Summertime community structure of intertidal macrobenthos in Changdao Archipelago, Shandong Province, China

The community structure of intertidal macrobenthos in Changdao Archipelago (north of Shandong Peninsula, between Bohai Bay and the northern Yellow Sea) was examined based on samples collected from 14 stations in five transects in June 2007. Three stations corresponding to high, medium and low tidal areas were set up for each transect. A total of 68 macrobenthic species were found in the research region, most of which belonged to Mollusca and Crustacea. The average abundance and biomass of the macrobenthos was 1383 ind./m(2) and 372.41 g/m(2), respectively. The use of an arbitrary similarity level of 20% resulted in identification of five groups among the 14 stations in the research region. There were remarkable differences in the biomass, abundance and Shannon-Wiener diversity index of the different sediments. Specifically, the order of biomass was rocky shores > gravel > mud-sand > coarse sand > stiff mud, while the order of abundance was rocky shores > coarse sand > mud-sand > gravel > stiff mud, and that of the diversity index was mud-sand > gravel > stiff mud > rocky shores > coarse sand. The above results revealed that the sediment type was the most important factor affecting the structure of the macrobenthic community of the intertidal zone.

Yo soy uno de los otros : La interpretación colectiva de textos sobre la diversidad de infancias del mundo

Fil: Paione, Alejandra Mabel. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; Argentina.

Implementación de una secuencia didáctica en la enseñanza de la lectura y escritura en contextos de estudio en la formación docente inicial

Fil: Sánchez, María de los Milagros. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; Argentina.

Las prácticas de lectura en las situaciones didácticas en las salas de Nivel Inicial en los Centros Educativos Complementarios

Fil: López, Aldana. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; Argentina.

Yo soy uno de los otros : La interpretación colectiva de textos sobre la diversidad de infancias del mundo

Fil: Paione, Alejandra Mabel. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; Argentina.

Implementación de una secuencia didáctica en la enseñanza de la lectura y escritura en contextos de estudio en la formación docente inicial

Fil: Sánchez, María de los Milagros. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; Argentina.

Las prácticas de lectura en las situaciones didácticas en las salas de Nivel Inicial en los Centros Educativos Complementarios

Fil: López, Aldana. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; Argentina.

Las prácticas de lectura en las situaciones didácticas en las salas de Nivel Inicial en los Centros Educativos Complementarios

Fil: López, Aldana. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; Argentina.

Yo soy uno de los otros : La interpretación colectiva de textos sobre la diversidad de infancias del mundo

Fil: Paione, Alejandra Mabel. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; Argentina.

Implementación de una secuencia didáctica en la enseñanza de la lectura y escritura en contextos de estudio en la formación docente inicial

Fil: Sánchez, María de los Milagros. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; Argentina.

Comprehensive study of surface chemistry of MCM-41 using 29Si CP/MAS NMR, FTIR, pyridine-TPD, and TGA

A comprehensive study was conducted on mesoporous MCM-41. Spectroscopic examinations demonstrated that three types of silanol groups, i.e., single, (SiO)3Si-OH, hydrogen-bonded, (SiO)3Si-OH-OH-Si(SiO)3, and geminal, (SiO)2Si(OH)2, can be observed. The number of silanol groups/nm2, ?OH, as determined by NMR, varies between 2.5 and 3.0 depending on the template-removal methods. All these silanol groups were found to be the active sites for adsorption of pyridine with desorption energies of 91.4 and 52.2 kJ mol-1, respectively. However, only free silanol groups (involving single and geminal silanols) are highly accessible to the silylating agent, chlorotrimethylsilane. Silylation can modify both the physical and chemical properties of MCM-41.

Advances in mesoporous molecular sieve MCM-41

The discovery of mesoporous molecular sieves, MCM-41, which possesses a regular hexagonal array of uniform pore openings, aroused a worldwide resurgence in this field. This is not only because it has brought about a series of novel mesoporous materials with various compositions which may find applications in catalysis, adsorption, and guest-host chemistry, but also it has opened a new avenue for creating zeotype materials. This paper presents a comprehensive overview of recent advances in the field of MCM-41. Beginning with the chemistry of surfactant/silicate solutions, progresses made in design and synthesis, characterization, and physicochemical property evaluation of MCM-41 are enumerated. Proposed formation mechanisms are presented, discussed, and identified. Potential applications are reviewed and projected. More than 100 references are cited.