Xuzhou Institute of Technology

About: Xuzhou Institute of Technology is a education organization based out in Xuzhou, China. It is known for research contribution in the topics: Catalysis & Computer science. The organization has 1696 authors who have published 1521 publications receiving 13541 citations.

Research and application on new type grouting material and control technology

Abstract: A kind of special grouting material, which is called QS-X material is put forward to solve the problem of grouting enhancement and some feature of QS-X material is investigated by author in this paper. In order to investigate the new type grouting material and realize the aim of enhancement, anti-seepage, anti-dynamic loading and anti-deformation about surrounding rock. A kind of key composing material, which has functions of swelling enhancement, anti-crack and waterproof, is designed, and mechanical property test is carried out. Through water absorption and swelling force experiment of QS-X material, linear equation of moisture content and swelling force is summed up; Through water absorption rate and expansion ratio experiment, different types of linear equations of moisture content and expansion ratio are summed up. Through confining stress—strain experiment, different types of stress—strain equations are summed up. Industrial test and monitoring results can show that, wall back filling and grouting reinforcement technique has a effect of waterproof, anti-seepage, anti-dynamic loading, which may be a good method for waterproof and dynamic support of underground engineering.

Coupling Effect of Strain Rate and Freeze-Thaw Temperature on Dynamic Mechanical Properties and Fractal Characteristic of Saturated Yellow Sandstone

Abstract: Strain rate is not only an important influence factor for deformation property but also an important parameter for analyzing the dynamic mechanical behavior of rock material. In this study, the dynamic compressive mechanical properties of saturated yellow sandstone at four strain rates and six freeze-thaw temperatures are investigated by using the SHPB test system. The coupling effect of strain rate and freeze-thaw temperatures on the mechanical parameters of rock material are discussed in detail, and the relationship formula of peak strain and dissipated energy with strain rate and freeze-thaw temperature are also established. Finally, the fractal dimension characteristic of fracture specimens with the strain rate and temperature are analyzed by using the fractal dimension method. The research results indicate that (1) with the increase of strain rate, the increase speed of peak strain, peak strength, and dissipated energy at medium strain rate level was obviously higher than that at high strain rate level, indicating that the strain rate effect weakened at high strain rate. (2) Freeze-thaw temperature can improve the brittleness-ductile transformation rate of saturated specimens. (3) According to the strain rate sensitivity coefficient, at room temperature, the strain rate effects on peak strain and peak strength are weakest, while at -20°C ~ -30°C, they are most significant. In addition, the strain rate effect on dissipated energy is significant at room temperature, while weakest at -30°C. (4) The fractal dimension gradually increases with strain rate increasing or freeze-thaw temperature decreasing, indicating that the freeze-thaw environment has a positive function for increasing the damage and fracture degree of specimens for saturated specimen. Our research results can provide an extremely important theoretical basis for the dynamic disaster prevention and structural design of rock engineering in cold regions.

Electronic structures and magnetism of transition metal doped BiAlO3: An ab initio study

Abstract: We theoretically investigated the electronic structures and magnetic properties of transition-metal (Cr, Mn and Fe) doped BiAlO3 based on the first-principle calculations. We found that the manganese ions can make the ferroelectric material ferromagnetic while the insulating feature is preserved. The ferromagnetic coupling is further confirmed by applying a DFT+U method and explained in terms of the super-exchange mechanism between two Mn ions. Other transition metals (Cr and Fe) cannot induce ferromagnetism.

Influence of Paclobutrazol on the Growth and Photosynthesis of Sequoia sempervirens Seedlings

Abstract: Paclobutrazol (PAC), as a commonly used plant regulator, has the important function of improving the plant’s stress resistance. Sequoia sempervirens Endl. is a large caliber, fast-growing timber species and one of the world’s five major landscaping tree species. This study researched the effects of spraying PAC on the growth and photosynthetic activity of S. sempervirens seedlings. The results showed the plant height and the plant crown diameter were decreased significantly with the increase in PAC concentration (500 – 3,000 mg·dm⁻³). However, the ground shoot diameter, net photosynthetic rate, stomatal conductance, inter-cellular CO₂ concentration, transpiration rate, actual photochemical quantum yield, and photosynthetic electron transport rate all showed the trend of increasing first reaching the maximum at 2,000 mg·dm⁻³ and then decreased. Water use efficiency showed the opposite trend. Spraying 2 times was better than once. The conclusion suggests that PAC can protect the photosynthetic activity and improve the resistance of S. sempervirens seedlings under natural cooling and draught in autumn and winter.