The paper presented the results regarding the decomposition of gaseous CF_2ClB_r by cold plasma method.After two minutes discharge,the maximum decomposition rate of 2660 Pa CF_2ClB_r pure and 2660 Pa CF_2ClBr plus 798...The paper presented the results regarding the decomposition of gaseous CF_2ClB_r by cold plasma method.After two minutes discharge,the maximum decomposition rate of 2660 Pa CF_2ClB_r pure and 2660 Pa CF_2ClBr plus 7980 Pa O_2 reached 60% and 80%,respectively.The pa- per also studied the cold plasma gas phase chemistry reaction mechanism of CF_2ClBr at low pres- sure,and the pressure effects of CF_2ClBr and added gas(He,N_2,O_2 and dry air)on the CF_2ClBr decomposition respectively by cold plasma method.These studies will be helpful to application of cold plasma method in the treatment of hazardous gaseous wastes.展开更多
The effects of plasma screening on the ^(1)P^(o) resonance states of H-and He below the n=3 and n=4 thresholds of the respective subsystemsare investigated using the stabilization method and correlated exponential wav...The effects of plasma screening on the ^(1)P^(o) resonance states of H-and He below the n=3 and n=4 thresholds of the respective subsystemsare investigated using the stabilization method and correlated exponential wave functions.Two plasma mediums,namely,the Debye plasma and quantum plasma environments are considered.The screened Coulomb potential(SCP)obtained from Debye-Hückel model is used to represent Debye plasma environments and the exponential cosine screened Coulomb potential(ECSCP)obtained from a modified Debye-Hückel model is used to represent quantum plasma environments.The resonance parameters(resonance positions and widths)are presented in terms of the screening parameters.展开更多
Theoretical analysis has demonstrated that the dispersion relation of chorus waves plays an essential role in the resonant interaction and energy transformation between the waves and magnetospheric electrons.Previous ...Theoretical analysis has demonstrated that the dispersion relation of chorus waves plays an essential role in the resonant interaction and energy transformation between the waves and magnetospheric electrons.Previous quantitative analyses often simplified the chorus dispersion relation by using the cold plasma assumption.However,the applicability of the cold plasma assumption is doubtful,especially during geomagnetic disturbances.We here present a systematic statistical analysis on the validity of the cold plasma dispersion relation of chorus waves based on observations from the Van Allen Probes over the period from 2012 to 2018.The statistical results show that the observed magnetic field intensities deviate substantially from those calculated from the cold plasma dispersion relation and that they become more pronounced with an increase in geomagnetic activity or a decrease in background plasma density.The region with large deviations is mainly concentrated in the nightside and expands in both the radial and azimuthal directions as the geomagnetic activity increases or the background plasma density decreases.In addition,the bounce-averaged electron scattering rates are computed by using the observed and cold plasma dispersion relation of chorus waves.Compared with usage of the cold plasma dispersion relation,usage of the observed dispersion relation considerably lowers the minimum resonant energy of electrons and lowers the scattering rates of electrons above tens of kiloelectronvolts but enhances those below.Furthermore,these differences are more pronounced with the enhancement of geomagnetic activity or the decrease in background plasma density.展开更多
Cold atmospheric plasmas(CAPs)have attracted considerable interest in the field of plasma medicine.Generated reactive species such as hydroxyl(OH)species play an important role in applications of CAPs.Transportation o...Cold atmospheric plasmas(CAPs)have attracted considerable interest in the field of plasma medicine.Generated reactive species such as hydroxyl(OH)species play an important role in applications of CAPs.Transportation of OH species towards the target and distribution of these OH species in the plasma plume play an important role in the applications of plasma medicine.In the present work,a computational model was built to simulate the transportation and distribution of OH species in CAP discharges,which was based on the level set method to dynamically track the propagation of plasma carrier gas in air.A reaction term was incorporated for the OH species.The OH species tended to diffuse around the main stream of the carrier gas,and thus covered larger radial and axial distances.A CAP discharge onto a skin layer led to the largest accumulation of OH species at the central part of the exposed area.The distribution of OH species on the skin was asymmetric,which agreed with experiments.The computational model itself and the obtained results would be useful for future development of plasma medicine.展开更多
The hurdle technology for food preservation effectively addresses the limitations of individual antimicrobial technologies by integrating their strengths.It can not only prolong the storage time of food but also maint...The hurdle technology for food preservation effectively addresses the limitations of individual antimicrobial technologies by integrating their strengths.It can not only prolong the storage time of food but also maintains its high quality.In this study,three antimicrobial and bactericidal technologies,namely soluble gas stabilization(SGS),modified atmosphere packaging(MAP),and cold plasma(CP),were applied to chilled chicken breasts.The packaging,total viable count(TVC),and physicochemical properties of chilled chicken breasts after treatments and storage at 4℃were monitored.The microbial diversity at the initial and end points of the storage time of each group was also analyzed.The results indicated that a 3−5 h SGS treatment can effectively increase the proportion of carbon dioxide in the MAP during the storage process of chilled chicken breasts,thereby alleviating the packaging collapse problem.Simultaneously,the effect of SGS,MAP,and CP combinational treatments significantly extended the storage time of chilled chicken breasts while maintaining the physicochemical qualities of samples.Compared to the control group,the TVC of chicken breast treated with SGS,MAP,and CP treatments decreased by 0.58(lg(CFU/g))at 0 day.The shelf life was extended by 5 days.After 8 days,the total volatile basic nitrogen(TVB-N)was 26.67 vs.19.50 mg/100 g,thiobarbituric acid reactive substances(TBARS)was 0.99 vs.0.72 mg MDA/kg,and TVC was 8.22 vs.6.52(lg(CFU/g)).High-throughput sequencing results showed that SGS and MAP treatments significantly reduce the proportion of Pseudomonas and Psychrobacter,which are sensitive to carbon dioxide,in the total bacterial genera.This study underscores the potential of integrating multiple antimicrobial technologies for effective food preservation.展开更多
It was found out that spices straight from the package are not sterile. The only way to receive sterile spices is to use radiation technology which means to irradiate spices with ionizing radiation. However, this meth...It was found out that spices straight from the package are not sterile. The only way to receive sterile spices is to use radiation technology which means to irradiate spices with ionizing radiation. However, this method is quite expensive and raises great resistance of public. And this is the reason why we are interested in implementing plasma technology. The first step of the research was to choose the most appropriate spice. The range of available spices is nearly unlimited, however, we took into account the following ones： sweet paprika, basil, rosemary, saffron, marjoram, thyme and black pepper. Finally, we chose black pepper because it is most often used by butchers to make meat products. It is also called the ＂King of Spices＂ or the ＂Black Gold＂. Black pepper is one of the most often used spices in the United States and in Europe. It is important to have sterile black pepper when we aim at ripening products for example ripening sausages or some kinds of cheeses. What is more, it was found out that black pepper has antimicrobial properties, antioxidant effects and also antipyretic and analgesic properties. The aim of the research was to receive sterile spices using low pressure cold plasma with oxygen, nitrogen, air, argon and hydrogen peroxide.展开更多
[Objective] The paper was to study the effect of cold plasma on binding strength of bamboo. [Method] The bamboos were treated by 4 kinds of cold plasma nitrogen, oxygen, ammonia and argon, and the changes of contact a...[Objective] The paper was to study the effect of cold plasma on binding strength of bamboo. [Method] The bamboos were treated by 4 kinds of cold plasma nitrogen, oxygen, ammonia and argon, and the changes of contact angle and binding strength of bamboos before and after treatment were tested. [Result] Oxygen cold plasma treatment could increase binding strength of bamboo by 25%-30%. The cold plasma treatment was very fast and effective, but the changes of contact angle was not great in this experiment. [Conclusion] Cold plasma treatment could increase the binding strength of bamboo.展开更多
In the test, woods were treated by N2, O2 cold plasma with the processing power 300 W, which last for 5 min; subsequently, the treated woods were bonded with MUF to valve the bonding performance, the contact angles of...In the test, woods were treated by N2, O2 cold plasma with the processing power 300 W, which last for 5 min; subsequently, the treated woods were bonded with MUF to valve the bonding performance, the contact angles of the treated/un- treated wood were tested. The chemical composition on the surface of wood with or without N2 cold plasma treatment was also studied by X-ray photoelectron spec- troscopy （XPS）. The results showed： the contact angles of the surface decreased; the surface free energy increased evidently that treated by N2 or O2 cold plasma; the average bonding performance of wood that treated by cold plasma （whether N2 or O2） increased obviously and more than 50% was proved compared with that un- treated by cold plasma. The XPS analysis showed the atomic ratio O/C has in- creased, and more groups were oxidized or more peroxides were formed on the surface of wood; N element was introduced to the wood surface after nitrogen cold plasma treatment and it was estimated to the group of -NH2.展开更多
Objective To observe the clinical efficacy of Wentong needling method in the treatment of long-term cough cases after common cold. Methods Wentong needling method was used in the treatment of 30 cases with long-term c...Objective To observe the clinical efficacy of Wentong needling method in the treatment of long-term cough cases after common cold. Methods Wentong needling method was used in the treatment of 30 cases with long-term cough after common cold. Acupoints including Quchi （曲池 LI 11, left side）, Hegu （合谷, LI 4, left side）, Lieque （列缺, LU 7, right side）, Fenglong （丰隆＇, ST 40, right side）, Chize （尺泽, LU 5, right side）, Zusanli （足三里, ST 36, right side）, Zhaohai （照海, KI 6, left side）, Taichong （太冲h, LR 3, both sides）, and Waiqiu （外丘, GB 36, left side） were selected. The treatment was given every other day. After one treatment course, the relation between the long-term cough cases after common cold and Wentong needling method clinical efficacy was observed from aspects of different ages, disease duration and disease degree. Results There were 18 cured cases （60.0%）, 8 markedly effective cases （26.7%）, 4 effective cases （13.33%）, and 0 invalid case （0.0%）. The total effective rate was 200%. The treatment efficacy of cough patients after common cold of less than 24 months was better than that of more than 24 months. Along with the increasing of age, the cured and markedly effective rate was of certain downward tendency. Along with the increasing of treatment times, the cured and markedly effective rate increased. Conclusion The clinical efficacy of Wentong needling method is obvious in the treatment of long-term cough cases after common cold.展开更多
Mg-based Mg-TiO2 composite powder was prepared by arc plasma evaporation of the Mg＋5%TiO2 mixture followed by passivation in air. ICP, XRD and SEM techniques were used to characterize the composition, phase component...Mg-based Mg-TiO2 composite powder was prepared by arc plasma evaporation of the Mg＋5%TiO2 mixture followed by passivation in air. ICP, XRD and SEM techniques were used to characterize the composition, phase components and microstructure of the composite powder. The hydrogen sorption properties of the composite powder were investigated by DSC and PCT techniques. According to the data from PCT measurements, the hydrogenation enthalpy and entropy changes of the composite powder are calculated to be-71.5 kJ/mol and-130.1 J/（K·mol）, respectively. Besides, the hydrogenation activation energy is determined to be 77.2 kJ/ mol. The results indicate that TiO2 added into Mg by arc plasma method can act as a catalyst to improve the hydrogen sorption kinetic properties of Mg.展开更多
This study investigated the effect of cold helium plasma treatment on seed germina- tion, growth and yield of wheat. The effects of different power of cold plasma on the germination of treated wheat seeds were studied...This study investigated the effect of cold helium plasma treatment on seed germina- tion, growth and yield of wheat. The effects of different power of cold plasma on the germination of treated wheat seeds were studied. We found that the treatment of 80 W could significantly improve seed germination potential （6.0%） and germination rate （6.7%） compared to the control group. Field experiments were carried out for wheat seeds treated with 80 W cold plasma. Com- pared with the control, plant height （20.3%）, root length （9.0%） and fresh weight （21.8%） were improved significantly at seedling stage. At booting stage, plant height, root length, fresh weight, stem diameter, leaf area and leaf thickness of the treated plant were respectively increased by 21.8%, 11.0%, 7.0%, 9.0%, 13.0% and 25.5%. At the same time, the chlorophyll content （9.8%）, nitrogen （10.0%） and moisture content （10.0%） were higher than those of the control, indicating that cold plasma treatment could promote the growth of wheat. The yield of treated wheat was 7.55 t-ha-1, 5.89% more than that of the control. Therefore, our results show that cold plasma has important application prospects for increasing wheat yield.展开更多
The effect of different cold plasma treatments on the germination and seedling growth of alfalfa（Medicago sativa L.） seeds under simulated drought stress conditions was investigated.Polyethyleneglycol-6000（PEG 6000...The effect of different cold plasma treatments on the germination and seedling growth of alfalfa（Medicago sativa L.） seeds under simulated drought stress conditions was investigated.Polyethyleneglycol-6000（PEG 6000）with the mass fraction of 0%（purified water）, 5%, 10%,and 15% were applied to simulate the drought environment. The alfalfa seeds were treated with15 different power levels ranged between 0–280 W for 15 s. The germination potential,germination rate, germination index, seedling root length, seedling height, and vigor index were investigated. Results indicated significant differences between treated with proper power and untreated alfalfa seeds. With the increase of treatment power, these indexes mentioned above almost presented bimodal curves. Under the different mass fractions of PEG 6000, results showed that the lower power led to increased germination, and the seedlings presented good adaptability to different drought conditions. Meanwhile, higher power levels resulted in a decreased germination rate. Seeds treated with 40 W resulted in higher germination potential,germination rate, seedling height, root length, and vigor index. Vigor indexes of the treated seeds under different PEG 6000 stresses increased by 38.68%, 43.91%, 74.34%, and 39.20%respectively compared to CK_（0-0）, CK_（5-0）, CK_（10-0）, and CK_（15-0）（the control sample under 0%, 5%,10%, and 15% PEG 6000）. Therefore, 40 W was regarded as the best treatment in this research.Although the trend indexes of alfalfa seeds treated with the same power were statistically the same under different PEG 6000 stresses, the cold plasma treatment had a significant effect on the adaptability of alfalfa seeds in different drought environments. Thus, this kind of treatment is worth implementing to promote seed growth under drought situations.展开更多
This paper presents the interactions between two cold atmospheric plasma jets. By changing the experimental conditions including the gas flow rate, the applied voltage, the power supply frequency and the inter-electro...This paper presents the interactions between two cold atmospheric plasma jets. By changing the experimental conditions including the gas flow rate, the applied voltage, the power supply frequency and the inter-electrode distance d, three different interaction modes, attraction, repulsion and combination, were observed. It is shown that the interaction modes of the two jets are principally affected by the electrodes, the gas flow rate, the plasma jets and the power supply frequency.展开更多
The effects of low-vacuum helium cold plasma treatment on the seed germination,plant growth and yield of oilseed rape（Brassica napus L.cv.Zhongshuang 9） were investigated.Seeds were exposed to low-vacuum helium cold...The effects of low-vacuum helium cold plasma treatment on the seed germination,plant growth and yield of oilseed rape（Brassica napus L.cv.Zhongshuang 9） were investigated.Seeds were exposed to low-vacuum helium cold plasma ranging from 0-120 W for 15 s.Cold plasma increased the germination,plant growth and yield of oilseed rape,and the treatment of 100 W provided the best result.The germination rate,germination and vigor indices,and uniformity of emergence were improved by cold plasma treatment.Cold plasma raised the relative conductivity and water uptake,and reduced the apparent contact angle.The characteristics of plant growth,including plant height,stem diameter,dry weights of shoot and root at the seedling,bolting and flowering stages were increased by the cold plasma treatment.Yield components,including pod numbers per plant and 1000 seed weights were increased by the cold plasma treatment.Furthermore,the yield per plant increased by 28.20%.These results suggest that cold plasma treatment has the potential to improve the yield of oilseed rape through the enhancement of permeability,wettability and capacity of water uptake of the seeds,seed germination and plant growth.展开更多
We report spectroscopic studies on plasma electron number density of laser-induced plasma produced by ns-Nd：YAG laser light pulses on an aluminum sample in air at atmospheric pressure. The effect of different laser e...We report spectroscopic studies on plasma electron number density of laser-induced plasma produced by ns-Nd：YAG laser light pulses on an aluminum sample in air at atmospheric pressure. The effect of different laser energy and the effect of different laser wavelengths were compared. The experimentally observed line profiles of neutral aluminum have been used to extract the excitation temperature using the Boltzmann plot method, whereas the electron number density has been determined from the Stark broadened as well as using the Saha-Boltzmann equation （SBE）. Each approach was also carried out by using the AI emission line and Mg emission lines. It was observed that the,SBE method generated a little higher electron number density value than the Stark broadening, method, but within the experimental uncertainty range. Comparisons of Ne determined by the two methods show the presence of a linear relation which is independent of laser energy or laser wavelength. These results show the applicability of the SBE method for Are determination, especially when the system does not have any pure emission lines whose electron impact factor is known, Also use of Mg lines gives superior results than Al lines.展开更多
Cold atmospheric plasmas(CAPs)have shown great applicability in agriculture.Many kinds of CAP sources have been studied in agricultural applications to promote plant growth and cure plant diseases.We briefly review th...Cold atmospheric plasmas(CAPs)have shown great applicability in agriculture.Many kinds of CAP sources have been studied in agricultural applications to promote plant growth and cure plant diseases.We briefly review the state-of-the-art stimulating effects of atmospheric-pressure dielectricbarrier-discharge(AP-DBD)plasmas,after the direct or indirect treatment of plants for growth promotion and disease control.We then discuss the special demands on the characteristics of the CAP sources for their applications in plant mutation breeding.An atmospheric and room temperature plasma(ARTP)jet generator with a large plasma irradiation area,a high enough concentration of chemically reactive species and a low gas temperature is designed for direct plant mutagenesis.Experimental measurements of the electrical,thermal and optical features of the ARTP generator are conducted.Then,an ARTP-P(ARTP for plant mutagenesis)mutation breeding machine is developed,and a typical case of plant mutation breeding by the ARTP-P mutation machine is presented using Coreopsis tinctoria Nutt.seeds.Physical and agricultural experiments show that the newly-developed ARTP-P mutation breeding machine with a large irradiation area can generate uniform CAP jets with high concentrations of chemically reactive species and mild gas temperatures,and have signiflcant mutagenesis effects on the Coreopsis tinctoria Nutt.seeds.The ARTP-P mutation breeding machine may provide a platform for systematic studies on mutation mechanisms and results for various plant seeds under different operating conditions in future research.展开更多
Rolling force and rolling moment are prime process parameter of external spline cold rolling.However,the precise theoretical formulae of rolling force and rolling moment are still very fewer,and the determination of t...Rolling force and rolling moment are prime process parameter of external spline cold rolling.However,the precise theoretical formulae of rolling force and rolling moment are still very fewer,and the determination of them depends on experience.In the present study,the mathematical models of rolling force and rolling moment are established based on stress field theory of slip-line.And the isotropic hardening is used to improve the yield criterion.Based on MATLAB program language environment,calculation program is developed according to mathematical models established.The rolling force and rolling moment could be predicted quickly via the calculation program,and then the reliability of the models is validated by FEM.Within the range of module of spline m=0.5-1.5 mm,pressure angle of reference circleα=30.0°-45.0°,and number of spline teeth Z=19-54,the rolling force and rolling moment in rolling process(finishing rolling is excluded)are researched by means of virtualizing orthogonal experiment design.The results of the present study indicate that:the influences of module and number of spline teeth on the maximum rolling force and rolling moment in the process are remarkable;in the case of pressure angle of reference circle is little,module of spline is great,and number of spline teeth is little,the peak value of rolling force in rolling process may appear in the midst of the process;the peak value of rolling moment in rolling process appears in the midst of the process,and then oscillator weaken to a stable value.The results of the present study may provide guidelines for the determination of power of the motor and the design of hydraulic system of special machine,and provide basis for the farther researches on the precise forming process of external spline cold rolling.展开更多
Oily cold rolling mill （CRM） sludge is one of the pollutants emitted by iron and steel plants. Recycling oily CRM sludge can not only reduce pollution but also bring social and environmental benefits. In this study,...Oily cold rolling mill （CRM） sludge is one of the pollutants emitted by iron and steel plants. Recycling oily CRM sludge can not only reduce pollution but also bring social and environmental benefits. In this study, using oily CRM sludge as sources of iron oxide, the strontium ferrite powders were synthesized in multiple steps including vacuum distillation, magnetic separation, oxidizing roasting, and solidstate reaction. The optimal technological conditions of vacuum distillation and oxidizing roasting were studied carefully. To consider the effects of Fe203/ SrCO3 tool ratio, calcination temperature, milling time and calcination time on magnetic properties of prepared strontium ferrite powders, the orthogonal experimental method was adopted. The maximum saturation magneti- zation （62.6 mA-m2.g-1） of the synthesized strontium ferrite powders was achieved at the Fe203/SrCO3 mol ratio of 6, 5 h milling time, 1250 ~C calcination temperature, and 1 h calcination time. Strontium ferrite powders syn- thesis method not only provides a cheap, high quality raw material for the production of strontium ferrite powders, but also effectively prevents the environmental pollution.展开更多
The piecewise linear recursive convolution （PLRC） finite-different time-domain （FDTD） method greatly improves accuracy over the original recursive convolution （RC） FDTD approach but retains its speed and efficie...The piecewise linear recursive convolution （PLRC） finite-different time-domain （FDTD） method greatly improves accuracy over the original recursive convolution （RC） FDTD approach but retains its speed and efficiency advantages. A PLRC-FDTD formulation for magnetized plasma which incorporates both anisotropy and frequency dispersion at the same time is presented, enabled the transient analysis of magnetized plasma media. The technique is illustrated by numerical simulations the reflection and transmission coefficients through a magnetized plasma layer. The results show that the PLRC-FDTD method has significantly improved the accuracy over the original RC method.展开更多
Surface-grafted poly(ethylene glycol) (PEG) molecules are known to prevent protein adsorption to the surface. Nitinol samples were coated under tetraglyme ECR cold plasma conditions to enhance its biocompatibility. Th...Surface-grafted poly(ethylene glycol) (PEG) molecules are known to prevent protein adsorption to the surface. Nitinol samples were coated under tetraglyme ECR cold plasma conditions to enhance its biocompatibility. The modified Nitinol surfaces were characterized by high resolution ESCA and contact angle, it was demonstrated that the deposited PEG-like coatings were built up mainly of-CH2-CH2-O- linkages in surfaces. The surface wettability of the modified Nitinol was increased compared with the control surface. Human plasma protein was adsorbed on Nitinol evaluated by SEM, the protein adsorption on modified surfaces decreased rapidly. Thus, the potential benefits of cold plasma technique will be of use to the biomedical industries improving the biocompatibility of metals.展开更多
文摘The paper presented the results regarding the decomposition of gaseous CF_2ClB_r by cold plasma method.After two minutes discharge,the maximum decomposition rate of 2660 Pa CF_2ClB_r pure and 2660 Pa CF_2ClBr plus 7980 Pa O_2 reached 60% and 80%,respectively.The pa- per also studied the cold plasma gas phase chemistry reaction mechanism of CF_2ClBr at low pres- sure,and the pressure effects of CF_2ClBr and added gas(He,N_2,O_2 and dry air)on the CF_2ClBr decomposition respectively by cold plasma method.These studies will be helpful to application of cold plasma method in the treatment of hazardous gaseous wastes.
基金Supported by the Natural Science Foundation of Heilongjiang Province(LH2024A025)。
文摘The effects of plasma screening on the ^(1)P^(o) resonance states of H-and He below the n=3 and n=4 thresholds of the respective subsystemsare investigated using the stabilization method and correlated exponential wave functions.Two plasma mediums,namely,the Debye plasma and quantum plasma environments are considered.The screened Coulomb potential(SCP)obtained from Debye-Hückel model is used to represent Debye plasma environments and the exponential cosine screened Coulomb potential(ECSCP)obtained from a modified Debye-Hückel model is used to represent quantum plasma environments.The resonance parameters(resonance positions and widths)are presented in terms of the screening parameters.
基金supported by the National Natural Science Foundation of China (NSFC) through Grant Number 42074193
文摘Theoretical analysis has demonstrated that the dispersion relation of chorus waves plays an essential role in the resonant interaction and energy transformation between the waves and magnetospheric electrons.Previous quantitative analyses often simplified the chorus dispersion relation by using the cold plasma assumption.However,the applicability of the cold plasma assumption is doubtful,especially during geomagnetic disturbances.We here present a systematic statistical analysis on the validity of the cold plasma dispersion relation of chorus waves based on observations from the Van Allen Probes over the period from 2012 to 2018.The statistical results show that the observed magnetic field intensities deviate substantially from those calculated from the cold plasma dispersion relation and that they become more pronounced with an increase in geomagnetic activity or a decrease in background plasma density.The region with large deviations is mainly concentrated in the nightside and expands in both the radial and azimuthal directions as the geomagnetic activity increases or the background plasma density decreases.In addition,the bounce-averaged electron scattering rates are computed by using the observed and cold plasma dispersion relation of chorus waves.Compared with usage of the cold plasma dispersion relation,usage of the observed dispersion relation considerably lowers the minimum resonant energy of electrons and lowers the scattering rates of electrons above tens of kiloelectronvolts but enhances those below.Furthermore,these differences are more pronounced with the enhancement of geomagnetic activity or the decrease in background plasma density.
基金funded by National Natural Science Foundation of China (Nos. U1632145, 81573093 and 81227902)funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD) and Jiangsu Provincial Key Laboratory of Radiation Medicine and Protection, China Postdoctoral Science Foundation (No. 2016M592584)Strategic Research Grant 7004641 from City University of Hong Kong
文摘Cold atmospheric plasmas(CAPs)have attracted considerable interest in the field of plasma medicine.Generated reactive species such as hydroxyl(OH)species play an important role in applications of CAPs.Transportation of OH species towards the target and distribution of these OH species in the plasma plume play an important role in the applications of plasma medicine.In the present work,a computational model was built to simulate the transportation and distribution of OH species in CAP discharges,which was based on the level set method to dynamically track the propagation of plasma carrier gas in air.A reaction term was incorporated for the OH species.The OH species tended to diffuse around the main stream of the carrier gas,and thus covered larger radial and axial distances.A CAP discharge onto a skin layer led to the largest accumulation of OH species at the central part of the exposed area.The distribution of OH species on the skin was asymmetric,which agreed with experiments.The computational model itself and the obtained results would be useful for future development of plasma medicine.
基金supported by the National Natural Science Foundation of China(32272252)the China Agriculture Research System(CARS-41)funded by the Chinese Ministry of Agriculture and Rural Affairs and Wens Fifth Five R&D Major Project(WENS-2020-1-ZDZX-007).
文摘The hurdle technology for food preservation effectively addresses the limitations of individual antimicrobial technologies by integrating their strengths.It can not only prolong the storage time of food but also maintains its high quality.In this study,three antimicrobial and bactericidal technologies,namely soluble gas stabilization(SGS),modified atmosphere packaging(MAP),and cold plasma(CP),were applied to chilled chicken breasts.The packaging,total viable count(TVC),and physicochemical properties of chilled chicken breasts after treatments and storage at 4℃were monitored.The microbial diversity at the initial and end points of the storage time of each group was also analyzed.The results indicated that a 3−5 h SGS treatment can effectively increase the proportion of carbon dioxide in the MAP during the storage process of chilled chicken breasts,thereby alleviating the packaging collapse problem.Simultaneously,the effect of SGS,MAP,and CP combinational treatments significantly extended the storage time of chilled chicken breasts while maintaining the physicochemical qualities of samples.Compared to the control group,the TVC of chicken breast treated with SGS,MAP,and CP treatments decreased by 0.58(lg(CFU/g))at 0 day.The shelf life was extended by 5 days.After 8 days,the total volatile basic nitrogen(TVB-N)was 26.67 vs.19.50 mg/100 g,thiobarbituric acid reactive substances(TBARS)was 0.99 vs.0.72 mg MDA/kg,and TVC was 8.22 vs.6.52(lg(CFU/g)).High-throughput sequencing results showed that SGS and MAP treatments significantly reduce the proportion of Pseudomonas and Psychrobacter,which are sensitive to carbon dioxide,in the total bacterial genera.This study underscores the potential of integrating multiple antimicrobial technologies for effective food preservation.
文摘It was found out that spices straight from the package are not sterile. The only way to receive sterile spices is to use radiation technology which means to irradiate spices with ionizing radiation. However, this method is quite expensive and raises great resistance of public. And this is the reason why we are interested in implementing plasma technology. The first step of the research was to choose the most appropriate spice. The range of available spices is nearly unlimited, however, we took into account the following ones： sweet paprika, basil, rosemary, saffron, marjoram, thyme and black pepper. Finally, we chose black pepper because it is most often used by butchers to make meat products. It is also called the ＂King of Spices＂ or the ＂Black Gold＂. Black pepper is one of the most often used spices in the United States and in Europe. It is important to have sterile black pepper when we aim at ripening products for example ripening sausages or some kinds of cheeses. What is more, it was found out that black pepper has antimicrobial properties, antioxidant effects and also antipyretic and analgesic properties. The aim of the research was to receive sterile spices using low pressure cold plasma with oxygen, nitrogen, air, argon and hydrogen peroxide.
基金Supported by Opening Research Project for Key Laboratory of Bamboo in Zhejiang Forestry Academy(2010K04)~~
文摘[Objective] The paper was to study the effect of cold plasma on binding strength of bamboo. [Method] The bamboos were treated by 4 kinds of cold plasma nitrogen, oxygen, ammonia and argon, and the changes of contact angle and binding strength of bamboos before and after treatment were tested. [Result] Oxygen cold plasma treatment could increase binding strength of bamboo by 25%-30%. The cold plasma treatment was very fast and effective, but the changes of contact angle was not great in this experiment. [Conclusion] Cold plasma treatment could increase the binding strength of bamboo.
基金Supported by National Natural Science Foundation of China(Project No.30930074)the Construction of Bamboo Research Innovation in Zhejiang Forestry Academy(No2012F20024)~~
文摘In the test, woods were treated by N2, O2 cold plasma with the processing power 300 W, which last for 5 min; subsequently, the treated woods were bonded with MUF to valve the bonding performance, the contact angles of the treated/un- treated wood were tested. The chemical composition on the surface of wood with or without N2 cold plasma treatment was also studied by X-ray photoelectron spec- troscopy （XPS）. The results showed： the contact angles of the surface decreased; the surface free energy increased evidently that treated by N2 or O2 cold plasma; the average bonding performance of wood that treated by cold plasma （whether N2 or O2） increased obviously and more than 50% was proved compared with that un- treated by cold plasma. The XPS analysis showed the atomic ratio O/C has in- creased, and more groups were oxidized or more peroxides were formed on the surface of wood; N element was introduced to the wood surface after nitrogen cold plasma treatment and it was estimated to the group of -NH2.
文摘Objective To observe the clinical efficacy of Wentong needling method in the treatment of long-term cough cases after common cold. Methods Wentong needling method was used in the treatment of 30 cases with long-term cough after common cold. Acupoints including Quchi （曲池 LI 11, left side）, Hegu （合谷, LI 4, left side）, Lieque （列缺, LU 7, right side）, Fenglong （丰隆＇, ST 40, right side）, Chize （尺泽, LU 5, right side）, Zusanli （足三里, ST 36, right side）, Zhaohai （照海, KI 6, left side）, Taichong （太冲h, LR 3, both sides）, and Waiqiu （外丘, GB 36, left side） were selected. The treatment was given every other day. After one treatment course, the relation between the long-term cough cases after common cold and Wentong needling method clinical efficacy was observed from aspects of different ages, disease duration and disease degree. Results There were 18 cured cases （60.0%）, 8 markedly effective cases （26.7%）, 4 effective cases （13.33%）, and 0 invalid case （0.0%）. The total effective rate was 200%. The treatment efficacy of cough patients after common cold of less than 24 months was better than that of more than 24 months. Along with the increasing of age, the cured and markedly effective rate was of certain downward tendency. Along with the increasing of treatment times, the cured and markedly effective rate increased. Conclusion The clinical efficacy of Wentong needling method is obvious in the treatment of long-term cough cases after common cold.
基金Project(11ZR1417600)supported by Shanghai Natural Science Foundation from Science and Technology Committee of Shanghai,ChinaProject(11PJ1406000)supported by‘Pujiang’Project from the Science and Technology Committee of Shanghai+1 种基金Project(12ZZ017)supported by Shanghai Education Commission,ChinaProject(20100073120007)supported by China Education Commission
文摘Mg-based Mg-TiO2 composite powder was prepared by arc plasma evaporation of the Mg＋5%TiO2 mixture followed by passivation in air. ICP, XRD and SEM techniques were used to characterize the composition, phase components and microstructure of the composite powder. The hydrogen sorption properties of the composite powder were investigated by DSC and PCT techniques. According to the data from PCT measurements, the hydrogenation enthalpy and entropy changes of the composite powder are calculated to be-71.5 kJ/mol and-130.1 J/（K·mol）, respectively. Besides, the hydrogenation activation energy is determined to be 77.2 kJ/ mol. The results indicate that TiO2 added into Mg by arc plasma method can act as a catalyst to improve the hydrogen sorption kinetic properties of Mg.
基金supported by Jiangsu Province Science and Technology Support Program of China(No.BE2013452)Main Direction Program of Knowledge Innovation of Chinese Academy of Sciences(No.KSCX-EW-B-6)
文摘This study investigated the effect of cold helium plasma treatment on seed germina- tion, growth and yield of wheat. The effects of different power of cold plasma on the germination of treated wheat seeds were studied. We found that the treatment of 80 W could significantly improve seed germination potential （6.0%） and germination rate （6.7%） compared to the control group. Field experiments were carried out for wheat seeds treated with 80 W cold plasma. Com- pared with the control, plant height （20.3%）, root length （9.0%） and fresh weight （21.8%） were improved significantly at seedling stage. At booting stage, plant height, root length, fresh weight, stem diameter, leaf area and leaf thickness of the treated plant were respectively increased by 21.8%, 11.0%, 7.0%, 9.0%, 13.0% and 25.5%. At the same time, the chlorophyll content （9.8%）, nitrogen （10.0%） and moisture content （10.0%） were higher than those of the control, indicating that cold plasma treatment could promote the growth of wheat. The yield of treated wheat was 7.55 t-ha-1, 5.89% more than that of the control. Therefore, our results show that cold plasma has important application prospects for increasing wheat yield.
基金supported by China Agriculture Research System(CARS-34)
文摘The effect of different cold plasma treatments on the germination and seedling growth of alfalfa（Medicago sativa L.） seeds under simulated drought stress conditions was investigated.Polyethyleneglycol-6000（PEG 6000）with the mass fraction of 0%（purified water）, 5%, 10%,and 15% were applied to simulate the drought environment. The alfalfa seeds were treated with15 different power levels ranged between 0–280 W for 15 s. The germination potential,germination rate, germination index, seedling root length, seedling height, and vigor index were investigated. Results indicated significant differences between treated with proper power and untreated alfalfa seeds. With the increase of treatment power, these indexes mentioned above almost presented bimodal curves. Under the different mass fractions of PEG 6000, results showed that the lower power led to increased germination, and the seedlings presented good adaptability to different drought conditions. Meanwhile, higher power levels resulted in a decreased germination rate. Seeds treated with 40 W resulted in higher germination potential,germination rate, seedling height, root length, and vigor index. Vigor indexes of the treated seeds under different PEG 6000 stresses increased by 38.68%, 43.91%, 74.34%, and 39.20%respectively compared to CK_（0-0）, CK_（5-0）, CK_（10-0）, and CK_（15-0）（the control sample under 0%, 5%,10%, and 15% PEG 6000）. Therefore, 40 W was regarded as the best treatment in this research.Although the trend indexes of alfalfa seeds treated with the same power were statistically the same under different PEG 6000 stresses, the cold plasma treatment had a significant effect on the adaptability of alfalfa seeds in different drought environments. Thus, this kind of treatment is worth implementing to promote seed growth under drought situations.
基金supported by National Natural Science Foundation of China (Nos.50537020,50528707)
文摘This paper presents the interactions between two cold atmospheric plasma jets. By changing the experimental conditions including the gas flow rate, the applied voltage, the power supply frequency and the inter-electrode distance d, three different interaction modes, attraction, repulsion and combination, were observed. It is shown that the interaction modes of the two jets are principally affected by the electrodes, the gas flow rate, the plasma jets and the power supply frequency.
基金supported by the National Key Research and Development Program of China(Nos.2016YFD0200305,2017YFD0200604)the Knowledge Innovation Program of the Institute of Soil Science,the Chinese Academy of Sciences(No.ISSASIP1634)+2 种基金the Jiangsu Provincial Public Institutions Program for Research Conditions and Building Capacity(No.BM2015019)the Foundation of Jiangsu Key Laboratory for the Research and Utilization of Plant Resources(No.JSPKLB201606)the Suzhou Xiangcheng District Science and Technology Project(No.201703)
文摘The effects of low-vacuum helium cold plasma treatment on the seed germination,plant growth and yield of oilseed rape（Brassica napus L.cv.Zhongshuang 9） were investigated.Seeds were exposed to low-vacuum helium cold plasma ranging from 0-120 W for 15 s.Cold plasma increased the germination,plant growth and yield of oilseed rape,and the treatment of 100 W provided the best result.The germination rate,germination and vigor indices,and uniformity of emergence were improved by cold plasma treatment.Cold plasma raised the relative conductivity and water uptake,and reduced the apparent contact angle.The characteristics of plant growth,including plant height,stem diameter,dry weights of shoot and root at the seedling,bolting and flowering stages were increased by the cold plasma treatment.Yield components,including pod numbers per plant and 1000 seed weights were increased by the cold plasma treatment.Furthermore,the yield per plant increased by 28.20%.These results suggest that cold plasma treatment has the potential to improve the yield of oilseed rape through the enhancement of permeability,wettability and capacity of water uptake of the seeds,seed germination and plant growth.
文摘We report spectroscopic studies on plasma electron number density of laser-induced plasma produced by ns-Nd：YAG laser light pulses on an aluminum sample in air at atmospheric pressure. The effect of different laser energy and the effect of different laser wavelengths were compared. The experimentally observed line profiles of neutral aluminum have been used to extract the excitation temperature using the Boltzmann plot method, whereas the electron number density has been determined from the Stark broadened as well as using the Saha-Boltzmann equation （SBE）. Each approach was also carried out by using the AI emission line and Mg emission lines. It was observed that the,SBE method generated a little higher electron number density value than the Stark broadening, method, but within the experimental uncertainty range. Comparisons of Ne determined by the two methods show the presence of a linear relation which is independent of laser energy or laser wavelength. These results show the applicability of the SBE method for Are determination, especially when the system does not have any pure emission lines whose electron impact factor is known, Also use of Mg lines gives superior results than Al lines.
基金supported by the National Key Research and Development Program of China(No.2016YFD0102106)National Natural Science Foundation of China(Nos.11475103,21627812)。
文摘Cold atmospheric plasmas(CAPs)have shown great applicability in agriculture.Many kinds of CAP sources have been studied in agricultural applications to promote plant growth and cure plant diseases.We briefly review the state-of-the-art stimulating effects of atmospheric-pressure dielectricbarrier-discharge(AP-DBD)plasmas,after the direct or indirect treatment of plants for growth promotion and disease control.We then discuss the special demands on the characteristics of the CAP sources for their applications in plant mutation breeding.An atmospheric and room temperature plasma(ARTP)jet generator with a large plasma irradiation area,a high enough concentration of chemically reactive species and a low gas temperature is designed for direct plant mutagenesis.Experimental measurements of the electrical,thermal and optical features of the ARTP generator are conducted.Then,an ARTP-P(ARTP for plant mutagenesis)mutation breeding machine is developed,and a typical case of plant mutation breeding by the ARTP-P mutation machine is presented using Coreopsis tinctoria Nutt.seeds.Physical and agricultural experiments show that the newly-developed ARTP-P mutation breeding machine with a large irradiation area can generate uniform CAP jets with high concentrations of chemically reactive species and mild gas temperatures,and have signiflcant mutagenesis effects on the Coreopsis tinctoria Nutt.seeds.The ARTP-P mutation breeding machine may provide a platform for systematic studies on mutation mechanisms and results for various plant seeds under different operating conditions in future research.
基金supported by National Natural Science Foundation of China(Grant No.50675145)Shanxi Provincial Key Project of Science and Technology of China(Grant No.2006031147)+1 种基金Shanxi Provincial Innovation Project for Graduate Students of China(Grant No.20061027)Shanxi Provincial Key Project for Studied-abroad Returnee of China
文摘Rolling force and rolling moment are prime process parameter of external spline cold rolling.However,the precise theoretical formulae of rolling force and rolling moment are still very fewer,and the determination of them depends on experience.In the present study,the mathematical models of rolling force and rolling moment are established based on stress field theory of slip-line.And the isotropic hardening is used to improve the yield criterion.Based on MATLAB program language environment,calculation program is developed according to mathematical models established.The rolling force and rolling moment could be predicted quickly via the calculation program,and then the reliability of the models is validated by FEM.Within the range of module of spline m=0.5-1.5 mm,pressure angle of reference circleα=30.0°-45.0°,and number of spline teeth Z=19-54,the rolling force and rolling moment in rolling process(finishing rolling is excluded)are researched by means of virtualizing orthogonal experiment design.The results of the present study indicate that:the influences of module and number of spline teeth on the maximum rolling force and rolling moment in the process are remarkable;in the case of pressure angle of reference circle is little,module of spline is great,and number of spline teeth is little,the peak value of rolling force in rolling process may appear in the midst of the process;the peak value of rolling moment in rolling process appears in the midst of the process,and then oscillator weaken to a stable value.The results of the present study may provide guidelines for the determination of power of the motor and the design of hydraulic system of special machine,and provide basis for the farther researches on the precise forming process of external spline cold rolling.
基金supported by the National Key Technology R&D Program (Nos. 2012BAC02B01, 2012BAC12B05, 2011BAE13B07, and 2011BAC10B02)the National High Technology Research and Development Program of China (No. 2012AA063202)+2 种基金the National Natural Science Foundation of China (Nos. 51174247 and 51004011)the Science and Technology Program of Guangdong Province, China (No. 2010A030200003)the Ph.D. Programs Foundation of the Ministry of Education of China (No. 2010000612003)
文摘Oily cold rolling mill （CRM） sludge is one of the pollutants emitted by iron and steel plants. Recycling oily CRM sludge can not only reduce pollution but also bring social and environmental benefits. In this study, using oily CRM sludge as sources of iron oxide, the strontium ferrite powders were synthesized in multiple steps including vacuum distillation, magnetic separation, oxidizing roasting, and solidstate reaction. The optimal technological conditions of vacuum distillation and oxidizing roasting were studied carefully. To consider the effects of Fe203/ SrCO3 tool ratio, calcination temperature, milling time and calcination time on magnetic properties of prepared strontium ferrite powders, the orthogonal experimental method was adopted. The maximum saturation magneti- zation （62.6 mA-m2.g-1） of the synthesized strontium ferrite powders was achieved at the Fe203/SrCO3 mol ratio of 6, 5 h milling time, 1250 ~C calcination temperature, and 1 h calcination time. Strontium ferrite powders syn- thesis method not only provides a cheap, high quality raw material for the production of strontium ferrite powders, but also effectively prevents the environmental pollution.
基金The project was supported by the National Natural Science Foundation of China (60471002) and the Jiangxi ProvincialNatural Science Foundation (0412014)
文摘The piecewise linear recursive convolution （PLRC） finite-different time-domain （FDTD） method greatly improves accuracy over the original recursive convolution （RC） FDTD approach but retains its speed and efficiency advantages. A PLRC-FDTD formulation for magnetized plasma which incorporates both anisotropy and frequency dispersion at the same time is presented, enabled the transient analysis of magnetized plasma media. The technique is illustrated by numerical simulations the reflection and transmission coefficients through a magnetized plasma layer. The results show that the PLRC-FDTD method has significantly improved the accuracy over the original RC method.
基金The project was supported by the National Natural Science Foundation of China(NSFC)(Grant No.19972071,50274065)subsidized by the Special Funds for Major State Basic Research Project(“973”Project)(Grant No.2002CB412704).
文摘Surface-grafted poly(ethylene glycol) (PEG) molecules are known to prevent protein adsorption to the surface. Nitinol samples were coated under tetraglyme ECR cold plasma conditions to enhance its biocompatibility. The modified Nitinol surfaces were characterized by high resolution ESCA and contact angle, it was demonstrated that the deposited PEG-like coatings were built up mainly of-CH2-CH2-O- linkages in surfaces. The surface wettability of the modified Nitinol was increased compared with the control surface. Human plasma protein was adsorbed on Nitinol evaluated by SEM, the protein adsorption on modified surfaces decreased rapidly. Thus, the potential benefits of cold plasma technique will be of use to the biomedical industries improving the biocompatibility of metals.
