Pore structure plays an important role in the gas storage and flow capacity of shale gas reservoirs. Fieldemission environmental scanning electron microscopy(FE-SEM) in combination with low-pressure carbon dioxide g...Pore structure plays an important role in the gas storage and flow capacity of shale gas reservoirs. Fieldemission environmental scanning electron microscopy(FE-SEM) in combination with low-pressure carbon dioxide gas adsorption(CO2GA),nitrogen gas adsorption(N2GA),and high-pressure mercury intrusion(HPMI) were used to study the nanostructure pore morphology and pore-size distributions(PSDs) of lacustrine shale from the Upper Triassic Yanchang Formation,Ordos Basin. Results show that the pores in the shale reservoirs are generally nanoscale and can be classified into four types: organic,interparticle,intraparticle,and microfracture. The interparticle pores between clay particles and organic-matter pores develop most often,l with pore sizes that vary from several to more than 100 nm. Mercury porosimetry analysis shows total porosities ranging between 1.93 and 7.68%,with a mean value of 5.27%. The BET surface areas as determined by N2 adsorption in the nine samples range from 10 to 20 m2/g and the CO2 equivalent surface areas(2 nm)vary from 18 to 71 m2/g. Together,the HPMI,N2 GA,and CO2 GA curves indicate that the pore volumes are mainly due to pores 100 nm in size. In contrast,however,most of the specific surface areas are provided by the micropores. The total organic carbon(TOC) and clay minerals are the primary controls of the structures of nanoscale pores(especially micropores and mesopores). Micropores are predominantly determined by the content of the TOC,and mesopores are possibly related to the content of clay minerals,particularly the illite-montmorillonite mixed-layer content.展开更多
Rutin,a flavonoid found in fruits and vegetables,is a potential anticancer compound with strong anticancer activity.Therefore,electrochemical sensor was developed for the detection of rutin.In this study,CoWO_(4) nano...Rutin,a flavonoid found in fruits and vegetables,is a potential anticancer compound with strong anticancer activity.Therefore,electrochemical sensor was developed for the detection of rutin.In this study,CoWO_(4) nanosheets were synthesized via a hydrothermal method,and porous carbon(PC)was prepared via high-temperature pyrolysis.Successful preparation of the materials was confirmed,and characterization was performed by transmission electron microscopy,scanning electron microscopy,and X-ray photoelectron spectroscopy.A mixture of PC and CoWO_(4) nanosheets was used as an electrode modifier to fabricate the electrochemical sensor for the electrochemical determination of rutin.The 3D CoWO_(4) nanosheets exhibited high electrocatalytic activity and good stability.PC has a high surface-to-volume ratio and superior conductivity.Moreover,the hydrophobicity of PC allows large amounts of rutin to be adsorbed,thereby increasing the concentration of rutin at the electrode surface.Owing to the synergistic effect of the 3D CoWO_(4) nanosheets and PC,the developed electrochemical sensor was employed to quantitively determine rutin with high stability and sensitivity.The sensor showed a good linear range(5-5000 ng/mL)with a detection limit of 0.45 ng/mL.The developed sensor was successfully applied to the determination of rutin in crushed tablets and human serum samples.展开更多
CCUS (carbon capture, utilization, and storage) technology is regarded as a bottom method to achieve carbon neutrality globally. CO_(2) storage in deep coal reservoirs serves as a feasible selection for CCUS, and its ...CCUS (carbon capture, utilization, and storage) technology is regarded as a bottom method to achieve carbon neutrality globally. CO_(2) storage in deep coal reservoirs serves as a feasible selection for CCUS, and its storage potential can be attributed to the CO_(2) adsorption capacity of the coal. In this paper, a series of CO_(2) adsorption isotherm experiments were performed at different pressures and temperatures in sub-bituminous coal from the southern Junggar Basin (reservoir temperature ∼25.9°C and pressure ∼3.91 MPa). In addition, the high-pressure CO_(2) adsorption characteristics of the southern Junggar Basin coal were characterized using a supercritical D-R adsorption model. Finally, the CO_(2) storage capacities in sub-bituminous coal under the in situ reservoir temperature and pressure were analyzed. Results indicated that the excess adsorption capacities increase gradually with increasing injection pressure before reaching an asymptotic maximum magnitude of ∼34.55 cm3/g. The supercritical D-R adsorption model is suitable for characterizing the excess/absolute CO_(2) adsorption capacity, as shown by the high correlation coefficients > 0.99. The CO_(2) adsorption capacity increases with declining temperature, indicating a negative effect of temperature on CO_(2) geological sequestration. By analyzing the statistical relationships of the D-R adsorption fitting parameters with the reservoir temperature, a CO_(2) adsorption capacity evolution model was established, which can be further used for predicting CO_(2) sequestration potential at in situ reservoir conditions. CO_(2) adsorption capacity slowly increases before reaching the critical CO_(2) density, following a rapid decrease at depths greater than ∼800 m in the southern Junngar Basin. The research results presented in this paper can provide guidance for evaluating CO_(2) storage potential in deep coal seams.展开更多
Combustion characteristics in a scramjet combustor equipped with a thin strut were observed and discussed in this paper.A series of numerical simulations were carried out under different flight dynamic pressure condit...Combustion characteristics in a scramjet combustor equipped with a thin strut were observed and discussed in this paper.A series of numerical simulations were carried out under different flight dynamic pressure conditions.The parameters of cold flow field and combustion field were used to analyze the combustion characteristics.Based on the basic data,the mixing efficiency,characteristics of flame establishment and propagation as well as combustion field characteristics were discussed in this paper.The influence laws of lower dynamic pressure conditions were further revealed to optimize combustor performance.Results indicated that properly reducing the flight dynamic pressure can enhance the mixing of kerosene.The diffusion of kerosene determined the distribution of combustion zone and heat release.Then,the influencing factor that affected the chemical reaction rate was revealed to shorten chemical reaction time.And the higher flight Mach number made the flame propagation velocity faster and the combustion stability stronger.The fuel mixing became the main factor and low dynamic pressure had little effect on laminar flame propagation velocity under high Mach number conditions.The investigations in this paper are helpful for understanding the combustion characteristics under low dynamic pressure conditions.展开更多
文摘Pore structure plays an important role in the gas storage and flow capacity of shale gas reservoirs. Fieldemission environmental scanning electron microscopy(FE-SEM) in combination with low-pressure carbon dioxide gas adsorption(CO2GA),nitrogen gas adsorption(N2GA),and high-pressure mercury intrusion(HPMI) were used to study the nanostructure pore morphology and pore-size distributions(PSDs) of lacustrine shale from the Upper Triassic Yanchang Formation,Ordos Basin. Results show that the pores in the shale reservoirs are generally nanoscale and can be classified into four types: organic,interparticle,intraparticle,and microfracture. The interparticle pores between clay particles and organic-matter pores develop most often,l with pore sizes that vary from several to more than 100 nm. Mercury porosimetry analysis shows total porosities ranging between 1.93 and 7.68%,with a mean value of 5.27%. The BET surface areas as determined by N2 adsorption in the nine samples range from 10 to 20 m2/g and the CO2 equivalent surface areas(2 nm)vary from 18 to 71 m2/g. Together,the HPMI,N2 GA,and CO2 GA curves indicate that the pore volumes are mainly due to pores 100 nm in size. In contrast,however,most of the specific surface areas are provided by the micropores. The total organic carbon(TOC) and clay minerals are the primary controls of the structures of nanoscale pores(especially micropores and mesopores). Micropores are predominantly determined by the content of the TOC,and mesopores are possibly related to the content of clay minerals,particularly the illite-montmorillonite mixed-layer content.
基金supported by the National Natural Science Foundation of China(Grant No.:81872509)the Baoan TCM Development Foundation(Grant No.:2020KJCX-KTYJ-200)+7 种基金Internal Research Project of the Shenzhen Baoan Authentic TCM Therapy Hospital(Grant Nos.:BCZY2021003 and BCZY2021007)Baoan District Medical and Health Basic Research Project(Grant No.:2020JD491)Natural Science Foundation of Hubei Province(Grant No.:2019CFB429)Chinese Medicine Research Fund of Health Commission of Hubei Province(Grant Nos.:ZY2021M038 and ZY2021M051),the Youth Talent Project of Sinopharm Dongfeng General Hospital(Grant No.:2021Q03)the Science and Technology Key Program of Shiyan(Grant No.:21Y77)Baoan District Medical and Health Basic Research Project(Grant Nos.:2021JD143,2021JD281,and 2021JD290)Hubei Province Health and Family Planning Scientific Research Project(Grant Nos.:WJ2021M063 and WJ2021M062)Sanming Project of Medicine in Shenzhen(Grant No.:SZZYSM202106004).
文摘Rutin,a flavonoid found in fruits and vegetables,is a potential anticancer compound with strong anticancer activity.Therefore,electrochemical sensor was developed for the detection of rutin.In this study,CoWO_(4) nanosheets were synthesized via a hydrothermal method,and porous carbon(PC)was prepared via high-temperature pyrolysis.Successful preparation of the materials was confirmed,and characterization was performed by transmission electron microscopy,scanning electron microscopy,and X-ray photoelectron spectroscopy.A mixture of PC and CoWO_(4) nanosheets was used as an electrode modifier to fabricate the electrochemical sensor for the electrochemical determination of rutin.The 3D CoWO_(4) nanosheets exhibited high electrocatalytic activity and good stability.PC has a high surface-to-volume ratio and superior conductivity.Moreover,the hydrophobicity of PC allows large amounts of rutin to be adsorbed,thereby increasing the concentration of rutin at the electrode surface.Owing to the synergistic effect of the 3D CoWO_(4) nanosheets and PC,the developed electrochemical sensor was employed to quantitively determine rutin with high stability and sensitivity.The sensor showed a good linear range(5-5000 ng/mL)with a detection limit of 0.45 ng/mL.The developed sensor was successfully applied to the determination of rutin in crushed tablets and human serum samples.
基金the National Natural Science Foundation of China(Grant Nos.42141012,41972168,and 42030810)the Peng Cheng Shang Xue Education Fund of CUMT Education Development Foundation(No.PCSX202204)+1 种基金the Fundamental Research Funds for the Central Universities(No.2020ZDPYZD01)aa project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘CCUS (carbon capture, utilization, and storage) technology is regarded as a bottom method to achieve carbon neutrality globally. CO_(2) storage in deep coal reservoirs serves as a feasible selection for CCUS, and its storage potential can be attributed to the CO_(2) adsorption capacity of the coal. In this paper, a series of CO_(2) adsorption isotherm experiments were performed at different pressures and temperatures in sub-bituminous coal from the southern Junggar Basin (reservoir temperature ∼25.9°C and pressure ∼3.91 MPa). In addition, the high-pressure CO_(2) adsorption characteristics of the southern Junggar Basin coal were characterized using a supercritical D-R adsorption model. Finally, the CO_(2) storage capacities in sub-bituminous coal under the in situ reservoir temperature and pressure were analyzed. Results indicated that the excess adsorption capacities increase gradually with increasing injection pressure before reaching an asymptotic maximum magnitude of ∼34.55 cm3/g. The supercritical D-R adsorption model is suitable for characterizing the excess/absolute CO_(2) adsorption capacity, as shown by the high correlation coefficients > 0.99. The CO_(2) adsorption capacity increases with declining temperature, indicating a negative effect of temperature on CO_(2) geological sequestration. By analyzing the statistical relationships of the D-R adsorption fitting parameters with the reservoir temperature, a CO_(2) adsorption capacity evolution model was established, which can be further used for predicting CO_(2) sequestration potential at in situ reservoir conditions. CO_(2) adsorption capacity slowly increases before reaching the critical CO_(2) density, following a rapid decrease at depths greater than ∼800 m in the southern Junngar Basin. The research results presented in this paper can provide guidance for evaluating CO_(2) storage potential in deep coal seams.
基金supported by the National Natural Science Foundation of China(Grants No.12102110).
文摘Combustion characteristics in a scramjet combustor equipped with a thin strut were observed and discussed in this paper.A series of numerical simulations were carried out under different flight dynamic pressure conditions.The parameters of cold flow field and combustion field were used to analyze the combustion characteristics.Based on the basic data,the mixing efficiency,characteristics of flame establishment and propagation as well as combustion field characteristics were discussed in this paper.The influence laws of lower dynamic pressure conditions were further revealed to optimize combustor performance.Results indicated that properly reducing the flight dynamic pressure can enhance the mixing of kerosene.The diffusion of kerosene determined the distribution of combustion zone and heat release.Then,the influencing factor that affected the chemical reaction rate was revealed to shorten chemical reaction time.And the higher flight Mach number made the flame propagation velocity faster and the combustion stability stronger.The fuel mixing became the main factor and low dynamic pressure had little effect on laminar flame propagation velocity under high Mach number conditions.The investigations in this paper are helpful for understanding the combustion characteristics under low dynamic pressure conditions.