支持CSCL中相关度监控的领域词典构建研究

提出了用领域词典代表给定协作主题特征,并且用机械分词与串频统计相结合的方法实现了一个计算机支持的协作学习中相关度监控的领域词典构建系统.从而可以通过对学习者协作内容文本与领域词典中代表协作主题的特征词的相似度计算,判断学习者协作活动与协作主题的相关度.     

无界区域Rn上GBBM方程的整体吸引子

研究了无界区域R^n上GBBM方程的长时间动力学行为，利用算子分解技巧和构造加权空间上紧算子等方法，通过对方程的解作先验范数估计，证明了无界区域R^n上GBBM方程整体吸引子的存在性。     

积分有关概念的教学设计

利用不同类型积分概念的本质——积分原理对积分有关概念的教学进行优化设计，突出各种积分概念之间的联系，以利于学生对积分本质思想的理解，提高教学效率。     

用算子半群理论研究转移函数的逼近

用算子半群方法研究了参数连续Markov链中转移函数的逼近.给出了最小转移函数收敛的Q-矩阵条件;证明了当转移函数是忠实的情况下,一列转移函数的收敛性与其相应的预解函数的收敛性是等价的     

虚拟区域法及其在流体力学中的应用

讨论了一类椭圆型算子Dirichlet问题的一种基于Lagrange乘子的虚拟区域方法;由此导出的鞍点问题用共轭梯度法迭代求解.为加速迭代收敛,构建了合适的预处理器.着重考虑了这种方法在不可压粘性流动数值模拟中的应用.通过基于算子分裂的劋laMarchukYanenko时间离散格式,将虚拟区域情形下的不可压NavierStokes方程分裂成非线性对流扩散方程、准Stokes方程和虚拟区域情形下的线性椭圆型方程三个子问题.给出了绕固定和运动圆二维流动的数值实验结果.     

关于扰动m-增生算子的注记

讨论了扰动m-增生算子满射性，给出一些新的结论，补充和改进了以往文献中的相应结果．     

无界域输运方程积分变换解法

积分变换法能对偏微分方程起到降维的作用，本文运用积分变换法对无界域和半无界域输运方程的定解问题进行了研究，得到了类似于达朗贝尔公式的无界域输运方程的直接求解公式，并运用此公式讨论了各种齐次边界条件下的半无界问题的求解．     

Software Practicalization for Analysis of Wind-Induced Vibrations of Large Span Roof Structures

Wind loads are key considerations in the structural design of large-span structures since wind loads can be more important than earthquake loads, especially for large flexible structures. The analysis of wind loads on large span roof structures (LSRS) requires large amounts of calculations. Due to the combined effects of horizontal and vertical winds, the wind-induced vibrations of LSRS are analyzed in this paper with the frequency domain method as the first application of method for the analysis of the wind response of LSRS. A program is developed to analyze the wind-induced vibrations due to a combination of wind vibration modes. The program, which predicts the wind vibration coefficient and the wind pressure acting on the LSRS, interfaces with other finite element software to facilitate analysis of wind loads in the design of LSRS. The effectiveness and accuracy of the frequency domain method have been verified by numerical analyses of practical projects.     

Oligomerization study of NHR3 and NHR4 domains from ETO protein involved in t（8;21）-associated acute myeloid leukemia

Little had been known about ETO protein until t(8;21) was found in 12%-15% of acute myeloid leukemia which resulted in AML1-ETO fusion protein. ETO protein has four conserved nervy homology regions termed NHR1-4. A lot have already been known about NHR1, 2, 4:NHR1 is homologous with the Drosophila TATA-box-associated factor 110 (TAF110); NHR2 is a dimerization domain associated with mSin3A/HDAC; NHR4 is MYND class of zinc fingers associated with NCoR/SMRT/HDAC. Only the function of NHR3 remains unclear. In order to investigate whether NHR3 domain could participate in oligomerization, we cloned and purified this domain. Through gel filtration chromatography, dynamic light scattering and dissolved crystal electrophoresis, we found that NHR3 domain was a tight tetramer. Then we cloned NHR3 4 domain (i.e. NHR3 domain plus NHR4 domain), and discovered, by gel filtration chromatography and native PAGE, that NHR3 4 domaincould form dimer in solution. This was the first time to observe that NHR3 and NHR4 domains may have some contribution to the oligomerization of ETO protein, which might recruit corepressors in the form of dimer, and stabilize ETO dimerization through convergent strength of NHR2, NHR3 and NHR4 domains and then stabilize corepressors recruitment. These speculations are very worthy of further evaluation.     

直接序列扩频信号快速捕获

提出一种新的基于频域并行搜捕法的改进型快捕电路结构.该结构利用设计复用技术实现FFT单元和IFFT单元的复用;通过软件计算本地伪码FFT,并将其结果存储在ROM中,使硬件规模大幅减少;采用并行设计提高系统的运算速度;采用块浮点算法提高动态范围和运算精度.整个快捕电路由一块FPGA XC2V3000-5实现,工作时钟为29 ns,精度为1/4码片情况下,伪码捕获仅需4.145 ms.仿真和测试结果验证了设计的正确性.