目的:检测慢性心力衰竭(CHF)患者血清Ⅲ型前胶原氨基末端前肽(N-terminal peptide of typeⅢprocollagen,PⅢNP)、高迁移率族蛋白B1(high mobility group box-1,HMGB1)的表达水平,探讨二者与左室射血分数(LVEF)的相关性以及对CHF的诊断...目的:检测慢性心力衰竭(CHF)患者血清Ⅲ型前胶原氨基末端前肽(N-terminal peptide of typeⅢprocollagen,PⅢNP)、高迁移率族蛋白B1(high mobility group box-1,HMGB1)的表达水平,探讨二者与左室射血分数(LVEF)的相关性以及对CHF的诊断价值。方法:收集2021年12月至2022年11月期间于佳木斯大学附属第一医院心内科住院治疗的慢性心力衰竭患者90例为实验组,按照LVEF将其分为HFrEF组(n=33)、HFmrEF组(n=27)和HFpEF组(n=30)。此外选取排除心功能不全诊断的同期住院患者30例为对照组。对比各组患者血清中氨基末端脑钠肽前体(NT-proBNP)、PⅢNP、HMGB1水平的差异,分析PⅢNP、HMGB1水平与心功能指标的相关性,并借助ROC曲线评估NT-proBNP、HMGB1、PⅢNP单独以及联合应用对不同表型CHF患者的诊断价值。结果:HFrEF组PⅢNP、HMGB1及NT-proBNP水平均高于HFpEF组和对照组,差异有统计学意义(P<0.05)。PⅢNP与HMGB1呈正相关(P<0.05);PⅢNP、HMGB1均与NT-proBNP、LVEDD呈正相关,与LVEF呈明显负相关(P<0.05);HMGB1与LAD呈正相关(P<0.05),PⅢNP与LAD无明显相关性(P>0.05)。血清NT-proBNP、HMGB1、PⅢNP水平诊断HFrEF患者的AUC分别为0.867、0.871、0.779;诊断HFmrEF患者的AUC分别为0.840、0.804、0.760;诊断HFpEF患者的AUC分别为0.851、0.728、0.769。多生物标志物模型NT-proBNP+PⅢNP、NT-proBNP+HMGB1、NT-proBNP+PⅢNP+HMGB1诊断HFrEF患者的AUC分别为0.887、0.954、0.954;诊断HFmrEF患者的AUC分别为0.942、0.937、0.951;诊断HFpEF患者的AUC分别为0.904、0.910、0.914。结论:CHF患者血清PⅢNP、HMGB1明显升高,并且,CHF患者血清PⅢNP、HMGB1水平与心脏功能指标具有良好的相关性,说明PⅢNP、HMGB1可反映疾病的严重程度。PⅢNP、HMGB1对各表型CHF患者均具有诊断价值,并且,多生物标志物联合检测能提高对CHF患者诊断的敏感性。展开更多
Coaxial plasma guns are a type of plasma source that produces plasma which propagates radially and axially controlled by the shape of the ground electrode, which has attracted much interest in several applications. In...Coaxial plasma guns are a type of plasma source that produces plasma which propagates radially and axially controlled by the shape of the ground electrode, which has attracted much interest in several applications. In this work, a 120° opening angle of CPG nozzle is used as a plasma gun configuration that operates at the energy of 150 J. The ionization of polyethylene insulator between the electrodes of the gun produces a cloud of hydrogen and carbon plasma.The triple Langmuir probe and Faraday cup are used to measure plasma density and plasma temperature. These methods are used to measure the on-axis and off-axis plasma divergence of the coaxial plasma gun. The peak values of ion densities measured at a distance of 25 mm on-axis from the plasma gun are(1.6±0.5)×10^(19)m^(-3)and(2.8±0.6)×10^(19)m^(-3)for hydrogen and carbon plasma respectively and the peak temperature is 3.02±0.5 eV. The mean propagation velocity of plasma is calculated using the transit times of plasma at different distances from the plasma gun and is found to be 4.54±0.25 cm/μs and 1.81±0.18 cm/μs for hydrogen and carbon plasma respectively. The Debye radius is obtained from the measured experimental data that satisfies the thin sheath approximation. The shot-to-shot stability of plasma parameters facilitates the use of plasma guns in laboratory experiments. These types of plasma sources can be used in many applications like plasma opening switches, plasma devices, and as plasma sources.展开更多
In astrophysics, the boundary conditions for plasma phenomena are provided by nature and the astronomer faces the problem of understanding them from a variety of observations [Hester J J et al 1996 Astrophys. J. 456 2...In astrophysics, the boundary conditions for plasma phenomena are provided by nature and the astronomer faces the problem of understanding them from a variety of observations [Hester J J et al 1996 Astrophys. J. 456 225], on the other hand, in laboratory plasma experiments the electromagnetic boundary conditions become a major problem in the set-up of the machine that produces the plasma, an issue that has to be investigated step by step and to be modified and adapted with great patience, in particular in the case of an innovative plasma confinement experiment. The PROTO-SPHERA machine [Alladio F et al 2006 Nucl. Fusion 46 S613] is a magnetic confinement experiment, that emulates in the laboratory the jet + torus plasma configurations often observed in astrophysics: an inner magnetized jet of plasma centered on the(approximate) axis of symmetry and surrounded by a magnetized plasma torus orthogonal to this jet. The PROTO-SPHERA plasma is simply connected, i.e., no metal current conducting rod is linked to the plasma torus, while instead it is the inner magnetized plasma jet(in the following always called the plasma centerpost) that is linked to the torus. It is mandatory that no spurious plasma current path modifies the optimal shape of the plasma centerpost. Moreover, as the plasma torus is produced and sustained, in absence of any applied inductive electric field, by the inner plasma centerpost through magnetic reconnections [Taylor J B and Turner M F 1989 Nucl.Fusion 29 219], it is required as well that spurious current paths do not surround the torus on its outboard, in order not to lower the efficiency of the magnetic reconnections that maintain the plasma torus at the expense of the plasma centerpost. Boundary conditions have been corrected,up to the point that the first sustainment in steady state has been achieved for the combined plasma.展开更多
During spacecraft re-entry,the challenge of measuring plasma sheath parameters directly contributes to difficulties in addressing communication blackout.In this work,we have discovered a phenomenon of multiple peaks i...During spacecraft re-entry,the challenge of measuring plasma sheath parameters directly contributes to difficulties in addressing communication blackout.In this work,we have discovered a phenomenon of multiple peaks in reflection data caused by the inhomogeneous plasma.Simulation results show that the multi-peak points fade away as the characteristic frequency is approached,resembling a series of gradually decreasing peaks.The positions and quantities of these points are positively correlated with electron density,yet they show no relation to collision frequency.This phenomenon is of significant reference value for future studies on the spatial distribution of plasmas,particularly for using microwave reflection signals in diagnosing the plasma sheath.展开更多
A two-dimensional fluid model based on COMSOL Multiphysics is developed to investigate the modulation of static magnetic field on plasma homogeneity in a capacitively coupled plasma(CCP)chamber. To generate a static m...A two-dimensional fluid model based on COMSOL Multiphysics is developed to investigate the modulation of static magnetic field on plasma homogeneity in a capacitively coupled plasma(CCP)chamber. To generate a static magnetic field, direct current is applied to a circular coil located at the top of the chamber. By adjusting the magnetic field's configuration, which is done by altering the coil current and position, both the plasma uniformity and density can be significantly modulated. In the absence of the magnetic field, the plasma density exhibits an inhomogeneous distribution characterized by higher values at the plasma edge and lower values at the center. The introduction of a magnetic field generated by coils results in a significant increase in electron density near the coils. Furthermore, an increase in the sets of coils improves the uniformity of the plasma. By flexibly adjusting the positions of the coils and the applied current,a substantial enhancement in overall uniformity can be achieved. These findings demonstrate the feasibility of using this method for achieving uniform plasma densities in industrial applications.展开更多
A three-fluid equilibrium plasma with bulk plasma and energetic electrons has been observed on the Xuanlong-50(EXL-50) spherical torus, where the energetic electrons play a crucial role in sustaining the plasma curren...A three-fluid equilibrium plasma with bulk plasma and energetic electrons has been observed on the Xuanlong-50(EXL-50) spherical torus, where the energetic electrons play a crucial role in sustaining the plasma current and pressure. In this study, the equilibrium of a multi-fluid plasma was investigated by analyzing the relationship between the external vertical magnetic field(B_(V)),plasma current(I_(p)), the poloidal ratio(β_(p)) and the Shafranov formula. Remarkably, our research demonstrates some validity of the Shafranov formula in the presence of multi-fluid plasma in EXL-50 spherical torus. This finding holds significant importance for future reactors as it allows for differentiation between alpha particles and background plasma. The study of multi-fluid plasma provides a significant reference value for the equilibrium reconstruction of burning plasma involving alpha particles.展开更多
Only a small amount of spectral information is collected because the collection solid angle of the optical fiber probe and lens is very limited when collecting spectral information.To overcome this limitation,this stu...Only a small amount of spectral information is collected because the collection solid angle of the optical fiber probe and lens is very limited when collecting spectral information.To overcome this limitation,this study presents a novel method for acquiring plasma spectral information from various spatial directions.A parabolic-shaped plasma spectral collection device(PSCD)is employed to effectively collect more spectral information into the spectrometer,thereby enhancing the overall spectral intensity.The research objects in this study were soil samples containing different concentrations of heavy metals Pb,Cr,and Cd.The results indicate that the PSCD significantly enhances the spectral signal,with an enhancement rate of up to 45%.Moreover,the signal-to-noise ratio also increases by as much as 36%.Simultaneously,when compared to the absence of a device,it is found that there is no significant variation in plasma temperature when the PSCD is utilized.This observation eliminates the impact of the spatial effect caused by the PSCD on the spectral intensity.Consequently,a concentrationspectral intensity relationship curve is established under the PSCD.The results revealed that the linear fitting R^(2)for Pb,Cr,and Cd increased by 0.011,0.001,and 0.054,respectively.Additionally,the limit of detection(LOD)decreased by 0.361 ppm,0.901 ppm,and 0.602 ppm,respectively.These findings indicate that the spectral enhancement rate elevates with the increase in heavy metal concentration.Hence,the PSCD can effectively enhance the spectral intensity and reduce the detection limit of heavy metals in soil.展开更多
This paper deals with wave propagation and power coupling in blue-core helicon plasma driven by various antennas and frequencies.It is found that compared to non-blue-core mode,for blue-core mode,the wave can propagat...This paper deals with wave propagation and power coupling in blue-core helicon plasma driven by various antennas and frequencies.It is found that compared to non-blue-core mode,for blue-core mode,the wave can propagate in the core region,and it decays sharply outside the core.The power absorption is lower and steeper in radius for blue-core mode.Regarding the effects of antenna geometry for blue-core mode,it shows that half helix antenna yields the strongest wave field and power absorption,while loop antenna yields the lowest.Moreover,near axis,for antennas with m=+1,the wave field increases with axial distance.In the core region,the wave number approaches to a saturation value at much lower frequency for non-blue-core mode compared to blue-core mode.The total loading resistance is much lower for blue-core mode.These findings are valuable to understanding the physics of blue-core helicon discharge and optimizing the experimental performance of blue-core helicon plasma sources for applications such as space propulsion and material treatment.展开更多
Enhancing plasma uniformity can be achieved by modifying coil and chamber structures in radio frequency inductively coupled plasma(ICP)to meet the demand for large-area and uniformly distributed plasma in industrial m...Enhancing plasma uniformity can be achieved by modifying coil and chamber structures in radio frequency inductively coupled plasma(ICP)to meet the demand for large-area and uniformly distributed plasma in industrial manufacturing.This study utilized a two-dimensional self-consistent fluid model to investigate how different coil configurations and chamber aspect ratios affect the radial uniformity of plasma in radio frequency ICP.The findings indicate that optimizing the radial spacing of the coil enhances plasma uniformity but with a reduction in electron density.Furthermore,optimizing the coil within the ICP reactor,using the interior point method in the Interior Point Optimizer significantly enhances plasma uniformity,elevating it from 56%to 96%within the range of the model sizes.Additionally,when the chamber aspect ratio k changes from 2.8 to 4.7,the plasma distribution changes from a center-high to a saddleshaped distribution.Moreover,the plasma uniformity becomes worse.Finally,adjusting process parameters,such as increasing source power and gas pressure,can enhance plasma uniformity.These findings contribute to optimizing the etching process by improving plasma radial uniformity.展开更多
The plasma density enhancement outside hollow electrodes in capacitively coupled radio-frequency(RF) discharges is investigated by a two-dimensional(2D) particle-in-cell/Monte-Carlo collision(PIC/MCC) model. Results s...The plasma density enhancement outside hollow electrodes in capacitively coupled radio-frequency(RF) discharges is investigated by a two-dimensional(2D) particle-in-cell/Monte-Carlo collision(PIC/MCC) model. Results show that plasma exists inside the cavity when the sheath inside the hollow electrode hole is fully collapsed, which is an essential condition for the plasma density enhancement outside hollow electrodes. In addition, the existence of the electron density peak at the orifice is generated via the hollow cathode effect(HCE), which plays an important role in the density enhancement. It is also found that the radial width of bulk plasma at the orifice affects the magnitude of the density enhancement, and narrow radial plasma bulk width at the orifice is not beneficial to obtain high-density plasma outside hollow electrodes.Higher electron density at the orifice, combined with larger radial plasma bulk width at the orifice,causes higher electron density outside hollow electrodes. The results also imply that the HCE strength inside the cavity cannot be determined by the magnitude of the electron density outside hollow electrodes.展开更多
Endometriosis(EMS)is one of the most common disorders among women of reproductive age and affects approximately 6%–10%of the world total population^([1]).Women with EMS often experience symptoms such as dysmenorrhea,...Endometriosis(EMS)is one of the most common disorders among women of reproductive age and affects approximately 6%–10%of the world total population^([1]).Women with EMS often experience symptoms such as dysmenorrhea,infertility,or difficulties in conceiving.Recent studies focusing on amino acids(AAs)metabolism have shed light on the mechanisms underlying the development and progression of EMS^([2]).展开更多
Particle-In-Cell(PIC)simulations were performed in this work to study the dynamics of the EUVinduced hydrogen plasma.The Monte-Carlo Collision(MCC)model was employed to deal with the collisions between charged particl...Particle-In-Cell(PIC)simulations were performed in this work to study the dynamics of the EUVinduced hydrogen plasma.The Monte-Carlo Collision(MCC)model was employed to deal with the collisions between charged particles and background gas molecules.The dynamic evolution of the plasma sheath,as well as the flux and energy distribution of ions impacting on the mirror surface,was discussed.It was found that the emission of secondary electrons under the EUV irradiation on the ruthenium mirror coating creates a positively charged wall and then prevents the ions from impacting on the mirror and therefore changes the flux and energy distribution of ions reaching the mirror.Furthermore,gas pressure has a notable effect on the plasma sheath and the characteristics of the ions impinging on the mirrors.With greater gas pressure,the sheath potential decreases more rapidly.The flux of ions received by the mirror grows approximately linearly and at the same time the energy corresponding to the peak flux decreases slightly.However,the EUV source intensity barely changes the sheath potential,and its influence on the ion impact is mainly limited to the approximate linear increase in ion flux.展开更多
Background:Androgenic alopecia(AGA)is the most common type of hair loss in men,and there are many studies on the treatment of hair loss by platelet-rich plasma(PRP).The human scalp contains a huge microbiome,but its r...Background:Androgenic alopecia(AGA)is the most common type of hair loss in men,and there are many studies on the treatment of hair loss by platelet-rich plasma(PRP).The human scalp contains a huge microbiome,but its role in the process of hair loss remains unclear,and the relationship between PRP and the microbiome needs further study.Therefore,the purpose of this study was to investigate the effect of PRP treatment on scalp microbiota composition.Methods:We performed PRP treatment on 14 patients with AGA,observed their clinical efficacy,and collected scalp swab samples before and after treatment.The scalp microflora of AGA patients before and after treatment was characterized by amplifying the V3-V4 region of the 16 s RNA gene and sequencing for bacterial identification.Results:The results showed that PRP was effective in the treatment of AGA patients,and the hair growth increased significantly.The results of relative abundance analysis of microbiota showed that after treatment,g_Cutibacterium increased and g_Staphylococcus decreased,which played a stable role in scalp microbiota.In addition,g_Lawsonella decreased,indicating that the scalp oil production decreased after treatment.Conclusions:The findings suggest that PRP may play a role in treating AGA through scalp microbiome rebalancing.展开更多
文摘目的:检测慢性心力衰竭(CHF)患者血清Ⅲ型前胶原氨基末端前肽(N-terminal peptide of typeⅢprocollagen,PⅢNP)、高迁移率族蛋白B1(high mobility group box-1,HMGB1)的表达水平,探讨二者与左室射血分数(LVEF)的相关性以及对CHF的诊断价值。方法:收集2021年12月至2022年11月期间于佳木斯大学附属第一医院心内科住院治疗的慢性心力衰竭患者90例为实验组,按照LVEF将其分为HFrEF组(n=33)、HFmrEF组(n=27)和HFpEF组(n=30)。此外选取排除心功能不全诊断的同期住院患者30例为对照组。对比各组患者血清中氨基末端脑钠肽前体(NT-proBNP)、PⅢNP、HMGB1水平的差异,分析PⅢNP、HMGB1水平与心功能指标的相关性,并借助ROC曲线评估NT-proBNP、HMGB1、PⅢNP单独以及联合应用对不同表型CHF患者的诊断价值。结果:HFrEF组PⅢNP、HMGB1及NT-proBNP水平均高于HFpEF组和对照组,差异有统计学意义(P<0.05)。PⅢNP与HMGB1呈正相关(P<0.05);PⅢNP、HMGB1均与NT-proBNP、LVEDD呈正相关,与LVEF呈明显负相关(P<0.05);HMGB1与LAD呈正相关(P<0.05),PⅢNP与LAD无明显相关性(P>0.05)。血清NT-proBNP、HMGB1、PⅢNP水平诊断HFrEF患者的AUC分别为0.867、0.871、0.779;诊断HFmrEF患者的AUC分别为0.840、0.804、0.760;诊断HFpEF患者的AUC分别为0.851、0.728、0.769。多生物标志物模型NT-proBNP+PⅢNP、NT-proBNP+HMGB1、NT-proBNP+PⅢNP+HMGB1诊断HFrEF患者的AUC分别为0.887、0.954、0.954;诊断HFmrEF患者的AUC分别为0.942、0.937、0.951;诊断HFpEF患者的AUC分别为0.904、0.910、0.914。结论:CHF患者血清PⅢNP、HMGB1明显升高,并且,CHF患者血清PⅢNP、HMGB1水平与心脏功能指标具有良好的相关性,说明PⅢNP、HMGB1可反映疾病的严重程度。PⅢNP、HMGB1对各表型CHF患者均具有诊断价值,并且,多生物标志物联合检测能提高对CHF患者诊断的敏感性。
基金supported by Bhabha Atomic Research Centre, Department of Atomic Energy, Government of IndiaDepartment of Atomic Energy, Government of India for financial assistance under DAE Doctoral Fellowship Scheme-2018。
文摘Coaxial plasma guns are a type of plasma source that produces plasma which propagates radially and axially controlled by the shape of the ground electrode, which has attracted much interest in several applications. In this work, a 120° opening angle of CPG nozzle is used as a plasma gun configuration that operates at the energy of 150 J. The ionization of polyethylene insulator between the electrodes of the gun produces a cloud of hydrogen and carbon plasma.The triple Langmuir probe and Faraday cup are used to measure plasma density and plasma temperature. These methods are used to measure the on-axis and off-axis plasma divergence of the coaxial plasma gun. The peak values of ion densities measured at a distance of 25 mm on-axis from the plasma gun are(1.6±0.5)×10^(19)m^(-3)and(2.8±0.6)×10^(19)m^(-3)for hydrogen and carbon plasma respectively and the peak temperature is 3.02±0.5 eV. The mean propagation velocity of plasma is calculated using the transit times of plasma at different distances from the plasma gun and is found to be 4.54±0.25 cm/μs and 1.81±0.18 cm/μs for hydrogen and carbon plasma respectively. The Debye radius is obtained from the measured experimental data that satisfies the thin sheath approximation. The shot-to-shot stability of plasma parameters facilitates the use of plasma guns in laboratory experiments. These types of plasma sources can be used in many applications like plasma opening switches, plasma devices, and as plasma sources.
文摘In astrophysics, the boundary conditions for plasma phenomena are provided by nature and the astronomer faces the problem of understanding them from a variety of observations [Hester J J et al 1996 Astrophys. J. 456 225], on the other hand, in laboratory plasma experiments the electromagnetic boundary conditions become a major problem in the set-up of the machine that produces the plasma, an issue that has to be investigated step by step and to be modified and adapted with great patience, in particular in the case of an innovative plasma confinement experiment. The PROTO-SPHERA machine [Alladio F et al 2006 Nucl. Fusion 46 S613] is a magnetic confinement experiment, that emulates in the laboratory the jet + torus plasma configurations often observed in astrophysics: an inner magnetized jet of plasma centered on the(approximate) axis of symmetry and surrounded by a magnetized plasma torus orthogonal to this jet. The PROTO-SPHERA plasma is simply connected, i.e., no metal current conducting rod is linked to the plasma torus, while instead it is the inner magnetized plasma jet(in the following always called the plasma centerpost) that is linked to the torus. It is mandatory that no spurious plasma current path modifies the optimal shape of the plasma centerpost. Moreover, as the plasma torus is produced and sustained, in absence of any applied inductive electric field, by the inner plasma centerpost through magnetic reconnections [Taylor J B and Turner M F 1989 Nucl.Fusion 29 219], it is required as well that spurious current paths do not surround the torus on its outboard, in order not to lower the efficiency of the magnetic reconnections that maintain the plasma torus at the expense of the plasma centerpost. Boundary conditions have been corrected,up to the point that the first sustainment in steady state has been achieved for the combined plasma.
文摘During spacecraft re-entry,the challenge of measuring plasma sheath parameters directly contributes to difficulties in addressing communication blackout.In this work,we have discovered a phenomenon of multiple peaks in reflection data caused by the inhomogeneous plasma.Simulation results show that the multi-peak points fade away as the characteristic frequency is approached,resembling a series of gradually decreasing peaks.The positions and quantities of these points are positively correlated with electron density,yet they show no relation to collision frequency.This phenomenon is of significant reference value for future studies on the spatial distribution of plasmas,particularly for using microwave reflection signals in diagnosing the plasma sheath.
基金financially supported by the National MCF Energy R&D Program of China(No.2022YFE03190100)National Natural Science Foundation of China(Nos.11935005,12105035 and U21A20438)+2 种基金the Guangdong Basic and Applied Basic Research Foundation(No.2021B1515120018)the Fundamental Research Funds for the Central Universities(No.DUT21TD104)the Advanced Space Propulsion Laboratory of BICE and Beijing Engineering Research Center of Efficient and Green Aerospace Propulsion Technology(No.Lab ASP-2020-01).
文摘A two-dimensional fluid model based on COMSOL Multiphysics is developed to investigate the modulation of static magnetic field on plasma homogeneity in a capacitively coupled plasma(CCP)chamber. To generate a static magnetic field, direct current is applied to a circular coil located at the top of the chamber. By adjusting the magnetic field's configuration, which is done by altering the coil current and position, both the plasma uniformity and density can be significantly modulated. In the absence of the magnetic field, the plasma density exhibits an inhomogeneous distribution characterized by higher values at the plasma edge and lower values at the center. The introduction of a magnetic field generated by coils results in a significant increase in electron density near the coils. Furthermore, an increase in the sets of coils improves the uniformity of the plasma. By flexibly adjusting the positions of the coils and the applied current,a substantial enhancement in overall uniformity can be achieved. These findings demonstrate the feasibility of using this method for achieving uniform plasma densities in industrial applications.
文摘A three-fluid equilibrium plasma with bulk plasma and energetic electrons has been observed on the Xuanlong-50(EXL-50) spherical torus, where the energetic electrons play a crucial role in sustaining the plasma current and pressure. In this study, the equilibrium of a multi-fluid plasma was investigated by analyzing the relationship between the external vertical magnetic field(B_(V)),plasma current(I_(p)), the poloidal ratio(β_(p)) and the Shafranov formula. Remarkably, our research demonstrates some validity of the Shafranov formula in the presence of multi-fluid plasma in EXL-50 spherical torus. This finding holds significant importance for future reactors as it allows for differentiation between alpha particles and background plasma. The study of multi-fluid plasma provides a significant reference value for the equilibrium reconstruction of burning plasma involving alpha particles.
基金supported by Department of Science and Technology of Jilin Province of China(Nos.YDZJ202301 ZYTS481,202202901032GX,and 20230402068GH)。
文摘Only a small amount of spectral information is collected because the collection solid angle of the optical fiber probe and lens is very limited when collecting spectral information.To overcome this limitation,this study presents a novel method for acquiring plasma spectral information from various spatial directions.A parabolic-shaped plasma spectral collection device(PSCD)is employed to effectively collect more spectral information into the spectrometer,thereby enhancing the overall spectral intensity.The research objects in this study were soil samples containing different concentrations of heavy metals Pb,Cr,and Cd.The results indicate that the PSCD significantly enhances the spectral signal,with an enhancement rate of up to 45%.Moreover,the signal-to-noise ratio also increases by as much as 36%.Simultaneously,when compared to the absence of a device,it is found that there is no significant variation in plasma temperature when the PSCD is utilized.This observation eliminates the impact of the spatial effect caused by the PSCD on the spectral intensity.Consequently,a concentrationspectral intensity relationship curve is established under the PSCD.The results revealed that the linear fitting R^(2)for Pb,Cr,and Cd increased by 0.011,0.001,and 0.054,respectively.Additionally,the limit of detection(LOD)decreased by 0.361 ppm,0.901 ppm,and 0.602 ppm,respectively.These findings indicate that the spectral enhancement rate elevates with the increase in heavy metal concentration.Hence,the PSCD can effectively enhance the spectral intensity and reduce the detection limit of heavy metals in soil.
基金Project supported by the National Natural Science Foundation of China(Grant No.92271113)the Fundamental Research Funds for the Central Universities(Grant No.2022CDJQY-003)+1 种基金Chongqing Entrepreneurship and Innovation Support Program for Overseas Returnees(Grant No.CX2022004)the Fund from Shanghai Engineering Research Center of Space Engine(Grant No.17DZ2280800).
文摘This paper deals with wave propagation and power coupling in blue-core helicon plasma driven by various antennas and frequencies.It is found that compared to non-blue-core mode,for blue-core mode,the wave can propagate in the core region,and it decays sharply outside the core.The power absorption is lower and steeper in radius for blue-core mode.Regarding the effects of antenna geometry for blue-core mode,it shows that half helix antenna yields the strongest wave field and power absorption,while loop antenna yields the lowest.Moreover,near axis,for antennas with m=+1,the wave field increases with axial distance.In the core region,the wave number approaches to a saturation value at much lower frequency for non-blue-core mode compared to blue-core mode.The total loading resistance is much lower for blue-core mode.These findings are valuable to understanding the physics of blue-core helicon discharge and optimizing the experimental performance of blue-core helicon plasma sources for applications such as space propulsion and material treatment.
基金supported by the Scientific Research Foundation of Xijing University,China(No.XJ19T03)the Opening Project of Science and Technology on Reliability Physics and Application Technology of Electronic Component Laboratory(No.ZHD201701)the Natural Science Basic Research Plan in Shaanxi Province of China(No.2024JC-YBMS-342).
文摘Enhancing plasma uniformity can be achieved by modifying coil and chamber structures in radio frequency inductively coupled plasma(ICP)to meet the demand for large-area and uniformly distributed plasma in industrial manufacturing.This study utilized a two-dimensional self-consistent fluid model to investigate how different coil configurations and chamber aspect ratios affect the radial uniformity of plasma in radio frequency ICP.The findings indicate that optimizing the radial spacing of the coil enhances plasma uniformity but with a reduction in electron density.Furthermore,optimizing the coil within the ICP reactor,using the interior point method in the Interior Point Optimizer significantly enhances plasma uniformity,elevating it from 56%to 96%within the range of the model sizes.Additionally,when the chamber aspect ratio k changes from 2.8 to 4.7,the plasma distribution changes from a center-high to a saddleshaped distribution.Moreover,the plasma uniformity becomes worse.Finally,adjusting process parameters,such as increasing source power and gas pressure,can enhance plasma uniformity.These findings contribute to optimizing the etching process by improving plasma radial uniformity.
文摘The plasma density enhancement outside hollow electrodes in capacitively coupled radio-frequency(RF) discharges is investigated by a two-dimensional(2D) particle-in-cell/Monte-Carlo collision(PIC/MCC) model. Results show that plasma exists inside the cavity when the sheath inside the hollow electrode hole is fully collapsed, which is an essential condition for the plasma density enhancement outside hollow electrodes. In addition, the existence of the electron density peak at the orifice is generated via the hollow cathode effect(HCE), which plays an important role in the density enhancement. It is also found that the radial width of bulk plasma at the orifice affects the magnitude of the density enhancement, and narrow radial plasma bulk width at the orifice is not beneficial to obtain high-density plasma outside hollow electrodes.Higher electron density at the orifice, combined with larger radial plasma bulk width at the orifice,causes higher electron density outside hollow electrodes. The results also imply that the HCE strength inside the cavity cannot be determined by the magnitude of the electron density outside hollow electrodes.
基金supported by the Key Collaborative Research Projects of the China Academy of Chinese Medicine Science[CI2022C003]The Escort Project of Guang’anmen Hospital,China Academy of Chinese Medicine Science-Backbone Talent Cultivation Project[9323065].
文摘Endometriosis(EMS)is one of the most common disorders among women of reproductive age and affects approximately 6%–10%of the world total population^([1]).Women with EMS often experience symptoms such as dysmenorrhea,infertility,or difficulties in conceiving.Recent studies focusing on amino acids(AAs)metabolism have shed light on the mechanisms underlying the development and progression of EMS^([2]).
基金supported by National Natural Science Foundation of China(Nos.12172356,U23B20110)the Interdisciplinary and Collaborative Teams of CAS。
文摘Particle-In-Cell(PIC)simulations were performed in this work to study the dynamics of the EUVinduced hydrogen plasma.The Monte-Carlo Collision(MCC)model was employed to deal with the collisions between charged particles and background gas molecules.The dynamic evolution of the plasma sheath,as well as the flux and energy distribution of ions impacting on the mirror surface,was discussed.It was found that the emission of secondary electrons under the EUV irradiation on the ruthenium mirror coating creates a positively charged wall and then prevents the ions from impacting on the mirror and therefore changes the flux and energy distribution of ions reaching the mirror.Furthermore,gas pressure has a notable effect on the plasma sheath and the characteristics of the ions impinging on the mirrors.With greater gas pressure,the sheath potential decreases more rapidly.The flux of ions received by the mirror grows approximately linearly and at the same time the energy corresponding to the peak flux decreases slightly.However,the EUV source intensity barely changes the sheath potential,and its influence on the ion impact is mainly limited to the approximate linear increase in ion flux.
基金supported by the Guangdong Enterprise Joint Fund(No.2022A1515220137)The Shenzhen Science and Technology Innovation Committee(No.JCYJ20220530141615035)the Internal project of Huazhong University of Science and Technology Union Shenzhen Hospital(Nos.YN2021042 and YN2021045)。
文摘Background:Androgenic alopecia(AGA)is the most common type of hair loss in men,and there are many studies on the treatment of hair loss by platelet-rich plasma(PRP).The human scalp contains a huge microbiome,but its role in the process of hair loss remains unclear,and the relationship between PRP and the microbiome needs further study.Therefore,the purpose of this study was to investigate the effect of PRP treatment on scalp microbiota composition.Methods:We performed PRP treatment on 14 patients with AGA,observed their clinical efficacy,and collected scalp swab samples before and after treatment.The scalp microflora of AGA patients before and after treatment was characterized by amplifying the V3-V4 region of the 16 s RNA gene and sequencing for bacterial identification.Results:The results showed that PRP was effective in the treatment of AGA patients,and the hair growth increased significantly.The results of relative abundance analysis of microbiota showed that after treatment,g_Cutibacterium increased and g_Staphylococcus decreased,which played a stable role in scalp microbiota.In addition,g_Lawsonella decreased,indicating that the scalp oil production decreased after treatment.Conclusions:The findings suggest that PRP may play a role in treating AGA through scalp microbiome rebalancing.
