Plasma in the discharge channel of a pulsed plasma thruster(PPT) with flared electrodes is simulated by a self-developed two-dimensional code. The fully particle-in-cell method with Monte Carlo collision is employed t...Plasma in the discharge channel of a pulsed plasma thruster(PPT) with flared electrodes is simulated by a self-developed two-dimensional code. The fully particle-in-cell method with Monte Carlo collision is employed to model the particle movement and collisions and investigate the plasma properties and acceleration process. Temporal and spatial variations of the electron density distribution and the ion velocity between electrodes are calculated and analyzed in detail.The computational results of the electron number density, which is in the order of 1023 m-3,show good agreements with experimental results of a PPT named ADD SIMP-LEX. The ion velocity distributions along the center line of the channel lead to a comprehensive understanding of ions accelerated by electromagnetic field. The electron distributions of PPT with discharge voltages varying from 1300 to 2000 V are compared. The diffusion of electrons presents strong dependency on discharge voltage and implies higher degree of ionization for higher voltage.展开更多
The self-induced magnetic field in a pulsed plasma thruster(PPT)with flared electrodes is investigated for a better understanding of the working process and the structural design of the thruster.A two-dimensional mode...The self-induced magnetic field in a pulsed plasma thruster(PPT)with flared electrodes is investigated for a better understanding of the working process and the structural design of the thruster.A two-dimensional model of the magnetic field is built and is validated by comparing the simulated results with the experimental results in literature.The magnetic flux density in the discharge channel during the working process is presented and analyzed regarding the electrode structures.The calculated magnetic field flux density decreases from 0.8 T at the upstream to 0.1 T and below at the downstream in the discharge channel(68 J).The peak of the magnetic flux density over time lags behind the current peak,which provides evidence for the existence of a moving plasma sheet in the discharge process.The magnetic field induced by the current in the extra bending part of the anode enhances the Lorentz force,which acts on the charged particles near the propellant.Finally,the geometric study indicates that the electromagnetic impulse bit does not monotonically increase with the flared angle of the electrodes.Instead,it reaches a maximum at a certain flared angle,which could provide significant suggestions for structural optimization.展开更多
Osteoarthritis and psoriasis arthritis are two degenerative forms of arthritis that share similar yet also different manifestations at the histological,cellular,and clinical levels.Rheumatologists have marked them as ...Osteoarthritis and psoriasis arthritis are two degenerative forms of arthritis that share similar yet also different manifestations at the histological,cellular,and clinical levels.Rheumatologists have marked them as two entirely distinct arthropathies.Given recent dis-coveries in disease initiation and progression,potential mechanisms,cellular signaling path-ways,and ongoing clinical therapeutics,there are now more opportunities for discovering osteoarthritis drugs.This review summarized the osteoarthritis and psoriasis arthritis signaling pathways,crosstalk between BMP,WNT,TGF-β,VEGF,TLR,and FGF signaling pathways,bio-markers,and anatomical pathologies.Through bench research,we demonstrated that regen-erative medicine is a promising alternative for treating osteoarthritis by highlighting significant scientific discoveries on entheses,multiple signaling blockers,and novel molecules such as immunoglobulin new antigen receptors targeted for potential drug evaluation.Furthermore,we offered valuable therapeutic approaches with a multidisciplinary strategy to treat patients with osteoarthritis or psoriasis arthritis in the coming future in the clinic.展开更多
The diamondback moth,Plutella xylostella(L.),is an economically important pest of cruciferous crops worldwide.This pest is notorious for rapid evolution of the resistance to diferent classes of insecticides,making it ...The diamondback moth,Plutella xylostella(L.),is an economically important pest of cruciferous crops worldwide.This pest is notorious for rapid evolution of the resistance to diferent classes of insecticides,making it increasingly dificult to control.Genetics-based control approaches,through manipulation of target genes,have been reported as promising supplements or alternatives to traditional methods of pest management.Here we identified a gene of pigmentation(yellow)in P.xylostella,Pxyellow,which encodes 1674 bp complementary DNA sequence with four exons and three introns.Using the clustered regularly interspersed palindromic repeats(CRISPR)CRISPR-associated protein 9 system,we knocked out Pxyellow,targeting two sites in Exon III,to generate 272 chimeric mutants(57%of the CRISPR-treated individuals)with color-changed phenotypes of the Ist to 3rd instar larvae,pupae,and adults,indicating that Pxyellow plays an essential role in the body pigmentation of P xlostella.Fitness analysis revealed no significant difference in the oviposition of adults,the hatchability of eggs,and the weight of pupac between homozygous mutants and wildtypes,suggesting that Pxyellow is not directly involved in regulation of growth,development,or reproduction.This work advances our understanding of the genetic and insect science molecular basis for body pigmentation of P xylostella,and opens a wide avenue for development of the genctcally based pest control techniques using Pxyellow as a screening marker.展开更多
This paper investigated the temperature dependence of the cryogenic small-signal ac performances of multi-finger partially depleted（PD） silicon-on-insulator（SOI） metal oxide semiconductor field effect transistors...This paper investigated the temperature dependence of the cryogenic small-signal ac performances of multi-finger partially depleted（PD） silicon-on-insulator（SOI） metal oxide semiconductor field effect transistors（MOSFETs）,with T-gate body contact（TB） structure.The measurement results show that the cut-off frequency increases from 78 GHz at 300 K to 120 GHz at 77 K and the maximum oscillation frequency increases from 54 GHz at 300 K to 80 GHz at 77 K,and these are mainly due to the effect of negative temperature dependence of threshold voltage and transconductance.By using a simple equivalent circuit model,the temperature-dependent small-signal parameters are discussed in detail.The understanding of cryogenic small-signal performance is beneficial to develop the PD SOI MOSFETs integrated circuits for ultra-low temperature applications.展开更多
基金supported by National Natural Science Foundation of China (Grant No. 11602016)
文摘Plasma in the discharge channel of a pulsed plasma thruster(PPT) with flared electrodes is simulated by a self-developed two-dimensional code. The fully particle-in-cell method with Monte Carlo collision is employed to model the particle movement and collisions and investigate the plasma properties and acceleration process. Temporal and spatial variations of the electron density distribution and the ion velocity between electrodes are calculated and analyzed in detail.The computational results of the electron number density, which is in the order of 1023 m-3,show good agreements with experimental results of a PPT named ADD SIMP-LEX. The ion velocity distributions along the center line of the channel lead to a comprehensive understanding of ions accelerated by electromagnetic field. The electron distributions of PPT with discharge voltages varying from 1300 to 2000 V are compared. The diffusion of electrons presents strong dependency on discharge voltage and implies higher degree of ionization for higher voltage.
基金National Natural Science Foundation of China(No.11602016).
文摘The self-induced magnetic field in a pulsed plasma thruster(PPT)with flared electrodes is investigated for a better understanding of the working process and the structural design of the thruster.A two-dimensional model of the magnetic field is built and is validated by comparing the simulated results with the experimental results in literature.The magnetic flux density in the discharge channel during the working process is presented and analyzed regarding the electrode structures.The calculated magnetic field flux density decreases from 0.8 T at the upstream to 0.1 T and below at the downstream in the discharge channel(68 J).The peak of the magnetic flux density over time lags behind the current peak,which provides evidence for the existence of a moving plasma sheet in the discharge process.The magnetic field induced by the current in the extra bending part of the anode enhances the Lorentz force,which acts on the charged particles near the propellant.Finally,the geometric study indicates that the electromagnetic impulse bit does not monotonically increase with the flared angle of the electrodes.Instead,it reaches a maximum at a certain flared angle,which could provide significant suggestions for structural optimization.
文摘Osteoarthritis and psoriasis arthritis are two degenerative forms of arthritis that share similar yet also different manifestations at the histological,cellular,and clinical levels.Rheumatologists have marked them as two entirely distinct arthropathies.Given recent dis-coveries in disease initiation and progression,potential mechanisms,cellular signaling path-ways,and ongoing clinical therapeutics,there are now more opportunities for discovering osteoarthritis drugs.This review summarized the osteoarthritis and psoriasis arthritis signaling pathways,crosstalk between BMP,WNT,TGF-β,VEGF,TLR,and FGF signaling pathways,bio-markers,and anatomical pathologies.Through bench research,we demonstrated that regen-erative medicine is a promising alternative for treating osteoarthritis by highlighting significant scientific discoveries on entheses,multiple signaling blockers,and novel molecules such as immunoglobulin new antigen receptors targeted for potential drug evaluation.Furthermore,we offered valuable therapeutic approaches with a multidisciplinary strategy to treat patients with osteoarthritis or psoriasis arthritis in the coming future in the clinic.
基金the National Natural Science Foundation of China(31972271)the Strait Postdoctoral Exchange Program of Fujian(2018B002)Fujian Science and Technology Major Program(2018NZ01010013).
文摘The diamondback moth,Plutella xylostella(L.),is an economically important pest of cruciferous crops worldwide.This pest is notorious for rapid evolution of the resistance to diferent classes of insecticides,making it increasingly dificult to control.Genetics-based control approaches,through manipulation of target genes,have been reported as promising supplements or alternatives to traditional methods of pest management.Here we identified a gene of pigmentation(yellow)in P.xylostella,Pxyellow,which encodes 1674 bp complementary DNA sequence with four exons and three introns.Using the clustered regularly interspersed palindromic repeats(CRISPR)CRISPR-associated protein 9 system,we knocked out Pxyellow,targeting two sites in Exon III,to generate 272 chimeric mutants(57%of the CRISPR-treated individuals)with color-changed phenotypes of the Ist to 3rd instar larvae,pupae,and adults,indicating that Pxyellow plays an essential role in the body pigmentation of P xlostella.Fitness analysis revealed no significant difference in the oviposition of adults,the hatchability of eggs,and the weight of pupac between homozygous mutants and wildtypes,suggesting that Pxyellow is not directly involved in regulation of growth,development,or reproduction.This work advances our understanding of the genetic and insect science molecular basis for body pigmentation of P xylostella,and opens a wide avenue for development of the genctcally based pest control techniques using Pxyellow as a screening marker.
基金Project supported by the National Natural Science Foundation of China(No.61331006)the National Defense Pre-Research Foundation of China(No.9140A11040114DZ04152)
文摘This paper investigated the temperature dependence of the cryogenic small-signal ac performances of multi-finger partially depleted（PD） silicon-on-insulator（SOI） metal oxide semiconductor field effect transistors（MOSFETs）,with T-gate body contact（TB） structure.The measurement results show that the cut-off frequency increases from 78 GHz at 300 K to 120 GHz at 77 K and the maximum oscillation frequency increases from 54 GHz at 300 K to 80 GHz at 77 K,and these are mainly due to the effect of negative temperature dependence of threshold voltage and transconductance.By using a simple equivalent circuit model,the temperature-dependent small-signal parameters are discussed in detail.The understanding of cryogenic small-signal performance is beneficial to develop the PD SOI MOSFETs integrated circuits for ultra-low temperature applications.
