We study the quantization of mesoscopic inductance coupling circuit and discuss its time evolution. Bymeans of the thermal field dynamics theory we study the quantum fluctuation of the system at finite temperature.
Elemental impurities(EIs)in drug products are a specific class of inorganic contaminants that may originate from various sources.These residual impurities provide no therapeutic benefit to patients and,in some cases,m...Elemental impurities(EIs)in drug products are a specific class of inorganic contaminants that may originate from various sources.These residual impurities provide no therapeutic benefit to patients and,in some cases,may even catalyze the degradation of drug substances.Therefore,their levels in drug products must be controlled within acceptable limits.The International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use(ICH)approved the harmonised Guideline for Elemental Impurities(ICH Q3D)on November 12,2014.On January 10,2020,the National Medical Products Administration(NMPA)announced the adoption of the ICH Q3D principles in China.Inductively coupled plasma mass spectrometry(ICP-MS)offers distinct advantages in detecting trace levels of EIs in drug products.Various validation criteria for the analytical procedure of ICP-MS are specified in the pharmacopoeias.This study compared differences in the validation criteria for ICP-MS,highlighting that the criteria adopted in the United States Pharmacopeia(USP)and European Pharmacopoeia(EP)were particularly specific and detailed,thereby facilitating analytical method development for drug quality control.The aim was to provide a useful reference for analysts conducting EI determination using ICP-MS.展开更多
Improving plasma uniformity is a critical issue in the development of large-area radio-frequency(RF)inductively coupled plasma(ICP)sources.In this work,the effects of coil structure and electromagnetic shielding on th...Improving plasma uniformity is a critical issue in the development of large-area radio-frequency(RF)inductively coupled plasma(ICP)sources.In this work,the effects of coil structure and electromagnetic shielding on the spatial distribution and uniformity of the plasma are systematically investigated using a three-dimensional fluid model.The model integrates plasma and electromagnetic field modules to simulate the discharge characteristics of a large-area RF ICP source with dimensions of 100 cm×50 cm.The results reveal that the electron density distribution varies significantly with the coil structure.For the rotating and translating coil structures,the electron density is high at off-axis positions and low at the center.In contrast,the mirror coil structure exhibits a significantly higher electron density at the chamber center,resulting in a high-center and low-edge density distribution.Among the three configurations,the rotating coil structure provides the best plasma uniformity.The incorporation of electromagnetic shielding further improves plasma uniformity,particularly for the mirror coil structure.For the rotating and translating coil structures,the electron density exhibits a saddle-shaped distribution regardless of electromagnetic shielding.However,introducing electromagnetic shielding into the mirror coil structure reduces the electron density at the chamber center and decreases the non-uniformity degree by 18.4%.Overall,the mirror coil structure with electromagnetic shielding achieves the highest uniformity,with an exceptional plasma uniformity of 94%.This work offers valuable insights for the design of large-area ICP sources in advanced plasma processing systems.展开更多
[Objectives]To determine the content of Zhuang medicine Sauropus spatulifolius Beille from Guangxi.[Methods]The amino acid content of S.spatulifolius Beille was determined by ultraviolet spectrophotometry(UVs).The con...[Objectives]To determine the content of Zhuang medicine Sauropus spatulifolius Beille from Guangxi.[Methods]The amino acid content of S.spatulifolius Beille was determined by ultraviolet spectrophotometry(UVs).The content of kaempferol-3-O-gentiobioside in S.spatulifolius Beille was determined by liquid chromatography-mass spectrometry(LC-MS).Pesticide residues in S.spatulifolius Beille were detected by gas chromatography-mass spectrometry(GC-MS).Heavy metal elements arsenic(As),cadmium(Cd),and lead(Pb)in S.spatulifolius Beille were detected by inductively coupled plasma mass spectrometry(ICP-MS).[Results]The amino acid content in S.spatulifolius Beille was 3.233 mg/g,with a relative standard deviation(RSD)of 0.36%.The content of kaempferol-3-O-gentiobioside was 1.15μg/mL.No pesticide residues or heavy metals were detected in the S.spatulifolius Beille medicinal material.[Conclusions]This study improves the quality control system for S.spatulifolius Beille and provides a reference basis for the quality standard control of Zhuang medicine S.spatulifolius Beille from Guangxi.展开更多
A transient multi-physics model incorporated with an electromagneto-thermomechanical coupling is developed to capture the multi-field behavior of a single-pancake(SP)insert no-insulation(NI)coil in a hybrid magnet dur...A transient multi-physics model incorporated with an electromagneto-thermomechanical coupling is developed to capture the multi-field behavior of a single-pancake(SP)insert no-insulation(NI)coil in a hybrid magnet during the charging and discharging processes.The coupled problem is resolved by means of the finite element method(FEM)for the magneto-thermo-elastic behaviors and the Runge-Kutta method for the transient responses of the electrical circuits of the hybrid superconducting magnet system.The results reveal that the transient multi-physics responses of the insert NI coil primarily depend on the charging/discharging procedure of the hybrid magnet.Moreover,a reverse azimuthal current and a compressive hoop stress are induced in the insert NI coil during the charging process,while a forward azimuthal current and a tensile hoop stress are observed during the discharging process.The induced voltages in the insert NI coil can drive the currents flowing across the radial turns where the contact resistance exists.Therefore,it brings forth significant Joule heat,causing a temperature rise and a uniform distribution of this heat in the coil turns.Accordingly,a thermally/mechanically unstable or quenching event may be encountered when a high operating current is flowing in the insert NI coil.It is numerically predicted that a quick charging will induce a compressive hoop stress which may bring a risk of buckling instability in the coil,while a discharging will not.The simulations provide an insight of hybrid superconducting magnets under transient start-up or shutdown phases which are inevitably encountered in practical applications.展开更多
Study on increasing the roughness of the polymer substrate surface to enhance the adhesion with the copper layer in an inductively coupling plasma （ICP） process was carried out. The microstructure of the polymer sub...Study on increasing the roughness of the polymer substrate surface to enhance the adhesion with the copper layer in an inductively coupling plasma （ICP） process was carried out. The microstructure of the polymer substrate surfaces, which were exposed to different kinds of plasma treatment, was identified by scanning electron microscopy（SEM） analysis, peel strength of the copper coating and water surface contact angle. The adhesion of the substrate was largely enhanced by plasma treatment and the copper deposited coating reached a value of 7.68 kgf/m in verifying the adhesion of the copper coating with polymer material. The quality of the line/space 50/50 μm produced in the laboratory was examined by the pressure cooker test and proved to meet the requirement.展开更多
Inductive coupling transmission system is an important measurement device for acquiring and transmitting marine environmental information.However,low transmission rate cannot meet the current demand for large data tra...Inductive coupling transmission system is an important measurement device for acquiring and transmitting marine environmental information.However,low transmission rate cannot meet the current demand for large data transmission in marine environment detection at home.In order to improve the transmission performance of the system in practical communication system,optimizing the design by directly changing the circuit parameters is time-consuming and expensive.Therefore,a set of inductive coupling transmission channel analysis system is designed based on virtual instrument to improve the transmission rate and reliability of inductive coupling transmission system.The bit error rate of channel system at different frequency and noise levels are tested by using three kinds of digital modulation mode including amplitude shift keying(ASK),frequency shift keying(FSK)and differential phase shift keying(DPSK),taking square wave and sine wave as a carrier.Finally,the sine wave is selected to be carrier signal and DPSK is chosen to be modulation mode.The reliable transmission of signal with the error rate less than0.005and the transmission rate of9600bps,at the noise level of-10dB,is realized and verified by the debugging circuit experiments with multi-nodes in the laboratory.The study provides an important experimental evidence for improving signal transmission reliability of inductive coupling transmission system.展开更多
In this study,a mathematical model of multipath channels is established,and the delay parameters of 10-path models are calculated at 300 m.A multipath-channel hardware simulator based on a field programmable gate arra...In this study,a mathematical model of multipath channels is established,and the delay parameters of 10-path models are calculated at 300 m.A multipath-channel hardware simulator based on a field programmable gate array(FPGA)is designed and verified at 100 k Hz,200 k Hz,500 k Hz,1 MHz,and 24 MHz transmission frequencies.According to the characteristics of the ocean induction coupling chain channel,the orthogonal frequency-division multiplexing(OFDM)algorithm parameters are designed by referring to the wireless communication protocol.The appropriate length cyclic prefix(CP)is added in the OFDM symbol to resist the multipath effect of the seawater channel,and the FPGA hardware transceiver based on the OFDM algorithm is realized.The hardware platform of the ocean induction coupling chain communication system is developed to resist the multipath effect of the seawater channel and tested at 24 MHz.The experimental results show that 800 ns is the best CP length for the developed system,which can effectively resist the multipath effect,with a signal-to-noise ratio above 24 d B and a bit error rate below 1%.This study provides a hardware simulation test platform and an effective method to resist the multipath effect of a seawater channel and improve the transmission performance of the seawater channel.展开更多
This work is devoted to study the behaviour of an inductively coupled plasma torch using argon,hydrogen and oxygen at atmospheric pressure.Thermal plasmas are generally used to form highly reactive species and to tran...This work is devoted to study the behaviour of an inductively coupled plasma torch using argon,hydrogen and oxygen at atmospheric pressure.Thermal plasmas are generally used to form highly reactive species and to transfer enthalpy.Precise characterisation of the plasma behaviour is thus relevant to evaluate chemical and thermal effects of the plasma.For equivalent configurations in terms of torch geometry and gas flows,a transition between two different coupling modes is identified affecting atomic species distribution and energy transmitted to a copper target.These two modes are affected by total electrical power input and oxygen and hydrogen flow rates,showing up hysteresis behaviour. Electrical current and frequency progress are analysed to highlight the transition between the two coupling modes. Optical spectroscopy is used to measure temperature profiles and radial atomic oxygen concentration profiles for different coupling modes.We observe that-depending on the coupling mode-temperature profile,atomic species distribution as well as the power transmission to a copper target are affected.展开更多
The harmonics and resonance of traction power supply systems(TPSSs)aggravate the electromagnetic interference(EMI)to adjacent metallic pipelines(MPs),which has aroused widespread concern.In this paper,an evaluation me...The harmonics and resonance of traction power supply systems(TPSSs)aggravate the electromagnetic interference(EMI)to adjacent metallic pipelines(MPs),which has aroused widespread concern.In this paper,an evaluation method on pipeline interference voltage under harmonic induction is presented.The results show that the Carson integral formula is more accurate in calculating the mutual impedance at higher frequencies.Then,an integrated train-network-pipeline model is established to estimate the influences of harmonic distortion and resonance on an MP.It is revealed that the higher the harmonic cur-rent distortion rate of the traction load,the larger the interference voltage on an MP.Particularly,the interference voltage is amplified up to 7 times when the TPSS resonates,which is worthy of attention.In addition,the parameters that affect the variation and sensitivity of the interference voltage are studied,namely,the pipeline coating material,locomotive position,and soil resistivity,indicating that soil resistivity and 3PE(3-layer polyethylene)anticorrosive coating are more sensitive to harmonic induction.Field test results show that the harmonic distortion can make the interference voltage more serious,and the protective measures are optimized.展开更多
We take the established inductively coupled plasma(ICP) wind tunnel as a research object to investigate the thermal protection system of re-entry vehicles. A 1.2-MW high power ICP wind tunnel is studied through numeri...We take the established inductively coupled plasma(ICP) wind tunnel as a research object to investigate the thermal protection system of re-entry vehicles. A 1.2-MW high power ICP wind tunnel is studied through numerical simulation and experimental validation. The distribution characteristics and interaction mechanism of the flow field and electromagnetic field of the ICP wind tunnel are investigated using the multi-field coupling method of flow, electromagnetic, chemical, and thermodynamic field. The accuracy of the numerical simulation is validated by comparing the experimental results with the simulation results. Thereafter, the wind tunnel pressure, air velocity, electron density, Joule heating rate, Lorentz force, and electric field intensity obtained using the simulation are analyzed and discussed. The results indicate that for the 1.2-MW ICP wind tunnel, the maximum values of temperature, pressure, electron number density, and other parameters are observed during coil heating. The influence of the radial Lorentz force on the momentum transfer is stronger than that of the axial Lorentz force. The electron number density at the central axis and the amplitude and position of the Joule heating rate are affected by the radial Lorentz force. Moreover, the plasma in the wind tunnel is constantly in the subsonic flow state, and a strong eddy flow is easily generated at the inlet of the wind tunnel.展开更多
Arsenic speciation in freshwater fish is crucial for providing meaningful consumption guidelines that allow the public to make informed decisions regarding its consumption.While marine fish have attractedmuch research...Arsenic speciation in freshwater fish is crucial for providing meaningful consumption guidelines that allow the public to make informed decisions regarding its consumption.While marine fish have attractedmuch research interest due to their higher arsenic content,research on freshwater fish is limited due to the challenges in quantifying and identifying arsenic species present at trace levels.We describe here a sensitivemethod and its application to the quantification of arsenic species in freshwater fish.Arsenic species from fish tissues were extracted using a methanol/water mixture(1:1 vol.ratio)and ultrasound sonication.Anion-exchange high-performance liquid chromatography(HPLC)enabled separation of arsenobetaine(AsB),inorganic arsenite(iAs^(Ⅲ)),dimethylarsinic acid(DMA),monomethylarsonic acid(MMA),inorganic arsenate(iAs^(Ⅴ)),and three new arsenic species.Inductively coupled plasma mass spectrometry(ICPMS)provided highly sensitive and specific detection of arsenic.A limit of detection of 0.25μg/kg(wet weight fish tissue)was achieved for the five target arsenic species:AsB,iAs^(Ⅲ),DMA,MMA,and iAs^(Ⅴ).A series of experimentswere conducted to ensure the accuracy and validity of the analytical method.The method was successfully applied to the determination of arsenic species in lakewhitefish,northern pike,and walleye,with AsB,DMA,and iAs^(Ⅴ) being frequently detected.Three new arsenic species were detected,but their chromatographic retention times did not match with those of any available arsenic standards.Future research is necessary to elucidate the identity of these new arsenic species detected in freshwater fish.展开更多
Recently,it has been observed that during the operation of an inductively coupled plasma(ICP),a luminescent target(BAM,BaMgAl10O17:Eu)can interact with the plasma beam and emit blue light.After excluding the influence...Recently,it has been observed that during the operation of an inductively coupled plasma(ICP),a luminescent target(BAM,BaMgAl10O17:Eu)can interact with the plasma beam and emit blue light.After excluding the influence of ultraviolet(UV)and electromagnetic wave radiation,the results indicate that the BAM target may undergo luminescent excitation due to collisions with electrons and ions.This led us to investigate the physical mechanism behind this plasma luminescence excitation phenomenon.A spectrometer was used to record the luminescent spectroscopy and peak light intensity.Under excitation by argon plasma,the BAM material emits a continuum spectrum from 400 nm to 550 nm,with the peak light intensity located at 462.58 nm,which is the same as the spectrum excited by UV torchlight.To identify the relationship between the plasma parameters and the luminescent intensity,Langmuir and Faraday probes were employed to determine the local plasma parameters such as electron density,electron temperature,and current density.After normalizing the peak light intensity to the plasma parameters,the most interesting point is that the current density is linearly correlated with the luminescent light intensity.To verify the repeatability and lifetime of the plasma-luminescence interaction,a 600 s lifetime test was conducted in a 200 W ICP discharge environment.The maximum difference for the peak light strength of the luminescent spectrum is 6.5%.From a voltage bias experiment and a theoretical derivation,we initially identified that bombardment by ions plays the dominant role in the luminescence excitation process,which also explains the mechanism by which the current density is proportional to the luminescence intensity.This new finding leads us to reconsider the possibility of applying this plasma luminescence phenomenon to optical plasma diagnostics.The BAM light intensity can potentially be used to predict the current density of a plasma beam for large-area two-dimensional(2D)measurements and can capture high spatial resolution in a single test.We believe that this method may lead to high-efficiency,spatially resolved plasma current density measurement.展开更多
This study investigates inductively coupled transmission technology using seawater and underwater anchor chains as the transmission medium for real-time data transfer from underwater measurement instruments.Because of...This study investigates inductively coupled transmission technology using seawater and underwater anchor chains as the transmission medium for real-time data transfer from underwater measurement instruments.Because of the physical properties of seawater,challenges,such as frequency selective fading and multipath effect,limit long-distance current signal transmission.Conventional modulation techniques,such as amplitude shift keying(ASK)and differential phase shift keying(DPSK),are constrained by low bandwidth utilization and high bit error rates(BER).To address these issues,we optimize the seawater channel model using data from the National Oceanographic Data Center and previous measurements,analyzing the relationship between seawater conductivity,depth,and signal frequency.We constructed an experimental platform using a six-winding manganese-zinc ferrite ring based on an inductive coupling model for data transmission.A steel cable is anchored at both ends of a seawater bucket through two rings,exposing the cable core to establish a closed loop in seawater.An orthogonal frequency division multiplexing(OFDM)algorithm is used to improve transmission performance by distributing data across multiple subcarriers,effectively mitigating multipath fading and frequency selective fading.Compared with ASK and DPSK,this method significantly reduces the BER and improves the channel capacity,exhibiting robustness in underwater communication.Finally,in our study,a mathematical model of the underwater multipath channel for distances of 300,1000,and 2000 m is established,showing an improvement in channel capacity of approximately 2.5 bps/Hz based on the OFDM algorithm.This advancement is essential for enhancing the performance of underwater signal transmission and supporting its practical application.展开更多
This work continues the studies on searching for plasma media with the inverse electron energy distribution function(EEDF)and providing recommendations for setting up subsequent experiments.The inverse EEDF is a distr...This work continues the studies on searching for plasma media with the inverse electron energy distribution function(EEDF)and providing recommendations for setting up subsequent experiments.The inverse EEDF is a distribution function that increases with an increase in energy at zero electron energy.The inverse EEDF plays a central role in the problem of negative conductivity.Based on the previously obtained criterion for the formation of an inverse EEDF in a spatially inhomogeneous plasma,a heuristic method is proposed that allows one to avoid resource-intensive calculations for spatially two-dimensional(2D)kinetic modeling on a large array of different glow discharges.It is shown that the conditions for EEDF inversion can be realized in two-chamber discharge structures due to violating the known Boltzmann distribution for electron density.The theoretical conclusions are validated by numerical modeling of lowpressure two-chamber inductively-coupled plasma(ICP)discharges in the COMSOL Multiphysics environment.As a result,areas of conditions with inverse EEDF were found for subsequent detailed kinetic analysis and experimental studies.展开更多
Developing a rapid and precise method for trace element analysis in geothermal water is crucial due to its high total dissolved solids and salinity,which can impact element determination.In this study,we optimized the...Developing a rapid and precise method for trace element analysis in geothermal water is crucial due to its high total dissolved solids and salinity,which can impact element determination.In this study,we optimized the determination of ferrum,manganese,strontium and barium in geothermal water samples collected from different regions.A matrix matching method was established for accurate quantification using Inductively Coupled Plasma Optical Emission Spectroscopy(ICP-OES).Instrumental conditions and experimental parameters were optimized,and the influence of storage medium and storage duration on measurement accuracy were evaluated.The results demonstrated that storing geothermal water samples in 1%nitric acid had no significant impact on measurement results over an eight-week period.Calibration curve correlation coefficients exceeded 0.9998 for all target elements.The detection limits of this method ranged from 0.0002 mg/L to 0.0031 mg/L,with Relative Standard Deviations(RSD)were 0.07%–2.33%,and spike recovery rates were from 96.8%to 103.2%.The obtained data were consistent with results from the standard addition method and dilution method,demonstrating the reliability of this approach.This method offers low detection limits,high precision and excellent recovery rate,providing a robust reference for the accurate determination of ferrum,manganese,strontium and barium in geothermal water,thereby laying a solid foundation for the development and utilization of geothermal resources.展开更多
RLC model is used to estimate the coupling noise between interconnect wires and make some analysis through the simulation result. Based on the analysis conclusion,some algorithms are developed to adjust the rou ting ...RLC model is used to estimate the coupling noise between interconnect wires and make some analysis through the simulation result. Based on the analysis conclusion,some algorithms are developed to adjust the rou ting result with crosstalk constraint.展开更多
[ Objective] To study the effects of different pretreatment methods on determination of microelement in feed and thus find the best pre treatment method for each microetement, t Method] The samples （concentrated feed...[ Objective] To study the effects of different pretreatment methods on determination of microelement in feed and thus find the best pre treatment method for each microetement, t Method] The samples （concentrated feeding stuff and fodder） were pretreated through throe methods, that is, dry incineration method, HNOs HCIO, wetdecomposition method and microwave digestion method. Then the content of seven kinds of mi croelement （AI, Ca, Cu, Fe, Mn, Se and Zn） was determined by inductively coupled plasma atomic emission spectrometer （ICPAES）. I Result] These three methods were all suitable for the determination of Cu, Mn and Zn in concentrated feeding stuff and the determination of Cu and Ca in fodder. The content of Cu and Ca was higher in fodder detected by HNO3 HCIO, wetdecomposition method. The microwave digestion method was suitable for the determination of AI and Ca in concentrated feeding stuff and the determination of AI, Fe, Mn and Zn in fodder. The dry incinera tion method was fit for the determination of Fe in concentrated feeding stuff. [ Condusionl The content of different microelements should be deter mined after the feed is treated with different Ioretreatment methods.展开更多
A high performance AlAs/In0.53 Ga0.47 As/InAs resonant tunneling diode （RTD） on InP substrate is fabricated by inductively coupled plasma etching. This RTD has a peak-to-valley current ratio （PVCR） of 7. 57 and a ...A high performance AlAs/In0.53 Ga0.47 As/InAs resonant tunneling diode （RTD） on InP substrate is fabricated by inductively coupled plasma etching. This RTD has a peak-to-valley current ratio （PVCR） of 7. 57 and a peak current density Jp = 39.08kA/cm^2 under forward bias at room temperature. Under reverse bias, the corresponding values are 7.93 and 34.56kA/cm^2 . A resistive cutoff frequency of 18.75GHz is obtained with the effect of a parasitic probe pad and wire. The slightly asymmetrical current-voltage characteristics with a nominally symmetrical structure are also discussed.展开更多
Large scale homogenous growth of microcrystalline silicon （μ.c-Si：H） on cheap substrates by inductively coupled plasma （ICP） of Ar diluted Sill4 has been studied. From XRD and Raman spectrum, we find that substr...Large scale homogenous growth of microcrystalline silicon （μ.c-Si：H） on cheap substrates by inductively coupled plasma （ICP） of Ar diluted Sill4 has been studied. From XRD and Raman spectrum, we find that substrates can greatly affect the crystalline orientation, and the μc-Si：H films are comprised of small particles. Thickness detection by surface profilometry shows that the thin μc-Si：H films are homogenous in large scale. Distributions of both ion density and electron temperature are found to be uniform in the vicinity of substrate by means of diagnosis of Langmuir probe. Based on these experimental results, it can be proposed that rough surfaces play important roles in the crystalline network formation and Ar can affect the reaction process and improve the characteristics of μc-Si：H films. Also, ICP reactor can deposit the thin film in large scale.展开更多
文摘We study the quantization of mesoscopic inductance coupling circuit and discuss its time evolution. Bymeans of the thermal field dynamics theory we study the quantum fluctuation of the system at finite temperature.
基金Subject construction funding project of Institute for Chemical Drug Control(Grant No.2024HYZX42)in National Institutes for Food and Drug Control,Beijing,China。
文摘Elemental impurities(EIs)in drug products are a specific class of inorganic contaminants that may originate from various sources.These residual impurities provide no therapeutic benefit to patients and,in some cases,may even catalyze the degradation of drug substances.Therefore,their levels in drug products must be controlled within acceptable limits.The International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use(ICH)approved the harmonised Guideline for Elemental Impurities(ICH Q3D)on November 12,2014.On January 10,2020,the National Medical Products Administration(NMPA)announced the adoption of the ICH Q3D principles in China.Inductively coupled plasma mass spectrometry(ICP-MS)offers distinct advantages in detecting trace levels of EIs in drug products.Various validation criteria for the analytical procedure of ICP-MS are specified in the pharmacopoeias.This study compared differences in the validation criteria for ICP-MS,highlighting that the criteria adopted in the United States Pharmacopeia(USP)and European Pharmacopoeia(EP)were particularly specific and detailed,thereby facilitating analytical method development for drug quality control.The aim was to provide a useful reference for analysts conducting EI determination using ICP-MS.
基金supported by the National Natural Science Foundation of China(Grant Nos.12075049 and 11935005)。
文摘Improving plasma uniformity is a critical issue in the development of large-area radio-frequency(RF)inductively coupled plasma(ICP)sources.In this work,the effects of coil structure and electromagnetic shielding on the spatial distribution and uniformity of the plasma are systematically investigated using a three-dimensional fluid model.The model integrates plasma and electromagnetic field modules to simulate the discharge characteristics of a large-area RF ICP source with dimensions of 100 cm×50 cm.The results reveal that the electron density distribution varies significantly with the coil structure.For the rotating and translating coil structures,the electron density is high at off-axis positions and low at the center.In contrast,the mirror coil structure exhibits a significantly higher electron density at the chamber center,resulting in a high-center and low-edge density distribution.Among the three configurations,the rotating coil structure provides the best plasma uniformity.The incorporation of electromagnetic shielding further improves plasma uniformity,particularly for the mirror coil structure.For the rotating and translating coil structures,the electron density exhibits a saddle-shaped distribution regardless of electromagnetic shielding.However,introducing electromagnetic shielding into the mirror coil structure reduces the electron density at the chamber center and decreases the non-uniformity degree by 18.4%.Overall,the mirror coil structure with electromagnetic shielding achieves the highest uniformity,with an exceptional plasma uniformity of 94%.This work offers valuable insights for the design of large-area ICP sources in advanced plasma processing systems.
基金Supported by Guangxi Key Research and Development Program Project(GuiKe AB18221095)Open Fund Project of Guangxi Key Laboratory of Research on Ethnic Medicinal Plants in the Youjiang River Basin(yykf2024-01)+1 种基金High-level Talent Research Project of Youjiang Medical University for Nationalities(1002018079)2023 National-level College Student Innovation and Entrepreneurship Training Program Project(202310599008).
文摘[Objectives]To determine the content of Zhuang medicine Sauropus spatulifolius Beille from Guangxi.[Methods]The amino acid content of S.spatulifolius Beille was determined by ultraviolet spectrophotometry(UVs).The content of kaempferol-3-O-gentiobioside in S.spatulifolius Beille was determined by liquid chromatography-mass spectrometry(LC-MS).Pesticide residues in S.spatulifolius Beille were detected by gas chromatography-mass spectrometry(GC-MS).Heavy metal elements arsenic(As),cadmium(Cd),and lead(Pb)in S.spatulifolius Beille were detected by inductively coupled plasma mass spectrometry(ICP-MS).[Results]The amino acid content in S.spatulifolius Beille was 3.233 mg/g,with a relative standard deviation(RSD)of 0.36%.The content of kaempferol-3-O-gentiobioside was 1.15μg/mL.No pesticide residues or heavy metals were detected in the S.spatulifolius Beille medicinal material.[Conclusions]This study improves the quality control system for S.spatulifolius Beille and provides a reference basis for the quality standard control of Zhuang medicine S.spatulifolius Beille from Guangxi.
基金the National Natural Science Foundation of China(Nos.11932008 and 11672120)the Fundamental Research Funds for the Central Universities of China(No.lzujbky-2022-kb01)。
文摘A transient multi-physics model incorporated with an electromagneto-thermomechanical coupling is developed to capture the multi-field behavior of a single-pancake(SP)insert no-insulation(NI)coil in a hybrid magnet during the charging and discharging processes.The coupled problem is resolved by means of the finite element method(FEM)for the magneto-thermo-elastic behaviors and the Runge-Kutta method for the transient responses of the electrical circuits of the hybrid superconducting magnet system.The results reveal that the transient multi-physics responses of the insert NI coil primarily depend on the charging/discharging procedure of the hybrid magnet.Moreover,a reverse azimuthal current and a compressive hoop stress are induced in the insert NI coil during the charging process,while a forward azimuthal current and a tensile hoop stress are observed during the discharging process.The induced voltages in the insert NI coil can drive the currents flowing across the radial turns where the contact resistance exists.Therefore,it brings forth significant Joule heat,causing a temperature rise and a uniform distribution of this heat in the coil turns.Accordingly,a thermally/mechanically unstable or quenching event may be encountered when a high operating current is flowing in the insert NI coil.It is numerically predicted that a quick charging will induce a compressive hoop stress which may bring a risk of buckling instability in the coil,while a discharging will not.The simulations provide an insight of hybrid superconducting magnets under transient start-up or shutdown phases which are inevitably encountered in practical applications.
文摘Study on increasing the roughness of the polymer substrate surface to enhance the adhesion with the copper layer in an inductively coupling plasma （ICP） process was carried out. The microstructure of the polymer substrate surfaces, which were exposed to different kinds of plasma treatment, was identified by scanning electron microscopy（SEM） analysis, peel strength of the copper coating and water surface contact angle. The adhesion of the substrate was largely enhanced by plasma treatment and the copper deposited coating reached a value of 7.68 kgf/m in verifying the adhesion of the copper coating with polymer material. The quality of the line/space 50/50 μm produced in the laboratory was examined by the pressure cooker test and proved to meet the requirement.
基金National Natural Science Foundation of China(No.41506122)
文摘Inductive coupling transmission system is an important measurement device for acquiring and transmitting marine environmental information.However,low transmission rate cannot meet the current demand for large data transmission in marine environment detection at home.In order to improve the transmission performance of the system in practical communication system,optimizing the design by directly changing the circuit parameters is time-consuming and expensive.Therefore,a set of inductive coupling transmission channel analysis system is designed based on virtual instrument to improve the transmission rate and reliability of inductive coupling transmission system.The bit error rate of channel system at different frequency and noise levels are tested by using three kinds of digital modulation mode including amplitude shift keying(ASK),frequency shift keying(FSK)and differential phase shift keying(DPSK),taking square wave and sine wave as a carrier.Finally,the sine wave is selected to be carrier signal and DPSK is chosen to be modulation mode.The reliable transmission of signal with the error rate less than0.005and the transmission rate of9600bps,at the noise level of-10dB,is realized and verified by the debugging circuit experiments with multi-nodes in the laboratory.The study provides an important experimental evidence for improving signal transmission reliability of inductive coupling transmission system.
基金supported by the National Key Research and Development Program of China(Nos.2017YFC1403403,2017YFC1403304)。
文摘In this study,a mathematical model of multipath channels is established,and the delay parameters of 10-path models are calculated at 300 m.A multipath-channel hardware simulator based on a field programmable gate array(FPGA)is designed and verified at 100 k Hz,200 k Hz,500 k Hz,1 MHz,and 24 MHz transmission frequencies.According to the characteristics of the ocean induction coupling chain channel,the orthogonal frequency-division multiplexing(OFDM)algorithm parameters are designed by referring to the wireless communication protocol.The appropriate length cyclic prefix(CP)is added in the OFDM symbol to resist the multipath effect of the seawater channel,and the FPGA hardware transceiver based on the OFDM algorithm is realized.The hardware platform of the ocean induction coupling chain communication system is developed to resist the multipath effect of the seawater channel and tested at 24 MHz.The experimental results show that 800 ns is the best CP length for the developed system,which can effectively resist the multipath effect,with a signal-to-noise ratio above 24 d B and a bit error rate below 1%.This study provides a hardware simulation test platform and an effective method to resist the multipath effect of a seawater channel and improve the transmission performance of the seawater channel.
文摘This work is devoted to study the behaviour of an inductively coupled plasma torch using argon,hydrogen and oxygen at atmospheric pressure.Thermal plasmas are generally used to form highly reactive species and to transfer enthalpy.Precise characterisation of the plasma behaviour is thus relevant to evaluate chemical and thermal effects of the plasma.For equivalent configurations in terms of torch geometry and gas flows,a transition between two different coupling modes is identified affecting atomic species distribution and energy transmitted to a copper target.These two modes are affected by total electrical power input and oxygen and hydrogen flow rates,showing up hysteresis behaviour. Electrical current and frequency progress are analysed to highlight the transition between the two coupling modes. Optical spectroscopy is used to measure temperature profiles and radial atomic oxygen concentration profiles for different coupling modes.We observe that-depending on the coupling mode-temperature profile,atomic species distribution as well as the power transmission to a copper target are affected.
基金This work was supported by the National Natural Science Foundation of China(No.51877182).
文摘The harmonics and resonance of traction power supply systems(TPSSs)aggravate the electromagnetic interference(EMI)to adjacent metallic pipelines(MPs),which has aroused widespread concern.In this paper,an evaluation method on pipeline interference voltage under harmonic induction is presented.The results show that the Carson integral formula is more accurate in calculating the mutual impedance at higher frequencies.Then,an integrated train-network-pipeline model is established to estimate the influences of harmonic distortion and resonance on an MP.It is revealed that the higher the harmonic cur-rent distortion rate of the traction load,the larger the interference voltage on an MP.Particularly,the interference voltage is amplified up to 7 times when the TPSS resonates,which is worthy of attention.In addition,the parameters that affect the variation and sensitivity of the interference voltage are studied,namely,the pipeline coating material,locomotive position,and soil resistivity,indicating that soil resistivity and 3PE(3-layer polyethylene)anticorrosive coating are more sensitive to harmonic induction.Field test results show that the harmonic distortion can make the interference voltage more serious,and the protective measures are optimized.
基金supported by the National Natural Science Foundation of China (Grant No. 11705143)the Open Foundation for Key Laboratories of National Defense Science and Technology of China (Grant No. 6142202031901)the Foundation for Research and Development of Applied Technology in Beilin District of Xi’an,China (Grant No. GX2047)。
文摘We take the established inductively coupled plasma(ICP) wind tunnel as a research object to investigate the thermal protection system of re-entry vehicles. A 1.2-MW high power ICP wind tunnel is studied through numerical simulation and experimental validation. The distribution characteristics and interaction mechanism of the flow field and electromagnetic field of the ICP wind tunnel are investigated using the multi-field coupling method of flow, electromagnetic, chemical, and thermodynamic field. The accuracy of the numerical simulation is validated by comparing the experimental results with the simulation results. Thereafter, the wind tunnel pressure, air velocity, electron density, Joule heating rate, Lorentz force, and electric field intensity obtained using the simulation are analyzed and discussed. The results indicate that for the 1.2-MW ICP wind tunnel, the maximum values of temperature, pressure, electron number density, and other parameters are observed during coil heating. The influence of the radial Lorentz force on the momentum transfer is stronger than that of the axial Lorentz force. The electron number density at the central axis and the amplitude and position of the Joule heating rate are affected by the radial Lorentz force. Moreover, the plasma in the wind tunnel is constantly in the subsonic flow state, and a strong eddy flow is easily generated at the inlet of the wind tunnel.
基金supported by Alberta Health,Alberta Innovates,the Canada Research Chairs Program,the Canadian Institutes of Health Research,and the Natural Sciences and Engineering Research Council of Canada。
文摘Arsenic speciation in freshwater fish is crucial for providing meaningful consumption guidelines that allow the public to make informed decisions regarding its consumption.While marine fish have attractedmuch research interest due to their higher arsenic content,research on freshwater fish is limited due to the challenges in quantifying and identifying arsenic species present at trace levels.We describe here a sensitivemethod and its application to the quantification of arsenic species in freshwater fish.Arsenic species from fish tissues were extracted using a methanol/water mixture(1:1 vol.ratio)and ultrasound sonication.Anion-exchange high-performance liquid chromatography(HPLC)enabled separation of arsenobetaine(AsB),inorganic arsenite(iAs^(Ⅲ)),dimethylarsinic acid(DMA),monomethylarsonic acid(MMA),inorganic arsenate(iAs^(Ⅴ)),and three new arsenic species.Inductively coupled plasma mass spectrometry(ICPMS)provided highly sensitive and specific detection of arsenic.A limit of detection of 0.25μg/kg(wet weight fish tissue)was achieved for the five target arsenic species:AsB,iAs^(Ⅲ),DMA,MMA,and iAs^(Ⅴ).A series of experimentswere conducted to ensure the accuracy and validity of the analytical method.The method was successfully applied to the determination of arsenic species in lakewhitefish,northern pike,and walleye,with AsB,DMA,and iAs^(Ⅴ) being frequently detected.Three new arsenic species were detected,but their chromatographic retention times did not match with those of any available arsenic standards.Future research is necessary to elucidate the identity of these new arsenic species detected in freshwater fish.
基金partly supported by National Natural Science Foundation of China(Nos.52302464 and 52177128)supported by the Key Scientific Research Project for Institutions of Higher Education of Henan Province(No.22B140002).
文摘Recently,it has been observed that during the operation of an inductively coupled plasma(ICP),a luminescent target(BAM,BaMgAl10O17:Eu)can interact with the plasma beam and emit blue light.After excluding the influence of ultraviolet(UV)and electromagnetic wave radiation,the results indicate that the BAM target may undergo luminescent excitation due to collisions with electrons and ions.This led us to investigate the physical mechanism behind this plasma luminescence excitation phenomenon.A spectrometer was used to record the luminescent spectroscopy and peak light intensity.Under excitation by argon plasma,the BAM material emits a continuum spectrum from 400 nm to 550 nm,with the peak light intensity located at 462.58 nm,which is the same as the spectrum excited by UV torchlight.To identify the relationship between the plasma parameters and the luminescent intensity,Langmuir and Faraday probes were employed to determine the local plasma parameters such as electron density,electron temperature,and current density.After normalizing the peak light intensity to the plasma parameters,the most interesting point is that the current density is linearly correlated with the luminescent light intensity.To verify the repeatability and lifetime of the plasma-luminescence interaction,a 600 s lifetime test was conducted in a 200 W ICP discharge environment.The maximum difference for the peak light strength of the luminescent spectrum is 6.5%.From a voltage bias experiment and a theoretical derivation,we initially identified that bombardment by ions plays the dominant role in the luminescence excitation process,which also explains the mechanism by which the current density is proportional to the luminescence intensity.This new finding leads us to reconsider the possibility of applying this plasma luminescence phenomenon to optical plasma diagnostics.The BAM light intensity can potentially be used to predict the current density of a plasma beam for large-area two-dimensional(2D)measurements and can capture high spatial resolution in a single test.We believe that this method may lead to high-efficiency,spatially resolved plasma current density measurement.
基金supported by grants from the National Natural Science Foundation of China(No.62071329)the National Science Foundation of Tianjin(No.23JCZDJC00440)the Key Areas R&D Programs of Guangdong Province(No.2020B1111020001).
文摘This study investigates inductively coupled transmission technology using seawater and underwater anchor chains as the transmission medium for real-time data transfer from underwater measurement instruments.Because of the physical properties of seawater,challenges,such as frequency selective fading and multipath effect,limit long-distance current signal transmission.Conventional modulation techniques,such as amplitude shift keying(ASK)and differential phase shift keying(DPSK),are constrained by low bandwidth utilization and high bit error rates(BER).To address these issues,we optimize the seawater channel model using data from the National Oceanographic Data Center and previous measurements,analyzing the relationship between seawater conductivity,depth,and signal frequency.We constructed an experimental platform using a six-winding manganese-zinc ferrite ring based on an inductive coupling model for data transmission.A steel cable is anchored at both ends of a seawater bucket through two rings,exposing the cable core to establish a closed loop in seawater.An orthogonal frequency division multiplexing(OFDM)algorithm is used to improve transmission performance by distributing data across multiple subcarriers,effectively mitigating multipath fading and frequency selective fading.Compared with ASK and DPSK,this method significantly reduces the BER and improves the channel capacity,exhibiting robustness in underwater communication.Finally,in our study,a mathematical model of the underwater multipath channel for distances of 300,1000,and 2000 m is established,showing an improvement in channel capacity of approximately 2.5 bps/Hz based on the OFDM algorithm.This advancement is essential for enhancing the performance of underwater signal transmission and supporting its practical application.
基金supported by the National Key R&D Program of China(No.2022YFE0204100)National Natural Science Foundation of China(Nos.12205067 and 12375199)the Fundamental Research Funds for the Central University(No.HIT.D?J.2023178)。
文摘This work continues the studies on searching for plasma media with the inverse electron energy distribution function(EEDF)and providing recommendations for setting up subsequent experiments.The inverse EEDF is a distribution function that increases with an increase in energy at zero electron energy.The inverse EEDF plays a central role in the problem of negative conductivity.Based on the previously obtained criterion for the formation of an inverse EEDF in a spatially inhomogeneous plasma,a heuristic method is proposed that allows one to avoid resource-intensive calculations for spatially two-dimensional(2D)kinetic modeling on a large array of different glow discharges.It is shown that the conditions for EEDF inversion can be realized in two-chamber discharge structures due to violating the known Boltzmann distribution for electron density.The theoretical conclusions are validated by numerical modeling of lowpressure two-chamber inductively-coupled plasma(ICP)discharges in the COMSOL Multiphysics environment.As a result,areas of conditions with inverse EEDF were found for subsequent detailed kinetic analysis and experimental studies.
基金supported jointly by National Natural Science Foundation of China(NO.42430718)National Natural Science Foundation of China(NO.42077179)+2 种基金Natural Science Foundation of Fujian Province of China(NO.2023J01227)Natural Science Foundation of Xiamen,China(NO.3502Z20227309)Basic Scientific Research Business Expenses Project of the Chinese Academy of Geological Sciences(NO.YK202303).
文摘Developing a rapid and precise method for trace element analysis in geothermal water is crucial due to its high total dissolved solids and salinity,which can impact element determination.In this study,we optimized the determination of ferrum,manganese,strontium and barium in geothermal water samples collected from different regions.A matrix matching method was established for accurate quantification using Inductively Coupled Plasma Optical Emission Spectroscopy(ICP-OES).Instrumental conditions and experimental parameters were optimized,and the influence of storage medium and storage duration on measurement accuracy were evaluated.The results demonstrated that storing geothermal water samples in 1%nitric acid had no significant impact on measurement results over an eight-week period.Calibration curve correlation coefficients exceeded 0.9998 for all target elements.The detection limits of this method ranged from 0.0002 mg/L to 0.0031 mg/L,with Relative Standard Deviations(RSD)were 0.07%–2.33%,and spike recovery rates were from 96.8%to 103.2%.The obtained data were consistent with results from the standard addition method and dilution method,demonstrating the reliability of this approach.This method offers low detection limits,high precision and excellent recovery rate,providing a robust reference for the accurate determination of ferrum,manganese,strontium and barium in geothermal water,thereby laying a solid foundation for the development and utilization of geothermal resources.
文摘RLC model is used to estimate the coupling noise between interconnect wires and make some analysis through the simulation result. Based on the analysis conclusion,some algorithms are developed to adjust the rou ting result with crosstalk constraint.
文摘[ Objective] To study the effects of different pretreatment methods on determination of microelement in feed and thus find the best pre treatment method for each microetement, t Method] The samples （concentrated feeding stuff and fodder） were pretreated through throe methods, that is, dry incineration method, HNOs HCIO, wetdecomposition method and microwave digestion method. Then the content of seven kinds of mi croelement （AI, Ca, Cu, Fe, Mn, Se and Zn） was determined by inductively coupled plasma atomic emission spectrometer （ICPAES）. I Result] These three methods were all suitable for the determination of Cu, Mn and Zn in concentrated feeding stuff and the determination of Cu and Ca in fodder. The content of Cu and Ca was higher in fodder detected by HNO3 HCIO, wetdecomposition method. The microwave digestion method was suitable for the determination of AI and Ca in concentrated feeding stuff and the determination of AI, Fe, Mn and Zn in fodder. The dry incinera tion method was fit for the determination of Fe in concentrated feeding stuff. [ Condusionl The content of different microelements should be deter mined after the feed is treated with different Ioretreatment methods.
文摘A high performance AlAs/In0.53 Ga0.47 As/InAs resonant tunneling diode （RTD） on InP substrate is fabricated by inductively coupled plasma etching. This RTD has a peak-to-valley current ratio （PVCR） of 7. 57 and a peak current density Jp = 39.08kA/cm^2 under forward bias at room temperature. Under reverse bias, the corresponding values are 7.93 and 34.56kA/cm^2 . A resistive cutoff frequency of 18.75GHz is obtained with the effect of a parasitic probe pad and wire. The slightly asymmetrical current-voltage characteristics with a nominally symmetrical structure are also discussed.
基金ACKNOWLEDGMENTS This work was supported by the National Natural Science Foundation of China （No.10575039） and the Chinese Specialized Research Fund for the Doctoral Program of Higher Education （No.2004057408）.
文摘Large scale homogenous growth of microcrystalline silicon （μ.c-Si：H） on cheap substrates by inductively coupled plasma （ICP） of Ar diluted Sill4 has been studied. From XRD and Raman spectrum, we find that substrates can greatly affect the crystalline orientation, and the μc-Si：H films are comprised of small particles. Thickness detection by surface profilometry shows that the thin μc-Si：H films are homogenous in large scale. Distributions of both ion density and electron temperature are found to be uniform in the vicinity of substrate by means of diagnosis of Langmuir probe. Based on these experimental results, it can be proposed that rough surfaces play important roles in the crystalline network formation and Ar can affect the reaction process and improve the characteristics of μc-Si：H films. Also, ICP reactor can deposit the thin film in large scale.
