This paper discusses the importance of standards in the fire extinguishing agent industry,and highlights the vital role of the standards in promoting technological innovation.China’s standards for fire extinguishing ...This paper discusses the importance of standards in the fire extinguishing agent industry,and highlights the vital role of the standards in promoting technological innovation.China’s standards for fire extinguishing agent products have evolved significantly,aligning with industrial development,market demands,regulatory requirements,to respond to the great impact of international competition in the industry.The paper analyzes the current state of China’s standards,including their composition and integration with industry growth,green development strategies,and international harmonization.Future development strategies for the standards framework should focus on valid period estimation,fire test model development,and raw material selection guidelines.By implementing these strategies,China’s fire protection industry can enhance product quality,contribute to public safety,and maintain a competitive edge in the global market.展开更多
Sodium metal batteries(SMBs)represent a promising alternative for large-scale energy storage and lowspeed electric vehicles,with resource-sustainable and cost-effective characteristics.However,its practical applicatio...Sodium metal batteries(SMBs)represent a promising alternative for large-scale energy storage and lowspeed electric vehicles,with resource-sustainable and cost-effective characteristics.However,its practical application is hindered by the high reactivity of sodium metal,interfacial and structural instability,and fire safety risks.Herein,a poly(1,3-dioxolane)(PDOL)crosslinked quasi-solid-state electrolyte(TPQSE)with fire extinguishing property and superior interface compatibility with sodium(Na)anodes and Na_(3)V_(2)(PO_(4))_(3)(NVP)cathodes is prepared via in situ polymerization at room temperature(RT),utilizing trimethylolpropane triglycidyl ether(TTE)as a crosslinker in coordination with ethoxy(pentafluoro)cyclotriphosphazene(PFPN).The crosslinked network of TPQSE and the distinct solvation properties of TPDOL and PFPN facilitate Na-ion desolvation while enhancing antioxidant stability of TPQSE.Moreover,multifunctional PFPN improves fire safety through condensed-phase dense char layer formation and gas-phase free radical capturing.It also constructs uniform,dense,and inorganic-rich interphases between electrodes and electrolytes,strengthening interfacial stability.Consequently,the prepared electrolyte exhibits high ionic conductivity(2.109 mS cm^(-1)at RT),high Na^(+)transference number(0.570),and extended electrochemical window to 4.805 V.The Na‖TPQSE‖Na symmetric cell presents impressive cycling stability over 4510 h,and the Na‖TPQSE‖NVP cell displays outstanding rate capability and stable long-term cycling(≥2300 cycles).This work provides a promising approach for developing safe and high-performance quasi-solid-state sodium metal batteries.展开更多
This study focuses on metaphorical terminology in scientific and technical texts,with reference to the English translation practice of a fire extinguisher product operation manual.The research demonstrates that the tr...This study focuses on metaphorical terminology in scientific and technical texts,with reference to the English translation practice of a fire extinguisher product operation manual.The research demonstrates that the translation methods for metaphorical terminology in fire extinguisher product manuals are crucial for Chinese products to gain international recognition.The English translation process must adhere to scientificity,rigor,and readability as fundamental principles,while adopting“literal translation”and“substitution translation”as the primary translation methods.Only by doing so can we facilitate the deep integration of Chinese products into international trade and promote their globalization.展开更多
To solve the problem of sealing between the barrel and the rubber ring of shell body during an launching process of aerodynamic extinguishing cannon, a rubber sealing model with bionic dimpled characteristics was esta...To solve the problem of sealing between the barrel and the rubber ring of shell body during an launching process of aerodynamic extinguishing cannon, a rubber sealing model with bionic dimpled characteristics was established based on the theory of bionic dimpled drag reduction and the principle of rubber sealing. In condition that the bionic dimpled characteristic diameters were 1, 2, 3, 4, and 5 mm, respectively, by numerical simulation, the influence of the installing compression of the rubber sealing ring on its surface stress and deformation was analyzed, and sealing performance of the rubber ring with different diameters of bionic dimpled was studied. The results show that the deformation of rubber ring appears prominent nonlinear characteristics when compression is increased from 1.5 mm to 2.5 ram. When the compression is 2.5 mm, the equivalent compression stress on the sealing areas of both sides of the rubber seal is greater than the working pressure of aerodynamic extinguishing cannon, which could meet the sealing requirement and would not cause leakage. So the rubber sealing ring with bionic dimpled surface possesses a good sealing characteristic and has no negative effect on the sealing of shell body; When the compression is 2.5 mm, the larger equivalent stress on the edge of sealing ring and the more even stress distribution in the high pressure area are generated due to the smaller compressive stress on the bionic dimple areas, which lays a foundation for the drag reduction characteristics of the shell body＇s rubber ring with bionic dimpled surface.展开更多
[Objective] This study was aimed to review the controlling experience of pine wilt disease in the past 25 years, explore the theories and methods of controlling pine wilt disease, and improve the scientific level of c...[Objective] This study was aimed to review the controlling experience of pine wilt disease in the past 25 years, explore the theories and methods of controlling pine wilt disease, and improve the scientific level of controlling techniques and the protection capacity of healthy pine trees. [Method] Eleven items of effects were used to refine the theory of clearing dead pine trees affected by pine wilt disease, namely, ＂1 priority＂, ＂2 objections＂, ＂3 principles＂, ＂4 measures＂, and ＂5 manage- ments＂. On the basis of comprehensive control and complete removal of the infect- ed pine trees, a variety of comprehensive and efficient controlling methods were developed to carry out targeted chemical ecology trapping, bionic pesticide killing and releasing natural enemies of Sclerodermus guani, Dastarcus helophoroides. High ef- ficient emamectin benzoate immune injection was developed to inject the healthy pine trees for prevention, so as to extinguish the pine wilt disease. [Result] The pine wilt disease dropped from the peak of 3.5 million dead trees with an infecting area of 28 273 hectares in 1999 to 0.068 million with an area of 4 333 hectares in 2012 gradually, reducing by 98.06% in number and 84.84% in area, respectively. On the basis of removal, Dastarcus helophoroides was also released, which could make the number of dead pines decrease more significantly than the control, and af- ter releasing for 5 consecutive years, the dead pine trees dropped to 0.511 plant/hm2 in 2012, with a mortality rate of 0.022 7%, which achieved the control effect, reaching extremely significant level. ＂Forest land removal＋infected trees isolation＋natural enemy release＂ could extinguish the pine wilt disease. The test of isolating 24 heaps of infected pine trees showed that there were 9 heaps of pine trees extinguished the pine wilt disease, which controlled the occurrence of pine wilt disease for 100%, accounting for 37.5% of the total, in which the number of those isolated using iron netting and nylon net were 4 for each, accounting for 88.9%, and there was one heap using polypropylene net, accounting for 11.1%. The invention of em- amectin benzoate immune injection laid the foundation for extinguishing pine wilt disease. The follow checking of the effects of emamectin benzoate immune injection on pine wilt disease found that the number of dead trees caused by pine wilt dis- ease decreased significantly after injecting, and became very small in October of the next year, and the disease was completely extinguished in the third year. [Conclusionl Pine wilt disease could be controlled and extinguished with positive control by using ＂comprehensive cleaning＋industrialized removal＂, ＂comprehensive cleaning＋ natural enemy release＂, ＂comprehensive cleaning＋infected trees isolation＋natural ene- my release＂ and ＂comprehensive cleaning＋emamectin benzoate immune＂.展开更多
In this study,a detailed analysis of the combustion behaviors of the lithium iron phosphate(LFP)and lithium manganese oxide(LMO)batteries used in electric bicycles was conducted.This research included quantitative mea...In this study,a detailed analysis of the combustion behaviors of the lithium iron phosphate(LFP)and lithium manganese oxide(LMO)batteries used in electric bicycles was conducted.This research included quantitative measurements of the combustion duration,flame height,combustion temperature,heat release rate,and total heat release.The results indicated that LMO batteries exhibited higher combustion temperatures of 600–700°C,flame heights of 70–75 cm,a significantly higher heat release rate of40.1 k W(12 Ah),and a total heat release of 1.04 MJ(12 Ah)compared to LFP batteries with the same capacity.Based on these experimental results,a normalized total heat release(NORTHR)parameter was proposed,demonstrating good universality for batteries with different capacities.Utilizing this parameter,quantitative calculations and optimization of the extinguishing agent dosage were conducted for fires involving these two types of batteries,and the method was validated by extinguishing fires for these two types of battery packs with water-based extinguishing fluids.展开更多
The dielectric barrier discharge(DBD)is presently used in many fields,in eluding plasma medicine,surface modification,and ozone synthesis;the influe nee of airflow on the DBD is a widely investigated topic.In this wor...The dielectric barrier discharge(DBD)is presently used in many fields,in eluding plasma medicine,surface modification,and ozone synthesis;the influe nee of airflow on the DBD is a widely investigated topic.In this work,a hysteresis characteristic on the initiating and extinguishing boundaries is observed in a nanosecond pulsed DBD,which is sensitive to the variation in the airflow velocities and pulse repetition frequencies(PRFs).It is found that,at a certain airflow velocity,the initiating PRF is higher than the extinguishing PRF.This differenee between the initiating PRF and the extinguishing PRF leads to a hysteresis phenomenon on the initiating and extinguishing boun daries.When the airflow velocity is in creased,both the initiating and extinguishing PRFs are increased and the differenee between the initiating PRF and the extinguishing PRF also increased.The hysteresis width between the initiating and extinguishing boundaries is enhanced.To explain these results,the physical processes involved with the seed particles and the mechanisms of forming discharge channels are discussed.展开更多
Water-based fire extinguishing agent is the main means to deal with smoldering fires.However,due to the hydrophobic properties of the particle surface,the porous medium channel provide resistance and slow down the ext...Water-based fire extinguishing agent is the main means to deal with smoldering fires.However,due to the hydrophobic properties of the particle surface,the porous medium channel provide resistance and slow down the extinguishing agent flow during the downward permeation process.To promote the liquid permeation process in such porous media,this work studied liquid imbibition process and analyzed the oscillating and attenuating process of liquid level in capillary channel by theoretical,experimental,and numerical methods.An empirical mathematical equation was proposed to describe the oscillating process,and the effects of the capillary diameter and contact angle parameters on the transportation process were analyzed.Based on this,the“relay-mode”was proposed to promote the liquid transportation forward.Finally,the transient simulation results of liquid permeation in coal stacks showed when the liquid flowed through the channel with changed diameter from large to small ones,the transportation distance was several times longer than that through the unidiameter ones.The trend of liquid“relay-mode”in capillaries can be used to promote the permeation in granular materials porous media stacks.The relevant results also provide new thoughts to develop the water-based fire extinguishing agents and then improve the firefighting efficiency of deep-seated fire in porous media stacks.展开更多
Various applications of volume dielectric barrier discharges(DBDs)with airflows have attracted significant attention such as in the fields of plasma medicine,surface modification,ozone synthesis,etc.In this work,the n...Various applications of volume dielectric barrier discharges(DBDs)with airflows have attracted significant attention such as in the fields of plasma medicine,surface modification,ozone synthesis,etc.In this work,the nonlinearity characteristics of DBDs in initiating and extinguishing boundaries with airflows are experimentally investigated.It is found that the difference between initiating pulse repetition frequencies(PRFs)and extinguishing PRFs is affected by the addition of airflows.A hysteresis region is produced between these two PRFs.A topological rule of Thom's classification theorem is proposed to investigate the hysteresis phenomenon of discharges with airflows.It is concluded that the discharge state is dependent on the operation route.The discharge state would transit from initiating to extinguishing,or in the opposite direction,while passing along a specific operation route.Based on the topological method,two nonlinear laws of discharge structure transition under the typical operation routes are predicted and verified in the discharge experiments.展开更多
The diagnosis process and extinguishment measures of a case of camel rabies was introduced from the aspects of medical history, clinical examination, emergency and extinguishment measures, in order to provide some ref...The diagnosis process and extinguishment measures of a case of camel rabies was introduced from the aspects of medical history, clinical examination, emergency and extinguishment measures, in order to provide some references for clinical veterinarians.展开更多
Traditional lightning protection measures can not solve the problem of superimposed lightning strikes.This paper presents a compressing arc extinguishing lightning protection device,which can solve the problem of supe...Traditional lightning protection measures can not solve the problem of superimposed lightning strikes.This paper presents a compressing arc extinguishing lightning protection device,which can solve the problem of superimposed lightning strikes.This device can extinguish the power frequency continuous current arc quickly in 1-2 ms.It is far less than the response time of relay protection,which can avoid lightning trips and improve the reliability of power supply.The computer simulation and engineering practice show that the compressing arc extinguishing device has good protection effect on superimposed lightning strikes.展开更多
Based on the testing restult of character of forest fire, with the aid mold of flameextinguishing and mathematical method, the combustion of the forest fuels and the energy transtfer under the convention condition wer...Based on the testing restult of character of forest fire, with the aid mold of flameextinguishing and mathematical method, the combustion of the forest fuels and the energy transtfer under the convention condition were studied and the mechanism and interrelated elements of flameextinguishing with high velocity airflow were given. The energy formulae is given:Nz =Ka0 L0 (15)GH/102η through combustion calculation and test revision This formula was checked through simulated testing for extinguishing low, medial and high intensity fires with high velocity airflow.展开更多
According to the physical and chemical characteristics of superfine powder extinguishing agent,three test methods are selected to measure the flow ability.By studying and comparing various test methods,apparatus and c...According to the physical and chemical characteristics of superfine powder extinguishing agent,three test methods are selected to measure the flow ability.By studying and comparing various test methods,apparatus and conditions,the optimum method and conditions to test flow property of superfine powder extinguishing agent are confirmed.展开更多
Based on the biological characteristics of Solenopsis invicta and the structural characteristics of its ant nest,a fast and efficient closed treatment device was developed.Compared with the simple chemical treatment c...Based on the biological characteristics of Solenopsis invicta and the structural characteristics of its ant nest,a fast and efficient closed treatment device was developed.Compared with the simple chemical treatment commonly used at present,the developed treatment device(the ant nest control cover)is a fast and efficient method to exterminate S.invicta in 7 d,featured by short course,quick results and good effect.展开更多
Fire incidents in commercial vehicles pose significant risks to passengers, drivers, and cargo. Traditional fire extinguishing systems, while effective, may have limitations in terms of response time, coverage, and hu...Fire incidents in commercial vehicles pose significant risks to passengers, drivers, and cargo. Traditional fire extinguishing systems, while effective, may have limitations in terms of response time, coverage, and human intervention [1]. This study investigates the efficacy of a novel fire suppression technology—the Exploding Fire Extinguishing Ball (EFEB) —as an alternative and complementary fire safety solution for commercial vehicles. The research employs a multidisciplinary approach, encompassing engineering, materials science, fire safety, and human factors analysis. A systematic literature review establishes a comprehensive understanding of existing fire suppression technologies, including EFEBs. Subsequently, this study analyzes the unique features of EFEBs, such as automatic activation, as well as manual activation upon exposure to fire, and their potential to provide rapid, localized, and autonomous fire suppression. The study presents original experimental investigations to assess the performance and effectiveness of EFEBs in various fire scenarios representative of commercial vehicles. Experiments include controlled fires in confined spaces and dynamic simulations to emulate real-world fire incidents. Data on activation times, extinguishing capability, and coverage area are collected and analyzed to compare the efficacy of EFEBs with traditional fire extinguishing methods. Furthermore, this research shows the practical aspects of implementing EFEBs in commercial vehicles. A feasibility study examines the integration challenges, cost-benefit analysis, and potential regulatory implications. The study also addresses the impact of EFEBs on vehicle weight, stability, and overall safety. Human factors and user acceptance are crucial elements in adopting new safety technologies. Therefore, this research utilizes an experimental design to assess the performance and effectiveness of EFEBs in various fire scenarios representative of commercial vehicles. This dissertation presents original controlled experiments to emulate real-world fire incidents, including controlled fires in confined spaces and dynamic simulations. The experimental approach ensures rigorous evaluation and objective insights into EFEBs’ potential as an autonomous fire suppression system for commercial vehicles. This includes the perspectives of drivers, passengers, fleet operators, insurance agencies, and regulatory bodies. Factors influencing trust, perceived safety, and willingness to adopt EFEBs are analyzed to provide insights into the successful integration of this technology. The findings of this research will contribute to the knowledge of fire safety technology and expand the understanding of the applicability of EFEBs in commercial vehicles.展开更多
The paper summarizes the structure and water-absorbing mechanism,classification,and preparation method of polymer fire extinguishing gel,and prospects for its application in aerial firefighting,forest ground fire exti...The paper summarizes the structure and water-absorbing mechanism,classification,and preparation method of polymer fire extinguishing gel,and prospects for its application in aerial firefighting,forest ground fire extinguishing,opening of firebreaks,and mitigating human casualties in forest fire extinguishing.展开更多
Once a forest fire occurs, it will inevitably have a very serious impact on forest resources and will also bring some obstacles to social development and progress. In order to improve the protection of forest resource...Once a forest fire occurs, it will inevitably have a very serious impact on forest resources and will also bring some obstacles to social development and progress. In order to improve the protection of forest resources, it is necessary to actively carry out forest fire prevention and extinguishment to avoid the fire problem from the source. Based on this, this paper mainly expounds the related problems of forest fire prevention and extinguishing, and provides some solutions for the fire prevention and extinguishing work, aiming at strengthening the forest fire prevention and extinguishing work and effectively protecting the forest resources in our country.展开更多
In order to solve the problem of spontaneous combustion in goaf, it is necessary to control the air leakage in the goaf to keep the internal and external pressure balance. Taking a specific project as an example, this...In order to solve the problem of spontaneous combustion in goaf, it is necessary to control the air leakage in the goaf to keep the internal and external pressure balance. Taking a specific project as an example, this paper briefly analyzes the factors affecting air leakage, discusses the working principle of pressure equalizing fire prevention, sorts out the technical innovation points of this project, and analyzes the actual benefits.展开更多
This study evaluates the performance of polymer fire-retardant and extinguishing gels through experimental comparisons with traditional foam extinguishing agents and water.The findings indicate that polymer fire-retar...This study evaluates the performance of polymer fire-retardant and extinguishing gels through experimental comparisons with traditional foam extinguishing agents and water.The findings indicate that polymer fire-retardant and extinguishing gels exhibit significant advantages over conventional water and foam in terms of fire suppression and prevention of re-ignition.Based on these results,the fire retardant mechanisms of the polymer gel are hypothesized.展开更多
Traditional mineral oil has long served as a liquid insulating medium in power transformers.However,its low fire resistance,poor biodegradability and dependence on finite fossil fuel resources,along with its low flash...Traditional mineral oil has long served as a liquid insulating medium in power transformers.However,its low fire resistance,poor biodegradability and dependence on finite fossil fuel resources,along with its low flash point,contribute to transformer explosions and fires.To overcome these limitations,developing insulating liquids with high flash points and self-extinguishing properties is essential.Although natural ester-based insulating oils and silicone oils have been proposed as alternatives,their performance requires further optimisation,and their application in transformers remains challenging.This study examines the combustion characteristics of three novel self-extinguishing fluorinated silicone oils using combustion experiments and reactive molecular dynamics simulations.The results demonstrate that methylfluorinated and hydrofluorinated silicone oils exhibit superior self-extinguishing performance compared to mineral oil and natural ester-based insulating oils.Simulation analyses indicate that fluorinated silicone oils generate silicon-oxygen polymers upon ignition,which influence subsequent chain reactions.However,hydroxyfluorinated silicone oil releases a higher concentration of key free radicals,intensifying chain reactions and diminishing its self-extinguishing capability.As a result,its self-extinguishing performance is significantly weaker than that of methylfluorinated and hydrofluorinated silicone oils.These findings provide valuable insights for the development of advanced liquid insulating media as potential replacements for mineral oil.展开更多
基金supported by the specialized fund project for the fundamental research operation of central-level public welfare scientific research institutes,titled“Research on the International Standards System Construction and Updates in the Field of Fire Protection(Project No.2023SJ09)”.
文摘This paper discusses the importance of standards in the fire extinguishing agent industry,and highlights the vital role of the standards in promoting technological innovation.China’s standards for fire extinguishing agent products have evolved significantly,aligning with industrial development,market demands,regulatory requirements,to respond to the great impact of international competition in the industry.The paper analyzes the current state of China’s standards,including their composition and integration with industry growth,green development strategies,and international harmonization.Future development strategies for the standards framework should focus on valid period estimation,fire test model development,and raw material selection guidelines.By implementing these strategies,China’s fire protection industry can enhance product quality,contribute to public safety,and maintain a competitive edge in the global market.
基金the National Natural Science Foundation of China(52274232)the Fundamental Research Funds for the Central Universities(2024ZYGXZR016)。
文摘Sodium metal batteries(SMBs)represent a promising alternative for large-scale energy storage and lowspeed electric vehicles,with resource-sustainable and cost-effective characteristics.However,its practical application is hindered by the high reactivity of sodium metal,interfacial and structural instability,and fire safety risks.Herein,a poly(1,3-dioxolane)(PDOL)crosslinked quasi-solid-state electrolyte(TPQSE)with fire extinguishing property and superior interface compatibility with sodium(Na)anodes and Na_(3)V_(2)(PO_(4))_(3)(NVP)cathodes is prepared via in situ polymerization at room temperature(RT),utilizing trimethylolpropane triglycidyl ether(TTE)as a crosslinker in coordination with ethoxy(pentafluoro)cyclotriphosphazene(PFPN).The crosslinked network of TPQSE and the distinct solvation properties of TPDOL and PFPN facilitate Na-ion desolvation while enhancing antioxidant stability of TPQSE.Moreover,multifunctional PFPN improves fire safety through condensed-phase dense char layer formation and gas-phase free radical capturing.It also constructs uniform,dense,and inorganic-rich interphases between electrodes and electrolytes,strengthening interfacial stability.Consequently,the prepared electrolyte exhibits high ionic conductivity(2.109 mS cm^(-1)at RT),high Na^(+)transference number(0.570),and extended electrochemical window to 4.805 V.The Na‖TPQSE‖Na symmetric cell presents impressive cycling stability over 4510 h,and the Na‖TPQSE‖NVP cell displays outstanding rate capability and stable long-term cycling(≥2300 cycles).This work provides a promising approach for developing safe and high-performance quasi-solid-state sodium metal batteries.
文摘This study focuses on metaphorical terminology in scientific and technical texts,with reference to the English translation practice of a fire extinguisher product operation manual.The research demonstrates that the translation methods for metaphorical terminology in fire extinguisher product manuals are crucial for Chinese products to gain international recognition.The English translation process must adhere to scientificity,rigor,and readability as fundamental principles,while adopting“literal translation”and“substitution translation”as the primary translation methods.Only by doing so can we facilitate the deep integration of Chinese products into international trade and promote their globalization.
基金Project(51275102)supported by the National Natural Science Foundation of ChinaProject(159070220011)supported by the Science and Technology Innovative Research Programs Foundation of Harbin city,ChinaProject(HEUCF110702)supported by the Fundamental Research Funds for the Central Universities of China
文摘To solve the problem of sealing between the barrel and the rubber ring of shell body during an launching process of aerodynamic extinguishing cannon, a rubber sealing model with bionic dimpled characteristics was established based on the theory of bionic dimpled drag reduction and the principle of rubber sealing. In condition that the bionic dimpled characteristic diameters were 1, 2, 3, 4, and 5 mm, respectively, by numerical simulation, the influence of the installing compression of the rubber sealing ring on its surface stress and deformation was analyzed, and sealing performance of the rubber ring with different diameters of bionic dimpled was studied. The results show that the deformation of rubber ring appears prominent nonlinear characteristics when compression is increased from 1.5 mm to 2.5 ram. When the compression is 2.5 mm, the equivalent compression stress on the sealing areas of both sides of the rubber seal is greater than the working pressure of aerodynamic extinguishing cannon, which could meet the sealing requirement and would not cause leakage. So the rubber sealing ring with bionic dimpled surface possesses a good sealing characteristic and has no negative effect on the sealing of shell body; When the compression is 2.5 mm, the larger equivalent stress on the edge of sealing ring and the more even stress distribution in the high pressure area are generated due to the smaller compressive stress on the bionic dimple areas, which lays a foundation for the drag reduction characteristics of the shell body＇s rubber ring with bionic dimpled surface.
基金Supported by the Scientific Research Project of National Level of YANG Zhongqi of Chinese Academy of Forestry(2012AA101503)~~
文摘[Objective] This study was aimed to review the controlling experience of pine wilt disease in the past 25 years, explore the theories and methods of controlling pine wilt disease, and improve the scientific level of controlling techniques and the protection capacity of healthy pine trees. [Method] Eleven items of effects were used to refine the theory of clearing dead pine trees affected by pine wilt disease, namely, ＂1 priority＂, ＂2 objections＂, ＂3 principles＂, ＂4 measures＂, and ＂5 manage- ments＂. On the basis of comprehensive control and complete removal of the infect- ed pine trees, a variety of comprehensive and efficient controlling methods were developed to carry out targeted chemical ecology trapping, bionic pesticide killing and releasing natural enemies of Sclerodermus guani, Dastarcus helophoroides. High ef- ficient emamectin benzoate immune injection was developed to inject the healthy pine trees for prevention, so as to extinguish the pine wilt disease. [Result] The pine wilt disease dropped from the peak of 3.5 million dead trees with an infecting area of 28 273 hectares in 1999 to 0.068 million with an area of 4 333 hectares in 2012 gradually, reducing by 98.06% in number and 84.84% in area, respectively. On the basis of removal, Dastarcus helophoroides was also released, which could make the number of dead pines decrease more significantly than the control, and af- ter releasing for 5 consecutive years, the dead pine trees dropped to 0.511 plant/hm2 in 2012, with a mortality rate of 0.022 7%, which achieved the control effect, reaching extremely significant level. ＂Forest land removal＋infected trees isolation＋natural enemy release＂ could extinguish the pine wilt disease. The test of isolating 24 heaps of infected pine trees showed that there were 9 heaps of pine trees extinguished the pine wilt disease, which controlled the occurrence of pine wilt disease for 100%, accounting for 37.5% of the total, in which the number of those isolated using iron netting and nylon net were 4 for each, accounting for 88.9%, and there was one heap using polypropylene net, accounting for 11.1%. The invention of em- amectin benzoate immune injection laid the foundation for extinguishing pine wilt disease. The follow checking of the effects of emamectin benzoate immune injection on pine wilt disease found that the number of dead trees caused by pine wilt dis- ease decreased significantly after injecting, and became very small in October of the next year, and the disease was completely extinguished in the third year. [Conclusionl Pine wilt disease could be controlled and extinguished with positive control by using ＂comprehensive cleaning＋industrialized removal＂, ＂comprehensive cleaning＋ natural enemy release＂, ＂comprehensive cleaning＋infected trees isolation＋natural ene- my release＂ and ＂comprehensive cleaning＋emamectin benzoate immune＂.
基金supported by the New Energy Vehicle Power Battery Life Cycle Testing and Verification Public Service Platform Project[2022-235-224]the Beijing Science and Technology Planning Project[Z221100005222004]+1 种基金the Key Technologies Research and Development Program[2021YFB2012504]the Beijing Goldenbridge Project[ZZ2023002]。
文摘In this study,a detailed analysis of the combustion behaviors of the lithium iron phosphate(LFP)and lithium manganese oxide(LMO)batteries used in electric bicycles was conducted.This research included quantitative measurements of the combustion duration,flame height,combustion temperature,heat release rate,and total heat release.The results indicated that LMO batteries exhibited higher combustion temperatures of 600–700°C,flame heights of 70–75 cm,a significantly higher heat release rate of40.1 k W(12 Ah),and a total heat release of 1.04 MJ(12 Ah)compared to LFP batteries with the same capacity.Based on these experimental results,a normalized total heat release(NORTHR)parameter was proposed,demonstrating good universality for batteries with different capacities.Utilizing this parameter,quantitative calculations and optimization of the extinguishing agent dosage were conducted for fires involving these two types of batteries,and the method was validated by extinguishing fires for these two types of battery packs with water-based extinguishing fluids.
文摘The dielectric barrier discharge(DBD)is presently used in many fields,in eluding plasma medicine,surface modification,and ozone synthesis;the influe nee of airflow on the DBD is a widely investigated topic.In this work,a hysteresis characteristic on the initiating and extinguishing boundaries is observed in a nanosecond pulsed DBD,which is sensitive to the variation in the airflow velocities and pulse repetition frequencies(PRFs).It is found that,at a certain airflow velocity,the initiating PRF is higher than the extinguishing PRF.This differenee between the initiating PRF and the extinguishing PRF leads to a hysteresis phenomenon on the initiating and extinguishing boun daries.When the airflow velocity is in creased,both the initiating and extinguishing PRFs are increased and the differenee between the initiating PRF and the extinguishing PRF also increased.The hysteresis width between the initiating and extinguishing boundaries is enhanced.To explain these results,the physical processes involved with the seed particles and the mechanisms of forming discharge channels are discussed.
基金the funding support of National Natural Science Foundation of China (21978204)
文摘Water-based fire extinguishing agent is the main means to deal with smoldering fires.However,due to the hydrophobic properties of the particle surface,the porous medium channel provide resistance and slow down the extinguishing agent flow during the downward permeation process.To promote the liquid permeation process in such porous media,this work studied liquid imbibition process and analyzed the oscillating and attenuating process of liquid level in capillary channel by theoretical,experimental,and numerical methods.An empirical mathematical equation was proposed to describe the oscillating process,and the effects of the capillary diameter and contact angle parameters on the transportation process were analyzed.Based on this,the“relay-mode”was proposed to promote the liquid transportation forward.Finally,the transient simulation results of liquid permeation in coal stacks showed when the liquid flowed through the channel with changed diameter from large to small ones,the transportation distance was several times longer than that through the unidiameter ones.The trend of liquid“relay-mode”in capillaries can be used to promote the permeation in granular materials porous media stacks.The relevant results also provide new thoughts to develop the water-based fire extinguishing agents and then improve the firefighting efficiency of deep-seated fire in porous media stacks.
基金supported by National Natural Science Foundation of China(Nos.51676053 and 91741204)。
文摘Various applications of volume dielectric barrier discharges(DBDs)with airflows have attracted significant attention such as in the fields of plasma medicine,surface modification,ozone synthesis,etc.In this work,the nonlinearity characteristics of DBDs in initiating and extinguishing boundaries with airflows are experimentally investigated.It is found that the difference between initiating pulse repetition frequencies(PRFs)and extinguishing PRFs is affected by the addition of airflows.A hysteresis region is produced between these two PRFs.A topological rule of Thom's classification theorem is proposed to investigate the hysteresis phenomenon of discharges with airflows.It is concluded that the discharge state is dependent on the operation route.The discharge state would transit from initiating to extinguishing,or in the opposite direction,while passing along a specific operation route.Based on the topological method,two nonlinear laws of discharge structure transition under the typical operation routes are predicted and verified in the discharge experiments.
文摘The diagnosis process and extinguishment measures of a case of camel rabies was introduced from the aspects of medical history, clinical examination, emergency and extinguishment measures, in order to provide some references for clinical veterinarians.
基金the National Natural Science Foundation of China(No.51467002)Special Projects for Innovation-driven Development(No.2018AA03001Y).
文摘Traditional lightning protection measures can not solve the problem of superimposed lightning strikes.This paper presents a compressing arc extinguishing lightning protection device,which can solve the problem of superimposed lightning strikes.This device can extinguish the power frequency continuous current arc quickly in 1-2 ms.It is far less than the response time of relay protection,which can avoid lightning trips and improve the reliability of power supply.The computer simulation and engineering practice show that the compressing arc extinguishing device has good protection effect on superimposed lightning strikes.
文摘Based on the testing restult of character of forest fire, with the aid mold of flameextinguishing and mathematical method, the combustion of the forest fuels and the energy transtfer under the convention condition were studied and the mechanism and interrelated elements of flameextinguishing with high velocity airflow were given. The energy formulae is given:Nz =Ka0 L0 (15)GH/102η through combustion calculation and test revision This formula was checked through simulated testing for extinguishing low, medial and high intensity fires with high velocity airflow.
文摘According to the physical and chemical characteristics of superfine powder extinguishing agent,three test methods are selected to measure the flow ability.By studying and comparing various test methods,apparatus and conditions,the optimum method and conditions to test flow property of superfine powder extinguishing agent are confirmed.
基金Science and Technology Research Program of Xiamen Customs(2020XK08).
文摘Based on the biological characteristics of Solenopsis invicta and the structural characteristics of its ant nest,a fast and efficient closed treatment device was developed.Compared with the simple chemical treatment commonly used at present,the developed treatment device(the ant nest control cover)is a fast and efficient method to exterminate S.invicta in 7 d,featured by short course,quick results and good effect.
文摘Fire incidents in commercial vehicles pose significant risks to passengers, drivers, and cargo. Traditional fire extinguishing systems, while effective, may have limitations in terms of response time, coverage, and human intervention [1]. This study investigates the efficacy of a novel fire suppression technology—the Exploding Fire Extinguishing Ball (EFEB) —as an alternative and complementary fire safety solution for commercial vehicles. The research employs a multidisciplinary approach, encompassing engineering, materials science, fire safety, and human factors analysis. A systematic literature review establishes a comprehensive understanding of existing fire suppression technologies, including EFEBs. Subsequently, this study analyzes the unique features of EFEBs, such as automatic activation, as well as manual activation upon exposure to fire, and their potential to provide rapid, localized, and autonomous fire suppression. The study presents original experimental investigations to assess the performance and effectiveness of EFEBs in various fire scenarios representative of commercial vehicles. Experiments include controlled fires in confined spaces and dynamic simulations to emulate real-world fire incidents. Data on activation times, extinguishing capability, and coverage area are collected and analyzed to compare the efficacy of EFEBs with traditional fire extinguishing methods. Furthermore, this research shows the practical aspects of implementing EFEBs in commercial vehicles. A feasibility study examines the integration challenges, cost-benefit analysis, and potential regulatory implications. The study also addresses the impact of EFEBs on vehicle weight, stability, and overall safety. Human factors and user acceptance are crucial elements in adopting new safety technologies. Therefore, this research utilizes an experimental design to assess the performance and effectiveness of EFEBs in various fire scenarios representative of commercial vehicles. This dissertation presents original controlled experiments to emulate real-world fire incidents, including controlled fires in confined spaces and dynamic simulations. The experimental approach ensures rigorous evaluation and objective insights into EFEBs’ potential as an autonomous fire suppression system for commercial vehicles. This includes the perspectives of drivers, passengers, fleet operators, insurance agencies, and regulatory bodies. Factors influencing trust, perceived safety, and willingness to adopt EFEBs are analyzed to provide insights into the successful integration of this technology. The findings of this research will contribute to the knowledge of fire safety technology and expand the understanding of the applicability of EFEBs in commercial vehicles.
基金Central Finance Forestry Science and Technology Promotion Demonstration Project(H[2023]TG31).
文摘The paper summarizes the structure and water-absorbing mechanism,classification,and preparation method of polymer fire extinguishing gel,and prospects for its application in aerial firefighting,forest ground fire extinguishing,opening of firebreaks,and mitigating human casualties in forest fire extinguishing.
文摘Once a forest fire occurs, it will inevitably have a very serious impact on forest resources and will also bring some obstacles to social development and progress. In order to improve the protection of forest resources, it is necessary to actively carry out forest fire prevention and extinguishment to avoid the fire problem from the source. Based on this, this paper mainly expounds the related problems of forest fire prevention and extinguishing, and provides some solutions for the fire prevention and extinguishing work, aiming at strengthening the forest fire prevention and extinguishing work and effectively protecting the forest resources in our country.
文摘In order to solve the problem of spontaneous combustion in goaf, it is necessary to control the air leakage in the goaf to keep the internal and external pressure balance. Taking a specific project as an example, this paper briefly analyzes the factors affecting air leakage, discusses the working principle of pressure equalizing fire prevention, sorts out the technical innovation points of this project, and analyzes the actual benefits.
基金Supported by Central Finance Forestry Science and Technology Promotion Demonstration Project(H[2023]TG31).
文摘This study evaluates the performance of polymer fire-retardant and extinguishing gels through experimental comparisons with traditional foam extinguishing agents and water.The findings indicate that polymer fire-retardant and extinguishing gels exhibit significant advantages over conventional water and foam in terms of fire suppression and prevention of re-ignition.Based on these results,the fire retardant mechanisms of the polymer gel are hypothesized.
基金supported by the National Natural Science Foundation of China(52407170)the Natural Science Foundation of Hubei Province(2024AFB306).
文摘Traditional mineral oil has long served as a liquid insulating medium in power transformers.However,its low fire resistance,poor biodegradability and dependence on finite fossil fuel resources,along with its low flash point,contribute to transformer explosions and fires.To overcome these limitations,developing insulating liquids with high flash points and self-extinguishing properties is essential.Although natural ester-based insulating oils and silicone oils have been proposed as alternatives,their performance requires further optimisation,and their application in transformers remains challenging.This study examines the combustion characteristics of three novel self-extinguishing fluorinated silicone oils using combustion experiments and reactive molecular dynamics simulations.The results demonstrate that methylfluorinated and hydrofluorinated silicone oils exhibit superior self-extinguishing performance compared to mineral oil and natural ester-based insulating oils.Simulation analyses indicate that fluorinated silicone oils generate silicon-oxygen polymers upon ignition,which influence subsequent chain reactions.However,hydroxyfluorinated silicone oil releases a higher concentration of key free radicals,intensifying chain reactions and diminishing its self-extinguishing capability.As a result,its self-extinguishing performance is significantly weaker than that of methylfluorinated and hydrofluorinated silicone oils.These findings provide valuable insights for the development of advanced liquid insulating media as potential replacements for mineral oil.
