电火花—直读光谱法测定纯铝薄板的Fe、Si、Cu、Mn、Mg、Ti、Zn

本文选用加电感低能放电火花光源，解决了纯铝薄板易击穿的难题，优化了激发条件，并研究了表面氧化层和光洁度对测定结果的影响，建立了一套直接测定厚度0.20mm以上纯铝薄板中各元素的分析方法。考核及对照分析实验表明，各元素的RSD及相对偏差良好。     

进出口铝及铝合金中Fe、Cu、Si、Mn、Mg、Cr、Zn、Ti、Ga等元素的测定

用10％NaOH溶液及30％H2O2溶液溶解样品，以HNO3（1＋1）酸化。采用ICP－AES法同时测定铝及铝合金中Fe等9元素含量。     

高纯La-Ni-Al合金成分及杂质元素的分析方法研究

叙述了镧－镍－铝（La-Ni-Al)合金分镍、铝及微量杂质元素锌、铁、锰、镁、硅、铜和钙的ICP－AES测定方法。样品以HNO3（1＋1）溶解,稀释后直接测定主量元素镍和铝;用基体匹配法补偿基体效应测定其他杂质元素。各元素回收率在95％－106％,相对标准偏差优于5％。     

萃取分离-电感耦合等离子体质谱法测定高纯铝中的杂质元素

采用APDC-MIBK萃取分离铝,电感耦合等离子体质谱(ICP-MS)法同时测定高纯铝中Co,Ni,Cu,Mo,Cd,Pb和Bi。详细地讨论了仪器工作参数,内标元素,分离、富集条件,样品基体的干扰,确定了实验的最佳测定条件。结果表明,方法的检出限为0.011～0.052 μg·L-1,回收率为92.2%～103.0%,相对标准偏差(RSD)小于2.3%。方法准确、快速、简便,应用于高纯铝中Co,Ni,Cu,Mo,Cd,Pb和Bi等杂质元素的测定,结果满意。     

镀锡薄板单位面积镀锡量新的测定方法—贝尔德直读光谱仪分析技术的开发

本文利用贝尔德公司生产的ＳＶ－１０００型（ＤＶ－４）直读光谱仪测定镀锡薄板单位面积镀锡量，开拓了光电光谱仪在镀层领域的应用，通过选用基体铁元素作内标，在适宜的激发条件下获得锡元素涨强比与镀锡量间的线性关系。选择合适条件，解决了薄板易击穿，内标元素光强值稳定性等技术关键，采用容量法制作一套不同镀锡量的标准镀锡薄板，绘制校准曲线，建立了光电光谱分析测定镀锡薄板单位面积镀锡量的方法。方法精度ＲＳＤ小于５     

氢化物发生-无色散原子荧光光谱法测定高纯阴极铜中砷、锑、铋、硒和碲

研究了在氨性溶液中，以镧盐为载体，共沉淀富集高纯阴极铜中杂质As、Sb、Bi、Se、Te,使之与基本铜分离，用氢化物原子荧光光谱法测定。考察了测定的最佳条件、共存元素对测定的影响及方法的准确度和精密度。     

纯硒中杂质元素的ICP-AES测定

电感耦合等离子体-原子发射光谱同时测定纯硒中的碲、铅、铋、锑、铜、铁、镍、铝、锡、砷和硼12种元素的含量,优化出各元素的分析波长和分析条件;用基体匹配补偿基体效应,方法简单,快速可靠,样品回收率为94%-107%.     

纯硅中钙、镁的原子吸收法测定

本文研究了纯硅中钙、镁的原子吸收分析。试样用氢氟酸—硝酸分解,加热蒸发驱除基体硅,残渣用盐酸溶解。用氯化锶消除共存元素的干扰。而铝对钙的干扰通过加锶无法全部消除。但随铝量的增加对钙的影响趋于恒定。本法采用在标准溶液中加入过量铝的方法来抵消铝对钙的干扰。方法简便快速,回收率在96—99之间,实验结果与其它分析方法测定结果符合。     

测定高纯水中痕量杂质Mn、Cd和Cr的原子吸收光谱分析技术

为了克服在环境无净化条件下的污染和采用化学处理预富集而引入较高的空白值，采用了“空气参比－炉内富集－先测样品后测标准”的无火焰原子吸收光谱分析技术，测定高纯水中ｐｐｂ级的痕量元素Ｍｎ、Ｃｄ、Ｃｒ。方法简便，快速。测定各元素的相对标准偏差＜１０％。     

纯元素厚试样的标识X射线强度比

本文在15—30kV加速电压下测定了电子激发的八种纯元素(从铝到锗)的K系X射线强度和四种纯元素(从镍到锗)的L系X射线强度。利用经过我们修正并简化的“完全扩散”电子扩散模型,计算出了这些元素的标识X射线强度比值。新模型本身包含了背散射效应,由模型给出的台阶状X射线分布函数,得出了各元素的吸收修正因子,还考虑了连续谱的荧光效应。计算值与实验值相符合,从而验证了模型的可靠性。 关键词：     

铝球弹丸超高速斜撞击薄铝板特性研究

 利用2017铝合金球形弹丸超高速斜撞击2A12铝合金薄板，模拟空间碎片对航天器防护屏的超高速撞击作用。分析了铝合金薄板超高速斜撞击穿孔特性与弹丸滑弹返溅特性，建立了铝合金球形弹丸超高速斜撞击铝合金薄板的穿孔经验公式。弹丸撞击速度分别为2.58、3.56和4.31 km/s，撞击角度为10°~80°。实验结果表明：铝合金薄板超高速斜撞击椭圆穿孔尺寸与撞击速度和撞击角度有关，直径为3.97 mm的铝合金球形弹丸超高速斜撞击厚度为1 mm的铝合金薄板时，发生滑弹返溅的临界撞击角在30°~40°之间。最大滑弹返溅角随着撞击角的增大而逐渐减小，此时滑弹返溅碎片云的影响范围缩小，但破坏能力增强。弹丸撞击速度对铝合金薄板超高速斜撞击穿孔的椭圆度影响较小。     

Electron probe microanalysis (EPMA) measurement of aluminum oxide film thickness in the nanometer range on aluminum sheets

By using Monte Carlo simulation, the thickness of an aluminum oxide film in the nanometer range on aluminum sheets given different heat treatments was determined by electron probe microanalysis (EPMA) and compared with transmission electron microscopy (TEM). The film thickness was ≤50 nm. As a result, although the same analysis areas were not measured, similar deviations between EPMA and TEM were found. Consequently, we found that the Monte Carlo method was useful for measuring the oxide film thickness in the nanometer range on aluminum sheets. Copyright © 2004 John Wiley & Sons, Ltd.     

Soft X-ray emissions by high-current vacuum discharges

Soft X-ray emissions by Z-pinch discharge between vacuum spark electrodes are examined. Mainly aluminum and molybdenum were utilized to generate soft X-rays, and emissions resulted for pulse currents of about 150 kA. These emissions increased as the discharge current increased. A large X-ray intensity was obtained when a spherical anode and a conical cathode were used. A stable spot plasma was produced for an electrode separation distance of 2 mm. For molybdenum, the X-ray emission of the 0.52-nm line and continuous X-rays of 0.65-1.2 nm were observed. The X-ray continuum was assumed to be a recombination continuum. For aluminum alloy containing magnesium, the 0.62-, 0.66-, 0.72-, 0.78-, and 0.92-nm lines were observed. The experimental results indicate that vacuum spark is a potential exposure source for X-ray lithography     

First principle calculations of thermodynamic properties of pure graphene sheet and graphene sheets with Si,Ge,Fe,and Co impurities

The thermal properties of pure graphene and graphene–impurity(impurity = Fe,Co,Si,and Ge) sheets have been investigated at various pressures(0–7 GPa) and temperatures(0–900 K).Some basic thermodynamic quantities such as bulk modulus,coefficient of volume thermal expansion,heat capacities at constant pressure and constant volume of these sheets as a function of temperature and pressure are discussed.Furthermore,the effect of the impurity density and tensile strain on the thermodynamic properties of these sheets are investigated.All of these calculations are performed based on the density functional theory and full quasi harmonic approximation.     

Comparative Investigations on the Reproducibility of the Hollow Cathode,Glow Discharge and Spark Light Sources

A comparison between the constancy and reproducibility of the hollow cathode, glow discharge and spark light sources was carried out. Samples of pure copper as well as of commercial brass and steel were investigated. Results show that the hollow cathode produces a better reproducibility of the measurements in all the cases examined.     

碎片云动量特性数值仿真研究

 铝合金球形弹丸高速撞击薄铝板时,会造成薄铝板穿孔并自身发生破碎,在铝板前后两侧产生碎片云,分别为反溅碎片云和穿透碎片云。反溅碎片云及穿透碎片云具有各自的动量特性,对其动量特性的研究有助于为碎片云理论建模提供依据。采用AUTODYN V6.0软件对直径为6.35 mm的Al 1100-O球形弹丸高速正撞击6种厚度的Al 6061-T6薄板进行了数值仿真计算,撞击速度为1.0～5.0 km/s。得到上述两种碎片云的动量,确定了动量值随撞击速度v及薄板厚度δ的变化规律。同时,利用仿真得到的动量数据,采用多元回归方法,分别建立了两种碎片云动量模型。最后,对美国国家航空航天局（NASA）报告给出的7种工况下的撞击实验进行了数值仿真计算,并将动量值与实验结果进行了比较,得到的比较结果可用以分析数值仿真的有效性。     

Estimation of the transient interfacial heat flux between substrate/melt at the initiation of magnesium solidification on aluminum substrates using the lumped capacitance method

Interfacial heat flux (IHF) between solid pure aluminum/magnesium melt and solid 413 aluminum alloy/magnesium melt couples was evaluated using lumped capacitance method, and the interface microstructures were assessed by scanning electronic microscope. The variation of maximum IHF with surface roughness for these two couples also was evaluated. The results showed that, for both solid aluminum/magnesium melt couples, with increasing the surface roughness, the maximum IHF increases at first and then starts to decrease after reaching a maximum value. In addition the measured maximum IHF for solid 413 aluminum alloy/magnesium melt couples was found to be higher than those measured for solid pure aluminum/magnesium melt couples. That seems to be because of the better wettability of 413 aluminum alloy than pure aluminum, by magnesium melt.     

Lead Inclusions in Silicon: Structure, Morphology, and Thermal Behavior

Small inclusions of lead have been embedded in pure silicon by rapid quenching. They are topotactic-truncated octahedra with a smaller aspect ratio than the ones found in aluminum. They appear also on single and multiple twins as a bicrystalline unit with a compound morphology. No overheating has been detected, while undercooling is size dependent and can reach 80 K. These results are compared to the structure, morphology and thermal behavior of lead inclusions in aluminum and other cubic matrices.     

碳纳米管增强铝基复合材料电子理论研究

采用自行开发计算机软件，建立了铝晶粒大角度重位点阵晶界模型及碳纳米管与铝金属的界面结构，利用递归法计算了纳米碳管增强铝基复合材料的电子结构参数(铝晶界、铝与纳米管界面及纳米管的结构能，体系费米能级等). 计算结果表明：Σ为5的晶界结构能最低，比较稳定；纳米碳管在铝晶粒的晶界处与铝形成的界面结构能较低，复合材料中纳米碳管主要分布在铝晶粒的晶界处；铝提高纳米碳管的结构能，降低纳米碳管的稳定性，增强碳管的物理化学活性，且管口处的碳原子稳定性较差，易与周围环境中的原子结合生成稳定结构. 关键词： 电子结构 晶界 铝复合材料 纳米管