The novel coronavirus disease outbreak started in December 2019 in Wuhan, China, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The CT image is used to assess the disease progress, whereas the continued two times of negative results from SARS-CoV-2 nucleic acid detection had been considered as a criterion for ending antiviral treatment. We compared the two COVID-19 cases with similar backgrounds and CT image repeated intervals under treatment. Our report highlighted the unsynchronized expression in the changes of CT image and nucleic acid detection in COVID-19, and lasting positive nucleic acid test result in patients recovered from pneumonia. It may be contributed to recognize the disease and improve prevention.

Radio frequency identification (RFID) provides a contactless approach for object identification. If there are multiple tags in the interrogation zone of a reader, tag collision occurs due to radio signal interference. To solve tags identification collision and improve identification efficiency in RFID system, a flood division anticollision (FDAC) algorithm has been presented. Firstly, the algorithm launches an estimation of the number of tags and according to the estimation result decides whether a flood diversion processing needs to be started or not. Secondly, when the flood diversion processing needs to be done, all tags are grouped and assigned to different models in which the tags are to be processed and identified in parallel. Thirdly, in the identification processing, for reducing data transmission, the reader needs only to send a three-dimensional-vector command to tags, tags respond to the command with part of collision-bit parameters, and stack and queue are adopted to store precious request command and tags' ID to avoid repeatedly transmitting them between the reader and the tags. Simulation experiment results show that FDAC is superior to the dynamic frame slotted (DFS) Aloha algorithm, the binary-retreat tree algorithm (BRT) and the dynamic binary-search tree (DBST) algorithm, in the performances of data bits transmission, identification time delay, and energy consumption by the reader.

In allusion to the low reliability and sensitivity of existing single-phase earth fault location method, this article proposed a new location method based on WAMS in mine non-effectively grounded network. It analyzed the logical relationship of zero-sequence current of each branch when single-phase earth fault occurred and deduced zero-sequence current formulae of each branch. The detailed description is given to calculating differential variable of zero-sequence current and explicating principle and realization of fault section location. The coal mine power supply model based on WAMS is introduced and the scheme was verified by simulation via MATLAB and calculation via Fast Fourier Transform. The results indicate that it avoids influences by load capacity and the voltage initial phase angle, then effectively enhances fault location reliability and sensitivity.

We take the overall architecture of internetware on-line evolution model as basic, and study on trust metric model of the software in internetware system. In view of the not accurate results from the rough and existing trust metric model granularity, this paper proposed a multi service and hierarchical dynamic trust metric model based on time frame. Model also offer a method to established time frame weighted factor based on inducing ordered weighted operator, which makes the trust measurement results more accurate. The trust measurement results obtained from the model will be used as decision-making basis for Bias game model.

The principle of gas path electrostatic circular sensor was discussed in this paper, in addition, a monitoring experiment with self-made circular sensor was carried out on turbojet engine, and electrostatic signals were collected successfully to verify the validity and feasibility of the sensor. According to the signals monitored over 131h, typical signals of 233-240 phases were analyzed. It was proved that the unusual particles were caused by carbon deposition from fuel spray nozzle. Therefore, under real-time monitoring of gas path changes with electrostatic circular sensor, early warning could be provided for initial fault condition as well as real-time reference for condition-based maintenance.