We deposited indium-tin-oxide(ITO)films on silicon and quartz substrates by magnetron sputtering technology in pure argon.Using electrostatic quadrupole plasma diagnostic technology,we investigate the effects of disch...We deposited indium-tin-oxide(ITO)films on silicon and quartz substrates by magnetron sputtering technology in pure argon.Using electrostatic quadrupole plasma diagnostic technology,we investigate the effects of discharge power and discharge pressure on the ion flux and energy distribution function of incidence on the substrate surface,with special attention to the production of high-energy negative oxygen ions,and elucidate the mechanism behind its production.At the same time,the structure and properties of ITO films are systematically characterized to understand the potential effects of high energy oxygen ions on the growth of ITO films.Combining with the kinetic property analysis of sputtering damage mechanism of transparent conductive oxide(TCO)thin films,this study provides valuable physical understanding of optimization of TCO thin film deposition process.展开更多
This study delves into ion behavior at the substrate position within RF magnetron discharges utilizing an indium tin oxide(ITO)target.The positive ion energies exhibit an upward trajectory with increasing RF power,att...This study delves into ion behavior at the substrate position within RF magnetron discharges utilizing an indium tin oxide(ITO)target.The positive ion energies exhibit an upward trajectory with increasing RF power,attributed to heightened plasma potential and initial emergent energy.Simultaneously,the positive ion flux escalates owing to amplified sputtering rates and electron density.Conversely,negative ions exhibit broad ion energy distribution functions(IEDFs)characterized by multiple peaks.These patterns are clarified by a combination of radiofrequency oscillation of cathode voltage and plasma potential,alongside ion transport time.This elucidation finds validation in a one-dimensional model encompassing the initial ion energy.At higher RF power,negative ions surpassing 100 e V escalate in both flux and energy,posing a potential risk of sputtering damages to ITO layers.展开更多
In this study, we found a kind of edge state located at the interface between plasma photonic crystals(PPCs) and traditional photonic crystals, which depends on the property of the photonic band gap rather than the su...In this study, we found a kind of edge state located at the interface between plasma photonic crystals(PPCs) and traditional photonic crystals, which depends on the property of the photonic band gap rather than the surface defect. Simulation and theoretical analysis show that by adjusting the plasma density, we can change the topological characteristics of the photonic band gap of PPCs. This makes it different from the photonic band gap of traditional PCs, and thus excites or closes the topological edge states. We further discussed the influence of plasma parameters on edge state characteristics, and the results showed that as the plasma density increased, the first photonic band gap(PBG) of the PPCs closed and then reopened, resulting in band inversion and a change in the PBG properties of the PPCs. We can control the generation of edge states through plasma and adjust the frequency and strength of the edge states. After the appearance of edge states, as the plasma density further increases, the first PBG of the PPCs will shift towards high frequencies and deepen. The frequency of edge states will shift towards higher frequencies, and their strength will also increase. We increased the first PBG depth of the PPCs by increasing the number of arrays and found that when the number of the PPCs arrays increased, only the intensity of the edge states would increase while the frequency remained unchanged. Therefore, flexible adjustment of edge state frequency and intensity can be achieved through plasma density and array quantity parameters. Our study demonstrates the properties of topological edge states in plasma photonic crystals, which we believe can provide some guidance for applications based on edge states.展开更多
Only few glufosinate-tolerant genes,such as phosphinothricin acetyltransferase(PAT)and bialaphos resistance(bar)identified from Streptomyces,are currently available for developing genetically modified rice in agricult...Only few glufosinate-tolerant genes,such as phosphinothricin acetyltransferase(PAT)and bialaphos resistance(bar)identified from Streptomyces,are currently available for developing genetically modified rice in agricultural application.Following the rapid development of genome editing technology,generation of novel glufosinate-tolerant gene resources through artificial evolution of endogenous genes is more promising and highly desirable in rice molecular breeding program.In this study,the endogenous Glutamine synthetase1(OsGS1)was artificially evolved by base-editing-mediated gene evolution(BEMGE)in rice cells to create novel alleles conferring glufosinate tolerance in rice germplasms.Two novel glufosinate-tolerant OsGS1 alleles(OsGS1-AVPS and OsGS1-+AF)and one reported tolerant allele(OsGS1-SGTA)were successfully identified from approximately 4200 independent hygromycin-tolerant calli.Germination assays and spray tests revealed that these three OsGS1 alleles confer glufosinate tolerance in rice.Furthermore,OsGS1-AVPS and OsGS1-SGTA were quickly deployed into the elite rice cultivar Nangeng 46 through precise base editing.Overall,our results demonstrate the feasibility of developing glufosinate-tolerant rice by editing an endogenous rice gene in molecular breeding programs.展开更多
Ion conductive membranes(ICMs)are frequently used as separators for energy conversion and storage technologies of fuel cells,flow battery,and hydrogen pump,because of their good ion-selective conduction and low electr...Ion conductive membranes(ICMs)are frequently used as separators for energy conversion and storage technologies of fuel cells,flow battery,and hydrogen pump,because of their good ion-selective conduction and low electronic conductivity.Firstly,this feature article reviews the recent studies on the development of new nonfluorinated ICMs with low cost and their macro/micro-structure control.In general,these new nonfluorinated ICMs have lower conductivity than commercial perfluorinated ones,due to their poor ion transport channels.Increasing ion exchange capacity(IEC)would create more continuous hydrophilic channels,thus enhancing the conductivity.However,high IEC also expands the overall hydrophilic domains,weakens the interaction between polymer chains,enhances the mobility of polymer chains,and eventually induces larger swelling.The micro-scale expansion and macro-scale swelling of the ICMs with high IEC could be controlled by limiting the mobility of polymer chains.Based on this strategy,some ef ficient techniques have been developed,including covalent crosslinking,semi-interpenatrating polymer network,and blending.Secondly,this review introduces the optimization of macro/microstructure of both perfluorinated and nonfluorinated ICMs to improve the performance.Macro-scale multilayer composite is an ef ficient way to enhance the mechanical strength and the dimensional stability of the ICMs,and could also decrease the content of per fluorosulfonic acid resin in the membrane,thereby reducing the cost of the perfluorinated ICMs.Long side chain,multiple functionalization,small molecule inducing micro-phase separation,electrospun nano fiber,and organic–inorganic hybrid could construct more ef ficient ion transport channels,improving the ion conductivity of ICMs.展开更多
The novel sulfonated polybenzimidazole(sPBI)/amine functionalized titanium dioxide(AFT) composite membrane is devised and studied for its capability of the application of high temperature proton exchange membrane fuel...The novel sulfonated polybenzimidazole(sPBI)/amine functionalized titanium dioxide(AFT) composite membrane is devised and studied for its capability of the application of high temperature proton exchange membrane fuel cells(HT-PEMFCs),unlike the prior low temperature AFT endeavors.The high temperature compatibility was actualized because of the filling of free volumes in the rigid aromatic matrix of the composite with AFT nanoparticles which inhibited segmental motions of the chains and improved its thermal stability.Besides,amine functionalization of TiO2 enhanced their dispersion character in the sPBI matrix and shortened the interparticle separation gap which finally improved the proton transfer after establishing interconnected pathways and breeding more phosphoric acid(PA) doping.In addition,the appeared assembled clusters of AFT flourished a superior mechanical stability.Thus,the optimized sPBI/AFT(10 wt%) showed 65.3 MPa tensile strength;0.084 S·cm^-1 proton conductivity(at 160℃;in anhydrous conditions),28.6% water uptake and PA doping level of 23 mol per sPBI repeat unit.The maximum power density peak for sPBI/AFT-10 met the figure of0.42 W·cm^-2 at 160℃(in dry conditions) under atmospheric pressure with 1.5 and 2.5 stoichiometric flow rates of H2/air.These results affirmed the probable fitting of sPBI/AFT composite for HT-PEMFC applications.展开更多
In this paper, N-doped diamond-like carbon(DLC) films were deposited on silicon substrates by using helicon wave plasma chemical vapor deposition(HWP-CVD) with the Ar/CH_4/N_2 mixed gas. The surface morphology, struct...In this paper, N-doped diamond-like carbon(DLC) films were deposited on silicon substrates by using helicon wave plasma chemical vapor deposition(HWP-CVD) with the Ar/CH_4/N_2 mixed gas. The surface morphology, structural and mechanical properties of the N-doped DLC films were investigated in detail by scanning electron microscopy(SEM), x-ray photoelectron spectroscopy(XPS), Raman spectra, and atomic force microscopy(AFM). It can be observed from SEM images that surface morphology of the films become compact and uniform due to the incorporation of N. The maximum of the deposition rate of the films is 143 nm min^(-1), which is related to the high plasma density. The results of XPS show that the N incorporates in the films and the C-C sp^3 bond content increases firstly up to the maximum(20%) at 10 sccm of N_2 flow rate, and then decreases with further increase in the N_2 flow rate. The maximum Young's modulus of the films is obtained by the doping of N and reaches 80 GPa at 10 sccm of N_2 flow rate, which is measured by AFM in the scanning probe microscope mode. Meanwhile, friction characteristic of the N-doped DLC films reaches a minimum value of 0.010.展开更多
The effects of crystallite size on the physicochemical properties and surface defects of pure monoclinic ZrO_(2) catalysts for isobutene synthesis were studied.We prepared a series of monoclinic ZrO_(2) catalysts with...The effects of crystallite size on the physicochemical properties and surface defects of pure monoclinic ZrO_(2) catalysts for isobutene synthesis were studied.We prepared a series of monoclinic ZrO_(2) catalysts with different crystallite size by changing calcination temperature and evaluated their catalytic performance for isobutene synthesis from syngas.ZrO_(2) with small crystalline size showed higher CO conversion and isobutene selectivity,while samples with large crystalline size preferred to form dimethyl ether(DME)instead of hydrocarbons,much less to isobutene.Oxygen defects(ODefects)analyzed by X-ray photoelectron spectroscopy(XPS)provided evidence that more ODefectsoccupied on the surface of ZrO_(2) catalysts with smaller crystalline size.Electron paramagnetic resonance(EPR)and ultraviolet–visible diffuse reflectance(UV–vis DRS)confirmed the presence of high concentration of surface defects and Zr3+on mZrO_(2)-5.9 sample,respectively.In situ diffuse reflectance infrared Fourier transform spectroscopy(in situ DRIFTS)analysis indicated that the adsorption strength of formed formate species on catalyst reduced as the crystalline size decreased.These results suggested that surface defects were responsible for CO activation and further influenced the adsorption strength of surface species,and thus the products distribution changed.This study provides an in-depth insight for active sites regulation of ZrO_(2) catalyst in CO hydrogenation reaction.展开更多
The conversion of CO_(2) electrocatalytic hydrogenation into energy-rich fuel is considered to be the most effective way to carbon recycle.Nitrogen-doping carbonized ZIF-8 is proposed as carrier of the earth-rich Sn c...The conversion of CO_(2) electrocatalytic hydrogenation into energy-rich fuel is considered to be the most effective way to carbon recycle.Nitrogen-doping carbonized ZIF-8 is proposed as carrier of the earth-rich Sn catalyst to overcome the limit of electron transfer and CO_(2) adsorption capacity of Sn.Hierarchically porous structure of Sn doped carbonized ZIF-8 is controlled by hydrothermal and carbonization conditions,which induces much higher specific surface area than that of the commercial Sn nanoparticle(1003.174 vs.7.410 m^(2)·g^(-1)).The shift of nitrogen peaks in X-ray Photoelectron Spectroscopy spectra indicates interaction between ZIF-8 and Sn,which induces the shift of electron cloud from Sn to the chemical nitrogen to enhance conductivity and regulate electron transfer from catalyst to CO_(2).Lower mass transfer resistance and Warburg resistance are investigated through EIS,which significantly improves the catalytic activity for CO_(2) reduction reaction(CO_(2)RR).Onset potential of the reaction is reduced from-0.74 V to less than-0.54 V vs.RHE.The total Faraday efficiency of HCOOH and CO reaches 68.9%at-1.14 V vs.RHE,which is much higher than that of the commercial Sn(45.0%)and some other Sn-based catalyst reported in the literature.展开更多
Parthenolide （PTN）, a selective nuclear factor kappa B （NF-κB） inhibitor, has been used extensively to inhibit NF-κB activation. The duration of the inhibitory effect of PTN on NF-kB in vivo remains unclear. Thi...Parthenolide （PTN）, a selective nuclear factor kappa B （NF-κB） inhibitor, has been used extensively to inhibit NF-κB activation. The duration of the inhibitory effect of PTN on NF-kB in vivo remains unclear. This study was to determine whether a lipopolysaccharide （LPS） challenge 6, 12 and 24 h after the administration of PTN could activate NF-κB. Rats were devided into five groups. The rats in the PTN, PTN＋LPS and DMSO groups were injected intraperitoneally with PTN or DMSO. After 6, 12 or 24 h, LPS was administered in LPS and PTN＋LPS groups. The expressions of NF-κB p50, IκBα and p-IκBα were inhibited in both PTN and PTN＋LPS group at end of 6 and 12 h and no effects at 24 h. In summary, myocardial NF-κB expression occurs 1 h after the administration of LPS. PTN blocks this effect given at 6 h and no inhibitory effect 24 h after administration in vivo.展开更多
The high magnetic field helicon experiment system is a helicon wave plasma（HWP）source device in a high axial magnetic field（B0）developed for plasma–wall interactions studies for fusion reactors.This HWP was reali...The high magnetic field helicon experiment system is a helicon wave plasma（HWP）source device in a high axial magnetic field（B0）developed for plasma–wall interactions studies for fusion reactors.This HWP was realized at low pressure（5×10^-3-10 Pa）and a RF（radio frequency,13.56 MHz）power（maximum power of 2 k W）using an internal right helical antenna（5 cm in diameter by 18 cm long）with a maximum B0of 6300 G.Ar HWP with electron density～10^18–10^20m^-3 and electron temperature～4–7 e V was produced at high B0 of 5100 G,with an RF power of 1500 W.Maximum Ar^＋ion flux of 7.8×10^23m^-2s^-1 with a bright blue core plasma was obtained at a high B0 of 2700 G and an RF power of 1500 W without bias.Plasma energy and mass spectrometer studies indicate that Ar^＋ ion-beams of 40.1 eV are formed,which are supersonic（～3.1cs）.The effect of Ar HWP discharge cleaning on the wall conditioning are investigated by using the mass spectrometry.And the consequent plasma parameters will result in favorable wall conditioning with a removal rate of 1.1×10^24N2/m^2 h.展开更多
An imidazolium functionalized poly(ether ether ketone ketone)(PEEKK-DIm OH)anion exchange membrane(AEM)readily soluble in certain low-boiling-point solvents(isopropanol)is prepared.The solubility results are consisten...An imidazolium functionalized poly(ether ether ketone ketone)(PEEKK-DIm OH)anion exchange membrane(AEM)readily soluble in certain low-boiling-point solvents(isopropanol)is prepared.The solubility results are consistent with the results of molecular dynamics simulations.By varying the chloromethylation reaction temperature or concentrated sulfuric acid concentration of PEEKK,the degrees of chloromethylation of PEEKK are changed from 54% to 92%,the corresponding PEEKK-DIm OH AEMs with the ion exchange capacities(IECs)of 1.14–1.65 mmol·g^(-1).The PEEKK-DIm OH 92% AEM shows high hydroxide conductivity(31 m S·cm^(-1)),suitable water uptake(94%)and acceptable swelling ratio(39%)at 60°C.In addition,the PEEKK-DIm OH AEMs possess good thermal and alkaline stability.The maximum power density(46.16 mW·cm^(-2))of fuel cell prepared with PEEKK-DIm OH 92%AEM as exchange membrane and ionomer is much higher than that with commercial AHA membranes.All the above results indicate that the PEEKK used in this study is a promising AEM matrix material for alkaline fuel cells.展开更多
Modification of exposure conditions downstream in the diffusion chamber has been performed in helicon antenna-excited helium plasma by adjusting the magnetic field(intensity and geometry).In the inductively coupled mo...Modification of exposure conditions downstream in the diffusion chamber has been performed in helicon antenna-excited helium plasma by adjusting the magnetic field(intensity and geometry).In the inductively coupled mode(H mode),a reduction in ion and heat fluxes is found with increasing magnetic field intensity,which is further explained by the more highly magnetized ions off-axis around the last magnetic field lines(LMFL).However,in helicon wave mode(W mode),the increase in magnetic field intensity can dramatically increase the ion and heat fluxes.Moreover,the effect of LMFL geometry on exposure conditions is investigated.In H mode with contracting LMFL,off-axis peaks of both plasma density and electron temperature profiles shift radially inwards,bringing about a beam with better radial uniformity and higher ion and heat fluxes.In W mode,although higher ion and heat fluxes can be achieved with suppressed plasma cross-field diffusion under converging LMFL,the poor radial uniformity and a small beam diameter will limit the size of samples suitable for plasma irradiation experiments.展开更多
Business administration education plays an important part in supporting the development of business industry and ensuring the ongoing supply of qualified human resources to meet the demanding industry requirements.How...Business administration education plays an important part in supporting the development of business industry and ensuring the ongoing supply of qualified human resources to meet the demanding industry requirements.However,the dramatic growth of the economy has not been accompanied by an adequate response from the education system.It is therefore,necessary to review the existing business administration programs.This paper will make a comparison of the current undergraduate programs in Business Administration in Guangdong-Hong Kong-Macao Greater Bay Area in the six dimensions:curriculum and instruction;strategic planning;administrative management;faculty;student achievements;and resources.Suggestions for the further development of Business Administration programs in the bay area will then be proposed.展开更多
Nitrogen-doped diamond-like carbon(N-DLC)films were synthesized by helicon wave plasma chemical vapor deposition(HWP-CVD).The mechanism of the plasma influence on the N-DLC structure and properties was revealed by the...Nitrogen-doped diamond-like carbon(N-DLC)films were synthesized by helicon wave plasma chemical vapor deposition(HWP-CVD).The mechanism of the plasma influence on the N-DLC structure and properties was revealed by the diagnosis of plasma.The effects of nitrogen doping on the mechanical and hydrophobicity properties of DLC films were studied.The change in the ratio of precursor gas flow reduces the concentration of film-forming groups,resulting in a decrease of growth rate with increasing nitrogen flow rate.The morphology and structure of N-DLC films were characterized by scanning probe microscopy,Raman spectroscopy,and X-ray photoemission spectroscopy.The mechanical properties and wettability of N-DLC were analyzed by an ultra-micro hardness tester and JC2000DM system.The results show that the content ratio of N^(+)and N_(2)^(+)is positively correlated with the mechanical properties and wettability of N-DLC films.The enhancement hardness and elastic modulus of N-DLC are attributed to the increase in sp3 carbon–nitrogen bond content in the film,reaching 26.5 GPa and 160 GPa respectively.Water contact measurement shows that the increase in the nitrogen-bond structure in N-DLC gives the film excellent hydrophobic properties,and the optimal water contact angle reaches 111.2°.It is shown that HWP technology has unique advantages in the modulation of functional nanomaterials.展开更多
In this study,the effects of plasma treatment parameters on surface morphology,chemical constituent,dycabiliiy and color fastness of silk fabric were investigated.Atmospheric pressure glow discharge plasma generated w...In this study,the effects of plasma treatment parameters on surface morphology,chemical constituent,dycabiliiy and color fastness of silk fabric were investigated.Atmospheric pressure glow discharge plasma generated with different applied voltages(0 kV to 45 kV)was used to treat the surface of silk fabrics.C I Natural Yellow 3 was used to dye untreated and plasma-treated silk fabrics.The physical analysis based on scanning electron microscopy showed that the surface of silk fabrics was affected by plasma treatment.The chemical analysis was investigated with x-ray photi>elcctron spectroscopy and attenuated total reflection Fourier transform infrared spectroscopy.The results showed that the content of C Is decreased with the increasing applied voltage,the content of N Is and O Is increased with the increasing applied voltage.The increasing K/S values represented that the dyeability of silk fabrics was improved after plasma treatment.The color fastness to dry and wet rubbing was decreased after plasma treatment.展开更多
The electron heating characteristics of magnetic enhancement capacitively coupled argon plasmas in presence of both longitudinal and transverse uniform magnetic field have been explored through both theoretical and nu...The electron heating characteristics of magnetic enhancement capacitively coupled argon plasmas in presence of both longitudinal and transverse uniform magnetic field have been explored through both theoretical and numerical calculations.It is found that the longitudinal magnetic field can affect the heating by changing the level of the pressure heating along the longitudinal direction and that of the Ohmic heating along the direction which is perpendicular to both driving electric field and the applied transverse magnetic field,and a continuously increased longitudinal magnetic field can induce pressure heating to become dominant.Moreover,the electron temperature as well as proportion of some low energy electrons will increase if a small longitudinal magnetic field is introduced,which is attributed to the increased average electron energy.We believe that the research will provide guidance for optimizing the magnetic field configuration of some discharge systems having both transverse and longitudinal magnetic field.展开更多
A reactive helicon wave plasma(HWP)sputtering method is used for the deposition of tungsten nitride(WNx)thin films.N_(2)is introduced downstream in the diffusion chamber.The impacts of N_(2)on the Ar-HWP parameters,su...A reactive helicon wave plasma(HWP)sputtering method is used for the deposition of tungsten nitride(WNx)thin films.N_(2)is introduced downstream in the diffusion chamber.The impacts of N_(2)on the Ar-HWP parameters,such as ion energy distribution functions(IEDFs),electron energy probability functions(EEPFs),electron temperature(Te)and density(ne),are investigated.With the addition of N_(2),a decrease in electron density is observed due to the dissociative recombination of electrons with N_(2)^(+).The similar IEDF curves of Ar+and N_(2)^(+) indicate that the majority ofN_(2)^(+) stems from the charge transfer in the collision between Ar+and N_(2).Moreover,due to the collisions between electrons and N_(2)ions,EEPFs show a relatively lower Tewith a depletion in the high-energy tail.With increasing negative bias from 50 to 200 V,a phase transition from hexagonal WN to fcc-WN0.5is observed,together with an increase in the deposition rate and roughness.展开更多
Herein we report the successful preparation of silver(Ag)-decorated vertically oriented graphene sheets(Ag/VGs)via helicon wave plasma chemical vapor deposition(HWP-CVD)and radiofrequency plasma magnetron sputtering(R...Herein we report the successful preparation of silver(Ag)-decorated vertically oriented graphene sheets(Ag/VGs)via helicon wave plasma chemical vapor deposition(HWP-CVD)and radiofrequency plasma magnetron sputtering(RF-PMS).VGs were synthesized in a mixture of argon and methane(Ar/CH_(4))by HWP-CVD and then the Ag nanoparticles on the prepared VGs were modified using the RF-PMS system for different sputtering times and RF power levels.The morphology and structure of the Ag nanoparticles were characterized by scanning electron microscopy and the results revealed that Ag nanoparticles were evenly dispersed on the mesoporous wall of the VGs.X-ray diffraction results showed that the diameter of the Ag particles increased with the increase in Ag loading,and the average size was between 10.49 nm and 25.9 nm,consistent with the transmission electron microscopy results.Ag/VGs were investigated as effective electrocatalysts for use in an alkaline aqueous system.Due to the uniquely ordered and interconnected wall structure of VGs,the area of active sites increased with the Ag loading,giving the Ag/VGs a good performance in the oxygen evolution reaction.The double-layer capacitance(C_(dl))of the Ag/VGs under different Ag loadings were studied,and the results showed that the highest Ag content gave the best C_(dl)(1.04 mF cm^(-2)).Our results show that Ag/VGs are likely to be credible electrocatalytic materials.展开更多
基金supported by the National Key R&D Program of China(Grant No.2022YFE03050001)the National Natural Science Foundation of China(Grant Nos.12175160 and 12305284).The authors thank Suzhou Maxwell Technologies Co.,Ltd.for partial hardware and particle financial support to carry out the research.
文摘We deposited indium-tin-oxide(ITO)films on silicon and quartz substrates by magnetron sputtering technology in pure argon.Using electrostatic quadrupole plasma diagnostic technology,we investigate the effects of discharge power and discharge pressure on the ion flux and energy distribution function of incidence on the substrate surface,with special attention to the production of high-energy negative oxygen ions,and elucidate the mechanism behind its production.At the same time,the structure and properties of ITO films are systematically characterized to understand the potential effects of high energy oxygen ions on the growth of ITO films.Combining with the kinetic property analysis of sputtering damage mechanism of transparent conductive oxide(TCO)thin films,this study provides valuable physical understanding of optimization of TCO thin film deposition process.
基金financial supports by National Natural Science Foundation of China(Nos.11975163 and 12175160)Nantong Basic Science Research-General Program(No.JC22022034)Natural Science Research Fund of Jiangsu College of Engineering and Technology(No.GYKY/2023/2)。
文摘This study delves into ion behavior at the substrate position within RF magnetron discharges utilizing an indium tin oxide(ITO)target.The positive ion energies exhibit an upward trajectory with increasing RF power,attributed to heightened plasma potential and initial emergent energy.Simultaneously,the positive ion flux escalates owing to amplified sputtering rates and electron density.Conversely,negative ions exhibit broad ion energy distribution functions(IEDFs)characterized by multiple peaks.These patterns are clarified by a combination of radiofrequency oscillation of cathode voltage and plasma potential,alongside ion transport time.This elucidation finds validation in a one-dimensional model encompassing the initial ion energy.At higher RF power,negative ions surpassing 100 e V escalate in both flux and energy,posing a potential risk of sputtering damages to ITO layers.
基金supported by National Natural Science Foundation of China (Nos. 11975163 and 12175160)Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)。
文摘In this study, we found a kind of edge state located at the interface between plasma photonic crystals(PPCs) and traditional photonic crystals, which depends on the property of the photonic band gap rather than the surface defect. Simulation and theoretical analysis show that by adjusting the plasma density, we can change the topological characteristics of the photonic band gap of PPCs. This makes it different from the photonic band gap of traditional PCs, and thus excites or closes the topological edge states. We further discussed the influence of plasma parameters on edge state characteristics, and the results showed that as the plasma density increased, the first photonic band gap(PBG) of the PPCs closed and then reopened, resulting in band inversion and a change in the PBG properties of the PPCs. We can control the generation of edge states through plasma and adjust the frequency and strength of the edge states. After the appearance of edge states, as the plasma density further increases, the first PBG of the PPCs will shift towards high frequencies and deepen. The frequency of edge states will shift towards higher frequencies, and their strength will also increase. We increased the first PBG depth of the PPCs by increasing the number of arrays and found that when the number of the PPCs arrays increased, only the intensity of the edge states would increase while the frequency remained unchanged. Therefore, flexible adjustment of edge state frequency and intensity can be achieved through plasma density and array quantity parameters. Our study demonstrates the properties of topological edge states in plasma photonic crystals, which we believe can provide some guidance for applications based on edge states.
基金supported by grants from the Shenzhen Science and Technology Program(KQTD20180411143628272)Special Funds for Science Technology Innovation and Industrial Development of Shenzhen Dapeng New District(PT202101-02)+3 种基金the Hainan Yazhou Bay Seed Lab(B21HJ0215),the National Natural Science Foundation of China(32102294)the China National Postdoctoral Program for Innovative Talents(BX2020378)the China Postdoctoral Science Foundation(2020M672902)the Central Publicinterest Scientific Institution Basal Research Fund(Y2022PT24).
文摘Only few glufosinate-tolerant genes,such as phosphinothricin acetyltransferase(PAT)and bialaphos resistance(bar)identified from Streptomyces,are currently available for developing genetically modified rice in agricultural application.Following the rapid development of genome editing technology,generation of novel glufosinate-tolerant gene resources through artificial evolution of endogenous genes is more promising and highly desirable in rice molecular breeding program.In this study,the endogenous Glutamine synthetase1(OsGS1)was artificially evolved by base-editing-mediated gene evolution(BEMGE)in rice cells to create novel alleles conferring glufosinate tolerance in rice germplasms.Two novel glufosinate-tolerant OsGS1 alleles(OsGS1-AVPS and OsGS1-+AF)and one reported tolerant allele(OsGS1-SGTA)were successfully identified from approximately 4200 independent hygromycin-tolerant calli.Germination assays and spray tests revealed that these three OsGS1 alleles confer glufosinate tolerance in rice.Furthermore,OsGS1-AVPS and OsGS1-SGTA were quickly deployed into the elite rice cultivar Nangeng 46 through precise base editing.Overall,our results demonstrate the feasibility of developing glufosinate-tolerant rice by editing an endogenous rice gene in molecular breeding programs.
基金Supported by the National Science Fund for Distinguished Young Scholars of China(Grant No.21125628)the Major National Scienti fic Instrument Development Project(Grant No.21527812)+3 种基金the National Natural Science Foundation of China(Grant Nos.21406031 and 21476044)the State Key Laboratory of Fine Chemicals(KF1507)the Fundamental Research Funds for the Central Universities(Grant Nos.DUTPJ14RC(3)003)State Key Laboratory of fine chemicals(Panjin)project(Grant No.JH2014009)
文摘Ion conductive membranes(ICMs)are frequently used as separators for energy conversion and storage technologies of fuel cells,flow battery,and hydrogen pump,because of their good ion-selective conduction and low electronic conductivity.Firstly,this feature article reviews the recent studies on the development of new nonfluorinated ICMs with low cost and their macro/micro-structure control.In general,these new nonfluorinated ICMs have lower conductivity than commercial perfluorinated ones,due to their poor ion transport channels.Increasing ion exchange capacity(IEC)would create more continuous hydrophilic channels,thus enhancing the conductivity.However,high IEC also expands the overall hydrophilic domains,weakens the interaction between polymer chains,enhances the mobility of polymer chains,and eventually induces larger swelling.The micro-scale expansion and macro-scale swelling of the ICMs with high IEC could be controlled by limiting the mobility of polymer chains.Based on this strategy,some ef ficient techniques have been developed,including covalent crosslinking,semi-interpenatrating polymer network,and blending.Secondly,this review introduces the optimization of macro/microstructure of both perfluorinated and nonfluorinated ICMs to improve the performance.Macro-scale multilayer composite is an ef ficient way to enhance the mechanical strength and the dimensional stability of the ICMs,and could also decrease the content of per fluorosulfonic acid resin in the membrane,thereby reducing the cost of the perfluorinated ICMs.Long side chain,multiple functionalization,small molecule inducing micro-phase separation,electrospun nano fiber,and organic–inorganic hybrid could construct more ef ficient ion transport channels,improving the ion conductivity of ICMs.
基金supported by the National Natural Science Foundation of China(Nos.21776034,21476044 and 21406031)Joint Funds of the National Natural Science Foundation of China(U1663223)+1 种基金National Key Research and Development Program of China(2016YFB0101203)Changjiang Scholars Program(T2012049)。
文摘The novel sulfonated polybenzimidazole(sPBI)/amine functionalized titanium dioxide(AFT) composite membrane is devised and studied for its capability of the application of high temperature proton exchange membrane fuel cells(HT-PEMFCs),unlike the prior low temperature AFT endeavors.The high temperature compatibility was actualized because of the filling of free volumes in the rigid aromatic matrix of the composite with AFT nanoparticles which inhibited segmental motions of the chains and improved its thermal stability.Besides,amine functionalization of TiO2 enhanced their dispersion character in the sPBI matrix and shortened the interparticle separation gap which finally improved the proton transfer after establishing interconnected pathways and breeding more phosphoric acid(PA) doping.In addition,the appeared assembled clusters of AFT flourished a superior mechanical stability.Thus,the optimized sPBI/AFT(10 wt%) showed 65.3 MPa tensile strength;0.084 S·cm^-1 proton conductivity(at 160℃;in anhydrous conditions),28.6% water uptake and PA doping level of 23 mol per sPBI repeat unit.The maximum power density peak for sPBI/AFT-10 met the figure of0.42 W·cm^-2 at 160℃(in dry conditions) under atmospheric pressure with 1.5 and 2.5 stoichiometric flow rates of H2/air.These results affirmed the probable fitting of sPBI/AFT composite for HT-PEMFC applications.
基金supported by the National Magnetic Confinement Fusion Science Program of China (Grant Nos. 2014GB106005 and 2014GB106000)National Natural Science Foundation of China (Nos. 11505123,11435009,11375126)Project funded by China Postdoctoral Science Foundation (No. 156455)
文摘In this paper, N-doped diamond-like carbon(DLC) films were deposited on silicon substrates by using helicon wave plasma chemical vapor deposition(HWP-CVD) with the Ar/CH_4/N_2 mixed gas. The surface morphology, structural and mechanical properties of the N-doped DLC films were investigated in detail by scanning electron microscopy(SEM), x-ray photoelectron spectroscopy(XPS), Raman spectra, and atomic force microscopy(AFM). It can be observed from SEM images that surface morphology of the films become compact and uniform due to the incorporation of N. The maximum of the deposition rate of the films is 143 nm min^(-1), which is related to the high plasma density. The results of XPS show that the N incorporates in the films and the C-C sp^3 bond content increases firstly up to the maximum(20%) at 10 sccm of N_2 flow rate, and then decreases with further increase in the N_2 flow rate. The maximum Young's modulus of the films is obtained by the doping of N and reaches 80 GPa at 10 sccm of N_2 flow rate, which is measured by AFM in the scanning probe microscope mode. Meanwhile, friction characteristic of the N-doped DLC films reaches a minimum value of 0.010.
基金financially supported by the Natural Science Foundation of China(21978312,21908235 and 21802155)the Key Research Program of Frontier Sciences,CAS(QYZDB–SSW–JS C043)+1 种基金Foundation of State Key Laboratory of Highefficiency Utilization of Coal and Green Chemical Engineering(2019-KF-05 and 2018-K22)Supported by Shanxi Scholarship Council of China and Fund Program for the Scientific Activities of Selected Returned Overseas Professionals in Shanxi Province are also greatly appreciated。
文摘The effects of crystallite size on the physicochemical properties and surface defects of pure monoclinic ZrO_(2) catalysts for isobutene synthesis were studied.We prepared a series of monoclinic ZrO_(2) catalysts with different crystallite size by changing calcination temperature and evaluated their catalytic performance for isobutene synthesis from syngas.ZrO_(2) with small crystalline size showed higher CO conversion and isobutene selectivity,while samples with large crystalline size preferred to form dimethyl ether(DME)instead of hydrocarbons,much less to isobutene.Oxygen defects(ODefects)analyzed by X-ray photoelectron spectroscopy(XPS)provided evidence that more ODefectsoccupied on the surface of ZrO_(2) catalysts with smaller crystalline size.Electron paramagnetic resonance(EPR)and ultraviolet–visible diffuse reflectance(UV–vis DRS)confirmed the presence of high concentration of surface defects and Zr3+on mZrO_(2)-5.9 sample,respectively.In situ diffuse reflectance infrared Fourier transform spectroscopy(in situ DRIFTS)analysis indicated that the adsorption strength of formed formate species on catalyst reduced as the crystalline size decreased.These results suggested that surface defects were responsible for CO activation and further influenced the adsorption strength of surface species,and thus the products distribution changed.This study provides an in-depth insight for active sites regulation of ZrO_(2) catalyst in CO hydrogenation reaction.
基金the National Natural Science Foundation of China(Joint Fund U1663223 and 21776034)Science Fund for Creative Research Groups of the National Natural Science Foundation of China(22021005)+3 种基金the National Key Research and Development Program of China(2016YFB0101203)Educational Department of Liaoning Province of China(LT2015007)Fundamental Research Funds for the Central Universities(DUT16TD19)the Changjiang Scholar Program(T2012049).
文摘The conversion of CO_(2) electrocatalytic hydrogenation into energy-rich fuel is considered to be the most effective way to carbon recycle.Nitrogen-doping carbonized ZIF-8 is proposed as carrier of the earth-rich Sn catalyst to overcome the limit of electron transfer and CO_(2) adsorption capacity of Sn.Hierarchically porous structure of Sn doped carbonized ZIF-8 is controlled by hydrothermal and carbonization conditions,which induces much higher specific surface area than that of the commercial Sn nanoparticle(1003.174 vs.7.410 m^(2)·g^(-1)).The shift of nitrogen peaks in X-ray Photoelectron Spectroscopy spectra indicates interaction between ZIF-8 and Sn,which induces the shift of electron cloud from Sn to the chemical nitrogen to enhance conductivity and regulate electron transfer from catalyst to CO_(2).Lower mass transfer resistance and Warburg resistance are investigated through EIS,which significantly improves the catalytic activity for CO_(2) reduction reaction(CO_(2)RR).Onset potential of the reaction is reduced from-0.74 V to less than-0.54 V vs.RHE.The total Faraday efficiency of HCOOH and CO reaches 68.9%at-1.14 V vs.RHE,which is much higher than that of the commercial Sn(45.0%)and some other Sn-based catalyst reported in the literature.
基金supported by grant No.30872453 (to Dr.Wang) from National Natural Science Foundation of ChinaNo.BK2008166 (to Dr.Wang) from Natural Science Foundation of Jiangsu Province+1 种基金No.2008-11 (to Dr.Wang) from Technology Bureau of Suzhou,ChinaNo.08KJD320005 (to Dr.Xie) from Natural Science Research Projects of Colleges and Universities in Jiangsu Province,China
文摘Parthenolide （PTN）, a selective nuclear factor kappa B （NF-κB） inhibitor, has been used extensively to inhibit NF-κB activation. The duration of the inhibitory effect of PTN on NF-kB in vivo remains unclear. This study was to determine whether a lipopolysaccharide （LPS） challenge 6, 12 and 24 h after the administration of PTN could activate NF-κB. Rats were devided into five groups. The rats in the PTN, PTN＋LPS and DMSO groups were injected intraperitoneally with PTN or DMSO. After 6, 12 or 24 h, LPS was administered in LPS and PTN＋LPS groups. The expressions of NF-κB p50, IκBα and p-IκBα were inhibited in both PTN and PTN＋LPS group at end of 6 and 12 h and no effects at 24 h. In summary, myocardial NF-κB expression occurs 1 h after the administration of LPS. PTN blocks this effect given at 6 h and no inhibitory effect 24 h after administration in vivo.
基金supported by the National Magnetic Confinement Fusion Science Program of China(Grant Nos.2014GB106005 and 2010GB106000)National Natural Science Foundation of China(Nos.11505123 11435009 11375126)a Project funded by China Postdoctoral Science Foundation(No.156455)
文摘The high magnetic field helicon experiment system is a helicon wave plasma（HWP）source device in a high axial magnetic field（B0）developed for plasma–wall interactions studies for fusion reactors.This HWP was realized at low pressure（5×10^-3-10 Pa）and a RF（radio frequency,13.56 MHz）power（maximum power of 2 k W）using an internal right helical antenna（5 cm in diameter by 18 cm long）with a maximum B0of 6300 G.Ar HWP with electron density～10^18–10^20m^-3 and electron temperature～4–7 e V was produced at high B0 of 5100 G,with an RF power of 1500 W.Maximum Ar^＋ion flux of 7.8×10^23m^-2s^-1 with a bright blue core plasma was obtained at a high B0 of 2700 G and an RF power of 1500 W without bias.Plasma energy and mass spectrometer studies indicate that Ar^＋ ion-beams of 40.1 eV are formed,which are supersonic（～3.1cs）.The effect of Ar HWP discharge cleaning on the wall conditioning are investigated by using the mass spectrometry.And the consequent plasma parameters will result in favorable wall conditioning with a removal rate of 1.1×10^24N2/m^2 h.
基金Supported by the National Natural Science Foundation of China(21706023,21476044,21406031)the National Key Research and Development Program of China(2016YFB0101203)+2 种基金Education Department of Liaoning Province of China(LT2015007)Fundamental Research Funds for the Central Universities(DUT16TD19)the Changjiang Scholars Program(T2012049)
文摘An imidazolium functionalized poly(ether ether ketone ketone)(PEEKK-DIm OH)anion exchange membrane(AEM)readily soluble in certain low-boiling-point solvents(isopropanol)is prepared.The solubility results are consistent with the results of molecular dynamics simulations.By varying the chloromethylation reaction temperature or concentrated sulfuric acid concentration of PEEKK,the degrees of chloromethylation of PEEKK are changed from 54% to 92%,the corresponding PEEKK-DIm OH AEMs with the ion exchange capacities(IECs)of 1.14–1.65 mmol·g^(-1).The PEEKK-DIm OH 92% AEM shows high hydroxide conductivity(31 m S·cm^(-1)),suitable water uptake(94%)and acceptable swelling ratio(39%)at 60°C.In addition,the PEEKK-DIm OH AEMs possess good thermal and alkaline stability.The maximum power density(46.16 mW·cm^(-2))of fuel cell prepared with PEEKK-DIm OH 92%AEM as exchange membrane and ionomer is much higher than that with commercial AHA membranes.All the above results indicate that the PEEKK used in this study is a promising AEM matrix material for alkaline fuel cells.
基金supported by National Natural Science Foundation of China(No.11975163)the Shenzhen Clean Energy Research Institute
文摘Modification of exposure conditions downstream in the diffusion chamber has been performed in helicon antenna-excited helium plasma by adjusting the magnetic field(intensity and geometry).In the inductively coupled mode(H mode),a reduction in ion and heat fluxes is found with increasing magnetic field intensity,which is further explained by the more highly magnetized ions off-axis around the last magnetic field lines(LMFL).However,in helicon wave mode(W mode),the increase in magnetic field intensity can dramatically increase the ion and heat fluxes.Moreover,the effect of LMFL geometry on exposure conditions is investigated.In H mode with contracting LMFL,off-axis peaks of both plasma density and electron temperature profiles shift radially inwards,bringing about a beam with better radial uniformity and higher ion and heat fluxes.In W mode,although higher ion and heat fluxes can be achieved with suppressed plasma cross-field diffusion under converging LMFL,the poor radial uniformity and a small beam diameter will limit the size of samples suitable for plasma irradiation experiments.
文摘Business administration education plays an important part in supporting the development of business industry and ensuring the ongoing supply of qualified human resources to meet the demanding industry requirements.However,the dramatic growth of the economy has not been accompanied by an adequate response from the education system.It is therefore,necessary to review the existing business administration programs.This paper will make a comparison of the current undergraduate programs in Business Administration in Guangdong-Hong Kong-Macao Greater Bay Area in the six dimensions:curriculum and instruction;strategic planning;administrative management;faculty;student achievements;and resources.Suggestions for the further development of Business Administration programs in the bay area will then be proposed.
基金supported by National Natural Science Foundation of China (Nos. 11975163, 12175160)Shenzhen Clean Energy Research Institute
文摘Nitrogen-doped diamond-like carbon(N-DLC)films were synthesized by helicon wave plasma chemical vapor deposition(HWP-CVD).The mechanism of the plasma influence on the N-DLC structure and properties was revealed by the diagnosis of plasma.The effects of nitrogen doping on the mechanical and hydrophobicity properties of DLC films were studied.The change in the ratio of precursor gas flow reduces the concentration of film-forming groups,resulting in a decrease of growth rate with increasing nitrogen flow rate.The morphology and structure of N-DLC films were characterized by scanning probe microscopy,Raman spectroscopy,and X-ray photoemission spectroscopy.The mechanical properties and wettability of N-DLC were analyzed by an ultra-micro hardness tester and JC2000DM system.The results show that the content ratio of N^(+)and N_(2)^(+)is positively correlated with the mechanical properties and wettability of N-DLC films.The enhancement hardness and elastic modulus of N-DLC are attributed to the increase in sp3 carbon–nitrogen bond content in the film,reaching 26.5 GPa and 160 GPa respectively.Water contact measurement shows that the increase in the nitrogen-bond structure in N-DLC gives the film excellent hydrophobic properties,and the optimal water contact angle reaches 111.2°.It is shown that HWP technology has unique advantages in the modulation of functional nanomaterials.
文摘In this study,the effects of plasma treatment parameters on surface morphology,chemical constituent,dycabiliiy and color fastness of silk fabric were investigated.Atmospheric pressure glow discharge plasma generated with different applied voltages(0 kV to 45 kV)was used to treat the surface of silk fabrics.C I Natural Yellow 3 was used to dye untreated and plasma-treated silk fabrics.The physical analysis based on scanning electron microscopy showed that the surface of silk fabrics was affected by plasma treatment.The chemical analysis was investigated with x-ray photi>elcctron spectroscopy and attenuated total reflection Fourier transform infrared spectroscopy.The results showed that the content of C Is decreased with the increasing applied voltage,the content of N Is and O Is increased with the increasing applied voltage.The increasing K/S values represented that the dyeability of silk fabrics was improved after plasma treatment.The color fastness to dry and wet rubbing was decreased after plasma treatment.
基金supported by National Natural Science Foundation of China (Nos. 11975163 and 12175160)a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)
文摘The electron heating characteristics of magnetic enhancement capacitively coupled argon plasmas in presence of both longitudinal and transverse uniform magnetic field have been explored through both theoretical and numerical calculations.It is found that the longitudinal magnetic field can affect the heating by changing the level of the pressure heating along the longitudinal direction and that of the Ohmic heating along the direction which is perpendicular to both driving electric field and the applied transverse magnetic field,and a continuously increased longitudinal magnetic field can induce pressure heating to become dominant.Moreover,the electron temperature as well as proportion of some low energy electrons will increase if a small longitudinal magnetic field is introduced,which is attributed to the increased average electron energy.We believe that the research will provide guidance for optimizing the magnetic field configuration of some discharge systems having both transverse and longitudinal magnetic field.
基金National Natural Science Foundation of China(Nos.11975163,12175160)Shenzhen Clean Energy Research Institute。
文摘A reactive helicon wave plasma(HWP)sputtering method is used for the deposition of tungsten nitride(WNx)thin films.N_(2)is introduced downstream in the diffusion chamber.The impacts of N_(2)on the Ar-HWP parameters,such as ion energy distribution functions(IEDFs),electron energy probability functions(EEPFs),electron temperature(Te)and density(ne),are investigated.With the addition of N_(2),a decrease in electron density is observed due to the dissociative recombination of electrons with N_(2)^(+).The similar IEDF curves of Ar+and N_(2)^(+) indicate that the majority ofN_(2)^(+) stems from the charge transfer in the collision between Ar+and N_(2).Moreover,due to the collisions between electrons and N_(2)ions,EEPFs show a relatively lower Tewith a depletion in the high-energy tail.With increasing negative bias from 50 to 200 V,a phase transition from hexagonal WN to fcc-WN0.5is observed,together with an increase in the deposition rate and roughness.
基金supported by National Natural Science Foundation of China(No.11975163)the Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)。
文摘Herein we report the successful preparation of silver(Ag)-decorated vertically oriented graphene sheets(Ag/VGs)via helicon wave plasma chemical vapor deposition(HWP-CVD)and radiofrequency plasma magnetron sputtering(RF-PMS).VGs were synthesized in a mixture of argon and methane(Ar/CH_(4))by HWP-CVD and then the Ag nanoparticles on the prepared VGs were modified using the RF-PMS system for different sputtering times and RF power levels.The morphology and structure of the Ag nanoparticles were characterized by scanning electron microscopy and the results revealed that Ag nanoparticles were evenly dispersed on the mesoporous wall of the VGs.X-ray diffraction results showed that the diameter of the Ag particles increased with the increase in Ag loading,and the average size was between 10.49 nm and 25.9 nm,consistent with the transmission electron microscopy results.Ag/VGs were investigated as effective electrocatalysts for use in an alkaline aqueous system.Due to the uniquely ordered and interconnected wall structure of VGs,the area of active sites increased with the Ag loading,giving the Ag/VGs a good performance in the oxygen evolution reaction.The double-layer capacitance(C_(dl))of the Ag/VGs under different Ag loadings were studied,and the results showed that the highest Ag content gave the best C_(dl)(1.04 mF cm^(-2)).Our results show that Ag/VGs are likely to be credible electrocatalytic materials.
