X射线荧光光谱测定钛合金样品中多元素

以化学法标定的钛合金作为标准样品,用理论α系数及干扰曲线法进行基体效应和谱线重叠干扰的校正,开发了用X射线荧光光谱测定钛合金样品中除Ti外的常量和微量元素的方法。用该方法测定结果与化学值相符。10次制样测量,各元素的RSD≤1.25%。     

电感耦合等离子体原子发射光谱法测定铅锑合金中九个杂质元素

拟定了电感耦合等离子体原子发射光谱（ＩＣＰ－ＡＥＳ）测定铅锑合金中Ａｓ、Ｂｉ、Ｃａ、Ｃｄ、Ｃｏ、Ｆｅ、Ｍｎ、Ｓｅ和Ｚｎ等九个元素的分析方法,考察了Ｐｂ、Ｓｂ基体对待测元素的干扰情况。样品以ＨＮＯ３分解,酒石酸抑制Ｓｂ水解,ＩＣＰ－ＡＥＳ同时测定多元素。方法对各元素的测定限在０．０７～５．２μｇ／ｇ,相对标准偏差（ｎ＝８）为０．７８％～２５．５％,加标回收率均大于８６％,经与原子吸收光谱法和原子荧光     

Thermal equation of state of iron and Fe0.91Si0.09

We have carried out an in situ synchrotron X-ray diffraction study on iron and an iron-silicon alloy Fe_0.91Si_0.09 at simultaneously high pressure and temperature. Unit-cell volumes, measured up to 8.9 GPa and 773 K on the bcc phases of iron and Fe_0.91Si_0.09, are analyzed using the Birch-Murnaghan equation of state and thermal pressure approach of Anderson. Equation of state parameters on iron are found to be in agreement with results of previous studies. For both iron and Fe_0.91Si_0.09, thermal pressures show strong dependence on volume; the (∂K_T/∂T)_V values are considerably larger than those previously reported for other solids. The present results, in combination with our previous results on ɛ-FeSi, suggest a small dependency of the room-temperature bulk modulus upon the silicon content, less than 0.3 GPa for 1 wt.% silicon. We also find that substitution of silicon in iron would not appreciably change the thermoelastic properties of iron-rich Fe−Si alloys. If this behavior persists over large pressure and temperature ranges, the relative density contrast between iron and iron-rich Fe−Si alloys at conditions of the outer core of the Earth could be close to that measured at ambient conditions, i.e., 0.6% for 1 wt.% Si. Received: 13 January 1998 / Revised, accepted: 8 May 1998     

海洋平台结构SMA阻尼隔振振动台试验与分析

本文针对渤海JZ20-2MUQ导管架式海洋平台进行比例为1∶10的模型结构的形状记忆合金阻尼隔振振动台试验研究。首先,根据原结构的基本参数,确定试验模型的几何参数,推导出相似比关系,并对形状记忆合金阻尼器和黏滞阻尼器进行性能试验,确定其基本力学性能;其次,对模型结构进行振动台试验研究,分别考察4种地震作用下无控结构、纯隔振结构、SMA隔振结构和SMA阻尼隔振结构的反应;最后,对模型结构进行数值计算分析。结果表明,各种隔振结构方案对平台结构导管架端帽位移和平台甲板加速度均有很好的控制效果。数值分析结果与试验结果吻合较好。     

基于状态空间法的SMA-复合支座隔震结构分析

研究了SMA(shape memory alloy)绞线-叠层橡胶复合支座的工作原理,将结构控制理论中的结构状态空间法应用到该复合支座隔震结构的数值模拟分析中。建立了普通框架、安装叠层橡胶支座和安装SMA复合支座框架的结构状态方程,应用SIMULINK工具箱建立结构仿真模型,得出不同条件下框架结构的时程反应曲线。通过对比分析可以看出SMA-复合支座能很好地改变结构的隔震效果,应用状态空间法进行SMA-复合支座隔震结构的数值模拟分析简单准确。     

Control devices incorporated with shape memory alloy

Shape Memory Alloy (SMA) is a type of material that offers some unique characteristics for use in devices for vibration control applications. Based on SMA's material properties, four types of control devices that incorporate NiTi SMA wires are introduced in this paper, which include three types of dampers (SMA damper, SMA-MR damper and SMA-friction damper) and one kind of isolation bearing (SMA-rubber bearing). Mechanical models of these devices and their experimental verifications are presented. To investigate the control performance of these devices, the SMA-MR damper and SMA-rubber bearing are applied to structures. The results show that the control devices could be effective in reducing the seismic response of structures.     

Alloy elements' effect on steel corrosion in marine environment

INTRODUCTIONBesidesprotectivecoatingandcathodicprotectionmethodsagainstcorrosionoflowalloysteelconstructuresinmarineenvironment,itisalsoimportanttoimprovethecorrosionresistanceofthelowalloysteelitself.Therearefewreportsontherelationshipofalloyelementandthecorrosionre sistanceofsteel .Larrabee (1 958)’s 5-9yearsseaexperimentusinglong scalesteelshowedthatthecorrosionresistanceof 0 .5%Ni-0 .5%Cu -0 .1 %Psteelwasthehighestinthesplashzone .HouandZhang (1 980 )consideredthataproperrelationshi…     

循环荷载作用下SMA-PSRCW结构力学性能影响因素分析

为了研究形状记忆合金(SMA)连接件对半刚接钢框架内填钢筋混凝土墙结构(PSRCW结构)受力性能的影响情况,在已有试验研究的基础上,建立了SMA-PSRCW结构的计算模型,对结构在循环荷载作用下的整体受力性能进行了数值模拟研究,考虑了配筋率、混凝土强度、内填墙厚度以及连接件布置位置和数量等因素对结构的滞回性能、骨架曲线...     

SMA-VED混合自复位支撑钢框架地震易损性与风险分析

本文提出了一种新型形状记忆合金（Shape Memory Alloy,SMA）-黏弹性阻尼器（ViscoelasticDamper,VED）自复位支撑,设计了普通预应力筋自复位支撑钢框架与SMA-VED自复位支撑钢框架。采用组合模型以及改进材料模型准确模拟了支撑的力学行为,详细讨论了考虑构件失效的模拟方法,通过试验确定了VED的失效应变范围,最后基于概率统计方法进行了易损性分析以及全周期风险分析。研究发现: SMA-VED自复位支撑可显著提升框架抗震性能;倒塌风险以及残余变形超越概率均显著低于普通预应力筋自复位支撑钢框架,下降比例最高超过50%。预应力筋断裂失效导致框架倒塌风险可提高5倍以上; SMA-VED自复位支撑失效会造成残余变形超越概率有所上升但幅度不大。总体来说,SMA-VED自复位支撑钢框架具备更好的地震鲁棒性。     

基于SEM-EDS及GC-MS技术研究有机氯分子结构对零价铜脱氯机制的影响

零价铜作为一种廉价金属很少应用于促进氯代有机物脱氯研究,其原因是零价铜的催化还原脱氯活性差,且反应机制复杂。本文采用机械球磨技术制备了Cu-Fe和Cu-Ni合金,研究零价铜在不同微观环境下对对氯苯酚(4-CP)的脱氯行为,旨在考察有机氯分子结构对零价铜脱氯机制的影响。应用扫描电镜-能谱(SEM-EDS)及色相色谱-质谱(GC-MS)分析发现,铜原子的微环境及有机氯分子结构均影响铜的脱氯机制。在Cu-Fe体系中,Cu遵循经典的催化加氢脱氯机制,4-CP的降解产物为苯酚;Cu-Ni体系的还原作用来源于零价铜,其中的镍金属并未起到催化加氢作用,Cu-Ni合金及单独零价铜对4-CP的降解产物是环己酮。零价铜对4-CP的降解率可达70%以上,而Cu-Fe体系的降解率仅为34%,两者对芳香族氯代物的降解效率差距显著。零价铜能够降解化学稳定性高的4-CP和苯酚,但不能降解化学稳定性相对较差的脂肪族氯代有机物(如一氯乙酸和二氯乙酸),因此认为零价铜脱氯机制并非传统的催化加氢机制,而是遵循直接电子传递还原机制,且有机氯分子的苯环结构是零价铜直接电子传递还原的诱因。