With the depletion of fossil fuels and the emergence of biofuels, ethanol-hydrogen fuel as a new generation of clean renewable fuel has attracted widespread attention. It is necessary to study the effects of ethanol-hydrogen air premixed flame combustion characteristics. Based on the constant volume combustion system, the laminar combustion characteristics of ethanol/hydrogen/air premixed flame were studied under the conditions of initial temperature of${400}\mathrm{\;K}$, hydrogen ratio of${20}\%$, equivalent ratio of${0.7}\sim {1.4}$and initial pressure of$2 \times {10}^{5},3 \times {10}^{5}$and$4 \times {10}^{5}\mathrm{\;{Pa}}$. Based on the mechanism of ethanol oxidation of Marinov and experimental data, the laminar combustion rate of Marinov was studied and the influencing factors were analyzed. Based on Chemkin-Pro software, the chemical reaction kinetics and numerical study were carried out. The results show that the laminar combustion rate of mixed fuel slows down with the increase of pressure.$\mathrm{H}$group is the main pathway of ethanol consumption, and$\mathrm{H},\mathrm{O}$, and$\mathrm{{OH}}$radicals play a leading role in the reaction of${\mathrm{{SC}}}_{2}{\mathrm{H}}_{4}\mathrm{{OH}}$and${\mathrm{{PC}}}_{2}{\mathrm{H}}_{4}\mathrm{{OH}}$from$\mathrm{H}$extracted by ethanol.$\mathrm{R}1 :\mathrm{H}+ {\mathrm{O}}_{2}\rightleftharpoons \mathrm{O}+ \mathrm{{OH}}$has the most positive effect on laminar combustion speed. The peak molar fraction of the active radical pool composed of active free radicals(H, OandOH) has a good correlation with the laminar combustion rate of ethanol in the whole equivalent ratio range, and the influence is huge. Further exploring this correlation, it is found that there is an approximate linear relationship, and the expression of laminar combustion rate with the peak molar fraction of$\mathrm{H}+ \mathrm{{OH}}+{\mathrm{{CH}}}_{3}$and$\mathrm{H}+\mathrm{{OH}}$is fitted.

With the construction of a new type of power system with new energy as the main body under the "double carbon" target, the challenges of natural disasters such as wildfires, icing and typhoons in the production, transmission and distribution of electric energy are more severe. Therefore, a fire point identification algorithm based on the world's first operational dawn-dusk orbit meteorological satellite Fengyun-3E satellite (FY-3E) was proposed, which was suitable for mountain fire monitoring in transmission line corridors, the adverse effects of large solar zenith angle observation conditions and satellite perspective differences on the accurate acquisition of infrared channel detection data were eliminated. Cloud information extraction and cloud pixel fire point extraction under complex atmospheric observation conditions were realized, which reduced fire point false alarms and missed alarms. The analysis of mixed pixel linear spectrum separation method shows that the fire point detection sensitivity of FY-3E mid-infrared channel is 4 times higher than that of geostationary meteorological satellite. The effectiveness of the proposed algorithm and the superiority of FY-3E in fire detection sensitivity, spatial range accuracy and positioning accuracy were verified. Compared with geostationary meteorological satellites, the fire location accuracy can be increased by more than one time, and it can effectively detect the fire time in advance by the transmission line operation and maintenance department, and guide the relevant departments to take timely measures to reduce the impact of wildfires on power grid operation.

The piers of sea-crossing bridge are always subject to the scouring effect of flow and waves. The flow environment around the piers is complex. There is a risk of foundation erosion, endangering the safety of the bridge. Based on computational fluid dynamics (CFD) and the open-source software OpenFOAM, three-dimensional numerical simulations of the flow field around the inclined oblong pier were conducted with different inclination angles and length-to-width ratios$\left({L/D}\right)$. The results demonstrate that under the influence of wave and current, a symmetrically distributed vortex is formed behind the pier and undergoes periodic changes. The wake vortex constantly strengthens and moves backward as the trough approaches the pier. It reaches the maximum than gradually reduces and dissipates before the crest reaches the pier. With an increased downstream inclination angle, the pier tends to be streamlined, resulting the decreasing of wake vortex intensity and the horizontal load of pier. As the length-to-width ratio$\left({L/D}\right)$increases, the tail vortex area behind the bridge pier decreases and the horizontal load increases. Within the range of$L/D = 1$to 3 and a range of$-{30}^{\circ }$to${30}^{\circ }$, the minimal load on the pier is achieved when$L/D$is 1 and inclination angle is${10}^{\circ }$.

In response to the common forms of specimens used for interface shear performance testing, these specimens fail to effectively reflect the actual situation of shear stress on the interface. An optimized improvement scheme for the traditional Z-type specimen was proposed. By employing the optimized Z-type specimen, experimental studies on the shear strength at the interface between ultra-high performance concrete (UHPC) and normal concrete (NC) were conducted, examining the influence of shear reinforcement ratio and interface roughness on the interface shear strength. The research results indicate that the failure occurs on the NC side or partially on the interface and partially on the NC side, which is characteristic of typical brittle failure. The shear strength of the interface increases with the increase of roughness, but when the roughness is larger than the value of 1.8, the effect of increasing interface roughness to enhance the interface shear strength is not very significant. Ribbed reinforcement as shear reinforcement can fully exert the anchoring effect and the effect of improving the interface shear strength is more evident than that of smooth-round reinforcement. A calculation formula for the interface shear capacity of UHPC and NC, which can consider the contribution of shear reinforcement and interface roughness, has been established. The theoretical calculation values are in good agreement with the experimental results, which can provide reference for the engineering design of composite components with UHPC and NC interfaces.

The digital twin technology of the distribution network is an important product resulting from the integration and development of the power system and information technology. The technology simulates the physical behavior and operational status of the distribution network in a digital space by constructing a virtual model of the physical distribution network, enabling comprehensive simulation and analysis. Due to the diverse systems and complex states involved, the existing digital twin simulation platform technology for distribution networks still requires improvement. A wavelet-LSTM fusion model for power state and weather factors was constructed based on the existing wavelet transform and long short-term memory (LSTM) neural network. The high-dimensional input data were converted into detail and contour coefficients using discrete wavelet transform. Subsequently, LSTM neural networks were constructed to process the data and fuse the results, thereby forming accurate prediction outcomes. This method was validated on real datasets, showing that the wavelet-LSTM fusion model significantly improves the mean absolute percentage error (MAPE) compared to the existing LSTM network. Additionally, the method was tested on datasets from different industries. Compared to wavelet-Lasso, LSTM, and STL-LSTM, it exhibits better performance in terms of MAPE, demonstrating that the wavelet LSTM prediction method can be applied to state data from various sectors, thereby providing robust support for future state prediction of digital twins.

To address the fuzziness and randomness in safety evaluations of liquefied natural gas (LNG) chemical plants, a novel risk assessment method was proposed based on the normal cloud model. The proposed method was based on the selection of evaluation indicators from the perspective of intrinsic safety, which was used to evaluate the severity and likelihood of accidents through expert judgment. The weights of the indicators were determined by combining the analytic hierarchy process (AHP) and the criteria importance though intercrieria correlation (CRITIC). The risk matrix thresholds were softened using a forward cloud generator, and the evaluation results were optimized through a backward cloud generator to obtain cloud characteristic numbers and generate corresponding two-dimensional cloud maps. By comparing the actual cloud map with the standard cloud map, the risk levels of the evaluation indicators were determined. The results show that the model effectively integrates the expert opinions with aims of retaining the randomness and fuzziness, and providing the visualizes the risk assessment results. The novel method also provides a new risk assessment tool for the safety management of LNG chemical plants.

In the winter water transfer process of the Northwest cold region long-distance water transfer project, channels and hydraulic structures such as gate piers are frequently subjected to damage from flowing ice impacts. To safeguard the stability and security of winter water transfer operations, it is imperative to investigate the mechanical response characteristics of gate piers under the influence of flowing ice impact. ANSYS/LS-DYNA finite element software was employed to establish a refined finite element model of the gate pier under ice-water coupling conditions using the arbitrary Lagrangian-Eulerian (ALE) fluid-solid interaction method. The accuracy and validity of the numerical model are were verified by comparing the impact forces of flowing ice against relevant standards. The mechanical response characteristics of flowing ice on the gate pier by varying models such as the ice-water coupling model, additional mass model, fluid-free model, and flowing ice characteristics (velocity and compression strength)was explored. The findings indicated that the impact damage from flowing ice on the gate pier primarily occurs at the collision contact area between flowing ice and the gate pier. The presence of the water medium significantly mitigates the damage caused by flowing ice, emphasizing its viscous effects. Comparing different collision condition models, the additional mass model exhibits the highest impact force and X-direction displacement peak values, followed by the fluid-free model, with the fluid-solid coupling model showing the least impact, thereby suggesting the suitability of the additional mass model for simulation calculations and structural design. Furthermore, the result revealed that both the peak and mean impact forces increase with higher flow ice velocities and compression strengths, underscoring the importance of considering these factors in impact force assessments. Practical measures such as installing ice stopping ropes are recommended to mitigate flow ice impact forces and ensure structural safety in real-world applications.

Recent studies indicate that for early-stage non-small cell lung cancer(NSCLC) classified as T1N0M0, sublobar resection offers long-term outcomes comparable to lobectomy. However, these early-stage patients may still experience pleural invasion, which is associated with poor prognosis. It is necessary to compare the long-term efficacy of sublobar resection versus lobectomy in patients with T≤3 cm N0M0 NSCLC accompanied by pleural invasion. Research data were sourced from the SEER(Surveillance, Epidemiology, and End Results) database. Patients diagnosed were from between 2010 and 2020 with T≤3 cm N0M0 NSCLC and pleural invasion. Patients were divided into sublobar resection and lobectomy groups, and their cancer-specific survival(CSS) and overall survival(OS) were compared. Univariate analysis post-matching reveale no significant differences in CSS and OS between the sublobar resection and lobectomy groups. Multivariate analysis also indicate that the surgical approach is not an independent prognostic factor for CSS(HR=1.185, 95% CI: 0.745~1.885, P=0.472) and OS (HR=1.171, 95% CI: 0.869~1.577, P=0.299)in patients with T≤3 cm N0M0 NSCLC and pleural invasion. Subgroup analyses show no significant differences in CSS and OS between the two groups across various subgroups. Competing risk model multivariate analysis also demonstrate no significant difference in lung cancer-specific mortality between sublobar resection and lobectomy. In conclusion, for patients with T≤3 cm N0M0 NSCLC accompanied by pleural invasion, sublobar resection offers long-term survival outcomes comparable to lobectomy and can be considered a viable surgical option for this patient population.

Variations in freezing and thawing of the roadbed are known to significantly influence the dynamic behavior of high-speed railway ballast tracks. This phenomenon potentially compromises the safety and efficiency of train operations. A comprehensive vehicle-ballastless track-roadbed spatial dynamic model was employed to examine the effects of different wavelengths, amplitudes, and velocities on track dynamics due to roadbed frost heave. It was found that, with a constant heave amplitude, an increase in wavelength initially boosted and then reduced the car’s vibration acceleration. Concurrently, the vertical wheel-rail force diminished as the wavelength extended, leading to a decrease in both the wheel load reduction rate and the risk of derailment. Conversely, when the wavelength was kept steady and the heave amplitude was increased, the car’s peak vibration acceleration escalated. At a 40 mm amplitude, the vertical wheel-rail force peaked at 198.642 kN before dropping to zero within 1.384 seconds, resulting in a brief airborne phase for the car. An increase in heave amplitude heightened both the wheel load reduction rate and the derailment coefficient, reaching critical safety thresholds at a 35 mm amplitude. Higher driving speeds intensified the dynamic indicators of the rail system.These insights provide crucial guidance for analyzing dynamic challenges in high-speed railway tracks and addressing structural issues effectively.

The evaluation of on-street parking efficiency is considered a necessary basis for the optimization and management of on-street parking as well as the development of urban intelligent parking systems. Therefore, an evaluation method of on-street parking efficiency based on the entropy weight Critic-Topsis model was proposed. Firstly, nine indexes, such as the number of parking spaces, the remaining width of the road, and the cumulative number of parking, were selected from three aspects: parking space attributes, operating characteristics, and traffic impact, to construct the evaluation index system of on-street parking efficiency. Secondly, an evaluation method of the entropy weight Critic-Topsis model was proposed based on the data characteristics of the evaluation index of on-street parking efficiency. The entropy weight method and Critic method were employed to calculate the weight of each index, and then the improved topsis model was utilized to quantitatively evaluate the parking lots. Finally, this model was utilized to analyze the data of 10 on-street parking lots in Beijing, resulting in the evaluation results and rankings for each parking lot. It is found that in the evaluation index system of on-street parking efficiency, the number of parking spaces, the utilization rate of parking spaces, and the remaining width of the road have significant influences on the evaluation results, with weights of 22.99%, 13.72%, and 13.71% respectively. In the case analysis of 10 on-street parking lots in Beijing, higher scores are observed for on-street parking lots such as Gongti East Road, Keyuan Road, and Huayuan North Road, which are 0.659 4, 0.611 3, and 0.608 1, respectively. Moreover, relevant suggestions and optimization measures are provided for the on-street parking lots of Chunhe Road and Lingnan Road, which have lower scores, aiming to enhance the long-term management system of urban on-street parking and improve the level of urban traffic management.