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1.
Héctor J. Sussmann 《Set-Valued Analysis》2002,10(2-3):233-285
It is shown that the construction of needle variations can be carried out for almost lower semicontinuous differential inclusions rather than for the case of ordinary single-valued continuously differentiable vector fields usually considered in the literature. The construction leads to needle variations whose flows are in general set-valued but still have good differentiability properties. The variations are constructed by using single-valued selections that are not necessarily continuous with respect to the state variable, but have instead a much weaker 'integral continuity' property, somewhat more general that the 'directional continuity' considered in previous work by A. Cambini and S. Querci, A. Pucci, and A. Bressan. The existence of many such selections is proved by slightly adapting an argument due to Bressan, extending it from the lower semicontinuous to the almost lower semicontinuous case, and strengthening it to yield not only directional continuity at all points but also full continuity at a specified point. 相似文献
2.
针形锂电池CR425的研制 总被引:1,自引:0,他引:1
采用Li—MnO2电池材料和工艺制造CR425锂电池.重点对正极活性物质的加工制备及电池组装工艺进行了试验和改进.通过XRD试验测试了热处理前后电解二氧化锰(EMD)的结构,对制备的电池在不同温度下进行恒电流和恒电阻放电,并对贮存1周、3个月和6个月电池的开路电压、短路电流、内阻及放电容量进行了测试.结果表明,电池性能完全满足CR425锂电池的技术要求,可作为夜间钓鱼时的发光浮标或商务通用笔夜间使用时的照明电源. 相似文献
3.
湿地松对松针褐斑病的抗性测定 总被引:2,自引:0,他引:2
从松针褐斑病(Lecanosticta acicola)重病林分中选出36个湿地松(Pinus elliottii)抗病表现型优树无性系,用人工喷洒病菌孢子液接种法对其进行抗病测定,结果表明,有22个是高度抗病的。与用松针褐斑病产生的毒素粗提液处理上述无性系的离体针叶进行抗病性测定的结果基本一致,相关系数为0.80。 相似文献
4.
Xuming Xie 《Journal of Differential Equations》2004,197(2):349-426
This paper concerns the existence of solutions to a steady needle crystal growth problem in a one-sided model. We rigorously prove that for small nonzero anisotropy γ, analytic symmetric needle crystal solutions exist in the limit of surface tension ε2 if only if the stokes constant S for a relatively simple nonlinear differential equation is zero. This Stokes constant S depends on the parameter β=29/7γε−8/7 and earlier numerical calculations by a number of investigators have shown this to be zero for a discrete set of values of β. It is also proven that for γ=0, there can be no symmetric needle crystal solution in the considered space.The methodology consists of two steps. First, the original problem is reduced to a weak half-strip problem for any γ in a compact set of [0,1) by relaxation of the symmetry condition. The weak problem is shown to have a unique solution in the function space considered for any γ∈[0,γm] for some γm>0. When a symmetry is invoked, the weak problem is shown equivalent to the original needle crystal problem. Next, by considering the behavior of the solution in neighborhood of an appropriate complex turning point for γ∈(0,γm], we extract an exponentially small term in ε as ε→0+ that generally violates the symmetric condition. We prove that the symmetry condition is satisfied for small ε when the parameter β is constrained appropriately. 相似文献
5.
6.
Histological and physiological studies indicated that most skeletal muscles can be divided into a series of relatively independent sub-volumes: "neuromuscular compartments" and the partitioning property of the muscle result in the localization of muscle reflex. In the present experiment we studied the recruitment properties of medial gastracnemius (MG) muscle motoneuron pool of decerebrate cat with two kinds of local mechanical stimulation: local stretch and acupuncture-like stimuli. The results indicate that: (ⅰ) there is an obvious property of localization of recruitment activity, only the MNs which innervate the stimulated compartment were recruited by weaker and shorter stimuli; (ⅱ) recruitment activity spread to those MNs which supply the adjacent and distal compartments during the strength of stimulation or duration of the stimulation was increased; and (ⅲ) the recruitment property of muscle activity elicited by the local mechanical stimulation is thought similar to that of "needle feeling" along the meridian pathway during stimulation of acupuncture point. 相似文献
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8.
本文以PC104为上位机,89C51单片机为下位机的主从两级控制系统的电子选针硬软件设计。重点阐述了下位机存储管理程序和电子选针过程的数据读取程序的设计。系统经调试运行满足圆纬机电子选针的要求,实现了多路电子选针的目的。 相似文献
9.
针对目前冲压驱动桥壳有限元建模方式繁琐低效的问题,在多学科优化集成软件Isight环境中,综合运用Pro_E参数化建模功能和ABAQUS有限元分析功能,建立了考虑冲压工艺和焊接工艺影响的驱动桥壳参数化有限元分析流程及参数化有限元模型.该方法有效地解决了复杂结构参数化有限元分析过程中的模型描述、参数驱动、自动更新等问题,不仅为解决类似问题提供了一种新的解决方案,也为桥壳可靠性预测和评估等问题提供了有效的工具.实例结果表明,该方法合理、可行. 相似文献
10.
微束X射线荧光分析谱仪及其对松针中元素的分布分析 总被引:1,自引:0,他引:1
介绍了一种小型的微束X射线荧光分析谱仪,它是由导管X光透镜和能量色散X射线荧光分析谱仪组成.谱仪具有较高的空间分辨率和能量分辨率.使用本谱仪对松树针叶进行了微区分析,得出各种元素沿松针长度方向和横切面径向的分布规律.结果表明使用X光透镜的微束X射线荧光分析方法可以实现植物样品的微区分析,有助于进一步了解植物的生长与元素迁移的关系. 相似文献