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。
This paper describes large thick flattened multiwalled carbon nanotubes (MWCTs) that have been synthesized using the precursors Co(CO) 3 NO or Fe(CO) 5 . TEM and HRTEM clearly show that even thick MWCNTs (more than 30 layers) can be collapsed or partially flattened. The transition from circular to flattened was observ…
The stability and electronic structure of a single monatomic Al wire has been studied using the ab initio pseudopotential method. The Al wire undergoes two structural rearrangements under compression, i.e., zigzag configurations at angles of $140^o$ and $60^o$. The evolution of electronic structures of the Al chain as…
The crystallization and subsequent polymorphic transformation from the β to the α form of glycine has been studied using optical microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy techniques. The crystal structure and morphology of β glycine have been determined, and the influence of solvent, s…
Based on the generalized valence bond picture, a Schwinger boson mean field theory is applied to the symmetric SU(4) spin-orbital systems. For a two-leg SU(4) ladder, the ground state is a spin-orbital liquid with a finite energy gap, in good agreement with recent numerical calculations. In two-dimensional square and…
We present the results of a systematic study using the density functional theory (within the local density approximation) of the effects of biaxial strain and composition on the self-diffusion of Si and Ge in SiGe alloys diffusing by a vacancy mechanism. The biaxial strain dependence of the vacancy formation energy wa…
The decay time of the linear polarization degree of the luminescence in strongly confined semiconductor quantum dots with asymmetrical shape is calculated in the frame of second-order quasielastic interaction between quantum dot charge carriers and LO phonons. The phonon bottleneck does not prevent significantly the r…
The stabilities of $(BN)_x(C_2)_{1-x}$ alloys and related superlattices are investigated by ab initio pseudopotential calculations. We find that the $(BN)_1/(C_2)_1$ superlattices in (111) orientations have the lowest formation energy among many short-range ordered $BNC_2$ structures due to the smallest number of B-C…
A novel magnetic nano-adsorbent has been developed using Fe3O4 nanoparticles (13.2 nm) as cores and polyacrylic acid (PAA) as ionic exchange groups. The Fe3O4 magnetic nanoparticles were prepared by co-precipitating Fe2+ and Fe3+ ions in an ammonia solution and treating under hydrothermal conditions. PAA was covalentl…
Single-walled and multiple-walled carbon nanotubes were functionalized with a polystyrene copolymer, poly(styrene- co - p -(4-(4‘-vinylphenyl)-3-oxabutanol)). The functionalization reaction conditions were designed for the esterification of the nanotube-bound carboxylic acids. The polymer-attached carbon nanotubes are…
The aim of this paper is to define optimal conditions for the extraction of chitin from shrimp shells. The kinetics of both demineralization and deproteinization with, in the latter case, the role of temperature are studied. The characterization of the residual calcium and protein contents, the molecular weights, and…
Abstract An AB 2 monomer, 1‐(2‐hydroxyethoxy)‐3,5‐bis‐(methoxymethyl)‐2,4,6‐trimethylbenzene, was synthesized from mesitol and melt‐polycondensed in the presence of an acid catalyst via a transetherification process at 145–150 °C to yield a soluble, moderately high molecular weight hyperbranched polyether. The degree…
Two novel high nuclearity copper(I) alkynyl complexes, [Cu16(hfac)8(CCBut)8] (1) and [Cu20(hfac)8(CCCH2Ph)12] (2), that consist of complicated alkynyl bridged Cu(I) cores ‘capped’ by peripheral hfac ligands have been synthesised and characterised by X-ray structure determination. The photoluminescent properties of 1 a…
Dendron rod–coil molecules (DRCs) spontaneously assemble into birefringent gel-forming networks when added to styrene in small amounts. It is shown that DRC gel derived polystyrene (PS) has greater birefringence than the PS homopolymer when drawn under similar conditions.The dispersed DRC nanophase is responsible for…
A hypothesis was developed, and successfully tested, to greatly increase the rates of biodegradation of polyolefins, by anchoring minute quantities of glucose, sucrose or lactose, onto functionalized polystyrene (polystyrene-co-maleic anhydride copolymer) and measuring their rates of biodegradation, which were found t…
Poly(ethylene oxide)-b-poly(methyl acrylate) diblock copolymer (EOmMAn) prepared via an atom transfer radical polymerization (ATRP) approach was used as a template to synthesize Ia3d mesostructured silica with thick walls under acidic conditions.
Linear and nonlinear optical constants of pulsed laser deposited (PLD) arsenic sulfide films are presented. It is shown that these constants are generally in good agreement with the results for films obtained by other deposition methods. Effects of annealing and exposure on optical constants of these films are investi…
In this study, the production of Poly-b-hydroxybutyrate (PHB) was determined in 1 Rhizobium japonicum, 6 Rhizobium cicer, 8 Rhizobium spp. and Bradyrhizobium japonicum USDA 110. The content of according to dry cell weight was determined to be 1.38-40.0%. In our study, Rhizobium spp. 2426, which produced the highest pe…
The static dielectric properties of (001)(GaAs)(p)/(AlAs)(p) superlattices have been calculated as a function of their period p for 1< or = p < or =12, starting from density-functional theory. The interplay between quantum confinement and local field effects is shown to be crucial. For light polarized in the growth di…
An zwei unterschiedlichen Positionen derivatisierbar sind die neuartigen Heteropolymolybdate wie das gezeigte [SeIVMo6O21(O2CCH2NH3)3]2−. Zudem eröffnen die terminalen Aminogruppen der Aminosäuren weitere Funktionalisierungsmöglichkeiten, sodass die hier vorgestellten 18 Verbindungen ideale Kandidaten für das Wirkstof…
Rare earth ion-exchanged zeolites exhibit a tremendous enhancement of luminescence upon treatment with suitable organic complexing agents, as reported here. For Eu3+ exchanged zeolite X, the β-diketone 1-thienyl-4,4,4-trifluoro-1,3-butane-1,3-dione leads to the formation of intra-zeolite complexes. Fully coordinated c…