Influence of Working Memory Capacity on the Frequency of Self-Repairs

This article explored the influence of working memory capacity on the frequency of self-repairs.The narrative task and listening span task were used.Twenty post-graduate students participated in this study.Overall,the results of this study illustrated that the working memory is a factor of self-repairs.Speakers who have higher working memory capacity produce lesser self-repairs.This finding provides teachers with a new insight into second language teaching;that is,teachers can improve the amount of lexical knowledge when teaching students who have lower working memory in order to help them produce more accurate language during the process of L2 speech production.

Supercritical carbon dioxide as a new working medium for pneumatic launch:A theoretical study

Compared with the conventionally gaseous or liquid working media,the specific internal energy of supercritical carbon dioxide(SCD)is higher at the same temperature and pressure,and the critical temperature of carbon dioxide is close to room temperature,making SCD a potential new working medium for pneumatic launch.To analyze the feasibility of this conception,an analytical model of a pneumatic catapult is established on basis of the conservations of mass and energy.The model consists of a high-pressure chamber and a low-pressure chamber connected by multiple valves,and there is a movable piston in the low-pressure chamber that can push an aircraft to accelerate.The effects of the launch readiness state of SCD in the high-pressure chamber,the initial volume of the low-pressure chamber and the valve control on the movement of the aircraft are analyzed.It is found that there is a restrictive relation between the temperature and pressure of the launch readiness state of SCD,i.e.,there is a maximum allowable launch readiness pressure when the launch readiness temperature is fixed.If this restrictive relation is not satisfied,the working medium in the low-pressure chamber will drop to its triple point within a few milliseconds,leading to a launch failure.Owing to this restrictive relation,there is an optimal launch readiness state of SCD with the highest working capacity for any allowable launch readiness temperature.The pressure of the low-pressure chamber will decrease significantly as the initial volume increases,leading to a decreased acceleration of the aircraft.The acceleration can be controlled below a critical value by a designed sequential blasting technique of multiple valves.The calculated results show that a 500 kg aircraft can be accelerated from 0 to 58 m/s in 0.9 s with 36 kg of carbon dioxide.This research provides a new technique for the controllable cold launch of an aircraft.

Mismatch negativity,social cognition,and functional outcomes in patients after traumatic brain injury

Mismatch negativity is generated automatically, and is an early monitoring indicator of neuronal integrity impairment and functional abnormality in patients with brain injury, leading to decline of cognitive function. Antipsychotic medication cannot affect mismatch negativity. The present study aimed to explore the relationships of mismatch negativity with neurocognition, daily life and social functional outcomes in patients after brain injury. Twelve patients with traumatic brain injury and 12 healthy controls were recruited in this study. We examined neurocogni-tion with the Wechsler Adult Intelligence Scale-Revised China, and daily and social functional outcomes with the Activity of Daily Living Scale and Social Disability Screening Schedule, re-spectively. Mismatch negativity was analyzed from electroencephalogram recording. The results showed that mismatch negativity amplitudes decreased in patients with traumatic brain injury compared with healthy controls. Mismatch negativity amplitude was negatively correlated with measurements of neurocognition and positively correlated with functional outcomes in patients after traumatic brain injury. Further, the most signiifcant positive correlations were found be-tween mismatch negativity in the fronto-central region and measures of functional outcomes. The most signiifcant positive correlations were also found between mismatch negativity at the FCz electrode and daily living function. Mismatch negativity amplitudes were extremely positive-ly associated with Social Disability Screening Schedule scores at the Fz electrode in brain injury patients. These experimental ifndings suggest that mismatch negativity might efifciently relfect functional outcomes in patients after traumatic brain injury.

OPTIMUM DESIGN OF HIGH-SPEED RAILWAY LOCOMOTIVE TRACTION GEAR

On the basis of deep investigation of locomotive traction gears manufactured at home and abroad , a variety of measures are putted forward to improve the driving load-bearing capacity and working life of our country's high-speed locomotive traction gears. The measures include the fol- lowing five aspects : optimally selecting the material and heat treatment process , optimally designing the tooth profile . reasonably choosing the manufacture accuracy and technique , optimally choosing the lubricant and the way of lubrication and seal , improving the dynamic feature of the gearing. In the respect of the tooth profile , a hob with optimal cutter angles is designed to make root thickness on the dangerous section as large as possible and the stress concentration as small as possible. Ad- dendum modification coefficient is optimized to minimize the maximum flash temperature in the course of meshing. Finally . finite element analysis method is used to calculate the deformation and the stress of teeth accurately. And on this basis , optimal profile correction and axial modification have been designed with regard to the start , continuious running and high speed travel of the loco- motive .

Wearable positive end-expiratory pressure valve improves exercise performance

We tested a PEEP(4.2 cmH_(2)O)mouthpiece(PMP)on maximal cycling performance in healthy adults.Experiment-1,PMP vs.non-PMP mouthpiece(CON)[n=9(5♂),Age=30±2 yr];Experiment-2,PMP vs.no mouthpiece(NMP)[n=10(7♂),Age=27±1 yr].At timepoint 1 in both experiments(mouthpiece condition randomized)subjects performed graded cycling testing(GXT)(Corival®cycle ergometer)to determine VO_(2peak)(ml*kg*min^(-1)),O2pulse(mlO2*bt^(-1)),GXT endurance time(GXT-T(s)),and VO_(2)(ml*kg*min^(-1))-at-ventilatory-threshold(VO_(2)@VT).At timepoint 272 h later,subjects completed a ventilatory-threshold-endurance-ride[VTER(s)]timed to exhaustion at VO_(2)@VT power(W).One week later at timepoints 3 and 4(time-of-day controlled),subjects repeated testing protocols under the alternate mouthpiece condition.Selected results(paired T-test,p<0.05):Experiment 1 PMP vs.CON,respectively:VO_(2peak)=45.2±2.4 vs.42.4±2.3 p<0.05;VO_(2)@VT=33.7±2.0 vs.32.3±1.6;GXTTTE=521.7±73.4 vs.495.3±72.8(p<0.05);VTER=846.2±166.0 vs.743.1±124.7;O2pulse=24.5±1.4 vs.23.1±1.3(p<0.05).Experiment 2 PMP vs.NMP,respectively:VO_(2peak)=43.3±1.6 vs.41.7±1.6(p<0.05);VO_(2)@VT=31.1±1.2 vs.29.1±1.3(p<0.05);GXT-TTE=511.7±49.6 vs.486.4±49.6(p<0.05);VTER 872.4±134.0 vs.792.9±122.4;O2pulse=24.1±0.9 vs.23.4±0.9(p<0.05).Results demonstrate that the PMP conferred a significant performance benefit to cyclists completing high intensity cycling exercise.