Fölling J  Polyakova S  Belov V  van Blaaderen A  Bossi ML  Hell SW 《Small (Weinheim an der Bergstrasse, Germany)》2008,4(1):134-142

We have designed and synthesized a new functional (amino reactive) highly efficient fluorescent molecular switch (FMS) with a photochromic diarylethene and a rhodamine fluorescent dye. The reactive group in this FMS -N-hydroxysuccinimide ester- allows selective labeling of amino containing molecules or other materials. In ethanolic solutions, the compound displays a large fluorescent quantum yield of 52 % and a large fluorescence modulation ratio (94 %) between two states that may be interconverted with red and near-UV light. Silica nanoparticles incorporating the new FMS were prepared and characterized, and their spectroscopic and switching properties were also studied. The dye retained its properties after the incorporation into the silica, thereby allowing light-induced reversible high modulation of the fluorescence signal of a single particle for up to 60 cycles, before undergoing irreversible photobleaching. Some applications of these particles in fluorescence microscopy are also demonstrated. In particular, subdiffraction images of nanoparticles were obtained, in the focal plane of a confocal microscope.  相似文献   

  总被引：3，自引：0，他引：3  

M. Hisada  S. Nagataki  N. Otsuki 《Cement and Concrete Composites》1999,21(5-6):443-448

Recently, it has been said that deterioration of concrete structures occurs due to migration of ions, such as Cl⁻ or Na⁺, through concrete. In addition, some electrochemical methods which control migration properties through concrete, like desalination or re-alkalization, are becoming more important. However, the mechanisms of ion migration, in electric fields, through concrete are not well understood. Moreover, the effects of mineral admixtures, such as fly ash, silica fume and ground-granulated blast furnace slag on ion migration through concrete have not been closely investigated. From this viewpoint, for the evaluation of mineral admixtures, the properties of chloride ion migration through mortar containing fly ash, silica fume and ground-granulated blast furnace slag have been investigated.  相似文献   

    

V. Bansal  A. Sanyal  D. Rautaray  A. Ahmad  M. Sastry 《Advanced materials (Deerfield Beach, Fla.)》2005,17(7):889-892

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B. Tan  H.&#x;J. Lehmler  S.&#x;M. Vyas  B.&#x;L. Knutson  S.&#x;E. Rankin 《Advanced materials (Deerfield Beach, Fla.)》2005,17(19):2368-2371

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Kickelbick G 《Small (Weinheim an der Bergstrasse, Germany)》2005,1(2):168-170

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Y. Li  Y. Bando  D. Golberg 《Advanced materials (Deerfield Beach, Fla.)》2004,16(1):37-40

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R. Ryoo  S. H. Joo  M. Kruk  M. Jaroniec 《Advanced materials (Deerfield Beach, Fla.)》2001,13(9):677-681

Ordered mesoporous carbons have recently been synthesized using ordered mesoporous silica templates. The synthesis procedure involves infiltration of the pores of the template with appropriate carbon precursor, its carbonization, and subsequent template removal. The template needs to exhibit three‐dimensional pore structure in order to be suitable for the ordered mesoporous carbon synthesis, otherwise disordered microporous carbon is formed. MCM‐48, SBA‐1, and SBA‐15 silicas were successfully used to synthesize carbons with cubic or hexagonal frameworks, narrow mesopore size distributions, high nitrogen Brunauer–Emmett–Teller (BET) specific surface areas (up to 1800 m² g^–1), and large pore volumes. Ordered mesoporous carbons are promising in many applications, including adsorption of large molecules, chromatography, and manufacturing of electrochemical double‐layer capacitors.  相似文献   

    

L. M. Bronstein  S. Polarz  B. Smarsly  M. Antonietti 《Advanced materials (Deerfield Beach, Fla.)》2001,13(17):1333-1336

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S. Vaudreuil  M. Bousmina  S. Kaliaguine  L. Bonneviot 《Advanced materials (Deerfield Beach, Fla.)》2001,13(17):1310-1312

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  总被引：9，自引：0，他引：9  

M. J. Shannag 《Cement and Concrete Composites》2000,22(6):399-406

Various combinations of a local natural pozzolan and silica fume were used to produce workable high to very high strength mortars and concretes with a compressive strength in the range of 69–110 MPa. The mixtures were tested for workability, density, compressive strength, splitting tensile strength, and modulus of elasticity. The results of this study suggest that certain natural pozzolan–silica fume combinations can improve the compressive and splitting tensile strengths, workability, and elastic modulus of concretes, more than natural pozzolan and silica fume alone. Furthermore, the use of silica fume at 15% of the weight of cement was able to produce relatively the highest strength increase in the presence of about 15% pozzolan than without pozzolan. This study recommends the use of natural pozzolan in combination with silica fume in the production of high strength concrete, and for providing technical and economical advantages in specific local uses in the concrete industry.  相似文献