The topologic structure of filled skutterudites (SKD)-based thermoelectric device was designed via full-parameter simulation. The influences of topologic structure factors and interfacial electrical resistance on the module output performance (i.e., conversion efficiency and output power density) were investigated by numerical analysis. An 8-pair module with an optimized design was fabricated using p-type CeFe_3.85Mn_0.15Sb₁₂ and n-type Yb_0.3Co₄Sb₁₂ filled skutterudites. The maximum conversion efficiency and output power density are 9.8% and 1.42 W/cm², respectively.

Cellulose acetate (CA) nanofibers were embedded with aggregated silver-nanocubes (AgNCs) by a coaxial electrospinning method. AgNCs were dispersed with CA and acetone-dimethylacetamide (DMAc) as a precursor solution, and AgNCs aggregation was induced with acetone. The nanofibers have a remarkable surface-enhanced Raman scattering (SERS) activity due to the strong plasmon coupling between neighboring AgNCs, which is 4 times of the monomeric-AgNC/CA sample. As a result, 0.1 nmol/L p-aminothiophenol (p-ATP) and 10 nmol/L methyl parathion can be identified, respectively. The nanofibers generate large-area homogeneous SERS signals with a relative signal deviation of less than 12% over 1 mm×1 mm area due to the homogeneous adsorption of target molecules. It is thus indicated that aggregated-AgNCs/CA nanofibers have a promising potential in SERS-based detection of organic pollutants in aqueous solutions.

This paper introduced the basic properties of the sub-lattice conductive network in chalcogenide diamond-like, ABX₂-type diamond-like and Cu₂Se thermoelectric materials. In our recent work, we developed the high-throughput screening method and electrical/thermal transport calculation methods. A novel thermoelectric material with ZT>1.0 was obtained when these methods were used to predict the thermoelectric performance of the diamond-like thermoelectric materials. Based on the data calculated by the methods, the sub-lattice conductive network is ubiquitous in the diamond-like structure system.

Laminated SiC/BN ceramics with different structures were prepared via tape casting and hot pressing sintering to develop high-performance ceramic armor with structural and functional designs. The sinter ability, microstructure, mechanical properties and impact resistance of the prepared ceramics were investigated. The results show that the laminated structure of the ceramics can achieve the strengthening and toughening effects, and the failure mode is non-brittle fracture, and its ability to maintain the structural integrity is improved. The flexural strength of 410 MPa and the fracture toughness of 7.6 MPa·m^1/2 can be obtained. The bullet shooting results show that the laminated ceramic has a good energy absorption effect and an ability to maintain the structural integrity, which can resist the impact of multiple projectiles. The impact depth is 7.5 mm, the diameter of crushing cone is 40 mm, and the dynamic damage is mainly circumferential damage. The comprehensive protection ability is improved.

Yb:YCa₄O(BO₃)₃ (Yb:YCOB) self-frequency doubling (SFD) crystals with different doping concentrations (5%-30%, mole fraction, the same below) were grown by the Czochralski method, and the relationship between the structure and doping concentration of the as-grown crystals was analyzed. The crystals were cut along the direction with a maximum effective nonlinear coefficient, and the microchip structure design was realized. The yellow laser output with a maximum power of 1.71 W can be obtained in Yb:YCOB crystal with a doping concentration of 30% and a crystal length of 4 mm with respect to the electric-phonon coupling effect. The conversion efficiency is 11.97% and the output wavelength is stabilized at 570 nm based on the proper coating parameter design. The results show that Yb:YCOB SFD crystals can realize the practical yellow laser.

Developing room-temperature superconductors is the ultimate goal of superconducting research field. Recent work focus onthe development of high-temperature superconductors in hydrogen-rich materials under high pressure. Sulfur hydride (H₃S) and lanthanide hydride (LaH₁₀) with superconducting transition temperatures (T_c) of >200 K are theoretically predicted and then experimentally confirmed. Hydrogen-rich materials are considered as one of optimum candidates for room-temperature superconductors, thus becoming a hot research aspect in physics and materials. Some contributions in this aspect were achieved involve a variety of new cage-like superhydridesPrH₉ and NdH₉ are synthesized under high pressure, and their T_c is determined, The magnetic properties of NdH₉ are discovered and its magnetic properties suppress a superconductivity; Novel cage-like superhydrides of CaH₉ are designed under high pressure, and its T_c is predicted to be 266 K; superconducting zirconium hydrogen compounds ZrH₃ and Zr₄H₁₅ are synthesized under mild pressure conditions by experimental and theoretical studie; The binary hydrides are extended to ternary hydrides, and MgXH₆ (X=Si, Ge) with T_c of 60 K are designed.

Sodium-ion batteries (SIBs) are regarded as one of the most promising electrochemical devices for large-scale energy storage due to the abundant sodium resource and the physical and chemical properties similar to lithium. This short review mainly represented recent studies on the development of some typical cathode and anode materials for SIBs, and provided the related information on the key electrode materials for the commercialization and practical application of SIBs.

Thermoelectric materials as novel clean energy materials have application prospects in waste-heat recovery and solid-state refrigeration. The thermoelectric compounds evolve from simple unitary- or binary-component crystalline systems to multinary complex systems. Among them, the multinary diamond-like compounds, the compounds with distinct sublattice and chemical bond hierarchy characteristics and their derivatives exhibit a complex crystalline-amorphous hybrid behavior in an atomic scale and present some transport effects, providing a prospect for the exploration of effects of electrical-thermal transport and systems of thermoelectric materials. This review summarized recent research progress on thermoelectric materials in sublattice engineering, including the structural design of novel "quasi-crystalline" thermoelectric compounds, the optimization of thermoelectric property and the characterization of microstructures in a sublattice scale. In addition, the relationship between the crystalline-semi-crystalline sublattice structure and the thermoelectric property of the compound was also discussed.

Metal-organic frameworks (MOFs) are a novel type of inorganic-organic hybrid material, which is composed of metal ions or metal clusters and organic bridging ligands through coordination. The combination of inorganic and organic components in the MOFs can possess the characteristics and performances of inorganic and organic elements simultaneously, and realize the cooperative optimization. Furthermore, the ordered micro-pores can be used to encapsulate the guest molecules within the MOFs to generate novel photonic functions. Therefore, the design and construction of MOFs for photonics applications become popular. This paper summarized the latest results obtained from a research project 'Investigation of photonic functions based on ordered microporous materials' supported by the National Natural Science Foundation of China, i.e., the design and controllable preparation methods of metal-organic frameworks, and the encapsulation of organic dyes and perovskite quantum dots in ordered microporous of the MOFs. In addition, future development and application prospects of the MOFs were also discussed.

The effects of water-to-binder ratio and basalt coarse aggregate on the compressive behavior of ultra-high-performance concrete (UHPC) were investigated. The results show that the compressive strength of UHPC firstly increases and then decreases, while the elastic modulus decreases with the increase of water-to-binder ratio, and the optimum compressive strength is obtained at a water-binder ratio of 0.16. The compressive strength firstly increases and then decreases, while the elastic modulus increases with the increase of coarse aggregate. In addition, a semi-empirical equation considering the parameters of coarse aggregate was also proposed for the prediction of elastic modulus of UHPC, which was validated using the existing literature data.

The effects of strength grade, steel fiber content on the compressive strength and its scale effect of ultra-high performance concrete (UHPC) were investigated via cubic compressive strength tests on the UHPC cubic specimens with different sizes, strength grades and fiber contents. The results show that the scale effect of the cubic compressive strength becomes more obvious with the increase of strength grade. The scale effect of the cubic compressive strength of the plain UHPC specimen with a strength grade R160 is 1.72 times greater than that of the specimen with a strength grade of R120. The content of steel fiber has an effect on the scale effect of the cubic compressive strength. The greater the content of steel fiber is, the more pronounced the scale effect will be. The scale effect on the cubic compressive strength of specimens with a fiber content of 3% is 46% greater than that of the specimens without steel fiber reinforcement. The size conversion factors for cubic compressive strength of the UHPC with different strength grade sand the calculation formulas for the scale effect law of the cubic compressive strength of the UHPC are proposed. The proposed formulas can be used to analyze the cubic compressive strength of the UHPC.

The non-uniform deformations of C50 concrete under drying at different relative humidities (i.e., 73%, 55% and 40%) from 1 d to 60 d were determined by a digital image correlation (DIC) technique. The equivalent tensile strains ɛ̃ in concrete were calculated based on the meso-scale damage model of concrete, which were used to identify the damage distribution in concrete. The results show that the mortar phase surrounding the coarse aggregates has great tensile strains, thus readily occurring damage and micro-cracks. The damage index (Dɛ̃) calculated from the value and distribution of ɛ̃ was used to quantify the drying-induced damage in concrete. The Dɛ̃ of the concretes under drying at 55% and 40% relative humidities increases to 101 μm/m and 135 μm/m, respectively, indicating that the drying conditions with ≤55% relative humidity could cause damage and micro-cracks.

Influence of plug flow on the nonlinearity and continuity of angular velocity-torque curve obtained in a Couette rhometer during the measurement of Bingham fluid was analyzed. The feasibility of linear regression on angular velocity-torque curve to obtain the Bingham parameters was discussed, showing the error caused by ignoring the influence of plug flow in the annulus of Couette rheometer. A method to obtain the Bingham fluid parameters based on linear regression of shear stress-shear rate curve with respect to the effect of plug flow was proposed. The denoise method of the angular velocity-torque data was recommended for guaranteeing the precision of the angular velocity-torque curve.

To reveal the evolution of pore structure damage of cement-based materials under cyclic freeze-thaw (F-T) loads, a typical white cement mortar was used as a research object, and the pore structure of the mortar saturated with water under certain F-T cycles was characterized by the low-field magnetic resonance (LF-NMR) spectroscopy. Mortar specimens were cured at 20℃ and 80℃ to yield the different initial pore structures, and suffered from fast and low F-T loads. The results show that the F-T resistance of mortar decreases, the distributions of the gel pores and the macro-capillary pores increase, but those of the meso-capillary pores maintain when curing in hot water at 80℃. By contrast, F-T load has a slight impact on the gel pores and macro-capillary pores, and enhances the distribution of micro-cracks. The rate of rising the micro-cracks under F-T loads for the mortar specimens cured at 80℃ is greater than that for the mortar specimens cured at 20℃. F-T rate has little influence on the pore structure evolution of the mortar. The micro-crack ratio is bi-linearly related to the mass loss ratio. The internal deterioration and surface spalling of the mortar under F-T loads are mainly induced by the generation and development of the micro-cracks in the mortar matrix, showing no direct association with the gel pores and macro-capillary pores.

A three dimensional(3D) model and a thin-film model were proposed for the glass ribbon forming process in float process. The forming process of glass ribbon in a 600 t/d tin bath was simulated via a software named Ansys Polyflow. Compared to the 3D model, the thin-film model is demonstrated to be more accurate and effective for the simulation of glass ribbon forming process. According to the simulation results, the forming process of glass ribbon in each zone of the tin bath was discussed. The influences of longitudinal and transverse temperature distributions on the forming process were analyzed for glass ribbons with different thicknesses. Finally, the optimized forming temperature condition is obtained for glass ribbon with a thickness of 4 mm or 10 mm, respectively.

A creep prediction model of concrete considering the viscoelasticity of interface transition zone was proposed based on the Laplace transform principle to analyze the influence of interface transition zone on the creep performance of concrete. The proposed model was compared with a model of concrete creep non-considering interface transition zone and verified by the related experiments. The results show that the data predicted by the concrete creep model considering the interfacial transition zone is consistent with the experimental results. The model can be used to analyze the effect of interface transition zone on the creep properties of concrete besides the experiments. The specific creep of concrete specimens with different fly ash contents (i.e., 0, 30% and 60%) is increased by 45.7%, 25.1% and 66.7%, respectively, when the loading age is 365 d due to the interface transition zone. The contribution of the interface transition zone of concrete specimens with different fly ash contents to the creep of concrete at different loading ages was analyzed via the prediction by the model. The interfacial transition zone of concrete with fly ash to the concrete creep contributes greater than that without fly ash. The interface transition zone of the baseline group in the later period has an increasing contribution to the concrete creep due to the continuous weakening of the interface transition zone under the load. For the concrete specimens with fly ash, the interface transition zone continuously enhances and the contribution of the interface transition zone to the creep of concrete continuously reduces with the increase of loading age because of the fly ash secondary hydration. The analysis of the influence of interface transition zone parameters on the concrete creep indicates that the concrete creep of different interface transition zones can be well described when the interface transition zone elasticity constant is in the range of 0.000 1<E_itz<0.01 and the viscosity coefficient is in the range of 0.1<η_itz<10.

Cementitious composites are inevitably to be cracked in engineering structures due to their inherent brittleness and low tensile strength. The capsule-based self-repairing system provides a feasible method for repairing and delaying the potential damage of cement-based material matrix. The occurring, spreading and fracturing process of micro-cracks and microcapsules fracture behavior in the self-repairing model material were simulated by an extended finite element method, and the hitting probability was validated. Meanwhile, the effective elastic modulus of self-repairing cementitious materials before and after repairing by spherical/spherical microcapsules with different contents was calculated via composite materials theory, and the repairing efficiency was characterized.

HZSM-5 zeolite was modified with levulinic acid produced in situ via glucose hydrolysis, and the catalysts were characterized by X-ray diffraction, X-ray fluorescence spectroscopy, N₂ adsorption-desorption, scanning electron microscopy, NH₃-temperature programmed desorption, Fourier transform infrared spectroscopy and thermal analysis. The catalytic performance was evaluated in a fixed-bed micro reactor. The results show that the modified HZSM-5 catalyst has a microporous-mesoporous structure based on the retaining complete crystal structure, its acid content and acid strength decrease and the ratio of B acid to L acid increases, which are conducive to improving the catalyst longevity, oil yield and total selectivity of benzene, toluene and xylene (BTX). At 410℃, 0.1 MPa and methanol (WHSV) 2.2 h^-1, the longevity of modified HZSM-5 catalyst reaches 174 h, the oil phase yield is 23.84%, and total selectivity of BTX is 61.39%. Compared to the unmodified catalyst, the longevity of modified HZSM-5 catalystis increased by 144 h, oil yield is increased by 7.29%, and total selectivity of BTX is increased by 3.42%.

Influence of silane emulsion hydrophobic agent as an additive on the strength and capillary water absorption behavior of concrete was investigated through strength test, hydration heat test, thermogravimetric analysis, capillary water absorption and mercury intrusion test. The results show that silane emulsion reduces the early-age compressive strength and splitting strength of concrete, which is mainly attributed to the retardation effect of silane emulsion on the early cement hydration. The capillary pore volume in 28-d harden cement paste is increased by adding silane emulsion because of the depressed cement hydration. However, the initial water absorption rate, the secondary water absorption rate and the total amount of water absorption of the 28-d concrete during capillary water absorption process are greatly reduced by silane agent. This is since silane emulsion reacts with cement hydration products to form an alkyl hydrophobic layer on the pore wall of the capillary pores, which changes the surface property of the wall from hydrophilic to hydrophobic, thus significantly reducing the rate and the amount of water absorption of concrete. Silane agent has a more profound influence on the concrete properties with a higher water-cement ratio due to the lager capillary pore volume.

Lightweight ultra-high performance concrete (LUHPC) was prepared with pre-wetting lightweight aggregate, Portland cement, silica fume, fly ash microsphere, steel fiber and expansion agent as raw materials. The influencing factors on the performance of LUHPC and the developing mechanism were investigated. The results show that the as-prepared LUHPC has a superior performance. The LUHPC can be self-compacting and has a low dry apparent density of 2 040 kg/m³. The 28-d compressive strength and flexural strength are 120 MPa and 18 MPa, respectively. The bending toughness index is 21.8, and the 56-d shrinkage rate is 2.62×10^-4. The superior performance of the LUHPC is mainly due to the ball effect of fly ash microsphere, the lightening, internal curing, "arch-shell" structure effects of pre-wetting lightweight aggregate and the shrinkage-compensating effect of expansion agent.

To clarify the dissolution behavior of K-containing silicate fertilizers produced by high-temperature sintering under acidic condition, the chemical element release and mineral evolution were investigated at ambient temperature in the extractants of hydrochloric and citric acids based on the chemical reactions of minerals contained in silicate fertilizer with acids. The results show that the more elements are released at a lower pH value of extractant. 2% citric acid with pH 2.1 is significantly more effective in dissolving the silicate fertilizer than hydrochloric acid with the same pH value. The dissolution rate of silicate fertilizer in hydrochloric acid at pH value of 0.3 is maximum, and only a mineral detected in the filter residue is leucite. Kaolinite and gibbsite are formed in the reactions of kalsilite and gehlenite with acid. Aluminum release is due to the further reactions of kaolinite and gibbsite with acid.

Foam concrete as one of the most widely used and investigated construction materials with integrated structural insulation has various unique properties such as low self-weight, fire resistance and air borne sound insulation. The compressive strength and thermal conductivity of foam concrete are the key factors affecting the application. The compressive strength of foam concrete increases while the thermal conductivity decreases with the increase of the density, thus hindering the application. In this review, the effects of foaming agent, density, porosity, admixture and water cement ratio on the compressive strength and thermal conductivity were discussed. Recent research work on lightweight foam concrete and integration of thermal insulation structure foam concrete were summarized. The existing problems (i.e., collapse of the slurry, incompatibility of mechanical and heat preservation properties and low durability) and the corresponding solutions to the problems were given. This review could provide a basis for future investigation and practical engineering application.

An appropriate amount of carbon nanotubes can be added into cement-based materials to obtain the unique conductive properties (i.e., self-sensing and intelligence of cement-based material). The electrical conductivity of carbon nanotube cement-based composites is affected and restricted by some factors such as physical field and material composition. Some recent works on influencing factors on electrical conductive properties of carbon nanotubes-reinforced cement based composite materials were reviewed. For the electrical indicators such as resistivity and current of composites, the mechanism of the physical field influencing the conductive properties of composites was analyzed. The effect of material component on the conductive mechanism of carbon nanotube cement-based composites was discussed. The problems to be further investigated were proposed, and the future research and trends of the conductive properties of carbon nanotube cement-based composite materials were prospected.

Admixtures play an important role in concrete engineering. The performance of admixtures is highly dependent on their releasing behavior. With the introduction of controlled release technology, the efficiency of admixtures is improved and the adverse effects caused by premature release is reduced, which are beneficial to the quality control of concrete. This review summarized the concept and classification of controlled release technologies and introduced recent work on controlled release technology in the field of concrete admixtures. The controlled release mechanism of concrete admixtures is also represented based on passive and active responses.

Concrete cracks will affect the building appearance and the structural safety. A novel type of concrete microbial self-healing material with the unique mineralization metabolic mechanism of bio-mineralizing bacteria can be used to repair concrete cracks intelligently and obtain the self-awareness and self-healing of concrete materials. This novel concrete microbial self-healing material can replace the conventional concrete with some disadvantages like poor repairing effect, high cost and even heavy environmental pressure. Recent development on the overall evolution, frontier hotspots and applications of this environment-friendly material by CiteSpace and knowledge map technology was represented.