Five phospholipids in human placenta were determined by phosphorus 31 nuclear magnetic resonance(^(31)P NMR)spectroscopy and thin-layer chromatography(TLC) scanning combined with the corrective method of absorbance pr...Five phospholipids in human placenta were determined by phosphorus 31 nuclear magnetic resonance(^(31)P NMR)spectroscopy and thin-layer chromatography(TLC) scanning combined with the corrective method of absorbance proportional coefficient. The NMR spectrometer used this investigation was a Bruker AM-500 spectrometer operating at 202.4 MHz for ^(31)P chemical shifts are relative to 85% phosphoric acid. TIC was carried out by silica gel H plate developed in chloroform-methanol-glacial acetic acid-ethanol-water(25:4:6:2:0.5),with Vaskovsky reagent as colour -developing agent of phospholipids.展开更多
A physical simulation method with a combination of dynamic displacement and imbibition was established by integrating nuclear magnetic resonance(NMR)and CT scanning.The microscopic production mechanism of tight/shale ...A physical simulation method with a combination of dynamic displacement and imbibition was established by integrating nuclear magnetic resonance(NMR)and CT scanning.The microscopic production mechanism of tight/shale oil in pore throat by dynamic imbibition and the influencing factors on the development effect of dynamic imbibition were analyzed.The dynamic seepage process of fracking-soaking-backflow-production integration was simulated,which reveals the dynamic production characteristics at different development stages and their contribution to enhancing oil recovery(EOR).The seepage of tight/shale reservoirs can be divided into three stages:strong displacement and weak imbibition as oil produced rapidly by displacement from macropores and fractures,weak displacement and strong imbibition as oil produced slowly by reverse imbibition from small pores,and weak displacement and weak imbibition at dynamic equilibrium.The greater displacement pressure results in the higher displacement recovery and the lower imbibition recovery.However,if the displacement pressure is too high,the injected water is easy to break through the front and reduce the recovery degree.The higher the permeability,the greater the imbibition and displacement recovery,the shorter the time of imbibition balance,and the higher the final recovery.The fractures can effectively increase the imbibition contact area between matrix and water,reduce the oil-water seepage resistance,promote the oil-water displacement between matrix and fracture,and improve the oil displacement rate and recovery of the matrix.The soaking after fracturing is beneficial to the imbibition replacement and energy storage of the fluid;also,the effective use of the carrying of the backflow fluid and the displacement in the mining stage is the key to enhancing oil recovery.展开更多
On March 11, 2019, the WHO declared COVID-19 a pandemic disease. It is a respiratory tropism SARS COV 2 infection. In the emergency of the pandemic, in medical imaging, only computed tomography (CT) of the lungs was f...On March 11, 2019, the WHO declared COVID-19 a pandemic disease. It is a respiratory tropism SARS COV 2 infection. In the emergency of the pandemic, in medical imaging, only computed tomography (CT) of the lungs was favored to assess lung lesions. In addition, many cases of post-COVID-19 cognitive disorders have been reported. As the curve dips and services restart correctly, other imaging techniques have been used to better explore the disease. The objective of this presentation is to illustrate the contribution of metabolic imaging in the exploration of post COVID-19 cognitive disorders and to discuss the pathophysiological mechanisms. Hypometabolism brain lesions are objective signs of functional impairment whose pathophysiological mechanism is not yet fully understood. Metabolic imaging with PET-SCAN is a suitable tool for exploring these disorders, both for the severity and extent of the lesions and for the topography of the brain damage.展开更多
Due to long-term water injection,often oilfields enter the so-called medium and high water cut stage,and it is difficult to achieve good oil recovery and water reduction through standard methods(single profile control...Due to long-term water injection,often oilfields enter the so-called medium and high water cut stage,and it is difficult to achieve good oil recovery and water reduction through standard methods(single profile control and flooding measures).Therefore,in this study,a novel method based on“plugging,profile control,and flooding”being implemented at the same time is proposed.To assess the performances of this approach,physical simulations,computer tomography,and nuclear magnetic resonance are used.The results show that the combination of a gel plugging agent,a polymer microsphere flooding agent,and a high-efficiency oil displacement agent leads to better results in terms of oil recovery with respect to the situation in which these approaches are used separately(the oil recovery is increased by 15.37%).Computer tomography scan results show that with the combined approach,a larger sweep volume and higher oil washing efficiency are obtained.The remaining oil in the cluster form can be recovered in the middle and low permeability layer,increasing the proportion of the columnar and blind end states of the oil.The nuclear magnetic resonance test results show that the combined“plugging,profile control,and flooding”treatment can also be used to control more effectively the dominant channels of the high permeability layer and further expand the recovery degree of the remaining oil in the pores of different sizes in the middle and low permeability layers.However,for the low permeability layer(permeability difference of 20),the benefits in terms of oil recovery are limited.展开更多
The properties of a Lanthanum bromide(LaBr3)detector and its response functions were investigated via experiments and simulations in this paper.The LaBr3detector had good relative energy resolution and higher efficien...The properties of a Lanthanum bromide(LaBr3)detector and its response functions were investigated via experiments and simulations in this paper.The LaBr3detector had good relative energy resolution and higher efficiency than a high-purity germanium detector.Monte Carlo and other numerical methods were used to calculate the efficiencies of a LaBr3detector with a square collimation window.A model of the numerical method was established based on a pure geometric model that was consistent with the experimental situation.The results showed that the detector response functions calculated by these methods were in great agreement with experimental results.展开更多
Titanium is one of the best hydrogen loading material. The pre dieted maximum loading ratio of hydrogen in titanium may reach to 2.0. In this work, a titanium layer on molybdenum substrate was deuterated with the atom...Titanium is one of the best hydrogen loading material. The pre dieted maximum loading ratio of hydrogen in titanium may reach to 2.0. In this work, a titanium layer on molybdenum substrate was deuterated with the atomic: ratio X =2H/Ti≥1.6. The change of the surface topography and rnicrostructurc of the sample before and after loading was observed by using Scan Electron Microscopy (SEM). The surface segregation of the samples after deutcron bombardment was also observed. A fluctuatingly-incrcasing trend of the deutcriuin density in titanium target was detected in the deuteron implantation experiments. which indicated a suddenly explosion (segregation) or fast diffusion of deuterium in the titanium. Significant amount of nitrogen contamination was found in thc Ti2Hx sample by nuclear reaction analysis (NRA), which indicated that the Ti2Hx structure might have the feature to trap nitrogen from air. The nitrogen contamination in Ti2Hx significantly affects the increase of the atomic ratio X展开更多
In order to understand the mechanism of air flooding shale oil, an online physical simulation method for enhanced shale oil recovery by air injection was established by integrating CT scanning and nuclear magnetic res...In order to understand the mechanism of air flooding shale oil, an online physical simulation method for enhanced shale oil recovery by air injection was established by integrating CT scanning and nuclear magnetic resonance(NMR). The development effect of shale oil by air flooding under different depletion pressures, the micro-production characteristics of pore throats with different sizes and the mechanism of shale oil recovery by air flooding were analyzed. The effects of air oxygen content, permeability, gas injection pressure, and fractures on the air flooding effect in shale and crude oil production in pores with different sizes were analyzed. The recovery of shale oil can be greatly improved by injecting air into the depleted shale reservoir, but the oil displacement efficiency and the production degree of different levels of pore throats vary with the injection timing. The higher the air oxygen content and the stronger the low-temperature oxidation, the higher the production degree of pores with different sizes and the higher the shale oil recovery. The higher the permeability and the better the pore throat connectivity, the stronger the fluid flow capacity and the higher the shale oil recovery. As the injection pressure increases, the lower limit of the production degree of pore throats decreases, but gas channeling may occur to cause a premature breakthrough;as a result, the recovery increases and then decreases. Fractures can effectively increase the contact area between gas and crude oil, and increase the air sweep coefficient and matrix oil drainage area by supplying oil to fractures through the matrix, which means that a proper fracturing before air injection can help to improve the oil displacement effect under a reasonable production pressure difference.展开更多
文摘Five phospholipids in human placenta were determined by phosphorus 31 nuclear magnetic resonance(^(31)P NMR)spectroscopy and thin-layer chromatography(TLC) scanning combined with the corrective method of absorbance proportional coefficient. The NMR spectrometer used this investigation was a Bruker AM-500 spectrometer operating at 202.4 MHz for ^(31)P chemical shifts are relative to 85% phosphoric acid. TIC was carried out by silica gel H plate developed in chloroform-methanol-glacial acetic acid-ethanol-water(25:4:6:2:0.5),with Vaskovsky reagent as colour -developing agent of phospholipids.
基金Supported by the PetroChina Science and Technology Major Project(2021-117)PetroChina CCUS Major Science and Technology Project(2021ZZ01-03)。
文摘A physical simulation method with a combination of dynamic displacement and imbibition was established by integrating nuclear magnetic resonance(NMR)and CT scanning.The microscopic production mechanism of tight/shale oil in pore throat by dynamic imbibition and the influencing factors on the development effect of dynamic imbibition were analyzed.The dynamic seepage process of fracking-soaking-backflow-production integration was simulated,which reveals the dynamic production characteristics at different development stages and their contribution to enhancing oil recovery(EOR).The seepage of tight/shale reservoirs can be divided into three stages:strong displacement and weak imbibition as oil produced rapidly by displacement from macropores and fractures,weak displacement and strong imbibition as oil produced slowly by reverse imbibition from small pores,and weak displacement and weak imbibition at dynamic equilibrium.The greater displacement pressure results in the higher displacement recovery and the lower imbibition recovery.However,if the displacement pressure is too high,the injected water is easy to break through the front and reduce the recovery degree.The higher the permeability,the greater the imbibition and displacement recovery,the shorter the time of imbibition balance,and the higher the final recovery.The fractures can effectively increase the imbibition contact area between matrix and water,reduce the oil-water seepage resistance,promote the oil-water displacement between matrix and fracture,and improve the oil displacement rate and recovery of the matrix.The soaking after fracturing is beneficial to the imbibition replacement and energy storage of the fluid;also,the effective use of the carrying of the backflow fluid and the displacement in the mining stage is the key to enhancing oil recovery.
文摘On March 11, 2019, the WHO declared COVID-19 a pandemic disease. It is a respiratory tropism SARS COV 2 infection. In the emergency of the pandemic, in medical imaging, only computed tomography (CT) of the lungs was favored to assess lung lesions. In addition, many cases of post-COVID-19 cognitive disorders have been reported. As the curve dips and services restart correctly, other imaging techniques have been used to better explore the disease. The objective of this presentation is to illustrate the contribution of metabolic imaging in the exploration of post COVID-19 cognitive disorders and to discuss the pathophysiological mechanisms. Hypometabolism brain lesions are objective signs of functional impairment whose pathophysiological mechanism is not yet fully understood. Metabolic imaging with PET-SCAN is a suitable tool for exploring these disorders, both for the severity and extent of the lesions and for the topography of the brain damage.
基金The authors gratefully acknowledge the financial support from the National Science and Technology Major Special Project(2016ZX05058-003).
文摘Due to long-term water injection,often oilfields enter the so-called medium and high water cut stage,and it is difficult to achieve good oil recovery and water reduction through standard methods(single profile control and flooding measures).Therefore,in this study,a novel method based on“plugging,profile control,and flooding”being implemented at the same time is proposed.To assess the performances of this approach,physical simulations,computer tomography,and nuclear magnetic resonance are used.The results show that the combination of a gel plugging agent,a polymer microsphere flooding agent,and a high-efficiency oil displacement agent leads to better results in terms of oil recovery with respect to the situation in which these approaches are used separately(the oil recovery is increased by 15.37%).Computer tomography scan results show that with the combined approach,a larger sweep volume and higher oil washing efficiency are obtained.The remaining oil in the cluster form can be recovered in the middle and low permeability layer,increasing the proportion of the columnar and blind end states of the oil.The nuclear magnetic resonance test results show that the combined“plugging,profile control,and flooding”treatment can also be used to control more effectively the dominant channels of the high permeability layer and further expand the recovery degree of the remaining oil in the pores of different sizes in the middle and low permeability layers.However,for the low permeability layer(permeability difference of 20),the benefits in terms of oil recovery are limited.
基金Supported by Research Fund for the Doctoral Program of Higher Education of China(No.20120073130009)National Natural Science Foundation of China(No.11175118)Research and innovation project of Shanghai Municipal Education Commission(No.12ZZ022)
文摘The properties of a Lanthanum bromide(LaBr3)detector and its response functions were investigated via experiments and simulations in this paper.The LaBr3detector had good relative energy resolution and higher efficiency than a high-purity germanium detector.Monte Carlo and other numerical methods were used to calculate the efficiencies of a LaBr3detector with a square collimation window.A model of the numerical method was established based on a pure geometric model that was consistent with the experimental situation.The results showed that the detector response functions calculated by these methods were in great agreement with experimental results.
基金Supported by a fund of the Chinese Academy of Sciences the special fund of the Nuclear Power Institute of China
文摘Titanium is one of the best hydrogen loading material. The pre dieted maximum loading ratio of hydrogen in titanium may reach to 2.0. In this work, a titanium layer on molybdenum substrate was deuterated with the atomic: ratio X =2H/Ti≥1.6. The change of the surface topography and rnicrostructurc of the sample before and after loading was observed by using Scan Electron Microscopy (SEM). The surface segregation of the samples after deutcron bombardment was also observed. A fluctuatingly-incrcasing trend of the deutcriuin density in titanium target was detected in the deuteron implantation experiments. which indicated a suddenly explosion (segregation) or fast diffusion of deuterium in the titanium. Significant amount of nitrogen contamination was found in thc Ti2Hx sample by nuclear reaction analysis (NRA), which indicated that the Ti2Hx structure might have the feature to trap nitrogen from air. The nitrogen contamination in Ti2Hx significantly affects the increase of the atomic ratio X
基金Supported by the PetroChina Major Scientific and Technological Research Project (2021DJ1102)PetroChina Science and Technology Major Project (2022kt1001)。
文摘In order to understand the mechanism of air flooding shale oil, an online physical simulation method for enhanced shale oil recovery by air injection was established by integrating CT scanning and nuclear magnetic resonance(NMR). The development effect of shale oil by air flooding under different depletion pressures, the micro-production characteristics of pore throats with different sizes and the mechanism of shale oil recovery by air flooding were analyzed. The effects of air oxygen content, permeability, gas injection pressure, and fractures on the air flooding effect in shale and crude oil production in pores with different sizes were analyzed. The recovery of shale oil can be greatly improved by injecting air into the depleted shale reservoir, but the oil displacement efficiency and the production degree of different levels of pore throats vary with the injection timing. The higher the air oxygen content and the stronger the low-temperature oxidation, the higher the production degree of pores with different sizes and the higher the shale oil recovery. The higher the permeability and the better the pore throat connectivity, the stronger the fluid flow capacity and the higher the shale oil recovery. As the injection pressure increases, the lower limit of the production degree of pore throats decreases, but gas channeling may occur to cause a premature breakthrough;as a result, the recovery increases and then decreases. Fractures can effectively increase the contact area between gas and crude oil, and increase the air sweep coefficient and matrix oil drainage area by supplying oil to fractures through the matrix, which means that a proper fracturing before air injection can help to improve the oil displacement effect under a reasonable production pressure difference.
