外资在华制药企业技术战略分析

生物制药行业是21世纪的前瞻性行业,也是外资大力争夺创新资源的行业。本文基于1985—2005年的专利数据,主要从创新范围和创新规模两方面分析了制药行业外资技术竞争以及创新活动的特点。本文原创性地运用聚类的统计方法,定义了规模-范围矩阵(简称为双 S 矩阵),对外资技术策略的特点进行分类,进而识别各类外资的角色。本文的研究结论为行业相关政策以及企业战略的制定提供参考。     

幂等的Hemite矩阵与矩阵的分解

研究了任意矩阵的分解与幂等的Hemite矩阵的一些内在的关系。     

Ds-echinoside A, a new triterpene glycoside derived from sea cucumber, exhibits antimetastatic activity via the inhibition of NF-κB-dependent MMP-9 and VEGF expressions

Ds-echinoside A (DSEA), a non-sulfated triterpene glycoside, was isolated from the sea cucumber Pearsonothuria graeffei. In vitro and in vivo investigations were conducted on the effects of DSEA on tumor cell adhesion, migration, invasion, and angiogenesis. In this study, we found that DSEA inhibited the proliferation of human hepatocellular liver carcinoma cells Hep G2, with a half-maximal inhibitory concentration (IC₅₀) of 2.65 μmol/L, and suppressed Hep G2 cell adhesion, migration, and invasion in a dose-dependent manner. DSEA also reduced tube formation of human endothelial cells ECV-304 on matrigel in vitro and attenuated neovascularization in the chick embryo chorioallantoic membrane (CAM) assay in vivo. Immunocytochemical analysis revealed that DSEA significantly decreased the expression of matrix metalloproteinase-9 (MMP-9), which plays an important role in the degradation of basement membrane in tumor metastasis and angiogenesis. DSEA also increased the protein expression level of tissue inhibitor of metalloproteinase-1 (TIMP-1), an important regulator of MMP-9 activation. From the results of Western blotting, the expressions of nuclear factor-kappa B (NF-κB) and vascular endothelial growth factor (VEGF) were found to be remarkably reduced by DSEA. These findings suggest that DSEA exhibits a significant antimetastatic activity through the specific inhibition of NF-κB-dependent MMP-9 and VEGF expressions.     

基于特征矩阵的高效数字识别算法

传统的数字识别算法存在识别速度、识别准确率和识别方法复杂度三者无法兼顾的问题,为解决该问题,提出了基于特征矩阵的高效数字识别算法。该算法首先在预处理的基础上获取字符的特征矩阵,然后用特征矩阵对字符的特征横线、竖线等特征进行提取,最后利用结构语句识别的方法实现数字识别。实验结果表明,基于特征矩阵的高效数字识别算法思路简单、速度快,且识别率达97％以上。     

On the p-norm joint spectral radius

INTRODUCTIONSupposeΣisaboundedcollectionofsquarematriceswithcomplexentriesandofthesamesize .LetLn =Ln(Σ)bethesetofallprod uctsoflengthnoftheelementsofΣandL0 theidentitymatrixI.Thep normjointspectralra diusthroughthelimitofnormalizednormsofproductsofΣi…     

火电公司分散控制系统的评估与选型

讨论了火电公司应用中分散控制系统评估的内容和一般准则,并介绍了一种评估和选型的具体方法和步骤,这对火电公司分散控制系统的工程设计以及提高发电效率具有一定的借鉴意义。     

Characterization of two-dimensional cellular automata over ternary fields

The set of papers [3], [4], [6] and [7] (Chattopadhyay et al., 1999; Dihidar and Choudhury, 2004; Khan et al., 1997, 1999) deals with the behavior of the uniform two-dimensional cellular automata over binary fields (Z₂). Some structural properties and precise mathematical models using matrix algebra over the field Z₂ are reported for characterizing the behavior of two-dimensional nearest neighborhood linear cellular automata with null and periodic boundary conditions [3], [4], [6] and [7] (Chattopadhyay et al., 1999; Dihidar and Choudhury, 2004; Khan et al., 1997, 1999). In this paper, we characterize two-dimensional linear cellular automata transformations by using matrix algebra built on Z₃. We analyze some results for two-dimensional CA with rule numbers 2460N and 2460P. Finally, we investigate the dimension of the kernel of two-dimensional cellular automata defined by the rule number 2460N.     

基于Cypress单片机的USB键盘设计

USB接口是一种简单易行又能够最大限度地节省计算机软硬件资源的接口,具有真正的即插即用、数据传输速度快、性能稳定等优点,USB设备在近几年得到了迅速普及。本文设计了一种基于Cypress单片机的USB键盘,首先简要介绍了USB接口协议的发展和CY7C63513芯片的特点,然后分析了键盘的硬件电路各部分的原理作用和键盘扫描程序流程。     

一类四重迭代差分不等式

建立了一类新的差分不等式,利用差分定义、求和技巧、差分方程比较原理,给出了不等式中未知函数的估计,推广了已有的结果。     

基于自标定的两视图三维重构研究

相机标定是三维重构中的关键步骤,本文对在自标定下的两视图三维几何模型恢复进行研究。先采用SURF算法得到图像匹配点对,在此基础上,利用RANSAC鲁棒估计基础矩阵;然后根据Kruppa方程所推导出的二次方程自标定出相机内参数,进一步地,通过分解本质矩阵求解出相机外参数;最后,根据三角化法求得空间三维坐标值。实验结果证实,该方法具有效性和正确性,并且能够真实地再现物体的三维模型。