spectral

摘要： Tylosin is a well-established antibiotic that has been widely employed in human and veterinary medicines. It can act as a potential ligand binding metal ions due to various donor atoms in the structure. Our study on the complexation of various metal ions with tylosin ligand revealed that they preferably coordinate with mycaminose fragment to establish Novel trends complexes. Tylosin ligand (TYS) behaves as bidentate for complexation with different metal ions such as Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II) and Zn(II). Various essential metal complexes of tylosin were synthesized and characterized by techniques such as UV, IR, Elemental analysis, magnetic susceptibility and ESR spectra of Cu(II) complex. These techniques are used to know their geometries and mode of bonding, with stoichiometry, 2:2 (M:L). Thermal analysis (TGA and DTA) of ligands and their metal complexes were carried out to distinguish between the coordinate and hydrate solvents and to estimate the stability ranges, peak temperatures. The thermodynamic parameters, such as activation energy (ΔE*), the enthalpy of activation (ΔH*), entropy of activation (ΔS*) and Gibbs free energy (ΔG*) are calculated and discussed. Some tylosin complexes show higher activity than tylosin for some bacterial and fungal strains. Low concentration value of minimum inhibitory concentration (MIC) results is 15.625 μg/ml for both complexes [Zn2(TYS)2Cl2(H2O)4]·25H2O and [Cu2(TYS)2Cl2(H2O)4]·25H2O with B. cereus genus maybe a valuable data used to produce novel therapeutic agent. This study constitutes several essential aspects for future research on tylosin metal complexes as antibacterial assessment and as potential medicinal agents.

摘要： Soil organic matter(SOM) is an important parameter related to soil nutrient and miscellaneous ecosystem services. This paper attempts to improve the performance of traditional partial least square regression(PLSR) model by considering the spatial autocorrelation and soil forming factors. Surface soil samples(n = 180) were collected from Honghu City located in the middle of Jianghan Plain, China. The visible and near infrared(VNIR) spectra and six environmental factors(elevation, land use types, roughness, relief amplitude, enhanced vegetation index, and land surface water index) were used as the auxiliary variables to construct the multiple linear regression(MLR), PLSR and geographically weighted regression(GWR) models. Results showed that: 1) the VNIR spectra can increase about 39.62% prediction accuracy than the environmental factors in predicting SOM; 2) the comprehensive variables of VNIR spectra and the environmental factors can improve about 5.78% and 44.90% relative to soil spectral models and soil environmental models, respectively; 3) the spatial model(GWR) can improve about 3.28% accuracy than MLR and PLSR. Our results suggest that the combination of spectral reflectance and the environmental variables can be used as the suitable auxiliary variables in predicting SOM, and GWR is a promising model for predicting soil properties.

摘要： The goal of this study is to provide a stochastic method to investigate the eff ects of the randomness of soil properties due to their natural spatial variability on the response spectra spatial variation at sites with varying conditions. For this purpose, Monte Carlo Simulations are used to include the variability of both incident ground motion and soil parameters in the response spectra by mean of an appropriate coherency loss function and a site-dependent transfer function, respectively. The approach is built on the assumption of vertical propagation of SH type waves in soil strata with uncertain parameters. The response spectra are obtained by numerical integration of the governing equation of a single-degree-of-freedom (SDOF) system under non-stationary site-dependent and spatially varying ground motion accelerations simulated with non-uniform spectral densities and coherency loss functions. Numerical examples showed that randomness of soil properties signifi cantly aff ects the amplitudes of the response spectra, indicating that as the heterogeneity induced by the randomness of the parameters of the medium increases, the spectral ordinates attenuate.

摘要： The spectral efficiency(SE)and energy efficiency(EE)tradeoff while ensuring rate fairness among users in non-orthogonal multiple access(NOMA)systems is investigated.In order to characterize the SE-EE tradeoff with rate fairness,a multi-objective optimization(MOO)problem is first formulated,where the rate fairness is represented with theα-fair utility function.Then,the MOO problem is converted into a single-objective optimization(SOO)problem by the weighted sum method.To solve the converted non-convex SOO problem,we apply sequential convex programming,which helps to propose a general power allocation algorithm to realize the SE-EE tradeoff with rate fairness.We prove the convergence of the proposed algorithm and the convergent solution satisfies the KKT conditions.Simulation results demonstrate the proposed power allocation algorithm can achieve various levels of rate fairness,and higher fairness results in degraded performance of SE-EE tradeoff.A pivotal conclusion is reached that NOMA systems significantly outperform orthogonal multiple access systems in terms of SE-EE tradeoff with the same level of rate fairness.

摘要： 1 Introduction Black soils are a soil type with good properties and high fertility,which is very suitable for plant growth(Liu et al.,2015).Black soil resources are widely distributed in North America,Eurasia,and South America,and cover about 916million ha around the world,35 million ha of this in northeast China(Liu et al.,2012).

摘要： The goal of this work is to identify human brain waves in different states non-invasively, and to distinguish them into different levels of mental states in order to provide immediate mental state feedback to a classroom instructor and maximize learning outcomes. In order to apply such knowledge, this project utilizes a commercial NeuroSky Mindwave Mobile EEG to collect brain signals, MATLAB to filter data, voltage thresholds to detect blinks, which are used in tandem with power spectral density (PSD) analysis in order to classify mental states. This knowledge can then be provided to a class instructor who can use it to maximize the learning experience for students.

摘要： Soil salinity is one of the most damaging environmental problems worldwide, especially in arid and semi-arid regions. Multispectral data Sentinel_2 are used to study saline soils in southern Tunisia. 34 soil samples were collected for ground truth data in the investigated region. A moderate correlation was found between electrical conductivity and the spectral indices from SWIR. Different spectral indices were used from original bands of Sentinel_2 data. Statistical correlation between ground measurements of Electrical Conductivity (EC), spectral indices and Sentinel_2 original bands showed that SWIR bands (b11 and b12) and the salinity index SI have the highest correlation with EC. Based on these results and combining these remotely sensed variables into a regression analysis model yielded a coefficient of determination R2 = 0.48 and an RMSE = 4.8 dS/m.

摘要： This paper proposes a rapid means of identifying clay type and quantifying clay content from new template crossplots that compare magnetic susceptibility measurements with standard borehole well log data. The templates are similar in format to standard industry charts, but have a number of advantages over the commonly used charts. Laboratory measurements of magnetic susceptibility on core samples and drill cuttings have recently shown strong correlations with key petrophysical parameters, particularly clay content and fluid permeability [1] [2]. A new template crossplot between magnetic susceptibility and borehole spectral gamma ray log data can firstly help to quickly identify the types of clay present in the formation. Additional new template crossplots between magnetic susceptibility and borehole bulk density data allow the mineral contents and porosities of binary mixtures of clay minerals and matrix minerals (such as illite clay + quartz) to be rapidly quantified. The templates can use ambient (room temperature) magnetic susceptibility data from measurements on core samples or drill cuttings in the laboratory or at the wellsite. Furthermore, the paper shows how the templates can potentially be extended to utilize borehole magnetic susceptibility data for in situ estimations of the type and content of clay. This requires accounting for the temperature dependence of the magnetic susceptibility of paramagnetic minerals (such as illite clay), which varies with depth in a borehole. Whilst borehole magnetic susceptibility measurements are rarely part of standard well logging operations, they could be a potentially useful tool for in situ clay type and content quantification, which in turn can help predict fluid permeability.

摘要： A spectral difference method is applied to get numerical solutions for a fluid-lubricated herringbone grooved journal bearing with trapezoidal grooves by previous work of the authors. However, an inexpedience in which Fourier series of the film profile does not converge at jump points of groove start or groove end in the case of rectangle groove was still remained. In the paper, an inexpedience of numerical analysis under a special case at rectangle groove is challenged to solve. As a result, for compensation of which Fourier series does not converge at jump points in a special case of rectangle groove, Fourier coefficient of fluid film thickness is proposed as taking the limit of which in a case trapezoidal groove at trapezoidal angle approaches 0.

摘要： Earlier it was shown by different authors that there are cavities (vacancies, holes) in any liquid. The cavities should play a prominent role in dissolution processes. Nevertheless this fact was ignored in previous model of dissolution. The sizes of the cavities in different solvents containing benzene molecules were determined using solvent induced spectral shift method. The measurements of S1←S0 benzene transition spectral shifts permit to conclude that 1) macroscopic excess volumes play an almost negligible role in processes of benzene dissolution in very different solvents and 2) the minimal size of the cavity in water able to accommodate benzene molecule coincides with the solute size. Generalization of this conclusion to other nonpolar aromatics leads to evaluation contraction of the solutes under aqueous solvent influence permits to predict the solubility values of other aromatics in water and to evaluate effect of enhancement hydrate cell around these molecules on solubility.

摘要： 本发明公开了基于Spectral Clustering空间轨迹的聚类算法，包括利用摄像机对道路进行视频图像采集，对视频图像中的每一帧图像中的所有运动目标采用ORB算法提取特征点，然后利用基于双向加权可逆性约束的KLT跟踪算法对特征点进行跟踪，得到所有运动目标的多条运动轨迹以及每条运动轨迹上每个轨迹点在图像坐标系中的坐标值；利用刚体运动约束对所有运动目标的n条运动轨迹构建相似矩阵进行谱聚类，得到不同类别的运动轨迹；对不同类别的运动轨迹进行类间合并，得到类间合并后的运动轨迹；本发明所提到的方法不受工程应用上各类环境的影响和限制，并且易于实现，能有效的对车辆进行实时精确的检测，因此具有很广的应用前景。

摘要： 本发明涉及一种基于Spectral/hp型有限元法求解二维非定常或定常对流扩散方程的计算方法，属于计算流体力学技术领域。分析二维非定常或定常对流扩散方程问题的控制方程；对二维非定常或定常对流扩散方程模型参数设置；根据Spectral/hp型有限元法的数学计算公式，引入二维非定常或定常对流扩散方程相关变量的数值，导入对二维非定常或定常对流扩散方程进行数值计算，求解完毕即可进行可视化处理和误差分析后处理得到数值模拟的L2范数和L∞范数误差；根据得到的误差分析后处理得到数值模拟的L2范数和L∞范数误差分别绘制出了速度u的p收敛和h收敛曲线图。本发明较使用其他方法所得结果精度更高的数值解。

摘要： 本发明公开了基于Spectral Clustering空间轨迹的聚类算法，包括利用摄像机对道路进行视频图像采集，对视频图像中的每一帧图像中的所有运动目标采用ORB算法提取特征点，然后利用基于双向加权可逆性约束的KLT跟踪算法对特征点进行跟踪，得到所有运动目标的多条运动轨迹以及每条运动轨迹上每个轨迹点在图像坐标系中的坐标值；利用刚体运动约束对所有运动目标的n条运动轨迹构建相似矩阵进行谱聚类，得到不同类别的运动轨迹；对不同类别的运动轨迹进行类间合并，得到类间合并后的运动轨迹；本发明所提到的方法不受工程应用上各类环境的影响和限制，并且易于实现，能有效的对车辆进行实时精确的检测，因此具有很广的应用前景。