Single neurons in the medial prefrontal cortex of the rat exhibit tonic and phasic coding during trace fear conditioning.

Trace fear conditioning is a learning task that requires the association of an auditory conditioned stimulus (CS) and a shock unconditioned stimulus (US) that are separated by a 20-s trace interval. Single neuron activity was recorded from the prelimbic and infralimbic areas of the medial prefrontal cortex in rats during trace fear conditioning or nonassociative unpaired training. Prelimbic neurons showed learning-related increases in activity to the CS and US, whereas infralimbic neurons showed learning-related decreases in activity to these stimuli. A subset of prelimbic neurons exhibited sustained increases in activity during the trace interval. These sustained prelimbic responses may provide a bridging code that allows for overlapping representations of CS and US information within the trace fear conditioning circuit. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

选择溶解条件--ICP-AES法测定铝合金中10元素

在铝合金中,对常量、微量、痕量元素等的测量,传统上采用化学的方法来分析,手续繁杂,分析时间 亦长,有时不能满足大批量快速分析的要求。ICP-AES分析法,以其优异的分析性能被广泛应用于各种材料 的主要、次要,痕量、超痕量多元素的同时分析。但是,影响等离子炬状态的因素很多,只有在最佳工作状态下 操作,才能充分发挥ICP光源的优越性。     

气割集箱管椭圆端孔的专用装置

为气割椭圆孔 ,采用行星轮装置控制割炬运动轨迹 ,不但提高了加工效率 ,而且提高了非圆气割的形状精度     

用LWR学习进行乒乓球轨道预测的仿真研究

乒乓机器人的任务是将球击回到对方的场地内．这个任务由两部分组成：知觉和行动．本文研究机器人的知觉问题，也就是利用ＬＷＲ（ＬｏｃａｌｙＷｅｉｇｈｔｅｄＲｅｇｒｅｓｓｉｏｎ）学习的方法预测接触反弹后的球的轨道．     

电感耦合等离子体质谱法测定高纯镓中痕量元素

探讨了电感耦合等离子体质谱仪(ICP—MS)测定高纯镓中痕量元素的新技术，实验采用气固反应原理分离镓主体，富集杂质元素；采用10ng/ml Rh和Se为双内标补偿校正镓基体的抑制效应，采用碰撞室(CCT)技术消除多元素分子离子的干扰；使分离富集技术与ICP—MS技术联用，可满足99．9999％超高纯镓的分析要求。方法的检出限0．001～0．01μg／L，加标回收在90．6％～111．1％之间，RSD为0．27％～7．00％。     

磁助捕集分离制样/X射线荧光测量微量Tc

建立了磁助捕集分离制样(MASP)/X射线荧光分析微量Tc的方法,使用磁化树脂作为固相捕集剂捕集溶液中的锝,利用外加磁场快速分离制样,实现捕集、分离及制样同时完成,可直接使用X射线荧光测量样品Tc含量。研究并分析了反应时间、磁化树脂用量、液相体积及酸度等因素对测量的影响,给出了推荐测量分析流程。使用磁助捕集分离制样,对Tc的检出限为0.33mg/L,满足PUREX流程1AW工艺点测量Tc的要求。     

在UO_2(NO_3)_2-TBP-CCI_4有机相中光化还原制备铀(Ⅳ)的研究

本文的目的是研究在TBP有机相中光化还原铀(Ⅵ)以制备铀(Ⅳ)。选用了高压汞灯作为激发光源,CCl_4为TBP的稀释剂。研究了反应温度、原始水相溶液组成等因素对铀(Ⅳ)产额和亚硝酸生成量的影响。推荐了制备铀(Ⅳ)的适宜条件。     

微量钒对高碳钢组织的影响

在“THERMECMASTDR—Z”热加工模拟试验装置上模拟了加热温度、保温时间、变形速度等对含钒高碳钢组织的影响,分析了不同变形温度下氮浓度对析出物的影响。     

Experimental study on mercury content in flue gas of coal-fired units based on laser-induced breakdown spectroscopy

Accurate measurement of trace heavy metal mercury(Hg) in flue gas of coal-fired units is great significance for ecological and environmental protection.Mixed gas was used to simulate the actual flue gas of a power plant in this study.A laser-induced breakdown spectroscopy(LIBS)system for Hg measurement in mixed gas was built to study the effect of mixed gas pressure,Hg concentration in mixed gas and delay time on Hg measurement.The experimental results show that the appropriate low mixed gas pressure can obtain high Hg signal intensity and signal to noise ratio.The Hg signal intensity and signal to noise ratio increased with the increase of Hg concentration in mixed gas.The Hg signal intensity and signal to noise ratio decreased with the increase in delay time.According to the above results,the optimized measurement conditions can be determined.Different Hg concentrations in mixed gas were quantitatively analyzed by the internal standard method and traditional calibration method respectively.The relative error of prediction of the test sample obtained by the internal standard method was within 11.11%.The relative error of prediction of the traditional calibration method was less than 14.54%.This proved that the internal standard method can improve the accuracy of quantitative analysis of Hg concentration in flue gas using LIBS.