The use of vacuum interrupters(VIs)as the current interruption component for switches,circuit breakers,reclosers and contactors operating at distribution voltages has escalated since their introduction in the mid-1950...The use of vacuum interrupters(VIs)as the current interruption component for switches,circuit breakers,reclosers and contactors operating at distribution voltages has escalated since their introduction in the mid-1950’s.This electrical product has developed a dominating position for switching and protecting distribution circuits.VIs are even being introduced into switching products operating at transmission voltages.Among the reasons for the VI’s popularity are its compactness,its range of application,its low cost,its superb electrical and mechanical life and its ease of application.Its major advantage is its well-established reliability.In this paper we show how this reliability has been achieved by design,by mechanical life testing and by electrical performance testing.We introduce the“sealed for life”concept for the VI’s integrity.We discuss this in terms of what is meant by a practical leak rate for VIs with a life of over 30 years.We show that a simple high voltage withstand test is an easy and effective method for monitoring the long-term vacuum integrity.Finally we evaluate the need for routine inspection of this electrical product when it is used in adverse ambient environments.展开更多
To enhance nominal current of high voltage vacuum circuit breakers （VCBs）, a gravity heat pipe was proposed to replace stationary conducting rod of a high voltage vacuum interrupter. The heat pipe is composed of two...To enhance nominal current of high voltage vacuum circuit breakers （VCBs）, a gravity heat pipe was proposed to replace stationary conducting rod of a high voltage vacuum interrupter. The heat pipe is composed of two coaxis tubes： the external tube is made of oxygen-free copper and the inner tube is made of stainless steel. The bottom end of the inner stainless steel tube is connected to the external copper tube by holes. Transient and static thermal performance of the heat pipe was measured, and the thermal resistance of it was compared with that of a solid copper rod with the same dimensions. Experimental results showed that thermal resistance of the heat pipe was about 1/3 of that of the copper rod, and it decreased slightly with the rising of the input heat flux. 3D thermal simulation on a 126 kV/2000 A single break VCB was done to compare the thermal performance between the proposed gravity heat pipe and the copper rod serving as the stationary conducting rod of the vacuum interrupter. Simulation results revealed that in the heat pipe case, the maximum temperature between contacts was 67 ℃ lower than that in the copper rod case.展开更多
To improve the limiting current interruption capability and minimizing vacuum interrupter with axial magnetic field （AMF） electrodes, it is significant to investigate the vacuum arc behaviours between the contacts. ...To improve the limiting current interruption capability and minimizing vacuum interrupter with axial magnetic field （AMF） electrodes, it is significant to investigate the vacuum arc behaviours between the contacts. AMF distributions of the slot type electrodes were studied by both numerical analysis and experiments. Furthermore, the behaviours of vacuum arcs for different parameters of the slot type AMF electrodes were investigated by using high-speed CCD camera. The influences of gap distance, contact diameter and phase shift time between AMF and arc current on the vacuum arc were investigated. The results provide a reference for research and development of vacuum interrupters with slot type or other types of AMF electrode.展开更多
The greenhouse effect of SFe is a great concern today. The development of high voltage vacuum circuit breakers becomes more important. The vacuum circuit breaker has minimum pollution to the environment. The vacuum in...The greenhouse effect of SFe is a great concern today. The development of high voltage vacuum circuit breakers becomes more important. The vacuum circuit breaker has minimum pollution to the environment. The vacuum interrupter is the key part of a vacuum circuit breaker. The interrupting characteristics in vacuum and arc-controlling techniue are the main problems to be solved for a longer gap distance in developing high voltage vacuum interrupters. To understand the vacuum arc characteristics and provide effective technique to control vacuum arc in a long gap distance, the arc mode transition of a cup-type axial magnetic field electrode is observed by a high-speed charge coupled device （CGD） video camera under different gap distances while the arc voltage and arc current are recorded. The controlling ability of the axial magnetic field on vacuum arc obviously decreases when the gap distance is longer than 40 ram. The noise components and mean value of the arc voltage significantly increase. The effective method for controlling the vacuum arc characteristics is provided by long gap distances based on the test results. The test results can be used as a reference to develop high voltage and large capacity vacuum interrupters.展开更多
When subjected to high voltages between opened contacts, vacuum interrupters may emit X-rays. In order to ensure that these are of an acceptable level, vacuum interrupters should comply with the limits for X-ray emiss...When subjected to high voltages between opened contacts, vacuum interrupters may emit X-rays. In order to ensure that these are of an acceptable level, vacuum interrupters should comply with the limits for X-ray emission and the test procedures to be carried out to verify this based on relevant standards and specifications. In this paper, a comprehensive experimental study has been performed for 126 kV vacuum interrupters used in a transmission system to understand the X-radiation level and its influence by three main parameters, namely applied power-frequency voltage, contact gap and power=frequency voltage conditioning. The radiation instrument is an FJ347 radiometer and the X-radiation dose was measured at the power-frequency test voltage. These tests demonstrated that the X-radiation emission level for a 126 kV vacuum interrupter did not exceed the following： 5 μSv per hour at a rated voltage of 126 kV and 150 μSv per hour at a power-frequency voltage of 230 kV at 1 m distance. The X-radiation dose increased with the applied power-frequency voltage increasing and decreased with the contact gap increasing. The X- radiation dose for 126 kV vacuum interrupters decreased by 57% after the conditioning procedure with a certain power-frequency voltage. During the conditioning procedure, the average value of the X-radiation dose was 4.49 mSv, which means if a professional conditions 180 interrupters per year, it will be safe at the 6.4 m distance.展开更多
The free shrinkage of ceramic or metal is restricted due to solidification of the solder. Hence the shrinkage stress arises and the jointing strength is reduced during the brazing of high-voltage vacuum interrupters ...The free shrinkage of ceramic or metal is restricted due to solidification of the solder. Hence the shrinkage stress arises and the jointing strength is reduced during the brazing of high-voltage vacuum interrupters （HVVIs）. The solder bound contour was gained by solved energy bound equation. The finite element model of weld beads was established with Surface Evolver software. Then the stress in two different cooling techniques （ natural cooling and force cooling） was calculated with ANSYS. Comparing the stress, a better cooling technique was selected for HVVIs. Its cooling time is shortened by 3 hours while the jointing stress doesn＇ t increase and the tensile strength of ceramic to metal seal is not decreased. The stress-rupture tests have validated the calculated results. More important, a method is found, by which the brazing technique could be improved in advance instead of blind experiments.展开更多
Due to the increasing power system capacity,the interruption of large fault currents has gradually become a major challenge in power systems.At the moment,such currents are interrupted mainly via circuit breakers base...Due to the increasing power system capacity,the interruption of large fault currents has gradually become a major challenge in power systems.At the moment,such currents are interrupted mainly via circuit breakers based on the method of active current commu-tation.However,these types of circuit breakers tend to be costly and oversized.One possible alternative—a fuse-based circuit breaker with current commutation process enhanced by an external transverse magnetic field(ETMF)—is proposed by the authors.Its main advantage lies in the fast current commutation achieved by an ETMF-enhanced three-stage increase of the vacuum arc voltage.The study of the current commutation process is mainly represented by the authors,and the influencing factors of the current commutation—contact opening speed and ETMF current—are discussed.At last,the proposed circuit breaker is verified by an experiment,whose results show that a short-circuit current of 42 kA can be interrupted within just 2 ms.展开更多
Background:To investigate SCL/TAL 1 interrupting locus(STIL)’s role and prognostic significance in lung adenocarcinoma(LUAD)progression,we examined STIL and E2 promoter binding factor 1(E2F1)expression and their impa...Background:To investigate SCL/TAL 1 interrupting locus(STIL)’s role and prognostic significance in lung adenocarcinoma(LUAD)progression,we examined STIL and E2 promoter binding factor 1(E2F1)expression and their impacts on LUAD prognosis using Gene Expression Profiling Interactive Analysis(GEPIA).Methods:Functional assays including CCK-8,wound-healing,5-ethynyl-2-deoxyuridine(EdU),Transwell assays,and flow cytometry,elucidated STIL and E2F1’s effects on cell viability,proliferation,apoptosis,and migration.Gene set enrichment analysis(GSEA)identified potential pathways,while metabolic assays assessed glucose metabolism.Results:Our findings reveal that STIL and E2F1 are overexpressed in LUAD,correlating with adverse outcomes.It enhances cell proliferation,migration,and invasion,and suppresses apoptosis,activating downstream of E2F1.Silencing E2F1 reversed the promotion effect of the STIL overexpression on cell viability and invasiveness.Importantly,STIL modulates glycolysis,influencing glucose consumption,lactate production,and energy balance in LUAD cells.Conclusion:Our model,incorporating STIL,age,and disease stage,robustly predicts patient prognosis,underscored STIL’s pivotal role in LUAD pathogenesis through metabolic reprogramming.This comprehensive approach not only confirms STIL’s prognostic value but also highlights its potential as a therapeutic target in LUAD.展开更多
Rulmonary function tests provide an objective means to verify ventilatory dysfunction and to estimate its severity in respiratory disorders. Measurement of forced expiratory volume in 1 second （FEV1） and forced vita...Rulmonary function tests provide an objective means to verify ventilatory dysfunction and to estimate its severity in respiratory disorders. Measurement of forced expiratory volume in 1 second （FEV1） and forced vital capacity （FVC） is considered to be the basic tests for the assessment of airway obstruction. Although they are useful diagnostically and prognostically, the results of FEV1 and FVC are strongly dependent on the cooperation of the patient. Lack of collaboration is particularly present in elderly patients because of mood alterations, fatigability or cognitive impairment. The forced oscillation technique （FOT） and the interrupter resistance technique are the two methods of measuring respiratory resistance during tidal breathing, they are of special interest because both of them are noninvasive, requires minimal cooperation, takes little time and can be easily repeated, especially in children and elderly subjects who cannot accomplish forced expiratory maneuvers in a reproducible manner.展开更多
In rice systems under continuous flooding(CF)irrigation,rice grains with high arsenic(As)concentration can be produced.In Argentina,these areas are located in the south of Corrientes Province and the north of Entre R&...In rice systems under continuous flooding(CF)irrigation,rice grains with high arsenic(As)concentration can be produced.In Argentina,these areas are located in the south of Corrientes Province and the north of Entre Ríos Province.The combination of agronomic management,genetic variability of rice varieties,and the characteristics of soil and irrigation water determines the concentration and proportion of grain As species.In this study,we evaluated two factors affecting grain As accumulation:irrigation management,CF and interrupted flooding(IF),and rice variety,rice with medium,long,and double long/wide grains.The experiments were conducted during four cropping cycles(2015–2016,2016–2017,2017–2018,and 2020–2021)on a farm in the north of Entre Ríos Province.Total As concentration in husked grains showed a wide range and was mostly above 0.30 mg kg^(-1),even after the polishing process.Fortunately,organic As was the predominant species.In polished rice,inorganic As concentration ranged between 0.02 and 0.28 mg kg^(-1).Significant differences were observed in grain As concentration between four rice varieties,with the highest inorganic and total As concentrations in grains of the medium-grain variety.The interaction of rice variety by irrigation management did not affect grain yield,but significantly reduced total As concentration in grains.Soil drainage under IF explained 43%–46%of the reduction of total As concentration in grains.The management practices of irrigation and rice variety had slight effects on inorganic As concentration in grains.In conclusion,a single soil drying period combined with proper rice varieties can be an effective management practice for mitigating As accumulation in rice grains.展开更多
Catalytic syntheses of silaoxycarbocyclics from an interrupted Catellani reaction of 3-iodochromones with bridged olefins and octamethyl-1,4-dioxacyclohexasilane is described.This protocol involves the oxidative addit...Catalytic syntheses of silaoxycarbocyclics from an interrupted Catellani reaction of 3-iodochromones with bridged olefins and octamethyl-1,4-dioxacyclohexasilane is described.This protocol involves the oxidative addition of chromonyl-norbornyl-palladacycle generated through successive oxidative addition of Pd(0)to 3-iodochromones,migratory insertion of NBE and intramolecular ortho-C(sp^(2))-H activation to the tetrasilane,thus motivating a(4+6)annulation and ring expansion.The synthetic practicality of current strategy is further proved by the late-stage modification of pharmaceuticals and natural products,gram-scale experiments,as well as the transformations of functional groups of silaoxycarbocyclics.展开更多
Digital avatars have become a standard feature on e-commerce platforms.As virtual hosts,they emulate human behavior,broadcast live programs without interruption,and present“Made in China”products to foreign consumer...Digital avatars have become a standard feature on e-commerce platforms.As virtual hosts,they emulate human behavior,broadcast live programs without interruption,and present“Made in China”products to foreign consumers,thanks to their proficiency in multiple languages.The impressive efficiency of these digital avatars is made possible by the colossal computing power that enables them to perform their functions.“This year,the storage requirements of the digital avatars have increased significantly,by approximately 500 times compared to last year.The current local storage capacity is no longer sufficient.”展开更多
BACKGROUND At present,prophylactic ileostomy is commonly used to protect distal intestinal anastomoses,particularly during the recovery period following colorectal surgery.However,after the ileum is returned to the ab...BACKGROUND At present,prophylactic ileostomy is commonly used to protect distal intestinal anastomoses,particularly during the recovery period following colorectal surgery.However,after the ileum is returned to the abdominal cavity,abdominal closure using traditional vertical interrupted suturing is associated with a higher incidence of wound infections.For patients undergoing ileostomy closure,selecting an appropriate suturing method for the skin incision at the stoma site is crucial for improving patient prognosis.AIM To investigate the impact of three different skin suturing methods at the ileostomy closure site on patient prognosis.METHODS Thirty patients who underwent ileostomy closure at the Affiliated Hospital of Qinghai University between January 2024 and October 2024 were selected based on inclusion and exclusion criteria.The patients were divided into three groups:The purse-string suture group,the cross-suture group,and the vertical interrupted suture group,with 10 cases in each group.The purse-string suture group,cross-suture group,and vertical interrupted suture group used purse-string,cross,and vertical interrupted suturing methods,respectively,for the skin incision at the ileostomy closure site.RESULTS There were no statistically significant differences among the three groups in terms of operative time,intraoperative blood loss,time to resume liquid diet,time to first bowel movement,postoperative hospital stay,hospitalization costs,or levels of white blood cell count,hemoglobin,and albumin on the third postoperative day(P>0.05).Nevertheless,significant differences(P<0.05)were observed in incision suture removal time,wound healing time,C-reactive protein levels on the third postoperative day,visual analog scale pain scores during the first three postoperative days,and the incidence of surgical site infection.Overall,the therapeutic outcomes of the pursestring suture group and the cross-suture group were superior to the vertical interrupted suture group.CONCLUSION Using purse-string or cross-suturing methods for skin incision at the ileostomy closure site can shorten wound healing and suture removal times,reduce surgical site infection incidence and postoperative inflammatory response,alleviate incision pain,and promote rapid postoperative recovery.展开更多
BACKGROUND Gastric subepithelial lesions(SELs)are elevated lesions originating from the muscularis mucosa,submucosa,or muscularis propria,and may also include extraluminal lesions.For small SELs(less than 5 cm),comple...BACKGROUND Gastric subepithelial lesions(SELs)are elevated lesions originating from the muscularis mucosa,submucosa,or muscularis propria,and may also include extraluminal lesions.For small SELs(less than 5 cm),complete endoscopic excision is the preferred treatment.Endoscopic full-thickness resection(EFTR)has proven to be an effective approach.AIM To evaluate the efficacy of the interrupted closure technique compared to the traditional closure technique in EFTR for gastric SELs.METHODS This single-center,prospective,randomized controlled trial was conducted at a tertiary hospital from September 2023 to September 2024.A total of 90 patients who underwent EFTR for gastric SELs were randomly allocated to either the interrupted closure group(n=44)or the traditional closure group(n=46).RESULTS All patients had complete resection and wound closure without any severe postoperative complications.The incidence of intraoperative gas-related complications was significantly lower in the interrupted closure group than in the traditional closure group(2.27%vs 26.09%,P=0.001),demonstrating interrupted closure technique can reduce the incidence of gas-related issues.Statistical analysis revealed that the incidence of postoperative infection was significantly lower in the experimental group than in the control group(15.91%vs 41.30%,P=0.008).Additionally,the median duration of antibiotic use was lower in the experimental group(3.5 days vs 5 days,P=0.013).Abdominal pain levels on postoperative days 1 and 4 were also lower in the experimental group compared to the control group(P<0.001).CONCLUSION The interrupted closure technique in EFTR for treating gastric SELs is safe and effective,reducing the incidence of intraoperative gas complications and postoperative infections.展开更多
The incremental capacity analysis(ICA)technique is notably limited by its sensitivity to variations in charging conditions,which constrains its practical applicability in real-world scenarios.This paper introduces an ...The incremental capacity analysis(ICA)technique is notably limited by its sensitivity to variations in charging conditions,which constrains its practical applicability in real-world scenarios.This paper introduces an ICA-compensation technique to address this limitation and propose a generalized framework for assessing the state of health(SOH)of batteries based on ICA that is applicable under differing charging conditions.This novel approach calculates the voltage profile under quasi-static conditions by subtracting the voltage increase attributable to the additional polarization effects at high currents from the measured voltage profile.This approach's efficacy is contingent upon precisely acquiring the equivalent impedance.To obtain the equivalent impedance throughout the batteries'lifespan while minimizing testing costs,this study employs a current interrupt technique in conjunction with a long short-term memory(LSTM)network to develop a predictive model for equivalent impedance.Following the derivation of ICA curves using voltage profiles under quasi-static conditions,the research explores two scenarios for SOH estimation:one utilizing only incremental capacity(IC)features and the other incorporating both IC features and IC sampling.A genetic algorithm-optimized backpropagation neural network(GABPNN)is employed for the SOH estimation.The proposed generalized framework is validated using independent training and test datasets.Variable test conditions are applied for the test set to rigorously evaluate the methodology under challenging conditions.These evaluation results demonstrate that the proposed framework achieves an estimation accuracy of 1.04%for RMSE and 0.90%for MAPE across a spectrum of charging rates ranging from 0.1 C to 1 C and starting SOCs between 0%and 70%,which constitutes a major advancement compared to established ICA methods.It also significantly enhances the applicability of conventional ICA techniques in varying charging conditions and negates the necessity for separate testing protocols for each charging scenario.展开更多
Spinal cord injury(SCI)interrupts the flow of information between the brain and the spinal cord,thus leading to a loss of sensory information and motor paralysis of the body below the lesion.Surprisingly,most SCIs are...Spinal cord injury(SCI)interrupts the flow of information between the brain and the spinal cord,thus leading to a loss of sensory information and motor paralysis of the body below the lesion.Surprisingly,most SCIs are incomplete and spare supraspinal pathways,especially those located within the peripheral white matter of the spinal cord,which includes reticulospinal pathways originating from the medullary reticular formation.Whereas there is abundant literature about the motor cortex,its corticospinal pathway,and its capacity to modulate functional recovery after SCI,less is known about the medullary reticular formation and its reticulospinal pathway.展开更多
In recent years,research on nursing interruptions has been conducted at various levels in emergency departments,intensive care units,hemodialysis centers,operating rooms,and sterilization and supply centers.Nursing in...In recent years,research on nursing interruptions has been conducted at various levels in emergency departments,intensive care units,hemodialysis centers,operating rooms,and sterilization and supply centers.Nursing interruptions are closely related to adverse nursing events,and interruptions in operating room nursing can significantly impact the success of a patient’s surgery.However,there is a lack of in-depth theoretical research on safety risk assessment and response decision-making by operating room nurses when faced with nursing interruptions.This article reviews the concept,current status,and impact of nursing interruptions in the operating room,analyzes the cognitive level,coping strategies,and negative emotions of operating room nurses,and elaborates on management strategies to provide references for research and management of nursing interruptions in the operating room.展开更多
In the context of the Diagnosis Related Groups(DRGs)system,the orthopedic hospital implemented refined drug control to provide a pharmacological reference for promoting rational clinical drug use.A statistical analysi...In the context of the Diagnosis Related Groups(DRGs)system,the orthopedic hospital implemented refined drug control to provide a pharmacological reference for promoting rational clinical drug use.A statistical analysis was conducted on the hospital’s data from January to December 2021(prior to the implementation of control),focusing on the types of unreasonable prescriptions.A multi-dimensional analysis was also conducted to identify the underlying causes of inappropriate medication practices.Following this,refined drug control measures were introduced,and data from January to December 2022(post-control)were compared,examining factors such as the average drug cost,drug expenses for the IC29 diagnosis group,and the drug cost ratio.An interrupted time-series analysis was employed to evaluate the effects of these interventions.The results showed that after the implementation of refined drug control in the orthopedic department,significant reductions were observed in the average cost per patient,average drug cost per patient,drug cost ratio,cost consumption index,average length of hospital stay,and allocation ratio(P<0.05).In particular,the first month of control(January 2022)saw a marked decrease in average drug costs per patient by 1272.90 yuan(P<0.01),a reduction in the drug cost ratio by 0.98%,and a decline in drug costs for the IC29 diagnosis group by 616.79 yuan(P>0.05).Moreover,the rate of unreasonable inappropriate prescribing dropped dramatically from 40.48%in 2021 to 3.57%by December 2022.The refined control of drug use within the orthopedic hospital significantly improved the rationality of clinical prescribing practices,reduced the occurrence of adverse drug reactions,and enhanced patient adherence to prescribed treatments.These findings demonstrated considerable clinical value in promoting efficient and safe drug use.展开更多
Nonperiodic interrupted sampling repeater jamming(ISRJ)against inverse synthetic aperture radar(ISAR)can obtain two-dimensional blanket jamming performance by joint fast and slow time domain interrupted modulation,whi...Nonperiodic interrupted sampling repeater jamming(ISRJ)against inverse synthetic aperture radar(ISAR)can obtain two-dimensional blanket jamming performance by joint fast and slow time domain interrupted modulation,which is obviously dif-ferent from the conventional multi-false-target deception jam-ming.In this paper,a suppression method against this kind of novel jamming is proposed based on inter-pulse energy function and compressed sensing theory.By utilizing the discontinuous property of the jamming in slow time domain,the unjammed pulse is separated using the intra-pulse energy function diffe-rence.Based on this,the two-dimensional orthogonal matching pursuit(2D-OMP)algorithm is proposed.Further,it is proposed to reconstruct the ISAR image with the obtained unjammed pulse sequence.The validity of the proposed method is demon-strated via the Yake-42 plane data simulations.展开更多
The effects of interrupted aging on mechanical properties and corrosion resistance of 7A75 aluminum alloy extruded bar were investigated through various analyses,including electrical conductivity,mechanical properties...The effects of interrupted aging on mechanical properties and corrosion resistance of 7A75 aluminum alloy extruded bar were investigated through various analyses,including electrical conductivity,mechanical properties,local corrosion properties,and slow strain rate tensile stress corrosion tests.Microstructure characterization techniques such as metallographic microscopy,scanning electron microscopy(SEM),and transmission electron microscopy(TEM)were also employed.The results indicate that the tensile strength of the alloy produced by T6I6 aging is similar to that produced by T6I4 aging,and it even exceeds 700 MPa.Furthermore,the yield strength increases by 52.7 MPa,reaching 654.8 MPa after T6I6 aging treatment.The maximum depths of intergranular corrosion(IGC)and exfoliation corrosion(EXCO)decrease from 116.3 and 468.5μm to 89.5 and 324.3μm,respectively.The stress corrosion factor also decreases from 2.1%to 1.6%.These findings suggest that the alloy treated with T6I6 aging exhibits both high strength and excellent stress corrosion cracking resistance.Similarly,when the alloy is treated with T6I4,T6I6 and T6I7 aging,the sizes of grain boundary precipitates(GBPs)are found to be 5.2,18.4,and 32.8 nm,respectively.The sizes of matrix precipitates are 4.8,5.7 and 15.7 nm,respectively.The atomic fractions of Zn in GBPs are 9.92 at.%,8.23 at.%and 6.87 at.%,respectively,while the atomic fractions of Mg are 12.66 at.%,8.43 at.%and 7.00 at.%,respectively.Additionally,the atomic fractions of Cu are 1.83 at.%,2.47 at.%and 3.41 at.%,respectively.展开更多
文摘The use of vacuum interrupters(VIs)as the current interruption component for switches,circuit breakers,reclosers and contactors operating at distribution voltages has escalated since their introduction in the mid-1950’s.This electrical product has developed a dominating position for switching and protecting distribution circuits.VIs are even being introduced into switching products operating at transmission voltages.Among the reasons for the VI’s popularity are its compactness,its range of application,its low cost,its superb electrical and mechanical life and its ease of application.Its major advantage is its well-established reliability.In this paper we show how this reliability has been achieved by design,by mechanical life testing and by electrical performance testing.We introduce the“sealed for life”concept for the VI’s integrity.We discuss this in terms of what is meant by a practical leak rate for VIs with a life of over 30 years.We show that a simple high voltage withstand test is an easy and effective method for monitoring the long-term vacuum integrity.Finally we evaluate the need for routine inspection of this electrical product when it is used in adverse ambient environments.
基金Project (No. 200806981005) supported by the New Teacher Foundation of MOE, China
文摘To enhance nominal current of high voltage vacuum circuit breakers （VCBs）, a gravity heat pipe was proposed to replace stationary conducting rod of a high voltage vacuum interrupter. The heat pipe is composed of two coaxis tubes： the external tube is made of oxygen-free copper and the inner tube is made of stainless steel. The bottom end of the inner stainless steel tube is connected to the external copper tube by holes. Transient and static thermal performance of the heat pipe was measured, and the thermal resistance of it was compared with that of a solid copper rod with the same dimensions. Experimental results showed that thermal resistance of the heat pipe was about 1/3 of that of the copper rod, and it decreased slightly with the rising of the input heat flux. 3D thermal simulation on a 126 kV/2000 A single break VCB was done to compare the thermal performance between the proposed gravity heat pipe and the copper rod serving as the stationary conducting rod of the vacuum interrupter. Simulation results revealed that in the heat pipe case, the maximum temperature between contacts was 67 ℃ lower than that in the copper rod case.
文摘To improve the limiting current interruption capability and minimizing vacuum interrupter with axial magnetic field （AMF） electrodes, it is significant to investigate the vacuum arc behaviours between the contacts. AMF distributions of the slot type electrodes were studied by both numerical analysis and experiments. Furthermore, the behaviours of vacuum arcs for different parameters of the slot type AMF electrodes were investigated by using high-speed CCD camera. The influences of gap distance, contact diameter and phase shift time between AMF and arc current on the vacuum arc were investigated. The results provide a reference for research and development of vacuum interrupters with slot type or other types of AMF electrode.
基金supported by National Natural Science Foundation of China(No.50477024)
文摘The greenhouse effect of SFe is a great concern today. The development of high voltage vacuum circuit breakers becomes more important. The vacuum circuit breaker has minimum pollution to the environment. The vacuum interrupter is the key part of a vacuum circuit breaker. The interrupting characteristics in vacuum and arc-controlling techniue are the main problems to be solved for a longer gap distance in developing high voltage vacuum interrupters. To understand the vacuum arc characteristics and provide effective technique to control vacuum arc in a long gap distance, the arc mode transition of a cup-type axial magnetic field electrode is observed by a high-speed charge coupled device （CGD） video camera under different gap distances while the arc voltage and arc current are recorded. The controlling ability of the axial magnetic field on vacuum arc obviously decreases when the gap distance is longer than 40 ram. The noise components and mean value of the arc voltage significantly increase. The effective method for controlling the vacuum arc characteristics is provided by long gap distances based on the test results. The test results can be used as a reference to develop high voltage and large capacity vacuum interrupters.
基金supported by National Key Basic Research Program of China(973 Program)(No.2015CB251002)
文摘When subjected to high voltages between opened contacts, vacuum interrupters may emit X-rays. In order to ensure that these are of an acceptable level, vacuum interrupters should comply with the limits for X-ray emission and the test procedures to be carried out to verify this based on relevant standards and specifications. In this paper, a comprehensive experimental study has been performed for 126 kV vacuum interrupters used in a transmission system to understand the X-radiation level and its influence by three main parameters, namely applied power-frequency voltage, contact gap and power=frequency voltage conditioning. The radiation instrument is an FJ347 radiometer and the X-radiation dose was measured at the power-frequency test voltage. These tests demonstrated that the X-radiation emission level for a 126 kV vacuum interrupter did not exceed the following： 5 μSv per hour at a rated voltage of 126 kV and 150 μSv per hour at a power-frequency voltage of 230 kV at 1 m distance. The X-radiation dose increased with the applied power-frequency voltage increasing and decreased with the contact gap increasing. The X- radiation dose for 126 kV vacuum interrupters decreased by 57% after the conditioning procedure with a certain power-frequency voltage. During the conditioning procedure, the average value of the X-radiation dose was 4.49 mSv, which means if a professional conditions 180 interrupters per year, it will be safe at the 6.4 m distance.
基金Sponsored by the National Natural Science Foundation of China(50377003).
文摘The free shrinkage of ceramic or metal is restricted due to solidification of the solder. Hence the shrinkage stress arises and the jointing strength is reduced during the brazing of high-voltage vacuum interrupters （HVVIs）. The solder bound contour was gained by solved energy bound equation. The finite element model of weld beads was established with Surface Evolver software. Then the stress in two different cooling techniques （ natural cooling and force cooling） was calculated with ANSYS. Comparing the stress, a better cooling technique was selected for HVVIs. Its cooling time is shortened by 3 hours while the jointing stress doesn＇ t increase and the tensile strength of ceramic to metal seal is not decreased. The stress-rupture tests have validated the calculated results. More important, a method is found, by which the brazing technique could be improved in advance instead of blind experiments.
基金National Key R&D Program of China,Grant/Award Number:2022YFB2403602National Natural Science Foundation of China,Grant/Award Numbers:52025074,52377158,U1966602。
文摘Due to the increasing power system capacity,the interruption of large fault currents has gradually become a major challenge in power systems.At the moment,such currents are interrupted mainly via circuit breakers based on the method of active current commu-tation.However,these types of circuit breakers tend to be costly and oversized.One possible alternative—a fuse-based circuit breaker with current commutation process enhanced by an external transverse magnetic field(ETMF)—is proposed by the authors.Its main advantage lies in the fast current commutation achieved by an ETMF-enhanced three-stage increase of the vacuum arc voltage.The study of the current commutation process is mainly represented by the authors,and the influencing factors of the current commutation—contact opening speed and ETMF current—are discussed.At last,the proposed circuit breaker is verified by an experiment,whose results show that a short-circuit current of 42 kA can be interrupted within just 2 ms.
文摘Background:To investigate SCL/TAL 1 interrupting locus(STIL)’s role and prognostic significance in lung adenocarcinoma(LUAD)progression,we examined STIL and E2 promoter binding factor 1(E2F1)expression and their impacts on LUAD prognosis using Gene Expression Profiling Interactive Analysis(GEPIA).Methods:Functional assays including CCK-8,wound-healing,5-ethynyl-2-deoxyuridine(EdU),Transwell assays,and flow cytometry,elucidated STIL and E2F1’s effects on cell viability,proliferation,apoptosis,and migration.Gene set enrichment analysis(GSEA)identified potential pathways,while metabolic assays assessed glucose metabolism.Results:Our findings reveal that STIL and E2F1 are overexpressed in LUAD,correlating with adverse outcomes.It enhances cell proliferation,migration,and invasion,and suppresses apoptosis,activating downstream of E2F1.Silencing E2F1 reversed the promotion effect of the STIL overexpression on cell viability and invasiveness.Importantly,STIL modulates glycolysis,influencing glucose consumption,lactate production,and energy balance in LUAD cells.Conclusion:Our model,incorporating STIL,age,and disease stage,robustly predicts patient prognosis,underscored STIL’s pivotal role in LUAD pathogenesis through metabolic reprogramming.This comprehensive approach not only confirms STIL’s prognostic value but also highlights its potential as a therapeutic target in LUAD.
文摘Rulmonary function tests provide an objective means to verify ventilatory dysfunction and to estimate its severity in respiratory disorders. Measurement of forced expiratory volume in 1 second （FEV1） and forced vital capacity （FVC） is considered to be the basic tests for the assessment of airway obstruction. Although they are useful diagnostically and prognostically, the results of FEV1 and FVC are strongly dependent on the cooperation of the patient. Lack of collaboration is particularly present in elderly patients because of mood alterations, fatigability or cognitive impairment. The forced oscillation technique （FOT） and the interrupter resistance technique are the two methods of measuring respiratory resistance during tidal breathing, they are of special interest because both of them are noninvasive, requires minimal cooperation, takes little time and can be easily repeated, especially in children and elderly subjects who cannot accomplish forced expiratory maneuvers in a reproducible manner.
基金the National Agency for the Promotion of Research,Technological Development and Innovation(Argentina)the National University of Entre Ríos(Argentina)+1 种基金the PROARROZ Foundation(Argentina)the company EBRO(Argentina)for the financial support of this research。
文摘In rice systems under continuous flooding(CF)irrigation,rice grains with high arsenic(As)concentration can be produced.In Argentina,these areas are located in the south of Corrientes Province and the north of Entre Ríos Province.The combination of agronomic management,genetic variability of rice varieties,and the characteristics of soil and irrigation water determines the concentration and proportion of grain As species.In this study,we evaluated two factors affecting grain As accumulation:irrigation management,CF and interrupted flooding(IF),and rice variety,rice with medium,long,and double long/wide grains.The experiments were conducted during four cropping cycles(2015–2016,2016–2017,2017–2018,and 2020–2021)on a farm in the north of Entre Ríos Province.Total As concentration in husked grains showed a wide range and was mostly above 0.30 mg kg^(-1),even after the polishing process.Fortunately,organic As was the predominant species.In polished rice,inorganic As concentration ranged between 0.02 and 0.28 mg kg^(-1).Significant differences were observed in grain As concentration between four rice varieties,with the highest inorganic and total As concentrations in grains of the medium-grain variety.The interaction of rice variety by irrigation management did not affect grain yield,but significantly reduced total As concentration in grains.Soil drainage under IF explained 43%–46%of the reduction of total As concentration in grains.The management practices of irrigation and rice variety had slight effects on inorganic As concentration in grains.In conclusion,a single soil drying period combined with proper rice varieties can be an effective management practice for mitigating As accumulation in rice grains.
基金financial support from the National Natural Science Foundation of China(Nos.22261057 and 21901265)Guizhou Provincial Natural Science Foundation(No.QKHJC-2020-1Z072)+3 种基金the Science and Technology Department of Guizhou Province(Nos.QKHPTRC-CXTD[2022]012 and QKHPTRCGCC[2023]003)Zunyi Medical University(No.18ZY-002)Science and Technology Department of Zunyi(Nos.ZSKH-2018-3,ZSKHHZZ[2020]70,ZSKRPT-2020-5 and ZSKRPT-2021-5)Fifth Batch of Talent Base in Guizhou Province(No.S-030-1).
文摘Catalytic syntheses of silaoxycarbocyclics from an interrupted Catellani reaction of 3-iodochromones with bridged olefins and octamethyl-1,4-dioxacyclohexasilane is described.This protocol involves the oxidative addition of chromonyl-norbornyl-palladacycle generated through successive oxidative addition of Pd(0)to 3-iodochromones,migratory insertion of NBE and intramolecular ortho-C(sp^(2))-H activation to the tetrasilane,thus motivating a(4+6)annulation and ring expansion.The synthetic practicality of current strategy is further proved by the late-stage modification of pharmaceuticals and natural products,gram-scale experiments,as well as the transformations of functional groups of silaoxycarbocyclics.
文摘Digital avatars have become a standard feature on e-commerce platforms.As virtual hosts,they emulate human behavior,broadcast live programs without interruption,and present“Made in China”products to foreign consumers,thanks to their proficiency in multiple languages.The impressive efficiency of these digital avatars is made possible by the colossal computing power that enables them to perform their functions.“This year,the storage requirements of the digital avatars have increased significantly,by approximately 500 times compared to last year.The current local storage capacity is no longer sufficient.”
文摘BACKGROUND At present,prophylactic ileostomy is commonly used to protect distal intestinal anastomoses,particularly during the recovery period following colorectal surgery.However,after the ileum is returned to the abdominal cavity,abdominal closure using traditional vertical interrupted suturing is associated with a higher incidence of wound infections.For patients undergoing ileostomy closure,selecting an appropriate suturing method for the skin incision at the stoma site is crucial for improving patient prognosis.AIM To investigate the impact of three different skin suturing methods at the ileostomy closure site on patient prognosis.METHODS Thirty patients who underwent ileostomy closure at the Affiliated Hospital of Qinghai University between January 2024 and October 2024 were selected based on inclusion and exclusion criteria.The patients were divided into three groups:The purse-string suture group,the cross-suture group,and the vertical interrupted suture group,with 10 cases in each group.The purse-string suture group,cross-suture group,and vertical interrupted suture group used purse-string,cross,and vertical interrupted suturing methods,respectively,for the skin incision at the ileostomy closure site.RESULTS There were no statistically significant differences among the three groups in terms of operative time,intraoperative blood loss,time to resume liquid diet,time to first bowel movement,postoperative hospital stay,hospitalization costs,or levels of white blood cell count,hemoglobin,and albumin on the third postoperative day(P>0.05).Nevertheless,significant differences(P<0.05)were observed in incision suture removal time,wound healing time,C-reactive protein levels on the third postoperative day,visual analog scale pain scores during the first three postoperative days,and the incidence of surgical site infection.Overall,the therapeutic outcomes of the pursestring suture group and the cross-suture group were superior to the vertical interrupted suture group.CONCLUSION Using purse-string or cross-suturing methods for skin incision at the ileostomy closure site can shorten wound healing and suture removal times,reduce surgical site infection incidence and postoperative inflammatory response,alleviate incision pain,and promote rapid postoperative recovery.
基金Supported by the Shenyang Science and Technology,No.22-321-32-15Department of Science and Technology of Liaoning Province,No.2023JH2/101600015.
文摘BACKGROUND Gastric subepithelial lesions(SELs)are elevated lesions originating from the muscularis mucosa,submucosa,or muscularis propria,and may also include extraluminal lesions.For small SELs(less than 5 cm),complete endoscopic excision is the preferred treatment.Endoscopic full-thickness resection(EFTR)has proven to be an effective approach.AIM To evaluate the efficacy of the interrupted closure technique compared to the traditional closure technique in EFTR for gastric SELs.METHODS This single-center,prospective,randomized controlled trial was conducted at a tertiary hospital from September 2023 to September 2024.A total of 90 patients who underwent EFTR for gastric SELs were randomly allocated to either the interrupted closure group(n=44)or the traditional closure group(n=46).RESULTS All patients had complete resection and wound closure without any severe postoperative complications.The incidence of intraoperative gas-related complications was significantly lower in the interrupted closure group than in the traditional closure group(2.27%vs 26.09%,P=0.001),demonstrating interrupted closure technique can reduce the incidence of gas-related issues.Statistical analysis revealed that the incidence of postoperative infection was significantly lower in the experimental group than in the control group(15.91%vs 41.30%,P=0.008).Additionally,the median duration of antibiotic use was lower in the experimental group(3.5 days vs 5 days,P=0.013).Abdominal pain levels on postoperative days 1 and 4 were also lower in the experimental group compared to the control group(P<0.001).CONCLUSION The interrupted closure technique in EFTR for treating gastric SELs is safe and effective,reducing the incidence of intraoperative gas complications and postoperative infections.
基金funded by the Bavarian State Ministry of ScienceResearch and Art(Grant number:H.2-F1116.WE/52/2)。
文摘The incremental capacity analysis(ICA)technique is notably limited by its sensitivity to variations in charging conditions,which constrains its practical applicability in real-world scenarios.This paper introduces an ICA-compensation technique to address this limitation and propose a generalized framework for assessing the state of health(SOH)of batteries based on ICA that is applicable under differing charging conditions.This novel approach calculates the voltage profile under quasi-static conditions by subtracting the voltage increase attributable to the additional polarization effects at high currents from the measured voltage profile.This approach's efficacy is contingent upon precisely acquiring the equivalent impedance.To obtain the equivalent impedance throughout the batteries'lifespan while minimizing testing costs,this study employs a current interrupt technique in conjunction with a long short-term memory(LSTM)network to develop a predictive model for equivalent impedance.Following the derivation of ICA curves using voltage profiles under quasi-static conditions,the research explores two scenarios for SOH estimation:one utilizing only incremental capacity(IC)features and the other incorporating both IC features and IC sampling.A genetic algorithm-optimized backpropagation neural network(GABPNN)is employed for the SOH estimation.The proposed generalized framework is validated using independent training and test datasets.Variable test conditions are applied for the test set to rigorously evaluate the methodology under challenging conditions.These evaluation results demonstrate that the proposed framework achieves an estimation accuracy of 1.04%for RMSE and 0.90%for MAPE across a spectrum of charging rates ranging from 0.1 C to 1 C and starting SOCs between 0%and 70%,which constitutes a major advancement compared to established ICA methods.It also significantly enhances the applicability of conventional ICA techniques in varying charging conditions and negates the necessity for separate testing protocols for each charging scenario.
基金supported by Craig H.Neilsen Foundation,Wings for Life Foundation,Canadian Institutes of Health Research,and Fonds de Recherche Québec-Santé(to FB).
文摘Spinal cord injury(SCI)interrupts the flow of information between the brain and the spinal cord,thus leading to a loss of sensory information and motor paralysis of the body below the lesion.Surprisingly,most SCIs are incomplete and spare supraspinal pathways,especially those located within the peripheral white matter of the spinal cord,which includes reticulospinal pathways originating from the medullary reticular formation.Whereas there is abundant literature about the motor cortex,its corticospinal pathway,and its capacity to modulate functional recovery after SCI,less is known about the medullary reticular formation and its reticulospinal pathway.
基金Analysis of Lung Compliance Measurement and its Guided Therapeutic Effects in Patients with ARDS Secondary to Severe Multiple Trauma(Project No.:XSD-2023-002)。
文摘In recent years,research on nursing interruptions has been conducted at various levels in emergency departments,intensive care units,hemodialysis centers,operating rooms,and sterilization and supply centers.Nursing interruptions are closely related to adverse nursing events,and interruptions in operating room nursing can significantly impact the success of a patient’s surgery.However,there is a lack of in-depth theoretical research on safety risk assessment and response decision-making by operating room nurses when faced with nursing interruptions.This article reviews the concept,current status,and impact of nursing interruptions in the operating room,analyzes the cognitive level,coping strategies,and negative emotions of operating room nurses,and elaborates on management strategies to provide references for research and management of nursing interruptions in the operating room.
基金Jiangxi Provincial Hospital Pharmacy Special Research Fund Project(Grant No.2024-ZXYJ02).
文摘In the context of the Diagnosis Related Groups(DRGs)system,the orthopedic hospital implemented refined drug control to provide a pharmacological reference for promoting rational clinical drug use.A statistical analysis was conducted on the hospital’s data from January to December 2021(prior to the implementation of control),focusing on the types of unreasonable prescriptions.A multi-dimensional analysis was also conducted to identify the underlying causes of inappropriate medication practices.Following this,refined drug control measures were introduced,and data from January to December 2022(post-control)were compared,examining factors such as the average drug cost,drug expenses for the IC29 diagnosis group,and the drug cost ratio.An interrupted time-series analysis was employed to evaluate the effects of these interventions.The results showed that after the implementation of refined drug control in the orthopedic department,significant reductions were observed in the average cost per patient,average drug cost per patient,drug cost ratio,cost consumption index,average length of hospital stay,and allocation ratio(P<0.05).In particular,the first month of control(January 2022)saw a marked decrease in average drug costs per patient by 1272.90 yuan(P<0.01),a reduction in the drug cost ratio by 0.98%,and a decline in drug costs for the IC29 diagnosis group by 616.79 yuan(P>0.05).Moreover,the rate of unreasonable inappropriate prescribing dropped dramatically from 40.48%in 2021 to 3.57%by December 2022.The refined control of drug use within the orthopedic hospital significantly improved the rationality of clinical prescribing practices,reduced the occurrence of adverse drug reactions,and enhanced patient adherence to prescribed treatments.These findings demonstrated considerable clinical value in promoting efficient and safe drug use.
基金supported by the National Natural Science Foundation of China(62001481,61890542,62071475)the Natural Science Foundation of Hunan Province(2022JJ40561)the Research Program of National University of Defense Technology(ZK22-46).
文摘Nonperiodic interrupted sampling repeater jamming(ISRJ)against inverse synthetic aperture radar(ISAR)can obtain two-dimensional blanket jamming performance by joint fast and slow time domain interrupted modulation,which is obviously dif-ferent from the conventional multi-false-target deception jam-ming.In this paper,a suppression method against this kind of novel jamming is proposed based on inter-pulse energy function and compressed sensing theory.By utilizing the discontinuous property of the jamming in slow time domain,the unjammed pulse is separated using the intra-pulse energy function diffe-rence.Based on this,the two-dimensional orthogonal matching pursuit(2D-OMP)algorithm is proposed.Further,it is proposed to reconstruct the ISAR image with the obtained unjammed pulse sequence.The validity of the proposed method is demon-strated via the Yake-42 plane data simulations.
基金the Tianjin Key Laboratory of Fastening and Connection Technology Enterprises 2022—2023,China(No.TKLF2022-02-C-02)the technical support from the School of Materials Science and Engineering,Central South University,China.
文摘The effects of interrupted aging on mechanical properties and corrosion resistance of 7A75 aluminum alloy extruded bar were investigated through various analyses,including electrical conductivity,mechanical properties,local corrosion properties,and slow strain rate tensile stress corrosion tests.Microstructure characterization techniques such as metallographic microscopy,scanning electron microscopy(SEM),and transmission electron microscopy(TEM)were also employed.The results indicate that the tensile strength of the alloy produced by T6I6 aging is similar to that produced by T6I4 aging,and it even exceeds 700 MPa.Furthermore,the yield strength increases by 52.7 MPa,reaching 654.8 MPa after T6I6 aging treatment.The maximum depths of intergranular corrosion(IGC)and exfoliation corrosion(EXCO)decrease from 116.3 and 468.5μm to 89.5 and 324.3μm,respectively.The stress corrosion factor also decreases from 2.1%to 1.6%.These findings suggest that the alloy treated with T6I6 aging exhibits both high strength and excellent stress corrosion cracking resistance.Similarly,when the alloy is treated with T6I4,T6I6 and T6I7 aging,the sizes of grain boundary precipitates(GBPs)are found to be 5.2,18.4,and 32.8 nm,respectively.The sizes of matrix precipitates are 4.8,5.7 and 15.7 nm,respectively.The atomic fractions of Zn in GBPs are 9.92 at.%,8.23 at.%and 6.87 at.%,respectively,while the atomic fractions of Mg are 12.66 at.%,8.43 at.%and 7.00 at.%,respectively.Additionally,the atomic fractions of Cu are 1.83 at.%,2.47 at.%and 3.41 at.%,respectively.
