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In this study, a novel strategy for preparation of Cu2(MII)(MIV)S4 thin films was creatively proposed. Three light absorption materials Cu2MnSnS4, Cu2ZnSnS4 and Cu2ZnGeS4 were successfully synthesized based on combustion method. It was found that the combustion synthesized powder is mainly consist of several metal oxides. The band gap energy of Cu2MnSnS4, Cu2ZnSnS4 and Cu2ZnGeS4 are determined to be 1.3 eV, 1.49 eV and 2.15 eV, respectively, showing a promising application on thin film solar cells. According to our experiment results, the combustion method was confirmed to be an efficient tool to synthesize various Cu-based absorber materials by using a post-sulfurization process, which provides a new view for fabrication of high-efficient low-cost photovoltaics.

Carbon fiber reinforced silicon carbide composite (Cf/SiC) is the new high temperature ceramic composite developed in recent years, widely used in the aviation, aerospace and other high-tech fields. In this paper, a variety of joining methods of Cf/SiC composite to metallic materials, including active filler brazing, solid phase diffusion welding, liquid infiltration joining, as well as chemical vapor deposition of niobium transition joining technology were introduced. At the same time, the features and disadvantages of each technique were evaluated. This review is intended to provide a comprehensive guide to the design and application of Cf/SiC composite joining to metals.

In this study, the stabilization/solidification of lead in soils using alkali-activated cementing materials with rich-silicon materials was investigated. The artificial Pb-polluted soil with 500mg/kg lead was treated using fly ash-, silica fume-and rice husk ash-based cementitious materials, respectively, at the dosages 25%. The effectiveness of treatment was assessed with unconfined compressive strength (UCS) and the toxicity characteristic leaching procedure (TCLP) after curing for 14 and 28 days. Overall, the UCS results showed that the UCS values are above the USA EPA’s recommended value of 0.35 MPa. The TCLP results indicated that the Pb concentrations extracted from soils amended with 25% cementitious materials after 14 and 28 days are near 0.25mg/L, far below 5mg/L (the TCLP regulatory limit). And the XRD results showed the immobilization of lead were due to the formation of PbSiO3, the sorption of C-S-H.

The mechanical properties, including the compressive strength, flexural strength and adhesion strength of the rapid setting conventional and polymer-modified waterproof mortars are systematically compared in this paper. The polymer modification is demonstrated to increase the flexural strength and adhesion strength of the rapid setting waterproof mortar whereas it reduces its compressive strength.

In order to study the influence of different types of weld defects, such as slag inclusion, porosity, incomplete fusion, incomplete fusion, burn through, crack on the mechanical performance of X65 marine pipe welding joint (Φ323.9 x 16 mm), the test on the mechanical properties of static tensile, fracture toughness CTOD and fatigue life were carried out to achieve the maximal defect tolerance size allowed in this paper. Research shows that the existence of crack defects would significantly reduce the fracture strength and the fatigue life of welded joint, the application of the maximal defect tolerance size allowed based on crack defects assessment can provide referential basis for the safe and stable operation of marine pipelines.

Perturbation method is used to resolve one-dimensional wave equation under the assumption of small strain conditions. The relationship of the second order relative nonlinear coefficients (SORNC) β', the third order relative nonlinear coefficient (TORNC) δ' as the functions of fundamental and harmonic amplitudes is determined. The specimens are loaded from-200 MPa to 320 MPa at increments of 40 MPa by the electron universal testing machines. The SORNC β' and TORNC δ' are detected by the nonlinear ultrasonic testing system when ultrasonic waves propagate in the specimens. Results show that the relative nonlinear coefficients increase with the stress. The SORNT β' is approximately linear with the stress when stress is lower than 84.6% of the yield strength. The TORNC δ' is approximately linear with the stress when stress is lower than 76.9% of the yield strength.

Type-I clathrates have been considered as very promising thermoelectric (TE) materials thus attracting attention widely. Here we report new clathrates Ba8CuxSiyGe46-x-y (4≤ x ≤ 6.5, y = 0 and 5.15 ≤ x ≤ 6.425, 2.05≤ y ≤ 36.9), focusing on their phase purity and TE properties. Our results show that samples prepared by arc melting followed by annealing are multi-phases alloys. The composition of the clathrate phase is also inhomogeneous. This indicates that the kinetic factor dominates the reaction of forming the clathrate phase during element-melting and sample-annealing. We select three compositions in these two series of samples, which have less impurity and better composition homogeneity for the clathrate phase, and the annealed alloys are furthered processed by ball milling (BM) and powder-solidification (either by hot pressing (HP) or by spark plasma sintering (SPS)) for TE properties investigations. The BM and HP/SPS processes can improve the phase purity and homogeneity. The TE measurements show that the Si-substituted samples have better performance than the Ge-based sample, mainly by decreasing the electrical resistivity. This indicates that the elemental substitution may be still an effective way to improve the TE performance of clathrates.

Numerical simulation of cooling roller in planar flow melt spinning process was accomplished using CFD software, Get cooling water flow characteristics and the cooling roller wall temperature and pressure distribution with cooling roller rotation speed range 0-50r/s, The results show that: heat transfer coefficient h and Nusselt number between the cooling water and the inner wall surface of a copper roller creases with the increase of the cooling roller rotate speed, but the increase rate is relatively small; Effect of cooling roller rotate speed on inner wall pressure is large, cooling roller inner wall pressure increases with the rotation speed increase. This study provided a theoretical reference of amorphous cooling roller design and optimization.

Controlling the morphology of platinum (Pt)-based nanomaterials is an effective strategy to enhance their catalytic performance for a given reaction. Here we report the syntheses of bimetallic Au-Pt nanomaterials with spherical or dendritic morphologies by a seed-mediated growth method. In this route, the gold (Au) nanoparticles are firstly prepared as seeds in oleylamine, which are subsequently seeded the growth of regular or dendritic Pt shells at different Au/Pt molar ratios. The electrochemical measurements show that the core-shell Au-Pt nanodendrites have better catalytic activity than that of core-shell Au-Pt nanoparticles for methanol oxidation reaction due to their abundant atomic steps, edges, and corner atoms in the branched Pt shells.

Ceramsite cellular concrete (CCC for short) is a kind of lightweight aggregate concrete. In this paper, the selection of materials and design of mix proportion have been discussed, and basic property tests has been done. The compressive strength was proved up to the National Standards of P. R. GB50003-2001(code for design of masonry structures), furthermore, elastic modulus and Poisson's ratio were also introduced. Questions remain regarding the quality control of the product, and further work is needed to resolve this contradiction.

H2S adsorption and dissociation on MoP(010) were investigated using density functional theory (DFT) together with periodic slab models. Several different possibilities for H2S, SH, S and H adsorption were considered. Our results show that the H2S, SH and H prefer to adsorb at bridge site, while S adsorbs preferentially at hcp and bridge sites. Additionally, the optimum co-adsorption configurations for SH/H and S/H were determined. The results indicate that the co-adsorbed species repel each other slightly on MoP(010) surface. Finally, the potential energy profile of H2S dissociation on MoP(010) surface was given out. The dissociation energy barriers of the S–H bond scission exhibit that H2S prefers to dissociate on MoP(010) surface. When compared with MoP(001) surface, the obvious differences in H2S decomposition arise demonstrate that the MoP-based catalysts are structure-sensitive.

Porous silicon (p-Si) was fabricated by single-groove electrochemical anodic etching method; the influence of large etching current density on the surface morphology was observed. And the surface microstructure and photoluminescence (PL) of p-Si were shown by scanning electron microscope (SEM) and PL spectra, respectively. The SEM image showed that a new microstructure was formed at the large current density etching area, which resembled a crater structure; and the area away from the crater appeared the porous structure. The comparison results of the PL spectra for the different areas indicated that PL of the crater area has a shorter wavelength.

Scaffolds material is the key factor for bone tissue engineering, and construction of the scaffolds is also an important part. Adopting the biocompatible, biodegradable, hydroxyapatite (HAP) and sodium alginate (SA) as the molding material, using three-dimensional printing technology, choosing cross grid filling paths, we manufactured the artificial bones through self-developed 3D printing equipment. Then we measured and analyzed important parameters of the work, and did composite culture experiment. It can be seen that the prepared artificial bone scaffold has good biocompatibility. The paper provides a reference for the study of bone tissue engineering materials.