Secondary decay effects of the isospin fractionation in the projectile fragmentation at GeV/nucleon

The isospin fractionations in 124Sn,107Sn+120Sn at 600 MeV/nucleon,and 136Xe,124Xe+208Pb at 1000 MeV/nucleon are investigated by the isospin-dependent quantum molecular dynamics model coupled with the statistical code GEMINI.The yield ratio as a function of the binding energy difference for light mirror nuclei 3H/3He,7Li/7Be,11B/11C,and 15N/15O is applied to estimate the ratio between neutrons and protons in the gas of the fragmenting system.By comparing the estimated values resulting from the simulations with and without the GEMINI code,it was found that the secondary decay distorts the signal of the isospin fractionation.To minimize the secondary decay effects,the yield ratio of the light mirror nuclei 3H/3He as well as its double ratio between two systems with different isospin asymmetries of the projectiles is recommended as robust isospin observables.

Effects of low dose Glibenclamide on secondary damage after acute spinal cord injury in rats

Objective To investigate the effects of Glibenclamide on reduction of secondary damage after acute spinal cord injury in rats.Methods Ninety rats were randomly divided into control group(laminectomy alone),spinal cord injury group(injury group),and treatment group(treated

Influence of Sub-Cloud Secondary Evaporation Effects on the Stable Isotopes in Precipitation of Urumqi Glacier No.1,Eastern Tianshan

In arid regions,the stable hydrogen and oxygen isotopic composition in raindrops is often modified by sub-cloud secondary evaporation when they descend from cloud base to ground through the unsaturated air.As a result of kinetic fractionation,the slope and intercept of the δ^(2)H-δ^(18)O correlation equation decrease.The variation of deuterium excess from cloud base to the ground is often used to quantitatively evaluate the influence of secondary evaporation effect on isotopes in precipitation.Based on the event-based precipitation samples collected at Urumqi Glacier No.1,eastern Tianshan during four-year observation,the existence and impact of secondary evaporation effects were analyzed by the methods of isotope-evaporation model.Under high air temperature,small raindrop diameter and precipitation amount,and low relative humidity conditions,the remaining rate of raindrops is small and the change of deuterium excess is large relatively,and the slope and intercept of δ^(2)H-δ^(18)O correlation equation are much lower than those of Global Meteoric Water Line,which mean that the influence secondary evaporation on precipitation enhanced.While on the conditions of low air temperature,high relative humidity,heavy rainfall,and large raindrop diameter,the change of deuterium excess is small relatively and the remaining rate of raindrops is large,and the slope and intercept of δ^(2)H-δ^(18)O correlation equation increase,the secondary evaporation is weakened.The isotope-evaporation model described a good linear correlation between changes of deuterium excess and evaporation proportion with the slope of 0.90‰/%,which indicated that an increase of 1%in evaporation may result in a decrease of deuterium excess about 0.90‰.

Research on Micro-Flow Self-Sensing Actuators Based on Piezoelectric Ceramic Stack `

The paper is concerned with the micro-flow self-sensing actuators,the work of which is based on the secondary piezoelectric effect. The piezoelectric ceramic stack can yield micro-displacement due to its first inverse piezoelectric effect. Therefore,we apply this micro-displacement to cell micro-flow injection. Moreover, due to the charge of the secondary direct piezoelectric effect,the piezoelectric ceramic stack is able to detect the force and displacement in the injection by itself. The experiments of first inverse piezoelectric effect and secondary direct piezoelectric effect are conducted. The experiment results show that,subjected to 0- 60 V input,the piezoelectric ceramic stack can generate 13. 45 μm displacement,and control accuracy can achieve 2 nm. It can completely meet the needs of cell micro-flow injection. Also,the experiments demonstrate that the micro-displacement due to the first inverse piezoelectric effect can be well self-sensed by the electric charge due to the secondary direct piezoelectric effect.

Breakdown Voltage Research of Penning Gas Mixture in Plasma Display Panel

Paschen law and equations, which ignore the influence of the Penning ionization on the electron ionization coefficient （α）, are always used as the approximation of the breakdown voltage criterion of the Penning gas mixture in current researches of discharge characteristics of the plasma display panel （PDP）. It is doubtful that whether their results match the facts. Based on the Townsend gas self-sustaining discharge condition and the chemical kinetics analysis of the Penning gas mixture discharging in PDP, the empirical equation to describe the breakdown of the Penning gas mixture is given. It is used to calculate the breakdown voltage curves of Ne-Xe/MgO and Ne-Ar/MgO in a testing macroscopic discharge cell of AC-PDP. The effective secondary electron emission coefficients （γeff） of the MgO protective layers are derived by comparing the breakdown voltage curves obtained from the empirical equation with the experimental data of breakdown voltages. In comparison with the results calculated by the Paschen law and the equation which ignore the influence of the Penning ionization on α , the results calculated by the empirical equation have better conformity with experimental data. The empirical equation characterizes the breakdown of the Penning gas mixture in PDP effectively, and gives a convenient way to study its breakdown characteristics and the secondary electron emission behaviors.

Effects of seed particles Al2O3, Al2（SO4）3 and H2SO4 on secondary organic aerosol

Seed particles Al2O3, Al2（SO4）3 and H2SO4 were selected to investigate their effects on secondary aerosol （SA） formation in toluene/NOx photooxidation under sulfur dioxide （SO2） and ammonia （NH3）. Effect of seed particles on SA formation was related to their acid-base properties and the presence of acid or alkaline gases. Under NH3-poor condition, SA formation increased with increasing SO2 concentration due to the acid-catalyzing effect of the oxidation products of SO2 （i.e. H2SO4）, The enhancing effect of SO2 became unobvious under NH3-rieh condition, because NH3 would eliminate the acid-catalyzing effect by neutralizing the acid products. Acidic seeds H2SO4 accelerated SA formation under either SO2 or NH3 condition. Weak acidic Al2（SO4）3 seeds didn＇t affect obviously on SA formation. The inhibiting effect of amphoteric seeds Al2O3 on SA formation was related to the presence of SO2 / NH3 due to their acid-base property. Under NH3-poor condition, the inhibiting effect of Al2O3 on SA formation decreased with increasing concentration of SO2, while under NH3-rich condition, the inhibiting effect wasn＇t remarkable.

EFFECT OF THE THERMAL FORCING ON THE SECONDARY CIRCULATION OF TYPHOONS

A non-dimensional secondary circulation equation for typhoons has been derived and then 11-yr com- positing typhoon data were used to estimate the thermally forced secondary circulation.The main results have been obtained as follows: (1)The diabatic heating and Cu vertical heat mixing are major thermal forcing factors.They have the same magnitude of order.(2)The effects of eddy flux and Cu horizontal mixing of heat are of minor im- portance.(3)Ekman pumping and Cu vertical heat mixing cooperatively work.This feedback process is favorable for the enhancement of the secondary circulation of typhoons.

Effect of secondary MO interaction on the regiospecificity in the reactions of α-ionones with singlet oxygen

The eme reactions of α-ionones with singlet oxygen were examined to ascertain the effect of secondary Me interaction between the reactants on the reaction regiospecificity. Exclusive formation of 3-hydroxy-γ-ionones found in the reactions reveals favorable interaction of singlet oxygen with the acyclic α-hydrogen atom,On the other hand,no formation of 3-hy- droxy-β-ionones implies that the steric requirement was not met for the bond formation between zwitterionic perepoxide with C_1-hydrogen in the process.The MMP21 and MNDO calculations indicate minus value of the secondary interaction energy for the aeyelie α-hydrogen abstrac- tion and a repulsion between the oxygen with C_1-hydrogen atom.Twisting tilting of the double bond may account for favorable attack of singlet oxygen on C_3.An explanation of the excellent regiospecificity was addressed and placed in proper mechanic prospective.

High-performance formaldehyde prediction for indoor air quality assessment using time series deep learning

Indoor air pollution resulting from volatile organic compounds(VOCs),especially formaldehyde,is a significant health concern needed to predict indoor formaldehyde concentration(Cf)in green intelligent building design.This study develops a thermal and wet coupling calculation model of porous fabric to account for the migration of formaldehyde molecules in indoor air and cotton,silk,and polyester fabric with heat flux in Harbin,Beijing,Xi’an,Shanghai,Guangzhou,and Kunming,China.The time-by-time indoor dry-bulb temperature(T),relative humidity(RH),and Cf,obtained from verified simulations,were collated and used as input data for the long short-term memory(LSTM)of the deep learning model that predicts indoor multivariate time series Cf from the secondary source effects of indoor fabrics(adsorption and release of formaldehyde).The trained LSTM model can be used to predict multivariate time series Cf at other emission times and locations.The LSTM-based model also predicted Cf with mean absolute percentage error(MAPE),symmetric mean absolute percentage error(SMAPE),mean absolute error(MAE),mean square error(MSE),and root mean square error(RMSE)that fell within 10%,10%,0.5,0.5,and 0.8,respectively.In addition,the characteristics of the input dataset,model parameters,the prediction accuracy of different indoor fabrics,and the uncertainty of the data set are analyzed.The results show that the prediction accuracy of single data set input is higher than that of temperature and humidity input,and the prediction accuracy of LSTM is better than recurrent neural network(RNN).The method’s feasibility was established,and the study provides theoretical support for guiding indoor air pollution control measures and ensuring human health and safety.

The snap-back effect of an RC-IGBT and its simulations

The RC-IGBT（reverse conducting insulated gate bipolar transistor） is a new kind of power semiconductor device which has many advantages such as smaller chip size,higher power density,lower manufacturing cost,softer turn off behavior,and better reliability.However,its performance has a number of drawbacks,such as the snap-back effect.In this paper,an introduction about the snap-back effect of the RC-IGBT is given firstly. Then the physical explanations are presented with two simplified models.After that,some numerical simulations are carried out to verify the correctness of the models.