Aim: To confirm the stability of exogenous genes in the generation of transgenic chickens using ejaculated chicken sperm, the deoxyribonuclease (DNase) activity was evaluated in the seminal plasma of ejaculated semen ...Aim: To confirm the stability of exogenous genes in the generation of transgenic chickens using ejaculated chicken sperm, the deoxyribonuclease (DNase) activity was evaluated in the seminal plasma of ejaculated semen and the stability of DNA was examined by adding lipofection reagents. Methods: A PCR fragment (249 bp) of pEGFPN-1 vector was used as the DNA substrate and was incubated with the seminal plasma at 40 ℃ for 30 min. Then, the whole reaction solution was subjected to agarose gel electrophoresis and the DNA size was evaluated under UV light. Results: The DNA substrate was completely diminished after incubation with seminal plasma. However, the substrate was intact after incubation with heat-treated seminal plasma or incubation with seminal plasma in the presence of 0.5 mmol/L -5 mmol/L EDTA. The substrate was stabilized in the seminal plasma by the addition of commercially available lipofection reagents. Conclusion: The DNase activity is present in the seminal plasma of ejaculated chicken semen. However, DNA is stable in the liposomal-DNA complex.展开更多
Based on the theory of EHD （electronhydrodynamic）, a simplified volume force model is applied to simulation to analyze the traits of plasma flow control in flow field, in which the cold plasma is generated by a DBD ...Based on the theory of EHD （electronhydrodynamic）, a simplified volume force model is applied to simulation to analyze the traits of plasma flow control in flow field, in which the cold plasma is generated by a DBD （dielectric-barrier-discharge） actuator. With the para- electric action of volume force in electric field, acceleration characteristics of the plasma flow are investigated for different excitation intensities of RF （radio frequency） power for the actuator. Furthermore, the plasma acceleration leads to an asymmetric distribution of flow field, and hence induces the deflection of jet plume, then results in a significant deflection angle of 6.26° thrustvectoring effect. It appears that the plasma flow control technology is a new tentative method for the thrust-vectoring control of a space vehicle.展开更多
A new neutron-gamma discriminator based on the support vector machine(SVM) method is proposed to improve the performance of the time-of-flight neutron spectrometer. The neutron detector is an EJ-299-33 plastic scintil...A new neutron-gamma discriminator based on the support vector machine(SVM) method is proposed to improve the performance of the time-of-flight neutron spectrometer. The neutron detector is an EJ-299-33 plastic scintillator with pulse-shape discrimination(PSD) property. The SVM algorithm is implemented in field programmable gate array(FPGA) to carry out the real-time sifting of neutrons in neutron-gamma mixed radiation fields. This study compares the ability of the pulse gradient analysis method and the SVM method. The results show that this SVM discriminator can provide a better discrimination accuracy of 99.1%. The accuracy and performance of the SVM discriminator based on FPGA have been evaluated in the experiments. It can get a figure of merit of 1.30.展开更多
Two-dimensional（2D） numerical simulations of thermochemical nonequilibrium inductively coupled plasma（ICP） flows inside a 10-kW inductively coupled plasma wind tunnel（ICPWT） were carried out with nitrogen as the...Two-dimensional（2D） numerical simulations of thermochemical nonequilibrium inductively coupled plasma（ICP） flows inside a 10-kW inductively coupled plasma wind tunnel（ICPWT） were carried out with nitrogen as the working gas.Compressible axisymmetric NavierStokes（N-S） equations coupled with magnetic vector potential equations were solved.A fourtemperature model including an improved electron-vibration relaxation time was used to model the internal energy exchange between electron and heavy particles.The third-order accuracy electron transport properties（3rd AETP） were applied to the simulations.A hybrid chemical kinetic model was adopted to model the chemical nonequilibrium process.The flow characteristics such as thermal nonequilibrium,inductive discharge,effects of Lorentz force were made clear through the present study.It was clarified that the thermal nonequilibrium model played an important role in properly predicting the temperature field.The prediction accuracy can be improved by applying the 3rd AETP to the simulation for this ICPWT.展开更多
The features of negative refraction are investigated by using a rotational plasma metamaterial. It is assumed that the plasma metamaterial is composed of plasma and dielectric material periodically. The analytical res...The features of negative refraction are investigated by using a rotational plasma metamaterial. It is assumed that the plasma metamaterial is composed of plasma and dielectric material periodically. The analytical results show that the plasma density, plasma filling factor, and rotation angle significantly changed the properties of negative refraction. Interestingly, the plasma metamaterial without exhibiting negative refraction effect will show negative refraction when rotating the optical axis of the metamaterial, while the range of incident angle for negative refraction will be reduced or even disappear for the plasma metamaterial exhibiting negative refraction effect when rotating the optical axis. Moreover, the full-angle negative refraction can be obtained by specific rotation angle and plasma density. The effects of plasma density, plasma filling factor and the rotation angle on the properties of THE negative refraction effect are also explored and discussed in detail.展开更多
This paper presents a composite magneto hydrodynamics（MHD） method to control the lowtemperature micro-ionized plasma flow generated by injecting alkali salt into the combustion gas to realize the thrust vector of an...This paper presents a composite magneto hydrodynamics（MHD） method to control the lowtemperature micro-ionized plasma flow generated by injecting alkali salt into the combustion gas to realize the thrust vector of an aeroengine.The principle of plasma flow with MHD control is analyzed.The feasibility of plasma jet deflection is investigated using numerical simulation with MHD control by loading the User-Defined Function model.A test rig with plasma flow controlled by MHD is established.An alkali salt compound with a low ionization energy is injected into combustion gas to obtain the low-temperature plasma flow.Finally,plasma plume deflection is obtained in different working conditions.The results demonstrate that plasma plume deflection with MHD control can be realized via numerical simulation.A low-temperature plasma flow can be obtained by injecting an alkali metal salt compound with low ionization energy into a combustion gas at 1800–2500 K.The vector angle of plasma plume deflection increases with the increase of gas temperature and the magnetic field intensity.It is feasible to realize the aim of the thrust vector of aeroengine by using MHD to control plasma flow deflection.展开更多
文摘Aim: To confirm the stability of exogenous genes in the generation of transgenic chickens using ejaculated chicken sperm, the deoxyribonuclease (DNase) activity was evaluated in the seminal plasma of ejaculated semen and the stability of DNA was examined by adding lipofection reagents. Methods: A PCR fragment (249 bp) of pEGFPN-1 vector was used as the DNA substrate and was incubated with the seminal plasma at 40 ℃ for 30 min. Then, the whole reaction solution was subjected to agarose gel electrophoresis and the DNA size was evaluated under UV light. Results: The DNA substrate was completely diminished after incubation with seminal plasma. However, the substrate was intact after incubation with heat-treated seminal plasma or incubation with seminal plasma in the presence of 0.5 mmol/L -5 mmol/L EDTA. The substrate was stabilized in the seminal plasma by the addition of commercially available lipofection reagents. Conclusion: The DNase activity is present in the seminal plasma of ejaculated chicken semen. However, DNA is stable in the liposomal-DNA complex.
基金supported by National Natural Science Foundation of China (No.90716025)
文摘Based on the theory of EHD （electronhydrodynamic）, a simplified volume force model is applied to simulation to analyze the traits of plasma flow control in flow field, in which the cold plasma is generated by a DBD （dielectric-barrier-discharge） actuator. With the para- electric action of volume force in electric field, acceleration characteristics of the plasma flow are investigated for different excitation intensities of RF （radio frequency） power for the actuator. Furthermore, the plasma acceleration leads to an asymmetric distribution of flow field, and hence induces the deflection of jet plume, then results in a significant deflection angle of 6.26° thrustvectoring effect. It appears that the plasma flow control technology is a new tentative method for the thrust-vectoring control of a space vehicle.
基金partially supported by the National Science and Technology Major Project of Ministry of Science and Technology of China (Grant Nos. 2014GB109003 and 2015GB111002)National Natural Science Foundation of China (Grant Nos. 11375195, 11575184, 11375004 and 11775068)
文摘A new neutron-gamma discriminator based on the support vector machine(SVM) method is proposed to improve the performance of the time-of-flight neutron spectrometer. The neutron detector is an EJ-299-33 plastic scintillator with pulse-shape discrimination(PSD) property. The SVM algorithm is implemented in field programmable gate array(FPGA) to carry out the real-time sifting of neutrons in neutron-gamma mixed radiation fields. This study compares the ability of the pulse gradient analysis method and the SVM method. The results show that this SVM discriminator can provide a better discrimination accuracy of 99.1%. The accuracy and performance of the SVM discriminator based on FPGA have been evaluated in the experiments. It can get a figure of merit of 1.30.
基金supported by Grant-in-Aid for Scientific Research(No.23560954)sponsored by the Japan Society for the Promotion of Science
文摘Two-dimensional（2D） numerical simulations of thermochemical nonequilibrium inductively coupled plasma（ICP） flows inside a 10-kW inductively coupled plasma wind tunnel（ICPWT） were carried out with nitrogen as the working gas.Compressible axisymmetric NavierStokes（N-S） equations coupled with magnetic vector potential equations were solved.A fourtemperature model including an improved electron-vibration relaxation time was used to model the internal energy exchange between electron and heavy particles.The third-order accuracy electron transport properties（3rd AETP） were applied to the simulations.A hybrid chemical kinetic model was adopted to model the chemical nonequilibrium process.The flow characteristics such as thermal nonequilibrium,inductive discharge,effects of Lorentz force were made clear through the present study.It was clarified that the thermal nonequilibrium model played an important role in properly predicting the temperature field.The prediction accuracy can be improved by applying the 3rd AETP to the simulation for this ICPWT.
基金supported by National Natural Science Foundation of China (No. 11575135)
文摘The features of negative refraction are investigated by using a rotational plasma metamaterial. It is assumed that the plasma metamaterial is composed of plasma and dielectric material periodically. The analytical results show that the plasma density, plasma filling factor, and rotation angle significantly changed the properties of negative refraction. Interestingly, the plasma metamaterial without exhibiting negative refraction effect will show negative refraction when rotating the optical axis of the metamaterial, while the range of incident angle for negative refraction will be reduced or even disappear for the plasma metamaterial exhibiting negative refraction effect when rotating the optical axis. Moreover, the full-angle negative refraction can be obtained by specific rotation angle and plasma density. The effects of plasma density, plasma filling factor and the rotation angle on the properties of THE negative refraction effect are also explored and discussed in detail.
基金supported by National Natural Science Foundation of China (No.90716025)
文摘This paper presents a composite magneto hydrodynamics（MHD） method to control the lowtemperature micro-ionized plasma flow generated by injecting alkali salt into the combustion gas to realize the thrust vector of an aeroengine.The principle of plasma flow with MHD control is analyzed.The feasibility of plasma jet deflection is investigated using numerical simulation with MHD control by loading the User-Defined Function model.A test rig with plasma flow controlled by MHD is established.An alkali salt compound with a low ionization energy is injected into combustion gas to obtain the low-temperature plasma flow.Finally,plasma plume deflection is obtained in different working conditions.The results demonstrate that plasma plume deflection with MHD control can be realized via numerical simulation.A low-temperature plasma flow can be obtained by injecting an alkali metal salt compound with low ionization energy into a combustion gas at 1800–2500 K.The vector angle of plasma plume deflection increases with the increase of gas temperature and the magnetic field intensity.It is feasible to realize the aim of the thrust vector of aeroengine by using MHD to control plasma flow deflection.
