SCI与我国科技评价的关系探讨

利用中国科学技术信息研究所出版的中国科技论文统计与分析年度研究报告2003年和2004年度报道的定量数据，对SCI收录论文情况进行比较分析。以具体的数据说明SCI论文在地域、学科和语种中分布极不均衡，如果简单绝对地使用SCI作为我国科技评价的主要指标将有碍于科学技术的发展，对SCI用于科技评价提出了相关建议。     

脑源性神经营养因子与脊髓损伤

脊髓损伤(SCI)后,神经轴突具有一定再生能力,但需要有神经营养因子(NTFs)的参与。脑源性神经营养因子(BDNF)作为该家族中的一员,在脊髓神经元以及胶质细胞中均可合成,不仅具有神经元保护作用,还可以促进神经细胞的分化和再生,对SCI后机体功能的恢复起重要作用。进一步研究BDNF在SCI后的作用机制及其在SCI后的含量变化是否与损伤时间、损伤程度具有相关性,有可能为SCI的治疗和法医学损伤时间的推断提供新的方法。     

Digital camera identification using PRNU: A feature based approach

Source camera identification is one of the emerging field in digital image forensics, which aims at identifying the source camera used for capturing the given image. The technique uses photo response non-uniformity (PRNU) noise as a camera fingerprint, as it is found to be one of the unique characteristic which is capable of distinguishing the images even if they are captured from similar cameras. Most of the existing PRNU based approaches are very sensitive to the random noise components existing in the estimated PRNU, and also they are not robust when some simple manipulations are performed on the images. Hence a new feature based approach of PRNU is proposed for the source camera identification by choosing the features which are robust for image manipulations. The PRNU noise is extracted from the images using wavelet based denoising method and is represented by higher order wavelet statistics (HOWS), which are invariant features for image manipulations and geometric variations. The features are fed to support vector machine classifiers to identify the originating source camera for the given image and the results have been verified by performing ten-fold cross validation technique. The experiments have been carried out using the images captured from various cell phone cameras and it demonstrated that the proposed algorithm is capable of identifying the source camera of the given image with good accuracy. The developed technique can be used for differentiating the images, even if they are captured from similar cameras, which belongs to same make and model. The analysis have also showed that the proposed technique remains robust even if the images are subjected to simple manipulations or geometric variations.     

SCI论文在我国司法鉴定科学研究中的意义探讨

在国际科学界,被SCI收录或引用的科技论文数量已经成为评价研究成果学术水平、衡量一个国家的基础研究水平和科技实力水平的重要评价指标。我国从上世纪80年代起开始广泛采用SCI论文评价科研水平。结合我国司法鉴定领域SCI论文发表现状,探讨其对科学研究的引领作用,对推进学科创新有积极意义。