Y3（Fe,Mo）29金属间化合物的结构特性

使用Ｒｉｅｔｖｅｌｄ方法对Ｙ３（Ｆｅ,Ｍｏ）２９金属间化合物的Ｘ射线衍射谱和中子衍射谱进行分析,得出了Ｙ３（Ｆｅ,Ｍｏ）２９金属间化合物Ａ２／ｍ空间群的结论。坐标变换结果表明：Ｙ３（Ｆｅ,Ｍｏ）２９金属间化合物的空间结构是１：１２和２：１７的混合特性。     

值域空间的正交分解与参数分组估计

在分析了向量空间中最小二乘原理的基础上，依据Ｈｉｌｂｅｒｔ空间的可分性，提出并论证了值域空间的正交分解定理及其推论，从而揭示了从观测向量空间到值域空间的投影算子的特性，提出了参数分组估计方法和相应的估计公式，为研究参数向量间复共线性影响最小二乘估计质量提供了一种有效的方法。     

银—钯微细粉的结构特性

本文用各种技术研究了新的微细球状Ａｇ－Ｐｄ粉的结构（７５％／２５％或７０％／３０％，平均直径为３００ｎｍ），用Ｘ－衍射测定了粉末和单个颗粒。结果表明，粉末金属中有两个明显的金属相，一相为纯Ａｇ，另一个是Ａｇ－Ｐｄ合金。用Ｘ射线进行ＳＥＭ显微分析，结果得到每个晶粒呈金属间特性，两种金属的存在比例近似为１／２：１／２，用三种不同分析技术得到了空间解析信息：即发射电子显微分析，Ｘ射线光电子谱和二级离子质     

La2O3基导电陶瓷高温电阻率的测试和研究

研究了不同组成的Ｌａ２Ｏ３基导电陶瓷的高温电阻率，结果表明：（Ｌａ２Ｏ３）１－ａ·（Ｘ２Ｏ５）ａ·ＣｕＯ及（Ｌａ２Ｏ３）１－２ａ·（Ｘ２Ｏ５）２ａ·ＣｕＯ具有较低的高温电阻率。由于兼有金属导电机制和半导体导电机制，且两种导电机制随温度变化的作用相反，Ｌａ２Ｏ３基导电陶瓷在室温到１０００℃的温度范围内电阻率变化不大     

CH4与N2流量比对Ti（C,N）涂层性能的影响

采用物理化学气相沉积（ＰＣＶＤ）技术，在硬质合金上涂复Ｔｉ（ＣＮ１－ｘ）膜（０＜Ｘ＜１），测定了涂层厚度、显微硬度、粘结强度与反应气体中ＣＨ４／Ｎ２比值的关系。在本实验条件下，当ＣＨ４／Ｎ＝１：１时，涂层具有最佳综合性能和最大沉积速率。采用ｘ射线衍射（ＸＲＤ）、扫描电子显微镜（ＳＥＭ）及ｘ射线光电子谱（ＸＰＳ）技术，分析了涂层微观组织、表面形貌、化学成分及涂层／基体界面区微观形貌。在此基础上，就ＣＨ４／Ｎ２值、微观结构及性能间的关系进行了讨论。     

平差模型的影响分析

概括了平差模型的影响分析的主要成果,研究了带约束的参数平差模型应用随机模型的协方差阵扰动影响的分析问题,建立了＾ＸＢ（Ｇ）与＾ＸＢ的一些关系式,这里＾ＸＢ（Ｇ）是扰动模型的未知参数向量Ｘ的最小二乘估计,＾ＸＢ是带约束的参数平差模型的Ｘ的最小二乘估计。此外还定义了扰动模型的ＷｅｌｓｃｈＫｕｈ统计量与Ｃｏｏｋ距离,给出了它们的简单计算式。     

焊接修复中常用钢材(低碳钢)的焊接

焊接修复中低碳钢的焊接涉及面广,其含碳量低合金元素少,而焊接性能较好,对于各种不同的接头形式和焊接位置,采用手工电弧焊修复容易掌握,速度快且焊接工艺和技术较为简单,因此应用广泛。 １、焊接设备;可选用交流弧焊机（ＢＸ１—３３０）,也可选用旋转直流弧焊机（ＡＸ－３２０）。 ２、焊条的选用：根据焊接修复部件的材质,如（２０、Ｑ２３５）,可选用Ｅ４３０３（Ｊ４２２）焊条匹配进行焊接。同时根据焊接修复的厚度及空间位置可选用下列不同直径的焊条,（２．５,３．２,,４．０）。 ３、焊接电流的选择：手工电弧焊焊…     

基于向量树搜索的1-1/2维配料算法与实现

针对工程项目中经常遇到的长大板材构件的一个方向和两个互相垂直方向的拼接问题，提出了一种基于向量树搜索的智能化处理算法。将拼接区间抽象为向量空间，求解的过程是对由向量空间内的节点构成的向量树进行深度优先搜索，直至搜索到向量空间树的叶节点（解节点）。向量空间搜索树的每一个节点是一个区段向量表，区段向量表是一个禁区边界线间距离值的有序排列。这种方法不但可以得出多种可供选择的方案，而且也有效地避免了利用组     

稀土,钛复合变质剂对贝本钢铸态晶粒细化的研究

系统研究了稀土、钛复合变质剂对锰硅工体铸钢晶粒尺寸的影响。表明，经稀土、钛复合变质处理后，贝氏体铸钢中形成大量的高熔点化全物，尺寸约１．２～２．５μｍ。这些高熔点化合物为非均匀形核核心，使液固相变形粒尺寸明一小，为变质前的１／３～１／２。经扫描电镜（ＳＥＭ）、能谱（ＥＤＳ）和Ｘ射线衍射分析（ＸＲＤ）表明，高熔点相为稀土氧化物（Ｌａ，Ｃｅ）２（Ｏ，Ｓ）３ｘ和碳、氮化物Ｉｉ（Ｃ，Ｎ）。根据错配度理论计     

铜在浓碱溶液中的阳极钝化膜

采用恒电流阴极还原法、Ｘ射线衍射（ＸＲＤ）和Ｘ射线光电子能谱（ＸＰＳ）对铜在ＮａＯＨ浓溶液中的两种阳极钝化膜进行了研究。结果表明，铜表面一次钝化膜由Ｃｕ２Ｏ和Ｃｕ２Ｏ·Ｈ２Ｏ组成，二次钝化膜由Ｃｕ２Ｏ内层和ＣｕＯＣｕ（ＯＨ）２Ｈ２Ｏ（ａｄ）外层组成，且外层各组分的相对含量呈规律性深度分布。对Ｃｕ（Ⅱ）物相的形成历程进行了讨论     

Synergistic Effect of Alloying Atoms on Intrinsic Stacking-Fault Energy in Austenitic Steels

Intrinsic stacking-fault energy is a critical parameter influencing the various mechanical performances of austenitic steels with high Mn concentrations.However,quantitative calculations of the stacking-fault energy(SFE) of the face-centered cubic(fcc) Fe,including the changes in concentrations and geometrical distribution of alloying atoms,cannot be obtained by using previous computation models.On the basis of the interaction energy model,we evaluated the effects of a single alloying atom(i.e.,Mn,Al,Si,C and N),as well as its aggregates,including the Mn-X dimer and Mn_2-X trimer(X = Al,Si,C and N) on the SFE of the fcc Fe via first-principle calculations.Given low concentrations(10 wt%) of alloying atoms,dimers and trimers,theoretical calculations reveal the following:(1) Alloying atom Mn causes a decrease in the SFE,whereas Al,Si,C and N significantly increase the SFE;(2) combination with other alloying atoms to form the Mn-X dimer(X = Al,Si,C and N) exerts an effect on SFE that,to a certain extent,is close to that of the corresponding single X atom;(3) the interaction between Mn_2-X and the stacking fault is stronger than that of the corresponding single X atom,inducing a significant increase in the SFE of fcc Fe.The theoretical results we obtained demonstrate that the increase in SFE in high-Mn steel originates from the synergistic effect of Mn and other trace alloy atoms.     

多参数点焊质量的偏最小二乘综合评价方法

将一种新型的统计回归方法--偏最小二乘(PLS,partial least square)方法用于点焊质量的多参数监测与分析中.借助于提取主元的思想,利用PLS方法对于点焊参数和焊接质量之间的相关信息进行筛选和综合,讨论和分析了点焊参数的各种数据信息.在此基础上,建立了点焊质量多参数综合评价模型.结果表明,该方法可以有效解决点焊质量综合评价模型中点焊参数存在的高维及多重相关性问题,建立的综合评价模型具有良好的评估能力.     

Structural investigation of the alluaudite-like mixed-valence iron phosphate: Na1.25Mg1.10Fe1.90(PO4)3

A new mixed-valence iron phosphate Na_1.25Mg_1.10Fe_1.90(PO₄)₃ has been synthesized as single crystals by a flux technique and its structure has been refined from X-ray data to a residual R₁ = 0.032. The compound crystallizes in the monoclinic space group C2/c with the parameters: a = 11.7831(3) Å, b = 12.4740(3) Å, c = 6.3761(2) Å, β = 113.643(2)° and Z = 4. The structure belongs to the alluaudite structural type, and thus it obeys to the X(2)X(1)M(1)M(2)₂(PO₄)₃ general formula. The X(2) and X(1) sites are occupied by sodium while the M(1) and M(2) sites feature a statistical distribution of iron and magnesium.

Additional information about the cation distribution has been extracted from a Mössbauer spectroscopy study which confirmed the mixed valency of the compound. A magnetic susceptibility study has also been undertaken and has shown the compound to be antiferromagnetic with a Neel temperature of about 35 K.     

基于预标定基坐标系及MIEKF算法的工业机器人标定方法

为了提高工业机器人的绝对定位精度和标定效率，提出一种基于预标定基坐标系及改进迭代扩展卡尔曼滤波(MIEKF)算法的运动学标定方法。该方法的优点在于用采集的位置数据进行基坐标系和工具坐标系预标定，节省两者拟合的时间。在建立位置误差模型时利用相关系数和复共线性分析去除模型的冗余参数。用MIEKF算法辨识模型的几何参数误差。通过实验对比验证，机器人经补偿后的绝对定位精度提高了88.07%。     

X-RAY POWDER DIFFRACTION DATA AND STRUCTURE REFINEMENT OF COMPOUND ErNi_2Si_2

１ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｒａｒｅｅａｒｔｈｃｏｍｐｏｕｎｄｓＲＥＴ２Ｓｉ２，ｗｈｅｒｅＲＥｉｓａｒａｒｅｅａｒｔｈｅｌｅｍｅｎｔａｎｄＴｉｓａｔｒａｎｓｉｔｉｏｎｍｅｔａｌｅｌｅｍｅｎｔ，ｈａｖｅｂｅｅｎｓｔｕｄｉｅｄｗｉｔｈｇｒｅａｔｉｎ?..     

Point defect concentrations of L1_2-Al_3X(Sc,Zr,Er)

The point defect concentrations of Ll_2-Al_3 X(Sc,Zr,Er) were systematically investigated using the firstprinciple calculations with thermodynamics approach.The results show that the constitutional point defects of offstoichiometric Ll_2-Al_3 X(Sc,Zr,Er) prefer to occur in X sublattice,that is X anti-site in X-rich alloy and X vacancy in Al-rich alloy,respectively.And A1 anti-site also has a high density in Al-rich Ll_2-Al_3 X(Sc,Er).It is found that the point defect concentrations of stoichiometric Ll_2-Al_3 X(Sc,Zr) follow in the sequence as: A1 vacancies(V_(A1)) X vacancies(V_X) X anti-sites(X_(Al)) A1 antisites(Al_X).The point defect concentration of stoichiometric Al_3 Er is similar to that of L12-A13 X(Sc,Zr).The result suggests that the A1 vacancy(V_(A1)) is a dominant point defect in L12-A13 X(Sc,Zr,Er).A simple parameter Hv_x-Hv_(Al) can be used for a rough estimation of the point defect concentrations in Ll_2-Al_3 X structure.Some rules of point defect concentrations for L1_2-Al_3 X(Sc,Zr,Er) are also revealed.     

Miniaturisierte elektrochemische Sensoren zur in-situ-Untersuchung der Spaltkorrosion in Modellsystemen

In-situ-investigation of crevice corrosion in model systems using miniaturized electrochemical sensors Measuring characteristics of miniaturized sensors for the determination of the parameters pH value, oxygen content, concentration of chloride ions and redox potential was tested and optimized with regard to the application in model crevices. The sensors were used for examinations of crevice corrosion in 0.1 molar and 1 molar solution of NaCl at the following alloys: X 20 Cr 13, X 2 CrNi 18 10, X 2 CrNiMoN 17 13 5, X 2 CrNiMoN 17 13 5*, X 2 CrNiMo CuN 20 25 6. Corrosion characteristic of the alloys and the change of crevice electrolyte without external polarization and with galvanostatic polarization (i = 10 μA/cm², i = 200 μA/cm²) were tested and discussed by the hand of the model concepts from Oldfield and Sutton [1]. In experiments with galvanostatic polarization the steels with increasing content of chromium or molybdenum showed a growing stability against crevice corrosion. The results showed that simultaneous measurements of the above mentioned chemical parameters of crevice electrolyte in connection with the corrosion potential can supply additional information about causes and mechanism of crevice corrosion.     

Korrosionsmonitoring mit elektrochemischen Sensoren unter Einsatz von Evolutionsstrategien

Corrosion monitoring with electrochemical sensors by using evolution-inspired optimization techniques A complex array of sensors for measurements of corrosion influencing parameters was investigated at the example of pitting corrosion of the alloy X 5 CrNi 18 10. Potentiodynamic measurements of pitting potential were performed in a flow circuit by varying chloride ion concentration (10^?3 … 1 mol 1^?1), pH-value (2 … 8), content of dissolved oxygen (0 … 8 mg 1^?1), temperature (10 … 60°C) and flow velocity (0 … 2 m s^?1). The influence of these parameters on the pitting potential was evaluated by using evolution-inspired optimization technique with an equation derived from literature data. This technique is indicated by stable convergence in the present application and results in an empirical equation facilitating the forecast of pitting potential in the investigated parameter field.     

Evaluation model for process stability of short-circuiting arc welding

stability of welding process is the prerequisite and assurance for ideal joint. The structure of stability model and its optimization are the key to on-line evaluation technology of arc welding. Characteristic parameters are extracted from the single transfer period while variation coefficients of the characteristic parameters are concerned for whole welding process of continuous drop transfer. Based on the characteristic parameters and their variation coefficients, stability model of short-circuit arc welding process is established by partial-least-square regression (PLSR) that can overcome multicollinearity of input parameters. The experiment results show that this model can meet the requirement of accuracy.