Materials Literature
按标题、摘要、年份、主题和来源检索公开元数据。结果保留作者、摘要、分类与原始来源链接。
Monolayer protected gold nanoparticles synthesised by a two-phase method contain a significant amount of tetraoctylammonium bromide (TOABr), the quaternary ammonium salt used as the phase transfer reagent, as a persistently retained impurity. A simple purification protocol is described.
An original nanocone with 240° disclination arises naturally from a planar hexagonal sheet when four 60° segments originating from adjacent hexagonal centers are cut out of the plane and the severed edges of the segments are rejoined. The comparison among the calculated total energies of several pure carbon nanocones…
An unexpected dependence on concentration was found for the quadratic hyperpolarizability β of Zn complexes with stilbazole and CF3SO3− ligands (see values given), which reaches very large values on dilution. This is surprising, because the concentration used for determining β is traditionally not given in the literat…
Abstract In surface‐enhanced Raman scattering (SERS), the magnitude of enhancement is highly dependent on the nanometer‐scale morphological and optical properties of the substrate employed. This paper reports the development of an improved SERS‐active substrate that is based on a combination of nanoparticle assembly a…
The Holocene diatom flora identified in three sediment cores from marine bays in the Windmill Islands (East Antarctica) is described and depicted for the first time. One hundred and twenty-four diatom taxa could be identified of which eighty-one taxa have a circum-Antarctic distribution. All taxa are listed in a table…
Abstract Melt polycondensation of L ‐lactic acid (LA) was examined in the presence of binary catalyst systems consisting of SnCl 2 ·2H 2 O and metal alkoxides as co‐catalysts. Among the co‐catalysts examined, viz (Al(O i Pr) 3 ,Ti(O i Pr) 4 ,Y(O i Pr) 3 ,Si(OEt) 4 and Ge(OEt) 4 ), Ge(OEt) 4 was found to be the most ef…
Abstract Blended films of poly( L ‐lactide) [ie poly( L ‐lactic acid)] (PLLA) and poly(ϵ‐caprolactone) (PCL) without or mixed with 10 wt% poly( L ‐lactide‐ co ‐ϵ‐caprolactone) (PLLA‐CL) were prepared by solution‐casting. The effects of PLLA‐CL on the morphology, phase structure, crystallization, and mechanical propert…
This paper discusses the heterogeneous nucleation of solidification, treating the fundamental process as taking place by adsorption on the surface of the heterogeneous nucleant. A theoretical framework for adsorption and nucleation catalysis is described, and some related experimental results are discussed.
The structural properties and phase stability of the four common polytypes of boron nitride, cubic zinc blende (c-BN), hexagonal (h-BN), wurtzite (w-BN) and rhombohedral (r-BN), are studied by ab initio calculations. Electronic energies are calculated using an ultra soft pseudopotential method under the density-functi…
We have investigated pressure-induced Raman peak shifts for various carbon nanostructures with distinct differences in the degree of structural order. The high-frequency tangential vibrational modes of the hollow nanostructures, as well as those of graphite crystals and a macroscopic carbon fiber used as reference mat…
Abstract The basic copper sulphates are of interest because of their appearance in many environmental situations such as copper pipe corrosion, restoration of brass and bronze objects, leaching from waste mineral dumps and the restoration of frescoes. The Raman spectra of the basic copper sulphate minerals antlerite,…
The oblique collision between an elastic disk and an elastic wall is numerically studied. We investigate the dependency of the tangential coefficient of restitution on the incident angle of impact. From the results of simulation, our model reproduces experimental results and can be explained by a phenomenological theo…
Iodine glue! Spontaneous iodine chemisorption on gold nanoparticles is demonstrated. The concomitant electron injection into gold nanoparticles results in particle fusion, fragmentation, and aggregation, excess KI addition leads to the formation of nanocrystals (see scheme). Surprisingly, iodine-“glued” surface-bound…
Resistivity measurements are reported for single crystals of Mn12-Acetate and Fe8Br8. Both materials exhibit a semiconductor-like, thermally activated behavior over the 200-300 K range. The activation energy, Ea, obtained for Mn12-Acetate was 0.37 +/- 0.05 eV, which is to be contrasted with the value of 0.55 eV deduce…
The off-diagonal disorder caused by random spin orientations in the paramagnetic (PM) state of the double exchange (DE) model is described by using the coherent-potential-approximation (CPA), which is combined with the variational mean-field approach for the Curie temperature (T_C). Our CPA approach is essentially non…
Abstract The properties of chitosan depend on several parameters including its origin (shrimp, squid, fungi etc), characteristics (mol fraction of N ‐acetylation; molecular weight) and treatments used to condition it (dissolving, precipitation, drying). These parameters can influence the material's sorption properties…
The study was to investigate the crosslinking characteristics, mechanical properties, and resistance against enzymatic degradation of biological tissues after fixation with genipin (a naturally occurring crosslinking agent) and/or carbodiimide. Fresh tissue was used as a control. It was found that both genipin and car…
Preface. 1 Metallocenium Salts of Radical Anion Bis(Dichalcogenate) Metalates (Vasco Gama and Maria Teresa Duarte). 1.1 Introduction. 1.2 Basic Structural Motifs. 1.3 Solid-state Structures and Magnetic Behavior. 1.4 Summary and Conclusions. References. 2 Chiral Molecule-Based Magnets (Katsuya Inoue, Shin-ichi Ohkoshi…
Fabrication processes for wet chemical and dry etching of hollow capillary leaky optical waveguides in high-purity fused silica for extended path cells for improved optical detection in analytical chemistry are described. We focus on microstructures with etch depths on the order of 80 μm. Special attention is paid…
A 2D array of ordered dodecanethiol-capped silver nanocrystals of average diameter of 6.5 nm is manufactured by controlled evaporation of the chloroform solvent. Additional particle ordering is obtained in a high magnetic field of 10 T because of the combined action of the attractive capillary force, enhanced by the v…