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1.
In this paper, we investigate the (2+1) dimensional nonlinear Rossby waves under non-traditional approximation. Using the asymptotic methods of multiple scales and weak nonlinear perturbation expansions, we derive a new modified Zakharov–Kuznetsov equation from the barotropic potential vorticity equation with the complete Coriolis parameter, the topography and the dissipation. Based on the new auxiliary equation method, new exact solutions of the new mZK equation are obtained when the dissipation is absent. However, the new auxiliary equation method fails to solve the new mZK equation with the dissipative term. Therefore, the weak nonlinear method and the homotopy perturbation method are developed to solve the obtained new mZK equation. Through numerical simulations, the results show the effects of different parameters on Rossby waves.  相似文献   

2.
近红外光谱分析技术可用于对样本的快速无损检测,在人们的生产和生活中发挥着越来越重要的作用。支持向量机是建立定性分析模型的常用方法,可通过寻找最优分类超平面将两类样本分开。在小样本情况下,支持向量机方法有其独特的优势。主成分分析是常用的数据降维方法,可将数据降维之后作为支持向量机方法的输入变量,简化模型并提高模型识别的准确性。因此,基于主成分分析的支持向量机(简称PCA-SVM)适合用于建立近红外光谱定性分析模型。多模型方法是人们使用较少的建模方法,用该方法建立的模型一般具有较好的稳定性。将多模型方法与PCA-SVM方法成功结合形成了新方法。以棉锦混合、棉涤混合纺织品为例,用新方法建立了这两类纺织品样本的近红外光谱定性分析模型。建模时将光谱数据按照波长分为4组,用每组光谱数据建立一个子模型,将子模型的输出值进行加权平均便得到最终的预测结果。这样可以更充分地使用光谱数据中所包含的信息。为了便于对比不同的方法,仍使用上述校正集和验证集,又用PCA-SVM方法建立了这两类纺织品样本的近红外光谱定性分析模型。对预测结果做交叉验证,用新方法所建模型判别的正确率的平均值为85.49%,正确率的标准差为0.066 7, 用PCA-SVM方法所建模型判别的正确率的平均值为83.34%,正确率的标准差为0.109 6。研究结果表明用新方法所建模型的分类效果好于用PCA-SVM方法所建模型的分类效果;用新方法建立的模型的稳定性明显高于用PCA-SVM方法建立的模型的稳定性。用PCA-SVM方法所建模型的预测效果受校正集构成情况的影响较大,而用新方法所建模型的预测效果则相对稳定。对废旧纺织品进行分类回收可大量节约纺织原材料,但采用人工分拣方式效率低且成本高。采用近红外光谱分析方法对纺织品进行分类,为废旧纺织品的大规模精细分拣和分级奠定了一定的基础。该新方法有望用于某些其他类型样本的分类。  相似文献   

3.
Based on the technique of integration within an ordered product (IWOP) of operators we show that the operator ordering method can lead us to derive new operator identities and new integration formulas regarding to Hermite polynomials. Work supported by specialized research fund for the doctoral progress of higher education of China.  相似文献   

4.
根据废旧纺织品所含成分对它们做分类回收和处理可节省大量纺织原材料。目前,在废旧纺织品的回收过程中往往使用人工分拣方法。这种方法成本高且效率低。近红外光谱分析是21世纪发展最迅速的技术之一,可以在不破坏样本的情况下快速测定样本的成分及每种成分的含量。利用该技术对废旧纺织品进行分析,预先判断废旧纺织品所含的成分及各种成分的含量,可为废旧纺织品的大规模精细分类回收提供帮助。多模型方法通过将各子模型的预测值做加权平均得到最终的预测值,用该方法建立的近红外光谱分析模型一般具有较好的稳定性。以废旧纺织品样本的锦纶含量为例,先用多模型方法建立了锦纶含量的近红外光谱分析模型。方法如下:将反射率向量按照波长划分为15组。用每组数据建立一个近红外光谱分析子模型。对子模型的预测值做加权平均得出锦纶含量的最终预测值。然后在多模型方法基础上,根据锦纶含量预测值与实验值之间的近似线性关系,通过用变量代替常量并对变量做标准化处理,给出了一种便于优化的预测锦纶含量的近红外光谱分析新模型。优化后的每个子模型中的参数比优化前减少了6个,这样可防止模型过拟合。将上述两个模型与常见的用偏最小二乘法建立的模型进行了对比。交叉验证的结果表明:(优化后的)新模型的拟合优度的平均值为0.820 7,单纯使用多模型方法所建模型的拟合优度的平均值为0.769 1,用偏最小二乘法建立的模型的拟合优度的平均值为0.746 7。因此, 使用多模型方法建立的模型的预测效果好于用偏最小二乘法建立的模型的预测效果。新模型的预测效果明显好于其他两个模型的预测效果。该研究主要创新之处是新模型的建立和优化。文中建模方法有望用于废旧纺织品样本其他成分的含量预测。  相似文献   

5.
食品掺假种类众多,手段隐蔽,成为食品安全检测一个重要难题。为摆脱传统模型识别食品中是否存在新掺假类别的局限性,实验以纯净的灵芝孢子油和掺杂不同比例花生油、玉米油、薏仁油、地沟油的五种类别为研究对象,采用傅里叶变换近红外光谱(Fourier transform near infrared spectroscopy, FT-NIR)收集12 400~4 000 cm-1范围内的近红外光谱。假设掺杂地沟油为新掺假类别,利用前四种类别的校正集样本构建相关向量机(RVM)多分类器,分别对建模的预测集样本和掺杂地沟油样本进行判别,并借助新聚类算法对判别为纯净的灵芝孢子油的样本做进一步分析验证。研究表明,RVM分类器对于建模的预测集样本判别准确率高达93.75%,说明模型有较强的判别能力,但由于模型局限性,掺杂地沟油样品被误判为纯净的灵芝孢子油;在新聚类算法的决策图上,纯净灵芝孢子油校正集和预测集混合样本的聚类中心数为1,而纯净灵芝孢子油校正集和掺杂了地沟油混合样本聚类中心数为2,直观验证判别结果的准确性。结果表明利用FT-NIR技术结合RVM分类器与新聚类算法对于灵芝孢子油掺假能够有效识别,并且能够定性识别新型掺假类型,为解决食品掺假多样化问题提供一种新思路。  相似文献   

6.
在图像配准和图像识别领域中,SIFT算法得到广泛应用。大量的噪声或是复杂的图像往往会导致匹配点的误判,从而降低了图像匹配效率。提出一个新的比较邻域,建立了一个新的"十字形"描述符并运用主成分分析法降低描述符计算时间,利用双向匹配方式来减少伪匹配点,以节省匹配时间。实验结果表明,改进SIFT算法能够成功匹配图像,应用于大型工业刀具的测量,为大型物体测量提供了一种新的方法。  相似文献   

7.
联立方程组新解法测定小儿退烧片的含量   总被引:2,自引:1,他引:1  
本文采用联立方程组新解法,不经提取分离,直接测定小儿退烧片中阿斯匹林和扑热息痛的含量。阿斯匹林和扑热息痛的平均回收率和变异系数分别为99.95%,1.74%和100.1%,0.93%(n=10),方法简便、快速、准确。  相似文献   

8.
本文经选择适当的测定波长,同时采用多波长直线回归,P-矩阵法和联立方程组新解法测定热痛灵注射液的含量。三咱方法简便、快速、准确,样品测定结果均和北京市药品标准法测定结果一致。  相似文献   

9.
本文叙述了吸光度比值-导数光谱新方法的原理,研究了在普通分光光度计上用计算法完成吸光度比值导数运算、同时测定苯酚和间苯二酚含量的实验方法,取得了较为满意的结果。苯酚的回收率为99.4%~104.2%(n=25,RSD=1.1%),间苯二酚的回收率为97.1%~102.8%(n=25,RSD=1.6%)。  相似文献   

10.
We report synthesis and characterization of new Sr2TiMnO6 manganite-like material. Samples were produced by the solid state reaction method. X-ray diffraction experiments reveal the presence of peaks, which are characteristics of the complex perovskite systems. Rietveld refinement showed that Sr2TiMnO6 crystallizes in a tetragonal structure, which corresponds to the space group I/4m. From measurements of magnetization as a function of temperature, we determine the occurrence of magnetic ordering for a critical temperature TC=44.8 K and strong evidence of frustration. Curves of magnetization as a function of applied field show hysteretic behavior. Curves of polarization as a function of applied voltage exhibit the ferroelectric response of Sr2TiMnO6 material. Results reveal the occurrence of magnetoelectric response for the temperature regime T<44.8 K.  相似文献   

11.
长期以来把研究热运动规律性的理论分割成热力学与统计物理两门课来讲,是不正确的。此文阐明从原子分子体系出发来研究热运动的规律,可使两者融合为一体,建立一个新的热运动理论体系。  相似文献   

12.
几类源打“新靶”和“旧靶”的对比实验   总被引:4,自引:4,他引:0       下载免费PDF全文
 根据氢气放电源、X光机X射线源和TiT源打“新靶”和“旧靶”的对比实验结果,证明了在氢气放电过程中产生了一种未知粒子,新谱线正是射线源轰击这种储存在“旧靶”中的未知粒子产生的。以此为依据得到如下推论:探测到的新谱线反映了未知粒子的能级特性,是未知粒子的能级谱线,所以这些新谱线是未知粒子存在的标志。  相似文献   

13.
We report synthesis and crystalline structure study of the Sm2FeMnO6 new complex perovskite, by X-ray diffraction experiments and through the application of Rietveld refinement. Results revealed the crystallization of system in a structure given by Pmn21 (#31) space group and lattice parameters a=7.621(1) Å, b=5.675(3) Å and c=5.378(3) Å. Ab initio calculations of density of states (DOS) and electronic structure were carried out for this perovskite-like system by the density functional theory (DFT) and using the full-potential linearized augmented plane waves (FP-LAPW) method. All calculations were carried out using spin polarization. Material evidences a conductor-like character, predominantly due to d–xy Fe orbital of the spin down channel. Magnetic response of system has contributions of Fe and Mn spin up orientation. The calculated magnetic moment in cell was 34.48 μB and the magnetic moment in interstitial was 1.54 μB.  相似文献   

14.
In order to investigate the nonlinear fractional Zoomeron equation, we propose three methods, namely the Jacobi elliptic function rational expansion method, the exponential rational function method and the new Jacobi elliptic function expansion method. Many kinds of solutions are obtained and the existence of these solutions is determined. For some parameters, these solutions can degenerate to the envelope shock wave solutions and the envelope solitary wave solutions. A comparison of our new results with the well-known results is made. The methods used here can also be applicable to other nonlinear partial differential equations. The fractional derivatives in this work are described in the modified Riemann–Liouville sense.  相似文献   

15.
基于新型植被指数对冬小麦蛋白质含量的估算研究   总被引:3,自引:0,他引:3  
小麦蛋白质含量是衡量小麦价格的一项重要指标。本文使用三年冬小麦蛋白质含量和光谱指数数据,用2008/2009和2009/2010年数据构建新的比率指数和乘积指数,并将灰色关联算法-偏最小二乘法(GRA-PLS)进行整合,尝试提高对冬小麦蛋白质含量估算的精度,用2011年/2012年数据进行验证。研究结果表明:比率指数与冬小麦蛋白质含量的相关系数要优于单一指数,单一指数和比率指数最高相关系数(r)分别为0.726和0.751,乘积指数也可改善部分单一指数的相关系数。通过GRA-PLS方法可以提高对冬小麦蛋白质含量的估算精度,单一指数、比率指数和乘积指数的决定系数(R2)分别为0.537,0.631和0.521,对应的均方根误差(RMSE)分别为0.665%,0.564%和0.574%。结果说明用新构建的比率指数和乘积指数,并使用GRA-PLS方法对冬小麦蛋白质含量估算是可行的。  相似文献   

16.
新资源食品中微量元素测定方法的研究   总被引:8,自引:2,他引:6  
用硝酸-高氯酸消解样品,用火焰原子吸收光谱法测定新资源食品葛根、葛花、四叶参、仙人掌、菊花、小麦胚和蚕蛹中Cu,Zn和Fe元素的含量,并对其结果进行了分析。结果显示: 在选定的实验条件下,测定方法的回收率为94.66%~105.24%,测定Cu,Zn和Fe的精密度RSD分别为1.79%,0.71%和4.78%。建立的原子吸收光谱法简便、快速、灵敏、准确。经F检验与SNK检验,河南省新资源食品葛根、葛花、四叶参、仙人掌、菊花、小麦胚和蚕蛹中微量元素Cu,Zn和Fe含量分别为: 铜的分布量依次为: 菊花≈蚕蛹>葛花≈小麦胚≈四叶参≈葛根>仙人掌,锌的分布量依次为: 仙人掌>蚕蛹≈葛花≈葛根≈小麦胚≈四叶参≈菊花;铁的分布量依次为: 蚕蛹≈菊花≈葛根>葛花≈小麦胚≈四叶参≈仙人掌。  相似文献   

17.
U Ayr 《Applied Acoustics》2003,64(2):129-145
The results of a wide acoustic environment survey are presented. Sound pressure measurements were carried out in a group of offices. These measurements lasted for five minutes and the resulting noise spectra were used to calculate the most significant acoustic parameters. During each measurement a questionnaire was administered to workers near each measuring position. The questionnaire asked them to indicate their subjective judgement about noise annoyance, noise loudness and dissatisfaction induced by noise present in the environment. The aim of the research was to investigate the performance of the measured noise indices in describing subjective responses to noise. A new method to calculate the average subjective responses is proposed. The performance of the noise indices was studied by means of linear regression analysis. Finally the A-weighted equivalent sound pressure level proved to be the best index among those analysed in describing subjective auditory sensations.  相似文献   

18.
We report synthesis and characterization of new Sr2ZrMnO6 manganite-like material. Samples were produced by the solid state reaction method with sinterization temperatures up to 1400 °C. X-ray diffraction experiments reveal that structure belongs to the perovskite system, space group . Lattice parameter was obtained by means of Rietveld-type refinement, through the GSAS code. Magnetic properties were studied by using an MPMS Quantum Design SQUID. From measurements of magnetization as a function of temperature, we determine the occurrence of a paramagnetic–antiferromagnetic transition with Néel temperature 50 K. Curie–Weiss fitting permitted to obtain the magnetic characteristic parameters. At temperature regimes below the Néel temperature, strong evidences of frustration and an irreversibility temperature between zero field cooling (ZFC) and field cooling (FC) measurements were observed. Curves of magnetization as a function of applied field were performed at . Results show a hysteretic feature for Sr2ZrMnO6 magnetic material. This response is attributed to formation of magnetic clusters as a consequence of cationic (magnetic and no magnetic) disorder along the double perovskite structure.  相似文献   

19.
以二硫化碳和金属钠为基础物质合成了四硫富瓦烯(TTF)锌的配合物(TTF)Zn(NBu4)2。利用该化合物与苯甲酰氯反应得到的稳定化合物C17H10O2S5在甲醇钠溶液中与2,3-二溴丙醇反应成功合成出目标化合物(一种新配体),其化学组成为C6H6OS5。利用IR谱、^1HNMR谱及元素分析对此化合物进行了表征。  相似文献   

20.
在聚乙烯吡咯烷酮(PVP)存在下,用多元醇还原硝酸银,Cu(NO3)2作为保护剂,快速有效的合成大量银纳米线,并优化了反应条件,得到结构均一、分散性较好的银纳米线。以罗丹明B为探针分子检测了该银纳米基底的表面增强效应,结果表明该基底对罗丹明B的表面增强效果明显,其表面增强因子可达6.4×105。文中利用这种基底得到了右旋肉碱的表面增强拉曼光谱(SERS),与其固体常规拉曼光谱(NRS)和10-3 mol·L-1水溶液的拉曼光谱对比,并对各自的峰位进行了归属。右旋肉碱固体在3 100~2800和1 700~200 cm-1处有明显拉曼振动峰,在右旋肉碱的表面增强拉曼光谱中,1700~200 cm-1处的峰得到了明显的增强。经分析,右旋肉碱分子与银纳米基底呈180°。本文还用合成的纳米银基底得到了不同浓度右旋肉碱溶液的表面增强拉曼光谱,其最低检测浓度为10-6 mol·L-1。右旋肉碱是一种重要的心血管药物,本文为其研究提供了较全面的拉曼光谱信息,为右旋肉碱的快速、特征、痕量监测提供了有力依据,也为进一步研究右旋肉碱的药理学提供了重要参考。  相似文献   

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