In order to avoid the deep-well oil shale roadway being deformed, damaged, or difficult to maintain after excavating and supporting in Haishiwan coal mine, this paper has analyzed the characteristics of the deformed r...In order to avoid the deep-well oil shale roadway being deformed, damaged, or difficult to maintain after excavating and supporting in Haishiwan coal mine, this paper has analyzed the characteristics of the deformed roadway and revealed its failure mechanism by taking comprehensively the methods of field geological investigation, displacement monitoring of surrounding rock, rock properties and hydration properties experiments and field application tests. Based on this work, the high-resistance controlled yielding supporting principle is proposed, which is： to ＂resist＂ by high pre-tightening force and high stiff- ness in the early stage, to ＂yield＂ by making use of the controlled deformation of a yielding tube in the middle stage, and to ＂fix＂ by applying total-section Gunite in the later stage. A high-resistance controlled yielding supporting technique of ＂high pre-tightening force yielding anchor bolt ＋ small-bore pre-tight- ening force anchor cable ＋ rebar ladder beam ＋ rhombic metal mesh ＋ lagging gunite＂ has been estab- lished, and industrial on site testing implemented. The practical results show that the high-resistance controlled yielding supporting technique can effectively control the large deformation and long-time rheology of deep-well oil shale roadways and can provide beneficial references for the maintenance of other con-generic roadways.Deep-well Oil shale展开更多
In recent years, microstrip antennas have been more widely applied in satellite communications, mobile phones, unmanned aerial vehicle （UAV）, and weapons. A micro-electro-mechanical systems-based （MEMS-based） high...In recent years, microstrip antennas have been more widely applied in satellite communications, mobile phones, unmanned aerial vehicle （UAV）, and weapons. A micro-electro-mechanical systems-based （MEMS-based） high-resistance silicon C-band microstrip antenna array has been designed for the intelligent ammunition. The center frequency is 4.5 GHz. A cavity has been designed in substrate to reduce the dielectric constant of silicon and high-resistance silicon has been used as the material of substrate to improve the gain of antenna. It is very easy to be manufactured by using MEMS technology because of the improved structure of the antenna. The results show that the gain of the antenna is 8 dB and voltage standing wave ratio （VSWR） is less than 2 by the analysis and simulation in high freauencv structure simulator （HFSS）.展开更多
For large generators, the problem of high-resistance grounding method and the advantages of resonance, grounding method are discussed in detail, and an overall comparison is given in this paper. It is recommended that...For large generators, the problem of high-resistance grounding method and the advantages of resonance, grounding method are discussed in detail, and an overall comparison is given in this paper. It is recommended that the latter should be adopted so as to increase the operation reliability of large generators and power systems.展开更多
Three kinds of coplanar waveguides （CPWs） are designed and fabricated on different silicon substrates---common low-resistivity silicon substrate （LRS）, LRS with a 3μm-thick silicon oxide interlayer, and high-resi...Three kinds of coplanar waveguides （CPWs） are designed and fabricated on different silicon substrates---common low-resistivity silicon substrate （LRS）, LRS with a 3μm-thick silicon oxide interlayer, and high-resistivity silicon （HRS） substrate. The results show that the microwave loss of a CPW on LRS is too high to be used, but it can be greatly reduced by adding a thick interlayer of silicon oxide between the CPW transmission lines and the LRS.A CPW directly on HRS shows a loss lower than 2dB/cm in the range of 0-26GHz and the process is simple,so HRS is a more suitable CPW substrate.展开更多
基金Financial support for this work, provided by the National Natural Science Foundation of China (No. 51174195)the Graduate Student Scientific Research Innovation Project of the Jiangsu Province Ordinary University (No. CXZZ12_0954)the Research Foundation of the State Key Laboratory of Coal Resources and Mine Safety (No. SKLCRSM08X04)
文摘In order to avoid the deep-well oil shale roadway being deformed, damaged, or difficult to maintain after excavating and supporting in Haishiwan coal mine, this paper has analyzed the characteristics of the deformed roadway and revealed its failure mechanism by taking comprehensively the methods of field geological investigation, displacement monitoring of surrounding rock, rock properties and hydration properties experiments and field application tests. Based on this work, the high-resistance controlled yielding supporting principle is proposed, which is： to ＂resist＂ by high pre-tightening force and high stiff- ness in the early stage, to ＂yield＂ by making use of the controlled deformation of a yielding tube in the middle stage, and to ＂fix＂ by applying total-section Gunite in the later stage. A high-resistance controlled yielding supporting technique of ＂high pre-tightening force yielding anchor bolt ＋ small-bore pre-tight- ening force anchor cable ＋ rebar ladder beam ＋ rhombic metal mesh ＋ lagging gunite＂ has been estab- lished, and industrial on site testing implemented. The practical results show that the high-resistance controlled yielding supporting technique can effectively control the large deformation and long-time rheology of deep-well oil shale roadways and can provide beneficial references for the maintenance of other con-generic roadways.Deep-well Oil shale
基金supported by the Chinese PLA General Armament Department under Grant No.51318020305
文摘In recent years, microstrip antennas have been more widely applied in satellite communications, mobile phones, unmanned aerial vehicle （UAV）, and weapons. A micro-electro-mechanical systems-based （MEMS-based） high-resistance silicon C-band microstrip antenna array has been designed for the intelligent ammunition. The center frequency is 4.5 GHz. A cavity has been designed in substrate to reduce the dielectric constant of silicon and high-resistance silicon has been used as the material of substrate to improve the gain of antenna. It is very easy to be manufactured by using MEMS technology because of the improved structure of the antenna. The results show that the gain of the antenna is 8 dB and voltage standing wave ratio （VSWR） is less than 2 by the analysis and simulation in high freauencv structure simulator （HFSS）.
文摘For large generators, the problem of high-resistance grounding method and the advantages of resonance, grounding method are discussed in detail, and an overall comparison is given in this paper. It is recommended that the latter should be adopted so as to increase the operation reliability of large generators and power systems.
文摘Three kinds of coplanar waveguides （CPWs） are designed and fabricated on different silicon substrates---common low-resistivity silicon substrate （LRS）, LRS with a 3μm-thick silicon oxide interlayer, and high-resistivity silicon （HRS） substrate. The results show that the microwave loss of a CPW on LRS is too high to be used, but it can be greatly reduced by adding a thick interlayer of silicon oxide between the CPW transmission lines and the LRS.A CPW directly on HRS shows a loss lower than 2dB/cm in the range of 0-26GHz and the process is simple,so HRS is a more suitable CPW substrate.
