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The development and utilization of large-scale distributed power generation and the increase of impact loads represented by electric locomotives and new energy electric vehicles have brought great challenges to the stable operation of the regional power grid. To improve the prediction accuracy of power systems with source-load twoterminal uncertainties, an adaptive cubature Kalman filter algorithm based on improved initial noise covariance matrix Q0 is proposed in this paper. In the algorithm, the Q0 is used to offset the modeling error, and solves the problem of large voltage amplitude and phase fluctuation of the source-load two-terminal uncertain systems. Verification of the proposed method is implemented on the IEEE 30 node system through simulation. The results show that, compared with the traditional methods, the improved adaptive cubature Kalman filter has higher prediction accuracy, which verifies the effectiveness and accuracy of the proposed method in state estimation of the new energy power system with source-load two-terminal uncertainties. [ABSTRACT FROM AUTHOR]

The insulating paper of the transformer is affected by many factors during the operation, meanwhile, the surface texture of the paper is easy to change. To explore the relationship between the aging state and surface texture change of insulating paper, firstly, the thermal aging experiment of insulating paper is carried out, and the insulating paper samples with different aging times are obtained. After then, the images of the aged insulating paper samples are collected and pre-processed. The pre-processing effect is verified by constructing and calculating the gray surface of the sample. Secondly, the texture features of the insulating paper image are extracted by box dimension and multifractal spectrum. Based on that, the extreme learning machine (ELM) is taken as the classification tool with texture features and aging time as the input and output, to train the algorithm and construct the corresponding relationship between the texture feature and the aging time. After then, the insulating paper with unknown aging time is predicted with a trained ELM algorithm. The numerical test results show that the texture features extracted from the fractal dimension of the micro image can effectively characterize the aging state of insulating paper, the average accuracy can reach 91.6%. It proves that the fractal dimension theory can be utilized for assessing the aging state of insulating paper for onsite applications. [ABSTRACT FROM AUTHOR]

The preventive effect of traditional Chinese medicine on the novel coronavirus (COVID-19) pneumonia is embodied in the "prevention before disease onset" of "treatment of disease" theory of thought, and it is considered that the key to the success or failure of prevention is whether the healthy qi is abundant or not. This article discusses and understands the "genuine qi" from the The Medical Classic of the Yellow Emperor, and describes its meaning comprehensively and systematically, combining with the expansion and supplement of many doctors in later generations. The "genuine qi" includes healthy qi, pulse qi, congenital qi, personal qi, Jing qi primordial qi and food energy, all of which are closely related to spleen-stomach. The function of spleen-stomach is normal, water and grain are transported properly, and the rise and fall of qi is appropriate, then the human body's qi is abundant, the anti-evil force is strong, and people are not easy to cause disease; even if the disease, the prognosis is better. This the novel coronavirus pneumonia comprehensive analysis, belongs to the traditional Chinese medicine science "damp-toxin epidemic", therefore the prevention should pay more attention to strengthen spleen and stomach, eliminate dampness, and Xiangsha Yangwei Pills is the appropriate choice. [ABSTRACT FROM AUTHOR]

A broadband absorber which was proposed by Thue-Morse structures containing graphene-based hyperbolic metamaterials (GHMM) is theoretically investigated. The Thue-Morse layer is composed of a lossy dielectric, conventional material layer, and GHMM. It is shown to absorb roughly 80% of all available electromagnetic waves at an 11 terahertz absorption bandwidth at normal angle incidence. The absorption bandwidth and absorptance is affected by incident angle, Fermi energy, and the thickness of dielectric. These findings can lead to the development of midinfrared photonic devices and have potential applications for designing broadband optoelectronic devices. [ABSTRACT FROM AUTHOR]

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Based on the Friedberg-Lee soliton bag model with consideration of the Fermi motion (including the effect of nucleon's binding) we study main A-dependence of the ratio of the structure function for bound and free nucleons in terms of a model in which bound nucleons have a slightly larger size than free nucleons. With our improved model, the theoretical curves are in good agreement with the experimental data. An empirical formula has been given about the effective radius of the quarks' confinement region of a bound nucleon R with atomic weight A and we also have discussed the influence of the masses of quarks upon the EMC effect. [ABSTRACT FROM AUTHOR]

A modified Sagnac imaging spectropolarimeter is conceptually described. It consists of a spectral-polarimetric modulator, a modified Sagnac interferometer with large optical path difference, and a CCD camera. This design modulates the Stokes components of the input light into different wave numbers and obtains the modulated interferogram in snapshot mode, and the spectra of the Stokes components can be separated and demodulated from the interferogram. The performance of the system is demonstrated through a numerical simulation, and a novel method is proposed to detect the polarization parameters including the degree of polarization and polarization direction for eliminating the aliasing effects between linear Stokes parameters. Compared with the existing imaging spectrometers, the modified Sagnac imaging spectropolarimeter can acquire one-dimensional spatial information and its full linear spectropolarimetric information in one exposure, and some other spatial information can be obtained by push-broom mode. [ABSTRACT FROM AUTHOR]