上三角矩阵代数上的保不变子空间格映射

设Tn是数域F上的n×n阶上三角矩阵代数,其中F是实数域R或复数域C.利用矩阵的可加性,证明了Tn上的每一个保不变子空间格的可加映射Φ为:Φ(A)=αA+φ(A)I ((A)A∈Tn),其中α是非零常数,φ∶Tn←F是可加映射,I∈Tn是单位算子.     

具有非线性边值条件的二阶脉冲积微分方程的解

脉冲微分方程在理论方面已取得重大进展,应用极其广泛.文中介绍了上下解的定义、单调迭代方法并给出几个引理.最后用上下解方法和单调迭代技巧讨论了具有非线性边值条件的二阶脉冲积微分方程,得到了最大解和最小解的存在性.     

基于虚拟仪器技术的轮荷测量仪电测系统开发

依据电阻应变测量原理,应用机电一体化技术,开发测量汽车轮荷的测量仪电测系统.该系统由数采硬件电路和上位机车辆轮荷测量系统软件组成.应变传感器测得的电压信号,先后经过调理电路、A/D转换电路和光电隔离电路,传输给MCU.通过串口通信协议,MCU与上位机轮荷测量系统间进行指令和数据的传输,数据经过存储和运算处理后,通过上位机系统面板把轮荷值传达给用户,并将结果储存到PC机中.采用砝码加载,在可倾斜卡具上对测量仪进行了实验标定.根据实验数据算得测量仪的非线性误差为±0.72%,重复性误差为±1.37%,迟滞性误差为±1.47%,灵敏度误差为±1.67%,最终得到综合误差为±2.71%,满足轮荷测量仪预期设计的测量精度和功能要求.     

Stability analysis for natural slope by kinematical approach

The stability of natural slope was analyzed on the basis of limit analysis. The sliding model of a kind of natural slope was presented. A new kinematically admissible velocity field for the new sliding model was constructed. The stability factor formulation by the upper bound theorem leads to a classical nonlinear programming problem, when the external work rate and internal energy dissipation were solved, and the constraint condition of the programming problem was given. The upper bound optimization problem can be solved efficiently by applying a nonlinear SQP algorithm, and stability factor was obtained, which agrees well with previous achievements.     

Influence of seismic input on response of Baihetan arch dam

The dynamic responses of the arch dam including dam-foundation-storage capacity of water system, using two different earthquake input models, i.e. viscous-spring artificial boundary （AB） condition and massless foundation （MF）, were studied and analyzed for the 269 m high Baihetan arch dam under construction in China. By using different input models, the stress and opening of contraction joints （OCJs） of arch dam under strong shock were taken into consideration. The results show that the earthquake input models have slight influence on the responses including earthquake stresses and openings of contraction joints in different extents.     

Upper bound limit analysis of roof collapse in shallow tunnels with arbitrary cross sections under condition of seepage force

The analytical solutions for predicting the exact shape of collapse mechanisms in shallow tunnels with arbitrary excavation profiles were obtained by virtue of the upper bound theorem of limit analysis and variation principle according to Hoek-Brown failure criterion. The seepage force was included in the upper bound limit analysis, and it was computed from the gradient of excess pore pressure distribution. The seepage was regarded as a work rate of external force. The numerical results of roof collapse in square and circular tunnels with different rock parameters were derived and discussed, which proves to be valid in comparison with the previous work. The influences of different parameters on the shape of collapsing blocks were also discussed.     

人体上肢运动对服装袖型松量设计的影响分析

为了解决服装袖型松量设计与人体上肢运动关系的问题,结合人体上肢的形态结构及几种常规运动,重点测量了7种人体上肢运动状态下的人体上肢各个部位的尺寸变化,结合衣袖结构设计的相关理论,对人体上肢尺寸变化情况的数据进行了分析,得出了与各种上肢运动状态对应的袖型松量设计的基本要求,进而分析了人体上肢运动对服装袖型松量设计的影响.     

概率约束规划逼近最优解集的几乎处处上半收敛性

对概率约束规划逼近最优解集序列的几乎处处上半收敛性进行讨论．利用概率测度方法建立随机规划模型,将带有约束的随机规划问题转化成与其等价的无约束随机规划问题．以概率测度弱收敛的性质给出概率约束规划可行解的几乎处处收敛性条件,得到概率约束规划逼近最优解集序列的几乎处处上半收敛性．     

基于极限分析上限法的加筋土坡临界高度

在塑性极限分析理论的基础上,假定破裂面为对数螺旋面,导出了加筋土坡临界高度的解.不计加筋力,该解与无筋土坡临界高度一致;和加筋土坡试验结果比较,虽计算的临界高度略偏低,但在工程中应用是可靠的,可用于加筋土坡设计时的参考.     

上横梁的有限元分析

用实体元素法建立了箱型截面梁的物理分析模型，并对电动螺旋轮胎定型硫化机的上横梁进行了有限元分析，在对上横梁的结构肯定的基础上提出了相应的改进措施。