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
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
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
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
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
The modulated electro-hyperthermia (mEHT) method is a unique approach that utilizes all the essential apoptotic pathways through an external radiofrequency (RF) signal. The high-frequency RF is amplitude-modulated and...The modulated electro-hyperthermia (mEHT) method is a unique approach that utilizes all the essential apoptotic pathways through an external radiofrequency (RF) signal. The high-frequency RF is amplitude-modulated and coupled capacitively to the target. The provided energy triggers the death receptors and FAS-FADD complexes in the malignant cells. Multi-pathway apoptosis produces immunogenic cell death (ICD). This ICD provides intracellular information about cancer cells by releasing damage-associated molecular patterns (DAMP), including membrane expression of calreticulin (CRT) and extracellular ATP, HMGB1, and HSP70, executing tumor-specific antigen presentation. The antigen-presenting cells (APCs) play a crucial role in reestablishing immune surveillance and hampering the tumor cells’ ability to hide, thereby evading immune attacks. The matured DCs (generally APCs) produce tumor-specific killer and helper T-cells, which have the potential to be active in distant metastases from the treated location. This unique mechanism of action underscores its potential in cancer treatment and extends the local mEHT treatment to the whole body anticancer therapy with an abscopal effect.展开更多
The treatments of malignant diseases nowadays are rapidly developing. One of the groups of novel therapies applies electromagnetic fields to destroy the malignant lesions. The thermal (heating) and nonthermal (polariz...The treatments of malignant diseases nowadays are rapidly developing. One of the groups of novel therapies applies electromagnetic fields to destroy the malignant lesions. The thermal (heating) and nonthermal (polarization, molecular excitations) processes are combined in novel methods. The non-ionizing energy absorption from the electric field may produce substantial heat, increasing the targeted lesion’s temperature and inducing hyperthermic effects. The modulated electro-hyperthermia (mEHT) uses thermal conditions to optimize and accelerate the chemical reactions induced by the nonthermal excitation of the electric field. The mEHT cooperates with the body’s homeostatic control and harmonizes the mutual efforts to destroy the malignancy. Our objective is to show in vivo proof of the combined complementary electromagnetic impact on various tumors produced by mEHT. Furthermore, we present evidence of the increasing efficacy of the complementary application of mEHT with conventional treatments.展开更多
Modulated electro-hyperthermia (mEHT) targets tissue’s natural electric and thermal heterogeneities to heat the cancer cells selectively. The applied 13.56 MHz radiofrequency (RF) is a carrier of the low-frequency mo...Modulated electro-hyperthermia (mEHT) targets tissue’s natural electric and thermal heterogeneities to heat the cancer cells selectively. The applied 13.56 MHz radiofrequency (RF) is a carrier of the low-frequency modulation. The high-frequency part was chosen to select the malignant lesion using the specialties of the tumor: the higher conductivity and dielectric constant of the tumor than its host. The electric field selects the tumor, and the low-frequency amplitude modulation polarizes and excites the transmembrane proteins of the malignant cells. The dominant absorption of the energy by the microscopic clusters of the membrane rafts acts like nanoparticle heating. Exciting the membrane produces various apoptotic signals. The processes were modeled using silico and phantom experiments, which proved the concept. The preclinical verification was made in vitro and in vivo, and in the end, clinical proofs validated the method. Our objective is to follow all the development steps from the laboratory to the clinics in a trilogy of articles. This present is the first part, which deals with in silico, phantom, and in vitro research.展开更多
Modulated electro-hyperthermia (mEHT) is one of the novel oncological treatments with many preclinical and clinical results showing its advantages. The basis of the method is the synergy of thermal and nonthermal effe...Modulated electro-hyperthermia (mEHT) is one of the novel oncological treatments with many preclinical and clinical results showing its advantages. The basis of the method is the synergy of thermal and nonthermal effects, similar to the thermal action of conventional hyperthermia combined with ionizing radiation (radiotherapy). The electric field and the radiofrequency current produced both the thermal and nonthermal processes. The thermal effects produce the elevated temperature as a thermal background to optimize the nonthermal impacts. The low frequency amplitude modulation ensures accurate targeting and promotes immunogenic cell death to develop the tumor specific memory T cells disrupting the malignant cells by immune surveillance. This process (abscopal effect) works like a vaccination. The low frequency amplitude modulation is combined in the new method with the high power pulses for short time, increasing the tumor distortion ability of the electric field. The new modulation combination has much deeper penetration triplicating the active thickness of the effective treatment. The short pulse absorption increases the safety and decreases the thermal toxicity of the treatment, making the treatment safer. The increased power allows for reduced treatment time with the prescribed dose.展开更多
The temperature is one of the principal controlling parameters of oncological hyperthermia. However, local heating forms a complicated thermal distribution in space and has developed over time, too. The decisional fac...The temperature is one of the principal controlling parameters of oncological hyperthermia. However, local heating forms a complicated thermal distribution in space and has developed over time, too. The decisional factors are the heterogeneity of the targeted volume, the electrolyte perfusions controlled by thermal homeostasis, and the spreading of the heat energy with time. A further complication is that the energy absorption sharply changes by depth, so the spatiotemporal development of the temperature distribution requires specialized methods to control. Most of the temperature imaging facilities (thermography, radiometry, electric impedance tomography, etc.) are less precise than the medical practice needs. In contrast, precise point sensing (like thermocouples, thermistors, and fluoroptical methods) is invasive and measures only a discrete point in the robustly changing thermal map. The two most precise thermal imaging methods, computer tomography, and magnetic resonance are expensive and have numerous technical complications. Our objective is to show the complexity of the temperature distribution inside the human body, and offer a relatively simple and cheap method to visualize its spatiotemporal development. A novel emerging technology, the application of ultrasound microbubble contrast agents is a promising method for solving complicated tasks of thermal distribution deep inside the living body. Noteworthy, the temperature distribution does not determine the full hyperthermia process, nonthermal effects make considerable impact, too. Additionally to the difficulties to measure the thermal heterogeneity during hyperthermia in oncology, numerous nonthermal processes, molecular and structural changes are triggered by the incoming electromagnetic energy, which presently has no spatiotemporal visualization technique. Microbubble imaging has a suitable spatiotemporal thermal resolution, and also it is sensitive to nonthermal effects. Its application for characterization of the modulated electrohyperthermia (mEHT) may open a new theranostic facility, using the synergy of the thermal and nonthermal effects of the radiofrequency delivered energy. This complex approach gives facility to follow the mEHT processes, and the proposed microbubble ultrasound imaging has a particularly promising advantage sensing and acting also nonthermally, having potential to characterize the thermally conditioned nonthermal electromagnetic effects in oncologic hyperthermia. The mEHT combined with microbubble ultrasound images could be a robust theranostic method against cancer.展开更多
Oncological hyperthermia is one of the most versatile forms of oncotherapy. It can complement every conventional treatment method and be applied to any tumorous cancer, irrespective of its stages and localization. Num...Oncological hyperthermia is one of the most versatile forms of oncotherapy. It can complement every conventional treatment method and be applied to any tumorous cancer, irrespective of its stages and localization. Numerous technical realizations are conventionally compared by their thermal effect, measured by temperature. However, nonthermal (mainly electric) excitation effects are more recognized nowadays. The technical variants alter the synergy between thermal and nonthermal energy components. Nonthermal energy absorption-induced molecular mechanisms include essential behaviors like selectivity and immunogenicity. The nonthermal electromagnetic effects excite molecular changes, intracellular signals, gene expressions, and many other chemical reactions. Their synergy with thermal conditions is based on the Arrhenius law, which describes the rapid growth of chemical reactions with temperature. A unique technical realization of hyperthermia, modulated electrohyperthermia (mEHT) tries to optimize the thermal and nonthermal effects. The results look very perspective, containing the high accuracy of targeting the tumor cells, the immunogenic cell death, and the activation of tumor-specific immune reactions restoring the healthy immune surveillance to destroy the cancer.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, 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
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
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
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
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
To compensate for the shortcomings of the thermal and catalytic regeneration of the diesel particulate filter(DPF),a self-designed packed-bed dielectric barrier discharge(DBD)reactor for DPF regeneration was developed...To compensate for the shortcomings of the thermal and catalytic regeneration of the diesel particulate filter(DPF),a self-designed packed-bed dielectric barrier discharge(DBD)reactor for DPF regeneration was developed.The DBD reactor with the main active substance of nonthermal plasma(NTP)as the target parameter was optimized by adjusting the feed gas,packing particles(material or size),and cooling water temperature.Moreover,a set of optimal working parameters(gas source,O_2;packing particles,1.2–1.4 mm ZrO_(2);and cooling water temperature,20℃)was selected to evaluate the effect of different O_(3) concentrations on DPF regeneration.The research results showed that selecting packing particles with high dielectric constant and large particles,as well as reducing the cooling water temperature,with oxygen as the feed gas,contributed to an increase in O_(3) concentration.During DPF regeneration,the following changes were observed:the power of the NTP reactor decreased to lower than 100 W,the O_(3) concentration increased from 15 g m^(-3) to 45 g m^(-3),the CO and CO_2 volume fractions of the particulate matter decomposition products increased,and the peak regeneration temperature increased to 173.4℃.The peak temperature arrival time was 60 min earlier,indicating that the regeneration rate of DPF increased with the increase in O_(3) concentration.However,the O_(3) utilization rate(the amount of carbon deposit removed per unit volume O_(3))initially increased and then decreased;when the O_(3) concentration was set to 25 g m^(-3),the highest O_(3) utilization rate was reached.The packed-bed DBD technology contributed to the increase in the concentration of NTP active substances and the regeneration efficiency of DPF.It provides a theoretical and experimental basis for high-efficiency regeneration of DPF at low temperatures(<200℃).展开更多
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.
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.
文摘The modulated electro-hyperthermia (mEHT) method is a unique approach that utilizes all the essential apoptotic pathways through an external radiofrequency (RF) signal. The high-frequency RF is amplitude-modulated and coupled capacitively to the target. The provided energy triggers the death receptors and FAS-FADD complexes in the malignant cells. Multi-pathway apoptosis produces immunogenic cell death (ICD). This ICD provides intracellular information about cancer cells by releasing damage-associated molecular patterns (DAMP), including membrane expression of calreticulin (CRT) and extracellular ATP, HMGB1, and HSP70, executing tumor-specific antigen presentation. The antigen-presenting cells (APCs) play a crucial role in reestablishing immune surveillance and hampering the tumor cells’ ability to hide, thereby evading immune attacks. The matured DCs (generally APCs) produce tumor-specific killer and helper T-cells, which have the potential to be active in distant metastases from the treated location. This unique mechanism of action underscores its potential in cancer treatment and extends the local mEHT treatment to the whole body anticancer therapy with an abscopal effect.
文摘The treatments of malignant diseases nowadays are rapidly developing. One of the groups of novel therapies applies electromagnetic fields to destroy the malignant lesions. The thermal (heating) and nonthermal (polarization, molecular excitations) processes are combined in novel methods. The non-ionizing energy absorption from the electric field may produce substantial heat, increasing the targeted lesion’s temperature and inducing hyperthermic effects. The modulated electro-hyperthermia (mEHT) uses thermal conditions to optimize and accelerate the chemical reactions induced by the nonthermal excitation of the electric field. The mEHT cooperates with the body’s homeostatic control and harmonizes the mutual efforts to destroy the malignancy. Our objective is to show in vivo proof of the combined complementary electromagnetic impact on various tumors produced by mEHT. Furthermore, we present evidence of the increasing efficacy of the complementary application of mEHT with conventional treatments.
文摘Modulated electro-hyperthermia (mEHT) targets tissue’s natural electric and thermal heterogeneities to heat the cancer cells selectively. The applied 13.56 MHz radiofrequency (RF) is a carrier of the low-frequency modulation. The high-frequency part was chosen to select the malignant lesion using the specialties of the tumor: the higher conductivity and dielectric constant of the tumor than its host. The electric field selects the tumor, and the low-frequency amplitude modulation polarizes and excites the transmembrane proteins of the malignant cells. The dominant absorption of the energy by the microscopic clusters of the membrane rafts acts like nanoparticle heating. Exciting the membrane produces various apoptotic signals. The processes were modeled using silico and phantom experiments, which proved the concept. The preclinical verification was made in vitro and in vivo, and in the end, clinical proofs validated the method. Our objective is to follow all the development steps from the laboratory to the clinics in a trilogy of articles. This present is the first part, which deals with in silico, phantom, and in vitro research.
文摘Modulated electro-hyperthermia (mEHT) is one of the novel oncological treatments with many preclinical and clinical results showing its advantages. The basis of the method is the synergy of thermal and nonthermal effects, similar to the thermal action of conventional hyperthermia combined with ionizing radiation (radiotherapy). The electric field and the radiofrequency current produced both the thermal and nonthermal processes. The thermal effects produce the elevated temperature as a thermal background to optimize the nonthermal impacts. The low frequency amplitude modulation ensures accurate targeting and promotes immunogenic cell death to develop the tumor specific memory T cells disrupting the malignant cells by immune surveillance. This process (abscopal effect) works like a vaccination. The low frequency amplitude modulation is combined in the new method with the high power pulses for short time, increasing the tumor distortion ability of the electric field. The new modulation combination has much deeper penetration triplicating the active thickness of the effective treatment. The short pulse absorption increases the safety and decreases the thermal toxicity of the treatment, making the treatment safer. The increased power allows for reduced treatment time with the prescribed dose.
文摘The temperature is one of the principal controlling parameters of oncological hyperthermia. However, local heating forms a complicated thermal distribution in space and has developed over time, too. The decisional factors are the heterogeneity of the targeted volume, the electrolyte perfusions controlled by thermal homeostasis, and the spreading of the heat energy with time. A further complication is that the energy absorption sharply changes by depth, so the spatiotemporal development of the temperature distribution requires specialized methods to control. Most of the temperature imaging facilities (thermography, radiometry, electric impedance tomography, etc.) are less precise than the medical practice needs. In contrast, precise point sensing (like thermocouples, thermistors, and fluoroptical methods) is invasive and measures only a discrete point in the robustly changing thermal map. The two most precise thermal imaging methods, computer tomography, and magnetic resonance are expensive and have numerous technical complications. Our objective is to show the complexity of the temperature distribution inside the human body, and offer a relatively simple and cheap method to visualize its spatiotemporal development. A novel emerging technology, the application of ultrasound microbubble contrast agents is a promising method for solving complicated tasks of thermal distribution deep inside the living body. Noteworthy, the temperature distribution does not determine the full hyperthermia process, nonthermal effects make considerable impact, too. Additionally to the difficulties to measure the thermal heterogeneity during hyperthermia in oncology, numerous nonthermal processes, molecular and structural changes are triggered by the incoming electromagnetic energy, which presently has no spatiotemporal visualization technique. Microbubble imaging has a suitable spatiotemporal thermal resolution, and also it is sensitive to nonthermal effects. Its application for characterization of the modulated electrohyperthermia (mEHT) may open a new theranostic facility, using the synergy of the thermal and nonthermal effects of the radiofrequency delivered energy. This complex approach gives facility to follow the mEHT processes, and the proposed microbubble ultrasound imaging has a particularly promising advantage sensing and acting also nonthermally, having potential to characterize the thermally conditioned nonthermal electromagnetic effects in oncologic hyperthermia. The mEHT combined with microbubble ultrasound images could be a robust theranostic method against cancer.
文摘Oncological hyperthermia is one of the most versatile forms of oncotherapy. It can complement every conventional treatment method and be applied to any tumorous cancer, irrespective of its stages and localization. Numerous technical realizations are conventionally compared by their thermal effect, measured by temperature. However, nonthermal (mainly electric) excitation effects are more recognized nowadays. The technical variants alter the synergy between thermal and nonthermal energy components. Nonthermal energy absorption-induced molecular mechanisms include essential behaviors like selectivity and immunogenicity. The nonthermal electromagnetic effects excite molecular changes, intracellular signals, gene expressions, and many other chemical reactions. Their synergy with thermal conditions is based on the Arrhenius law, which describes the rapid growth of chemical reactions with temperature. A unique technical realization of hyperthermia, modulated electrohyperthermia (mEHT) tries to optimize the thermal and nonthermal effects. The results look very perspective, containing the high accuracy of targeting the tumor cells, the immunogenic cell death, and the activation of tumor-specific immune reactions restoring the healthy immune surveillance to destroy the cancer.
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.
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 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.
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 National Natural Science Foundation of China (No. 51806085)China Postdoctoral Science Foundation (No. 2018M642175)+2 种基金Jiangsu Planned Projects for Postdoctoral Research Fund (No. 2018K101C)Open Research Subject of Key Laboratory of Automotive Measurement, Control and Safety (Xihua University) (No. QCCK2021-007)the Graduate Student Innovation Fund Project of Jiangsu Province (No. KYCX21_3354)
文摘To compensate for the shortcomings of the thermal and catalytic regeneration of the diesel particulate filter(DPF),a self-designed packed-bed dielectric barrier discharge(DBD)reactor for DPF regeneration was developed.The DBD reactor with the main active substance of nonthermal plasma(NTP)as the target parameter was optimized by adjusting the feed gas,packing particles(material or size),and cooling water temperature.Moreover,a set of optimal working parameters(gas source,O_2;packing particles,1.2–1.4 mm ZrO_(2);and cooling water temperature,20℃)was selected to evaluate the effect of different O_(3) concentrations on DPF regeneration.The research results showed that selecting packing particles with high dielectric constant and large particles,as well as reducing the cooling water temperature,with oxygen as the feed gas,contributed to an increase in O_(3) concentration.During DPF regeneration,the following changes were observed:the power of the NTP reactor decreased to lower than 100 W,the O_(3) concentration increased from 15 g m^(-3) to 45 g m^(-3),the CO and CO_2 volume fractions of the particulate matter decomposition products increased,and the peak regeneration temperature increased to 173.4℃.The peak temperature arrival time was 60 min earlier,indicating that the regeneration rate of DPF increased with the increase in O_(3) concentration.However,the O_(3) utilization rate(the amount of carbon deposit removed per unit volume O_(3))initially increased and then decreased;when the O_(3) concentration was set to 25 g m^(-3),the highest O_(3) utilization rate was reached.The packed-bed DBD technology contributed to the increase in the concentration of NTP active substances and the regeneration efficiency of DPF.It provides a theoretical and experimental basis for high-efficiency regeneration of DPF at low temperatures(<200℃).
