;物种多样性特征表现为,乔木层:次生常绿阔叶林>次生落叶阔叶林>杂木林>人工水冬瓜林;灌木层:次生常绿阔叶林>杂木林>次生落叶阔叶林,人工水冬瓜林无灌木层分布;草本层:次生落叶阔叶林>人工水冬瓜林>次生常绿阔叶林>杂木林。植被分布的物种丰富度和均匀度对物种多样性存在交叉影响。     

贵州喀斯特山区大型土壤动物多样性研究

为了解贵州喀斯特地区土壤动物生物多样性特点,选取贵州4个典型喀斯特山地为研究区进行大型土壤动物多样性和群落特征分析。得出如下结论:（1）4个研究区共获得的大型土壤动物分别隶属于3门8纲21目,共21个类群。优势类群为4类（占总个体数的10%以上）,分别是鞘翅目（占19.7%）、腹足纲（占17.86%）、蚁科（占17.03%）、蜘蛛目（占11.69%）。（2）大型土壤动物的类群数依次是荔波 > 毕节 > 清镇 > 花江;荔波研究区采集到20个类群,该区土壤动物类群组成相对完整,可以作为喀斯特生态系统退化程度的参照标准。土壤动物个体数依次是荔波 > 清镇 > 毕节 > 花江;Shannon-Wiener多样性指数反映出与类群数同样的结果:荔波 > 毕节 > 清镇 > 花江。喀斯特生态环境因子的改变对腹足纲、蜘蛛目、带马陆目等类群的组成结构和数量产生了很大的影响,可以作为喀斯特生态退化程度的指示种。（3）相似性分析表明,毕节研究区大型土壤动物群落与荔波最相似,生态环境较好,清镇次之,花江最差,同时也与其石漠化等级程度相吻合。     

不同控释肥类型及施肥方式对肥料利用率和氮素平衡的影响

采用草莓盆栽试验研究了3种肥料类型（普通肥料、控释氮肥、控释复合肥）及其不同施肥方式对氮磷钾利用率、氮素在土壤一作物体系中的平衡及草莓生长的影响。结果表明，相对于普通肥料、控释氮肥和控释复合肥提高了土壤中有效养分的含量，促进了草莓生长，提高了草莓糖酸比和维生紊C含量。不同肥料类型间，植株干重、草莓产量和氮磷钾利用率大小顺序为：控释复合肥〉控释氮肥〉普通肥料。控释氮肥处理土壤中氮的残留率最高，其次为控释复合肥。氮的损失率大小顺序为：普通肥料〉控释氮肥〉控释复合肥。不同施肥方式间草莓糖酸比和维生素C含量、土壤氮残留率差异不显著。植株干重、草莓产量、氮钾利用率大小顺序为：底施〉混施和侧施〉表施；底施处理的磷素利用率最高，其他处理间差异不显著，氮损失率大小顺序为：表施〉混施和侧施〉底施。