Highly efficient toughening effect of ultrafine full-vulcanized powdered rubber on poly(lactic acid)(PLA)

A unique ultrafine full-vulcanized powdered ethyl acrylate rubber (EA-UFPR) was used as the toughening modifier for poly (lactic acid) (PLA). Largely improved tensile toughness was successfully achieved with the incorporation of only 1 wt% EA-UFPR, while the tensile strength and modulus of the blends were almost the same as pure PLA. The highly efficient toughening of PLA by UFPR is mainly ascribed to the strong interfacial interaction between PLA and UFPR and good dispersion of UFPR particles in PLA matrix. Our work provides an effective toughening method to largely improve the mechanical properties of PLA without sacrificing its stiffness, which is very important for the wide application of PLA materials.     

Preparation of sol–gel materials doped with ionic liquid and extractant for cerium(III) extraction

Silica materials (ILDEHPASGs) consisting of ionic liquids and di-(2-ethylhexyl)phosphoric acid (DEHPA) for Ce(III) extraction was prepared by a sol–gel method using the hydrophobic ionic liquid 1-octyl-3-methylimidazolium hexafluorophosphate ([C₈mim]PF₆) as porogen and solvent medium. The ILDEHPASGs were characterized by scanning electron microscopy, Brunauer–Emmett–Teller surface area, Fourier transform infrared, and thermogravimetric analyses. The results indicated the doping of DEHPA and [C₈mim]PF₆ in ILDEHPASG-3 would evidently affect the formation of porous structure of sol–gel materials. ILDEHPASG-3 also possessed more channels and macropores than the blank sorbent; the surface area and pore volume of ILDEHPASG-3 were 409 m² g^?1 and 0.444 cm³ g^?1, respectively. [C₈mim]PF₆ and DEHPA were only physically confined or entrapped in the growing covalent silica network rather than chemically bound to the inorganic matrix. The majority of [C₈mim]PF₆ and DEHPA were stably immobilized in the gel. Then, the effects of contact time and pH were determined. The results showed the sorption of Ce(III) strongly depended on the contact time and pH, and ILDEHPASGs had high sorption ability for Ce(III). The results were analyzed by both Langmuir and Freundlich adsorption isotherm models, and the latter was found to give a better fit.     

The behavior of technetium in technetium-scrubbing stage of PUREX process

Technetium decontamination factor as a function of the acidity, flow ratio, scrubbing stage number was investigated by counter-current cascade experiments or mixer-settler batch tests. Results showed that the acidity of the scrubbing acid has little influence on the decontamination factor of technetium when the acidity was kept in the range of 4.5–6 M. The most effective method to increase the decontamination factor is to lower the feed-to-acid flow ratio. Keeping other condition same the factor increased to 10.3 from 3.1 when feed-to-acid ratio changed to 4 from 5.6. The loss of uranium and plutonium can be recovered through a re-extraction technology.     

Coherent X-rays excited by a relativistic electron crossing a periodic stratified structure in Bragg scattering geometry

The dynamic theory of coherent X-rays excited by a relativistic electron crossing an artificial periodic stratified structure in Bragg scattering geometry has been developed for the general case of asymmetric reflection. Expressions describing the spectral-angular characteristics of radiation have been derived and investigated.     

Spin-injection radiation of terahertz waves in ferromagnetic structures

We propose and discuss the mechanisms of terahertz sd exchange radiation during transmission of the spin-polarized current in a structure from a thin steel rod pressured to an ultrathin ferromagnetic film. The two mechanisms considered are quantum transitions between the quasi-Fermi levels in the film near the rod and precession of injected spins around the film magnetization.     

Simulation of variations in mechanical properties of polyurethane elastomers modified with carbon nanotubes

The addition of extremely small portions of single-wall carbon nanotubes causes an anomalous change in mechanical properties of a cross-linked polyurethane-amide-urea elastomer containing 10% of polyamide-6; namely, with a nanofiller content of hundredths and thousandths of a percent, local maxima of elastic modulus and ultimate stress are observed. In the work, the anomalous variation in the elastic modulus is simulated relying on the concept of intermediate phase layer formation at the boundary of contacting particles of the initial material.     

Some coercive problems for the system of Poisson equations

In the paper, two boundary value problems for the system of Poisson equations in three-dimensional domains are studied.