SiH4激光等离子体内H谱线的线型研究

本文利用OMA-Ⅲ系统测量了脉冲TEA CO_2激光诱发的SiH_4等离子体发光谱内H巴耳末系的H_α、H_β和H_γ线的线型及线宽。通过理论及实验分析,认为这些谱线的主要加宽机制为Stark加宽。由实验线型和理论线型的拟合得到等离子体的电子温度T≈40000K和电子密度N≈10~(17)cm~(-3)。     

氮碳薄膜反应溅射沉积过程的OES诊断

氮碳薄膜反应溅射沉积过程的ＯＥＳ诊断赵菁，王金国，康宁，王荣瑶，徐积仁（中国科学院物理研究所光物理实验室北京１０００８０）等离子体光发射谱（ＯＥＳ）作为一种实验的手段常用于等离子体薄膜沉积过程中气相物种及化学反应过程的诊断，它有助于对薄膜生长机理的了...     

南通产业结构与竞争力评价研究

利用三次产业分类法,根据近年来统计数据,从南通产业经济现状入手,分析其内部结构,并运用偏离—份额模型,评价基于长三角的南通三次产业结构优劣及竞争力状况,认为南通在长三角具备区位上的比较优势,但产业结构因素对经济增长起消极影响.随着建设长三角北翼经济中心战略的实施,南通应抓住发展机遇,不断调整产业结构,构建产业结构高级化、产业竞争力高端化的现代产业体系.     

Effect of second phase precipitation behavior on mechanical properties of casting Al-Cu alloys

The effect of the second phase precipitation behavior on the mechanical properties and fracture behavior of the modified casting Al-Cu alloys was investigated. The tensile strength of the alloys increases firstly and then decreases due to the appearance of θ＇ precipitation phases, which increases firstly and then become coarser with the aging time increasing from 10 h to 20 h at 155 ℃. The strength of the alloys reaches the peak, resulting from ,Ω and θ＇ precipitation phases, and decreases due to ,Ω phases becoming coarser and θ＇ precipitation decreasing with the aging time increasing from 10 h to 20 h at 165 ℃. ,θ phase becoming coarser and θ＇ precipitation decreasing result in the strength of the alloys drastically decreasing after aging at 175 ℃ for 20 h. The ductility remains high level with increasing aging time at 155 ℃. The ductility irregularly changes as aging time prolongs at 165 ℃. The ductility is very low and at the same time gradually decreases with increasing aging time at 175 ℃. The Al-Cu alloy with a promising combination of tensile strength and ductility of about 474 MPa and 12.0% after aging at 165℃ for 10 h is due to a dense, uniform distribution of,Ω precipitation phases together with a heterogeneous distribution of θ＇ precipitations.     

应用水面线法进行双库连通调洪演算的实践

针对山东省墙夼水库由两个既独立又相互连通的水库组成的特点,分析、探讨双库连通调洪演算理论方法,建立双库连通调洪演算的计算模型,给出水面线数学模型和算法,用于墙夼水库设计洪水复核.计算结果表明,该方法中间环节少,操作性强,可应用于水库工程的抗洪能力评价和调度运用方案制定.     

Effect of Cu-Ti-C reaction composition on reinforcing particles size of TiC<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>/Cu composites

TiC _x /Cu composites were fabricated by combustion synthesis and hot press technology. Using XRD, SEM, EDS, FESEM analysis methods, the effects of various carbon sources and different Cu contents on the microstructures of TiC _x /Cu composites and the size of TiC _x particles were investigated. Results showed that TiC _x reinforcing particles size increases with decreasing Cu content in Cu-Ti-C reaction system. With carbon nanotubes (carbon black) serving as carbon source, the generated TiC _x particles size transits from nanometer to submicron when Cu content corresponding to the reaction system is reduced to 60 vol% (70 vol%); while graphite serves as carbon source, there is no clear limiting concentration. C particles with smaller size, larger specific surface area and better distribution result in finer TiC _x particles, which is more beneficial to generating nano-sized TiC _x /Cu composites.     

TiC颗粒对铸态球墨铸铁组织和力学性能的影响

采用高能球磨方法对TiC粉末进行改性,并加入到球墨铸铁熔体。使用光镜、扫描电镜、能谱仪对其组织进行分析。结果表明,球墨铸铁的石墨和基体组织均得到改善。一部分TiC颗粒作为石墨异质核心,促进了石墨形核,使石墨球数目增加40.5%,石墨球尺寸细化,铁素体含量升高了4.5%,球化率提高了9.1%。另一部分进入基体的TiC颗粒,不仅改变了周围的渗碳体形貌,甚至形成独特的"珠光体团"结构;而且能阻碍晶界运动进而细化铁素体晶粒。采用拉伸试验机和冲击试验机对铸态球墨铸铁进行力学性能测试,结果表明,外加少量TiC颗粒使球墨铸铁的断裂总伸长率提高了19.1%,室温冲击韧性提高了31.1%,低温(-20℃)冲击韧性提高了21.8%。     

基于MATLABR的矿井涌水量神经网络预测方法及应用

在MATLAB神经网络工具箱的基础上实现基于时序的神经网络动态预测方法 ,通过采用快速的L—M算法 ,提高神经网络训练的速度与精度 ,实现煤矿安全监测数据的连续预测与提前预警。以一种相对简单的途径实现了神经网络这种复杂而有效的非线性预测方法。     

情缘

你，钟情撤榄绿，身着橄榄绿，这的确是一种情缘。你“哇”的一声脱离母体时．你的爸爸正在奋战火魔。你到世的第三日，你那没有了眉毛的父亲才拖着疲惫的身子带着一张烤黑的脸和一头参差不齐的头发回来。你的妈妈心疼地哭了，可你的爸爸却笑得很甜……     

巧妙设置,让共享片刻全部禁用

在Windows XP中,如果要取消自己所共享的文件,通常都是通过打开的“共享和安全”命令对话框,然后将“共享此文件夹”选项取消来解决的。但是,有时因某些原因我们需要暂时取消所有的共享,如果使用上述方法逐一取消共享会非常麻烦。[编者按]