Assumption about the inner surface of mold is made according to the forming mechanisms of frictional force. The frictional force between billet and mold can be analysed by calculating the thermal shrinkage and the she...Assumption about the inner surface of mold is made according to the forming mechanisms of frictional force. The frictional force between billet and mold can be analysed by calculating the thermal shrinkage and the shearing strength of the meniscus.The model is used to calculate the maximum drawing speed at different conditions. The results are very satisfactory.展开更多
The program to predict the microstructure evolutions during hot strip rolling of C-M n steels has been developed in this paper, BV using this program, the microstructure changes with the processing parameters were ana...The program to predict the microstructure evolutions during hot strip rolling of C-M n steels has been developed in this paper, BV using this program, the microstructure changes with the processing parameters were analysed in detail. showing not only a good agreement of prediction with the measured values, but also entirely possibility to optimize hot strip rolling precess by computer simulation展开更多
The cooling water flow rate for hearth of large blast furnaces was calculated by simulation. The results show that the cooling water flow rate shall be above 4 200m3/ h for hearth of large blast furnaces; to meet requ...The cooling water flow rate for hearth of large blast furnaces was calculated by simulation. The results show that the cooling water flow rate shall be above 4 200m3/ h for hearth of large blast furnaces; to meet requirements of the increasing smelting intensity and to ensure the safety at the end of the first campaign,the designed maximum cooling water flow rate should be 5 900m3/ h; according to the flow distribution stability and the calculated resistance loss,hearth cooling stave pipes with the specification of 76 mm × 6 mm shall be adopted to assure the flow velocity in pipes of hearth cooling stave in the range of 1. 9- 2. 3 m / s.展开更多
Through on-site defect investigation,special inspection,and finite element simulation calculation of a high-speed upper-span(30+32+30)m prestressed concrete box girder bridge,the overall sliding force of the bridge on...Through on-site defect investigation,special inspection,and finite element simulation calculation of a high-speed upper-span(30+32+30)m prestressed concrete box girder bridge,the overall sliding force of the bridge on the right side of platform 0#is analyzed.In this situation,typical defects such as overall girder slippage,support dislocation,pier column deviation,and pier bottom side cracks have occurred in the overpass.At the same time,combined with simulation calculation analysis,it is interpreted that the 0#and 1#foundation has been damaged at a certain position below the ground line.The occurrence of broken piles has provided a reliable basis for the later reinforcement and maintenance of the bridge and ideas for emergency inspection and analysis of bridges damaged by the same type of landslides.展开更多
This paper reports that the YBa2Cu3-xZnxO7-δ (x = 0-0.4) samples are researched by means of x-ray diffraction, calculations of binding energy, the positron experiments and variations of oxygen content. The results ...This paper reports that the YBa2Cu3-xZnxO7-δ (x = 0-0.4) samples are researched by means of x-ray diffraction, calculations of binding energy, the positron experiments and variations of oxygen content. The results of simulated calculations, positron experiments and variations of oxygen content support the existence of cluster effect. Moreover, it is concluded that the cluster effect is an important factor on suppression of high-Tc cuprate superconductivity and the Tc does not depend on the density of valence electron directly.展开更多
A metamaterial absorber is computed numerically and measured experimentally in a 150-THz^300-THz range.The measured absorber achieves high absorption rate for both transverse electric(TE) and transverse magnetic(TM...A metamaterial absorber is computed numerically and measured experimentally in a 150-THz^300-THz range.The measured absorber achieves high absorption rate for both transverse electric(TE) and transverse magnetic(TM) polarizations at large angles of incidence.An absorption sensor scheme is proposed based on the measured absorber and the variations of surrounding media.Different surrounding media are applied to the surface of the absorption sensor(including air,water,and glucose solution).Measured results show that high figure of merit(FOM) values are obtained for different surrounding media.The proposed sensor does not depend on the substrate,which means that it can be transplanted to different sensing platforms conveniently.展开更多
High-performance electromagnetic(EM)wave absorbers,covalently bonded reduced graphene oxideFe_(3)O_(4) nanocomposites(rGO-Fe_(3)O_(4)),are synthesized via hydrothermal reaction,amidation reaction and reduction process...High-performance electromagnetic(EM)wave absorbers,covalently bonded reduced graphene oxideFe_(3)O_(4) nanocomposites(rGO-Fe_(3)O_(4)),are synthesized via hydrothermal reaction,amidation reaction and reduction process.The microstructure,surface element composition and morphology of rGO-Fe_(3)O_(4) nanocomposites are characterized and corresponding EM wave absorption properties are analyzed in great detail.It demonstrates that Fe_(3)O_(4) nanoparticles are successfully covalently grafted onto graphene by amide bonds.When the mass ratio of rGO and Fe_(3)O_(4) is 2:1(sample S2),the absorber exhibits the excellent EM wave absorption performance that the maximum reflection loss(RL)reaches up to-48.6 dB at 14.4 GHz,while the effective absorption bandwidth(RL<-10 dB)is 6.32 GHz(11.68-18.0 GHz)with a matching thickness of 2.1 mm.Furthermore,radar cross section(RCS)simulation calculation is also adopted to evaluate the ability of absorbers to scatter EM waves,which proves again that the absorption performance of absorber S2 is optimal.The outstanding EM wave absorption performance is attributed to the synergistic effect between dielectric and magnetic loss,good attenuation ability and excellent impedance matching.Moreover,covalent bonds considered to be carrier channels can facilitate electron migration,adjust EM parameters and then enhance EM wave absorption perfo rmance.This work provides a possible method for preparing efficient EM wave absorbers.展开更多
Accurate battlefield collection plays a crucial role in the end of thewar. How to effectively improve the ability of accurate battlefield collection hasbecome a hot issue of research. However, the existing support for...Accurate battlefield collection plays a crucial role in the end of thewar. How to effectively improve the ability of accurate battlefield collection hasbecome a hot issue of research. However, the existing support force is limited. Tosolve the problem, an improved ant algorithm is applied to the path optimizationproblem of battlefield collection equipment. A model for solving the collectionpath optimization problem of battlefield collection vehicles was designed, andan example was used to simulate calculations. The final results show that thealgorithm is effective and practical,which improves the army’s ability to accuratelycollect equipment in the modern battlefield.展开更多
文摘Assumption about the inner surface of mold is made according to the forming mechanisms of frictional force. The frictional force between billet and mold can be analysed by calculating the thermal shrinkage and the shearing strength of the meniscus.The model is used to calculate the maximum drawing speed at different conditions. The results are very satisfactory.
文摘The program to predict the microstructure evolutions during hot strip rolling of C-M n steels has been developed in this paper, BV using this program, the microstructure changes with the processing parameters were analysed in detail. showing not only a good agreement of prediction with the measured values, but also entirely possibility to optimize hot strip rolling precess by computer simulation
文摘The cooling water flow rate for hearth of large blast furnaces was calculated by simulation. The results show that the cooling water flow rate shall be above 4 200m3/ h for hearth of large blast furnaces; to meet requirements of the increasing smelting intensity and to ensure the safety at the end of the first campaign,the designed maximum cooling water flow rate should be 5 900m3/ h; according to the flow distribution stability and the calculated resistance loss,hearth cooling stave pipes with the specification of 76 mm × 6 mm shall be adopted to assure the flow velocity in pipes of hearth cooling stave in the range of 1. 9- 2. 3 m / s.
文摘Through on-site defect investigation,special inspection,and finite element simulation calculation of a high-speed upper-span(30+32+30)m prestressed concrete box girder bridge,the overall sliding force of the bridge on the right side of platform 0#is analyzed.In this situation,typical defects such as overall girder slippage,support dislocation,pier column deviation,and pier bottom side cracks have occurred in the overpass.At the same time,combined with simulation calculation analysis,it is interpreted that the 0#and 1#foundation has been damaged at a certain position below the ground line.The occurrence of broken piles has provided a reliable basis for the later reinforcement and maintenance of the bridge and ideas for emergency inspection and analysis of bridges damaged by the same type of landslides.
基金supported by the National Natural Science Foundation of China (Grant No 10647145)The Basic Science Foundation of Henan Educational Bureau of China
文摘This paper reports that the YBa2Cu3-xZnxO7-δ (x = 0-0.4) samples are researched by means of x-ray diffraction, calculations of binding energy, the positron experiments and variations of oxygen content. The results of simulated calculations, positron experiments and variations of oxygen content support the existence of cluster effect. Moreover, it is concluded that the cluster effect is an important factor on suppression of high-Tc cuprate superconductivity and the Tc does not depend on the density of valence electron directly.
基金Project supported by the National Natural Science Foundation of China(Grant No.11547196)the Key Projects of Sichuan Provincial Department of Education,China(Grant No.15ZA0224)+1 种基金the Project of Sichuan Provincial Key Laboratory of Artificial Intelligence,China(Grant No.2014RYJ01)the Key Plan Projects of Science and Technology of Zigong,China(Grant No.2016CXM05)
文摘A metamaterial absorber is computed numerically and measured experimentally in a 150-THz^300-THz range.The measured absorber achieves high absorption rate for both transverse electric(TE) and transverse magnetic(TM) polarizations at large angles of incidence.An absorption sensor scheme is proposed based on the measured absorber and the variations of surrounding media.Different surrounding media are applied to the surface of the absorption sensor(including air,water,and glucose solution).Measured results show that high figure of merit(FOM) values are obtained for different surrounding media.The proposed sensor does not depend on the substrate,which means that it can be transplanted to different sensing platforms conveniently.
基金financially supported by the National Natural Science Foundation of China(No.51672222)the Joint Fund Project-Enterprise-Shaanxi Coal Joint Fund Project(No.2019JLM-32)the Spaceflight Foundation of China(No.2014-HT-XGD)。
文摘High-performance electromagnetic(EM)wave absorbers,covalently bonded reduced graphene oxideFe_(3)O_(4) nanocomposites(rGO-Fe_(3)O_(4)),are synthesized via hydrothermal reaction,amidation reaction and reduction process.The microstructure,surface element composition and morphology of rGO-Fe_(3)O_(4) nanocomposites are characterized and corresponding EM wave absorption properties are analyzed in great detail.It demonstrates that Fe_(3)O_(4) nanoparticles are successfully covalently grafted onto graphene by amide bonds.When the mass ratio of rGO and Fe_(3)O_(4) is 2:1(sample S2),the absorber exhibits the excellent EM wave absorption performance that the maximum reflection loss(RL)reaches up to-48.6 dB at 14.4 GHz,while the effective absorption bandwidth(RL<-10 dB)is 6.32 GHz(11.68-18.0 GHz)with a matching thickness of 2.1 mm.Furthermore,radar cross section(RCS)simulation calculation is also adopted to evaluate the ability of absorbers to scatter EM waves,which proves again that the absorption performance of absorber S2 is optimal.The outstanding EM wave absorption performance is attributed to the synergistic effect between dielectric and magnetic loss,good attenuation ability and excellent impedance matching.Moreover,covalent bonds considered to be carrier channels can facilitate electron migration,adjust EM parameters and then enhance EM wave absorption perfo rmance.This work provides a possible method for preparing efficient EM wave absorbers.
文摘Accurate battlefield collection plays a crucial role in the end of thewar. How to effectively improve the ability of accurate battlefield collection hasbecome a hot issue of research. However, the existing support force is limited. Tosolve the problem, an improved ant algorithm is applied to the path optimizationproblem of battlefield collection equipment. A model for solving the collectionpath optimization problem of battlefield collection vehicles was designed, andan example was used to simulate calculations. The final results show that thealgorithm is effective and practical,which improves the army’s ability to accuratelycollect equipment in the modern battlefield.