Off line programming provides an essential link between CAD and CAM, whose development will result in greater use of robotic arc welding. An arc welding system with a robot and a rotating/tilting positioner is one of...Off line programming provides an essential link between CAD and CAM, whose development will result in greater use of robotic arc welding. An arc welding system with a robot and a rotating/tilting positioner is one of the most typical workcells. The inverse kinematics of robot and positioner is the foundation of the off line programming system. The previous researchers only focused on a special solution of the positioner inverse kinematics, which is the solution at down hand welding position. In this paper, we introduce a method for representing welding position. Then a general algorithm of rotating/tilting positioner inverse kinematics is presented, and an approach to find the unique solution of the inverse kinematics is discussed. The simulation experiment results show that the general algorithm can improve the ability of robotic arc welding off line programming system to program all types of welding positions.展开更多
A new intelligent control method for welding positioner is proposed. Applying an improved fuzzy controller and a variable PID controller, a two-mode intelligent coordinating controller ( TMICC ) is designed on basis o...A new intelligent control method for welding positioner is proposed. Applying an improved fuzzy controller and a variable PID controller, a two-mode intelligent coordinating controller ( TMICC ) is designed on basis of fuzzy logic and rules. The simulation and experimental results show that this control system can obtain better dynamic and static characteristics.展开更多
Aiming at the robotic welding positioner with characteristic of parameter change, load change, nonlinearity, and an intelligent control system was researched and developed. This control system used a two-mode controll...Aiming at the robotic welding positioner with characteristic of parameter change, load change, nonlinearity, and an intelligent control system was researched and developed. This control system used a two-mode controller that based on Fuzzy and PID control method. The results of simulation show that the dynamic and steady performances of the intelligent controller are better than that of single PID or Fuzzy controller. This paper has made a detail theoretical analysis of the constitution design and real-time controlled software and brought up the design and fulfillment method of multi-task real-time control software of high precisely and numerically controlled welding positioner, which has a good result in practice.展开更多
A large workspace flexure parallel positioner system is developed, which can attain sub-micron scale accuracy over cubic centimeter motion range for utilizing novel wide-range flexure hinges instead of the conventiona...A large workspace flexure parallel positioner system is developed, which can attain sub-micron scale accuracy over cubic centimeter motion range for utilizing novel wide-range flexure hinges instead of the conventional mechanism joints. Flexure hinges eliminate backlash and friction, but on the other hand their deformation caused by initial loads influences the positioning accuracy greatly, so discussions about loads＇ influence analysis on this flexure parallel positioner is very necessary. The stiffness model of the whole mechanism is presented via stiffness assembly method based on the stiffness model of individual flexure hinge, And the analysis results are validated by the finite element analysis （FEA） simulation and experiment tests, which provide essential data to the practical application of this positioner system.展开更多
Traditional CAD technique does not support the design processes such as function definition, conceptual design and preliminary design, which are most creative and play significant roles on the design quality. Because ...Traditional CAD technique does not support the design processes such as function definition, conceptual design and preliminary design, which are most creative and play significant roles on the design quality. Because scheme design has close relationship with product structure, performance and technology cost, it is important for applying the intelligent CAD of scheme design to improve the quality and competitive level of the product. The definition and function of welding positioner are discussed in this paper. The new definition of welding positioner extends the research scope of welding positioner to welding fixture and welding positioning motion mechanism. The design process of welding fixture and positioning motion system is described, and the cased based and knowledge based design strategy of welding positioner scheme design intelligent CAD is then put forward, which lays foundation for developing proto type system of welding positioner scheme design.展开更多
This paper presents an adaptive saturated integral sliding mode controller(ASISMC)integrated with an adaptive extended state observer(AESO)to address the challenges of nonlinear time-varying characteristics,parameter ...This paper presents an adaptive saturated integral sliding mode controller(ASISMC)integrated with an adaptive extended state observer(AESO)to address the challenges of nonlinear time-varying characteristics,parameter uncertainties,and external disturbances in valve positioner systems(VPS).To begin with,the VPS dynamic model is established by combining the valve positioner model,the control valve model,and the Euler-Lagrange model,where the uncertain parameters are estimated using the adaptive laws.Moreover,a tracking differentiator(TD)is implemented to ensure smooth and continuous signal processing.The AESO with structural self-regulation capability is also developed to estimate system perturbations and uncertainties effectively.Meanwhile,the proposed ASISMC is designed using adaptive laws based on the backstepping technique,further enhanced by setting saturation constraints on the integral sliding film surface.Finally,experimental validation confirms the superiority of the proposed approach over existing methods in improving control precision,response velocity,and disturbance rejection capability.展开更多
Severe acute pancreatitis(SAP)can induce acute respiratory distress syndrome(ARDS)and abdominal compartment syndrome(ACS).Although prone position ventilation(PPV)can improve outcomes in patients with ARDS,there is sig...Severe acute pancreatitis(SAP)can induce acute respiratory distress syndrome(ARDS)and abdominal compartment syndrome(ACS).Although prone position ventilation(PPV)can improve outcomes in patients with ARDS,there is significant controversy regarding its concurrent use with ACS owing to concerns of increased risk of intra-abdominal pressure(IAP).[1]We present a case of successful PPV application without adverse eff ects.展开更多
Background:Pressure injury(PI)is a prevalent complication in pediatric cardiac surgery,with higher incidence than in general pediatric populations due to children’s thin skin,underdeveloped subcutaneous tissue,and pr...Background:Pressure injury(PI)is a prevalent complication in pediatric cardiac surgery,with higher incidence than in general pediatric populations due to children’s thin skin,underdeveloped subcutaneous tissue,and prolonged intraoperative pressure.Objective:To evaluate the effectiveness of the curvilinear supine position(CSP)in preventing PI among children undergoing congenital heart disease(CHD)surgery.Methods:Between October 2024 and February 2025,a single-center randomized controlled trial was conducted.Of the 80 children initially enrolled for congenital heart disease(CHD)surgery,77(aged 1 month to 14 years)completed the study and were included in the final analysis after 3 were excluded due to protocol violations.Participants were randomly assigned to the CSP group(n=38)or the conventional supine position group(n=39).Results:The incidence of PI was significantly lower in the CSP group(2.6%)compared to the control group(20.5%)(p=0.029).Postoperative LDH levels were also significantly reduced in the CSP group(422.67±86.52 U/L vs.592.92±215.71 U/L;p=0.031),while preoperative LDH and surgical variables(e.g.,cardiopulmonary bypass time)were comparable between groups.Although the CSP group had a shorter hospital stay(17.24 vs.22.51 days),the difference was not statistically significant(p=0.085).Caregiver satisfaction was significantly higher in the CSP group(100.0%vs.84.6%;p=0.025).Conclusion:CSP effectively reduces PI incidence,mitigates tissue injury,and enhances caregiver satisfaction in pediatric cardiac surgery,offering a safe and feasible strategy for perioperative PI prevention.展开更多
The high-quality assembly of Large Aircraft Components(LACs)is essential in modern aviation manufacturing.Numerical control locators are employed for the posture adjustment of LAC,yet the system's multi-input mult...The high-quality assembly of Large Aircraft Components(LACs)is essential in modern aviation manufacturing.Numerical control locators are employed for the posture adjustment of LAC,yet the system's multi-input multi-output,nonlinearity,and strong coupling presents significant challenges.The substantial internal force generated during the adjustment process can potentially damage the LAC and degrade the assembly quality.Hence,a workspace-based hybrid force position control scheme was developed to achieve high quality assembly with high-precision and lower internal force.Firstly,an offline workspace analysis with inherent geometric characteristics to form time-varying posture error constraint.Then,the posture error is integrated into the online position axis control to ensure tracking the ideal posture,while the force control axis compensates for posture deviation by minimizing internal force,thereby achieving high precision and low internal force.Finally,the effectiveness was demonstrated through experiments.The root mean square errors of orientation and position are 104 rad and 0.1 mm,respectively.A reduction in internal force can range from 10.96%to 57.4%compared to the traditional method.Key points'max position error is decreased from 0.32 mm to 0.18 mm,satisfying the 0.5 mm tolerance.Therefore,the proposed method will help promote the development of high-performance manufacturing.展开更多
Although machine learning models have achieved high enough accuracy in predicting shield position deviations,their“black box”nature makes the prediction mechanisms and decision-making processes opaque,leading to wea...Although machine learning models have achieved high enough accuracy in predicting shield position deviations,their“black box”nature makes the prediction mechanisms and decision-making processes opaque,leading to weaker explanations and practicability.This study introduces a novel explainable deep learning framework comprising the Informer model with enhanced attention mechanisms(EAMInfor)and deep learning important features(DeepLIFT),aimed at improving the prediction accuracy of shield position deviations and providing interpretability for predictive results.The EAMInfor model attempts to integrate channel attention,spatial attention,and simple attention modules to improve the Informer model's performance.The framework is tested with the four different geological conditions datasets generated from the Xiamen metro line 3,China.Results show that the EAMInfor model outperforms the traditional Informer and comparison models.The analysis with the DeepLIFT method indicates that the push thrust of push cylinder and the earth chamber pressure are the most significant features,while the stroke length of the push cylinder demonstrated lower importance.Furthermore,the variation trends in the significance of data points within input sequences exhibit substantial differences between single and composite strata.This framework not only improves predictive accuracy but also strengthens the credibility and reliability of the results.展开更多
AIM:To evaluate and compare alterations in the effective lens position(ELP)and refractive outcomes among three distinct intraocular lens(IOL)types.METHODS:Patients with cataracts were enrolled and allocated to 3 group...AIM:To evaluate and compare alterations in the effective lens position(ELP)and refractive outcomes among three distinct intraocular lens(IOL)types.METHODS:Patients with cataracts were enrolled and allocated to 3 groups:Group A(implanted with the SN6CWS),Group B(implanted with the MI60),and Group C(implanted with the Aspira-aA).ELP measurements were obtained with swept-source optical coherence tomography(SS-OCT)at 1d,1wk,1mo,and 3mo postoperatively.Subjective refraction assessments were conducted at 1wk,1mo,and 3mo following surgery.RESULTS:The study included 189 eyes of 150 cataract patients(66 males).There were 77 eyes in Group A,55 eyes in Group B,and 57 eyes in Group C.The root mean square of the ELP(ELPRMS)within the initial 3mo was significantly lower for Group A than for Groups B and C.Refractive changes within Group A were not significant across the time points of 1wk,1mo,and 3mo.Conversely,both Group B and Group C demonstrated statistically significant shifts toward hyperopia from 1wk to 3mo postsurgery.CONCLUSION:Among the three IOLs examined,the SN6CWS IOL showes the greatest stability during the first 3mo postoperatively.Between 1wk and 3mo after surgery,notable hyperopic shifts are evident in eyes implanted with the MI60 and Aspira-aA IOLs,whereas refractive outcomes remain relatively constant in eyes implanted with SN6CWS IOLs.展开更多
The fluorination strategy has been proven effective in significantly enhancing the photovoltaic performance of organic solar cells(OSCs) based on non-fused ring electron acceptors(NFREAs).However,research on the impac...The fluorination strategy has been proven effective in significantly enhancing the photovoltaic performance of organic solar cells(OSCs) based on non-fused ring electron acceptors(NFREAs).However,research on the impact of fluorination positions at side chains on NFREAs device performance remains scant.In this study,we introduce two isomeric NFREAs,designated as GA-2F-E and GA-2F,distinguished by their fluorination positions at the side chains.Both NFREAs share a thiophene[3,2-b]thiophene core,but their side chains differ:GA-2F-E features two(4-butylphenyl)-N-(4-fluorophenyl) amino groups,whereas GA-2F's side chains consist of bis(4-fluorophenyl)amino and bis(4-butylphenyl)amino groups attached to opposite sides of the core.To delve into the influence of fluorination positions on the optoelectronic properties,aggregation behavior,and overall efficiency of the acceptor molecules,a comprehensive investigation was conducted.The findings reveal that,despite similar photophysical properties and comparable absorption bandwidths,GA-2F-E,with fluorine atoms positioned on both sides of the molecular framework,demonstrates more compact π-π stacking,reduced bimolecular recombination,superior exciton transport,and a more balanced,higher mobility.As a result of these advantages,OSCs optimized with D18:GA-2F-E achieve a remarkable power conversion efficiency(PCE) of 16.45 %,surpassing the 15.83 %PCE of devices utilizing D18:GA-2F.This research underscores the potential of NFREAs in future applications and highlights the significance of fluorination positions in enhancing OSC performance,paving the way for the development of more efficient NFREAs.展开更多
The Hainan FTP is a game changer,and those who seize the opportunities it offers early will be in an advantageous position As it provides a vital new model for China’s international trade and logistics,the Hainan Fre...The Hainan FTP is a game changer,and those who seize the opportunities it offers early will be in an advantageous position As it provides a vital new model for China’s international trade and logistics,the Hainan Free Trade Port(FTP)stands out among similar opening-up initiatives.展开更多
BACKGROUND:Tracheal intubation(TI)is a fundamental procedure for securing the airway or assisting ventilation in emergency medicine.Tracheal intubation in the lateral position(TILP)has been utilized in clinical practi...BACKGROUND:Tracheal intubation(TI)is a fundamental procedure for securing the airway or assisting ventilation in emergency medicine.Tracheal intubation in the lateral position(TILP)has been utilized in clinical practice,demonstrating potential advantages in specific scenarios,including emergency settings.However,there is a lack of comprehensive reviews and practical protocols on TILP application.To address this gap,we performed a narrative review,and provided evidence-based recommendations to formulate a practice protocol,to assist clinicians to effectively apply TILP.METHODS:We conducted a narrative review of TILP applications and developed recommendations based on clinical research evidence and clinical experience.Delphi method was used among the TILP consortium to grade the strength of the recommendations and to help reach consensus.The practice protocols were formulated as warranted by advancements in medical knowledge,technology,and practice.RESULTS:This narrative review summarized the current evidence on TILP application,highlighting its safety,efficacy,challenges,and potential complications.In total,24 recommendations and a clinical protocol for TILP application in emergency patients were established.CONCLUSION:TILP is a valuable technique in emergency medicine.We reviewed its application in emergency settings and formulated recommendations along with a clinical practice protocol.Future studies are needed to evaluate the safety and efficacy of TILP,broaden its scope of application,and explore effective training protocols.展开更多
The intensified kernel position effect is a common phenomenon in maize production under higher plant density,which limits crop productivity.Subsoiling is an effective agronomic practice for improving crop productivity...The intensified kernel position effect is a common phenomenon in maize production under higher plant density,which limits crop productivity.Subsoiling is an effective agronomic practice for improving crop productivity.To clarify the effect of subsoiling before winter wheat on the kernel position effect of densely grown summer maize and its regulatory mechanism,field experiments were conducted during the 2020-2021 and 2021-2022 growing seasons using a split-plot design.The main plots included two tillage practices:conventional tillage practice(CT)and subsoiling before the sowing of winter wheat(SS);and the subplots consisted of three plant densities(D1-D3 at 6.0×10~4,7.5×10~4,and 9.0×10~4 plants ha-1).Compared with CT,SS alleviated the kernel position effect by increasing the weight ratio of inferior to superior kernels(WR)in the D2 and D3 treated plants.The higher WR of SS treated plants contributed largely to the improved flling of inferior kernels.Under the same plant density,SS signifcantly improved the root dry matter accumulation(DMA)and antioxidant enzyme activities(superoxide dismutase(SOD)and peroxidase(POD)),and it reduced the malondialdehyde(MDA)content,especially for the plants grown under higher plant densities.These results indicated that SS delayed the root senescence,which is associated with the reduced soil bulk density.In addition,compared with CT,SS increased the leaf chlorophyll content from 20 days after silking to physiological maturity and the post-silking leaf area duration,and it reduced the post-silking leaf chlorophyll reduction rate and leaf area reduction rate,indicating that the post-silking leaf senescence had been alleviated.Under the same plant density,the post-silking DMA of SS was obviously higher than that of CT,which was probably related to the improved leaf area duration and photosynthetic enzyme activities(phosphoenolpyruvate carboxylase(PEPC)and Rubisco).The correlation analysis revealed that the main mechanism of SS in alleviating the kernel position effect of densely grown summer maize is as follows:SS delays the post-silking root-shoot senescence by regulating soil physical properties,and further improves the post-silking DMA and flling of inferior kernels,which ultimately alleviates the kernel position effect and improves grain yield.The results of this study provide new theoretical support for the promotion of summer maize yield by subsoiling before winter wheat.展开更多
Accurate measurement of helicopter rotor motion parameters(flap,lead-lag,torsion,and azimuth angles)is essential for rotor blade design,helicopter dynamics modeling,and flight safety and health monitoring.However,the ...Accurate measurement of helicopter rotor motion parameters(flap,lead-lag,torsion,and azimuth angles)is essential for rotor blade design,helicopter dynamics modeling,and flight safety and health monitoring.However,the existing methods face challenges in testing equipment installation,calibration,and data transmission,resulting in limited reports on real-time in-flight measurements of blade motion parameters.This paper proposes a non-contact optoelectronic method based on two-dimensional position-sensitive detectors for in-flight measurement and a ground calibration system to obtain real-time rotor motion parameters during helicopter flight.The proposed method establishes the time evolution relationship of rotor motion parameters and verifies the performance of the in-flight measurement system regarding measurement resolution and accuracy through the construction of a blade motion posture experimental platform.The proposed method has been applied to the flight measurement of a medium-sized single-rotor helicopter,and the obtained results have been compared with theoretical analysis outcomes.Furthermore,this paper examines the characteristics of blade motion parameters during flight and discusses the challenges and potential solutions for measuring rotor motion parameters during helicopter flight using the proposed method.展开更多
Mountainous areas are the priority for forest restoration in semiarid regions,with hillslopes serving as the basic units of mountains.Precipitation is the only water source in these regions,and the uneven distribution...Mountainous areas are the priority for forest restoration in semiarid regions,with hillslopes serving as the basic units of mountains.Precipitation is the only water source in these regions,and the uneven distribution of hillslope soil moisture replenishment after precipitation determines vegetation survival and growth.Therefore,in this study experiments were performed on a hillslope in the Liupan Mountains,Ningxia Hui Autonomous Region,China,to quantify the unevenness of soil moisture replenishment.Soil water content(SWC)in the 0–60 cm layer and precipitation were monitored throughout the growing season in 2020 and 2021.The results showed that(1)Annual soil moisture replenishment was the highest at the mid-slope position,with an average of 309.9 mm,especially under moderate and heavy rain grade conditions,reaching 38.7% and 30.8% of the total replenishment,respectively;(2)Vertical replenishment played a dominant role in the total replenishment,accounting for 82.8%;lateral replenishment played an important but lesser role,accounting for up to 17.2% of the total replenishment;(3)Based on a soil moisture replenishment model established in this study,the maximal replenishment occurred at 90 m from the top of the slope;(4)The dominant factors contributing to the soil moisture replenishment were rainfall amount and saturated hydraulic conductivity(Ks).These findings suggest that attention should be given to both vertical and lateral soil moisture replenishment,and the mid-slope position could be preferred for site selection to achieve precise and integrated forest-water management on hillslopes in semi-arid mountainous regions.展开更多
Digital technology and the digital economy are at the forefront of the global technological revolution and industrial transformation.They are profoundly reshaping the international landscape of competition and restruc...Digital technology and the digital economy are at the forefront of the global technological revolution and industrial transformation.They are profoundly reshaping the international landscape of competition and restructuring the world economy.Major countries and economies around the globe are increasingly competing on digital technology and the digital economy,striving to secure a strategic advantage in the new round of international competition and establish a strong position in the evolving international order.展开更多
A general metal-free photochemcial oxidation of benzylic C—H bonds has been successfully accomplished via a hydrogen atom transfer(HAT)process.A range of high value-added aromatic ketones were facilely synthesized wi...A general metal-free photochemcial oxidation of benzylic C—H bonds has been successfully accomplished via a hydrogen atom transfer(HAT)process.A range of high value-added aromatic ketones were facilely synthesized with high chemoselectivity under mild conditions.Moreover,the mild conditions by using air as the oxidant render the developed proto-col more ecofriendly and environmentally sustainable.展开更多
基金ThispaperissupportedbyNationalNatureScienceFoundation (No .5 96 35 16 0 )AdvancedUniversityDoctoralSubjectFoundation (No .980 2 1311)
文摘Off line programming provides an essential link between CAD and CAM, whose development will result in greater use of robotic arc welding. An arc welding system with a robot and a rotating/tilting positioner is one of the most typical workcells. The inverse kinematics of robot and positioner is the foundation of the off line programming system. The previous researchers only focused on a special solution of the positioner inverse kinematics, which is the solution at down hand welding position. In this paper, we introduce a method for representing welding position. Then a general algorithm of rotating/tilting positioner inverse kinematics is presented, and an approach to find the unique solution of the inverse kinematics is discussed. The simulation experiment results show that the general algorithm can improve the ability of robotic arc welding off line programming system to program all types of welding positions.
文摘A new intelligent control method for welding positioner is proposed. Applying an improved fuzzy controller and a variable PID controller, a two-mode intelligent coordinating controller ( TMICC ) is designed on basis of fuzzy logic and rules. The simulation and experimental results show that this control system can obtain better dynamic and static characteristics.
文摘Aiming at the robotic welding positioner with characteristic of parameter change, load change, nonlinearity, and an intelligent control system was researched and developed. This control system used a two-mode controller that based on Fuzzy and PID control method. The results of simulation show that the dynamic and steady performances of the intelligent controller are better than that of single PID or Fuzzy controller. This paper has made a detail theoretical analysis of the constitution design and real-time controlled software and brought up the design and fulfillment method of multi-task real-time control software of high precisely and numerically controlled welding positioner, which has a good result in practice.
基金This project is supported by National Hi-tech Research and Development Program of China(863 Program, No.2002AA422260).
文摘A large workspace flexure parallel positioner system is developed, which can attain sub-micron scale accuracy over cubic centimeter motion range for utilizing novel wide-range flexure hinges instead of the conventional mechanism joints. Flexure hinges eliminate backlash and friction, but on the other hand their deformation caused by initial loads influences the positioning accuracy greatly, so discussions about loads＇ influence analysis on this flexure parallel positioner is very necessary. The stiffness model of the whole mechanism is presented via stiffness assembly method based on the stiffness model of individual flexure hinge, And the analysis results are validated by the finite element analysis （FEA） simulation and experiment tests, which provide essential data to the practical application of this positioner system.
文摘Traditional CAD technique does not support the design processes such as function definition, conceptual design and preliminary design, which are most creative and play significant roles on the design quality. Because scheme design has close relationship with product structure, performance and technology cost, it is important for applying the intelligent CAD of scheme design to improve the quality and competitive level of the product. The definition and function of welding positioner are discussed in this paper. The new definition of welding positioner extends the research scope of welding positioner to welding fixture and welding positioning motion mechanism. The design process of welding fixture and positioning motion system is described, and the cased based and knowledge based design strategy of welding positioner scheme design intelligent CAD is then put forward, which lays foundation for developing proto type system of welding positioner scheme design.
基金supported by the National Key Research and Development Program of China(Grant No.2022YFF0708902)the Ningbo Key Technology Research and Development Program(Grant No.2023Z018)+1 种基金the Liupanshan Laboratory Basic Research Program(Grant No.LPS-2024-KY-D-JC-0008)the Youth Fund of National Natural Science Foundation of China(Grant No.52205043)。
文摘This paper presents an adaptive saturated integral sliding mode controller(ASISMC)integrated with an adaptive extended state observer(AESO)to address the challenges of nonlinear time-varying characteristics,parameter uncertainties,and external disturbances in valve positioner systems(VPS).To begin with,the VPS dynamic model is established by combining the valve positioner model,the control valve model,and the Euler-Lagrange model,where the uncertain parameters are estimated using the adaptive laws.Moreover,a tracking differentiator(TD)is implemented to ensure smooth and continuous signal processing.The AESO with structural self-regulation capability is also developed to estimate system perturbations and uncertainties effectively.Meanwhile,the proposed ASISMC is designed using adaptive laws based on the backstepping technique,further enhanced by setting saturation constraints on the integral sliding film surface.Finally,experimental validation confirms the superiority of the proposed approach over existing methods in improving control precision,response velocity,and disturbance rejection capability.
文摘Severe acute pancreatitis(SAP)can induce acute respiratory distress syndrome(ARDS)and abdominal compartment syndrome(ACS).Although prone position ventilation(PPV)can improve outcomes in patients with ARDS,there is significant controversy regarding its concurrent use with ACS owing to concerns of increased risk of intra-abdominal pressure(IAP).[1]We present a case of successful PPV application without adverse eff ects.
文摘Background:Pressure injury(PI)is a prevalent complication in pediatric cardiac surgery,with higher incidence than in general pediatric populations due to children’s thin skin,underdeveloped subcutaneous tissue,and prolonged intraoperative pressure.Objective:To evaluate the effectiveness of the curvilinear supine position(CSP)in preventing PI among children undergoing congenital heart disease(CHD)surgery.Methods:Between October 2024 and February 2025,a single-center randomized controlled trial was conducted.Of the 80 children initially enrolled for congenital heart disease(CHD)surgery,77(aged 1 month to 14 years)completed the study and were included in the final analysis after 3 were excluded due to protocol violations.Participants were randomly assigned to the CSP group(n=38)or the conventional supine position group(n=39).Results:The incidence of PI was significantly lower in the CSP group(2.6%)compared to the control group(20.5%)(p=0.029).Postoperative LDH levels were also significantly reduced in the CSP group(422.67±86.52 U/L vs.592.92±215.71 U/L;p=0.031),while preoperative LDH and surgical variables(e.g.,cardiopulmonary bypass time)were comparable between groups.Although the CSP group had a shorter hospital stay(17.24 vs.22.51 days),the difference was not statistically significant(p=0.085).Caregiver satisfaction was significantly higher in the CSP group(100.0%vs.84.6%;p=0.025).Conclusion:CSP effectively reduces PI incidence,mitigates tissue injury,and enhances caregiver satisfaction in pediatric cardiac surgery,offering a safe and feasible strategy for perioperative PI prevention.
基金co-supported by the National Natural Science Foundation of China(No.52125504)the Liaoning Revitalization Talents Program(No.XLYC2202017)Dalian Support Policy Project for Innovation of Technological Talents(No.2023RG001)。
文摘The high-quality assembly of Large Aircraft Components(LACs)is essential in modern aviation manufacturing.Numerical control locators are employed for the posture adjustment of LAC,yet the system's multi-input multi-output,nonlinearity,and strong coupling presents significant challenges.The substantial internal force generated during the adjustment process can potentially damage the LAC and degrade the assembly quality.Hence,a workspace-based hybrid force position control scheme was developed to achieve high quality assembly with high-precision and lower internal force.Firstly,an offline workspace analysis with inherent geometric characteristics to form time-varying posture error constraint.Then,the posture error is integrated into the online position axis control to ensure tracking the ideal posture,while the force control axis compensates for posture deviation by minimizing internal force,thereby achieving high precision and low internal force.Finally,the effectiveness was demonstrated through experiments.The root mean square errors of orientation and position are 104 rad and 0.1 mm,respectively.A reduction in internal force can range from 10.96%to 57.4%compared to the traditional method.Key points'max position error is decreased from 0.32 mm to 0.18 mm,satisfying the 0.5 mm tolerance.Therefore,the proposed method will help promote the development of high-performance manufacturing.
基金supported by the National Natural Science Foundation of China(Grant Nos.52378392,52408356)the Foal Eagle Program Youth Top-notch Talent Project of Fujian Province,China(Grant No.00387088).
文摘Although machine learning models have achieved high enough accuracy in predicting shield position deviations,their“black box”nature makes the prediction mechanisms and decision-making processes opaque,leading to weaker explanations and practicability.This study introduces a novel explainable deep learning framework comprising the Informer model with enhanced attention mechanisms(EAMInfor)and deep learning important features(DeepLIFT),aimed at improving the prediction accuracy of shield position deviations and providing interpretability for predictive results.The EAMInfor model attempts to integrate channel attention,spatial attention,and simple attention modules to improve the Informer model's performance.The framework is tested with the four different geological conditions datasets generated from the Xiamen metro line 3,China.Results show that the EAMInfor model outperforms the traditional Informer and comparison models.The analysis with the DeepLIFT method indicates that the push thrust of push cylinder and the earth chamber pressure are the most significant features,while the stroke length of the push cylinder demonstrated lower importance.Furthermore,the variation trends in the significance of data points within input sequences exhibit substantial differences between single and composite strata.This framework not only improves predictive accuracy but also strengthens the credibility and reliability of the results.
基金Supported by the Zhejiang Medical Health Science and Technology Project(No.2021KY217)the Basic Public Welfare Research Project of Wenzhou Municipal Science and Technology Bureau(No.2024Y1221).
文摘AIM:To evaluate and compare alterations in the effective lens position(ELP)and refractive outcomes among three distinct intraocular lens(IOL)types.METHODS:Patients with cataracts were enrolled and allocated to 3 groups:Group A(implanted with the SN6CWS),Group B(implanted with the MI60),and Group C(implanted with the Aspira-aA).ELP measurements were obtained with swept-source optical coherence tomography(SS-OCT)at 1d,1wk,1mo,and 3mo postoperatively.Subjective refraction assessments were conducted at 1wk,1mo,and 3mo following surgery.RESULTS:The study included 189 eyes of 150 cataract patients(66 males).There were 77 eyes in Group A,55 eyes in Group B,and 57 eyes in Group C.The root mean square of the ELP(ELPRMS)within the initial 3mo was significantly lower for Group A than for Groups B and C.Refractive changes within Group A were not significant across the time points of 1wk,1mo,and 3mo.Conversely,both Group B and Group C demonstrated statistically significant shifts toward hyperopia from 1wk to 3mo postsurgery.CONCLUSION:Among the three IOLs examined,the SN6CWS IOL showes the greatest stability during the first 3mo postoperatively.Between 1wk and 3mo after surgery,notable hyperopic shifts are evident in eyes implanted with the MI60 and Aspira-aA IOLs,whereas refractive outcomes remain relatively constant in eyes implanted with SN6CWS IOLs.
基金financially supported by the National Natural Science Foundation of China (Nos.22375024,21975031,51933001,and 21734009)。
文摘The fluorination strategy has been proven effective in significantly enhancing the photovoltaic performance of organic solar cells(OSCs) based on non-fused ring electron acceptors(NFREAs).However,research on the impact of fluorination positions at side chains on NFREAs device performance remains scant.In this study,we introduce two isomeric NFREAs,designated as GA-2F-E and GA-2F,distinguished by their fluorination positions at the side chains.Both NFREAs share a thiophene[3,2-b]thiophene core,but their side chains differ:GA-2F-E features two(4-butylphenyl)-N-(4-fluorophenyl) amino groups,whereas GA-2F's side chains consist of bis(4-fluorophenyl)amino and bis(4-butylphenyl)amino groups attached to opposite sides of the core.To delve into the influence of fluorination positions on the optoelectronic properties,aggregation behavior,and overall efficiency of the acceptor molecules,a comprehensive investigation was conducted.The findings reveal that,despite similar photophysical properties and comparable absorption bandwidths,GA-2F-E,with fluorine atoms positioned on both sides of the molecular framework,demonstrates more compact π-π stacking,reduced bimolecular recombination,superior exciton transport,and a more balanced,higher mobility.As a result of these advantages,OSCs optimized with D18:GA-2F-E achieve a remarkable power conversion efficiency(PCE) of 16.45 %,surpassing the 15.83 %PCE of devices utilizing D18:GA-2F.This research underscores the potential of NFREAs in future applications and highlights the significance of fluorination positions in enhancing OSC performance,paving the way for the development of more efficient NFREAs.
文摘The Hainan FTP is a game changer,and those who seize the opportunities it offers early will be in an advantageous position As it provides a vital new model for China’s international trade and logistics,the Hainan Free Trade Port(FTP)stands out among similar opening-up initiatives.
基金National Natural Science Foundation of China(U24A20714 to XMF and 82102238 to PC)。
文摘BACKGROUND:Tracheal intubation(TI)is a fundamental procedure for securing the airway or assisting ventilation in emergency medicine.Tracheal intubation in the lateral position(TILP)has been utilized in clinical practice,demonstrating potential advantages in specific scenarios,including emergency settings.However,there is a lack of comprehensive reviews and practical protocols on TILP application.To address this gap,we performed a narrative review,and provided evidence-based recommendations to formulate a practice protocol,to assist clinicians to effectively apply TILP.METHODS:We conducted a narrative review of TILP applications and developed recommendations based on clinical research evidence and clinical experience.Delphi method was used among the TILP consortium to grade the strength of the recommendations and to help reach consensus.The practice protocols were formulated as warranted by advancements in medical knowledge,technology,and practice.RESULTS:This narrative review summarized the current evidence on TILP application,highlighting its safety,efficacy,challenges,and potential complications.In total,24 recommendations and a clinical protocol for TILP application in emergency patients were established.CONCLUSION:TILP is a valuable technique in emergency medicine.We reviewed its application in emergency settings and formulated recommendations along with a clinical practice protocol.Future studies are needed to evaluate the safety and efficacy of TILP,broaden its scope of application,and explore effective training protocols.
基金fnancially supported by the Natural Science Foundation of Hebei Province,China(C2021301004)the State Key Laboratory of North China Crop Improvement and Regulation,China(NCCIR2023KF-10)the HAAFS Science and Technology Innovation Special Project,China(2022KJCXZX-LYS-9)。
文摘The intensified kernel position effect is a common phenomenon in maize production under higher plant density,which limits crop productivity.Subsoiling is an effective agronomic practice for improving crop productivity.To clarify the effect of subsoiling before winter wheat on the kernel position effect of densely grown summer maize and its regulatory mechanism,field experiments were conducted during the 2020-2021 and 2021-2022 growing seasons using a split-plot design.The main plots included two tillage practices:conventional tillage practice(CT)and subsoiling before the sowing of winter wheat(SS);and the subplots consisted of three plant densities(D1-D3 at 6.0×10~4,7.5×10~4,and 9.0×10~4 plants ha-1).Compared with CT,SS alleviated the kernel position effect by increasing the weight ratio of inferior to superior kernels(WR)in the D2 and D3 treated plants.The higher WR of SS treated plants contributed largely to the improved flling of inferior kernels.Under the same plant density,SS signifcantly improved the root dry matter accumulation(DMA)and antioxidant enzyme activities(superoxide dismutase(SOD)and peroxidase(POD)),and it reduced the malondialdehyde(MDA)content,especially for the plants grown under higher plant densities.These results indicated that SS delayed the root senescence,which is associated with the reduced soil bulk density.In addition,compared with CT,SS increased the leaf chlorophyll content from 20 days after silking to physiological maturity and the post-silking leaf area duration,and it reduced the post-silking leaf chlorophyll reduction rate and leaf area reduction rate,indicating that the post-silking leaf senescence had been alleviated.Under the same plant density,the post-silking DMA of SS was obviously higher than that of CT,which was probably related to the improved leaf area duration and photosynthetic enzyme activities(phosphoenolpyruvate carboxylase(PEPC)and Rubisco).The correlation analysis revealed that the main mechanism of SS in alleviating the kernel position effect of densely grown summer maize is as follows:SS delays the post-silking root-shoot senescence by regulating soil physical properties,and further improves the post-silking DMA and flling of inferior kernels,which ultimately alleviates the kernel position effect and improves grain yield.The results of this study provide new theoretical support for the promotion of summer maize yield by subsoiling before winter wheat.
基金the funding provided by the National Helicopter Development Project of China。
文摘Accurate measurement of helicopter rotor motion parameters(flap,lead-lag,torsion,and azimuth angles)is essential for rotor blade design,helicopter dynamics modeling,and flight safety and health monitoring.However,the existing methods face challenges in testing equipment installation,calibration,and data transmission,resulting in limited reports on real-time in-flight measurements of blade motion parameters.This paper proposes a non-contact optoelectronic method based on two-dimensional position-sensitive detectors for in-flight measurement and a ground calibration system to obtain real-time rotor motion parameters during helicopter flight.The proposed method establishes the time evolution relationship of rotor motion parameters and verifies the performance of the in-flight measurement system regarding measurement resolution and accuracy through the construction of a blade motion posture experimental platform.The proposed method has been applied to the flight measurement of a medium-sized single-rotor helicopter,and the obtained results have been compared with theoretical analysis outcomes.Furthermore,this paper examines the characteristics of blade motion parameters during flight and discusses the challenges and potential solutions for measuring rotor motion parameters during helicopter flight using the proposed method.
基金financially supported by the Central Public-Interest Scientific Institution Basal Research Fund of Chinese Academy of Forestry(CAFYBB2021ZW002)the National Key Research and Development Program of China(2022YFF1300404)the National Natural Science Foundation of China(U21A2005)。
文摘Mountainous areas are the priority for forest restoration in semiarid regions,with hillslopes serving as the basic units of mountains.Precipitation is the only water source in these regions,and the uneven distribution of hillslope soil moisture replenishment after precipitation determines vegetation survival and growth.Therefore,in this study experiments were performed on a hillslope in the Liupan Mountains,Ningxia Hui Autonomous Region,China,to quantify the unevenness of soil moisture replenishment.Soil water content(SWC)in the 0–60 cm layer and precipitation were monitored throughout the growing season in 2020 and 2021.The results showed that(1)Annual soil moisture replenishment was the highest at the mid-slope position,with an average of 309.9 mm,especially under moderate and heavy rain grade conditions,reaching 38.7% and 30.8% of the total replenishment,respectively;(2)Vertical replenishment played a dominant role in the total replenishment,accounting for 82.8%;lateral replenishment played an important but lesser role,accounting for up to 17.2% of the total replenishment;(3)Based on a soil moisture replenishment model established in this study,the maximal replenishment occurred at 90 m from the top of the slope;(4)The dominant factors contributing to the soil moisture replenishment were rainfall amount and saturated hydraulic conductivity(Ks).These findings suggest that attention should be given to both vertical and lateral soil moisture replenishment,and the mid-slope position could be preferred for site selection to achieve precise and integrated forest-water management on hillslopes in semi-arid mountainous regions.
文摘Digital technology and the digital economy are at the forefront of the global technological revolution and industrial transformation.They are profoundly reshaping the international landscape of competition and restructuring the world economy.Major countries and economies around the globe are increasingly competing on digital technology and the digital economy,striving to secure a strategic advantage in the new round of international competition and establish a strong position in the evolving international order.
文摘A general metal-free photochemcial oxidation of benzylic C—H bonds has been successfully accomplished via a hydrogen atom transfer(HAT)process.A range of high value-added aromatic ketones were facilely synthesized with high chemoselectivity under mild conditions.Moreover,the mild conditions by using air as the oxidant render the developed proto-col more ecofriendly and environmentally sustainable.
