The military situation of the thirteenth century required that the Song and the Mongols construct a great number of defensive works,relying on the mountains or facing the rivers,in the mountainous Sichuan Province and...The military situation of the thirteenth century required that the Song and the Mongols construct a great number of defensive works,relying on the mountains or facing the rivers,in the mountainous Sichuan Province and Chongqing.In recent years,a special kind of explosive firearms,huolei火雷(bombs),was unearthed in the large-scale excavations of the site of Diaoyu Fortress钓鱼城in Hechuan District合川and the Baidicheng白帝城in Fengjie County奉节,both of which were defensive works constructed in this mountainous area during the Southern Song dynasty.In addition,the ruins of kilns and the clay molds that were relevant to the casting of iron huolei have been discovered at the site of Baidicheng,indicating that these huolei might have been produced locally.The Southern Song iron huolei unearthed in Chongqing are the most direct evidence of the evolvement of gunpowder and firearms,and are of great significance to the history of science and technology,in particular the history of military technology.展开更多
The world’s earliest bomb with an iron casing,the iron huopao鐵火砲(cast-iron bomb,also referred to as zhentian lei震天雷,literally“thunder-crash bomb”),is one of the most important inventions of ancient China rela...The world’s earliest bomb with an iron casing,the iron huopao鐵火砲(cast-iron bomb,also referred to as zhentian lei震天雷,literally“thunder-crash bomb”),is one of the most important inventions of ancient China relating to gunpowder and firearms.Until recently,however,academics were not able to conduct substantial research on the topic,as no actual remains of a huopao had yet been found.Since 2013,in the excavation of two sites of Southern Song ancient cities(Diaoyu Fortress and Baidicheng)in Chongqing,archaeologists from the Chongqing Cultural Heritage Research Institute have discovered a number of iron huopao of the Southern Song dynasty.This finding not only provides first-hand material for research on the history of the invention of gunpowder and firearms,which has always been lacking,but also offers new physical evidence for an exploration of the history of war and the military history of the thirteenth century(in particular the Mongol-Song war),and is thus historically significant.展开更多
WHEN Isnina Jelle wanted to visit a fair, she decided to wait for two days first. It wasn＇t that the 26-year-old livelihood officer with an NGO was inordinately fussy or busy. It was simply that she was living in a c...WHEN Isnina Jelle wanted to visit a fair, she decided to wait for two days first. It wasn＇t that the 26-year-old livelihood officer with an NGO was inordinately fussy or busy. It was simply that she was living in a country going through an extraordinary situation where even going to a book fair could become a matter of life and death.展开更多
The ‘two bombs and one satellite’ project was a major achievement of China after 1949 and has since been an important subject in historical and sociological research on science and technology in modern China. Howeve...The ‘two bombs and one satellite’ project was a major achievement of China after 1949 and has since been an important subject in historical and sociological research on science and technology in modern China. However, most accounts of the history or sociology of the project focus on physicists and engineers, rather than the chemists. This study examines the chemists' work of preparing fuels and materials in the project and their post-project research. By analysing how Chinese scientists engaged in the project, how they understood the relationship between basic and applied research in their scientific practice and how they positioned themselves on issues of science policy, this article offers different and shifting concepts of basic and applied research with cultural variation in the context of China.展开更多
Nanoparticle-based drug delivery system remains a significant challenge in the current treatment of solid tumors,primarily due to their limited penetration capabilities.Herein,we successfully engineer photodynamic gel...Nanoparticle-based drug delivery system remains a significant challenge in the current treatment of solid tumors,primarily due to their limited penetration capabilities.Herein,we successfully engineer photodynamic gel-bombs(DCM@OPR)capable of penetrating deeply into tumor tissues utilizing the photodynamic-triggered explosive energy and receptor-mediated transcytosis,significantly enhancing the therapeutic efficacy of breast cancer.The photodynamic gel-bombs were fabricated by loading powerful components of chlorin e6 and MnO_(2) nanoparticles,as wellas Doxorubicin,into a crosslinked Ca^(2+)-gel.Upon exposure to laser irradiation,the obtained photodynamic gel-bombs are capable of generating explosive energy,resulting in their fragmentation into numerous nanofragments.The photodynamic-triggered explosive energy subsequently drives these nanofragments to deeply penetrate into tumor tissues through gap leakage among tumor cells.In addition,the photodynamictriggered explosive energy also promotes the escape of those therapeutic components(including chlorin e6,MnO_(2) nanoparticles,and doxorubicin)and nanofragments from lysosomes.In the subsequent stages,these nanofragments also exhibit excellent transcytosis capacity,facilitating deep penetration into tumor tissues.As expected,the enhanced penetration and accumulation of therapeutic components into tumor tissues can be achieved,significantly enhancing the anti-proliferation capacity against breast cancer.展开更多
The legacy of United States cluster munition use in Laos and Cambodia during the Second Indochina War is residual bomblets that unexpectedly detonate years later, killing and injuring children, farmers, and other civi...The legacy of United States cluster munition use in Laos and Cambodia during the Second Indochina War is residual bomblets that unexpectedly detonate years later, killing and injuring children, farmers, and other civilians. Cluster munitions release dozens of smaller bomblets that rain deadly ammunition on troops, armored tanks, and vegetation, effectively striking broad sections of war zone landscapes in one launch. While many bomblets detonate immediately, others fail to detonate and can lie dormant on the ground for years. The primary objectives of this study were to document the long-term consequences and impacts of the US Air Force bombing of Laos and Cambodia during the Second Indochina War (1959 to 1973). The historical lessons learned by United States should be shared with Russia and Ukraine governments and military. These countries need to discontinue the use of cluster bombs to prevent additional people living along the Russia-Ukraine border from having to live and die with the consequences of unexploded ordnance, including cluster bombs, for the next century.展开更多
On a summer morning in Boqiang Village,tucked beneath the emerald mountains of Fanshi County,Shanxi Province,the Ultra Trail Mount Wutai 2025 commenced with the sound of the starting pistol-an event that was much more...On a summer morning in Boqiang Village,tucked beneath the emerald mountains of Fanshi County,Shanxi Province,the Ultra Trail Mount Wutai 2025 commenced with the sound of the starting pistol-an event that was much more than just a competition.As soon as the colourful smoke bombs lit up the sky,some 2,000 runners from China and abroad set off to reach one of the country’s most sacred Buddhist peaks.Over the past decade,this race has become a fixture on the global running calendar and a symbol of the growing popularity of endurance sports.展开更多
This study calculates the combustion characteristics of various gas-generating and micro gas pyrotechnic charges,including aluminium/potassium perchlorate,boron/potassium nitrate,carbon black/potassium nitrate,and sil...This study calculates the combustion characteristics of various gas-generating and micro gas pyrotechnic charges,including aluminium/potassium perchlorate,boron/potassium nitrate,carbon black/potassium nitrate,and silicon-based delay compositions,using thermodynamic software.A multiphase flowthermal-solid coupling model was established,and the combustion process of the pyrotechnic charges within a closed bomb was simulated.The pyrotechnic shock generated by combustion was predicted.The combustion pressures and pyrotechnic shocks were measured.The simulation results demonstrated good agreement with experimental results.Additionally,the mechanism of shock generation by the combustion of pyrotechnic charges in the closed bomb was analyzed.The effects of the combustion characteristics of the pyrotechnic charges on the resulting pyrotechnic shocks were systematically investigated.Notably,the shock response spectrum of the gas-generating pyrotechnic charges is greater than that of the micro gas compositions at most frequencies,particularly in the mid-field pyrotechnic shocks(3-10 kHz).Furthermore,the pyrotechnic shocks increase approximately linearly with the impulse of the gas-generating pyrotechnic charges.展开更多
Bomb cyclones are rapidly deepening extratropical cyclones predominantly found in midlatitude regions.These extreme events are particularly frequent over the North Pacific(NP),posing significant societal and environme...Bomb cyclones are rapidly deepening extratropical cyclones predominantly found in midlatitude regions.These extreme events are particularly frequent over the North Pacific(NP),posing significant societal and environmental risks.Currently,our understanding of the variability of bomb cyclones over the NP remains limited.This study analyzes the variations in multiple NP bomb cyclone characteristics from 1980 onward using four major reanalysis datasets.The results show a weakening trend of bomb cyclones since the beginning of the 21st century,which is characterized by significant reductions in maximum near-surface wind speeds,increases in minimum sea level pressure,and slower deepening rates.Further analysis reveals that the observed weakening trend of bomb cyclones is closely linked to a reduction in maximum 850 hPa Eady growth rate,driven primarily by reduced vertical wind shear within the 30°-45°N latitudinal band.Furthermore,our findings indicate that the Aleutian Low acts to modulate the meridional air temperature gradient over the midlatitude NP,which is corroborated by climate model outputs.This modulation provides a pathway for the Aleutian Low to affect low-level baroclinicity and thus bomb cyclone characteristics.These results have important implications for future projections of bomb cyclone activity over the NP,aiding in risk assessment and mitigating the impacts of these extreme events.展开更多
Different cultural values see award-winning U.S. melodrama run aground in China It had audiences on the edge of their seats in 202 countries and regions around the world, but in China the show was a deleterious bridge...Different cultural values see award-winning U.S. melodrama run aground in China It had audiences on the edge of their seats in 202 countries and regions around the world, but in China the show was a deleterious bridge too far. The award-winning American soap opera Desperate Housewives, came, was seen, but failed to conquer Chinese TV audiences, exposing the enormous展开更多
Taking steps to prevent storage catastrophes like the Tianjin blast防范悲剧重演,探寻危险化学品的栖身之所The warehouse explosions in Tianjin on August 12 claimed over 160 lives,one of the most serious chemical explosio...Taking steps to prevent storage catastrophes like the Tianjin blast防范悲剧重演,探寻危险化学品的栖身之所The warehouse explosions in Tianjin on August 12 claimed over 160 lives,one of the most serious chemical explosions in a decade.The warehouse,located in a port at the Tianjin Binhai New Area,stored large amounts of hazardous chemicals including展开更多
The laser-guided bomb(LGB)is an air-to-ground pre-cision-guided weapon that offers high hit rates,great power,and ease of use.LGBs are guided by semi-active laser ground-seek-ing technology,which means that atmospheri...The laser-guided bomb(LGB)is an air-to-ground pre-cision-guided weapon that offers high hit rates,great power,and ease of use.LGBs are guided by semi-active laser ground-seek-ing technology,which means that atmospheric conditions can affect their accuracy.The spatial release region(SRR)of LGBs is difficult to calculate precisely,especially when there is a poor field of view.This can result in a lower real hit probability.To increase the hit probability of LGBs in tough atmospheric situa-tions,a novel method for calculating the SRR has been pro-posed.This method is based on the transmittance model of the 1.06μm laser in atmospheric species and the laser diffuse reflection model of the target surface to determine the capture target time of the laser seeker.Then,it calculates the boundary ballistic space starting position by ballistic model and gets the spatial scope of the spatial release region.This method can determine the release region of LGBs based on flight test data such as instantaneous velocity,altitude,off-axis angle,and atmospheric visibility.By more effectively employing aircraft release conditions,atmospheric visibility and other factors,the SRR calculation method can improve LGB hit probabi-lity by 9.2%.展开更多
Lung cancer is one of the most common malignant tumors with the fastest increase in the incidence rate and mortality.Even after maximum tumor resection assistance with a radiotherapy and chemotherapy combination,the r...Lung cancer is one of the most common malignant tumors with the fastest increase in the incidence rate and mortality.Even after maximum tumor resection assistance with a radiotherapy and chemotherapy combination,the recurrence of non-small cell lung cancer is still inevitable.In addition,low targeting efficiency and poor permeability of drug delivery systems strongly affect the therapeutic efficiency of anti-cancer drugs on non-small cell lung cancer.Here we designed a gemcitabine(GEM)loaded arginineglycine-aspartic acid-cysteine(RGDc)-modified gold mineralization“hybrid nanozyme bomb”(RGTG)to overcome those obstacles.RGDc modification improved the active targeting of liposomes to the tumor tissues with the second near-infrared(NIR-Ⅱ)-triggered gold-shell disruption and GEM release.The collapsed gold-shell particles with a smaller size could penetrate the tumor solid barrier and act as photothermal therapy(PTT)agents to improve PTT therapy and starvation therapy via generating gluconic acid and reactive oxygen species(ROS).Moreover,the resting reversal effect of gold particles on tumor fibroblasts can achieve accelerating tumor penetration of gold particles and GEM.Compared to monotherapy,RGTG showed significant improvement in tumor inhibition,with a tumor volume reduction of 83%compared to the control group,which provides a promising tumor treatment platform for non-small cell lung cancer(NSCLC).展开更多
To reduce the damage of the pressurizing panel structure of a fuselage caused by an explosion at the“least risk bomb location”in an aircraft structure,a new pre-separation panel structure was designed to resist blas...To reduce the damage of the pressurizing panel structure of a fuselage caused by an explosion at the“least risk bomb location”in an aircraft structure,a new pre-separation panel structure was designed to resist blast loading.First,the dynamic strain response and morphology of impact damage of the new pre-separation panel were measured in an impact damage test.Second,the commercial software LS-DYNA was used to calculate the propagation of the blast shock wave,and the results were compared with empirical equations to verify the rationality of the numerical calculation method.Finally,the fluid–structure coupling method was used to calculate the damage process of the pre-separation panel structure under the impact of an explosion wave and an impact block.The calculated results were in good agreement with the test results,which showed the rationality of the calculation method and the model.The residual strength of the damaged pre-separation panel was significantly higher than that of the original damaged panel.The results show that the new pre-separation panel structure is reasonable and has certain significance for guiding the design of plenum chambers with strong resistance to implosion for aircraft fuselages.展开更多
In modern warfare,unpowered glide munitions,represented by JDAM,are widely used.Accurately predicting the future trajectory of such targets is crucial for intercepting them.This paper proposes a future point predictio...In modern warfare,unpowered glide munitions,represented by JDAM,are widely used.Accurately predicting the future trajectory of such targets is crucial for intercepting them.This paper proposes a future point prediction method for unpowered gliding targets based on attitude computation.By estimating the current state of the target,we derive the target’s attitude coordinate system.Subsequently,the paper analyzes the forces acting on the target and updates the state transition matrix,ultimately calculating the future position of the target.Experimental results show that,compared to traditional methods,this approach improves the accuracy of future point predictions by 9%to 45%.展开更多
Aim To study the effect of aerodynamically stabilized seeker dynamics on guided bomb system analysis. Methods A thorough analysis of aerodynamically stabilized seeker dynamics was made to show that because of the mu...Aim To study the effect of aerodynamically stabilized seeker dynamics on guided bomb system analysis. Methods A thorough analysis of aerodynamically stabilized seeker dynamics was made to show that because of the much smaller time constant, its dynamic model can be greatly simplified. Results and Conclusion In guided bomb guidance/control digital simulation, with the use of the simplified seeker model, simulation time can be reduced without the loss of simulation accuracy.展开更多
Using an oral history approach, this study analyzed the narratives obtained from semi-structured interviews administered to three Japanese women who worked as nurses for the Hiroshima Atomic Bomb Casualty Commission (...Using an oral history approach, this study analyzed the narratives obtained from semi-structured interviews administered to three Japanese women who worked as nurses for the Hiroshima Atomic Bomb Casualty Commission (ABCC). The analysis of the data in the narratives showed details of the health surveys and health checkups conducted during the early period of operation of ABCC. During the early period of operation of ABCC some survivors showed negative behaviors toward the health surveys and health checkups at the ABCC. However, it can be inferred that dedicated nursing played an important role in alleviating the stress and emotional issues of survivors at the health surveys and health checkups. The findings of the study could be beneficial to research into nursing activities for patients exposed to radiation at the present day.展开更多
The sequential dispersing results of aerial cluster bomb are discussed. The ballistic model and the mod- el for impact point distribution of bullets are established. The main factors influencing impact point distribut...The sequential dispersing results of aerial cluster bomb are discussed. The ballistic model and the mod- el for impact point distribution of bullets are established. The main factors influencing impact point distribution are analyzed by numerical simulation. And the feasibility of improving distribution effect through sequential dis- persing is validated. Sequential dispersion and optimized airdrop parameters can help to achieve better battle effec- tiveness.展开更多
The buried village is Vinh Moc where more than 1200 Vietnamese, including soldiers, who lived underground during the Vietnam War (1965 to 1972) were hand dug into red basalt bedrock. The Vinh Moc Village was strategic...The buried village is Vinh Moc where more than 1200 Vietnamese, including soldiers, who lived underground during the Vietnam War (1965 to 1972) were hand dug into red basalt bedrock. The Vinh Moc Village was strategically located on the border of North Vietnam and South Vietnam approximately 14 km north of the DMZ and along the shoreline of the South China Sea. During the Vietnam War, the US Air Force heavily bombed Vinh Moc. The North Vietnamese Army (NVA) had an important military base on nearby Con Co Island. Brave civil volunteers from Vinh Moc would make the 28 km dangerous journey to the island, disguised as fishermen, to deliver supplies to the soldiers stationed there. The people who remained at Vinh Moc dug tunnels into red basalt hills in order to survive this onslaught. The American forces assessed the villagers of Vinh Moc were supplying food and armaments to the NVA garrison on the island of Con Co, which was in turn hindering the American bombers on their way to bomb Hanoi. The US military objective was to force the villagers of Vinh Moc to leave the area. The villagers initially dug the tunnels to a 10 m depth but the American forces designed bombs that burrowed down 10 m before exploding. The soil tunnels were then deepened to 30 m to provide safety for the soldiers and civilians working there during the intense US Air Force bombing. The primary objective of the research study was to determine how the soils and parent material of Vinh Moc Village, protected their villagers from the United States Air Force bombardment during the Vietnam War. In addition, the natural parent material at both the Vinh Moc and Cu Chi were assessed to determine why the tunnels were so resilient. The Cu Chi and Iron Triangle soil tunnels were dug by hand in the Old Alluvium soils and parent material where iron in solution precipitated and became the soil binding material. The Vinh Moc tunnels were hand dug in porous, red basalt (bedrock) hills where the consolidated rock structure itself provided the required binding material. Neither site needed support beams to hold up the ceilings.展开更多
文摘The military situation of the thirteenth century required that the Song and the Mongols construct a great number of defensive works,relying on the mountains or facing the rivers,in the mountainous Sichuan Province and Chongqing.In recent years,a special kind of explosive firearms,huolei火雷(bombs),was unearthed in the large-scale excavations of the site of Diaoyu Fortress钓鱼城in Hechuan District合川and the Baidicheng白帝城in Fengjie County奉节,both of which were defensive works constructed in this mountainous area during the Southern Song dynasty.In addition,the ruins of kilns and the clay molds that were relevant to the casting of iron huolei have been discovered at the site of Baidicheng,indicating that these huolei might have been produced locally.The Southern Song iron huolei unearthed in Chongqing are the most direct evidence of the evolvement of gunpowder and firearms,and are of great significance to the history of science and technology,in particular the history of military technology.
文摘The world’s earliest bomb with an iron casing,the iron huopao鐵火砲(cast-iron bomb,also referred to as zhentian lei震天雷,literally“thunder-crash bomb”),is one of the most important inventions of ancient China relating to gunpowder and firearms.Until recently,however,academics were not able to conduct substantial research on the topic,as no actual remains of a huopao had yet been found.Since 2013,in the excavation of two sites of Southern Song ancient cities(Diaoyu Fortress and Baidicheng)in Chongqing,archaeologists from the Chongqing Cultural Heritage Research Institute have discovered a number of iron huopao of the Southern Song dynasty.This finding not only provides first-hand material for research on the history of the invention of gunpowder and firearms,which has always been lacking,but also offers new physical evidence for an exploration of the history of war and the military history of the thirteenth century(in particular the Mongol-Song war),and is thus historically significant.
文摘WHEN Isnina Jelle wanted to visit a fair, she decided to wait for two days first. It wasn＇t that the 26-year-old livelihood officer with an NGO was inordinately fussy or busy. It was simply that she was living in a country going through an extraordinary situation where even going to a book fair could become a matter of life and death.
基金supported by the National Social Science Fund of China (grant no.19BZX041)
文摘The ‘two bombs and one satellite’ project was a major achievement of China after 1949 and has since been an important subject in historical and sociological research on science and technology in modern China. However, most accounts of the history or sociology of the project focus on physicists and engineers, rather than the chemists. This study examines the chemists' work of preparing fuels and materials in the project and their post-project research. By analysing how Chinese scientists engaged in the project, how they understood the relationship between basic and applied research in their scientific practice and how they positioned themselves on issues of science policy, this article offers different and shifting concepts of basic and applied research with cultural variation in the context of China.
基金supported by the National Natural Science Foundation of China(82293650,82293651,82293652,22075127,22275080)GuangDong Basic and Applied Basic Research Foundation(2023A1515111182)President Foundation of Zhujiang Hospital,Southern Medical University(yzij2023qn07).
文摘Nanoparticle-based drug delivery system remains a significant challenge in the current treatment of solid tumors,primarily due to their limited penetration capabilities.Herein,we successfully engineer photodynamic gel-bombs(DCM@OPR)capable of penetrating deeply into tumor tissues utilizing the photodynamic-triggered explosive energy and receptor-mediated transcytosis,significantly enhancing the therapeutic efficacy of breast cancer.The photodynamic gel-bombs were fabricated by loading powerful components of chlorin e6 and MnO_(2) nanoparticles,as wellas Doxorubicin,into a crosslinked Ca^(2+)-gel.Upon exposure to laser irradiation,the obtained photodynamic gel-bombs are capable of generating explosive energy,resulting in their fragmentation into numerous nanofragments.The photodynamic-triggered explosive energy subsequently drives these nanofragments to deeply penetrate into tumor tissues through gap leakage among tumor cells.In addition,the photodynamictriggered explosive energy also promotes the escape of those therapeutic components(including chlorin e6,MnO_(2) nanoparticles,and doxorubicin)and nanofragments from lysosomes.In the subsequent stages,these nanofragments also exhibit excellent transcytosis capacity,facilitating deep penetration into tumor tissues.As expected,the enhanced penetration and accumulation of therapeutic components into tumor tissues can be achieved,significantly enhancing the anti-proliferation capacity against breast cancer.
文摘The legacy of United States cluster munition use in Laos and Cambodia during the Second Indochina War is residual bomblets that unexpectedly detonate years later, killing and injuring children, farmers, and other civilians. Cluster munitions release dozens of smaller bomblets that rain deadly ammunition on troops, armored tanks, and vegetation, effectively striking broad sections of war zone landscapes in one launch. While many bomblets detonate immediately, others fail to detonate and can lie dormant on the ground for years. The primary objectives of this study were to document the long-term consequences and impacts of the US Air Force bombing of Laos and Cambodia during the Second Indochina War (1959 to 1973). The historical lessons learned by United States should be shared with Russia and Ukraine governments and military. These countries need to discontinue the use of cluster bombs to prevent additional people living along the Russia-Ukraine border from having to live and die with the consequences of unexploded ordnance, including cluster bombs, for the next century.
文摘On a summer morning in Boqiang Village,tucked beneath the emerald mountains of Fanshi County,Shanxi Province,the Ultra Trail Mount Wutai 2025 commenced with the sound of the starting pistol-an event that was much more than just a competition.As soon as the colourful smoke bombs lit up the sky,some 2,000 runners from China and abroad set off to reach one of the country’s most sacred Buddhist peaks.Over the past decade,this race has become a fixture on the global running calendar and a symbol of the growing popularity of endurance sports.
文摘This study calculates the combustion characteristics of various gas-generating and micro gas pyrotechnic charges,including aluminium/potassium perchlorate,boron/potassium nitrate,carbon black/potassium nitrate,and silicon-based delay compositions,using thermodynamic software.A multiphase flowthermal-solid coupling model was established,and the combustion process of the pyrotechnic charges within a closed bomb was simulated.The pyrotechnic shock generated by combustion was predicted.The combustion pressures and pyrotechnic shocks were measured.The simulation results demonstrated good agreement with experimental results.Additionally,the mechanism of shock generation by the combustion of pyrotechnic charges in the closed bomb was analyzed.The effects of the combustion characteristics of the pyrotechnic charges on the resulting pyrotechnic shocks were systematically investigated.Notably,the shock response spectrum of the gas-generating pyrotechnic charges is greater than that of the micro gas compositions at most frequencies,particularly in the mid-field pyrotechnic shocks(3-10 kHz).Furthermore,the pyrotechnic shocks increase approximately linearly with the impulse of the gas-generating pyrotechnic charges.
基金supported by the National Natural Science Foundation of China(Grant No.42030410)the Laoshan Laboratory(Grant Nos.LSKJ202202404 and LSKJ202202403)+1 种基金the Startup Foundation for Introducing Tal-ent of NUIST,Jiangsu Innovation Research Group(Grant No.JSS-CTD202346)the Jiangsu Funding Program for Excellent Post-doctoral Talent(Grant No.2023ZB690).
文摘Bomb cyclones are rapidly deepening extratropical cyclones predominantly found in midlatitude regions.These extreme events are particularly frequent over the North Pacific(NP),posing significant societal and environmental risks.Currently,our understanding of the variability of bomb cyclones over the NP remains limited.This study analyzes the variations in multiple NP bomb cyclone characteristics from 1980 onward using four major reanalysis datasets.The results show a weakening trend of bomb cyclones since the beginning of the 21st century,which is characterized by significant reductions in maximum near-surface wind speeds,increases in minimum sea level pressure,and slower deepening rates.Further analysis reveals that the observed weakening trend of bomb cyclones is closely linked to a reduction in maximum 850 hPa Eady growth rate,driven primarily by reduced vertical wind shear within the 30°-45°N latitudinal band.Furthermore,our findings indicate that the Aleutian Low acts to modulate the meridional air temperature gradient over the midlatitude NP,which is corroborated by climate model outputs.This modulation provides a pathway for the Aleutian Low to affect low-level baroclinicity and thus bomb cyclone characteristics.These results have important implications for future projections of bomb cyclone activity over the NP,aiding in risk assessment and mitigating the impacts of these extreme events.
文摘Different cultural values see award-winning U.S. melodrama run aground in China It had audiences on the edge of their seats in 202 countries and regions around the world, but in China the show was a deleterious bridge too far. The award-winning American soap opera Desperate Housewives, came, was seen, but failed to conquer Chinese TV audiences, exposing the enormous
文摘Taking steps to prevent storage catastrophes like the Tianjin blast防范悲剧重演,探寻危险化学品的栖身之所The warehouse explosions in Tianjin on August 12 claimed over 160 lives,one of the most serious chemical explosions in a decade.The warehouse,located in a port at the Tianjin Binhai New Area,stored large amounts of hazardous chemicals including
基金This work was supported by the major research projects within the military-international class(JY2021B077).
文摘The laser-guided bomb(LGB)is an air-to-ground pre-cision-guided weapon that offers high hit rates,great power,and ease of use.LGBs are guided by semi-active laser ground-seek-ing technology,which means that atmospheric conditions can affect their accuracy.The spatial release region(SRR)of LGBs is difficult to calculate precisely,especially when there is a poor field of view.This can result in a lower real hit probability.To increase the hit probability of LGBs in tough atmospheric situa-tions,a novel method for calculating the SRR has been pro-posed.This method is based on the transmittance model of the 1.06μm laser in atmospheric species and the laser diffuse reflection model of the target surface to determine the capture target time of the laser seeker.Then,it calculates the boundary ballistic space starting position by ballistic model and gets the spatial scope of the spatial release region.This method can determine the release region of LGBs based on flight test data such as instantaneous velocity,altitude,off-axis angle,and atmospheric visibility.By more effectively employing aircraft release conditions,atmospheric visibility and other factors,the SRR calculation method can improve LGB hit probabi-lity by 9.2%.
基金supported by the National Natural Science Foundation of China(No.81972892)。
文摘Lung cancer is one of the most common malignant tumors with the fastest increase in the incidence rate and mortality.Even after maximum tumor resection assistance with a radiotherapy and chemotherapy combination,the recurrence of non-small cell lung cancer is still inevitable.In addition,low targeting efficiency and poor permeability of drug delivery systems strongly affect the therapeutic efficiency of anti-cancer drugs on non-small cell lung cancer.Here we designed a gemcitabine(GEM)loaded arginineglycine-aspartic acid-cysteine(RGDc)-modified gold mineralization“hybrid nanozyme bomb”(RGTG)to overcome those obstacles.RGDc modification improved the active targeting of liposomes to the tumor tissues with the second near-infrared(NIR-Ⅱ)-triggered gold-shell disruption and GEM release.The collapsed gold-shell particles with a smaller size could penetrate the tumor solid barrier and act as photothermal therapy(PTT)agents to improve PTT therapy and starvation therapy via generating gluconic acid and reactive oxygen species(ROS).Moreover,the resting reversal effect of gold particles on tumor fibroblasts can achieve accelerating tumor penetration of gold particles and GEM.Compared to monotherapy,RGTG showed significant improvement in tumor inhibition,with a tumor volume reduction of 83%compared to the control group,which provides a promising tumor treatment platform for non-small cell lung cancer(NSCLC).
文摘To reduce the damage of the pressurizing panel structure of a fuselage caused by an explosion at the“least risk bomb location”in an aircraft structure,a new pre-separation panel structure was designed to resist blast loading.First,the dynamic strain response and morphology of impact damage of the new pre-separation panel were measured in an impact damage test.Second,the commercial software LS-DYNA was used to calculate the propagation of the blast shock wave,and the results were compared with empirical equations to verify the rationality of the numerical calculation method.Finally,the fluid–structure coupling method was used to calculate the damage process of the pre-separation panel structure under the impact of an explosion wave and an impact block.The calculated results were in good agreement with the test results,which showed the rationality of the calculation method and the model.The residual strength of the damaged pre-separation panel was significantly higher than that of the original damaged panel.The results show that the new pre-separation panel structure is reasonable and has certain significance for guiding the design of plenum chambers with strong resistance to implosion for aircraft fuselages.
文摘In modern warfare,unpowered glide munitions,represented by JDAM,are widely used.Accurately predicting the future trajectory of such targets is crucial for intercepting them.This paper proposes a future point prediction method for unpowered gliding targets based on attitude computation.By estimating the current state of the target,we derive the target’s attitude coordinate system.Subsequently,the paper analyzes the forces acting on the target and updates the state transition matrix,ultimately calculating the future position of the target.Experimental results show that,compared to traditional methods,this approach improves the accuracy of future point predictions by 9%to 45%.
文摘Aim To study the effect of aerodynamically stabilized seeker dynamics on guided bomb system analysis. Methods A thorough analysis of aerodynamically stabilized seeker dynamics was made to show that because of the much smaller time constant, its dynamic model can be greatly simplified. Results and Conclusion In guided bomb guidance/control digital simulation, with the use of the simplified seeker model, simulation time can be reduced without the loss of simulation accuracy.
文摘Using an oral history approach, this study analyzed the narratives obtained from semi-structured interviews administered to three Japanese women who worked as nurses for the Hiroshima Atomic Bomb Casualty Commission (ABCC). The analysis of the data in the narratives showed details of the health surveys and health checkups conducted during the early period of operation of ABCC. During the early period of operation of ABCC some survivors showed negative behaviors toward the health surveys and health checkups at the ABCC. However, it can be inferred that dedicated nursing played an important role in alleviating the stress and emotional issues of survivors at the health surveys and health checkups. The findings of the study could be beneficial to research into nursing activities for patients exposed to radiation at the present day.
基金Supported by the Independent Scientific Research of Nanjing University of Science and Technology(2011YBXM110)~~
文摘The sequential dispersing results of aerial cluster bomb are discussed. The ballistic model and the mod- el for impact point distribution of bullets are established. The main factors influencing impact point distribution are analyzed by numerical simulation. And the feasibility of improving distribution effect through sequential dis- persing is validated. Sequential dispersion and optimized airdrop parameters can help to achieve better battle effec- tiveness.
文摘The buried village is Vinh Moc where more than 1200 Vietnamese, including soldiers, who lived underground during the Vietnam War (1965 to 1972) were hand dug into red basalt bedrock. The Vinh Moc Village was strategically located on the border of North Vietnam and South Vietnam approximately 14 km north of the DMZ and along the shoreline of the South China Sea. During the Vietnam War, the US Air Force heavily bombed Vinh Moc. The North Vietnamese Army (NVA) had an important military base on nearby Con Co Island. Brave civil volunteers from Vinh Moc would make the 28 km dangerous journey to the island, disguised as fishermen, to deliver supplies to the soldiers stationed there. The people who remained at Vinh Moc dug tunnels into red basalt hills in order to survive this onslaught. The American forces assessed the villagers of Vinh Moc were supplying food and armaments to the NVA garrison on the island of Con Co, which was in turn hindering the American bombers on their way to bomb Hanoi. The US military objective was to force the villagers of Vinh Moc to leave the area. The villagers initially dug the tunnels to a 10 m depth but the American forces designed bombs that burrowed down 10 m before exploding. The soil tunnels were then deepened to 30 m to provide safety for the soldiers and civilians working there during the intense US Air Force bombing. The primary objective of the research study was to determine how the soils and parent material of Vinh Moc Village, protected their villagers from the United States Air Force bombardment during the Vietnam War. In addition, the natural parent material at both the Vinh Moc and Cu Chi were assessed to determine why the tunnels were so resilient. The Cu Chi and Iron Triangle soil tunnels were dug by hand in the Old Alluvium soils and parent material where iron in solution precipitated and became the soil binding material. The Vinh Moc tunnels were hand dug in porous, red basalt (bedrock) hills where the consolidated rock structure itself provided the required binding material. Neither site needed support beams to hold up the ceilings.
