Thermal shocking effect occurs when the coalbed methane(CBM)reservoirs meet liquid nitrogen(LN2)of extremely low temperature.In this study,3D via X-ray microcomputer tomography(μCT)and scanning electron microscope(SE...Thermal shocking effect occurs when the coalbed methane(CBM)reservoirs meet liquid nitrogen(LN2)of extremely low temperature.In this study,3D via X-ray microcomputer tomography(μCT)and scanning electron microscope(SEM)are employed to visualize and quantify morphological evolution characteristics of fractures in coal after LN2 thermal shocking treatments.LN2 thermal shocking leads to a denser fracture network than its original state with coal porosity growth rate increasing up to 183.3%.The surface porosity of theμCT scanned layers inside the coal specimen is influenced by LN2 thermal shocking which rises from 18.76%to 215.11%,illustrating the deformation heterogeneity of coal after LN2 thermal shocking.The cracking effect of LN2 thermal shocking on the surface of low porosity is generally more effective than that of high surface porosity,indicating the applicability of LN2 thermal shocking on low-permeability CBM reservoir stimulation.The characteristics of SEM scanned coal matrix in the coal powder and the coal block after the LN2 thermal shocking presented a large amount of deep and shallow progressive scratch layers,fracture variation diversity(i.e.extension,propagation,connectivity,irregularity)on the surface of the coal block and these were the main reasons leading to the decrease of the uniaxial compressive strength of the coal specimen.展开更多
Laser plays an important role in synthesizing nanometer material. A three-dimensional mathematical model is established in this paper when single pulsed millisecond laser shocks the surface of the metal target at a li...Laser plays an important role in synthesizing nanometer material. A three-dimensional mathematical model is established in this paper when single pulsed millisecond laser shocks the surface of the metal target at a liquid-solid interface. By changing laser power density and target size, the temperature field variation of the metal target is investigated. Results show that the generation process of nanoparticles includes heating, melting and boiloff.展开更多
Correction to:Acta Metallurgica Sinica(English Letters)https://doi.org/10.1007/s40195-023-01576-x In the original publication,the afiliation citation appears incorrectly.The corrected affiliation citation should read ...Correction to:Acta Metallurgica Sinica(English Letters)https://doi.org/10.1007/s40195-023-01576-x In the original publication,the afiliation citation appears incorrectly.The corrected affiliation citation should read as below.展开更多
This article reports the latest development of a wireless sensing system,named Martlet,on high-g shock acceleration measurement.The Martlet sensing node design is based on a Texas Instruments Piccolo microcontroller,w...This article reports the latest development of a wireless sensing system,named Martlet,on high-g shock acceleration measurement.The Martlet sensing node design is based on a Texas Instruments Piccolo microcontroller,with clock frequency programmable up to 90 MHz.The high clock frequency of the microcontroller enables Martlet to support high-frequency data acquisition and high-speed onboard computation.In addition,the extensible design of the Martlet node conveniently allows incorporation of multiple sensor boards.In this study,a high-g accelerometer interface board is developed to allow Martlet to work with the selected microelectromechanical system(MEMS)high-g accelerometers.Besides low-pass and highpass filters,amplification gains are also implemented on the high-g accelerometer interface board.Laboratory impact experiments are conducted to validate the performance of the Martlet wireless sensing system with the high-g accelerometer board.The results of this study show that the performance of the wireless sensing system is comparable to the cabled system.展开更多
Tungsten has promising applications in high-radiation,high-erosion and high-impact environments.Laser peening is an effective method to enhance the surface mechanical properties of tungsten materials.However,the ultra...Tungsten has promising applications in high-radiation,high-erosion and high-impact environments.Laser peening is an effective method to enhance the surface mechanical properties of tungsten materials.However,the ultrafast dynamic mechanism of defect evolutions induced by laser shockwave in tungsten lattice is unclear.Here,we investigated the evolutions and interactions of various defects under ultrafast compressive process in tungsten lattice using molecular dynamic method.The results confirm the brittleness of tungsten and reveal that void can reduce the yield strain and strength of the tungsten lattice by accelerating defect mesh extension and promoting the dislocation nucleation around itself.Dislocation density is increased with compressive strain rate.Meanwhile,dislocation multiplication and motion reduce the elastic stage and play a dominant role during the plastic deformation of tungsten lattice.Additionally,void can disrupt the dislocation displacement and promote the pinning effect on dislocations by defect mesh extension.展开更多
Titanium(Ti)and its alloys are frequently utilized as critical components in a variety of engineering ap-plications because of their high specific strength and excellent corrosion resistance.Compared to conven-tional ...Titanium(Ti)and its alloys are frequently utilized as critical components in a variety of engineering ap-plications because of their high specific strength and excellent corrosion resistance.Compared to conven-tional surface strengthening technologies,laser shock peening(LSP)has increasingly attracted attention from researchers and industries,since it significantly improves the surface strength,biocompatibility,fa-tigue resistance,and anti-corrosion ability of Ti and its alloys.Despite numerous studies that have been carried out to elucidate the effects of LSP on microstructural evolution and mechanical properties of Ti and its alloys in recent years,a comprehensive review of recent advancements in the field of Ti and its alloys subjected to LSP is still lacking.In this review,the standard LSP and the novel process designs of LSP assisted by thermal,cryogenic,electropulsing and magnetic fields are discussed and compared.Microstructural evolution,with focuses on the dislocation dynamics,deformation twinning,grain refine-ment and surface amorphization,during LSP processing of Ti alloys is reviewed.Furthermore,the en-hanced engineering performance of the L SP-processed(L SPed)Ti alloys,including surface hardness,wear resistance,fatigue life and corrosion resistance are summarized.Finally,this review concludes by present-ing an overview of the current challenges encountered in this field and offering insights into anticipated future trends.展开更多
The thermochemical non-equilibrium phenomena encountered by hypersonic vehicles present significant challenges in their design.To investigate the thermochemical reaction flow behind shock waves,the non-equilibrium rad...The thermochemical non-equilibrium phenomena encountered by hypersonic vehicles present significant challenges in their design.To investigate the thermochemical reaction flow behind shock waves,the non-equilibrium radiation in the visible range using a shock tube was studied.Experiments were conducted with a shock velocity of 4.7 km/s,using nitrogen at a pressure of 20 Pa.To address measurement difficulties associated with weak radiation,a special square section shock tube with a side length of 380 mm was utilized.A high-speed camera characterized the shock wave’s morphology,and a spectrograph and a monochromator captured the radiation.The spectra were analyzed,and the numerical spectra were compared with experimental results,showing a close match.Temperature changes behind the shock wave were obtained and compared with numerical predictions.The findings indicate that the vibrational temperatures are overestimated,while the vibrational relaxation time is likely underestimated,due to the oversimplified portrayals of the non-equilibrium relaxation process in the models.Additionally,both experimental and simulated time-resolved profiles of radiation intensity at specific wavelengths were analyzed.The gathered data aims to enhance computational fluid dynamics codes and radiation models,improving their predictive accuracy.展开更多
Traffic engineering such as tunnels in various altitudinal gradient zone are at risk of accidental explosion,which can damage personnel and equipment.Accurate prediction of the distribution pattern of explosive loads ...Traffic engineering such as tunnels in various altitudinal gradient zone are at risk of accidental explosion,which can damage personnel and equipment.Accurate prediction of the distribution pattern of explosive loads and shock wave propagation process in semi-enclosed structures at various altitude environment is key research focus in the fields of explosion shock and fluid dynamics.The effect of altitude on the propagation of shock waves in tunnels was investigated by conducting explosion test and numerical simulation.Based on the experimental and numerical simulation results,a prediction model for the attenuation of the peak overpressure of tunnel shock waves at different altitudes was established.The results showed that the peak overpressure decreased at the same measurement points in the tunnel entrance under the high altitude condition.In contrast,an increase in altitude accelerated the propagation speed of the shock wave in the tunnel.The average error between the peak shock wave overpressure obtained using the overpressure prediction formula and the measured test data was less than15%,the average error between the propagation velocity of shock waves predicted values and the test data is less than 10%.The method can effectively predict the overpressure attenuation of blast wave in tunnel at various altitudes.展开更多
BACKGROUND:The lack of a stable,easy-to-operate animal model for severe trauma has hindered the research progress.The aim of this study is to develop a mouse model that replicates the pathophysiological conditions of ...BACKGROUND:The lack of a stable,easy-to-operate animal model for severe trauma has hindered the research progress.The aim of this study is to develop a mouse model that replicates the pathophysiological conditions of severe trauma,providing a reliable research tool.METHODS:Male C57BL/6J mice(aged 8-10 weeks and weighting approximately 20 g)were used to establish the severe trauma model.Under anesthesia,a midshaft femoral fracture was created and packed with sterile cotton.A midline incision was made from the inguinal region to the sternum,exposing the abdominal organs for 30 min.The right femoral artery was cannulated to induce controlled blood loss at 30%,35%,40%,and 50%of the total blood volume.Survival rates were monitored for 24 h post-induction.In the mice that experienced 30%blood loss,the mean arterial pressure,body temperature,blood gas parameters,peripheral blood inflammatory markers,and major organ pathological changes were assessed.RESULTS:Mice with femoral fractures,soft tissue injuries,abdominal organ exposure,and 30%blood loss exhibited stable survival rates.Increased blood loss significantly reduced survival rates.Mean arterial pressure decreased initially,recovering within 0-15 min and returning to baseline by 50 min.Similarly,the body temperature decreased initially and gradually recovered to baseline within 50 min.Levels of peripheral blood inflammatory markers remained elevated for 12 h post-injury.Distant organs,including intestines,lungs,liver,spleen and kidneys,displayed varying degrees of injury.CONCLUSION:The established mouse model replicates the pathophysiological responses to severe trauma,indicating stability and reproducibility,which could be an useful tool for further trauma research.展开更多
We are intrigued by the issues of shock instability,with a particular emphasis on numerical schemes that address the carbuncle phenomenon by reducing dissipation rather than increasing it.For a specific class of plana...We are intrigued by the issues of shock instability,with a particular emphasis on numerical schemes that address the carbuncle phenomenon by reducing dissipation rather than increasing it.For a specific class of planar flow fields where the transverse direction exhibits vanishing but non-zero velocity components,such as a disturbed onedimensional(1D)steady shock wave,we conduct a formal asymptotic analysis for the Euler system and associated numerical methods.This analysis aims to illustrate the discrepancies among various low-dissipative numerical algorithms.Furthermore,a numerical stability analysis of steady shock is undertaken to identify the key factors underlying shock-stable algorithms.To verify the stability mechanism,a consistent,low-dissipation,and shock-stable HLLC-type Riemann solver is presented.展开更多
The stability of supersonic inlets faces challenges due to various changes in flight conditions,and flow control methods that address shock wave/boundary layer interactions under only one set of conditions cannot meet...The stability of supersonic inlets faces challenges due to various changes in flight conditions,and flow control methods that address shock wave/boundary layer interactions under only one set of conditions cannot meet developmental requirements.This paper proposes an adaptive bump control scheme and employs dynamic mesh technology for numerical simulation to investigate the unsteady control effects of adaptive bumps.The obtained results indicate that the use of moving bumps to control shock wave/boundary layer interactions is feasible.The adaptive control effects of five different bump speeds are evaluated.Within the range of bump speeds studied,the analysis of the flow field structure reveals the patterns of change in the separation zone area during the control process,as well as the relationship between the bump motion speed and the control effect on the separation zone.It is concluded that the moving bump endows the boundary layer with additional energy.展开更多
BACKGROUND Various stone factors can affect the net results of shock wave lithotripsy(SWL).Recently a new factor called variation coefficient of stone density(VCSD)is being considered to have an impact on stone free r...BACKGROUND Various stone factors can affect the net results of shock wave lithotripsy(SWL).Recently a new factor called variation coefficient of stone density(VCSD)is being considered to have an impact on stone free rates.AIM To assess the role of VCSD in determining success of SWL in urinary calculi.METHODS Charts review was utilized for collection of data variables.The patients were subjected to SWL,using an electromagnetic lithotripter.Mean stone density(MSD),stone heterogeneity index(SHI),and VCSD were calculated by generating regions of interest on computed tomography(CT)images.Role of these factors were determined by applying the relevant statistical tests for continuous and categorical variables and a P value of<0.05 was gauged to be statistically significant.RESULTS There were a total of 407 patients included in the analysis.The mean age of the subjects in this study was 38.89±14.61 years.In total,165 out of the 407 patients could not achieve stone free status.The successful group had a significantly lower stone volume as compared to the unsuccessful group(P<0.0001).Skin to stone distance was not dissimilar among the two groups(P=0.47).MSD was significantly lower in the successful group(P<0.0001).SHI and VCSD were both significantly higher in the successful group(P<0.0001).CONCLUSION VCSD,a useful CT based parameter,can be utilized to gauge stone fragility and hence the prediction of SWL outcomes.展开更多
M50 steel,commonly utilized in aircraft engine bearings,is susceptible to friction-induced failures,particularly in high-temperature service conditions.To address this issue,various strategies have been proposed,with ...M50 steel,commonly utilized in aircraft engine bearings,is susceptible to friction-induced failures,particularly in high-temperature service conditions.To address this issue,various strategies have been proposed,with laser shock peening(LSP)garnering significant attention due to its deeper residual stress penetration and excellent surface integrity,whereas the underlying strengthening mechanisms have not yet been fully elucidated.In this study,we systematically investigate the impact of LSP treatment on the tribological properties of M50 steel at temperatures of 25 and 300℃,alongside elucidating the relevant micro-mechanisms.Microstructural analysis reveals that laser impact strengthening primarily arises from dislocation proliferation,resulting in a surface hardness increase of approximately 14%and the formation of a substantial compressive stress layer reaching a maximum value of about 1200 MPa,with a depth of around 2 mm.Friction test results demonstrate reduced coefficients of friction and wear rates following LSP treatment at both temperatures.Notably,a more pronounced reduction is observed at 300℃,with values decreasing by 41.4%and 55.8%,respectively.The enhanced performance is attributed to the synergistic interplay of compressive residual stresses,work-hardening layers,increased density of dislocations,and substantial microstructure refinement.展开更多
Sodium-ion batteries have emerged as competitive substitutes for low-temperature applications due to severe capacity loss and safety concerns of lithium-ion batteries at−20°C or lower.However,the key capability o...Sodium-ion batteries have emerged as competitive substitutes for low-temperature applications due to severe capacity loss and safety concerns of lithium-ion batteries at−20°C or lower.However,the key capability of ultrafast charging at ultralow temperature for SIBs is rarely reported.Herein,a hybrid of Bi nanoparticles embedded in carbon nanorods is demonstrated as an ideal material to address this issue,which is synthesized via a high temperature shock method.Such a hybrid shows an unprecedented rate performance(237.9 mAh g^(−1) at 2 A g^(−1))at−60℃,outperforming all reported SIB anode materials.Coupled with a Na_(3)V_(2)(PO_(4))_(3)cathode,the energy density of the full cell can reach to 181.9 Wh kg^(−1) at−40°C.Based on this work,a novel strategy of high-rate activation is proposed to enhance performances of Bi-based materials in cryogenic conditions by creating new active sites for interfacial reaction under large current.展开更多
The synthesis of carbon supporter/nanoscale high-entropy alloys(HEAs)electromagnetic response composites by carbothermal shock method has been identified as an advanced strategy for the collaborative competition engin...The synthesis of carbon supporter/nanoscale high-entropy alloys(HEAs)electromagnetic response composites by carbothermal shock method has been identified as an advanced strategy for the collaborative competition engineering of conductive/dielectric genes.Electron migration modes within HEAs as manipulated by the electronegativity,valence electron configurations and molar proportions of constituent elements determine the steady state and efficiency of equivalent dipoles.Herein,enlightened by skin-like effect,a reformative carbothermal shock method using carbonized cellulose paper(CCP)as carbon supporter is used to preserve the oxygencontaining functional groups(O·)of carbonized cellulose fibers(CCF).Nucleation of HEAs and construction of emblematic shell-core CCF/HEAs heterointerfaces are inextricably linked to carbon metabolism induced by O·.Meanwhile,the electron migration mode of switchable electronrich sites promotes the orientation polarization of anisotropic equivalent dipoles.By virtue of the reinforcement strategy,CCP/HEAs composite prepared by 35%molar ratio of Mn element(CCP/HEAs-Mn_(2.15))achieves efficient electromagnetic wave(EMW)absorption of−51.35 dB at an ultra-thin thickness of 1.03 mm.The mechanisms of the resulting dielectric properties of HEAs-based EMW absorbing materials are elucidated by combining theoretical calculations with experimental characterizations,which provide theoretical bases and feasible strategies for the simulation and practical application of electromagnetic functional devices(e.g.,ultra-wideband bandpass filter).展开更多
BACKGROUND Hypernatremia represents a significant electrolyte imbalance associated with numerous adverse outcomes,particularly in cases of intensive care unit(ICU)-acquired hypernatremia(IAH).Nevertheless,its relevanc...BACKGROUND Hypernatremia represents a significant electrolyte imbalance associated with numerous adverse outcomes,particularly in cases of intensive care unit(ICU)-acquired hypernatremia(IAH).Nevertheless,its relevance in patients with septic shock remains uncertain.AIM To identify independent risk factors and their predictive efficacy for IAH to improve outcomes in patients with septic shock.METHODS In the present retrospective single-center study,a cohort of 157 septic shock patients with concurrent hypernatremia in the ICU at The First Affiliated Hospital of Soochow University,between August 1,2018,and May 31,2023,were analyzed.Patients were categorized based on the timing of hypernatremia occurrence into the IAH group(n=62),the non-IAH group(n=41),and the normonatremia group(n=54).RESULTS In the present study,there was a significant association between the high serum sodium concentrations,excessive persistent inflammation,immunosuppression and catabolism syndrome and chronic critical illness,while rapid recovery had an apparent association with normonatremia.Moreover,multivariable analyses revealed the following independent risk factors for IAH:Total urinary output over the preceding three days[odds ratio(OR)=1.09;95%CI:1.02–1.17;P=0.014],enteral nutrition(EN)sodium content of 500 mg(OR=2.93;95%CI:1.13–7.60;P=0.027),and EN sodium content of 670 mg(OR=6.19;95%CI:1.75–21.98;P=0.005)were positively correlated with the development of IAH.Notably,the area under the curve for total urinary output over the preceding three days was 0.800(95%CI:0.678–0.922,P=0.001).Furthermore,maximum serum sodium levels,the duration of hypernatremia,and varying sodium correction rates were significantly associated with 28-day in-hospital mortality in septic shock patients(P<0.05).CONCLUSION The present findings illustrate that elevated serum sodium level was significantly associated with a poor prognosis in septic shock patients in the ICU.It is highly recommended that hypernatremia be considered a potentially important prognostic indicator for the outcome of septic shock.展开更多
Electrocatalytic reduction of carbon dioxide(CO_(2))to carbon monoxide(CO)is an effective strategy to achieve carbon neutrality.High selective and low-cost catalysts for the electrocatalytic reduction of CO_(2)have re...Electrocatalytic reduction of carbon dioxide(CO_(2))to carbon monoxide(CO)is an effective strategy to achieve carbon neutrality.High selective and low-cost catalysts for the electrocatalytic reduction of CO_(2)have received increasing attention.In contrast to the conventional tube furnace method,the high-temperature shock(HTS)method enables ultra-fast thermal processing,superior atomic efficiency,and a streamlined synthesis protocol,offering a simplified method for the preparation of high-performance single-atom catalysts(SACs).The reports have shown that nickel-based SACs can be synthesized quickly and conveniently using the HTS method,making their application in CO_(2)reduction reactions(CO_(2)RR)a viable and promising avenue for further exploration.In this study,the effect of heating temperature,metal loading and different nitrogen(N)sources on the catalyst morphology,coordination environment and electrocatalytic performance were investigated.Under optimal conditions,0.05Ni-DCD-C-1050 showed excellent performance in reducing CO_(2)to CO,with CO selectivity close to 100%(−0.7 to−1.0 V vs RHE)and current density as high as 130 mA/cm^(2)(−1.1 V vs RHE)in a flow cell under alkaline environment.展开更多
BACKGROUND Cytomegalovirus(CMV)infections can cause significant morbidity and mortality in immunocompromised individuals.CMV targets dysfunctional lymphocytes.Chronic rituximab(RTX)therapy can cause B-lymphocyte dysfu...BACKGROUND Cytomegalovirus(CMV)infections can cause significant morbidity and mortality in immunocompromised individuals.CMV targets dysfunctional lymphocytes.Chronic rituximab(RTX)therapy can cause B-lymphocyte dysfunction,increasing CMV risk.Rarely,CMV infections present with critical illness such as septic shock.CASE SUMMARY A 64-year-old African American woman presented with generalized weakness and non-bloody watery diarrhea of 4-6 weeks duration.She did not have nausea,vomiting or,abdominal pain.She had been on monthly RTX infusions for neuromyelitis optica.She was admitted for septic shock due to pancolitis.Blood investigations suggested pancytopenia and serology detected significantly elevated CMV DNA.Valganciclovir treatment led to disease resolution.CONCLUSION This case illustrates an extremely rare case of CMV colitis associated with RTX use presenting with septic shock.High suspicion for rare opportunistic infections is imperative in individuals with long-term RTX use.展开更多
BACKGROUND Coronavirus disease 2019(COVID-19)pneumonia with severe septic shock and acute respiratory distress syndrome(ARDS)are critical illnesses for patients following transplant.Intravenous immunoglobulin(IVIG)pla...BACKGROUND Coronavirus disease 2019(COVID-19)pneumonia with severe septic shock and acute respiratory distress syndrome(ARDS)are critical illnesses for patients following transplant.Intravenous immunoglobulin(IVIG)plays a role in both immune support and inflammation control,especially in immunocompromised patients.This case report describes the first successful experience using IVIG and pulse steroids to manage this critical condition following lung transplantation.CASE SUMMARY A 65-year-old male patient reported a history of chronic obstructive pulmonary disease and poor lung function and received bilateral sequential lung transplantations.Postoperatively,he developed COVID-19 pneumonia,severe septic shock,and ARDS.He recovered from this critical condition after empirical antibiotics administration and veno-venous extracorporeal membrane oxygenation,in addition to IVIG and pulse steroids.CONCLUSION IVIG is a valuable adjunct in managing severe sepsis in lung transplant recipients after COVID-19 infection.We aim,for the first time,to report the success of such a management approach for COVID-19 ARDS and sepsis in the post-lung transplant setting.With further investigations,this is a starting point for wider analysis of such an approach in this setting and consequently helps guide clinical practice for such a challenging patient population moving forward.展开更多
基金Project(2017XKQY012)supported by the Fundamental Research Funds for the Central Universities,China。
文摘Thermal shocking effect occurs when the coalbed methane(CBM)reservoirs meet liquid nitrogen(LN2)of extremely low temperature.In this study,3D via X-ray microcomputer tomography(μCT)and scanning electron microscope(SEM)are employed to visualize and quantify morphological evolution characteristics of fractures in coal after LN2 thermal shocking treatments.LN2 thermal shocking leads to a denser fracture network than its original state with coal porosity growth rate increasing up to 183.3%.The surface porosity of theμCT scanned layers inside the coal specimen is influenced by LN2 thermal shocking which rises from 18.76%to 215.11%,illustrating the deformation heterogeneity of coal after LN2 thermal shocking.The cracking effect of LN2 thermal shocking on the surface of low porosity is generally more effective than that of high surface porosity,indicating the applicability of LN2 thermal shocking on low-permeability CBM reservoir stimulation.The characteristics of SEM scanned coal matrix in the coal powder and the coal block after the LN2 thermal shocking presented a large amount of deep and shallow progressive scratch layers,fracture variation diversity(i.e.extension,propagation,connectivity,irregularity)on the surface of the coal block and these were the main reasons leading to the decrease of the uniaxial compressive strength of the coal specimen.
基金Supported by National Natural Science Foundation of China(No.50902103)
文摘Laser plays an important role in synthesizing nanometer material. A three-dimensional mathematical model is established in this paper when single pulsed millisecond laser shocks the surface of the metal target at a liquid-solid interface. By changing laser power density and target size, the temperature field variation of the metal target is investigated. Results show that the generation process of nanoparticles includes heating, melting and boiloff.
文摘Correction to:Acta Metallurgica Sinica(English Letters)https://doi.org/10.1007/s40195-023-01576-x In the original publication,the afiliation citation appears incorrectly.The corrected affiliation citation should read as below.
文摘This article reports the latest development of a wireless sensing system,named Martlet,on high-g shock acceleration measurement.The Martlet sensing node design is based on a Texas Instruments Piccolo microcontroller,with clock frequency programmable up to 90 MHz.The high clock frequency of the microcontroller enables Martlet to support high-frequency data acquisition and high-speed onboard computation.In addition,the extensible design of the Martlet node conveniently allows incorporation of multiple sensor boards.In this study,a high-g accelerometer interface board is developed to allow Martlet to work with the selected microelectromechanical system(MEMS)high-g accelerometers.Besides low-pass and highpass filters,amplification gains are also implemented on the high-g accelerometer interface board.Laboratory impact experiments are conducted to validate the performance of the Martlet wireless sensing system with the high-g accelerometer board.The results of this study show that the performance of the wireless sensing system is comparable to the cabled system.
基金financially support from the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDA25040201)the National Natural Science Foundation of China(Grant No.51727901)support provided by the Deanship of Scientific Research(DSR)at King Fahd University of Petroleum&Minerals(KFUPM)(Grant No.DF201020)
文摘Tungsten has promising applications in high-radiation,high-erosion and high-impact environments.Laser peening is an effective method to enhance the surface mechanical properties of tungsten materials.However,the ultrafast dynamic mechanism of defect evolutions induced by laser shockwave in tungsten lattice is unclear.Here,we investigated the evolutions and interactions of various defects under ultrafast compressive process in tungsten lattice using molecular dynamic method.The results confirm the brittleness of tungsten and reveal that void can reduce the yield strain and strength of the tungsten lattice by accelerating defect mesh extension and promoting the dislocation nucleation around itself.Dislocation density is increased with compressive strain rate.Meanwhile,dislocation multiplication and motion reduce the elastic stage and play a dominant role during the plastic deformation of tungsten lattice.Additionally,void can disrupt the dislocation displacement and promote the pinning effect on dislocations by defect mesh extension.
基金supported by the National Key R&D Plan of China(No.2022YFB3705603)the National Natural Science Foundation of China(No.52101046)+1 种基金the Excellent Youth Overseas Project of National Science and Natural Foundation of China,the Baowu Special Metallurgy Cooperation Limited(No.22H010101336)the Medicine-Engineering Interdisciplinary Project of Shanghai Jiao Tong University(No.YG2022QN076).
文摘Titanium(Ti)and its alloys are frequently utilized as critical components in a variety of engineering ap-plications because of their high specific strength and excellent corrosion resistance.Compared to conven-tional surface strengthening technologies,laser shock peening(LSP)has increasingly attracted attention from researchers and industries,since it significantly improves the surface strength,biocompatibility,fa-tigue resistance,and anti-corrosion ability of Ti and its alloys.Despite numerous studies that have been carried out to elucidate the effects of LSP on microstructural evolution and mechanical properties of Ti and its alloys in recent years,a comprehensive review of recent advancements in the field of Ti and its alloys subjected to LSP is still lacking.In this review,the standard LSP and the novel process designs of LSP assisted by thermal,cryogenic,electropulsing and magnetic fields are discussed and compared.Microstructural evolution,with focuses on the dislocation dynamics,deformation twinning,grain refine-ment and surface amorphization,during LSP processing of Ti alloys is reviewed.Furthermore,the en-hanced engineering performance of the L SP-processed(L SPed)Ti alloys,including surface hardness,wear resistance,fatigue life and corrosion resistance are summarized.Finally,this review concludes by present-ing an overview of the current challenges encountered in this field and offering insights into anticipated future trends.
基金supported by the Key-Area Research and Development Program of Guangdong Province(Grant No.2021B0909060004)the National Natural Science Foundation of China(Grant Nos.12072355 and 92271117)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB0620202).
文摘The thermochemical non-equilibrium phenomena encountered by hypersonic vehicles present significant challenges in their design.To investigate the thermochemical reaction flow behind shock waves,the non-equilibrium radiation in the visible range using a shock tube was studied.Experiments were conducted with a shock velocity of 4.7 km/s,using nitrogen at a pressure of 20 Pa.To address measurement difficulties associated with weak radiation,a special square section shock tube with a side length of 380 mm was utilized.A high-speed camera characterized the shock wave’s morphology,and a spectrograph and a monochromator captured the radiation.The spectra were analyzed,and the numerical spectra were compared with experimental results,showing a close match.Temperature changes behind the shock wave were obtained and compared with numerical predictions.The findings indicate that the vibrational temperatures are overestimated,while the vibrational relaxation time is likely underestimated,due to the oversimplified portrayals of the non-equilibrium relaxation process in the models.Additionally,both experimental and simulated time-resolved profiles of radiation intensity at specific wavelengths were analyzed.The gathered data aims to enhance computational fluid dynamics codes and radiation models,improving their predictive accuracy.
基金financially supported by National Natural Science Foundation of China(Grant Nos.52378401,52278504)the Fundamental Research Funds for the Central Universities(Grant No.30922010918)。
文摘Traffic engineering such as tunnels in various altitudinal gradient zone are at risk of accidental explosion,which can damage personnel and equipment.Accurate prediction of the distribution pattern of explosive loads and shock wave propagation process in semi-enclosed structures at various altitude environment is key research focus in the fields of explosion shock and fluid dynamics.The effect of altitude on the propagation of shock waves in tunnels was investigated by conducting explosion test and numerical simulation.Based on the experimental and numerical simulation results,a prediction model for the attenuation of the peak overpressure of tunnel shock waves at different altitudes was established.The results showed that the peak overpressure decreased at the same measurement points in the tunnel entrance under the high altitude condition.In contrast,an increase in altitude accelerated the propagation speed of the shock wave in the tunnel.The average error between the peak shock wave overpressure obtained using the overpressure prediction formula and the measured test data was less than15%,the average error between the propagation velocity of shock waves predicted values and the test data is less than 10%.The method can effectively predict the overpressure attenuation of blast wave in tunnel at various altitudes.
基金supported by the National Natural Science Foundation of China(82102315).
文摘BACKGROUND:The lack of a stable,easy-to-operate animal model for severe trauma has hindered the research progress.The aim of this study is to develop a mouse model that replicates the pathophysiological conditions of severe trauma,providing a reliable research tool.METHODS:Male C57BL/6J mice(aged 8-10 weeks and weighting approximately 20 g)were used to establish the severe trauma model.Under anesthesia,a midshaft femoral fracture was created and packed with sterile cotton.A midline incision was made from the inguinal region to the sternum,exposing the abdominal organs for 30 min.The right femoral artery was cannulated to induce controlled blood loss at 30%,35%,40%,and 50%of the total blood volume.Survival rates were monitored for 24 h post-induction.In the mice that experienced 30%blood loss,the mean arterial pressure,body temperature,blood gas parameters,peripheral blood inflammatory markers,and major organ pathological changes were assessed.RESULTS:Mice with femoral fractures,soft tissue injuries,abdominal organ exposure,and 30%blood loss exhibited stable survival rates.Increased blood loss significantly reduced survival rates.Mean arterial pressure decreased initially,recovering within 0-15 min and returning to baseline by 50 min.Similarly,the body temperature decreased initially and gradually recovered to baseline within 50 min.Levels of peripheral blood inflammatory markers remained elevated for 12 h post-injury.Distant organs,including intestines,lungs,liver,spleen and kidneys,displayed varying degrees of injury.CONCLUSION:The established mouse model replicates the pathophysiological responses to severe trauma,indicating stability and reproducibility,which could be an useful tool for further trauma research.
基金Project supported by the National Natural Science Foundation of China(Nos.12471367 and12361076)the Research Program of Science and Technology at Universities of Inner Mongolia Autonomous Region(Nos.NJZY19186,NJZY22036,and NJZY23003)。
文摘We are intrigued by the issues of shock instability,with a particular emphasis on numerical schemes that address the carbuncle phenomenon by reducing dissipation rather than increasing it.For a specific class of planar flow fields where the transverse direction exhibits vanishing but non-zero velocity components,such as a disturbed onedimensional(1D)steady shock wave,we conduct a formal asymptotic analysis for the Euler system and associated numerical methods.This analysis aims to illustrate the discrepancies among various low-dissipative numerical algorithms.Furthermore,a numerical stability analysis of steady shock is undertaken to identify the key factors underlying shock-stable algorithms.To verify the stability mechanism,a consistent,low-dissipation,and shock-stable HLLC-type Riemann solver is presented.
基金supported by the National Key R&D Program of China(Grant No.2019YFA0405300)the National Natural Science Foundation of China(Grant No.11972368)the Natural Science Foundation of Hunan Province(Grant No.2021JJ10045).
文摘The stability of supersonic inlets faces challenges due to various changes in flight conditions,and flow control methods that address shock wave/boundary layer interactions under only one set of conditions cannot meet developmental requirements.This paper proposes an adaptive bump control scheme and employs dynamic mesh technology for numerical simulation to investigate the unsteady control effects of adaptive bumps.The obtained results indicate that the use of moving bumps to control shock wave/boundary layer interactions is feasible.The adaptive control effects of five different bump speeds are evaluated.Within the range of bump speeds studied,the analysis of the flow field structure reveals the patterns of change in the separation zone area during the control process,as well as the relationship between the bump motion speed and the control effect on the separation zone.It is concluded that the moving bump endows the boundary layer with additional energy.
文摘BACKGROUND Various stone factors can affect the net results of shock wave lithotripsy(SWL).Recently a new factor called variation coefficient of stone density(VCSD)is being considered to have an impact on stone free rates.AIM To assess the role of VCSD in determining success of SWL in urinary calculi.METHODS Charts review was utilized for collection of data variables.The patients were subjected to SWL,using an electromagnetic lithotripter.Mean stone density(MSD),stone heterogeneity index(SHI),and VCSD were calculated by generating regions of interest on computed tomography(CT)images.Role of these factors were determined by applying the relevant statistical tests for continuous and categorical variables and a P value of<0.05 was gauged to be statistically significant.RESULTS There were a total of 407 patients included in the analysis.The mean age of the subjects in this study was 38.89±14.61 years.In total,165 out of the 407 patients could not achieve stone free status.The successful group had a significantly lower stone volume as compared to the unsuccessful group(P<0.0001).Skin to stone distance was not dissimilar among the two groups(P=0.47).MSD was significantly lower in the successful group(P<0.0001).SHI and VCSD were both significantly higher in the successful group(P<0.0001).CONCLUSION VCSD,a useful CT based parameter,can be utilized to gauge stone fragility and hence the prediction of SWL outcomes.
基金supported by the National Science and Technology Major Project of China(No.2017-VII-0003-0096)the National Natural Science Foundation of China(Grant Nos.52205240 and 52201140)+2 种基金the Young Elite Scientist Sponsorship Program by CAST(Grant No.YESS20200321)the Natural Science Foundation for Youths of Shaanxi Province(No.2023-JC-QN-0521)the China Postdoctoral Science Foundation(Grant No.2022M723874).
文摘M50 steel,commonly utilized in aircraft engine bearings,is susceptible to friction-induced failures,particularly in high-temperature service conditions.To address this issue,various strategies have been proposed,with laser shock peening(LSP)garnering significant attention due to its deeper residual stress penetration and excellent surface integrity,whereas the underlying strengthening mechanisms have not yet been fully elucidated.In this study,we systematically investigate the impact of LSP treatment on the tribological properties of M50 steel at temperatures of 25 and 300℃,alongside elucidating the relevant micro-mechanisms.Microstructural analysis reveals that laser impact strengthening primarily arises from dislocation proliferation,resulting in a surface hardness increase of approximately 14%and the formation of a substantial compressive stress layer reaching a maximum value of about 1200 MPa,with a depth of around 2 mm.Friction test results demonstrate reduced coefficients of friction and wear rates following LSP treatment at both temperatures.Notably,a more pronounced reduction is observed at 300℃,with values decreasing by 41.4%and 55.8%,respectively.The enhanced performance is attributed to the synergistic interplay of compressive residual stresses,work-hardening layers,increased density of dislocations,and substantial microstructure refinement.
基金supported from Science and Technology Development Program of Jilin Province(Nos.20240101128JC,20230402058GH)National Natural Science Foundation of China(No.52130101).
文摘Sodium-ion batteries have emerged as competitive substitutes for low-temperature applications due to severe capacity loss and safety concerns of lithium-ion batteries at−20°C or lower.However,the key capability of ultrafast charging at ultralow temperature for SIBs is rarely reported.Herein,a hybrid of Bi nanoparticles embedded in carbon nanorods is demonstrated as an ideal material to address this issue,which is synthesized via a high temperature shock method.Such a hybrid shows an unprecedented rate performance(237.9 mAh g^(−1) at 2 A g^(−1))at−60℃,outperforming all reported SIB anode materials.Coupled with a Na_(3)V_(2)(PO_(4))_(3)cathode,the energy density of the full cell can reach to 181.9 Wh kg^(−1) at−40°C.Based on this work,a novel strategy of high-rate activation is proposed to enhance performances of Bi-based materials in cryogenic conditions by creating new active sites for interfacial reaction under large current.
基金Financial support from the National Natural Science Foundation of China(52372289,52102368,52231007,12327804,T2321003,22088101,22178037 and U22A20424)Regional Joint Fund for Basic Research and Applied Basic Research of Guangdong Province(No.2020A1515110905)+1 种基金Guangdong Special Fund for key Areas(20237DZX3042)Shenzhen Stable Support Project,Liaoning Revitalization Talents Program(XLYC2002114)are highly appreciated.
文摘The synthesis of carbon supporter/nanoscale high-entropy alloys(HEAs)electromagnetic response composites by carbothermal shock method has been identified as an advanced strategy for the collaborative competition engineering of conductive/dielectric genes.Electron migration modes within HEAs as manipulated by the electronegativity,valence electron configurations and molar proportions of constituent elements determine the steady state and efficiency of equivalent dipoles.Herein,enlightened by skin-like effect,a reformative carbothermal shock method using carbonized cellulose paper(CCP)as carbon supporter is used to preserve the oxygencontaining functional groups(O·)of carbonized cellulose fibers(CCF).Nucleation of HEAs and construction of emblematic shell-core CCF/HEAs heterointerfaces are inextricably linked to carbon metabolism induced by O·.Meanwhile,the electron migration mode of switchable electronrich sites promotes the orientation polarization of anisotropic equivalent dipoles.By virtue of the reinforcement strategy,CCP/HEAs composite prepared by 35%molar ratio of Mn element(CCP/HEAs-Mn_(2.15))achieves efficient electromagnetic wave(EMW)absorption of−51.35 dB at an ultra-thin thickness of 1.03 mm.The mechanisms of the resulting dielectric properties of HEAs-based EMW absorbing materials are elucidated by combining theoretical calculations with experimental characterizations,which provide theoretical bases and feasible strategies for the simulation and practical application of electromagnetic functional devices(e.g.,ultra-wideband bandpass filter).
基金Supported by The National Natural Science Foundation of China,No.82072130Key Medical Research Projects in Jiangsu Province,No.ZD2022021Suzhou Clinical Medical Center for Anesthesiology,No.Szlcyxzxj202102。
文摘BACKGROUND Hypernatremia represents a significant electrolyte imbalance associated with numerous adverse outcomes,particularly in cases of intensive care unit(ICU)-acquired hypernatremia(IAH).Nevertheless,its relevance in patients with septic shock remains uncertain.AIM To identify independent risk factors and their predictive efficacy for IAH to improve outcomes in patients with septic shock.METHODS In the present retrospective single-center study,a cohort of 157 septic shock patients with concurrent hypernatremia in the ICU at The First Affiliated Hospital of Soochow University,between August 1,2018,and May 31,2023,were analyzed.Patients were categorized based on the timing of hypernatremia occurrence into the IAH group(n=62),the non-IAH group(n=41),and the normonatremia group(n=54).RESULTS In the present study,there was a significant association between the high serum sodium concentrations,excessive persistent inflammation,immunosuppression and catabolism syndrome and chronic critical illness,while rapid recovery had an apparent association with normonatremia.Moreover,multivariable analyses revealed the following independent risk factors for IAH:Total urinary output over the preceding three days[odds ratio(OR)=1.09;95%CI:1.02–1.17;P=0.014],enteral nutrition(EN)sodium content of 500 mg(OR=2.93;95%CI:1.13–7.60;P=0.027),and EN sodium content of 670 mg(OR=6.19;95%CI:1.75–21.98;P=0.005)were positively correlated with the development of IAH.Notably,the area under the curve for total urinary output over the preceding three days was 0.800(95%CI:0.678–0.922,P=0.001).Furthermore,maximum serum sodium levels,the duration of hypernatremia,and varying sodium correction rates were significantly associated with 28-day in-hospital mortality in septic shock patients(P<0.05).CONCLUSION The present findings illustrate that elevated serum sodium level was significantly associated with a poor prognosis in septic shock patients in the ICU.It is highly recommended that hypernatremia be considered a potentially important prognostic indicator for the outcome of septic shock.
基金supported by the National Key R&D Program of China(2024YFB4106400)National Natural Science Foundation of China(22209200,52302331)。
文摘Electrocatalytic reduction of carbon dioxide(CO_(2))to carbon monoxide(CO)is an effective strategy to achieve carbon neutrality.High selective and low-cost catalysts for the electrocatalytic reduction of CO_(2)have received increasing attention.In contrast to the conventional tube furnace method,the high-temperature shock(HTS)method enables ultra-fast thermal processing,superior atomic efficiency,and a streamlined synthesis protocol,offering a simplified method for the preparation of high-performance single-atom catalysts(SACs).The reports have shown that nickel-based SACs can be synthesized quickly and conveniently using the HTS method,making their application in CO_(2)reduction reactions(CO_(2)RR)a viable and promising avenue for further exploration.In this study,the effect of heating temperature,metal loading and different nitrogen(N)sources on the catalyst morphology,coordination environment and electrocatalytic performance were investigated.Under optimal conditions,0.05Ni-DCD-C-1050 showed excellent performance in reducing CO_(2)to CO,with CO selectivity close to 100%(−0.7 to−1.0 V vs RHE)and current density as high as 130 mA/cm^(2)(−1.1 V vs RHE)in a flow cell under alkaline environment.
文摘BACKGROUND Cytomegalovirus(CMV)infections can cause significant morbidity and mortality in immunocompromised individuals.CMV targets dysfunctional lymphocytes.Chronic rituximab(RTX)therapy can cause B-lymphocyte dysfunction,increasing CMV risk.Rarely,CMV infections present with critical illness such as septic shock.CASE SUMMARY A 64-year-old African American woman presented with generalized weakness and non-bloody watery diarrhea of 4-6 weeks duration.She did not have nausea,vomiting or,abdominal pain.She had been on monthly RTX infusions for neuromyelitis optica.She was admitted for septic shock due to pancolitis.Blood investigations suggested pancytopenia and serology detected significantly elevated CMV DNA.Valganciclovir treatment led to disease resolution.CONCLUSION This case illustrates an extremely rare case of CMV colitis associated with RTX use presenting with septic shock.High suspicion for rare opportunistic infections is imperative in individuals with long-term RTX use.
文摘BACKGROUND Coronavirus disease 2019(COVID-19)pneumonia with severe septic shock and acute respiratory distress syndrome(ARDS)are critical illnesses for patients following transplant.Intravenous immunoglobulin(IVIG)plays a role in both immune support and inflammation control,especially in immunocompromised patients.This case report describes the first successful experience using IVIG and pulse steroids to manage this critical condition following lung transplantation.CASE SUMMARY A 65-year-old male patient reported a history of chronic obstructive pulmonary disease and poor lung function and received bilateral sequential lung transplantations.Postoperatively,he developed COVID-19 pneumonia,severe septic shock,and ARDS.He recovered from this critical condition after empirical antibiotics administration and veno-venous extracorporeal membrane oxygenation,in addition to IVIG and pulse steroids.CONCLUSION IVIG is a valuable adjunct in managing severe sepsis in lung transplant recipients after COVID-19 infection.We aim,for the first time,to report the success of such a management approach for COVID-19 ARDS and sepsis in the post-lung transplant setting.With further investigations,this is a starting point for wider analysis of such an approach in this setting and consequently helps guide clinical practice for such a challenging patient population moving forward.
