热处理工艺对新型高锰钢组织和性能的影响

研究了热处理工艺对Cr、Mo、Ti、Al、Ca、RE新型高锰钢组织和力学性能的影响.试验结果表明,热处理工艺对新型高锰钢组织和力学性能有显著影响.低温等温预处理温度为580 ℃,保温3 h;高温水韧处理加热温度为 1 040～1 050 ℃, 保温3 h.可以改善高锰钢金相组织和力学性能,使σb=954 MPa , σs=507 Mpa,δ=46.8%,αK=338 J/cm2,HBS219.新型高锰钢履带板装车寿命考核结果,使用寿命由原来的3 200 Km提高到7 000 Km以上,取得了明显的经济效益.     

MATLAB在幂型几何亚式期权定价中的应用

针对幂型几何亚式期权,在存在连续红利的条件下,分别给出期权价格解析式解的MATLAB语言和二叉树模型、三叉树模型数值解的MATLAB语言,从而可从计算机语言的角度简化一类新型期权的定价过程。通过实证研究,分析三种算法所得结果的差异及参数对结果的影响程度,验证了算法的有效性,可为相关幂型期权的产生和定价提供一定的理论依据。     

铝铜合金阴极的铝电解研究

在实验室小型电解槽上用铝铜合金做阴极,研究电流效率[CE]与极距,电流密度和阴极合金组成的关系,当极距超过一定值时,电流效率达到几乎不变的最大值;当阳极电流密度达到一定值时电流效率也出现最大值,在阴极合金组成低于33％重量铜以下,电流效率随含铜量增加而增加,根据试验结果推导出电流效率和阴极合金组成的数学关系式。     

铜锡合金热弹马氏体金相形貌研究

本文研究了Cu——Sn合金系列热弹马氏体的金相组织形貌,并研究了不同配比成分及不同热处理工艺参数对马氏体形貌和热弹效应的影响。提出了两类不同马氏体β′与γ′按成分的区域划分并非固定不变的,随着冷却速度加大,区域将左移。     

不同种类稳定剂对化学镀Ni-P性能的影响

在合理选择化学镀Ni-P合金配方和工艺条件的基础上,研究了稳定剂KI、Pb（Ac）2和Na2S2O3对化学镀Ni-P合金镀液的稳定性、镀速以及镀层硬度、孔隙率、耐蚀性能等的影响。结果表明：KI的最佳加入量为8mg/L,稳定剂Pb（Ac）2在用量为1mg/L效果也较好,而Na2S2O3浓度应小于2mg/L,但是稳定剂KI的综合效果要优于Pb（Ac）2、Na2S2O3。     

Microstructural evolution and mechanical properties of Nb-Si-Cr ternary alloys with a tri-phase Nb/Nb5Si3/Cr2Nb microstructure fabricated by spark plasma sintering

In this work, pure Nb, Nb₅Si₃ and Laves Cr₂Nb compound powders were used as raw materials to prepare Nb-Si-Cr ternary alloys by spark plasma sintering (SPS). A comprehensive estimation of the microstructure and properties, including room temperature fracture toughness, high temperature strength and oxidation resistance, of the Nb-Si-Cr ternary alloys as a function of the Nb/Nb₅Si₃/Cr₂Nb phase volume fraction combinations was conducted. The results showed that Nb-Si-Cr ternary samples with the relative density larger than 98.42% were obtained by SPS processing, and the samples all consisted of Nb, Nb₅Si₃ and Cr₂Nb phases that were distributed homogeneously. The fracture toughness K_Q of the Nb/Nb₅Si₃/Cr₂Nb microstructure, which was dominated by the Nb phase, naturally increased with the Nb fraction. As expected, the room-temperature Vickers hardness and the high-temperature strength of the bulk alloys increased monotonically with the increasing of the stiffening Nb₅Si₃ fraction. Interestingly, the binary Cr₂Nb phase played a positive role in the high temperature strength and oxidation resistance. Finally, the fracture modes of the typical Nb/Nb₅Si₃/Cr₂Nb microstructures under bending and compression conditions at room and high temperatures as well as the oxidation mechanism are described and discussed.     

Strategies for improving ductility of ordered intermetallics

Ordered intermetallics possess attractive high-temperature properties; however, low ductility and brittle fracture limit their use as engineering materials in many cases. This paper provides a comprehensive review on the recent progress in the development of ductile ordered intermetallics and summarizes the strategies used to improve the tensile ductility of ordered intermetallics, including control of ordered crystal structures, engineering grain-boundary structure and chemistry, eliminating environmental embrittlement, microstructure optimization, control of phase stability, and promoting transformation-/twining-induced plasticity. The basic ideas and related mechanisms underlying these ductilizing strategies are discussed. In addition, a brief mention of the current use of intermetallic alloys for structural and corrosion applications is made.     

多元杂交羔羊育肥技术及效果研究

采用无角多赛特×小尾寒羊×滩羊三元杂交繁育的羔羊其初生重、断奶重、繁殖成活率、６ 月龄体重及平均日增重比小尾寒羊×滩羊二元杂交羔羊分别提高２０ ． ９２％ 、１６ ． ２９％ 、１３ ． ００％ 、２８ ． ５８％及３６ ． ２９ ％ ， 而且三元杂交羔羊适应性好， 肉用特征明显， 是开展羔羊快速育肥生产的理想组合．     

小AI-Ni合金团簇的结构

本文选用了基于紧束缚模型的Gupta多体势，采用遗传算法研究了团簇的原子数目为13和19以及21的Al—Ni混合团基的基态构形。将Al团簇中的一个或多个Al原子替换成Ni原子，Aln团簇的基态构形转化为象Ni团蔟一样规则的，具有高对称性的结构。当替换的Ni原子数目增加时，混合团簇会形成一些复杂结构。