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991.
Effects of Heat Treatment on the Transformation Temperature and the Microstructure of Ni-Ti-Nb Shape Memory Alloy 总被引:1,自引:0,他引:1
The effects of heat treatment on the phase transformation temperature and the microstructure of Ni-Ti-Nb alloy have been investigated by means of R-T method, TEM and EPMA. With the increase of annealing temperature, cooling rate and ageing temperature, the Ms temperature increases. TEM observations show no new precipitated phase was found in the B2 parent phase after heat treatment, but EPMA shows the content of Ni (or Ni/Ti ratio) in the B2 matrix changed. The main reason for the change of transformation temperature lies in the change of the matrix composition (or Ni/Ti ratio) with the variation of heat treatment procedure. 相似文献
992.
Wei Lin 《Automatic Control, IEEE Transactions on》1995,40(4):776-782
For multi-input multi-output nonlinear systems whose free dynamics are Lyapunov stable, the author shows how the problem of global stabilization via dynamic output feedback can be solved by using the technique of input saturation. The power of this technique is also illustrated by solving the problem of global stabilization via bounded state feedback for affine nonlinear systems with stable unforced dynamics. Analogous results are established for discrete-time nonlinear systems 相似文献
993.
采用时间,空间分辨的等离子体光辐射诊断技术,研究了脉冲TEACO2激光诱发SiH4+CH4击穿产生的等离子体膨胀过程,得到不同空间位置,不同实验条件下等离子体发光的时间特性,证明了SiH4+CH4气体击穿产生爆燃波而后诱发激波是等离子体中基本宏观动力学过程,并在实验上分析了激波对等离体内化学反应的影响,为激光等离子体合成SiC粉末微观反应动力学过程的研究提供了参考数据。 相似文献
994.
995.
TA Woolsey CM Rovainen SB Cox MH Henegar GE Liang D Liu YE Moskalenko J Sui L Wei 《Canadian Metallurgical Quarterly》1996,6(5):647-660
How neuronal activity changes cerebral blood flow is of biological and practical importance. The rodent whisker-barrel system has special merits as a model for studies of changes in local cerebral blood flow (LCBF). Stimulus-evoked changes in neural firing and 'intrinsic signals' recorded through a cranial window were used to define regions of interest for repeated flow measurements. Whisker-activated changes in flow were measured with intravascular markers at the pia. LCBF changes were always prompt and localized over the appropriate barrel. Stimulus-related changes in parenchymal flow monitored continuously with H2 electrodes recorded short latency flow changes initiated in middle cortical layers. Activation that increased flow to particular barrels often led to reduced flow to adjacent cortex. Dye was injected into single penetrating arterioles from the pia of the fixed brain and injected into arterioles in slices of cortex where barrels were evident without stains. Arteriolar and venular domains at the surface were not directly related to underlying barrels. Capillary tufts in layer IV were mainly coincident with barrels. The matching between a capillary plexus (a vascular module) and a barrel (a functional neuronal unit) is a spatial organization of neurons and blood vessels that optimizes local interactions between the two. The paths of communication probably include: neurons to neurons, neurons to glia, neurons to vessels, glia to vessels, vessels to vessels and vessels to brain. Matching a functional grouping of neurons with a vascular module is an elegant means of reducing the risk of embarrassment for energy-expensive neuronal activity (ion pumping) while minimizing energy spent for delivery of the energy (cardiac output). For imaging studies this organization sets biological limits to spatial, temporal and magnitude resolution. Reduced flow to nearby inactive cortex enhances local differences. 相似文献
996.
菱镁复合装饰板质量保证措施 总被引:1,自引:0,他引:1
分析了菱镁复合装饰板起霜,翘曲等原因,并论述了原材料,配合比、复合外加剂和生产工艺的影响,提出了一套有效的质量保证措施。 相似文献
997.
两种具有电双稳态的全有机络合物 总被引:9,自引:0,他引:9
首次发现两种在室温下即具有电双稳态的全有机(有机-有机)络合物,分别称为MCA+TCNQ和BBDN+TCNQ。它们可在真空中制备成薄膜,在数伏电压的作用下,从高电阻至低电阻的跃迁时间小于100ns,因此可作为一次写入的存储器材料。根据我国目前最小刻线宽度的水平,可望在1.6cm2的SiO2平面上做出64Mb的存储器。 相似文献
998.
999.
1000.
本文介绍了对63CY14-IB型轴向柱塞泵配流副油膜的实验研究结果。该研究结果为改进该泵配流副的性能提供了依据。 相似文献