The recovery factor from tight gas reservoirs is typically less than 15%, even with multistage hydraulic fracturing stimulation. Such low recovery is exacerbated in tight gas condensate reservoirs, where the depletion...The recovery factor from tight gas reservoirs is typically less than 15%, even with multistage hydraulic fracturing stimulation. Such low recovery is exacerbated in tight gas condensate reservoirs, where the depletion of gas leaves the valuable condensate behind. In this paper, three enhanced gas recovery(EGR) methods including produced gas injection,CO_2 injection and water injection are investigated to increase the well productivity for a tight gas condensate reservoir in the Montney Formation, Canada. The production performance of the three EGR methods is compared and their economic feasibility is evaluated. Sensitivity analysis of the key factors such as primary production duration, bottom-hole pressures,and fracture conductivity is conducted and their effects on the well production performance are analyzed. Results show that, compared with the simple depletion method, both the cumulative gas and condensate production increase with fluids injected. Produced gas injection leads to both a higher gas and condensate production compared with those of the CO_2 injection, while waterflooding suffers from injection difficulty and the corresponding low sweep efficiency. Meanwhile, the injection cost is lower for the produced gas injection due to the on-site available gas source and minimal transport costs,gaining more economic benefits than the other EGR methods.展开更多
Cytoplasmic male sterility(CMS)-restorer system is a useful tool to exploit heterosis in soybean.The major restorer gene for the M-type CMS is known as Rf-m,located in the 162.4-kb region on chromosome 16.Sequence ana...Cytoplasmic male sterility(CMS)-restorer system is a useful tool to exploit heterosis in soybean.The major restorer gene for the M-type CMS is known as Rf-m,located in the 162.4-kb region on chromosome 16.Sequence analysis has revealed that the Rf-m locus in Glycine max consists of seven penta tricopeptide repeat(GmPPR)genes.The deduced amino acid sequences contain 8 to 14 PPR motifs,and a phylogenetic analysis grouped these GmPPR proteins into two PPR subfamilies:Glyma.16G161800 belongs to the PLS subfamily,and the P subfamily consists.of Glyma.16G161900,Glyma 16G162000,Glyma.16G162100,Glyma.16G162700,Glyma.16G162800,and Gly-ma 16G163100.The phylogenetic analysis of seven GmPPR proteins and 27 other plant PPR proteins also showed that proteins in the same subfamilies cluster together.Comparative sequence analysis was conducted using the seven Rf-m candidate GmPPR genes from the sterile line W931A,the maintainer line W931B,and the restorer line WR016,the result showed that Glyma 16G161900 had higher polymorphism than the other candidate genes.Based on real-time quantitative RT-PCR data,all seven GmPPR genes were differentially expressed but showed constitutive expression in roots,stems,leaves,and pollen grains.Additionally,the expression level of Gly-ma 16G161900 in the sterile line W931 A was significantly higher in all tissues than in the restorer line WR016.Taken together,these results suggest that Glyma 16G161900 is the most likely candidate for the restorer gene Rf-m.This study is the first report and analysis of candidate fertility restorer(Rf)genes encoding PPR proteins in soybean.展开更多
The fundamental measurement of space gravitational wave detection is to monitor the relative motion between pairs of freely falling test masses using heterodyne laser interferometry to a precision of 10 pm. The masses...The fundamental measurement of space gravitational wave detection is to monitor the relative motion between pairs of freely falling test masses using heterodyne laser interferometry to a precision of 10 pm. The masses under test are millions of kilometers apart. The inter-spacecraft laser interferometry telescope deliver laser efficiently from one spacecraft to another. It is an important component of the gravitational wave detection observatory. It needs to meet the requirements of large compression ratio, high image quality and extraordinary stray light suppression ability. Based on the primary aberration theory, the method of the large compression ratio off-axis four-mirror optical system design is explored. After optimization, the system has an entrance pupil of 200 mm, compression ratio of 40 times, scientific field of view (FOV) of ±8 μrad. To facilitate suppressing the stray light and delivering the laser beam to the back-end scientific interferometers, the intermediate images and the real exit pupils are spatially available. Over the full FOV, the maximum root mean square (RMS) wavefront error is less than 0.007λ, PV value is less than 0.03λ (λ = 1064 nm). The image quality is approached to the diffraction-limit. The TTL noise caused by the wavefront error of the telescope is analyzed. The TTL noise in the image space of 300 μrad range is less than 1 × 10-10 m whose slope is lower than 0.6 μm/rad, which is under the noise budget of the laser interferometer space antenna (LISA), satisfying the requirements of space gravitational wave detection.展开更多
Urban lakes were critical in aquatic ecology environments,but how environmental factors affected the distribution and change characteristics of algal communities in urban lakes of Xi’an city was not clearly.Here,we i...Urban lakes were critical in aquatic ecology environments,but how environmental factors affected the distribution and change characteristics of algal communities in urban lakes of Xi’an city was not clearly.Here,we investigated the algal community structure of six urban lakes in Xi’an and evaluated the effects of water quality parameters on algae.The results indicated that the significant differences on physicochemical parameters existed in different urban lakes.The maximum concentration of total phosphorus in urban lakes was(0.18±0.01)mg/L and there was a phenomenon of phosphorus limitation.In addition,51 genera of algae were identified and Chlorella sp.was the dominant algal species,which was affiliated with Chlorophyta.Network analysis elucidated that each lake had a unique algal community network and the positive correlation was dominant in the interaction between algae species,illustrating that mature microbial communities existed or occupied similar niches.Redundancy analysis illustrated that environmental factors explained 47.35% variance of algal species-water quality correlation collectively,indicating that water quality conditions had a significant influence on the temporal variations of algae.Structural equation model further verified that algal community structure was directly or indirectly regulated by different water quality conditions.Our study shows that temporal patterns of algal communities can reveal the dynamics and interactions of different urban ecosystem types,providing a theoretical basis for assessing eutrophication levels and for water quality management.展开更多
Wastewater treatment plants(WWTPs) are deemed reservoirs of antibiotic resistance genes(ARGs). Bacterial phylogeny can shape the resistome in activated sludge. However, the co-occurrence and interaction of ARGs abunda...Wastewater treatment plants(WWTPs) are deemed reservoirs of antibiotic resistance genes(ARGs). Bacterial phylogeny can shape the resistome in activated sludge. However, the co-occurrence and interaction of ARGs abundance and bacterial communities in different WWTPs located at continental scales are still not comprehensively understood. Here, we applied quantitative PCR and Miseq sequence approaches to unveil the changing profiles of ARGs(sul1, sul2, tet W, tet Q, tet X), int I1 gene, and bacterial communities in 18 geographically distributed WWTPs. The results showed that the average relative abundance of sul1 and sul2 genes were 2.08 × 10^(-1) and 1.32 × 10^(-1) copies/16 S rRNA copies, respectively. The abundance of tet W gene was positively correlated with the Shannon diversity index(H′), while both studied sul genes had significant positive relationship with the int I1 gene. The highest average relative abundances of sul1, sul2, tet X, and int I1 genes were found in south region and oxidation ditch system. Network analysis found that 16 bacterial genera co-occurred with tet W gene. Co-occurrence patterns were revealed distinct community interactions between aerobic/anoxic/aerobic and oxidation ditch systems. The redundancy analysis model plot of the bacterial community composition clearly demonstrated that the sludge samples were significant differences among those from the different geographical areas,and the shifts in bacterial community composition were correlated with ARGs. Together,these findings from the present study will highlight the potential risks of ARGs and bacterial populations carrying these ARGs, and enable the development of suitable technique to control the dissemination of ARGs from WWTPs into aquatic environments.展开更多
基金funding from Natural Sciences and Engineering Research Council of Canada (NSERC) for this researchsupport from the University of Calgary Beijing Research Site, a research initiative associated with the University of Calgary Global Research Initiative in Sustainable Low Carbon Unconventional Resources, the Kerui Group, and the Mitacs Accelerate program
文摘The recovery factor from tight gas reservoirs is typically less than 15%, even with multistage hydraulic fracturing stimulation. Such low recovery is exacerbated in tight gas condensate reservoirs, where the depletion of gas leaves the valuable condensate behind. In this paper, three enhanced gas recovery(EGR) methods including produced gas injection,CO_2 injection and water injection are investigated to increase the well productivity for a tight gas condensate reservoir in the Montney Formation, Canada. The production performance of the three EGR methods is compared and their economic feasibility is evaluated. Sensitivity analysis of the key factors such as primary production duration, bottom-hole pressures,and fracture conductivity is conducted and their effects on the well production performance are analyzed. Results show that, compared with the simple depletion method, both the cumulative gas and condensate production increase with fluids injected. Produced gas injection leads to both a higher gas and condensate production compared with those of the CO_2 injection, while waterflooding suffers from injection difficulty and the corresponding low sweep efficiency. Meanwhile, the injection cost is lower for the produced gas injection due to the on-site available gas source and minimal transport costs,gaining more economic benefits than the other EGR methods.
基金the National Key Research and Development Program of China(Grant No.2016YFD0101503)the Key Research and Development Program of Anhui Province(Grant No.202004a06020034)+1 种基金the Major Science and Technology Project of Anhui Province(Grant No.18030701178)the Program on Industrial Technology System of National Soybean(Grant No.CARS-04-PS07)。
文摘Cytoplasmic male sterility(CMS)-restorer system is a useful tool to exploit heterosis in soybean.The major restorer gene for the M-type CMS is known as Rf-m,located in the 162.4-kb region on chromosome 16.Sequence analysis has revealed that the Rf-m locus in Glycine max consists of seven penta tricopeptide repeat(GmPPR)genes.The deduced amino acid sequences contain 8 to 14 PPR motifs,and a phylogenetic analysis grouped these GmPPR proteins into two PPR subfamilies:Glyma.16G161800 belongs to the PLS subfamily,and the P subfamily consists.of Glyma.16G161900,Glyma 16G162000,Glyma.16G162100,Glyma.16G162700,Glyma.16G162800,and Gly-ma 16G163100.The phylogenetic analysis of seven GmPPR proteins and 27 other plant PPR proteins also showed that proteins in the same subfamilies cluster together.Comparative sequence analysis was conducted using the seven Rf-m candidate GmPPR genes from the sterile line W931A,the maintainer line W931B,and the restorer line WR016,the result showed that Glyma 16G161900 had higher polymorphism than the other candidate genes.Based on real-time quantitative RT-PCR data,all seven GmPPR genes were differentially expressed but showed constitutive expression in roots,stems,leaves,and pollen grains.Additionally,the expression level of Gly-ma 16G161900 in the sterile line W931 A was significantly higher in all tissues than in the restorer line WR016.Taken together,these results suggest that Glyma 16G161900 is the most likely candidate for the restorer gene Rf-m.This study is the first report and analysis of candidate fertility restorer(Rf)genes encoding PPR proteins in soybean.
文摘The fundamental measurement of space gravitational wave detection is to monitor the relative motion between pairs of freely falling test masses using heterodyne laser interferometry to a precision of 10 pm. The masses under test are millions of kilometers apart. The inter-spacecraft laser interferometry telescope deliver laser efficiently from one spacecraft to another. It is an important component of the gravitational wave detection observatory. It needs to meet the requirements of large compression ratio, high image quality and extraordinary stray light suppression ability. Based on the primary aberration theory, the method of the large compression ratio off-axis four-mirror optical system design is explored. After optimization, the system has an entrance pupil of 200 mm, compression ratio of 40 times, scientific field of view (FOV) of ±8 μrad. To facilitate suppressing the stray light and delivering the laser beam to the back-end scientific interferometers, the intermediate images and the real exit pupils are spatially available. Over the full FOV, the maximum root mean square (RMS) wavefront error is less than 0.007λ, PV value is less than 0.03λ (λ = 1064 nm). The image quality is approached to the diffraction-limit. The TTL noise caused by the wavefront error of the telescope is analyzed. The TTL noise in the image space of 300 μrad range is less than 1 × 10-10 m whose slope is lower than 0.6 μm/rad, which is under the noise budget of the laser interferometer space antenna (LISA), satisfying the requirements of space gravitational wave detection.
基金supported by the Ministry of Science and Technology of China(2018YFA0703200 and 2022YFB3603800)the National Natural Science Foundation of China(21875259,52233010,51725304,61890943 and 22021002)+4 种基金the Chinese Academy of Sciences Project for Young Scientists in Basic Research(YSBR-053)the Youth Innovation Promotion Association of the Chinese Academy of Sciencesthe National Program for Support of Top-notch Young ProfessionalsBeijing National Laboratory for Molecular Sciences(BNLMS-CXXM-202012)the Key Research Program of the Chinese Academy of Sciences(XDPB13)。
基金supported by the National Science Foundation of China(Nos.51978561 and 51979217)the Youth Innovation Team of Shaanxi Universities in 2021(PI:Zhang Haihan)+1 种基金the Grant from Youth Innovation Team of Shaanxi Universities in 2021(No.21JP061)Natural Science Basic Research Program of Shaanxi Province(No.2022JM-224).
文摘Urban lakes were critical in aquatic ecology environments,but how environmental factors affected the distribution and change characteristics of algal communities in urban lakes of Xi’an city was not clearly.Here,we investigated the algal community structure of six urban lakes in Xi’an and evaluated the effects of water quality parameters on algae.The results indicated that the significant differences on physicochemical parameters existed in different urban lakes.The maximum concentration of total phosphorus in urban lakes was(0.18±0.01)mg/L and there was a phenomenon of phosphorus limitation.In addition,51 genera of algae were identified and Chlorella sp.was the dominant algal species,which was affiliated with Chlorophyta.Network analysis elucidated that each lake had a unique algal community network and the positive correlation was dominant in the interaction between algae species,illustrating that mature microbial communities existed or occupied similar niches.Redundancy analysis illustrated that environmental factors explained 47.35% variance of algal species-water quality correlation collectively,indicating that water quality conditions had a significant influence on the temporal variations of algae.Structural equation model further verified that algal community structure was directly or indirectly regulated by different water quality conditions.Our study shows that temporal patterns of algal communities can reveal the dynamics and interactions of different urban ecosystem types,providing a theoretical basis for assessing eutrophication levels and for water quality management.
基金supported by the International Science and Technology Cooperation Program(No.2018KW-011)the National Key Research and Development Program of China(No.2016YFC0400706)+1 种基金the grant from "Young Outstanding Talents" in Universities of Shaanxi Provincesupport from the "Yanta Outstanding Youth Scholar" project from Xi'an University of Architecture and Technology(XAUAT)
文摘Wastewater treatment plants(WWTPs) are deemed reservoirs of antibiotic resistance genes(ARGs). Bacterial phylogeny can shape the resistome in activated sludge. However, the co-occurrence and interaction of ARGs abundance and bacterial communities in different WWTPs located at continental scales are still not comprehensively understood. Here, we applied quantitative PCR and Miseq sequence approaches to unveil the changing profiles of ARGs(sul1, sul2, tet W, tet Q, tet X), int I1 gene, and bacterial communities in 18 geographically distributed WWTPs. The results showed that the average relative abundance of sul1 and sul2 genes were 2.08 × 10^(-1) and 1.32 × 10^(-1) copies/16 S rRNA copies, respectively. The abundance of tet W gene was positively correlated with the Shannon diversity index(H′), while both studied sul genes had significant positive relationship with the int I1 gene. The highest average relative abundances of sul1, sul2, tet X, and int I1 genes were found in south region and oxidation ditch system. Network analysis found that 16 bacterial genera co-occurred with tet W gene. Co-occurrence patterns were revealed distinct community interactions between aerobic/anoxic/aerobic and oxidation ditch systems. The redundancy analysis model plot of the bacterial community composition clearly demonstrated that the sludge samples were significant differences among those from the different geographical areas,and the shifts in bacterial community composition were correlated with ARGs. Together,these findings from the present study will highlight the potential risks of ARGs and bacterial populations carrying these ARGs, and enable the development of suitable technique to control the dissemination of ARGs from WWTPs into aquatic environments.