Dear Editor,This letter addresses the impulse game problem for a general scope of deterministic,multi-player,nonzero-sum differential games wherein all participants adopt impulse controls.Our objective is to formulate...Dear Editor,This letter addresses the impulse game problem for a general scope of deterministic,multi-player,nonzero-sum differential games wherein all participants adopt impulse controls.Our objective is to formulate this impulse game problem with the modified objective function including interaction costs among the players in a discontinuous fashion,and subsequently,to derive a verification theorem for identifying the feedback Nash equilibrium strategy.展开更多
While the moisture content of soil affects significantly the blast impulse of shallow buried explosives,the role of surface-covering water(SCW)on soil in such blast impulse remains elusive.A combined experimental and ...While the moisture content of soil affects significantly the blast impulse of shallow buried explosives,the role of surface-covering water(SCW)on soil in such blast impulse remains elusive.A combined experimental and numerical study has been carried out to characterize the effect of SCW on transferred impulse and loading magnitude of shallow buried explosives.Firstly,blast tests of shallow buried explosives were conducted,with and without the SCW,to quantitatively assess the blast loading impulse.Subsequently,finite element(FE)simulations were performed and validated against experimental measurement,with good agreement achieved.The validated FE model was then employed to predict the dynamic response of a fully-clamped metallic circular target,subjected to the explosive impact of shallow buried explosives with SCW,and explore the corresponding physical mechanisms.It was demonstrated that shallow buried explosives in saturated soil generate a greater impulse transferred towards the target relative to those in dry soil.The deformation displacement of the target plate is doubled.Increasing the height of SCW results in enhanced center peak deflection of the loaded target,accompanied by subsequent fall,due to the variation of deformation pattern of the loaded target from concentrated load to uniform load.Meanwhile,the presence of SCW increases the blast impulse transferred towards the target by three times.In addition,there exists a threshold value of the burial depth that maximizes the impact impulse.This threshold exhibits a strong sensitivity to SCW height,decreasing with increasing SCW height.An empirical formula for predicting threshold has been provided.Similar conclusions can be drawn for different explosive masses.The results provide technical guidance on blast loading intensity and its spatial distribution considering shallow buried explosives in coast-land battlefields,which can ultimately contribute to better protective designs.展开更多
The problem of collision avoidance for non-cooperative targets has received significant attention from researchers in recent years.Non-cooperative targets exhibit uncertain states and unpredictable behaviors,making co...The problem of collision avoidance for non-cooperative targets has received significant attention from researchers in recent years.Non-cooperative targets exhibit uncertain states and unpredictable behaviors,making collision avoidance significantly more challenging than that for space debris.Much existing research focuses on the continuous thrust model,whereas the impulsive maneuver model is more appropriate for long-duration and long-distance avoidance missions.Additionally,it is important to minimize the impact on the original mission while avoiding noncooperative targets.On the other hand,the existing avoidance algorithms are computationally complex and time-consuming especially with the limited computing capability of the on-board computer,posing challenges for practical engineering applications.To conquer these difficulties,this paper makes the following key contributions:(A)a turn-based(sequential decision-making)limited-area impulsive collision avoidance model considering the time delay of precision orbit determination is established for the first time;(B)a novel Selection Probability Learning Adaptive Search-depth Search Tree(SPL-ASST)algorithm is proposed for non-cooperative target avoidance,which improves the decision-making efficiency by introducing an adaptive-search-depth mechanism and a neural network into the traditional Monte Carlo Tree Search(MCTS).Numerical simulations confirm the effectiveness and efficiency of the proposed method.展开更多
Dear Editor,This letter studies finite-time stability (FTS) of impulsive and switched hybrid systems with delay-dependent impulses. Some conditions, based on Lyapunov method, are proposed for ensuring FTS and estimati...Dear Editor,This letter studies finite-time stability (FTS) of impulsive and switched hybrid systems with delay-dependent impulses. Some conditions, based on Lyapunov method, are proposed for ensuring FTS and estimating settling-time function (STF) of the hybrid systems.When switching dynamics are FTS and impulsive dynamics involve destabilizing delay-dependent impulses, the FTS is retained if the impulses occur infrequently.展开更多
This paper proposes a novel impulsive thrust strategy guided by optimal continuous thrust strategy to address two-player orbital pursuit-evasion game under impulsive thrust control.The strategy seeks to enhance the in...This paper proposes a novel impulsive thrust strategy guided by optimal continuous thrust strategy to address two-player orbital pursuit-evasion game under impulsive thrust control.The strategy seeks to enhance the interpretability of impulsive thrust strategy by integrating it within the framework of differential game in traditional continuous systems.First,this paper introduces an impulse-like constraint,with periodical changes in thrust amplitude,to characterize the impulsive thrust control.Then,the game with the impulse-like constraint is converted into the two-point boundary value problem,which is solved by the combined shooting and deep learning method proposed in this paper.Deep learning and numerical optimization are employed to obtain the guesses for unknown terminal adjoint variables and the game terminal time.Subsequently,the accurate values are solved by the shooting method to yield the optimal continuous thrust strategy with the impulse-like constraint.Finally,the shooting method is iteratively employed at each impulse decision moment to derive the impulsive thrust strategy guided by the optimal continuous thrust strategy.Numerical examples demonstrate the convergence of the combined shooting and deep learning method,even if the strongly nonlinear impulse-like constraint is introduced.The effect of the impulsive thrust strategy guided by the optimal continuous thrust strategy is also discussed.展开更多
In this article,we study the approximate controllability of neutral partial differential equations with Hilfer fractional derivative and not instantaneous impulses effects.By using the Sadovskii's fixed point theo...In this article,we study the approximate controllability of neutral partial differential equations with Hilfer fractional derivative and not instantaneous impulses effects.By using the Sadovskii's fixed point theorem,fractional calculus and resolvent operator functions,we prove the approximate controllability of the considered system.展开更多
Economically and effectively managing the risk of landslide-generated impulse waves(LGIWs)presents a significant challenge following the impoundment of newly constructed reservoirs in western China.To address this iss...Economically and effectively managing the risk of landslide-generated impulse waves(LGIWs)presents a significant challenge following the impoundment of newly constructed reservoirs in western China.To address this issue,we selected the Wangjiashan(WJS)landslide in the Baihetan Reservoir area as a case study to evaluate LGIW hazards and develop corresponding mitigation strategies.Using 2D physical model tests and 3D numerical simulations,we established a 3D hazard assessment method for LGIWs based on 2D experimental results.This method confirmed the effectiveness of slope-cutting engineering in mitigating LGIW hazards.Based on this assessment framework,we proposed a novel approach for LGIW risk reduction.The results showed that the maximum wave amplitude reached 19.64 m in the Jinsha River channel,and the maximum run-up was 11.5 m in the XiangBiLing(XBL)community,indicating a substantial LGIW threat to the area.By reducing the rear edge of the sliding mass to 920 m above sea level(asl),the LGIW risk to the XBL community could be lowered to a tolerable level.Compared with traditional landslide prevention and control measures,the proposed mitigation scheme can reduce excavation costs by approximately 37 million CNY,making it a more scientifically sound and economically feasible solution.We explored the concept and the implementation of LGIW risk mitigation in depth,offering new insights for global LGIW risk management.This case study enhances our understanding of LGIW hazard prevention and provides valuable guidance for policymaking and engineering practices in similar geological settings worldwide.展开更多
Sound is considered an important aspect of an ecosystem and acoustic methods have emerged as effective tools for ecosystems research.Xincun Lagoon,Hainan Island,is an important ecosystem characterized by dense seagras...Sound is considered an important aspect of an ecosystem and acoustic methods have emerged as effective tools for ecosystems research.Xincun Lagoon,Hainan Island,is an important ecosystem characterized by dense seagrass,which has been declining due to increased human activities,raising great concerns.Previous studies have identified various threats to seagrass,including heavy metal pollution,poor quality water,and so on.In this study,we investigate sources and levels of noise in seagrass beds and attempt to point out potential threats from noise pollution.A line array of six hydrophones was deployed over a period of seven days,from January 15 to January 21,2024.The recordings captured various sounds from marine life,human activities,and natural processes.Biological sounds,such as fish sounds and whale calls,were the most prevalent.Low-frequency noise from wind and tide were often recorded.Xincun Bay hosts more than 1500 fishing vessels;however,due to bad weather conditions that kept most vessels docked during the recording period,only one segment of boat noise was recorded;it lasted for 7 minutes,exhibiting strong energy over a broad frequency band.This event underscores the necessity of long-term monitoring of noise to identify and evaluate not only boat noise but other noise sources,especially ones that are intermittent but strong,that were not encountered during the limited period of observation on which this report is based.展开更多
Traditional Chinese medicine has opened new pathways and provided fresh perspectives for the treatment of uremic pruritus(UP)through syndrome differentiation and treatment.This paper summarizes the clinical experience...Traditional Chinese medicine has opened new pathways and provided fresh perspectives for the treatment of uremic pruritus(UP)through syndrome differentiation and treatment.This paper summarizes the clinical experience of Professor Li Qi in treating this condition.Professor Li Qi points out that the fundamental pathogenesis of UP lies in yang deficiency of the spleen and kidney.On this basis,either external cold entering the interior or yang deficiency leading to cold congelation may result in malnutrition of the skin,thereby triggering pruritus.In clinical practice,slight sweating therapy is applied to release the exterior and expel pathogenic factors or to warm and resolve cold fluid retention,achieving satisfactory therapeutic outcomes.展开更多
Current experimental techniques still face challenges in clarifying the structural and dynamic properties of helium(He)in liquid lithium(Li).A critical example of this technical hurdle is the formation of He bubbles,w...Current experimental techniques still face challenges in clarifying the structural and dynamic properties of helium(He)in liquid lithium(Li).A critical example of this technical hurdle is the formation of He bubbles,which significantly affects the transport of He within liquid Li—a vital aspect when considering liquid Li as a plasma-facing material in nuclear fusion reactors.We develop a machine-learning-based deep potential(DP)with ab initio accuracy for the Li-He system and perform molecular dynamics simulations at temperatures ranging from 470 K to 1270 K with a wide range of He concentrations.We observe that He atoms exhibit a tendency to aggregate and form clusters and bubbles in liquid Li.Notably,He clusters exhibit a significant increase in size at elevated temperatures and high concentrations of He,accompanied by the phase separation of Li and He atoms.We also observe an anomalous non-linear relationship between the diffusion coefficient of He and temperature,which is attributed to the larger cluster size at higher temperatures.Our study provides a deeper understanding of the behavior of He in liquid Li and further supports the potential application of liquid Li under extreme conditions.展开更多
The water-quenched(WQ)2195 Al−Li alloy was subjected to stretching at different temperatures,from room temperature(RT)to−196℃(CT),to investigate the effect of cryogenic deformation on the aging precipitation behavior...The water-quenched(WQ)2195 Al−Li alloy was subjected to stretching at different temperatures,from room temperature(RT)to−196℃(CT),to investigate the effect of cryogenic deformation on the aging precipitation behaviors and mechanical properties.The precipitation kinetics of the T1 phase and the microstructures in peak aging state were investigated through the differential scanning calorimetric(DSC)tests and electron microscopy observation.The results show that−196℃deformation produces a high dislocation density,which promotes the precipitation of the T1 phase and refines its sizes significantly.In addition,the grain boundary precipitates(GBPs)of−196℃-stretched samples are suppressed considerably due to the high dislocation density in the grain interiors,which increases the ductility.In comparison,the strength remains nearly constant.Thus,it is indicated that cryogenic forming has the potential to provide the shape and property control for the manufacture of critical components of aluminum alloys.展开更多
High-pressure electrides,characterized by the presence of interstitial quasi-atoms(ISQs),possess unique electronic structures and physical properties,such as diverse dimensions of electride states exhibiting different...High-pressure electrides,characterized by the presence of interstitial quasi-atoms(ISQs),possess unique electronic structures and physical properties,such as diverse dimensions of electride states exhibiting different superconductivity,which has attracted significant attention.Here,we report a new electron-deficient type of electride Li_(4)Al and identify its phase transition progress with pressurization,where the internal driving force behind phase transitions,bonding characteristics,and superconducting behaviors have been revealed based on first-principles density functional theory.Through analysis of the bonding properties of electride Li_(4)Al,we demonstrate that the ISQs exhibiting increasingly covalent characteristics between Al ions play a critical role in driving the phase transition.Our electron–phonon coupling calculations indicate that all phases exhibit superconducting behaviors.Importantly,we prove that the ISQs behave as free electrons and demonstrate that the factor governing T_(c) is primarily derived from Li-p-hybridized electronic states with ISQ compositions.These electronic states are scattered by low-frequency phonons arising from mixed vibrations of Li and Al affected by ISQs to enhance electron–phonon coupling.Our study largely expands the research scope of electrides,provides new insight for understanding phase transitions,and elucidates the effects of ISQs on superconducting behavior.展开更多
AIM: To evaluate the utility of liver reserve function by acoustic radiation force impulse(ARFI) imaging in patients with liver tumors. METHODS: Seventy-six patients with liver tumors were enrolled in this study. Seru...AIM: To evaluate the utility of liver reserve function by acoustic radiation force impulse(ARFI) imaging in patients with liver tumors. METHODS: Seventy-six patients with liver tumors were enrolled in this study. Serum biochemical indexes, such as aminotransferase(ALT), aspartate aminotransferase(AST), serum albumin(ALB), total bilirubin(T-Bil), and other indicators were observed. Liver stiffness(LS) was measured by ARFI imaging, measurements were repeated 10 times, and the average value of the results was taken as the final LS value. Indocyanine green(ICG) retention was performed, and ICG-K and ICG-R15 were recorded. Child-Pugh(CP) scores were carried out based on patient's preoperative biochemical tests and physical condition. Correlations among CP scores,ICG-R15, ICG-K and LS values were observed and analyzed using either the Pearson correlation coefficient or the Spearman rank correlation coefficient. KruskalWallis test was used to compare LS values of CP scores, and the receiver-operator characteristic(ROC) curve was used to analyze liver reserve function assessment accuracy. RESULTS: LS in the ICG-R15 10%-20% group was significantly higher than in the ICG-R15 < 10% group; and the difference was statistically significant(2.19 ± 0.27 vs 1.59 ± 0.32, P < 0.01). LS in the ICG-R15 > 20% group was significantly higher than in the ICG-R15 < 10% group; and the difference was statistically significant(2.92 ± 0.29 vs 1.59 ± 0.32, P < 0.01). The LS value in patients with CP class A was lower than in patients with CP class B(1.57 ± 0.34 vs 1.86 ± 0.27, P < 0.05), while the LS value in patients with CP class B was lower than in patients with CP class C(1.86 ± 0.27 vs 2.47 ± 0.33, P < 0.01). LS was positively correlated with ICG-R15(r = 0.617, P < 0.01) and CP score(r = 0.772, P < 0.01). Meanwhile, LS was negatively correlated with ICG-K(r =-0.673, P < 0.01). AST, ALT and T-Bil were positively correlated with LS, while ALB was negatively correlated with LS(P < 0.05). The ROC curve revealed that the when the LS value was 2.34 m/s, the Youden index was at its highest point, sensitivity was 69.2% and specificity was 92.1%. CONCLUSION: For patients with liver tumors, ARFI imaging is a useful tool for assessing liver reserve function.展开更多
AIM:To investigate the diagnostic performance of acoustic radiation force impulse(ARFI) elastography for characterizing focal liver mass by quantifying their stiffness.METHODS:This prospective study included 62 patien...AIM:To investigate the diagnostic performance of acoustic radiation force impulse(ARFI) elastography for characterizing focal liver mass by quantifying their stiffness.METHODS:This prospective study included 62 patients with a focal liver mass that was well visualized on conventional ultrasonography performed in our institution from February 2011 to November 2011.Among them,12 patients were excluded for ARFI measurement failure due to a lesion that was smaller than the region of the interest and at an inaccessible location(deeper than 8 cm)(n = 7) or poor compliance to hold their breath as required(n = 5).Finally,50 patients with valid ARFI measurements were enrolled.If a patient had multiple liver masses,only one mass of interest was chosen.The masses were diagnosed by histological examination or clinical diagnostic criteria.During ultrasonographic evaluation,stiffness,expressed as velocity,was checked 10 times per focal liver mass and the surrounding liver parenchyma.RESULTS:After further excluding three masses that were non-diagnostic on biopsy,a total of 47 focal mass lesions were tested,including 39(83.0%) malignant masses [24 hepatocellular carcinomas(HCC),seven cholangiocellular carcinomas(CCC),and eight liver metastases] and eight(17.0%) benign masses(five hemangiomas and three focal nodular hyperplasias,FNH).Thirty-seven(74.0%) masses were confirmed by histological examination.The mean velocity was 2.48 m/s in HCCs,1.65 m/s in CCCs,2.35 m/s in metastases,1.83 m/s in hemangiomas,and 0.97 m/s in FNHs.Although considerable overlap was still noted between malignant and benign masses,significant differences in ARFI values were observed between malignant and benign masses(mean 2.31 m/s vs 1.51 m/s,P = 0.047),as well as between HCCs and benign masses(mean 2.48 m/s vs 1.51 m/s,P = 0.006).The areas under the receiver operating characteristics curves(AUROC) for discriminating the malignant masses from benign masses was 0.724(95%CI,0.566-0.883,P = 0.048),and the AUROC for discriminating HCCs from benign masses was 0.813(95%CI,0.649-0.976,P = 0.008).To maximize the sum of sensitivity and specificity,an ARFI value of 1.82 m/s was selected as the cutoff value to differentiate malignant from benign liver masses.Furthermore,the cutoff value for distinguishing HCCs from benign masses was also determined to be 1.82 m/s.The diagnostic performance of the sum of the ARFI values for focal liver masses and the surrounding liver parenchyma to differentiate liver masses improved(AUROC = 0.853;95%CI,0.745-0.960;P = 0.002 in malignant liver masses vs benign ones and AUROC = 0.948;95%CI,0.896-0.992,P < 0.001 in HCCs vs benign masses).CONCLUSION:ARFI elastography provides additional information for the differential diagnosis of liver masses.However,our results should be interpreted in clinical context,because considerable overlap in ARFI values existed among liver masses.展开更多
基金supported in part by the National Natural Science Foundation of China(62173051)the Fundamental Research Funds for the Central Universities(2024CDJCGJ012,2023CDJXY-010)+1 种基金the Chongqing Technology Innovation and Application Development Special Key Project(CSTB2022TIADCUX0015,CSTB2022TIAD-KPX0162)the China Postdoctoral Science Foundation(2024M763865)
文摘Dear Editor,This letter addresses the impulse game problem for a general scope of deterministic,multi-player,nonzero-sum differential games wherein all participants adopt impulse controls.Our objective is to formulate this impulse game problem with the modified objective function including interaction costs among the players in a discontinuous fashion,and subsequently,to derive a verification theorem for identifying the feedback Nash equilibrium strategy.
基金supported by the National Natural Science Foundation of China(Grant Nos.12002156,11972185,12372136)Research Fund of State Key Laboratory of Mechanics and Control for Aerospace Structures(Grant No.MCMS-I-0222K01)。
文摘While the moisture content of soil affects significantly the blast impulse of shallow buried explosives,the role of surface-covering water(SCW)on soil in such blast impulse remains elusive.A combined experimental and numerical study has been carried out to characterize the effect of SCW on transferred impulse and loading magnitude of shallow buried explosives.Firstly,blast tests of shallow buried explosives were conducted,with and without the SCW,to quantitatively assess the blast loading impulse.Subsequently,finite element(FE)simulations were performed and validated against experimental measurement,with good agreement achieved.The validated FE model was then employed to predict the dynamic response of a fully-clamped metallic circular target,subjected to the explosive impact of shallow buried explosives with SCW,and explore the corresponding physical mechanisms.It was demonstrated that shallow buried explosives in saturated soil generate a greater impulse transferred towards the target relative to those in dry soil.The deformation displacement of the target plate is doubled.Increasing the height of SCW results in enhanced center peak deflection of the loaded target,accompanied by subsequent fall,due to the variation of deformation pattern of the loaded target from concentrated load to uniform load.Meanwhile,the presence of SCW increases the blast impulse transferred towards the target by three times.In addition,there exists a threshold value of the burial depth that maximizes the impact impulse.This threshold exhibits a strong sensitivity to SCW height,decreasing with increasing SCW height.An empirical formula for predicting threshold has been provided.Similar conclusions can be drawn for different explosive masses.The results provide technical guidance on blast loading intensity and its spatial distribution considering shallow buried explosives in coast-land battlefields,which can ultimately contribute to better protective designs.
基金co-supported by the Foundation of Shanghai Astronautics Science and Technology Innovation,China(No.SAST2022-114)the National Natural Science Foundation of China(No.62303378),the National Natural Science Foundation of China(Nos.124B2031,12202281)the Foundation of China National Key Laboratory of Science and Technology on Test Physics&Numerical Mathematics,China(No.08-YY-2023-R11)。
文摘The problem of collision avoidance for non-cooperative targets has received significant attention from researchers in recent years.Non-cooperative targets exhibit uncertain states and unpredictable behaviors,making collision avoidance significantly more challenging than that for space debris.Much existing research focuses on the continuous thrust model,whereas the impulsive maneuver model is more appropriate for long-duration and long-distance avoidance missions.Additionally,it is important to minimize the impact on the original mission while avoiding noncooperative targets.On the other hand,the existing avoidance algorithms are computationally complex and time-consuming especially with the limited computing capability of the on-board computer,posing challenges for practical engineering applications.To conquer these difficulties,this paper makes the following key contributions:(A)a turn-based(sequential decision-making)limited-area impulsive collision avoidance model considering the time delay of precision orbit determination is established for the first time;(B)a novel Selection Probability Learning Adaptive Search-depth Search Tree(SPL-ASST)algorithm is proposed for non-cooperative target avoidance,which improves the decision-making efficiency by introducing an adaptive-search-depth mechanism and a neural network into the traditional Monte Carlo Tree Search(MCTS).Numerical simulations confirm the effectiveness and efficiency of the proposed method.
基金supported by the National Natural Science Foundation of China(61833005)
文摘Dear Editor,This letter studies finite-time stability (FTS) of impulsive and switched hybrid systems with delay-dependent impulses. Some conditions, based on Lyapunov method, are proposed for ensuring FTS and estimating settling-time function (STF) of the hybrid systems.When switching dynamics are FTS and impulsive dynamics involve destabilizing delay-dependent impulses, the FTS is retained if the impulses occur infrequently.
基金funded by the National Natural Science Foundation of China(No.U21B6001)。
文摘This paper proposes a novel impulsive thrust strategy guided by optimal continuous thrust strategy to address two-player orbital pursuit-evasion game under impulsive thrust control.The strategy seeks to enhance the interpretability of impulsive thrust strategy by integrating it within the framework of differential game in traditional continuous systems.First,this paper introduces an impulse-like constraint,with periodical changes in thrust amplitude,to characterize the impulsive thrust control.Then,the game with the impulse-like constraint is converted into the two-point boundary value problem,which is solved by the combined shooting and deep learning method proposed in this paper.Deep learning and numerical optimization are employed to obtain the guesses for unknown terminal adjoint variables and the game terminal time.Subsequently,the accurate values are solved by the shooting method to yield the optimal continuous thrust strategy with the impulse-like constraint.Finally,the shooting method is iteratively employed at each impulse decision moment to derive the impulsive thrust strategy guided by the optimal continuous thrust strategy.Numerical examples demonstrate the convergence of the combined shooting and deep learning method,even if the strongly nonlinear impulse-like constraint is introduced.The effect of the impulsive thrust strategy guided by the optimal continuous thrust strategy is also discussed.
基金Supported by Shandong University of Finance and Economics 2023 International Collaborative Projectsthe National Natural Science Foundation of China(Grant No.62073190)。
文摘In this article,we study the approximate controllability of neutral partial differential equations with Hilfer fractional derivative and not instantaneous impulses effects.By using the Sadovskii's fixed point theorem,fractional calculus and resolvent operator functions,we prove the approximate controllability of the considered system.
基金supported by the National Natural Science Foundation of China(No.U23A2045)the China Three Gorges Corporation(YM(BHT)/(22)022).
文摘Economically and effectively managing the risk of landslide-generated impulse waves(LGIWs)presents a significant challenge following the impoundment of newly constructed reservoirs in western China.To address this issue,we selected the Wangjiashan(WJS)landslide in the Baihetan Reservoir area as a case study to evaluate LGIW hazards and develop corresponding mitigation strategies.Using 2D physical model tests and 3D numerical simulations,we established a 3D hazard assessment method for LGIWs based on 2D experimental results.This method confirmed the effectiveness of slope-cutting engineering in mitigating LGIW hazards.Based on this assessment framework,we proposed a novel approach for LGIW risk reduction.The results showed that the maximum wave amplitude reached 19.64 m in the Jinsha River channel,and the maximum run-up was 11.5 m in the XiangBiLing(XBL)community,indicating a substantial LGIW threat to the area.By reducing the rear edge of the sliding mass to 920 m above sea level(asl),the LGIW risk to the XBL community could be lowered to a tolerable level.Compared with traditional landslide prevention and control measures,the proposed mitigation scheme can reduce excavation costs by approximately 37 million CNY,making it a more scientifically sound and economically feasible solution.We explored the concept and the implementation of LGIW risk mitigation in depth,offering new insights for global LGIW risk management.This case study enhances our understanding of LGIW hazard prevention and provides valuable guidance for policymaking and engineering practices in similar geological settings worldwide.
基金supported financially by the Director General’s Scientific Research Fund of Guangzhou Marine Geological Survey(Grant Number:2023GMGSJZJJ00029).
文摘Sound is considered an important aspect of an ecosystem and acoustic methods have emerged as effective tools for ecosystems research.Xincun Lagoon,Hainan Island,is an important ecosystem characterized by dense seagrass,which has been declining due to increased human activities,raising great concerns.Previous studies have identified various threats to seagrass,including heavy metal pollution,poor quality water,and so on.In this study,we investigate sources and levels of noise in seagrass beds and attempt to point out potential threats from noise pollution.A line array of six hydrophones was deployed over a period of seven days,from January 15 to January 21,2024.The recordings captured various sounds from marine life,human activities,and natural processes.Biological sounds,such as fish sounds and whale calls,were the most prevalent.Low-frequency noise from wind and tide were often recorded.Xincun Bay hosts more than 1500 fishing vessels;however,due to bad weather conditions that kept most vessels docked during the recording period,only one segment of boat noise was recorded;it lasted for 7 minutes,exhibiting strong energy over a broad frequency band.This event underscores the necessity of long-term monitoring of noise to identify and evaluate not only boat noise but other noise sources,especially ones that are intermittent but strong,that were not encountered during the limited period of observation on which this report is based.
基金Supported by National Program for Inheriting the Academic Experience of Senior TCM Experts(Seventh Batch),National Administration of Traditional Chinese Medicine([2022]No.76)Yunnan Provincial Collaborative Research Project on Major and Difficult Diseases with Integrated Traditional Chinese and Western Medicine(Yun Cai She No.163[2024])-Chronic Renal Failure(300072)Yunnan Provincial Senior TCM Expert Li Qi Heritage Studio Project.
文摘Traditional Chinese medicine has opened new pathways and provided fresh perspectives for the treatment of uremic pruritus(UP)through syndrome differentiation and treatment.This paper summarizes the clinical experience of Professor Li Qi in treating this condition.Professor Li Qi points out that the fundamental pathogenesis of UP lies in yang deficiency of the spleen and kidney.On this basis,either external cold entering the interior or yang deficiency leading to cold congelation may result in malnutrition of the skin,thereby triggering pruritus.In clinical practice,slight sweating therapy is applied to release the exterior and expel pathogenic factors or to warm and resolve cold fluid retention,achieving satisfactory therapeutic outcomes.
基金Project supported by the Excellence Research Group Program for Multiscale Problems in Nonlinear Mechanics of the National Natural Science Foundation of China(Grant No.12588201)the National Key R&D Program of China(Grant No.2025YFB3003603)+1 种基金the National Natural Science Foundation of China(Grant No.12135002)the Fundamental Research Funds for the Central Universities,Peking University,the Beijing Natural Science Foundation(Grant No.QY23030)。
文摘Current experimental techniques still face challenges in clarifying the structural and dynamic properties of helium(He)in liquid lithium(Li).A critical example of this technical hurdle is the formation of He bubbles,which significantly affects the transport of He within liquid Li—a vital aspect when considering liquid Li as a plasma-facing material in nuclear fusion reactors.We develop a machine-learning-based deep potential(DP)with ab initio accuracy for the Li-He system and perform molecular dynamics simulations at temperatures ranging from 470 K to 1270 K with a wide range of He concentrations.We observe that He atoms exhibit a tendency to aggregate and form clusters and bubbles in liquid Li.Notably,He clusters exhibit a significant increase in size at elevated temperatures and high concentrations of He,accompanied by the phase separation of Li and He atoms.We also observe an anomalous non-linear relationship between the diffusion coefficient of He and temperature,which is attributed to the larger cluster size at higher temperatures.Our study provides a deeper understanding of the behavior of He in liquid Li and further supports the potential application of liquid Li under extreme conditions.
基金financially supported by the National Key Research and Development Program of China (No. 2019YFA0708801)the National Natural Science Foundation of China (No. 51875125)。
文摘The water-quenched(WQ)2195 Al−Li alloy was subjected to stretching at different temperatures,from room temperature(RT)to−196℃(CT),to investigate the effect of cryogenic deformation on the aging precipitation behaviors and mechanical properties.The precipitation kinetics of the T1 phase and the microstructures in peak aging state were investigated through the differential scanning calorimetric(DSC)tests and electron microscopy observation.The results show that−196℃deformation produces a high dislocation density,which promotes the precipitation of the T1 phase and refines its sizes significantly.In addition,the grain boundary precipitates(GBPs)of−196℃-stretched samples are suppressed considerably due to the high dislocation density in the grain interiors,which increases the ductility.In comparison,the strength remains nearly constant.Thus,it is indicated that cryogenic forming has the potential to provide the shape and property control for the manufacture of critical components of aluminum alloys.
基金supported by the National Key Research and Development Program of China (Grant Nos.2023YFA1406200 and 2022YFA-1405500)the National Natural Science Foundation of China (Grant Nos.12304021 and 52072188)+3 种基金Zhejiang Provincial Natural Science Foundation of China (Grant Nos.LQ23A040004 and MS26A040028)Natural Science Foundation of Ningbo (Grant Nos.2022J091 and ZX2025001430)the Program for Science and Technology Innovation Team in Zhejiang (Grant No.2021R01004)the Program for Changjiang Scholars and Innovative Research Team in University (Grant No.IRT_15R23)。
文摘High-pressure electrides,characterized by the presence of interstitial quasi-atoms(ISQs),possess unique electronic structures and physical properties,such as diverse dimensions of electride states exhibiting different superconductivity,which has attracted significant attention.Here,we report a new electron-deficient type of electride Li_(4)Al and identify its phase transition progress with pressurization,where the internal driving force behind phase transitions,bonding characteristics,and superconducting behaviors have been revealed based on first-principles density functional theory.Through analysis of the bonding properties of electride Li_(4)Al,we demonstrate that the ISQs exhibiting increasingly covalent characteristics between Al ions play a critical role in driving the phase transition.Our electron–phonon coupling calculations indicate that all phases exhibit superconducting behaviors.Importantly,we prove that the ISQs behave as free electrons and demonstrate that the factor governing T_(c) is primarily derived from Li-p-hybridized electronic states with ISQ compositions.These electronic states are scattered by low-frequency phonons arising from mixed vibrations of Li and Al affected by ISQs to enhance electron–phonon coupling.Our study largely expands the research scope of electrides,provides new insight for understanding phase transitions,and elucidates the effects of ISQs on superconducting behavior.
文摘AIM: To evaluate the utility of liver reserve function by acoustic radiation force impulse(ARFI) imaging in patients with liver tumors. METHODS: Seventy-six patients with liver tumors were enrolled in this study. Serum biochemical indexes, such as aminotransferase(ALT), aspartate aminotransferase(AST), serum albumin(ALB), total bilirubin(T-Bil), and other indicators were observed. Liver stiffness(LS) was measured by ARFI imaging, measurements were repeated 10 times, and the average value of the results was taken as the final LS value. Indocyanine green(ICG) retention was performed, and ICG-K and ICG-R15 were recorded. Child-Pugh(CP) scores were carried out based on patient's preoperative biochemical tests and physical condition. Correlations among CP scores,ICG-R15, ICG-K and LS values were observed and analyzed using either the Pearson correlation coefficient or the Spearman rank correlation coefficient. KruskalWallis test was used to compare LS values of CP scores, and the receiver-operator characteristic(ROC) curve was used to analyze liver reserve function assessment accuracy. RESULTS: LS in the ICG-R15 10%-20% group was significantly higher than in the ICG-R15 < 10% group; and the difference was statistically significant(2.19 ± 0.27 vs 1.59 ± 0.32, P < 0.01). LS in the ICG-R15 > 20% group was significantly higher than in the ICG-R15 < 10% group; and the difference was statistically significant(2.92 ± 0.29 vs 1.59 ± 0.32, P < 0.01). The LS value in patients with CP class A was lower than in patients with CP class B(1.57 ± 0.34 vs 1.86 ± 0.27, P < 0.05), while the LS value in patients with CP class B was lower than in patients with CP class C(1.86 ± 0.27 vs 2.47 ± 0.33, P < 0.01). LS was positively correlated with ICG-R15(r = 0.617, P < 0.01) and CP score(r = 0.772, P < 0.01). Meanwhile, LS was negatively correlated with ICG-K(r =-0.673, P < 0.01). AST, ALT and T-Bil were positively correlated with LS, while ALB was negatively correlated with LS(P < 0.05). The ROC curve revealed that the when the LS value was 2.34 m/s, the Youden index was at its highest point, sensitivity was 69.2% and specificity was 92.1%. CONCLUSION: For patients with liver tumors, ARFI imaging is a useful tool for assessing liver reserve function.
基金Supported by A Grant of the Korea Healthcare Technology R and D Project,Ministry of Health and Welfare,South Korea, A102065
文摘AIM:To investigate the diagnostic performance of acoustic radiation force impulse(ARFI) elastography for characterizing focal liver mass by quantifying their stiffness.METHODS:This prospective study included 62 patients with a focal liver mass that was well visualized on conventional ultrasonography performed in our institution from February 2011 to November 2011.Among them,12 patients were excluded for ARFI measurement failure due to a lesion that was smaller than the region of the interest and at an inaccessible location(deeper than 8 cm)(n = 7) or poor compliance to hold their breath as required(n = 5).Finally,50 patients with valid ARFI measurements were enrolled.If a patient had multiple liver masses,only one mass of interest was chosen.The masses were diagnosed by histological examination or clinical diagnostic criteria.During ultrasonographic evaluation,stiffness,expressed as velocity,was checked 10 times per focal liver mass and the surrounding liver parenchyma.RESULTS:After further excluding three masses that were non-diagnostic on biopsy,a total of 47 focal mass lesions were tested,including 39(83.0%) malignant masses [24 hepatocellular carcinomas(HCC),seven cholangiocellular carcinomas(CCC),and eight liver metastases] and eight(17.0%) benign masses(five hemangiomas and three focal nodular hyperplasias,FNH).Thirty-seven(74.0%) masses were confirmed by histological examination.The mean velocity was 2.48 m/s in HCCs,1.65 m/s in CCCs,2.35 m/s in metastases,1.83 m/s in hemangiomas,and 0.97 m/s in FNHs.Although considerable overlap was still noted between malignant and benign masses,significant differences in ARFI values were observed between malignant and benign masses(mean 2.31 m/s vs 1.51 m/s,P = 0.047),as well as between HCCs and benign masses(mean 2.48 m/s vs 1.51 m/s,P = 0.006).The areas under the receiver operating characteristics curves(AUROC) for discriminating the malignant masses from benign masses was 0.724(95%CI,0.566-0.883,P = 0.048),and the AUROC for discriminating HCCs from benign masses was 0.813(95%CI,0.649-0.976,P = 0.008).To maximize the sum of sensitivity and specificity,an ARFI value of 1.82 m/s was selected as the cutoff value to differentiate malignant from benign liver masses.Furthermore,the cutoff value for distinguishing HCCs from benign masses was also determined to be 1.82 m/s.The diagnostic performance of the sum of the ARFI values for focal liver masses and the surrounding liver parenchyma to differentiate liver masses improved(AUROC = 0.853;95%CI,0.745-0.960;P = 0.002 in malignant liver masses vs benign ones and AUROC = 0.948;95%CI,0.896-0.992,P < 0.001 in HCCs vs benign masses).CONCLUSION:ARFI elastography provides additional information for the differential diagnosis of liver masses.However,our results should be interpreted in clinical context,because considerable overlap in ARFI values existed among liver masses.
