期刊文献+
共找到61,681篇文章
< 1 2 250 >
每页显示 20 50 100
A study of pulsed high voltage driven hollow-cathode electron beam sources through synchronous optical trigger
1
作者 霍卫杰 贺伟国 +2 位作者 韩罗峰 朱康武 王锋 《Plasma Science and Technology》 SCIE EI CAS CSCD 2024年第5期82-90,共9页
In this study,a pulsed,high voltage driven hollow-cathode electron beam sources through an optical trigger is designed with characteristics of simple structure,low cost,and easy triggering.To validate the new design,t... In this study,a pulsed,high voltage driven hollow-cathode electron beam sources through an optical trigger is designed with characteristics of simple structure,low cost,and easy triggering.To validate the new design,the characteristics of hollow-cathode discharge and electron beam characterization under pulsed high voltage drive are studied experimentally and discussed by discharge characteristics and analyses of waveform details,respectively.The validation experiments indicate that the pulsed high voltage supply significantly improves the frequency and stability of the discharge,which provides a new solution for the realization of a high-frequency,high-energy electron beam source.The peak current amplitude in the high-energy electron beam increases from 6.2 A to 79.6 A,which indicates the pulsed power mode significantly improves the electron beam performance.Besides,increasing the capacitance significantly affects the highcurrent,lower-energy electron beam more than the high-energy electron beam. 展开更多
关键词 hollow-cathode nanosecond pulsed electron beam sources optical trigger pulsed high voltage supply beam current distribution
下载PDF
Stable photocurrent-voltage characteristics of perovskite single crystal detectors obtained by pulsed bias
2
作者 刘新 陈之龙 +4 位作者 王虎 张雯清 董昊 王鹏祥 邵宇川 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第4期209-214,共6页
Photocurrent-voltage characterization is a crucial method for assessing key parameters in x-ray or y-ray semiconductor detectors,especially the carrier mobility lifetime product.However,the high biases during photocur... Photocurrent-voltage characterization is a crucial method for assessing key parameters in x-ray or y-ray semiconductor detectors,especially the carrier mobility lifetime product.However,the high biases during photocurrent measurements tend to cause severe ion migration,which can lead to the instability and inaccuracy of the test results.Given the mixed electronic-ionic charac teristics,it is imperative to devise novel methods capable of precisely measuring photocurrentvoltage characteristics under high bias conditions,free from interference caused by ion migration.In this paper,pulsed bias is employed to explore the photocurrent-voltage characteristics of MAPbBr_(3) single crystals.The method yields stable photocurrent-voltage characteristics at a pulsed bias of up to 30 V,proving to be effective in mitigating ion migration.Through fitting the modified Hecht equation,we determined the mobility lifetime products of 1.0×10^(2) cm^(2)·V^(-1)for hole and 2.78×10~(-3)cm^(2)·V^(-1)for electron.This approach offers a promising solution for accurately measuring the transport properties of carriers in perovskite. 展开更多
关键词 perovskites ion migration pulsed bias mobility lifetime product
下载PDF
Model prediction of inactivation of Aeromonas salmonicida grown on poultry in situ by intense pulsed light
3
作者 Jingwen Wang Zhenzhen Ning +2 位作者 Yifan Chen Xinglian Xu Huhu Wang 《Food Science and Human Wellness》 SCIE CSCD 2024年第2期1011-1017,共7页
The aim of this study was to evaluate the factors influencing the inactivation effect of intense pulsed light(IPL)on Aeromonas salmonicida grown on chicken meat and skin,and to further develop prediction models of ina... The aim of this study was to evaluate the factors influencing the inactivation effect of intense pulsed light(IPL)on Aeromonas salmonicida grown on chicken meat and skin,and to further develop prediction models of inactivation.In this work,chicken meat and skin inoculated with meat-borne A.salmonicida isolates were subjected to IPL treatments under different conditions.The results showed that IPL had obvious bactericidal effect in the chicken skin and thickness groups when the treatment voltage and time were 7 V combined with 5 s.In addition,the lethality curves of A.salmonicida were fitted under IPL conditions of 3.5-7.5 V.The comparison of statistical parameters revealed that the Weibull model could best fit the mortality curves and could accurately predict the mortality dynamic of A.salmonicida grown on chicken skin.And further a secondary model between the scale factor b and the treatment voltage in Weibull model was established using linear equations,which determined that the secondary model could accurately predict the inactivation of A.salmonicida.This study provides a theoretical basis for future prediction models of Aeromonas,and also provides new ideas for sterilization approaches of meat-borne Aeromonas. 展开更多
关键词 Aeromonas salmonicida Intense pulsed light INACTIVATION Chicken meat MODEL
下载PDF
Electrokinetic-mechanism of water and furfural oxidation on pulsed laser-interlaced Cu_(2)O and CoO on nickel foam 被引量:1
4
作者 Yewon Oh Jayaraman Theerthagiri +3 位作者 M.L.Aruna Kumari Ahreum Min Cheol Joo Moon Myong Yong Choi 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第4期145-154,共10页
The electrocatalytic oxidation of biomass-derived furfural(FF)feedstocks into 2-furoic acid(FA)holds immense industrial potential in optics,cosmetics,polymers,and food.Herein,we fabricated Co O/Ni O/nickel foam(NF)and... The electrocatalytic oxidation of biomass-derived furfural(FF)feedstocks into 2-furoic acid(FA)holds immense industrial potential in optics,cosmetics,polymers,and food.Herein,we fabricated Co O/Ni O/nickel foam(NF)and Cu_(2)O/Ni O/NF electrodes via in situ pulsed laser irradiation in liquids(PLIL)for the bifunctional electrocatalysis of oxygen evolution reaction(OER)and furfural oxidation reaction(FOR),respectively.Simultaneous oxidation of NF surface to NiO and deposition of CoO and/or Cu_(2)O on NF during PLIL offer distinct advantages for enhancing both the OER and FOR.CoO/NiO/NF electrocatalyst provides a consistently low overpotential of~359 m V(OER)at 10 m A/cm^(2),achieving the maximum FA yield(~16.37 m M)with 61.5%selectivity,79.5%carbon balance,and a remarkable Faradaic efficiency of~90.1%during 2 h of FOR at 1.43 V(vs.reversible hydrogen electrode).Mechanistic pathway via in situ electrochemical-Raman spectroscopy on CoO/NiO/NF reveals the involvement of phase transition intermediates(NiOOH and CoOOH)as surface-active centers during electrochemical oxidation.The carbonyl carbon in FF is attacked by hydroxyl groups to form unstable hydrates that subsequently undergo further oxidation to yield FA products.This method holds promise for large-scale applications,enabling simultaneous production of renewable building materials and fuel. 展开更多
关键词 pulsed laser irradiation in liquids Water and furfural oxidation In situ Raman spectroscopy CoO/NiO/nickel foam Cu_(2)O/Nio/nickel foam 2-furoic acid
下载PDF
Performance of pulsed plasma thruster at low discharge energy
5
作者 李鸿俊 林泽豪 +3 位作者 胡浩俊 吴文东 陈爱虹 杜德扬 《Plasma Science and Technology》 SCIE EI CAS CSCD 2024年第4期122-132,共11页
As the size of satellites scales down, low-power and compact propulsion systems such as the pulsed plasma thruster(PPT) are needed for stabilizing these miniature satellites in orbit. Most PPT systems are operated at ... As the size of satellites scales down, low-power and compact propulsion systems such as the pulsed plasma thruster(PPT) are needed for stabilizing these miniature satellites in orbit. Most PPT systems are operated at 2 J or more of discharge energy. In this work, the performance of a PPT with a side-fed, tongue-flared electrode configuration operated within a lower discharge energy range of 0.5-2.5 J has been investigated. Ablation and charring of the polytetrafluoroethylene propellant surface were analyzed through field-effect scanning electron microscopy imaging and energy-dispersive X-ray spectroscopy. When the discharge energy fell below 2 J, inconsistencies occurred in the specific impulse and the thrust efficiency due to the measurement of the low mass bit. At energy ≥2 J, the performance parameters are compared with other PPT systems of similar configuration and discussed in depth. 展开更多
关键词 pulsed plasma thruster low discharge energy performance parameters
下载PDF
Dielectric barrier discharge plasma-assisted catalytic ammonia synthesis:synergistic effect of Ni-MOF-74 catalyst and nanosecond pulsed plasma
6
作者 徐晓芳 孙萌 +4 位作者 宋勤龙 吴璇 陈冲冲 陈强 张海宝 《Plasma Science and Technology》 SCIE EI CAS CSCD 2024年第6期40-49,共10页
Ammonia is one of the most important chemical raw materials in both manufacture and life of human.Traditionally Haber-Bosch method for ammonia synthesis involves high temperature and high pressure conditions,leading t... Ammonia is one of the most important chemical raw materials in both manufacture and life of human.Traditionally Haber-Bosch method for ammonia synthesis involves high temperature and high pressure conditions,leading to significant energy consumption and environmental pollution.Non-thermal plasma(NTP) is a promising alternative approach to ammonia synthesis at low temperature and atmospheric pressure.In this study,the synergistic effect of nanosecond pulsed dielectric barrier discharge(np-DBD) and Ni-MOF-74 catalyst was investigated in ammonia synthesis by utilizing nitrogen and hydrogen as feedstock.The results demonstrated that the plasma catalytic-synthesis process parameters play a crucial role in the synthesis process of ammonia.The highest ammonia synthesis rate of 5145.16 μmol·g^(-1)·h^(-1)with an energy efficiency of 1.27 g·kWh^(-1)was observed in the presence of the Ni-MOF-74 catalyst,which was3.7 times higher than that without Ni-MOF-74 catalyst.The synergistic effect of Ni-MOF-74catalyst and nanosecond pulsed plasma was explored by in-situ plasma discharge diagnostics. 展开更多
关键词 AMMONIA SYNTHESIS low-temperature plasma nanosecond pulsed power source Ni-MOF-74
下载PDF
Electron characteristics and dynamics in sub-millimeter pulsed atmospheric dielectric barrier discharge
7
作者 方骏林 张亚容 +4 位作者 卢陈梓 顾莉莉 徐少锋 郭颖 石建军 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第1期496-502,共7页
The discharge characteristics and mechanism of sub-millimeter pulsed dielectric barrier discharge in atmosphericpressure helium are investigated experimentally and theoretically, demonstrating that when the discharge ... The discharge characteristics and mechanism of sub-millimeter pulsed dielectric barrier discharge in atmosphericpressure helium are investigated experimentally and theoretically, demonstrating that when the discharge gap distance is reduced from 1.00 mm to 0.20 mm, the discharge ignition time is reduced to approximately 40 ns and discharge intensity is enhanced in terms of the discharge optical emission intensity and density of the plasma species,(energetic electrons with energy above 8.40 e V). The simulated results show that as the discharge gap distance is further reduced to 0.10 mm,the number of energetic electrons decreases, which is attributable to the contraction of plasma bulk regime and reduction of electron density in the discharge bulk. Conversely, the proportion of energetic electrons to the total electrons in the discharge monotonically increases as the discharge gap distance is reduced from 1.00 mm to 0.10 mm. It is proposed that a gap distance of 0.12 mm is optimal to achieve a high concentration and proportion of energetic electrons in sub-millimeter pulsed atmosphere dielectric barrier discharge. 展开更多
关键词 sub-millimeter pulsed discharge plasma simulation electron dynamics and sheath
下载PDF
Experimental study on the effect of H_(2)O and O_(2) on the degradation of SF_(6) by pulsed dielectric barrier discharge
8
作者 李亚龙 万昆 +5 位作者 王宇非 张晓星 杨照迪 傅明利 卓然 王邸博 《Plasma Science and Technology》 SCIE EI CAS CSCD 2024年第2期125-131,共7页
SF_(6) has excellent insulation performance and arc extinguishing ability,and is widely used in the power industry.However,its global warming potential is about 23,500 times that of C0_(2),it can exist stably in the a... SF_(6) has excellent insulation performance and arc extinguishing ability,and is widely used in the power industry.However,its global warming potential is about 23,500 times that of C0_(2),it can exist stably in the atmosphere,it is not easily degradable and is of great potential harm to the environment.Based on pulsed dielectric barrier discharge plasma technology,the effects of H_(2)O and 0_(2) on the degradation of SF_(6) were studied.Studies have shown that H_(2)O can effectively promote the decomposition of SF_(6) and improve its degradation rate and energy efficiency of degradation.Under the action of a pulse input voltage and input frequency of 15 kV and 15 kHz,respectively,when H_(2)O is added alone the effect of 1% H_(2)O is the best,and the rate and energy efficiency of degradation of SF_(6) reach their maximum values,which are 91.9% and 8.25 g kWh^(-1),respectively.The synergistic effect of H_(2)O and O_(2) on the degradation of SF_(6) was similar to that of H_(2)O.When the concentration of H_(2)O and O_(2) was 1%,the system obtained the best rate and energy efficiency of degradation,namely 89.7% and 8.05 g kWh~(-1),respectively.At the same time,different external gases exhibit different capabilities to regulate decomposition products.The addition of H_(2)O can effectively improve the selectivity of S0_(2).Under the synergistic effect of H_(2)O and O_(2),with increase in O_(2) concentration the degradation products gradually transformed into SO_(2)F_(2).From the perspective of harmless treatment of the degradation products of SF_(6),the addition of O_(2) during the SF_(6) degradation process should be avoided. 展开更多
关键词 SF_(6) pulsed dielectric barrier discharge DEGRADATION discharge gas
下载PDF
Atmospheric transmission algorithm for pulsed X-rays from high-altitude nuclear detonations based on scattering correction
9
作者 Ding-Han Zhu Xiong Zhang +3 位作者 Xiao-Qiang Li Peng Li Yan-Bin Wang Shuang Zhang 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2024年第3期40-52,共13页
In high-altitude nuclear detonations,the proportion of pulsed X-ray energy can exceed 70%,making it a specific monitoring signal for such events.These pulsed X-rays can be captured using a satellite-borne X-ray detect... In high-altitude nuclear detonations,the proportion of pulsed X-ray energy can exceed 70%,making it a specific monitoring signal for such events.These pulsed X-rays can be captured using a satellite-borne X-ray detector following atmospheric transmission.To quantitatively analyze the effects of different satellite detection altitudes,burst heights,and transmission angles on the physical processes of X-ray transport and energy fluence,we developed an atmospheric transmission algorithm for pulsed X-rays from high-altitude nuclear detonations based on scattering correction.The proposed method is an improvement over the traditional analytical method that only computes direct-transmission X-rays.The traditional analytical method exhibits a maximum relative error of 67.79% compared with the Monte Carlo method.Our improved method reduces this error to within 10% under the same conditions,even reaching 1% in certain scenarios.Moreover,its computation time is 48,000 times faster than that of the Monte Carlo method.These results have important theoretical significance and engineering application value for designing satellite-borne nuclear detonation pulsed X-ray detectors,inverting nuclear detonation source terms,and assessing ionospheric effects. 展开更多
关键词 High-altitude nuclear detonation Atmospheric transmission pulsed X-rays Scattering correction Analytical method Monte Carlo method
下载PDF
A comparative study on the spectral characteristics of nanosecond pulsed discharges in atmospheric He and a He+2.3%H_(2)O mixture
10
作者 陈传杰 彭东宇 +4 位作者 刘博通 张婷琳 钱沐杨 周锋 王如刚 《Plasma Science and Technology》 SCIE EI CAS CSCD 2024年第6期22-30,共9页
Nanosecond pulsed discharges at atmospheric pressure in a pin-to-pin electrode configuration are well reproducible in time and space, which is beneficial to the fundamentals and applications of low-temperature plasmas... Nanosecond pulsed discharges at atmospheric pressure in a pin-to-pin electrode configuration are well reproducible in time and space, which is beneficial to the fundamentals and applications of low-temperature plasmas. In this experiment, the discharges in helium(He) and He with 2.3%water vapor(H_(2)O) are driven by a series of 10 ns overvoltage pulses(~13 k V). Special attention is paid to the spectral characteristics obtained in the center of discharges by time-resolved optical emission spectroscopy. It is found that in helium, the emission of atomic and molecular helium during the afterglow is more intense than that in the active discharge, while in the He+2.3%H_(2)O mixture, helium emission is only observed during the discharge pulse and the molecular helium emission disappears. In addition, the emissions of OH(A-X) and Hα present similar behavior that increases sharply during the falling edge of the voltage pulse as the electrons cool down rapidly. The gas temperature is set to remain low at 540 K by fitting the OH(A-X) band. A comparative study on the emission of radiative species(He, He_(2), OH and H)is performed between these two discharge cases to derive their main production mechanisms. In both cases, the dominant primary ion is He^(+) at the onset of discharges, but their He^(+) charge transfer processes are quite different. Based on these experimental data and a qualitative discussion on the discharge kinetics, with regard to the present discharge conditions, it is shown that the electron-assisted three-body recombination processes appear to be the significant sources of radiative OH and H species in high-density plasmas. 展开更多
关键词 nanosecond repetitively pulsed discharge helium and water vapor optical emission spectroscopy atmospheric pressure micro-discharge kinetics
下载PDF
Pulsed lavage in joint arthroplasty: A systematic review and metaanalysis
11
作者 Mohammad Daher Gaby Haykal +4 位作者 Marven Aoun Marc Moussallem Ali Ghoul Jean Tarchichi Amer Sebaaly 《World Journal of Orthopedics》 2024年第3期293-301,共9页
BACKGROUND Knee and hip osteoarthritis affects millions of people around the world and is expected to rise even more in frequency as the population ages.Joint arthroplasty is the surgical management of choice in these... BACKGROUND Knee and hip osteoarthritis affects millions of people around the world and is expected to rise even more in frequency as the population ages.Joint arthroplasty is the surgical management of choice in these articulations.Heterotopic ossi-fication and radiolucent lines formation are two frequent problems faced in hip and knee replacements respectively.Some studies show that the usage of pulsed lavage may prevent their formation.AIM To compare pulsed lavage to standard lavage in joint arthroplasty.METHODS PubMed,Cochrane,and Google Scholar(page 1-20)were searched till December 2023.Only comparative studies were included.The clinical outcomes evaluated were the heterotopic ossification formation in hip replacements,radiolucent lines formation,and functional knee scores in knee replacements.RESULTS Four studies met the inclusion criteria and were included in this meta-analysis.Pulsed lavage was shown to reduce the formation of radiolucent lines(P=0.001).However,no difference was seen in the remaining outcomes CONCLUSION Pulsed lavage reduced the formation of radiolucent lines in knee replacements.No difference was seen in the remaining outcomes.Furthermore,the clinical significance of these radiolucent lines is poorly understood.Better conducted randomized controlled studies and cost-effectivity studies are needed to reinforce these findings. 展开更多
关键词 Knee arthroplasty Hip arthroplasty pulsed lavage Syringe lavage Heterotopic ossification Radiolucent lines
下载PDF
Evaluation of genetic response of mesenchymal stem cells to nanosecond pulsed electric fields by whole transcriptome sequencing
12
作者 Jian-Jing Lin Tong Ning +5 位作者 Shi-Cheng Jia Ke-Jia Li Yong-Can Huang Qiang Liu Jian-Hao Lin Xin-Tao Zhang 《World Journal of Stem Cells》 SCIE 2024年第3期305-323,共19页
BACKGROUND Mesenchymal stem cells(MSCs)modulated by various exogenous signals have been applied extensively in regenerative medicine research.Notably,nanosecond pulsed electric fields(nsPEFs),characterized by short du... BACKGROUND Mesenchymal stem cells(MSCs)modulated by various exogenous signals have been applied extensively in regenerative medicine research.Notably,nanosecond pulsed electric fields(nsPEFs),characterized by short duration and high strength,significantly influence cell phenotypes and regulate MSCs differentiation via multiple pathways.Consequently,we used transcriptomics to study changes in messenger RNA(mRNA),long noncoding RNA(lncRNA),microRNA(miRNA),and circular RNA expression during nsPEFs application.AIM To explore gene expression profiles and potential transcriptional regulatory mechanisms in MSCs pretreated with nsPEFs.METHODS The impact of nsPEFs on the MSCs transcriptome was investigated through whole transcriptome sequencing.MSCs were pretreated with 5-pulse nsPEFs(100 ns at 10 kV/cm,1 Hz),followed by total RNA isolation.Each transcript was normalized by fragments per kilobase per million.Fold change and difference significance were applied to screen the differentially expressed genes(DEGs).Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses were performed to elucidate gene functions,complemented by quantitative polymerase chain reaction verification.RESULTS In total,263 DEGs were discovered,with 92 upregulated and 171 downregulated.DEGs were predominantly enriched in epithelial cell proliferation,osteoblast differentiation,mesenchymal cell differentiation,nuclear division,and wound healing.Regarding cellular components,DEGs are primarily involved in condensed chromosome,chromosomal region,actin cytoskeleton,and kinetochore.From aspect of molecular functions,DEGs are mainly involved in glycosaminoglycan binding,integrin binding,nuclear steroid receptor activity,cytoskeletal motor activity,and steroid binding.Quantitative real-time polymerase chain reaction confirmed targeted transcript regulation.CONCLUSION Our systematic investigation of the wide-ranging transcriptional pattern modulated by nsPEFs revealed the differential expression of 263 mRNAs,2 miRNAs,and 65 lncRNAs.Our study demonstrates that nsPEFs may affect stem cells through several signaling pathways,which are involved in vesicular transport,calcium ion transport,cytoskeleton,and cell differentiation. 展开更多
关键词 Nanosecond pulsed electric fields Whole transcriptome sequencing Mesenchymal stem cells Genetic response Stem cell engineering
下载PDF
Application of a Pulsed Electric Field to Modify the Free Energy of the Active Site of an Azoreductase
13
作者 Jesus Magyber de Jesus Miranda Pedro Guillermo Reyes-Romero +1 位作者 Jorge Mulia-Rodríguez Daniel Osorio-González 《Journal of Applied Mathematics and Physics》 2024年第1期249-255,共7页
The Gibbs free energy is strongly related to the stability and catalytic function of an enzyme through the energetic changes that occur in the chemical reactions the enzyme catalyzes. In this in silico study, a pulsed... The Gibbs free energy is strongly related to the stability and catalytic function of an enzyme through the energetic changes that occur in the chemical reactions the enzyme catalyzes. In this in silico study, a pulsed electric field was applied to an azoreductase, and its effect on the Gibbs free energy of molecular docking with two dyes was measured. We propose that certain stimuli from a pulsed electric field favor the structural stability of the enzyme by promoting an arrangement in the active site, potentially leading to an enhancement of enzymatic activity overall. 展开更多
关键词 pulsed Electric Field Molecular Dynamics DOCKING AZOREDUCTASE
下载PDF
Pulsed laser interference patterning of transition-metal carbides for stable alkaline water electrolysis kinetics
14
作者 Yewon Oh Jayaraman Theerthagiri +3 位作者 Ahreum Min Cheol Joo Moon Yiseul Yu Myong Yong Choi 《Carbon Energy》 SCIE EI CAS CSCD 2024年第5期65-80,共16页
We investigated the role of metal atomization and solvent decomposition into reductive species and carbon clusters in the phase formation of transition-metal carbides(TMCs;namely,Co_(3)C,Fe_(3)C,TiC,and MoC)by pulsed ... We investigated the role of metal atomization and solvent decomposition into reductive species and carbon clusters in the phase formation of transition-metal carbides(TMCs;namely,Co_(3)C,Fe_(3)C,TiC,and MoC)by pulsed laser ablation of Co,Fe,Ti,and Mo metals in acetone.The interaction between carbon s-p-orbitals and metal d-orbitals causes a redistribution of valence structure through charge transfer,leading to the formation of surface defects as observed by X-ray photoelectron spectroscopy.These defects influence the evolved TMCs,making them effective for hydrogen and oxygen evolution reactions(HER and OER)in an alkaline medium.Co_(3)C with more oxygen affinity promoted CoO(OH)intermediates,and the electrochemical surface oxidation to Co_(3)O_(4)was captured via in situ/operando electrochemical Raman probes,increasing the number of active sites for OER activity.MoC with more d-vacancies exhibits strong hydrogen binding,promoting HER kinetics,whereas Fe_(3)C and TiC with more defect states to trap charge carriers may hinder both OER and HER activities.The results show that the assembled membrane-less electrolyzer with Co_(3)C∥Co_(3)C and MoC∥MoC electrodes requires~2.01 and 1.99 V,respectively,to deliver a 10 mA cm−2 with excellent electrochemical and structural stability.In addition,the ascertained pulsed laser synthesis mechanism and unit-cell packing relations will open up sustainable pathways for obtaining highly stable electrocatalysts for electrolyzers. 展开更多
关键词 ACETONE H_(2)and O_(2)evolution reactions pulsed laser ablation surface defects transition-metal carbides water electrolyzer
下载PDF
Absolute Wall Thickness Measurement of Conducting Plates Using Pulsed Eddy Currents
15
作者 Victor-O. de Haan Riccardo Scottini 《Journal of Electromagnetic Analysis and Applications》 2024年第3期25-41,共17页
The method using pulsed eddy currents to determine the thickness of a conduction plate is extended to enable the simultaneous measurement of the plate thickness and material properties. For optimal performance, a prob... The method using pulsed eddy currents to determine the thickness of a conduction plate is extended to enable the simultaneous measurement of the plate thickness and material properties. For optimal performance, a probe must be designed depending on the thickness range that should be accessible. The need for a calibration of the material properties of a conducting plate to enable the measurement of its thickness has been removed. All that is needed is a probe with known dimensions and suitable hardware to create a current pulse and measure a transient magnetic induction. 展开更多
关键词 pulsed Eddy Currents Wall Thickness Absolute and Relative Measurements
下载PDF
Low-intensity pulsed ultrasound reduces alveolar bone resorption during orthodontic treatment via Lamin A/C-Yes-associated protein axis in stem cells
16
作者 Tong Wu Fu Zheng +7 位作者 Hong-Yi Tang Hua-Zhi Li Xin-Yu Cui Shuai Ding Duo Liu Cui-Ying Li Jiu-Hui Jiang Rui-Li Yang 《World Journal of Stem Cells》 SCIE 2024年第3期267-286,共20页
BACKGROUND The bone remodeling during orthodontic treatment for malocclusion often requires a long duration of around two to three years,which also may lead to some complications such as alveolar bone resorption or to... BACKGROUND The bone remodeling during orthodontic treatment for malocclusion often requires a long duration of around two to three years,which also may lead to some complications such as alveolar bone resorption or tooth root resorption.Low-intensity pulsed ultrasound(LIPUS),a noninvasive physical therapy,has been shown to promote bone fracture healing.It is also reported that LIPUS could reduce the duration of orthodontic treatment;however,how LIPUS regulates the bone metabolism during the orthodontic treatment process is still unclear.AIM To investigate the effects of LIPUS on bone remodeling in an orthodontic tooth movement(OTM)model and explore the underlying mechanisms.METHODS A rat model of OTM was established,and alveolar bone remodeling and tooth movement rate were evaluated via micro-computed tomography and staining of tissue sections.In vitro,human bone marrow mesenchymal stem cells(hBMSCs)were isolated to detect their osteogenic differentiation potential under compression and LIPUS stimulation by quantitative reverse transcription-polymerase chain reaction,Western blot,alkaline phosphatase(ALP)staining,and Alizarin red staining.The expression of Yes-associated protein(YAP1),the actin cytoskeleton,and the Lamin A/C nucleoskeleton were detected with or without YAP1 small interfering RNA(siRNA)application via immunofluorescence.RESULTS The force treatment inhibited the osteogenic differentiation potential of hBMSCs;moreover,the expression of osteogenesis markers,such as type 1 collagen(COL1),runt-related transcription factor 2,ALP,and osteocalcin(OCN),decreased.LIPUS could rescue the osteogenic differentiation of hBMSCs with increased expression of osteogenic marker inhibited by force.Mechanically,the expression of LaminA/C,F-actin,and YAP1 was downregulated after force treatment,which could be rescued by LIPUS.Moreover,the osteogenic differentiation of hBMSCs increased by LIPUS could be attenuated by YAP siRNA treatment.Consistently,LIPUS increased alveolar bone density and decreased vertical bone absorption in vivo.The decreased expression of COL1,OCN,and YAP1 on the compression side of the alveolar bone was partially rescued by LIPUS.CONCLUSION LIPUS can accelerate tooth movement and reduce alveolar bone resorption by modulating the cytoskeleton-Lamin A/C-YAP axis,which may be a promising strategy to reduce the orthodontic treatment process. 展开更多
关键词 Low-intensity pulsed ultrasound Bone resorption OSTEOGENESIS Cytoskeleton-Lamin A/C-Yes-associated protein axis Bone marrow mesenchymal stem cells Orthodontic tooth movement
下载PDF
Prevalence and Study of the Clonality of Extended-Spectrum Beta-Lactamase-Producing Klebsiella pneumoniae Strains in Neonatology at the University Hospitals of Abidjan by the Pulsed Field Gel Electrophoresis and the Quantitative Antibiogram
17
作者 Valérie M’Bengue Gbonon Sidjè Arlette Afran +6 位作者 Stanislas Assohoun Egomli Djeda Franck Arnaud Gnahoré Aboubakar Sylla N’Golo David Coulibaly Nathalie Guessennd Assanvo Simon-Pierre N’Guetta Mireille Dosso 《Advances in Microbiology》 CAS 2024年第9期416-429,共14页
Background: ESBL-producing strains of Klebsiella pneumoniae, one of the main causes of nosocomial and hospital-acquired infections, are commonly associated with therapeutic impasses. Surveillance of these multidrug-re... Background: ESBL-producing strains of Klebsiella pneumoniae, one of the main causes of nosocomial and hospital-acquired infections, are commonly associated with therapeutic impasses. Surveillance of these multidrug-resistant pathogens is a crucial tool for controlling and preventing infections. This surveillance involves the use of appropriate molecular and phenotypic typing techniques. The choice of techniques is based on criteria such as discriminatory power, intra- and inter-laboratory reproducibility, epidemiological concordance, ease of use and cost. The aim of our study was to identify clusters of Extended-Spectrum Beta-Lactamase-producing Klebsiella pneumoniae (ESBL-K. pneumoniae) strains circulating in neonatology using quantitative antibiogram (QA) and Pulsed Field Gel Electrophoresis (PFGE). Materials and Methods: This cross-sectional study included 55 K. pneumoniae strains isolated from a total of 513 samples. These various samples are taken from newborns, healthcare personnel, and the environment. K. pneumoniae identification followed standard bacteriological procedures and was confirmed using the Vitek® 2 (bioMérieux). The detection of the ESBL phenotype was performed using the synergy test. QA and PFGE were used to identify clonal relationships between the various strains isolated. Concordance between these two methods was assessed by calculating Cohen’s KAPPA coefficient and Simpson’s diversity index. Results: Among the 55 K. pneumoniae strains included in this study, 58.2% (32/55) were found to be Extended-Spectrum Beta-Lactamase (ESBL) producers. Most of these strains were isolated from neonatal samples (blood samples and rectal swabs). The quantitative antibiogram method applied to 28 out of the 32 ESBL-producing strains revealed that the isolates were grouped into 5 clusters. Pulsed Field Gel Electrophoresis performed on a total of 16 ESBL-producing strains showed the existence of four profiles. A perfect concordance was observed between the two methods. Conclusion: The results of this study highlighted the existence of clonal strains of various origins within neonatology units. 展开更多
关键词 Resistance-Clone-Klebsiella pneumoniae-pulsed Field Gel Electrophoresis-Quantitative Antibiogram
下载PDF
基于PULSE Labshop的双通道测量航空噪声方法研究
18
作者 张青 蒋思毅 +1 位作者 闫国华 杨晓军 《科技与创新》 2024年第14期31-34,共4页
根据《航空器型号和适航合格审定噪声规定》(CCAR-36)中噪声测量规范,使用PULSE Labshop噪声振动测量仪进行双通道法测量航空噪声。针对PLUSE系统从硬件、软件2个方面进行了研究和分析,可为后续的多通道测量振动、噪声的各项测试提供基... 根据《航空器型号和适航合格审定噪声规定》(CCAR-36)中噪声测量规范,使用PULSE Labshop噪声振动测量仪进行双通道法测量航空噪声。针对PLUSE系统从硬件、软件2个方面进行了研究和分析,可为后续的多通道测量振动、噪声的各项测试提供基础性的理论帮助。同时,双通道法测量航空噪声实现了试验的冗余设计,一定程度上可提高试验的准确性。 展开更多
关键词 双通道法 航空噪声 pulsE系统 适航规范
下载PDF
Efficient and selective extraction of uranium from seawater based on a novel pulsed liquid chromatography radionuclide separation method 被引量:2
19
作者 Jian‑Hua Ye Tao Yu 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2023年第2期13-27,共15页
The novel pulsed liquid chromatography radionuclide separation method presented here provides a new and promising strategy for the extraction of uranium from seawater.In this study,a new chromatographic separation met... The novel pulsed liquid chromatography radionuclide separation method presented here provides a new and promising strategy for the extraction of uranium from seawater.In this study,a new chromatographic separation method was proposed,and a pulsed nuclide automated separation device was developed,alongside a new chromatographic column.The length of this chromatographic column was 10 m,with an internal warp of 3 mm and a packing size of 1 mm,while the total separation units of the column reached 12,250.The most favorable conditions for the separation of nuclides were then obtained through optimizing the separation conditions of the device:Sample pH in the column=2,sample injection flow rate=5.698 mL/min,chromatographic column heating temperature=60℃.Separation experiments were also carried out for uranium,europium,and sodium ions in mixed solutions;uranium and sodium ions in water samples from the Ganjiang River;and uranium,sodium,and magnesium ions from seawater samples.The separation factors between the different nuclei were then calculated based on the experimental data,and a formula for the separation level was derived.The experimental results showed that the separation factor in the mixed solution of uranium and europium(1:1)was 1.088,while achieving the initial separation of uranium and europium theoretically required a 47-stage separation.Considering the separation factor of 1.50for the uranium and sodium ions in water samples from the Ganjiang River,achieving the initial separation of uranium and sodium ions would have theoretically required at least a 21-stage separation.Furthermore,for the seawater sample separation experiments,the separation factor of uranium and sodium ions was 1.2885;therefore,more than 28 stages of sample separation would be required to achieve uranium extraction from seawater.The novel pulsed liquid chromatography method proposed in this study was innovative in terms of uranium separation and enrichment,while expanding the possibilities of extracting uranium from seawater through chromatography. 展开更多
关键词 pulsed liquid chromatography Nuclide separation Seawater uranium extraction Uranium enrichment
下载PDF
Pulsed electrolysis of carbon dioxide by large-scale solid oxide electrolytic cells for intermittent renewable energy storage 被引量:2
20
作者 Anqi Wu Chaolei Li +5 位作者 Beibei Han Wu Liu Yang Zhang Svenja Hanson Wanbing Guan Subhash C.Singhal 《Carbon Energy》 SCIE CSCD 2023年第4期2-12,共11页
CO_(2) electrolysis with solid oxide electrolytic cells(SOECs)using intermittently available renewable energy has potential applications for carbon neutrality and energy storage.In this study,a pulsed current strategy... CO_(2) electrolysis with solid oxide electrolytic cells(SOECs)using intermittently available renewable energy has potential applications for carbon neutrality and energy storage.In this study,a pulsed current strategy is used to replicate intermittent energy availability,and the stability and conversion rate of the cyclic operation by a large-scale flat-tube SOEC are studied.One hundred cycles under pulsed current ranging from -100 to -300 mA/cm^(2) with a total operating time of about 800 h were carried out.The results show that after 100 cycles,the cell voltage attenuates by 0.041%/cycle in the high current stage of−300 mA/cm^(2),indicating that the lifetime of the cell can reach up to about 500 cycles.The total CO_(2) conversion rate reached 52%,which is close to the theoretical value of 54.3% at -300 mA/cm^(2),and the calculated efficiency approached 98.2%,assuming heat recycling.This study illustrates the significant advantages of SOEC in efficient electrochemical energy conversion,carbon emission mitigation,and seasonal energy storage. 展开更多
关键词 carbon dioxide cyclic electrolysis pulse current solid oxide electrolytic cells
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部