Four-Electron Systems in the Impurity Hubbard Model. Second Triplet State. Spectra of the System in the ν-Dimensional Lattice Zν

We consider an energy operator of four-electron system in the Impurity Hubbard model with a coupling between nearest-neighbors. The spectrum of the systems in the second triplet state in a ν-dimensional lattice is investigated. For investigation the structure of essential spectra and discrete spectrum of the energy operator of four-electron systems in an impurity Hubbard model, for which the momentum representation is convenient. In addition, we used the tensor products of Hilbert spaces and tensor products of operators in Hilbert spaces and described the structure of essential spectrum and discrete spectrum of the energy operator of four-electron systems in an impurity Hubbard model for the second triplet state of the system. The investigations show that the essential spectrum of the system consists of the union of no more than sixteen segments, and the discrete spectrum of the system consists of no more than eleven eigenvalues.

RETRACTED: Nuclear Structure Study of Odd-Odd Yttrium Nuclei within Interacting-Boson Fermi-Fermion Model (IBFFM)

Short Retraction NoticeThe paper does not meet the standards of "Journal of Applied Mathematics and Physics". This article has been retracted to straighten the academic record. In making this decision the Editorial Board follows COPE's Retraction Guidelines. The aim is to promote the circulation of scientific research by offering an ideal research publication platform with due consideration of internationally accepted standards on publication ethics. The Editorial Board would like to extend its sincere apologies for any inconvenience this retraction may have caused.Editor guiding this retraction: Prof. Wen-Xiu Ma (EiC of JAMP)The full retraction notice in PDF is preceding the original paper, which is marked "RETRACTED".

Spectra of the Energy Operator of Two-Electron System in the Impurity Hubbard Model

We consider two-electron systems for the impurity Hubbard Model and investigate the spectrum of the system in a singlet state for the v-dimensional integer valued lattice Zv. We proved the essential spectrum of the system in the singlet state is consists of union of no more then three intervals, and the discrete spectrum of the system in the singlet state is consists of no more then five eigenvalues. We show that the discrete spectrum of the system in the triplet and singlet states differ from each other. In the singlet state the appear additional two eigenvalues. In the triplet state the discrete spectrum of the system can be empty set, or is consists of one-eigenvalue, or is consists of two eigenvalues, or is consists of three eigenvalues. For investigation the structure of essential spectra and discrete spectrum of the energy operator of two-electron systems in an impurity Hubbard model, for which the momentum representation is convenient. In addition, we used the tensor products of Hilbert spaces and tensor products of operators in Hilbert spaces and described the structure of essential spectrum and discrete spectrum of the energy operator of two-electron systems in an impurity Hubbard model.

Spectra of the Energy Operator of Four-Electron Systems in the Impurity Hubbard Model. Triplet State

We consider the energy operator of four-electron systems in an impurity Hubbard model and investigated the structure of essential spectra and discrete spectrum of the system in the first triplet state in a one-dimensional lattice. For investigation the structure of essential spectra and discrete spectrum of the energy operator of four-electron systems in an impurity Hubbard model, for which the momentum representation is convenient. In addition, we used the tensor products of Hilbert spaces and tensor products of operators in Hilbert spaces and described the structure of essential spectrum and discrete spectrum of the energy operator of four-electron systems in an impurity Hubbard model. The investigations show that there are such cases: 1) the essential spectrum of the system consists of the union of no more than eight segments, and the discrete spectrum of the system consists of no more than three eigenvalues;2) the essential spectrum of the system consists of the union of no more than sixteen segments, and the discrete spectrum of the system consists of no more than eleven eigenvalues;3) the essential spectrum of the system consists of the union of no more than three segments, and the discrete spectrum of the system is the empty set. Consequently, the essential spectrum of the system consists of the union of no more than sixteen segments, and the discrete spectrum of the system consists of no more than eleven eigenvalues.

Modeling the temperature-dependent peptide vibrational spectra based on implicit-solvent model and.enhance sampling technique

We herein review our studies on simulating the thermal unfolding Fourier transform infrared and two-dimensional infrared spectra of peptides. The peptide-water configuration ensembles, required forspectrum modeling, aregenerated at a series of temperatures using the GBOBC implicit solvent model and the integrated tempering sampling technique. The fluctuating vibrational Hamiltonians of the amide I vibrational band are constructed using the Frenkel exciton model. The signals are calculated using nonlinear exciton propagation. The simulated spectral features such as the intensity and ellipticity are consistent with the experimental observations. Comparing the signals for two beta-hairpin polypeptides with similar structures suggests that this technique is sensitive to peptide foldinz landscapes.

X-ray spectra of high temperature tungsten plasma calculated with collisional radiative model

Tungsten is regarded as an important candidate of plasma facing material in international thermonuclear experimental reactor （ITER）, so the determination and modeling of spectra of tungsten plasma, especially the spectra at high temperature were intensely focused on recently. In this work, using the atomic structure code of Cowan, a collisional radiative model （CRM） based on the spin-orbit-split-arrays is developed. Based on this model, the charge state distribution of tungsten ions is determined and the soft X-ray spectra from high charged ions of tungsten at different temperatures are calculated. The results show that both the average ionization charge and line positions are well agreed with others calculations and measurements with discrepancies of less than 0.63% and 1.26%, respectively. The spectra at higher temperatures are also reported and the relationship between ion abundance and temperature is predicted in this work.

氧化物中存在O2p空穴的典型实验结果和磁性氧化物的O2p巡游电子模型

负二价氧离子具有满壳层价电子结构(2s^(2)2p^(6)).负一价氧离子的价电子结构为2s^(2)2p^(5),相当于存在1个O2p空穴.传统的凝聚态物理和材料化学研究中都假设氧化物中的氧离子全部为负二价离子,在迄今为止的绝大多数研究氧化物磁性和电输运性质的报道中,采用关于磁有序的超交换和双交换作用模型,都没有考虑O2p空穴的影响.然而,许多价电子状态实验证明,在氧化物中存在不可忽略的O2p空穴,即存在不可忽略的负一价氧离子,其占比可达30%或更多.基于这些实验结果,对传统磁有序模型进行改进,英美学者首先进行了探讨,笔者所在课题组与中国科学院物理研究所磁学国家重点实验室合作进行了系统的研究.介绍了相关的典型实验结果和理论模型.

滨里海盆地东缘速度建模方法研究与应用

滨里海盆地东缘阿克若尔地区石炭系碳酸盐岩顶面低幅度构造具有较大的油气勘探潜力,由于上覆下二叠统地层分布复杂,横向速度变化大,使得石炭系低幅度构造成图存在很大难度;为了解决研究区构造快速成图的问题,通过3种速度建模方法对比,优选出分频层速度反演方法,建立研究区的速度模型,解决了分频层速度反演受常规层速度反演方法横向连续性的限制问题,对下二叠统碳酸盐岩异常体的速度刻画更为准确;同时,分频层速度反演方法与井—震速度谱协同速度建模方法和常规井约束层速度反演相对比,提高了研究区下伏石炭系低幅度构造的深度域成图精度,取得了较好的效果。

基于修正分数Poynting-Thomson模型的高压XLPE海缆绝缘评估

为利用频域介电谱准确评估高压交联聚乙烯(XLPE)海缆的绝缘状态,建立考虑直流电导率的修正分数Poynting-Thomson模型(分数P-T模型)以解析高压XLPE海缆的介电特性。首先,通过加速老化试验制备不同老化程度的高压XLPE海缆试样,并测得各组老化试样的力学、理化和介电数据。然后,应用修正分数P-T模型对实测介电曲线进行拟合,对比修正前后分数P-T模型表征实测介电曲线的效果。最后,通过仿真探究模型参数对介电曲线的影响规律,构建模型参数与绝缘程度之间的联系,将提出的老化特征参数与断裂伸长率(EAB)进行量化研究。研究结果表明,修正分数P-T模型能够准确拟合出不同老化程度高压XLPE海缆试样的介电曲线,提出的老化特征参数α、ε_(a)、ε_(b)和σ_(dc)可实现对高压XLPE海缆绝缘状态的量化评估。

生菜镉污染可见-近红外光谱分析模型

为了快速无损监测生菜受镉污染的程度,利用可见-近红外光谱进行生菜镉污染的分类监测。将土壤镉污染样品设置为0(CK,对照组)、 5、 10和20 mg·kg^(-1),以不同污染程度下种植的生菜为研究对象,采集生菜叶片的可见-近红外反射光谱,分析镉污染下生菜叶片可见-近红外光谱反射率的变化规律。光谱信息经分析表明,在510~730 nm波段之间,随着土壤中镉含量的增加,生菜叶片的可见-近红外光谱反射率表现为先降低后增加;在730~799.53 nm波段之间,5和20 mg·kg^(-1)镉胁迫下生菜叶片反射率高于CK组,10 mg·kg^(-1)镉胁迫下生菜叶片反射率低于CK组;且在762.199 nm处出现了一个吸收谷。首先采用平滑(SG)、多元散射校正(MSC)、标准正态化(SNV)、平均归一化(MN)、 SG+MSC、 SG+SNV、 SG+MN、 SG+一阶导数(FD)、 SG+二阶导数(SD)方法对原始光谱进行预处理,以提高信噪比。然后通过主成分分析(PCA)对原始光谱和各种预处理的光谱进行降维处理,最后将降维处理后的数据按照4∶1的比例划分训练集和测试集,分别与粒子群优化随机森林(PSO-RF)、遗传算法优化支持向量机(GA-SVM)、 BP神经网络(BP-NN)、极限学习机(ELM)、朴素贝叶斯(Naive Bayes)结合建立生菜镉污染的分类监测模型,并进行分析比较。结果表明,在不同的模型中,PSO-RF(SG)模型的识别效果最佳,其次是GA-SVM(SG+FD)模型和ELM(MSC)模型,PSO-RF(SG)、 GA-SVM(SG+FD)、 ELM(MSC)模型训练集的准确率均为100%,而测试集的准确率分别为100%、 83.33%和79.17%;BP-NN模型和Naive Bayes模型的效果较差,BP-NN(SNV)模型训练集的准确率为42.72%,测试集准确率为50%;Naive Bayes(SG+FD)模型训练集准确率为71.84%,测试集准确率为83.33%。说明采用可见-近红外光谱结合粒子群优化随机森林建模能够为生菜重金属污染监测提供一种新思路。

Quantitative Relationship between Leaf Area Index and Canopy Reflectance Spectra of Rice under Different Nitrogen Levels

Monitoring rice growth by spectral remote sensing technology can provide scientific basis for the high yield and efficient production of rice. Field experiments with different nitrogen application amounts using Tianyouhuazhan rice as test sam- ples were set up to study the relationship between rice leaf area index （LAI） and canopy reflectance spectral. The results showed that： the LAI increased with the amount of applied nitrogen; the canopy reflectance spectral showed significant re- sponse characteristics to groups with different nitrogen application levels; the corre- lation coefficient of LAI and canopy spectral reflectance reached the maximum at 720 nm red edge region. The mathematical model was constructed to predict the LAI according to the canopy reflectance spectra of rice.

消能摇摆钢框架结构地震反应的计算方法

消能摇摆钢框架结构(SRF)通过摇摆钢桁架抑制各楼层发生不均匀地震变形,通过位于转动底脚的阻尼器消耗地震输入能量,抗震性能良好.推导消能摇摆钢框架结构的弹性计算方法,提出SRF等效单自由度(SDOF)分析模型,基于等效线性化原理给出SRF非线性地震反应的计算方法.采用ATC-63推荐的地震动记录集进行结构弹塑性地震反应分析,得到SRF在3类地震动激励下的延性需求谱.研究表明,由弹性计算方法可以得到SRF在水平作用下的力学反应,等效单自由度分析模型能准确描述整体结构的受力机理和非线性地震反应,依此推导所得的SRF地震反应计算方法可用于预估实际结构的地震反应.相比于普通钢框架结构,SRF屈服后刚度比的取值范围更大,计算所得的延性需求谱与之匹配,可作为设计参考.

气固两相湍流非定常压力脉动特性数值模拟研究

与发动机振荡燃烧相关的气固两相流中的压力脉动现象长期以来备受关注。为了解发动机气固两相流动中的非定常压力脉动特性,以典型的后台阶气固两相流动为研究对象,使用发展的自适应湍流模拟(Self-adaptive turbulence eddy simulation,SATES)和离散相模型(Discrete phase model,DPM)相结合的方法,对两相流场进行了三维非定常高精度数值计算。以实验数据作为参考验证了计算方法的精度和可靠性。通过将两相流场的压力脉动信号与纯气相流场进行对比,发现加入颗粒后流场压力脉动主导频率略有变化,无量纲压力脉动幅值明显减小;进一步研究了固体颗粒直径和质量分数对脉动特性的影响规律,发现随着颗粒直径变大,流场振幅先减小后增大。颗粒直径为10μm时,振幅最小;随着质量分数的增大,流场振幅呈现出下降趋势。研究表明气固两相流中颗粒的参数变化对振荡主频影响较小,对脉动振幅影响显著。

Simulation of Typhoon-Driven Waves in the Yangtze Estuary with Multiple-Nested Wave Models

Typhoon-generated waves are simulated with two numerical wave models, the SWAN model for the coastal and Yangtze Estuary domain, nested within the WAVEWATCHIII （WW3） for the basin-scale East China Sea domain. Typhoon No. 8114 is chosen because it was very strong, and generated high waves in the Estuary. WW3 was implemented for the East China Sea coarse-resolution computational domain, to simulate the waves over a large spatial scale and provide boundary conditions for SWAN model simulations, implemented on a fine-resolution nested domain for the Yangtze Estuary area. The Takahashi wind model is applied to the simulation of the East China Sea scale （3-hourly） and Yangtze Estuary scale （1-hourly） winds. Simulations of significant wave heights in the East China Sea show that the highest waves are on the right side of the storm track, and maxima tend to occur at the eastern deep-water open boundary of the Yangtze Estuary. In the Yangtze Estuary, incoming swell is dominant over locally generated waves before the typhoon approaches the Estuary. As the typhoon approaches the Estuary, wind waves and swell coexist, and the wave direction is mainly influenced by the swell direction and the complex topography.

Establishment Method of a Mixture Model and Its Practical Application for Transmission Gears in an Engineering Vehicle

Highly versatile machines, such as wheel loaders, forklifts, and mining haulers, are subject to many kinds of working conditions, as well as indefinite factors that lead to the complexity of the load. The load probability distribution function （PDF） of transmission gears has many distributions centers; thus, its PDF cannot be well represented by just a single-peak function. For the purpose of representing the distribution characteristics of the complicated phenomenon accurately, this paper proposes a novel method to establish a mixture model. Based on linear regression models and correlation coefficients, the proposed method can be used to automatically select the best-fitting function in the mixture model. Coefficient of determination, the mean square error, and the maximum deviation are chosen and then used as judging criteria to describe the fitting precision between the theoretical distribution and the corresponding histogram of the available load data. The applicability of this modeling method is illustrated by the field testing data of a wheel loader. Meanwhile, the load spectra based on the mixture model are compiled. The comparison results show that the mixture model is more suitable for the description of the load-distribution characteristics. The proposed research improves the flexibility and intelligence of modeling, reduces the statistical error and enhances the fitting accuracy, and the load spectra complied by this method can better reflect the actual load characteristic of the gear component.

A modified multi-group model of angular and momentum distribution of cosmic ray muons for thickness measurement and material discrimination of slabs

Muon tomography is a capable imaging technique to measure the geometry of high-Z objects. However,most existed algorithms used in muon tomography have obscured the effects of angular distribution and momentum spectra of cosmic ray muons and reduced the spatial resolution. We present a modified multi-group model that takes into account these effects and calibrates the model by the material of lead. Performance tests establish that the model is capable of measuring the thickness of a Pb slab and identifying the material of an unknown slab on a reasonable exposure timescale, in both cases of complete and incomplete angular data. Results show that the modified multi-group model is helpful for improvements in image resolution in real applications.

Mesons in the Constituent Quark Model

The quark-antiquark （q^-q） spectrum is studied by solving the Schrōdinger equation in the framework of nonrelativistic constituent quark model. An overall good fit to the experimental data of meson is obtained. The interactions between quark and antiquark consist of quadratic colour confinement-exchange, one-gluon-exchange, and Goldstone-boson-exchange potentials.

Complex Impedance Spectra Analysis of SnO_2-glaze Composites

SnO2-glaze composites were prepared by Sb-doped SnO2 and SiO2-CaO-Al2O3-B2O3 glaze. The composites changed from an electrical insulator to a conductor as the SnO2 content increased from Owt% to 90 wt% . The complex impedance spectra of the fabricated composites were investigated in the frequency range of 100Hz-40 MHz and three kinds of typical shape of complex impedance spectra were recorded and analyzed. The ,spectrum is quite close to the model of conduction via nonohmic contactiug when the SnO2 content is relatively low, In high loading region, the spectrum shows the conduction pattern through ohmic contact chains . In the moderate loading region, the model is a mixture of the above two models. Equivalent circuit of the composite changes from resistor-capacitor circuit to resistor-inductor circuit as the content of SnO2 increases.

An alternative construction of normalized seismic design spectra for near-fault regions

This paper presents a methodology for constructing seismic design spectra in near-fault regions. By analyzing the characteristics of near-fault pulse-type ground motions, an equivalent pulse model is proposed, which can well represent the characteristics of the near-fault forward-directivity and fling-step pulse-type ground motions. The normalized horizontal seismic design spectra for near-fault regions are presented using recorded near-fault pulse-type ground motions and equivalent pulse-type ground motions, which are derived based on the equivalent pulse model coupled with ground motion parameter attenuation relations. The normalized vertical seismic design spectra for near-fault regions are obtained by scaling the corresponding horizontal spectra with the vertical-to-horizontal acceleration spectral ratios of near-fault pulse-type ground motions. The proposed seismic design spectra appear to have relatively small dispersion in a statistical sense. The seismic design spectra for both horizontal and vertical directions can provide alternative spectral shapes for seismic design codes.

Ground State Meson Spectrum in a Relativistic Model with Instanton Induced Interaction

The mass spectrum of the S-wave mesons is considered in the frame work of relativistic harmonic model （RHM）. The full Hamiltonian used in the investigation has the Lorentz scalar plus a vector harmonic-oscillator potential, the confined-one-gluon-exchange potential （COGEP） and the instanton-induced quark-antiquak interaction （Ⅲ）. A good description of the mass spectrum is obtained. The respective role of Ⅲ and COGEP in the S-wave meson spectrum is discussed.