Applications, evaluations, funding, and management of National Natural Science Foundation of China programs on inorganic nonmetallic materials in 2021 were summarized and statistically analyzed. The specific measures of inorganic nonmetallic materials on scientific fund reform, talents and academic teams, academic exchange and seminars, in-depth researches on the 14^th five-year and medium and long-term development plan were introduced detailedly.

A composite of porous carbon coated Li₄Ti₅O₁₂ was prepared by a hydrothermal synthesis and high-temperature activation method. The microstructure and electrochemical properties of the composite were investigated. The results show that Li₄Ti₅O₁₂ is completely coated on the porous carbon layer. Meanwhile, the surface pores of Li₄Ti₅O₁₂@porous C composite are evenly distributed, and the carbon layer thickness is approximately (8.5±3.6) nm. The discharge capacity at first cycle is 363 mAh/g, which is approximately twice greater than that of pure Li₄Ti₅O₁₂. The AC impedance value of Li₄Ti₅O₁₂@porous C composite decreases, which is only the half of that of pure Li₄Ti₅O₁₂. The discharge specific capacity of Li₄Ti₅O₁₂@porous-C composite is 251 mAh/g and the retention rate is 97.7 % after 200 cycles (i.e., the specific capacity of pure Li₄Ti₅O₁₂ is 143 mAh/g and the retention rate is 94.7%), the discharge specific capacity is nearly doubled, especially when the rate test is carried out at different discharge rates. The reversible capacity is twice greater than that of Li₄Ti₅O₁₂. The porous carbon coated modification of Li₄Ti₅O₁₂ can increase the specific surface area and the electron transfer rate for the higher electrochemical properties.

The thermal conductivity of cement paste with different water-cement ratios and curing ages were measured. Moreover, the thermal conductivity of cement paste was predicted by parallel model, series model, Maxwell model, MT model, EMT model and SC model, respectively. In addition, the thermal conductivity of each phase in cement paste was calculated by a molecular dynamics method. The results show that the thermal conductivity of cement paste decreases with the increase of curing age and water-cement ratio. SC model can be used to predict the thermal conductivity of cement paste at different water-cement ratios or curing ages, and the relative error between the predicted and the experimental values is 0.3%-4.7%. The Maxwell model and MT model can be used to calculate the thermal conductivity of cement paste at a large water-cement ratio and a long curing age.

Microwave absorbing materials are widely used in military and civil fields. The current research focusses on novel microwave absorbing materials with intense absorption, wide bandwidth, light weight and thin thickness. Black phosphorus (BP) and sulfur-doped black phosphorus (BP-S) crystals were prepared at a high temperature and a high pressure, and then BP and BP-S nanosheets were obtained via liquid-phase exfoliation. Compared with BP, the complex permittivity and ε_r″/ε_r′ of BP-S are enhanced at 1.0-16.5 GHz. The minimum reflection loss (RL) reaches -41.4 dB at 9.6 GHz, and the RL exceeding -10 dB in a frequency range of 7.0 to 16.1 GHz is obtained for the absorber thickness of 1.0-2.0 mm. The minimum RL frequency dependence of the absorber thickness for BP-S comply with a λ/4 matching model. BP-S has broad application prospects as a high-performance microwave absorbing material.

Cement-based materials are brittle and easy to crack, which are concerned as the key problems to be solved in engineering application. The microscale brittleness of the material phases of cement-based materials needs to be investigated, and a relationship between the micro-scale brittleness and the overall brittleness needs to be established for the toughening design of cement-based materials. In this work, the fracture toughness-displacement curves were obtained via micro-scratch test, and the phases corresponding to the scratch area were analyzed by high resolution scanning electron microscopy, thus charactering quantitatively the fracture toughness of cement paste and its material phases, and establishing the relationship between the overall brittleness of cement paste and the brittleness of calcium silicate hydrate gel.

To ascertain the influences of bentonite and its content on the printability of 3D printing mortar, the extrudability of mortar was evaluated via fluidity, and its buildability was evaluated by height retention rate and penetration resistance. Also, the rheological behavior of cement pastes with bentonite was characterized via dynamic and static shear tests. Effects of bentonite and its content on the printability of mortars were analyzed via rheology. The results show that the fluidity of printable mortars is linearly correlated to the plastic viscosity of cement pastes and logarithmically to the dynamic yield stress of cement pastes. Besides, there is an exponential relationship between the height retention rate of printable mortars and the static yield stress of cement pastes. The addition of bentonite in the mortar increases the plastic viscosity and dynamic yield stress of cement pastes, resulting in a decrease in the extrudability of mortar. Also, the addition of bentonite improves the static yield stress and structural rebuilding rate of cement pastes, thereby improving the buildability of mortar. Therefore, appropriate amount of bentonite can make the mortar maintain good extrudability while improving its buildability. A width ratio between the top and bottom layers of the printed sample with 2% bentonite is 0.96.

The mechanical properties, hydration process and microstructure characteristics of the calcined hydrotalcite modified cementitious material at different fly ash contents were analyzed. Based on the results by the compressive strength test calcined hydrotalcite can greatly improve the compressive strength of cement-fly ash mortar. The phase composition of hardened cement paste was characterized by X-ray diffractionand and thermogravimetric analysis. The results show that calcined hydrotalcite can promote the hydration of cement-fly ash cementitious materials, thereby increasing the content of hydration products. It is incidiacted that calcined hydrotalcite can accelerate the dissolution of fly ash, and its nucleation effect is beneficial to the formation of hydration products.

The residual effect of fractured glass, which is greatly affected by its fracture morphology, is correlated to the post-fracture performance of laminated glass. For tempered glass in laminated glass, its fracture morphology is affected by some major variables such as surface compressive stress, thickness, and fracture point. However, a few previous work concerning the fracture morphology characterization are reported. In this paper, fragmentation tests were firstly conducted on 81 tempered glass specimens. The fracture morphology and spatial distribution, including fragment area, perimeter, circularity and distribution intensity, were analyzed. The fracture morphology and spatial distribution obtained at the given variables (i.e., surface compressive stress of 60-105 MPa, thickness of 6-12 mm, three fracture points) were discussed. Also, a new seeds generation approach for the centroid of fragments to control nearest neighbor distance and global distribution intensity of fragments was proposed, which was combined with the Voronoi tessellation to characterize the fracture morphology of tempered glass. The proposed method has a satisfactory accuracy in generating the fracture morphology.

The fatigue properties of ultra-high performance concrete (UHPC) at 20 ℃ and -10 ℃ were investigated via flexural fatigue tests under different stress levels. The results show that, the degradation of UHPC flexural fatigue performance and the fatigue strength decrease under a cyclic load with the decrease of temperature due to the cold brittleness characteristics of steel fibers at the cracked section. Compared with the test results at 20 ℃, the fatigue strength of UHPC at -10 ℃ is decreased by 15.6%. Although the fatigue strength of the specimens at a low temperature is lower than that of the specimens at normal temperature, their fatigue deformation modulus ratios (E_n/E₀) corresponding to their fatigue strengths are similar, which are 0.48. The residual strength of UHPC specimens undergoing 2 million cycles without flexural fatigue failure is close to the static strength under monotonic loading, at normal temperature or low temperature. Based on the results, a model of predicting the fatigue life of UHPC at 20 ℃ and -10 ℃ was proposed, and the predicted results could be used as reference in the practical application.

Carbonatable calcium silicate cementitious material is a novel low-carbon building material with a great potential for development. γ-dicalcium silicate is one of the most carbonation reactive minerals among calcium silicates. In this paper, a wet powder of γ-dicalcium silicate was used as an experimental material. The influences of reaction duration, particle size, relative humidity, temperature, partial pressure and water-to-solid ratio on the degree of carbonation were investigated. The carbonation kinetic equation was proposed based on the modified shrinking-core model and empirical equation. It is indicated that the data predicted by the kinetic model are in reasonable agreement with the experimental results. The obstruction of ions diffusion attributed to the coating of carbonation products is a major factor of controlling the carbonation reaction.