Patent-based technological developments and surfactants application of lithium-ion batteries fire-extinguishing agent

While newer,more efficient Lithium-ion batteries(LIBs)and extinguishing agents have been developed to reduce the occurrence of thermal runaway accidents,there is still a scarcity of research focused on the application of surfactants in different LIBs extinguishing agents,particularly in terms of patented technologies.The aim of this review paper is to provide an overview of the technological progress of LIBs and LIBs extinguishing agents in terms of patents in Korea,Japan,Europe,the United States,China,etc.The initial part of this review paper is sort out LIBs technology development in different regions.In addition,to compare LIBs extinguishing agent progress and challenges of liquid,solid,combination of multiple,and microencapsulated.The subsequent section of this review focuses on an in-depth analysis dedicated to the efficiency and challenges faced by the surfactants corresponding design principles of LIBs extinguishing agents,such as nonionic and anionic surfactants.A total of 451,760 LIBs-related patent and 20 LIBs-fire-extinguishing agent-related patent were included in the analyses.The extinguishing effect,cooling performance,and anti-recombustion on different agents have been highlighted.After a comprehensive comparison of these agents,this review suggests that temperature-sensitive hydrogel extinguishing agent is ideal for the effective control of LIBs fire.The progress and challenges of surfactants have been extensively examined,focusing on key factors such as surface activity,thermal stability,foaming properties,environmental friendliness,and electrical conductivity.Moreover,it is crucial to emphasize that the selection of a suitable surfactant must align with the extinguishing strategy of the extinguishing agent for optimal firefighting effectiveness.

Study on thermal decomposition kinetics of azobenzene-4,4′-dicarboxylic acid by using compensation parameter method and nonlinear fitting evaluation

Recently,azobenzene-4,4'-dicarboxylic acid(ADCA)has been produced gradually for use as an organic synthesis or pharmaceutical intermediate due to its eminent performance.With large quantities put into application in the future,the thermal stability of this substance during storage,transportation,and use will become quite important.Thus,in this work,the thermal decomposition behavior,thermal decomposition kinetics,and thermal hazard of ADCA were investigated.Experiments were conducted by using a SENSYS evo DSC device.A combination of differential iso-conversion method,compensation parameter method,and nonlinear fitting evaluation were also used to analyze thermal kinetics and mechanism of ADCA decomposition.The results show that when conversion rate α increases,the activation energies of ADCA's first and main decomposition peaks fall.The amount of heat released during decomposition varies between 182.46 and 231.16 J·g^(-1).The proposed kinetic equation is based on the Avrami-Erofeev model,which is consistent with the decomposition progress.Applying the Frank-Kamenetskii model,a calculated self-accelerating decomposition temperature of 287.0℃is obtained.

Experimental crushing behavior and energy absorption of angular gradient honeycomb structures under quasi-static and dynamic compression

The high variability of shock in terrorist attacks poses a threat to people's lives and properties,necessitating the development of more effective protective structures.This study focuses on the angle gradient and proposes four different configurations of concave hexagonal honeycomb structures.The structures'macroscopic deformation behavior,stress-strain relationship,and energy dissipation characteristics are evaluated through quasi-static compression and Hopkinson pressure bar impact experiments.The study reveals that,under varying strain rates,the structures deform starting from the weak layer and exhibit significant interlayer separation.Additionally,interlayer shear slip becomes more pronounced with increasing strain rate.In terms of quasi-static compression,symmetric gradient structures demonstrate superior energy absorption,particularly the symmetric negative gradient structure(SNG-SMS)with a specific energy absorption of 13.77 J/cm~3.For dynamic impact,unidirectional gradient structures exhibit exceptional energy absorption,particularly the unidirectional positive gradient honeycomb structure(UPG-SML)with outstanding mechanical properties.The angle gradient design plays a crucial role in determining the structure's stability and deformation mode during impact.Fewer interlayer separations result in a more pronounced negative Poisson's ratio effect and enhance the structure's energy absorption capacity.These findings provide a foundation for the rational design and selection of seismic protection structures in different strain rate impact environments.

Small-scale area survey and analysis of Xinjiang's coal field fire in China

In this paper, Xinjiang＇s coal field is selected as the investigation area. Through a series of field surveys in Xinjiang, we made the small-scale area analysis of coal field fire using the ground remote sensing technique, and presented the reasonable evaluation of thermal anomaly conditions of Xinjiang＇s coal field arising from coal self-ignition fires. The results show that the method of small-scale area analysis is available for examining the extinguished actuality of coal fires and detecting fire spots. Therefore, for the selected fire-extlngulshed coal field in Xinjiang, the fire extinguishing effect was effectively analyzed by the means, and the new hidden thermal dangers were sought and diagnosed. For the coal field where the fire has not been extinguished, the utilization of this means approximately identified the severity and range of the fire area, and provided the quantitative and ground references for extinguish engineering.

Modeling and analysis of a catastrophic oil spill and vapor cloud explosion in a confined space upon oil pipeline leaking

Oil spill-induced vapor cloud explosions in a confined space can cause catastrophic consequences.In this work,investigation was conducted on the catastrophic pipeline leak,oil spill,and the resulting vapor cloud explosion accident occurring in China in 2013 by modeling analysis,field surveys,and numerical simulations.The total amount of the spilled oil was up to2044.4 m3 due to improper disposal.The long residence time of the oil remaining in a confined space permitted the formation of explosive mixtures and caused the vapor cloud explosion.A numerical model was developed to estimate the consequence of the explosion based on volatilization testing results.The results show that the death-leading zone and the glass-breaking zone could be 18 m and 92 m,respectively,which are consistent with the field investigation.The severity of the explosion is related to the amount of the oil spill,properties of oil,and volatilization time.It is recommended that a comprehensive risk assessment be conducted to analyze the possible consequences upon oil spilling into a confined space.Prompt collection and ventilation measures should be taken immediately after the spill occurs to reduce the time for oil volatilization and prevent the mixture from reaching its explosive limit.

Investigation of stability of a tunnel in a deep coal mine in China

Stability level of tunnels that exist in an underground mine has a great influence on the safety,production and economic performance of mines.Ensuring of stability for soft-rock tunnels is an important task for deep coal mines located in high in situ stress conditions.Using the available information on stratigraphy,geological structures,in situ stress measurements and geo-mechanical properties of intact rock and discontinuity interfaces,a three-dimensional numerical model was built by using 3DEC software to simulate the stress conditions around a tunnel located under high in situ stress conditions in a coal rock mass in China.Analyses were conducted for several tunnel shapes and rock support patterns.Results obtained for the distribution of failure zones,and stress and displacement felds around the tunnel were compared to select the best tunnel shape and support pattern to achieve the optimum stability conditions.

Safety assessment of waste rock dump built on existing tailings ponds

The construction of waste rock dumps on existing tailing ponds has been put into practice in China to save precious land resources. This work focuses on the safety assessment of the Daheishan molybdenum mine waste rock dump under construction on two adjoining tailings ponds. The consolidation of the tailings foundation and the filling quality of the waste rock are investigated by the transient electromagnetic method through detecting water-rich areas and loose packing areas, from which, the depth of phreatic line is also estimated. With such information and the material parameters, the numerical method based on shear strength reduction is applied to analyzing the overall stability of the waste rock dump and the tailings ponds over a number of typical cross sections under both current and designed conditions, where the complex geological profiles exposed by site investigation are considered. Through numerical experiments, the influence of soft lenses in the tailings and possible loose packing areas in the waste rock is examined. Although large displacements may develop due to the soft tailings foundation, the results show that the waste rock dump satisfies the safety requirements under both present and designed conditions.

Present State of Explosion Seismic Wave Research and Primary Investigation on Its Characteristics

The present state and the significance of research on explosion seismic waves are discussed, and meanwhile the main contents and the basic problems to be solved in the study of explosion seismic waves are analyzed. The spectra characteristics of explosion seismic waves, functions of the isolated-seismic grooves and influences of the detonating methods on explosion seismic waves are investigated by experiments. The experimental method is introduced. Some experimental results are presented which are concerned with the influences of topographical conditions, explosive charges, ignition patterns, isolated-seismic grooves and the other related factors on the characteristics of seismic waves.

Plasma membrane-anchored fluorescent tracker based on boron-dipyrromethene

The construction of a stable-membrane tracker has significant implications for the visualization of the membrane in live cells.However,most current plasma trackers are not suitable for tracking plasma membranes for a long time due to their limited retention time.Herein,Mem580-F-Sulfo is designed to target and anchor cell membranes and therefore track cell membranes for a longer time.This tracker is composed of a lipophilic boron-dipyrromethene(BODIPY)derivative and a hydrophilic zwitterion to form an amphiphilic structure,which enables its targeting ability toward cell membranes.Moreover,a reactive ester group is included to bind with proteins through covalent bonds in cell membranes nonspecifically,which extends retention time in cell membranes.Mem580-F-Sulfo shows intense brightness(94600),with a high molar absorption coefficient of up to about 100000 L·mol^(-1)·cm^(-1)and a fluorescence quantum yield of up to 0.97.It shows fast cell membrane targeting ability and long retention up to 90 min.In brief,this work has not only developed a tracker with good cell membrane targetability but also provided a new strategy for improving the targeting stability of cell membranes.

Stress analysis on large-diameter buried gas pipelines under catastrophic landslides

This paper presents a method for analysis of stress and strain of gas pipelines under the effect of horizontal catastrophic landslides. A soil spring model was used to analyze the nonlinear characteristics concerning the mutual effects between the pipeline and the soil. The Ramberg–Osgood model was used to describe the constitutive relations of pipeline materials. This paper also constructed a finite element analysis model using ABAQUS finite element software and studied the distribution of the maximum stress and strain of the pipeline and the axial stress and strain along the pipeline by referencing some typical accident cases. The calculation results indicated that the maximum stress and strain increased gradually with the displacement of landslide.The limit values of pipeline axial stress strain appeared at the junction of the landslide area and non-landslide area. The stress failure criterion was relatively more conservative than the strain failure criterion. The research results of this paper may be used as a technical reference concerning the design and safety management of large-diameter gas pipelines under the effects of catastrophic landslides.

Effect of inlet area on the performance of a two-stage cyclone separator

The cyclone separator is an important separation device.This paper presents a new type of embedded two-stage cyclone,which includes a 2 nd-stage cyclone(internal traditional cyclone)with multiple inlets and a 1 st-stage cyclone(outer cylinder)that unifies the 2 nd-stage cyclone inlets into one inlet.The Taguchi experimental method was used to study the two-stage cyclone separator’s inlet area on its performance.Studies have shown that the increase of the 1 st-stage cyclone inlet area and the increase in the number of 2 nd-stage cyclone inlets(N)positively affect reducing the pressure drop and a negative effect on efficiency.It is recommended to use 2 S(the original 1 st-stage cyclone inlet area)of the 1 st-stage cyclone inlet area and 2 N of the 2 nd-stage cyclone inlets when separating fine particles.Compared with a traditional cyclone,the pressure drop is reduced by 1303 Pa,the mass separation efficiency(Eq)is increased by 0.56%,and the number separation efficiency(En)is increased by 2.05%.When separating larger particles,it is recommended to use 2 S of the 1 st-stage cyclone inlet area and 4 N of the 2 nd-stage cyclone inlets.Compared with a traditional cyclone,although Endecreases slightly,the pressure drop is reduced by 3055 Pa,and the Eqis increased by 0.56%.The research results provide new insight into the design of the cyclone.

Some improvements of the marching cubes algorithm for the rendering of an orebody

Orebody-rendering techniques are developed using the marching cubes (MC) algorithm. The shape of an orebody is viv- idly displayed in real time and can be used to guide mining design as well. The MC algorithm has been improved in two aspects. By analyzing the principles of the MC algorithm, as well as the features of the specific application, improvements were developed to: eliminate ambiguities by using a unified isosurface constructing method in the voxels, and improve the operating efficiency of the MC algorithm by incorporating an octree structure. The analytical results of the examples demonstrate the effectiveness of our proposal.

Simulation of three-dimensional tension-induced cracks based on cracking potential function-incorporated extended finite element method

In the finite element method,the numerical simulation of three-dimensional crack propagation is relatively rare,and it is often realized by commercial programs.In addition to the geometric complexity,the determination of the cracking direction constitutes a great challenge.In most cases,the local stress state provides the fundamental criterion to judge the presence of cracks and the direction of crack propagation.However,in the case of three-dimensional analysis,the coordination relationship between grid elements due to occurrence of cracks becomes a difficult problem for this method.In this paper,based on the extended finite element method,the stress-related function field is introduced into the calculation domain,and then the boundary value problem of the function is solved.Subsequently,the envelope surface of all propagation directions can be obtained at one time.At last,the possible surface can be selected as the direction of crack development.Based on the aforementioned procedure,such method greatly reduces the programming complexity of tracking the crack propagation.As a suitable method for simulating tension-induced failure,it can simulate multiple cracks simultaneously.

Numerical study on the strain capacity of girth-welded X80 grade pipes

Strain capacity is an important performance indicator for designing and evaluating high-grade steel pipelines.Due to the inhomogeneity of material properties in welded structures,girth welds are one of the main factors that restrict the strain capacity of pipelines.In this paper,girth-welded pipes with cracks in the inner surface of the weld have been studied,and the ductile crack initiation and propagation behavior have been simulated using the Gurson model.The corresponding nominal strain at the onset of crack initiation was defined as the characteristic value of strain capacity.The influencing factors on the strain concentration area,strain concentration factor,and strain capacity of girth-welded pipes were quantitatively analyzed.A semiempirical calculation formula for the strain capacity of typical girthwelded X80 grade pipes has been proposed as a function of the crack size,mismatch coefficient of the weld,and softening degree of the heat affected zone(HAZ).This study can facilitate the defect assessment of girth-welded pipes.

Acoustic emission parameters and energy dissipation law of cyclic load and unload damage of dihydrate gypsum under different loading rate

In order to explore the effect of loading rate on physical and mechanical properties of dihydrate gypsum,cyclic loading and unloading mechanical tests were carried out at different loading rates.Test results were analyzed from the aspects of stress-strain curve,energy distribution mode,damage law and failure mode of specimen.The main research results obtained in the thesis are as follows:with the increase of the loading rate,the peak value of specimen damage first increases rapidly,and then in-creases slowly,and there is a damage threshold.In the early stage of loading,the dissipated energy of the specimen accounts for about 70%of the total energy,most of the total energy input is converted into dissipated energy.The elastic energy density shows an increasing trend with the increase of the loading rate.The elastic energy density is the highest when the loading rate is 400 N/s,and more elastic energy can be stored.The ratio of elastic energy ue/u increases with the in-crease of loading rate and tends to be stable.The acoustic emission data show that the acoustic emission signals present a certain agglomeration phenomenon at the unloading point,and there is a“blank period”between the unloading point and the emergence of the next acoustic emission activity.In the early stage of specimen loading,friction-type acoustic emission is mainly generated.The cumulative ringing count when the load reaches the peak failure stress at low loading rate is more,indicating that low loading rate will produce more acoustic emission activities.With the increase of loading rate,the cumulative ringing number per unit time increases,indicating that the increase of loading rate accelerates the damage and failure of dihydrate gypsum near the peak value.The failure mode of gypsum specimens is shear failure,and the increase of loading rate of shear failure angle shows an increasing trend.The larger the loading rate is,the higher the strength of the specimen is.The more energy the press inputs during the loading process,the higher the energy absorbed by the unit volume specimen,which aggravates the development,expansion and penetration of the internal cracks of the specimen,resulting in the larger shear angle of the specimen.The test results provide a more comprehensive theoretical basis for the study of damage characteristics of dihydrate gypsum during cyclic loading and unloading.

The regulatory roles of DDIT4 in TDCIPP-induced autophagy and apoptosis in PC12 cells

Tris(1,3-dichloro-2-propyl) phosphate(TDCIPP) is a commonly used organophosphatebased flame retardant and can bio-accumulate in human tissues and organs. As its structure is similar to that of neurotoxic organophosphate pesticides, the neurotoxicity of TDCIPP has raised widespread concerns. TDCIPP can increase neuronal apoptosis and induce autophagy.However, its regulatory mechanism remains unclear. In this study, we found that the expression upregulation of the DNA Damage-Inducible Transcript 4(DDIT4) protein, which might play essential roles in TDCIPP-induced neuronal autophagy and apoptosis, was observed in TDCIPP-treated differentiated rat PC12 cells. Furthermore, we determined the protective effect of the DDIT4 suppression on the autophagy and apoptosis induced by TDCIPP using Western blot(WB) and Flow cytometry(FACS) analysis. We observed that TDCIPP treatment increased the DDIT4, the autophagy marker Beclin-1, and the microtubule-associated protein light chain 3-II(LC_(3)II) expressions and decreased the mTOR phosphorylation levels. Conversely, the suppression of DDIT4 expression increased the p-mTOR expression and decreased cell autophagy and apoptosis. Collectively, our results revealed the function of DDIT4 in cell death mechanisms triggered by TDCIPP through the m TOR signaling axis in differentiated PC12 cells. Thus, this study provided vital evidence necessary to explain the mechanism of TDCIPP-induced neurotoxicity in differentiated PC12 cells.

Rock burst risk evaluation based on equivalent surrounding rock strength

On-site investigations consistently show that the rock burst inherent to coal seams varies greatly with coal seam thickness.In this study,impact factors related to coal seam thickness and surrounding rock strength were analyzed and a corresponding rock burst risk assessment method was constructed.The model reflects the influence of coal seam thickness on the stress distribution of surrounding rock at the roadway.Based on the roadway excavation range,a stress distribution model of surrounding roadway rock is established and the influence of coal seam thickness on rock burst risk is analyzed accordingly.The proposed rock burst risk assessment method is based on the equivalent surrounding rock strength and coal seam bursting liability.The proposed method was tested in a 3500 mining area to find that it yields rock burst risk assessment results as per coal seam thickness that are in accordance with real-world conditions.The results presented here suggest that coal seam thickness is a crucial factor in effective rock burst risk assessment.

On the possible use of fire by Homo erectus at Zhoukoudian,China

For decades,the so-called Peking Man(Homo erectus pekinensis)at Zhoukoudian has been considered to be a hominin that engaged in the controlled production and management of fire.However,relatively recent analyses have cast doubt on this assertion.The most compelling reason for this doubt was the absence of siliceous aggregates in the Zhoukoudian deposits.This study presents evidence establishing the controlled use of fire by Homo erectus pekinensis through analyses of four soil samples sourced from Layers 4 and 6 at Zhoukoudian Locality 1.These results demonstrate that all four specimens contain siliceous aggregates as well as elemental carbon,and the potassium content of the insoluble residues of these specimens ranges between 1.21%and 2.94%.The analyses provide strong evidence of the in situ use of fire by Homo erectus pekinensis.

Interaction between local corrosion and flow field of natural gas long-distance pipeline by artificial rectangular defect pit

The corrosive environment in long-distance natural gas pipeline was simulated by the online high shear stress flow test platform.The interaction between flow fields and local corrosion in different local corrosion stages was studied by machining different depths rectangular defect pit(RDP)on X80 pipe steel specimens.The electrochemical signals of each specimen under high shear stress flow were measured online using an integrated three-electrode and electrochemical system.Raman spectroscopy confirmed that the corrosion scale of X80 pipeline steel in CO_(2)-saturated National Association of Corrosion Engineers solution was composed of FeCO_(3).The scanning electron microscope images displayed variations in microstructure of the corrosion scale at different RDP depths and different areas.The flow field fluctuations induced by RDP were analyzed by computational fluid dynamics simulations and the development of local corrosion pits was discussed in terms of integrity of corrosion scale,convective mass transfer,and diffusion mass transfer.

A Novel Web Query Automatic Expansion Based on Rough Set

One of important reasons caused low precision was presented, which was due to inaccurate express of the query. So a new method of automatic query expansion based on tolerance rough was put forward. In the algorithm, the uncertain connection between query terms and retrial documents was described as term tolerance class. The upper approximation set of query sentence was considered as query expansion. The new additional terms were also given weight numbers. The results of experiment on collection of Google 5 000 Web pages showed that the approach was effective on query expansion and high search precision was gained.