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ObjectiveTo determine the epidemic characteristics of anthrax in Chengde City， Hebei Province from 2005 to 2021， and to provide evidence for formulating prevention and control measures of anthrax and reducing incidence rate.MethodsThis study collected the data of anthrax epidemic in Chengde City and conducted descriptive analysis.ResultsFrom 2005 to 2021， a total of 11 anthrax cases were reported in Chengde City with no death. The average incidence rate was 0.08/105， which remained low. Furthermore， 10 cases were cutaneous anthrax and 1 case was pulmonary anthrax. The cases were mainly reported in Weichang County， accounting for 90.91% of the total reported cases， followed by Pingquan City. In addition， the cases were mainly reported from July to August and mainly between 30 and 59 years old with a gender ratio of 2.67∶1.ConclusionThe anthrax epidemic in Chengde City is likely to increase. It mainly occurs in summer， rural areas， and male young and middle-aged farmers. It is necessary to improve epidemic monitoring， health education， disease prevention capacity， early identification of the epidemic， and active response.

Electric energy measurement system of rail transit train has no national standard. At present, IEC 61000-4-30 Electromagnetic compatibility-Part 4-30:Testing and measurement techniques-Power quality measurement methods is only applicable to power frequency (50 Hz or 60 Hz) power quality measurement methods. With the rapid development of rail transit equipment and technology, in order to apply the current nominal traction system AC voltage frequency (50 Hz or 16.7 Hz) and DC-powered electric energy measurement, this paper puts forward measurement methods of voltage, current and electric energy and a new method of uncertainty calculation of active power, according to IEC 62888-2:2018 Electric energy measurement of rail transit trains -Part 2: Electric energy measurement. Combined with the research results of design and application of electric energy test system, typical solutions of train electric energy measurement system are provided. Practical measurement results show that by these solutions, relative uncertainty of active power of the system is better than 4‰, which meets and exceeds the requirements of international standards, and the correctness of the new calculation method of the uncertainty of active power is verified.

Permanent magnet motors restart at high speeds is an essential and important function in applications in many key fields. Due to the unknown initial position of rotor and the observation error in this condition, improper control may cause current inrush or overcurrent fault. This paper focuses on the engineering practice and proposes a three-stage control mode based method for high speed restart of permanent magnet motors without position sensors. Zero-voltage vector control method with closed-loop current amplitude is used for initial input to control the motor current in closed loop and limit the sudden change of the current; subsequently, through a reasonable switching strategy, the control strategy is naturally transitioned to d-q axis current closed loop based vector control, and virtual resistance method is adopted to improve the accuracy of rotor position observation, which smoothly brings the motor into normal control mode. It presents a numerical simulation of the whole process of the built-in permanent magnet synchronous motor with high speed restart, during the whole process of restarting. There is no inrush of motor current and no sudden change of speed and position angle estimation, the observation method of rotor position angle, control strategy and modulation strategy all realize smooth switching, and the motor is pulled to the normal operating condition stably. Simulation results verify the feasibility and effectiveness of the proposed method.

Biodegradable poly(butanediol succinate-co-L-lactate) (PBSLA) copolyesters were modified using organic modified montmorillonite (OMMT) and Mica layered silicate inorganic fillers in solution blending method. The thermal properties, crystallization properties, barrier properties and mechanical properties of PBSLA/laminosilicate composites were studied. The results show that when the mass fraction of the layered silicate filler is less than 4%, its dispersion in copolyester matrix is good. The inorganic filler acts as the heterogeneous nucleating agent, which improves the crystallization property of the matrix material to some extent. In terms of mechanical properties, a certain amount of layered silicate filler plays an enhanced role. When the addition of OMMT and Mica is 2% and 3%, respectively, the tensile strength of the composites reache the maximum value, and can be increased by 18.4% and 34.4% compared with PBSLA, respectively. The layered structure effectively increases the zigzag path of gas molecules. With the increase of filler content, the water vapor and oxygen permeability coefficients of the composite show a downward trend. Therefore, the addition of layered silicate fillers can improve the barrier properties of PBSLA matrix materials. [ABSTRACT FROM AUTHOR]

Objective To establish a rapid diagnosis method for the biological toxicity of soil, accurately and rapidly evaluate the toxicity of contaminated sites and identify the dominant pollutants. Methods Take the soil pollution of a galvanized factory as an example, while the metal concentration level was analyzed and detected, a rapid biological toxicity detection method based on the acute toxicity test of luminescent bacteria （Vibrio qinghaiensis sp.-Q67） was established, and the dominant pollutants were identified by stepwise multiple regression. Results The pollutants came from wastewater and metal plating fragments directly discharged from the manufacturing line of the factory. The concentration of those pollutants was correlated with the acute toxicity of Vibrio qinghaiensis sp.-Q67. The dominant pollutants in the study were zinc （Zn）, aluminum （Al） and copper （Cu）. Conclusion The luminescent bacteria toxicity test method based on Vibrio qinghaiensis sp.-Q67 can conveniently and rapidly assess the degree of toxic damage of polluted soil and identify the dominant pollutants and can be applied to the acute toxicity evaluation of polluted soil.

Aiming at the safety problems of trusted computing platform due to the Apps lack of trust, this paper presented a software identification distributing system, and introduced its function modules and workflow. Software identification acted as its safety carriers and authentication means, software behavior statement solved the problem of legitimacy and trust before distribution. It designed an authentication protocol to ensure the integrity of software during distribution, and provided a recommended strategies for choosing suitable software based on trustworthy behavior. Application examples demonstrate that the system has a higher research and practical value of enhancing the trustworthiness of the platform. [ABSTRACT FROM AUTHOR]

This paper designed a kind of active measurement model named mixed-chain & character pre-setting active-measurement model(MC-CPSAM). By making improvement of the traditional chain structure of trust, MC-CPSAM made the metric agents more trusted. It made an achievement for a kind of active measurement by protecting metric agents and upgrading rights of metric agents. At last, it designed a hardware structure based on MC-CPSAM and made an attestation for the security of this model. [ABSTRACT FROM AUTHOR]

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The mechanical eccentricity makes much more influence on precision of one pair pole reluctance resolver. One pair pole axial flux reluctance resolver with new magnetic structure is put forward, which has compensating character inside its two side air gap. The prototype has both exciting windings and signal windings in its stator, which are vertical to each other. There is no winding in its rotor and one inclined ring is set in it. By using analytical method, the conclusion is got that the resistance of the reluctance resolver is varied by changing its electro-magnetic coupling area. At the same time, by selecting appropriate shape of the inclined ring of rotor, the output sine and cosine signal of the EMF is optimized. To analyze the axial flux through the stator and the rotor, 3D transient FEM is used. The character of the EMF in signal windings is got at the same time. The FEM result agrees well with the analytical result, this will offer us the basic parameters for the further analysis in the future. [ABSTRACT FROM AUTHOR]

Computer Application course is a basic course in officer schools, and computer skills are one of the most basic skills for students. We propose some methods to improve the students' interest in learning Computer Application course, which include an elaborate design of the lead-in step, enrichment of classroom teaching methods, improvement in teaching language skills, and hierarchical design methods such as teaching target, elaborate organization skills and competition. [ABSTRACT FROM AUTHOR]

The magnetic hydrostatic equation and the magnetic hydrodynamics equation are investigated as a basic theory which lays the cornerstone for decoupled computation and application. The method used for decoupled computation is the Boundary-Step by step-Hand and hand Iterative Method. Under the effect of traveling wave magnetic field, the flux of magnetic fluid has a direct relationship with the rotating angle of magnetic pole of the permanent magnetic rotor which is used to produce traveling wave magnetic field. The flux increases with the enlarged rotating angle of the permanent magnetic rotor. The intensity of traveling wave magnetic field also influences the magnetic fluid flux. At the same rotating angle of the magnetic pole of permanent magnetic rotor, the flux increases with the strengthened magnetic field; the frequency of traveling magnetic field only affects the flow velocity of magnetic fluid, and it has no direct influence on the flux. [ABSTRACT FROM AUTHOR]