The Hailar-Tamtsag Basin is a typical rift basin where two sets of regional caprocks are developed,i.e.,mudstone caprocks(containing a small amount of tuff)developed in strong rifting stage and fault-depression stage,...The Hailar-Tamtsag Basin is a typical rift basin where two sets of regional caprocks are developed,i.e.,mudstone caprocks(containing a small amount of tuff)developed in strong rifting stage and fault-depression stage,respectively.The caprocks have a cumulative thickness of 50-120 m in general,and a single-layer thickness of 20-50 m,interbedded with sandstone about 1-2 m thick.The large set of mudstone is distributed continuously,as pure mudstone caprock.Forty-three mudstone and tuff samples were taken to perform displacement pressure test with our independently developed displacement pressure tester.Test result shows that the displacement pressure is 0.04-10.00 MPa,which is equivalent to 0.09-20.01 MPa after being corrected to the actual burial depth.As the burial depth increases,the displacement pressure rises gradually,and is 1-10 times greater than that of oil-bearing sandstone or conglomerate reservoir at the same burial depth.The difference between displacement pressure of mudstone caprock and sandstone or conglomerate reservoir increases greatly if the burial depth exceeds 1000 m.Because of the displacement pressure difference between caprock and reservoir,the maximum height of hydrocarbon column sealed by the caprock ranges from 300 m to 2000 m,much higher than the height of the trap closure at the same burial depth.No hydrocarbons will leak through such caprocks.Analysis of the reservoir GOI,homogeneous temperature,and crude maturity of both deep and shallow reservoirs in Well Wu-20 in the Wuerxun Depression shows that Damoguaihe II Member reservoir is a secondary reservoir developed during adjustment of early reservoir.It is mainly distributed in inverted structures.Faulting is one of the main factors breaking the integrity of caprocks.Three kinds of faults are often related to the migration of hydrocarbons across regional caprocks:the first type refers to the positive inverted faults breaking the early sealing conditions and making the hydrocarbons accumulated in the early period re-migration;the second展开更多
Permanent magnet synchronous motor (PMSM) is widely used in mining, and there exists chaotic behav- ior when it runs. In order to dispel its adverse effect on security in mining, the chaotic system of PMSM was analyze...Permanent magnet synchronous motor (PMSM) is widely used in mining, and there exists chaotic behav- ior when it runs. In order to dispel its adverse effect on security in mining, the chaotic system of PMSM was analyzed. With noise disturbances, the complex dynamic characteristics of chaos were also analyzed, and proved the objective existence of chaos. As we all know, it is very difficult for conventional PMSM control to meet the design requirements, therefore, in order to ensure the robustness of the system, the chaotic orbits were stabilized to arbitrary chosen fixed points and periodic orbits by means of sliding mode method. Finally MATLAB simulations were presented to confirm the validity of the controller. The results show that the PMSM with the sliding mode control has a good dynamic performance and steady state accuracy.展开更多
Because of its economical and environmentally friendly characteristics, the warm mix asphalt(WMA) is widely used in pavement engineering. However, the lack of microscopic study of WMA brings difficulties in understand...Because of its economical and environmentally friendly characteristics, the warm mix asphalt(WMA) is widely used in pavement engineering. However, the lack of microscopic study of WMA brings difficulties in understanding of its mechanical behavior and mechanisms at macroscopic scale which finally hinders the enhancement of WMA's performance. Therefore, this article aims to use atomic force microscopy(AFM), a promising microscopic technique, to investigate the effects of wax-based warm mix agents on asphalt microstructures and micromechanical properties at different temperatures. For simplicity's sake, microcrystalline waxes are selected as an alternative of these wax-based additives. It is shown that the sample preparation method has a vital impact on the morphology of asphalt samples. The effects of microcrystalline wax on asphalt's mechanical properties can be well captured by AFM tests. Results show that the blending of #70, #80 and #90 microcrystalline waxes lowers the modulus(20—60 MPa) of Pen70 asphalt at 25 ℃ while increasing its adhesion force(5—20 n N). The results of this study may shed some light on the comprehension of the effects of wax-based additives on asphalt materials at macroscopic level which can help estimate and predict its actual performance.展开更多
基金supported by National Natural Science Foundation of China (Grant Nos. 41072163,41172135)New Century Excellent Talents in Heilongjiang Provincial University (Grant No. 1251-NCET-015)National Oil and Gas Project (Grant No. 2008ZX05003-002)
文摘The Hailar-Tamtsag Basin is a typical rift basin where two sets of regional caprocks are developed,i.e.,mudstone caprocks(containing a small amount of tuff)developed in strong rifting stage and fault-depression stage,respectively.The caprocks have a cumulative thickness of 50-120 m in general,and a single-layer thickness of 20-50 m,interbedded with sandstone about 1-2 m thick.The large set of mudstone is distributed continuously,as pure mudstone caprock.Forty-three mudstone and tuff samples were taken to perform displacement pressure test with our independently developed displacement pressure tester.Test result shows that the displacement pressure is 0.04-10.00 MPa,which is equivalent to 0.09-20.01 MPa after being corrected to the actual burial depth.As the burial depth increases,the displacement pressure rises gradually,and is 1-10 times greater than that of oil-bearing sandstone or conglomerate reservoir at the same burial depth.The difference between displacement pressure of mudstone caprock and sandstone or conglomerate reservoir increases greatly if the burial depth exceeds 1000 m.Because of the displacement pressure difference between caprock and reservoir,the maximum height of hydrocarbon column sealed by the caprock ranges from 300 m to 2000 m,much higher than the height of the trap closure at the same burial depth.No hydrocarbons will leak through such caprocks.Analysis of the reservoir GOI,homogeneous temperature,and crude maturity of both deep and shallow reservoirs in Well Wu-20 in the Wuerxun Depression shows that Damoguaihe II Member reservoir is a secondary reservoir developed during adjustment of early reservoir.It is mainly distributed in inverted structures.Faulting is one of the main factors breaking the integrity of caprocks.Three kinds of faults are often related to the migration of hydrocarbons across regional caprocks:the first type refers to the positive inverted faults breaking the early sealing conditions and making the hydrocarbons accumulated in the early period re-migration;the second
基金supported in part by the National Natural Science Foundation of China (No. 50879072)the Fundamental Research Funds for the Central Universities of CUMT (No.2010QNB33)The National Undergraduate Innovation Programof CUMT (No. 101029013)
文摘Permanent magnet synchronous motor (PMSM) is widely used in mining, and there exists chaotic behav- ior when it runs. In order to dispel its adverse effect on security in mining, the chaotic system of PMSM was analyzed. With noise disturbances, the complex dynamic characteristics of chaos were also analyzed, and proved the objective existence of chaos. As we all know, it is very difficult for conventional PMSM control to meet the design requirements, therefore, in order to ensure the robustness of the system, the chaotic orbits were stabilized to arbitrary chosen fixed points and periodic orbits by means of sliding mode method. Finally MATLAB simulations were presented to confirm the validity of the controller. The results show that the PMSM with the sliding mode control has a good dynamic performance and steady state accuracy.
基金financial support of the Education Department of Jiangsu Province under Grant No.JZ-007the Jiangsu Natural Science Foundation under Grant No.BK 20140111
文摘Because of its economical and environmentally friendly characteristics, the warm mix asphalt(WMA) is widely used in pavement engineering. However, the lack of microscopic study of WMA brings difficulties in understanding of its mechanical behavior and mechanisms at macroscopic scale which finally hinders the enhancement of WMA's performance. Therefore, this article aims to use atomic force microscopy(AFM), a promising microscopic technique, to investigate the effects of wax-based warm mix agents on asphalt microstructures and micromechanical properties at different temperatures. For simplicity's sake, microcrystalline waxes are selected as an alternative of these wax-based additives. It is shown that the sample preparation method has a vital impact on the morphology of asphalt samples. The effects of microcrystalline wax on asphalt's mechanical properties can be well captured by AFM tests. Results show that the blending of #70, #80 and #90 microcrystalline waxes lowers the modulus(20—60 MPa) of Pen70 asphalt at 25 ℃ while increasing its adhesion force(5—20 n N). The results of this study may shed some light on the comprehension of the effects of wax-based additives on asphalt materials at macroscopic level which can help estimate and predict its actual performance.
