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This paper introduces a novel neural-network-based approach for extracting some eigenpairs of real normal matrices of ordern. Based on the proposed algorithm, the eigenvalues that have the largest and smallest modulus, real parts, or absolute values of imaginary parts can be extracted, respectively, as well as the corresponding eigenvectors. Although the ordinary differential equation on which our proposed algorithm is built is onlyn-dimensional, it can succeed to extractn-dimensional complex eigenvectors that are indeed 2n-dimensional real vectors. Moreover, we show that extracting eigen-pairs of general real matrices can be reduced to those of real normal matrices by employing the norm-reducing skill. Numerical experiments verified the computational capability of the proposed algorithm.

Rationale:Epithelioid angiosarcoma (EAS) is an extremely rare malignant disease, which accounts no more than 1% of all soft tissue sarcomas. In this article, we would report a new case of EAS with multiple bone destruction and right femoral pathological fracture, which was an even rarer manifestation of EAS.Patient concerns:In this case, a 64-year-old man with right femoral fracture was reported. He had suffered from a progressive low back pain for about 8 months, and the imaging examinations prompted a multiple bone destruction in his vertebra and lower limbs. He then got a right femoral fracture without any obvious traumatic injury, and came to our hospital.Interventions:He underwent an operation of radical resection, bone cement filling and dynamic condylar screw internal fixation. During the operation, we found that the soft tissue around the fracture had a rotten fish change, which suggested a malignant disease.Diagnoses:The postoperative pathological diagnosis reported an EAS, which is extremely rare and highly malignant.Outcomes:The patient died in 83 days after the surgery, and the survival time from the symptoms started to the end was only 11 months, which showed a rapid progress and poor prognosis of EAS.Lessons:EAS is very hard to be diagnosed by clinical manifestation or radiological examinations. As in our case, pathological analysis is the final diagnosis. The images of the patient may offer some tips for the skeletal presentation of EAS, and do more help in future study of this disease.

The application of HTSC (high temperature superconductor) microwave devices in a UHF digital trunking communication system is introduced. The replacement between the HTSC microwave devices and the normal microwave devices is conducted. The digital sensitivity of the base station in complex electromagnetic environment has been increased to 6 dB, as the results of the experiment indicated, and this means that the coverage radius of the base station has been improved about twice, that is to say, the coverage area can be extended to four times as large as that of the current method. high temperature superconductor (HTSC), receiver, digital trunking communication system Citation: Yang K, Lai J M, Bu S R, et al. Investigation of HTSC digital trunking communication receiver subsystem.The high temperature superconductor (HTSC) microwave filters and multiplexers are very important devices in the radio frequency (RF) and microwave subsystems, and have more advantages in lower loss, higher selectivity, lighter weight, and easier to integrate with other microwave solid circuits than normal ones. Nowadays, the application of the HTSC microwave devices in mobile communication and satellite communication has aroused much concern for this reason. Both at home and abroad [1-3], many technologies have been developed for the design and fabrication, especially for the miniaturization of filters [3,4]. In this paper, very low noise figure (NF) is gained, due to a HTSC filter with low loss and high selectivity and a low noise amplifier (LNA) working in the liquid nitrogen temperature environment. In this design, the HTSC filter is laid in the front of the LNA to improve the anti-jamming capability of the receiver.The sensitivity of the digital trunking communication system not only depends on the RF front-end circuit, but also directly depends on the digital sensitivity. It is very necessary to lay the filter in the front of the receiver because there are very serious interferences in UHF band. The advantage of the HTSC technology is presented obviously.