A decomposition of Moran's I for clustering detection

The test statistics I_h, I_c, and I_n are derived by decomposing the numerator of the Moran's I test for high-value clustering, low-value clustering, and negative autocorrelation, respectively. Formulae to compute the means and variances of these test statistics are derived under a random permutation test scheme, and the p-values of the test statistics are computed by asymptotic normality. A set of simulations shows that test statistic I_h is likely to be significant only for high-value clustering, test statistic I_c is likely to be significant only for low-value clustering, and test statistic I_n is likely to be significant only for negatively correlated spatial structures. These test statistics were used to reexamine spatial distributions of sudden infant death syndrome in North Carolina and the pH values of streams in the Great Smoky Mountains. In both analyses, low-value clustering and high-value clustering were shown to exit simultaneously.     

Developing Biotechnology Clusters in Non-high Technology Regions—The Case of Austria

This paper explores the role of distant knowledge links and policy actions for the development of biotechnology clusters. It seeks to challenge the prevailing view that the birth and early development of high technology industries are always spontaneous phenomena which are mainly based on local knowledge. Departing from the theoretical concept of regional innovation systems (RIS), a distinction between “RIS with strong potentials for high technology industries” and “RIS with weak potentials for high technology industries” will be drawn. It will be argued that in the latter case the development of biotechnology clusters is more dependent on distant knowledge sources and proactive policy efforts to create a favourable environment for high technology activities. Furthermore, it will be shown that a far-reaching transformation of the regional innovation system is crucial for catching-up processes of regions which are latecomers in high technology sectors such as biotechnology.     

BmNn和BmNnˉ团簇结构及其光电子能谱的研究

采用密度泛函理论（DFT）的B3LYP方法，在6-31G（d）水平上对BmNn（m＋n≤5）团簇及其阴离子的几何构型、电子结构和振动光谱等性质进行了理论研究．并在相同水平下计算了BmNnˉ（／m＋n≤5）的垂直电离能和BmNn（m＋n≤5）的绝热电子亲和势．结果表明：BmNnˉ（m＋n≤5）团簇的基态构型中，BN、B2N、B3N、B2 N3和B3N：为线形结构，其余均为平面结构；BmNnˉ（m＋n≤5）团簇的基态构型中，BN3ˉ、B2N3ˉ、BN4ˉ和B4Nˉ为平面结构，其余均为线形结构．     

含二硫代甲酸酯配体铁硫簇合物的合成与表征

报道通过2–呋喃甲硫醇/十二羰基三铁/三乙胺体系所形成的中间物[（μ-2-SCH2C4H3O）（μ-CO）Fe2（CO）6]Et3NH同CS2作用生成络阴离子[（μ-2-SCH2C4H3O）（μ-S C—S—）Fe2（CO）6]后,同卤代物原位反应,合成了3个新颖的含μ–二硫代甲酸酯配体的铁硫簇合物（μ-2-SCH2C4H3O）（μ-RS—C S）Fe2（CO）6（R=CH3、CH2Ph、CH2COOC2H5）.这3个新颖配合物均通过核磁共振氢谱、红外光谱和元素分析表征了其结构.     

密集簇中心二次模糊聚类算法

针对模糊C-均值聚类算法偏好发现球形簇,以及对孤立点非常敏感的问题,提出了密集簇中心二次模糊聚类算法,其中引入聚类有效性度量函数,并进行了有效的孤立点处理,最终的模糊簇由多个代表点共同表示,故算法可有效发现数据集中的自然簇数目,对簇的大小和形状没有偏好性,且在孤立点的处理上具有较好的健壮性.另外,随机采样过程方便地实现了上述算法在大型数据集上的扩展;与模糊C-均值聚类算法的实验结果比较也表明了该算法的优越性.     

乙硫醇与金表面相互作用的TOF—SIMS研究

利用飞行时间型静态二次离子质谱（TOF－SIMS）,以乙硫醇为代表,在二次离子质谱的特定条件下,分析了乙硫醇与金的表面相互作用,发现了丰富的、有一定规律性的金硫团簇。从而首次在质谱中再现了硫醇与金的分子自组装过程。这一结果不仅表明高性能静态二次离子质谱能够用于分子自组装;而且,有可能用于新类型自组装分子的探索。     

汽车企业集群备件管理及信息系统设计

分析汽车企业集群中备件管理的重要性和备件管理中存在的问题,对汽车企业集群的备件进行分类,并提出相应的管理策略。在此基础上设计信息系统方案,最后给出该管理策略及信息系统方案在一个汽车企业集群中的初步应用情况。     

Hydrothermal synthesis of hexagonal ZnO clusters

Hydrothermal process was applied to synthesize zinc oxide nanocrystals. X-ray powder diffraction and scanning electron microscopy were used to analyze the crystal structure and surface morphology. XRD pattern analysis showed that the ZnO clusters are single hexagonal phase of wurtzite structure (space group P63 mc) with no impurity of Zn and Zn(OH)₂. Also, SEM images revealed that the size of a single ZnO crystal is between 200-500 nm in diameter and 2-5 μm in length. The influence of potassium iodide (KI) as a surfactant on the crystallinity of ZnO has been investigated.     

密度泛函理论研究金属镧离子的水合团簇

Y型分子筛具有许多工整均匀的孔道结构,经常作为酸催化剂、双功能助推剂和择形催化剂,被广泛应用于干燥、洁净过滤、吸附分离和催化等领域。工业生产中稀土Y型分子筛的制备一般选用稀土离子水溶液与NaY型分子筛通过离子交换置换制取,但稀土离子水合结构以及通过分子筛孔的微观机理仍不清楚。本工作采用密度泛函理论(DFT)在M06-2X-D3/def2-SVP计算水平下,La3+采用LANL2DZ赝势基组,采用SMD=water隐式溶剂模型研究了La3+水合团簇及其不同价态时的结构性质,对水合团簇结构尺寸、Mulliken电荷、结合能以及能量分解进行了分析。结果表明,La3+水合团簇结构柔性较大,并非大于某个水合数无法通过分子筛孔;随水合数目的增大,La-O(H2O)平均半径有着增大的趋势,La3+在水溶液中总是趋于更稳定的多水合团簇结构;La-O(OH-)形成的键能比La-O(H2O)强;在[La(H2O)n]3+水合数目小于等于9时,团簇结构中以静电为主导作用,其次是诱导作用和交换互斥作用,色散作用所占比例最小;当水合数目大于9时,诱导作用所占比例升高,静电作用所占比例降低。研究结果对于深入认识稀土水合结构和分子筛制备机理具有重要理论指导意义。     

Scientists as Midwives to Cluster Emergence: An Institutional Work Framework

The question of how embedded actors can create institutions that support cluster emergence remains unsolved in the cluster and national innovation systems literature. The present paper extends the recent literature on institutional entrepreneurship and institutional work to solve this paradox of embedded agency in the context of science-based clusters. Building on a longitudinal single case study of a functional foods cluster in Finland, we present an institutional work framework for cluster formation. We argue that, in addition to ideational, material and bridging work, authentic leadership work is critical for cluster emergence. The results of the study highlight the opportunities that scientists have to act as midwives to cluster formation, but they also show that well-functioning clusters need a broader support base.