Catalpa bungei,a fast-growing timber tree,is threatened by the lepidopteran pest Omphisa plagialis.Previous studies in our laboratory successfully generated transgenic C.bungei lines overexpressing Cry genes(Cry1Ab,Cr...Catalpa bungei,a fast-growing timber tree,is threatened by the lepidopteran pest Omphisa plagialis.Previous studies in our laboratory successfully generated transgenic C.bungei lines overexpressing Cry genes(Cry1Ab,Cry2A,and Cry9-2)that exhibited resistance to O.plagialis,but their potential impact on soil bacterial communities remains unclear.In this study,we analyzed nine transgenic C.bungei lines(three independent lines for each Cry gene)to characterize their rhizosphere bacterial communities using high-throughput sequencing of the 16S ribosomal DNA(rDNA)V4-V5 regions.A total of 628 amplicon sequence variants(ASVs)were shared among all transgenic and wild-type(WT)lines,forming a stable core microbiome dominated by Proteobacteria,Bacteroidota,Acidobacteriota,and Actinobacteriota.Alpha diversity showed no significant differences,while beta diversity revealed minor but distinct compositional shifts.Cry1Ab lines exhibited higher abundances of fast-growing taxa,particularly Proteobacteria and Bacteroidota;Cry2A lines displayed intermediate profiles,whereas Cry9-2 lines were nearly indistinguishable from WT communities.Linear discriminant analysis of the effect size revealed significant enrichment of taxa such as Burkholderiaceae and Ralstonia in the Cry1Ab rhizosphere,in contrast to the higher abundance of Chloroflexi in the WT.Functional predictions indicated consistent metabolic pathways across all treatments,suggesting strong ecological redundancy.This study demonstrates minimal impact on rhizosphere microbial communities in transgenic C.bungei plants.The Cry9-2 construct exhibited superior environmental stability,whereas the Cry1Ab construct caused only slight but ecologically acceptable shifts.These findings support the ecological safety of Bt-transgenic C.bungei and identify Cry9-2 as a particularly favorable candidate for forestry applications.This comparative evaluation of three Cry genes in a tree species provides a framework for future gene-specific biosafety assessments in woody plants.展开更多
Considering that the fluid is inviscid and incompressible and the flow is irrotational in a fixed frame of reference and using the multiple scale analysis method, we derive a nonlinear Schrodinger equation(NLSE) descr...Considering that the fluid is inviscid and incompressible and the flow is irrotational in a fixed frame of reference and using the multiple scale analysis method, we derive a nonlinear Schrodinger equation(NLSE) describing the evolution dynamics of gravity-capillary wavetrains in arbitrary constant depth. The gravity-capillary waves(GCWs) are influenced by a linear shear flow(LSF) which consists of a uniform flow and a shear flow with constant vorticity. The modulational instability(MI) of GCWs with the LSF is analyzed using the NLSE. The MI is effectively modified by the LSF. In infinite depth, there are four asymptotes which are the boundaries between MI and modulational stability(MS) in the instability diagram. In addition, the dimensionless free surface elevation as a function of time for different dimensionless water depth,surface tension, uniform flow and vorticity is exhibited. It is found that the decay of free surface elevation and the steepness of free surface amplitude change over time, which are greatly affected by the water depth, surface tension, uniform flow and vorticity.展开更多
Assume that a fluid is inviscid, incompressible, and irrotational. A nonlinear Schr?dinger equation(NLSE) describing the evolution of gravity waves in finite water depth is derived using the multiple-scale analysis me...Assume that a fluid is inviscid, incompressible, and irrotational. A nonlinear Schr?dinger equation(NLSE) describing the evolution of gravity waves in finite water depth is derived using the multiple-scale analysis method. The gravity waves are influenced by a linear shear flow, which is composed of a uniform flow and a shear flow with constant vorticity. The modulational instability(MI) of the NLSE is analyzed, and the region of the MI for gravity waves(the necessary condition for existence of freak waves) is identified. In this work, the uniform background flows along or against wave propagation are referred to as down-flow and up-flow, respectively. Uniform up-flow enhances the MI, whereas uniform down-flow reduces it. Positive vorticity enhances the MI, while negative vorticity reduces it. Hence, the influence of positive(negative)vorticity on MI can be balanced out by that of uniform down(up) flow. Furthermore, the Peregrine breather solution of the NLSE is applied to freak waves. Uniform up-flow increases the steepness of the free surface elevation, while uniform down-flow decreases it. Positive vorticity increases the steepness of the free surface elevation, whereas negative vorticity decreases it.展开更多
The fluorescence staining method and scanning electron microscopy （SEM） were used to study the effect of ozone （O3） inactivating Cryptosporidium in water and cell ultrastructures variation to shed light on the mec...The fluorescence staining method and scanning electron microscopy （SEM） were used to study the effect of ozone （O3） inactivating Cryptosporidium in water and cell ultrastructures variation to shed light on the mechanism of inactivation preliminarily. Results indicated that O3 had a stronger inactivating capability. When the concentration of O3 was above 3.0 mg/L and the contact time was up to 7 min, a significant inactivating effect could be achieved. The turbidity on inactivation effects was also found to be statistically significant in artificial water. With increases in turbidity, the inactivating effect decreased. Inactivation rate improved with a temperature increase from 5 to 25℃, but decreased beyond this. The inactivating capability of O3 was found to be stronger under acidic than that under alkalic conditions. When the concentration of organic matter in the reaction system was increased, the competition between Cryptosporidium and organics with O3 probably took place, thereby reducing the inactivation rate. In addition, the cellular morphology of Cryptosporidium varied with different contact times. At zero contact time, cells were rotundity and sphericity, at 60 sec they became folded, underwent emboly, and burst at 480 sec, the cell membrane of Cryptosporidium shrinked and collapsed completely.展开更多
An anti-oxidized NiS2 electrocatalyst with improved catalytic activity was developed using a Fe-induced conversion strateg3a X-ray photoelectron spectroscopy reveals that betatopic Ni species with high valence states ...An anti-oxidized NiS2 electrocatalyst with improved catalytic activity was developed using a Fe-induced conversion strateg3a X-ray photoelectron spectroscopy reveals that betatopic Ni species with high valence states are present within the Fe-NiS2 matrix and relatively less oxidized layers exist on the catalyst＇s surface, indicating its greatly enhanced anti-oxidized capability. Density functional theory calculations reveal that the Ni and Fe sites on the Fe-NiS2 catalyst surface possess strong adsorption capacity toward hydroxyl ions compared with the Ni sites on NiS2. Benefiting from its unique microstructure and modulated electronic structure due to the effects of iron species, the Fe-NiS2 catalyst prepared on carbon fiber delivers a remarkably enhanced catalytic activity and superior long-life durability for overall water splitting. The present results provide an efficient strategy for the design and configuration of anti-oxidation catalysts, especially for energy storage and catalysis.展开更多
Asteroid mining is a potentially lucrative method for extracting resources from space. Water resources found on asteroids can serve as fuel supplies for spacecrafts in deep space, and some asteroids are rich in precio...Asteroid mining is a potentially lucrative method for extracting resources from space. Water resources found on asteroids can serve as fuel supplies for spacecrafts in deep space, and some asteroids are rich in precious metals, offering immense potential economic value. The 12th Global Trajectory Optimization Competition, held in 2023, introduced a challenge to trajectory design for sustainable asteroid mining. Participating teams were tasked with maximizing the mining quantity over a 15-yr period by utilizing as many mining ships as possible to depart from the Earth, deploy miners on multiple asteroids, recover minerals, and return to the Earth. Σ team devised a strategy in which one ship completes one sequence, enabling the collection of minerals from 203 asteroids using 26 mining ships. This paper outlines the design methodology and outcomes of this approach, encompassing a preliminary analysis of the problem, optimization for the Earth departure and return, flight sequence search, and low-thrust conversion and optimization. Through methods such as asteroid selection and clustering, database building for Earth–asteroid transfers, global search with an impulsive model, local optimization with a low-thrust model, and conversion of remaining fuel into mining time, the computational efficiency was significantly enhanced, fuel consumption per unit mineral collection was reduced, and mining quantity was improved. Finally, the design outcomes of this approach are presented. The proposed trajectory design method enables the completion of multiple asteroid rendezvouses in a short time, providing valuable insights for future missions involving a single spacecraft conducting multiple rendezvouses with multiple asteroids.展开更多
Microcystins, which represents one kind of cancerogenic organic compounds, is abundant in eutro- phication water. The effects of reaction factors on chlorine dioxide （C102） for removal of low-concentration Micro- cy...Microcystins, which represents one kind of cancerogenic organic compounds, is abundant in eutro- phication water. The effects of reaction factors on chlorine dioxide （C102） for removal of low-concentration Micro- cystin-LR, Microcystin-RR, and Microcystin-YR in water as well as the reaction mechanisms was investigated by using enzyme-linked immunosorbent assay （ELISA） kit and gas chromatography-mass spectrometry （GC-MS）. The results showed that MC-LR, MC-RR, and MC-YR could be efficiently decomposed by C102. The degradation efficiency was shown positively correlated to the concen- tration of C102 and reaction time; while the effect of reaction temperature and pH is slight. The kinetic constants and activation energies of the reaction ofMC-LR, MC-RR, and MC-YR with C102 are determined as 459.89, 583.15, 488.43 L.（mol.min）I and 64.78, 53.01, 59.15kJ.mok1, respectively. As indicated by high performance liquid chromatography mass spectrometer （HPLC-MS） analysis, degradation should be accomplished via destruction of Adda group by oxidation, with the formation of dihydroxy substituendums as end products. This study has provided a fundamental demonstration of C102 serving as oxidizing disinfectant to eliminate microcystins from raw water source.展开更多
Meta-analysis is a statistical method used to synthesize the cumulative effect of an interventional treatment or a certain relationship that has been subjected to empirical investigation.Notwithstanding the increasing...Meta-analysis is a statistical method used to synthesize the cumulative effect of an interventional treatment or a certain relationship that has been subjected to empirical investigation.Notwithstanding the increasing popularity of meta-analysis in second language acquisition(SLA)research,there is considerable methodological inconsistency in the 22SLA meta-analyses published to date.Also,given the highly technical nature of some aspects of this statistical procedure and the specialized knowledge associated with it,it is a daunting task to conduct a meta-analysis and understand or interpret meta-analytic results.This paper seeks to solve the conundrum surrounding metaanalysis by explicating its basic procedure and technical aspects in an accessible manner.Utilizing SLA meta-analyses as examples,it discusses the methodological options of each stage of a meta-analysis,makes recommendations about how to handle some key issues,and points out the pitfalls that might undermine the robustness and credibility of meta-analytic findings.展开更多
基金funded by the Chinese Academy of Forestry-Special funds for basic scientific research service expenses of the central level public welfare research institutes(Grant No.CAFYBB2020QD001)the National Natural Science Foundation of China(Grant Nos.32101550,32271917)+1 种基金Jiangsu Agricultural Science and Technology Innovation Fund(Grant No.CX(24)3052)National Forestry and Grassland Administration’s Center for Science and Technology Development Projects(Grant No.KJZXSA202202).
文摘Catalpa bungei,a fast-growing timber tree,is threatened by the lepidopteran pest Omphisa plagialis.Previous studies in our laboratory successfully generated transgenic C.bungei lines overexpressing Cry genes(Cry1Ab,Cry2A,and Cry9-2)that exhibited resistance to O.plagialis,but their potential impact on soil bacterial communities remains unclear.In this study,we analyzed nine transgenic C.bungei lines(three independent lines for each Cry gene)to characterize their rhizosphere bacterial communities using high-throughput sequencing of the 16S ribosomal DNA(rDNA)V4-V5 regions.A total of 628 amplicon sequence variants(ASVs)were shared among all transgenic and wild-type(WT)lines,forming a stable core microbiome dominated by Proteobacteria,Bacteroidota,Acidobacteriota,and Actinobacteriota.Alpha diversity showed no significant differences,while beta diversity revealed minor but distinct compositional shifts.Cry1Ab lines exhibited higher abundances of fast-growing taxa,particularly Proteobacteria and Bacteroidota;Cry2A lines displayed intermediate profiles,whereas Cry9-2 lines were nearly indistinguishable from WT communities.Linear discriminant analysis of the effect size revealed significant enrichment of taxa such as Burkholderiaceae and Ralstonia in the Cry1Ab rhizosphere,in contrast to the higher abundance of Chloroflexi in the WT.Functional predictions indicated consistent metabolic pathways across all treatments,suggesting strong ecological redundancy.This study demonstrates minimal impact on rhizosphere microbial communities in transgenic C.bungei plants.The Cry9-2 construct exhibited superior environmental stability,whereas the Cry1Ab construct caused only slight but ecologically acceptable shifts.These findings support the ecological safety of Bt-transgenic C.bungei and identify Cry9-2 as a particularly favorable candidate for forestry applications.This comparative evaluation of three Cry genes in a tree species provides a framework for future gene-specific biosafety assessments in woody plants.
基金Project supported by the National Natural Science Foundation of China(Grant No.41830533)the National Key Research and Development Program of China(Grant Nos.2016YFC1401404 and 2017YFA0604102).
文摘Considering that the fluid is inviscid and incompressible and the flow is irrotational in a fixed frame of reference and using the multiple scale analysis method, we derive a nonlinear Schrodinger equation(NLSE) describing the evolution dynamics of gravity-capillary wavetrains in arbitrary constant depth. The gravity-capillary waves(GCWs) are influenced by a linear shear flow(LSF) which consists of a uniform flow and a shear flow with constant vorticity. The modulational instability(MI) of GCWs with the LSF is analyzed using the NLSE. The MI is effectively modified by the LSF. In infinite depth, there are four asymptotes which are the boundaries between MI and modulational stability(MS) in the instability diagram. In addition, the dimensionless free surface elevation as a function of time for different dimensionless water depth,surface tension, uniform flow and vorticity is exhibited. It is found that the decay of free surface elevation and the steepness of free surface amplitude change over time, which are greatly affected by the water depth, surface tension, uniform flow and vorticity.
基金Project supported by the National Key Research and Development Program of China(Grant Nos.2016YFC1401404 and 2017YFA0604102)the National Natural Science Foundation of China(Grant No.41830533)
文摘Assume that a fluid is inviscid, incompressible, and irrotational. A nonlinear Schr?dinger equation(NLSE) describing the evolution of gravity waves in finite water depth is derived using the multiple-scale analysis method. The gravity waves are influenced by a linear shear flow, which is composed of a uniform flow and a shear flow with constant vorticity. The modulational instability(MI) of the NLSE is analyzed, and the region of the MI for gravity waves(the necessary condition for existence of freak waves) is identified. In this work, the uniform background flows along or against wave propagation are referred to as down-flow and up-flow, respectively. Uniform up-flow enhances the MI, whereas uniform down-flow reduces it. Positive vorticity enhances the MI, while negative vorticity reduces it. Hence, the influence of positive(negative)vorticity on MI can be balanced out by that of uniform down(up) flow. Furthermore, the Peregrine breather solution of the NLSE is applied to freak waves. Uniform up-flow increases the steepness of the free surface elevation, while uniform down-flow decreases it. Positive vorticity increases the steepness of the free surface elevation, whereas negative vorticity decreases it.
基金supported by the National High Technology Research and Development Program (863) of China(No. 2006AAZ309)
文摘The fluorescence staining method and scanning electron microscopy （SEM） were used to study the effect of ozone （O3） inactivating Cryptosporidium in water and cell ultrastructures variation to shed light on the mechanism of inactivation preliminarily. Results indicated that O3 had a stronger inactivating capability. When the concentration of O3 was above 3.0 mg/L and the contact time was up to 7 min, a significant inactivating effect could be achieved. The turbidity on inactivation effects was also found to be statistically significant in artificial water. With increases in turbidity, the inactivating effect decreased. Inactivation rate improved with a temperature increase from 5 to 25℃, but decreased beyond this. The inactivating capability of O3 was found to be stronger under acidic than that under alkalic conditions. When the concentration of organic matter in the reaction system was increased, the competition between Cryptosporidium and organics with O3 probably took place, thereby reducing the inactivation rate. In addition, the cellular morphology of Cryptosporidium varied with different contact times. At zero contact time, cells were rotundity and sphericity, at 60 sec they became folded, underwent emboly, and burst at 480 sec, the cell membrane of Cryptosporidium shrinked and collapsed completely.
文摘An anti-oxidized NiS2 electrocatalyst with improved catalytic activity was developed using a Fe-induced conversion strateg3a X-ray photoelectron spectroscopy reveals that betatopic Ni species with high valence states are present within the Fe-NiS2 matrix and relatively less oxidized layers exist on the catalyst＇s surface, indicating its greatly enhanced anti-oxidized capability. Density functional theory calculations reveal that the Ni and Fe sites on the Fe-NiS2 catalyst surface possess strong adsorption capacity toward hydroxyl ions compared with the Ni sites on NiS2. Benefiting from its unique microstructure and modulated electronic structure due to the effects of iron species, the Fe-NiS2 catalyst prepared on carbon fiber delivers a remarkably enhanced catalytic activity and superior long-life durability for overall water splitting. The present results provide an efficient strategy for the design and configuration of anti-oxidation catalysts, especially for energy storage and catalysis.
基金supported by the Space Debris and Near-Earth Asteroid Defense Research Project(KJSP2023020303)Youliang Wang is grateful to the Youth Innovation Promotion Association of the Chinese Academy of Sciences(2022146).
文摘Asteroid mining is a potentially lucrative method for extracting resources from space. Water resources found on asteroids can serve as fuel supplies for spacecrafts in deep space, and some asteroids are rich in precious metals, offering immense potential economic value. The 12th Global Trajectory Optimization Competition, held in 2023, introduced a challenge to trajectory design for sustainable asteroid mining. Participating teams were tasked with maximizing the mining quantity over a 15-yr period by utilizing as many mining ships as possible to depart from the Earth, deploy miners on multiple asteroids, recover minerals, and return to the Earth. Σ team devised a strategy in which one ship completes one sequence, enabling the collection of minerals from 203 asteroids using 26 mining ships. This paper outlines the design methodology and outcomes of this approach, encompassing a preliminary analysis of the problem, optimization for the Earth departure and return, flight sequence search, and low-thrust conversion and optimization. Through methods such as asteroid selection and clustering, database building for Earth–asteroid transfers, global search with an impulsive model, local optimization with a low-thrust model, and conversion of remaining fuel into mining time, the computational efficiency was significantly enhanced, fuel consumption per unit mineral collection was reduced, and mining quantity was improved. Finally, the design outcomes of this approach are presented. The proposed trajectory design method enables the completion of multiple asteroid rendezvouses in a short time, providing valuable insights for future missions involving a single spacecraft conducting multiple rendezvouses with multiple asteroids.
文摘Microcystins, which represents one kind of cancerogenic organic compounds, is abundant in eutro- phication water. The effects of reaction factors on chlorine dioxide （C102） for removal of low-concentration Micro- cystin-LR, Microcystin-RR, and Microcystin-YR in water as well as the reaction mechanisms was investigated by using enzyme-linked immunosorbent assay （ELISA） kit and gas chromatography-mass spectrometry （GC-MS）. The results showed that MC-LR, MC-RR, and MC-YR could be efficiently decomposed by C102. The degradation efficiency was shown positively correlated to the concen- tration of C102 and reaction time; while the effect of reaction temperature and pH is slight. The kinetic constants and activation energies of the reaction ofMC-LR, MC-RR, and MC-YR with C102 are determined as 459.89, 583.15, 488.43 L.（mol.min）I and 64.78, 53.01, 59.15kJ.mok1, respectively. As indicated by high performance liquid chromatography mass spectrometer （HPLC-MS） analysis, degradation should be accomplished via destruction of Adda group by oxidation, with the formation of dihydroxy substituendums as end products. This study has provided a fundamental demonstration of C102 serving as oxidizing disinfectant to eliminate microcystins from raw water source.
文摘Meta-analysis is a statistical method used to synthesize the cumulative effect of an interventional treatment or a certain relationship that has been subjected to empirical investigation.Notwithstanding the increasing popularity of meta-analysis in second language acquisition(SLA)research,there is considerable methodological inconsistency in the 22SLA meta-analyses published to date.Also,given the highly technical nature of some aspects of this statistical procedure and the specialized knowledge associated with it,it is a daunting task to conduct a meta-analysis and understand or interpret meta-analytic results.This paper seeks to solve the conundrum surrounding metaanalysis by explicating its basic procedure and technical aspects in an accessible manner.Utilizing SLA meta-analyses as examples,it discusses the methodological options of each stage of a meta-analysis,makes recommendations about how to handle some key issues,and points out the pitfalls that might undermine the robustness and credibility of meta-analytic findings.
