The injection performance of the storage ring is one of the most important factors to consider at a synchrotron radiation facility, especially in the top-up mode. To evaluate the injection performance of the storage r...The injection performance of the storage ring is one of the most important factors to consider at a synchrotron radiation facility, especially in the top-up mode. To evaluate the injection performance of the storage ring at the Shanghai Synchrotron Radiation Facility, we have built a bunch-by-bunch position measuring system based on an oscilloscope Input/Output Controller. Accurate assessment of energy mismatching, distribution of residual oscillation, and angle error of injection kickers can be achieved by this system.展开更多
Introducing a thin InGaN interlayer with a relatively lower indium content between the quantum well （QW） and barrier results in a step-like InxGa1-xN/GaN potential barrier on one side of the QW. This change in the a...Introducing a thin InGaN interlayer with a relatively lower indium content between the quantum well （QW） and barrier results in a step-like InxGa1-xN/GaN potential barrier on one side of the QW. This change in the active region leads to a significant shift in photolumineseence （PL） and electroluminescence （EL） emissions to a longer wavelength compared with the conventional QW based light-emitting diodes. More importantly, an improvement against efficiency droop and an enhancement in light output power at the high-current injection are observed in the modified light-emitting diode structures. The role of the inserted layer in these improvements is investigated by simulation in detail, which shows that the creation of more sublevels in the valence band and the increase of hole concentration inside QWs are the main reasons for these improvements.展开更多
A dynamic transient flow analysis method considering complex factors such as the cyclic injection and production history in a gas field storage facility was established in view of the limitations of the existing metho...A dynamic transient flow analysis method considering complex factors such as the cyclic injection and production history in a gas field storage facility was established in view of the limitations of the existing methods for transient flow analysis and the characteristics of the injection-production operation of strongly heterogeneous gas reservoirs, and the corresponding theoretical charts were drawn. In addition, an injection-production dynamic transient flow analysis model named "three points and two stages" suitable for an underground gas storage(UGS) well with alternate working conditions was proposed. The "three points" refer to three time points during cyclic injection and production, namely, the starting point of gas injection for UGS construction, the beginning and ending points of the injection-production analysis stage;and the "two stages" refer to historical flow stage and injection-production analysis stage. The study shows that the dimensionless pseudo-pressure and dimensionless pseudo-pressure integral curves of UGS well flex downward in the early stage of the injection and production process, and the dimensionless pseudo-pressure integral derivative curve is convex during the gas production period and concave during the gas injection period, and the curves under different flow histories have atypical features. The new method present in this paper can analyze transient flow of UGS accurately. The application of this method to typical wells in Hutubi gas storage shows that the new method can fit the pressure history accurately, and obtain reliable parameters and results.展开更多
The advantages of pellet injection as a competitive means of fuelling a tokamak are well known. They include： （ 1 ） deep deposition of fuel, （ 2 ） better fuelling efficiency, （ 3 ） purer plasma, and so on. Mea...The advantages of pellet injection as a competitive means of fuelling a tokamak are well known. They include： （ 1 ） deep deposition of fuel, （ 2 ） better fuelling efficiency, （ 3 ） purer plasma, and so on. Meanwhile, improving plasma performance by pellet injection has been proven in many tokamak experiments. The deposition of pellet particles following pellet injection causes a temporal change of the local plasma temperature and density gradients which affects the transport properties of the plasma, so pellet injection can be used as a method of studying the transport process as well.展开更多
Micro-scale and nano-scale dispersed gel particles(DPG)are capable of deep migration in oil reservoirs due to their deformability,viscoelasticity,and suitable particle size.Therefore,it has been widely studied and app...Micro-scale and nano-scale dispersed gel particles(DPG)are capable of deep migration in oil reservoirs due to their deformability,viscoelasticity,and suitable particle size.Therefore,it has been widely studied and applied in reservoir conformance control in recent years.However,for highly permeable channels,their plugging performance is still limited.In addition,conventional in situ cross-linked polymer gels(ISCPGs)have fast gelation time under extremely high-temperature conditions,which often causes problems such as difficulty in pumping.Therefore,a re-cross linkable dispersed particle gel(RDPG)system applied for conformance control in highly permeable channels of extremely high-temperature petroleum reservoirs was investigated.The particle size distribution,gelation time,gel strength,injection performance,and perfo rmance strength in po rous media were investigated using a laser particle size meter,the Sydansk bottle test method,rheometer,and core displacement experiments,respectively.Results show that the RDPG suspension can be stable for more than 6 months at room temperature with storage modulus G’much lower than 10 Pa.It can pass through the pore throat by elastic deformation effect and does not cause strong blockage.Moreover,it can undergo re-crosslinking reaction at 150℃to form a strong bulk gel.The gel strength G’of re-crosslinked RDPG can be as high as 69.3 Pa,which meets the strength requirement of conformance control.The RDPG suspension has the properties of easy injection,and it also has strong plugging,and high-temperature resistance after re-crosslinked in the core,which can be a very promising material for conformance improvement in extremely high-temperature reservoirs.展开更多
基金Supported by National Natural Science Foundation of China(11375255)
文摘The injection performance of the storage ring is one of the most important factors to consider at a synchrotron radiation facility, especially in the top-up mode. To evaluate the injection performance of the storage ring at the Shanghai Synchrotron Radiation Facility, we have built a bunch-by-bunch position measuring system based on an oscilloscope Input/Output Controller. Accurate assessment of energy mismatching, distribution of residual oscillation, and angle error of injection kickers can be achieved by this system.
基金Supported by the National Natural Science Foundation of China under Grant Nos 61334005,51272008 and 60990314the Beijing Municipal Science and Technology Project under Grant No H030430020000the National Basic Research Program of China under Grant Nos 2012CB619304 and 2012CB619306
文摘Introducing a thin InGaN interlayer with a relatively lower indium content between the quantum well （QW） and barrier results in a step-like InxGa1-xN/GaN potential barrier on one side of the QW. This change in the active region leads to a significant shift in photolumineseence （PL） and electroluminescence （EL） emissions to a longer wavelength compared with the conventional QW based light-emitting diodes. More importantly, an improvement against efficiency droop and an enhancement in light output power at the high-current injection are observed in the modified light-emitting diode structures. The role of the inserted layer in these improvements is investigated by simulation in detail, which shows that the creation of more sublevels in the valence band and the increase of hole concentration inside QWs are the main reasons for these improvements.
基金Supported by the CNPC Major Scientific and Technological Project(2019B-3204)PetroChina Major Scientific and Technological Project(kt2020-16-01)。
文摘A dynamic transient flow analysis method considering complex factors such as the cyclic injection and production history in a gas field storage facility was established in view of the limitations of the existing methods for transient flow analysis and the characteristics of the injection-production operation of strongly heterogeneous gas reservoirs, and the corresponding theoretical charts were drawn. In addition, an injection-production dynamic transient flow analysis model named "three points and two stages" suitable for an underground gas storage(UGS) well with alternate working conditions was proposed. The "three points" refer to three time points during cyclic injection and production, namely, the starting point of gas injection for UGS construction, the beginning and ending points of the injection-production analysis stage;and the "two stages" refer to historical flow stage and injection-production analysis stage. The study shows that the dimensionless pseudo-pressure and dimensionless pseudo-pressure integral curves of UGS well flex downward in the early stage of the injection and production process, and the dimensionless pseudo-pressure integral derivative curve is convex during the gas production period and concave during the gas injection period, and the curves under different flow histories have atypical features. The new method present in this paper can analyze transient flow of UGS accurately. The application of this method to typical wells in Hutubi gas storage shows that the new method can fit the pressure history accurately, and obtain reliable parameters and results.
文摘The advantages of pellet injection as a competitive means of fuelling a tokamak are well known. They include： （ 1 ） deep deposition of fuel, （ 2 ） better fuelling efficiency, （ 3 ） purer plasma, and so on. Meanwhile, improving plasma performance by pellet injection has been proven in many tokamak experiments. The deposition of pellet particles following pellet injection causes a temporal change of the local plasma temperature and density gradients which affects the transport properties of the plasma, so pellet injection can be used as a method of studying the transport process as well.
基金supported by the Research Foundation of China University of Petroleum-Beijing at Karamay(No.XQZX20200010)the Natural Science Foundation of Xinjiang Uygur Autonomous Region(No.2019D01B57)+2 种基金the Tianshan Talent Project(No.2019Q025)the Sichuan Province Regional Innovation Cooperation Project(No.2020YFQ0036)the CNPC Strategic Cooperation Science and Technology Project(ZLZX2020-01-04-04)
文摘Micro-scale and nano-scale dispersed gel particles(DPG)are capable of deep migration in oil reservoirs due to their deformability,viscoelasticity,and suitable particle size.Therefore,it has been widely studied and applied in reservoir conformance control in recent years.However,for highly permeable channels,their plugging performance is still limited.In addition,conventional in situ cross-linked polymer gels(ISCPGs)have fast gelation time under extremely high-temperature conditions,which often causes problems such as difficulty in pumping.Therefore,a re-cross linkable dispersed particle gel(RDPG)system applied for conformance control in highly permeable channels of extremely high-temperature petroleum reservoirs was investigated.The particle size distribution,gelation time,gel strength,injection performance,and perfo rmance strength in po rous media were investigated using a laser particle size meter,the Sydansk bottle test method,rheometer,and core displacement experiments,respectively.Results show that the RDPG suspension can be stable for more than 6 months at room temperature with storage modulus G’much lower than 10 Pa.It can pass through the pore throat by elastic deformation effect and does not cause strong blockage.Moreover,it can undergo re-crosslinking reaction at 150℃to form a strong bulk gel.The gel strength G’of re-crosslinked RDPG can be as high as 69.3 Pa,which meets the strength requirement of conformance control.The RDPG suspension has the properties of easy injection,and it also has strong plugging,and high-temperature resistance after re-crosslinked in the core,which can be a very promising material for conformance improvement in extremely high-temperature reservoirs.
