Contagion of network products in small-world networks

We formulate a model in which agents embedded in an exogenous social network decide whether to adopt a new network product or not. In the theoretical part of the paper, we characterize the stochastically stable equilibria for complete networks and cycles. For an arbitrary network structure, we develop a novel graph decomposition method to characterize the set of recurrent communication states, which is a superset of stochastically stable equilibria of the adoption game presented in our model. In the simulation part, we study the contagion process of a network product in small-world networks that systematically represent social networks. We simulate a generalization of the Morris (Rev Econ Stud 67(1):57–78, 2000) Contagion model that can explain the chasm between early adopters and early majority. Our numerical analysis shows that the failure of a new network product is less likely in a highly cliquish network. In addition, the contagion process reaches to steady state faster in random networks than in highly cliquish networks. It turns out that marketers should work with mixed marketing strategies, which will result in a full contagion of a network product and faster contagion rates with a higher probability.

     

Ecophysiology and niche differentiation of Nitrospira-like bacteria, the key nitrite oxidizers in wastewater treatment plants.

Nitrite-oxidizing bacteria of the genus Nitrospira are key nitrifiers in wastewater treatment plants. Pure cultures of these organisms are unavailable, but cultivation-independent molecular methods make it possible to detect Nitrospira-like bacteria in environmental samples and to investigate their ecophysiology. Comprehensive screening of natural and engineered habitats and of public databases for 16S rRNA sequences of Nitrospira-like bacteria revealed a surprisingly high biodiversity in the genus Nitrospira, which comprises at least four phylogenetic sublineages. All Nitrospira-like bacteria detected in wastewater treatment plants belonged to the sublineages I and II. Subsequently, the population dynamics of different Nitrospira-like bacteria were monitored, by quantitative fluorescence in situ hybridization with rRNA-targeted probes, confocal laser scanning microscopy and digital image analysis, during incubation of nitrifying activated sludge in media containing different nitrite concentrations. These experiments showed that Nitrospira-like bacteria, which were affiliated with the phylogenetic sublineages I or II of the genus Nitrospira, responded differently to nitrite concentration shifts. Previously unknown properties of Nitrospira-like bacteria were discovered in the course of an environmental genomics project. Implications of the obtained results for fundamental understanding of the microbial ecology of nitrite oxidizers as well as for future improvement of nutrient removal in wastewater treatment plants are discussed.     

龙滩水电站地下厂房进水口高边坡加固支护设计

龙滩水电站地下厂房进水口高边坡开挖坡高达435m，坡面面积达27万m^2，为典型的反倾向层状结构岩质高边坡。为了确保进水口坝段的稳定，必须保持边坡岩体有足够的稳定性，通过采取边坡轮廓设计，防渗、排水设计，加固支护设计及施工控制等一系列措施，确保边坡稳定。文章简要论述了边坡设计的原则、标准、高边坡轮廓设计、防渗排水系统、加固支护措施、施工控制等情况。     

浅谈实质重于形式原则在我国会计中的运用

实质重于形式原则是国际上普遍遵循的原则，它要求企业在会计核算过程中，注重交易和事项的经济实质，而不完全拘泥于其外在表现形式。我国在会计准则制定过程中已广泛地运用了实质重于形式原则，并在规范企业交易方面取得了一定的成绩。     

Retention of Escherichia coli in municipal sewage by means of planted soil filters in two-stage pilot plant systems.

Different types of constructed wetlands in a pilot-plant system were fed with identical municipal waste water to compare the sanitisation process in two-stage systems. With combinations of a vertical and a horizontal flow filter an E. coli reduction of 5 log10 with an E. coli influent concentration of 10(7) MPN/100 ml was achieved. Using different filter materials in each stage the total performance of the two-stage system was independent from the sequence of these materials. However, using coarser filter material in the first stage makes the filter less prone to clogging and is thus the preferential option with regard to operational reliability.     

正度拟齐次Toeplitz算子的乘积

在Bergman空间上讨论了以拟齐次函数为符号的Toeplitz算子的乘积问题.使用Mellin变换作为工具,得出了当拟齐次函数的度都为正度时两个Toeplitz算子乘积仍是Toeplitz算子的充分必要条件,完善了以往文献中的有关结果.     

Grounded Theory und ihre bisherige Anwendung in der empirischen Controlling- und Rechnungswesenforschung

Zusammenfassung  Die Bildung von Forschungshypothesen ist zwar immer ein kreativer, sollte aber gleichzeitig kein unsystematischer Prozess sein. Im vorliegenden Artikel liegt der Fokus auf der Methodenunterstützung des Entdeckungszusammenhangs. Die Methode der Grounded Theory bietet einen Bezugsrahmen für qualitative empirische Studien, mit dem Theorien entwickelt werden, die aus dem Textmaterial zu begründen sind. Eine Literaturanalyse verdeutlicht, dass das Potenzial dieser Methode bisher in der Controlling- und Rechnungswesenforschung weitgehend ungenutzt bleibt. Anhand einer Diskussion empirischer Studien, welche auf die Methode zurückgreifen, werden Anwendungsm?glichkeiten der Grounded Theory für diese Disziplinen aufgezeigt.

---

Summary  Creating research hypotheses is always a creative but not necessarily an unsystematic process. In our study we introduce a method supporting the logic of discovery. The grounded theory approach provides a framework for a systematic development of theories emerging from empirical data. A literature review stresses that the potential of the method so far is unused in accounting research. The grounded theory approach is introduced to support empirical work within this research field. Options for an application of the method in accounting research are shown by the means of a discussion of empirical studies. Furthermore the reader gets hints for reference studies.