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。
The surface segregation behavior of poly(dimethylsiloxane)/polyethylene (PDMS/PE) and poly(dimethylsiloxane)/polypropylene (PDMS/PP) blends has been studied using X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). It is shown that the overall concentration of silicon-containing species at the su…
The in situ polymerization of organic monomers to consolidate ceramic suspensions in the form of gelled bodies with very complex shapes has recently been employed for the manufacture of both dense and porous ceramics. The control of the polymerization rate is very important, particularly for the porous ceramics where…
We analyze the recent experimental data on photofissility for ${}^{237}\mathrm{Np}$, ${}^{238}\mathrm{U}$, and ${}^{232}\mathrm{Th}$ at incident photon energies above $200\mathrm{MeV}$. For this analysis, we developed a Monte Carlo algorithm for the nuclear evaporation process in photonuclear reactions. This code is u…
The influence of a partial boron substitution on the crystal structure, Curie temperature, easy magnetization direction and magnetostriction of Tb 0.7 Pr 0.3 Fe 2 has been studied. The matrix of Tb 0.7 Pr 0.3 Fe 2 consists of the (Tb, Pr)Fe 2 phase with a cubic MgCu 2 -type structure coexisting with a large amount of…
Abstract A cubic mesoporous silicate (CMS) was prepared, characterised, and assessed as an adsorbent for tetramethyl ammonium hydroxide (TMAH) from aqueous solution. The adsorption process was studied as a function of temperature and time. Sorption closely followed the Langmuir model. The adsorption of TMAH on CMS was…
Micrometer-sized carbon tubes can be conveniently prepared via a new chemical approach by pyrolyzing the composite fibers consisting of a polypyrrole skin layer and a PET core fiber at 1000 °C under a N 2 atmosphere. The resultant carbon tubes were found to be amorphous carbon. After further annealing at 1000−2400 °C,…
When incorporated into proteins, fluorinated amino acids have been utilized as 19F NMR probes of protein structure and protein-ligand interactions, and as subtle structural replacements for their parent amino acids which is not possible using the standard 20-amino acid repertoire. Recent investigations have shown the…
Surface-alkoxylated silica can be prepared by reacting precipitated silica with high-boiling and polymeric alcohols. The structure of the products was investigated through 13 C and 29 Si MAS NMR experiments. The influence of the alkoxy group structure and density on the hydrolytic stability of the alkoxylated silicas…
Chlorin building blocks incorporating a geminal dimethyl group in the reduced ring and synthetic handles in specific patterns at the perimeter of the macrocycle are expected to have utility in biomimetic and materials chemistry. A prior route employed condensation of a dihydrodipyrrin (Western half) and a bromodipyrro…
A family of diaminobutane core, poly(propylene imine) dendrimers coordinated to Cu(II), DAB-Am(n)-Cu(II)x (n = 4, 8, 16, 32, 64, x = n/2), was studied by means of extended X-ray absorption fine structure (EXAFS) and X-ray absorption near-edge structure (XANES) spectroscopies. The geometry of the dipropylene triamine (…
An XAS investigation was undertaken to understand the mechanism of our platinum deposition process. This process is based on H 2 PtCl 6 impregnation onto activated carbon followed by current pulses reduction. After each step of the process and during the electrochemical reduction, ex situ and in situ dispersive X-ray…
The effect of initial chain length before cross-linking and sulfur/accelerator amount during curing of natural rubber samples on network parameters (effective chain density, gel fraction, amount of chain ends, entanglement density, trapping factor, and relaxation and correlation times) is investigated by means of prot…
Low-density polyethylene (LDPE) filled with a small amount of titanium dioxide proves to be very suitable for studying the molecular motion of polyethylene by means of dielectric spectroscopy. The titanium dioxide acts as an oxidizing agent that introduces a small concentration of polar carbonyl groups, which does not…
The design, synthesis, and structural and magnetic properties of the two new bimetallic complexes [Sm(DMF)(4)(H(2)O)(2)Cr(CN)(6)].H(2)O and [Sm(DMF)(2)(H(2)O)(3)Cr(CN)(6)].H(2)O (DMF = N,N-dimethylformamide) are presented. [Sm(DMF)(4)(H(2)O)(2)Cr(CN)(6)].H(2)O was prepared by the reaction between Sm(3+) and [Cr(CN)(6)…
A new process is described for the preparation of chitosan gel beads using molybdate as the gelling agent. This new gelation technique leads to a structure different from that produced during alkaline coagulation of a chitosan solution. Instead of a morphology characterized by large open pores, gel beads produced in a…
We report the hydrothermal synthesis of 10 μm × 100 μm × 10 μm single crystals of the microporous titanosilicate sodium-ETS-4. The crystallization of large needle-shaped Na-ETS-4 crystals is preceded by the formation and subsequent dissolution of the titanosilicate GTS-1. Large Na-ETS-4 crystals are obtained with puri…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTOptimization of the Relaxivity of MRI Contrast Agents: Effect of Poly(ethylene glycol) Chains on the Water-Exchange Rates of GdIII ComplexesDan M. J. Doble, Mauro Botta, Jay Wang, Silvio Aime, Alessandro Barge, and Kenneth N. RaymondView Author Information Department o…
Ab initio density-functional (DFT) investigations of the O−H stretching frequencies are performed on the kaolinite structure. Four distinct OH groups form weak hydrogen bonds with O−H···O distances between 1.8 and 2.6 Å. The O−H stretching frequencies, calculated as the Fourier transforms of the velocity autocorrelati…
We investigate the flow properties of a 2D foam (a confined monolayer of jammed bubbles) submitted to a continuous shear in a Couette geometry. A strong localization of the flow at the moving inner wall is evidenced. Moreover, velocity fluctuations measurements reveal self-similar dynamical structures consisting of cl…
The Si(111)7x7 surface was observed by reflection electron microscopy (REM) and scanning tunneling microscopy (STM) simultaneously in an ultra-high vacuum electron microscope. The distance between the STM tip and the Si surface was detected from the REM image, which showed the real and the mirror image of the tip. We…