Efficient low-temperature soot combustion by bimetallic Ag-Cu/SBA-15 catalysts.

In this study, the effects of copper (Cu) additive on the catalytic performance of Ag/SBA-15 in complete soot combustion were investigated. The soot combustion performance of bimetallic Ag-Cu/SBA-15 catalysts was higher than that of monometallic Ag and Cu catalysts. The optimum catalytic performance was acquired with the 5Ag1-Cu0.1/SBA-15 catalyst, on which the soot combustion starts at Tig=225°C with a T50=285°C. The temperature for 50% of soot combustion was lower than that of conventional Ag-based catalysts to more than 50°C (Aneggi et al., 2009). Physicochemical characterizations of the catalysts indicated that addition of Cu into Ag could form smaller bimetallic Ag-Cu nanolloy particles, downsizing the mean particle size from 3.7nm in monometallic catalyst to 2.6nm in bimetallic Ag-Cu catalyst. Further experiments revealed that Ag and Cu species elicited synergistic effects, subsequently increasing the content of surface active oxygen species. As a result, the structure modifications of Ag by the addition of Cu strongly intensified the catalytic performance.

Intercalation of nanostructured CeO2 in MgAl2O4 spinel illustrates the critical interaction between metal oxides and oxides.

Heterogeneous catalytic oxidation arises from the prerequisite oxygen activation and transfer ability of metal oxide catalysts. Thus, engineering intercalated nanounits and heterophase metal oxide structures, and forming interstitial catalyst supports at the nanoscale level can drastically alter the catalytic performances of metal oxides. This is particularly important for ceria-based nanomaterial catalysts, where the interactions of reducible ceria (CeO2) and nonreducible oxides are fundamental for the preparation of enhanced catalysts for oxygen-involved reactions. Herein, we intercalated nanostructured CeO2 in the bulk phase of magnesium aluminate spinel (MgAl2O4, referred to as MgAl), produced the interstitial effect between CeO2 nanoparticles and MgAl crystallites, thus boosting their oxygen transfer and activation capability. This nanoscaled intercalation engineering significantly enhanced the number and quality of tight contact points between the nanostructured CeO2 and MgAl units. Therefore, the oxygen storage/release capability (OSC) is exceptionally improved as revealed by various characterizations and catalytic carbon oxidation reaction. A mechanism similar to the Mars-van Krevelen process at the nanoscale level was invoked to explain the catalytic oxidation mechanisms. The reactive oxygen species of gaseous O2 originate formed the bulk of the as-obtained nanomaterial, where strong interactions between the CeO2 and MgAl components occured, which were subsequently released and diffused to the catalyst-interface at elevated temperatures. Silver supported on Ce-MgAl produced an approximately 4-fold higher concentration of active oxygen species than Ag/MgAl, and gives the optimum low-temperature oxidation at 229 °C. This study verifies the importance of the redox performance of ceria-spinel with enhanced OSC, which validates that the arrangement of contacts at the nanoscale can substantially boost the catalytic reactivity without varying the microscale structure and properties of spinel.

Exploration of the financing and management model of a children's critical disease security system in China based on the implementation of Shanghai Children Hospital Care Aid.

This study is designed to serve as a reference for the establishment of health security systems for children's critical diseases. Through analysis of the operation of Shanghai Children Hospital Care Aid (SCHCA), this study explored the financing model and management of a children's critical disease healthcare system and analyzed the possibility of expanding this system to other areas. It is found that a premium as low as RMB 7 per capita per year under SCHCA can provide high-level security for children's critical diseases. With the good experience in Shanghai and based on the current basic medical insurance system for urban residents and the new rural cooperative medical scheme (NRCMS), it is necessary and feasible to build a health security system for children's critical diseases at the national level.

Life sciences and biotechnology in China.

Life science and biotechnology have become a top priority in research and development in many countries as the world marches into the new century. China as a developing country with a 1.3 billion population and booming economy is actively meeting the challenge of a new era in this area of research. Owing to support from the government and the scientific community, and reform to improve the infrastructure, recent years have witnessed a rapid progress in some important fields of life science and biotechnology in China, such as genomics and protein sciences, neuroscience, systematics, super-hybrid rice research, stem cell and cloning technology, gene therapy and drug/vaccine development. The planned expansion and development of innovation in related sectors and the area of bioethics are described and discussed.