Momentum-Dependent Symmetry Potential from Nuclear Collective Flows in Heavy Ion Collisions at Intermediate Energies

Within the isospin-dependent quantum molecular dynamics model, we investigate the nuclear collective flows produced in semi-central 197 Au＋197 Au collisions at intermediate energies. The neutron proton differential flows and difference of neutron proton collective flows are sensitive to the momentum-dependent symmetry potential. This sensitivity is less affected by both the isoscalar part of nuclear equation of state and in-medium nucleon- nucleon cross sections. Moreover, this sensitivity becomes pronounced with increasing the rapidity cut.

The influence of charge characteristics of suspension droplets on the ion flow field in different temperatures and humidity

In order to clarify the charging characteristics of suspension droplets in ion flow field under different temperatures and humidity,the effective charging factor used to characterize the charging characteristics of suspension droplets is introduced in this paper,and a calculation method of charging factor is proposed based on the upstream finite element method(FEM).Then,the charging factor under different temperatures and humidity is calculated,and the analytic expression of the charging factor considering the influence of temperature and humidity is obtained by fitting the calculation results.The influence of suspension droplets on the ion flow field is analyzed.The results show that the charging factor is small and increases little with the relative humidity when the relative humidity is less than 60%,and the charging factor is large and increases rapidly with the relative humidity when the relative humidity is more than 60%.At the same relative humidity,the charging factor increases linearly with the temperature.The influence of charged suspension droplets on the ion flow field can be ignored when the relative humidity is less than 60%and must be considered under high temperature and humidity.The calculation method and analytic expression of the charging factor proposed in this paper can be used to model of ion flow field considering the influence of temperature and humidity and provide technical support for the construction of HVDC transmission lines across high temperature and humidity.

An Investigation of Ionic Flows in a Sphere-Plate Electrode Gap

This paper presents analyses of ion flow characteristics and ion discharge pulses in a sphere-ground plate electrode system. As a result of variation in electric field intensity in the electrode gap, the ion flows towards electrodes generate non-uniform discharging pulses. Inspection of these pulses provides useful information on ionic stream kinetics, the effective thickness of ion cover around electrodes, and the timing of ion clouds discharge pulse sequences. A finite difference time domain （FDTD） based space-charge motion simulation is used for the numerical analysis of the spatio-temporal development of ionic flows following the first Townsend avalanche, and the simulation results demonstrate expansion of the positive ion flow and compression of the negative ion flow, which results in non-uniform discharge pulse characteristics.

Conductivity and applications of Li-biphenyl-1,2-dimethoxyethane solution for lithium ion batteries

The total conductivity of Li-biphenyl-1,2-dimethoxyethane solution（Li_xBp（DME）_（9.65）, Bp = biphenyl, DME = 1,2-dimethoxyethane, x = 0.25, 0.50, 1.00, 1.50, 2.00） is measured by impedance spectroscopy at a temperature range from 0℃ to 40℃. The Li_（1.50）Bp（DME）_（9.65） has the highest total conductivity 10.7 m S/cm. The conductivity obeys Arrhenius law with the activation energy（E_（a（x=0.50））= 0.014 eV, E_（a（x=1.00））= 0.046 eV）. The ionic conductivity and electronic conductivity of Li_xBp（DME）_（9.65） solutions are investigated at 20℃ using the isothermal transient ionic current（ITIC） technique with an ion-blocking stainless steal electrode. The ionic conductivity and electronic conductivity of Li_（1.00）Bp（DME）_（9.65） are measured as 4.5 mS/cm and 6.6 mS/cm, respectively. The Li_（1.00）Bp（DME）_（9.65） solution is tested as an anode material of half liquid lithium ion battery due to the coexistence of electronic conductivity and ionic conductivity. The lithium iron phosphate（LFP） and Li_（1.5）Al_（0.5）Ti_（1.5）（PO_4）_3（LATP） are chosen to be the counter electrode and electrolyte, respectively. The assembled cell is cycled in the voltage range of 2.2 V-3.75 V at a current density of 50 mA/g. The potential of Li_（1.00）Bp（DME）_（9.65） solution is about 0.3 V vs. Li~＋/Li, which indicates the solution has a strong reducibility. The Li_（1.00）Bp（DME）_（9.65） solution is also used to prelithiate the anode material with low first efficiency, such as hard carbon, soft carbon and silicon.

Measurement of surface charges on the dielectric film based on field mills under the HVDC corona wire

The ion flow field on the ground is one of the significant parameters used to evaluate the electromagnetic environment of high voltage direct current（HVDC） power lines.HVDC lines may cross the greenhouses due to the restricted transmission corridors.Under the condition of ion flow field,the dielectric films on the greenhouses will be charged,and the electric fields in the greenhouses may exceed the limit value.Field mills are widely used to measure the groundlevel direct current electric fields under the HVDC power lines.In this paper,the charge inversion method is applied to calculate the surface charges on the dielectric film according to the measured ground-level electric fields.The advantages of hiding the field mill probes in the ground are studied.The charge inversion algorithm is optimized in order to decrease the impact of measurement errors.Based on the experimental results,the surface charge distribution on a piece of quadrate dielectric film under a HVDC corona wire is studied.The enhanced effect of dielectric film on ground-level electric field is obviously weakened with the increase of film height.Compared with the total electric field strengths,the normal components of film-free electric fields at the corresponding film-placed positions have a higher effect on surface charge accumulation.

Micro-nondestructive detection of the moisture and ion of rice seeds during germination under salt stress

Salt stress is one of the major stress factors limiting rice productivity.Its damaging effects include water deficit due to osmotic stress,and ionic toxicity caused by ionic stress.It is very important to study the salt-tolerance mechanism of rice under salt stress,in order to improve the salt-tolerance capacity of rice and thereby increase the yield.In this experiment,the low field nuclear magnetic resonance(LF NMR)technique and the traditional dry-weight weighing method,the non-invasive micro-test technique(NMT)and the inductively coupled plasma emission spectrometry(ICP-AES)were applied to analyze the distribution of water and the flow of K^(+)and Na^(+)of rice seeds during germination under NaCl stress.The results suggested that for all different NaCl concentrations,as germination hours grew,the amplitude of NMR signals of the bound water that of the free water and the total amplitude all increased gradually.And the higher the NaCl concentration is,the weaker the increase trend is.In addition,the moisture content of the seeds and the total amplitude of NMR signals were positively correlated.The regression equation was y=191.53x+1463.6,the correlation coefficient was R=0.9823,and the determination coefficient was R2=0.9650.By this regression equation,the moisture content of each state of water during seed germination can be calculated.When without NaCl stress,the rice seeds absorbed K^(+)in the germination process.However,when under NaCl stress at different concentrations,K^(+)efflux was detected.The contents of K^(+)and K^(+)/Na^(+)were lower than that under the control condition.The higher NaCl concentration is,the lower the K^(+)and K^(+)/Na^(+)contents are.These results are in consistence with the K^(+)and Na^(+)contents detected by the inductively coupled technique.These empirical data offer a reference for the study of rice-seeds’response mechanism under salt stress during germination and the screening of germplasm resources,and also put forward a new method of biopsy micro-nondestructive test for plants under stress.