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Abstract Coal pitch, an important by-product in the coal coking industry with a high output, is a low-cost and high-carbon yield precursor for the manufacturing of high-value carbon materials. Herein, N/O co-doped carbon fiber (CFCP), fabricated by electrospinning using pre-oxidized coal pitch as the precursor, was employed as the sulfur host for Li-S batteries. The presence of more pyrrolic N and graphic N in CFCP than carbon fiber made from polyacrylonitrile benefits the adsorption of lithium polysulfide and the battery’s life. Sulphur-CFCP cathode (S@CFCP) exhibited excellent specific capacity and cyclability, with a specific capacity of 701.1 mAh/g and a low capacity decay rate of 0.088% per cycle over 200 cycles at 2.0 C, respectively. The high ion diffusion rate, low charge transfer resistance, and effective conversion of lithium polysulfides enable the high electrochemical performance of S@CFCP.

To achieve a balanced combination of high strength and high plasticity in high-strength low-alloy (HSLA) steel through a hot-rolling process, post-heat treatment is essential. The effects of post-roll air cooling and oil quenching and subsequent tempering treatment on the microstructure and mechanical properties of HSLA steels were investigated, and the relevant strengthening and toughening mechanisms were analyzed. The microstructure after hot rolling consists of fine martensite and/or bainite with a high density of internal dislocations and lattice defects. Grain boundary strengthening and dislocation strengthening are the main strengthening mechanisms. After tempering, the specimens’ microstructures are dominated by tempered martensite, with fine carbides precipitated inside. The oil-quenched and tempered specimens exhibit tempering performance, with a yield strength (YS) of 1410.5 MPa, an ultimate tensile strength (UTS) of 1758.6 MPa, and an elongation of 15.02%, which realizes the optimization of the comprehensive performance of HSLA steel.

Forest fires are characterized by hidden ignition points, rapid spread, large burning areas, intense flames, and significant influence from meteorological conditions. Due to the complexity of terrain and surrounding environments, conventional firefighting equipment often struggles to reach the core ignition areas from the ground, greatly increasing the difficulty and cost of forest fire prevention and control. Fire suppression munition, due to their ability to control fires at medium and long distances, are commonly used in the field of forest firefighting. This paper conducts research and experiments on the development of new fire suppression munition after analyzing the advantages and disadvantages of current fire suppression munition, aiming to effectively suppress forest fires. Through experiments, it was found that the fire suppression aerial munition were stable and reliable throughout the entire test process. The dispersal range and concentration of the fire suppressant after explosion met the expected requirements. Good suppression effects were achieved in field tests on large ground fires and crown fires, with flames being extinguished and no reignition occurring within 10 min.

Abstract Background Thoracic aortic aneurysm or dissections (TAADs) represent a group of life-threatening diseases. Genetic aetiology can affect the age of onset, clinical phenotype, and timing of intervention. We conducted a prospective trial to determine the prevalence of pathogenic variants in TAAD patients and to elucidate the traits related to harbouring the pathogenic variants. One hundred and one unrelated TAAD patients underwent genetic sequencing and analysis for 23 TAAD-associated genes using a targeted PCR and next-generation sequencing-based panel. Results A total of 47 variants were identified in 52 TAAD patients (51.5%), including 5 pathogenic, 1 likely pathogenic and 41 variants of uncertain significance. The pathogenic or likely pathogenic (P/LP) variants in 4 disease-causing genes were carried by 1 patient with familial and 5 patients with sporadic TAAD (5.9%). In addition to harbouring one variant causing familial TAAD, the FBN1 gene harboured half of the P/LP variants causing sporadic TAAD. Individuals with an age of onset less than 50 years or normotension had a significantly increased genetic risk. Conclusions TAAD patients with a younger age at diagnosis or normotension were more likely to carry a P/LP variant; thus, routine genetic testing will be beneficial to a better prognosis through genetically personalized care prior to acute rupture or dissection.

Suppression of forest fires has been one of the important research directions in the field of fire safety, ammonium phosphate and its mixture of inhibitors commonly used in solid combustible fires, for forest fire scenarios, also has a good fire suppression effectiveness, inexpensive and easy to store, but also the current suppression of forest fires is one of the main inhibitors. However, there are few studies on the interaction between ammonium phosphate and forest fires. In this paper, to facilitate the study, we enter the previous research ideas for gas fires, reduce the scale of the research object, establish a small-sized simplified flame model for suppressing wood fires, take red pine wood as the research object, analyze the pyrolysis gas components after high-temperature pyrolysis, and construct the Cup-burner experimental system, together with an improved powder delivery control system, so that the process of NH4H2PO4 powder quenching fuel flames such as red pine pyrolysis gas at 350 °C, 450 °C and 550 °C was well presented on this device. It was found that the flame morphology was not only related to the gas composition but also the amount of NH4H2PO4 powder added and the particle size; the Minimum fire extinguishing concentration(MEC) value was not only related to the gas composition but also the particle size of NH4H2PO4 powder. This is because the CO2 content decreases and the H2 and CH4 content increase significantly in the gas composition at 550 °C compared to the 450 °C gas composition. Among the same pyrolysis gas components, the MEC value gradually increased as the particle size of NH4H2PO4 powder decreased, and the MEC value of 30 μm–40μm particle size powder was the lowest, and the difference between the particle size MEC value and the other two particle sizes was large, while the difference between the MEC values of 20 μm–30μm particle size powder and 10 μm–20μm particle size powder was small; according to the Cup-burner test The chemical thermodynamic analysis was carried out according to the results of the Cup-burner test to obtain the proportion of NH4H2PO4 powders playing a physical role in fire extinguishing. When NH4H2PO4 powder is involved in syngas/air combustion, the end product is P2O5 and xsp = 2.35%. When the end product is HPO3, xsp = 7.29%. The products were collected after the interaction of NH4H2PO4 powder with the synthesis gas flame, and the analysis of the products revealed that the products were sticky and not dry solids, and the material analysis of them revealed that they contained more HPO3 and its mixture, which shows that the physical heat absorption played a greater role when NH4H2PO4 powder interacted with the synthesis gas flame.

In combustion research, the laminar flame speed (SL) is an important basis for the study of fuel combustion and mechanism verification. A large number of studies have been done on various combustibles, mostly focusing on gas and liquid combustibles, but less on solid combustibles, and the SL of solid combustibles cannot be measured directly and effectively by conventional methods. This paper uses red pine wood as the object of study, analyses the pyrolysis gas components after high-temperature pyrolysis, and uses the Bunsen burner experimental system to study the SL of pyrolysis gas, and obtains the laminar flame speed (SL) of the gas-phase flame when burning red pine wood, which has certain guiding significance for the study of the laminar flame speed (SL) of solid combustibles. In this paper, firstly, the pyrolysis gas products of red pine wood were analyzed by TG-DSC as well as GC/MS, and it was found that the direct reaction was the most violent at 210°C–410 °C, and the reaction rate gradually levelled off after 410 °C. It was also found that the gas mainly consisted of H2, CO2, C2H4, CO, CH4, C2H6, C3H6 and C3H8, accounting for more than 98%, and with the pyrolysis Secondly, the laminar flame speed (SL) of the gas products was investigated using the Bunsen burner, and it was found that the laminar flame speed (SL) of the pyrolysis gases gradually increased with the increase of the pyrolysis temperature, with 15.7 cm-s−1, 32.94 cm-s−1 and 36.89 cm-s−1 for the pyrolysis gases at 350 °C, 450 °C and 550 °C, respectively Finally, numerical simulations were carried out to investigate the effects of initial temperature and altitude induced changes in air pressure and oxygen concentration on the laminar flame speed of the gas products, and it was found that the laminar flame speed of pyrolysis gases gradually increased with increasing initial temperature and decreased with increasing altitude. The effect of hydrocarbon gases on the SL-max of CH4 is essentially linear in the concentration range of 40%, while the effect of H2, CO and CO2 is essentially in the quadratic polynomial distribution.

The suppression of forest fires has been one of the important research directions in the field of fire safety, fine water mist because of the advantages of easy access to materials, low price and no pollution to become one of the commonly used inhibitors to suppress forest fires, so previous research done for fine water mist suppression of forest fires, mostly for the macro level of fire suppression effectiveness and methodological research, for fine water mist and forest fire interaction mechanism research is less, this paper for the convenience of research, the In this paper, to facilitate the study of red pine wood as the research object, after high temperature pyrolysis analysis of pyrolysis gas components, the construction of fine water mist suppression of red pine wood pyrolysis gas flame Bunsen burner experimental system, study the effect of different additions of fine water mist on the laminar flame speed (SL) of red pine wood pyrolysis gas flame, and the use of chemkin software to study the mechanism of interaction between fine water mist and red pine wood pyrolysis gas flame, on the study of the interaction between fine water mist and red pine pyrolysis gas flames using chemkin software has some implications for the suppression of forest fires. In this paper, the pyrolysis gas products of red pine wood were firstly analysed by TG-DSC as well as GC/MS and found to consist mainly of H2, CO2, C2H4, CO, CH4, C2H6, C3H6 and C3H8, accounting for more than 98% of the gases. The Bunsen burner experimental system constructed for the suppression of red pine pyrolysis gas flames by fine water mist revealed that the flame height gradually increased with increasing fine water mist addition and the flame cone angle gradually decreased, indicating that the flame speed was gradually decreasing with increasing fine water mist addition. It was observed that the flame height did not change significantly at low equivalents as the amount of extinguishing agent added increased, indicating that the fine water mist had a weak pro-ignition effect on the red pine pyrolysis gas/air system. The influence of the gas content on the flame promotion effect of the fine water mist was investigated by chemkin software. It was found that the ratio of CO/H2 in the pyrolysis gas composition of red pine wood will determine the strength of the combustion promoting effect of the fine water mist in the interaction with the pyrolysis gas flame, the higher the ratio of CO/H2, the stronger the combustion promoting effect of the fine water mist in the interaction with the pyrolysis gas flame, and conversely the lower the ratio, the weaker the combustion promoting effect of the fine water mist in the interaction with the pyrolysis gas flame.

A ZK61-Y magnesium (Mg) alloy wheel hub was prepared via liquid forging—isothermal forging process. The effects of Y-element contents on the microstructure and mechanical properties of liquid forging blanks were investigated. The formation order of the second phase was I-phase (Mg3Zn6Y) → W-phase (Mg3Zn3Y2) → Z-phase (Mg12ZnY) with the increase of the Y-element content. Meanwhile, the I-phase and Z-phase formed in the liquid forging process were beneficial to the grain refinement. The numerical simulation of the isothermal forging process was carried out to analyze the effects of forming temperature on the temperature and stress field in the forming parts using the software Deform-3D. Isothermal forging experiments and post heat treatments were conducted. The influence of isothermal forging temperature, heat treatment temperature and preservation time on the microstructure and mechanical properties of the forming parts were also studied. The dynamic recrystallization (DRX), second-phase hardening, and work hardening account for the improvement of properties after the isothermal forging process. The forming part forged at 380 °C displayed the outstanding properties. The elongation, yield strength, and ultimate tensile strength were 18.5%, 150 MPa and 315 MPa, respectively. The samples displayed an increased elongation and decreased strength after heat treatments. The 520 °C—1 h sample possessed the best mechanical properties, the elongation was 25.5%, the yield stress was 125 MPa and the ultimate tensile strength was 282 MPa. This can be ascribed to the recrystallization and the elimination of working hardening. Meanwhile, the second phase transformation (I-phase → W-phase → Mg2Y + MgZn2), dissolution, and decomposition can be observed, as well.

A quantitative feeding system of molten metal was designed based on a special vehicle cover, which achieved the quantitative transport of molten metal in a fully enclosed environment. There are lots of advantages of this novel device, such as improving the accuracy of the molten metal pouring, reducing the oxide inclusions defects, improving the quality of forming parts, etc. The numerical simulation of the casting process of filling mold was carried out based on the software ProCAST, which optimized the processing parameters of the quantitative feeding device. The result shows that the optimal movement speed of the punch piston is 0.08 m/s. The forming process of the aluminum alloy cover was designed and the process was conducted on the novel quantitative feeding device of molten metal. The structure and process performance of the forming parts were summarized and the defects were analyzed. The influence of technological parameters such as pouring temperature, filling speed, initial mold temperature, and feeding distance on the quality of forming parts was studied, which resulted in the optimum process parameters for the dosing device.

This paper presents a single-degree-of-freedom energy optimization strategy to solve the energy management problem existing in power-split hybrid electric vehicles (HEVs). The proposed strategy is based on a quadratic performance index, which is innovatively designed to simultaneously restrict the fluctuation of battery state of charge (SOC) and reduce fuel consumption. An extended quadratic optimal control problem is formulated by approximating the fuel consumption rate as a quadratic polynomial of engine power. The approximated optimal control law is obtained by utilizing the solution properties of the Riccati equation and adjoint equation. It is easy to implement in real-time and the engineering significance is explained in details. In order to validate the effectiveness of the proposed strategy, the forward-facing vehicle simulation model is established based on the ADVISOR software (Version 2002, National Renewable Energy Laboratory, Golden, CO, USA). The simulation results show that there is only a little fuel consumption difference between the proposed strategy and the Pontryagin’s minimum principle (PMP)-based global optimal strategy, and the proposed strategy also exhibits good adaptability under different initial battery SOC, cargo mass and road slope conditions.

OBJECTIVE: Acute kidney injury (AKI) in patients hospitalized for acute heart failure (AHF) is usually type 1 of the cardiorenal syndrome (CRS) and has been associated with increased morbidity and mortality. Early recognition of AKI is critical. This study was to determine if the new KDIGO criteria (Kidney Disease: Improving Global Outcomes) for identification and short-term prognosis of early CRS type 1 was superior to the previous RIFLE and AKIN criteria. METHODS: The association between AKI diagnosed by KDIGO but not by RIFLE or AKIN and in-hospital mortality was retrospectively evaluated in 1005 Chinese adult patients with AHF between July 2008 and May 2012. AKI was defined as RIFLE, AKIN and KDIGO criteria, respectively. Cox regression was used for multivariate analysis of in-hospital mortality. RESULTS: Within 7 days on admission, the incidence of CRS type 1 was 38.9% by KDIGO criteria, 34.7% by AKIN, and 32.1% by RIFLE. A total of 110 (10.9%) cases were additional diagnosed by KDIGO criteria but not by RIFLE or AKIN. 89.1% of them were in Stage 1 (AKIN) or Stage Risk (RIFLE). They accounted for 18.4% (25 cases) of the overall death. After adjustment, this proportion remained an independent risk factor for in-hospital mortality [odds ratios (OR)3.24, 95% confidence interval(95%CI) 1.97-5.35]. Kaplan-Meier curve showed AKI patients by RIFLE, AKIN, KDIGO and [K(+)R(-)+K(+)A(-)] had lower hospital survival than non-AKI patients (Log Rank P

Cell-to-pack (CTP) NCM lithium battery cell has been widely applied in electric vehicles (EVs). However, severe heat generation issue significantly affects its safety and wide application. To analyze and solve the severe heat generation issue of large capacity CTP NCM523 (LiNi0.5Co0.2Mn0.3O2) lithium battery cell, internal temperature detection is carried out through thermocouple insertion, the peak temperature value of the internal rolled cell is proved to be about 2°C and 5°C higher than the temperature value of the external surface under 1/3 C and 1 C discharging, respectively. The relationship between the temperature rising trend and the internal resistance during the charging and discharging has also been found: with a lower state of charge level, the heat generation rate increases, and the peak temperature value occurs at the end of discharging process. Furthermore, a precise battery cell model considering the thermo-physical properties' difference of the battery casing and the internal rolled cell is proposed based on the internal temperature measurement in simulation and numerical calculation, closer to the real heat generation and conduction condition. Finally, the thermal performance of a side plate-based battery thermal management system is investigated through numerical calculation and simulation, the maximum temperature and temperature SD of the battery module under 1 C discharging for 3454 seconds are proved to be decreased by 0.7 K without any supplementary energy cost and coolant devices. Besides, the temperature uniformity of the battery module can be reduced to 0.51°C through the design. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) organic–inorganic hybrid perovskites (OIHPs) have drawn increased attention due to rich physical properties such as ferroelectricity and photovoltaic properties. Nevertheless, it is challenging to discover novel 2D OIHPs within the vast chemical composition space. Herein, a diagrammatic machine learning model was employed to improve this issue. We collected 179 OIHPs with a variety of organic cations and screened out 6 features from 10,622 descriptors. Subsequently, a decision tree model was created to predict the dimensionality of OIHPs, achieving a LOOCV accuracy of 0.94 and a test accuracy of 0.89, respectively. Then, one candidate from a virtual space with 8256 samples was successfully synthesized, which was consistent with the prediction of the model. Finally, three rules were produced by visualization of the tree structure to generally discriminate 2D from non-2D OIHPs. It is believed that the diagrammatic model has reliability in identifying 2D OIHPs and will serve further property studies of OIHPs in the future.

Aim of this study was to investigate influence of heat transfer coefficient of fireworks and crackers on thermal explosion, critical ambient temperature and ignition time. It is proposed that heat transfer coefficient is power function of temperature, mathematical model to describe thermal explosion, steady-state and unsteady-state of finite cylindrical fireworks and crackers with complex shell structures are established. Models have been based on two-dimensional steady-state thermal explosion theory. The influence of variable heat transfer coefficient on thermal explosion critical ambient temperature and time to ignition are analyzed. When heat transfer coefficient is changing with temperature and in the condition of natural convection heat transfer, critical ambient temperature lessen, thermal explosion time to ignition shorten. If ambient temperature is close to critical ambient temperature, the influence of variable heat transfer coefficient on ignition time will be large. For firework with inner barrel, the critical ambient temperature of propellant is 463.88 K and ignition time is 4054.9 s. At ambient temperature 466 K, and with constant heat transfer coefficient critical temperature is 0.26 K lower and time to ignition 450.8 s less smaller. The calculation results show that the influence of variable heat transfer coefficient on thermal explosion time to ignition is greater in this example. Therefore, the effect of variable heat transfer coefficient should be considered into thermal safety evaluation of fireworks to reduce potential safety hazard. [ABSTRACT FROM AUTHOR]