Genetically modified(GM) organisms are widely adopted. However, their safety assessments and control are still of special concern to the public. Identifying and localizing transgene insertion is an essentially prerequ...Genetically modified(GM) organisms are widely adopted. However, their safety assessments and control are still of special concern to the public. Identifying and localizing transgene insertion is an essentially prerequisite step. In this study, 2 independent transgene soybean lines were selected(LB4-AtDCGS-1-20-5-2 and CGS-ZG11) as typical cases. Both lines contained expression cassette of At-DCGS that encoding a feedback-insensitive cystathionine gamma-synthase to produce higher level methionine(Met). LB4-AtDCGS-1-20-5-2 was whole genome sequenced with one paired-end 500 bp library and two mate-paired 1 kb and 2 kb libraries using Illumina HiSeq sequencing platform. CGS-ZG11 was sequenced with only one paired-end 500 bp library. Both genomes were assembled,and 2 scaffold sequences(1 for each line) were screened out by aligning with transgene.Then the transgene insertion and its flanking regions in soybean genome were further identified and confirmed by PCR cloning and Sanger sequencing. Results showed that these 2 transgene lines had single copy of inserted transgene. Their transgene insertion contents were identified, which facilitates further safety assessment. These results indicated that genome assembly using high throughput sequencing is a powerful tool for identifying transgene insertions, even with limited knowledge.展开更多
The purposeful construction of dual Z-scheme system to the formation of intimate interface contact and multi-channel charge flow through the system remains a huge challenge.Herein,a tandem 2D/0D/2D g-C_(3)N_(4)nanoshe...The purposeful construction of dual Z-scheme system to the formation of intimate interface contact and multi-channel charge flow through the system remains a huge challenge.Herein,a tandem 2D/0D/2D g-C_(3)N_(4)nanosheets/FeOOH quantum dots/ZnIn_(2)S_(4)nanosheets(CNFeZn)dual Z-scheme system(DZSS)has been successfully constructed using electrostatic self-assembly method.Owing to the band structure and elaborate morphology of 2D g-C_(3)N_(4),0D FeOOH and 2D ZnIn_(2)S_(4)in unique designed DZSS,plenty of spatial charge transfer channels are formed between the g-C_(3)N_(4)/FeOOH and FeOOH/ZnIn_(2)S_(4)interfaces,which greatly accelerate the charge separation and transfer.As bifunctional catalysts,CNFeZn DZSS achieves the highest H_(2)evolution rate of~436.6 mmol/h with a great promotion of~10.6 folds and~6.9 folds compared to pristine g-C_(3)N_(4)and ZnIn_(2)S_(4),respectively.Meanwhile,the H_(2)O_(2)production rate reached~301.19 mmol/L after 60 min irradiation,up to~5.1 times and~2.3 times that of pristine g-C_(3)N_(4)and ZnIn_(2)S_(4).Experiment and DFT calculation further confirmed that the stable double built-in electronic field can be formed owing to the electron configuration between double interfaces,and reveal that the ample atomic-level charge transfer channels were established in the strong interaction connected double interfaces,which can act as the charge migration pathway promote the separation of photogenerated charges.展开更多
Catalysts that can rapidly degrade tetracycline(TC)in water without introducing secondary ion pollution have always been challenging.Herein,a cobalt-based catalyst(CoO_(x)@P-C)is prepared so that CoOx quantum particle...Catalysts that can rapidly degrade tetracycline(TC)in water without introducing secondary ion pollution have always been challenging.Herein,a cobalt-based catalyst(CoO_(x)@P-C)is prepared so that CoOx quantum particles(5e10 nm)are uniformly distributed on a linear substrate,and the outer layer is covered with a shell(P-C).The quantum particles of CoO_(x) provide many active sites for the reaction,which ensures the efficient degradation effect of the catalyst,and 30 mg/L TC can be completely degraded in only 5 min.The shell of the quantum particles'outer layer can effectively reduce ions'extravasation.The combination of the shell-like structure and the linear substrate greatly enhances the catalysis's stability and ensures that the catalyst is prepared into a film for practical application.The high catalytic activity of CoO_(x)@P-C is mainly due to the following factors:(1)Uniformly distributed ultra-small nanoparticles can provide many active sites.(2)The microenvironment formed by the core-shell structure enhances not only catalytic stability but also provides the driving force to improve the reaction rate.(3)The composite of CoO_(x) and P-C core-shell structure can accelerate electron transfer and generate many reactive oxygen species in a short time,which makes TC degrade extremely rapidly.展开更多
Graphene-like C3N4/Ag3PO4 photocatalysts are synthesized by calcination and solutions precipitating method.The obtained g-C3N4/Ag3PO4 composites display excellent photocatalytic activity for the degradation of methyle...Graphene-like C3N4/Ag3PO4 photocatalysts are synthesized by calcination and solutions precipitating method.The obtained g-C3N4/Ag3PO4 composites display excellent photocatalytic activity for the degradation of methylene orange(MO),rhodamine B(RhB)and tetracycline(TC)under visible light irradiation.The solutions containing RhB(10 mg/L)and MO(10 mg/L)can be efficiently degraded within15 min and 30 min.Especially,nearly 80%of TC(50 mg/L)is degraded within 20 min.which are much better than those of pure g-C3N4 nanosheets and Ag3PO4,implying that strong interaction and reasonable energy band alignment in the contact interface can effectively transfer the carries.Furthermore,the g-C3N4/Ag3PO4 composites exhibit the improved stability,and only a slight decrease is observed after three recycling runs.Moreover,the impact of inorganic ions and PH values on the degradation performance is rather small.The Z-scheme photocatalytic mechanism of the g-C3N4/Ag3PO4 composites based on the active species trapping experimental is proposed.This work demonstrates the promising applications of the g-C3N4/Ag3PO4 composites in environmental issues.展开更多
The development of noble-metal-free catalysts with high efficiency photocatalytic properties is critical to the heterogeneous catalysis. Herein, zero-dimensional(0 D) metal sulfide quantum dots/two-dimensional(2 D) g-...The development of noble-metal-free catalysts with high efficiency photocatalytic properties is critical to the heterogeneous catalysis. Herein, zero-dimensional(0 D) metal sulfide quantum dots/two-dimensional(2 D) g-C3N4 nanosheets(Co3S4/CNNS) nanocomposites are synthesized by a two-step method, including the ways of in-situ deposition and water bath. The highly dispersed Co3S4 quantum dots(particle size is2–4 nm) are evenly and tightly fixed on CNNS, which can be used as co-catalyst to effectively replace noble metals to improve the photocatalytic properties of CNNS. Co3S4/CNNS-900 has the apparent quantum efficiency, which is up to 7.85% at 400 nm. At the same time, the H2 evolution rate of Co3S4/CNNS-900 is 20,536.4 lmol gà1 hà1, which is 555 times than CNNS. The excellent photocatalytic performance is due to the highly dispersed Co3S4 quantum dots on 2 D CNNS, which facilitate the formation of more active sites, Co3S4/CNNS promotes the separation and migration of photogenerated carriers, shortens the migration distance of photogenerated carriers, and eventually leads to an increase of the photocatalytic performance.展开更多
The multi-axial forging (MAF) process was introduced into the strain induced metal activation (SIMA) process to replace conventional forging. Microstructure evolution of MAF formed AZ80 magnesium alloy during part...The multi-axial forging (MAF) process was introduced into the strain induced metal activation (SIMA) process to replace conventional forging. Microstructure evolution of MAF formed AZ80 magnesium alloy during partial remelting was investigated. Furthermore, the tensile mechanical properties for AZ80 magnesium alloy thixoextruded from the starting materials treated by MAF were determined. For comparison, as-cast AZ80 magnesium alloy was also thixoextruded. The results show that the SIMA route produced ideal, fine semi-solid microstructure, in which almost completely spheroidal primary solid grains had a little amount of entrapped liquid. The microstructure of the as-cast alloy in the semi-solid state is less spheroidized compared with the MAF alloy under the similar isothermal holding conditions. With prolonged holding time, the size of the solid grain increases and the degree of spheroidization is improved in the MAF formed alloys. However, the solid grain size of the as-cast alloys decreases initially, and then increases with further increasing temperature. The tensile mechanical properties for AZ80 magnesium alloy thixoextruded from the starting material produced by MAF are better than those of AZ80 magnesium alloy thixoextruded from the starting material produced by casting. The ultimate tensile strength, yield strength and elongation of the alloy thixoextruded from the starting material produced by MAF are 314 MPa, 238 MPa and 14%, respectively.展开更多
Improving the separation efficiency of photogenerated carriers and broadening the light absorption range of the photocatalyst are two important factors for improving the performance of the photocatalyst.In this paper,...Improving the separation efficiency of photogenerated carriers and broadening the light absorption range of the photocatalyst are two important factors for improving the performance of the photocatalyst.In this paper,a new and efficient Z-scheme Cd S/iron phthalocyanine(Cd S/Fe Pc)core-shell nanostructure composite material is prepared by a simple solid-phase reaction method.There are two key points in the preparation of composite materials:one is that hydrogen bonding energy is closely connected with Fe Pc,another is that Fe Pc can be uniformly assembled on Cd S nanoparticles.The photocatalytic hydrogen evolution(PHE)of the Cd S/Fe Pc nanocomposite(73.01μmol/h)is 2.6 times higher than that of pure Cd S(26.67μmol/h).In addition,after 4 photocatalytic cycles,the PHE of the Cd S/Fe Pc composite is still 92.3%of the first cycle.There are three reasons for this situation:(1)The Z-scheme heterojunction is formed to improve the separation efficiency of photogenerated carriers;(2)Fe Pc expands the visible light absorption range of Cd S;(3)The large core-shell contact area is favorable for the separation of photo-induced carriers at the interfaces.This research is conducive to the further development of new photocatalytic materials with high efficiency,low cost and simple preparation.展开更多
基金supported by the Genetically Modified Organisms Breeding Major Projects of China (2016ZX08011-003)China Agriculture Research System (CARS-04)CAAS Agricultural Science and Technology Innovation Project
文摘Genetically modified(GM) organisms are widely adopted. However, their safety assessments and control are still of special concern to the public. Identifying and localizing transgene insertion is an essentially prerequisite step. In this study, 2 independent transgene soybean lines were selected(LB4-AtDCGS-1-20-5-2 and CGS-ZG11) as typical cases. Both lines contained expression cassette of At-DCGS that encoding a feedback-insensitive cystathionine gamma-synthase to produce higher level methionine(Met). LB4-AtDCGS-1-20-5-2 was whole genome sequenced with one paired-end 500 bp library and two mate-paired 1 kb and 2 kb libraries using Illumina HiSeq sequencing platform. CGS-ZG11 was sequenced with only one paired-end 500 bp library. Both genomes were assembled,and 2 scaffold sequences(1 for each line) were screened out by aligning with transgene.Then the transgene insertion and its flanking regions in soybean genome were further identified and confirmed by PCR cloning and Sanger sequencing. Results showed that these 2 transgene lines had single copy of inserted transgene. Their transgene insertion contents were identified, which facilitates further safety assessment. These results indicated that genome assembly using high throughput sequencing is a powerful tool for identifying transgene insertions, even with limited knowledge.
基金supported by the Natural Science Foundation of Shandong Province(Grant No.ZR2021ME143,ZR2020MA076).
文摘The purposeful construction of dual Z-scheme system to the formation of intimate interface contact and multi-channel charge flow through the system remains a huge challenge.Herein,a tandem 2D/0D/2D g-C_(3)N_(4)nanosheets/FeOOH quantum dots/ZnIn_(2)S_(4)nanosheets(CNFeZn)dual Z-scheme system(DZSS)has been successfully constructed using electrostatic self-assembly method.Owing to the band structure and elaborate morphology of 2D g-C_(3)N_(4),0D FeOOH and 2D ZnIn_(2)S_(4)in unique designed DZSS,plenty of spatial charge transfer channels are formed between the g-C_(3)N_(4)/FeOOH and FeOOH/ZnIn_(2)S_(4)interfaces,which greatly accelerate the charge separation and transfer.As bifunctional catalysts,CNFeZn DZSS achieves the highest H_(2)evolution rate of~436.6 mmol/h with a great promotion of~10.6 folds and~6.9 folds compared to pristine g-C_(3)N_(4)and ZnIn_(2)S_(4),respectively.Meanwhile,the H_(2)O_(2)production rate reached~301.19 mmol/L after 60 min irradiation,up to~5.1 times and~2.3 times that of pristine g-C_(3)N_(4)and ZnIn_(2)S_(4).Experiment and DFT calculation further confirmed that the stable double built-in electronic field can be formed owing to the electron configuration between double interfaces,and reveal that the ample atomic-level charge transfer channels were established in the strong interaction connected double interfaces,which can act as the charge migration pathway promote the separation of photogenerated charges.
基金supported by the Independent Cultivation Program of Innovation Team of Jinan City(2019GXRC011)the Natural Science Foundation of Shandong Province(ZR2021ME143)the National Natural Science Foundation of China(51908242).
基金supported by the Joint Funds of the National Natural Science Foundation of China(U22A20140),the Independent Cultivation Program of Innovation Team of Ji'nan City(No.2019GXRC011),the Natural Science Foundation of Shandong Province(Grant No.ZR2021ME143,ZR2021MA073)and National Natural Science Foundation of China(Grant No.51908242)and.All the authors discussed the results and commented on the manuscript.
文摘Catalysts that can rapidly degrade tetracycline(TC)in water without introducing secondary ion pollution have always been challenging.Herein,a cobalt-based catalyst(CoO_(x)@P-C)is prepared so that CoOx quantum particles(5e10 nm)are uniformly distributed on a linear substrate,and the outer layer is covered with a shell(P-C).The quantum particles of CoO_(x) provide many active sites for the reaction,which ensures the efficient degradation effect of the catalyst,and 30 mg/L TC can be completely degraded in only 5 min.The shell of the quantum particles'outer layer can effectively reduce ions'extravasation.The combination of the shell-like structure and the linear substrate greatly enhances the catalysis's stability and ensures that the catalyst is prepared into a film for practical application.The high catalytic activity of CoO_(x)@P-C is mainly due to the following factors:(1)Uniformly distributed ultra-small nanoparticles can provide many active sites.(2)The microenvironment formed by the core-shell structure enhances not only catalytic stability but also provides the driving force to improve the reaction rate.(3)The composite of CoO_(x) and P-C core-shell structure can accelerate electron transfer and generate many reactive oxygen species in a short time,which makes TC degrade extremely rapidly.
基金financially supported by the National Natural Science Foundation of China (Nos. 61504048, 51672109, 21707043)Natural Science Foundation of Shandong Province for Excellent Young Scholars (Nos. ZR2016JL015, ZR2017BEE005)
文摘Graphene-like C3N4/Ag3PO4 photocatalysts are synthesized by calcination and solutions precipitating method.The obtained g-C3N4/Ag3PO4 composites display excellent photocatalytic activity for the degradation of methylene orange(MO),rhodamine B(RhB)and tetracycline(TC)under visible light irradiation.The solutions containing RhB(10 mg/L)and MO(10 mg/L)can be efficiently degraded within15 min and 30 min.Especially,nearly 80%of TC(50 mg/L)is degraded within 20 min.which are much better than those of pure g-C3N4 nanosheets and Ag3PO4,implying that strong interaction and reasonable energy band alignment in the contact interface can effectively transfer the carries.Furthermore,the g-C3N4/Ag3PO4 composites exhibit the improved stability,and only a slight decrease is observed after three recycling runs.Moreover,the impact of inorganic ions and PH values on the degradation performance is rather small.The Z-scheme photocatalytic mechanism of the g-C3N4/Ag3PO4 composites based on the active species trapping experimental is proposed.This work demonstrates the promising applications of the g-C3N4/Ag3PO4 composites in environmental issues.
基金supported by the National Natural Science Foundation of China(51672109)the Natural Science Foundation of Shandong Province for Excellent Young Scholars(ZR2016JL015)
文摘The development of noble-metal-free catalysts with high efficiency photocatalytic properties is critical to the heterogeneous catalysis. Herein, zero-dimensional(0 D) metal sulfide quantum dots/two-dimensional(2 D) g-C3N4 nanosheets(Co3S4/CNNS) nanocomposites are synthesized by a two-step method, including the ways of in-situ deposition and water bath. The highly dispersed Co3S4 quantum dots(particle size is2–4 nm) are evenly and tightly fixed on CNNS, which can be used as co-catalyst to effectively replace noble metals to improve the photocatalytic properties of CNNS. Co3S4/CNNS-900 has the apparent quantum efficiency, which is up to 7.85% at 400 nm. At the same time, the H2 evolution rate of Co3S4/CNNS-900 is 20,536.4 lmol gà1 hà1, which is 555 times than CNNS. The excellent photocatalytic performance is due to the highly dispersed Co3S4 quantum dots on 2 D CNNS, which facilitate the formation of more active sites, Co3S4/CNNS promotes the separation and migration of photogenerated carriers, shortens the migration distance of photogenerated carriers, and eventually leads to an increase of the photocatalytic performance.
基金supported by Department of Education of Heilongjiang Province(No.12511069)Heilongjiang Province Natural Science Foundation(No.QC2010110)+1 种基金Special Fund Project for Scientific and Technological Innovation Talents of Harbin(No.2012RFQXS113)Entrepreneurship for Under-graduates(No.201210214008)
文摘The multi-axial forging (MAF) process was introduced into the strain induced metal activation (SIMA) process to replace conventional forging. Microstructure evolution of MAF formed AZ80 magnesium alloy during partial remelting was investigated. Furthermore, the tensile mechanical properties for AZ80 magnesium alloy thixoextruded from the starting materials treated by MAF were determined. For comparison, as-cast AZ80 magnesium alloy was also thixoextruded. The results show that the SIMA route produced ideal, fine semi-solid microstructure, in which almost completely spheroidal primary solid grains had a little amount of entrapped liquid. The microstructure of the as-cast alloy in the semi-solid state is less spheroidized compared with the MAF alloy under the similar isothermal holding conditions. With prolonged holding time, the size of the solid grain increases and the degree of spheroidization is improved in the MAF formed alloys. However, the solid grain size of the as-cast alloys decreases initially, and then increases with further increasing temperature. The tensile mechanical properties for AZ80 magnesium alloy thixoextruded from the starting material produced by MAF are better than those of AZ80 magnesium alloy thixoextruded from the starting material produced by casting. The ultimate tensile strength, yield strength and elongation of the alloy thixoextruded from the starting material produced by MAF are 314 MPa, 238 MPa and 14%, respectively.
基金the Independent Cultivation Program of Innovation Team of Ji’nan City(No.2019GXRC011)the National Natural Science Foundation of China(Nos.21707043 and 51908242)the Natural Science Foundation of Shandong Province(No.ZR2017BEE005)。
文摘Improving the separation efficiency of photogenerated carriers and broadening the light absorption range of the photocatalyst are two important factors for improving the performance of the photocatalyst.In this paper,a new and efficient Z-scheme Cd S/iron phthalocyanine(Cd S/Fe Pc)core-shell nanostructure composite material is prepared by a simple solid-phase reaction method.There are two key points in the preparation of composite materials:one is that hydrogen bonding energy is closely connected with Fe Pc,another is that Fe Pc can be uniformly assembled on Cd S nanoparticles.The photocatalytic hydrogen evolution(PHE)of the Cd S/Fe Pc nanocomposite(73.01μmol/h)is 2.6 times higher than that of pure Cd S(26.67μmol/h).In addition,after 4 photocatalytic cycles,the PHE of the Cd S/Fe Pc composite is still 92.3%of the first cycle.There are three reasons for this situation:(1)The Z-scheme heterojunction is formed to improve the separation efficiency of photogenerated carriers;(2)Fe Pc expands the visible light absorption range of Cd S;(3)The large core-shell contact area is favorable for the separation of photo-induced carriers at the interfaces.This research is conducive to the further development of new photocatalytic materials with high efficiency,low cost and simple preparation.