Shale gas reservoirs have poor physical properties and a large number of micro-nano pores have been developed.Shale gas wells have no natural productivity and need fracturing reconstruction measures to put into produc...Shale gas reservoirs have poor physical properties and a large number of micro-nano pores have been developed.Shale gas wells have no natural productivity and need fracturing reconstruction measures to put into production.However,the fracturing fluid will enter the reservoir space of shale matrix after fracturing and affect the production of shale gas.At present,there is no consensus on the influence of fracturing fluid retention on gas well production.Based on this,the paper adopts gas molecular transport analyzer to carry out experimental research on the influence of fracturing fluid on shale gas diffusion law after entering matrix pores.The results show that:(1)Compared with the diffusion capacity of single-phase shale gas,the diffusion capacity of shale gas decreases significantly when fracturing fluid is present in the reservoir;(2)In the process of fracturing fluid flowback,when the water saturation in the reservoir decreases from 50%to 0,the gas well productivity increases by about 60%.(3)When fracturing fluid exists in the reservoir,the pore diameter has an exponential relationship with the shale gas diffusion coefficient,and the diffusion coefficient increases exponentially with the increase of pore diameter.The research of this paper provides theoretical basis for guiding the efficient development of shale gas wells.展开更多
Antibiotic pollution imposes urgent threats to public health and microbial-mediated ecological processes.Existing studies have primarily focused on bacterial responses to antibiotic pollution,but they ignored the micr...Antibiotic pollution imposes urgent threats to public health and microbial-mediated ecological processes.Existing studies have primarily focused on bacterial responses to antibiotic pollution,but they ignored the microeukaryotic counterpart,though microeukaryotes are functionally important(e.g.,predators and saprophytes)in microbial ecology.Herein,we explored how the assembly of sediment microeukaryotes was affected by increasing antibiotic pollution at the inlet(control)and across the outlet sites along a shrimpwastewater discharge channel.The structures of sedimentmicroeukaryotic community were substantially altered by the increasing nutrient and antibiotic pollutions,whichwere primarily controlled by the direct effects of phosphate and ammonium(−0.645 and 0.507,respectively).In addition,tetracyclines exerted a large effect(0.209),including direct effect(0.326)and indirect effect(−0.117),on the microeukaryotic assembly.On the contrary,the fungal subcommunity was relatively resistant to antibiotic pollution.Segmented analysis depicted nonlinear responses of microeukaryotic genera to the antibiotic pollution gradient,as supported by the significant tipping points.We screened 30 antibiotic concentration-discriminatory taxa of microeukaryotes,which can quantitatively and accurately predict(98.7%accuracy)the in-situ antibiotic concentration.Sediment microeukaryotic(except fungal)community is sensitive to antibiotic pollution,and the identified bioindicators could be used for antibiotic pollution diagnosis.展开更多
The ability to perform short-term traffic flow forecasting is a crucial component of intelligent transportation systems. However, accurate and reliable traffic flow forecasting is still a significant issue due to the ...The ability to perform short-term traffic flow forecasting is a crucial component of intelligent transportation systems. However, accurate and reliable traffic flow forecasting is still a significant issue due to the complexity and variability of real traffic systems. To improve the accuracy of short-term traffic flow forecasting, this paper presents a novel hybrid prediction framework based on Support Vector Regression （SVR） that uses a Random Forest （RF） to select the most informative feature subset and an enhanced Genetic Algorithm （GA） with chaotic characteristics to identify the optimal forecasting model parameters. The framework is evaluated with real-world traffic data collected from eight sensors located near the 1-605 interstate highway in California. Results show that the proposed RF- CGASVR model achieves better performance than other methods.展开更多
Twenty new species of extinct spiders belonging to 10 genera in five families from Late Cretaceous Kachin amber are reported.One new genus,Triangulum Jiang&Li,gen.nov.,of the family Theridiidae Sundevall,1833 was ...Twenty new species of extinct spiders belonging to 10 genera in five families from Late Cretaceous Kachin amber are reported.One new genus,Triangulum Jiang&Li,gen.nov.,of the family Theridiidae Sundevall,1833 was established with T.thutai Jiang&Li,sp.nov.as the type species.The remaining 19 new species are:Retrooecobius lwini Jiang&Li,sp.nov.,Zamilia arkari Jiang&Li,sp.nov.,Z.sheini Jiang&Li,sp.nov.,Z.shwayi Jiang&Li,sp.nov.from Oecobiidae Blackwall,1862;Furcembolus inzaliae Jiang&Li,sp.nov.from Pacullidae Simon,1894;Priscaleclercera chimei Jiang&Li,sp.nov.,P.foshou Jiang&Li,sp.nov.,P.hlaingi Jiang&Li,sp.nov.,P.kani Jiang&Li,sp.nov.,P.kyawae Jiang&Li,sp.nov.,P.thanae Jiang&Li,sp.nov.,P.thaungi Jiang&Li,sp.nov.from Psilodercidae Machado,1951;Bicornoculus aungi Jiang&Li,sp.nov.,B.wunnai Jiang&Li,sp.nov.,B.yarzari Jiang&Li,sp.nov.,Cymbioblemma ohnmari Jiang&Li,sp.nov.,Palpalpaculla phyui Jiang&Li,sp.nov.from Tetrablemmidae O.Pickard-Cambridge,1873;Burmatheridon cetani Jiang&Li,sp.nov.,Cretotheridion champoi Jiang&Li,sp.nov.,from Theridiidae.All species are described based on males.All types are deposited in the Institute of Zoology,Chinese Academy of Sciences(IZCAS)in Beijing,China.展开更多
Nitrogen loss from purple soil can lead to large negative impacts to the environment considering the wide distribution of this soil type in the upper reaches of the Yangtze River.Therefore,nitrogen loss patterns from ...Nitrogen loss from purple soil can lead to large negative impacts to the environment considering the wide distribution of this soil type in the upper reaches of the Yangtze River.Therefore,nitrogen loss patterns from sloping cropland of purple soil in the Sichuan Basin with the following fertilization regimes were studied in a wheat-maize rotation system:100%organic fertilizer(OM),using pig manure to replace 30%of mineral N(OMNPK)and crop residue to replace 15%of the mineral N(CRNPK)plus standard mineral fertilization(NPK)and no fertilizer control.The cumulative hydrological N loss could be as high as 45 kg·ha^(−1) N.The interflow accounted for up to 90%of the total N loss followed by sediment and overland flow losses.The high N loss via interflow found in this study highlighting that sloping cropland of purple soil may be one of the hot spots of N leaching.Compared to the NPK regime,organic substitution regimes(i.e.,OM,OMNPK and CRNPK)decreased total hydrological N loss loadings by 30%−68%.In addition,they can maintain annual crop yields and decrease yield-scaled total hydrological N losses by 18%−71%.In conclusion,long-term substitution of mineral N with organic amendments can maintain high crop productivity and reduce environmental N loss loadings,and thereby recommended as good N management practices to minimize the risk of agricultural non-point source pollution in the purple soil region of China.展开更多
Two new spider families from Late Cretaceous Kachin amber(Myanmar),Pilosarachnidae Jiang&Li,fam.nov.and Gigarachnidae Jiang&Li,fam.nov.,are described:Pilosarachne ju Jiang&Li,gen.&sp.nov.and Gigarachne...Two new spider families from Late Cretaceous Kachin amber(Myanmar),Pilosarachnidae Jiang&Li,fam.nov.and Gigarachnidae Jiang&Li,fam.nov.,are described:Pilosarachne ju Jiang&Li,gen.&sp.nov.and Gigarachne bian Jiang&Li,gen.&sp.nov.Type specimens are deposited in the Institute of Zoology,Chinese Academy of Sciences in Beijing(IZCAS).Both families bear three tarsal claws and are most likely entelegyne.Diagnostic characters of extinct families in Kachin amber with uncertain relationships with extant fauna are listed and discussed.展开更多
A new species, Belisana cas sp. nov. is reported based on description of B. ＂xtbg＂. B. ＂xtbg＂ mentioned by Yao et al.（2018） is unavailable after the ICZN（article 11.3）.
基金supported by the Science and Technology Innovation Foundation of CNPC“Multiscale Flow Law and Flow Field Coupling Study of Tight Sandstone Gas Reservoir”(2016D-5007-0208)13th Five-Year National Major Project“Multistage Fracturing Effect and Production of Fuling Shale Gas Horizontal Well Law Analysis Research”(2016ZX05060-009).
文摘Shale gas reservoirs have poor physical properties and a large number of micro-nano pores have been developed.Shale gas wells have no natural productivity and need fracturing reconstruction measures to put into production.However,the fracturing fluid will enter the reservoir space of shale matrix after fracturing and affect the production of shale gas.At present,there is no consensus on the influence of fracturing fluid retention on gas well production.Based on this,the paper adopts gas molecular transport analyzer to carry out experimental research on the influence of fracturing fluid on shale gas diffusion law after entering matrix pores.The results show that:(1)Compared with the diffusion capacity of single-phase shale gas,the diffusion capacity of shale gas decreases significantly when fracturing fluid is present in the reservoir;(2)In the process of fracturing fluid flowback,when the water saturation in the reservoir decreases from 50%to 0,the gas well productivity increases by about 60%.(3)When fracturing fluid exists in the reservoir,the pore diameter has an exponential relationship with the shale gas diffusion coefficient,and the diffusion coefficient increases exponentially with the increase of pore diameter.The research of this paper provides theoretical basis for guiding the efficient development of shale gas wells.
基金supported by the Natural Science Fund for Distinguished Young Scholars of Zhejiang Province (No. LR19C030001)the National Natural Science Foundation of China (Nos. 31872693, 32071549)+1 种基金the Key Public Welfare Technology Application Research Project of Ningbo (No. 202002N3032)the K.C. Wong Magna Fund in Ningbo University
文摘Antibiotic pollution imposes urgent threats to public health and microbial-mediated ecological processes.Existing studies have primarily focused on bacterial responses to antibiotic pollution,but they ignored the microeukaryotic counterpart,though microeukaryotes are functionally important(e.g.,predators and saprophytes)in microbial ecology.Herein,we explored how the assembly of sediment microeukaryotes was affected by increasing antibiotic pollution at the inlet(control)and across the outlet sites along a shrimpwastewater discharge channel.The structures of sedimentmicroeukaryotic community were substantially altered by the increasing nutrient and antibiotic pollutions,whichwere primarily controlled by the direct effects of phosphate and ammonium(−0.645 and 0.507,respectively).In addition,tetracyclines exerted a large effect(0.209),including direct effect(0.326)and indirect effect(−0.117),on the microeukaryotic assembly.On the contrary,the fungal subcommunity was relatively resistant to antibiotic pollution.Segmented analysis depicted nonlinear responses of microeukaryotic genera to the antibiotic pollution gradient,as supported by the significant tipping points.We screened 30 antibiotic concentration-discriminatory taxa of microeukaryotes,which can quantitatively and accurately predict(98.7%accuracy)the in-situ antibiotic concentration.Sediment microeukaryotic(except fungal)community is sensitive to antibiotic pollution,and the identified bioindicators could be used for antibiotic pollution diagnosis.
基金supported by the Science and Technology Department of Sichuan Province of China (Nos. 2017JY0007, 2016JY0073, and 2016JZ0031)the Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministrythe Fundamental Research Funds for the Central Universities (No. ZYGX2015J063)
文摘The ability to perform short-term traffic flow forecasting is a crucial component of intelligent transportation systems. However, accurate and reliable traffic flow forecasting is still a significant issue due to the complexity and variability of real traffic systems. To improve the accuracy of short-term traffic flow forecasting, this paper presents a novel hybrid prediction framework based on Support Vector Regression （SVR） that uses a Random Forest （RF） to select the most informative feature subset and an enhanced Genetic Algorithm （GA） with chaotic characteristics to identify the optimal forecasting model parameters. The framework is evaluated with real-world traffic data collected from eight sensors located near the 1-605 interstate highway in California. Results show that the proposed RF- CGASVR model achieves better performance than other methods.
基金supported by Beijing Outstanding Young Scholar Programthe National Key Research and Development Program of China (2021YFA0718303, 2021YFA1400904, and 2016YFA0301501)+1 种基金the National Natural Science Foundation of China (91736208, 11974202, 61975092, 11920101004,61727819, 11934002, 11734010, and 92165203)the XPLORER Prize。
基金supported by the Southeast Asia Biodiversity Research Institute,Chinese Academy of Sciences(2015CASEABRI005,Y4ZK111B01).
文摘Twenty new species of extinct spiders belonging to 10 genera in five families from Late Cretaceous Kachin amber are reported.One new genus,Triangulum Jiang&Li,gen.nov.,of the family Theridiidae Sundevall,1833 was established with T.thutai Jiang&Li,sp.nov.as the type species.The remaining 19 new species are:Retrooecobius lwini Jiang&Li,sp.nov.,Zamilia arkari Jiang&Li,sp.nov.,Z.sheini Jiang&Li,sp.nov.,Z.shwayi Jiang&Li,sp.nov.from Oecobiidae Blackwall,1862;Furcembolus inzaliae Jiang&Li,sp.nov.from Pacullidae Simon,1894;Priscaleclercera chimei Jiang&Li,sp.nov.,P.foshou Jiang&Li,sp.nov.,P.hlaingi Jiang&Li,sp.nov.,P.kani Jiang&Li,sp.nov.,P.kyawae Jiang&Li,sp.nov.,P.thanae Jiang&Li,sp.nov.,P.thaungi Jiang&Li,sp.nov.from Psilodercidae Machado,1951;Bicornoculus aungi Jiang&Li,sp.nov.,B.wunnai Jiang&Li,sp.nov.,B.yarzari Jiang&Li,sp.nov.,Cymbioblemma ohnmari Jiang&Li,sp.nov.,Palpalpaculla phyui Jiang&Li,sp.nov.from Tetrablemmidae O.Pickard-Cambridge,1873;Burmatheridon cetani Jiang&Li,sp.nov.,Cretotheridion champoi Jiang&Li,sp.nov.,from Theridiidae.All species are described based on males.All types are deposited in the Institute of Zoology,Chinese Academy of Sciences(IZCAS)in Beijing,China.
基金supported by the National Natural Science Foundation of China(U20A20107 and 42007100)the Special Assistant Researcher Foundation of the Chinese Academy of Sciences(Zhiyuan Yao)the IMHE Youth S&T Foundation(SDS-QN-2101)。
文摘Nitrogen loss from purple soil can lead to large negative impacts to the environment considering the wide distribution of this soil type in the upper reaches of the Yangtze River.Therefore,nitrogen loss patterns from sloping cropland of purple soil in the Sichuan Basin with the following fertilization regimes were studied in a wheat-maize rotation system:100%organic fertilizer(OM),using pig manure to replace 30%of mineral N(OMNPK)and crop residue to replace 15%of the mineral N(CRNPK)plus standard mineral fertilization(NPK)and no fertilizer control.The cumulative hydrological N loss could be as high as 45 kg·ha^(−1) N.The interflow accounted for up to 90%of the total N loss followed by sediment and overland flow losses.The high N loss via interflow found in this study highlighting that sloping cropland of purple soil may be one of the hot spots of N leaching.Compared to the NPK regime,organic substitution regimes(i.e.,OM,OMNPK and CRNPK)decreased total hydrological N loss loadings by 30%−68%.In addition,they can maintain annual crop yields and decrease yield-scaled total hydrological N losses by 18%−71%.In conclusion,long-term substitution of mineral N with organic amendments can maintain high crop productivity and reduce environmental N loss loadings,and thereby recommended as good N management practices to minimize the risk of agricultural non-point source pollution in the purple soil region of China.
基金supported by the National Natural Science Foundation of China(31530067)the Southeast Asia Biodiversity Research Institute,Chinese Academy of Sciences(2015CASEABRI005,Y4ZK111B01)。
文摘Two new spider families from Late Cretaceous Kachin amber(Myanmar),Pilosarachnidae Jiang&Li,fam.nov.and Gigarachnidae Jiang&Li,fam.nov.,are described:Pilosarachne ju Jiang&Li,gen.&sp.nov.and Gigarachne bian Jiang&Li,gen.&sp.nov.Type specimens are deposited in the Institute of Zoology,Chinese Academy of Sciences in Beijing(IZCAS).Both families bear three tarsal claws and are most likely entelegyne.Diagnostic characters of extinct families in Kachin amber with uncertain relationships with extant fauna are listed and discussed.
文摘A new species, Belisana cas sp. nov. is reported based on description of B. ＂xtbg＂. B. ＂xtbg＂ mentioned by Yao et al.（2018） is unavailable after the ICZN（article 11.3）.
