Recent studies have indicated that the injection of carbon dioxide(CO_(2))can lead to increased oil recovery in fractured shale reservoirs following natural depletion.Despite advancements in understanding mass exchang...Recent studies have indicated that the injection of carbon dioxide(CO_(2))can lead to increased oil recovery in fractured shale reservoirs following natural depletion.Despite advancements in understanding mass exchange processes in subsurface formations,there remains a knowledge gap concerning the disparities in these processes between the matrix and fractures at the pore scale in formations with varying permeability.This study aims to experimentally investigate the CO_(2) diffusion behaviors and in situ oil recovery through a CO_(2) huff‘n’puff process in the Jimsar shale oil reservoir.To achieve this,we designed three matrix-fracture models with different permeabilities(0.074 mD,0.170 mD,and 0.466 mD)and experimented at 30 MPa and 91℃.The oil concentration in both the matrix and fracture was monitored using a low-field nuclear magnetic resonance(LF-NMR)technique to quantify in situ oil recovery and elucidate mass-exchange behaviors.The results showed that after three cycles of CO_(2) huff‘n’puff,the total recovery degree increased from 30.28%to 34.95%as the matrix permeability of the core samples increased from 0.074 to 0.466 mD,indicating a positive correlation between CO_(2) extraction efficiency and matrix permeability.Under similar fracture conditions,the increase in matrix permeability further promoted CO_(2) extraction efficiency during CO_(2) huff‘n’puff.Specifically,the increase in matrix permeability of the core had the greatest effect on the extraction of the first-cycle injection in large pores,which increased from 16.42%to 36.64%.The findings from our research provide valuable insights into the CO_(2) huff‘n’puff effects in different pore sizes following fracturing under varying permeability conditions,shedding light on the mechanisms of CO_(2)-enhanced oil recovery in fractured shale oil reservoirs.展开更多
A Laue microdiffraction beamline(BL03HB) was constructed at the Shanghai Synchrotron Radiation Facility(SSRF).This beamline features two consecutive focusing points in two different sectors within its end station, the...A Laue microdiffraction beamline(BL03HB) was constructed at the Shanghai Synchrotron Radiation Facility(SSRF).This beamline features two consecutive focusing points in two different sectors within its end station, the first dedicated to protein crystallography and the other tailored to materials science applications. Based on a superbend dipole magnet with a magnetic field of 2.29 T, a two-stage focusing design was implemented with two sets of Kirkpatrick-Baez mirrors to achieve a micro white beam as small as 4.2 μ m ×4.3 μ m at the first sector and 0.9 μ m ×1.3 μ m at the second sector in the standard beamline operation mode at SSRF. The X-ray microbeam in the two sectors can be easily switched between monochromatic and white beams by moving a four-bounce monochromator in or out of the light path, respectively. In the protein crystallography sector, white-beam Laue microdiffraction was demonstrated to successfully determine the structure of protein crystals from only a few images of diffraction data collected by a Pilatus 2 M area detector. In the materials science sector,the white-beam Laue diffraction was collected in a reflection geometry using another Pilatus 2 M area detector, which could map the microstructural distribution on the sample surface by scanning the samples. In general, the BL03HB beamline promotes the application of Laue microdiffraction in both protein crystallography and materials science. This paper presents a comprehensive overview of the BL03HB beamline, end station, and the first commission results.展开更多
Plants overcome environmental stress by generating metabolic pathways.Thus,it is crucial to understand the physiological mechanisms of plant responses to changing environments.Ardisia crenata var.bicolor has an import...Plants overcome environmental stress by generating metabolic pathways.Thus,it is crucial to understand the physiological mechanisms of plant responses to changing environments.Ardisia crenata var.bicolor has an important ornamental and medicinal value.To reveal the impact of elevational gradient on the habitat soil and plant physiological attributes of this species,we collected root topsoil(0–20 cm)and subsoil(20–40 cm)samples and upper leaves at the initial blooming phase,in a survey of six elevations at 1,257 m,1,538 m,1,744 m,1,970 m,2,135 m,and 2,376 m,with 18 block plots,and 5sampling points at each site.Temperature decreases with an increase in elevation,and soil variables,and enzymatic activities fluctuated in both the topsoil and subsoil,with all of them increasing with elevation and decreasing with soil depth.Redundancy analysis was conducted to explore the correlation between the distribution of A.crenata var.bicolor along the elevational gradient and soil nutrients and enzyme activities,the soil properties were mainly affected by p H at low elevations,and governed by total phosphorus(TP)and available nitrogen(AN)at high elevations.The levels of chlorophyll,carbohydrates,and enzymatic activity except for anthocyanin in this species showed significant variation depending on physiological attributes evaluated at the different collection elevations.The decline in chlorophyll a and b may be associated with the adaptive response to avoid environmental stress,while its higher soluble sugar and protein contents play important roles in escaping adverse climatic conditions,and the increases in activities of antioxidant enzymes except peroxidase(POD)reflect this species’higher capacity for reactive oxygen scavenging(ROS)at high elevations.This study provides supporting evidence that elevation significantly affects the physiological attributes of A.crenata var.bicolor on Gaoligong Mountain,which is helpful for understanding plant adaptation strategies and the plasticity of plant physiological traits along the elevational gradients.展开更多
Backgrounds:Percutaneous ultrasound(US)and endoscopic ultrasound(EUS)-guided pancreatic biopsies are widely accepted in the diagnosis of pancreatic diseases.Studies comparing the diagnostic performance of US-and EUS-g...Backgrounds:Percutaneous ultrasound(US)and endoscopic ultrasound(EUS)-guided pancreatic biopsies are widely accepted in the diagnosis of pancreatic diseases.Studies comparing the diagnostic performance of US-and EUS-guided pancreatic biopsies are lacking.This study aimed to evaluate and compare the diagnostic yields of US-and EUS-guided pancreatic biopsies and identify the risk factors for inconclusive biopsies.Methods:Of the 1074 solid pancreatic lesions diagnosed from January 2017 to February 2021 in our center,275 underwent EUS-guided fine needle aspiration(EUS-FNA),and 799 underwent US-guided core needle biopsy(US-CNB/FNA).The outcomes were inconclusive pathological biopsy,diagnostic accuracy and the need for repeat biopsy.All of the included factors and diagnostic performances of both USCNB/FNA and EUS-FNA were compared,and the independent predictors for the study outcomes were identified.Results:The diagnostic accuracy was 89.8%for EUS-FNA and 95.2%for US-CNB/FNA(P=0.001).Biopsy under EUS guidance[odds ratio(OR)=1.808,95%confidence interval(CI):1.083-3.019;P=0.024],lesion size<2 cm(OR=2.069,95%CI:1.145-3.737;P=0.016),hypoechoic appearance(OR=0.274,95%CI:0.097-0.775;P=0.015)and non-pancreatic ductal adenocarcinoma carcinoma(PDAC)diagnosis(OR=2.637,95%CI:1.563-4.449;P<0.001)were identified as factors associated with inconclusive pathological biopsy.Hypoechoic appearance(OR=0.236,95%CI:0.064-0.869;P=0.030),lesions in the uncinate process of the pancreas(OR=3.506,95%CI:1.831-6.713;P<0.001)and non-PDAC diagnosis(OR=2.622,95%CI:1.278-5.377;P=0.009)were independent predictors for repeat biopsy.Biopsy under EUS guidance(OR=2.024,95%CI:1.195-3.429;P=0.009),lesions in the uncinate process of the pancreas(OR=1.776,95%CI:1.014-3.108;P=0.044)and hypoechoic appearance(OR=0.127,95%CI:0.047-0.347;P<0.001)were associated with diagnostic accuracy.Conclusions:In conclusion,both percutaneous US-and EUS-guided biopsies of solid pancreatic lesions are safe and effective;though the diagnostic accuracy of EUS-FNA is inferior to US-CNB/FNA.A tailored pancreatic biopsy should be considered a part of the management algorithm for the diagnosis of solid pancreatic disease.展开更多
Grain filling is the physiological process for determining the obtainment of yield in cereal crops.The grain-filling characteristics of 50 maize brand hybrids released from 1964 to 2014 in China were assayed across mu...Grain filling is the physiological process for determining the obtainment of yield in cereal crops.The grain-filling characteristics of 50 maize brand hybrids released from 1964 to 2014 in China were assayed across multiple environments.We found that the grain-filling duration(54.46%)and rate(43.40%)at the effective grain-filling phase greatly contributed to the final performance parameter of 100-kernel weight(HKW).Meanwhile,along with the significant increase in HKW,the accumulated growing degree days(GDDs)for the actual grain-filling period duration(AFPD)among the selected brand hybrids released from the 1960s to the 2010s in China had a decadal increase of 23.41℃ d.However,there was a decadal increase of only 19.76℃ d for GDDs of the days from sowing to physiological maturity(DPM),which was also demonstrated by a continuous decrease in the ratio between the days from sowing to silking(DS)and DPM(i.e.,from 53.24%in the 1960s to 49.78%in the 2010s).In contrast,there were no significant changes in grain-filling rate along with the release years of the selected hybrids.Moreover,the stability of grain-filling characteristics across environments also significantly increased along with the hybrid release years.We also found that the exotic hybrids showed a longer grain-filling duration at the effective grain-filling phase and more stability of the grain-filling characteristics than those of the Chinese local hybrids.According to the results of this study,it is expected that the relatively longer grain-filling duration,shorter DS,higher grain-filling rate,and steady grain-filling characteristics would contribute to the yield improvement of maize hybrids in the future.展开更多
基金National Natural Science Foundation of China via grant number 52174035,52304048China Postdoctoral Science Foundation(2022M722637)Research and Innovation Fund for Graduate Students of Southwest Petroleum University(2022KYCX026).
文摘Recent studies have indicated that the injection of carbon dioxide(CO_(2))can lead to increased oil recovery in fractured shale reservoirs following natural depletion.Despite advancements in understanding mass exchange processes in subsurface formations,there remains a knowledge gap concerning the disparities in these processes between the matrix and fractures at the pore scale in formations with varying permeability.This study aims to experimentally investigate the CO_(2) diffusion behaviors and in situ oil recovery through a CO_(2) huff‘n’puff process in the Jimsar shale oil reservoir.To achieve this,we designed three matrix-fracture models with different permeabilities(0.074 mD,0.170 mD,and 0.466 mD)and experimented at 30 MPa and 91℃.The oil concentration in both the matrix and fracture was monitored using a low-field nuclear magnetic resonance(LF-NMR)technique to quantify in situ oil recovery and elucidate mass-exchange behaviors.The results showed that after three cycles of CO_(2) huff‘n’puff,the total recovery degree increased from 30.28%to 34.95%as the matrix permeability of the core samples increased from 0.074 to 0.466 mD,indicating a positive correlation between CO_(2) extraction efficiency and matrix permeability.Under similar fracture conditions,the increase in matrix permeability further promoted CO_(2) extraction efficiency during CO_(2) huff‘n’puff.Specifically,the increase in matrix permeability of the core had the greatest effect on the extraction of the first-cycle injection in large pores,which increased from 16.42%to 36.64%.The findings from our research provide valuable insights into the CO_(2) huff‘n’puff effects in different pore sizes following fracturing under varying permeability conditions,shedding light on the mechanisms of CO_(2)-enhanced oil recovery in fractured shale oil reservoirs.
文摘A Laue microdiffraction beamline(BL03HB) was constructed at the Shanghai Synchrotron Radiation Facility(SSRF).This beamline features two consecutive focusing points in two different sectors within its end station, the first dedicated to protein crystallography and the other tailored to materials science applications. Based on a superbend dipole magnet with a magnetic field of 2.29 T, a two-stage focusing design was implemented with two sets of Kirkpatrick-Baez mirrors to achieve a micro white beam as small as 4.2 μ m ×4.3 μ m at the first sector and 0.9 μ m ×1.3 μ m at the second sector in the standard beamline operation mode at SSRF. The X-ray microbeam in the two sectors can be easily switched between monochromatic and white beams by moving a four-bounce monochromator in or out of the light path, respectively. In the protein crystallography sector, white-beam Laue microdiffraction was demonstrated to successfully determine the structure of protein crystals from only a few images of diffraction data collected by a Pilatus 2 M area detector. In the materials science sector,the white-beam Laue diffraction was collected in a reflection geometry using another Pilatus 2 M area detector, which could map the microstructural distribution on the sample surface by scanning the samples. In general, the BL03HB beamline promotes the application of Laue microdiffraction in both protein crystallography and materials science. This paper presents a comprehensive overview of the BL03HB beamline, end station, and the first commission results.
基金supported by the Doctoral Research Fund Project of Southwest Forestry University(CN)(Grant No.111806)。
文摘Plants overcome environmental stress by generating metabolic pathways.Thus,it is crucial to understand the physiological mechanisms of plant responses to changing environments.Ardisia crenata var.bicolor has an important ornamental and medicinal value.To reveal the impact of elevational gradient on the habitat soil and plant physiological attributes of this species,we collected root topsoil(0–20 cm)and subsoil(20–40 cm)samples and upper leaves at the initial blooming phase,in a survey of six elevations at 1,257 m,1,538 m,1,744 m,1,970 m,2,135 m,and 2,376 m,with 18 block plots,and 5sampling points at each site.Temperature decreases with an increase in elevation,and soil variables,and enzymatic activities fluctuated in both the topsoil and subsoil,with all of them increasing with elevation and decreasing with soil depth.Redundancy analysis was conducted to explore the correlation between the distribution of A.crenata var.bicolor along the elevational gradient and soil nutrients and enzyme activities,the soil properties were mainly affected by p H at low elevations,and governed by total phosphorus(TP)and available nitrogen(AN)at high elevations.The levels of chlorophyll,carbohydrates,and enzymatic activity except for anthocyanin in this species showed significant variation depending on physiological attributes evaluated at the different collection elevations.The decline in chlorophyll a and b may be associated with the adaptive response to avoid environmental stress,while its higher soluble sugar and protein contents play important roles in escaping adverse climatic conditions,and the increases in activities of antioxidant enzymes except peroxidase(POD)reflect this species’higher capacity for reactive oxygen scavenging(ROS)at high elevations.This study provides supporting evidence that elevation significantly affects the physiological attributes of A.crenata var.bicolor on Gaoligong Mountain,which is helpful for understanding plant adaptation strategies and the plasticity of plant physiological traits along the elevational gradients.
基金supported by grants from The Development Project of National Major Scientific Research Instrument(82027803)National Natural Science Foundation of China(81971623)Key Project of Natural Science Foundation of Zhejiang Province(LZ20H180001)。
文摘Backgrounds:Percutaneous ultrasound(US)and endoscopic ultrasound(EUS)-guided pancreatic biopsies are widely accepted in the diagnosis of pancreatic diseases.Studies comparing the diagnostic performance of US-and EUS-guided pancreatic biopsies are lacking.This study aimed to evaluate and compare the diagnostic yields of US-and EUS-guided pancreatic biopsies and identify the risk factors for inconclusive biopsies.Methods:Of the 1074 solid pancreatic lesions diagnosed from January 2017 to February 2021 in our center,275 underwent EUS-guided fine needle aspiration(EUS-FNA),and 799 underwent US-guided core needle biopsy(US-CNB/FNA).The outcomes were inconclusive pathological biopsy,diagnostic accuracy and the need for repeat biopsy.All of the included factors and diagnostic performances of both USCNB/FNA and EUS-FNA were compared,and the independent predictors for the study outcomes were identified.Results:The diagnostic accuracy was 89.8%for EUS-FNA and 95.2%for US-CNB/FNA(P=0.001).Biopsy under EUS guidance[odds ratio(OR)=1.808,95%confidence interval(CI):1.083-3.019;P=0.024],lesion size<2 cm(OR=2.069,95%CI:1.145-3.737;P=0.016),hypoechoic appearance(OR=0.274,95%CI:0.097-0.775;P=0.015)and non-pancreatic ductal adenocarcinoma carcinoma(PDAC)diagnosis(OR=2.637,95%CI:1.563-4.449;P<0.001)were identified as factors associated with inconclusive pathological biopsy.Hypoechoic appearance(OR=0.236,95%CI:0.064-0.869;P=0.030),lesions in the uncinate process of the pancreas(OR=3.506,95%CI:1.831-6.713;P<0.001)and non-PDAC diagnosis(OR=2.622,95%CI:1.278-5.377;P=0.009)were independent predictors for repeat biopsy.Biopsy under EUS guidance(OR=2.024,95%CI:1.195-3.429;P=0.009),lesions in the uncinate process of the pancreas(OR=1.776,95%CI:1.014-3.108;P=0.044)and hypoechoic appearance(OR=0.127,95%CI:0.047-0.347;P<0.001)were associated with diagnostic accuracy.Conclusions:In conclusion,both percutaneous US-and EUS-guided biopsies of solid pancreatic lesions are safe and effective;though the diagnostic accuracy of EUS-FNA is inferior to US-CNB/FNA.A tailored pancreatic biopsy should be considered a part of the management algorithm for the diagnosis of solid pancreatic disease.
基金partly supported by the National Key R&D Program of China(2016YFD0100303 and 2016YFD0100103)the Fundamental Research Funds for Central Non-Profit of Institute of Crop Sciences,Chinese Academy of Agricultural Sciences(Y2020YJ09 and CAAS-ZDRW202109)the Agricultural Science and Technology Innovation Program,China(ASTIP)。
文摘Grain filling is the physiological process for determining the obtainment of yield in cereal crops.The grain-filling characteristics of 50 maize brand hybrids released from 1964 to 2014 in China were assayed across multiple environments.We found that the grain-filling duration(54.46%)and rate(43.40%)at the effective grain-filling phase greatly contributed to the final performance parameter of 100-kernel weight(HKW).Meanwhile,along with the significant increase in HKW,the accumulated growing degree days(GDDs)for the actual grain-filling period duration(AFPD)among the selected brand hybrids released from the 1960s to the 2010s in China had a decadal increase of 23.41℃ d.However,there was a decadal increase of only 19.76℃ d for GDDs of the days from sowing to physiological maturity(DPM),which was also demonstrated by a continuous decrease in the ratio between the days from sowing to silking(DS)and DPM(i.e.,from 53.24%in the 1960s to 49.78%in the 2010s).In contrast,there were no significant changes in grain-filling rate along with the release years of the selected hybrids.Moreover,the stability of grain-filling characteristics across environments also significantly increased along with the hybrid release years.We also found that the exotic hybrids showed a longer grain-filling duration at the effective grain-filling phase and more stability of the grain-filling characteristics than those of the Chinese local hybrids.According to the results of this study,it is expected that the relatively longer grain-filling duration,shorter DS,higher grain-filling rate,and steady grain-filling characteristics would contribute to the yield improvement of maize hybrids in the future.
