RBOE is a new type of DNAN-based high-energy melt-cast mixed explosive,whose safety under thermal stimulation is significantly affected by heating conditions and venting area of the warhead.Based on the thermal decomp...RBOE is a new type of DNAN-based high-energy melt-cast mixed explosive,whose safety under thermal stimulation is significantly affected by heating conditions and venting area of the warhead.Based on the thermal decomposition reaction characteristics and combustion characteristics of each component of RBOE explosive,the cook-off calculation models of RBOE warhead before and after ignition were established.In addition,closed and vented warheads were designed,as well as fast and slow cook-off test devices.The cook-off characteristics and thermal safety venting area of RBOE warhead were extensively studied.The results showed that the closed RBOE warhead underwent deflagration reaction under both slow and fast cook-off conditions.The calculation result of the shell wall temperature before slow cookoff ignition response of the warhead was 454.06 K,with an error of+1.75%compared to the test result of462.15 K,and the temperature rise rate calculated was in good agreement with the test.The calculated ignition time of RBOE warhead under fast cook-off was 161 s,with an error of+8.8%compared to the test result of 148 s,which verified the accuracy of cook-off model of RBOE warhead before ignition.According to the cook-off calculation model of the warhead after ignition and cook-off test of the vented warhead,it was determined that the thermal safety venting area was 1124.61 mm^(2)for fast cook-off and 530.66 mm~2 for slow cook-off,effectively preventing the reaction of warhead above combustion.Therefore,this study provides a scientific basis for the thermal safety design and evaluation of insensitive warheads.展开更多
The internal and external flow fields during vented explosions of methane were characterized through numerical simulation,and the capability of numerical simulation thereof was validated by previous experimental data ...The internal and external flow fields during vented explosions of methane were characterized through numerical simulation,and the capability of numerical simulation thereof was validated by previous experimental data at three ignition positions.The venting mechanism was revealed by the simulated concentration distribution,temperature profile,and airflow velocity.The results show rear ignition results in the external methane mass distribution taking the form of"mushroom"and columnar flames in the external space,which can be expressed as a third-order polynomial relationship with distance;central ignition forms a relationship of the form y=AxB.Front ignition causes the temperature to show a tendency to repeated oscillations(rising,falling,and rising).Central ignition generates the maximum vented airflow velocity(V_(max)=320 m/s)upon vent opening.The results indicate that it is acceptable to apply numerical simulation of methane explosions in practice.展开更多
Bathymodiolus mussels distribute in both deep-sea cold seep and hydrothermal vent environments,whose endosymbiotic gill tissue is a prominent character for the adaptation of extreme habitats.However,few studies explor...Bathymodiolus mussels distribute in both deep-sea cold seep and hydrothermal vent environments,whose endosymbiotic gill tissue is a prominent character for the adaptation of extreme habitats.However,few studies explored the adaptation mechanisms through comparative transcriptome sequencing and analysis of different tissues between seep mussels and vent mussels.We performed the comparative transcriptome sequencing and analysis for three tissue types(gill,mantle,and adductor muscle)of Bathymodiolus mussels collected from a cold seeping site Station S 11 and the 50-km away hydrothermal field Minami-Ensei Knoll in the Okinawa Trough.Results show that gene expression patterns had distinct tissue specificity.Compared with the non-endosymbiotic tissues(mantle and adductor muscle),the significantly strengthened gene functions in endosymbiotic gill included microbial recognition(fibrinogen C domain-containing protein 1-B-like(fibcd),fibrinogen-related protein 8(frp),peptidoglycan recognition proteins(pgrp),and C-type lectin(clec)),cell apoptosis and immunity(interferon regulatory factor 1/2-like 1(ir f),cathepsin D(ctsd),caspase 2(casp 2)),and antioxidant capacity(copper/zinc superoxide dismutase(czsod),glutathione peroxidase(gpx),selenoprotein(sel)),in both seep and vent individuals.Consistent with metal accumulation,high expression levels of genes related to heavy metal detoxification(cytochrome P 450(cyp),ferritin-like(ftl),metallothionein(mt),glutathione S-transferase(gst))were also observed in gill.Moreover,to adapt to high hydrostatic pressure in the deep sea,the Kyoto Encyclopedia of Genes and Genomes(KEGG)pathways associated with cellular community were significantly enriched in all three tissues,suggesting the regulation of cell structure and cell adhesion at transcriptional level.This study obtained gene expression profiles of deep-sea mussels subsisting at cold seep and hydrothermal vent sites,which could lay foundations for comprehensive investigations of molecular basis in adaptation of deep-sea mussels to the two extreme ecosystems.展开更多
Post-reperfusion syndrome(PRS)in liver transplant recipients remains one of the most dreaded complications in liver transplant surgery.PRS can impact the short-term and long-term patient and graft outcomes.The definit...Post-reperfusion syndrome(PRS)in liver transplant recipients remains one of the most dreaded complications in liver transplant surgery.PRS can impact the short-term and long-term patient and graft outcomes.The definition of PRS has evolved over the years,from changes in arterial blood pressures and heart and/or de-creases in the systemic vascular resistance and cardiac output to including the fibrinolysis and grading the severity of PRS.However,all that did not reflect on the management of PRS or its impact on the outcomes.In recent years,new scientific techniques and new technology have been in the pipeline to better understand,manage and maybe prevent PRS.These new methods and techniques are still in the infancy,and they have to be proven not in prevention and management of PRS but their effects in the patient and graft outcomes.In this article,we will review the long history of PRS,its definition,etiology,mana-gement and most importantly the new advances in science and technology to prevent and properly manage PRS.展开更多
The safety valve is an important component to ensure the safe operation of lithium-ion batteries(LIBs).However,the effect of safety valve type on the thermal runaway(TR)and gas venting behavior of LIBs,as well as the ...The safety valve is an important component to ensure the safe operation of lithium-ion batteries(LIBs).However,the effect of safety valve type on the thermal runaway(TR)and gas venting behavior of LIBs,as well as the TR hazard severity of LIBs,are not known.In this paper,the TR and gas venting behavior of three 100 A h lithium iron phosphate(LFP)batteries with different safety valves are investigated under overheating.Compared to previous studies,the main contribution of this work is in studying and evaluating the effect of gas venting behavior and TR hazard severity of LFP batteries with three safety valve types.Two significant results are obtained:(Ⅰ)the safety valve type dominates over gas venting pressure of battery during safety venting,the maximum gas venting pressure of LFP batteries with a round safety valve is 3320 Pa,which is one order of magnitude higher than other batteries with oval or cavity safety valve;(Ⅱ)the LFP battery with oval safety valve has the lowest TR hazard as shown by the TR hazard assessment model based on gray-fuzzy analytic hierarchy process.This study reveals the effect of safety valve type on TR and gas venting,providing a clear direction for the safety valve design.展开更多
Many locations with concentrated hydrates at vents have confirmed the presence of abundant thermogenic gas in the middle of the Qiongdongnan Basin(QDNB).However,the impact of deep structures on gasbearing fluids migra...Many locations with concentrated hydrates at vents have confirmed the presence of abundant thermogenic gas in the middle of the Qiongdongnan Basin(QDNB).However,the impact of deep structures on gasbearing fluids migration and gas hydrates distribution in tectonically inactive regions is still unclear.In this study,the authors apply high-resolution 3D seismic and logging while drilling(LWD)data from the middle of the QDNB to investigate the influence of deep-large faults on gas chimneys and preferred gasescape pipes.The findings reveal the following:(1)Two significant deep-large faults,F1 and F2,developed on the edge of the Songnan Low Uplift,control the dominant migration of thermogenic hydrocarbons and determine the initial locations of gas chimneys.(2)The formation of gas chimneys is likely related to fault activation and reactivation.Gas chimney 1 is primarily arises from convergent fluid migration resulting from the intersection of the two faults,while the gas chimney 2 benefits from a steeper fault plane and shorter migration distance of fault F2.(3)Most gas-escape pipes are situated near the apex of the two faults.Their reactivations facilitate free gas flow into the GHSZ and contribute to the formation of fracture‐filling hydrates.展开更多
Unmanned Aerial Vehicles(UAvs)as aerial base stations to provide communication services for ground users is a flexible and cost-effective paradigm in B5G.Besides,dynamic resource allocation and multi-connectivity can ...Unmanned Aerial Vehicles(UAvs)as aerial base stations to provide communication services for ground users is a flexible and cost-effective paradigm in B5G.Besides,dynamic resource allocation and multi-connectivity can be adopted to further harness the potentials of UAVs in improving communication capacity,in such situations such that the interference among users becomes a pivotal disincentive requiring effective solutions.To this end,we investigate the Joint UAV-User Association,Channel Allocation,and transmission Power Control(J-UACAPC)problem in a multi-connectivity-enabled UAV network with constrained backhaul links,where each UAV can determine the reusable channels and transmission power to serve the selected ground users.The goal was to mitigate co-channel interference while maximizing long-term system utility.The problem was modeled as a cooperative stochastic game with hybrid discrete-continuous action space.A Multi-Agent Hybrid Deep Reinforcement Learning(MAHDRL)algorithm was proposed to address this problem.Extensive simulation results demonstrated the effectiveness of the proposed algorithm and showed that it has a higher system utility than the baseline methods.展开更多
Eleven novel clerodane-type diterpenoids,grewiifopenes A-K(1-4 and 12-18),along with nine known compounds(5-11,19,and 20)were purified from the dichloromethane extract of the twigs and stems of Casearia grewiifolia Ve...Eleven novel clerodane-type diterpenoids,grewiifopenes A-K(1-4 and 12-18),along with nine known compounds(5-11,19,and 20)were purified from the dichloromethane extract of the twigs and stems of Casearia grewiifolia Vent.(Salicaceae).Their spectroscopic data,including the NMR,HRESIMS,and electronic circular dichroism calculations were employed to completely characterize and elucidate the chemical structures and absolute configurations.The clerodane diterpenoids possessing a 6-OH group and no substitution at C-7 exhibited greater cytotoxic activity than others,with their IC50 values ranging from 0.3 to 2.9μM.Isocaseamembrin E(7)exhibited antibacterial activity against Staphylococcus aureus,while isocaseamembrin E(7),corymbulosin X(8),caseargrewiin A(9),kurzipene A(10),and balanspene F(11)exhibited antibacterial activity against Bacillus cereus.展开更多
Due to the wide application of closely spaced multi-well horizontal pads for developing unconventional gas reservoirs,interference between wells becomes a significant concern.Communication between wells mainly occurs ...Due to the wide application of closely spaced multi-well horizontal pads for developing unconventional gas reservoirs,interference between wells becomes a significant concern.Communication between wells mainly occurs through natural fractures.However,previous studies have found that interwell communication through natural fractures is varied,and non-communication also appears in the mid and late stages of production due to natural fracture closure.This study proposes a boundary element method for coupling multi-connected regions for the first time.Using this method,we coupled multiple flow fields to establish dual-well models with various connectivity conditions of the stimulated reservoir volume(SRV)region.These models also take into consideration of adsorption and desorption mechanism of natural gas as well as the impact of fracturing fluid retention.The study found that when considering the non-communication of SRV regions between multi-well horizontal pads,the transient behavior of the targeted well exhibits a transitional flow stage occurring before the well interference flow stage.In addition,sensitivity analysis shows that the well spacing and production regime,as well as the connectivity conditions of the SRV region,affect the timing of interwell interference.Meanwhile,the productivity of the two wells,reservoir properties,and fracturing operations affect the intensity of interwell interference.展开更多
基金National Natural Science Foundation of china(Grant No.12402468)。
文摘RBOE is a new type of DNAN-based high-energy melt-cast mixed explosive,whose safety under thermal stimulation is significantly affected by heating conditions and venting area of the warhead.Based on the thermal decomposition reaction characteristics and combustion characteristics of each component of RBOE explosive,the cook-off calculation models of RBOE warhead before and after ignition were established.In addition,closed and vented warheads were designed,as well as fast and slow cook-off test devices.The cook-off characteristics and thermal safety venting area of RBOE warhead were extensively studied.The results showed that the closed RBOE warhead underwent deflagration reaction under both slow and fast cook-off conditions.The calculation result of the shell wall temperature before slow cookoff ignition response of the warhead was 454.06 K,with an error of+1.75%compared to the test result of462.15 K,and the temperature rise rate calculated was in good agreement with the test.The calculated ignition time of RBOE warhead under fast cook-off was 161 s,with an error of+8.8%compared to the test result of 148 s,which verified the accuracy of cook-off model of RBOE warhead before ignition.According to the cook-off calculation model of the warhead after ignition and cook-off test of the vented warhead,it was determined that the thermal safety venting area was 1124.61 mm^(2)for fast cook-off and 530.66 mm~2 for slow cook-off,effectively preventing the reaction of warhead above combustion.Therefore,this study provides a scientific basis for the thermal safety design and evaluation of insensitive warheads.
基金supported by the Young Scientists Fund of National Natural Science Foundation of China(Grant Nos.12202202 and 12202494)the National Key Research and Development Program of China(Grant No.2021YFC3100700)。
文摘The internal and external flow fields during vented explosions of methane were characterized through numerical simulation,and the capability of numerical simulation thereof was validated by previous experimental data at three ignition positions.The venting mechanism was revealed by the simulated concentration distribution,temperature profile,and airflow velocity.The results show rear ignition results in the external methane mass distribution taking the form of"mushroom"and columnar flames in the external space,which can be expressed as a third-order polynomial relationship with distance;central ignition forms a relationship of the form y=AxB.Front ignition causes the temperature to show a tendency to repeated oscillations(rising,falling,and rising).Central ignition generates the maximum vented airflow velocity(V_(max)=320 m/s)upon vent opening.The results indicate that it is acceptable to apply numerical simulation of methane explosions in practice.
基金Supported by the National Natural Science Foundation of China(Nos.91858208,92358301)the Laoshan Laboratory(No.LSKJ 202203500),the China Postdoctoral Science Foundation of China(No.2019M663209)the Fundamental Research Funds for the Central Universities in China(No.19lGPY100)。
文摘Bathymodiolus mussels distribute in both deep-sea cold seep and hydrothermal vent environments,whose endosymbiotic gill tissue is a prominent character for the adaptation of extreme habitats.However,few studies explored the adaptation mechanisms through comparative transcriptome sequencing and analysis of different tissues between seep mussels and vent mussels.We performed the comparative transcriptome sequencing and analysis for three tissue types(gill,mantle,and adductor muscle)of Bathymodiolus mussels collected from a cold seeping site Station S 11 and the 50-km away hydrothermal field Minami-Ensei Knoll in the Okinawa Trough.Results show that gene expression patterns had distinct tissue specificity.Compared with the non-endosymbiotic tissues(mantle and adductor muscle),the significantly strengthened gene functions in endosymbiotic gill included microbial recognition(fibrinogen C domain-containing protein 1-B-like(fibcd),fibrinogen-related protein 8(frp),peptidoglycan recognition proteins(pgrp),and C-type lectin(clec)),cell apoptosis and immunity(interferon regulatory factor 1/2-like 1(ir f),cathepsin D(ctsd),caspase 2(casp 2)),and antioxidant capacity(copper/zinc superoxide dismutase(czsod),glutathione peroxidase(gpx),selenoprotein(sel)),in both seep and vent individuals.Consistent with metal accumulation,high expression levels of genes related to heavy metal detoxification(cytochrome P 450(cyp),ferritin-like(ftl),metallothionein(mt),glutathione S-transferase(gst))were also observed in gill.Moreover,to adapt to high hydrostatic pressure in the deep sea,the Kyoto Encyclopedia of Genes and Genomes(KEGG)pathways associated with cellular community were significantly enriched in all three tissues,suggesting the regulation of cell structure and cell adhesion at transcriptional level.This study obtained gene expression profiles of deep-sea mussels subsisting at cold seep and hydrothermal vent sites,which could lay foundations for comprehensive investigations of molecular basis in adaptation of deep-sea mussels to the two extreme ecosystems.
文摘Post-reperfusion syndrome(PRS)in liver transplant recipients remains one of the most dreaded complications in liver transplant surgery.PRS can impact the short-term and long-term patient and graft outcomes.The definition of PRS has evolved over the years,from changes in arterial blood pressures and heart and/or de-creases in the systemic vascular resistance and cardiac output to including the fibrinolysis and grading the severity of PRS.However,all that did not reflect on the management of PRS or its impact on the outcomes.In recent years,new scientific techniques and new technology have been in the pipeline to better understand,manage and maybe prevent PRS.These new methods and techniques are still in the infancy,and they have to be proven not in prevention and management of PRS but their effects in the patient and graft outcomes.In this article,we will review the long history of PRS,its definition,etiology,mana-gement and most importantly the new advances in science and technology to prevent and properly manage PRS.
基金supported by the National Key R&D Program of China(No.2021YFB2402001)the Postgraduate Innovation and Entrepreneurship Practice Project of Anhui Province(No.2022cxcysj013)+2 种基金the China Postdoctoral Science Foundation(No.2022T150615)the Fundamental Research Funds for the Central Universities(No.WK5290000002)supported by Youth Innovation Promotion Association CAS(No.Y201768)。
文摘The safety valve is an important component to ensure the safe operation of lithium-ion batteries(LIBs).However,the effect of safety valve type on the thermal runaway(TR)and gas venting behavior of LIBs,as well as the TR hazard severity of LIBs,are not known.In this paper,the TR and gas venting behavior of three 100 A h lithium iron phosphate(LFP)batteries with different safety valves are investigated under overheating.Compared to previous studies,the main contribution of this work is in studying and evaluating the effect of gas venting behavior and TR hazard severity of LFP batteries with three safety valve types.Two significant results are obtained:(Ⅰ)the safety valve type dominates over gas venting pressure of battery during safety venting,the maximum gas venting pressure of LFP batteries with a round safety valve is 3320 Pa,which is one order of magnitude higher than other batteries with oval or cavity safety valve;(Ⅱ)the LFP battery with oval safety valve has the lowest TR hazard as shown by the TR hazard assessment model based on gray-fuzzy analytic hierarchy process.This study reveals the effect of safety valve type on TR and gas venting,providing a clear direction for the safety valve design.
基金supported by the National Natural Science Foundation of China(42376221,42276083)Director Research Fund Project of Guangzhou Marine Geological Survey(2023GMGSJZJJ00030)+2 种基金National Key Research and Development Program of China(2021YFC2800901)Guangdong Major Project of Basic and Applied Basic Research(2020B030103003)the project of the China Geological Survey(DD20230064).
文摘Many locations with concentrated hydrates at vents have confirmed the presence of abundant thermogenic gas in the middle of the Qiongdongnan Basin(QDNB).However,the impact of deep structures on gasbearing fluids migration and gas hydrates distribution in tectonically inactive regions is still unclear.In this study,the authors apply high-resolution 3D seismic and logging while drilling(LWD)data from the middle of the QDNB to investigate the influence of deep-large faults on gas chimneys and preferred gasescape pipes.The findings reveal the following:(1)Two significant deep-large faults,F1 and F2,developed on the edge of the Songnan Low Uplift,control the dominant migration of thermogenic hydrocarbons and determine the initial locations of gas chimneys.(2)The formation of gas chimneys is likely related to fault activation and reactivation.Gas chimney 1 is primarily arises from convergent fluid migration resulting from the intersection of the two faults,while the gas chimney 2 benefits from a steeper fault plane and shorter migration distance of fault F2.(3)Most gas-escape pipes are situated near the apex of the two faults.Their reactivations facilitate free gas flow into the GHSZ and contribute to the formation of fracture‐filling hydrates.
基金supported in part by the National Natural Science Foundation of China(grant nos.61971365,61871339,62171392)Digital Fujian Province Key Laboratory of IoT Communication,Architecture and Safety Technology(grant no.2010499)+1 种基金the State Key Program of the National Natural Science Foundation of China(grant no.61731012)the Natural Science Foundation of Fujian Province of China No.2021J01004.
文摘Unmanned Aerial Vehicles(UAvs)as aerial base stations to provide communication services for ground users is a flexible and cost-effective paradigm in B5G.Besides,dynamic resource allocation and multi-connectivity can be adopted to further harness the potentials of UAVs in improving communication capacity,in such situations such that the interference among users becomes a pivotal disincentive requiring effective solutions.To this end,we investigate the Joint UAV-User Association,Channel Allocation,and transmission Power Control(J-UACAPC)problem in a multi-connectivity-enabled UAV network with constrained backhaul links,where each UAV can determine the reusable channels and transmission power to serve the selected ground users.The goal was to mitigate co-channel interference while maximizing long-term system utility.The problem was modeled as a cooperative stochastic game with hybrid discrete-continuous action space.A Multi-Agent Hybrid Deep Reinforcement Learning(MAHDRL)algorithm was proposed to address this problem.Extensive simulation results demonstrated the effectiveness of the proposed algorithm and showed that it has a higher system utility than the baseline methods.
基金The grants from Thailand Science Research and Innovation(TSRI)and Chulabhorn Research Institute(grant numbers 48296/4691995)Center of Excellence on Environmental Health and Toxicology(EHT),OPS,Ministry of Higher Education,Science,Research and Innovation were supported the research funding.
文摘Eleven novel clerodane-type diterpenoids,grewiifopenes A-K(1-4 and 12-18),along with nine known compounds(5-11,19,and 20)were purified from the dichloromethane extract of the twigs and stems of Casearia grewiifolia Vent.(Salicaceae).Their spectroscopic data,including the NMR,HRESIMS,and electronic circular dichroism calculations were employed to completely characterize and elucidate the chemical structures and absolute configurations.The clerodane diterpenoids possessing a 6-OH group and no substitution at C-7 exhibited greater cytotoxic activity than others,with their IC50 values ranging from 0.3 to 2.9μM.Isocaseamembrin E(7)exhibited antibacterial activity against Staphylococcus aureus,while isocaseamembrin E(7),corymbulosin X(8),caseargrewiin A(9),kurzipene A(10),and balanspene F(11)exhibited antibacterial activity against Bacillus cereus.
基金supported by the National Science Fund for Excellent Young Scholars(No.52222402)State Key Program of National Natural Science Foundation of China(No.U23A2022)+7 种基金State Key Program of National Natural Science Foundation of China(No.52234003)Sichuan Science and Technology Program(No.2022JDJQ0009)National Natural Science Foundation of China(No.52074235)Science and Technology Cooperation Project of the CNPC-SWPU Innovation Alliance(Nos.2020CX020202 and 2020CX030202)Shale Gas industry Development Institute of Sichuan Province111 Project(No.D18016)China Postdoctoral Science Foundation(No.2022M722637)the Science Foundation of Sichuan Province(No.2022NSFSC0186)。
文摘Due to the wide application of closely spaced multi-well horizontal pads for developing unconventional gas reservoirs,interference between wells becomes a significant concern.Communication between wells mainly occurs through natural fractures.However,previous studies have found that interwell communication through natural fractures is varied,and non-communication also appears in the mid and late stages of production due to natural fracture closure.This study proposes a boundary element method for coupling multi-connected regions for the first time.Using this method,we coupled multiple flow fields to establish dual-well models with various connectivity conditions of the stimulated reservoir volume(SRV)region.These models also take into consideration of adsorption and desorption mechanism of natural gas as well as the impact of fracturing fluid retention.The study found that when considering the non-communication of SRV regions between multi-well horizontal pads,the transient behavior of the targeted well exhibits a transitional flow stage occurring before the well interference flow stage.In addition,sensitivity analysis shows that the well spacing and production regime,as well as the connectivity conditions of the SRV region,affect the timing of interwell interference.Meanwhile,the productivity of the two wells,reservoir properties,and fracturing operations affect the intensity of interwell interference.
