Chemical solvents instead of pure water being as hydraulic fracturing fluid could effectively increase permeability and improve clean methane extraction efficiency.However,pore-fracture variation features of lean coal...Chemical solvents instead of pure water being as hydraulic fracturing fluid could effectively increase permeability and improve clean methane extraction efficiency.However,pore-fracture variation features of lean coal synergistically affected by solvents have not been fully understood.Ultrasonic testing,nuclear magnetic resonance analysis,liquid phase mass spectrometry was adopted to comprehensively analyze pore-fracture change characteristics of lean coal treated by combined solvent(NMP and CS_(2)).Meanwhile,quantitative characterization of above changing properties was conducted using geometric fractal theory.Relationship model between permeability,fractal dimension and porosity were established.Results indicate that the end face fractures of coal are well developed after CS2and combined solvent treatments,of which,end face box-counting fractal dimensions range from 1.1227 to 1.4767.Maximum decreases in ultrasonic longitudinal wave velocity of coal affected by NMP,CS_(2)and combined solvent are 2.700%,20.521%,22.454%,respectively.Solvent treatments could lead to increasing amount of both mesopores and macropores.Decrease ratio of fractal dimension Dsis 0.259%–2.159%,while permeability increases ratio of NMR ranges from 0.1904 to 6.4486.Meanwhile,combined solvent could dissolve coal polar and non-polar small molecules and expand flow space.Results could provide reference for solvent selection and parameter optimization of permeability-enhancement technology.展开更多
The non-chain chemical HF(DF)laser is one of the most powerful electrically-driven lasers operating in mid-infrared,in which SF6-C2H6 mixtures are often used as lasering media.Due to the electronegativity of SF6,the d...The non-chain chemical HF(DF)laser is one of the most powerful electrically-driven lasers operating in mid-infrared,in which SF6-C2H6 mixtures are often used as lasering media.Due to the electronegativity of SF6,the discharge in SF6-C2H6 presents a complicated discharge mode.To achieve reproducible pulsed laser output,pulsed discharge in SF6-C2H6 mixtures is investigated for discharge mode using plane electrodes assisted by array pre-ionization spark pins in cathode surface.Firstly,two modes can be distinguished.One mode is called the selfsustained volume discharge(SSVD),which is characterized by spatial uniformity in the discharge gap and pulse to pulse repeatability.On the contrary,another mode includes random arc passages in the discharge gap and therefore cannot conduct lasering.By varying discharge conditions(gap voltage,gas pressure,etc)two discharge modes are observed.Secondly,the holding scope of the SSVD mode is analyzed for the optimal mixture ratio of 20:1,and the boundary tend of the holding scope of SSVD indicates there exists maximum gas pressure and maximum charging voltage for SSVD.Finally,the peak current of SSVD relates positively to charging voltage,while negatively to gas pressure,from which it is drawn that synchronous electron avalanches initiated by the sliding array overlap spatially into SSVD and thus SSVD is essentially an α ionization avalanche.展开更多
Of the more than 370000 species of higher plants in nature,fewer than 0.1%can be geneticallymodified due to limitations of the current gene delivery systems.Even for those that can be genetically modified,the modifica...Of the more than 370000 species of higher plants in nature,fewer than 0.1%can be geneticallymodified due to limitations of the current gene delivery systems.Even for those that can be genetically modified,the modification involves a tedious and costly tissue culture process.Here,we describe an extremely simple cut-dip-budding(CDB)delivery system,which uses Agrobacterium rhizogene to inoculate explants,generating transformed roots that produce transformed buds due to root suckering.We have successfully used CDB to achieve the heritable transformation of plant species inmultiple plant families,including two herbaceous plants(Taraxacum kok-saghyz and Coronilla varia),a tuberous root plant(sweet potato),and three woody plant species(Ailanthus altissima,Aralia elata,and Clerodendrum chinense).These plants have previously been difficult or impossible to transform,but the CDB method enabled efficient transformation or gene editing in them using a very simple explant dipping protocol,under non-sterile conditions and without the need for tissue culture.Our work suggests that large numbers of plants could be amenable to genetic modifications using the CDB method.展开更多
Gene-editing technologies have ushered in a significant advancement in plant genetics research and molecular breeding.However,a critical challenge hindering the widespread adoption of these technologies is the efficie...Gene-editing technologies have ushered in a significant advancement in plant genetics research and molecular breeding.However,a critical challenge hindering the widespread adoption of these technologies is the efficient delivery of gene-editing tools.The predominant methods for introducing these tools into plants typically involve Agrobacterium tumefaciens-mediated transformation or particle bombardment(Mao et al.,2019).Unfortunately,these traditional gene delivery methods require delicate and timeconsuming tissue culture procedures and show limited success,especially in medicinal and other less studied plants.A recent breakthrough is the development of the Cut-Dip-Budding(CDB)gene delivery system.The CDB system is highly effective for plants with root-suckering capabilities.It allows the delivery of transgenes and gene-editing tools into plants through hairy root induction followed by shoot regeneration from transformed hairy roots,bypassing the need for tissue culture processes(Cao et al.,2023).展开更多
基金financially supported by National Natural Science Foundation of China(No.52274171)Joint National-Local Engineering Research Centre for Safe and Precise Coal Mining Fund(No.EC2023015)+1 种基金Excellent Youth Project of Universities in Anhui Province(No.2023AH030042)Unveiled List of Bidding Projects of Shanxi Province(No.20201101001)。
文摘Chemical solvents instead of pure water being as hydraulic fracturing fluid could effectively increase permeability and improve clean methane extraction efficiency.However,pore-fracture variation features of lean coal synergistically affected by solvents have not been fully understood.Ultrasonic testing,nuclear magnetic resonance analysis,liquid phase mass spectrometry was adopted to comprehensively analyze pore-fracture change characteristics of lean coal treated by combined solvent(NMP and CS_(2)).Meanwhile,quantitative characterization of above changing properties was conducted using geometric fractal theory.Relationship model between permeability,fractal dimension and porosity were established.Results indicate that the end face fractures of coal are well developed after CS2and combined solvent treatments,of which,end face box-counting fractal dimensions range from 1.1227 to 1.4767.Maximum decreases in ultrasonic longitudinal wave velocity of coal affected by NMP,CS_(2)and combined solvent are 2.700%,20.521%,22.454%,respectively.Solvent treatments could lead to increasing amount of both mesopores and macropores.Decrease ratio of fractal dimension Dsis 0.259%–2.159%,while permeability increases ratio of NMR ranges from 0.1904 to 6.4486.Meanwhile,combined solvent could dissolve coal polar and non-polar small molecules and expand flow space.Results could provide reference for solvent selection and parameter optimization of permeability-enhancement technology.
基金National Natural Science Foundation of China(No.11375041).
文摘The non-chain chemical HF(DF)laser is one of the most powerful electrically-driven lasers operating in mid-infrared,in which SF6-C2H6 mixtures are often used as lasering media.Due to the electronegativity of SF6,the discharge in SF6-C2H6 presents a complicated discharge mode.To achieve reproducible pulsed laser output,pulsed discharge in SF6-C2H6 mixtures is investigated for discharge mode using plane electrodes assisted by array pre-ionization spark pins in cathode surface.Firstly,two modes can be distinguished.One mode is called the selfsustained volume discharge(SSVD),which is characterized by spatial uniformity in the discharge gap and pulse to pulse repeatability.On the contrary,another mode includes random arc passages in the discharge gap and therefore cannot conduct lasering.By varying discharge conditions(gap voltage,gas pressure,etc)two discharge modes are observed.Secondly,the holding scope of the SSVD mode is analyzed for the optimal mixture ratio of 20:1,and the boundary tend of the holding scope of SSVD indicates there exists maximum gas pressure and maximum charging voltage for SSVD.Finally,the peak current of SSVD relates positively to charging voltage,while negatively to gas pressure,from which it is drawn that synchronous electron avalanches initiated by the sliding array overlap spatially into SSVD and thus SSVD is essentially an α ionization avalanche.
基金supported by Shandong Shunfeng BiotechnologyCo.Ltd.,Jinan,China.
文摘Of the more than 370000 species of higher plants in nature,fewer than 0.1%can be geneticallymodified due to limitations of the current gene delivery systems.Even for those that can be genetically modified,the modification involves a tedious and costly tissue culture process.Here,we describe an extremely simple cut-dip-budding(CDB)delivery system,which uses Agrobacterium rhizogene to inoculate explants,generating transformed roots that produce transformed buds due to root suckering.We have successfully used CDB to achieve the heritable transformation of plant species inmultiple plant families,including two herbaceous plants(Taraxacum kok-saghyz and Coronilla varia),a tuberous root plant(sweet potato),and three woody plant species(Ailanthus altissima,Aralia elata,and Clerodendrum chinense).These plants have previously been difficult or impossible to transform,but the CDB method enabled efficient transformation or gene editing in them using a very simple explant dipping protocol,under non-sterile conditions and without the need for tissue culture.Our work suggests that large numbers of plants could be amenable to genetic modifications using the CDB method.
基金supported by the National Key R&D Program of China (2021YFA1300404 to J.-K.Z)National Natural Science Foundation of China (32188102 to J.-K.Z)by Bellagen Biotechnology Co. Ltd., Jinan, China
文摘Gene-editing technologies have ushered in a significant advancement in plant genetics research and molecular breeding.However,a critical challenge hindering the widespread adoption of these technologies is the efficient delivery of gene-editing tools.The predominant methods for introducing these tools into plants typically involve Agrobacterium tumefaciens-mediated transformation or particle bombardment(Mao et al.,2019).Unfortunately,these traditional gene delivery methods require delicate and timeconsuming tissue culture procedures and show limited success,especially in medicinal and other less studied plants.A recent breakthrough is the development of the Cut-Dip-Budding(CDB)gene delivery system.The CDB system is highly effective for plants with root-suckering capabilities.It allows the delivery of transgenes and gene-editing tools into plants through hairy root induction followed by shoot regeneration from transformed hairy roots,bypassing the need for tissue culture processes(Cao et al.,2023).
