The Markit Slope is an important area for the petroleum exploration in the Tarim Basin. Elucidation of the oil filling history of discovered oilfields has great significance for recognizing the accumulation processes ...The Markit Slope is an important area for the petroleum exploration in the Tarim Basin. Elucidation of the oil filling history of discovered oilfields has great significance for recognizing the accumulation processes of the whole region. Using molecular geochemistry, fluid inclusion techniques and basin modeling, we studied the oil filling process of the Bashituo Oilfield that is located in the west of the Markit Slope. The molecular migration indexes, such as the methyldibenzothiophene ratio （4-/1-MDBT）, trimethylnaphthalene ratio （TMNr） and pyrrolic nitrogen compounds content, decrease from west to east, indicating that the charging direction and migration pathways are from west to east. Lithological analysis and homogenization temperatures of saline fluid inclusions accompanied with oil fluid inclusions suggest that two charging periods occurred in the Devonian oil reservoir. Combining the burial history and heating history of well BT4, Basinmod 1D software modeling shows the two oil filling periods are from 290 Ma to 285 Ma and from l0 Ma to 4 Ma, respectively, and later oil filling dominates. This study may be helpful to understand the accumulation process and provide useful references for oil and gas exploration in the Markit Slope.展开更多
The filling and exhausting processes in a pneumatic system are involved with many factors, and numerical solutions of many partial differential equations are always adapted in the study of those processes, which have ...The filling and exhausting processes in a pneumatic system are involved with many factors, and numerical solutions of many partial differential equations are always adapted in the study of those processes, which have been proved to be troublesome and less intuitive. Analytical solutions based on loss-less tube model and average friction tube model are found respectively by using fluid net theory, and they fit the experimental results well. The research work shows that： Fluid net theory can be used to solve the analytical solution of filling and exhausting processes of pneumatic system, and the result of loss-less tube model is close to that of average friction model, so loss-less tube model is recommended since it is simpler, and the difference between filling time and exhausting time is determined by initial and final pressures, the volume of container and the section area of tube, and has nothing to do with the length of the tube.展开更多
The casting nozzle location plays an important role in die casting. Improper location results in defects, such as cold shut, air cavity, shrinkage, etc. Therefore, it’s sure that the molten metal full fills the mould...The casting nozzle location plays an important role in die casting. Improper location results in defects, such as cold shut, air cavity, shrinkage, etc. Therefore, it’s sure that the molten metal full fills the mould cavity before it solidifies. And, it’s to be wished that no vortex occur during the filling process, because the vortex is a main source that induces gas entrapment. To get the high quality and performance product, the inlet and outlet locations must be set properly. This paper, an optimal design problem of nozzle and vent locations, which is constrained by nonlinear partial differential equations and boundary and initial conditions, is introduced to describe the location selection on die casting filling process. By numerical simulation, one can compare the filling time, flow pattern and temperature field at different inlet and outlet locations, then choose the most proper locations.展开更多
AIM:To evaluate the peripheral arterial filling time(PAFT)and venous filling time(VFT)in eyes without known diseases that may influence filling process using ultra-widefield(UWF)fluorescein angiography(FA),and to revi...AIM:To evaluate the peripheral arterial filling time(PAFT)and venous filling time(VFT)in eyes without known diseases that may influence filling process using ultra-widefield(UWF)fluorescein angiography(FA),and to review the peripheral retina fluorescence features.METHODS:A total of 30 eyes of 30 patients were retrospectively reviewed in this observational study.UWFFA was performed using Optos 200Tx.PAFT and VFT was recorded.The interval between the arterial or venous filling completion and the previous photo was documented.The appearance of the far peripheral retina was described as either granular background fluorescence or mottled fluorescent band or vascular leakage.Terminal vascular patterns was described as loop pattern or branching pattern.Microvascular abnormalities such as arteriovenous shunting,vessels crossing the horizontal raphe,right angle vessels,terminal networks,capillary nonperfusion,drusen or microaneurysms were evaluated.RESULTS:The normal limits of PAFT was 3.397-8.984s and 4.399-11.753s for VFT.The appearance of the far peripheral retina,defined as granular background(63%),mottled fluorescence(20%),or vascular leakage(17%),was symmetrical between both eyes.Capillary nonperfusion(23%)and microaneurysms(40%)were more frequently found in eyes with loop pattern than in eyes with branching pattern.Other peripheral signs such as right-angle vessels(73%),and terminal networks(80%)were commonly seen on UWF-FA in the normal peripheral retina.CONCLUSION:The main courses of retinal artery and vein filling time are overlapping with each other on UWF-FA.Notably,the arterial filling process is completed in the arteriovenous phase rather than the traditionally named arterial phase.There are various manifestations in the peripheral retina of normal eyes.展开更多
Real time control （RTC） of urban drainage systems （UDSs） is an important measure to reduce combined sewer overflow （CSO） and urban flooding, helping achieve the aims of ＂Sponge City＇. Application of RTC requir...Real time control （RTC） of urban drainage systems （UDSs） is an important measure to reduce combined sewer overflow （CSO） and urban flooding, helping achieve the aims of ＂Sponge City＇. Application of RTC requires three main steps： strategy design, simulation-based evaluation and field test. But many of published RTC studies are system-specific, lacking discussions on how to design a strategy step by step. In addition, the existing studies are prone to use hydrologic model to evaluated strategics, but a more precise and dynamic insight into strategy performance is needed. To fill these knowledge gaps, based on a case UDS in Kunming city, a studio on RTC strategy design and Management Model （SWMM） - uncier four typical rainfall events characterized by different return periods （1-year or 0.5 year） and different spatial distributions （uniform or uneven）. The equal filling strategy outperformss other two strategies and it can achieve 10% more CSO reduction and 5% more flooding reduction relative to the no-tank case.展开更多
基金supported by the Natural Science Foundation of China (Grant No.40972089)the Foundation of the State Key Laboratory of Petroleum Resources and Prospecting (Grant No.PRPDX2008-01)
文摘The Markit Slope is an important area for the petroleum exploration in the Tarim Basin. Elucidation of the oil filling history of discovered oilfields has great significance for recognizing the accumulation processes of the whole region. Using molecular geochemistry, fluid inclusion techniques and basin modeling, we studied the oil filling process of the Bashituo Oilfield that is located in the west of the Markit Slope. The molecular migration indexes, such as the methyldibenzothiophene ratio （4-/1-MDBT）, trimethylnaphthalene ratio （TMNr） and pyrrolic nitrogen compounds content, decrease from west to east, indicating that the charging direction and migration pathways are from west to east. Lithological analysis and homogenization temperatures of saline fluid inclusions accompanied with oil fluid inclusions suggest that two charging periods occurred in the Devonian oil reservoir. Combining the burial history and heating history of well BT4, Basinmod 1D software modeling shows the two oil filling periods are from 290 Ma to 285 Ma and from l0 Ma to 4 Ma, respectively, and later oil filling dominates. This study may be helpful to understand the accumulation process and provide useful references for oil and gas exploration in the Markit Slope.
基金This project is supported by National Natural Science Foundation of China(No.50575209).
文摘The filling and exhausting processes in a pneumatic system are involved with many factors, and numerical solutions of many partial differential equations are always adapted in the study of those processes, which have been proved to be troublesome and less intuitive. Analytical solutions based on loss-less tube model and average friction tube model are found respectively by using fluid net theory, and they fit the experimental results well. The research work shows that： Fluid net theory can be used to solve the analytical solution of filling and exhausting processes of pneumatic system, and the result of loss-less tube model is close to that of average friction model, so loss-less tube model is recommended since it is simpler, and the difference between filling time and exhausting time is determined by initial and final pressures, the volume of container and the section area of tube, and has nothing to do with the length of the tube.
文摘The casting nozzle location plays an important role in die casting. Improper location results in defects, such as cold shut, air cavity, shrinkage, etc. Therefore, it’s sure that the molten metal full fills the mould cavity before it solidifies. And, it’s to be wished that no vortex occur during the filling process, because the vortex is a main source that induces gas entrapment. To get the high quality and performance product, the inlet and outlet locations must be set properly. This paper, an optimal design problem of nozzle and vent locations, which is constrained by nonlinear partial differential equations and boundary and initial conditions, is introduced to describe the location selection on die casting filling process. By numerical simulation, one can compare the filling time, flow pattern and temperature field at different inlet and outlet locations, then choose the most proper locations.
基金Supported by Capital Health Development Research Special Fund(No.2020-2-2053)。
文摘AIM:To evaluate the peripheral arterial filling time(PAFT)and venous filling time(VFT)in eyes without known diseases that may influence filling process using ultra-widefield(UWF)fluorescein angiography(FA),and to review the peripheral retina fluorescence features.METHODS:A total of 30 eyes of 30 patients were retrospectively reviewed in this observational study.UWFFA was performed using Optos 200Tx.PAFT and VFT was recorded.The interval between the arterial or venous filling completion and the previous photo was documented.The appearance of the far peripheral retina was described as either granular background fluorescence or mottled fluorescent band or vascular leakage.Terminal vascular patterns was described as loop pattern or branching pattern.Microvascular abnormalities such as arteriovenous shunting,vessels crossing the horizontal raphe,right angle vessels,terminal networks,capillary nonperfusion,drusen or microaneurysms were evaluated.RESULTS:The normal limits of PAFT was 3.397-8.984s and 4.399-11.753s for VFT.The appearance of the far peripheral retina,defined as granular background(63%),mottled fluorescence(20%),or vascular leakage(17%),was symmetrical between both eyes.Capillary nonperfusion(23%)and microaneurysms(40%)were more frequently found in eyes with loop pattern than in eyes with branching pattern.Other peripheral signs such as right-angle vessels(73%),and terminal networks(80%)were commonly seen on UWF-FA in the normal peripheral retina.CONCLUSION:The main courses of retinal artery and vein filling time are overlapping with each other on UWF-FA.Notably,the arterial filling process is completed in the arteriovenous phase rather than the traditionally named arterial phase.There are various manifestations in the peripheral retina of normal eyes.
文摘Real time control （RTC） of urban drainage systems （UDSs） is an important measure to reduce combined sewer overflow （CSO） and urban flooding, helping achieve the aims of ＂Sponge City＇. Application of RTC requires three main steps： strategy design, simulation-based evaluation and field test. But many of published RTC studies are system-specific, lacking discussions on how to design a strategy step by step. In addition, the existing studies are prone to use hydrologic model to evaluated strategics, but a more precise and dynamic insight into strategy performance is needed. To fill these knowledge gaps, based on a case UDS in Kunming city, a studio on RTC strategy design and Management Model （SWMM） - uncier four typical rainfall events characterized by different return periods （1-year or 0.5 year） and different spatial distributions （uniform or uneven）. The equal filling strategy outperformss other two strategies and it can achieve 10% more CSO reduction and 5% more flooding reduction relative to the no-tank case.
