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High voltage electrical pulse fracturing technology based on electrohydraulic effect is a new type of rock mass fracturing technology. This technique is characterized by its safety, high efficiency, environmental friendliness and controllable energy usage. It holds a significant potential for its application in the stress control of surrounding rock in coal mines because the complex stress conditions present in underground rock mass. To further investigate the cracking effect of the technology on hard rock mass under different surrounding rock stress conditions, the numerical simulation of high voltage electric pulse rock mass cracking was carried out on the rock sample based on the RHT damage constitutive model by LS-DYNA. The processes of damage evolution and effective stress evolution inside the rock mass were collected. The cracking characteristics and crack propagation mechanism of the rock mass were analyzed. The numerical simulation overcomes the problem that it is difficult to effectively monitor the internal rock mass during the cracking process due to the fast discharge process and large electromagnetic interference in the indoor test. The self-developed high-voltage electrical pulse rock fracturing test platform was used to carry out the high voltage electrical pulse rock fracturing test under different surrounding rock stress conditions, and the reliability of the numerical simulation results was verified by the obtained rock surface fracture characteristics. The following conclusions are obtained: ① The numerical model of LS-DYNA high voltage electric pulse rock mass fracturing is established based on the RHT constitutive model. The equivalent parameters for the numerical simulation are derived according to the energy equivalent relationship between explosive blasting and high voltage electric pulse. The reliability of these parameters is confirmed by comparing the laboratory tests results with the numerical simulation results. ② By analyzing the crack propagation on the upper surface of specimens, it reveals that the crack will deflect in the direction of the maximum compressive initial stress. Initially, the total length of the crack first decreases gradually during this process. As the angle between all cracks and the maximum initial compressive stress becomes less than 45°, the total crack length begins to increase gradually. ③ Numerical simulations demonstrate that the dynamic stress resulting from high voltage electric pulse discharge is much greater than the initial stress in the surrounding rock during the early stages of fracturing. Dynamic stress plays a leading role in rock failure in this process. As the dynamic stress quickly diminishes during propagation, the initial surrounding rock stress is gradually close to the dynamic stress and finally dominates the initiation and propagation of cracks. The results indicate that surrounding rock stress plays a crucial role in determining the development and expansion characteristics of rock mass cracks. It notably influences the direction of crack expansion. When the high voltage electric pulse fracturing technology is used to crack the deep rock mass, the stress state of the rock mass should be considered. The scientific fracturing scheme should be formulated to achieve an efficient fracturing of the rock mass. The research results provide a reliable numerical simulation method for high voltage electric pulse rock fracturing and a reference for the formulation of deep rock mass fracturing scheme.

Based on field investigation, InSAR, GNSS monitoring, and deep displacement monitoring, a deformed loess landslide in Lingwan Village, Yujiaping Town, West-East Gas Pipeline Project was analyzed to understand its deformation characteristics and landslide formation mechanism from 2017 to 2022. The analysis shows that the groundwater level of the landslide has reached the toe of the slope, and numerous soil slips have been formed at the front edge of the landslide. The surface of the landslide exhibits vertical subsurface erosion cracks, while the penetrating cracks can be seen at the trailing edge. InSAR data shows that the landslide has been slowly deformed, with an annual deformation rate between 2.0 - 4.0 cm. GNSS deformation and crack deformation show that since August 2020, the surface deformation rate has increased significantly, with a deformation rate between 4.0 - 10.0 cm. The variation of deep deformation monitoring data is minimal, between 0.05 to 1.36 mm. Analysis of rainfall and soil moisture data shows that the landslide has displacement deformation after rainstorm. The comprehensive analysis of monitoring data reveals that the landslide in Lingwan Village is a shallow landslide induced by rainfall. Natural heavy rainfall and human engineering economic activities in the region are the primary inducing factors for the occurrence and development of landslide. Combined with pipeline strain monitoring data, the risk of landslide disasters in Shaanxi Province section of West-East Gas Pipeline Project is controllable.

Micro-channel vaporizer has the advantages of high heat exchange efficiency, high pressure resistance and compact structure, and has broad application prospect as an LNG vaporizer. Presently, most of the LNG micro-channel vaporizers are designed by the segmentation method, which requires massive calculation by the programming computation, and it is not conductive for its promotion and application in engineering. Therefore, a four-segmented design method was proposed for the LNG micro-channel vaporizer. The vaporizer is divided into 4 segments based on the temperature of working fluids under different phases. Then, the heat transfer amount, heat transfer area and pressure drop of each segment can be obtained through the heat balance calculation and structural design calculation, and thereby the total heat transfer area can be calculated. The calculation results have an error of 13.4% compared with that given in the reference. The numerical simulation for the flow and heat transfer characteristics of the designed micro-channel unit shows that the simulated values of the channel temperature and the pressure drop are well consistent with the calculated values of the four-segmented method, and thereby, the reliability of the four-segmented design method for the LNG micro-channel vaporizer is verified.Generally, the method has the characteristics of reasonable segmentation, less calculation, and intuitive and reliable results, which provides an effective way for the design and optimization of LNG micro-channel vaporizer.

ObjectiveTo study the impact of ambient temperature on hand, foot and mouth disease (HFMD) and to explore the source of heterogeneity in the impact and the HFMD burden attributable to ambient temperature in Guangdong province. MethodsThe data on daily reported HFMD cases and meteorological condition from 2009 through 2016 in Guangdong province were collected. The distributed lag nonlinear model (DLNM) was adopted to assess the effect of average daily ambient temperature on HFMD incidence at city level with the pooled effect estimates from multivariate meta-regression model analysis. Fraction and number of HFMD incidents attributable to variation in ambient temperature were estimated according to the results of DLNM analysis. Results Totally 2 279 647 HFMD cases were reported during the period. The risk of HFMD incidence increased with the increment of average daily ambient temperature. The cumulative relative risk (RR) of HFMD incidence reached the highest for the average daily ambient temperature of 30.5 ℃ versus that of 24 ℃ (RR = 1.24, 95% confidence interval [95% CI]: 1.12 – 1.37). The most obvious effect of low average daily ambient temperature on HFMD incidence was on the lag day 8 but that of high temperature was on the lag day zero. The disparity in the effect of average daily ambient temperature on HFMD incidence among various cities was derived from population density, growth rate of gross domestic production, location longitude, and average annual temperature/humidity/hours of sunshine. The estimated total number of HFMD incidents attributed to the exposure to high average daily temperature was 241 918, accounting for 10.61% (95% CI: 9.67% – 11.53%) of all the cases during the period. When exposed to high average daily ambient temperature, the elderly and the children less than 5 years old were at a higher risk of HFMD incidence than other populations. ConclusionHigh average daily ambient temperature could increase the risk of HFMD incidence and the impact of the high temperature may appear immediately or at lag days. The results suggest that specific measures should be taken in vulnerable populations during seasons with high temperature for the prevention of HFMD incidents.

Objective To study the association of humidex with bacillary dysentery (BD) incidence and its regional heterogeneity in North China. Methods The daily BD incidence and meteorological data from January 1, 2014 through December 31, 2016 in North China were collected from Chinese Center for Disease Control and Prevention and China Meteorological Science Data Sharing Service Network. Distributed lag non-linear model was used to assess associations of average ambient temperature, relative humidity and humidex with BD incidence. Multivariate meta-analysis was employed to pool region-specific analytic estimates and then meta-regression analysis was adopted to explore modifiers of the association between humidex and BD incidence. Results Approximately J-shaped relationships were observed between pooled BD risk and average ambient temperature, relative humidity and humidex. The humidex showed a promotion effect on BD incidence of the same day; the effect was the most obvious for the lag day 3 (relative risk [RR] = 1.07, 95% confidence interval [95% CI]: 1.05 – 1.09) and lasted until the lag day 7. Taking the median humidex as a reference, the humidex of 42.4 manifested a highest promotion effect on BD incidence, with the RR of 1.96 (95% CI: 1.52 – 2.53). The effect of humidex was more obvious in city-level regions at high latitude and longitude, with high natural population growth rate but low gross domestic production per capita. Conclusion The meteorological condition with high humidex may promote bacillary dysentery incidence in North China and the situation needs to be concerned in the control of the disease, especially in some vulnerable cities.

Aiming at the problem of spontaneous combustion prevention in the process of mining close distance coal seams in southern Sichuan Mining Area, this paper takes the first mining face of No. 8 coal seam in Xinwei Mine as an example, and analyzes spontaneous combustion risk factors during the recovery of 8102 working face. It is concluded that high residual coal and goaf residual coal are high risk areas of spontaneous combustion. The comprehensive fire prevention technical measures with spontaneous combustion prediction and forecasting as the lead, the plugging and controlling wind, the open area nitrogen injection and the high position grouting as the core are proposed, which fundamentally reduces the natural fire probability of the coal seam. During the recovery process, the CO concentration in the working face and the goaf is always kept below 20 ppm, which ensures the safe recovery of the working face.

In order to discuss the "entropy weight method" for weighting various indicators in the comprehensive evaluation of Angelicae Sinensis Radix slices(ASR), the quality of ASR was comprehensively evaluated by entropy weight-based gray systematic theory and cluster analysis. In this study, the contents of ferulic acid, volatile oil, polysaccharide, alcohol extract, water extract, moisture, total ash and acid-insoluble ash in 44 batches of ASR from different sources were determined. The entropy weight method was used for objective weighting. With relative correlation(r_i) as a measure, a multi-index comprehensive evaluation model was constructed for the quality of ASR. The results showed that the relative correlation value of 44 batches of ASR ranged from 0.301 9 to 0.662 9. There were certain differences in the quality of ASR from different sources. The ASR S1-S8, traceable and standardized in processing techno-logy, showed a high relative correlation degree and high quality ranking, indicating that the implementation of systemic management of the production chain of Chinese herbal pieces was beneficial to the quality control of ASR. The quality evaluation results of 44 batches of ASR were consistent with those of traditional geo-authentic habitats for ASR and the mainstream varieties of ASR on market, and basically consistent with the results of cluster analysis. This study suggests that the gray systematic theory based on the entropy weighting method can be used for the quality evaluation of ASR. The objective weighting of the entropy weight method improves the reliability of the gray correlation method and the scientificity of ASR quality evaluation.

Hypoxia-inducible factors(HIFs)are the key transcription factors that sense and regulate cellular oxygen concentration in vivo. HIF-1 is composed of 2 subunits,α and β,in which,the molecular regulatory mechanism of HIF-1α involves the main processes of its degradation and activation. The degradation of HIF-1α is regulated by oxygen-dependent pathways,including "von hippel-lindau protein(pVHL)-dependent pathway" and "pVHL-independent pathway". The activation of HIF-1α is regulated by oxygen-independent pathways,including mammalian target of rapamycin(mTOR)/eukaryotic initiation factor 4 E-binding protein 1(4 EBP1)/HIF-1α pathway,phosphatidylinositol 3-kinase(PI3 K)/proteirrserinc-threonine kinases(Akt)/HIF-1α pathway and silent information regulator1(Sirt1)/HIF-1α pathway. In recent years,based on the molecular regulatory mechanism of HIFs,Roxadustat,a new drug for the treatment of renal anemia has been developed. Besides, some macromolecular substances with similar pharmacological effect to HIFs have been found in the extracts from Chinese herbal medicine(CHM),such as emodin,notoginseng triterpenes,honokiol and clematichinenoside. These natural macromolecular substances play the regulatory roles in inflammatory response,epigenetic modification and auto-phagy. It is worth noting that,for common hypoxic-related diseases including diabetic kidney disease,HIFs-mediated "pyroptosis" may be a new target of CHMs for clearing dampness and heat and its representative classical prescriptions(Ermiao Pills)in treating inflammatory injury in cells and tissues.