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Application status of various mine-used wireless communication technologies was analyzed, including wireless communication technologies of PHS, WiFi, TD-SCDMA, WCDMA and Femtocell. A mine-used WCDMA wireless communication system based on Femtocell was put forward according to environment characteristics of coal mine underground, key technologies and advantages of the system were introduced in details. Finally, development trend of mine-used wireless communication technology was summarized.

Carbon loading in airway cells has shown to worsen function of antimicrobial peptides, permitting increased survival of pathogens in the respiratory tract; however, data on the impacts of carbon particles on childhood acute respiratory infection (ARI) is limited. We assembled daily health data on outpatient visits for ARI (bronchitis, pneumonia, and total upper respiratory infection [TURI]) in children aged 0–14 years between 2015 and 2019 in Beijing, China. Anthropogenic carbons, including black carbon (BC) and its emission sources, and wood smoke particles (delta carbon, ultra‐violet absorbing particulate matter, and brown carbon) were continuously monitored. Using a time‐stratified case‐crossover approach, conditional logistic regression was performed to derive risk estimates for each outcome. A total of 856,899 children were included, and a wide range of daily carbon particle concentrations was observed, with large variations for BC (0.36–20.44) and delta carbon (0.48–57.66 μg/m3). Exposure to these particles were independently associated with ARI, with nearly linear exposure‐response relationships. Interquartile range increases in concentrations of BC and delta carbon over prior 0–8 days, we observed elevation of the odd ratio of bronchitis by 1.201 (95% confidence interval, 1.180, 1.221) and 1.048 (95% CI, 1.039, 1.057), respectively. Stronger association was observed for BC from traffic sources, which increased the odd ratio of bronchitis by 1.298 (95% CI, 1.273, 1.324). Carbon particles were also associated with elevated risks of pneumonia and TURI, and subgroup analyses indicated greater risks among children older than 6 years. Our findings suggested that anthropogenic carbons in metropolitan areas may pose a significant threat to clinical manifestations of respiratory infections in vulnerable populations. Plain Language Summary: Carbon air pollution has been linked to potential biological mechanisms responsible for respiratory diseases, but its impact on childhood respiratory infection remain sparse. In this study, we examined the associations of carbon particles with childhood hospital visits for acute respiratory infection in the megacity Beijing. The results indicated that recent exposure to ambient black carbon and wood smoke‐related particles (delta carbon, ultra‐violet absorbing particulate matter, and brown carbon) was associated with heightened risks of upper and lower respiratory tract infections in children. Greater detrimental respiratory effects were observed for carbon particles from traffic. Up to date, the global pandemic of pediatric respiratory infection and air pollution episodes occurs frequently under the context of climate crisis, our findings highlighted the importance of discerning adverse respiratory effects caused by source‐specific carbon particles in real‐world settings, particularly at the extreme levels of anthropogenic carbon exposures faced by billions of children living in urban areas worldwide today. Key Points: Extremely high levels of ambient black carbon and wood smoke‐related particles were found during the study periodCarbon particles, particularly from traffic, were associated with increased risks of childhood respiratory infectionsGreater risks were found among children older than 6 years [ABSTRACT FROM AUTHOR]

As an advanced connection technology for large thick-walled components, narrow gap laser welding has the advantages of small heat input and high efficiency and quality. However, porosity defects are prone to occur inside the weld due to the complex welding environment. In this study, the influence of the process parameters and pollutants such as water and oil on the porosity defect were explored. The action mechanism of water on the electron temperature and spectral intensity of the laser-induced plasma was analyzed. The results showed that the spectral intensity during narrow gap laser welding was weaker than that of flat plate butt welding. Under the optimal welding process conditions, the electron temperature during narrow gap laser self-fusion welding was calculated as 7413.3 K by the Boltzmann plot method. The electron density was 5.6714 × 1015 cm−3, conforming to the thermodynamic equilibrium state. With six groups of self-fusion welding parameters, only sporadic porosity defects were observed according to the X-ray detection. When there was water on the base metal surface, a large number of dense pores were observed on the weld surface and in the weld through X-ray inspection. Compared with the spectral data obtained under the normal process, the relative light intensity of the spectrometer in the whole band was reduced. The electron temperature decreased to the range of 6900 to 7200 K, while the electron density increased. The spectrum variation during narrow gap laser wire filling welding was basically the same as that of laser self-fusion welding. The porosity defects caused by water and oil pollutants in the laser welding could be effectively identified based on the intensity of the Fe I spectral lines. [ABSTRACT FROM AUTHOR]

Background: Thromboembolism is less common in children than in adults, but it is frequently associated with Mycoplasma pneumoniae infection in many cases. This study aimed to investigate the clinical characteristics of pediatric M. pneumoniae pneumonia complicated with thromboembolism. Methods: Hospitalized patients with M. pneumoniae pneumonia complicated by thromboembolism were enrolled from January 2012 to December 2021 in Beijing Children's Hospital, Capital Medical University, China. The data on clinical manifestations, laboratory tests, and treatment were evaluated. Results: A total of 49 cases were enrolled, with a mean age of 7.9 years old, including 27 boys and 22 girls. Consolidation of pulmonary lobe or segment was observed in 95.9% (47/49) of the cases, whereas interstitial change was found only in two patients; 85.7% (42/49) of patients had pleural effusion. Pulmonary vascular thromboembolism was most common in 35 patients, whereas 13 cases had thromboembolism of multiple anatomic sites. The levels of C‐reaction protein, lactate dehydrogenase, and erythrocyte sedimentation rate were all increased, with a mean value of 54.08 ± 52.27 g/L, 451.12 ± 218.76 U/L, 43.40 ± 29.43 mm/h, respectively. Blood coagulation test showed that all 49 patients had elevated D‐dimer values (median 3.81 ng/ml, range, 0.34–48 ng/ml) and normal PT. aPTT.LA was positive in 74.3% (26/35) of the cases. aCL‐IgM was positive in 66.7% (26/39) of the cases. aβ2GPI‐IgM was positive in 79.4% (27/34) of the cases. The prognosis was generally good in this group. Conclusion: Pulmonary arteriovenous thromboembolism is the most common thromboembolism complicated in MPP, and cerebral artery embolism and cardiac thrombosis are common in extrapulmonary thromboembolism. In the cases of MPP with thromboembolic complications, pulmonary consolidation with pleural effusion is the main characteristic. About two thirds of the cases are positive for antiphospholipid antibodies. [ABSTRACT FROM AUTHOR]

Residential thermostat control is considered to be an effective way to allow individual regulation, and to encourage energy saving behavior. However, energy savings resulting from occupants' regulating behavior still needs to be quantified. We investigated several district heating systems that had thermostatic radiator valves (TRVs) installed, in Beijing and Tianjin, and evaluated the energy saving ratio, and the influence of heat transfer from adjacent apartments for four typical regulation scenarios. To separate out the effects of the occupants' regulation, a reference analysis method is proposed for comparison. Results indicate that when an individual occupant adjusted the TRVs according to a daily schedule for intermittent heating, the energy saving ratio was only about 6%. When the TRVs of an apartment are kept closed for a long unoccupied period (more than 4 days), the daily energy saving ratio was about 20%, and the total quantity of heat transferred from adjacent apartments was about 80% of the heat consumption of the reference apartment. In addition, when the TRVs were kept at a set-value (such as 3), energy saving ratios of about 12% were obtained. The results of this study provide further data for developing better management policies for heating terminal customization. [ABSTRACT FROM AUTHOR]