High pressure die casting(HPDC)AlSi10Mn Mg alloy castings are widely used in the automobile industry.Mg can optimize the mechanical properties of castings through heat treatment,while the release of thermal stress aro...High pressure die casting(HPDC)AlSi10Mn Mg alloy castings are widely used in the automobile industry.Mg can optimize the mechanical properties of castings through heat treatment,while the release of thermal stress arouses the deformation of large integrated die-castings.Herein,the development of non-heat treatment Al alloys is becoming the hot topic.In addition,HPDC contains externally solidified crystals(ESCs),which are detrimental to the mechanical properties of castings.To achieve high strength and toughness of non-heat treatment die-casting Al-Si alloy,we used AlSi9Mn alloy as matrix with the introduction of Zr,Ti,Nb,and Ce.Their influences on ESCs and mechanical properties were systematically investigated through three-dimensional reconstruction and thermodynamic simulation.Our results reveal that the addition of Ti increased ESCs'size and porosity,while the introduction of Nb refined ESCs and decreased porosity.Meanwhile,large-sized Al_3(Zr,Ti)phases formed and degraded the mechanical properties.Subsequent introduction of Ce resulted in the poisoning effect and reduced mechanical properties.展开更多
The present status and perspectives of Chinese die-casting market were commented. In 2003, the total output of die castings in the whole country was 708000 tons, in which the outputs of Al-alloy, Zn-alloy, Mg-alloy, C...The present status and perspectives of Chinese die-casting market were commented. In 2003, the total output of die castings in the whole country was 708000 tons, in which the outputs of Al-alloy, Zn-alloy, Mg-alloy, Cu-alloy die castings were 474600 tons, 222000 tons, 5800 tons, 5600 tons, respectively, each accounted for 67%, 31.35%, 0.85%, 0.8% of the total. The annual sale volume of die-casting machines was approximately 1800. And the gross output value of dies approached RMB 38 billion, in which die-casting dies accounted for about 10%. In the die-casting industry of the entire country, the foreign capital enterprises, public-run enterprises, township and village enterprises, private enterprises accounted for over 80% of the total die-casting enterprises. Super huge die-casting groups are forming.展开更多
BACKGROUND Living donor kidney transplantation is the optimal method of long-term renal replacement therapy.Minimally invasive donor nephrectomy techniques,such as robot-assisted(RALDN)and hand-assisted(HALDN)laparosc...BACKGROUND Living donor kidney transplantation is the optimal method of long-term renal replacement therapy.Minimally invasive donor nephrectomy techniques,such as robot-assisted(RALDN)and hand-assisted(HALDN)laparoscopic procedures,are well-established in high-income countries and are being increasingly adopted worldwide.Nevertheless,no studies have reported surgical outcomes of RALDN donor nephrectomy from a United Kingdom center to date.AIM To compare surgical outcomes between RALDN and HALDN laparoscopic donor nephrectomy in a United Kingdom high-volume living kidney donor transplant program.METHODS A case-control matching analysis was performed based on the following parameters:Sex,age,body mass index,procedure laterality,number of renal arteries,and previous abdominal surgeries.Key surgical outcomes,including primary warm ischemia time,operative duration,and post-operative recovery,were evaluated.RESULTS In this cohort of 140 living donors(70 RALDN vs 70 HALDN),donor and recipient outcomes were equivalent across key metrics:Pain scores,overall complication rates,readmissions,reoperations,and creatinine levels at 30 days and 1 year.Recipient long-term renal function did not differ between groups.Operative time for RALDN decreased significantly over the study period,indicating progressive improvement along the learning curve.Although RALDN was associated with a modestly longer mean warm ischaemia time(3.53 minutes vs 2.76 minutes,P<0.001)and extended hospital stay(4.21 days vs 3.17 days,P<0.001),these did not translate into any disadvantage in clinical outcomes.CONCLUSION In this first United Kingdom comparative cohort,RALDN demonstrated excellent safety and efficacy,even in the early phase of our programme,matching the outcomes of the well-established,gold-standard HALDN approach.Moreover,the pronounced learning-curve trajectory suggests considerable potential for further improvements in robotic surgical outcomes as the programme matures.展开更多
The rise of the aging population parallels the rapidly increasing cases of neurological disorders. This puts pressure on scientists and physicians to find novel methods that can prevent and treat neurodegeneration. Th...The rise of the aging population parallels the rapidly increasing cases of neurological disorders. This puts pressure on scientists and physicians to find novel methods that can prevent and treat neurodegeneration. The brain is made up of a complex network of different cell types that work in tandem to maintain systemic homeostasis.展开更多
GW63K （Mg-6Gd-3Y-0.5Zr） magnesium alloys were prepared successfully by high-vacuum die-casting. Effects of fast shot speed and vacuum level on the grain size and mechanical properties of this alloy were studied. Mic...GW63K （Mg-6Gd-3Y-0.5Zr） magnesium alloys were prepared successfully by high-vacuum die-casting. Effects of fast shot speed and vacuum level on the grain size and mechanical properties of this alloy were studied. Microstructure of the alloys was analyzed by SEM, EDX and optical microscope （OM）. The effect of heat treatment on high vacuum die-casting （HVDC） GW63K alloy was also studied. The results indicate that with the increase of fast velocity, the tensile yield strength hardly changes, but the elongation first increases, then decreases. The optimum heat treatment process is solution treatment at 748 K for 2 h and aging at 473 K for 80 h. Under this condition, GW63K magnesium alloy exhibits a maximum tensile strength and elongation of 308 MPa and 9.45%. There is significant correlation between ductility and the presence of external solidified cells （ESCs）. The as-cast GW63K alloy consists ofα-Mg and Mg24（Gd,Y）5 particles. After heat treatment, Gd and Y atoms dissolve intoα-Mg matrix.展开更多
Vehicle mass reduction in the automotive industry has become an industry-wide objective.Increasing fuel efficiency and greenhouse gas emission targets for engine-powered vehicles,and ambitions for extended range elect...Vehicle mass reduction in the automotive industry has become an industry-wide objective.Increasing fuel efficiency and greenhouse gas emission targets for engine-powered vehicles,and ambitions for extended range electric vehicles have motivated these reductions in vehicle mass.Mass reduction opportunities in structural automotive applications are increasingly realized through lightweight alloy castings,such as magnesium,primarily due to the ease of component substitution.The traditional benefits of magnesium die-castings including lightweighting and associated compounded mass savings,excellent strength-to-weight ratio,part consolidation,near net-shape forming,dimensional repeatability,and integration of additional components can be realized in closure applications.One recent example is the application of a magnesium die-casting for the structural inner of the liftgate in the 2017 Chrysler Pacifica,replacing nine parts in the previous generation and resulting in a liftgate assembly weight reduction of nearly 50%.The work presented here reviews past and current developments of magnesium die-castings in closure applications and discusses the benefits and challenges of magnesium alloys for these applications,including casting design,corrosion and fastening strategies,and the manufacturing design and assembly methodologies.展开更多
The vacuum die-casting process,started 25 years ago in Japan,has been widely applied.This technology contributes very much to improvement of castings quality.The main factor causing the defects of die castings is the ...The vacuum die-casting process,started 25 years ago in Japan,has been widely applied.This technology contributes very much to improvement of castings quality.The main factor causing the defects of die castings is the trapped air in the mold cavity,while the key technology of vacuum die-casting process is to avoid the trapped air effectively by evacuating the cavity before casting.At the same time,due to the shot speed and the casting pressure reduced in half,the service life of the die is prolonged and the productivity is enhanced,as well.Vacuum die-casting process is of great signif icance in improving the die castings quality and making up the shortcomings of super-high-speed shot casting.展开更多
Al-Si-Mg alloys are the most commonly used material in high vacuum die-casting(HVDC),in which the morphology and distribution ofα-Al grains have important effect on mechanical properties.A multi-component quantitativ...Al-Si-Mg alloys are the most commonly used material in high vacuum die-casting(HVDC),in which the morphology and distribution ofα-Al grains have important effect on mechanical properties.A multi-component quantitative cellular automaton(CA)model was developed to simulate the microstructure and microsegregation of HVDC Al-Si-Mg alloys with different Si contents(7%and 10%)and cooling rates during solidification.The grain number and average grain size with electron backscatter diffraction(EBSD)analysis were used to verify the simulation.The relationship between grain size and nucleation order as well as nuclei density was investigated and discussed.It is found that the growth of grains will be restrained in the location with higher nuclei density.The influence of composition and cooling rate on the solute transport reveals that for AlSi7Mg0.3 alloy the concentration of solute Mg in liquid is higher at the beginning of eutectic solidification.The comparison between simulation and experiment results shows that externally solidified crystals(ESCs)have a significant effect for samples with high cooling rate and narrow solidification interval.展开更多
Silicon-based aluminum casting alloys are known to be one of the most widely used alloy systems mainly due to their superior casting characteristics and unique combination of mechanical and physical properties. Howeve...Silicon-based aluminum casting alloys are known to be one of the most widely used alloy systems mainly due to their superior casting characteristics and unique combination of mechanical and physical properties. However,manufacturing of thin-walled aluminum die-casting components,less than 1.0 mm in thickness,is generally known to be very difficult task to achieve aluminum casting alloys with high fluidity.Therefore,in this study,the optimal die-casting conditions for producing 297 mm×210 mm×0.7 mm thin-walled aluminum component was examined experimentally by using 2 different gating systems,tangential and split type,and vent design.Furthermore,computational solidification simulation was also conducted.The results showed that split type gating system was preferable gating design than tangential type gating system at the point of view of soundness of casting and distortion generated after solidification.It was also found that proper vent design was one of the most important factors for producing thin-wall casting components because it was important for the fulfillment of the thin-wall cavity and the minimization of the casting distortion.展开更多
This paper presents some results of direct observation of mold filling in a specially designed die-casting by X-ray diffraction, including comparison with numerical simulation. Based on such work the authors discuss h...This paper presents some results of direct observation of mold filling in a specially designed die-casting by X-ray diffraction, including comparison with numerical simulation. Based on such work the authors discuss how to prevent gas entrapment and propose new methods.展开更多
Due to its high hardness,good red hardness and excellent wear resistance at high temperature,high speed steel(HSS)is fit for the roll manufacture.In order to overcome the segregation of centrifugal casting of HSS roll...Due to its high hardness,good red hardness and excellent wear resistance at high temperature,high speed steel(HSS)is fit for the roll manufacture.In order to overcome the segregation of centrifugal casting of HSS roll,die-cast processes were developed and its effects on the properties of the HSS roll were investigated.It was found that pressure,pressing time and speed are three important factors affecting shrinkage cavity.For pouring temperature of 1 400-1 450 ℃,pressure of 150-160 MPa,pressing time of 120-150 sand pressing speed of 14-16mm/s,a compact HSS roll was obtained,which has no segregation and small working allowance.In the high speed wire rod rolling mill,service life of the HSS roll is 5to 8times longer than that of high nickel chromium infinite chilled cast iron roll.展开更多
A code-generation and recognition technology that uses a modified ejection system in the diecasting process is presented.To achieve the highest level of quality management,the first requirement in the manufacturing pr...A code-generation and recognition technology that uses a modified ejection system in the diecasting process is presented.To achieve the highest level of quality management,the first requirement in the manufacturing process is to establish a product management system according to the specific product unit.Thus,a method to individually identify each product,such as a barcode or QR code,is required during the production process.Products manufactured in the die-casting process always have ejector pin(EP)marks.Herein,an ejection system was modified to generate a unique code using EP marks.This ejection system has two features:an EP with a modified head to show the direction of rotation,and a function to dependently rotate EPs(five or six EPs)with a constant angle.The EPs are numbered according to the rotation angle.Thus,the EP marks can be viewed as a five-or six-digit code.A program was also developed to individually identify the products by automatically detecting and reading the EPs using deep learning-based object detection and classification technology.展开更多
The two production lines for the first phase of the semi-solid die-casting high-end parts project were put into production in this October, and can monthly produce more than 30 thousand die casting parts.
The new energy power generation is becoming increasingly important in the power system.Such as photovoltaic power generation has become a research hotspot,however,due to the characteristics of light radiation changes,...The new energy power generation is becoming increasingly important in the power system.Such as photovoltaic power generation has become a research hotspot,however,due to the characteristics of light radiation changes,photovoltaic power generation is unstable and random,resulting in a low utilization rate and directly affecting the stability of the power grid.To solve this problem,this paper proposes a coordinated control strategy for a newenergy power generation system with a hybrid energy storage unit based on the lithium iron phosphate-supercapacitor hybrid energy storage unit.Firstly,the variational mode decomposition algorithm is used to separate the high and low frequencies of the power signal,which is conducive to the rapid and accurate suppression of the power fluctuation of the energy storage system.Secondly,the fuzzy control algorithm is introduced to balance the power between energy storage.In this paper,the actual data is used for simulation,and the simulation results show that the strategy realizes the effective suppression of the bus voltage fluctuation and the accurate control of the internal state of the energy storage unit,effectively avoiding problems such as overshoot and over-discharge,and can significantly improve the stability of the photovoltaic power generation systemand the stability of the Direct Current bus.It is of great significance to promote the development of collaborative control technology for photovoltaic hybrid energy storage units.展开更多
BACKGROUND The need for an emergency upgrade of a hospitalized trauma patient from the floor to the trauma intensive care unit(ICU)is an unanticipated event with possible life-threatening consequences.Unplanned ICU ad...BACKGROUND The need for an emergency upgrade of a hospitalized trauma patient from the floor to the trauma intensive care unit(ICU)is an unanticipated event with possible life-threatening consequences.Unplanned ICU admissions are associated with increased morbidity and mortality and are an indicator of trauma service quality.Two different types of unplanned ICU admissions include upgrades(patients admitted to the floor then moved to the ICU)and bounce backs(patients admitted to the ICU,discharged to the floor,and then readmitted to the ICU).Previous studies have shown that geriatric trauma patients are at higher risk for unfavorable outcomes.AIM To analyze the characteristics,management and outcomes of trauma patients who had an unplanned ICU admission during their hospitalization.METHODS This institutional review board approved,retrospective cohort study examined 203 adult trauma patients with unplanned ICU admission at an urban level 1 trauma center over a six-year period(2017-2023).This included 134 upgrades and 69 bounce backs.Analyzed variables included:(1)Age;(2)Sex;(3)Comorbidities;(4)Mechanism of injury(MOI);(5)Injury severity score(ISS);(6)Glasgow Coma Scale(GCS);(7)Type of injury;(8)Transfusions;(9)Consultations;(10)Timing and reason for unplanned admission;(11)Intubations;(12)Surgical interventions;(13)ICU and hospital lengths of stay;and(14)Mortality.RESULTS Unplanned ICU admissions comprised 4.2%of total ICU admissions.Main MOI was falls.Mean age was 70.7 years,ISS was 12.8 and GCS was 13.9.Main injuries were traumatic brain injury(37.4%)and thoracic injury(21.7%),and main reason for unplanned ICU admission was respiratory complication(39.4%).The 47.3%underwent a surgical procedure and 46.8%were intubated.Average timing for unplanned ICU admission was 2.9 days.Bounce backs occurred half as often as upgrades,however had higher rates of transfusions(63.8%vs 40.3%,P=0.002),consultations(4.8 vs 3.0,P<0.001),intubations(63.8%vs 38.1%%,P=0.001),longer ICU lengths of stay(13.2 days vs 6.4 days,P<0.001)and hospital lengths of stay(26.7 days vs 13.0 days,P<0.001).Mortality was 25.6%among unplanned ICU admissions,31.9%among geriatric unplanned ICU admissions and 11.9%among all trauma ICU patients.CONCLUSION Unplanned ICU admissions constituted 4.2%of total ICU admissions.Respiratory complications were the main cause of unplanned ICU admissions.Bounce backs occurred half as often as upgrades,but were associated with worse outcomes.展开更多
BACKGROUND As red blood cell distribution width(RDW)and albumin have been shown to be independent predictors of mortality from various diseases,this study aimed to investigate the effect of the RDW to albumin ratio(RA...BACKGROUND As red blood cell distribution width(RDW)and albumin have been shown to be independent predictors of mortality from various diseases,this study aimed to investigate the effect of the RDW to albumin ratio(RA)as an independent predictor of the prognosis of patients admitted to the coronary care unit(CCU).AIM To use the RDW and albumin level to predict the prognosis of patients in the CCU.METHODS Data were obtained from the Medical Information Mart Intensive Care III database.The primary outcome was 365-day all-cause mortality,whereas the secondary outcomes were 30-and 90-day all-cause mortality,hospital length of stay(LOS),and CCU LOS.Cox proportional hazards regression model,propen-sity score matching,and receiver operating characteristic curve analyses were used.RESULTS The hazard ratio(95%confidence interval)of the upper tertile(RA>4.66)was 1.62(1.29 to 2.03)when compared with the reference(RA<3.84)in 365-day all-cause mortality.This trend persisted after adjusting for demographic and clinical variables in the propensity score-matching analysis.Similar trends were observed for the secondary outcomes of hospital and CCU LOS.Receiver operating characteristic curve analysis was performed by combining the RA and sequential organ failure assessment(SOFA)scores,and the C-statistic was higher than that of the SOFA scores(0.733 vs 0.702,P<0.001).CONCLUSION RA is an independent prognostic factor in patients admitted to the CCU.RA combined with the SOFA score can improve the predictive ability of the SOFA score.However,our results should be verified in future prospective studies.展开更多
BACKGROUND Newborns are immediately admitted to the neonatal intensive care unit(NICU)after birth,and thus mothers suffer from the pain of mother-infant separation.Some mothers worry about alterations in their child’...BACKGROUND Newborns are immediately admitted to the neonatal intensive care unit(NICU)after birth,and thus mothers suffer from the pain of mother-infant separation.Some mothers worry about alterations in their child’s condition and the uncertainty and high medical costs of possible sequelae,which frequently cause anxiety,depression,and other adverse emotions.AIM To investigate the anxiety and depression status of mothers of children in the NICU and its related factors.METHODS A convenient sampling method is adopted.The research objects included the mothers of 191 children in the NICU of Suzhou Ninth Hospital Affiliated with Suzhou University from January 2023 to July 2024.The general information questionnaire,personal control scale,self-rating anxiety scale,and self-rating depression scale were utilized for investigation.Anxiety and depression status in mothers of children in the NICU and its related factors were analyzed.RESULTS The incidences of maternal anxiety and depression among 191 hospitalized children in the NICU were 32.98%(63/191)and 23.56%(45/191),respectively.Single-factor analysis reveals that family monthly income,individual sense of control,gestational age of the child,and the number of diseases in the child are associated with the anxiety and depression experienced by the mother of the child in the NICU(P<0.05).Multivariate logistic regression analysis revealed that family monthly income of<5000 yuan(RMB),poor individual control,gestational age of<32 weeks,and the number of diseases of≥3 kinds are all related factors for anxiety and depression in mothers of children admitted to the NICU(P<0.05).CONCLUSION Mothers of children admitted to the NICU demonstrated high anxiety and depression incidences.The nursing staff in the neonatal department established intervention measures for each related factor,strengthened communication and communication with the mother of the child,and did a good job in psychological counseling.展开更多
Large-scale new energy grid connection leads to the weakening of the system frequency regulation capability,and the system frequency stability is facing unprecedented challenges.In order to solve rapid frequency fluct...Large-scale new energy grid connection leads to the weakening of the system frequency regulation capability,and the system frequency stability is facing unprecedented challenges.In order to solve rapid frequency fluctuation caused by new energy units,this paper proposes a new energy power system frequency regulation strategy with multiple units including the doubly-fed pumped storage unit(DFPSU).Firstly,based on the model predictive control(MPC)theory,the state space equations are established by considering the operating characteristics of the units and the dynamic behavior of the system;secondly,the proportional-differential control link is introduced to minimize the frequency deviation to further optimize the frequency modulation(FM)output of the DFPSU and inhibit the rapid fluctuation of the frequency;lastly,it is verified on theMatlab/Simulink simulation platform,and the results show that the model predictive control with proportional-differential control link can further release the FM potential of the DFPSU,increase the depth of its FM,effectively reduce the frequency deviation of the system and its rate of change,realize the optimization of the active output of the DFPSU and that of other units,and improve the frequency response capability of the system.展开更多
Typhoons can cause large-area blackouts or partial outages of distribution networks.We define a partial outage state in the distribution network as a gray state and propose a gray-start strategy and two-stage distribu...Typhoons can cause large-area blackouts or partial outages of distribution networks.We define a partial outage state in the distribution network as a gray state and propose a gray-start strategy and two-stage distribution network emergency recovery framework.A phase-space reconstruction and stacked integrated model for predicting wind and photovoltaic generation during typhoon disasters is proposed in the first stage.This provides guidance for second-stage post-disaster emergency recovery scheduling.The emergency recovery scheduling model is established in the second stage,and this model is supported by a thermal power-generating unit,mobile emergency generators,and distributed generators.Distributed generation includes wind power generation,photovoltaics,fuel cells,etc.Simultaneously,we con-sider the gray-start based on the pumped storage unit to be an important first step in the emergency recovery strategy.This model is val-idated on the improved IEEE 33 node system,which utilizes data from the 2022 super typhoon“Muifa”in Zhoushan,Zhejiang,China.Simulations indicate the superiority of a gray start with a pumped storage unit and the proposed emergency recovery strategy.展开更多
在一个经过篡改的视频可以传播虚假信息、欺凌他人和煽动负面情绪的时代,加州大学河滨分校和谷歌的研究人员联合开发了“通用篡改与合成视频识别网络”(Universal Network for Identifying Tampered and synth Etic videos, UNITE)的新...在一个经过篡改的视频可以传播虚假信息、欺凌他人和煽动负面情绪的时代,加州大学河滨分校和谷歌的研究人员联合开发了“通用篡改与合成视频识别网络”(Universal Network for Identifying Tampered and synth Etic videos, UNITE)的新系统来揭露这些伪造视频。即使在人脸不可见的情况下,该系统依然能检测深度伪造视频。通过扫描背景、运动和细微线索来识别视频是否伪造。随着虚假内容越来越容易生成且越来越难以检测,该工具可能成为新闻编辑室和社交媒体平台努力捍卫真相的必备武器。展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.52175284 and 52474396)the National Key Research and Development Program of China(No.2022YFB3404201)。
文摘High pressure die casting(HPDC)AlSi10Mn Mg alloy castings are widely used in the automobile industry.Mg can optimize the mechanical properties of castings through heat treatment,while the release of thermal stress arouses the deformation of large integrated die-castings.Herein,the development of non-heat treatment Al alloys is becoming the hot topic.In addition,HPDC contains externally solidified crystals(ESCs),which are detrimental to the mechanical properties of castings.To achieve high strength and toughness of non-heat treatment die-casting Al-Si alloy,we used AlSi9Mn alloy as matrix with the introduction of Zr,Ti,Nb,and Ce.Their influences on ESCs and mechanical properties were systematically investigated through three-dimensional reconstruction and thermodynamic simulation.Our results reveal that the addition of Ti increased ESCs'size and porosity,while the introduction of Nb refined ESCs and decreased porosity.Meanwhile,large-sized Al_3(Zr,Ti)phases formed and degraded the mechanical properties.Subsequent introduction of Ce resulted in the poisoning effect and reduced mechanical properties.
文摘The present status and perspectives of Chinese die-casting market were commented. In 2003, the total output of die castings in the whole country was 708000 tons, in which the outputs of Al-alloy, Zn-alloy, Mg-alloy, Cu-alloy die castings were 474600 tons, 222000 tons, 5800 tons, 5600 tons, respectively, each accounted for 67%, 31.35%, 0.85%, 0.8% of the total. The annual sale volume of die-casting machines was approximately 1800. And the gross output value of dies approached RMB 38 billion, in which die-casting dies accounted for about 10%. In the die-casting industry of the entire country, the foreign capital enterprises, public-run enterprises, township and village enterprises, private enterprises accounted for over 80% of the total die-casting enterprises. Super huge die-casting groups are forming.
文摘BACKGROUND Living donor kidney transplantation is the optimal method of long-term renal replacement therapy.Minimally invasive donor nephrectomy techniques,such as robot-assisted(RALDN)and hand-assisted(HALDN)laparoscopic procedures,are well-established in high-income countries and are being increasingly adopted worldwide.Nevertheless,no studies have reported surgical outcomes of RALDN donor nephrectomy from a United Kingdom center to date.AIM To compare surgical outcomes between RALDN and HALDN laparoscopic donor nephrectomy in a United Kingdom high-volume living kidney donor transplant program.METHODS A case-control matching analysis was performed based on the following parameters:Sex,age,body mass index,procedure laterality,number of renal arteries,and previous abdominal surgeries.Key surgical outcomes,including primary warm ischemia time,operative duration,and post-operative recovery,were evaluated.RESULTS In this cohort of 140 living donors(70 RALDN vs 70 HALDN),donor and recipient outcomes were equivalent across key metrics:Pain scores,overall complication rates,readmissions,reoperations,and creatinine levels at 30 days and 1 year.Recipient long-term renal function did not differ between groups.Operative time for RALDN decreased significantly over the study period,indicating progressive improvement along the learning curve.Although RALDN was associated with a modestly longer mean warm ischaemia time(3.53 minutes vs 2.76 minutes,P<0.001)and extended hospital stay(4.21 days vs 3.17 days,P<0.001),these did not translate into any disadvantage in clinical outcomes.CONCLUSION In this first United Kingdom comparative cohort,RALDN demonstrated excellent safety and efficacy,even in the early phase of our programme,matching the outcomes of the well-established,gold-standard HALDN approach.Moreover,the pronounced learning-curve trajectory suggests considerable potential for further improvements in robotic surgical outcomes as the programme matures.
文摘The rise of the aging population parallels the rapidly increasing cases of neurological disorders. This puts pressure on scientists and physicians to find novel methods that can prevent and treat neurodegeneration. The brain is made up of a complex network of different cell types that work in tandem to maintain systemic homeostasis.
基金Projects(51171113,51301107)supported by the National Natural Science Foundation of ChinaProjects(2012M511089,2013T60444)supported by China Postdoctoral Science Foundation
文摘GW63K （Mg-6Gd-3Y-0.5Zr） magnesium alloys were prepared successfully by high-vacuum die-casting. Effects of fast shot speed and vacuum level on the grain size and mechanical properties of this alloy were studied. Microstructure of the alloys was analyzed by SEM, EDX and optical microscope （OM）. The effect of heat treatment on high vacuum die-casting （HVDC） GW63K alloy was also studied. The results indicate that with the increase of fast velocity, the tensile yield strength hardly changes, but the elongation first increases, then decreases. The optimum heat treatment process is solution treatment at 748 K for 2 h and aging at 473 K for 80 h. Under this condition, GW63K magnesium alloy exhibits a maximum tensile strength and elongation of 308 MPa and 9.45%. There is significant correlation between ductility and the presence of external solidified cells （ESCs）. The as-cast GW63K alloy consists ofα-Mg and Mg24（Gd,Y）5 particles. After heat treatment, Gd and Y atoms dissolve intoα-Mg matrix.
文摘Vehicle mass reduction in the automotive industry has become an industry-wide objective.Increasing fuel efficiency and greenhouse gas emission targets for engine-powered vehicles,and ambitions for extended range electric vehicles have motivated these reductions in vehicle mass.Mass reduction opportunities in structural automotive applications are increasingly realized through lightweight alloy castings,such as magnesium,primarily due to the ease of component substitution.The traditional benefits of magnesium die-castings including lightweighting and associated compounded mass savings,excellent strength-to-weight ratio,part consolidation,near net-shape forming,dimensional repeatability,and integration of additional components can be realized in closure applications.One recent example is the application of a magnesium die-casting for the structural inner of the liftgate in the 2017 Chrysler Pacifica,replacing nine parts in the previous generation and resulting in a liftgate assembly weight reduction of nearly 50%.The work presented here reviews past and current developments of magnesium die-castings in closure applications and discusses the benefits and challenges of magnesium alloys for these applications,including casting design,corrosion and fastening strategies,and the manufacturing design and assembly methodologies.
文摘The vacuum die-casting process,started 25 years ago in Japan,has been widely applied.This technology contributes very much to improvement of castings quality.The main factor causing the defects of die castings is the trapped air in the mold cavity,while the key technology of vacuum die-casting process is to avoid the trapped air effectively by evacuating the cavity before casting.At the same time,due to the shot speed and the casting pressure reduced in half,the service life of the die is prolonged and the productivity is enhanced,as well.Vacuum die-casting process is of great signif icance in improving the die castings quality and making up the shortcomings of super-high-speed shot casting.
基金funded by the National Natural Science Foundation of China(No.51875211)the Key Area Research and Development Program of Guangdong Province(No.2020B010186002)the Key Technology Program of Foshan(1920001001040),China.
文摘Al-Si-Mg alloys are the most commonly used material in high vacuum die-casting(HVDC),in which the morphology and distribution ofα-Al grains have important effect on mechanical properties.A multi-component quantitative cellular automaton(CA)model was developed to simulate the microstructure and microsegregation of HVDC Al-Si-Mg alloys with different Si contents(7%and 10%)and cooling rates during solidification.The grain number and average grain size with electron backscatter diffraction(EBSD)analysis were used to verify the simulation.The relationship between grain size and nucleation order as well as nuclei density was investigated and discussed.It is found that the growth of grains will be restrained in the location with higher nuclei density.The influence of composition and cooling rate on the solute transport reveals that for AlSi7Mg0.3 alloy the concentration of solute Mg in liquid is higher at the beginning of eutectic solidification.The comparison between simulation and experiment results shows that externally solidified crystals(ESCs)have a significant effect for samples with high cooling rate and narrow solidification interval.
基金Acknowledgement This work was supported by Korea Institute of Industrial Technology and Gwangju Metropolitan City through ＂The Advanced Materials and Components Industry Development Program＂.
文摘Silicon-based aluminum casting alloys are known to be one of the most widely used alloy systems mainly due to their superior casting characteristics and unique combination of mechanical and physical properties. However,manufacturing of thin-walled aluminum die-casting components,less than 1.0 mm in thickness,is generally known to be very difficult task to achieve aluminum casting alloys with high fluidity.Therefore,in this study,the optimal die-casting conditions for producing 297 mm×210 mm×0.7 mm thin-walled aluminum component was examined experimentally by using 2 different gating systems,tangential and split type,and vent design.Furthermore,computational solidification simulation was also conducted.The results showed that split type gating system was preferable gating design than tangential type gating system at the point of view of soundness of casting and distortion generated after solidification.It was also found that proper vent design was one of the most important factors for producing thin-wall casting components because it was important for the fulfillment of the thin-wall cavity and the minimization of the casting distortion.
文摘This paper presents some results of direct observation of mold filling in a specially designed die-casting by X-ray diffraction, including comparison with numerical simulation. Based on such work the authors discuss how to prevent gas entrapment and propose new methods.
基金Item Sponsored by Provincial Natural Science Foundation of Henan of China(2003460001)University Young Backbone Teacher Fund of Henan ProvinceTackle-Key-Program of Science and Technology Committee of Henan Province(0424260002)
文摘Due to its high hardness,good red hardness and excellent wear resistance at high temperature,high speed steel(HSS)is fit for the roll manufacture.In order to overcome the segregation of centrifugal casting of HSS roll,die-cast processes were developed and its effects on the properties of the HSS roll were investigated.It was found that pressure,pressing time and speed are three important factors affecting shrinkage cavity.For pouring temperature of 1 400-1 450 ℃,pressure of 150-160 MPa,pressing time of 120-150 sand pressing speed of 14-16mm/s,a compact HSS roll was obtained,which has no segregation and small working allowance.In the high speed wire rod rolling mill,service life of the HSS roll is 5to 8times longer than that of high nickel chromium infinite chilled cast iron roll.
基金the development project of Industrial and Manufacturing Source Technology of the Korea Institute of Industrial Technology(KITECH)granted financial resource by the Ministry of Economy and Finance,Republic of Korea(No.EO190031).
文摘A code-generation and recognition technology that uses a modified ejection system in the diecasting process is presented.To achieve the highest level of quality management,the first requirement in the manufacturing process is to establish a product management system according to the specific product unit.Thus,a method to individually identify each product,such as a barcode or QR code,is required during the production process.Products manufactured in the die-casting process always have ejector pin(EP)marks.Herein,an ejection system was modified to generate a unique code using EP marks.This ejection system has two features:an EP with a modified head to show the direction of rotation,and a function to dependently rotate EPs(five or six EPs)with a constant angle.The EPs are numbered according to the rotation angle.Thus,the EP marks can be viewed as a five-or six-digit code.A program was also developed to individually identify the products by automatically detecting and reading the EPs using deep learning-based object detection and classification technology.
文摘The two production lines for the first phase of the semi-solid die-casting high-end parts project were put into production in this October, and can monthly produce more than 30 thousand die casting parts.
基金supported by the State Grid Corporation of China Science and Technology Project,grant number 52270723000900K.
文摘The new energy power generation is becoming increasingly important in the power system.Such as photovoltaic power generation has become a research hotspot,however,due to the characteristics of light radiation changes,photovoltaic power generation is unstable and random,resulting in a low utilization rate and directly affecting the stability of the power grid.To solve this problem,this paper proposes a coordinated control strategy for a newenergy power generation system with a hybrid energy storage unit based on the lithium iron phosphate-supercapacitor hybrid energy storage unit.Firstly,the variational mode decomposition algorithm is used to separate the high and low frequencies of the power signal,which is conducive to the rapid and accurate suppression of the power fluctuation of the energy storage system.Secondly,the fuzzy control algorithm is introduced to balance the power between energy storage.In this paper,the actual data is used for simulation,and the simulation results show that the strategy realizes the effective suppression of the bus voltage fluctuation and the accurate control of the internal state of the energy storage unit,effectively avoiding problems such as overshoot and over-discharge,and can significantly improve the stability of the photovoltaic power generation systemand the stability of the Direct Current bus.It is of great significance to promote the development of collaborative control technology for photovoltaic hybrid energy storage units.
文摘BACKGROUND The need for an emergency upgrade of a hospitalized trauma patient from the floor to the trauma intensive care unit(ICU)is an unanticipated event with possible life-threatening consequences.Unplanned ICU admissions are associated with increased morbidity and mortality and are an indicator of trauma service quality.Two different types of unplanned ICU admissions include upgrades(patients admitted to the floor then moved to the ICU)and bounce backs(patients admitted to the ICU,discharged to the floor,and then readmitted to the ICU).Previous studies have shown that geriatric trauma patients are at higher risk for unfavorable outcomes.AIM To analyze the characteristics,management and outcomes of trauma patients who had an unplanned ICU admission during their hospitalization.METHODS This institutional review board approved,retrospective cohort study examined 203 adult trauma patients with unplanned ICU admission at an urban level 1 trauma center over a six-year period(2017-2023).This included 134 upgrades and 69 bounce backs.Analyzed variables included:(1)Age;(2)Sex;(3)Comorbidities;(4)Mechanism of injury(MOI);(5)Injury severity score(ISS);(6)Glasgow Coma Scale(GCS);(7)Type of injury;(8)Transfusions;(9)Consultations;(10)Timing and reason for unplanned admission;(11)Intubations;(12)Surgical interventions;(13)ICU and hospital lengths of stay;and(14)Mortality.RESULTS Unplanned ICU admissions comprised 4.2%of total ICU admissions.Main MOI was falls.Mean age was 70.7 years,ISS was 12.8 and GCS was 13.9.Main injuries were traumatic brain injury(37.4%)and thoracic injury(21.7%),and main reason for unplanned ICU admission was respiratory complication(39.4%).The 47.3%underwent a surgical procedure and 46.8%were intubated.Average timing for unplanned ICU admission was 2.9 days.Bounce backs occurred half as often as upgrades,however had higher rates of transfusions(63.8%vs 40.3%,P=0.002),consultations(4.8 vs 3.0,P<0.001),intubations(63.8%vs 38.1%%,P=0.001),longer ICU lengths of stay(13.2 days vs 6.4 days,P<0.001)and hospital lengths of stay(26.7 days vs 13.0 days,P<0.001).Mortality was 25.6%among unplanned ICU admissions,31.9%among geriatric unplanned ICU admissions and 11.9%among all trauma ICU patients.CONCLUSION Unplanned ICU admissions constituted 4.2%of total ICU admissions.Respiratory complications were the main cause of unplanned ICU admissions.Bounce backs occurred half as often as upgrades,but were associated with worse outcomes.
文摘BACKGROUND As red blood cell distribution width(RDW)and albumin have been shown to be independent predictors of mortality from various diseases,this study aimed to investigate the effect of the RDW to albumin ratio(RA)as an independent predictor of the prognosis of patients admitted to the coronary care unit(CCU).AIM To use the RDW and albumin level to predict the prognosis of patients in the CCU.METHODS Data were obtained from the Medical Information Mart Intensive Care III database.The primary outcome was 365-day all-cause mortality,whereas the secondary outcomes were 30-and 90-day all-cause mortality,hospital length of stay(LOS),and CCU LOS.Cox proportional hazards regression model,propen-sity score matching,and receiver operating characteristic curve analyses were used.RESULTS The hazard ratio(95%confidence interval)of the upper tertile(RA>4.66)was 1.62(1.29 to 2.03)when compared with the reference(RA<3.84)in 365-day all-cause mortality.This trend persisted after adjusting for demographic and clinical variables in the propensity score-matching analysis.Similar trends were observed for the secondary outcomes of hospital and CCU LOS.Receiver operating characteristic curve analysis was performed by combining the RA and sequential organ failure assessment(SOFA)scores,and the C-statistic was higher than that of the SOFA scores(0.733 vs 0.702,P<0.001).CONCLUSION RA is an independent prognostic factor in patients admitted to the CCU.RA combined with the SOFA score can improve the predictive ability of the SOFA score.However,our results should be verified in future prospective studies.
文摘BACKGROUND Newborns are immediately admitted to the neonatal intensive care unit(NICU)after birth,and thus mothers suffer from the pain of mother-infant separation.Some mothers worry about alterations in their child’s condition and the uncertainty and high medical costs of possible sequelae,which frequently cause anxiety,depression,and other adverse emotions.AIM To investigate the anxiety and depression status of mothers of children in the NICU and its related factors.METHODS A convenient sampling method is adopted.The research objects included the mothers of 191 children in the NICU of Suzhou Ninth Hospital Affiliated with Suzhou University from January 2023 to July 2024.The general information questionnaire,personal control scale,self-rating anxiety scale,and self-rating depression scale were utilized for investigation.Anxiety and depression status in mothers of children in the NICU and its related factors were analyzed.RESULTS The incidences of maternal anxiety and depression among 191 hospitalized children in the NICU were 32.98%(63/191)and 23.56%(45/191),respectively.Single-factor analysis reveals that family monthly income,individual sense of control,gestational age of the child,and the number of diseases in the child are associated with the anxiety and depression experienced by the mother of the child in the NICU(P<0.05).Multivariate logistic regression analysis revealed that family monthly income of<5000 yuan(RMB),poor individual control,gestational age of<32 weeks,and the number of diseases of≥3 kinds are all related factors for anxiety and depression in mothers of children admitted to the NICU(P<0.05).CONCLUSION Mothers of children admitted to the NICU demonstrated high anxiety and depression incidences.The nursing staff in the neonatal department established intervention measures for each related factor,strengthened communication and communication with the mother of the child,and did a good job in psychological counseling.
基金supported by the National Natural Science Foundation of China(Project No.52377082)the Scientific Research Program of Jilin Provincial Department of Education(Project No.JJKH20230123KJ).
文摘Large-scale new energy grid connection leads to the weakening of the system frequency regulation capability,and the system frequency stability is facing unprecedented challenges.In order to solve rapid frequency fluctuation caused by new energy units,this paper proposes a new energy power system frequency regulation strategy with multiple units including the doubly-fed pumped storage unit(DFPSU).Firstly,based on the model predictive control(MPC)theory,the state space equations are established by considering the operating characteristics of the units and the dynamic behavior of the system;secondly,the proportional-differential control link is introduced to minimize the frequency deviation to further optimize the frequency modulation(FM)output of the DFPSU and inhibit the rapid fluctuation of the frequency;lastly,it is verified on theMatlab/Simulink simulation platform,and the results show that the model predictive control with proportional-differential control link can further release the FM potential of the DFPSU,increase the depth of its FM,effectively reduce the frequency deviation of the system and its rate of change,realize the optimization of the active output of the DFPSU and that of other units,and improve the frequency response capability of the system.
基金supported in part by the National Nat-ural Science Foundation of China(52177110)Key Pro-gram of the National Natural Science Foundation of China(U22B20106,U2142206)+2 种基金Shenzhen Science and Technology Program(JCYJ20210324131409026)the Science and Technology Project of the State Grid Corpo-ration of China(5200-202319382A-2-3-XG)State Grid Zhejiang Elctric Power Co.,Ltd.Science and Tech-nology Project(B311DS24001A).
文摘Typhoons can cause large-area blackouts or partial outages of distribution networks.We define a partial outage state in the distribution network as a gray state and propose a gray-start strategy and two-stage distribution network emergency recovery framework.A phase-space reconstruction and stacked integrated model for predicting wind and photovoltaic generation during typhoon disasters is proposed in the first stage.This provides guidance for second-stage post-disaster emergency recovery scheduling.The emergency recovery scheduling model is established in the second stage,and this model is supported by a thermal power-generating unit,mobile emergency generators,and distributed generators.Distributed generation includes wind power generation,photovoltaics,fuel cells,etc.Simultaneously,we con-sider the gray-start based on the pumped storage unit to be an important first step in the emergency recovery strategy.This model is val-idated on the improved IEEE 33 node system,which utilizes data from the 2022 super typhoon“Muifa”in Zhoushan,Zhejiang,China.Simulations indicate the superiority of a gray start with a pumped storage unit and the proposed emergency recovery strategy.
文摘在一个经过篡改的视频可以传播虚假信息、欺凌他人和煽动负面情绪的时代,加州大学河滨分校和谷歌的研究人员联合开发了“通用篡改与合成视频识别网络”(Universal Network for Identifying Tampered and synth Etic videos, UNITE)的新系统来揭露这些伪造视频。即使在人脸不可见的情况下,该系统依然能检测深度伪造视频。通过扫描背景、运动和细微线索来识别视频是否伪造。随着虚假内容越来越容易生成且越来越难以检测,该工具可能成为新闻编辑室和社交媒体平台努力捍卫真相的必备武器。
