The preparation of functional material titanium carbide by the carbothermal reduction of Ti-bearing blast furnace slag with microwave heating is an effective method for valuable metals recovery;it can alleviate the en...The preparation of functional material titanium carbide by the carbothermal reduction of Ti-bearing blast furnace slag with microwave heating is an effective method for valuable metals recovery;it can alleviate the environmental pressure caused by slag stocking.The dynamic dielectric parameters of Ti-bearing blast furnace slag/pulverized coal mixture under high-temperature heating are measured by the cylindrical resonant cavity perturbation method.Combining the transient dipole and large π bond delocalization polarization phenomena, the interaction mechanism of the microwave macroscopic non-thermal effect on the titanium carbide synthesis reaction was revealed.The material thickness range during microwave heating was optimized by the joint analysis of penetration depth and reflection loss, which is of great significance to the design of the microwave reactor for the carbothermal reduction of Ti-bearing blast furnace slag.展开更多
Rice line 1892S is an elite thermo-sensitive genic male sterile(TGMS)line for two-line hybrid rice production.However,1892S is susceptible to rice blast,bacterial blight and submergence.Here we reported the introducti...Rice line 1892S is an elite thermo-sensitive genic male sterile(TGMS)line for two-line hybrid rice production.However,1892S is susceptible to rice blast,bacterial blight and submergence.Here we reported the introduction of blast resistance(R)gene Pi9,bacterial blight R gene Xa21 and submergence tolerance gene Sub1A into 1892S genetic background through backcrossing and marker-assisted selection.The improved TGMS line 31892S and its hybrids conferred disease resistance to rice blast and bacterial blight,and showed submergence tolerance for over 14 d without significant loss of viability.The sterility-fertility conversion of 31892S was similar to that of 1892S.31892S and its derived hybrid rice had similar agronomic traits and grain quality with 1892S and the control hybrid rice,respectively.The newly developed 31892S provided an improved TGMS line for two-line hybrid rice production with disease resistance to rice blast and bacterial blight,and submergence tolerance with no yield penalty or change in grain quality.展开更多
The aim of this study is to create alternative approaches to predict human response to ground vibration.Site measurements were conducted in an urban quarry.The multiple discriminant analysis technique was used to deve...The aim of this study is to create alternative approaches to predict human response to ground vibration.Site measurements were conducted in an urban quarry.The multiple discriminant analysis technique was used to develop classification models.The measured ground vibration values were grouped based on the limit values appearing in the literature.Two classification models were created to predict human response to ground vibration.In addition,classical predictor equations were developed to compare to the classification models.The best equations were chosen considering several error measures.All the models were tested on the independent data.The prediction accuracy of the discriminant analysis models is quite promising.Nearly eighty-nine percent of the test data were correctly classified.The classification models have a combined structure.The results of the models can be directly presented to the neighbors of the studied quarry.The models are not complex.They do not require additional software or information to practice and can be easily used by site engineers.展开更多
The valorization solutions for dredged sediment have been the subject of a great number of investigations over the previous decades.In the current present study,treatment of polluted dredged sediment fom the commercia...The valorization solutions for dredged sediment have been the subject of a great number of investigations over the previous decades.In the current present study,treatment of polluted dredged sediment fom the commercial port of Sfax,Tunisia,is proposed.An industrial byproduct(blast furnace slag)was used to bind raw sediment for a reuse in road engineering.Following standards of this field,the raw sediment first was identified and classified according to the French technical guidance.Then an environmental assessment was applied due to the presence of heavy metals.The concentrations were measured on the raw sediment particles so as to control the binding effect on heavy metals.Sediment mixtures consisted of a mix of sand and a blast furnace slag activated with quicklime.Different mixtures were tested and some were proposed for sub-layer applications.The Sfax commercial port raw sediment is considered as a sandy loam with a very low fraction of clay.The measured concentrations of heavy metals exceed the recommended thresholds for cadmium,copper,lead,and zinc.These can induce hazardous effects in the case of their dumping into the sea.On the other hand,the concentrations of the detected elements after leaching tests run on raw sediment samples are very low compared to the thresholds;such results highlight a possible recycling of the raw sediment in subgrade layers without any negative impact.Suitable formulations were deduced for road engineering tests relying on the ratio the California Bearing Ratio index and the immediate bearing index.If the obtained ratio exceeds one,the treated sediment can be recycled and used in road layers.展开更多
There are several underground mines in India which operate in close proximity to an operating surface mine.Under such scenario,the blast induced stress waves generated due to surface blasting may be a potential source...There are several underground mines in India which operate in close proximity to an operating surface mine.Under such scenario,the blast induced stress waves generated due to surface blasting may be a potential source to cause instability of adjoining underground mine structures.Using seismographs,54 blast induced vibration data were recorded at various locations in the roof,floor and pillars of the underground mine at Hingir Rampur mine of Coal India Limited by synchronizing the timing of surface blasting carried at an adjacent Samleshwari opencast mine.Results of this study show that Artificial Neural Network(ANN)has better prediction potential of peak particle velocity(PPV)and damage to adjacent underground structures due to surface blasting as compared to conventional regression methods.In order to assess and predict the impact of surface blasts on underground workings,Blast Damage Factor(BDF)has been evolved.The study shows that site specific charts can predict the blast damage class at an underground location due to surface blasting for known distances and explosive charge per delay.The severe damage in case study mine site took place when peak particle velocity exceeded 162 mm/s and PPV less than 51 mm/s had no probability of damage to underground structures due to surface blasting.展开更多
We report a case of blast injury to the left hand which resulted in fractures of the fingers with exposure of bones and joints of the phalanges. We used three reverse adipofascial cross finger flaps raised at the same...We report a case of blast injury to the left hand which resulted in fractures of the fingers with exposure of bones and joints of the phalanges. We used three reverse adipofascial cross finger flaps raised at the same time from 2 fingers to reconstruct adjacent fingers of the patient. The patient recovered well postoperatively and had good range of movement of the fingers. This avoided the complications of the use of regional or distal flaps. To our knowledge, this is the first case reported in which three reverse adipofascial cross fingers flaps are raised at the same time, two of them from an injured finger, to cover three raw areas on two fingers of a patient.展开更多
Objective To observe the dynamic impacts of shock waves on the severity of lung injury in rats with different injury distances.Methods Simulate open-field shock waves;detect the biomechanical effects of explosion sour...Objective To observe the dynamic impacts of shock waves on the severity of lung injury in rats with different injury distances.Methods Simulate open-field shock waves;detect the biomechanical effects of explosion sources at distances of 40,44,and 48 cm from rats;and examine the changes in the gross anatomy of the lungs,lung wet/dry weight ratio,hemoglobin concentration,blood gas analysis,and pathology.Results Biomechanical parameters such as the overpressure peak and impulse were gradually attenuated with an increase in the injury distance.The lung tissue hemorrhage,edema,oxygenation index,and pathology changed more significantly for the 40 cm group than for the 44 and 48 cm groups.The overpressure peak and impulse were significantly higher for the 40 cm group than for the 44 and 48 cm groups(P<0.05 or P<0.01).The animal mortality was significantly higher for the 40 cm group than for the other two groups(41.2%vs.17.8%and 10.0%,P<0.05).The healing time of injured lung tissues for the 40 cm group was longer than those for the 44 and 48 cm groups.Conclusions The effects of simulated open-field shock waves on the severity of lung injuries in rats were correlated with the injury distances,the peak overpressure,and the overpressure impulse.展开更多
Blast furnace ironmaking process is the most mature and highly effective process for producing liquid iron.Blast furnace is a gas-solid and gas-solid-liquid countercurrent reactor,and maintaining gas permeability is t...Blast furnace ironmaking process is the most mature and highly effective process for producing liquid iron.Blast furnace is a gas-solid and gas-solid-liquid countercurrent reactor,and maintaining gas permeability is the precondition of smooth production.Therefore,improving the gas permeability throughout the blast furnace remains a hot issue which is concerned by many metallurgical scholars.According to the research results of many scholars,the dominant factors influencing the gas permeability of different locations in the blast furnace(locations are distinguished according to the morphology change of the burdens)were reviewed.And the strategies for improving the gas permeability of different locations in the blast furnace were summarized based on these dominant influencing factors,such as suppressing the low-temperature reduction degradation of sinter in the lump zone,improving the indirect reduction degree and suppressing the interaction between different burdens.It is hoped to provide both theoretical and practical values for guiding the blast furnace so as to improve smooth operation and smelting efficiency.展开更多
Based on the technology of gas-injection blast furnace(BF),the characteristics of primary slag formation with H2 addition were researched.The results indicate that,compared with traditional BF,the primary melt is form...Based on the technology of gas-injection blast furnace(BF),the characteristics of primary slag formation with H2 addition were researched.The results indicate that,compared with traditional BF,the primary melt is formed at a lower temperature,which promotes the deformation of the solid burden particles.With the increase in temperature and H2 content,the quantity of formed melt containing FeO decreases sharply,corresponding to the crystallization of solid 2CaO Si02 during reduction.A wider softening range and narrower melting zone could be found in the gas-injection BF with a higher reduction potential.The permeability of burden layer is ameliorated as a result of decreased melt quantity.The influence of H2 on the high-temperature properties of burden is not so conspicuous when the H2 addition is from 10 to 15 vol.%against 5 to 10 vol.%.What is more,the slag shows a better liquidity with the decrease in basicity,owing to the transformation of melt composition from a primary phase field with high melting point to that with low melting point.The process of slag forming in gas-injection BF is characterized by earlier melt formation,less primary slag,higher melting temperature,better permeability and better liquidity,and the phase compositions of primary slag are close to those of final slag.展开更多
Purpose:To establish a severe blast lung injury model of goats and investigate the feasibility of lung ultrasonic score in the evaluation of blast lung injury.Methods:Twenty female healthy goats were randomly divided ...Purpose:To establish a severe blast lung injury model of goats and investigate the feasibility of lung ultrasonic score in the evaluation of blast lung injury.Methods:Twenty female healthy goats were randomly divided into three groups by different driving pressures:4.0 MPa group(n=4),4.5 MPa group(n=12)and 5.0 MPa group(n=4).The severe blast lung injury model of goats was established using a BST-I bio-shock tube.Vital signs(respiration,heart rate and blood pressure),lung ultrasound score(LUS),PO2/FiO2 and extravascular lung water(EVLW)were measured before injury(0 h)and at 0.5 h,3 h,6 h,9 h,12 h after injury.Computed tomography scan was performed before injury(0 h)and at 12 h after injury for dynamic monitoring of blast lung injury and measurement of lung volume.The correlation of LUS with PaO2/FiO2,EVLW,and lung injury ratio(lesion volume/total lung volume*100%)was analyzed.All animals were sacrificed at 12 h after injury for gross observation of lung injury and histopathological examination.Statistical analysis was performed by the SPSS 22.0 software.The measurement data were expressed as mean±standard deviation.The means of two samples were compared using independent-sample t-test.Pearson correlation analysis was conducted.Results:(1)At 12 h after injury,the mortality of goats was 0,41.67% and 100%in the 4.0 Mpa,4.5 MPa and 5.0 MPa groups,respectively;the area of pulmonary hemorrhage was 20.00%±13.14% in the 4.0 Mpa group and 42.14%±15.33% in the 4.5 MPa group.A severe lung shock injury model was established under the driving pressure of 4.5 MPa.(2)The respiratory rate,heart rate,LUS and EVLW were significantly increased,while PaO2/FiO2 was significantly reduced immediately after injury,and then they gradually recovered and became stabilized at 3 h after injury.(3)LUS was positively correlated with EVLW(3 h:r=-0.597,6 h:r=-0.698,9 h:r=-0.729;p<0.05)and lung injury ratio(12 h:r=-0.884,p<0.05),negatively correlated with PaO2/FiO2(3 h:r=-0.871,6 h:r=-0.637,9 h:r=-0.658;p<0.05).Conclusion:We established a sever展开更多
Precast concrete structures have developed rapidly in the last decades due to the advantages of better quality,non-pollution and fast construction with respect to conventional cast-in-place structures.In the present s...Precast concrete structures have developed rapidly in the last decades due to the advantages of better quality,non-pollution and fast construction with respect to conventional cast-in-place structures.In the present study,a theoretical model and nonlinear 3D model are developed and established to assess the dynamic behavior of precast concrete slabs under blast load.At first,the 3D model is validated by an experiment performed by other researchers.The verified model is adopted to investigate the blast performance of fabricated concrete panels(FCPs)in terms of parameters of the explosive charge,panel thickness,and reinforcement ratio.Finally,a simplified theoretical model of the FCP under blast load is developed to predict the maximum deflection.It is indicated that the theoretical model can precisely predict the maximum displacement of FCP under blast loads.The results show that the failure modes of the panels varied from bending failure to shear failure with the mass of TNT increasing.The thickness of the panel,reinforcement ratio,and explosive charges have significant effects on the anti-blast capacity of the FCPs.展开更多
The numerical simulation of a blast wave of a multilayer composite charge is investigated.A calculation model of the near-field explosion and far-field propagation of the shock wave of a composite charge is establishe...The numerical simulation of a blast wave of a multilayer composite charge is investigated.A calculation model of the near-field explosion and far-field propagation of the shock wave of a composite charge is established using the AUTODYN finite element program.Results of the near-field and far-field calculations of the shock wave respectively converge at cell sizes of 0.25-0.5 cm and 1-3 cm.The Euler--fluxcorrected transport solver is found to be suitable for the far-field calculation after mapping.A numerical simulation is conducted to study the formation,propagation,and interaction of the shock wave of the composite charge for different initiation modes.It is found that the initiation mode obviously affects the shock-wave waveform and pressure distribution of the composite charge.Additionally,it is found that the area of the overpressure distribution is greatest for internal and external simultaneous initiation,and the peak pressure of the shock wave exponentially decays,fitting the calculation formula of the peak overpressure attenuation under different initiation modes,which is obtained and verified by experiment.The difference between numerical and experimental results is less than 10%,and the peak overpressure of both internal and external initiation is 56.12% higher than that of central single-point initiation.展开更多
Purpose:Blast lung injury(BLI)is the most common damage resulted from explosion-derived shock wave in military,terrorism and industrial accidents.However,the molecular mechanisms underlying BLI induced by shock wave a...Purpose:Blast lung injury(BLI)is the most common damage resulted from explosion-derived shock wave in military,terrorism and industrial accidents.However,the molecular mechanisms underlying BLI induced by shock wave are still unclear.Methods:In this study,a goat BLI model was established by a fuel air explosive power.The key genes involved in were identified.The goats of the experimental group were fixed on the edge of the explosion cloud,while the goats of the control group were 3 km far away from the explosive environment.After successful modeling for 24 h,all the goats were sacrificed and the lung tissue was harvested for histopathological observation and RNA sequencing.Gene ontology(GO)and kyoto encyclopedia of genes and genomes(KEGG)analysis were performed to identify the main enriched biological functions of differentially expressed genes(DEGs).Quantitative real-time polymerase chain reaction(qRT-PCR)was used to verify the consistency of gene expression.Results:Of the sampled goat lungs,895 genes were identified to be significantly differentially expressed,and they were involved in 52 significantly enriched GO categories.KEGG analysis revealed that DEGs were highly enriched in 26 pathways,such as cytokine-cytokine receptor interaction,antifolate resistance,arachidonic acid metabolism,amoebiasis and bile secretion,JAK-STAT,and IL-17 signaling pathway.Furthermore,15 key DEGs involved in the biological processes of BLI were confirmed by qRTPCR,and the results were consistent with RNA sequencing.Conclusion:Gene expression profiling provide a better understanding of the molecular mechanisms of BLI,which will help to set strategy for treating lung injury and preventing secondary lung injury induced by shock wave.展开更多
The load-carrying capacities and failure patterns of reinforced concrete components can be significantly changed by membrane effects.However,limited work has been carried out to investigate the blast resistance of Hyb...The load-carrying capacities and failure patterns of reinforced concrete components can be significantly changed by membrane effects.However,limited work has been carried out to investigate the blast resistance of Hybrid Fiber Reinforced Lightweight Aggregate Concrete(HFR-LWC)members accompanying membrane action.This paper presents a theoretical approach to quantitatively depicting the membrane behavior and its contribution on the behavior of HFR-LWC beams under close-range blast loadings,and the suitability of the proposed model is validated by a series of field tests.An improved Single-Degree-of-Freedom(SDOF)model was employed to describe the dynamic responses of beam-like members under blast loadings accompanying membrane action,where the mass-load coefficient is determined according to the nonuniformly distributed load induced by close-range explosion,and the membrane action is characterized by an in-plane(longitudinal)force and a resisting moment.The elastoplastic and recovery responses of HFR-LWC beams under the combined action of blast load and membrane force were analyzed by the promoted model.A specially built end-constrain clamp was developed to provide membrane action for the beam member when they are subjected to blast load simultaneously.It is demonstrated that the analytical displacement-time histories are in good agreement with experimental results before peak deflections and that the improved SDOF model is an acceptable tool for predicting the behavior of HFR-LWC beams under blast loadings accompanying membrane action.展开更多
The resistance of dominant rice varieties in Guangzhou against rice blast(Magnaporthe oryzae)and bacterial blight(Xanthomonas oryzae pv.oryzae)were evaluated by artificial inoculation and field natural blast nursery i...The resistance of dominant rice varieties in Guangzhou against rice blast(Magnaporthe oryzae)and bacterial blight(Xanthomonas oryzae pv.oryzae)were evaluated by artificial inoculation and field natural blast nursery identification.Among 11 varieties tested,seven varieties showed resistance to rice blast,accounting for 63.6%;two varieties were highly resistant,accounting for 18.2%;three varieties were resistant,accounting for 27.3%;two varieties were moderately resistant,accounting for 18.2%;four varieties were susceptible(moderately susceptible),accounting for 36.4%.Varieties showed different resistance against the prevailing pathotype IV of bacterial blight;one variety was resistant,accounting for 9.1%;three varieties were moderately resistant,accounting for 27.3%;five varieties were moderately susceptible,accounting for 45.5%;one variety was susceptible,accounting for 9.1%;one variety was highly susceptible,accounting for 9.1%;all varieties tested showed susceptible to the virulent pathotype V.Huanghuazhan,Yuejingsimiao 2 and Fengxiuzhan showed resistance against both bacterial blight(pathotype IV)and rice blast,accounting for 27.3%.It is helpful to reduce the production risk by extending such dominant rice varieties with good resistance to rice blast and bacterial blight.展开更多
Three doses of silicon fertilizer and seven dominant rice varieties were selected to study the effects of silicon fertilizer on rice blast(Magnaporthe oryzae)green control,rice growth and yield.The results showed appl...Three doses of silicon fertilizer and seven dominant rice varieties were selected to study the effects of silicon fertilizer on rice blast(Magnaporthe oryzae)green control,rice growth and yield.The results showed application of silicon fertilizer had certain control effect on panicle blast,and was beneficial for rice growth and yield.However,application effect varied among different varieties,and application of silicon fertilizer at the dose of 225 kg/hm2 received the best effect.Applying silicon fertilizer to control rice blast is safe and environmental-friendly,which is beneficial to the production of green food production.展开更多
基金financially supported by the National Key R&D Program of China (No.2018YFC1900500)the National Natural Science Foundation of China (No.51961020)+1 种基金the Key Technology Research and Industrialization Application Demonstration Project of the Renewable Multi-energy Complementary (No.2018IB020)the Academician Workstation of Kefa Cen (No.2018IC085)。
文摘The preparation of functional material titanium carbide by the carbothermal reduction of Ti-bearing blast furnace slag with microwave heating is an effective method for valuable metals recovery;it can alleviate the environmental pressure caused by slag stocking.The dynamic dielectric parameters of Ti-bearing blast furnace slag/pulverized coal mixture under high-temperature heating are measured by the cylindrical resonant cavity perturbation method.Combining the transient dipole and large π bond delocalization polarization phenomena, the interaction mechanism of the microwave macroscopic non-thermal effect on the titanium carbide synthesis reaction was revealed.The material thickness range during microwave heating was optimized by the joint analysis of penetration depth and reflection loss, which is of great significance to the design of the microwave reactor for the carbothermal reduction of Ti-bearing blast furnace slag.
文摘Rice line 1892S is an elite thermo-sensitive genic male sterile(TGMS)line for two-line hybrid rice production.However,1892S is susceptible to rice blast,bacterial blight and submergence.Here we reported the introduction of blast resistance(R)gene Pi9,bacterial blight R gene Xa21 and submergence tolerance gene Sub1A into 1892S genetic background through backcrossing and marker-assisted selection.The improved TGMS line 31892S and its hybrids conferred disease resistance to rice blast and bacterial blight,and showed submergence tolerance for over 14 d without significant loss of viability.The sterility-fertility conversion of 31892S was similar to that of 1892S.31892S and its derived hybrid rice had similar agronomic traits and grain quality with 1892S and the control hybrid rice,respectively.The newly developed 31892S provided an improved TGMS line for two-line hybrid rice production with disease resistance to rice blast and bacterial blight,and submergence tolerance with no yield penalty or change in grain quality.
基金Research Fund of the Istanbul Technical University under Grant No.MGA-2017-40581the Scientific and Technological Research Council of Turkey-TUBITAK-under Grant No.217M071。
文摘The aim of this study is to create alternative approaches to predict human response to ground vibration.Site measurements were conducted in an urban quarry.The multiple discriminant analysis technique was used to develop classification models.The measured ground vibration values were grouped based on the limit values appearing in the literature.Two classification models were created to predict human response to ground vibration.In addition,classical predictor equations were developed to compare to the classification models.The best equations were chosen considering several error measures.All the models were tested on the independent data.The prediction accuracy of the discriminant analysis models is quite promising.Nearly eighty-nine percent of the test data were correctly classified.The classification models have a combined structure.The results of the models can be directly presented to the neighbors of the studied quarry.The models are not complex.They do not require additional software or information to practice and can be easily used by site engineers.
文摘The valorization solutions for dredged sediment have been the subject of a great number of investigations over the previous decades.In the current present study,treatment of polluted dredged sediment fom the commercial port of Sfax,Tunisia,is proposed.An industrial byproduct(blast furnace slag)was used to bind raw sediment for a reuse in road engineering.Following standards of this field,the raw sediment first was identified and classified according to the French technical guidance.Then an environmental assessment was applied due to the presence of heavy metals.The concentrations were measured on the raw sediment particles so as to control the binding effect on heavy metals.Sediment mixtures consisted of a mix of sand and a blast furnace slag activated with quicklime.Different mixtures were tested and some were proposed for sub-layer applications.The Sfax commercial port raw sediment is considered as a sandy loam with a very low fraction of clay.The measured concentrations of heavy metals exceed the recommended thresholds for cadmium,copper,lead,and zinc.These can induce hazardous effects in the case of their dumping into the sea.On the other hand,the concentrations of the detected elements after leaching tests run on raw sediment samples are very low compared to the thresholds;such results highlight a possible recycling of the raw sediment in subgrade layers without any negative impact.Suitable formulations were deduced for road engineering tests relying on the ratio the California Bearing Ratio index and the immediate bearing index.If the obtained ratio exceeds one,the treated sediment can be recycled and used in road layers.
文摘There are several underground mines in India which operate in close proximity to an operating surface mine.Under such scenario,the blast induced stress waves generated due to surface blasting may be a potential source to cause instability of adjoining underground mine structures.Using seismographs,54 blast induced vibration data were recorded at various locations in the roof,floor and pillars of the underground mine at Hingir Rampur mine of Coal India Limited by synchronizing the timing of surface blasting carried at an adjacent Samleshwari opencast mine.Results of this study show that Artificial Neural Network(ANN)has better prediction potential of peak particle velocity(PPV)and damage to adjacent underground structures due to surface blasting as compared to conventional regression methods.In order to assess and predict the impact of surface blasts on underground workings,Blast Damage Factor(BDF)has been evolved.The study shows that site specific charts can predict the blast damage class at an underground location due to surface blasting for known distances and explosive charge per delay.The severe damage in case study mine site took place when peak particle velocity exceeded 162 mm/s and PPV less than 51 mm/s had no probability of damage to underground structures due to surface blasting.
文摘We report a case of blast injury to the left hand which resulted in fractures of the fingers with exposure of bones and joints of the phalanges. We used three reverse adipofascial cross finger flaps raised at the same time from 2 fingers to reconstruct adjacent fingers of the patient. The patient recovered well postoperatively and had good range of movement of the fingers. This avoided the complications of the use of regional or distal flaps. To our knowledge, this is the first case reported in which three reverse adipofascial cross fingers flaps are raised at the same time, two of them from an injured finger, to cover three raw areas on two fingers of a patient.
基金supported by the Major Project of Military Logistical Support Department[grant number AWS15J003and ALB19J001]。
文摘Objective To observe the dynamic impacts of shock waves on the severity of lung injury in rats with different injury distances.Methods Simulate open-field shock waves;detect the biomechanical effects of explosion sources at distances of 40,44,and 48 cm from rats;and examine the changes in the gross anatomy of the lungs,lung wet/dry weight ratio,hemoglobin concentration,blood gas analysis,and pathology.Results Biomechanical parameters such as the overpressure peak and impulse were gradually attenuated with an increase in the injury distance.The lung tissue hemorrhage,edema,oxygenation index,and pathology changed more significantly for the 40 cm group than for the 44 and 48 cm groups.The overpressure peak and impulse were significantly higher for the 40 cm group than for the 44 and 48 cm groups(P<0.05 or P<0.01).The animal mortality was significantly higher for the 40 cm group than for the other two groups(41.2%vs.17.8%and 10.0%,P<0.05).The healing time of injured lung tissues for the 40 cm group was longer than those for the 44 and 48 cm groups.Conclusions The effects of simulated open-field shock waves on the severity of lung injuries in rats were correlated with the injury distances,the peak overpressure,and the overpressure impulse.
基金National Key Research and Development Program of China(No.2016YFB0601304).
文摘Blast furnace ironmaking process is the most mature and highly effective process for producing liquid iron.Blast furnace is a gas-solid and gas-solid-liquid countercurrent reactor,and maintaining gas permeability is the precondition of smooth production.Therefore,improving the gas permeability throughout the blast furnace remains a hot issue which is concerned by many metallurgical scholars.According to the research results of many scholars,the dominant factors influencing the gas permeability of different locations in the blast furnace(locations are distinguished according to the morphology change of the burdens)were reviewed.And the strategies for improving the gas permeability of different locations in the blast furnace were summarized based on these dominant influencing factors,such as suppressing the low-temperature reduction degradation of sinter in the lump zone,improving the indirect reduction degree and suppressing the interaction between different burdens.It is hoped to provide both theoretical and practical values for guiding the blast furnace so as to improve smooth operation and smelting efficiency.
基金National Natural Science Foundation of China(U1360205,51674122)Iron and Steel Research Foundation of Hebei(E2016209367).
文摘Based on the technology of gas-injection blast furnace(BF),the characteristics of primary slag formation with H2 addition were researched.The results indicate that,compared with traditional BF,the primary melt is formed at a lower temperature,which promotes the deformation of the solid burden particles.With the increase in temperature and H2 content,the quantity of formed melt containing FeO decreases sharply,corresponding to the crystallization of solid 2CaO Si02 during reduction.A wider softening range and narrower melting zone could be found in the gas-injection BF with a higher reduction potential.The permeability of burden layer is ameliorated as a result of decreased melt quantity.The influence of H2 on the high-temperature properties of burden is not so conspicuous when the H2 addition is from 10 to 15 vol.%against 5 to 10 vol.%.What is more,the slag shows a better liquidity with the decrease in basicity,owing to the transformation of melt composition from a primary phase field with high melting point to that with low melting point.The process of slag forming in gas-injection BF is characterized by earlier melt formation,less primary slag,higher melting temperature,better permeability and better liquidity,and the phase compositions of primary slag are close to those of final slag.
基金supported by State Key Laboratory of Trauma,Burns and Combined Injury Project(No.SKLYQ201901,No.SKLKF201801).
文摘Purpose:To establish a severe blast lung injury model of goats and investigate the feasibility of lung ultrasonic score in the evaluation of blast lung injury.Methods:Twenty female healthy goats were randomly divided into three groups by different driving pressures:4.0 MPa group(n=4),4.5 MPa group(n=12)and 5.0 MPa group(n=4).The severe blast lung injury model of goats was established using a BST-I bio-shock tube.Vital signs(respiration,heart rate and blood pressure),lung ultrasound score(LUS),PO2/FiO2 and extravascular lung water(EVLW)were measured before injury(0 h)and at 0.5 h,3 h,6 h,9 h,12 h after injury.Computed tomography scan was performed before injury(0 h)and at 12 h after injury for dynamic monitoring of blast lung injury and measurement of lung volume.The correlation of LUS with PaO2/FiO2,EVLW,and lung injury ratio(lesion volume/total lung volume*100%)was analyzed.All animals were sacrificed at 12 h after injury for gross observation of lung injury and histopathological examination.Statistical analysis was performed by the SPSS 22.0 software.The measurement data were expressed as mean±standard deviation.The means of two samples were compared using independent-sample t-test.Pearson correlation analysis was conducted.Results:(1)At 12 h after injury,the mortality of goats was 0,41.67% and 100%in the 4.0 Mpa,4.5 MPa and 5.0 MPa groups,respectively;the area of pulmonary hemorrhage was 20.00%±13.14% in the 4.0 Mpa group and 42.14%±15.33% in the 4.5 MPa group.A severe lung shock injury model was established under the driving pressure of 4.5 MPa.(2)The respiratory rate,heart rate,LUS and EVLW were significantly increased,while PaO2/FiO2 was significantly reduced immediately after injury,and then they gradually recovered and became stabilized at 3 h after injury.(3)LUS was positively correlated with EVLW(3 h:r=-0.597,6 h:r=-0.698,9 h:r=-0.729;p<0.05)and lung injury ratio(12 h:r=-0.884,p<0.05),negatively correlated with PaO2/FiO2(3 h:r=-0.871,6 h:r=-0.637,9 h:r=-0.658;p<0.05).Conclusion:We established a sever
基金This work was supported by the National Natural Science Foundation of China(Grant No.51508148)China Postdoctoral Science Foundation Funded Project(Nos.2016T90563 and 2015M581980)+1 种基金open fund of Anhui Key Laboratory of Civil Engineering Structures and Materials in Hefei University of Technology,and State Key Laboratory of Structural Analysis for Industrial Equipment(Grant No.GZ19106)The authors also highly ppreciate the acknowledgment of the China Scholarship Council(CSC).
文摘Precast concrete structures have developed rapidly in the last decades due to the advantages of better quality,non-pollution and fast construction with respect to conventional cast-in-place structures.In the present study,a theoretical model and nonlinear 3D model are developed and established to assess the dynamic behavior of precast concrete slabs under blast load.At first,the 3D model is validated by an experiment performed by other researchers.The verified model is adopted to investigate the blast performance of fabricated concrete panels(FCPs)in terms of parameters of the explosive charge,panel thickness,and reinforcement ratio.Finally,a simplified theoretical model of the FCP under blast load is developed to predict the maximum deflection.It is indicated that the theoretical model can precisely predict the maximum displacement of FCP under blast loads.The results show that the failure modes of the panels varied from bending failure to shear failure with the mass of TNT increasing.The thickness of the panel,reinforcement ratio,and explosive charges have significant effects on the anti-blast capacity of the FCPs.
基金funded by the National Natural Science Foundation of China under NO.11202103Qing-lan Project of Jiangsu Province。
文摘The numerical simulation of a blast wave of a multilayer composite charge is investigated.A calculation model of the near-field explosion and far-field propagation of the shock wave of a composite charge is established using the AUTODYN finite element program.Results of the near-field and far-field calculations of the shock wave respectively converge at cell sizes of 0.25-0.5 cm and 1-3 cm.The Euler--fluxcorrected transport solver is found to be suitable for the far-field calculation after mapping.A numerical simulation is conducted to study the formation,propagation,and interaction of the shock wave of the composite charge for different initiation modes.It is found that the initiation mode obviously affects the shock-wave waveform and pressure distribution of the composite charge.Additionally,it is found that the area of the overpressure distribution is greatest for internal and external simultaneous initiation,and the peak pressure of the shock wave exponentially decays,fitting the calculation formula of the peak overpressure attenuation under different initiation modes,which is obtained and verified by experiment.The difference between numerical and experimental results is less than 10%,and the peak overpressure of both internal and external initiation is 56.12% higher than that of central single-point initiation.
基金This work was supported by Science and Technology Development Fund for Institute for Hygiene of Ordnance(KY202007).
文摘Purpose:Blast lung injury(BLI)is the most common damage resulted from explosion-derived shock wave in military,terrorism and industrial accidents.However,the molecular mechanisms underlying BLI induced by shock wave are still unclear.Methods:In this study,a goat BLI model was established by a fuel air explosive power.The key genes involved in were identified.The goats of the experimental group were fixed on the edge of the explosion cloud,while the goats of the control group were 3 km far away from the explosive environment.After successful modeling for 24 h,all the goats were sacrificed and the lung tissue was harvested for histopathological observation and RNA sequencing.Gene ontology(GO)and kyoto encyclopedia of genes and genomes(KEGG)analysis were performed to identify the main enriched biological functions of differentially expressed genes(DEGs).Quantitative real-time polymerase chain reaction(qRT-PCR)was used to verify the consistency of gene expression.Results:Of the sampled goat lungs,895 genes were identified to be significantly differentially expressed,and they were involved in 52 significantly enriched GO categories.KEGG analysis revealed that DEGs were highly enriched in 26 pathways,such as cytokine-cytokine receptor interaction,antifolate resistance,arachidonic acid metabolism,amoebiasis and bile secretion,JAK-STAT,and IL-17 signaling pathway.Furthermore,15 key DEGs involved in the biological processes of BLI were confirmed by qRTPCR,and the results were consistent with RNA sequencing.Conclusion:Gene expression profiling provide a better understanding of the molecular mechanisms of BLI,which will help to set strategy for treating lung injury and preventing secondary lung injury induced by shock wave.
基金the financial support from the National Natural Science Foundation of China(Grant:51578541,51378498)the Natural Science Foundation of Jiangsu Province(Grant:BK20141066).
文摘The load-carrying capacities and failure patterns of reinforced concrete components can be significantly changed by membrane effects.However,limited work has been carried out to investigate the blast resistance of Hybrid Fiber Reinforced Lightweight Aggregate Concrete(HFR-LWC)members accompanying membrane action.This paper presents a theoretical approach to quantitatively depicting the membrane behavior and its contribution on the behavior of HFR-LWC beams under close-range blast loadings,and the suitability of the proposed model is validated by a series of field tests.An improved Single-Degree-of-Freedom(SDOF)model was employed to describe the dynamic responses of beam-like members under blast loadings accompanying membrane action,where the mass-load coefficient is determined according to the nonuniformly distributed load induced by close-range explosion,and the membrane action is characterized by an in-plane(longitudinal)force and a resisting moment.The elastoplastic and recovery responses of HFR-LWC beams under the combined action of blast load and membrane force were analyzed by the promoted model.A specially built end-constrain clamp was developed to provide membrane action for the beam member when they are subjected to blast load simultaneously.It is demonstrated that the analytical displacement-time histories are in good agreement with experimental results before peak deflections and that the improved SDOF model is an acceptable tool for predicting the behavior of HFR-LWC beams under blast loadings accompanying membrane action.
基金Supported by National Key R&D Program of China(2017YFD0100100)Guangdong Science and Technology Project(2019B020217003,2018B030311035,2020A1515011213).
文摘The resistance of dominant rice varieties in Guangzhou against rice blast(Magnaporthe oryzae)and bacterial blight(Xanthomonas oryzae pv.oryzae)were evaluated by artificial inoculation and field natural blast nursery identification.Among 11 varieties tested,seven varieties showed resistance to rice blast,accounting for 63.6%;two varieties were highly resistant,accounting for 18.2%;three varieties were resistant,accounting for 27.3%;two varieties were moderately resistant,accounting for 18.2%;four varieties were susceptible(moderately susceptible),accounting for 36.4%.Varieties showed different resistance against the prevailing pathotype IV of bacterial blight;one variety was resistant,accounting for 9.1%;three varieties were moderately resistant,accounting for 27.3%;five varieties were moderately susceptible,accounting for 45.5%;one variety was susceptible,accounting for 9.1%;one variety was highly susceptible,accounting for 9.1%;all varieties tested showed susceptible to the virulent pathotype V.Huanghuazhan,Yuejingsimiao 2 and Fengxiuzhan showed resistance against both bacterial blight(pathotype IV)and rice blast,accounting for 27.3%.It is helpful to reduce the production risk by extending such dominant rice varieties with good resistance to rice blast and bacterial blight.
基金Supported by National Key R&D Program of China(2017YFD0100100)&Guangdong Science and Technology Project(2019B020217003).
文摘Three doses of silicon fertilizer and seven dominant rice varieties were selected to study the effects of silicon fertilizer on rice blast(Magnaporthe oryzae)green control,rice growth and yield.The results showed application of silicon fertilizer had certain control effect on panicle blast,and was beneficial for rice growth and yield.However,application effect varied among different varieties,and application of silicon fertilizer at the dose of 225 kg/hm2 received the best effect.Applying silicon fertilizer to control rice blast is safe and environmental-friendly,which is beneficial to the production of green food production.