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The zero-value piece of insulator string can be detected by measuring its electric field strength. The traditional way is always by measuring the electric field distribution curve of the whole string to judge out the zero-value piece position, which is inefficient and difficult to operate in field. In this paper, an improved method of identifying zero-value insulator by just measuring the partial electric field of insulator unit is proposed. Firstly, the simulation model of insulator string zero-value unit detection is established, and the partial electric field distortion characteristic caused by zero-value piece is analysed. Then the partial electric field variation criterion for zero-value identifying is obtained basing on the simulation result. Finally, the identification method is verified by designing the detection device and carrying out the point to point zero-value piece evaluating experiments. The results show that the point to point zero-value insulator detection can be realized using the three-array-probe electric field measuring method. The length of the array should be larger than the length of the electric field distortion interval, which can be taken as 130 mm for the research object in this paper. The identification criteria is that the deviation between probe 1 and 3 is less than 10%, and the deviation between probe 2 and the average is less than 50% at the same time. When detecting zero-value piece at the high-voltage and medium-voltage end, the best position for the sensor device identification is directly facing the steel foot, while for the low-voltage end, the best position is facing the shed edge. The results of the study can provide theoretical support for the intelligent operation and maintenance of external insulation in power transmission and distribution.

Background: The exosome is a critical component of the intercellular communication., playing a vital role in regulating cell function. These small vesicles contain proteins, mRNAs, miRNAs, and lncRNAs, surrounded by lipid bilayer substances. Most cells in the human body can produce exosomes, released into various body fluids such as urine, blood, and cerebrospinal fluid. Bladder cancer is the most common tumor in the urinary system, with high recurrence and metastasis rates. Early diagnosis and treatment are crucial for improving patient outcomes. Methods: This study employed the PubMed search engine to retrieve publicly accessible data pertaining to urinary exosomes. Results: We summarize the origins and intricate biological characteristics of urinary exosomes, the introduction of research methodologies used in basic experiments to isolate and analyze these exosomes, the discussion of their applications and progress in the diagnosis and treatment of bladder cancer, and the exploration of the current limitations associated with using urinary exosomes as molecular biomarkers for diagnosing bladder cancer. Conclusion: Exosomes isolated from urine may be used as molecular biomarkers for early detection of bladder cancer.

In order to improve the detection efficiency of zero value insulator of transmission line, the unmanned aerial vehicles (UAV) equipped with an electric field detection device can realize live detection without climbing the tower. Firstly, the 1:1 simulation model of 220 kV porcelain insulator string is established. Through Comsol finite element numerical simulation, the influence of string type, path jitter, UAV and electric field probe on the spatial electric field distribution of insulator string is analyzed. Then, the identification model and background detection system of zero value insulator are established. Finally, the laboratory and field measurements are carried out. The results show that when double insulator strings have zero value insulators at the same time, their spatial electric field distribution does not affect each other. The offset distance of straight line detection path should be less than 50 mm during UAV flight. The space electric field distribution of insulator string is not affected by UAV and electric field probe. Using the zero-value insulator detection algorithm proposed in this paper, the field detection of zero-value insulators is realized by the UAV equipped with an electric field detection device.

In recent years, the external insulation discharge and pollution flashover of transmission lines have occurred several times in the vicinity of nickel plant in Yancheng, and they cannot be effectively suppressed after the use of composite insulators. This phenomenon does not happened in the nearby chemical zone. Therefore, pollution samples of insulators are conducted in nickel plants and chemical plants within the jurisdiction of Yancheng power grid for analyzing and testing pollution chemical components, including anion and cation content, insoluble element composition, main compound composition. Then, based on the results of component analysis, a test under mixed pollution is carried out to obtain the flashover characteristics of composite insulators under typical pollution components of different pollution sources. Comparison between pollution composition of near chemical plants and nickel plants indicates that the latter has higher nitrates densities but lower chloride salts density. For one large and two small composite insulators, the flashover gradient under the typical pollution of nickel plants is 5% to 10% lower than that of chemical plants. For the external insulation configuration in heavy industrial dust areas, it is recommended to use one large and one small insulator to improve the electrical strength.

The flat plate specimens of nickel-based single-crystal superalloy with 14 film cooling holes, which made by different drilling techniques, were used to study the high-cycle fatigue (HCF) properties at 980°C in an ambient atmosphere. At the same time, the electrical discharge machining (EDM) specimens with a single hole were also used to study the HCF properties under different temperatures. The hole and fracture micrographs were analyzed by scanning electron microscope. The results indicated that different drilling techniques have a great influence on HCF life. The fatigue limit of the millisecond laser drilling is 353 MPa, while the EDM is 359 MPa and the electro-stream machining (ESM) is 378 MPa. The fatigue life decreases gradually with the temperature increasing. The fatigue limit of EDM specimens with a single hole at 900°C, 980°C, and 1,050°C are 472, 430, and 293 MPa, respectively. The destruction of the specimens is a typical multisource rupture, and the fracture morphology includes three parts: the cracks sources around the film cooling hole, the propagation zone along the {001} planes, and instant rupture zone along the {111} planes.

In this paper, the heat balance integral method was employed to solve the internal temperature of ice layer and the position of melting interface by stages, due to its main advantage of converting the governing partial differential equation to an ordinary differential one, which can effectively reduce numerical efforts. Then the deicing time of hot water for insulator was calculated and analyzed. Taking LXY-120 insulator as the verification object, after natural icing at Xuefeng mountain natural icing test base, the validation experiments of deicing time were carried out in the natural environment. The initial water temperature and outlet pressure were optimized for deicing efficiency. Finally, the leakage current of water jet was measured. The research results indicate that the deicing rate increases and the energy consumption gradually decreases as the initial temperature of hot water increases. As the outlet pressure increases, the deicing rate increases. For the deicing condition of 1.2 mm nozzle, ambient temperature of -1 °C, wind speed of 3 m/s, ice weight of 2 kg/piece and deicing distance of 2 m, when the initial temperature of hot water and outlet pressure are 85.21 °C and 3.35 MPa respectively, the comprehensive deicing efficiency is the highest. The leakage current through water jet decreases with the increasing distance. The leakage current increases with the increase of water conductivity and outlet pressure. Hot water deicing for insulator in 110 kV system can be carried out according to the safety distance of the existing regulation.

In recent years, some composite insulators operating in coastal foggy areas have shown different levels of degradation phenomena. This paper presents several performances and properties of silicone rubber under the salt-fog environment with AC voltage. Analysis conducted after salt-fog treatment by techniques, such as static contact angle, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), dielectric parameter, and flashover voltage show a significant degradation of samples. The absorption peak of the hydrophobic groups (Si-(CH3)2 and Si-CH3) decreased, the surface of the material became rough, and the dielectric and electrical properties were also deteriorated. Due to the thermal effects and impact of high-energy particles, the molecular chains on the surface of silicone rubber were broken, and the smooth surface structure was destroyed, resulting in the formation of hydrophilic chemical bonds and precipitation of inorganic substances. The intrusion of moisture further reduces the dielectric parameters and the electrical strength of the material. In addition, the samples in the salt-fog environment with a greater conductivity are more degraded, indicating that the salt-fog has an aggravating effect on the aging of the silicone rubber. Thus, it is recommended to pay attention to the monitoring and examining the work of composite insulators operating in a foggy and high humidity environment.

Under the background of the rapid development of Internet technology, the emergence of Internet platform accelerates the industrial agglomeration. As a chain connecting the material circulation between industries, the rise of logistics industry is inevitable. As a key link of logistics industry, transportation, along with the rise of logistics industry, has led to an increase in traffic accidents year by year. Therefore, based on the national road traffic accident data from 2006 to 2019, this paper uses SPSS 26.0 to analyse the accident incidence, casualties and direct property loss indicators of different regions and occupation, and study the characteristics of perpetrators and casualties. The results show that the traffic accidents in the whole country show a downward trend, but they are unbalanced. Workers and farmers accounted for the largest proportion, but the death and injury rate showed a downward trend. Other showed an upward trend in the past five years, especially in the delivery industry. Future road traffic safety management should take corresponding measures to reduce the accident rate from the perspective of the development of related industries.