The electrically assisted(EA)deformation process has received considerable attention in recent years,ac-companied by research on current-induced deformation mechanisms.However,there are still challenges in eliminating...The electrically assisted(EA)deformation process has received considerable attention in recent years,ac-companied by research on current-induced deformation mechanisms.However,there are still challenges in eliminating thermal effects,which have prevented a comprehensive understanding of the underlying current-induced mechanisms.Opting for a single crystal(SC)in research provides advantages in decou-pling the nonthermal effect of electric current at smaller scales and eliminating the complex interactions that exist in polycrystalline materials.Therefore,the innovation of this work lies in decoupling the non-thermal effect of electric current and conducting a comprehensive analysis of anisotropic deformation and mechanisms within a Ni-based SC with different crystallographic axes and various current directions dur-ing electrically assisted tensile simulation.A significant tension axis direction in the SC during EA tension was induced by the combination of a higher current direction factor(|cosθ|)and a dimensionless factor for the current density(|J^(α)/J_(0)^(α)|)along the[100]axis.The stress drop within the SC due to the nonthermal effect of electric current generally increased with increasing current direction.This was attributed to the increased dislocation density differences and decreased temperature.The increased stress anisotropy of the SC at a current direction of 45°was attributed to fewer activated(111)slip systems and the pinning effect of more dislocations within these systems.This study advances our understanding of the thermal and nonthermal effects of electric current and offers valuable insights for the informed application of EA deformations in industrial and aerospace settings with SC superalloys.展开更多
The humidity effects on the benzene decomposition process were investigated by the dielectric barrier discharge（DBD） plasma reactor.The results showed that the water vapor played an important role in the benzene oxi...The humidity effects on the benzene decomposition process were investigated by the dielectric barrier discharge（DBD） plasma reactor.The results showed that the water vapor played an important role in the benzene oxidation process.It was found that there was an optimum humidity value for the benzene removal efficiency,and at around 60% relative humidity（RH）,the optimum benzene removal efficiency was achieved.At a SIE of 378 J/L,the removal efficiency was 66% at 0% RH,while the removal efficiency reached 75.3% at 60% RH and dropped to 69% at 80% RH.Furthermore,the addition of water inhibited the formation of ozone and NO2 remarkably.Both of the concentrations of ozone and NO2 decreased with increasing of the RH at the same specific input energy.At a SIE of 256 J/L,the concentrations of ozone and NO2 were 5.4 mg/L and 1791 ppm under dry conditions,whereas they were only 3.4 mg/L and 1119 ppm at 63.5%RH,respectively.Finally,the outlet gas after benzene degradation was qualitatively analyzed by FT-IR and GC-MS to determine possible intermediate byproducts.The results suggested that the byproducts in decomposition of benzene primarily consisted of phenol and substitutions of phenol.Based on these byproducts a benzene degradation mechanism was proposed.展开更多
In this study, we employed a nonthermal atmospheric pressure plasma(NTAPP) jet to evaluate the effect of plasma treatment on the durability of resin–dentin bonding under a thermocycling challenge. Furthermore, we ass...In this study, we employed a nonthermal atmospheric pressure plasma(NTAPP) jet to evaluate the effect of plasma treatment on the durability of resin–dentin bonding under a thermocycling challenge. Furthermore, we assessed the degradation resistance of plasma-treated collagen under a sodium hypochlorite(NaClO) challenge. We assessed the beneficial effect of NTAPP treatment on the acid-etched dentin–bonding interface by testing the micro-tensile bond strength and examining the morphology. We found that the immediate bonding strength of the dentin significantly increased after NTAPP treatment. Compared with the control group, NTAPP resulted in a more prominent effect on the bonding durability of the dentin–adhesive interface after treatment for 5 or 10 s. Simultaneously, the mechanical strength of dentin collagen under the NaClO challenge was improved. Our results indicate that, in optimal conditions, NTAPP could be a promising method to protect dentin collagen and to improve the bonding durability between dentin and etch-and-rinse adhesives.展开更多
Using a new tortoise coordinate transformation, this paper investigates the Hawking effect from an arbitrarily accelerating charged black hole by the improved Damour-Ruffini method. After the tortoise coordinate trans...Using a new tortoise coordinate transformation, this paper investigates the Hawking effect from an arbitrarily accelerating charged black hole by the improved Damour-Ruffini method. After the tortoise coordinate transformation, the Klein-Gordon equation can be written as the standard form at the event horizon. Then extending the outgoing wave from outside to inside of the horizon analytically, the surface gravity and Hawking temperature can be obtained automatically. It is found that the Hawking temperatures of different points on the surface are different. The quantum nonthermal radiation characteristics of a black hole near the event horizon is also discussed by studying the Hamilton-Jacobi equation in curved spacetime and the maximum overlap of the positive and negative energy levels near the event horizon is given. There is a dimensional problem in the standard tortoise coordinate and the present results may be more reasonable.展开更多
With the rapid increase in the number of cars and the development of industry, nitrogen oxide （NOx） emissions have become a serious and pressing problem. This work reports on the development of a water-cooled dielec...With the rapid increase in the number of cars and the development of industry, nitrogen oxide （NOx） emissions have become a serious and pressing problem. This work reports on the development of a water-cooled dielectric barrier discharge reactor for gaseous NOx removal at low temperature. The characteristics of the reactor are evaluated with and without packing of the reaction tube with 2 mm diameter dielectric beads composed of glass, ZnO, MnO2, ZrO2, or Fe203. It is found that the use of a water-cooled tube reduces the temperature, which stabilizes the reaction, and provides a much greater NO conversion efficiency （28.8%） than that obtained using quartz tube （14.1%） at a frequency of 8 kHz with an input voltage of 6.8 kV. Furthermore, under equivalent conditions, packing the reactor tube with glass beads greatly increases the NO conversion efficiency to 95.85%. This is because the dielectric beads alter the distribution of the electric field due to the influence of polarization at the glass bead surfaces, which ultimately enhances the plasma discharge intensity. The presence of the dielectric beads increases the gas residence time within the reactor. Experimental verification and a theoretical basis are provided for the industrial application of the proposed plasma NO removal process employing dielectric bead packing.展开更多
Upconversion based nanothermometry has received much attention due to its merits of stability,narrow band emission and rich emission peaks.However,the previous works are mainly focused on the emissions from thermally ...Upconversion based nanothermometry has received much attention due to its merits of stability,narrow band emission and rich emission peaks.However,the previous works are mainly focused on the emissions from thermally coupled energy levels which is theoretically limited by Boltzmann distribution theory with resultant low temperature sensitivity in particular at ultralow temperatures.Here we report a LiYF_(4):Yb/Ho@LiYF_(4) core-shell nanostructure to improve the sensitivity at low temperatures by taking advantage of non-thermally coupled energy levels of Ho^(3+).In detail,the green upconversion emission of Ho^(3+)shows an increase with reducing temperature while its red upconversion emission presents a decline during the same process.This is primarily due to the suppression of the non-radiative multiphonon relaxation occurred at the green emitting levels(^(5)F_(4),^(5)S_(2)) and the intermediate level(^(5)I_(6)) at low temperatures.Such a feature contributes to a high relative sensitivity of 7.17%/K at 11 K,much higher than reported values.Our results provide a promising candidate for the development of nanothermometer with high-sensitive low-temperature sensing performance.展开更多
We developed a technique of generating nonthermal atmospheric plasma-activated solution that had broad-spectrum antibacterial properties. Plasma-activated phosphate-buffered saline (PBS) causes rapid inactivation of b...We developed a technique of generating nonthermal atmospheric plasma-activated solution that had broad-spectrum antibacterial properties. Plasma-activated phosphate-buffered saline (PBS) causes rapid inactivation of bacteria following generation of oxidative stress. However, dose optimization requires understanding of cellular mechanisms. The objective of this study was to explore genome-wise response to develop gene expression profile of Escherichia coli using DNA microarray following exposure to plasma-activated PBS solution. Upon exposure to plasma-treated PBS solution, E. coli cells had differentially expressed genes involved in oxidative stress, and cell envelope and membrane associated porin and transporters. The genes involved in house-keeping and metabolism, energy generation, motility and virulence were conversely downregulated. This is the first report which demonstrates a severe oxidative stress induced in E. coli cells in response to an exposure to nonequilibrium nonthermal dielectric-barrier discharge plasma-activated PBS solution, and the genes that are responsive to reactive oxygen species appeared to play a role in cellular stress. Such studies are important to identify targets of inactivation, and to understand plasma-treated solution and bacterial cell interactions.展开更多
This paper studied the propagating characteristics of(2+1)-dimensional nonlinear ion acoustic waves in a multicomponent plasma with nonthermal electrons,positrons,and bipolar ions.The dispersion relations are initiall...This paper studied the propagating characteristics of(2+1)-dimensional nonlinear ion acoustic waves in a multicomponent plasma with nonthermal electrons,positrons,and bipolar ions.The dispersion relations are initially explored by using the small amplitude wave's dispersion relation.Then,the Sagdeev potential method is employed to study large amplitude ion acoustic waves.The analysis involves examining the system's phase diagram,Sagdeev potential function,and solitary wave solutions through numerical solution of an analytical process in order to investigate the propagation properties of nonlinear ion acoustic waves under various parameters.It is found that the propagation of nonlinear ion acoustic waves is subject to the influence of various physical parameters,including the ratio of number densities between the unperturbed positrons,electrons to positive ions,nonthermal parameters,the mass ratio of positive ions to negative ions,and the charge number ratio of negative ions to positive ions,the ratio of the electrons'temperature to positrons'temperature.In addition,the multicomponent plasma system has a compressive solitary waves with amplitude greater than zero or a rarefactive solitary waves with amplitude less than zero,in the meantime,compressive and rarefactive ion acoustic wave characteristics depend on the charge number ratio of negative ions to positive ions.展开更多
Using a new tortoise coordinate transformation,we discuss the quantum nonthermal radiation characteristics near an event horizon by studying the Hamilton-Jacobi equation of a scalar particle in curved space-time,and o...Using a new tortoise coordinate transformation,we discuss the quantum nonthermal radiation characteristics near an event horizon by studying the Hamilton-Jacobi equation of a scalar particle in curved space-time,and obtain the event horizon surface gravity and the Hawking temperature on that event horizon.The results show that there is a crossing of particle energy near the event horizon.We derive the maximum overlap of the positive and negative energy levels.It is also found that the Hawking temperature of a black hole depends not only on the time,but also on the angle.There is a problem of dimension in the usual tortoise coordinate,so the present results obtained by using a correct-dimension new tortoise coordinate transformation may be more reasonable.展开更多
Hyperthermia in oncology is an emerging complementary therapy. The clinical results depend on multiple conditional factors, like the type of cancer, the stage, the applied treatment device, and the complementary conve...Hyperthermia in oncology is an emerging complementary therapy. The clinical results depend on multiple conditional factors, like the type of cancer, the stage, the applied treatment device, and the complementary conventional therapy. The molecular effect could also be different depending on the temperature, heating dose, kind of energy transfer, and timing sequences compared to the concomitant treatment. This article examines the molecular impacts of a specific technique used in oncological hyperthermia called modulated electro-hyperthermia (mEHT). What sets mEHT apart is its emphasis on harnessing the combined effects of thermal and nonthermal factors. Nonthermal energy absorption occurs through the excitation of molecules, while the thermal component ensures the ideal conditions for this process. The applied radiofrequency current selects the malignant cells, and the modulation drives the nonthermal effects to immunogenic cell death, helping to develop tumor-specific antitumoral immune reactions. The synergy of the thermal and nonthermal components excites the lipid-assembled clusters of transmembrane proteins (membrane rafts) as the channels of transient receptor potentials (TRPs), the heat-shock proteins (HSPs), the voltage-gated channels, and the voltage-sensitive phosphatases (VSPs). All these transmembrane compartments channeling various ionic species (like calcium and proton) interact with the cytoskeleton and are involved in the apoptotic signal pathways.展开更多
In this paper we have investigated the effect of ion nonthermality on nonlinear dust acoustic wave propagation in a complex plasma in presence of weak secondary electron emission from dust grains. Equilibrium dust cha...In this paper we have investigated the effect of ion nonthermality on nonlinear dust acoustic wave propagation in a complex plasma in presence of weak secondary electron emission from dust grains. Equilibrium dust charge in this case is negative. Dusty plasma under our consideration consists of inertialess nonthermal ions, Boltzman distributed primary and secondary electrons and negatively charged inertial dust grains. Both adiabatic and nonadiabatic dust charge variations have been taken into account. Our analysis shows that in case of adiabatic dust charge variation, at a fixed non-zero ion nonthermality increasing secondary electron emission decreases amplitude and increases width of the rarefied dust acoustic soliton whereas for a fixed secondary electron yield increasing ion nonthermality increases amplitude and decreases width of such rarefied dust acoustic soliton. Thus shape of the soliton may be retained if strength of both the secondary electron yield and the ion nonthermality are increased. Nonadiabatic dust charge variation shows that, at fixed non-zero ion nonthermality, increasing secondary electron emission suppresses oscillation of oscillatory dust acoustic shock at weak nonadiabaticity and pronounces monotonicity of monotonic dust acoustic shock at strong nonadiabaticity. On the other hand at a fixed value of the secondary electron yield, increasing ion nonthermality enhances oscillation of oscillatory dust acoustic shock at weak nonadiabaticity and reduces monotonicity of monotonic dust acoustic shock at strong nonadiabaticity. Thus nature of dust acoustic shock may also remain unchanged if both secondary electron yield and ion nonthermality are increased.展开更多
In this paper we have developed a model to study the role of both electron and ion nonthermalities on dust acoustic wave propagation in a complex plasma in presence of positively charged dust grains. Secondary electro...In this paper we have developed a model to study the role of both electron and ion nonthermalities on dust acoustic wave propagation in a complex plasma in presence of positively charged dust grains. Secondary electron emission from dust grains has been considered as the source of positive dust charging. As secondary emission current depends on the flux of primary electrons, nonthermality of primary electrons changes the expression of secondary emission current from that of earlier work where primary electrons were thermal. Expression of nonthermal electron current flowing to the positively charged dust grains and consequently the expression of secondary electron current flowing out of the dust grains have been first time calculated in this paper, whereas the expression for nonthermal ion current flowing to the positively charged dust grains is present in existing literature. Dispersion relation of dust acoustic wave has been derived. From this dispersion relation real frequency and growth rate of the wave have been calculated. Results have been plotted for different strength of nonthermalities of electrons and ions.展开更多
Using the Hamilton-Jacobi equation of a scalar particle in the curve space-time and a correct- dimension new tortoise coordinate transformation, the quantum nonthermal radiation of the Vaidya-Bonner-de Sitter black ho...Using the Hamilton-Jacobi equation of a scalar particle in the curve space-time and a correct- dimension new tortoise coordinate transformation, the quantum nonthermal radiation of the Vaidya-Bonner-de Sitter black hole is investigated. The energy condition for the occurrence of the Starobinsky-Unruh process is obtained. The event horizon surface gravity and the Hawking temperature on the event horizon are also given.展开更多
Objectives:The aim of this study was to provide a comprehensive understanding of the nonthermal plasma(NTP)-induced inactivated behaviors on a multiple antibiotic-resistant(MAR)Staphylococcus aureus(S.aureus).Material...Objectives:The aim of this study was to provide a comprehensive understanding of the nonthermal plasma(NTP)-induced inactivated behaviors on a multiple antibiotic-resistant(MAR)Staphylococcus aureus(S.aureus).Materials and Methods:A dielectric barrier discharge(DBD)NTP system was employed for the inactivation of a MAR S.aureus under various applied powers of 35,45,and 55 W,and gas distances of 4,6,and 8 mm.The inactivation kinetics of S.aureus were estimated with linear and nonlinear predictive models.In addition,degradation of carotenoid pigment,peroxidation of fatty acids,oxidation of nucleic acids and proteins,and alteration in gene expression were analyzed after NTP treatment.Results and Discussion:The computationally simulated results indicated that the densities of various reactive species increased with enhanced applied powers and decreased discharge distances.These species were further transformed into reactive oxidative and nitrogen species in the gas-liquid interphase and liquid phase.The oxidative and nitrosative stress of NTP resulted in severe damage to cellular components and the morphological structure of S.aureus.On the other hand,the plasma reactive species could also induce the sublethal injury of S.aureus through upregulating the general stress response,antioxidative and antinitrosative defensive systems.Once the cumulative damages overrode the stress tolerance of S.aureus,the completed cell death was finally achieved by NTP.Conclusions:This work infers the possible risk of inducing the repair and resistant capacity of pathogens when the applied NTP parameters are inappropriate,which helps the optimization of NTP process to achieve sufficient inactivation.展开更多
The propagation properties of ion-acoustic solitary and shock waves in the magnetized viscous plasma with nonthermal trapped electrons are investigated.The Cairns-Gurevich distribution as the electron distribution is ...The propagation properties of ion-acoustic solitary and shock waves in the magnetized viscous plasma with nonthermal trapped electrons are investigated.The Cairns-Gurevich distribution as the electron distribution is considered to describe the plasma nonthermality and particle trapping.By adopting the reductive perturbation technique,we derived the nonlinear Schamel-Korteweg-de Vries-Burgers(SKdVB)equation,and then obtained the ion-acoustic shock and solitary wave solutions of the SKdVB equation for different limiting cases.It is found that the impact of nonthermal parameterα,external magnetic fieldΩ,obliqueness lz,wave speed U0,and the ion kinematic viscosityη0can significantly change the characteristics of the shock and solitary waves.These results may be useful for better understanding the propagation of nonlinear structures in space(i.e.Earth's magnetosphere and ionosphere,auroral regions)and laboratory plasma with nonthermal trapped electrons.展开更多
In this study, reduction and desorption of oxides of nitrogen （NOx） were conducted using an electrical discharge plasma technique. The study was carried out using a simulated gas mixture to explore the possibility o...In this study, reduction and desorption of oxides of nitrogen （NOx） were conducted using an electrical discharge plasma technique. The study was carried out using a simulated gas mixture to explore the possibility of re-generation of used adsorbents by a nonthermal plasma desorption technique. Three different types of corona electrodes, namely, pipe, helical wire, and straight wire, were used for analyzing their effectiveness in NOx reduction/desorption. The pipe- type corona electrode exhibited a nitric oxide （NO） conversion of 50%, which is 1.5 times that of the straight-wire-type electrode at an energy density of 175 J/L. The helical-wire-type corona electrode exhibited a NOx desorption efficiency almost 4 times that of the pipe-type electrode, indicating the possibility that corona-generated species play a crucial role in desorption.展开更多
Oxidative decomposition of dilute nitrobenzene in air was carried out in a catalytic plasma reactor with an inner electrode made of sintered metal fibres(SMF)that also acted as catalyst.The parameters of the concentra...Oxidative decomposition of dilute nitrobenzene in air was carried out in a catalytic plasma reactor with an inner electrode made of sintered metal fibres(SMF)that also acted as catalyst.The parameters of the concentration,specific input energy,and gas residence time were optimized.The modification of the SMF inner electrode with transition metal oxides like MnOx and CoOx oxides promoted complete oxidation,especially at low input energy.CoOx/SMF showed higher activity than MnOx/SMF and SMF,and could oxidise completely 100 ppm of nitrobenzene at 300 J/L.展开更多
A new method was introduced to detect the concentration of OH radical in dielectric barrier discharge(DBD)reaction.A film, which was impregnated with salicylic acid,was used to detect OH radical in plasma reaction at ...A new method was introduced to detect the concentration of OH radical in dielectric barrier discharge(DBD)reaction.A film, which was impregnated with salicylic acid,was used to detect OH radical in plasma reaction at room temperature and atmospheric pressure.Salicylic acid reacts with OH radical and produces 2,5-dihydroxybenzoic acid(2,5-DHBA).Then,a high performance liquid chromatography(HPLC)was carried out to detect the concentration of 2,5-DHBA.Therefore,OH radical in nonthermal plasma reaction could be...展开更多
Non-thermal plasma(NTP)has been demonstrated as one of the promising technologies that can degrade volatile organic compounds(VOCs)under ambient condition.However,one of the key challenges of VOCs degradation in NTP i...Non-thermal plasma(NTP)has been demonstrated as one of the promising technologies that can degrade volatile organic compounds(VOCs)under ambient condition.However,one of the key challenges of VOCs degradation in NTP is its relatively low mineralization rate,which needs to be addressed by introducing catalysts.Therefore,the design and optimization of catalysts have become the focus of NTP coupling catalysis research.In thiswork,a series of two-dimensional nanosheet Co-Ni metal oxides were synthesized by microwave method and investigated for the catalytic oxidation of benzene in an NTP-catalysis coupling system.Among them,Co_(2)Ni_(1)O_(x)achieves 60%carbon dioxide(CO_(2))selectivity(SCO_(2))when the benzene removal efficiency(REbenzene)reaches more than 99%,which is a significant enhancement compared with the CO_(2)selectivity obtained without any catalysts(38%)under the same input power.More intriguingly,this SCO_(2)is also significantly higher than that of single metal oxides,NiO or Co_(3)O_(4),which is only around 40%.Such improved performance of this binary metal oxide catalyst is uniquely attributed to the synergistic effects of Co and Ni in Co_(2)Ni_(1)O_(x)catalyst.The introduction of Co_(2)Ni_(1)O_(x)was found to promote the generation of acrolein significantly,one of the key intermediates found in NTP alone system reported previously,suggest the benzene ring open reaction is promoted.Compared with monometallic oxides NiO and Co_(3)O_(4),Co_(2)Ni_(1)O_(x)also shows higher active oxygen proportion,better oxygenmobility,and stronger low-temperature redox capability.The above factors result in the improved catalytic performance of Co_(2)Ni_(1)O_(x)in the NTP coupling removal of benzene.展开更多
We suggest a short-lived supermassive magnetar model to account for the X-ray flares following short γ-ray bursts. In this model the central engine of the short γ-ray bursts is a supermassive millisecond magnetar, f...We suggest a short-lived supermassive magnetar model to account for the X-ray flares following short γ-ray bursts. In this model the central engine of the short γ-ray bursts is a supermassive millisecond magnetar, formed in coalescence of double neutron stars. The X-ray flares are powered by the dipole radiation of the magnetar. When the magnetar has lost a significant part of its angular momentum, it collapses to a black hole and the X-ray flares cease abruptly.展开更多
基金National Science Fund for Distinguished Young Scholars(No.52225505)the National Sci-ence and Technology Major Project(No.J2019-VII-0014-0154)+1 种基金the National Natural Science Foundation of China(No.52005412)the Tianjin Natural Science Foundation of China-Multi-input key projects(No.22JCZDJC00650)for financial supports given to this research.
文摘The electrically assisted(EA)deformation process has received considerable attention in recent years,ac-companied by research on current-induced deformation mechanisms.However,there are still challenges in eliminating thermal effects,which have prevented a comprehensive understanding of the underlying current-induced mechanisms.Opting for a single crystal(SC)in research provides advantages in decou-pling the nonthermal effect of electric current at smaller scales and eliminating the complex interactions that exist in polycrystalline materials.Therefore,the innovation of this work lies in decoupling the non-thermal effect of electric current and conducting a comprehensive analysis of anisotropic deformation and mechanisms within a Ni-based SC with different crystallographic axes and various current directions dur-ing electrically assisted tensile simulation.A significant tension axis direction in the SC during EA tension was induced by the combination of a higher current direction factor(|cosθ|)and a dimensionless factor for the current density(|J^(α)/J_(0)^(α)|)along the[100]axis.The stress drop within the SC due to the nonthermal effect of electric current generally increased with increasing current direction.This was attributed to the increased dislocation density differences and decreased temperature.The increased stress anisotropy of the SC at a current direction of 45°was attributed to fewer activated(111)slip systems and the pinning effect of more dislocations within these systems.This study advances our understanding of the thermal and nonthermal effects of electric current and offers valuable insights for the informed application of EA deformations in industrial and aerospace settings with SC superalloys.
基金supported by National Natural Science Foundation of China(Nos.11205007 and 11205029)
文摘The humidity effects on the benzene decomposition process were investigated by the dielectric barrier discharge（DBD） plasma reactor.The results showed that the water vapor played an important role in the benzene oxidation process.It was found that there was an optimum humidity value for the benzene removal efficiency,and at around 60% relative humidity（RH）,the optimum benzene removal efficiency was achieved.At a SIE of 378 J/L,the removal efficiency was 66% at 0% RH,while the removal efficiency reached 75.3% at 60% RH and dropped to 69% at 80% RH.Furthermore,the addition of water inhibited the formation of ozone and NO2 remarkably.Both of the concentrations of ozone and NO2 decreased with increasing of the RH at the same specific input energy.At a SIE of 256 J/L,the concentrations of ozone and NO2 were 5.4 mg/L and 1791 ppm under dry conditions,whereas they were only 3.4 mg/L and 1119 ppm at 63.5%RH,respectively.Finally,the outlet gas after benzene degradation was qualitatively analyzed by FT-IR and GC-MS to determine possible intermediate byproducts.The results suggested that the byproducts in decomposition of benzene primarily consisted of phenol and substitutions of phenol.Based on these byproducts a benzene degradation mechanism was proposed.
基金supported by grants from National Natural Science Foundation of China(Nos.81701014,81801310,31700076)the Basic Research of Natural Science Project funded by the Department of Science and Technology of Shaanxi Province(No.2017JM8038)the Science and Technology Project funded by the Science and Technology Bureau of Weiyang District,Xi’an city(No.201846)。
文摘In this study, we employed a nonthermal atmospheric pressure plasma(NTAPP) jet to evaluate the effect of plasma treatment on the durability of resin–dentin bonding under a thermocycling challenge. Furthermore, we assessed the degradation resistance of plasma-treated collagen under a sodium hypochlorite(NaClO) challenge. We assessed the beneficial effect of NTAPP treatment on the acid-etched dentin–bonding interface by testing the micro-tensile bond strength and examining the morphology. We found that the immediate bonding strength of the dentin significantly increased after NTAPP treatment. Compared with the control group, NTAPP resulted in a more prominent effect on the bonding durability of the dentin–adhesive interface after treatment for 5 or 10 s. Simultaneously, the mechanical strength of dentin collagen under the NaClO challenge was improved. Our results indicate that, in optimal conditions, NTAPP could be a promising method to protect dentin collagen and to improve the bonding durability between dentin and etch-and-rinse adhesives.
基金supported by the National Natural Science Foundation of China (Grant Nos. 10873003 and 11045005)the Natural Science Foundation of Zhejiang Province,China (Grant No. Y6090739)
文摘Using a new tortoise coordinate transformation, this paper investigates the Hawking effect from an arbitrarily accelerating charged black hole by the improved Damour-Ruffini method. After the tortoise coordinate transformation, the Klein-Gordon equation can be written as the standard form at the event horizon. Then extending the outgoing wave from outside to inside of the horizon analytically, the surface gravity and Hawking temperature can be obtained automatically. It is found that the Hawking temperatures of different points on the surface are different. The quantum nonthermal radiation characteristics of a black hole near the event horizon is also discussed by studying the Hamilton-Jacobi equation in curved spacetime and the maximum overlap of the positive and negative energy levels near the event horizon is given. There is a dimensional problem in the standard tortoise coordinate and the present results may be more reasonable.
基金supported by the National High Technology Research and Development Program of China (863 program Grant No. 2015AA03A401)+1 种基金Program for Changjiang Scholars and Innovative Research Team in University (Grant No. IRT_15R46)the Program of Science and Technology Innovation Team in Bingtuan (Grant No. 2015BD003)
文摘With the rapid increase in the number of cars and the development of industry, nitrogen oxide （NOx） emissions have become a serious and pressing problem. This work reports on the development of a water-cooled dielectric barrier discharge reactor for gaseous NOx removal at low temperature. The characteristics of the reactor are evaluated with and without packing of the reaction tube with 2 mm diameter dielectric beads composed of glass, ZnO, MnO2, ZrO2, or Fe203. It is found that the use of a water-cooled tube reduces the temperature, which stabilizes the reaction, and provides a much greater NO conversion efficiency （28.8%） than that obtained using quartz tube （14.1%） at a frequency of 8 kHz with an input voltage of 6.8 kV. Furthermore, under equivalent conditions, packing the reactor tube with glass beads greatly increases the NO conversion efficiency to 95.85%. This is because the dielectric beads alter the distribution of the electric field due to the influence of polarization at the glass bead surfaces, which ultimately enhances the plasma discharge intensity. The presence of the dielectric beads increases the gas residence time within the reactor. Experimental verification and a theoretical basis are provided for the industrial application of the proposed plasma NO removal process employing dielectric bead packing.
基金Project supported by the National Natural Science Foundation of China (Grant Nos.51972119 and 52272151)the Fundamental Research Funds for the Central Universities (2022ZYGXZR015)the Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program (2017BT01X137)。
文摘Upconversion based nanothermometry has received much attention due to its merits of stability,narrow band emission and rich emission peaks.However,the previous works are mainly focused on the emissions from thermally coupled energy levels which is theoretically limited by Boltzmann distribution theory with resultant low temperature sensitivity in particular at ultralow temperatures.Here we report a LiYF_(4):Yb/Ho@LiYF_(4) core-shell nanostructure to improve the sensitivity at low temperatures by taking advantage of non-thermally coupled energy levels of Ho^(3+).In detail,the green upconversion emission of Ho^(3+)shows an increase with reducing temperature while its red upconversion emission presents a decline during the same process.This is primarily due to the suppression of the non-radiative multiphonon relaxation occurred at the green emitting levels(^(5)F_(4),^(5)S_(2)) and the intermediate level(^(5)I_(6)) at low temperatures.Such a feature contributes to a high relative sensitivity of 7.17%/K at 11 K,much higher than reported values.Our results provide a promising candidate for the development of nanothermometer with high-sensitive low-temperature sensing performance.
文摘We developed a technique of generating nonthermal atmospheric plasma-activated solution that had broad-spectrum antibacterial properties. Plasma-activated phosphate-buffered saline (PBS) causes rapid inactivation of bacteria following generation of oxidative stress. However, dose optimization requires understanding of cellular mechanisms. The objective of this study was to explore genome-wise response to develop gene expression profile of Escherichia coli using DNA microarray following exposure to plasma-activated PBS solution. Upon exposure to plasma-treated PBS solution, E. coli cells had differentially expressed genes involved in oxidative stress, and cell envelope and membrane associated porin and transporters. The genes involved in house-keeping and metabolism, energy generation, motility and virulence were conversely downregulated. This is the first report which demonstrates a severe oxidative stress induced in E. coli cells in response to an exposure to nonequilibrium nonthermal dielectric-barrier discharge plasma-activated PBS solution, and the genes that are responsive to reactive oxygen species appeared to play a role in cellular stress. Such studies are important to identify targets of inactivation, and to understand plasma-treated solution and bacterial cell interactions.
文摘This paper studied the propagating characteristics of(2+1)-dimensional nonlinear ion acoustic waves in a multicomponent plasma with nonthermal electrons,positrons,and bipolar ions.The dispersion relations are initially explored by using the small amplitude wave's dispersion relation.Then,the Sagdeev potential method is employed to study large amplitude ion acoustic waves.The analysis involves examining the system's phase diagram,Sagdeev potential function,and solitary wave solutions through numerical solution of an analytical process in order to investigate the propagation properties of nonlinear ion acoustic waves under various parameters.It is found that the propagation of nonlinear ion acoustic waves is subject to the influence of various physical parameters,including the ratio of number densities between the unperturbed positrons,electrons to positive ions,nonthermal parameters,the mass ratio of positive ions to negative ions,and the charge number ratio of negative ions to positive ions,the ratio of the electrons'temperature to positrons'temperature.In addition,the multicomponent plasma system has a compressive solitary waves with amplitude greater than zero or a rarefactive solitary waves with amplitude less than zero,in the meantime,compressive and rarefactive ion acoustic wave characteristics depend on the charge number ratio of negative ions to positive ions.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 10873003,11045005,and 11273009)the Natural Science Foundation of Zhejiang Province,China (Grant No. Y6090739)
文摘Using a new tortoise coordinate transformation,we discuss the quantum nonthermal radiation characteristics near an event horizon by studying the Hamilton-Jacobi equation of a scalar particle in curved space-time,and obtain the event horizon surface gravity and the Hawking temperature on that event horizon.The results show that there is a crossing of particle energy near the event horizon.We derive the maximum overlap of the positive and negative energy levels.It is also found that the Hawking temperature of a black hole depends not only on the time,but also on the angle.There is a problem of dimension in the usual tortoise coordinate,so the present results obtained by using a correct-dimension new tortoise coordinate transformation may be more reasonable.
文摘Hyperthermia in oncology is an emerging complementary therapy. The clinical results depend on multiple conditional factors, like the type of cancer, the stage, the applied treatment device, and the complementary conventional therapy. The molecular effect could also be different depending on the temperature, heating dose, kind of energy transfer, and timing sequences compared to the concomitant treatment. This article examines the molecular impacts of a specific technique used in oncological hyperthermia called modulated electro-hyperthermia (mEHT). What sets mEHT apart is its emphasis on harnessing the combined effects of thermal and nonthermal factors. Nonthermal energy absorption occurs through the excitation of molecules, while the thermal component ensures the ideal conditions for this process. The applied radiofrequency current selects the malignant cells, and the modulation drives the nonthermal effects to immunogenic cell death, helping to develop tumor-specific antitumoral immune reactions. The synergy of the thermal and nonthermal components excites the lipid-assembled clusters of transmembrane proteins (membrane rafts) as the channels of transient receptor potentials (TRPs), the heat-shock proteins (HSPs), the voltage-gated channels, and the voltage-sensitive phosphatases (VSPs). All these transmembrane compartments channeling various ionic species (like calcium and proton) interact with the cytoskeleton and are involved in the apoptotic signal pathways.
文摘In this paper we have investigated the effect of ion nonthermality on nonlinear dust acoustic wave propagation in a complex plasma in presence of weak secondary electron emission from dust grains. Equilibrium dust charge in this case is negative. Dusty plasma under our consideration consists of inertialess nonthermal ions, Boltzman distributed primary and secondary electrons and negatively charged inertial dust grains. Both adiabatic and nonadiabatic dust charge variations have been taken into account. Our analysis shows that in case of adiabatic dust charge variation, at a fixed non-zero ion nonthermality increasing secondary electron emission decreases amplitude and increases width of the rarefied dust acoustic soliton whereas for a fixed secondary electron yield increasing ion nonthermality increases amplitude and decreases width of such rarefied dust acoustic soliton. Thus shape of the soliton may be retained if strength of both the secondary electron yield and the ion nonthermality are increased. Nonadiabatic dust charge variation shows that, at fixed non-zero ion nonthermality, increasing secondary electron emission suppresses oscillation of oscillatory dust acoustic shock at weak nonadiabaticity and pronounces monotonicity of monotonic dust acoustic shock at strong nonadiabaticity. On the other hand at a fixed value of the secondary electron yield, increasing ion nonthermality enhances oscillation of oscillatory dust acoustic shock at weak nonadiabaticity and reduces monotonicity of monotonic dust acoustic shock at strong nonadiabaticity. Thus nature of dust acoustic shock may also remain unchanged if both secondary electron yield and ion nonthermality are increased.
文摘In this paper we have developed a model to study the role of both electron and ion nonthermalities on dust acoustic wave propagation in a complex plasma in presence of positively charged dust grains. Secondary electron emission from dust grains has been considered as the source of positive dust charging. As secondary emission current depends on the flux of primary electrons, nonthermality of primary electrons changes the expression of secondary emission current from that of earlier work where primary electrons were thermal. Expression of nonthermal electron current flowing to the positively charged dust grains and consequently the expression of secondary electron current flowing out of the dust grains have been first time calculated in this paper, whereas the expression for nonthermal ion current flowing to the positively charged dust grains is present in existing literature. Dispersion relation of dust acoustic wave has been derived. From this dispersion relation real frequency and growth rate of the wave have been calculated. Results have been plotted for different strength of nonthermalities of electrons and ions.
文摘Using the Hamilton-Jacobi equation of a scalar particle in the curve space-time and a correct- dimension new tortoise coordinate transformation, the quantum nonthermal radiation of the Vaidya-Bonner-de Sitter black hole is investigated. The energy condition for the occurrence of the Starobinsky-Unruh process is obtained. The event horizon surface gravity and the Hawking temperature on the event horizon are also given.
基金supported by the National Natural Science Foundation of China(No.31772079).
文摘Objectives:The aim of this study was to provide a comprehensive understanding of the nonthermal plasma(NTP)-induced inactivated behaviors on a multiple antibiotic-resistant(MAR)Staphylococcus aureus(S.aureus).Materials and Methods:A dielectric barrier discharge(DBD)NTP system was employed for the inactivation of a MAR S.aureus under various applied powers of 35,45,and 55 W,and gas distances of 4,6,and 8 mm.The inactivation kinetics of S.aureus were estimated with linear and nonlinear predictive models.In addition,degradation of carotenoid pigment,peroxidation of fatty acids,oxidation of nucleic acids and proteins,and alteration in gene expression were analyzed after NTP treatment.Results and Discussion:The computationally simulated results indicated that the densities of various reactive species increased with enhanced applied powers and decreased discharge distances.These species were further transformed into reactive oxidative and nitrogen species in the gas-liquid interphase and liquid phase.The oxidative and nitrosative stress of NTP resulted in severe damage to cellular components and the morphological structure of S.aureus.On the other hand,the plasma reactive species could also induce the sublethal injury of S.aureus through upregulating the general stress response,antioxidative and antinitrosative defensive systems.Once the cumulative damages overrode the stress tolerance of S.aureus,the completed cell death was finally achieved by NTP.Conclusions:This work infers the possible risk of inducing the repair and resistant capacity of pathogens when the applied NTP parameters are inappropriate,which helps the optimization of NTP process to achieve sufficient inactivation.
文摘The propagation properties of ion-acoustic solitary and shock waves in the magnetized viscous plasma with nonthermal trapped electrons are investigated.The Cairns-Gurevich distribution as the electron distribution is considered to describe the plasma nonthermality and particle trapping.By adopting the reductive perturbation technique,we derived the nonlinear Schamel-Korteweg-de Vries-Burgers(SKdVB)equation,and then obtained the ion-acoustic shock and solitary wave solutions of the SKdVB equation for different limiting cases.It is found that the impact of nonthermal parameterα,external magnetic fieldΩ,obliqueness lz,wave speed U0,and the ion kinematic viscosityη0can significantly change the characteristics of the shock and solitary waves.These results may be useful for better understanding the propagation of nonlinear structures in space(i.e.Earth's magnetosphere and ionosphere,auroral regions)and laboratory plasma with nonthermal trapped electrons.
文摘In this study, reduction and desorption of oxides of nitrogen （NOx） were conducted using an electrical discharge plasma technique. The study was carried out using a simulated gas mixture to explore the possibility of re-generation of used adsorbents by a nonthermal plasma desorption technique. Three different types of corona electrodes, namely, pipe, helical wire, and straight wire, were used for analyzing their effectiveness in NOx reduction/desorption. The pipe- type corona electrode exhibited a nitric oxide （NO） conversion of 50%, which is 1.5 times that of the straight-wire-type electrode at an energy density of 175 J/L. The helical-wire-type corona electrode exhibited a NOx desorption efficiency almost 4 times that of the pipe-type electrode, indicating the possibility that corona-generated species play a crucial role in desorption.
基金DST India for financial support under the SERC scheme
文摘Oxidative decomposition of dilute nitrobenzene in air was carried out in a catalytic plasma reactor with an inner electrode made of sintered metal fibres(SMF)that also acted as catalyst.The parameters of the concentration,specific input energy,and gas residence time were optimized.The modification of the SMF inner electrode with transition metal oxides like MnOx and CoOx oxides promoted complete oxidation,especially at low input energy.CoOx/SMF showed higher activity than MnOx/SMF and SMF,and could oxidise completely 100 ppm of nitrobenzene at 300 J/L.
基金supported by the National Natural Sci-ence Foundation of China(No.50708021)the GuangzhouUniversity Xinmiao Project(No.gyf1-1001)the Guangzhou University Scientific Research Start-up Project(No.gyf1-1002)
文摘A new method was introduced to detect the concentration of OH radical in dielectric barrier discharge(DBD)reaction.A film, which was impregnated with salicylic acid,was used to detect OH radical in plasma reaction at room temperature and atmospheric pressure.Salicylic acid reacts with OH radical and produces 2,5-dihydroxybenzoic acid(2,5-DHBA).Then,a high performance liquid chromatography(HPLC)was carried out to detect the concentration of 2,5-DHBA.Therefore,OH radical in nonthermal plasma reaction could be...
基金supported by the National Key Research and Development Program of China(No.2017YFE0127500)National Natural Science Foundation of China(No.U1832155).
文摘Non-thermal plasma(NTP)has been demonstrated as one of the promising technologies that can degrade volatile organic compounds(VOCs)under ambient condition.However,one of the key challenges of VOCs degradation in NTP is its relatively low mineralization rate,which needs to be addressed by introducing catalysts.Therefore,the design and optimization of catalysts have become the focus of NTP coupling catalysis research.In thiswork,a series of two-dimensional nanosheet Co-Ni metal oxides were synthesized by microwave method and investigated for the catalytic oxidation of benzene in an NTP-catalysis coupling system.Among them,Co_(2)Ni_(1)O_(x)achieves 60%carbon dioxide(CO_(2))selectivity(SCO_(2))when the benzene removal efficiency(REbenzene)reaches more than 99%,which is a significant enhancement compared with the CO_(2)selectivity obtained without any catalysts(38%)under the same input power.More intriguingly,this SCO_(2)is also significantly higher than that of single metal oxides,NiO or Co_(3)O_(4),which is only around 40%.Such improved performance of this binary metal oxide catalyst is uniquely attributed to the synergistic effects of Co and Ni in Co_(2)Ni_(1)O_(x)catalyst.The introduction of Co_(2)Ni_(1)O_(x)was found to promote the generation of acrolein significantly,one of the key intermediates found in NTP alone system reported previously,suggest the benzene ring open reaction is promoted.Compared with monometallic oxides NiO and Co_(3)O_(4),Co_(2)Ni_(1)O_(x)also shows higher active oxygen proportion,better oxygenmobility,and stronger low-temperature redox capability.The above factors result in the improved catalytic performance of Co_(2)Ni_(1)O_(x)in the NTP coupling removal of benzene.
基金Supported by the National Natural Science Foundation of China.
文摘We suggest a short-lived supermassive magnetar model to account for the X-ray flares following short γ-ray bursts. In this model the central engine of the short γ-ray bursts is a supermassive millisecond magnetar, formed in coalescence of double neutron stars. The X-ray flares are powered by the dipole radiation of the magnetar. When the magnetar has lost a significant part of its angular momentum, it collapses to a black hole and the X-ray flares cease abruptly.
