结合PCA的SVM方法在学校财务风险预警中的运用

利用支持向量机方法对中职学校财务风险进行预测,设置22个评价指标,运用主成分分析降维处理数据,然后通过Libsvm进行实验。通过对评价指标的主成分分析,发现前8个主分量的累计贡献率为89.18%,占有绝对重要的比重。选取前8个主分量为支持向量机的输入,最后得到5组实验数据,平均预测分类精度为93.75%,表明支持向量机方法在财务风险预测中的可行性和实用性。     

雷达装备课士官教员队伍建设思考

为促进士官教员队伍的可持续发展,对雷达装备课教员队伍中引入士官教员的相关问题进行了探讨。首先分析了雷达装备课士官教员的特点,论述了士官教员的使用策略和能力提升途径,最后提出了建立制度机制、选好苗子、改善条件、营造良好育人环境等思路。     

合金化对非晶形成能力影响的电子理论计算

根据分子动力学理论建立了非晶Ni64Pd16Al20的结构模型，利用Recursion方法计算了Ni64X17Al20系非晶及相应晶态的电子结构。结果表明，Ni64X16Al20合金的非晶形成能力与过渡元素局域电子态密度的双峰位置、电子得失形成的离子键及非晶与晶态合金的总结构能差有关。局域电子态密度的结果表明，A1与过渡元素间存在电子耦合一共价相互作用，合金元素使Ni64X16Al2合金非晶形成能力从强到弱的顺序是：Ir，Pt，Rh，Pd，Au，Ag，Cu；Ni64X16Al20合金中离子键的存在使其非晶形成能力增强。非晶与晶态合金的总结构能差越小的过渡元素使其形成非晶的驱动力越强，对非晶形成越有利，由此得出的规律与上述共价键的作用规律一致。     

Formation and crystallization of bulk Pd_(82)Si_(18) amorphous alloys

1　INTRODUCTIONMetallicglassisregardedasastatethatisofdis orderunlikecrystalalloyswith periodicatomstruc ture.Soitshowsexcellentcapabilitiesofsoftmag netism ,mechanics ,corrosionresistance ,etc .How ever ,mostofamorphousalloyswereproducedbyus ingrapidsolidificationmethodssuchassplatquench ing ,meltspinning ,andsoon ,withcharacteristiccoolingratesof 10 4 10 6 K/s .Becauseamorphousal loysarepreparedwithsilk ,powderandribbon ,itisgreatlylimitedinengineeringapplication .Recently ,severalbulk…     

Preparation, thermal stability, and magnetic properties of Fe---Co---Zr---Mo---W---B bulk metallic glass

A bulk metallic glass (BMG) cylinder of Fe₆₀Co₈Zr₁₀Mo₅W₂B₁₅ with a diameter of 1.5 mm was prepared by copper mould casting of industrial raw materials. The amorphous state and the crystallization behavior were investigated by X-ray diffraction (XRD). The thermal stability parameters, such as glass transition temperature (T_g), crystallization temperature (T_x), supercooled liquid region (ΔT_x) between T_g and T_x, and reduced glass transition temperature T_rg (T_g/T_m) were measured by differential scanning calorimetry (DSC) to be 891, 950, 59 K, and 0.62, respectively. The crystallization process took place through a single stage, and involved crystallization of the phases -Fe, ZrFe₂, Fe₃B, MoB₂, Mo₂FeB₂, and an unknown phase, as determined by X-ray analysis of the sample annealed for 1.5 ks at 1023 K, 50 K above the DSC peak temperature of crystallization. Mössbauer spectroscopy was studied for this alloy. The spectra exhibit a broadened and asymmetric doublet-like structure that indicated paramagnetic behavior and a fully amorphous structure. -Fe was found in the amorphous matrix for a cylinder with a diameter of 2.5 mm. The success of synthesis of the Fe-based bulk metallic glass from industrial materials is important for the future progress in research and practical application of new bulk metallic glasses.     

Design of Bulk metallic glasses with high glass forming ability and enhancement of plasticity in metallic glass matrix composites: A review

To overcome some of the limits of existing metallic alloys, a new alloy design concept has been introduced recently in order to control the crystallinity, i.e. to utilize crystalline, quasicrystalline, and amorphous structures. In particular, bulk metallic glasses (BMGs) receive great attention because of their unique properties due to their different atomic configuration. Recently, significant progress in enhancing glass forming ability (GFA) has led to the fabrication of BMGs having potential for application as structural and functional materials. Moreover, successful design of BMG matrix composite microstructure suggests that the plasticity of BMGs can be controlled properly. In this review article, we introduce recent research results on the design of BMGs with high GFA and on the enhancement of plasticity in metallic glass matrix composites.     

对本科生导师制的思考

实行本科生导师制可以改变中国高校人才培养模式 ,进一步深化中国高等教育教学改革 ,培养出大批具有丰富个性的杰出人才。本科生导师的主要责任是培养学生的自学和独立思考的能力。要成功地实施本科生导师制 ,必须进一步完善学分制 ,大力提高教师素质 ,加快高等教育信息化进程。     

H13钢经不同表面处理后的静态抗铝热熔损性能比较

将经过蒸汽氧化、离子渗氮和渗硼等不同表面处理的H13钢试样浸入铝液进行静态熔损试验，探索并建立了一套熔损评定方法一即用试样质量损失的方法评定熔损情况。对铁铝界面进行了显微观察和能谱分析。结果表明，在相同试验条件下熔损后，铁铝界面组织颜色自深至浅依次为：深色的H13钢基体、深灰色致密金属问化合物层、浅灰色致密金属问化合物层、含游离金属间化合物的铝层以及附着的铝。离子渗氮试样和渗硼试样的热熔质量损失要比氧化试样更少，显示了更好的热熔损抗力。     

电场作用对提高微生物浸矿性能的影响

在排土场微生物强化浸出过程中,结合电场生物工程技术,以氧化亚铁硫杆菌为研究对象,提出利用电场作用提高微生物浸矿性能的方法,探讨电场作用对微生物生长代谢以及渗流特性的影响。结果表明：电场作用对氧化亚铁硫杆菌生长代谢的影响非常明显,适当的电场可有效强化其生长代谢能力,过高的电流会抑制氧化亚铁硫杆菌生长;电场作用下,排土场孔隙中微生物的渗流能力明显增强,微生物电动渗流效应在渗透率高排土场中尤为明显。     

泡沫铝层合圆管纵向和横向压缩力学性能研究

用碳化硅颗粒增强泡沫铝为夹芯,不锈钢圆管为面板制备层合圆管,研究了层合圆管在准静态压缩条件下的纵向和横向变形行为和能量吸收性能.研究表明,层合圆管的纵向压缩变形方式与空管相比发生了改变,由不对称变形模式变为轴对称变形模式;载荷-位移曲线平台段锯齿形波动与曲屈圈的形成呈现对应关系;层合圆管纵向和横向的吸能能力均远大于不锈钢圆管和泡沫铝吸收的能量之和,并且随着应变的增加,层合圆管的吸能能力增加更为快速;层合圆管在保持泡沫铝轻质的同时,在纵向和横向两个方向上均大幅度提高泡沫铝的吸能能力.