锶胁迫条件下生菜光谱效应特征

锶（Sr）胁迫条件下生菜的反射光谱特征会发生明显改变。通过室内生菜水培试验，获取了36个不同生长期、6个不同锶浓度胁迫的生菜叶片400～950 nm波段区间的生化参数信息（叶绿素含量、细胞结构、叶片金属含量）和反射光谱信息，利用光谱技术并结合数学统计方法研究了生菜叶片7个光谱特征参数与实测叶片锶元素含量之间的相关性，优选了较敏感光谱特征参数，建立了其与生菜叶片锶含量的线性回归模型。结果表明，锶胁迫生菜叶片叶绿素含量呈先上升后下降的规律，细胞结构差异不明显。锶胁迫生菜叶片反射光谱直观上无规律，通过采用光谱技术方法分析得出锶胁迫生菜叶片的红边波段位置先“红移”再“蓝移”，红谷波段位置则“红移”，植被指数B4/B3比值先升高后降低，红边归一化植被指数（NDVI）值随着锶浓度的升高而降低。相关性及线性回归模型分析表明红边波段位置与叶片锶含量显著相关。本文为下一步基于光谱特征的叶片重金属含量反演模型的构建提供了较好的数据源和基础理论。     

基于高光谱的大叶女贞叶片水分定量测定

较传统水分化学检测法相比,高光谱是一种新兴的简单、快速、无损、原位的绿色检测方法.大叶女贞是一种具有经济、医药、欣赏价值的树种,研究价值较高,然而有关高光谱对其的研究鲜有报道,将其作为研究对象,利用可见近红外高光谱采集40个叶片样本的高光谱数据,利用ENVI 4.7从中提取出反射光谱数据,在MATLAB7.0平台对光谱数据进行直接正交信号校正(DOSC)预处理后,采用共生矩阵法(SPXY)选取30个样本作为建模集,其余作为预测集,构建支持向量回归(SVR)模型,然后在此全波段建模基础上采用自适应权重采样法(CARS)、连续投影变换(SPA)等波段筛选法进行特征波段建模分析,结果表明DOSC-SPA-SVR模型效果最优,预测平方相关系数R2p=0.974 3,预测均方根误差(RMSEP)为4.4×10-5,较全波段模型相比,精度相当甚至有所提升,模型简单、稳定,能够用于对女贞叶片水分进行快速无损的定量分析,为其他作物营养诊断和精准灌溉提供一定的参考价值,减少水资源的浪费.     

基于可见/近红外光谱技术的新鲜茶叶叶片含水率快速测定

提出了利用可见/近红外光谱技术检测新鲜茶叶叶片中含水量的方法.首先采集350~2500nm波段范围内177个新鲜茶叶叶片的光谱反射率信息,作为X变量.将不同预处理后的光谱数据建立偏最小二乘(partial least squares,PLS)模型,再利用回归系数法(regression coefficients,RC)提取全波段光谱中的特征波长并建立基于特征波长的预测模型.结果显示,利用全谱段光谱信息建立的模型中,未经预处理建立的模型最优,建模集和预测集中决定系数(coefficient of determination,R~2)分别是0.9039和0.8856,均方根误差(root mean square error,RMSE)分别是0.0092和0.0120,剩余预测偏差(residual predictive deviation,RPD)是2.9659;基于特征波长的模型中,也是未经预处理建立的模型最优,建模集和预测集中R~2分别是0.9070和0.8199,RMSE分别是0.0107和0.0151,RPD是2.3701.结果表明,可见-近红外光谱技术结合特征波长提取进行新鲜茶叶叶片中含水率检测是可行的.     

土壤磷形态的反射光谱特征及其光谱建模

由于对土壤磷的可见-近红外反射光谱的特征认识不足,土壤磷的光谱模型稳定性较差。为此,通过分离不同磷组分,分别以标准白板和残渣样品为参考光谱,间接和直接测定了不同磷组分的反射光谱。通过分析其光谱特征及光谱模型的间接和直接结果,发现各磷形态具有显著不同的反射光谱特征,光谱形状、反射率大小及峰/谷位置均不同,能够被现有可见-近红外光谱（200~1000 nm）定性和定量分析。在现有研究波段内,250 ~750 nm是土壤磷的敏感波段。研究结果为认识全磷的反射光谱特征及预测全磷含量提供了理论依据。     

哈姆林甜橙叶片锰锌缺乏症状的高光谱识别

柑橘树锰、锌等缺乏问题普遍存在,但其症状有时不易识别,不利于对这些微量元素丰缺与否的诊断和有针对性的矫治．采用高光谱成像技术,研究了哈姆林甜橙叶片不同程度缺锰、缺锌症状的光谱响应特征及差异,对Fisher线性判别分析和最小二乘支持向量机两种识别模型的识别精度进行了比对分析．结果表明,利用高光谱原始全光谱反射率,结合最小二乘支持向量机建立叶片缺锰、缺锌症状识别模型,其建模集识别精度达91.88％,预测集识别率可以达到90.00％;利用连续投影算法筛选的40个特征波长,建立最小二乘支持向量机判别模型,其建模集识别精度为90.00％,预测集识别精度也达82.50％．表明基于高光谱成像技术对柑橘树缺锰、缺锌的准确识别是可行的,为高光谱成像技术应用于柑橘树缺素症的快速无损识别奠定了基础．     

独立成分分析-支持向量机回归模型及其在近红外光谱分析中的应用

首先采用独立成分分析(ICA)提取近红外光谱数据矩阵的独立成分和相应的混合矩阵,然后用支持向量机回归(SVR)对混合矩阵和实测浓度矩阵进行建模,建立了独立成分分析-支持向量机回归(ICA SVR)的近红外分析建模方法.结果表明,ICA SVR模型的预测结果明显优于SVR和偏最小二乘法(PLS)方法,方法用于肉样品中水分、脂肪和蛋白质的同时测定,获得了满意的结果.     

利用地面光谱数据反演悬浮泥沙质量浓度

为研究用高光谱数据反演悬浮泥沙质量浓度的方法,以近海悬浮泥沙为实验材料,配制了不同质量浓度悬浮泥沙样品,利用2种方法对样品进行建模:一种是将可见光和近红外光谱进行小波变换并将小波低频系数以偏最小二乘回归建模,另一种为波段组合法.利用交叉检验方法,分析了交叉检验结果,并将2种方法建立的模型进行了比较.研究表明:波段组合法中,TM4与TM1波段反射率比值的指数模型效果最好;在预测能力上,小波偏最小二乘模型总体上比波段组合模型精度高并且稳定性好,适用于悬浮泥沙光谱定量分析.     

基于CARS与PCA的高光谱煤岩特征信息检测方法

针对采煤机智能化截割时存在煤岩识别精度低、稳定性差等问题,提出一种基于高光谱成像技术的煤岩检测方案。使用8种不同类型的煤岩样本(训练集800块、预测集200块)进行分析,利用竞争性自适应重加权算法将光谱全波段降维至11个特征波长形成光谱特征向量;通过灰度共生矩阵来描述煤岩的纹理特征,选取对比度、能量、同质性3个特征参数值作为纹理特征向量;通过主成分分析融合剔除光谱与纹理特征中解释能力较差的特征信息,利用预测集样本分别对光谱全波段、CARS提取特征波长、图像纹理、CARS提取特征波长融合纹理特征、光谱全波段融合纹理特征和PCA融合特征波长与特征纹理特征的特征向量建立偏最小二乘回归模型,通过对比6种特征向量的建模预测性能,选出煤岩最优特征向量。PCA算法融合后特征向量预测性能的R_2,RMSE,平均绝对误差MAE和准确率分别为0.912,0.201,0.151和94%.该方法可改善煤岩特征信息检测的稳定性与可靠性,为煤岩识别提供有效的特征信息,对实现采煤机智能化开采具有重要意义。     

基于分区的太湖叶绿素a遥感估测模型

以太湖为研究区域,测试水体的反射光谱和表层水质并分析叶绿素的光谱特征,对比MODIS波段并找出与叶绿素a质量浓度相关性较好或对叶绿素a质量浓度变化较为敏感的波段,根据主成分变换后的MODIS图像色调对太湖进行分区并分别用主成分、单波段及波段组合因子建立各区内相应的叶绿素a质量浓度估测模型.结果表明:对太湖合理分区可以提高叶绿素a质量浓度的遥感估测精度;经过主成分变化后的第2主成分,MODIS波段1,3~4,10~14的反射率及波段反射率组合可以较好地估测分区后的叶绿素a质量浓度.     

博斯腾湖西岸湖滨绿洲土壤含盐量高光谱估算

以博斯腾湖西岸湖滨绿洲土壤盐分及其对应的高光谱数据为研究对象,对原始光谱反射率(R)进行均方根(R)、对数(lg R)、倒数(1/R)、对数倒数(1/lg R)变换,引入分数阶微分对变换的光谱反射率进行0～2内的微分预处理,通过显著性检验优选特征波段,并利用特征波段进行偏最小二乘回归的建模和验证。结果表明:1)通过显著性检验较多的特征波段是:1/R为691个波段,比通过原始波段多226个波段;且随着阶数的增加,在各阶数中通过显著性检验的波段数量呈先增加后减少的趋势;通过数量较多的特征波段是1/R的0. 4阶和0. 6阶,分别为145、150;2)原始光谱反射率的相关性极大值绝对值是:2阶为0. 53,其他4种数学变换的相关性极大值绝对值比R高0. 11～0. 16,特征波段主要集中在600～1 000 nm和2 020～2 330 nm;3)在原始光谱反射率及其变换值的各分数阶微分利用偏最小二乘回归建模中,1/lgR的0. 2阶建立的模型为最佳模型,R_C~2=0. 78,RMSE_C=1. 56,R_V~2=0. 63,RMSE_V=1. 44。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with