[en] A novel milk-like Cu-thiourea colloid has been synthesized. Nanocrystalline quaternary copper sulfide Cu₂FeSnS₄ was obtained through the Cu-thiourea colloidal precursor cooperative conversion route at low temperature. The samples were characterized by means of X-ray powder diffraction, transmission electron microscopy, scanning electron microscopy, inductively coupled plasma atomic emission spectroscopy, and X-ray energy dispersive spectroscopy techniques. The reaction details and features were described and discussed

[en] A dynamic flammability study of flame-retardant compound consisting of HDPE, EPDM and silicon elastomer blended with additives, as wire and cable insulation was made before and after irradiation. The data of RHR, EHC, SEC and the concentration of CO and CO₂ from cone colorimeter shown in the burning process were accessed. By blending silicon elastomer, CO release rate was reduced and the thermal endurance was improved. Oxygen index, mechanical property, morphology of the char formed in dynamical flame and thermal stability were also investigated

[en] The platform which is used to carry diagnostic instruments on Shenguang facility requires high positioning accuracy and working stability, and can aim at the target with reliability. A double optical path automatic adjusting and aiming system is designed, its position accuracy is 20 μm. It employs a double optical image system and a 3-DOF motion components. In this system, visual servo technology is used to realize the automatic aiming. Automatic positioning test indicates that pointing accuracy is 11 μm in x direction, 12 μm in y direction and radical positioning accuracy is 14 μm. Laser shot test with X-ray framing camera shows that the automatic aiming system can satisfy the projects requirement. (authors)

[en] Highlights: • A one-step in situ approach for reducing and functionalizing GO with Mg-AMP is proposed in the absence of a reducing agent. • Mg-rGO is used as a novel toughening and flame-retardant agent in PF foam. • Mg-rGO shows better toughening, flame-retardant, and smoke-suppression performances than GO and Mg-AMP in PF foam. - Abstract: This study presents a one-step synthesis of a magnesium amino-tris-(methylenephosphonate) (Mg-AMP)-reduced graphene oxide (Mg-rGO) hybrid involving graphene oxide (GO) reduction and growth in situ of Mg-AMP nanoparticles in the absence of a reducing agent. Mg-rGO was characterized by X-ray diffraction, X-ray photoelectron and Fourier-transform infrared spectroscopies, transmission electronic microscopy, and thermogravimetric analysis (TGA). Mg-rGO was then used to prepare flame-retardant and toughened phenolic (PF) foam. This additive was found to enhance the compressive and flexural strengths of PF foam as well as to reduce its high friability and brittleness. The limiting oxygen index of the foam with 4 phr Mg-rGO (sample PF/4Mg-rGO) increased to 41.5%, compared with the 38% of untreated foam; the peak heat release rate and total heat release of sample PF/4Mg-rGO were decreased by 28.7 and 18.4%, respectively. Also, the total smoke release and peak CO production rate of PF/4Mg-rGO were reduced by 52.5 and 38.1%, respectively. TGA results indicated that Mg-rGO clearly improved the thermal stability of PF foam.

[en] The effects of drawing process, heat treatment temperature and drawing rate on the basic mechanical properties of stainless steel wire were studied by room temperature tensile test. Results indicated that with the increase of drawing passes, the tensile strength and the yield strength of stainless steel wire increased gradually and the elongation after fracture decreased gradually. With the increase of heat treatment temperature, the tensile strength decreased and the elongation after fracture increased gradually. Under the same heat treatment temperature, the tensile strength of the specimens treated by the two-drawing process was greater than that of those treated by the one-drawing process, while the elongation after fracture was less than that of those treated by the one-drawing process. The increase in drawing rate would increase the strength and modulus of elasticity of the stainless steel wire. (paper)

[en] Highlights: • Mg-AMP was synthesized and evaluated as a novel phosphorus and nitrogen-containing flame retardant for RPU foam. • Mg-AMP nanoparticles improved compressive strength, thermal stability and flame retardancy of RPU foam. • Mg-AMP nanoparticles and EG showed good synergistic effect on flame-retardant and physico-mechanical properties in RPU foam. A novel nano phosphorus and nitrogen based flame retardant, i.e. magnesium amino-tris-(methylenephosphonate) (Mg-AMP) was synthesized and characterized by Fourier-transform infrared and X-ray diffraction spectroscopies, transmission electronic microscopy, and thermogravimetric analysis (TGA). Flame retarded rigid polyurethane (RPU) foams filled with nano Mg-AMP and expandable graphite (EG) were prepared, and a synergistic effect in flame retardancy between Mg-AMP and EG in RPU foam was observed. The RPU foam containing 12 wt% EG and 3 wt% Mg-AMP (sample RPU/12EG/3Mg-AMP) reached a V0 rating in vertical UL-94 test with a limiting oxygen index of 29.5%. The peak heat release rate and total heat release of sample RPU/12EG/3Mg-AMP were obviously decreased by 52.4 and 42.9%, respectively compared with the foam with 15 wt% EG (sample RPU/15EG). Moreover, the compressive strength of sample RPU/12EG/3Mg-AMP was 35% higher than that of sample RPU/15EG, and the thermal conductivity of the former was lower than the one of the latter. TGA results indicated that the combination of Mg-AMP and EG clearly improved the thermal stability and yield of residual char of RPU foam.

[en] Halogen-free flame retarded ethylene vinyl acetate copolymer (EVA) composites using Mg-Al-CO₃ hydrotalcite (MALDH) and microcapsulated red phosphorus (MRP) have been prepared in a melt process. The flame retardation of the composites has been studied by the limited oxygen index (LOI) and UL-94 methods, and the thermal decomposition by the thermogravimetric analysis (TGA). The changes of their properties of the composites before and after the Gamma irradiation are compared. The synergistic effect in the flame retardation between MALDH and MRP in EVA has been found. The EVA/MALDH/MRP composites after the irradiation crosslinking result in a great increase in the Vicat softening point. The LOI value, the mechanical properties and thermal stability are also improved for the composites irradiated by a suitable irradiation dose

[en] Interfacial charge transfer has a vital role in tailoring the thermoelectric performance of superlattices (SLs), which, however, is rarely clarified by experiments. Herein, based on epitaxially grown p-type (MnTe)${}_x$(Sb${}_2$Te${}_3$)${}_y$ superlattice-like films, synergistically optimized thermoelectric parameters of carrier density, carrier mobility, and Seebeck coefficient are achieved by introducing interfacial charge transfer, in which effects of hole injection, modulation doping, and energy filtering are involved. Carrier transport measurements and angle-resolved photoemission spectroscopy (ARPES) characterizations reveal a strong hole injection from the MnTe layer to the Sb${}_2$Te${}_3$ layer in the SLs, originating from the work function difference between MnTe and Sb${}_2$Te${}_3$. By reducing the thickness of MnTe less than one monolayer, all electronic transport parameters are synergistically optimized in the quantum-dots (MnTe)${}_x$(Sb${}_2$Te${}_3$)${}_{12}$ superlattice-like films, leading to much improved thermoelectric power factors (PFs). The (MnTe)${}_{0.1}$(Sb${}_2$Te${}_3$)${}_{12}$ obtains the highest room-temperature PF of 2.50 mWm${}^{-<!--\; ???\; -->1}$ K${}^{-<!--\; ???\; -->2}$, while the (MnTe)${}_{0.25}$(Sb${}_2$Te${}_3$)${}_{12}$ possesses the highest PF of 2.79 mWm${}^{-<!--\; ???\; -->1}$ K${}^{-<!--\; ???\; -->2}$ at 381 K, remarkably superior to the values acquired in binary MnTe and Sb${}_2$Te${}_3$ films. This research provides valuable guidance on understanding and rationally tailoring the interfacial charge transfer of thermoelectric SLs to further enhance thermoelectric performances. (© 2022 Wiley‐VCH GmbH)

[en] On the basis of the highly oriented ZnO nanoparticle nanoribbons as the growth seed layer (GSL) and solution growth technique, we have synthesized vertical ZnO nanorod arrays with high density over a large area and multi-teeth brush nanostructure, respectively, according to the density degree of the arrangement of nanoparticle nanoribbons GSL on the glass substrate. This controllable and convenient technique opens the possibility of creating nanostructured film for industrial fabrication and may represent a facile way to get similar structures of other compounds by using highly oriented GSL to promote the vertical arrays growth. The growth mechanism of the formation of the ordered nanorod arrays is also discussed. The second-order nonlinear optical coefficient d ₃₁ of the vertical ZnO nanorod arrays measured by the Maker fringes technique is 11.3 times as large as that of d ₃₆ KH₂PO₄ (KDP). - Graphical abstract: SEM images of the arrays at different locations and magnifications. These images are representatives of the entire surface