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921.
La+Ce复合细化CuZnAl形状记忆合金 总被引:9,自引:0,他引:9
通过金相观察、拉伸和弯曲试验、电阻测量、电子探针和扫描电镜等方法,研究了La+Ce对CuZnAl形状记忆合金的微观结构和性能的影响。结果表明,复合添加微量稀土(La:Ce=1:1),能够明显细化CuZnAl形状记忆合金的晶粒组织,提高合金的综合机械性能,显著改善合金的冷加工性能。合金经过La+Ce复合细化后(〈0.10%),仍具有良好的形状记忆效应,同时降低了马氏体相变温度滞后宽度,并使马氏体不易 相似文献
922.
中性变密度盘的加工与检测 总被引:1,自引:0,他引:1
本文就加工-精度要求高,且口径厚度比为35:1的薄形零件,设计了多种加工及上下盘方法,并用激光平面干涉仪测试加工过程,从而加工出高质量的零件. 相似文献
923.
Optical detection of magnetic resonance (ODMR) and magnetic-field-induced level crossings reveal two distinct S=1 excited states in the luminescence of 6H SiC containing titanium. Resolved structure on the lines is interpreted as an unusally large isotope effect, the zero field splitting D changing per unit atomic mass change for the five naturally occuring titanium isotopes. The sharp level crossings result from cross relaxation between one of these excited triplet states and other spin systems. 相似文献
924.
二阶非线性中立型微分方程的振动性 总被引:4,自引:0,他引:4
利用广义Riccati变换和权函数积分平均技巧,建立了非线性时滞中立型方程:[r(t)(x(t)-p(t)x(t-τ))']'+q(t)f(x(t-δ))h(x'(t))=0的振动准则,其中τ和δ是非负常数,a,p,q∈C([to,∞),R),f和h∈C(R,R).这些结果补充了大量存在性结论和处理以前结果不能解决的问题.特别地,以实例说明本文结果是实质性推广. 相似文献
925.
926.
Viewing scheduling as an opportunistic problem-solving process 总被引:2,自引:0,他引:2
In a search for more efficient yet effective ways of solving combinatorially complex problems such as jobshop scheduling, we move towards opportunistic approaches that attempt to exploit the structure of a given problem. Rather than adhere to a single problem-solving plan, such approaches are characterized by almost continual surveillance of the current problem-solving state to possibly modify plans so that activity is consistently directed toward those actions that currently seem most promising. Opportunistic behavior may occur in problem decomposition down to selective application of scheduling heuristics. We developed and performed limited testing of a scheduling system, called OPIS 0, that exhibits such behavior to some extent. The results are encouraging when compared to ISIS and a dispatching system. It is believed that such opportunistic views of scheduling would lead to systems that allow more flexibility in terms of designing scheduling procedures and supporting the scheduling function.This research is sponsored in part by the Air Force Office of Scientific Research under Contract No. F49620-82-K-0017 and the Westinghouse Corporation. 相似文献
927.
A steady-state theory is worked out for the dynamic response of a saturated poro-elastic ground to pressure distribution travelling along the ground surface. A boundary layer approximation is applied to Biot's equations for two phases. Sample result for supersonic, transonic and subsonic loads are presented. 相似文献
928.
固载氧化剂在有机合成中的应用 总被引:3,自引:0,他引:3
对近15年来主要的固载氧化剂在有机合成中的应用进行了综述。参考文献71篇。 相似文献
929.
本文就火焰原子吸收法测定血清中K、Fe、Mg三种元素常用的三种前处理方法,即用去离子水稀释、用1%硝酸稀释、用硝酸-高氯酸消化进行了比较,并用数理统计方法进行差异显著性测验,证明三种前处理方法所得结果一致。其中1%硝酸稀释法操作简便快速,适于批量样品的分析。 相似文献
930.
The influence of nine small organic molecules on the phosphorescence properties of β-cyclodextrin (β-CD)/1-naphthol/1,2-dibromoethane (DBE) and β-CD/2-naphthol/DBE ternary inclusion complexes are examined by means of room temperature phosphorescence (RTP) measurements. It was demonstrated that the rigidity of β-CD/naphthol inclusion complex, RTP intensity and lifetime could be enhanced when different small organic molecules (less than 1% v/v) were added respectively; the analytical characters of two kinds of naphthols in host-guest stabilized-RTP were improved. The linear range of 1-naphthol become broad in the presence of n-propanol, methanol, ethanol or 2-propanol and its detection limit was reduced from 4×10−6 to 7.5×10−8 mol l−1 in the presence of 0.6% (v/v) methanol. Likewise, for 2-naphthol, the detection limit was reduced from 2.0×10−6 to 2.8×10−7 mol l−1 and to 8.1×10−7 mol l−1 after 0.5% (v/v) glycol and 0.2% (v/v) 2-propanol being added, respectively. 相似文献