BACKGROUND Hepatic hemangioma represents the most common benign primary hepatic neo-plasm.Although most such tumors are small and asymptomatic,giant cavernous hemangioma(GCH)is frequently symptomatic,and needs interve...BACKGROUND Hepatic hemangioma represents the most common benign primary hepatic neo-plasm.Although most such tumors are small and asymptomatic,giant cavernous hemangioma(GCH)is frequently symptomatic,and needs intervention.More-over,diffuse hepatic hemangiomatosis(DHH)is not rare in the liver parenchyma adjacent to a GCH.The management strategy for hepatic hemangiomas can differ depending on the presence of associated hemangiomatosis and the amount and distribution of the residual hepatic parenchyma.CASE SUMMARY Herein,we report two patients with GCH coexistent with DHH successfully treated by laparoscopic microwave ablation.The two GCHs were ablated com-pletely and the ablated zone atrophied obviously in imaging follow-ups after ablation.Surprisingly,there was a trend toward gradual reduction and dimini-shment of DHH.CONCLUSION Thermal ablation treatment might be an effective and less invasive treatment for GCH coexistent with DHH around the hemangioma.展开更多
The effect of gradient exhaust strategy and blind plate installation on the inhibition of backflow and thermal stratification in data center cabinets is systematically investigated in this study through numericalmetho...The effect of gradient exhaust strategy and blind plate installation on the inhibition of backflow and thermal stratification in data center cabinets is systematically investigated in this study through numericalmethods.The validated Re-Normalization Group(RNG)k-ε turbulence model was used to analyze airflow patterns within cabinet structures equipped with backplane air conditioning.Key findings reveal that server-generated thermal plumes induce hot air accumulation at the cabinet apex,creating a 0.8℃ temperature elevation at the top server’s inlet compared to the ideal situation(23℃).Strategic increases in backplane fan exhaust airflow rates reduce server 1’s inlet temperature from 26.1℃(0%redundancy case)to 23.1℃(40%redundancy case).Gradient exhaust strategies achieve equivalent server temperature performance to uniform exhaust distributions while requiring 25%less redundant airflow.This approach decreases the recirculation ratio from1.52%(uniformexhaust at 15%redundancy)to 0.57%(gradient exhaust at equivalent redundancy).Comparative analyses demonstrate divergent thermal behaviors:in bottom-server-absent configurations,gradient exhaust reduces top server inlet temperatures by 1.6℃vs.uniformexhaust,whereas top-serverabsent configurations exhibit a 1.8℃ temperature increase under gradient conditions.The blind plate implementation achieves a 0.4℃ top server temperature reduction compared to 15%-redundancy uniform exhaust systems without requiring additional airflow redundancy.Partially installed server arrangements with blind plates maintain thermal characteristics comparable to fully populated cabinets.This study validates gradient exhaust and blind plate technologies as effective countermeasures against cabinet-scale thermal recirculation,providing actionable insights for optimizing backplane air conditioning systems in mission-critical data center environments.展开更多
Understanding the formation of lithium-rich pegmatites is critical for meeting global lithium demand.The 509 Daobanxi Li pegmatite deposit,located in the West Kunlun orogenic belt of northwestern China,represents a si...Understanding the formation of lithium-rich pegmatites is critical for meeting global lithium demand.The 509 Daobanxi Li pegmatite deposit,located in the West Kunlun orogenic belt of northwestern China,represents a significant example of an LCT-type(Li-Cs-Ta)pegmatite system.This study investigates the paragenetic sequence of lithium(Li)minerals and the factors controlling their crystallization,providing new insights into the magmatic-hydrothermal evolution of rare-element pegmatites.Pegmatite dikes exhibit distinct zonation,comprising a wall rock zone,a border zone(aplitic layer),and a core zone(pegmatitic layer),with Li mineralization concentrated in the pegmatitic and aplitic layers.The primary Li minerals include spodumene(Spd),montebrasite(Mbs),eucryptite(Ecr),elbaite(Elb),and lepidolite(Lpd),which crystallize in the order of spodumene→montebrasite→elbaite→lepidolite.Spodumene,the dominant Li-bearing mineral,crystallizes from a Li-saturated melt during the magmatic stage.Montebrasite,a Li-phosphate mineral,forms in P-rich environments,coexisting with spodumene and columbite-group minerals(CGM).During the magmatic-hydrothermal transition,elbaite crystallizes from a B-rich melt,exhibiting skeletal and patchy zoning due to undercooling and disequilibrium crystallization.Hydrothermal alteration leads to the breakdown of spodumene and the formation of secondary minerals such as eucryptite and lepidolite,with lepidolite being the final Li-bearing phase,enriched in fluorine.The coupled dissolution-precipitation processes during the magmatic-hydrothermal transition play a critical role in the remobilization and enrichment of rare elements such as Li,Nb,Ta,and Sn.This deposit,characterized by spodumene crystallization in the Spd+Quartz stability field(≥300 MPa,≤725℃)and subsequent alteration to Ecr+quartz assemblages(<270℃,<160 MPa),exhibits broader temperature-pressure conditions exceeding typical global pegmatites like Tanco,with no petalite formation observed due to its persistent exclusion from petalite stability fields throughout mineralization.The shear zone controls the pegmatite emplacement and lithium enrichment in the 509 Daobanxi lithium deposit,and its deformation-fluid coupling mechanism provides new insights for the exploration of LCT pegmatite deposits.The present study highlights the importance of understanding both magmatic and hydrothermal processes in the formation of LCT-type pegmatites and provides valuable insights for the exploration of critical metal resources in similar geological settings.展开更多
The Propellant Feed System(PFS)is a crucial component of Electric Propulsion System(EPS)which is widely used in satellites for its high reliability and specific impulse.The Switching and Proportional Hybrid-controlled...The Propellant Feed System(PFS)is a crucial component of Electric Propulsion System(EPS)which is widely used in satellites for its high reliability and specific impulse.The Switching and Proportional Hybrid-controlled Xenon Feed System(SPHXFS)is a novel type of PFS with high flow regulation precision.This study develops a system-level simulation model with 75 components for the SPHXFS.The accuracy of the model is validated through the comparison with test data,showing an error of less than 3%during the startup phase and less than 0.1%after stabilization.The study analyzes the startup process and finds that the two-stage pressure reduction system avoids two-phase flow interference downstream,achieving a regulation accuracy of±0.1%.A long-term operation simulation of the system is conducted,revealing that pressure fluctuations occur upstream at 4767 s due to Bang-Bang control.However,with proportional control adjustments,these fluctuations do not affect the flow supply.Further research examines the impact of synchronous and asynchronous control modes of the Bang-Bang Valve(TPBBV)under the tank pressures of 6-10 MPa on the system's dynamic characteristics.It is found that the asynchronous control scheme results in a flow supply settling time that is 7.2-10s longer than the synchronous control scheme,with an overshoot increase of 4.1%-4.9%.These insights provide valuable reference and guidance for system optimization design and the formulation of operational strategies.展开更多
With the global oil and gas industry increasingly targeting ultra-deep well development,the demand for wear resistance in polycrystalline diamond compact(PDC)bits is increasing.However,further improvement of the mecha...With the global oil and gas industry increasingly targeting ultra-deep well development,the demand for wear resistance in polycrystalline diamond compact(PDC)bits is increasing.However,further improvement of the mechanical properties of PDC incurs prohibitively elevated costs and stringent technological challenges.Here,we present a two-stage high-pressure infiltration(HPI)methodology involving cobalt removal pretreatment followed by lubricant infiltration.The successful infiltration of lubricants into diamond micropores has been systematically verified,and the effects of lubricant phase composition,infiltration pressure,and temperature on infiltration depth have been thoroughly investigated.Fractal dimension analysis characterizes the pore structure of cobalt-removed diamonds,revealing a strong correlation between the fractal dimension and friction coefficient reduction.Tribological testing confirms the formation of lubricating films at friction interfaces,achieving a 71.5%reduction in the coefficient of friction for lubricant-containing diamond materials.This straightforward strategy opens a gate to developing the next generation of self-lubricating diamond materials.展开更多
Electron-positron colliders operating in the GeV center-of-mass range,or tau-charm energy region,have been proved to enable competitive frontier research due to several unique features.With the progress of high-energy...Electron-positron colliders operating in the GeV center-of-mass range,or tau-charm energy region,have been proved to enable competitive frontier research due to several unique features.With the progress of high-energy physics in the last two decades,a new-generation Tau-Charm factory,called the Super Tau-Charm Facility(STCF),has been actively promoted by the particle physics community in China.STCF has the potential to address fundamental questions such as the essence of color confinement and the matter-antimatter asymmetry within the next decades.The main design goals of the STCF are a center-of-mass energy ranging from 2 to 7 GeV and a luminosity surpassing 5×10^(34)cm^(−2)s^(−1)that is optimized at a center-of-mass energy of 4 GeV,which is approximately 50 times that of the currently operating Tau-Charm factory-BEPCII.The STCF accelerator has two main parts:a double-ring collider with a crab-waist collision scheme and an injector that provides top-up injections for both electron and positron beams.As a typical third-generation electron-positron circular collider,the STCF accelerator faces many challenges in both accelerator physics and technology.In this paper,the conceptual design of the STCF accelerator complex is presented,including the ongoing efforts and plans for technological research and develop-ment,as well as the required infrastructure.The STCF project aims to secure support from the Chinese central government for its construction during the 15th Five-Year Plan(2026-2030).展开更多
Compared with ground first aid, aviation medical rescue has better advantages in mountain disaster relief, remote transfer and rapid medical rescue response, which is an effective supplement to ground medical first ai...Compared with ground first aid, aviation medical rescue has better advantages in mountain disaster relief, remote transfer and rapid medical rescue response, which is an effective supplement to ground medical first aid. China’s aviation medical rescue is in its infancy, compared with the level of developed countries there is a big gap. Based on the development and characteristics of aviation medical rescue in China, this paper combs the process of air-ground cooperative rescue, analyzes the demand and current situation of air-ground cooperative rescue in aviation medical rescue in China, and puts forward some countermeasures to improve the ability of aviation medical rescue in China.展开更多
The primary focus of this study was to investigate a series of novel motors and pumps,based on a new type of structure called double-stator.The double-stator structure can be used as pump or motor just based on the ap...The primary focus of this study was to investigate a series of novel motors and pumps,based on a new type of structure called double-stator.The double-stator structure can be used as pump or motor just based on the application requirements.A certain amount of pumps or motors can be formed in one shell,and these sub-pumps or sub-motors can work alone or be combined without influence on each other.So this kind of double-stator pump(motor) is called a multi-pump(multi-motor).Through the analysis of multifarious connection modes of the double-acting double-stator multi-pumps and multi-motors,the mathematical expressions of the output flow rate and the rotational speed are acquired.The results indicate that a quantity of different flow rates can be provided by one fixed-displacement multi-pump under the condition of unalterable driven speed by electromotor.Likewise,when supplied by settled input flow,without complex variable mechanism,the functions of double-speed,multiple-speed,and even differential connection can be obtained by employing the use of a double-stator multi-motor.The novel hydraulic transmission is made of such a double-stator multi-pump and multi-motor,and has broad application prospects.展开更多
The increase in neurotrophic factors after craniocerebral injury has been shown to promote fracture healing. Moreover, neurotrophic factors play a key role in the regeneration and repair of peripheral nerve. However, ...The increase in neurotrophic factors after craniocerebral injury has been shown to promote fracture healing. Moreover, neurotrophic factors play a key role in the regeneration and repair of peripheral nerve. However, whether craniocerebral injury alters the repair of peripheral nerve injuries remains poorly understood. Rat injury models were established by transecting the left sciatic nerve and using a free-fall device to induce craniocerebral injury. Compared with sciat- ic nerve injury alone after 6-12 weeks, rats with combined sciatic and craniocerebral injuries showed decreased sciatic functional index, increased recovery of gastrocnemius muscle wet weight, recovery of sciatic nerve ganglia and corresponding spinal cord segment neuron mor- phologies, and increased numbers of horseradish peroxidase-labeled cells. These results indicate that craniocerebral injury promotes the repair of peripheral nerve injury.展开更多
AIM: To compare safety and therapeutic efficacy of laparoscopic radiofrequency(RF) ablation vs computed tomography(CT)-guided RF ablation for large hepatic hemangiomas abutting the diaphragm.METHODS: We retrospectivel...AIM: To compare safety and therapeutic efficacy of laparoscopic radiofrequency(RF) ablation vs computed tomography(CT)-guided RF ablation for large hepatic hemangiomas abutting the diaphragm.METHODS: We retrospectively reviewed our sequential experience of treating 51 large hepatic hemangiomas abutting the diaphragm in 51 patients by CT-guided or laparoscopic RF ablation due to either the presence of symptoms and/or the enlargement of hemangioma.Altogether, 24 hemangiomas were ablated via a CTguided percutaneous approach(CT-guided ablation group), and 27 hemangiomas were treated via a laparoscopic approach(laparoscopic ablation group).RESULTS: The mean diameter of the 51 hemangiomas was 9.6 ± 1.8 cm(range, 6.0-12.0 cm). There was nodifference in the diameter of hemangiomas between the two groups(P > 0.05). RF ablation was performed successfully in all patients. There was no difference in ablation times between groups(P > 0.05). There were 23 thoracic complications in 17 patients: 15(62.5%, 15/24) in the CT-guided ablation group and2(7.4%, 2/27) in the laparoscopic ablation group(P< 0.05). According to the Dindo-Clavien classification,two complications(pleural effusion and diaphragmatic rupture grade Ⅲ) were major in two patients. All others were minor(grade Ⅰ). Both major complications occurred in the CT-guided ablation group. The minor complications were treated successfully with conservative measures, and the two major complications underwent treatment by chest tube drainage and thoracoscopic surgery, respectively. Complete ablation was achieved in 91.7%(22/24) and 96.3%(26/27) in the CT-guided and the laparoscopic ablation groups,respectively(P > 0.05).CONCLUSION: Laparoscopic RF ablation therapy should be used as the first-line treatment option for large hepatic hemangiomas abutting the diaphragm.It avoids thermal injury to the diaphragm and reduces thoracic complications.展开更多
AIM:To evaluate long-term outcomes of radiofrequency(RF) ablation as first-line therapy for single hepatocellular carcinoma(HCC) ≤ 3 cm and to determine survival and prognostic factors.METHODS:We included all 184 pat...AIM:To evaluate long-term outcomes of radiofrequency(RF) ablation as first-line therapy for single hepatocellular carcinoma(HCC) ≤ 3 cm and to determine survival and prognostic factors.METHODS:We included all 184 patients who underwent RF ablation as a first-line treatment for single HCC ≤ 3 cm between April 2005 and December 2013.According to the criteria of Livraghi,the 184 patients were divided into two groups:those suitable for surgical resection(84 cases) and those unsuitable for surgical resection(100 cases).The primary endpoints were the overall survival(OS) rate and safety;the secondary endpoints were primary technique effectiveness and recurrence rate.RESULTS:There were 19(10.3%) cases of ablation related minor complications.The complete tumor ablation rate after one RF session was 97.8%(180/184).The rate of local tumor progression,extrahepatic metastases and intrahepatic distant recurrence were 4.9%(9/184),9.8%(18/184) and 37.5%(69/184),respectively.In the 184 patients,the 1-,3-,and 5-year OS rates were 99.5%,81.0%,and 62.5%,respectively.The 1-,3-,and 5-year OS rates were 100%,86.9%,and 71.4%,respectively,in those suitable for surgical resection and 99.0%,76.0%,and 55.0%,respectively,in those unsuitable for surgical resection(P = 0.021).On univariate and multivariate analyses,poorer OS was associated with Child-Pugh B class and portal hypertension(P < 0.05).CONCLUSION:RF ablation is a safe and effective treatment for single HCC ≤ 3 cm.The OS rate of patients suitable for surgical resection was similar to those reported in surgical series.展开更多
Extractive distillation is an effective method for separating azeotropic or close boiling point mixtures by adding a third component.Various technologies for performing the extractive distillation process have been ex...Extractive distillation is an effective method for separating azeotropic or close boiling point mixtures by adding a third component.Various technologies for performing the extractive distillation process have been explored to protect the environment and save resources.This paper focuses on the improvement of these advanced technologies in recent years.Extractive distillation is retrieved and analyzed from the view of phase equilibrium,selection of solvent in extractive distillation,process design,energy conservation,and dynamic control.The quantitative structure–property relationship used in extractive distillation is discussed,and the future development of extractive distillation is proposed to determine how the solvent affects the relative volatility of the separated mixture.In the steady state design,the relationship between the curvature of the residue curve and parameters of the optimal steady state is also highlighted as another field worthy of further study to simplify the distillation process.展开更多
By utilizing the time difference of arrival （TDOA） and frequency difference of arrival （FDOA） measurements of signals received at a number of receivers, a constrained least-square （CLS） algorithm for estimating ...By utilizing the time difference of arrival （TDOA） and frequency difference of arrival （FDOA） measurements of signals received at a number of receivers, a constrained least-square （CLS） algorithm for estimating the position and velocity of a moving source is proposed. By utilizing the Lagrange multipliers technique, the known relation between the intermediate variables and the source location coordinates could be exploited to constrain the solution. And without requiring apriori knowledge of TDOA and FDOA measurement noises, the proposed algorithm can satisfy the demand of practical applications. Additionally, on basis of con- volute and polynomial rooting operations, the Lagrange multipliers can be obtained efficiently and robustly allowing real-time imple- mentation and global convergence. Simulation results show that the proposed estimator achieves remarkably better performance than the two-step weighted least square （WLS） approach especially for higher measurement noise level.展开更多
文摘BACKGROUND Hepatic hemangioma represents the most common benign primary hepatic neo-plasm.Although most such tumors are small and asymptomatic,giant cavernous hemangioma(GCH)is frequently symptomatic,and needs intervention.More-over,diffuse hepatic hemangiomatosis(DHH)is not rare in the liver parenchyma adjacent to a GCH.The management strategy for hepatic hemangiomas can differ depending on the presence of associated hemangiomatosis and the amount and distribution of the residual hepatic parenchyma.CASE SUMMARY Herein,we report two patients with GCH coexistent with DHH successfully treated by laparoscopic microwave ablation.The two GCHs were ablated com-pletely and the ablated zone atrophied obviously in imaging follow-ups after ablation.Surprisingly,there was a trend toward gradual reduction and dimini-shment of DHH.CONCLUSION Thermal ablation treatment might be an effective and less invasive treatment for GCH coexistent with DHH around the hemangioma.
基金financially supported by the Basic Research Funds for the Central Government“Innovative Team of Zhejiang University”under contract number(2022FZZX01-09).
文摘The effect of gradient exhaust strategy and blind plate installation on the inhibition of backflow and thermal stratification in data center cabinets is systematically investigated in this study through numericalmethods.The validated Re-Normalization Group(RNG)k-ε turbulence model was used to analyze airflow patterns within cabinet structures equipped with backplane air conditioning.Key findings reveal that server-generated thermal plumes induce hot air accumulation at the cabinet apex,creating a 0.8℃ temperature elevation at the top server’s inlet compared to the ideal situation(23℃).Strategic increases in backplane fan exhaust airflow rates reduce server 1’s inlet temperature from 26.1℃(0%redundancy case)to 23.1℃(40%redundancy case).Gradient exhaust strategies achieve equivalent server temperature performance to uniform exhaust distributions while requiring 25%less redundant airflow.This approach decreases the recirculation ratio from1.52%(uniformexhaust at 15%redundancy)to 0.57%(gradient exhaust at equivalent redundancy).Comparative analyses demonstrate divergent thermal behaviors:in bottom-server-absent configurations,gradient exhaust reduces top server inlet temperatures by 1.6℃vs.uniformexhaust,whereas top-serverabsent configurations exhibit a 1.8℃ temperature increase under gradient conditions.The blind plate implementation achieves a 0.4℃ top server temperature reduction compared to 15%-redundancy uniform exhaust systems without requiring additional airflow redundancy.Partially installed server arrangements with blind plates maintain thermal characteristics comparable to fully populated cabinets.This study validates gradient exhaust and blind plate technologies as effective countermeasures against cabinet-scale thermal recirculation,providing actionable insights for optimizing backplane air conditioning systems in mission-critical data center environments.
基金supported by the National Natural Science Foundation of China(Nos.42250202,92162323,42272075)the Fundamental Research Funds for the Central Universities,Sun Yat-sen University(No.24lgqb01).
文摘Understanding the formation of lithium-rich pegmatites is critical for meeting global lithium demand.The 509 Daobanxi Li pegmatite deposit,located in the West Kunlun orogenic belt of northwestern China,represents a significant example of an LCT-type(Li-Cs-Ta)pegmatite system.This study investigates the paragenetic sequence of lithium(Li)minerals and the factors controlling their crystallization,providing new insights into the magmatic-hydrothermal evolution of rare-element pegmatites.Pegmatite dikes exhibit distinct zonation,comprising a wall rock zone,a border zone(aplitic layer),and a core zone(pegmatitic layer),with Li mineralization concentrated in the pegmatitic and aplitic layers.The primary Li minerals include spodumene(Spd),montebrasite(Mbs),eucryptite(Ecr),elbaite(Elb),and lepidolite(Lpd),which crystallize in the order of spodumene→montebrasite→elbaite→lepidolite.Spodumene,the dominant Li-bearing mineral,crystallizes from a Li-saturated melt during the magmatic stage.Montebrasite,a Li-phosphate mineral,forms in P-rich environments,coexisting with spodumene and columbite-group minerals(CGM).During the magmatic-hydrothermal transition,elbaite crystallizes from a B-rich melt,exhibiting skeletal and patchy zoning due to undercooling and disequilibrium crystallization.Hydrothermal alteration leads to the breakdown of spodumene and the formation of secondary minerals such as eucryptite and lepidolite,with lepidolite being the final Li-bearing phase,enriched in fluorine.The coupled dissolution-precipitation processes during the magmatic-hydrothermal transition play a critical role in the remobilization and enrichment of rare elements such as Li,Nb,Ta,and Sn.This deposit,characterized by spodumene crystallization in the Spd+Quartz stability field(≥300 MPa,≤725℃)and subsequent alteration to Ecr+quartz assemblages(<270℃,<160 MPa),exhibits broader temperature-pressure conditions exceeding typical global pegmatites like Tanco,with no petalite formation observed due to its persistent exclusion from petalite stability fields throughout mineralization.The shear zone controls the pegmatite emplacement and lithium enrichment in the 509 Daobanxi lithium deposit,and its deformation-fluid coupling mechanism provides new insights for the exploration of LCT pegmatite deposits.The present study highlights the importance of understanding both magmatic and hydrothermal processes in the formation of LCT-type pegmatites and provides valuable insights for the exploration of critical metal resources in similar geological settings.
基金supported by the Fundamental Research Funds for the Central Universities,China(No.JKF-2025009442288)the Excellent Youth Team Cultivation Project for Central Universities of the Ministry of Education,China(No.YWF-22/23/24-JT-106)。
文摘The Propellant Feed System(PFS)is a crucial component of Electric Propulsion System(EPS)which is widely used in satellites for its high reliability and specific impulse.The Switching and Proportional Hybrid-controlled Xenon Feed System(SPHXFS)is a novel type of PFS with high flow regulation precision.This study develops a system-level simulation model with 75 components for the SPHXFS.The accuracy of the model is validated through the comparison with test data,showing an error of less than 3%during the startup phase and less than 0.1%after stabilization.The study analyzes the startup process and finds that the two-stage pressure reduction system avoids two-phase flow interference downstream,achieving a regulation accuracy of±0.1%.A long-term operation simulation of the system is conducted,revealing that pressure fluctuations occur upstream at 4767 s due to Bang-Bang control.However,with proportional control adjustments,these fluctuations do not affect the flow supply.Further research examines the impact of synchronous and asynchronous control modes of the Bang-Bang Valve(TPBBV)under the tank pressures of 6-10 MPa on the system's dynamic characteristics.It is found that the asynchronous control scheme results in a flow supply settling time that is 7.2-10s longer than the synchronous control scheme,with an overshoot increase of 4.1%-4.9%.These insights provide valuable reference and guidance for system optimization design and the formulation of operational strategies.
基金supported by the National Natural Science Foundation of China(grant number:52203375 and 52073254)。
文摘With the global oil and gas industry increasingly targeting ultra-deep well development,the demand for wear resistance in polycrystalline diamond compact(PDC)bits is increasing.However,further improvement of the mechanical properties of PDC incurs prohibitively elevated costs and stringent technological challenges.Here,we present a two-stage high-pressure infiltration(HPI)methodology involving cobalt removal pretreatment followed by lubricant infiltration.The successful infiltration of lubricants into diamond micropores has been systematically verified,and the effects of lubricant phase composition,infiltration pressure,and temperature on infiltration depth have been thoroughly investigated.Fractal dimension analysis characterizes the pore structure of cobalt-removed diamonds,revealing a strong correlation between the fractal dimension and friction coefficient reduction.Tribological testing confirms the formation of lubricating films at friction interfaces,achieving a 71.5%reduction in the coefficient of friction for lubricant-containing diamond materials.This straightforward strategy opens a gate to developing the next generation of self-lubricating diamond materials.
基金supported by the National Key Research and Development Program of China(No.2022YFA1602200)the National Natural Science Foundation of China(Nos.12341501 and 12405174)the Hefei Comprehensive National Science Center for the strong support on the STCF key technology research project.
文摘Electron-positron colliders operating in the GeV center-of-mass range,or tau-charm energy region,have been proved to enable competitive frontier research due to several unique features.With the progress of high-energy physics in the last two decades,a new-generation Tau-Charm factory,called the Super Tau-Charm Facility(STCF),has been actively promoted by the particle physics community in China.STCF has the potential to address fundamental questions such as the essence of color confinement and the matter-antimatter asymmetry within the next decades.The main design goals of the STCF are a center-of-mass energy ranging from 2 to 7 GeV and a luminosity surpassing 5×10^(34)cm^(−2)s^(−1)that is optimized at a center-of-mass energy of 4 GeV,which is approximately 50 times that of the currently operating Tau-Charm factory-BEPCII.The STCF accelerator has two main parts:a double-ring collider with a crab-waist collision scheme and an injector that provides top-up injections for both electron and positron beams.As a typical third-generation electron-positron circular collider,the STCF accelerator faces many challenges in both accelerator physics and technology.In this paper,the conceptual design of the STCF accelerator complex is presented,including the ongoing efforts and plans for technological research and develop-ment,as well as the required infrastructure.The STCF project aims to secure support from the Chinese central government for its construction during the 15th Five-Year Plan(2026-2030).
文摘Compared with ground first aid, aviation medical rescue has better advantages in mountain disaster relief, remote transfer and rapid medical rescue response, which is an effective supplement to ground medical first aid. China’s aviation medical rescue is in its infancy, compared with the level of developed countries there is a big gap. Based on the development and characteristics of aviation medical rescue in China, this paper combs the process of air-ground cooperative rescue, analyzes the demand and current situation of air-ground cooperative rescue in aviation medical rescue in China, and puts forward some countermeasures to improve the ability of aviation medical rescue in China.
基金Project(No.50975246)supported by the National Natural Science Foundation of China
文摘The primary focus of this study was to investigate a series of novel motors and pumps,based on a new type of structure called double-stator.The double-stator structure can be used as pump or motor just based on the application requirements.A certain amount of pumps or motors can be formed in one shell,and these sub-pumps or sub-motors can work alone or be combined without influence on each other.So this kind of double-stator pump(motor) is called a multi-pump(multi-motor).Through the analysis of multifarious connection modes of the double-acting double-stator multi-pumps and multi-motors,the mathematical expressions of the output flow rate and the rotational speed are acquired.The results indicate that a quantity of different flow rates can be provided by one fixed-displacement multi-pump under the condition of unalterable driven speed by electromotor.Likewise,when supplied by settled input flow,without complex variable mechanism,the functions of double-speed,multiple-speed,and even differential connection can be obtained by employing the use of a double-stator multi-motor.The novel hydraulic transmission is made of such a double-stator multi-pump and multi-motor,and has broad application prospects.
基金supported by a grant from Hebei Provincial Science and Technology Department in China,No.142777105D,13277772D
文摘The increase in neurotrophic factors after craniocerebral injury has been shown to promote fracture healing. Moreover, neurotrophic factors play a key role in the regeneration and repair of peripheral nerve. However, whether craniocerebral injury alters the repair of peripheral nerve injuries remains poorly understood. Rat injury models were established by transecting the left sciatic nerve and using a free-fall device to induce craniocerebral injury. Compared with sciat- ic nerve injury alone after 6-12 weeks, rats with combined sciatic and craniocerebral injuries showed decreased sciatic functional index, increased recovery of gastrocnemius muscle wet weight, recovery of sciatic nerve ganglia and corresponding spinal cord segment neuron mor- phologies, and increased numbers of horseradish peroxidase-labeled cells. These results indicate that craniocerebral injury promotes the repair of peripheral nerve injury.
基金Supported by the Dr.Jieping Wu Medical Foundation,No.320675007131 and No.32067501207Clinical-Basic Medicine Cooperation Fund of Capital Medical University,No.1300171711the Program for Medical Key Discipline of Shijingshan District,No.20130001
文摘AIM: To compare safety and therapeutic efficacy of laparoscopic radiofrequency(RF) ablation vs computed tomography(CT)-guided RF ablation for large hepatic hemangiomas abutting the diaphragm.METHODS: We retrospectively reviewed our sequential experience of treating 51 large hepatic hemangiomas abutting the diaphragm in 51 patients by CT-guided or laparoscopic RF ablation due to either the presence of symptoms and/or the enlargement of hemangioma.Altogether, 24 hemangiomas were ablated via a CTguided percutaneous approach(CT-guided ablation group), and 27 hemangiomas were treated via a laparoscopic approach(laparoscopic ablation group).RESULTS: The mean diameter of the 51 hemangiomas was 9.6 ± 1.8 cm(range, 6.0-12.0 cm). There was nodifference in the diameter of hemangiomas between the two groups(P > 0.05). RF ablation was performed successfully in all patients. There was no difference in ablation times between groups(P > 0.05). There were 23 thoracic complications in 17 patients: 15(62.5%, 15/24) in the CT-guided ablation group and2(7.4%, 2/27) in the laparoscopic ablation group(P< 0.05). According to the Dindo-Clavien classification,two complications(pleural effusion and diaphragmatic rupture grade Ⅲ) were major in two patients. All others were minor(grade Ⅰ). Both major complications occurred in the CT-guided ablation group. The minor complications were treated successfully with conservative measures, and the two major complications underwent treatment by chest tube drainage and thoracoscopic surgery, respectively. Complete ablation was achieved in 91.7%(22/24) and 96.3%(26/27) in the CT-guided and the laparoscopic ablation groups,respectively(P > 0.05).CONCLUSION: Laparoscopic RF ablation therapy should be used as the first-line treatment option for large hepatic hemangiomas abutting the diaphragm.It avoids thermal injury to the diaphragm and reduces thoracic complications.
基金Dr.Jieping Wu Medical Foundation,Nos.320675007131 and 32067501207Clinical-Basic Medicine Cooperation Fund of Capital Medical University,No.1300171711Program for Medical Key Discipline of Shijingshan District,No.20130001
文摘AIM:To evaluate long-term outcomes of radiofrequency(RF) ablation as first-line therapy for single hepatocellular carcinoma(HCC) ≤ 3 cm and to determine survival and prognostic factors.METHODS:We included all 184 patients who underwent RF ablation as a first-line treatment for single HCC ≤ 3 cm between April 2005 and December 2013.According to the criteria of Livraghi,the 184 patients were divided into two groups:those suitable for surgical resection(84 cases) and those unsuitable for surgical resection(100 cases).The primary endpoints were the overall survival(OS) rate and safety;the secondary endpoints were primary technique effectiveness and recurrence rate.RESULTS:There were 19(10.3%) cases of ablation related minor complications.The complete tumor ablation rate after one RF session was 97.8%(180/184).The rate of local tumor progression,extrahepatic metastases and intrahepatic distant recurrence were 4.9%(9/184),9.8%(18/184) and 37.5%(69/184),respectively.In the 184 patients,the 1-,3-,and 5-year OS rates were 99.5%,81.0%,and 62.5%,respectively.The 1-,3-,and 5-year OS rates were 100%,86.9%,and 71.4%,respectively,in those suitable for surgical resection and 99.0%,76.0%,and 55.0%,respectively,in those unsuitable for surgical resection(P = 0.021).On univariate and multivariate analyses,poorer OS was associated with Child-Pugh B class and portal hypertension(P < 0.05).CONCLUSION:RF ablation is a safe and effective treatment for single HCC ≤ 3 cm.The OS rate of patients suitable for surgical resection was similar to those reported in surgical series.
基金Supported by the National Natural Science Foundation of China(21676152)
文摘Extractive distillation is an effective method for separating azeotropic or close boiling point mixtures by adding a third component.Various technologies for performing the extractive distillation process have been explored to protect the environment and save resources.This paper focuses on the improvement of these advanced technologies in recent years.Extractive distillation is retrieved and analyzed from the view of phase equilibrium,selection of solvent in extractive distillation,process design,energy conservation,and dynamic control.The quantitative structure–property relationship used in extractive distillation is discussed,and the future development of extractive distillation is proposed to determine how the solvent affects the relative volatility of the separated mixture.In the steady state design,the relationship between the curvature of the residue curve and parameters of the optimal steady state is also highlighted as another field worthy of further study to simplify the distillation process.
基金supported by the National High Technology Research and Development Program of China (863 Program) (2010AA7010422 2011AA7014061)
文摘By utilizing the time difference of arrival （TDOA） and frequency difference of arrival （FDOA） measurements of signals received at a number of receivers, a constrained least-square （CLS） algorithm for estimating the position and velocity of a moving source is proposed. By utilizing the Lagrange multipliers technique, the known relation between the intermediate variables and the source location coordinates could be exploited to constrain the solution. And without requiring apriori knowledge of TDOA and FDOA measurement noises, the proposed algorithm can satisfy the demand of practical applications. Additionally, on basis of con- volute and polynomial rooting operations, the Lagrange multipliers can be obtained efficiently and robustly allowing real-time imple- mentation and global convergence. Simulation results show that the proposed estimator achieves remarkably better performance than the two-step weighted least square （WLS） approach especially for higher measurement noise level.
