To reduce the viscosity and promote the workability of ultra-high performance concrete (UHPC), this paper selected aminosilane (KH550) with a hydrophilic functional group as auxiliary admixtures for UHPC mixtures. The effects of the mixture ratio and dosage of hydrolyzed silane on the mechanical properties and rheology of UHPC were investigated. The silane modification mechanism of UHPC was discussed. The results show that KH550 is suitable for hydrolysis in the mixed solvent of anhydrous ethanol and deionized water (or tap water). The optimum hydrolysis ratio (mass ratio) is determined as m₁ (KH550): m₂ (deionized water or tap water): m₃ (anhydrous ethanol)=1.0∶3.0∶(2.5-5.0). The hydrolysis process is carried out under stirring for 3 min and hydrolyzed for more than 2 h. The optimum silane content in UHPC (calculated according to a mass ratio with silica fume in UHPC) is 1%. The Bingham model can be used to describe the rheological behavior of fresh UHPC modified by hydrolyzed silane. The rheological properties of fresh UHPC modified by hydrolyzed silane are improved, but the effect on the mechanical properties is ignored.

To thoroughly study and implement General Secretary Xi Jinping's important expositions on scientific and technological innovation and basic research, and to actively implement and deepen the reform implementation plan of National Natural Science Foundation of China, the inorganic nonmetallic materials of the department of engineering and materials science piloted a series of reform measures on original projects. This paper deeply analyzes the applications and funding status of projects in the category of "Encourage exploration and highlight originality" on inorganic nonmetallic materials from 2019 to 2022 and in the original discovery program from 2020 to 2022. The innovative reform measures and initial results achieved are also introduced. Finally, based on the characteristics of the discipline and the connotation of the original project, some suggestions and thoughts are proposed to further optimize the funding mechanism and to continuously stimulate the original innovation.

Incorporating magnesia expansive agents (MEA) into concrete is one of the effective ways to solve the deterioration of concrete performance due to cracking caused by shrinkage. S-type MEA can provide a stable micro-expansive to compensate for shrinkage of concrete over a long period of time because of the low activity of hydration, which is widely used in engineering. In this paper, S-type MEA was mixed with concrete at different MEA contents (i.e., 4%, 5% and 6%, mass fraction). The effect of MEA on the microstructure and macroscopic properties (i.e., mechanical, shrinkage and durability) of concrete was investigated. The results show that the crystal growth of the hydration product magnesium hydroxide expands the microscopic pores of concrete with MEA, and the porosity of concrete increases from 7.93% to 10.63% at 28 d when the MEA content is 5%. Therefore, the concrete strength before 28 d and the resistance to chloride ion penetration are reduced. Also, the content of pores in the range of 10-50 nm decreases, thus improving the shrinkage performance of the concrete. The autogenous shrinkage is reduced by 25.66%, 18.58% and 46.02% when the MEA content is 4%, 5%, and 6%, respectively. As the MEA hydrates continuously, the gradual filling effect of magnesium hydroxide reduces the porosity and improves the strength of concrete with MEA. However, swelling from un-hydrated MEA is coupled with the effect of either freeze-thaw cycles or sulfate attack with increasing the MEA content, thus having a negative effect on the durability of concrete. In addition, the shrinkage model and chloride ion permeability coefficient model of concrete with MEA were also proposed to predict the long-term performance of concrete, thus having a certain guiding value on the engineering applications.

This paper was to synthesize C-S-H with different Ca/Si ratios by a hydrothermal synthesis method, and decalcify it using 6 mol/L NH₄Cl solutions. The chemical composition, chain structure and microstructure were analyzed. The results show that C-S-H is a gel structure formed by irregular aggregates. The content of dimer and chain end groups in C-S-H increases, while the average degree of polymerization and average chain length decreases with the increase of Ca/Si ratio. The change of C-S-H structure includes decreased interlayer distance, cross-linked silicate chains, and amorphous silica gels formed after decalcification, resulting in the loss of C-S-H cohesion.

Diamond as a representative of ultra-wide bandgap semiconductor material has attracted recent attention. Although some progress is made in material preparation, device development and performance, semiconductor doping technology is not resolved so far. Hydrogen-terminated (C-H) diamond is widely used in microwave power devices due to its typical two-dimensional hole gas, but it has some problems such as poor stability and high interface state concentration. In contrast, silicon-terminated (C-Si) diamond that emerged in recent years has some advantages of lower interface state density, higher threshold voltage, carrier density, and stability rather than C-H diamond. C-Si diamond electronics exhibit the enhanced properties with high threshold voltages through an unclear mechanism. This review analyzed the structure and conduction mechanism of C-H diamond, the main problems that limit its development, represented the conduction mechanism, preparation method and corresponding interface structure of C-Si diamond, and discussed the performance level of C-Si diamond MOSFETs. In addition, the existing problems in the development of C-Si diamond were also discussed, and its future development was prospected.

To analyze the triaxial mechanical properties of coral seawater sea sand concrete, the effects of aggregate and lateral confining pressure on the failure mode, stress-strain curve, yield stress, yield strain, and damage evolution of specimens were investigated via conventional triaxial tests. The results show that the coral coarse aggregate specimen is more susceptible to the influence of confining pressure value. The cracks form transformation and plastic flow appear on the surface of the specimen at a confining pressure value of 9 MPa. The stress-strain curve appears a stress platform section' at a confining pressure value of 12 MPa, while the gravel coarse aggregate specimen appears the above changes at confining pressure values of 15 MPa and 24 MPa, respectively. After a confining pressure value reaches 15 MPa, the stress-strain curve of the coral coarse aggregate specimen shows a bilinear shape with a second linear branch. The dissipation energy of the specimens gradually increases and the damage development gradually delays with the increase of confining pressure, yield stress and yield strain. In addition, the yield stress calculation formula of coral seawater sea sand concrete was aslo proposed, thus providing a reference for the relevant theoretical analysis and engineering application.

Magnesium phosphate cement (MPC) can be used to solidify heavy metal ions in hazardous waste, and the introduction of heavy metal ions can significantly reduce the long-term mechanical properties of the solidified body. A method for strengthening MPC solidification of Pb²⁺ by adding K-struvite was proposed to solve the problem of the mechanical property loss in the later stage of MPC solidification and ensure that the toxicity leaching meets the requirements. The results show that the leaching concentrations of K-struvite enhanced the MPC solidification of Pb²⁺ at 28 d and 180 d are 0.63 mg/L and 1.91 mg/L, the compressive strength at 180 d is similar to that of MPC uncured Pb²⁺ (without K-struvite), thus improving the mechanical properties of MPC and meeting the toxicity leaching requirements. The strengthening/solidification effect of K-struvite is mainly due to the improvement of the compactness and adsorption of the solidified body, improving the long-term solidification effect on Pb²⁺.

A coral sand cement mortar was prepared with 2.0% SiO₂ nanoparticles, 0.4% basalt fiber and artificial seawater. The impact compression strength of the samples at different confining pressures (i.e., 0-20 MPa) was determined by using a split Hopkinson pressure bar with an active confining pressure device. The dynamic mechanical properties of SiO₂ nanoparticles reinforced coral sand cement mortar were analyzed at different confining pressures and strain rates. The results show that the failure pattern of unconfined (uniaxial impact) specimens occurs, indicating the brittle characteristics. The better integrity of the specimen after being impacted appears under the active confinement, which belongs to a compressive-shear failure. Moreover, the specimen undergoes a transition from brittle to plastic, thus improving the toughness. From the obtained dynamic stress-strain curve, the strength of the specimen is increased by 2.08-3.43 times, compared to that under static conditions, and the dynamic compressive strength is 1.88-2.35 times greater than that of unconfined (uniaxial impact) specimens. The relevant empirical formulas were obtained via analyzing the dynamic increase factor and confinement increase factor of the material and their corresponding effects on strain rate and confining pressure variation. At the same confining pressure, the specific energy absorption of materials shows a linear increase with the incident wave energy. Through the analysis of energy dissipation, the confining pressure can increase the specific energy absorption value of SiO₂ nanoparticles reinforced coral cement mortar.

Low silicon aluminum ratio X molecular sieve (LSX) modified by lithium is widely used in the field of pressure swing adsorption (PSA) due to its high N₂ adsorption capacity and nitrogen-to-oxygen separation ratio. However, the price of raw materials for the LSX synthesis increases, resulting in a higher production cost. Potassium feldspar (i.e., KAlSi₃O₈) is rich in aluminum oxide and silicon oxide, and potassium can also be used as a structural guide agent for LSX as an ideal raw material that can greatly reduce the production cost for the LSX synthesis. LSX was synthesized by using seed crystal as a guiding agent with a potassium feldspar from Songxian, China as a raw material, which was firstly calcined and activated at a high temperature. The effects of silicon aluminum ratio (n(SiO₂/n(Al₂O₃)), alkali silicon ratio (n(Na₂O+K₂O)/n(SiO₂), water alkali ratio (n(H₂O)/n(Na₂O+K₂O)), amount of seed guide agent (ω_SDA), crystallization temperature (T_cry), and crystallization time (t_cry) on the structure and properties of samples were investigated. The results show that when n(SiO₂)/n(Al₂O₃)=2.1-2.2, n(Na₂O+K₂O)/n(SiO₂)=2.0-2.2, n(H₂O)/n(Na₂O+K₂O)=35-40, ω_SDA=3%-5%, T_cry=90-100 ℃, t_cry=10-14 h, the obtained LSX molecular sieve has a high crystallinity, and a uniform morphology, and the exchange degree of Li⁺ can reach 98.7%, which obtain the properties for nitrogen and oxygen adsorption separation in industry.