Current status and technology development in implementing low carbon emission energy on underground coal gasification (UCG)

Although coal mining has played a substantial role in world’s development as a critical fuel source for at least 25 years, its value is partly offset by the massive environmental issues it presents during combustion. The shift to a net-zero CO2 emission will open unique possibilities for new coal technological models in which progressive studies and policies, development, and modernization will play a significant role. Therefore, a collection of technologies has been proposed, one of which is cost-effective is the Underground Coal Gasification (UCG) coupled with carbon capture storage (CCS) and utilization technology (CCU) UCG-CCS/CCU. This paper reviews the current status and technology development in implementing low carbon emission energy on underground coal gasification. The study, therefore, leads to discussing the modern stage of underground coal gasification and carbon capture storage development, recent pilot operations, and current developments of the growing market. At the same time, it provides a reference for underground coal gasification combined with CCUS technology

A potential therapeutic drug for osteoporosis: prospect for osteogenic LncRNAs

Long non-coding RNAs (LncRNAs) play essential roles in multiple physiological processes including bone formation. Investigators have revealed that LncRNAs regulated bone formation through various signaling pathways and micro RNAs (miRNAs). However, several problems exist in current research studies on osteogenic LncRNAs, including sophisticated techniques, high cost for in vivo experiment, as well as low homology of LncRNAs between animal model and human, which hindered translational medicine research. Moreover, compared with gene editing, LncRNAs would only lead to inhibition of target genes rather than completely knocking them out. As the studies on osteogenic LncRNA gradually proceed, some of these problems have turned osteogenic LncRNA research studies into slump. This review described some new techniques and innovative ideas to address these problems. Although investigations on osteogenic LncRNAs still have obtacles to overcome, LncRNA will work as a promising therapeutic drug for osteoporosis in the near future

Evaluation of Innovation and Entrepreneurship Ability of Computer Majors Based on Neural Network Optimized by Particle Swarm Optimization

The current evaluation index systems (EISs) of innovation and entrepreneurship (I&E) ability are not sufficiently systematic, scientific, or practical. To solve the problem, this paper tries to evaluate the I&E ability of computer majors, using neural networks improved by particle swarm optimization (PSO). Firstly, an EIS of 22 second-level indexes under 5 first-level indexes was designed to evaluate the I&E ability of college computer majors. Next, an evaluation model was developed based on fuzzy neural network (FNN), and the corresponding training algorithm was created. Moreover, an improved PSO was introduced to optimize the FNN, and the optimization process was detailed. The proposed model was proved effective through experiments

Experimental Study on Novel Energy-Dissipating Prefabricated Beam-Column Joints

A new dapped-end beam to column connection is designed in this paper. Its assembly connection zone changes from inside the joint to midspan of the beam. The proposed connection can not only provide good structural integrity but also ensure that the plastic hinge moves away from the column edge. The rotational capacity of the plastic hinge determines the internal force redistribution of the joint and the energy dissipation capacity. The high-strength bolts and steel plates are used to realize connection, further enhancing the rotation of the plastic hinge and minimizing the cast-in-place concrete volume. Three full-scale exterior beam to column joints are casted and then subjected to reversal cyclic loading. The finite element (FE) analyses are carried out to compare with experimental results and study the effect of connection position on the structural behaviours. The obtained results show that the plastic hinges of all three specimens are firstly developed to a distance from the column edge, thus revealing that this kind of joint can achieve beam hinge mechanism and prevent joint shear failure. And the connection position is the most disadvantaged when coinciding with the plastic hinge zone, which would result in the excessive deformation and the early failure of the steel bar anchor system. The new type of joint shows good seismic performance during earthquake if the connection can be properly designed, and thus this kind of structural form can be applied to actual engineering structures in seismic regions

金属镁的氧化及氧化机理研究进展

As the lightest commercial metal structure material, magnesium alloy shows a wide application prospect in aerospace, automobile, 3C pro-ducts and other fields. At the same time, it is of great strategic significance to promote the application of magnesium alloy materials, in the face of the increasing shortage of iron and aluminum resources in the world and the dilemma of a large number of imported iron and aluminum ores. Compared with common steel and aluminum alloy, the research and development of magnesium alloy are not enough, and its application is also limited. The poor corrosion resistance of magnesium alloy is partly due to the high chemical activity of magnesium and the lack of protective effect of the film formed on the surface. Especially at high temperature, magnesium and its alloys are easy to oxidize, even burn, and release a lot of heat, which has become one of the bottlenecks limiting the extensive application of magnesium alloys. In recent years, a lot of researches have been carried out on the oxidation mechanism and influencing factors of magnesium and its alloys. It is considered that the oxidation of magnesium alloy is affected by factors, such as P-B value of oxide film, evaporation and diffusion of magnesium and so on. At present, the oxidation resistance of magnesium is improved by alloying. This provides theoretical support for the preparation of magnesium alloy with high oxidation resistance. At the same time, it expands the application prospect of magnesium alloy at high temperature, and will bring huge economic benefits to magnesium alloy industry. This paper summarizes the research progress of oxidation characteristics and mechanism of magnesium and its alloys at home and abroad. Firstly, the oxidation of magnesium is briefly introduced. Secondly, the mechanism and influencing factors of magnesium oxidation are analyzed, and the influence rules and mechanism of P-B value, diffusion, evaporation, microstructure and alloy elements on the oxidation behavior of magnesium are emphatically discussed. Finally, the shortcomings of the current research are summarized, and suggestions on the research direction of magnesium oxidation resistance are put forward

The Difference between Plasmon Excitations in Chemically Heterogeneous Gold and Silver Atomic Clusters

Weak doping can broaden, shift, and quench plasmon peaks in nanoparticles, but the mechanistic intricacies of the diverse responses to doping remain unclear. In this study, we used the time-dependent density functional theory (TD-DFT) to compute the excitation properties of transition-metal Pd- or Pt-doped gold and silver atomic arrays and investigate the evolution characteristics and response mechanisms of their plasmon peaks. The results demonstrated that the Pd or Pt doping of the off-centered 10 × 2 atomic arrays broadened or shifted the plasmon peaks to varying degrees. In particular, for Pd-doped 10 × 2 Au atomic arrays, the broadened plasmon peak significantly blueshifted, whereas a slight red shift was observed for Pt-doped arrays. For the 10 × 2 Ag atomic arrays, Pd doping caused almost no shift in the plasmon peak, whereas Pt doping caused a substantial red shift in the broadened plasmon peak. The analysis revealed that the diversity in these doping responses was related to the energy positions of the d electrons in the gold and silver atomic clusters and the positions of the doping atomic orbitals in the energy bands. The introduction of doping atoms altered the symmetry and gap size of the occupied and unoccupied orbitals, so multiple modes of single-particle transitions were involved in the excitation. An electron transfer analysis indicated a close correlation between excitation energy and the electron transfer of doping atoms. Finally, the differences in the symmetrically centered 11 × 2 doped atomic array were discussed using electron transfer analysis to validate the reliability of this analytical method. These findings elucidate the microscopic mechanisms of the evolution of plasmon peaks in doped atomic clusters and provide new insights into the rational control and application of plasmons in low-dimensional nanostructures

Modelling and Simulation of Vessel Surgery based on Mass-spring

As the technology developing, precision and accuracy required in medical surgery can be realized through virtual-reality technology in computer aided systems, so that it can satisfy with medical experiments and teaching. In surgery simulation on soft tissues, Mass-spring takes the important roles on simulating the surface transformation of tissues. In this article, we established an intelligent simulation platform for surgery of vein in which includes the transformation based on Mass-spring. This platform can provide good human-computer interface and control some simple motions. It is convenient for medical teaching to instruct the operation scene

Modelling and Simulation of Vessel Surgery based on Mass-spring

As the technology developing, precision and accuracy required in medical surgery can be realized through virtual-reality technology in computer aided systems, so that it can satisfy with medical experiments and teaching. In surgery simulation on soft tissues, Mass-spring takes the important roles on simulating the surface transformation of tissues. In this article, we established an intelligent simulation platform for surgery of vein in which includes the transformation based on Mass-spring. This platform can provide good human-computer interface and control some simple motions. It is convenient for medical teaching to instruct the operation scene

Fabrication, microstructure, and thermal conductivity of multilayered Cu mesh/AZ31 Mg foil composites

In this study, multilayered Cu mesh/AZ31 Mg foil composites were designed and fabricated by diffusion bonding in a closed graphite mold at 400–445 °C. The effects of temperature on the microstructure of the joints formed and the thermal conductivity of the composite was evaluated. The mechanism responsible for the observed improvement in thermal conductivity was analyzed. After diffusion bonding, the thermal conductivity of the multilayered composite was as high as 122.3 W/m·K at room temperature (25 °C), which is 109.4% higher than that of the AZ31 Mg alloy (58.4 W/m·K) fabricated using the same process. Moreover, the fabricated Mg matrix composites had a maximum density of 2.21 g/cm3, indicating that they were lightweight. A continuous film-like structure composed of intermetallic compounds and α-Mg region with good contribution to heat conduction has been found, which has a reference for the design and fabrication of high-thermal-conductivity Mg matrix composites